2022/12/09 更新

写真a

モリタ イツロウ
森田 逸郎
Scopus 論文情報  
論文数: 0  Citation: 0  h-index: 31

Citation Countは当該年に発表した論文の被引用数

所属
理工学術院 基幹理工学部
職名
教授

他学部・他研究科等兼任情報

  • 理工学術院   大学院基幹理工学研究科

学歴

  • 2004年04月
    -
    2005年03月

    東京工業大学   大学院理工学研究科   電気電子工学専攻 博士課程  

  • 1990年04月
    -
    1992年03月

    東京工業大学   大学院理工学研究科   電子物理工学専攻 修士課程  

  • 1986年04月
    -
    1990年03月

    東京工業大学   工学部   電子物理工学科  

経歴

  • 2022年04月
    -
    継続中

    早稲田大学   基幹理工学部   教授

  • 1999年08月
    -
    2022年03月

    (株)KDD研究所(現(株)KDDI総合研究所)

  • 1998年08月
    -
    1999年08月

    Stanford大学   客員研究員

  • 1994年03月
    -
    1998年08月

    国際電信電話(株)   研究所

  • 1992年04月
    -
    1994年03月

    国際電子電話(株)   大阪国際通信センター

所属学協会

  • 2008年
    -
    継続中

    IEEE

  • 1994年
    -
    継続中

    電子情報通信学会

 

研究分野

  • 情報ネットワーク

研究キーワード

  • 光ファイバ通信

論文

  • Scalability analysis of machine learning QoT estimators for a cloud-native SDN controller on a WDM over SDM network

    C. Manso, R. Vilalta, R. Munoz, N. Yoshikane, R. Casellas, R. Martinez, C. Wang, F. Balasis, T. Tsuritani, I. Morita

    Journal of Optical Communications and Networking   14 ( 4 ) 257 - 266  2022年04月

     概要を見る

    Maintaining a good quality of transmission (QoT) in optical transport networks is key to maintaining the service level agreement between the user and the service provider. QoT prediction techniques have been used to assure the quality of new lightpaths as well as that of the previously provisioned ones. Traditionally, two different approaches have been used: analytical methods, which take into account most physical impairments that are accurate but complex, and high margin formulas, which require much less computational resources at the cost of high margins. With the recent progress of machine learning (ML) together with software defined networking (SDN), ML has been considered as another option that could be both accurate and that does not consume as many resources as analytical methods. SDN architectures are difficult to scale because they are usually centralized; this is even worse with QoT predictors using ML. In this paper, a solution to this issue is presented using a cloud-native architecture, and its scalability is evaluated using three different ML QoT predictors and experimentally validated in a real wavelength-division multiplexing (WDM) over spatial-division multiplexing (SDM) testbed.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Long-Haul Coupled 4-Core Fiber Transmission Over 7,200 Km With Real-Time MIMO DSP

    Shohei Beppu, Masahiro Kikuta, Koji Igarashi, Hiroshi Mukai, Masahiro Shigihara, Yasuo Saito, Daiki Soma, Hidenori Takahashi, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    JOURNAL OF LIGHTWAVE TECHNOLOGY   40 ( 6 ) 1640 - 1649  2022年03月

     概要を見る

    In this work, we present an experimental demonstration of real-time transoceanic space-division multiplexed transmission with coupled-core multicore fibers. To compensate for modal coupling in the coupled-core multicore fibers, we implement real-time multiple-input multiple-output (MIMO) digital signal processing based on field programmable gate array circuits. Using optical receivers with a real-time MIMO, we demonstrate 16-channel wavelength-division multiplexed coupled four-core fiber transmission over 7200 km. The results show the feasibility of real-time coupled-core multicore fiber transmission.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Trans-Pacific class transmission over a standard cladding ultralow-loss 4-core fiber

    Daiki Soma, Shohei Beppu, Yuta Wakayama, Seiya Sumita, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani, Masatoshi Suzuki

    OPTICS EXPRESS   30 ( 6 ) 9482 - 9493  2022年03月

     概要を見る

    The total capacity of optical submarine cable systems as a global communication infrastructure must be continuously enlarged. Multi-core fibers (MCFs) have been studied as methods to maximize the total cable capacity under electrical power and cable space limitations. In particular, standard cladding MCFs, which are expected to have high productivity and mechanical reliability, are attractive for early deployment in submarine cable systems. In this paper, we demonstrate high-capacity trans-Pacific class transmission using standard cladding uncoupled 4-core fibers, achieving a transmission capacity of 55.94 Tbit/s over 12,040 km. In addition, based on the results of this and our previous coupled MCF transmission experiments, we summarize the characteristics of coupled and uncoupled MCFs applied to optical submarine cable systems. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

    DOI PubMed

    Scopus

    3
    被引用数
    (Scopus)
  • 50.47-Tbit/s Standard Cladding Coupled 4-Core Fiber Transmission Over 9,150 km

    Daiki Soma, Shohei Beppu, Yuta Wakayama, Seiya Sumita, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani, Masatoshi Suzuki

    JOURNAL OF LIGHTWAVE TECHNOLOGY   39 ( 22 ) 7099 - 7105  2021年11月

     概要を見る

    Since optical submarine cable systems are a part of the global communications infrastructure, their total capacity must be continuously and dramatically enlarged. Recently, methods how to maximize the transmission capacity under electrical power limitations have been studied, and it has been reported that a single band (C-band only) transmission system with more fiber pairs (FPs) could be a promising technology. This finding has triggered work on submarine cables with more FPs. For a further increase in FPs in optical submarine cable systems, which also have space limitations in existing cable designs, space-division multiplexing (SDM) technologies such as multi-core fibers (MCFs) and multi-mode fibers (MMFs) could be promising solutions. In particular, 125-mu m standard cladding SDM fibers are attractive for early deployment in submarine cable systems since they are expected to have high productivity and high mechanical reliability similar to existing single-mode fibers (SMFs) with the same cladding diameter. In this paper, we report transpacific MCF transmission over a 30-nm bandwidth using standard cladding ultralow-loss coupled 4-core fibers, extending our previous work. The Q(2)-factors of 608 (4 core x 152 WDM) SDM/WDM channels modulated with 24-Gbaud DP (dual polarization)-QPSK (quadrature phase shift keying) exceeded the assumed forward error correction (FEC) limits after a 9,150-km transmission. As a result, transmission capacity of 50.47 Tbit/s and a capacity-distance product of 461.8 Pbit/s center dot km were achieved for standard cladding diameter SDM fibers.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Experimental evaluation of control and monitoring protocols for optical SDN networks and equipment [Invited Tutorial]

    Ricard Vilalta, Carlos Manso, Noboru Yoshikane, Ramon Casellas, Ricardo Martinez, Takehiro Tsuritani, Itsuro Morita, Raul Munoz

    JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING   13 ( 10 ) D1 - D12  2021年08月

     概要を見る

    This paper presents an experimental evaluation of network protocols for control and management of optical networks and optical network equipment as seen in current trends. This paper presents the YANG data modeling language and its associated RESTCONF/NETCONF protocols. Later, it details multiple data models used in optical networks, such as IETF TEAS, ONF Transport API, OpenROADM, and OpenConfig. It also presents multiple protocols for telemetry (i.e., YANG PUSH, gRPC, and gNMI). Later, a zero-touch SDN controller architecture for multiple standard-defining organizations (SDOs) is presented, to support the usage of multiple protocols in a zero-touch optical network. Finally, the presented protocol implementations are experimentally evaluated and compared in terms of latency and overhead. The paper explores the use of these protocols (e.g., in research, demonstrations, and open-source optical networking projects) and provides results and recommendations for their integration in equipment and networks. (C) 2021 Optical Society of America

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Experimental evaluation of control and monitoring protocols for optical SDN networks and equipment [Invited Tutorial]

    Ricard Vilalta, Carlos Manso, Noboru Yoshikane, Ramon Casellas, Ricardo Martinez, Takehiro Tsuritani, Itsuro Morita, Raul Munoz

    JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING   13 ( 8 ) D1 - D12  2021年08月

     概要を見る

    This paper presents an experimental evaluation of network protocols for control and management of optical networks and optical network equipment as seen in current trends. This paper presents the YANG data modeling language and its associated RESTCONF/NETCONF protocols. Later, it details multiple data models used in optical networks, such as IETF TEAS, ONF Transport API, OpenROADM, and OpenConfig. It also presents multiple protocols for telemetry (i.e., YANG PUSH, gRPC, and gNMI). Later, a zero-touch SDN controller architecture for multiple standard-defining organizations (SDOs) is presented, to support the usage of multiple protocols in a zero-touch optical network. Finally, the presented protocol implementations are experimentally evaluated and compared in terms of latency and overhead. The paper explores the use of these protocols (e.g., in research, demonstrations, and open-source optical networking projects) and provides results and recommendations for their integration in equipment and networks. (C) 2021 Optical Society of America

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Real-time Transoceanic Coupled 4-core Fiber Transmission

    S. Beppu, M. Kikuta, K. Igarashi, H. Mukai, M. Shigihara, Y. Saito, D. Soma, H. Takahashi, N. Yoshikane, I. Morita, M. Suzuki, T. Tsuritani

    2021 Optical Fiber Communications Conference and Exhibition, OFC 2021 - Proceedings    2021年06月

     概要を見る

    We report the first experimental demonstration of transoceanic distance real-time transmission over coupled multicore fibers. The WDM DP-QPSK signals were transmitted over 7, 200-km coupled-core four-core fibers by a recirculating loop and demodulated by real-time MIMO DSP.

  • Real-time MIMO-DSP Technologies for SDM Systems

    S. Beppu, K. Igarashi, M. Kikuta, H. Mukai, M. Shigihara, Y. Saito, D. Soma, H. Takahashi, N. Yoshikane, I. Morita, T. Tsuritani

    2021 Optical Fiber Communications Conference and Exhibition, OFC 2021 - Proceedings    2021年06月

     概要を見る

    We implement an FPGA-based real-time MIMO-DSP for equalizing spatial modes and polarizations. With MIMO-DSP, we demonstrate real-time transmission over weakly coupled 10-mode fibers and strongly coupled 4-core fibers using WDM DP-QPSK signals.

  • TAPI-enabled SDN control for partially disaggregated multi-domain (OLS) and multi-layer (WDM over SDM) optical networks [Invited]

    C. Manso, R. Munoz, N. Yoshikane, R. Casellas, R. Vilalta, R. Martinez, T. Tsuritani, I. Morita

    Journal of Optical Communications and Networking   13 ( 1 ) A21 - A33  2021年01月

     概要を見る

    Network operators are facing a critical issue on their optical transport networks to deploy 5G$+$+ and Internet of Things services. They need to address the capacity increase by a factor of 10, while keeping a similar cost per user. Over the past years, network operators have been working on the optical disaggregated approach with great interest for achieving the required efficiency and cost reduction. In particular, partially disaggregated optical networks make it possible to decouple the transponders from the transport system (known as an open line system) that are provided by different vendors. On the other hand, space division multiplexing (SDM) has been proposed as the key technology to overcome the capacity crunch that the optical standard single-mode fibers are facing to support the forecasted $10 \times$10× growth. Spatial core switching is gaining interest because it makes it possible to deploy SDM networks to bypass the overloaded wavelength division multiplexing (WDM) networks, by provisioning spatial media channels between WDM nodes. This paper presents, to the best of our knowledge, the first experimental demonstration of transport-application-programming-interface-enabled software defined networking control architecture for partially disaggregated multi-domain and multi-layer (WDM over SDM) optical networks.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • 85.2-Tbit/s coupled 4-core fiber transmission over 3,120 km using PS-16QAM signals

    S. Beppu, D. Soma, H. Takahashi, N. Yoshikane, I. Morita, T. Tsuritani

    Optics InfoBase Conference Papers    2021年

     概要を見る

    We adopted probabilistic shaping (PS) to couple multicore fiber transmission to maximize the transmission capacity for the first time. By utilizing 152-WDM 24-Gbaud DP-PS-16QAM signals, 85.2-Tbit/s coupled four-core fiber transmission over 3,120 km was demonstrated.

  • SDN Control Architectures for WDM over SDM (WDMoSDM) Networks

    R. Munõz, N. Yoshikane, C. Manso, R. Casellas, R. Vilalta, R. Martínez, F. Balasis, C. Wang, T. Tsuritani, I. Morita

    Optics InfoBase Conference Papers    2021年

     概要を見る

    We provide an overview of SDN control architectures for WDM over SDM (WDMoSDM) optical networks. We address dynamic management of end-to-end connectivity services and WDM virtual network topologies (VNTs) for partially disaggregated multi-domain WDMoSDM networks.

  • First Demonstration of Dynamic Deployment of SDN-enabled WDM Virtual Network Topologies (VNTs) over SDM networks

    C. Manso, R. Munoz, F. Balasis, R. Casellas, R. Vilalta, R. Martinez, C. Wang, N. Yoshikane, T. Tsuritani, I. Morita

    2021 European Conference on Optical Communication, ECOC 2021    2021年

     概要を見る

    We present the dynamic deployment of logical WDM VNTs by deploying virtual links between ROADM/OXC nodes using spatial channels provided by SDM networks. We propose a cloud-native WDM over SDM (WDMoSDM) SDN orchestrator that is responsible for the lifecycle management of the SDN-enabled WDM VNTs.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • First Scalable Machine Learning Based Architecture for Cloud-native Transport SDN Controller

    Carlos Manso, Noboru Yoshikane, Ricard Vilalta, Raul Munoz, Ramon Casellas, Ricardo Martinez, Cen Wang, Filippos Balasis, Takehiro Tsuritani, Itsuro Morita

    2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)    2021年

     概要を見る

    We present a cloud-native architecture with a machine learning QoT predictor that enables cognitive functions in transport SDN controllers. We evaluate the QoT predictor training and auto-scaling capabilities in a real WDM/SDM testbed. (c) 2021 The Author(s)

  • 50.47-Tbit/s Standard Cladding Ultra-Low-Loss Coupled 4-Core Fiber Transmission over 9,150 km

    Daiki Soma, Shohei Beppu, Yuta Wakayama, Seiya Sumita, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani, Masatoshi Suzuki

    2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)    2021年

     概要を見る

    50.47-Tbit/s transpacific coupled multi-core fiber transmission has been experimentally demonstrated using standard cladding ultra-low-loss coupled 4-core fibers. The Q-factors of all SDM/WDM channels modulated with 24-Gbaud DP-QPSK exceeded the assumed FEC limits after 9,150-km transmission. (C) 2021 The Author(s)

  • Telemetry-enabled Cloud-native Transport SDN Controller for Real-time Monitoring of Optical Transponders Using gNMI

    R. Vilalta, C. Manso, N. Yoshikane, R. Munoz, R. Casellas, R. Martinez, T. Tsuritani, I. Morita

    2020 European Conference on Optical Communications, ECOC 2020    2020年12月

     概要を見る

    This paper presents novel extensions for Cloud-native SDN controller for partially disaggregated optical networks that allow real-time monitoring of optical transponders. New SDN controller components are presented, as well as overall architecture. Evaluation is performed with gNMI enabled OpenConfig transceivers.

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • Controlling and Monitoring Optical Network Equipment in Optical SDN Networks

    R. Vilalta, N. Yoshikane, R. Casellas, R. Martinez, T. Tsuritani, I. Morita, R. Munoz

    2020 European Conference on Optical Communications, ECOC 2020    2020年12月

     概要を見る

    This paper presents an overview of current trends in network protocols for control and management of optical networks and optical network equipment. The paper explores the usage of these protocols in open source optical networking projects.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Weakly coupled 10-mode-division multiplexed transmission over 48-km few-mode fibers with real-time coherent MIMO receivers

    Shohei Beppu, Koji Igarashi, Masahiro Kikuta, Daiki Soma, Tomoyuki Nagai, Yasuo Saito, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    OPTICS EXPRESS   28 ( 13 ) 19655 - 19668  2020年06月

     概要を見る

    For weakly coupled mode-division multiplexed (MDM) transmission systems, we design and implement optical coherent receiver prototypes with real-time multiple-input multiple-output (MIMO) digital signal processing to equalize two degenerate linearly polarized modes with dual polarization. Using field programmable gate array circuits, we implement real-value 8 x 2 MIMO adaptive equalization with externally separated phase compensators based on the least mean square algorithm, which enables not only training equalization but also fast carrier-phase tracking. With the optical coherent MIMO receiver prototype, we demonstrate real-time weakly coupled 10 x MDM wavelength-division multiplexed dual-polarization quadrature phase shift keying transmission over 48-km few-mode fibers. This report shows a record number of multiplexed spatial modes, namely, 10 modes with dual polarization, in real-time MDM transmission experiments. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

    DOI PubMed

    Scopus

    19
    被引用数
    (Scopus)
  • 402.7-Tb/s MDM-WDM Transmission Over Weakly Coupled 10-Mode Fiber Using Rate-Adaptive PS-16QAM Signals

    Shohei Beppu, Daiki Soma, Seiya Sumita, Yuta Wakayama, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    JOURNAL OF LIGHTWAVE TECHNOLOGY   38 ( 10 ) 2834 - 2840  2020年05月

     概要を見る

    The mode-division-multiplexing (MDM) transmission technique using a few-mode fiber (FMF) has been investigated to overcome the theoretical limitation of the transmission capacity of a single-mode fiber. In MDM transmission, multiple-input multiple-output (MIMO) digital signal processing (DSP) is generally required on the receiver side to compensate for the modal crosstalk (XT) between the spatial modes. However, the computational cost is high, especially for high-order MDM systems that use many spatial modes. To reduce the MIMO matrix size, MDM transmission with partial MIMO-based DSP has been proposed using weakly coupled FMFs. The modal XT in such fibers can be suppressed by a special fiber design; however, the modal XT still remains and strongly limits the signal-to-noise-ratio (SNR) and capacity. To further increase the capacity for a given SNR, an optimization of the modulation format is significant. Recently, probabilistic shaping (PS) has received attention since it can gradually change the entropy of a modulation format and maximize the capacity for a given SNR. In this article, we demonstrate weakly coupled 10-mode-multiplexed transmission with four 4 x 4 MIMOs and two 2 x 2 MIMOs using rate-adaptive PS-16QAM signals over 48-km FMF, achieving a record transmission capacity of 402.7 Tb/s in 125-mu m cladding single-core fiber transmission experiments. Furthermore, we also show the possibility of a further capacity increase by adjusting the entropies of the PS-16QAM signals depending on the spatial mode.

    DOI

    Scopus

    19
    被引用数
    (Scopus)
  • Real-time strongly-coupled 4-core fiber transmission

    S. Beppu, K. Igarashi, H. Mukai, M. Kikuta, M. Shigihara, D. Soma, T. Tsuritani, I. Morita

    Optics InfoBase Conference Papers   Part F174-OFC 2020  2020年

     概要を見る

    We show a real-time optical coherent MIMO receiver for 4-mode division multiplexed transmission. With the receiver, we demonstrate real-time strongly-coupled 4-core fiber transmission of WDM DP-QPSK signals over 60 km.

    DOI

  • Experimental Verification on Digital Back Propagation Gain in MCF transmission over 6020-km Uncoupled and Coupled 4-Core Fibres

    Shohei Beppu, Daiki Soma, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani

    2020 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATIONS (ECOC)    2020年

     概要を見る

    We experimentally verify the nonlinear compensation gain of digital back propagation in ultra long-haul 4-core fibre transmissions over 6020 km. The gain was 1.1 dB in the uncoupled core transmission. By contrast, this gain was not observed in the coupled core transmission with spatial modal dispersion.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Network control and orchestration in SDM and WDM optical networks

    Raul Munoz, Noboru Yoshikane, Ricard Vilalta, Ramon Casellas, Ricardo Martinez, Takehiro Tsuritani, Itsuro Morita

    2020 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)   Part F174-OFC 2020  2020年

     概要を見る

    We present the first SDN-enabled multi-domain multi-layer (WDM/SDM) control architecture for partially disaggregated optical networks with multiple WDM and SDM OLS domains and transponders to provision end-to-end TAPI connectivity services involving spatial and optical channels. (C) 2020 The Author(s)

    DOI

    Scopus

  • Performance Comparison for Standard Cladding Ultra-Low Loss Uncoupled and Coupled 4-Core Fibre Transmission over 15,000 km

    Daiki Soma, Shohei Beppu, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani

    2020 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATIONS (ECOC)    2020年

     概要を見る

    We compared the ultra-long-haul multi-core fibre (MCF) transmission performance of standard cladding ultra-low-loss uncoupled and coupled 4-core fibres. From the results obtained, 15,652-km transmission in uncoupled MCF and 16,856-km transmission in coupled MCF was demonstrated using a centre channel of 16-WDM 24-Gbaud DP-QPSK signals.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Ultra-High Capacity Optical Transmission over 10-Pbit/s Based on Optical Space Division Multiplexing Technologies

    Masatoshi Suzuki, Daiki Soma, Takehiro Tsuritani, Itsuro Morita

    2020 22ND INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON 2020)   2020-July  2020年

     概要を見る

    Recent progress on ultra-high capacity, space division multiplexed optical transmission is reviewed. The highest capacity of 10.16 Pbit/s has been achieved by using 19 core 6 mode fiber, and the highest capacity of 402.7 Tbit/s for multimode single core fiber has been demonstrated by using weakly-coupled 10 mode fiber with a standard cladding diameter.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Adaptive software defined networking control of space division multiplexing super-channels exploiting the spatial-mode dimension

    Munoz, R., Yoshikane, N., Vilalta, R., Fabrega, J.M., Rodriguez, L., Soma, D., Beppu, S., Sumita, S., Casellas, R., Martinez, R., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   12 ( 1 ) A58 - A69  2020年

     概要を見る

    Space division multiplexing (SDM) super-channels are the only way to guarantee a sustainable scaling of the optical line interface rate. High-capacity terabit interfaces can be deployed by logically associating several optical sub-channels transmitted in parallel in different spatial cores or modes in order to create an (logical) optical channel with the desired interface rate. This paper is focused on the use of spatial modes for SDM super-channels. First, we present a software defined networking (SDN)-controlled disaggregated SDM network architecture that deploys the proposed sliceable-mode transceivers with multiple-input multiple-output equalization. Then, we present the adaptive SDN workflow and heuristics for the provisioning, scaling up/down, and soft-failure restoration of SDM super-channels using spatial modes. Two proofs of concept are deployed in the joint testbed between KDDI Research and CTTC.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • SDN/NFV Control and Orchestration for SDM Networks

    R. Munoz, R. Vilalta, J. M. Fabrega, R. Casellas, R. Martinez, N. Yoshikane, T. Tsuritani, I. Morita

    OECC/PSC 2019 - 24th OptoElectronics and Communications Conference/International Conference Photonics in Switching and Computing 2019    2019年07月

     概要を見る

    We present an SDM network and node architecture based on sliceable spatial-mode, spatial-core and spectral transceivers, and a centralized SDN controller with NETCONF and TAPI for the management of SDM super-channels by multiple NFVorchestrators.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Orchestration of Optical Networks and Cloud/Edge Computing for IoT Services

    R. Munoz, R. Vilalta, R. Casellas, R. Martinez, N. Yoshikane, T. Tsuritani, I. Morita

    OECC/PSC 2019 - 24th OptoElectronics and Communications Conference/International Conference Photonics in Switching and Computing 2019    2019年07月

     概要を見る

    We present an IoT-aware cloud and network orchestration architecture for multi-domain transport SDN networks and cloud/edge computing that deploys an IoT-traffic control and congestion avoidance mechanism for dynamic distribution of IoT analytics to the edge.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • SDN-Enabled Scaling Up/Down of SDM Super-Channels Exploiting Spatial Modes with Adaptive MIMO Equalization and Modulation Format Assignment

    R. Munoz, N. Yoshikane, J. M. Fabrega, L. Rodriguez, R. Vilalta, D. Soma, S. Beppu, S. Sumita, R. Casellas, R. Martinez, T. Tsuritani, I. Morita

    2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings   Part F160-OFC 2019  2019年04月

     概要を見る

    We propose a heuristic and experimentally demonstrate dynamic scaling up/down of SDM super-channels to increase/decrease the capacity by exploiting the spatial modes. We deploy mode-adaptive MIMO equalization and modulation format assignment controlled by SDN.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • GRPC-based SDN control and telemetry for soft-failure detection of spectral/spacial superchannels

    Ricard Vilalta, Noboru Yoshikane, Ramon Casellas, Ricardo Martínez, Shohei Beppu, Daiki Soma, Seiya Sumita, Takehiro Tsuritani, Itsuro Morita, Raul Muñoz

    IET Conference Publications   2019 ( CP765 )  2019年

     概要を見る

    This paper presents the first experimental demonstration of gRPC-based SDN control and telemetry architecture for spectral/spatial super-channels with SDM/WDM transceivers that monitor the BER to detect soft-failures over an 11-km 6-mode 19-core fiber. An evaluation of possible SDN protocols is provided for the discussed scenario.

  • 402.7-Tb/s weakly-coupled 10-mode-multiplexed transmission using rate-adaptive PS PDM-16QAM WDM signals

    Daiki Soma, Shohei Beppu, Seiya Sumita, Yuta Wakayama, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    IET Conference Publications   2019 ( CP765 )  2019年

     概要を見る

    We demonstrate a weakly-coupled 10-mode-multiplexed transmission with four 4u4 and two 2u2 MIMOs using rate-adaptive probabilistically-shaped (PS) PDM-16QAM signals over 48-km step-index few-mode fibre, achieving a record transmission capacity of 402.7 Tb/s in 125-Pm cladding single-core fibre transmission experiments.

  • Field Test of Installed High-Density Optical Fiber Cable with Multi-Core Fibers toward Practical Deployment

    Takehiro Tsuritani, Daiki Soma, Yuta Wakayama, Yuichi Miyagawa, Mikoto Takahashi, Itsuro Morita, Koichi Maeda, Kohei Kawasaki, Toshikazu Matsuura, Masatoshi Tsukamoto, Ryuichi Sugizaki

    2019 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)   Part F160-OFC 2019  2019年

     概要を見る

    A field trial of high-density 0.92-km 200-fiber cable with 5-core fibers (5CFs) was conducted for reliability tests. No degradation of cable attenuation of 5CFs was observed even after installation into underground conduits and aerial area.

    DOI

    Scopus

    13
    被引用数
    (Scopus)
  • Dynamic complex deep Neural Network Nonlinear Equalizer for 64 QAM Long-haul Transmission Systems

    Govind Sharan Yadav, Takehiro Tsuritani, Shohei Beppu, Hidenori Takahashi, Itsuro Morita, Kai-Ming Feng, Jhih-heng Yan

    2019 24TH OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) AND 2019 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING AND COMPUTING (PSC)    2019年

     概要を見る

    We implemented a two-hidden-layer dynamic complex deep neural network nonlinear equalizer which outperforms the linear equalizer, static and dynamic single hidden layer CDNN-NLE by 1.38-dB, 1.01-dB and 0.62-dB for a 34-GBaud/s, 64-QAM signal over 1200-km.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • SDN control of sliceable multidimensional (spectral and spatial) transceivers with YANG/NETCONF

    Munoz, R., Yoshikane, N., Vilalta, R., Fabrega, J.M., Rodriguez, L., Casellas, R., Moreolo, D.M.S., Martinez, R., Nadal, L., Soma, D., Wakayama, Y., Beppu, S., Sumita, S., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   11 ( 2 ) A123 - A133  2019年

     概要を見る

    The combination of spatial division multiplexing (SDM) with flexi-grid wavelength division multiplexing (WDM) enables optical transceivers to provide super-channels that exploit the spectral and spatial dimensions. For the first time to the best of our knowledge, in this paper we extend SDM-WDM transceivers to support sliceability and make effective use of spatial and spectral resources. The proposed architecture provides multiple independent spectral-spatial super-channels (i.e., slices) sharing the same transceiver and exploiting different spectrum/core/mode resources. The proposed architecture also enables us to monitor the bit error rate of the provisioned slices in order to detect any signal-quality degradation due to the provisioning of additional slices. On the other hand, there is a general trend toward the disaggregation of optical networks. In this paper, we also propose the first open application program interface based on a YANG data model and NETCONF protocol for software-defined-networking-enabled sliceable SDM-WDM transceivers. The proposed transceiver is experimentally validated in a joint test bed between CTTC and KDDI research.

    DOI

    Scopus

    23
    被引用数
    (Scopus)
  • SDN Control and Monitoring System for Soft-Failure Detection and Optical Restoration of Spectral/Spatial Superchannels

    R. Muñoz, N. Yoshikane, J. M. Fàbrega, R. Vilalta, L. Rodríguez, M. Svaluto Moreolo, R. Casellas, R. Martínez, S. Beppu, D. Soma, T. Tsuritani, I. Morita

    European Conference on Optical Communication, ECOC   2018-September  2018年11月

     概要を見る

    First experimental demonstration of an SDN monitoring and restoration architecture for spectral/spatial superchannels with SDM/WDM transceivers that monitor the BER/OSNR to detect soft failures and restore the degraded channels by reconfiguring the transmission formats over an 11-km 6-mode 19-core fiber.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • SDN Control and Monitoring of SDM/WDM and Packet Transport Networks for 5G Fronthaul/Backhaul

    R. Munoz, J. M. Fabrega, R. Vilalta, M. Svaluto Moreolo, R. Martinez, Ramon Casellas, N. Yoshikane, T. Tsuritani, I. Morita

    IEEE Photonics Society Summer Topicals Meeting Series, SUM 2018     151 - 152  2018年09月

     概要を見る

    This paper presents optical (SDM/WDM) and packet transport solutions for 5G fronthaul/backhaul and the hierarchical Transport SDN control and monitoring architecture. It dynamically provides multiple spectral-spatial super-channels and packet flows, and monitors the signal quality degradation of the optical super-channels and the aggregated packet traffic.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • SDN-enabled sliceable multi-dimensional (spectral and spatial) transceiver controlled with YANG/NETCONF

    R. Munoz, N. Yoshikane, R. Casellas, J. M. Fabrega, R. Vilalta, M. Svaluto Moreolo, L. Nadal, R. Martinez, D. Soma, Y. Wakayama, S. Beppu, S. Sumita, T. Tsuritani, I. Morita

    2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings   Part F84-OFC 2018   1 - 3  2018年06月

     概要を見る

    We demonstrate the first SDN-enabled sliceable SDM-WDM transceiver providing multiple spectral-spatial super-channels spanning different cores and modes over a 11-km 6-mode 19-core fiber. We define an open API based on YANG/NETCONF for disaggregated optical networks.

    DOI

    Scopus

  • Low-loss and Low-crosstalk All-fiber-based Six-mode Multiplexer and Demultiplexer for Mode-Multiplexed QAM Signals in C-band

    Koji Igarashi, Yuta Wakayama, Daiki Soma, Takehiro Tsuritani, Itsuro Morita, Kyung Jun Park, Jaekwon Ko, Byoung Yoon Kim

    2018 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)   Part F84-OFC 2018   1 - 3  2018年

     概要を見る

    We show all-fiber-based six-mode multiplexer and demultiplexer. The OSNR penalty due to six-mode multiplexing is suppressed to be 2 dB in DP-16QAM with 12 12MIMO and 3 dB in DP-QPSK even with 4 4/2 2MIMO over C-band.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • 10 Pbit/s transmission using space-division-multiplexing

    Itsuro Morita, Daiki Soma, Takehiro Tsuritani

    2018 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES (SUM)     175 - 176  2018年

     概要を見る

    Space-division-multiplexing is a promising technology to increase a system capacity drastically and the highest capacity in a single optical fiber has reached to 10 Pbit/s recently. In this paper, we review 10.16 Pbit/s transmission experiment using 6-mode 19-core fiber.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Ultra High-Capacity Transmission Using Space-Division-Multiplexing

    Itsuro Morita, Daiki Soma, Takehiro Tsuritani, Masatoshi Suzuki

    23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)    2018年

     概要を見る

    Space-division multiplexing is a promising technology enabling significant growth of a fiber capacity. By using a combination of SDM and DWDM in C+L bands, the fiber capacity has recently reached to 10.16 Pbit/s.

    DOI

    Scopus

  • Recent Progress on Space Division Multiplexing Technology

    Kazuhide Nakajima, Takashi Matsui, Yukihiro Goto, Yutaka Miyamoto, Itsuro Morita

    23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)    2018年

     概要を見る

    This paper reviews recent progress on research of space division multiplexing (SDM) technology in Japan. Three multi-vendor SDM transmission trials, which have been conducted based on the four national projects since 2010, are summarized.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • 10 Pbit/s SDM/WDM transmission

    Daiki Soma, Takehiro Tsuritani, Itsuro Morita

    2018 IEEE PHOTONICS CONFERENCE (IPC)    2018年

     概要を見る

    This paper reports our recent demonstrations of ultra-dense SDM transmission using C+L-band 739-WDM 12-Gbaud dual polarization- 64-quadrature amplitude modulation (QAM) / 16-QAM signals over 11.3-km 6-mode 19-core fiber. We achieve a record fiber capacity of 10.16 Pbit/s with an aggregate spectral efficiency of 1099.9 bit/s/Hz.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • 257-Tbit/s Weakly Coupled 10-Mode C + L-Band WDM Transmission

    Soma, D., Beppu, S., Wakayama, Y., Igarashi, K., Tsuritani, T., Morita, I., Suzuki, M.

    Journal of Lightwave Technology   36 ( 6 ) 1375 - 1381  2018年

     概要を見る

    Partial multiple-input multiple-output (MIMO)based weakly coupled mode-division multiplexing (MDM) transmission is proposed to reduce the MIMO matrix size in MDM. This technique can mitigate the burden of MIMO processing for high-order few-mode fiber (FMF) transmission. In this paper, we first show that modal XT can be sufficiently suppressed over the C+L band using a weakly coupled FMF and a highly mode-selective multiplexer/demultiplexer. Next, 10-mode-multiplexed 336-WDM transmission of dual-carrier 12-Gbaud dual-polarization-quadrature phase-shift keying signals over a 48-km weakly coupled FMF using only 2 x 2 or 4 x 4 partial MIMOs is demonstrated. To the best of our knowledge, in this experiment, we achieved a record fiber capacity of 257 Tbps with an aggregate spectral efficiency of 30.5 bit/s/Hz in single-core fiber transmission.

    DOI

    Scopus

    62
    被引用数
    (Scopus)
  • All-fiber-based selective mode multiplexer and demultiplexer for weakly-coupled mode-division multiplexed systems

    Igarashi, K., Park, K.J., Tsuritani, T., Morita, I., Kim, B.Y.

    Optics Communications   408   58 - 62  2018年

     概要を見る

    We show all-fiber-based selective mode multiplexers and demultiplexers for weakly-coupled mode-division multiplexed systems. We fabricate a set of six-mode multiplexer and demultiplexer based on fiber mode selective couplers, and experimentally evaluate the performance for the six-mode dual-polarization (DP) quadrature phase shift keying (QPSK) optical signals. In the mode multiplexer and demultiplexer, the mode couplings between the lower three modes and the higher three modes are suppressed to be less than -20 dB, which enables us to apply partial 6x6 MIMO equalizers even for the six-mode demultiplexing. For the six-mode DP-QPSK signals, the penalty of optical signal-to-noise ratio by replacing the full 12x12MIMO to the partial 6x6 MIMO is suppressed by less than 1 dB. (C) 2017 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • 10.16-Peta-B/s Dense SDM/WDM Transmission over 6-Mode 19-Core Fiber Across the C+L Band

    Soma, D., Wakayama, Y., Beppu, S., Sumita, S., Tsuritani, T., Hayashi, T., Nagashima, T., Suzuki, M., Yoshida, M., Kasai, K., Nakazawa, M., Takahashi, H., Igarashi, K., Morita, I., Suzuki, M.

