Details of a Researcher - Yamanaka, Naoaki

Papers - Yamanaka, Naoaki

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Energy efficient network design tool for green IP/Ethernet networks

Hidetoshi Takeshita, NAOAKI YAMANAKA, Satoru Okamoto, Sho Shimizu, Shan Gao

Elsevier Journal Optical Switching and Networking 9 ( Issue 3 ) 264-270 2012.07

Research paper (conference, symposium, etc.), Joint Work

An innovative energy-efficient network design algorithm and a tool to lower the network power consumption are proposed. The goal is an energy efficient network that carries its rated communication load while meeting the QoS requirements by using the minimum set of nodes and links. QoS metrics include hop limit, bandwidth limit reliability and stability. The proposed algorithm addresses the set-covered problem. To discover the optimum network configuration efficiently, we propose a network configuration generation algorithm that utilizes DAPDNA-2, a parallel data flow type reconfigurable processer. The processor automatically produces the node/link set in n-digit binary form where links are modeled as ‘‘1’’ for power on and ‘‘0’’ for power off; it also confirms that the QoS requirements are satisfied. Evaluation results show that DAPDNA-2 is 2-orders faster than the conventional sequential method running on a Pentium-4 processor. Prototype Gigabit Layer-2 switches having remote link power on/off and traffic monitoring functions are developed. Using these switches, we successfully demonstrate an energy efficient IP/Ethernet network. The evaluation results show that network power savings of up to 30% can be realized under the NFSNET topology model. The proposed algorithm and power efficient network architecture can be applied to realize the future green network.

Hybrid Passive/Active Optical Access Network Architecture that Reduces OLT Power Consumption

Kazumasa Tokuhashi, Daisuke Ishii, Satoru Okamoto, NAOAKI YAMANAKA

Cyber Journals: Multidisciplinary Journals in Science and Technology, Journal of Selected Areas in Telecommunications(JSAT) ( June Edition ) 2012.06

Research paper (conference, symposium, etc.), Joint Work

A State-of-the-Art Low-Power Optical Network Research

NAOAKI YAMANAKA, Kazumasa Tokuhashi, Hidetoshi Takeshita

The Review of Laser Engineering 40 ( 5 ) 351-355 2012.05

Research paper (conference, symposium, etc.), Joint Work

The power consumption of network devices will continue to increase due to the increase in transmission speed and reach 97 GW by 2020. This paper introduces urgently needed network power reduction methods. First, the paper focuses on the optical access network architectures that use active devices such as high-speed optical switches or variable wavelength lasers to achieve slgnificant energy savings. These new architectures are expected to dramatically reduce the Optical Network Unit (ONU)'s power consumption by introducing an effective sleep mode. Second, this paper introduces an extremely energy efficient future-Internet architecture that uses a large optical aggregation network. It combinesthe centralized Service Cloud with the Cloud Router and application servers and the Optical Aggregation Network. The optical aggregation network can be realized with just simple optical circuit switches, wavelength-Converters,and wavelength-multiplexers/demultiplexers; the complicated layer-3 function is realized only at the center Cloud Router. The optical aggregation network realizes a network structure well suited to today's traffic centralization. According to our evaluation, total network power consumption Can be reduced to Just 1/1000 compare to the electrical based network architecture.

MPCP based Active Optical Access Network with PLZT High-speed Optical Switch

Kazumasa Tokuhashi, Kunitaka Ashizawa, Daisuke Ishii, Satoru Okamoto, NAOAKI YAMANAKA, Koji Wakayama, Keiichi Nashimoto