    Journal of Lightwave Technology   36 ( 6 ) 1362 - 1368  2018年

     概要を見る

    Space-division multiplexing (SDM) is an attractive technique for dramatically enhancing the transmission capacity in a single optical fiber. Recently, ultradense SDM transmission experiments with a spatial multiplicity of over 100 have been reported by using few mode multicore fibers (FM-MCFs). Considering the maximum capacity of around 100 Tb/s reported in single-mode single-core fiber transmission experiments, the capacity in FM-MCF transmission with more than 100 spatial channels is expected to reach 10 peta-b/s; however, the maximum capacity has been limited to 2 peta-b/s. In this paper, we demonstrate ultradense SDM transmission of 739 WDM 12-Gbd dual polarization-64-quadrature amplitude modulation (QAM)/16-QAM signals over 11.3-km 6-mode 19-core fiber using the C+L band, achieving a record fiber capacity of 10.16 peta-b/s with an aggregate spectral efficiency of 1099.9 b/s/Hz.

    DOI

    Scopus

    92
    被引用数
    (Scopus)
  • Adaptive DC interconnection provisioning in distributed all-optical micro-datacenters using holistically SDN orchestration for dynamic access

    Cao, X., Chen, G., Popescu, I., Guo, H., Yoshikane, N., Tsuritani, T., Wu, J., Morita, I.

    Photonic Network Communications   35 ( 2 ) 129 - 140  2018年

     概要を見る

    The metro-embedded datacenter (ME-DC) architecture which is based on micro-DCs (mDC) is introduced and implemented to deliver more flexible services with less access latency. Hierarchical SDN control is employed to adaptively interconnect the distributed mDCs and the metro network slices into re-configurable virtual DC (VDC). Such an approach improves the overall resource mobility, especially for traveling users that need to dynamically access the service. In this paper, the VDC re-configuration and pre-configuration mechanisms for dynamic user access are proposed and demonstrated for the first time. In specific, by re-configuring the VDC with the most accessible resources with user location tracking, fast and flexible service is provided with consistent service access. Furthermore, by pre-configuring the VDC with user prediction, mDC and metro network resources are reserved in advance for users in order to provide seamless service. Demonstration based on the implemented ME-DC prototype shows that VDC is adaptively constructed for dynamic user access with fast and flexible service provisioning.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Integration of IoT, Transport SDN, and Edge/Cloud Computing for Dynamic Distribution of IoT Analytics and Efficient Use of Network Resources

    Muñoz, R., Vilalta, R., Yoshikane, N., Casellas, R., Martínez, R., Tsuritani, T., Morita, I.

    Journal of Lightwave Technology   36 ( 7 ) 1420 - 1428  2018年

     概要を見る

    Internet of Things (IoT) requires cloud infrastructures for data analysis (e.g., temperature monitoring, energy consumption measurement, etc.). Traditionally, cloud services have been implemented in large datacenters in the core network. Core cloud offers high-computational capacity with moderate response time, meeting the requirements of centralized services with low-delay demands. However, collecting information and bringing it into one core cloud infrastructure is not a long-term scalable solution, particularly as the volume of IoT devices and data is forecasted to explode. A scalable and efficient solution, both at the network and cloud level, is to distribute the IoT analytics between the core cloud and the edge of the network (e.g., first analytics on the edge cloud and the big data analytics on the core cloud). For an efficient distribution of IoT analytics and use of network resources, it requires to integrate the control of the transport networks (packet and optical) with the distributed edge and cloud resources in order to deploy dynamic and efficient IoT services. This paper presents and experimentally validates the first IoT-aware multilayer (packet/optical) transport software defined networking and edge/cloud orchestration architecture that deploys an IoT-traffic control and congestion avoidance mechanism for dynamic distribution of IoT processing to the edge of the network (i.e., edge computing) based on the actual network resource state.

    DOI

    Scopus

    92
    被引用数
    (Scopus)
  • 118.5 Tbit/s transmission over 316 km-long multi-core fiber with standard cladding diameter

    T. Matsui, T. Kobayashi, H. Kawahara, E. L.T. De Gabory, T. Nagashima, T. Nakanishi, S. Saitoh, Y. Amma, K. Maeda, S. Arai, R. Nagase, Y. Albe, S. Aozasa, Y. Wakayama, H. Takeshita, T. Tsuritani, H. Ono, T. Sakamoto, I. Morita, Y. Miyamoto, K. Nakajima

    2017 Opto-Electronics and Communications Conference, OECC 2017 and Photonics Global Conference, PGC 2017   2017-November   1 - 2  2017年11月

     概要を見る

    A world record capacity 118.5 Tbit/s transmission through optical fiber with a 125 micron cladding diameter was achieved using a low loss and 316 km-long full space division multiplexing link incorporating multiple vendor technologies.

    DOI

    Scopus

    70
    被引用数
    (Scopus)
  • Bit-Error Ratio Performance Improvement Using Iterative Decoding for Polybinary-Shaped Super-Nyquist Wavelength Division Multiplexed Signals

    Shuai Yuan, Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    JOURNAL OF LIGHTWAVE TECHNOLOGY   35 ( 21 ) 4605 - 4612  2017年11月

     概要を見る

    In super-Nyquist wavelength division multiplexed (WDM) systems with frequency spacing smaller than the signal baudrate, the maximum-likelihood (ML) decoder in the receiver is usually introduced to compensate for intersymbol interference due to tight spectral filtering, such as polybinary shaping. After the ML decoder, symbol errors tend to propagate, causing excess continuous errors. Considering that forward error correction (FEC) is commonly introduced, the excess continuous errors degrade bit-error ratio (BER) performance after FEC, so-called post-FEC BER. In order to suppress the performance degradation, we introduce iterative decoding between the first ML decoder for polybinary shaping and the second FEC decoder in the receiver. First, we calculate BER characteristics of polybinary-shaped super-Nyquist WDM quadrature phase-shift keying (QPSK) signals. The results show that iterative decoding is effective for improving post-FEC BER performance. A lager pre-FEC BER threshold for post-FEC BER < 10(-5) is obtained in super-Nyquist WDM case than in the Nyquist WDM case, although a higher signal-to-noise ratio (SNR) is required. Next, we measure the BER characteristics of three-channel duobinary-shaped super-Nyquist WDM 12.5-Gbaud dual-polarization QPSK signals. The iterative decoding reduces the optical SNR penalty by 0.8 dB. A larger pre-FEC BER threshold of 3.1 x 10(-2) is obtained in the duobinary-shaped super-Nyquist WDM case, compared with the threshold of 2.2 x 10(-2) in the Nyquist WDM case.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • IoT-aware Multi-layer Transport SDN and Cloud Architecture for Traffic Congestion Avoidance Through Dynamic Distribution of IoT Analytics

    Raul Munoz, Ricard Vilalta, Noboru Yoshikane, Ramon Casellas, Ricardo Martinez, Takehiro Tsuritani, Itsuro Morita

    43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017)   2017-September   1 - 3  2017年

     概要を見る

    We present and experimentally assess the first IoT-aware SDN and cloud architecture that deploys IoT flow monitoring and traffic-congestion avoidance techniques in order to dynamically and efficiently distribute the processing of IoT analytics from core datacentres to the network edge.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • 10.16 Peta-bit/s Dense SDM/WDM transmission over Low-DMD 6-Mode 19-Core Fibre across C plus L Band

    Daiki Soma, Yuta Wakayama, Shohei Beppu, Seiya Sumita, Takehiro Tsuritani, Tetsuya Hayashi, Takuji Nagashima, Masato Suzuki, Hidenori Takahashi, Koji Igarashi, Itsuro Morita, Masatoshi Suzuki

    43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017)   2017-September   1 - 3  2017年

     概要を見る

    Over 10 peta-bit/s transmission has been experimentally demonstrated for the first time using 11.3-km-length low-DMD 6-mode 19-core fibre across C+L band. Q-factors of all 84,246 SDM/WDM channels modulated with 12-Gbaud DP-64QAM/16QAM exceeded the assumed FEC limits.

    DOI

    Scopus

    138
    被引用数
    (Scopus)
  • Peta Bit Per Second Optical Transmission with Spatial Division Multiplexing

    Masatoshi Suzuki, Itsuro Morita, Takehiro Tsuritani

    43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017)   2017-September   1 - 3  2017年

     概要を見る

    Recent progress on space division multiplexed optical transmission is reviewed. 2.05 peta bit/s transmission with 114 spatial multiplecity, ultra-high aggregate spectral efficiency of 947 bit/s/Hz and long haul transmission over 6160km with 200 Gbit/s channel bit rate have been achieved.

    DOI

    Scopus

  • End-to-End SDN/NFV Orchestration of Video Analytics Using Edge and Cloud Computing over Programmable Optical Networks

    Ricard Vilalta, Ion Popescu, Arturo Mayoral, Xiaoyuan Cao, Ramon Casellas, Noboru Yoshikane, Ricardo Martinez, Takehiro Tsuritani, Itsuro Morita, Raul Munoz

    2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)   Part F40-OFC 2017  2017年

     概要を見る

    This paper proposes the introduction of SDN-enabled containers to support the deployment of SDN/NEV applications located at the network edge, which are able to trigger on demand connectivity services. A video analytics use case is demonstrated.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Ultra-High Spectral Efficiency Few-Mode Multicore Fibre Transmission

    Yuta Wakayama, Daiki Soma, Takehiro Tsuritani, Itsuro Morita

    43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017)   2017-September   1 - 3  2017年

     概要を見る

    This paper reviews recent progress on space-division multiplexed (SDM) transmission with focusing on aggregate spectral efficiency (SE) and discusses current issues with SDM transmission toward ultra-high SE.

    DOI

    Scopus

  • Impact of metro-embedded data centers on metropolitan network design and traffic profile

    Popescu, I., Cao, X., Chen, G., Guo, H., Yoshikane, N., Tsuritani, T., Wu, J., Morita, I.

    Journal of Optical Communications and Networking   9 ( 10 ) 900 - 908  2017年

     概要を見る

    Traditional data centers (DCs) that are located in distant areas usually lack flexibility and also have long service latency for metro users. On the other hand, the recently introduced and implemented metro-embedded data center (ME-DC) architecture, based on micro-data centers (mDCs), delivers more flexible services with less access latency. Hierarchical software-defined network control is employed to virtualize and holistically coordinate the distributed mDCs and metro network slices into a reconfigurable virtual data center. Such an approach improves the overall resource mobility and access to the service; however, the impact on the metro network traffic profile induced by user/mDC and inter-mDC connections due to the dispersion of mDCs has not been evaluated. In this paper, we develop a mixed integer linear programming model that optimizes the total DC traffic, taking into consideration the intra-, inter-, and external DC communications. Furthermore, we numerically assess the changes in the metro network traffic induced by ME-DC architecture, considering different types of DCs and their corresponding traffic profile. Simulation shows that the distribution of the mDCs has a beneficial effect, leading to a fourfold reduction in the total traffic load.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Control orchestration protocol: Unified transport API for distributed cloud and network orchestration

    Mayoral, A., Vilalta, R., Munoz, R., Casellas, R., Martinez, R., Moreolo, M.S., Fabrega, J.M., Aguado, A., Yan, S., Simeonidou, D., Gran, J.M., Lopez, V., Kaczmarek, P., Szwedowski, R., Szyrkowiec, T., Autenrieth, A., Yoshikane, N., Tsuritani, T., Morita, I., Shiraiwa, M., Wada, N., Nishihara, M., Tanaka, T., Takahara, T., Rasmussen, J.C., Yoshida, Y., Kitayama, K.-I.

    Journal of Optical Communications and Networking   9 ( 2 ) A216 - A222  2017年

     概要を見る

    In the context of the fifth generation of mobile technology (5G), multiple technologies will converge into a unified end-to-end system. For this purpose, software defined networking (SDN) is proposed, as the control paradigm will integrate all network segments and heterogeneous optical and wireless network technologies together with massive storage and computing infrastructures. The control orchestration protocol is presented as a unified transport application programming interface solution for joint cloud/network orchestration, allowing interworking of heterogeneous control planes to provide provisioning and recovery of quality of service (QoS)-aware end-to-end services. End-to-end QoS is guaranteed by provisioning and restoration schemes, which are proposed for optical circuit/packet switching restoration bymeans of signalmonitoring and adaptivemodulation and adaptive route control, respectively. The proposed solution is experimentally demonstrated in an international multi-partner test bed, which consists of a multi-domain transport network comprising optical circuit switching and optical packet switching domains controlled by SDN/OpenFlow and Generalized Multiprotocol Label Switching (GMPLS) control planes and a distributed cloud infrastructure. The results show the dynamic provisioning of IT and network resources and recovery capabilities of the architecture.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • Software-defined optical networks and network abstraction with functional service design [invited]

    Cao, X., Yoshikane, N., Popescu, I., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   9 ( 4 ) C65 - C75  2017年

     概要を見る

    The combination of software-defined networking (SDN) and optics, i.e., a software-defined optical network (SDON), offers combined benefits that include flexible SDN control and large optical transport capacity. In this paper, we introduce the unified SDN as a common control solution for end-to-end OCS/OPS networks, with the introduction of an additional network element, namely the OpenFlow agent. The SDN control plane is implemented in the OPS network for simplified data plane design, optimal network organization, and contention alleviation, as well as improved control flexibility and advanced handling of network dynamics. The SDON demonstration is conducted in the nationwide transport networks constructed with different technologies via various internetworking testbeds. Based on the SDON platform, we further introduce the service design concept for advanced network abstraction. The general network architecture based on a service design concept offering flexible, reconfigurable, and economical end-to-end (FREE) service features is described. This service design aims to provide customized service and maximum network freedom with virtualized and flexibly selected functionalities, while maintaining a moderate network configuration cost and promoting network innovation at the same time. Moreover, the service design concept could easily be extended to any layers and any network domains, thus providing the unified network abstraction ability and the end-to-end control solution. Based on the service design, control, coordinated, and orchestrated optical transmission is demonstrated by reconfiguring the virtualized optical functions. This type of approach to network abstraction is further exploited in the heterogeneous multidomain networks, where differentiated and featured service provisioning is demonstrated.

    DOI

    Scopus

    19
    被引用数
    (Scopus)
  • Optimal and dynamic virtual datacenter provisioning over metro-embedded datacenters with holistic SDN orchestration

    Cao, X., Popescu, I., Chen, G., Guo, H., Yoshikane, N., Tsuritani, T., Wu, J., Morita, I.

    Optical Switching and Networking   24   1 - 11  2017年

     概要を見る

    Conventional mega datacenter (DC) lacks flexibility and has poor service connectivity for users faraway. Therefore, the metro-embeded DC architecture has been introduced to deliver more reliable and flexible services with less access latency. For fine-grained all-optical switching ability and high bandwidth connection, optical burst switching (OBS) ring is deployed inside the micro-DCs (mDC) and OBS over wavelength switched optical network paradigm is used for inter-mDC communication. Meanwhile, hierarchical SDN control is employed to virtualize and holistically coordinate the distributed mDCs and the metro network slices into reconfigurable virtual DC (VDC). Optimal VDC provisioning based on an integer linear programming (ILP) formulation is also developed in the SDN control plane to provide services With minimum latency and traffic load. A dynamic VDC provisioning algorithm based on partial ILP is further Proposed to reconfigure the VDC with reduced complexity considering the user and resource dynamics. Experimental demonstrations conducted on the implemented metro-embedded DC prototype testbed show that optimal and fast VDC provisioning is realized based on the proposed ILP, while dynamic VDC reconfiguration makes sure that VDC is adjusted accordingly with the change of user location and resource requirement.

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • Demonstration of Adaptive SDN Orchestration: A Real-Time Congestion-Aware Services Provisioning over OFDM-Based 400G OPS and Flexi-WDM OCS

    Fabrega, J.M., Svaluto Moreolo, M., Mayoral, A., Vilalta, R., Casellas, R., Martinez, R., Munoz, R., Yoshida, Y., Kitayama, K., Kai, Y., Nishihara, M., Okabe, R., Tanaka, T., Takahara, T., Rasmussen, J.C., Yoshikane, N., Cao, X., Tsuritani, T., Morita, I., Habel, K., Freund, R., Lopez, V., Aguado, A., Yan, S., Simeonidou, D., Szyrkowiec, T., Autenrieth, A., Shiraiwa, M., Awaji, Y., Wada, N.

    Journal of Lightwave Technology   35 ( 3 ) 506 - 512  2017年

     概要を見る

    In this Paper, we experimentally demonstrate highly flexible and intelligent interdomain coordinated actions based on adaptive software-defined networking (SDN) orchestration. An advanced multidomain multitechnology testbed is implemented, which consists of a 400-Gb/s variable capacity optical packet switching domain and a Tb/s-class flexi-grid wavelength division multiplexed optical circuit switching domain. The SDN-controllable transponders and the extended transport applications programming interface enable the congestion-aware provisioning of end-to-end real-time services. At the data plane level, different transponders based on orthogonal frequency division multiplexing are employed for inter/intradomain links in order to adaptively provision services with fine granularity. For adaptation, SDN-capable domain-specific optical performance monitors are also introduced. In the control plane, the applications based network operations architecture has been extended and addressed as an adaptive SDN orchestrator.

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • First experimental demonstration of a distributed cloud and heterogeneous network orchestration with a common Transport API for E2E services with QoS

    A. Mayoral, R. Vilalta, R. Munoz, R. Casellas, R. Martinez, M. Svaluto Moreolo, J. M. Fabrega, S. Yan, A. Aguado, E. Hugues-Salas, S. Peng, F. Meng, Y. Shu, G. Zervas, R. Nejabati, D. Simeonidou, J. M. Gran, V. Lopez, O. Gonzalez De Dios, J. P. Fernandez-Palacios, P. Kaczmarek, R. Szwedowski, T. Szyrkowiec, A. Autenrieth, N. Yoshikane, X. Cao, T. Tsuritani, I. Morita, M. Shiraiwa, N. Wada, M. Nishihara, T. Tanaka, T. Takahara, J. C. Rasmussen, Y. Yoshida, K. Kitayama

    2016 Optical Fiber Communications Conference and Exhibition, OFC 2016    2016年08月

     概要を見る

    A common Transport API is proposed for joint cloud/network orchestration, allowing interworking of heterogeneous control planes to provide provisioning/recovery of QoS-aware E2E services. We present its first demonstration in a multi-partner testbed including data-plane monitoring.

    DOI

    Scopus

    21
    被引用数
    (Scopus)
  • First demonstration of cognitive SDN orchestration: A real-time congestion-aware services provisioning over OFDM-based 400G OPS and Flexi-WDM OCS networks

    Y. Yoshida, K. Kitayama, Y. Kai, M. Nishihara, R. Okabe, T. Tanaka, T. Takahara, J. C. Rasmussen, N. Yoshikane, X. Cao, T. Tsuritani, I. Morita, A. Mayoral, J. M. Fabrega, R. Vilalta, R. Casellas, R. Martinez, M. Svaluto Moreolo, R. Munoz, K. Habel, R. Freund, V. Lopez, A. Aguado, S. Yan, D. Simeonidou, T. Szyrkowiec, A. Autenrieth, M. Shiraiwa, Y. Awaji, N. Wada

    2016 Optical Fiber Communications Conference and Exhibition, OFC 2016    2016年08月

     概要を見る

    Cognitive SDN orchestration over 400-Gbps OPS and Tbps-class Flexi-WDM networks is demonstrated, where the SDN-controllable OFDM transponders and the extended transport API enable the congestion-aware provisioning of end-to-end real-time services.

  • Peer SDN orchestration: End-to-end connectivity service provisioning through multiple administrative domains

    R. Vilalta, A. Mayoral, V. López, V. Uceda, R. Casellas, R. Martinez, R. Muñoz, A. Aguado, J. Marhuenda, R. Nejabati, D. Simeonidou, N. Yoshikane, T. Tsuritani, I. Morita, T. Szyrkowiec, A. Autenrieth

    European Conference on Optical Communication, ECOC     184 - 186  2016年

     概要を見る

    This papers proposes the usage of Control Orchestration Protocol (COP) as an East-West interface in order to interconnect different SDN controllers (peer model) through multiple administrative domains. An experimental validation of network connectivity provisioning is presented in an international testbed.

  • Improvement on FEC performance by turbo equalization for super-nyquist WDM systems

    Shuai Yuan, Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    European Conference on Optical Communication, ECOC     571 - 573  2016年

     概要を見る

    In Super-Nyquist WDM systems, maximum likelihood decoder for duobinary shaping degrades the post-FEC BER performance. We experimentally confirm that degradation of post-FEC BER characteristics can be remarkably suppressed by introducing turbo equalization.

  • Network abstraction with functional service design in the software-defined optical networks

    Xiaoyuan Cao, Noboru Yoshikane, Ion Popescu, Takehiro Tsuritani, Itsuro Morita

    Optics InfoBase Conference Papers    2016年

     概要を見る

    The unified SDN-enabled OCS/OPS network infrastructure is presented. Moreover, with function abstraction and virtualization based on the service design concept, orchestrated optical system control and customized service provisioning are realized in the software-defined optical networks.

    DOI

    Scopus

  • Turbo equalization with 20%-overhead turbo code in super-nyquist WDM systems

    Shuai Yuan, Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    Optics InfoBase Conference Papers    2016年

     概要を見る

    We investigate turbo equalization with 20%-overhead turbo code for duobinary-shaped signals introduced in Super-Nyquist WDM systems. The turbo equalization can efficiently suppress the degradation of BER performance due to duobinary shaping.

    DOI

    Scopus

  • Dynamic Support and Demonstration for Orchestrated Multi-domain Software-defined Optical Networks

    Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    20TH INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING (ONDM 2016)    2016年

     概要を見る

    Software-defined optical network has the combined benefit of both control flexibility and large transport capacity, thus having the potential of realizing a new ground-breaking optical network framework. In this paper, we introduce our recent efforts that have been devoted to the research supported by the STRAUSS project on SDN/Openflow controlled optical networks. The unified SDN control plane is able to configure the optical nodes/devices and thus the optical network through the cooperation of Openflow agents with more flexibility and optimization, thanks to its global knowledge of network resource and centralized controllability. Furthermore, we are able to interconnect our network with other heterogeneous multidomain networks, while demonstrating the end-to-end flexible service provisioning over both nationwide and international testbeds with SDN orchestration via unified interface based on control orchestration protocol.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Functional Service Design with SDN Orchestration across Heterogeneous Multi-domain Networks

    Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Masaki Shiraiwa, Naoya Wada

    2016 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)    2016年

     概要を見る

    A "service design" paradigm is presented to flexibly accommodate customized services by applying and chaining reconfigurable virtual network functions. Functional and featured service provisioning is demonstrated across heterogeneous IP/OPS/OCS domain networks with end-to-end SDN orchestration.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Software-defined Optical Transmission and Networking with Functional Service Design

    Xiaoyuan Cao, Noboru Yoshikane, Koki Takeshima, Ion Popescu, Takehiro Tsuritani, Itsuro Morita

    2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)    2016年

     概要を見る

    A service design concept is introduced into the optical transport network. Customized and orchestrated optical transmission is realized by coordinating and reconfiguring the sharable virtualized optical functions, while better flexibility is provided for optical networking.

  • Optimized Multicast Scheduling in Datacenter Optical Burst Ring Network

    Gang Chen, Dongxu Zhang, Hongxiang Guo, Jian Wu, Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)    2016年

     概要を見る

    We propose an ILP-based model and a time-efficient heuristic algorithm for multicast scheduling in optical burst ring network. Simulation results verify the proposed methods could improve latency and throughput performance significantly compared to unicast transmission.

  • Bit-error Rate Performance of Six-mode-mulitplexed DP-64QAM signals

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2016 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES (SUM)     232 - 233  2016年

     概要を見る

    We experimentally evaluate the bit-error rate performance of six-mode-multiplexed DP-QAM signals in back-to-back configuration. In Nyquist WDM and 64QAM format cases, BERs of less than 2x10(-2) for all modes are achieved.

    DOI

    Scopus

  • Ultra-high-capacity Transmission over Few-mode Multi-core Fibers

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)    2016年

     概要を見る

    We present ultra-dense-SDM Super-Nyquist-WDM transmission over 9.8-km six-mode nineteen-core fibers with a spatial multiplicity of 114, achieving a transmission capacity of 2.05 Pbit/s with a record aggregate spectral efficiency of 456 bit/s/Hz in C band.

  • Ultra-Dense Space Division Multiplexing Technologies Towards Multi-Peta Bit/s Optical Transmission

    Masatoshi Suzuki, Daiki Soma, Koji Igarashi, Yuta Wakayama, Koki Takeshima, Yu Kawaguchi, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    2016 18TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON)   2016-August  2016年

     概要を見る

    In this paper, recent progress on ultra-dense, space division multiplexed (SDM) optical transmission towards multi-Peta bit/s are reviewed. By using 6-mode 19-core fiber, we have demonstrated 2.05 Pbit/s transmission over 9.8 km just using C-band. High spatial multiplicity of 114 and ultra-high aggregate spectral efficiency of 456 bit/s/Hz/fiber have been achieved.

    DOI

    Scopus

  • User-access-frequency statistics based hotspot adjustment in all-optically interconnected metro-embedded datacenters

    Chen, G., Guo, H., Zhang, D., Wu, J., Cao, X., Yoshikane, N., Tsuritani, T., Morita, I.

    Optics Communications   381   437 - 442  2016年

     概要を見る

    Traditional datacenters are typically deployed with highly clustered resources and built-in remote areas far away from users, requiring huge floor space and power consumption. The proposed metro-embedded datacenter architecture with distributed resources spreading across the metro area close to users could be a promising solution, which exhibits lower access latency and more flexibility for service orchestration. Based on metro-embedded datacenter, we propose the conception of "follow the user" with user access location aware dynamic hotspots adjustments. By enabling service hotspots adjustment according to user access frequency statistics, the quality of service can be significantly improved in terms of reduced latency. Finally, we experimentally demonstrate low-latency service provisioning based on the proposed principle. (C) 2016 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Polybinary Shaping for Highly-Spectral-Efficient Super-Nyquist WDM QAM Signals

    Igarashi, K., Tsuritani, T., Morita, I.

    Journal of Lightwave Technology   34 ( 8 ) 1724 - 1731  2016年

     概要を見る

    In Super-Nyquist wavelength-division multiplexed (WDM) systems, in which WDM channel spacing is smaller than a signal baudrate, there is a tradeoff relationship between the WDM crosstalk and inter-symbol interference due to the tight spectral shaping. For optimizing the tradeoff relationship, polybinary shaping with maximum likelihood sequence estimation is introduced. In this paper, we numerically and experimentally investigate the bit-error rate characteristics of the Super-Nyquist WDM quadrature amplitude modulated signals with polybinary shaping in order to clarify the relationship between the spectral efficiency and required signal-to-noise ratio (SNR). These results indicate that the Super-Nyquist WDM technique based on polybinary shaping is effective to optimize the spectral efficiency for the target required SNR equivalent to the target transmission distance.

    DOI

    Scopus

    27
    被引用数
    (Scopus)
  • Ultra-dense spatial-division-multiplexed optical fiber transmission over 6-mode 19-core fibers

    Igarashi, K., Soma, D., Wakayama, Y., Takeshima, K., Kawaguchi, Y., Yoshikane, N., Tsuritani, T., Morita, I., Suzuki, M.

    Optics Express   24 ( 10 ) 10213 - 10231  2016年

     概要を見る

    Ultra-dense spatial-division multiplexing (SDM) is achieved by mode multiplexed technique with multiple cores in a single fiber, namely few-mode multi-core fiber. Using a 9.8-km six-mode nineteen-core fiber, we demonstrate an ultra-dense SDM transmission of 16-channels wavelength-division-multiplexed (WDM) dual-polarization quadrature phase shift keying signals, achieving a record spatial multiplicity of 114. With the help of ultra-dense Super-Nyquist WDM techniques in the 4.5-THz bandwidth of the full C-band, we demonstrate 2.05 Pbit/s transmission over 9.8-km six-mode nineteen-core fibers. In this experiment, the highest aggregate spectral efficiency of 456 bit/s/Hz is achieved. (C) 2016 Optical Society of America

    DOI

    Scopus

    66
    被引用数
    (Scopus)
  • 51.1-Tbit/s MCF Transmission over 2520 km Using Cladding-Pumped Seven-Core EDFAs

    Takeshima, K., Tsuritani, T., Tsuchida, Y., Maeda, K., Saito, T., Watanabe, K., Sasa, T., Imamura, K., Sugizaki, R., Igarashi, K., Morita, I., Suzuki, M.

    Journal of Lightwave Technology   34 ( 2 ) 761 - 767  2016年

     概要を見る

    Multicore erbium-doped fiber amplifiers (MCEDFAs) are essential components to achieve long-haul multicore fiber (MCF) transmission. An attractive technique for reducing the number of components and power consumption is the cladding-pumping scheme in MC-EDFAs in which all cores are simultaneously pumped using a single high-power multimode laser diode. In this paper, we experimentally demonstrate long-haul MCF transmission using cladding-pumped seven-core EDFAs. We confirm that 73 x 128-Gbit/s Nyquist-pulse-shaped dual-polarization quadrature phase-shift keying signals are successfully transmitted over 2520-km seven-core fiber.

    DOI

    Scopus

    37
    被引用数
    (Scopus)
  • 2.05 Peta-bit/s super-nyquist-WDM SDM transmission using 9.8-km 6-mode 19-core fiber in full C band

    D. Soma, K. Igarashi, Y. Wakayama, K. Takeshima, Y. Kawaguchi, N. Yoshikane, T. Tsuritani, I. Morita, M. Suzuki

    European Conference on Optical Communication, ECOC   2015-November  2015年11月

     概要を見る

    We demonstrate ultra-dense SDM transmission of 360-channel Super-Nyquist-WDM DP-QPSK signals over 9.8-km 6-mode 19-core fiber, achieving the record fiber capacity of 2.05 Pbit/s (360WDM×114SDM×50Gbit/s) with the highest aggregate spectral efficiency of 456 bit/s/Hz.

    DOI

    Scopus

    83
    被引用数
    (Scopus)
  • WDM/SDM transmission of 76 × 128-Gbit/s Nyquist-pulse-shaped DP-QPSK Signals over 4,200 km using cladding pumped 7-Core EDFA

    K. Takeshima, T. Tsuritani, K. Igarashi, I. Morita, Y. Tsuchida, K. Maeda, T. Saito, K. Watanabe, T. Sasa, K. Imamura, R. Sugizaki

    2015 Opto-Electronics and Communications Conference, OECC 2015    2015年11月

     概要を見る

    We experimentally demonstrate ultra-long-haul multi-core fiber transmission using a cladding pumped 7-core erbium-doped fiber amplifier. We confirm 76 × 128-Gbit/s Nyquist-pulse-shaped DP-QPSK signals are successfully transmitted over 4,200-km 7-core fiber.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Demonstration of dynamic congestion control in optical packet switching network employing rate-adaptive transmitter and receiver

    N. Yoshikane, X. Cao, Y. Yoshida, M. Nishihara, M. Shiraiwa, T. Tsuritani, I. Morita, T. Takahara, T. Tanaka, J. C. Rasmussen, N. Wada, K. Kitayama

    2015 International Conference on Photonics in Switching, PS 2015     282 - 284  2015年11月

     概要を見る

    We experimentally demonstrate dynamic congestion control in an optical packet switching network employing an optical packet counter for traffic flow diagnosis and a rate-adaptive transmitter and receiver to reduce packet loss ratio while preserving the transmission capacity.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • The need for a Control Orchestration Protocol in research projects on optical networking

    R. Vilalta, V. López, A. Mayoral, N. Yoshikane, M. Ruffini, D. Siracusa, R. Martínez, T. Szyrkowiec, A. Autenrieth, S. Peng, R. Casellas, R. Nejabati, D. Simeonidou, X. Cao, T. Tsuritani, I. Morita, J. P. Fernández-Palacios, R. Muñoz

    2015 European Conference on Networks and Communications, EuCNC 2015     340 - 344  2015年08月

     概要を見る

    The Control Orchestration Protocol (COP) abstracts a common set of control plane functions used by an various SDN controllers, allowing the interworking of heterogeneous control plane paradigms (i.e., OpenFlow, GMPLS/PCE). COP has been defined using YANG model language and can be transported using RESTconf, which is being incorporated by industry. COP has been defined in the scope of STRAUSS due to the need for an overarching control plane protocol for network orchestration. In this paper, several research projects describe how the COP could fit in their architecture and propose a use case for COP usage. The proposed COP use cases cover the following research projects: STRAUSS, IDEALIST, DISCUS, COMBO, INSPACE.

    DOI

    Scopus

    30
    被引用数
    (Scopus)
  • Network virtualization controller for abstraction and control of OpenFlow-enabled multi-tenant multi-technology transport networks

    R. Vilalta, R. Munoz, R. Casellas, R. Martinez, F. Francois, S. Peng, R. Nejabati, D. Simeonidou, N. Yoshikane, T. Tsuritani, I. Morita, V. Lopez, T. Szyrkowiec, A. Autenrieth

    Conference on Optical Fiber Communication, Technical Digest Series   2015-June  2015年06月

     概要を見る

    A network hypervisor is introduced to dynamically deploy multi-tenant virtual networks on top of multi-technology optical networks. It provides an abstract view of each virtual network and enables its control through an independent SDN controller.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • Heterogeneous Multi-domain 1N etwork Virtualization with End-to-end Differentiated Service Provisioning and Virtual 1N etwork Organization

    Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)   2015-June  2015年

     概要を見る

    Hierarchical network virtualization is demonstrated on a heterogeneous multi-domain network testbed, based on SDN/Openflow and two-level Flowvisor. Differentiated services with various sets of QoS requirements are provisioned in the end-to-end optimally organized virtual networks.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Dynamic Optical Packet Switching Network with Advanced SDN/Openflow Control (Invited talk)

    Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Masaki Shiraiwa, Naoya Wada

    2015 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)    2015年

     概要を見る

    The dynamic optical packet switching network based on advanced SDN/Openflow control is introduced in this paper. Promoted resource allocation and prompt network adjustment is achieved under dynamic network environment with real-time optical packet monitoring.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • First Demonstration of Holistically-organized Metro-embedded Cloud Platform with All-optical Interconnections for Virtual Datacenter Provisioning

    Gang Chen, Hongxiang Guo, Dongxu Zhang, Yong Zhu, Cen Wang, Haomin Yu, Yusheng Wang, Jialiang Wang, Jian Wu, Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    2015 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)    2015年

     概要を見る

    We demonstrated a novel metro-embedded datacenter architecture with intra-datacenter optical burst switching ring and inter-datacenter optical burst switching over wavelength switched optical network interconnections, and virtual datacenter provisioning under the coordination of SDN control plane.

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • 114 Space-division-multiplexed WDM Transmission Using 6-mode 19-core Fibers

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    2015 PHOTONICS CONFERENCE (IPC)     643 - 644  2015年

     概要を見る

    We show transmission experiments of 16-Nyquist-WDM 6-mode-multiplexed DP-QPSK signals over 9.8-km 6-mode 19-core fibers. The record spatial multiplicity of 114 and the aggregate spectral efficiency over 345 bit/s/Hz have been achieved.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Experimental Study on Polybinary-Pulse-Shaped QAM Signals for Highly-Spectral-Efficient Super-Nyquist-WDM Systems

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    ECOC 2015 41ST EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION   2015-November  2015年

     概要を見る

    We experimentally evaluate bit-error rate performance of polybinary-pulse-shaped QAM signals in Super-Nyquist-WDM conditions, and clarify the relationship between spectral efficiency and SNR compared with conventional Nyquist-pulse-shaped signals.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Super-Nyquist-WDM Techniques for Ultra-Long-Haul High-Capacity Optical Fiber Transmission Systems

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    2015 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)    2015年

     概要を見る

    We review Super-Nyquist WDM techniques for ultra-long-haul high-capacity transmission. In Super-Nyquist WDM systems, optical signals are multiplexed with the frequency spacing of less than baud rate. With the help of multi-core fibers with multi-core EDFA, 140.7-Tbit/s, 7 x 326-km transmission of 201-channel 25-GHz-spaced Super-Nyquist-WDM 100-Gbit/s DP-QPSK signals has been demonstrated, achieving the capacity-distance product over 1 Exabit/s. km.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • 114 Space-Division-Multiplexed Transmission over 9.8-km Weakly-Coupled-6-Mode Uncoupled-19-Core Fibers

    Koji Igarashi, Daiki Souma, Yuta Wakayama, Koki Takeshima, Yu Kawaguchi, Takehiro Tsuritani, Itsuro Morita, Masatoshi Suzuki

    2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)    2015年

     概要を見る

    We present space-division multiplexed transmission with spatial multiplicity over 100 using weakly-coupled-6-mode uncoupled-19-core fiber. Suppressing mode coupling and core-to core crosstalk, MIMO complexity can be reduced. The record aggregate spectral efficiency over 345 bit/s/Hz is achieved.

  • Network Control and Virtualization Technologies for Carrier Services

    Itsuro Morita

    2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)   2015-June  2015年

     概要を見る

    Network virtualization is a promising technology to reduce CAPEX and OPEX of telecommunication networks together with providing new service agility. This paper reviews recent research activities on network virtualization to enhance its benefits.

    DOI

    Scopus

  • SDN-based network orchestration of variable-capacity optical packet switching network over programmable flexi-grid elastic optical path network

    Yoshida, Y., Maruta, A., Kitayama, K.-I., Nishihara, M., Tanaka, T., Takahara, T., Rasmussen, J.C., Yoshikane, N., Tsuritani, T., Morita, I., Yan, S., Shu, Y., Yan, Y., Nejabati, R., Zervas, G., Simeonidou, D., Vilalta, R., Munoz, R., Casellas, R., Martinez, R., Aguado, A., Lopez, V., Marhuenda, J.

    Journal of Lightwave Technology   33 ( 3 ) 609 - 617  2015年

     概要を見る

    A multidomain and multitechnology optical network orchestration is demonstrated in an international testbed located in Japan, the U.K., and Spain. The application-based network operations architecture is proposed as a carrier software-defined network solution for provisioning end-to-end optical transport services through a multidomain multitechnology network scenario, consisting of a 46-108 Gb/s variable-capacity Open-Flow-capable optical packet switching network and a programmable, flexi-grid elastic optical path network.

    DOI

    Scopus

    35
    被引用数
    (Scopus)
  • Ultra-long-haul high-capacity super-nyquist-WDM transmission experiment using multi-core fibers

    Igarashi, K., Tsuritani, T., Morita, I., Suzuki, M.

    Journal of Lightwave Technology   33 ( 5 ) 1027 - 1036  2015年

     概要を見る

    This paper describes promising techniques for approaching the capacity-distance product over 1 Exabit/sxkm in the transoceanic-class optical fiber transmission. One is the Super-Nyquist wavelength-division multiplexing (WDM) technique based on poly-binary-pulse shaping with maximum likelihood sequence estimation, in which it is possible to multiplex optical signals with WDM spacing of less than the signal baudrate. Another technique is the space-division multiplexing technique based on multi-core fibers (MCFs) with multi-core Erbium-doped fiber amplifiers (ED-FAs), in which the fiber capacity can be increased when the number of cores of MCF is increased. Finally, we present a demonstration of 140.7-Tbit/s, 7 326-km transmission of 201-channel 25-GHz-spaced Super-Nyquist-WDM 100-Gbit/s optical signals using seven-core fibers and full C-band seven-core EDFAs.

    DOI

    Scopus

    35
    被引用数
    (Scopus)
  • Multidomain network hypervisor for abstraction and control of openflow-enabled multitenant multitechnology transport networks [Invited]

    Vilalta, R., Munoz, R., Casellas, R., Martinez, R., Peng, S., Nejabati, R., Simeonidou, D., Yoshikane, N., Tsuritani, T., Morita, I., Lopez, V., Szyrkowiec, T., Autenrieth, A.

    Journal of Optical Communications and Networking   7 ( 11 ) B55 - B61  2015年

     概要を見る

    A virtualization architecture is presented for deploying multitenant virtual networks on top of multi-technology optical networks. A multidomain network hypervisor (MNH) and a multidomain SDN orchestrator (MSO) are introduced with this purpose. The MNH provides an abstract view of each virtual network and gives control of it to each independent customer SDN controller. The MNH is able to provide virtual networks across heterogeneous control domains (i.e., generalized multiprotocol label switching and OpenFlow) and transport technologies (i.e., optical packet switching and elastic optical networks). The MSO is responsible for providing the necessary end-to-end connectivity. We have designed, implemented, and experimentally evaluated the MNH and MSO in an international testbed across Spain, UK, Germany, and Japan.

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • SDN orchestration of OpenFlow and GMPLS flexi-grid networks with a stateful hierarchical PCE [invited]

    Casellas, R., Munoz, R., Martinez, R., Vilalta, R., Liu, L., Tsuritani, T., Morita, I., Lopez, V., De Dios, O.G., Fernandez-Palacios, J.P.

    Journal of Optical Communications and Networking   7 ( 1 ) A106 - A117  2015年

     概要を見る

    New and emerging use cases, such as the interconnection of geographically remote data centers, are drawing attention to the need for provisioning end-to-end connectivity services spanning multiple and heterogeneous network domains. This heterogeneity is due not only to the data transmission and switching technology (the so-called data plane) but also to the deployed control plane, which may be used within each domain to automate the setup and recovery of such services, dynamically. The choice of a control plane is affected by factors such as availability, maturity, operator's preference, and the ability to satisfy a list of functional requirements. Given the current developments around OpenFlow and software-defined networking (SDN) along with the need to account for existing deployments based on GMPLS, the problem of heterogeneous control plane interworking needs to be solved. The retained solution must equally address the specific issues of multidomain networks, such as limited domain topology visibility, given the scalability and confidentiality constraints that characterize them. In this setting, we propose a functional and protocol architecture for such interworking, based on the key concepts of network abstraction and overarching control, implemented in terms of a hierarchical stateful path computation element (PCE), which provides the orchestration and coordination layer. In the proposed architecture, the PCEP and BGP-LS protocols are extended to support OpenFlow addresses and datapath identifiers, unifying both GMPLS and OpenFlow domains. The solution is deployed in an experimental testbed and validated. Although the main scope of the approach is the interworking of OpenFlow and GMPLS, the same approach can be directly applied to a wide range of multidomain scenarios, with either homogeneous or heterogeneous control technologies.

    DOI

    Scopus

    33
    被引用数
    (Scopus)
  • Overarching control of flexi grid optical networks: Interworking of GMPLS and openflow domains

    Casellas, R., Munoz, R., Martinez, R., Vilalta, R., Mayoral, A., Liu, L., Tsuritani, T., Morita, I.

    Journal of Lightwave Technology   33 ( 5 ) 1054 - 1062  2015年

     概要を見る

    Optical transport networks provide transport, multiplexing, routing, management, supervision, and survivability of optical channels. Within a flexible dense wavelength division multiplexing grid, the optical spectrum can be allocated in multiples of a width granularity, depending on the client signal rate and modulation format. A control plane (CP) can be used for efficient and dynamic provisioning and recovery of flexi-grid connections. Two main CP architectures coexist, with common functions like addressing, automatic topology discovery, network abstraction, path computation, and connection provisioning: a distributed generalized multiprotocol label switching CP (with optional path computation element, PCE path computation and instantiation/modification) and a CP based on software-defined networking, with a logically centralized controller and an open protocol, such as the OpenFlow protocol. Both architectures have their own strengths and weaknesses, and are being extended to address the new requirements associated with the aforementioned emerging optical technologies, such as flexible spectrum allocation, efficient corouted connection setup, and configuration of related optical parameters. However, new use cases such as remote data center interconnection highlight the need for multidomain service provisioning, and heterogeneous CP interworking, potentially requiring an overarching control. Different alternatives, with varying degrees of integration and flexibility, are available: straightforward approaches characterized by the adaptation of one control model to the other or more advanced interworking requiring the definition of common models (e.g., a subset of attributes for network elements) and of coordination and orchestration functions. This paper discusses the main relevant interworking architectures and presents a selected set of use cases and proof-of-concepts.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • Dynamic openflow-based lightpath restoration in elastic optical networks on the GENI testbed

    Liu, L., Peng, W.-R., Casellas, R., Tsuritani, T., Morita, I., Martinez, R., Munoz, R., Suzuki, M., Yoo, S.J.B.

    Journal of Lightwave Technology   33 ( 8 ) 1531 - 1539  2015年

     概要を見る

    Elastic optical networking (EON), with its flexible use of the optical spectrum, is a promising solution for future metro/core optical networking. For the deployment of EON in a real-operational scenario, the dynamic lightpath restoration, driven by an intelligent control plane, is a necessary network function. Dynamic restoration can restore network services automatically and, thus, greatly reduce the operational cost, compared with traditional manual or semistatic lightpath restoration strategies enabled by network operators via a network management system. To this end, in this paper, we present an OpenFlow-enabled dynamic lightpath restoration in elastic optical networks, detailing the restoration framework and algorithm, the failure isolation mechanism, and the proposed OpenFlow protocol extensions. We quantitatively present the restoration performance via control plane experimental tests on the Global Environment for Network Innovations testbed.

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • Dynamic multi-domain virtual optical network deployment with heterogeneous control domains [invited]

    Vilalta, R., Munoz, R., Casellas, R., Martinez, R., Peng, S., Channegowda, M., Vlachogiannis, T., Nejabati, R., Simeonidou, D., Cao, X., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   7 ( 1 ) A135 - A141  2015年

     概要を見る

    We propose a multi-domain resource broker to dynamically provision multi-domain virtual optical networks across heterogeneous control domains (i.e., GMPLS and OpenFlow) and transport (i.e., optical packet switching and elastic optical networks) technologies. We have designed, implemented, and experimentally evaluated the multi-domain resource broker in an international test-bed across Spain, the UK, and Japan.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Dynamic openflow-controlled optical packet switching network

    Cao, X., Yoshikane, N., Tsuritani, T., Morita, I., Suzuki, M., Miyazawa, T., Shiraiwa, M., Wada, N.

    Journal of Lightwave Technology   33 ( 8 ) 1500 - 1507  2015年

     概要を見る

    This paper presents and experimentally demonstrates the generalized architecture of Openflow-controlled optical packet switching (OPS) network. Openflow control is enabled by introducing the Openflow/OPS agent into the OPS network, which realizes the Openflow protocol translation and message exchange between the Openflow control plane and the underlying OPS nodes. With software-defined networking (SDN) and Openflow technique, the complex control functions of the conventional OPS network can be offloaded into a centralized and flexible control plane, while promoted control and operations can be provided due to centralized coordination of network resources. Furthermore, a contention-aware routing/rerouting strategy as well as a fast network adjustment mechanism is proposed and demonstrated for the first time as advanced Openflow control to route traffic and handle the network dynamics. With centralized SDN/Openflow control, the OPS network has the potential to have better resource utilization and enhanced network resilience at lower cost and less node complexity. Our work will accelerate the development of both OPS and SDN evolution.

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • Interworking of GMPLS and OpenFlow domains: Overarching control of flexi grid optical networks

    R. Casellas, R. Muñoz, R. Martínez, R. Vilalta, L. Liu, T. Tsuritani, I. Morita

    European Conference on Optical Communication, ECOC    2014年11月

     概要を見る

    Both GMPLS and OpenFlow are positioned to become the pillars of a dynamic control plane for optical transport networks, each with its own strengths and weaknesses. This paper summarizes both approaches and discusses potential SDN interworking architectures.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Cladding-pumped L-band multicore EDFA with reduced power consumption

    Y. Tsuchida, K. Maeda, K. Watanabe, T. Saito, S. Takasaka, M. Tadakuma, R. Sugizaki, H. Ogoshi, K. Doi, H. Matsuura, K. Takeshima, T. Tsuritani, I. Morita

    Proceedings - 2014 Summer Topicals Meeting Series, SUM 2014     148 - 149  2014年09月

     概要を見る

    Seven-core MC-EDFA pumped with single MM-LD optimized for L-band is developed. Output power of 19 dBm for each core is realized between 1576-1603nm with 33% reduced power consumption.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • SDN based provisioning orchestration of OpenFlow/GMPLS flexi-grid networks with a stateful hierarchical PCE

    R. Casellas, R. Muñoz, R. Martínez, R. Vilalta, L. Liu, T. Tsuritani, I. Morita, V. López, O. González de Dios, J. P. Fernández-Palacios

    Optics InfoBase Conference Papers    2014年

     概要を見る

    We report the experimental testbed evaluation of connectivity provisioning in which OpenFlow and GMPLS control planes interwork by means of an orchestrating stateful PCE. The hierarchical nature of the PCE allows seamless multi-domain operation. © 2014 OSA.

  • First international SDN-based network orchestration of variable-capacity OPS over programmable flexi-grid EON

    Y. Yoshida, A. Maruta, K. Kitayama, M. Nishihara, T. Tanaka, T. Takahara, J. C. Rasmussen, N. Yoshikane, T. Tsuritani, I. Morita, S. Yan, Y. Shu, M. Channegowda, Y. Yan, B. R. Rofoee, E. Hugues-Salas, G. Saridis, G. Zervas, R. Nejabati, D. Simeonidou, R. Vilalta, R. Munoz, R. Casellas, R. Martinez, M. Svaluto, J. M. Fabrega, A. Aguado, V. Lopez, J. Marhuenda, O. Gonzalez De Dios, J. P. Fernandez-Palacios

    Conference on Optical Fiber Communication, Technical Digest Series    2014年

     概要を見る

    The first experimental demonstrator of 46-108Gb/s discrete-multi-tone (DMT) fixedlength variable capacity OPS over programmable, flexi-grid elastic optical path network (EON), orchestrated via multiple OpenFlow controllers in the framework of SDN is presented. © 2014 OSA.

    DOI

    Scopus

    20
    被引用数
    (Scopus)
  • Openflow-controlled Optical Packet Switching Network with Advanced Handling of Network Dynamics

    Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Takaya Miyazawa, Naoya Wada

    2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)    2014年

     概要を見る

    We have experimentally demonstrated Openflow-controlled optical packet switching network, while also proposed and demonstrated an advanced Openflow control mechanism to handle the network dynamics with prompt response.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Bit-Error Rate Performance of Super-Nyquist-WDM DP-QPSK Signals with Duobinary-Pulse Shaping

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)    2014年

     概要を見る

    We experimentally investigate crosstalk characteristics of Super-Nyquist-WDM DP-QPSK signals with duobinary-pulse shaping. The bit-error rate performance of 100-Gbit/s-class duobinary-pulse shaped DP-QPSK WDM signals with frequency spacing of 25 GHz is evaluated experimentally.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • 1-Exabit/sxkm Super-Nyquist-WDM Multi-Core-Fiber Transmission

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)   2013 ( 622 CP ) 1251 - 1253  2014年

     概要を見る

    We review recent experimental demonstration of transoceanic multi-core-fiber transmission with multi-core EDFAs. With the help of Super-Nyquist WDM techniques, the product of the transmission capacity and distance of 1 Exabit/sxkm has been achieved.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • 1-Exabit/s.km Super-Nyquist-WDM Transmission using Multi-Core Fibers

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2014 12TH INTERNATIONAL CONFERENCE ON OPTICAL INTERNET (COIN)    2014年

     概要を見る

    We review trans-oceanic-class multi-core fiber transmission systems with Super-Nyquist-WDM technique, in which optical signals are multiplexed with frequency spacing of less than baudrate. The capacity-distance product over 1 Exabit/s.km has been achieved.

    DOI

    Scopus

  • Experimental Demonstration of OpenFlow-based Dynamic Restoration in Elastic Optical Networks on GENI Testbed

    Lei Liu, Wei-Ren Peng, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Ricardo Martinez, Rauel Munoz, S. J. Ben Yoo

    2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)    2014年

     概要を見る

    We present OpenFlow-enabled dynamic restoration in elastic optical networks, detailing the restoration framework and algorithm, failure isolation mechanism, OpenFlow protocol extensions, and quantitatively presenting the restoration performance via the experimental validation on the Global Environment for Network Innovations (GENI) testbed.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • 1 Exabit/s.km Transmission with Multi-core Fiber and Spectral Efficient Modulation Format

    Itsuro Morita, Koji Igarashi, Takehiro Tsuritani

    2014 OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE AND AUSTRALIAN CONFERENCE ON OPTICAL FIBRE TECHNOLOGY (OECC/ACOFT 2014)     316 - 318  2014年

     概要を見る

    Space-division multiplexing with multi-core fiber is a promising technology to increase a system capacity drastically. By using a combination of MCF and spectral efficient modulation format, trans-oceanic transmission with a capacity-distance product of 1.03 Ebit/s.km has been achieved.

  • Design and performance evaluation of an OpenFlow-based control plane for softwaredefined elastic optical networks with directdetection optical OFDM (DDO-OFDM) transmission

    Liu, L., Peng, W.-R., Casellas, R., Tsuritani, T., Morita, I., Martínez, R., Muñoz, R., Yoo, S.J.B.

    Optics Express   22 ( 1 ) 30 - 40  2014年

     概要を見る

    Optical Orthogonal Frequency Division Multiplexing (O-OFDM), which transmits high speed optical signals using multiple spectrally overlapped lower-speed subcarriers, is a promising candidate for supporting future elastic optical networks. In contrast to previous works which focus on Coherent Optical OFDM (CO-OFDM), in this paper, we consider the direct-detection optical OFDM (DDO-OFDM) as the transport technique, which leads to simpler hardware and software realizations, potentially offering a low-cost solution for elastic optical networks, especially in metro networks, and short or medium distance core networks. Based on this network scenario, we design and deploy a software-defined networking (SDN) control plane enabled by extending OpenFlow, detailing the network architecture, the routing and spectrum assignment algorithm, OpenFlow protocol extensions and the experimental validation. To the best of our knowledge, it is the first time that an OpenFlow-based control plane is reported and its performance is quantitatively measured in an elastic optical network with DDO-OFDM transmission. (C) 2013 Optical Society of America

    DOI PubMed

    Scopus

    33
    被引用数
    (Scopus)
  • Super-Nyquist-WDM transmission over 7,326-km seven-core fiber with capacity-distance product of 1.03 Exabit/s.km

    Igarash, K., Tsuritani, T., Morita, I., Tsuchida, Y., Maeda, K., Tadakuma, M., Saito, T., Watanabe, K., Imamura, K., Sugizaki, R., Suzuki, M.

    Optics Express   22 ( 2 ) 1220 - 1228  2014年

     概要を見る

    We show super-Nyquist-WDM transmission technique, where optical signals with duobinary-pulse shaping can be wavelength-multiplexed with frequency spacing of below baudrate. Duobinary-pulse shaping can reduce the signal bandwidth to be a half of baudrate while controlling inter-symbol interference can be compensated by the maximum likelihood sequence estimation in a receiver. First, we experimentally evaluate crosstalk characteristics as a function of channel spacing between the dual-channel DP-QPSK signals with duobinary-pulse shaping. As a result, the crosstalk penalty can be almost negligible as far as the ratio of baudrate to frequency spacing is maintained to be less than 1.20. Next, we demonstrate 140.7-Tbit/s, 7,326-km transmission of 7 x 201-channel 25-GHz-spaced super-Nyquist-WDM 100-Gbit/s optical signals using seven-core fiber and full C-band seven-core EDFAs. To the best of our knowledge, this is one of the first reports of high-capacity transmission experiments with capacity-distance product in excess of 1 Exabit/s.km. (C) 2014 Optical Society of America

    DOI

    Scopus

    70
    被引用数
    (Scopus)
  • Performance evaluation of selective mode conversion based on phase plates for a 10-mode fiber

    Igarashi, K., Souma, D., Tsuritani, T., Morita, I.

    Optics Express   22 ( 17 ) 20881 - 20893  2014年

     概要を見る

    We numerically and experimentally evaluate the performance of higher-order mode conversion based on phase plates for 10-mode fibers (10MFs). The phase plates have the phase jump of pi between multiple planes, which match the phase patterns of linearly polarized (LP) modes of 10MF. First, we numerically investigate the effects of the fabrication errors such as the phase-difference error and the slope in the phase jump of the phase plate. The simulation results for the mode conversion to LP11 indicate that such errors make the spatial pattern of the converted beam asymmetric. In order to maintain the symmetric pattern, the phase-difference error is required to be less than +/- 2%, and the ratio of the slope width to the input beam waist should be suppressed to be less than 0.05. Next, we calculate the coupling power efficiencies of the excitation of LP modes in 10MF when the converted beams after the phase plate are launched into 10MF using a lens. As the calculation results, highly accurate adjustment of the input beam waist is required to suppress the crosstalk due to coupling of undesirable LP modes by less than -20 dB. For mode excitation of LP11 or LP12, crosstalk of more than -20 dB is not avoidable even if the input beam waist is carefully adjusted. In contrast, the crosstalk for the mode excitation of LP21 or LP31 is easily suppressed to be less than -20 dB without careful adjustment of the input beam waist. These results suggest that phase plates are not applicable to mode conversion to LP11 and LP12 in 10MF while they are suitable for conversion to LP02, LP21 and LP31. Finally, we experimentally demonstrate conversion from LP01 to LP21 and LP31 modes in 10MF using phase plates. We obtain nearly ideal LP21 and LP31 modes with the small crosstalk due to the coupling of the other undesirable LP modes. (C) 2014 Optical Society of America

    DOI

    Scopus

    38
    被引用数
    (Scopus)
  • Trans-oceanic class ultra-long-haul transmission using multi-core fiber

    Morita, I., Igarashi, K., Takahashi, H., Tsuritani, T., Suzuki, M.

    Optics Express   22 ( 26 ) 31761 - 31773  2014年

     概要を見る

    Space-division multiplexing with uncoupled multi-core fiber is a promising technology to drastically increase a fiber capacity in optical communication systems. Trans-oceanic class ultra-long-haul transmission was successfully achieved by using 7-core MCF with suppressed inter-core crosstalk. By using a combination of MCF and spectral efficient modulation format, the fiber capacity could be increased from 28.8 Tbit/s to 140 Tbit/s and a capacity-distance product exceeding 1 Exabit/s.km was obtained in 7 cores x 201 lambda x 100 Gbit/s transmission over 7326 km. These results indicate that the MCF transmission will be one of promising candidates for future ultra-high capacity optical communication systems. (C) 2014 Optical Society of America

    DOI PubMed

    Scopus

    10
    被引用数
    (Scopus)
  • High-capacity long-haul optical transport technologies with optical space division multiplexing

    Morita, I., Miyamoto, Y.

    Journal of the Institute of Electronics, Information and Communication Engineers   97 ( 2 ) 113 - 118  2014年

  • Demonstration of a Dynamic Transparent Optical Network Employing Flexible Transmitters/Receivers Controlled by an OpenFlow-Stateless PCE Integrated Control Plane

    Lei Liu, Hyeon Yeong Choi, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Ricardo Martinez, Rauel Munoz

    JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING   5 ( 10 ) A66 - A75  2013年10月

     概要を見る

    OpenFlow, which allows operators to control the network using software running on a network operating system within an external controller, has recently been proposed and experimentally validated as a promising intelligent control plane technique. To mitigate the potential scalability issue of an OpenFlow-based centralized control plane and to leverage the mature, well-defined, and feature-complete path computation element (PCE) communication protocol, the complex path computation function required in optical networks can be formally decoupled from the OpenFlow controller so the controller can off-load the task to one or more dedicated PCEs. In addition to the control plane intelligence, future optical networks also feature data plane intelligence such as the introduction of flexible transmitters and receivers, which can dynamically change the modulation format and transmission rate of the optical signal without hardware modifications. In this paper, for the first time, we successfully demonstrate a dynamic transparent wavelength-switched optical network employing flexible transmitters and receivers controlled by an OpenFlow-stateless PCE integrated control plane. Our designed flexible transmitter is implemented by a cascade of a dual-drive Mach-Zehnder modulator (MZM) and a dual-parallel MZM. By adjusting the electrical binary drive signals, the flexible transmitter is able to flexibly switch the symbol rate and the modulation format, including binary phase shift keying, quadrature phase shift keying, 8-ary quadrature amplitude modulation (8QAM), and 16QAM. The flexible receiver is able to automatically detect different modulation formats and symbol rates and measure the bit-error rate. All the network elements, including optical switching nodes and flexible transmitters and receivers, are extended with OpenFlow interfaces, which can be intelligently controlled by the OpenFlow-stateless PCE integrated control plane with significant protocol extensions. On an actual network testbed with real hardware, we successfully validate dynamic and seamless interworking operations between the OpenFlow controller, a stateless PCE, and all the data plane hardware. The overall feasibility and efficiency of the proposed solutions are verified, and dynamic end-to-end path provisioning and lightpath restoration in such a new network scenario are quantitatively evaluated. We also tested the scalability of the proposed control plane; the experiment results indicated that dynamic path provisioning and restoration can be achieved within hundreds of milliseconds by using the proposed approach, and the overall architecture scales well with a batch of requests.

    DOI

    Scopus

    26
    被引用数
    (Scopus)
  • Simple Carrier Recovery Approach for RF-Pilot-Assisted PDM-CO-OFDM Systems

    Wei-Ren Peng, Takehiro Tsuritani, Itsuro Morita

    JOURNAL OF LIGHTWAVE TECHNOLOGY   31 ( 15 ) 2555 - 2564  2013年08月

     概要を見る

    For RF-pilot-assisted PDM-CO-OFDM systems, we propose and demonstrate a carrier recovery method applying a simple moving average filter (MAF) to extract the central RF-pilot for phase noise compensation. Because only two additions per output sample would be required to implement such a MAF, its computational complexity is rather simple compared to any other direct-form finite impulse response (FIR) filter. To handle its weak side-lobe attenuation, which would cause the spectrally nearby OFDM signal to interfere with the extracted pilot signal, we further propose using multiple MAFs in cascade to enhance the side-lobe attenuation. We evaluate the performance of a 16-QAM and 40-Gbps PDM-CO-OFDM signal, in terms of the bandwidth tolerance, optical signal to noise ratio (OSNR) tolerance, nonlinear tolerance, linewidth tolerance, and residual carrier frequency offset (RFO) tolerance, with different filters including the simple MAF, cascaded MAFs, and the previously-demonstrated multi-stage decimation and interpolation filter (MDIF). We've found that 1) all the filters exhibit similar performance to the ideal brick-wall filter in terms of noise and nonlinear tolerances, 2) the MAF1 exhibits the worse tolerances against linewidth and RFO, and 3) the MDIF has to be carefully designed to enhance its tolerances against both the linewidth and RFO.

    DOI

  • OpenSlice: an OpenFlow-based control plane for spectrum sliced elastic optical path networks

    Lei Liu, Rauel Munoz, Ramon Casellas, Takehiro Tsuritani, Ricardo Martinez, Itsuro Morita

    OPTICS EXPRESS   21 ( 4 ) 4194 - 4204  2013年02月

     概要を見る

    A control plane is a key enabling technique for dynamic and intelligent end-to-end path provisioning in optical networks. In this paper, we present an OpenFlow-based control plane for spectrum sliced elastic optical path networks, called OpenSlice, for dynamic end-to-end path provisioning and IP traffic offloading. Experimental demonstration and numerical evaluation show its overall feasibility and efficiency. (C)2013 Optical Society of America

    DOI

    Scopus

    71
    被引用数
    (Scopus)
  • Experimental demonstration of an OpenFlow/PCE integrated control plane for IP over translucent WSON with the assistance of a per-request-based dynamic topology server

    Lei Liu, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Ricardo Martinez, Rauel Munoz

    OPTICS EXPRESS   21 ( 4 ) 4183 - 4193  2013年02月

     概要を見る

    To mitigate the potential scalability issues of an OpenFlow-based control plane, a seamless OpenFlow and Path Computation Element (PCE) integrated control plane is proposed, by means of an architecture in which the path computation function is formally decoupled from the controller so the controller can off-load the task to one or more dedicated PCEs using an open and standard interface and protocol, and where the PCE obtains its topology database by means of a dedicated dynamic topology server, which is accessed by the PCE on a per-request basis. The overall feasibility and performance metrics of this integrated control plane are experimentally verified and quantitatively evaluated on a real IP over translucent Wavelength Switched Optical Network (WSON) testbed. (C)2013 Optical Society of America

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • An integrated stateful PCE / OpenFlow controller for the control and management of flexi-grid optical networks

    R. Casellas, R. Martínez, R. Muñoz, L. Liu, T. Tsuritani, I. Morita

    2013 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2013    2013年

     概要を見る

    We report the design, implementation and experimental evaluation of a centralized control plane based on a stateful PCE, acting as an OpenFlow controller. We detail the protocol extensions for elastic optical networks and the performance. © 2013 OSA.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • OSNR monitoring technique of m-ary QAM formats based on analysis of power spectral density in the presence of fiber nonlinearities

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    2013 18th OptoElectronics and Communications Conference Held Jointly with 2013 International Conference on Photonics in Switching, OECC/PS 2013    2013年

     概要を見る

    We propose the OSNR monitoring technique for m-ary QAM formats in the presence of fiber nonlinearities, which is based on the analysis of the power spectral density of amplitude noises in a digital coherent receiver. © 2013 IEICE.

  • OpenFlow-based control plane for the application-aware LOBS network

    Dongxu Zhang, Songtao Mai, Hongxiang Guo, Takehiro Tsuritani, Jian Wu, Itsuro Morita

    2013 18th OptoElectronics and Communications Conference Held Jointly with 2013 International Conference on Photonics in Switching, OECC/PS 2013    2013年

     概要を見る

    This paper presents an extended OpenFlow-based control plane for labeled optical burst switching networks to achieve application-aware burst assembly and scheduling, and experimental demonstration verifies its overall feasibility. © 2013 IEICE.

  • Higher-order mode conversion using cascaded phase plates

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita

    2013 18th OptoElectronics and Communications Conference Held Jointly with 2013 International Conference on Photonics in Switching, OECC/PS 2013    2013年

     概要を見る

    We propose a technique for higher-order mode conversion based on cascade multiple phase plates with simple phase patterns. Using our scheme, the mode conversion to LP11 and LP21 has been demonstrated. © 2013 IEICE.

  • Ultra-long-haul transmission using multicore fiber repeatered by multicore EDFA

    Hidenori Takahashi, Koji Igarashi, Koki Takeshima, Takehiro Tsuritani, Itsuro Morita

    2013 18th OptoElectronics and Communications Conference Held Jointly with 2013 International Conference on Photonics in Switching, OECC/PS 2013    2013年

     概要を見る

    The multicore fiber transmission technologies is promising candidate to increase the capacity per fiber. In this paper, ultra-long-haul transmission using multicore fiber and multicore EDFA is explained. © 2013 IEICE.

  • Optical network control and management technology using OpenFlow

    Lei Liu, Takehiro Tsuritani, Itsuro Morita, S. J.B. Yoo

    2013 18th OptoElectronics and Communications Conference Held Jointly with 2013 International Conference on Photonics in Switching, OECC/PS 2013    2013年

     概要を見る

    In this paper, we review OpenFlow-based control and management technology for optical networks including multi-layer optical networks, multi-domain optical networks and elastic optical networks. We also present the interworking between OpenFlow and PCE/GMPLS control planes. © 2013 IEICE.

  • Modified walsh-hadamard transform for PDL mitigation

    Wei Ren Peng, Takehiro Tsuritani, Itsuro Morita

    IET Conference Publications   2013 ( 622 CP ) 960 - 962  2013年

     概要を見る

    We propose a modified Walsh-Hadamard transform (MWHT) that reduces the PDL penalty by equalizing the performance of both polarization tributaries. The realization of MWHT requires just one piece of PMF and therefore exhibits a very low-cost PDL solution.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Digital nonlinear noise cancellation approach for long-haul optical transmission systems

    Wei Ren Peng, Takehiro Tsuritani, Itsuro Morita

    IET Conference Publications   2013 ( 622 CP ) 39 - 41  2013年

     概要を見る

    We propose a practically-implementable nonlinear noise cancellation (NLNC) method that effectively removes the "1st-order" fiber nonlinearities. After 6720-km (84x80-km) SSMF transmission, the signal performance in terms of Q-factor is improved by ∼1.4 dB with the proposed NLNC method.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Dynamic provisioning via a stateful PCE with instantiation capabilities in GMPLS-controlled flexi-grid DWDM networks

    R. Casellas, R. Martínez, R. Muñoz, L. Liu, T. Tsuritani, I. Morita

    IET Conference Publications   2013 ( 622 CP ) 1104 - 1106  2013年

     概要を見る

    We report the implementation and performance evaluation of an active stateful PCE that relies on a GMPLS control plane for the actual provisioning of elastic connections in a flexi-grid DWDM network. It is based on experimental extensions to the PCEP protocol and enables more advanced and concurrent path computations.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Seven-core fiber with enlarged aeff and full-C-band seven-core EDFA for 100-Tbit/s-class transoceanic transmission

    K. Igarashi, K. Takeshima, T. Tsuritani, H. Takahashi, S. Sumita, I. Morita, Y. Tsuchida, M. Tadakuma, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, M. Suzuki

    IET Conference Publications   2013 ( 622 CP ) 4 - 6  2013年

     概要を見る

    We report fabrication of a 45.5-km seven-core fiber with enlarged Aeff and a high-power seven-core EDFA with 5-THz bandwidth. Using them, we confirmed the feasibility of 100-Tbit/s-class transoceanic transmission.