Elsevier Journal Optical Switching and Networking 9 ( Issue 2 ) 118-129 2012.04

Research paper (conference, symposium, etc.), Joint Work

An active optical access network architecture with our newly developed PLZT ((Pb, La) (Zr, Ti)O3) high-speed optical switch is introduced, with a view to realizing the nextgeneration high capacity scalable access network. This system is developed based on the latest IEEE standard of PON (10G-EPON; IEEE802.3av) in consideration of the coordination with future high capacity PON. PLZT high-speed optical switches are able to switch an optical signal at nano-second speed (<5–10 ns). Generally, the merits of using optical switches are increasing the number of subscribers and transmission distance easily, preventing malicious ONUs from interfacing with the communication between OLT and the other ONUs, realizing fast fiber and OLT protection/restoration and providing various services by controlling optical switches dynamically. This paper focuses on two key technologies; a PLZT optical switch and a new discovery process for active optical access network based on MPCP defined at IEEE802.3. A major challenge in designing active optical access network is supporting the discovery process of MPCP because it does not offer broadcast transmission unlike the regular PON. We propose here a new discovery process; it has been tested successfully in an implementation of our proposed system.

Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

Kunitaka Ashizawa, Takehiro Sato, Kazumasa Tokuhashi, Daisuke Ishii, Satoru Okamoto, NAOAKI YAMANAKA, Eiji Oki

IEICE TRANSACTIONS on Communications E95-B ( 3 ) 730-739 2012.03

Research paper (conference, symposium, etc.), Joint Work

This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30 msec, which is acceptable for on-demand broadcast services.

Fast Optimal Replica Placement with Exhaustive Search Using Dynamically Reconfigurable Processor

Hidetoshi Takeshita, Sho Shimizu, Hiroyuki Ishikawa, Akifumi Watanabe, Yutaka Arakawa, NAOAKI YAMANAKA, Kosuke Shiba

Journal of Computer Networks and Communications 2011 ( Article ID 707592 ) 1-11 2011.12

Research paper (conference, symposium, etc.), Joint Work

This paper proposes a new replica placement algorithm that expands the exhaustive search limit with reasonable calculation time.
It combines a new type of parallel data-flow processor with an architecture tuned for fast calculation. The replica placement
problem is to find a replica-server set satisfying service constraints in a content delivery network (CDN). It is derived from the
set cover problem which is known to be NP-hard. It is impractical to use exhaustive search to obtain optimal replica placement in
large-scale networks, because calculation time increases with the number of combinations. To reduce calculation time, heuristic
algorithms have been proposed, but it is known that no heuristic algorithm is assured of finding the optimal solution. The proposed
algorithm suits parallel processing and pipeline execution and is implemented on DAPDNA-2, a dynamically reconfigurable
processor. Experiments show that the proposed algorithm expands the exhaustive search limit by the factor of 18.8 compared
to the conventional algorithm search limit running on a Neumann-type processor.

A Design Method High-Reliability and Low-Optical-Loss Optical Aggregation Network Using 2×2 Optical Switch

Takehiro SATO, Kunitaka ASHIZAWA, Kazumasa TOKUHASHI, Daisuke ISHII, Satoru OKAMOTO, Eiji OKI, NAOAKI YAMANAKA

IEICE TRANSACTIONS on Communications J94-B ( 11 ) 1508-1512 2011.11

Research paper (conference, symposium, etc.), Joint Work

Fast Fault Recovery Method with Preestablished Recovery Table for ReliableWide Area Layer-2 Network

Takashi Kurimoto, Midori Terasawa, Sho Shimizu, Satoru Okamoto,NAOAKI YAMANAKA

International Scholarly Research Network(ISRN) Communications and Networking 2011 ( 941605 ) 1-8 2011.10

Research paper (conference, symposium, etc.), Joint Work

Recently, wide area Ethernet, which provides virtual connections between company branches by using Ethernet technology, has become wide spread. Ethernet originally lacked fault recovery mechanisms required in wide area networks (WANs) since it originated as local area network (LAN) technology. Protection mechanism against link or node failure is proposed in Ethernet network, but many frame losses are inevitable during the switch over to the backup path. Therefore, to improve reliability of wide area Ethernet, a fault recovery method with few frame losses is required. This paper proposes a fast fault recovery method for reducing frame losses during the switching over to another route. To achieve fast recovery, a pre-established forwarding table is introduced, which is searched when a fault occurs and frames are forwarded. This paper also proposes a bandwidth control function to guarantee the quality of service of connections that do not use the failed link when a fault occurs. A computer simulation showed that by adding the proposed fault recovery method to the conventional protection method, frame losses can be decreased. The proposed fault recovery method was implemented on a software switch framework to confirm its effectiveness.

Energy Optimal Topology Calculation Method for Self Organized Network MiDORi

Haruka Yonezu, Daisuke Ishii, Satoru Okamoto, Eiji Oki, NAOAKI YAMANAKA

IEICE TRANSACTIONS on Communications J94-B ( 10 ) 1323-1331 2011.10

Research paper (conference, symposium, etc.), Joint Work

In order to reduce the energy consumption of transport/data center networks, MiDORi network technology is introduced. This network is based on the concept of aggregating traffic into specific links, and powering off interfaces of routers/switches that do not convey traffic. In this paper, a practical energy-optimal topology calculation method is proposed for the MiDORi PCE. The proposal can adjust the link reduction rate and the calculation time by setting different values for the depth. Moreover, two failure management methods are proposed in order to reduce the risk of traffic aggregation. By computer simulation, it is shown that the proposed method is effective from several perspectives. Lastly, a prototype system of MiDORi network is described to observe the aspect of self organization.

High Density Short-Term Forecasting Photovoltic Output Power Architecture without Meteorological Observations in Smart Grid

Jun Matsumoto, Daisuke Ishii, Satoru Okamoto, Eiji Oki, NAOAKI YAMANAKA

IEICE TRANSACTIONS on Communications J94-B ( 10 ) 1373-1382 2011.10

Research paper (conference, symposium, etc.), Joint Work

近年日本では家庭用ソーラーパネルやマイクロCHPが急速に普及しており, それらの分散化された発電エネルギーの利用法が日本におけるスマートグリッド研究課題の一つである. 効率的な発電エネルギー利用のため消費デバイスとのスケジューリング連携が有効であり, 太陽光発電出力量の短期的な予測が重要となる. 従来の太陽光発電出力予測手法は主に中長期的な規則性を伴う出力変動について議論しており, 気候による不規則な変動の激しい短期的な予測には適さない. また既存の短期的な予測手法についても特別な気象観測機器が必要であるという課題が残る. そこで本論文では, 気象観測情報を用いずに各ソーラーパネルの発電出力情報のみを用いて予測する手法を提案する. 本手法では, ネットワークに接続されたスマートメータから各地点の発電出力情報をサンプリングし, データ補間及びオプティカルフロー推定技術を用いて, 各地点における将来の発電出力量を予測する. その際, 過去のサンプリングデータを仮想的に補間元データとして用いるバーチャルサンプリングにより, 少ないサンプリング数でも高精度な予測を可能とする. コンピュータシミュレーションにより, 本予測手法の有効性及びバーチャルサンプリングによる予測精度の改善を示す.

Performance Evaluation of TCP/IP over SCTP/IP Parallel Networking with Parallel Route Transmission

Shota YAMADA, Daisuke ISHII, Satoru OKAMOTO,NAOAKI YAMANAKA

IEICE TRANSACTIONS on Communications E94-B ( 8 ) 2394-2396 2011.08

Research paper (conference, symposium, etc.), Joint Work

In this paper, Transmission Control Protocol/Intemet Protocol(TCP/IP) over Stream Control Transmission Protocol (SCTP)/IP parallel transmission system is proposed to realize large TCP/IP throughput. The proposed system enables SCTP/IP connection between switches by protocol stacking. The proposed system is implemented on a software switch to evaluate its performance. The evaluation result indicates that proposed system can achieve 90% throughput compared with serial transmission when the delay difference among parallel routes is 20 msec.