    DOI

    Scopus

  • OpenFlow-controlled elastic optical networks with direct-detection optical OFDM (DDO-OFDM) transmission

    Lei Liu, Wei Ren Peng, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Ricardo Martínez, Raül Muñoz, S. J.Ben Yoo

    IET Conference Publications   2013 ( 622 CP ) 384 - 386  2013年

     概要を見る

    We design and deploy an extended OpenFlow-based control plane for elastic optical networks with DDO-OFDM transmission, detailing the network architecture, the two-phase routing and spectrum assignment algorithm, OpenFlow protocol extensions and the experimental validation.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • A New Multi-Purpose Optical Transmitter for Higher-Order QAM Generation

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)    2013年

     概要を見る

    We present a versatile optical transmitter composed of tandem I/Q modulators driven by electrical binary signals. This transmitter is able to simply generate higher-order QAM formats (from BPSK up to 64QAM) without hardware modification.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Feasibility Demonstration of Flexible Tx/Rx for Spectrum Defragmentation in Elastic Optical Networks

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)    2013年

     概要を見る

    We demonstrate the feasibility of spectrum defragmentation in a flexible-grid optical network utilizing the flexible transmitter and receiver. According to the defragmentation controller, the flexible transmitter dynamically switches the modulation format/symbol rate/wavelength without hardware modification.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Frequency Stabilization of Multiple Semiconductor Lasers for Nyquist-WDM Transmission Systems

    Koji Igarashi, Takehiro Tsuritani, Itsuro Morita, Kazuhiro Katoh, Kazuro Kikuchi

    2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)    2013年

     概要を見る

    We propose a technique for stabilizing frequencies of multiple semiconductor lasers, which can reduce the fluctuation of the frequency spacing to below 3MHz. Using our scheme, we demonstrate 10-GBaud Nyquist-WDM PDM 16QAM transmission over 1,000km.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • GPU-Accelerated Hash and Wildcard Hybrid Flow Switching for Tackling Massive Flow Entries

    Nobutaka Matsumoto, Michiaki Hayashi, Itsuro Morita

    2013 IEEE 14TH INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE SWITCHING AND ROUTING (HPSR)     213 - 214  2013年

     概要を見る

    GPU-accelerated high performance switching design using hybrid flow tables allocated in host and GPU memories is proposed based on LightFlow architecture. In this work, careful placement of hash and wildcard tables is proposed considering overhead of data copy during lookup process, in order to tackle massive flow entries using commodity hardware. Experimental results show that the proposal achieves 14.6 Mpps which is the fastest record of the software flow switch operated under a large scale reaching 4 million flow entries. With this proposal, it is also demonstrated that the average processing delay is about one forth compared with Open vSwitch.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Long-distance and high-capacity transmission with multicore fiber

    Itsuro Morita

    2013 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES     127 - 128  2013年

     概要を見る

    Space-division-multiplexing is an attractive approach to increase the capacity of submarine cable systems. The feasibility of transoceanic class transmission with multicore fiber was confirmed in 7 x 40 x 128 Gbit/s transmission over 6160 km.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Long-haul transmission technologies with multi-core fiber

    Itsuro Morita

    2013 IEEE PHOTONICS CONFERENCE (IPC)     297 - 298  2013年

     概要を見る

    Space-division multiplexing with multi-core fiber is an attractive technology to increase a system capacity drastically. In this paper, the feasibility of trans-oceanic transmission using multi-core fibers is discussed.

    DOI

    Scopus

  • Ultra-Large Capacity Transmission over Trans-Oceanic Distances with Multi-Core Fibers and EDFAs

    Masatoshi Suzuki, Hidenori Takahashi, Koji Igarashi, Koki Takeshima, Takehiro Tsuritani, Itsuro Morita

    2013 15TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON 2013)    2013年

     概要を見る

    Space-division multiplexing (SDM) with multi-core/multi-mode fibers has potential to increase the transmission capacity drastically. In this paper, we investigate the feasibility of trans-oceanic transmission towards beyond 100 Tbit/s using multi-core fibers. Experimental results using 7-core fibers/EDFAs are also presented.

    DOI

    Scopus

  • Multicore Erbium Doped Fiber Amplifier with 5 THz Bandwidth, High-gain and Low NF

    Yukihiro Tsuchida, Koichi Maeda, Jutaro Miura, Kengo Watanabe, Tsunetoshi Saito, Koji Igarashi, Takehiro Tsuritani, Itsuro Morita, Toshiharu Ito, Kiyoshi Fukuchi, Ryuichi Sugizaki

    2013 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES     105 - +  2013年

     概要を見る

    Core-pumped 7-core EDFA with two stage amplification is realized. Combination of its higher gain and GFF enables wide bandwidth operation. NF of Less than 5.5 dB is achieved with improved fan-in device.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Dynamic Wavelength Assignment and Burst Contention Mitigation for the LOBS-over-WSON Multilayer Networks with an OpenFlow based Control Plane

    Dongxu Zhang, Hongxiang Guo, Lei Liu, Takehiro Tsuritani, Jian Wu, Itsuro Morita

    2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)    2013年

     概要を見る

    A novel scheme capable of dynamic wavelength assignment and burst contention mitigation is proposed to achieve efficient optical burst flow grooming in the OpenFlow controlled LOBS-over-WSON network. Simulation and experiment verified its feasibility.

    DOI

    Scopus

  • On the long-memory filtering gain in optical high-order QAM transmission systems

    Peng, W.-R., Takahashi, H., Tsuritani, T., Morita, I.

    Optics Express   21 ( 9 ) 11021 - 11030  2013年

     概要を見る

    In this paper, we verify the effectiveness of the last-stage long memory filter (LMF) in mitigating the long-memory response (LMR) of hardware, i.e. the transmitter and receiver. Based on the experimental results, we draw the following conclusions: 1) LMF can effectively mitigate the LMR impact, such as transmitter reflections, and its efficiency is more significant for high-order QAM signals. 2) Using LMF, a partially-correlated pattern exhibits similar performance to that of an uncorrelated pattern both in back-to-back and after 320-km standard single mode fiber (SSMF) transmission. Moreover, a simple solution to the computational complexity of LMF, effective-tap (ET) LMF, is proposed and demonstrated. (C) 2013 Optical Society of America

    DOI PubMed

    Scopus

    2
    被引用数
    (Scopus)
  • Per-symbol-based digital back-propagation approach for PDM-CO-OFDM transmission systems

    Peng, W.-R., Takahashi, H., Morita, I., Tsuritani, T.

    Optics Express   21 ( 2 ) 1547 - 1554  2013年

     概要を見る

    For polarization-division-multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) systems, we propose a per-symbol-based digital back-propagation (DBP) approach which, after cyclic prefix removal, conducts DBP for each OFDM symbol. Compared with previous DBP, this new proposal avoids the use of inefficient overlap-and-add operation and saves one fast Fourier transform (FFT) module, therefore simplifying the hardware implementation. Transmitting a 16-QAM, 42.8-Gb/s PDM-CO-OFDM signal over 960-km standard single mode fiber (SSMF), we compare the previous and the proposed DBP approaches with different receiver's sampling rates and different step lengths in each DBP iteration, and found that the proposed DBP can achieve a similar performance as that of the previous DBP while enjoying a simpler implementation. We have also specifically introduced a small self-phase modulation (SPM) model for DBP and demonstrated its feasibility with the same experimental setup. (C) 2013 Optical Society of America

    DOI PubMed

    Scopus

    10
    被引用数
    (Scopus)
  • Interdomain wavelength path control for translucent wavelength switched optical networks: From rationales to experiments

    Liu, L., Tsuritani, T., Morita, I., Casellas, R., Martinez, R., Muñoz, R., Tsurusawa, M.

    IEEE Communications Magazine   51 ( 8 ) 136 - 147  2013年

     概要を見る

    A translucent wavelength switched optical network (WSON), with sparse 3R regenerators to guarantee the signal quality of an optical connection, is a promising paradigm for a metro/core network. This is because a translucent WSON can achieve performance comparable to that of an all-electronic switching (i.e., opaque) network with far lower network cost and a great reduction in power consumption. Because of its advantages, many recent research and standardization efforts have focused on translucent WSONs. However, most of them study the intradomain case, and issues related to multidomain translucent WSONs are largely open at present. In light of this, in this article, we present two possible strategies to improve interdomain path computation and lightpath establishment in a multidomain translucent WSON. Both approaches are experimentally demonstrated and quantitatively evaluated. Our aim is to provide feasible and efficient solutions for supporting a multidomain translucent WSON, as well as to obtain valuable insight into the proposed strategies through experiments, which will be beneficial for the potential industrial deployment of translucent optical networks.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Transmission of high-baud PDM-64QAM signals

    Peng, W.-R., Tsuritani, T., Morita, I.

    Journal of Lightwave Technology   31 ( 13 ) 2146 - 2162  2013年

     概要を見る

    In this paper we demonstrate high-baud generation and transmission of PDM-64QAM signals. The 64QAM signal is generated using one single in-phase/quadrature (I/Q) modulator driven with eight-level signals synthesized by all binary electrical inputs. With hard-decision forward error correction (HD-FEC), we first demonstrate 11.2-GBd and 22.4-GBd PDM-64QAM transmissions over 320-km standard single mode fiber (SSMF). Then we specifically introduce a long memory filter (LMF) and prove its effectiveness in reflection compensation both theoretically and experimentally. With the aid of soft-decision FEC (SD-FEC), optical pre-shaping, and LMF, we transmit a 41.4-GBd PDM-64QAM signal over 1200-km SSMF. Finally, using per-channel 41.6-GBd PDM-64QAM with SD-FEC, we successfully demonstrate 50-GHz-spaced, 8 499-Gb/s transmission over 720-km SSMF. This is the first demonstration of 400-Gb/s/ch WDM transmission on the 50-GHz ITU grid that uses a per-channel single-carrier scheme.

    DOI

    Scopus

    51
    被引用数
    (Scopus)
  • First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF

    Takahashi, H., Tsuritani, T., De Gabory, E.L.T., Ito, T., Peng, W.R., Igarashi, K., Takeshima, K., Kawaguchi, Y., Morita, I., Tsuchida, Y., Mimura, Y., Maeda, K., Saito, T., Watanabe, K., Imamura, K., Sugizaki, R., Suzuki, M.

    Optics Express   21 ( 1 ) 789 - 795  2013年

     概要を見る

    We demonstrate the first 7-core multicore erbium-doped fiber amplified (MC-EDFA) transmission of 40 × 128-Gbit/s PDM-QPSK signals over 6,160-km 7-core multicore fiber (MCF). The crosstalk (XT) from all of the other 6 cores of a MC-EDFA and a 55-km length MCF are about -46.5 dB and -45.6 dB at center core, respectively. The core-to-core rotation approach at every amplified span is used to average the XT of all cores. The averaged optical signal-to-noise ratio (OSNR) after 6,160-km transmission is 15.6 dB with 0.1 nm resolution bandwidth. The Q-factor of all 40 channels surpasses the threshold of the forward-error-correction of 6.4 dB with 1 dB margin after 6,160 km. The total net capacity is 28.8 Tbit/s per fiber and achieved capacity-distance product is 177 Pbit/s·km per fiber. We confirmed the feasibility of MC-EDFA repeatered systems for trans-oceanic transmission. © 2013 Optical Society of America.

    DOI

    Scopus

    46
    被引用数
    (Scopus)
  • OpenSlice: An OpenFlow-based control plane for spectrum sliced elastic optical path networks

    Liu, L., Muñoz, R., Casellas, R., Tsuritani, T., Martínez, R., Morita, I.

    Optics Express   21 ( 4 ) 4194 - 4204  2013年

     概要を見る

    We present an OpenFlow-based control plane for spectrum sliced elastic optical path networks, called OpenSlice, for dynamic end-to-end path provisioning and IP traffic offloading. Experimental demonstration and numerical evaluation show its overall feasibility and efficiency.

    DOI PubMed

    Scopus

    71
    被引用数
    (Scopus)
  • Design of a GMPLS control plane with PCE-based impairment-aware full restoration capability for translucent WSON: Enabling techniques, service demonstration, and performance evaluation

    Liu, L., Tsuritani, T., Casellas, R., Morita, I., Martínez, R., Muñoz, R.

    Optical Switching and Networking   10 ( 1 ) 16 - 31  2013年

     概要を見る

    The control plane techniques based on the Generalized Multi-Protocol Label Switching (GMPLS) and Path Computation Element (PCE) architectures are promising candidates for potential industrial deployment in Wavelength Switched Optical Networks (WSON), because they can greatly reduce operational expenses and improve the network intelligence. Moreover, link failures have a critical effect on WSON, since a single failure may result in the loss of a huge amount of data. In light of this, in this paper, we detail the design and implementation of a GMPLS control plane, with PCE-based, impairment-aware, full restoration capability for translucent WSON. We investigate the enabling techniques for such a PCE/GMPLS control plane by surveying a series of solutions, and, based on these enabling techniques, we present an experimental demonstration of service recovery for uncompressed video stream in a GMPLS controlled WSON with PCE-based full lightpath restoration. We also quantitatively evaluate the performance of the PCE-based full restoration, and compare it with the PCE-based pre-planned restoration and the PCE-based pre-computed dynamic restoration in terms of signaling latency and restorability. To the best of our knowledge, it is the first time that the PCE-based full restoration is experimentally investigated on an actual GMPLS controlled WSON testbed, which is beneficial for verifying the overall feasibility and efficiency of the proposed solutions, obtaining valuable insights for its future deployment in a real operational scenario, and providing active contribution in support of the on-going Internet Engineering Task Force (IETF) standardization activities. © 2012 Elsevier B.V.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Experimental demonstration of an OpenFlow/PCE integrated control plane for IP over translucent WSON with the assistance of a per-request-based dynamic topology server

    Liu, L., Casellas, R., Tsuritani, T., Morita, I., Martínez, R., Muñoz, R.

    Optics Express   21 ( 4 ) 4183 - 4193  2013年

     概要を見る

    A seamless OpenFlow/PCE integrated control plane for IP over translucent WSON is presented via a per-request-based dynamic topology server. The overall feasibility and performance metrics of this integrated control plane are experimentally verified and quantitatively evaluated.

    DOI PubMed

    Scopus

    12
    被引用数
    (Scopus)
  • Experimental demonstration of an OpenFlow based software-defined optical network employing packet, fixed and flexible DWDM grid technologies on an international multidomain testbed

    Channegowda, M., Nejabati, R., Rashidi Fard, M., Peng, S., Amaya, N., Zervas, G., Simeonidou, D., Vilalta, R., Casellas, R., Martínez, R., Munoz, R., Liu, L., Tsuritani, T., Morita, I., Autenrieth, A., Elbers, J.P., Kostecki, P., Kaczmarek, P.

    Optics Express   21 ( 5 ) 5487 - 5498  2013年

     概要を見る

    Software defined networking (SDN) and flexible grid optical transport technology are two key technologies that allow network operators to customize their infrastructure based on application requirements and therefore minimizing the extra capital and operational costs required for hosting new applications. In this paper, for the first time we report on design, implementation & demonstration of a novel OpenFlow based SDN unified control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet transport domains. We verify and experimentally evaluate OpenFlow protocol extensions for flexible DWDM grid transport technology along with its integration with fixed DWDM grid and layer-2 packet switching. © 2013 Optical Society of America.

    DOI

    Scopus

    87
    被引用数
    (Scopus)
  • Design and experimental validation of a GMPLS/PCE control plane for elastic CO-OFDM optical networks

    Casellas, R., Muñoz, R., Fabrega, J.M., Moreolo, M.S., Martinez, R., Liu, L., Tsuritani, T., Morita, I.

    IEEE Journal on Selected Areas in Communications   31 ( 1 ) 49 - 61  2013年

     概要を見る

    ITU-T Recommendation G.694.1 [1] defines normative DWDM frequency grids, each being a reference set of values that correspond to allowed nominal central frequencies, obtained using a fixed channel spacing (e.g., 12.5 GHz, 25 GHz, 50 GHz or 100 GHz). This rigid, grid-based approach does not seem well adapted for data rates beyond 100 Gb/s, is particularly inefficient when a whole wavelength is assigned to a lower rate optical path, and is not flexible enough for multi-rate systems [2]. Consequently, the next generation of optical networks will require a flexible, highly efficient and adaptive management of the optical spectrum, along with advanced optical modulation schemes that efficiently use allocated spectrum slots, and recent progress on optical network technology justifies research on both new optical transmission systems as well as the applicability of control and management frameworks to such networks.We design and deploy a GMPLS control plane for flexible optical networks with coherent optical orthogonal frequency-division multiplexing (O-OFDM) transmission; we detail its functional architecture, which combines a centralized entity that performs path routing and modulation assignment, with a distributed spectrum allocation. The centralized entity (i.e., a path computation element) uses pre-configured static path characterizations, based on exhaustive OFDM transmission simulations, when performing dynamic path computation in line with GMPLS constrained shortest path mechanisms. The distributed spectrum allocation assigns frequency ranges (slots) to connection requests, by using dynamic signaling procedures and applying slot assignment policies. We summarize the control plane protocol extensions involved in the main functional aspects: routing and topology dissemination, path computation, signaling and resource reservation.We experimentally validate and evaluate the integrated centralized PCE and GMPLS control plane in a control plane testbed, obtaining key performance indicators such as path setup latency and blocking probability for different frequency slot assignment policies.

    DOI

    Scopus

    51
    被引用数
    (Scopus)
  • Feasibility demonstration of spectrum defragmentation in flexigrid optical network employing multi-format and multi-rate transmitter/receiver

    Choi, H.Y., Tsuritani, T., Morita, I.

    Electronics Letters   49 ( 5 ) 361 - 362  2013年

     概要を見る

    The feasibility of spectrum defragmentation is demonstrated in a flexigrid optical network employing the multi-format and multi-rate transmitter and receiver. For efficient defragmentation, the push-pull defragmentation technique is improved with additional functionality, which tunes the occupied frequency slots as well as the centre frequency. © The Institution of Engineering and Technology 2013.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Field trial of an openflow-based unified control plane for multilayer multigranularity optical switching networks

    Liu, L., Zhang, D., Tsuritani, T., Vilalta, R., Casellas, R., Hong, L., Morita, I., Guo, H., Wu, J., Martinez, R., Munoz, R.

    Journal of Lightwave Technology   31 ( 4 ) 506 - 514  2013年

     概要を見る

    Software defined networking and OpenFlow, which allow operators to control the network using software running on a network operating system within an external controller, provide the maximum flexibility for the operator to control a network, and match the carrier's preferences given its centralized architecture, simplicity, and manageability. In this paper, we report a field trial of an OpenFlow-based unified control plane (UCP) for multilayer multigranularity optical switching networks, verifying its overall feasibility and efficiency, and quantitatively evaluating the latencies for end-to-end path creation and restoration. To the best of our knowledge, the field trial of an OpenFlow-based UCP for optical networks is a world first.

    DOI

    Scopus

    72
    被引用数
    (Scopus)
  • 110.9-Tbit/s SDM transmission over 6,370 km using a full C-band seven-core EDFA

    Igarashi, K., Takeshima, K., Tsuritani, T., Takahashi, H., Sumita, S., Morita, I., Tsuchida, Y., Tadakuma, M., Maeda, K., Saito, T., Watanabe, K., Imamura, K., Sugizaki, R., Suzuki, M.

    Optics Express   21 ( 15 ) 18053 - 18060  2013年

     概要を見る

    We confirm the feasibility of 100-Tbit/s-class trans-oceanic SDM transmission. Using seven-core fiber spans with seven-core full C-band EDFAs, 7 x 264-channel quasi-Nyquist-WDM 60-Gbit/s PDM-QPSK signals are transmitted over 6,370 km. (C) 2013 Optical Society of America

    DOI PubMed

    Scopus

    65
    被引用数
    (Scopus)
  • Demonstration of BER-adaptive WSON employing flexible transmitter/receiver with an extended OpenFlow-based control plane

    Choi, H.Y., Liu, L., Tsuritani, T., Morita, I.

    IEEE Photonics Technology Letters   25 ( 2 ) 119 - 121  2013年

     概要を見る

    A bit-error rate (BER)-adaptive wavelength-switched optical network (WSON) employing the multiformat and multirate transmitter/receiver is experimentally demonstrated. The flexible transmitter is capable of generating binary phase-shift-keying, quadrature phase-shift-keying, eight-ary quadrature amplitude modulation, 8QAM, and 16QAM, as well as changing the symbol rate. On the other hand, the flexible receiver based on a coherent detection scheme is utilized not only to detect the optical signal with any modulation format/rate, but also to send the BER information to an OpenFlow controller via extended OpenFlow protocols. Since the measured BER is a reliable barometer of the optical path conditions, an extended OpenFlow-based control plane with the OpenFlow controller intelligently determines and assigns either appropriate modulation format/rate or a backup path in WSON in accordance with BER information.

    DOI

    Scopus

    23
    被引用数
    (Scopus)
  • Control and management of flexi-grid optical networks with an integrated stateful path computation element and OpenFlow controller [invited]

    Casellas, R., Martinez, R., Munoz, R., Vilalta, R., Liu, L., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   5 ( 10 ) A57 - A65  2013年

     概要を見る

    A path computation element (PCE) is briefly defined as a control plane functional component (physical or logical) that is able to perform constrained path computation on a graph representing (a subset of) a network. A stateful PCE is a PCE that is able to consider the set of active connections, and its development is motivated by the fact that such knowledge enables the deployment of improved, more efficient algorithms. Additionally, a stateful PCE is said to be active if it is also able to affect (modify or suggest the modification of) the state of such connections. A stateful active PCE is thus able not only to use the knowledge of the active connections as available information during the computation, but also to reroute existing ones, resulting in a more efficient use of resources and the ability to dynamically arrange and reoptimize the network. An OpenFlow controller is a logically centralized entity that implements a control plane and configures the forwarding plane of the underlying network devices using the OpenFlow protocol. From a control plane perspective, an OpenFlow controller and the aforementioned stateful PCE have several functions in common, for example, in what concerns network topology or connection management. That said, both entities also complement each other, since a PCE is responsible mainly for path computation accessible via an open, standard, and flexible protocol, and the OpenFlow controller assumes the task of the actual data plane forwarding provisioning. In other words, the stateful PCE becomes active by virtue of relying on an OpenFlow controller for the establishment of connections. In this framework, the integration of both entities presents an opportunity allowing a return on investment, reduction of operational expenses, and reduction of time to market, resulting in an efficient approach to operate transport networks. In this paper, we detail the design, implementation, and experimental evaluation of a centralized control plane based on a stateful PCE, acting as an OpenFlow controller, targeting the control and management of optical networks. We detail the extensions to both the OpenFlow and the PCE communication protocol (PCEP), addressing the requirements of elastic optical networks as well as the system performance, obtained when deployed in a laboratory trial.

    DOI

    Scopus

    74
    被引用数
    (Scopus)
  • Demonstration of a dynamic transparent optical network employing flexible transmitters/receivers controlled by an OpenFlow-stateless PCE integrated control plane [invited]

    Liu, L., Choi, H.Y., Casellas, R., Tsuritani, T., Morita, I., Martinez, R., Munoz, R.

    Journal of Optical Communications and Networking   5 ( 10 ) A66 - A75  2013年

     概要を見る

    By using an OpenFlow/stateless PCE integrated control plane with significant protocol extensions, we successfully demonstrate and quantitatively evaluate dynamic end-to-end path provisioning and lightpath restoration in a transparent WSON employing flexible transmitters/receivers.

    DOI

    Scopus

    26
    被引用数
    (Scopus)
  • Experimental evaluation of efficient routing and distributed spectrum allocation algorithms for GMPLS elastic networks

    Raul Munoz, Ramon Casellas, Ricardo Martinez, Lei Liu, Takehiro Tsuritani, Itsuro Morita

    OPTICS EXPRESS   20 ( 27 ) 28532 - 28537  2012年12月

     概要を見る

    This paper presents and experimentally evaluates efficient strategies for dynamic source/Path Computation Element (PCE) routing with aggregated resource information and advanced distributed spectrum allocation algorithms in Generalized Multi-Protocol Label Switching (GMPLS)-controlled elastic optical networks. (C)2012 Optical Society of America

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • 50-GHz-spaced, 8x499-Gb/s WDM transmission over 720-km SSMF using per-channel 41.6-GBd PDM-64QAM

    Wei Ren Peng, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita

    Asia Communications and Photonics Conference, ACP    2012年

     概要を見る

    We demonstrate the world's first single-carrier-based, 400-Gb/s-class and 50-GHzspaced WDM system using 41.6-GBd PDM-64QAM per channel. Eight channels are successfully transmitted over 720-km SSMF with hybrid Raman and EDF amplification. © OSA 2012.

  • Interworking between openflow and PCE for dynamic wavelength path control in multi-domain WSON

    Lei Liu, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Ricardo Martínez, Raül Muñoz

    Optics InfoBase Conference Papers    2012年

     概要を見る

    We experimentally present the seamless interworking between OpenFlow and PCE for dynamic wavelength path control in multi-domain WSON, assessing the overall feasibility and quantitatively evaluating both the path computation and lightpath provisioning latencies. © 2012 OSA.

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • 7×1.12-Tbit/s, 200-GHz-spaced, PDM-16QAM transmission over all-EDFA 400-km SSMF and 2 ROADMs

    Wei Ren Peng, Itsuro Morita, Takahashi Hidenori, Takehiro Tsuritani

    2012 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2012    2012年

     概要を見る

    We have successfully demonstrated the first terabit-class WDM transmission (7 × 1.12 Tb/s PDM-16QAM) over all-EDFA 400-km standard single mode fiber (SSMF) and 2 ROADMs. Q factors larger than 9.4 dB are found for all channels. © 2012 OSA.

  • Experimental demonstration of OBS/WSON multi-layer optical switched networks with an OpenFlow-based unified control plane

    Dong Xu Zhang, L. L. Liu, Linfeng Hong, Hong Xiang Guo, Takehiro Tsuritani, Jian Wu, Itsuro Morita

    2012 16th International Conference on Optical Networking Design and Modelling, ONDM 2012    2012年

     概要を見る

    In the current IP/optical multi-layer networks, the control approaches for IP and optical domains are separated, which is inconvenient for the end-to-end service provisioning. Therefore, the investigation of a unified control plane for multi-layer networks is a very important issue for network carriers, since it can simplify the network manageability, improve the network agility and reduce the operational expenditure (OPEX) and capital expenditure (CAPEX). The OpenFlow protocol, which has been proposed recently, provides a potential solution to address such an issue. On the other hand, the multi-layer optical burst switching (OBS) /wavelength switched optical network (WSON) has been proposed as one of the promising paradigms for future optical Internet, and the respective control plane for OBS and WSON layers under an overlay model has been intensively investigated in our previous works. In light of this, in this paper, we experimentally present an OpenFlow-based unified control plane for OBS/WSON multi-layer optical switched networks. The protocol extensions and design details of the OpenFlow-controlled OBS/WSON are discussed. By using two different signaling approaches (with and without confirmation mechanism during the lightpath provisioning period), we successfully demonstrate the overall feasibility of a unified control plane for OBS/WSON networks, and the performance of two signaling solutions is quantitatively evaluated in terms of end-to-end signaling latency and packet loss rate. © 2012 IEEE.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • Effects of LN modulator chirp on performance of digital coherent optical transmission system

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    10th International Conference on Optical Internet, COIN 2012     50 - 51  2012年

     概要を見る

    We investigate the effects of LiNbO 3 modulator chirp on the performances of optical multilevel signals detected by a digital coherent receiver and evaluate the optical filtering tolerances of multilevel signals. The results show that return-to-zero (RZ) pulse carving is useful to prevent the performance deterioration caused by the modulator chirp. © 2012 IEICE Institute of Electronics Informati.

  • OpenFlow-based reliable service provisioning and dynamic differentiation for optical networks

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    10th International Conference on Optical Internet, COIN 2012     57 - 58  2012年

     概要を見る

    In this paper, for the first time, we experimentally investigate OpenFlow-based reliable service provisioning and dynamic service differentiation in IP/DWDM multi-layer optical networks. All the solutions are experimentally demonstrated on a real testbed with both control and data planes, verifying their overall feasibility and efficiency, and quantitatively evaluating their performance. © 2012 IEICE Institute of Electronics Informati.

  • Multi-format and multi-rate transmitter for flexible and elastic optical networks

    H. Y. Choi, T. Tsuritani, I. Morita

    Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012     773 - 774  2012年

     概要を見る

    We propose a novel optical transmitter which can change flexibly the modulation format and/or bit rate of the optical signal. This transmitter can be used to generate BPSK, QPSK, 6PSK/6QAM, and 8PSK/8QAM formats. © 2012 IEEE.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Coherent OTD Mux and ETD Demux (OMED) systems with transmitter imperfections

    Wei Ren Peng, Takehiro Tsuritani, Itsuro Morita

    Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012     775 - 776  2012年

     概要を見る

    In this paper we numerically investigate the impacts of 1) pulse width, 2) pulse chirp, 3) power imbalance, and 4) timing offset, for a 16-QAM, 448-Gb/s signal that uses optical time-division-multiplexing and electronic time-division-demultiplexing (OMED) scheme. © 2012 IEEE.

    DOI

    Scopus

  • Performance comparison of 413-Gb/s multi-band OFDM transmission with 32/64-QAM

    Yu Kawaguchi, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita

    Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012     449 - 450  2012年

     概要を見る

    We compare the transmission performance of 413-Gb/s multi-band OFDM with 32-QAM (7%FEC) and 64-QAM (20%FEC) by simulations. The reachable distance with 64-QAM is longer than 32-QAM due to the filtering effects of 50-GHz-grid ROADMs. © 2012 IEEE.

    DOI

    Scopus

  • Optical OFDM for beyond 100Gbit/s transmission

    H. Takahashi, W. R. Peng, Y. Kawaguchi, T. Tsuritani, I. Morita

    Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012     162 - 163  2012年

     概要を見る

    Optical OFDM is a promising technology for increasing the bit-rate per WDM channel. The transmission experiments of 400 Gbit/s OFDM signal per WDM channel with 4bit/s/Hz and 8bit/s/Hz spectral efficiency are explained. © 2012 IEEE.

    DOI

    Scopus

  • Benefits of router offload utilizing superchannel technology for beyond-100-Gb/s network

    Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    National Fiber Optic Engineers Conference, NFOEC 2012    2012年

     概要を見る

    This paper shows the architecture of a router offloading method utilizing a superchannel signal technology that shows significant savings in energy consumption, compared to a router offloading method utilizing a sub-wavelength switching technology. © 2012 OSA.

    DOI

    Scopus

  • Transmission performances of differential 6-ary PSK signal with 10.7-Gb/s NRZ-OOK neighboring channels over SMF and DSF Links

    H. Y. Choi, I. Morita

    National Fiber Optic Engineers Conference, NFOEC 2012    2012年

     概要を見る

    We demonstrate a differential 6-ary PSK-based transmission system with 10-Gb/s NRZOOK neighboring channels over 320-km long SMF with in-line dispersion compensation and DSF links and compare its performances with that of a classical PDM-DQPSK-based system. ©2012 Optical Society of America.

    DOI

    Scopus

  • Polarization demultiplexing using linearly-estimated channel matrix in PDM systems with MIMO processing

    Koki Takeshima, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita

    National Fiber Optic Engineers Conference, NFOEC 2012    2012年

     概要を見る

    We propose a polarization demultiplexing using linearly-estimated channel matrix for faster polarization tracking. Through experiments, we confirm that the proposed method can enhance tolerance of SOP change compared with demultiplexing using an identical channel matrix. ©2012 Optical Society of America.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • First demonstration of an openflow based software-defined optical network employing packet, fixed and flexible DWDM grid technologies on an international multi-domain testbed

    M. Channegowda, R. Nejabati, M. Rashidifard, S. Peng, N. Amaya, G. Zervas, D. Simeonidou, Ricard Vilalta, Ramon Casellas, Ricardo Martínez, Raül Muñoz, Lei Liu, Takehiro Tsuritani, Itsuro Morita, Achim Autenrieth, Jörg Peter Elbers, Paweł Kostecki, Paweł Kaczmarek

    European Conference on Optical Communication, ECOC    2012年

     概要を見る

    We demonstrate for the first time an extended OpenFlow based control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet domains. We also demonstrate for the first time multi-domain network slicing and verified results on a global scale trial involving test-beds in UK, Spain and Japan. © 2012 OSA.

    DOI

    Scopus

    23
    被引用数
    (Scopus)
  • 3 x 458-Gbit/s optical multi-band OFDM transmission at 50-GHz WDM spacing over 160 km of SSMF with EDFA-only amplification

    Hidenori Takahashi, Wei Ren Peng, Yu Kawaguchi, Takehiro Tsuritani, Itsuro Morita

    Optics InfoBase Conference Papers    2012年

     概要を見る

    We have successfully demonstrated 3 x 458-Gbit/s Optical Multi-band OFDM transmission over 160 km of SSMF with EDFA-only amplification at 50 GHz WDM spacing by utilizing narrowband optical filter. © 2012 OSA.

  • 7xl.l2-Tbit/s, 200-GHz-Spaced, PDM-16QAM transmission over All-EDFA 400-km SSMF and 2 ROADMs

    Wei Ren Peng, Itsuro Morita, Takahashi Hidenori, Takehiro Tsuritani

    Optics InfoBase Conference Papers    2012年

     概要を見る

    We have successfully demonstrated the first terabit-class WDM transmission (7 x 1.12 Tb/s PDM-16QAM) over all-EDFA 400-km standard single mode fiber (SSMF) and 2 ROADMs. Q factors larger than 9.4 dB are found for all channels. © 2011 OSA.

  • Transmission of power-efficient CO-OFDM signals over 9360 km of ultra-large-area fiber

    Wei Ren Peng, Itsuro Morita, Takehiro Tsuritani

    Optics InfoBase Conference Papers    2012年

     概要を見る

    In this paper we introduced two power-efficient CO-OFDM systems and showed that both systems can have ~1-dB gain in receiving sensitivity (BER = 1e-3) and exhibit ~1.1-dB benefit in Q factor after 9360-km transmission when compared with the regular PDM-CO-OFDM. © 2012 OSA.

  • Experimental assessment of a combined PCE-RMA and distributed spectrum allocation mechanism for GMPLS elastic CO-OFDM Optical Networks

    Ramon Casellas, Raül Muñoz, Josep Ma Fàbrega, Michela Svaluto Moreolo, Ricardo Martínez, Lei Liu, Takehiro Tsuritani, Itsuro Morita

    Optics InfoBase Conference Papers    2012年

     概要を見る

    We design and deploy a GMPLS control plane for elastic CO-OFDM optical networks, detailing its functional architecture combining PCE routing and modulation assignment (RMA) with distributed spectrum allocation, the protocol extensions and the experimental validation. © 2012 OSA.

  • Generation Method of Optical 64QAM Signal Using Electrical Binary Drive Signals

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    2012 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE (ACP)    2012年

     概要を見る

    We propose a new method of generating 64QAM using electrical binary drive signals. The proposed technique has a potential to achieve the high symbol rate since it does not require the multilevel drive signals.

    DOI

    Scopus

  • A Novel Transmitter for 320-Gb/s PDM-RZ-16QAM Generation Using Electrical Binary Drive Signals

    Hyeon Yeong Choi, Takehiro Tsuritani, Itsuro Morita

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    We propose a new transmitter for 16QAM generation based on a combination of a dual-drive Mach-Zehnder modulator (DD-MZM) and a dual-parallel Mach-Zehnder modulator (DP-MZM) with electrical binary drive signals. By using the proposed transmitter, we successfully evaluated the performances of 224-Gb/s and 320-Gb/s PDM-RZ-16QAM signals.

    DOI

    Scopus

  • Control Plane Techniques for Elastic Optical Networks: GMPLS/PCE vs OpenFlow

    Lei Liu, Takehiro Tsuritani, Itsuro Morita, Ramon Casellas, Ricardo Martinez, Rauel Munoz

    2012 IEEE GLOBECOM WORKSHOPS (GC WKSHPS)     352 - 357  2012年

     概要を見る

    Elastic Optical Networks (EON), which are able to allocate an appropriate optical spectrum range and modulation format to an optical path according to the client (e.g. IP) traffic demand and path attributes (e.g., physical length or optical impairments), have been proposed to more efficiently utilize network spectrum resources. A control plane is a key enabling technique for dynamic and intelligent end-to-end path provisioning and recovery in such networks. In this paper, we design and deploy two different control planes for EON. One is based on the Generalized Multi-Protocol Label Switching (GMPLS) / Path Computation Element (PCE) architecture and protocols, and the other one is based on a centralized model extending OpenFlow. We detail the protocol extensions involved in the main functional aspects, and we experimentally validate both control plane approaches in a control plane testbed and compare them in terms of path provisioning latency.

    DOI

    Scopus

    13
    被引用数
    (Scopus)
  • From GMPLS to PCE/GMPLS to Open Flow: How Much Benefit can We Get from the Technical Evolution of Control Plane in Optical Networks?

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    2012 14TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON 2012)    2012年

     概要を見る

    Control plane techniques are very important for optical networks since they can enable dynamic lightpath provisioning and restoration, improve the network intelligence, and greatly reduce the processing latency and operational expenditure. In recent years, there have been great progresses in this area, ranged from the traditional generalized multi-protocol label switching (GMPLS) to a path computation element (PCE)/GMPLS-based architecture. The latest studies have focused on an OpenFlow-based control plane for optical networks, which is also known as software-defined networking. In this paper, we review our recent research activities related to the GMPLS-based, PCE/GMPLS-based, and OpenFlow-based control planes for a translucent wavelength switched optical network (WSON). We present enabling techniques for each control plane, and we summarize their advantages and disadvantages.

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Experimental Demonstration of OpenFlow/GMPLS Interworking Control Plane for IP/DWDM Multi-Layer Optical Networks

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    2012 14TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON 2012)    2012年

     概要を見る

    A unified control plane (UCP) for IP/Dense Wavelength Division Multiplexing (DWDM) multi-layer optical networks is a very important issue for network carriers. Generalized Multi-Protocol Label Switching (GMPLS), with a decade of development and standardization work, is a mature control plane technique for optical transport networks. But GMPLS-based UCP for IP/DWDM multi-layer networks is overly complex for deployment in a real operational scenario. On the other hand, OpenFlow has been verified as a promising solution for a UCP, but it is not mature enough to control optical switching nodes so far. Therefore, as an intermediate step towards a fully OpenFlow-based UCP, a logical choice at present is to introduce an OpenFlow/GMPLS interworking control plane which is able to use GMPLS to control the optical layer and use OpenFlow to dynamically coordinate between IP and optical layers. In light of this, in this paper, we experimentally present three interworking solutions (parallel, overlay and integrated) between OpenFlow and GMPLS for intelligent wavelength path control in IP/DWDM multi-layer optical networks. The overall feasibility of these solutions is assessed and their performance is quantitatively evaluated and compared on an actual network testbed.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Experimental Investigation of Dynamic Impairment-aware Bi-directional Lightpath Provisioning in GMPLS-enabled Optical Networks

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    2011 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE AND EXHIBITION (ACP)   8310  2012年

     概要を見る

    The lightpaths within a wavelength switched optical network (WSON) are usually bi-directional, with a same route and a same wavelength which are allocated for both directions from the viewpoint of optical network operation. On the other hand, the introduction of generalized multi-protocol label switching (GMPLS) as a network control plane is expected to bring more intelligence and to provision the end-to-end lightpath in a cost-efficient manner. In this paper, we experimentally demonstrate and evaluate dynamic provisioning of bidirectional lightpaths in GMPLS controlled optical networks, considering the wavelength continuity constraint and the physical impairment constraint on both directions.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • OpenFlow-based Dynamic Wavelength Path Control for Future Photonic Networks

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    2012 International Conference on Photonics in Switching (PS)    2012年

     概要を見る

    OpenFlow, which allows operators to control the network using software running on an external controller, provides the maximum flexibility for operators, and matches the carrier's preferences given its centralized architecture, simplicity and manageability. In this paper, we present an OpenFlow-based approach for dynamic wavelength path control in future photonic networks, assessing its overall feasibility and efficiency through a field trial.

  • High Capacity WDM Transmission Using Terabit Super-Channels

    Itsuro Morita, Wei-Ren Peng

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    This paper gives an overview of recent high capacity WDM transmission experiments using superchannels, in which multiple optical carriers are utilized to generate terabit-class channels.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • 500-Gb/s Transmission by 41-GBd PDM-64QAM

    Wei-Ren Peng, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita

    2012 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE (ACP)    2012年

     概要を見る

    In this paper we will review our recent works on DAC-free-generated 41-GBd PDM-64QAM (similar to 497 Gb/s) using one single I/Q modulator. Reaches from 720 to 1200 km on SSMF can be achieved by different receiving algorithms.

  • Per-Symbol-Based Digital Back-Propagation Approach for PDM-CO-OFDM Transport Systems

    Wei-Ren Peng, Hidenori Takahashi, Itsuro Morita, Takehiro Tsuritani

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    For PDM-CO-OFDM we propose and experimentally demonstrate a per-symbol-based digital back-propagation method which avoids the use of inefficient overlap-add method, saves one FFT circuit, and exhibits a similar performance when compared with the previous proposal

    DOI

    Scopus

  • Generation and Detection of 22.4-GBd 64QAM Using Coherent OTD Multiplexing and ETD De-multiplexing Approach

    Wei-Ren Peng, Hyeon Yeong Choi, Hidenori takahashi, Itsuro Morita, Takehiro Tsuritani

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    With optical time-division-multiplexing and electronic time-division-demultiplexing (OMED), we experimentally demonstrate the generation and detection of 22.4-GBd/s (2xOTDM) 64QAM and investigate the system sensitivities against both the power imbalance and timing offset between OTDM tributaries.

    DOI

    Scopus

  • DAC-free Generation and 320-km Transmission of 11.2-GBd PDM-64QAM Using a Single I/Q Modulator

    Wei-Ren Peng, Hidenori Takahashi, Takehiro Tsuritani, Itsuro Morita

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    We successfully generate 11.2-GBd PDM-64QAM using one I/Q modulator driven with eightlevel signals synthesized by all binary electrical inputs. The signal quality is verified with similar to 1-dB Q margin (from 7% FEC threshold) after 320-km SSMF transmission.

    DOI

    Scopus

  • High-Speed Transmission by Direct-Detection Optical OFDM

    Wei-Ren Peng, Hidenori Takahashi, Itsuro Morita, Takehiro Tsuritani

    2011 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE AND EXHIBITION (ACP)   8309  2012年

     概要を見る

    In this paper we review our previously-proposed direct-detection optical OFDM superchannel and the corresponding optical-multi band receiving. With this technique we have successfully demonstrated the transmissions of no-and 1200-km SSMF, respectively, at 214- and 117-Gb/s data rates.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Optimization of Joint 32/64-QAM Subcarrier Modulation for 515-Gbit/s Multi-band OFDM WDM transmission with 50-GHz channel spacing through 320-km SSMF transmission

    Hidenori Takahashi, Wei-Ren Peng, Yu Kawaguchi, Takehiro Tsuritani, Itsuro Morita

    2012 38TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC)    2012年

     概要を見る

    Optimization of the joint 32/64-QAM subcarrier modulation is investigated using 3x515-Gbit/s multi-band OFDM transmission over 320-km SSMF with 50-GHz frequency grid. It is confirmed that the optimized joint 32/64-QAM with 20%-overhead FEC enables to increase OSNR sensitivity compared to 32-QAM with 7%-overhead FEC and 64-QAM with 20%-overhead FEC.

    DOI

    Scopus

  • Optical OFDM for Higher Spectral Efficiency System

    Hidenori Takahashi, Wei-ren Peng, Yu Kawaguchi, Takehiro Tsuritani, Itsuro Morita

    2012 International Conference on Photonics in Switching (PS)    2012年

     概要を見る

    Optical OFDM is a promising technology for highly spectrally efficient (SE) wavelength-division-multiplexing (WDM) system. Furthermore, the bit-rate 400 Gbit/s per WDM channel with SE of 8 bit/s/Hz is expected to be adopted for the next generation WDM system. For the application, optical OFDM is one of promising candidates because of the scalability for higher SE and higher bit-rate using multi-band OFDM technique. In this paper, the SE of multi-band OFDM is explained first, and WDM transmission experiments of multi-band OFDM signals with SE of over 8bit/s/Hz are introduced.

  • Experimental evaluation of efficient routing and distributed spectrum allocation algorithms for GMPLS elastic networks

    Muñoz, R., Casellas, R., Martínez, R., Liu, L., Tsuritani, T., Morita, I.

    Optics Express   20 ( 27 ) 28532 - 28537  2012年

     概要を見る

    We present and experimentally evaluate efficient strategies in GMPLS-controlled elastic optical networks for dynamic source/PCE routing algorithms. These operate with aggregated optical spectrum information in combination with advanced distributed spectrum allocation algorithms which collect the status of all basic spectrum slots on each link.

    DOI PubMed

    Scopus

    8
    被引用数
    (Scopus)
  • Optical transmitter for 320-Gb/s PDM-RZ-16QAM generation using electrical binary drive signals

    Choi, H.Y., Tsuritani, T., Morita, I.

    Optics Express   20 ( 27 ) 28772 - 28778  2012年

     概要を見る

    We propose a new 16QAM optical transmitter based on a combination of a dual-drive Mach-Zehnder modulator (DD-MZM) and a dual-parallel Mach-Zehnder modulator (DP-MZM) with electrical binary drive signals. For 16QAM generation, two arms of DD-MZM are independently driven by two different binary data, and consequently, the DD-MZM produces an offset square 4QAM of the 16QAM constellation. This 4QAM signal is then switched over other quadrants through a typical QPSK modulation scheme by the following DP-MZM, and resulting in 16QAM. By using the proposed transmitter together with a digital coherent receiver, we successfully demonstrate the 224-Gb/s and 320-Gb/s PDM-RZ-16QAM systems. Their OSNR sensitivities at 3.8x10(-3) BER are observed to be 19.8 dB and 23 dB, respectively. (C) 2012 Optical Society of America

    DOI PubMed

    Scopus

    6
    被引用数
    (Scopus)
  • Inter-layer traffic engineering with hierarchical-PCE in MPLS-TP over wavelength switched optical networks

    Casellas, R., Martinez, R., Muñoz, R., Liu, L., Tsuritani, T., Morita, I.

    Optics Express   20 ( 28 ) 29137 - 29142  2012年

     概要を見る

    We present the implementation and validation of an Inter-layer Traffic Engineering (TE) architecture based on a hierarchical path computation element (PCE), where the parent PCE is notified of established optical layer Label Switched Paths that induce packet traffic engineering (TE) links, thus not requiring full topology visibility. We summarize the architecture, the control plane extensions and its experimental evaluation in a control plane testbed. © 2012 Optical Society of America.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Generation and detection of 240-Gb/s PDM-64QAM using optical binary synthesizing approach and phase-folded decision-directed equalization

    Choi, H.Y., Tsuritani, T., Takahashi, H., Peng, W.-R., Morita, I.

    Optics Express   20 ( 25 ) 27933 - 27940  2012年

     概要を見る

    We present new generation and detection methods for high symbol-rate 64-ary quadrature amplitude modulation (64QAM). The 64QAM signal is created by tandem in-phase/quadrature (I/Q) modulators driven by electrical binary signals. The first I/Q modulator, which has four drive arms (i.e. a dual-drive I/Q modulator), yields 16QAM with an offset at the 1st quadrant of the complex plane. Subsequently, the second modulator switches this 16QAM signal over four quadrants via the typical quadrature phase-shift-keying (QPSK) modulation scheme, hence the desired 64QAM is generated. To mitigate the impacts of transmitter imperfections, we also propose a phase-folded decision-directed (PF-DD) linear equalizer at the receiver. Using these new techniques, we experimentally demonstrate the 120- and 240-Gb/s polarization-division-multiplexed (PDM) return-to-zero (RZ) 64QAM systems. The required optical signal-to-noise ratio (OSNR) for a bit-error rate (BER) of 2.4x10(-2) is measured at 20.2 or 23 dB, respectively, which is similar to 3.5 dB off the theoretical limit. (C)2012 Optical Society of America

    DOI PubMed

    Scopus

    11
    被引用数
    (Scopus)
  • Method to generate 112Gbit/s polarisation-multiplexed 8QAM signal

    Choi, H.Y., Tsuritani, T., Morita, I.

    Electronics Letters   48 ( 9 ) 511 - 513  2012年

     概要を見る

    Proposed is a new method to synthesise the 8-ary quadrature amplitude modulation (8QAM) signal and demonstrate the 112Gbit/s polarisation-multiplexed 8QAM system. The proposed transmitter consists of a dual-drive Mach-Zehnder modulator (DD-MZM) and phase modulators in tandem. The DD-MZM is utilised to manipulate the amplitude and phase of the optical signal by adjusting its chirp. The optical signal-to-noise ratio sensitivity of the 112Gbit/s polarisation-multiplexed 8QAM signal to achieve the bit error rate of 10 -3 is measured to be 18.8dB (in 0.1nm resolution bandwidth). © 2012 The Institution of Engineering and Technology.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • GMPLS/PCE control of flexi-grid DWDM optical networks using CO-OFDM transmission [Invited]

    Casellas, R., Muñoz, R., Fàbrega, J.M., Moreolo, M.S., Martínez, R., Liu, L., Tsuritani, T., Morita, I.

    Journal of Optical Communications and Networking   4 ( 11 ) B1 - B10  2012年

     概要を見る

    Current optical transport networks use optical channel carriers (wavelengths) that are defined and constrained by a fixed ITU-T dense wavelength division multiplexing (DWDM) grid. Such a grid is not adapted to high data rates (beyond 100 Gb/s) and is inefficient when a wavelength is assigned to a low-rate optical signal. Consequently, the ITU-T is updating the set of DWDM reference frequencies with the inclusion of a smaller channel spacing (e. g., 6.25 GHz) while allowing the allocation of frequency slots, that is, variable-sized frequency ranges composed of a number of slices. In this paper, we propose the design, implementation, and experimental validation of a Generalized Multi-Protocol Label Switching/path computation element (GMPLS/PCE) control plane for such flexible optical networks, using optical orthogonal frequency division multiplexing transmission technology, given its unique flexibility, bit-rate/bandwidth scalability, and subwavelength granularity. The control plane uses a distance-adaptive and PCE-based routing and modulation assignment, combined with distributed frequency slot (spectrum) selection. A comparative analysis of path computation algorithms is carried out, highlighting the benefits of extending the path computation function with the knowledge of the status of the slices and the spectral efficiency of the modulation formats.

    DOI

    Scopus

    36
    被引用数
    (Scopus)
  • Nonlinear tolerance of 53.5-Gb/s differential 6-ary PSK surrounded by 10.7-Gb/s NRZ-OOK neighbors in SMF and DSF transmission links

    Choi, H.Y., Morita, I.

    IEEE Photonics Technology Letters   24 ( 10 ) 806 - 808  2012年

     概要を見る

    We demonstrate an optical transmission system based on a 53.5-Gb/s differential 6-ary phase-shift-keying (D6PSK) signal with copropagating 10.7-Gb/s nonreturn-to-zero (NRZ) on-off keying (OOK) channels over either 320-km-long single-mode fiber link with in-line dispersion compensation or 320-km-long dispersion-shifted fiber link, and compare its performances with that of a classical polarization-division-multiplexing differential quadrature phase-shift-keying (DQPSK)-based system. The results show that the nonlinear tolerance of the D6PSK signal outperforms that of the PDM-DQPSK signal in terms of the cross-phase modulation effect induced by the 10.7-Gb/s NRZ-OOK neighboring channels.

    DOI

    Scopus

  • Transmission of high-speed (&gt; 100 Gb/s) direct-detection optical OFDM superchannel

    Peng, W.-R., Morita, I., Takahashi, H., Tsuritani, T.

    Journal of Lightwave Technology   30 ( 12 ) 2025 - 2034  2012年

     概要を見る

    In this paper, we propose and experimentally demonstrate the direct-detection optical orthogonal-frequency-division-multiplexing superchannel (DDO-OFDM-S) and optical multiband receiving method (OMBR) to support >100-Gb/s data rate and a longer distance for direct-detection systems. For the new OMBR, we discuss the optimum carrier-to-sideband power ratio (CSPR) both in the cases of back-to-back and after transmission, and derive the analytical form for CSPR which is verified with numerical results. An overhead-efficient training method for in-phase/quadrature-phase imbalance estimation is also introduced in order to obtain a better performance while maintaining the high throughput of the system. With experimental setups, we evaluate the two systems with 1) 16-QAM, 214-Gb/s (190 Gb/s without overhead) and 2) 4-QAM, 117-Gb/s (100 Gb/s without overhead) systems. The new proposals enable the record data rate per wavelength (214 Gb/s) and record distance of 720-km standard single-mode fiber (SSMF) for the >100-Gb/s DDO-OFDM systems, and achieve the record optical signal-to-noise ratio sensitivity of 21.2 dB and record distance of 1200-km SSMF (similar to 1 dB penalty) for the 100-Gb/s class DDO-OFDM systems.

    DOI

    Scopus

    79
    被引用数
    (Scopus)
  • BER-adaptive flexible-format transmitter for elastic optical networks

    Choi, H.Y., Tsuritani, T., Morita, I.

    Optics Express   20 ( 17 ) 18652 - 18658  2012年

     概要を見る

    We propose a new optical transmitter which is capable of changing flexibly the modulation format of the optical signal. By using this transmitter, we can handle and assign various modulation formats: binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), 8-ary quadrature amplitude modulation (8QAM), and 16QAM. The proposed transmitter is based on a combination of a dual-drive Mach-Zehnder modulator (DD-MZM) and a dual-parallel MZM (DP-MZM) with electrical binary drive signals. DD-MZM is a key element to produce the 8QAM and 16QAM formats where each arm of DD-MZM is driven by independent binary data. This is because we can modulate the amplitude and phase of the optical signal by using a frequency chirp of the modulator when we adjust properly the amplitudes of the electrical drive signals. In addition, we show an algorithm by which the proposed transmitter can intelligently select the modulation format in accordance with the signal quality. (C)2012 Optical Society of America

    DOI PubMed

    Scopus

    44
    被引用数
    (Scopus)
  • Field and lab trials of PCE-based OSNR-aware dynamic restoration in multi-domain GMPLS-enabled translucent WSON

    Lei Liu, Ramon Casellas, Takehiro Tsuritani, Itsuro Morita, Shuichi Okamoto, Ricardo Martinez, Rauel Munoz

    OPTICS EXPRESS   19 ( 27 ) 26568 - 26577  2011年12月

     概要を見る

    Dynamic lightpath restoration is a key issue in wavelength switched optical networks (WSON). On the other hand, the introduction of the path computation element (PCE) and the generalized multi-protocol label switching (GMPLS) architectures into WSON as control plane technologies is expected to bring more intelligence and to enable the dynamic computation and control of end-to-end lightpaths in a cost-efficient manner. In this paper, for the first time and through a lab trial with four domains and a field trial located in Japan and Spain, we experimentally present PCE-based optical signal to noise ratio (OSNR)-aware dynamic restoration in multi-domain GMPLS-enabled translucent WSON, assessing the overall feasibility of the proposed techniques and quantitatively evaluating the service disruption time and path computation latency during end-to-end lightpath restoration. (C) 2011 Optical Society of America

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Network architecture and transmision technologies for terabit transport network

    Itsuro Morita, Takehiro Tsuritani, Masatoshi Suzuki

    2011 IEEE Photonics Society Summer Topical Meeting Series     111 - 112  2011年

     概要を見る

    Network architecture and transmission technologies to increase an overall efficiency in transport networks are discussed. Traffic grooming in a flexible grid with rate-tunable transponders by optical OFDM is an attractive solution. © 2011 IEEE.

    DOI

    Scopus

  • Optical OFDM transmission with high spectral efficiency

    Hidenori Takahashi, Wei Ren Peng, Ituro Morita, Hideaki Tanaka

    16th Opto-Electronics and Communications Conference, OECC 2011     818 - 819  2011年

     概要を見る

    Optical OFDM is one of promising technology to increase spectral efficiency. We explain the modulation scheme and WDM transmission experiments of 458 Gbit/s OFDM signal per WDM channel with 8 bit/s/Hz spectral efficiency. © 2011 National Sun Yat-Sen Univ.

  • Hybrid QAM transmission techniques for single-carrier ultra-dense WDM systems

    Wei Ren Peng, Itsuro Morita, Hideaki Tanaka

    16th Opto-Electronics and Communications Conference, OECC 2011     824 - 825  2011年

     概要を見る

    We demonstrate a hybrid QAM transmission technique for single-carrier ultra-dense wavelength division multiplexing (UD-WDM) systems. With 112-Gb/s per channel on 25-GHz grid, we found the hybrid 4 and 8QAM technique shows a much better performance than the pure 4QAM and exhibits an ∼0.9-dB OSNR benefit over the pure 8QAM. © 2011 National Sun Yat-Sen Univ.

  • Over 100-Gb/s direct-detection optical OFDM transmission

    Wei Ren Peng, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    16th Opto-Electronics and Communications Conference, OECC 2011     37 - 38  2011年

     概要を見る

    We will review our recent works on the transmission of a high-speed (> 100Gb/s) direct-detection optical OFDM super-channel (DDO-OFDM-S) over the dispersion-unmanaged standard-single-mode-fiber (SSMF) link. © 2011 National Sun Yat-Sen Univ.

  • Polarization demultiplexing using linearly interpolated channel matrix in PDM systems with MIMO processing

    K. Takeshima, H. Takahashi, I. Morita, H. Tanaka

    16th Opto-Electronics and Communications Conference, OECC 2011     419 - 420  2011年

     概要を見る

    We propose a polarization demultiplexing scheme using linearly interpolated channel matrix in PDM systems with MIMO processing. We confirm that the proposed scheme can double a tolerance for polarization changes compared to the conventional scheme. © 2011 National Sun Yat-Sen Univ.

  • Study of router off-loading effectiveness on power consumption and cost in a network

    Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita

    16th Opto-Electronics and Communications Conference, OECC 2011     768 - 769  2011年

     概要を見る

    Effectiveness of the MPLS-TP based router off-loading method is studied from power consumption and node cost perspectives. We compare power consumption and node cost between a conventional network and a router-off loading network utilizing a reference network. © 2011 National Sun Yat-Sen Univ.

  • Direct-detection superchannel using optical OFDM

    Wei Ren Peng, Hidenori Takahashi, Itsuro Morita, Takehiro Tsuritani

    IET Conference Publications   2011 ( 597 CP )  2011年

     概要を見る

    We will review the transmissions of a high-speed (> 100Gb/s) direct-detection superchannel using optical OFDM over an all- EDFA-based standard-single-mode-fiber (SSMF) link.

    DOI

    Scopus

  • Performance evaluation of 6-level PSK signal using differential demodulation with partial symbol delay

    H. Y. Choi, I. Morita

    Optics InfoBase Conference Papers   8309  2011年

     概要を見る

    We demonstrate an optical transmission system based on a 6-level PSK modulation format and differential detection with a partial symbol delay. The 6-level PSK signal is simply generated by using a chirp-free Mach-Zehnder modulator followed by a phase modulator. In order to convert the phase information of the 6-level PSK signal into the intensity, we utilize a pair of two Mach-Zehnder delay-line interferometers with having a differential delay less than the symbol duration of the signal unlike a conventional differential detection scheme. We evaluate the performances of the differential 6-level PSK signal and compare them with that of a conventional DQPSK signal. In addition, the transmission performance of the 21.4-Gb/s 6-level PSK signal is experimentally verified in a 240-km long dispersionmanaged fiber link. Furthermore, additional simulation results show that the tolerance to optical filtering and chromatic dispersion of the 107-Gb/s differential 6-level PSK signal is improved significantly by adopting the partial demodulation scheme. © 2011 SPIE-OSA-IEEE.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Experimental Investigation of Dynamic Impairment-aware Bi-directional Lightpath Provisioning in GMPLS-enabled Optical Networks

    Lei Liu, Takehiro Tsuritani, Itsuro Morita

    NETWORK ARCHITECTURES, MANAGEMENT, AND APPLICATIONS IX   8310  2011年

     概要を見る

    The lightpaths within a wavelength switched optical network (WSON) are usually bi-directional, with a same route and a same wavelength which are allocated for both directions from the viewpoint of optical network operation. On the other hand, the introduction of generalized multi-protocol label switching (GMPLS) as a network control plane is expected to bring more intelligence and to provision the end-to-end lightpath in a cost-efficient manner. In this paper, we experimentally demonstrate and evaluate dynamic provisioning of bidirectional lightpaths in GMPLS controlled optical networks, considering the wavelength continuity constraint and the physical impairment constraint on both directions.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • OpenFlow-based Wavelength Path Control in Transparent Optical Networks: a Proof-of-Concept Demonstration

    Lei Liu, Takehiro Tsuritani, Itsuro Morita, Hongxiang Guo, Jian Wu

    2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)    2011年

     概要を見る

    We experimentally present a proof-of-concept demonstration of OpenFlow-based wavelength path control for lightpath provisioning in transparent optical networks, assessing its overall feasibility and quantitatively evaluating the network performances.

  • Field Demonstration of Dynamic Circuit Provisioning by Web Services Interface Proxy for Lambda and Ethernet based Administrative Domains

    Takahiro Miyamoto, Jin Tanaka, Hideki Otsuki, Tomohiro Kudoh, Ryousei Takano, Michiaki Hayashi, Itsuro Morita, Kosuke Nishimura, Shinji Shimojo

    NETWORK ARCHITECTURES, MANAGEMENT, AND APPLICATIONS VIII   7989   465 - 466  2011年

     概要を見る

    To provide end-to-end wide-bandwidth data transfer over lambda and Ethernet networks, we demonstrate dynamic circuit provisioning by web services interface proxy which enables interoperability among different network provisioning systems.

    DOI

    Scopus

  • 117-Gb/s Optical OFDM Super-channel Transmission over 1200-km SSMF Using Direct Detection and EDFA-Only Amplification

    Wei-Ren Peng, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE    2011年

     概要を見る

    With EDFA-only amplification, we successfully demonstrate the transmission of a 4-QAM, 117-Gb/s (100 Gb/s without overhead) DDO-OFDM super-channel over 1200-km SSMF with only 1-dB OSNR penalty. We also discuss the impact of PMD on the transmission link. (C)2011 Optical Society of America

  • Scattered Pilot Channel Tracking Method for PDM-CO-OFDM Transmissions Using Polar-Based Intra-Symbol Frequency-Domain Average

    Wei-Ren Peng, Koki Takeshima, Itsuro Morita, Hidenori Takahashi, Hideaki Tanaka

    2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE    2011年

     概要を見る

    We have demonstrated an efficient scattered pilot channel tracking approach with a new polar-based intra-symbol frequency domain average (ISFA) for 16-QAM, 40-Gb/s PDM-CO-OFDM systems. This proposal could promise an relatively stable performance even under an rapidly time-varying environment. (C)2011 Optical Society of America

  • Direct-Detection Optical OFDM Superchannel

    Wei-Ren Peng, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)    2011年

     概要を見る

    We will review the transmission and signal processing techniques (phase noise & IQ imbalance compensation) of our previously-proposed direct-detection optical OFDM super-channel (DDO-OFDM-S) over dispersion-unmanaged standard single mode fiber (SSMF) link.

  • Practical Carrier Recovery Method for Carrier-Assisted PDM-CO-OFDM Transmissions

    Wei-Ren Peng, Itsuro Morita, Hidenori Takahashi, Hideaki Tanaka

    2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)    2011年

     概要を見る

    For carrier-assisted PDM-CO-OFDM systems, we propose and demonstrate a practical carrier recovery method applying a very-simple moving average filter (MAF). Besides simplicity, we confirm its excellent performance from the results of a 16-QAM, 40-Gbps OFDM transmission experiment.

  • The Impact of the Combined 8-QAM and QPSK Subcarrier Modulation for Coherent Optical OFDM

    Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE    2011年

     概要を見る

    We investigated the optimized signal condition of the combined 8-QAM and QPSK subcarrier modulation for optical OFDM. The performance improvement was confirmed by WDM transmission experiments with the optimized power difference and subcarrier number.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • 7 x 463-Gbit/s Optical OFDM transmission at 100-GHz WDM spacing over 960 km of SSMF with EDFA-only Amplification

    Hidenori Takahashi, Wei-Ren Peng, Itsuro Morita, Hideaki Tanaka

    2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)    2011年

     概要を見る

    We have demonstrated 7 x 463-Gbit/s Optical OFDM transmission over 960 km of SSMF with EDFA-only amplification at 100-GHz WDM spacing. It is confirmed that the intra-channel penalty is dominant compared to inter-channel penalty.

  • Demonstration of Optical Wireless USB 2.0 System with Wireless Power Transfer

    Tomonori Yazaki, Itsuro Morita, Hideaki Tanaka

    IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE 2011)     11 - 12  2011年

     概要を見る

    We design and fabricate an optical wireless USB 2.0 system with a wireless power transfer. A coverage of the optical wireless transceiver is expanded by more than 30 % at the optimum distance for the power transfer, which can maximize the coverage of the system with the commercially available power transfer module. Wireless data and power transfer are successfully demonstrated between a portable music/video player and a PC using the fabricated system.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • On-demand virtual optical network access using 100 Gb/s ethernet

    Ishida, O., Takamichi, T., Arai, S., Kawate, R., Toyoda, H., Morita, I., Araki, S., Ichikawa, T., Hoshida, T., Murai, H.

    Optics Express   19 ( 26 ) 218 - 228  2011年

     概要を見る

    Our Terabit LAN challenges are to enhance the scalability and utilization of lambda resources. Bandwidth-on-demand virtualized 100GE access to WDM networks on a field fiber test-bed using multi-domain optical-path provisioning is described.

    DOI

    Scopus

  • Technological innovation and challenges facing optical submarine cable systems

    Morita, I., Suzuki, M.

    Journal of the Institute of Electrical Engineers of Japan   131 ( 9 ) 614 - 616  2011年

    DOI

    Scopus

  • The evaluation for required bit resolution of digital-analog-converter in optical OFDM signal generation

    Takahashi, H., Morita, I., Tanaka, H.

    IEICE Transactions on Communications   E94-B ( 2 ) 425 - 429  2011年

     概要を見る

    The required bit resolution of digital-analog-converter (DAC) for optical OFDM was evaluated through simulation and experiment. We found that the signal degradation caused by quantization depends on the number of subcarriers theoretically, but the other noise generated in experiment suppresses the dependency. Additionally, signal degradation caused by quantization is independent of subcarrier modulation, and the performance improvement saturates with increasing bit resolution. With the criteria for the BER of 1 x 10(-3), the required DAC resolution by simulation with ideal analog-digital-converter at receiver is 3 bits for QPSK, 4 bits for 8-QAM and 5 bits for 16-QAM and 32-QAM. From the experimental result, the required bit resolution is increased as 6 bits for 32-QAM.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Special section on extremely advanced optical transmission technologies and transmission optical fiber technologies towards exabit era

    Nakazawa, M., Morioka, T., Suzuki, M., Kashima, N., Awaji, Y., Ohashi, M., Koshiba, M., Nakajima, K., Namiki, S., Fukuchi, K., Matsuo, S., Morita, I., Yonenaga, K., Abedin, K.S.

    IEICE Transactions on Communications   E94-B ( 2 ) 375 - 375  2011年

  • Experimental study of energy-efficient WDM transponder utilizing adaptive interface control with link-aggregation of ethernet links

    Yoshikane, N., Morita, I., Tanaka, H.

    IEICE Transactions on Communications   E94-B ( 7 ) 1860 - 1867  2011年

     概要を見る

    The design of an energy-efficient wavelength division multiplexing (WDM) transponder is proposed and effectiveness of the proposed WDM transponder is experimentally studied. The proposed WDM transponder interworking with the link-aggregation technique possessed by a layer 2 switch can achieve power saving depending on traffic volume variations by utilizing an adaptive interface control. Monitoring methods for the link connectivity of a sleep link are also discussed.

    DOI

    Scopus

  • Experimental validation and performance evaluation of OpenFlow-based wavelength path control in transparent optical networks

    Liu, L., Tsuritani, T., Morita, I., Guo, H., Wu, J.

    Optics Express   19 ( 27 ) 26578 - 26593  2011年

     概要を見る

    OpenFlow, as an open-source protocol for network virtualization, is also widely regarded as a promising control plane technique for heterogeneous networks. But the utilization of the OpenFlow protocol to control a wavelength switched optical network has not been investigated. In this paper, for the first time, we experimentally present a proof-of-concept demonstration of OpenFlow-based wavelength path control for lightpath provisioning in transparent optical networks. We propose two different approaches (sequential and delayed approaches) for lightpath setup and two different approaches (active and passive approaches) for lightpath release by using the OpenFlow protocol. The overall feasibility of these approaches is experimentally validated and the network performances are quantitatively evaluated. More importantly, all the proposed methodologies are demonstrated and evaluated on a real transparent optical network testbed with both OpenFlow-based control plane and data plane, which allows their feasibility and effectiveness to be verified, and valuable insights of the proposed solutions to be obtained for deploying into real OpenFlow controlled optical networks. (C) 2011 Optical Society of America

    DOI PubMed

    Scopus

    75
    被引用数
    (Scopus)
  • Field and lab trials of PCE-based OSNR-aware dynamic restoration in multi-domain GMPLS-enabled translucent WSON

    Liu, L., Casellas, R., Tsuritani, T., Morita, I., Okamoto, S., Martínez, R., Muñoz, R.

    Optics Express   19 ( 27 ) 26568 - 26577  2011年

     概要を見る

    We experimentally present a lab trial of PCE-based OSNR-aware dynamic restoration in multi-domain GMPLS-enabled translucent WSON, assessing the overall feasibility and quantitatively evaluating the service disruption time and path computation latency during end-toend lightpath restoration.

    DOI PubMed

    Scopus

    5
    被引用数
    (Scopus)
  • Experimental assessment of a resilient PCE/GMPLS controlled translucent wavelength switched optical network

    Liu, L., Tsuritani, T., Casellas, R., Martínez, R., Muñoz, R., Tsurusawa, M., Morita, I.