通信技術が生むスマートネットワークの新しいビジネスチャンス

NAOAKI YAMANAKA

CIAJ Journal ( 6月 ) 12-17 2011.06

Research paper (scientific journal), Single Work

On-Demand Multicast Slot Allocaton Scheme For Active Optical Access Network Using PLZT High-Speed Optical Switches

Kunitaka Ashizawa, Takehiro Sato, Kazumasa Tokuhashi, Daisuke Ishii, Naoaki Yamanaka, Eiji Oki

Cyber Journals: Multidisciplinary Journals in Science and Technlogy, Journal of Selected Areas in Telecommunications JSAT ( May 2011 Edition ) 19-27 2011.05

Research paper (scientific journal), Joint Work

This paper proposes an on-demand multicast slot allocation scheme for an active optical access network that uses Mach-Zehnder-type high-speed optical switches, which are achieved by the Plumbum Lanthanum Zirconate Titanate (PLZT) switching technology. The Active Optical Network, called ActiON, is based on slot-based switching. Compared to the Passive Optical Network (PON), ActiON quadruples the number of subscribers (128 users) per optical line terminal (OLT) and doubles the maximum transmission distance (40 km) between OLT and optical network units (ONUs). However, as ActiON uses slot-based switching, it needs a large number of slots to deliver multicast contents to the requesting users. This greatly lowers network utilization rates. The proposed multicast slot allocation scheme overcomes this problem to provide on-demand multicast services, while keeping the advantages of ActiON. Multicast delivery is realized by running the Mach-Zehnder-type high-speed optical switch elements in distribution mode, which forces the switch to behave as an optical splitter. The proposed scheme iteratively solves the integer linear programming (ILP) problem to associate multicast users with slots. Numerical results show that the proposed scheme dramatically reduces the required number of slots, compared to non-multicast ActiON and provides comparable the performance of bandwidth efficiency to 10 G-EPON, and the required computation time of the proposed scheme is less than 0.3 sec, which is feasible for on-demand services.

Highly Energy Efficient Layer-3 Network Architecture Based on Service Cloud and Optical Aggregation Network

Hidetoshi TAKESHITA, Daisuke ISHII, Satoru OKAMOTO, Eiji OKI,NAOAKI YAMANAKA

IEICE Transactions on Communications E94-B ( 4 ) 894-903 2011.04

Research paper (conference, symposium, etc.), Joint Work

The Internet is an extremely convenient network and has become one of the key infrastructures for daily life. However, it suffers from three serious problems; its structure does not suit traffic centralization, its power consumption is rapidly increasing, and its round-trip time (RTT) and delay jitter are large. This paper proposes an extremely energy efficient layer-3 network architecture for the future Internet. It combines the Service Cloud with the Cloud Router and application servers, with the Optical Aggregation Network realized by optical circuit switches, wavelength-converters, and wavelength-multiplexers/demultiplexers. User IP packets are aggregated and transferred through the Optical Aggregation Network to Cloud transparently. The proposed network scheme realizes a network structure well suited to traffic centralization, reduces the power consumption to 1/20-1/30 compared to the existing Internet, reduces the RTT and delay jitter due to its simplicity, and offers easy migration from the existing Internet.

光スイッチを用いた10ギガビット／秒アクティブ光アクセスシステムの研究開発

Koji Wakayama, NAOAKI YAMANAKA

Electronics Product Digest 27 ( 12 ) 17 2010.12

Research paper (conference, symposium, etc.), Joint Work

50th Anniversary of Birth of Lasers

Hiromichi SHINOHARA, NAOAKI YAMANAKA

THE JOURNAL OF THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATIONS ENGINEERS 93 ( 12 ) 1057-1059 2010.12

Research paper (conference, symposium, etc.), Joint Work

1960年にT.H.Maimanがヒューズ・リサーチ・ラボラトリで初めてレ-ザ光の発振に成功してから50年を迎えた.電子情報通信学会東京支部では,記念すべきこの年に,レ-ザの発展に多大な貢献をされた霜田光一,末松安晴両博士の講演会を7月1日に開催した.レ-ザ研究の経緯や発見・発明のエピソード,開発の苦労,その後の応用について,当時を知る両氏からしか聞くことのできない貴重な話を伺った.講演会の後,両氏の厚意により, 50年前の古い資料を拝見するアーカイブズ展示会を実施した. Maiman,Javan, Lambら,メ-ザ・レ-ザのれい明期の論文や手書き原稿,当時の写真,レ-ザ発明当時の製造機器,世界をリードしてきた日本国内各社のレ-ザ製品,関連するノーベル賞受賞者と講師の交流の記録などに多くの参加者が見入った.今日,情報,通信,映像などのICT産業のみならず, 医療,加工,分析などあらゆる分野においてレ-ザが果たしている役割の大きさは計り知れない.講演会,展示会とも,レ-ザ発明の歴史的偉業とその後の発展の歴史のみならず,日本の進むべき技術立国のビジョンに対して勇気と活力を与えられるものであった.講演会当日は, 200名を超える聴衆が会場を埋め尽くしたが,このような貴重な講演は,聴講者だけでなく,その一端だけでも広く会員に紹介すべきとの意見を多数頂だいしたため,本誌に寄稿するものである.

Dynamic Packet (Frame) Based Ranging Method for Active Optical Access Network

Kazumasa Tokuhashi, Kunitaka Ashizawa, Daisuke Ishii, Yutaka Arakawa, Satoru Okamoto,NAOAKI YAMANAKA

IEICE Trans. On Communications J93-B ( 8 ) 1087-1091 2010.08

Research paper (conference, symposium, etc.), Joint Work

High-energy Efficient Layer-3 Network Architecture based on Solitary Universal Cloud Router and Optical Aggregation Network

Hidetoshi Takeshita, Daisuke Ishii, NAOAKI YAMANAKA

9th International Conference on Optical Internet 2010(COIN2010) 2010.07

Research paper (conference, symposium, etc.), Joint Work

Network Designing Algorithm for Low Power Consumption under QoS restriction

Haruka Yonezu, Yutaka Arakawa, NAOAKI YAMANAKA

SCAT TECHNICAL JOURNAL TELECOM FRONTIER NO.67 2010 SPRING ( 67 ) 19-31 2010.05

Research paper (conference, symposium, etc.), Joint Work

Green ITとよばれ近年, 地球環境に配慮した技術開発が重視されつつある. 情報ネットワークの分野においてもネットワークの広帯域化とサービスの質の向上による増え続ける需要をさばくためのネットワークリソースは急増し, それによる看過できない電力消費の伸びが指摘され始めるなどており, ネットワークの省電力化は今後重視すべき課題である. 装置やデバイスのみではなく, 運用方法やアーキテクチャを組み合わせた検討が必要である. 本提案は, いままであまりアプローチされていなかった, 通信ネットワークの消費電力を通信品質を保証しながら最適に制御する方法を, すべての組み合わせを計算する方法を研究した. いままでは計算時間が膨大過ぎて現実的ではないと思われていた集合被覆問題に帰着させ, リコンフィギャラブルプロセッサデバイスを用いて高速に解き, さまざまなネットワークリソースを, もっとも省電力で使用する構成を動的に求めることを可能にするものである. 具体的にはネットワークリンクを必要最小数のみパワーオンし, またルートも必要最少とするような省電力ルータの制御を行うことができる計算エンジンを提案する. また, エンジンによって計算した結果を実ネットワークに反映させ, リンクをon/offするプロトコルをGMPLSを拡張して実現し, また, プロトタイプシステムで実験的に確認した.

Active Optical Access Network (ActiON) based on newly developed 10-ns High-speed PLZT Optical Switch

NAOAKI YAMANAKA

NewBreeze 22 ( 2 ) 16-17 2010.04

Research paper (scientific journal), Single Work

A new optical access network architecture called called Active Optical Network (ActiON) is proposed which uses a newly-developed 10 nsec PLZT((Pb, La)(Zr, Ti)O3) high-speed optical switch. ActiON can handle four times the number of subscribers(128) that GEPON can handle as well as doubling the transmission distance(to 40 km). Moreover, users can enjoy secure communication in ActiON because it is a switch-based system. However, ActiON has to overcome a Discovery-Ranging process issue because an optical switch cannot broadcast signals. In this paper, the architecture of ActiON and a novel Discovery-Ranging process technique is proposed. The proposed access system architecture and high-speed PLZT switch will be able to be applied to next generation broadband access systems.
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