    IEICE Transactions on Communications   E94-B ( 7 ) 1831 - 1844  2011年

     概要を見る

    A translucent wavelength switched optical network (WSON) is a cost-efficient infrastructure between opaque networks and transparent optical networks, which aims at seeking a graceful balance between network cost and service provisioning performance. In this paper, we experimentally present a resilient translucent WSON with the control of an enhanced path computation element (PCE) and extended generalized multi-protocol label switching (GMPLS) controllers. An adaptive routing and wavelength assignment scheme with the consideration of accumulated physical impairments, wavelength availabilities and regenerator allocation is experimentally demonstrated and evaluated for dynamic provisioning of lightpaths. By using two different network scenarios, we experimentally verify the feasibility of the proposed solutions in support of translucent WSON, and quantitatively evaluate the path computation latency, network blocking probability and service disruption time during end-to-end light-path restoration. We also deeply analyze the experimental results and discuss the synchronization between the PCE and the network status. To the best of our knowledge, the most significant progress and contribution of this paper is that, for the first time, all the proposed methodologies in support of PCE/GMPLS controlled translucent WSON, including protocol extensions and related algorithms, are implemented in a network testbed and experimentally evaluated in detail, which allows verifying their feasibility and effectiveness when being potentially deployed into real translucent WSON.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Dynamic virtual link mesh topology aggregation in multi-domain translucent WSON with hierarchical-PCE

    Casellas, R., Martínez, R., Muñoz, R., Liu, L., Tsuritani, T., Morita, I., Tsurusawa, M.

    Optics Express   19 ( 26 ) 611 - 620  2011年

     概要を見る

    We present a lab-trial of the designed and implemented path computation architecture for multi-domain translucent wavelength switched optical networks (WSON), using hierarchical Path Computation Elements (H-PCE). The approach is based on the dynamic aggregation of the domain topologies, represented as a virtual link meshes at a higher level, in order to perform dynamic domain sequence selection. We detail the extended path computation procedures, involving both domain selections considering inter domain links and segment expansions which are impairment-aware, along with the proposed control plane protocol extensions. We validate the approach with the overall performance of the end to end path computation latency, highlighting the benefits of parallelization. (C) 2011 Optical Society of America

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • 100-Gb/s Direct-Detection OFDM Transmission on Independent Polarization Tributaries

    Abdullah Al Amin, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    IEEE PHOTONICS TECHNOLOGY LETTERS   22 ( 7 ) 468 - 470  2010年04月

     概要を見る

    We propose a low-overhead method of polarization-multiplexed direct detection optical orthogonal frequency-division-multiplexing transmission that requires no digital multiple-input and multiple-output processing at the receiver. Optical filtering of carrier components allows a simple polarization separation. Using 16-quadrature amplitude modulation and only 31-GHz bandwidth, 100-Gb/s transmission over 80 km of standard single-mode fiber is successfully demonstrated. The crosstalk penalty was only 1.2 dB. We also investigated the laser frequency offset tolerance for the proposed 100-Gb/s transmission method.

    DOI

    Scopus

    44
    被引用数
    (Scopus)
  • Impact of inter-channel crosstalk in coherent PDM-OFDM long-haul transmission with high spectral efficiency

    H. Takahashi, I. Morita, H. Tanaka

    Technical Digest - 15th OptoElectronics and Communications Conference, OECC2010     464 - 465  2010年

     概要を見る

    The inter-channel crosstalk in high spectral efficient coherent PDM-OFDM transmission is experimentally studied. We confirm that the inter-channel nonlinear penalty is 0.1dB in 8x66.8-Gbit/s transmission over 640 km with up to 5.6bit/s/Hz spectral efficiency.

  • Manageable translucent optical network technologies

    Takehiro Tsuritani, Lei Liu, Itsuro Morita

    2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010     455 - 456  2010年

     概要を見る

    Key technologies for manageable and controllable translucent optical networks are reviewed. The overall demonstrations on PCE-based and fully distributed translucent optical network are also presented. ©2010 Optical Society of America.

    DOI

    Scopus

  • Experimental evaluation of tolerable polarization change in PDM-OFDM systems with training symbols

    K. Takeshima, H. Takahashi, I. Morita, H. Tanaka

    2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010     3 - 4  2010年

     概要を見る

    In order to determine the optimal training symbol interval, we have experimentally evaluated the tolerable polarization change in PDM-OFDM systems. It was confirmed that the allowable polarization change is 0.17 radians in a TS interval of 20.88 μs. ©2010 IEEE.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • GMPLS-ENABLED DYNAMIC TRANSLUCENT OPTICAL NETWORKS: AN EXPERIMENTAL STUDY

    Lei Liu, Takehiro Tsuritani, Itsuro Morita, Munefumi Tsurusawa

    PROCEEDINGS OF THE 2010 INTERNATIONAL CONFERENCE ON ADVANCED INTELLIGENCE AND AWARENESS INTERNET, AIAI2010   2010 ( 571 CP ) 225 - 229  2010年

     概要を見る

    A translucent optical network is a cost-efficient infrastructure between-opaque networks and transparent optical networks, which aims at seeking a graceful balance between network cost and service provisioning performance. This paper addresses the dynamic provisioning of lightpath within a GMPLS-enabled translucent optical network. The GMPLS extensions are implemented, and dynamic lightpath establishment with explicit 3R regeneration control is experimentally demonstrated and evaluated. All the proposed methodologies are evaluated on a real network testbed with both control plane and data plane, which allows verifying their feasibility and effectiveness when being potentially deployed into real translucent optical networks.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Innovations for Future Optical Submarine Cable Systems

    Itsuro Morita, Masatoshi Suzuki

    2010 15TH OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)     46 - 47  2010年

     概要を見る

    This paper overviews the recent technologies in the optical submarine cable systems and discusses technical challenges in order to raise the capacity-distance product to the order of 'exa' in Trans-Pacific systems.

  • Transmission of a 213.7-Gb/s Single-Polarization Direct-Detection Optical OFDM Superchannel over 720-km Standard Single Mode Fiber with EDFA-only Amplification

    Wei-Ren Peng, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2   1-2  2010年

     概要を見る

    We propose and demonstrate the optical multiband receiving method which supports transmission of a 16-QAM, 213.7-Gb/s (189.7-Gb/s) DDO-OFDM super-channel over 720-km SSMF. After transmission all the 9 OFDM bands exhibit BERs lower than the FEC threshold (BER = 3.8e-3).

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • Enabling High Capacity Direct-Detection Optical OFDM Transmissions Using Beat Interference Cancellation Receiver

    Wei-Ren Peng, Itsuro Morita, Hideaki Tanaka

    2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2   1-2  2010年

     概要を見る

    We demonstrate a simple beat interference cancellation approach enabling higher spectral efficiency and better sensitivity (>2 dB) for DDO-OFDM. The associated benefits of enhanced phase noise and PMD tolerances, as well as the impacts of diverse filter parameters, are also discussed.

    DOI

    Scopus

    25
    被引用数
    (Scopus)
  • Digital Phase Noise Estimation and Mitigation Approach for Direct-Detection Optical OFDM Transmissions

    Wei-Ren Peng, Itsuro Morita, Hideaki Tanaka

    2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2   1-2  2010年

     概要を見る

    We demonstrate the first digital laser-phase-noise (PN) mitigation approach for DDO-OFDM which applies a simple Wiener filter for adaptively estimating the statistical-unknown PN. The PN tolerance, in terms of the achievable fibre length, is about tripled with this PN mitigation technique.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Required Resolution of Digital-Analog-Converter for Optical OFDM

    Hidenori Takahashi, Abdullah Al Amin, Itsuro Morita, Hideaki Tanaka

    2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC    2010年

     概要を見る

    The required resolution of digital-analog-converter for optical OFDM was evaluated through simulation and experiment. Signal degradation caused by quantization was independent of subcarrier modulation, and the performance improvement saturates with increasing bit resolution. (C) 2010 Optical Society of America

    DOI

    Scopus

  • 400-Gbit/s Optical OFDM Transmission over 80 km in 50-GHz Frequency Grid

    Hidenori Takahashi, Koki Takeshima, Itsuro Morita, Hideaki Tanaka

    2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2   1-2  2010年

     概要を見る

    400-Gbit/s coherent PDM-OFDM transmission over 80 km has been successfully demonstrated in 50-GHz frequency grid. The use of multiband OFDM with 32-QAM subcarrier modulation enables to increase a spectral efficiency to 8.0 bit/s/Hz at 400 Gbit/s.

    DOI

    Scopus

    35
    被引用数
    (Scopus)
  • Optical Wireless USB 2.0 System with 1 Gbit/s Optical Transceiver

    Tomonori Yazaki, Itsuro Morita, Hideaki Tanaka

    2010 15TH OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)     128 - 129  2010年

     概要を見る

    We newly design and fabricate an optical wireless USB 2.0 system with a 1 Gbit/s optical transceiver. A performance of the 1 Gbit/s optical transceiver is evaluated, and a wireless music/video data transfer is successfully demonstrated using the system.

  • Proposal And Demonstration of Optical Wireless USB 2.0

    Tomonori Yazaki, Itsuro Morita, Hideaki Tanaka

    2010 DIGEST OF TECHNICAL PAPERS INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS ICCE     423 - 424  2010年

     概要を見る

    We propose an optical wireless USB 2.0 system with a 1 Gbit/s optical wireless interface and a new protocol which does not require any change of existing USB peripherals. A wireless video transmission and a data transmission are successfully demonstrated using the proposed system.

    DOI

    Scopus

  • Design of Energy Efficient WDM transponder utilizing Adaptive Interface Control with Link-Aggregation of Ethernet Links

    Noboru Yoshikane, Itsuro Morita, Hideaki Tanaka

    2010 15TH OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)     780 - 781  2010年

     概要を見る

    Design of an energy efficient wavelength division multiplexing (WDM) transponder is proposed and demonstrated. The WDM transponder interworking with the link-aggregation (LAG) technique possessed by a layer 2 switch (L2SW) can achieve power saving depending on traffic variations by utilizing an adaptive interface control.

  • A hybrid IQ imbalance compensation method for optical OFDM transmission

    Amin, A.A., Jansen, S.L., Takahashi, H., Morita, I., Tanaka, H.

    Optics Express   18 ( 5 ) 4859 - 4866  2010年

     概要を見る

    Transmitter and receiver IQ imbalance causes image interference that degrades performance in high capacity and high spectral efficiency optical orthogonal frequency division multiplexing (OFDM) schemes. Digital compensation is an attractive method to relax component specifications. In this paper we report the details of a hybrid compensation method for IQ imbalance compensation, comprising of orthogonal training symbol-based method for transmitter-side compensation and an iterative image reduction-based method for receiver-side imbalance compensation. We demonstrate performance improvement using the hybrid method in presence of frequency dependent imbalance by both simulation and back-to-back direct detection optical OFDM experiment. We report on the tolerable limit of transmitter IQ imbalance under presence of carrier frequency offset. (C) 2010 Optical Society of America

    DOI

    Scopus

    20
    被引用数
    (Scopus)
  • Highly Spectrally Efficient DWDM Transmission at 7.0 b/s/Hz Using 8 × 65.1-Gb/s Coherent PDM-OFDM

    Takahashi, H., Al Amin, A., Morita, I., Tanaka, H., Jansen, S.L.

    Journal of Lightwave Technology   28 ( 4 ) 406 - 414  2010年

     概要を見る

    In this paper, we discuss the realization of wavelength-division multiplexing (WDM) transmission at high spectral efficiency. For this experiment, coherent polarization-division multiplexing--orthogonal frequency-division multiplexing (PDM-OFDM) is used as a modulation format. PDM-OFDM uses training symbols for channel estimation. This makes OFDM easily scalable to higher level modulation formats as channel estimation is realized with training symbols that are independent of the constellation size. Furthermore, because of its well-defined spectrum OFDM requires only a small guard band between WDM channels. The dependence of the number of OFDM subcarriers is investigated with respect to the interchannel linear crosstalk. At a constant data rate the number of OFDM subcarriers is estimated to achieve lower linear crosstalk in order to achieve higher spectral efficiency. We then experimentally demonstrate dense WDM (DWDM) transmission with 7.0-b/s/Hz net spectral efficiency using 8 x 65.1-Gb/s coherent PDM-OFDM signals with 8-GHz WDM channel spacing utilizing 32-quadrature-amplitude-modulation subcarrier modulation. Successful transmission is achieved over 240 km standard single-mode fiber (SSMF) spans with hybrid erbium-doped fiber amplifiers/Raman amplification.

    DOI

    Scopus

    55
    被引用数
    (Scopus)
  • 光OFDMを用いた長距離高速光伝送技術

    森田 逸郎, ヤンセン サンダー, 高橋 英憲, アルアミン アブドゥッラー, 田中 英明

    レーザー研究   37 ( 3 ) 182 - 187  2009年03月

     概要を見る

    Orthogonal frequency division multiplexing (OFDM) is an attractive modulation format that recently

    DOI CiNii

  • Effect of hybrid IQ imbalance compensation in 27.3-Gbit/s direct-detection OFDM transmission

    A. Al Amin, H. Takahashi, S. L. Jansen, I. Morita, H. Tanaka

    Conference on Optical Fiber Communication, Technical Digest Series    2009年

     概要を見る

    A hybrid compensation method for transmitter and receiver IQ imbalance in high capacity OFDM is investigated. Effectiveness is confirmed by simulation and a 16QAM 27.3-Gbit/s transmission experiment. After 320km SSMF, 3.5dB OSNR improvement is achieved. © 2009 OSA.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Effect of coherent crosstalk on optical OFDM transmission

    A. Al Amin, H. Takahashi, I. Morita, H. Tanaka

    2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009    2009年

     概要を見る

    We investigate the effect of reflection-generated coherent crosstalk on the performance of optical OFDM transmission. From simulation, allowable total crosstalk at a given OSNR was found to be independent of the number of subcarriers. Experimental comparison is provided, showing a similar crosstalk-generated variance for optical OFDM and NRZ-OOK format. ©2009 Optical Society of America.

    DOI

    Scopus

  • Polarization Multiplexed 100 Gbps Direct-Detection OFDM Transmission without MIMO Processing

    Abdullah Al Amin, Hidenori Takahashi, Itsuro Morita, Hideaki Tanaka

    2009 35TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)    2009年

     概要を見る

    We propose a low-overhead method of polarization multiplexing in direct detection OFDM that requires no digital MIMO processing. Using 16QAM and only 31GHz bandwidth, 100 Gbps transmission over 80 km of SSMF is successfully demonstrated.

  • Optical OFDM for High-Speed Transmission

    Itsuro Morita

    2009 14TH OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC 2009)     582 - 583  2009年

     概要を見る

    Optical orthogonal frequency division multiplexing for high-speed, long-haul optical transmission systems is reviewed. Some important aspects of the systems are discussed and demonstrations of high-speed transmission up to 122 Gbit/s are presented.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • DWDM Transmission with 7.0-bit/s/Hz Spectral Efficiency using 8x65.1-Gbit/s Coherent PDM-OFDM Signals

    Hidenori Takahashi, Abdullah Al Amin, Sander L. Jansen, Itsuro Morita, Hideaki Tanaka

    OFC: 2009 CONFERENCE ON OPTICAL FIBER COMMUNICATION, VOLS 1-5     3096 - 3098  2009年

     概要を見る

    Spectral efficient transmission of 8x65.1-Gbit/s PDM-OFDM is reported over 240 km. Using coherent detection and 32-QAM subcarrier modulation the channel spacing is reduced to 8 GHz, allowing a net spectral efficiency of 7.0 bit/s/Hz. (C) 2009 Optical Society of America

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • 160 Gb/s-based field transmission experiments using polarizer-based PMD compensator with optical power monitor

    Daikoku, M., Miyazaki, T., Morita, I., Hattori, T., Tanaka, H., Kubota, F., Suzuki, M.

    Journal of Lightwave Technology   27 ( 5 ) 451 - 461  2009年

     概要を見る

    Higher bit-rate transmission is attractive for improving network resource efficiency and reducing the complexity of network management in future transmission systems. However, chromatic dispersion and polarization mode dispersion (PMD) are one of the most serious impairments. In particular, PMD should be compensated for dynamically because it changes rapidly according to environmental variations such as temperature change and mechanical vibration. Therefore, an adaptive PMD compensator is indispensable for higher bit-rate transmission systems. In this paper, we employed a simple and bit-rate independent PMD compensator based on a polarizer with an optical power monitoring scheme in 160 Gb/s-based field experiments. By using the PMD compensator, the single channel transmission of a 160 Gb/s return-to-zero differential phase-shift-keying modulation signal over an installed fiber link with buried and aerial cable routes was successfully achieved. Approximately 1 dB of Q-factor was improved by using the PMD compensator when PMD impairment was maximized. Through these experiments, the effectiveness of the PMD compensator in the higher bit-rate transmission systems was confirmed in the field environment. Furthermore, single-polarization 8 x 160 Gb/s wavelength division multiplexing transmission over the installed 200 km standard single mode fiber without polarization demultiplexing was successfully achieved by using the simple PMD compensator.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • 132.2-Gb/s PDM-8QAM-OFDM transmission at 4-b/s/Hz spectral efficiency

    Jansen, S.L., Al Amin, A., Takahashi, H., Morita, I., Tanaka, H.

    IEEE Photonics Technology Letters   21 ( 12 ) 802 - 804  2009年

     概要を見る

    In this letter, we investigate 132.2-Gb/s polarization-division-multiplexed orthogonal frequency-division-multiplexing (PDM-OFDM) transmission at 25-GHz channel spacing. We show that the nonlinear tolerance is dependent on the OFDM symbol length. By using 14.4-ns-long OFDM symbols, 7 x 132.2-Gb/s transmission of PDM-OFDM at 4-b/s/Hz spectral efficiency is reported over 1300-km standard single-mode fiber.

    DOI

    Scopus

    52
    被引用数
    (Scopus)
  • 121.9-Gb/s PDM-OFDM transmission with 2-b/s/Hz spectral efficiency over 1000 km of SSMF

    Jansen, S.L., Morita, I., Schenk, T.C.W., Tanaka, H.

    Journal of Lightwave Technology   27 ( 3 ) 177 - 188  2009年

     概要を見る

    We discuss optical multi-band orthogonal frequency division multiplexing (OFDM) and show that by using multiple parallel OFDM bands, the required bandwidth of the digital-to-analogue/ analogue-to-digital converters and the required cyclic prefix can significantly be reduced. With the help of four OFDM hands and polarization division multiplexing (PDM) we report continuously detectable transmission of 10 x 121.9-Gb/s (112.6-Gb/s without OFDM overhead) at 50-GHz channel spacing over 1,000-km standard single mode fiber (SSMF) without any inline dispersion compensation. In this experiment 8 QAM subcarrier modulation is used which confines the spectrum of the 121.9 Gb/s PDM-OFDM signal within a 22.8 GHz optical bandwidth. Moreover, we propose a digital signal processing method to reduce the matching requirements for the wideband transmitter IQ mixer structures required for PDM-OFDM.

    DOI

    Scopus

    206
    被引用数
    (Scopus)
  • 100GbE: QPSK versus OFDM

    Jansen, S.L., Spinnler, B., Morita, I., Randel, S., Tanaka, H.

    Optical Fiber Technology   15 ( 5-6 ) 407 - 413  2009年

     概要を見る

    In this paper the optical performance and complexity of polarization division multiplexed quadrature phase shift keying (PDM-QPSK) is compared to that of PDM orthogonal frequency division multiplexing (PDM-OFDM). The benefits and drawbacks of each modulation format are discussed with respect to the implementation, complexity and transmission performance. (C) 2009 Elsevier Inc. All rights reserved.

    DOI

    Scopus

    50
    被引用数
    (Scopus)
  • Design tradeoffs in optical OFDM transmission systems

    Itsuro Morita, Sander Lars Jansen, Hideaki Tanaka

    Optics InfoBase Conference Papers    2008年

     概要を見る

    Optical orthogonal frequency division multiplexing for long-haul optical transmission systems is reviewed. We discuss some important aspects of the systems and present a demonstration of long-haul transmission at 122 Gb/s without dispersion compensation. © 2008 Optical Society of America.

    DOI

    Scopus

  • Transmission experiment using installed submarine cable for system upgrade with RZ-DPSK

    I. Morita, N. Takeda, N. Yoshikane, H. Tanaka

    European Conference on Optical Communication, ECOC    2008年

     概要を見る

    We have shown that a capacity of the transpacific system designed to support 8 × 2.5 Gbit/s can be increased to a factor of eight by using 16 × 10 Gbit/s RZ-DPSK in transmission experiments using a deployed submarine cable. © 2008 IEEE.

    DOI

    Scopus

  • The influence of the dispersion map in coherent optical OFDM transmission systems

    Kamyar Forozesh, Sander Lars Jansen, Sebastian Randel, Itsuro Morita, Hideaki Tanaka

    2008 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS     135 - +  2008年

     概要を見る

    The influence of the dispersion map is studied on the nonlinear tolerance of OFDM transmission systems. We show that the nonlinear tolerance is severely degraded when inline dispersion compensation is employed in the transmission line.

    DOI

    Scopus

    39
    被引用数
    (Scopus)
  • Optical OFDM, a hype or is it for real?

    Sander L. Jansen, Itsuro Morita, Kamyar Forozesh, Sebastian Randel, Dirk van den Borne, Hideaki Tanaka

    2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)    2008年

     概要を見る

    During the last two years, numerous researchers have dedicated their work in optical OFDM and, consequently, the number of papers has grown exponentially. In this paper we evaluate the suitability of OFDM for long-haul 100GbE applications.

    DOI

    Scopus

    60
    被引用数
    (Scopus)
  • Narrowband Filtering Tolerance and Spectral Efficiency of 100GbE PDM-OFDM

    Sander L. Jansen, Itsuro Morita, Hideaki Tanaka

    2008 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS     247 - 248  2008年

     概要を見る

    We show that the tolerance of 100GbE PDM-OFDM with respect to narrowband optical filtering is comparable to that of its single-carrier counterpart. This translates into a comparable spectral efficiency of OFDM and single-carrier modulated signals.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • PMD Mitigation by Polarization Filtering for High-Speed Optical Transmission Systems

    Masatoshi Suzuki, Masahiro Daikoku, Michiaki Hayashi, Itsuro Morita, Hideaki Tanaka

    2008 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS     149 - 150  2008年

     概要を見る

    The automatic PMD compensator using polarization filtering with a polarizer was evaluated in 40Gbit/s and 160Gbit/s WDM transmission over installed fiber cables. The performance and long-term stability were enhanced with the simple PMD mitigation scheme.

    DOI

    Scopus

  • Comparison between Single-band and Multi-band Optical OFDM at 120-Gb/s

    Hidenori Takahashi, Sander L. Jansen, Abdullah A. Amin, Itsuro Morita, Hideaki Tanaka

    2008 7TH INTERNATIONAL CONFERENCE ON THE OPTICAL INTERNET (COIN)     61 - 62  2008年

     概要を見る

    We discuss the use of multi-band OFDM for 120-Gb/s polarization division multiplexed orthogonal frequency division multiplexing (PDM-OFDM). Compared to single-band OFDM we show that a significant reduction in required DAC/ADC bandwidth is obtained at comparable computational complexity.

  • 8x66.8-Gbit/s Coherent PDM-OFDM Transmission over 640 km of SSMF at 5.6-bit/s/Hz Spectral Efficiency

    Hidenori Takahashi, Abdullah Al Amin, Sander L. Jansen, Itsuro Morita, Hideaki Tanaka

    2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)    2008年

     概要を見る

    8x66.8-Gbit/s DWDM transmission is demonstrated over 640-km SSMF with 9-GHz channel spacing. Employing coherent detected polarization-division-multiplexing OFDM with 16-QAM subcarrier modulation, a record spectral efficiency of 5.6 bit/s/Hz is achieved.

    DOI

    Scopus

    27
    被引用数
    (Scopus)
  • Coherent optical 25.8-Gb/s OFDM transmission over 4160-km SSMF

    Jansen, S.L., Morita, I., Schenk, T.C.W., Takeda, N., Tanaka, H.

    Journal of Lightwave Technology   26 ( 1 ) 6 - 15  2008年

     概要を見る

    We discuss coherent optical orthogonal frequency division multiplexing (CO-OFDM) as a suitable modulation technique for long-haul transmission systems. Several design and implementation aspects of a CO-OFDM system are reviewed, but we especially focus on phase noise compensation. As conventional CO-OFDM transmission systems are very sensitive to laser phase noise a novel method to compensate for phase noise is introduced. With the help of this phase noise compensation method we show continuously detectable OFDM transmission at 25.8 Gb/s data rate (20 Gb/s after coding) over 4160-km SSMF without dispersion compensation.

    DOI

    Scopus

    406
    被引用数
    (Scopus)
  • Long-haul transmission of 16×52.5 Gbits/s polarization-division- multiplexed OFDM enabled by MIMO processing (Invited)

    Jansen, S.L., Morita, I., Schenk, T.C.W., Tanaka, H.

    Journal of Optical Networking   7 ( 2 ) 173 - 182  2008年

     概要を見る

    We discuss the realization and performance of polarization-division-multiplexed orthogonal frequency division multiplexing (PDM-OFDM) for long-haul transmission systems. Polarization demultiplexing of the PDM signal at the receiver is realized by employing a multiple-input multiple-output (MIMO) detector. Using a recirculating loop a long-haul transmission experiment is reported of 52.5 Gbits/s PDM-OFDM (40 Gbits/s after coding) over 4160 km of standard single-mode fiber (SSMF). In this transmission experiment, 16 wavelength-division-multiplexed (WDM) channels are transmitted at 50 GHz channel spacing, and we show that MIMO processing in the receiver enables both polarization demultiplexing and a large PMD tolerance. (c) 2008 Optical Society of America.

    DOI

    Scopus

    231
    被引用数
    (Scopus)
  • 100-Gb/s DQPSK transmission experiment without OTDM for 100G ethernet transport

    Masahiro Daikoku, Itsuro Morita, Hidenori Taga, Hideaki Tanaka, Tetsuya Kawanishi, Takahide Sakamoto, Tetsuya Miyazaki, Takahisa Fujita

    JOURNAL OF LIGHTWAVE TECHNOLOGY   25 ( 1 ) 139 - 145  2007年01月

     概要を見る

    In order to realize a future 100-Gb Ethernet (100 GbE) transport, 100-Gb/s transmission without 100-GHz-class electronics and optical time-division-multiplexing technique was demonstrated. By using a differential quadrature phase-shift-keying (DQPSK) modulation format and commercially available electronics, 2- and 50-km transmissions of 100-Gb/s signal were successfully achieved over a standard single mode fiber. The receiver sensitivity, chromatic dispersion, and differential group delay tolerances of 100-Gb/s DQPSK signal were also evaluated. Through these evaluations, the possibility of DQPSK modulation for future 100-GbE transport is verified.

    DOI

    Scopus

    58
    被引用数
    (Scopus)
  • Experimental study of XPM in 10-Gb/s NRZ precompensated transmission systems

    S. L. Jansen, I. Morita, D. Van Den Borne, G. D. Khoe, H. De Waardt, P. M. Krummrich

    Optics InfoBase Conference Papers    2007年

     概要を見る

    We experimentally assess the nonlinear tolerance of 10-Gb/s NRZ in a precompensated dispersion map. It is observed that even for relatively wide 100-GHz channelspacing, XPM further reduces the nonlinear tolerance in contrast to periodically-compensated maps. © 2006 Optical Society of America.

  • 20-Gb/s OFDM transmission over 4,160-km SSMF enabled by RF-pilot tone phase noise compensation

    S. L. Jansen, I. Morita, N. Takeda, H. Tanaka

    Optics InfoBase Conference Papers    2007年

     概要を見る

    We introduce a novel method to compensate for local oscillator offset and phase-noise in coherent-OFDM systems and report continuously detectable transmission at 20-Gb/s data rate (25.8 Gb/s before coding) over 4,160-km SSMF without dispersion compensation. © 2007 Optical Society of America.

  • 10-Gb/s OFDM with conventional DFB lasers

    Sander L. Jansen, Itsuro Morita, Hideaki Tanaka

    2007 33rd European Conference and Exhibition of Optical Communication, ECOC 2007    2007年

     概要を見る

    We show that using RF-pilot tone phase noise compensation optical coherent 10-Gb/s OFDM (12.5 Gb/s before coding) can be realized with conventional DFB lasers.

    DOI

    Scopus

    13
    被引用数
    (Scopus)
  • High speed transmission technologies for 100-Gbit/s-class ethernet

    Itsuro Morita, Sander L. Jansen

    2007 33rd European Conference and Exhibition of Optical Communication, ECOC 2007    2007年

     概要を見る

    This paper gives an overview of recent 100-Gbitls transmission experiments and reviews enabling technologies for the realization of single-channel 100 Gbit/s Ethernet.

  • Advanced modulation format for 100-Gbit/s transmission

    Itsuro Morita

    2007 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS     252 - 253  2007年

     概要を見る

    This paper discusses advanced modulation formats for the realization of single-channel 100-Gbit/s transmission in optical fiber communication systems.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • 100-Gb/s DQPSK transmission experiment without OTDM for 100G ethernet transport

    Daikoku, M., Morita, I., Taga, H., Tanaka, H., Kawanishi, T., Sakamoto, T., Miyazaki, T., Fujita, T.

    Journal of Lightwave Technology   25 ( 1 ) 2744 - +  2007年

     概要を見る

    We demonstrate 100Gbit/s DQPSK transmission experiment over 50km SMF. Without resorting OTDM, 100Gbit/s transmission was enabled with DQPSK format and commercially available electronics. Possibility of DQPSK modulation for future 100G Ethernet transport is verified. (C) 2006 Optical Society of America.

    DOI

    Scopus

    58
    被引用数
    (Scopus)
  • Performance comparison of modulation formats for 40 gbit/s dwdm transmission systems

    Masahiro Daikoku, Noboru Yoshikane, Itsuro Morita

    Optics InfoBase Conference Papers    2006年

     概要を見る

    The performance of various modulation formats, namely OOK, DPSK and DQPSK with and without RZ carving, were experimentally compared to clarify the optimum modulation formats for 40 Gbit/s DWDM transmission systems with 50 GHz channel spacing. © 2004 Optical Society of America.

  • Study of 40 Gbit/s modulation format to upgrade 10 Gbit/s long-haul transmission systems with 50 GHz channel spacing

    Masahiro Daikoku, Itsuro Morita, Hideaki Tanaka

    2006 European Conference on Optical Communications Proceedings, ECOC 2006    2006年

     概要を見る

    The optimum 42.7 Gbit/s modulation format to upgrade 10.7 Gbit/s transmission systems with 50 GHz channel spacing was studied. RZ-DQPSK was more suitable than duobinary, since 1600 km transmission was achievable with a wider tolerance to PMD.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • 100Gbit/s DQPSK transmission experiment without OTDM for 100G Ethernet transport

    Masahiro Daikoku, Itsuro Morita, Hidenori Taga, Hideaki Tanaka, Tetsuya Kawanishi, Takahide Sakamoto, Tetsuya Miyazaki, Takahisa Fujita

    2006 Optical Fiber Communication Conference, and the 2006 National Fiber Optic Engineers Conference   2006  2006年

     概要を見る

    We demonstrate 100Gbit/s DQPSK transmission experiment over 50km SMF. Without resorting OTDM, 100Gbit/s transmission was enabled with DQPSK format and commercially available electronics. Possibility of DQPSK modulation for future 100G Ethernet transport is verified. © 2006 Optical Society of America.

  • 8 × 160-Gb/s WDM field transmission experiment with single-polarization RZ-DPSK signals and PMD compensator

    Daikoku, M., Miyazaki, T., Morita, I., Tanaka, H., Kubota, F., Suzuki, M.

    IEEE Photonics Technology Letters   18 ( 2 ) 391 - 393  2006年

     概要を見る

    Single-polarization 160-Gb/s-based wavelength-division-multiplexing (WDM) field transmission has been successfully demonstrated. By using a return-to-zero differential phase-shiftkeying modulation format and a simple polarization-mode dispersion compensator, we have successfully demonstrated single-polarization 8 × 160 Gb/s WDM transmission without the polarization demultiplexing. © 2005 IEEE.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • 160 Gbit/s-based field transmission experiments with singlepolarization RZ-DPSK signals and simple PMD compensator

    Masahiro Daikoku, Tetsuya Miyazaki, Itsuro Morita, Hideaki Tanaka, Fumito Kubota, Masatoshi Suzuki

    IET Conference Publications   2005 ( CP502 ) 375 - 378  2005年

     概要を見る

    Single-polarization 160 Gbit/s-based field transmission experiments have been successfully conducted. By utilizing 160 Gbit/s RZ-DPSK signals and a simple PMD compensator, single-channel transmission and 8 WDM transmission with 300 GHz channel spacing have been achieved over the inter-city 200 km SMF.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Merits of DQPSK for ultrahigh capacity transmission

    Itsuro Morita, Noboru Yoshikane

    Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS   2005   487 - 488  2005年

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Optimization of WDM (N × 40 Gbit/s) transmission in strong symmetric dispersion maps

    Shapiro, E.G., Fedoruk, M.P., Mezentsev, V., Turitsyn, S.K., Shafarenko, A., Tanaka, K., Morita, I., Edagawa, N., Suzuki, M.

    Journal of Optical Communications   26 ( 1 ) 32 - 36  2005年

     概要を見る

    We have performed numerical and experimental optimization of dispersion-managed Wavelength Division Multiplexed (WDM) Return-to-Zero (RZ) transmission without in-line control at 40 Gbit/s per channel in symmetric dispersion maps using effective area enlarged positive dispersion fiber and reverse dispersion fiber. Our results show the feasibility of transmission over 2800 km without Forward Error Correction (FEC) and over 4500 km with 8 % FEC overhead. The results of numerical modeling are in good agreement with experimental data. © by Fachverlag Schiele & Schön 2005.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • 1.14 b/s/Hz spectrally efficient 50 × 85.4-Gb/s transmission over 300 km using copolarized RZ-DQPSK signals

    Yoshikane, N., Morita, I.

    Journal of Lightwave Technology   23 ( 1 ) 108 - 114  2005年

     概要を見る

    1.14 b/s/Hz spectrally efficient 50 × 85.4-Gb/s copolarized return-to-zero differential quarternary phase-shift keying (RZ-DQPSK) signals have been transmitted over 300 km of nonzero dispersion-shifted fiber (NZ-DSF), using optical prefiltering and conventional C-band erbium-doped fiber amplifier (EDFA) repeaters. In this study, in order to enhance the spectral efficiency, the impact of optical prefiltering on the RZ-DQPSK signal was experimentally investigated in comparison to the DQPSK signal, and we found that the RZ-DQPSK signal had better sensitivity with almost the same nonlinear tolerance than the DQPSK signal even with 65-GHz bandwidth optical prefiltering. © 2005 IEEE.

    DOI

    Scopus

    41
    被引用数
    (Scopus)
  • 1.14 b/s/Hz spectrally-efficient 50 × 85.4 Gb/s transmission over 300 km using copolarized CS-RZ DQPSK signals

    Noboru Yoshikane, Itsuro Morita

    OSA Trends in Optics and Photonics Series   95 B   754 - 756  2004年

     概要を見る

    1.14 b/s/Hz spectrally-efficient 50 × 85.4 Gb/s transmission over 300 km (75 km × 4 spans) of NZ-DSF has been successfully demonstrated with copolarized CS-RZ DQPSK signals. 42.7 Gsymbol/s-based 4 Tb/s DQPSK transmission has been achieved for the first time without polarization multiplexing. © 2004 Optical Society of America.

  • High spectral efficiency for large-capacity optical communication systems

    Masatoshi Suzuki, Itsuro Morita

    Proceedings of 2004 6th International Conference on Transparent Optical Networks   1   171 - 176  2004年

     概要を見る

    High spectral efficiency is the key to achieve ultra DWDM transmission with a finite bandwidth. This paper reviews highly spectral efficient transmission experiments using bandlimited signals for terrestrial systems and ultra long-haul systems.

  • Optically filtered modulation formats and their transmission performance

    Itsuro Morita, Noboru Yoshikane

    2004 IEEE/LEOS - Workshop on Advanced Modulation Formats     33 - 34  2004年

     概要を見る

    High spectral efficiency is a key to cost-effective capacity expansion in WDM systems. This paper discusses the characteristics of optically filtered CS-RZ OOK and DPSK signals for higher spectral efficiency. © 2004 IEEE.

  • Study on optimum pre-filtering condition for 42.7 Gbit/s CS-RZ DPSK signal

    Keiji Tanaka, Itsuro Morita, Noboru Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   1   410 - 412  2004年

     概要を見る

    The impact of asymmetric pre-filtering for 42.7Gbit/s CS-RZ DPSK signals were investigated experimentally and numerically, including 9000km WDM transmission experiments. We have found that asymmetric pre-filtering is effective for quasi-linear system applications. © 2003 Optical Society of America.

  • Ultra-long-haul 40-Gbit/s-based DWDM transmission using optically prefiltered CS-RZ signals

    Tsuritani, T., Agata, A., Morita, I., Edagawa, N., Akiba, S.

    IEEE Journal on Selected Topics in Quantum Electronics   10 ( 2 ) 403 - 411  2004年

     概要を見る

    Ultra-long-haul 42.7-Gbit/s-based dense wavelength-division multiplexing (DWDM) transmission using optically prefiltered carrier-suppressed return-to-zero (CS-RZ) signal has been experimentally investigated. First, we have numerically and experimentally evaluated the impact of 3-dB bandwidth and filter detuning of bandlimiting filters on the 42.7-Gbit/s CS-RZ signal in back-to-back condition. We found that the asymmetrically filtered CS-RZ signal had a great potential for ultra-DWDM applications. Next, we have numerically and experimentally investigated the basic transmission characteristics of a 45-GHz-wide prefiltered CS-RZ signal, such as the robustness against residual dispersion, nonlinear effects, and PMD, and have confirmed that the prefiltered CS-RZ signal had less tolerance against fiber nonlinearity than an unfiltered CS-RZ signal. Finally, we have experimentally investigated the optimum filtering condition for 65- or 45-GHz-wide prefiltered CS-RZ signals in the ultra-long-haul DWDM transmission and have conducted the 70- and 50-GHz spaced 32 × 42.7 Gbit/s transmission using prefiltered CS-RZ signals. Through these experiments, we have confirmed the effectiveness of prefiltered CS-RZ signal ultra-long-haul DWDM transmission.

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • Benefit of SPM-based all-optical reshaper in receiver for long-haul DWDM transmission systems

    Yoshikane, N., Morita, I., Tsuritani, T., Agata, A., Edagawa, N., Akiba, S.

    IEEE Journal on Selected Topics in Quantum Electronics   10 ( 2 ) 412 - 420  2004年

     概要を見る

    The effectiveness of a self-phase modulation (SPM)-based all-optical reshaper with optically time-division-demultiplexing receiver was experimentally investigated using 42.7-Gb/s carrier-suppressed return-to-zero (CS-RZ) signals. We have confirmed that this scheme is quite effective to suppress the waveform degradation due to optical signal bandlimitation. We have demonstrated 80% spectral efficiency without using polarization demultiplexing by using the all-optical reshaper. We have also demonstrated 50-GHz-spaced 55 × 42.7 Gb/s signals transmission over 2500 km, using an optically bandlimited CS-RZ signal and the SPM-based all-optical reshaper in receiver without using polarization demultiplexing. A Q-factor improvement of about 1.5 dB was obtained by using the all-optical reshaper.

    DOI

    Scopus

    26
    被引用数
    (Scopus)
  • 70-GHz-Spaced 40 × 42.7 Gb/s Transpacific Transmission Over 9400 km Using Prefiltered CSRZ-DPSK Signals, All-Raman Repeaters, and Symmetrically Dispersion-Managed Fiber Spans

    Tsuritani, T., Ishida, K., Agata, A., Shimomura, K., Morita, I., Tokura, T., Taga, H., Mizuochi, T., Edagawa, N., Akiba, S.

    Journal of Lightwave Technology   22 ( 1 ) 215 - 224  2004年

     概要を見る

    70-GHz-spaced 40 × 42.7 Gb/s prefiltered carrier-suppressed return-to-zero differential phase-shift keying (CSRZ-DPSK) signals have been transmitted over transpacific distances for the first time, using all-Raman repeaters with two pump-wavelengths, dispersion-managed fiber commercially available in volume, and an ETDM receiver. In this paper, first, in order to enhance the spectral efficiency, the impact of bandlimitation to a CSRZ-DPSK signal was experimentally investigated in comparison to a conventional CSRZ-on-off-keying (OOK) signal, and we found that the bandlimitation tolerance of CSRZ-DPSK signal was smaller than that of CSRZ-OOK signal in back-to-back condition. We also confirmed that the prefiltering CSRZ-DPSK signal with up to 65 GHz bandlimitation potentially had better transmission performance than the prefiltered CSRZ-OOK signal. In addition, we found that, although the nonlinear transmission penalty was increased by bandlimitation, this penalty for CSRZ-DPSK signal was smaller than that for CSRZ-OOK signal. Through this study, long-term stability of the transmission performance was also evaluated with low-speed signal polarization scrambling without using any polarization mode dispersion (PMD) compensation.

    DOI

    Scopus

    40
    被引用数
    (Scopus)
  • Study on capacity upgrade of JIH (Japan information highway) submarine cable system using 40 Gbit/s-based WDM transmission technologies

    Tanaka, K., Morita, I., Yoshikane, N., Edagawa, N.

    IEICE Transactions on Communications   E87-B ( 6 ) 1463 - 1469  2004年

     概要を見る

    We numerically and experimentally investigated the upgradability of the longest and the typical segments of the JIH system. Through these studies, we confirmed that a 100 GHz-spaced 25×42.7 Gbit/s transmission with the total capacity of 1 Tbit/s can be attainable even by using NRZ signal and standard FEC for the typical segments. We also found that RZ signal format was desirable for the longest segment and a further wide system margin could be expected by using adjacent channel polarization control and advanced FEC technologies.

  • Study on Optimum Optical Pre-Filtering Condition for Highly Spectral-Efficient Ultralong-Haul Transmission Using 40Gbit/s CS-RZ Signal and All-Raman Repeaters

    T. Tsuritani, I. Morita, A. Agata, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   86   660 - 662  2003年

     概要を見る

    We have studied the transmission characteristics of optically pre-filtered 32× 42.7Gbit/s CS-RZ signals in 57% and 80% spectral-efficient all-Raman repeatered transmission over > 4000km under various pre-filtering conditions. We found that the advantage of asymmetrical pre-filtering reduced with transmission distance.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Performance Evaluation of Spectral Crosstalk Suppressor Based on Optical Gating of Dispersed Pulse

    I. Morita, T. Tsuritani, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   86   748 - 750  2003年

    DOI

    Scopus

  • A Study on Gain Modulation Dynamics of 80nm-Band High-Power Raman Amplifier

    K. Imai, I. Morita, H. Sakata, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   86   158 - 159  2003年

     概要を見る

    We have studied the gain modulation characteristics of 80nm-band high-power backward-pumped Raman amplifier. We found that flat gain modulation response was obtained over the entire signal bandwidth by intensity-modulating the longest-wavelength pump light source at a frequency higher than 10kHz.

  • Characteristics of Asymmetrically Filtered 40Gblt/s CS-RZ Signals

    A. Agata, I. Morita, T. Tsuritani, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   86   97 - 98  2003年

     概要を見る

    We have numerically and experimentally studied the benefit of asymmetrically filtered 40Gbit/s CS-RZ signals, We also evaluated their tolerance to chromatic dispersion, fiber nonlinearity and polarization mode dispersion in comparison with symmetrically filtered and unfiltered CS-RZ signals.

  • 70GHz-spaced 40 × 42.7Gbit/s transmission over 8700km using CS-RZ DPSK signal, all-Raman repeaters and symmetrically dispersion-managed fiber span

    T. Tsuritani, K. Ishida, A. Agata, K. Shimomura, I. Morita, T. Tokura, H. Taga, T. Mizuochi, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   86   869 - 871  2003年

     概要を見る

    70GHz-spaced 40×42.7Gbit/s pre-filtered CS-RZ DPSK signals have been successfully transmitted over 8700km for the first time, using all-Raman repeaters, "ABA" dispersion map and an ETDM receiver. Long-term stability was also confirmed with low-speed polarization scrambling and without using PMD compensation. © 2003 Optical Society of America.

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Recent advances in 40 Gbit/s-based transoceanic transmission

    Itsuro Morita

    Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS   1   318 - 319  2003年

     概要を見る

    40 Gbit/s-based transoceanic transmission was achieved by introducing various kinds of technologies to suppress the nonlinear effects in the transmission fiber, including fiber dispersion management, distributed Raman amplified, modified modulation format and powerful FEC codes. The possibility of enhancing the practicality and commercial viability of 40 Gbit/s-based transoceanic systems further was emphasized.

  • Improvement of dispersion tolerance by SPM-based all-optical reshaping in receiver

    Yoshikane, N., Morita, I., Edagawa, N.

    IEEE Photonics Technology Letters   15 ( 1 ) 111 - 113  2003年

     概要を見る

    Dispersion tolerance improvement through self-phase modulation-based all-optical reshaping in receiver was experimentally investigated using 10-Gb/s return-to-zero signal. We have confirmed that this scheme is quite effective to restore the optical signal deformed due to chromatic dispersion.

    DOI

    Scopus

    28
    被引用数
    (Scopus)
  • 40 Gbit/s × 25WDM 306km unrepeatered transmission using 175 μm2-Aeff fibre

    Tanaka, K., Sakata, H., Miyakawa, T., Morita, I., Imai, K., Edagawa, N.

    IEE Proceedings: Optoelectronics   150 ( 3 ) 224 - 228  2003年

     概要を見る

    The authors have successfully demonstrated 40 Gbit/s-based terabit-capacity unrepeatered transmission over 306 km. They transmitted 100 GHz-spaced 25 × 40 Gbit/s RZ signals with Q-factors all better than 15.6 dB using a hybrid transmission line configuration of 175 μm2-Aeff (effective core area) fibres and NZ-DSF and using a remote EDFA that requires no dedicated pump light transmission fibre. The attained transmission distance was over 306 km for 40 Gbit/s-based unrepeatered transmission.

    DOI

    Scopus

  • Pattern-dependent bit error characteristics induced by asymmetrically filtering of CS-RZ signal

    Agata, A., Tsuritani, T., Morita, I., Edagawa, N.

    Electronics Letters   39 ( 14 ) 1080 - 1081  2003年

     概要を見る

    The pattern dependency in bit error characteristics of asymmetrically filtered CS-RZ signals has been experimentally and numerically studied. It was found that the bit error intensively occurs just after the end of a long sequence of 1s or 0s for strong asymmetrical filtering.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Study on the optimum signal format for long-haul 40 Gbit/s-based WDM systems

    Keiji Tanaka, Itsuro Morita, Akira Agata, Takehiro Tsuritani, Noboru Edagawa

    Proceedings of SPIE - The International Society for Optical Engineering   4872   40 - 48  2002年

     概要を見る

    The optimum signal format and forward error correction (FEC) code rate for 40 Gbit/s-based WDM signals was investigated. The impact of optical filtering for 40 Gbits/s signals was studied. Results showed that the symmetrically filtered signals had more tolerance for dispersion compensation for fiber nonlinearity.

    DOI

    Scopus

  • Study on optimum OTDM signals for long-distance 40 Gbit/s transmission

    Itsuro Morita, Noboru Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   70   5 - 6  2002年

     概要を見る

    The impact of the inter-pulse relative optical phase in optical time division multiplexing (OTDM) signals on long-distance 40 Gbit/s transmission performance was investigated. The transmission performance between OTDM and conventional 40 Gbit/s carrier-suppressed (CS)-RZ signals was compared. It was found that the OTDM CS-RZ signals had superb large tolerance in pulse generation process.

  • Benefit of SPM-based all-optical reshaper for DWDM system using OTDM receiver

    Nobom Yoshikane, Itsuro Morita, Noboru Edagawa

    European Conference on Optical Communication, ECOC   3  2002年

     概要を見る

    Bit error rate performance improvement using an SPM-based all-optical reshaper with OTDM receiver was demonstrated. We have achieved 80% spectral efficiency without using polarisation demultiplexing at the receiver for 42.7 Gb/s-based DWDM CS-RZ signals.

  • 100 % spectral-efficient 25 × 42.7 Gbit/s transmission using asymmetrically filtered CS-RZ signal and a novel crosstalk suppressor

    I. Morita, T. Tsuritani, N. Yoshikane, A. Agata, K. Imai, N. Edagawa

    European Conference on Optical Communication, ECOC   5  2002年

     概要を見る

    40 GHz-spaced 25 × 42.7Gbit/s transmission was successfully conducted over 320km by using EDFA repeaters, asymmetrically filtered CS-RZ signal, an OTDM receiver and a novel spectral crosstalk suppressor based on the optical gating of dispersively stretched signal.

  • SPM-based all-optical reshaping for 10 Gbit/s RZ signals bandlimited by optical filtering

    Yoshikane, N., Morita, I., Edagawa, N.

    Electronics Letters   38 ( 24 ) 1570 - 1572  2002年

     概要を見る

    Bit error rate performance improvement by using self-phase modulation-based all-optical reshaping in a receiver was experimentally investigated using 10 Gbit/s return-to-zero (RZ) signals. We have confirmed this scheme quite effective in restoring the degraded pulse shape due to optical bandlimitation.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • 40 Gbit/s × 25 WDM unrepeatered transmission over 362 km

    Miyakawa, T., Morita, I., Edagawa, N.

    Electronics Letters   38 ( 14 ) 726 - 727  2002年

     概要を見る

    40 Gbit/s-based unrepeatered wavelength division multiplexed transmission over 362 km has been demonstrated for the first time. The obtained bit error rate was better than 1 × 10-9 for all 25 channels despite the highly dispersive transmission line (∼8000 ps/nm).

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Experimental study on optically band-limited 40-Gb/s RZ signals with optically time-division demultiplexing receiver

    Morita, I., Tsuritani, T., Edagawa, N.

    Journal of Lightwave Technology   20 ( 12 ) 2182 - 2188  2002年

     概要を見る

    The impact of optical filtering on 40-Gb/s return-to-zero (RZ) signals was experimentally investigated with an optically time-division multiplexing (OTDM) receiver. Through the evaluation of the signal performance by changing the interpulse-phase conditions of the symmetrically band-limited 40-Gb/s signals, we have confirmed that the similar performance was obtained regardless of the interpulse-phase condition, owing to the pulse-reshaping capability of an OTDM receiver. The performance comparison was also conducted between the symmetrically and asymmetrically filtered 40-Gb/s RZ signals. It was found that the symmetrically filtered signal was more tolerant for the dispersion-compensation error, while the asymmetrically filtered signal was more tolerant for the fiber nonlinearity with optical filters that have a 3-dB bandwidth of 45 GHz.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Impact of fibre span configuration on Raman gain shape in dispersion-flattened transmission systems

    Yazaki, T., Morita, I., Sakata, H., Miyakawa, T., Edagawa, N.

    Electronics Letters   38 ( 23 ) 1420 - 1422  2002年

     概要を見る

    The Raman gain shape of several types of dispersion-flattened fibre span was evaluated under different operating conditions in backward pumping. It was found that the overall gain shape depends on the fibre span configuration. It was also found that the Raman gain shape has little dependence on the operating conditions in the fibre span configurations.

    DOI

    Scopus

  • Long distance 40 Gbit/s-based WDM transmission using dispersion-flattened low-nonlinear fiber span

    Morita, I., Tanaka, K., Edagawa, N., Suzuki, M.

    IEICE Transactions on Communications   E85-B ( 2 ) 478 - 483  2002年

     概要を見る

    The effectiveness of Aeff enlarged positive dispersion fiber (EE-PDF) and hybrid amplification configuration with erbium-doped fiber amplifier (EDFA) and fiber Raman amplifier for reducing the fiber nonlinearity and improving the transmission performance in long distance 40 Gbit/s-based WDM transmission was investigated. We have confirmed that the use of EE-PDF in modified dispersion map for 40 Gbit/s transmission is quite effective to increase the transmissible distance and have successfully demonstrated 16 × 40 Gbit/s WDM transmission over 2000 km with proper dispersion management. We have also confirmed that the use of distributed Raman amplification is quite effective to extend the repeated spacing. By adding the optimum Raman amplification, almost the same transmission performance was obtained with a doubled repeater spacing in long distance 40 Gbit/s-based WDM transmission.

  • 21.4 Gbit/s X 56 WDM 9170 KM transmission using symmetrically dispersion-managed fibre span

    T. Tsuritani, A. Agata, I. Morita, N. Edagawa

    European Conference on Optical Communication, ECOC   6   12 - 13  2001年

     概要を見る

    The transmission of 20 Gbit/s-based terabit wavelength division multiplexing (WDM) signals over 9170 km was demonstrated. A 23-nm bandwidth C-band erbium doped fiber amplifier (EDFA) and symmetrically dispersion-managed fibre span were used for the purpose. The use of enhanced forward error correction (FEC) with 7% redundancy resulted in the enhancement of the FEC gain for the transpacific transmission.

  • Benefit of Raman amplification in ultra-long-distance 40 Gbit/s-based WDM transmission

    I. Morita, K. Tanaka, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   54 ( 2 )  2001年

     概要を見る

    Optimum configuration for hybrid Raman/EDFA amplification in ultra-long-distance 40 Gbit/s WDM transmission was investigated. By optimizing the Raman gain, 16 × 40 Gbit/s WDM transmission over 2000 km was achieved with 80 km amplifier spacing.

  • Performance comparison between DSB and VSB signals in 20Gbit/s-based ultra-long-haul WDM systems

    T. Tsuritani, A. Agata, I. Morita, K. Tanaka, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   54 ( 1 )  2001年

     概要を見る

    Transmission performance of DSB and VSB signals was compared for the first time in 20Gbit/s-based ultra-long-haul WDM transmission systems. Impact of channel spacing, repeater output power variation and terminal dispersion compensation error was investigated.

  • 2.56Tbit/s (40Gbit/s × 64WDM) unrepeatered 230km transmission with 0.8bit/s/Hz spectral efficiency using low-noise fiber Raman amplifier and 170μm2-Aeff fiber

    T. Miyakawa, I. Morita, K. Tanaka, H. Sakata, N. Edagawa

    Conference on Optical Fiber Communication, Technical Digest Series   54 ( 4 )  2001年

     概要を見る

    We have demonstrated 50GHz-spaced 40Gbit/s × 64WDM unrepeated transmission over 230km using a low-noise Raman amplifier, 170μm2-Aeff fiber and bandlimited RZ signals without polarization-demultiplexing at the receiver. 2.56Tbit/s capacity was transmitted with only 25.8nm bandwidth.

  • Ultra long-haul transmission with multi-terabit capacity

    T. Tsuritani, I. Morita, N. Edagawa

    Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS   1   151 - 152  2001年

     概要を見る

    The possible key technologies for the ultra long-haul multi-terabit transmission systems were studied. The effectiveness of VSB-RZ transmission for high spectral efficiency and the need for further nonlinearity suppression in the transmission line for 40Gbit/s based WDM system applications was shown. The reconstruction of the suppressed sideband was found to be very small, thus the overall signal spectrum was kept narrow after 4260 km transmission. The Q-factor after 1935 km and 4260 km transmission was found to be 15.7dB and 12.6dB.

  • Study on PMD and dispersion tolerance of 20 Gbit/s VSB-RZ optical signal

    Takehiro Tsuritani, Itsuro Morita, Noboru Edagawa

    Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest   2  2001年

     概要を見る

    The study of polarization mode dispersion (PMD) and dispersion tolerance of 20 Gbit/s vestigial-sideband (VSB)-RZ optical signal was presented. The performance degradation of 20 Gbit/s double-sideband (DSB)-RZ and VSB-RZ signals were compared against PMD/PDL and dispersion compensation error. Results showed that the VSB-RZ signal had similar tolerance for first-order PMD with better tolerance for dispersion.

  • 21.4 Gbit/s × 56 WDM 9170 km transmission using symmetrically dispersion-managed fibre span

    Tsuritani, T., Agata, A., Morita, I., Edagawa, N.

    Electronics Letters   37 ( 25 ) 1536 - 1538  2001年

     概要を見る

    The transmission of 20 Gbit/s-based terabit wavelength division multiplexing (WDM) signals over transpacific distances was reported. The transmission was done using a 23 nm-bandwidth C-band erbium-doped fibre amplifiers (EDFA) and symmetrically dispersion-managed fibre span. The average Q-factor and averaged optical signal-to-noise ratio (OSNR) of all channels against transmission distance was presented. Results showed that both Q-factor and OSNR degrade almost linearly with transmission distance in the 6500 to 9200 km range.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • 50 GHz spaced 40 Gbit/s×25WDM transmission over 480 km using bandlimited RZ signals

    Tanaka, K., Morita, I., Edagawa, N.

    Electronics Letters   37 ( 12 ) 775 - 777  2001年

     概要を見る

    50 GHz spaced 40 Gbit/s×25WDM transmission over 480 km has been successfully demonstrated using bandlimited RZ signals and an SMF-based dispersion-flattened transmission line. What the authors believe is the longest distance transmission for a spectral efficiency of 0.8 bit/s/Hz was achieved without using polarisation demultiplexing.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Benefit of Raman amplification in ultra-long-distance 40 Gbit/s-based WDM transmission using dispersion-flattened fibre span

    Morita, I., Tanaka, K., Edagawa, N.

    Electronics Letters   37 ( 8 ) 507 - 509  2001年

     概要を見る

    The optimum configuration for hybrid Raman/EDFA amplification in ultra-long-distance 40Gbit/s WDM transmission using a dispersion-flattened fibre span is investigated. By optimising the Raman gain, 16 × 40Gbit/s WDM transmission over 2000km was achieved with 80km repeater spacing.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • 40 Gbit/s × 25 WDM 306 km unrepeatered transmission using 175 μm2-Aeff fibre

    Tanaka, K., Sakata, H., Miyakawa, T., Morita, I., Imai, K., Edagawa, N.

    Electronics Letters   37 ( 22 ) 62 - 63  2001年

     概要を見る

    The unrepeatered transmission of 40 Gbit/s-based teracapacity 306 km wavelength division multiplexed (WDM) signals using 175 μm2-Aeff fibre was demonstrated. The system used remote-erbium doped fiber amplifiers (EDFA) and Raman amplification without using a separate fibre for pump power transmission. The development of ultra-large-Aeff positive dispersion fibre (PDF) cables was stated to be necessary for the realization of ultra-long-distance unrepeatered systems.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • 分散フラット伝送路を用いた40Gbit/s-WDM伝送方式に関する検討

    森田 逸郎, 田中 啓仁, 鈴木 正敏, 枝川 登

    映像情報メディア学会技術報告   24 ( 55 ) 31 - 35  2000年09月

     概要を見る

    正分散ファイバと負分散ファイバを組み合わせて伝送スパンを構成する分散フラット伝送系における40Gbit/s-WDM伝送方式に関する実験的検討を行った。大きな分散値を有するSMF系のファイバを用いた伝送系では、波長間隔を0.8nmまで狭めた40Gbit/s-WDM伝送においても、WDM化による伝送劣化は小さいことを確認した。さらに、SMF系伝送路での主要な伝送制限要因と考えられる同一チャンネル内の非線形干渉を抑制する方法として、分布ラマン増幅方式および低非線形ファイバの使用について検討した。低非線形ファイバを用いた伝送路の分散マップを最適化することにより、40Gbit/s×16WDM伝送実験において2000km以上の伝送を達成した。

    DOI CiNii

  • 40 Gbit/s single-channel transmission over standard singlemode fibre using distributed Raman amplification

    Morita, I., Tanaka, K., Edagawa, N., Suzuki, M.

    Electronics Letters   36 ( 25 ) 2084 - 2085  2000年

     概要を見る

    A 40 Gbit/s single-channel transmission experiment over standard single mode fiber was conducted using distributed Raman amplification (DRA). A transmission distance of over 10000 km was achieved using dispersion management on dispersion shifted fiber (DSF). It was found that DRA reduced the effect of pulse interactions and improved the transmission performance.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Impact of nonlinear crosstalk in 0.8 nm-spaced 40 Gbit/s DWDM systems

    Tanaka, K., Morita, I., Edagawa, N., Suzuki, M.

    Electronics Letters   36 ( 14 ) 1217 - 1218  2000年

     概要を見る

    Dispersion-flattened fiber spans with a single mode fiber (SMF) and a slope-compensating dispersion compensation fiber (SCDCF) have been demonstrated as fiber link for 40 Gbit/s wavelength division multiplexed (WDM) transmission. However, massive dense WDM (DWDM) transmission may cause significant interchannel crosstalk due to fiber nonlinearities. The impact of nonlinear penalty due to increase of the channel count in a 0.8 nm-spaced SMF/SCDCF-based 40-Gbit/s DWDM system is investigated. It is shown that the performance degradation for the increase of WDM channel count is not so large and that the penalty due to nonlinear crosstalk was <1 dB even in 16-channel transmission over 1500 km.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Impact of the dispersion map on long-haul 40 Gbit/s single-channel soliton transmission with periodic dispersion compensation

    Itsuro Morita, Keiji Tanaka, Noboru Edagawa, Masatoshi Suzuki

    OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication   4   62 - 64  1999年

     概要を見る

    The impact of the dispersion map on 10-Gbit/s single-channel transmission was experimentally investigated. The transmission performance was significantly varied with the dispersion map. By using the optimum dispersion map, 40-Gbit/s transmission over 10,200 km has been achieved.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Large cross-phase modulation and four wave mixing in tellurite EDFAs

    Marhic, M.E., Morita, I., Ho, M.-C., Akasaka, Y., Kazovsky, L.G.

    Electronics Letters   35 ( 23 )  1999年

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Long-haul soliton WDM transmission with periodic dispersion compensation and dispersion slope compensation

    Morita, I., Suzuki, M., Edagawa, N., Tanaka, K., Yamamoto, S.

    Journal of Lightwave Technology   17 ( 1 ) 80 - 85  1999年

     概要を見る

    A 20 Gb/s-based soliton wavelength division multiplexed (WDM) transmission experiments using periodic dispersion compensation and dispersion slope compensation were demonstrated. Accumulated dispersion slope was compensated with two methods. The first method was periodical individual dispersion compensation. By using this technique, 60 Gb/s (20 Gb/s × 3 WDM) transmission over 8000 km was demonstrated. The second method was the use of a dispersion-flattened transmission fiber. 160 Gb/s (20 Gb/s × 8 WDM) transmission over 4000 km using periodically dispersion compensated dispersion-flattened fiber was also demonstrated. © 1999 IEEE.

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • 1 Tbit/s (10×10.7 Gbit/s) transoceanic transmission using 30 nm wide broadband optical repeaters with A<inf>eff</inf>-enlarged positive dispersion fibre and slope-compensating DCF

    Tsuritani, T., Takeda, N., Imai, K., Tanaka, K., Agata, A., Morita, I., Yamauchi, H., Edagawa, N., Suzuki, M.

    Electronics Letters   35 ( 24 ) 2126 - 2128  1999年

     概要を見る

    1 Tbit/s (10×10.7 Gbit/s) transmission over 6200 km is obtained using 30 nm wide single-stage C-band optical repeaters (gain flatness <+/-10.1 dB), Aeff-enlarged positive dispersion fiber (Aeff>110 μm2) and slope-compensating dispersion-compensating fiber with a channel spacing of 0.3 nm. This transmission is investigated to study the possibility of terabit/s submarine systems.

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • 40 Gb/s single-channel soliton transmission over transoceanic distances by reducing Gordon-Haus timing jitter and soliton-soliton interaction

    Morita, I., Tanaka, K., Edagawa, N., Suzuki, M.

    Journal of Lightwave Technology   17 ( 12 ) 2506 - 2511  1999年

     概要を見る

    Forty Gb/s single-channel soliton transmission experiments using periodic dispersion compensation were conducted. The impact of the dispersion map on the transmission performance was experimentally investigated. The transmission performance was significantly varied with the dispersion map. The improvement of the transmission performance by the polarization division multiplexing, which reduced soliton-soliton interaction furthermore, was also confirmed. By using the polarization division multiplexing in the optimum dispersion map, 40 Gb/s single-channel transmission over 10 200 km has been successfully demonstrated without any active inline transmission control.

    DOI

    Scopus

    47
    被引用数
    (Scopus)
  • 170 Gb/s transmission over 10,850 km using large core transmission fiber

    M. Suzuki, H. Kidorf, N. Edagawa, H. Taga, N. Takeda, K. Imai, I. Morita, S. Yamamoto, E. Shibano, T. Miyakawa, E. Nazuka, M. Ma, F. Kerfoot, R. Maybach, H. Adelmann, V. Arya, C. Chen, S. Evangelides, D. Gray, B. Pedersen, A. Puc

    Conference on Optical Fiber Communication, Technical Digest Series   1998-January   491 - 494  1998年

  • 400 Gbit/s (20×20 Gbit/s) dense WDM transmission using soliton-based RZ signals

    Keiji Tanaka, Itsuro Morita, Masatoshi Suzuki, Noboru Edagawa, Shu Yamamoto

    European Conference on Optical Communication, ECOC   1   85 - 86  1998年

     概要を見る

    400 Gbit/s (20×20 Gbit/s) wavelength division multiplexing (WDM) transmission over 2000 km with a channel spacing of 0.8 nm using pre- and periodic dispersion compensation scheme and dispersion flattened fiber (DFF) is demonstrated. A bit error rate of less than 10-9 is obtained for all the channels after over 2000 km transmission. The transmission scheme is quite effective to increase the number of channels keeping higher channel bit rate in ultra large capacity transmission. Transmission distance seems to be limited by the signal-to-noise ratio after the transmission. Small effective area of around 35·m2 of DFF prevents increasing the signal power level.

  • 40 Gbit/s single-channel soliton transmission over 10200 km without active inline transmission control

    Itsuro Morita, Keiji Tanaka, Noboru Edagawa, Masatoshi Suzuki

    European Conference on Optical Communication, ECOC   3  1998年

     概要を見る

    By reducing the timing jitter and soliton-soliton interaction effectively, 40 Gbit/s transmission over 10200 km has been successfully demonstrated for the first time without any active components in the transmission line.

  • 400Gbit/s (20 × 20Gbit/s) dense WDM soliton-based RZ signal transmission using dispersion flattened fibre

    Tanaka, K., Morita, I., Suzuki, M., Edagawa, N., Yamamoto, S.

    Electronics Letters   34 ( 23 ) 2257 - 2258  1998年

     概要を見る

    400Gbit/s (20 × 20Gbit/s) soliton-based return-to-zero signals were successfully transmitted over 2000km of dispersion flattened fibre with a channel spacing of 0.8nm by using a pre- and periodical dispersion compensation scheme.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • 40Gbit/s single-channel soliton transmission over 8600km using periodic dispersion compensation

    Morita, I., Tanaka, K., Edagawa, N., Yamamoto, S., Suzuki, M.

    Electronics Letters   34 ( 19 ) 1863 - 1865  1998年

     概要を見る

    A 40Gbit/s single-channel soliton transmission experiment using periodic dispersion compensation is described. By applying dispersion management and optimum initial phase modulation, single-channel 40Gbit/s transmission over 8600km has been successfully demonstrated, for the first time, without any active transmission control in the transmission line.

    DOI

    Scopus

    20
    被引用数
    (Scopus)
  • 160Gbit/s (8 × 20Gbit/s) soliton WDM transmission experiments using dispersion flattened fibre and periodic dispersion compensation

    Suzuki, M., Morita, I., Tanaka, K., Edagawa, N., Yamamoto, S., Akiba, S.

    Electronics Letters   34 ( 5 ) 475 - 476  1998年

     概要を見る

    160Gbit/s (8 × 20 Gbit/s) soliton WDM signals were successfully transmitted over 4000km with a BER of < 10-9, by using periodically dispersion-compensated dispersion-flattened fibre with an average dispersion slope of 0.0005 ps/km/nm2.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • 40 Gbit/s single-channel soliton transmission using periodic dispersion compensation

    Morita, I.

    IEICE Transactions on Electronics   E81-C ( 8 ) 1309 - 1314  1998年

     概要を見る

    The effectiveness of periodic dispersion compensation on single-channel 40 Gbit/s soliton transmission system was experimentally investigated. This technique requires just the dispersion compensation fibers and wideband optical filters in the transmission line, which has no difficulty to be used in the practical system. By using polarization-division-multiplexing together with periodic dispersion compensation, single-channel 40 Gbit/s transmission over 4700 km was demonstrated. Single-polarization 40 Gbit/s transmission experiments, which are more suitable for system implementation and compatible with WDM were also conducted. We investigated the transmission characteristics and pulse dynamics in different dispersion maps and in the optimized dispersion map, single-channel, single-polarization 40 Gbit/s transmission over 6300 km was successfully demonstrated.

  • 160 Gbit/s (8×20 Gbit/s) soliton WDM transmission experiments using dispersion flattened fibre and periodic dispersion compensation

    M. Suzuki, I. Morita, K. Tanaka, N. Edagawa, S. Yamamoto, S. Akiba

    IEE Conference Publication   ( 448 /3 ) 99 - 102  1997年

     概要を見る

    160 Gbit/s (8×20 Gbit/s) soliton WDM signals were successfully transmitted over 4000 km with BER of less than 10-9, by using periodically dispersion-compensated dispersion flattened fibre with average dispersion slope of 0.0005 ps/km/nm2.

  • Effect of initial pulse overlapping on 20 Gbit/s-based soliton WDM transmission using periodic compensation of dispersion and its slope

    Itsuro Morita, Masatoshi Suzuki, Noboru Edagawa, Shu Yamamoto, Shigeyuki Akiba

    Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest     86 - 87  1997年

     概要を見る

    The influence of initial pulse overlapping conditions on the transmission performance in soliton wavelength division multiplexing (WDM) transmission scheme was investigated using periodic dispersion and dispersion slope compensation. The effect of the initial pulse overlap on the transmission performance was small in the 2-channel 20 Gbit/s soliton WDM system. A transmission over 10000 km was possible regardless of the initial pulse overlap conditions indicating the applicability of the optical add-drop multiplexing to soliton WDM systems.

  • Soliton-based return-to-zero transmission over transoceanic distances by periodic dispersion compensation

    Suzuki, M., Edagawa, N., Morita, I., Yamamoto, S., Akiba, S.

    Journal of the Optical Society of America B: Optical Physics   14 ( 11 ) 2953 - 2959  1997年

     概要を見る

    The accumulation of Gordon-Haus jitter can be effectively suppressed by the use of periodic dispersion compensation and in-line optical filters. The feasibility of 20-Gbit/s soliton-based transoceanic systems has been confirmed through 1000-km loop transmission experiments and 8100-km straight-line transmission experiments that employed periodic dispersion compensation. For a 20-Gbit/s, 9000-km transmission system, a Q2 of 19 dB, a sufficient power window of 2.5 dB, and robustness to repeater output power reduction have been demonstrated, as has compatibility with the conventional supervision scheme. A dramatic increase in system capacity can be expected from soliton wavelength-division multiplexing with periodic compensation of dispersion and its slope. © 1997 Optical Society of America.

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • 20Gbit/s-based soliton WDM transmission over transoceanic distances using periodic compensation of dispersion and its slope

    Suzuki, M., Morita, I., Edagawa, N., Yamamoto, S., Akiba, S.

    Electronics Letters   33 ( 8 ) 691 - 692  1997年

     概要を見る

    Soliton WDM transmission of two and three-channel 20Gbit/s signals over transoceanic distances has been demonstrated, for the first time, using periodic compensation of dispersion and its slope of the transmission fibre without any active soliton control, sliding frequency guiding filters, or dispersion tapering fibre.

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Single-channel 40Gbit/s, 5000km straight-line soliton transmission experiment using periodic dispersion compensation

    Morita, I., Suzuki, M., Edagawa, N., Yamamoto, S., Akiba, S.

    Electronics Letters   33 ( 8 ) 698 - 699  1997年

     概要を見る

    The authors have demonstrated the effectiveness of periodic dispersion compensation and polarisation-division-multiplexing for timing jitter reduction in 40Gbit/s single-channel soliton transmission, and have succeeded in 5000km straight-line transmission experiments at 40Gbit/s for the first time.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Performance improvement by initial phase modulation in 20Gbit/s soliton-based RZ transmission with periodic dispersion compensation

    Morita, I., Suzuki, M., Edagawa, N., Tanaka, K., Yamamoto, S., Akiba, S.

    Electronics Letters   33 ( 12 ) 1021 - 1022  1997年

     概要を見る

    Transmission performance has been greatly improved by employing bit-synchronous phase modulation to source pulses in 20Gbit/s soliton-based RZ transmission experiments. The tolerable window for both repeater output power and signal wavelength, for 9000km transmission, was doubled with phase modulation.

    DOI

    Scopus

    28
    被引用数
    (Scopus)
  • Single-channel 40 Gbit/s, 5000 km straight-line soliton transmission experiment using periodic dispersion compensation

    Itsuro Morita, Masatoshi Suzuki, Noboru Edagawa, Shu Yamamoto, Shigeyuki Akiba

    European Conference on Optical Communication, ECOC   2   191 - 194  1996年

     概要を見る

    We have demonstrated the effectiveness of the periodic dispersion compensation and polarization-division-multiplexing for timing jitter reduction in 40 Gbit/s single-channel soliton transmission, and have succeeded in 5000 km straight-line transmission experiments at 40 Gbit/s for the first time.

  • 20-Gb/s single-channel soliton transmission over 9000 km without inline filters

    Morita, I., Suzuki, M., Edagawa, N., Yamamoto, S., Taga, H., Akiba, S.

    IEEE Photonics Technology Letters   8 ( 11 ) 1573 - 1574  1996年

     概要を見る

    20 Gb/s single-channel soliton signal has been successfully transmitted over 9000 km without inline filters, for the first time, using periodic dispersion compensation. The Gordon-Haus timing jitter at 9000 km was reduced by a factor of more than 3 just with the dispersion management.

    DOI

    Scopus

    22
    被引用数
    (Scopus)
  • 20 Gbit/s, 8100 km straight-line single-channel soliton-based RZ transmission experiment using periodic dispersion compensation

    N. Edagawa, I. Morita, M. Suzuki, S. Yamamoto, H. Taga, S. Akiba

    European Conference on Optical Communication, ECOC   3   983 - 986  1995年

     概要を見る

    Straight-line single-channel 20 Gbit/s transmission experiments were conducted over 8100 km for the first time. The obtained Q2 was 19 dB. Superimposed-tone transmission capability and robustness to repeater output power reduction were also confirmed.

  • Dark pulse generation and detection using bright-dark conversion

    Masatoshi Suzuki, Noboru Edagawa, Itsuro Morita, Shigeyuki Akiba

    European Conference on Optical Communication, ECOC   1   299 - 302  1995年

     概要を見る

    Novel techniques for data-coded dark pulse generation and detection using bright-dark conversion have been proposed. 10 Gbit/s data-coded dark pulse generation using a nonlinear optical loop mirror and dark pulse detection using an electroabsorption modulator were demonstrated.

  • Reduction of Gordon-Haus timing jitter by periodic dispersion compensation in soliton transmission

    Suzuki, M., Morita, I., Edagawa, N., Yamamoto, S., Taga, H., Akiba, S.

    Electronics Letters   31 ( 23 ) 2027 - 2029  1995年

     概要を見る

    A novel soliton transmission scheme to suppress the accumulation of the Gordon-Haus jitter using periodic dispersion compensation and inline optical filters has been proposed. With 90% dispersion compensation rate and optimum optical filters, a Q2 of 19dB and a large power window of 2dB were confirmed for a 20Gbit/s, 9000 km transmission system by using a 1000km-long recirculating loop. © 1995, IEE. All rights reserved.

    DOI

    Scopus

    261
    被引用数
    (Scopus)
  • 1.5 μm GaInAsP/InP Distributed Reflector (DR) Lasers with SCH Structure

    Arima, I., Shim, J.-I., Arai, S., Morita, I., Somchai, R., Suematsu, Y., Komori, K.

    IEEE Photonics Technology Letters   2 ( 6 )  1990年

    DOI

    Scopus

    10
    被引用数
    (Scopus)

▼全件表示

書籍等出版物

  • 長距離光ファイバ通信システム : 大洋横断伝送に焦点をあてた高速・大容量化技術の進化と将来展望

    鈴木, 正敏, 森田, 逸郎, 秋葉, 重幸( 担当: 共著)

    オプトロニクス社  2019年07月 ISBN: 9784902312607

  • 光海底ケーブル

    光海底ケーブル執筆委員会( 担当: 分担執筆)

    パレード,星雲社 (発売)  2010年05月 ISBN: 9784434144943

Misc

  • 大容量光中継伝送技術 (創立100周年記念特集 通信技術の進化と未来への展望 : 通信分野が目指す社会貢献と技術の将来像) -- (有線伝送技術の進化と将来像)

    宮本 裕, 森田 逸郎

    電子情報通信学会誌 = The journal of the Institute of Electronics, Information and Communication Engineers   100 ( 8 ) 783 - 788  2017年08月

    CiNii

  • 空間分割多重光伝送方式を用いたペタビット級伝送技術 (特集 空間分割多重を中心としたペタビット級光通信技術)

    森田 逸郎, 相馬 大樹, 五十嵐 浩司, 釣谷 剛宏

    O plus E : Optics・Electronics   38 ( 8 ) 726 - 729  2016年08月

    CiNii

  • スーパーナイキスト波長多重システムにおけるターボ等化 (光通信システム)

    袁 帥, 五十嵐 浩司, 釣谷 剛宏, 森田 逸郎

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 164 ) 17 - 22  2016年07月

    CiNii

  • スーパーナイキスト波長多重QAM信号に対するポリバイナリ整形の性能評価実験 (光通信システム)

    五十嵐 浩司, 釣谷 剛宏, 森田 逸郎

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 164 ) 11 - 16  2016年07月

    CiNii

  • 100Gbit/sコヒーレント C-Band WDM システムを用いたSMF及ずDSF混在フィールド伝送路への適応性検討

    小西 悠介, 大黒 將弘, 中田 力, 森田 逸郎, 小野寺 雅輝, 井上 正純

    電子情報通信学会技術研究報告. OCS, 光通信システム   110 ( 392 ) 1 - 5  2011年01月

     概要を見る

    従来のC-Band波長帯WDMシステムでは分散シフトファイバ(DSF)内で発生する非線形光学効果の影響で長距離伝送品質の確保が困難であったが,近年のコヒーレント光通信技術の発展によりシングルモードファイバ(SMF)やDSFなどの敷設光伝送路種類に依存しない光バックボーンネットワーク構築が期待されている.さらに,敷設光伝送路種類を意識しない光バックボーンネットワーク設計の自由度向上に伴ったコスト効果が大きく期待される.我々は,C-Band波長帯とデジタルコヒーレント光受信技術を用いた100Gbit/s WDMシステムの全長744kmに及ぶフィールド伝送実験を,SMF及びDSFの混在敷設ファイバを用いて実施し適用性評価を行ったので報告する.

    CiNii

  • B-6-8 複数のドメインに跨る多地点接続の仮想ネットワークにおけるネットワークパス分解手法の提案(B-6.ネットワークシステム,一般セッション)

    宮本 崇弘, 林 通秋, 森田 逸郎

    電子情報通信学会総合大会講演論文集   2010 ( 2 ) 8 - 8  2010年03月

    CiNii

  • B-6-110 NGNドメインを跨る帯域確保型サービスのためのRiインタフェースの実装(B-6.ネットワークシステム,一般セッション)

    松本 延孝, 林 通秋, 森田 逸郎, 田中 英明

    電子情報通信学会総合大会講演論文集   2010 ( 2 ) 110 - 110  2010年03月

    CiNii

  • NGNアーキテクチャにおけるIGMPシグナリングと連動したマルチキャストQoS制御方法

    松本 延孝, 林 通秋, 森田 逸郎, 田中 英明

    電子情報通信学会技術研究報告. NS, ネットワークシステム   109 ( 448 ) 297 - 300  2010年02月

     概要を見る

    NGNにおける検討では,セッション単位でのQoS制御をIPマルチキャスト通信に適用することが検討されている.しかし,NGNの一般的なシグナリング方法であるSIPを使ってQoS制御を行う方法では,エンドホスト(アプリケーションサーバ,ユーザ端末)へのSIPシグナリング実装の追加が必要となる.そのため,すでに提供されているIPマルチキャスト通信システムに対してこれを適用すると,エンドホスト改修のコストと作業量が大きくなる.本稿では,既存システムへの変更を少なくすることを目的とする,NGNにおけるマルチキャストQoS制御手法を提案する.本手法では,既存のIPマルチキャストで使用されているIGMPシグナリングをトリガーとして利用し,エンドホストを収容するエッジルータが持つイベント通知機能を用いてNGNフレームワークのQoSサーバと連携することで,ネットワーク制御を行なう.それにより,エンドホストへの改修やネットワーク機器への機能追加を伴わず,NGNのQoS制御をIPマルチキャスト通信へ適用することが可能となる.また,プロトタイプ実装の設計手法を示し,実機による動作検証により本手法の実現可能性を示す.

    CiNii

  • 高性能なクラウド環境のためのネットワークサービス基盤

    宮本崇弘, 林 通秋, 森田 逸郎

    2010信学総大, March     SS77 - SS78  2010年

    CiNii

  • IQインバランス補償を用いた光OFDM伝送

    アルアミン アブドゥッラー, ヤンセン サンダー, 高橋 英憲, 森田 逸郎, 田中 英明

    電子情報通信学会技術研究報告. OCS, 光通信システム   109 ( 31 ) 7 - 12  2009年05月

     概要を見る

    直交周波数分割多重光伝送方式(光OFDM)は光分散補償が不要な大容量光伝送方式の候補として注目を浴びている。OFDM送受信系におけるIQインバランスはイメージ干渉により特に16QAMなど高次の変調フォーマットを用いた大容量システムにおいて問題になることが知られている。本研究では、直交トレーニングシンボルと最適なイメージ抑制の両方を併用したIQインバランス補償法を提案し、シミュレーションを用いて光OFDMにおける特性改善を確認した。16QAM、27.3Gbpsの直接検波光OFDM伝送系において、320km SMF伝送後に本方式により残留インバランスを補償することで3.5dBのOSNR特性の改善が得られることを確認した。更にキャリア周波数オフセットがある場合でも本方式が有効なことを50Gbps直接検波光OFDM伝送系で確認した。

    CiNii

  • B-10-48 光OFDM方式による9GHz間隔66.8Gbit/s×8WDM-640km伝送実験(B-10.光通信システムA(線路),一般セッション)

    高橋 英憲, アルアミン アブドゥッラー, サンダー ヤンセン, 森田 逸郎, 田中 英明

    電子情報通信学会総合大会講演論文集   2009 ( 2 ) 367 - 367  2009年03月

    CiNii

  • BS-9-8 分散耐力を向上した100Gbit/s単一波長光伝送方式の検討(BS-9.テラビットLAN/MANを実現する光波長アクセス技術,シンポジウムセッション)

    森田 逸郎, 高橋 英憲, ヤンセン サンダー, 田中 英明

    電子情報通信学会ソサイエティ大会講演論文集   2008 ( 2 ) "S - 87"-"S-88"  2008年09月

    CiNii

  • λアクセス技術の研究開発 : 単一波長100Gbit/s光伝送技術

    森田 逸郎

    電子情報通信学会技術研究報告. PN, フォトニックネットワーク   107 ( 544 ) 41 - 45  2008年03月

     概要を見る

    高精細動画伝送等の新たな広帯域サービスを実現するための超高速ユーザネットワークインタフェース技術の必要性が高まっている.その基本技術の確立を目指して発足した「λアクセスプロジェクト」では,波長多重およびフレーム多重方式による100Gbit/s級インタフェース技術の研究開発を行っている.本稿では,本プロジェクトの中の1テーマとしても検討が行われている単一波長を用いた100Gbit/s級高速光伝送技術について、光変復調方式を中心に紹介する.

    CiNii

  • BS-7-10 MIMO estimation for polarization division multiplexing in fiber-optic OFDM transmission systems

    Jansen Sander, Morita Itsuro, Tanaka Hideaki

    電子情報通信学会総合大会講演論文集   2008 ( 2 ) "S - 100"-"S-101"  2008年03月

    CiNii

  • CS-7-5 Optical OFDM Transmission Technologies

    Jansen Sander, Morita Itsuro, Tanaka Hideaki

    電子情報通信学会ソサイエティ大会講演論文集   2007 ( 1 ) "S - 86"-"S-87"  2007年08月

    CiNii

  • B-10-24 Carrier-to-signal power ratio in fiber-optic SSB-OFDM transmission systems(B-10.光通信システムB(光通信),一般講演)

    Jansen Sander, Morita Itsuro, Tanaka Hideaki

    電子情報通信学会総合大会講演論文集   2007 ( 2 ) 363 - 363  2007年03月

    CiNii

  • 超高密度光波長多重伝送技術

    森田 逸郎, 吉兼 昇

    電子情報通信学会誌 = THE JOURNAL OF THE INSTITUTE OF ELECTRONICS, INFOMATION AND COMMUNICATION ENGINEERS   89 ( 6 ) 518 - 523  2006年06月

     概要を見る

    当初は実効的に無尽蔵な伝送帯域を有すると目されていた光ファイバ伝送システムにおいて,近年,波長多重伝送技術の拡充により広帯域化が進んだ結果,経済的に利用可能な信号帯域に制限が生じるようになってきている.このような制限が将来の伝送容量拡大における主たる課題として顕在化してきており,限られた光信号帯域において総伝送容量を増大するための周波数利用効率向上技術が,各国の研究機関で活発に検討されている.本稿では,周波数利用効率を現行システムの5〜10倍程度に向上するために有効な各種の超高密度光波長多重伝送技術の最新動向について紹介する.

    CiNii

  • 将来のバックボーンを支える超高速光伝送技術

    大黒 將弘, 森田 逸郎

    電子情報通信学会誌 = THE JOURNAL OF THE INSTITUTE OF ELECTRONICS, INFOMATION AND COMMUNICATION ENGINEERS   89 ( 4 ) 347 - 349  2006年04月

    CiNii

  • B-10-63 帯域制限時の40Gbit/s Duobinary変調方式の特性評価(B-10.光通信システムB(光通信),一般講演)

    大黒 將弘, 森田 逸郎, 田中 英明

    電子情報通信学会総合大会講演論文集   2006 ( 2 ) 383 - 383  2006年03月

    CiNii

  • PMD補償器を用いた単一偏波160Gbit/sベース信号フィールド伝送実験(超高速伝送・変復調技術, 超高速光・電子デバイス技術, 広帯域WDMデバイス技術, 一般)

    大黒 將弘, 宮崎 哲弥, 森田 逸郎, 田中 英明, 久保田 文人, 鈴木 正敏

    電子情報通信学会技術研究報告. OPE, 光エレクトロニクス   105 ( 381 ) 27 - 30  2005年10月

     概要を見る

    伝送速度の高速化は、WDMチャネル数を削減できるため、ネットワークリソース管理の観点から有利であるが、各種制限要因により伝送特性の劣化が大きくなる。制限要因の中でも、特にPMDは、実伝送路で急速に激しく変化するため補償することは難しい。出力光パワーをモニタする方式を適用した偏光子ベースのPMD補償器を用いて、フィールド環境下で160Gbit/s RZ-DPSK光信号の伝送を行い、その有効性を示した。さらに、このPMD補償器を用いて、単一偏波160Gbit/s信号の8WDMフィールド伝送実験を行い、良好な伝送結果を得た。

    CiNii

  • B-10-41 160Gbit/s信号伝送システムに適した偏波モード分散補償器の検討(B-10.光通信システムB(光通信), 通信2)

    大黒 將弘, 宮崎 哲弥, 森田 逸郎, 田中 英明

    電子情報通信学会ソサイエティ大会講演論文集   2005 ( 2 ) 259 - 259  2005年09月

    CiNii

  • 帯域制限RZ DQPSK信号による高周波数利用効率WDM伝送の検討

    吉兼 昇, 森田 逸郎

    電子情報通信学会技術研究報告. OPE, 光エレクトロニクス   104 ( 413 ) 21 - 24  2004年11月

     概要を見る

    光フィルタで帯域制限された40Gsymbol/sベースのRZ DQPSK信号の送受信機対向状態特性を実験的に評価した。その結果、50%のduty比を持つRZ DQPSK信号はduty比33%と66%のRZ DQPSK信号よりも良い特性を持つことを確認した。また,帯域制限RZ DQPSK信号を用いて受信端で偏波分離方式を用いずに周波数利用効率160%のWDM伝送の可能性を実証した。

    CiNii

  • 帯域制限CS-RZ DPSK光信号を用いた40Gbit/sベース長距離波長多重伝送に関する検討

    森田 逸郎, 田中 啓仁, 釣谷 剛宏, 枝川 登

    電子情報通信学会技術研究報告. OCS, 光通信システム   104 ( 25 ) 33 - 37  2004年04月

     概要を見る

    光フィルタで帯域制限した42.7Gbit/s Carrier-suppressed Return-to-zero Differential Phase-Shift Keying (CSRZ-DPSK)光信号を用いた高周波数利用効率40Gbit/sベース大洋横断伝送について検討した。受信器構成を最適化することにより、帯域幅が約45GHzの光フィルタで42.7Gbit/s信号を帯域制限しても帯域制限による特性劣化は1.5dB以下となることを確認した。この結果をもとに、通常のCバンドEDFA中継器を用いた50GHz間隔64x42.7Gbit/s, 8200km伝送実験を行い、全チャネルにおいて誤り訂正符号のしきい値以上の受信特性が得られることを確認した。

    CiNii

  • 70GHz 間隔40 x 42.7Gbit/s CSRZ-DPSK 光信号の 太平洋横断伝送実験

    釣谷 剛宏, 石田 和行, 縣 亮, 下村 健吉, 森田 逸郎, 十倉 俊之, 多賀 秀徳, 水落 隆司, 枝川 登

    電子情報通信学会技術研究報告. OCS, 光通信システム   103 ( 108 ) 39 - 44  2003年06月

     概要を見る

    高周波数利用効率40Gbit/sベース太平洋横断伝送を実現するため、光帯域制限を行った42.7Gbit/s Carrier-Suppressed Return-to-zero Differential Phase Shift Keying(CSRZ-DPSK)光信号の有効性について検討した。その結果、約65GHz幅の光フィルタリングでは、フィルタリングによる特性劣化は0.5dB程度と小さく、また9400km伝送後の伝送ペナルティーも約1.5dBであることから、従来のCSRZ-OOK信号と比べて優位であることがわかった。以上の結果をもとに、オールラマン中継系を用いた70GHz間隔40x42.7Gbit/s,9400km伝送実験を行い、FEC復号前においてQ値9.7dB以上(FEC limitからのマージン約1dB)を全チャネルで達成した。

    CiNii

  • NZ-DSF系およびSMFベース分散フラット系光ファイバ線路の高精度ラマン利得形状測定

    矢崎 智基, 宮川 哲之, 森田 逸郎, 坂田 治久, 枝川 登

    電子情報通信学会技術研究報告. OCS, 光通信システム   102 ( 40 ) 47 - 52  2002年04月

     概要を見る

    ラマン増幅は将来の光伝送システムの重要な要素技術として注目されている。各中継器の利得形状を精密に等化する必要がある超長距離多中継伝送システムに、このようなラマン増幅を適用する場合、使用する光ファイバの特性や中継スパンを構成する光ファイバの組み合わせによって、ラマン利得形状がどのような影響を受けるのかを高精度に把握しておく必要がある。本稿では、各種NZ-DSFおよび数種類のSMFベース分散フラット光ファイバスパンについて、ラマン利得形状を高精度に測定した結果を報告する。

    CiNii

  • B-10-89 帯域制限光RZ信号を用いたチャネル間隔 50GHz, 40Gbit/s x 25WDM, 480km伝送実験

    田中 啓仁, 森田 逸郎, 枝川 登

    電子情報通信学会ソサイエティ大会講演論文集   2001 ( 2 ) 427 - 427  2001年08月

    CiNii

  • 光フィルタを用いた帯域削減RZ光信号による20Gbit/s WDM伝送に関する検討

    釣谷 剛宏, 縣 亮, 今井 薫, 森田 逸郎, 田中 啓仁, 宮川 哲之, 枝川 登, 鈴木 正敏

    電子情報通信学会技術研究報告. OCS, 光通信システム   101 ( 111 ) 1 - 6  2001年06月

     概要を見る

    超長距離WDM伝送において、周波数利用効率の向上は経済性の高いシステムを実現する上で非常に重要である。本稿では、超長距離光伝送システムにおける周波数利用効率の向上を目的として、光フィルタにより帯域削減したVSB-RZ光信号の許容チャネル間隔/PMD/分散トレランスや中継器出力マージン等を従来のRZ光信号と性能比較した。さらに、チャネル間隔35GHzの20Gbit/s VSB-RZ光信号を100ch用いた2Tbit/s、2700km伝送を行い、その有効性を確認した。

    CiNii

  • B-10-150 40Gbit/sベースDWDMシステムにおける帯域制限光信号伝送方式の有効性に関する検討

    田中 啓仁, 縣 亮, 森田 逸郎, 枝川 登

    電子情報通信学会総合大会講演論文集   2001 ( 2 ) 583 - 583  2001年03月

    CiNii

  • 分散フラット伝送路を用いた40Gbit/s-WDM伝送方式に関する検討

    森田 逸郎, 田中 啓仁, 鈴木 正敏, 枝川 登

    電子情報通信学会技術研究報告. OCS, 光通信システム   100 ( 314 ) 31 - 35  2000年09月

     概要を見る

    正分散ファイバと負分散ファイバを組み合わせて伝送スパンを構成する分散フラット伝送系における40Gbit/s-WDM伝送方式に関する実験的検討を行った。大きな分散値を有するSMF系のファイバを用いた伝送系では、波長間隔を0.8nmまで狭めた40Gbit/s-WDM伝送においても、WDM化による伝送劣化は小さいことを確認した。さらに、SMF系伝送路での主要な伝送制限要因と考えられる同一チャンネル内の非線形干渉を抑制する方法として、分布ラマン増幅方式および低非線形ファイバの使用について検討した。低非線形ファイバを用いた伝送路の分散マップを最適化することにより、40Gbit/s×16WDM伝送実験において2000km以上の伝送を達成した。

    CiNii

  • B-10-79 分布ラマン増幅を用いたSMF系での単一チャンネル40Gbit/s伝送

    森田 逸郎, 田中 啓仁, 枝川 登, 鈴木 正敏

    電子情報通信学会ソサイエティ大会講演論文集   2000 ( 2 ) 302 - 302  2000年09月

    CiNii

  • B-10-77 SMF/分散スロープ補償ファイバ伝送路を用いたチャネル間隔0.8nm-40Gbit/sDWDM伝送システムにおける非線形クロストークに関する検討

    田中 啓仁, 森田 逸郎, 枝川 登, 鈴木 正敏

    電子情報通信学会ソサイエティ大会講演論文集   2000 ( 2 ) 300 - 300  2000年09月

    CiNii

  • 30nm C-band超広帯域光中継器を用いた1Tbit/s(100×10.7Gbit/s)、6,200km伝送実験

    釣谷 剛宏, 武田 憲幸, 今井 薫, 田中 啓仁, 縣 亮, 森田 逸郎, 山内 啓嗣, 枝川 登, 鈴木 正敏

    電子情報通信学会総合大会講演論文集   2000 ( 2 ) 570 - 570  2000年03月

    CiNii

  • B-10-90 周期分散補償を用いた単一チャネル40Gbit/s光ソリトン10200km伝送

    森田 逸郎, 田中 啓仁, 枝川 登, 鈴木 正敏

    電子情報通信学会総合大会講演論文集   1999 ( 2 ) 451 - 451  1999年03月

     概要を見る

    高速伝送を可能とする光ソリトン通信は、次世代の長距離・大容量光伝送システムとして有望である。周期分散補償の分散マップを最適化することにより、単一チャネル40Gbit/s-8600kmの光ソリトン伝送が可能であることを前回報告した。今回は、さらに偏波多重技術を用いることにより、伝送特性の大幅な改善が確認でき、単一チャネル40Gbit/sで10200km以上の伝送に成功したので報告する。

    CiNii

  • 周期的分散補償を用いた単一チャンネル40Gbit/s光ソリトン8600km伝送

    森田 逸郎, 田中 啓仁, 枝川 登, 山本 周, 鈴木 正敏

    電子情報通信学会ソサイエティ大会講演論文集   1998 ( 2 ) 390 - 390  1998年09月

    CiNii

  • 周期的分散補償を用いた 単一チャンネル, 単一偏波40Gtib/s, 6300km光ソリトン伝送

    森田 逸郎, 鈴木 正敏, 枝川 登, 田中 啓仁, 山本 周

    電子情報通信学会総合大会講演論文集   1998 ( 2 ) 544 - 544  1998年03月

    CiNii

  • 分散フラットファイバを用いた160Gbit/s(8×20Gbit/s)ソリトンWDM伝送

    田中 啓仁, 鈴木 正敏, 森田 逸郎, 枝川 登, 山本 周

    電子情報通信学会総合大会講演論文集   1998 ( 2 ) 541 - 541  1998年03月

    CiNii

  • 周期的分散補償光ソリトン伝送における位相変調による伝送特性の改善

    森田 逸郎, 鈴木 正敏, 枝川 登, 田中 啓仁, 山本 周, 秋葉 重幸

    電子情報通信学会ソサイエティ大会講演論文集   1997 ( 2 ) 495 - 495  1997年08月

     概要を見る

    光ソリトン伝送において、ゴードンハウスジッタ等の制限要因を抑制するためには、種々の伝送路中でのソリトン制御技術や分散制御技術が有効であることが示されている。伝送特性をさらに向上させるためには、伝送路中に加えて送受信部でのソリトン制御を行うことはより効果的である。このような目的で、筆者らは周期的分散補償を用いた波長多重光ソリトン伝送実験において送信部でのビット同期位相変調を用いた。今回、その効果の詳細について、単一波長20Gbit/s光ソリトン伝送実験により確認したので報告する。

    CiNii

  • 分散フラットファイバを用いた光ソリトンWDM伝送におけるチャネル間隔の影響

    田中 啓仁, 鈴木 正敏, 森田 逸郎, 枝川 登, 山本 周, 秋葉 重幸

    電子情報通信学会ソサイエティ大会講演論文集   1997   493 - 493  1997年

     概要を見る

    1波当たりの伝送速度を高速化できる光ソリトンWDM伝送は、長距離・大容量光伝送システム技術として有望である。WDM伝送方式における隣接チャネル間相互作用の影響は、パルスの形態、チャネル間隔などにより異なるため、その特性を把握することは伝送システムを設計する上で重要となる。本報告では、周期分散補償と分散フラットファイバを用いた光ソリトンWDM伝送におけるチャネル間隔の影響を実験的に検討したので報告する。

    CiNii

  • 周期的分散補償8100kmストレート伝送系を用いた20Gbit/s光ソリトン伝送実験

    枝川 登, 森田 逸郎, 鈴木 正敏, 山本 周, 多賀 秀徳, 秋葉 重幸

    電子情報通信学会総合大会講演論文集   1996 ( 2 ) 600 - 600  1996年03月

     概要を見る

    次世代の長距離・大容量光通信技術として光ソリトン通信方式が注目されている。光ソリトンシステムの実用性を考察する上で、各種システムパラメータに対するマージンや監視方式に関する検討が重要である。本稿では、約8100kmのストレート20Gbit/sRZ光信号伝送系を用いて行った、ソリトン伝送システムの中継器出力変動に対する許容度や監視方式に関する実験結果について報告する。

    CiNii

  • ブライト/ダーク変換によるダークソリトン送受信器

    鈴木 正敏, 枝川 登, 森田 逸郎, 秋葉 重幸

    電子情報通信学会総合大会講演論文集   1996 ( 2 ) 602 - 602  1996年03月

     概要を見る

    ダークソリトン伝送は通常のブライトソリトン伝送に比較するとGordon-Hausジッタやソリトン干渉が少ないという特徴がある。ダークソリトン送受信装置の実現にあたっては、データ変調や光TDMの難しさから、これまで、報告例は限られている。本文では、ブライト/ダーク変換を用いる光TDMとの互換性のあるダークソリトン送受信装置を提案し、20Gb/sでの基本動作を確認したので報告する。

    CiNii

  • 光フィルタを用いない伝送系での20Gbit/s光ソリトン伝送

    森田 逸郎, 鈴木 正敏, 枝川 登, 山本 周, 多賀 秀徳, 秋葉 重幸

    電子情報通信学会総合大会講演論文集   1996 ( 2 ) 601 - 601  1996年03月

     概要を見る

    次世代の長距離・大容量光通信システムとして、光ソリトン通信が注目されている。光ソリトン伝送における主たる制限要因はGordon-Hausジッタであるが、我々は、周期的に伝送路の累積分散値を補償する方法と光フィルタにより、Gordon-Hausジッタを効果的に抑圧することを提案した。今回、光フィルタを用いずに周期的分散補償のみにより、20Gbit/s光ソリトン伝送が可能であることを9000km伝送により確認したので報告する。

    CiNii

  • DDFを用いたプリエンファシス光ソリトン圧縮

    森田 逸郎, 鈴木 正敏, 枝川 登, 秋葉 重幸

    電子情報通信学会ソサイエティ大会講演論文集   1995 ( 2 ) 398 - 398  1995年09月

     概要を見る

    高密度光TDMソリトン伝送に必要となるデューティ10%以下のトランスフォームリミット(TL)短光パルスを得る方法として、入力光パルスを分散減少光ファイバ(DDF)を用いてソリトン断熱圧縮する方法が有望である。本報告では、これまであまり報告されていない、比較的幅の広い(10ps以上)光パルスをDDFを用いてパルス圧縮を行い、本パルスが20Gb/s,10000km光ソリトン伝送に適用可能であることを確認したので報告する。

    CiNii

  • 20Gbit/s光ソリトン伝送における光フィルタの影響

    森田 逸郎, 鈴木 正敏, 枝川 登, 多賀 秀徳, 田中 英明, 山本 周, 秋葉 重幸

    電子情報通信学会総合大会講演論文集   1995 ( 2 ) 593 - 593  1995年03月

     概要を見る

    次世代の長距離・大容量光通信システムとして、光ソリトン通信が注目されている。前回、20Gbit/s光ソリトン伝送について、交番振幅と比較的帯域幅の広い光バンドパスフィルタ(OBPF)を用いることにより、1万km以上の伝送が可能であることを報告した。本稿では、伝送路中に挿入するOBPFの形状および帯域幅の20Gbit/s光ソリトン伝送に与える影響について実験的に明らかにしたので報告する。

    CiNii

  • 20Gb/s長距離光ソリトン伝送実験

    鈴木 正敏, 枝川 登, 多賀 秀徳, 田中 英明, 森田 逸郎, 山本 周, 秋葉 重幸

    電子情報通信学会秋季大会講演論文集   1994 ( 2 ) 501 - 501  1994年09月

     概要を見る

    次世代の超高速光伝送システムとして、光ソリトンによる光増幅多中継伝送システムの研究が活発に行なわれている。10Gb/s伝送については、スライディング・フィルタやインライン光変調器と光フィルタを用いてGprdon-Hausジッタを抑制することにより、数万kmから百万km以上の伝送が可能であることが示されている。又、伝送路中でのソリトン制御を行わない単純な伝送系でも、交番振幅ソリトンの採用により1万km以上の伝送が可能であることが示されている。しかしながら、1波長での更なる大容量化については、これまでは20Gb/sで2000kmの伝送実験が最大である。本稿では、交番振幅ソリトンと比較的帯域幅の広い光BPFの採用により、20Gb/sで10000km以上の伝送が可能で あることを周回伝送実験により確認したので報告する。

    CiNii

▼全件表示

受賞

  • 業績賞

    2021年06月   電子情報通信学会   10ペタビット級超大容量光空間多重伝送基盤技術の先駆的研究  

  • テレコムシステム技術賞

    2021年03月   電気通信普及財団   10.16-Peta-B/s Dense SDM/WDM Transmission Over 6-Mode 19-Core Fiber Across the C+L Band  

  • Fellow

    2021年01月   IEEE   Contributions to large-capacity transmission systems with high-speed signals  

  • フェロー

    2020年03月   電子情報通信学会   高速光信号の大洋横断級長距離伝送技術の研究  

  • 第50回市村産業賞 貢献賞

    2018年04月   (財)市村清新技術財団   テラビット級長距離大容量光海底ケーブルシステムの開発  

  • 前島密賞

    2012年03月   (財)逓信協会   光通信における分散制御ソリントン通信方式の考案と実証  

  • 先端技術大賞 経済産業大臣賞

    2006年07月   フジサンケイ・ビジネスアイ   160Gbit/s超高速光伝送技術の研究開発  

▼全件表示

共同研究・競争的資金等の研究課題

 

現在担当している科目

▼全件表示

 

委員歴

  • 2020年04月
    -
    2022年03月

    電子情報通信学会  光通信インフラの飛躍的な高度化に関する特別研究専門委員会 委員長

  • 2021年01月
    -
    2021年12月

    IEEE  Photonics Society Tokyo Section Chapter Chair

  • 2017年06月
    -
    2019年05月

    電子情報通信学会  光通信システム研究専門委員会 委員長