Misc - FUJIMOTO Akihiro

Scheduling beacon transmissions in receiver initiated MAC protocols for low-delay wireless sensor networks

桝井 優香里, 藤本 章宏, 吉廣 卓哉, 内尾 文隆

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 ( 電子情報通信学会 )  115 ( 483 ) 303 - 308   2016.03

フラッシュクラウド発生時のレスポンス低下を改善するアクセス元情報を利用した処理資源割り当て手法

大村 昂, 藤本 章宏, 内尾 文隆

電子情報通信学会技術研究報告   115 ( 483 ) 505 - 510   2016.03

WLANにおけるQoSと公平性を考慮したパケットスケジューリングと動的なコンテンションウィンドウ制御の併用に関する性能評価

ルアンサイ コンシリ, 藤本章宏, 内尾文隆

電子情報通信学会技術研究報告   115 ( 483 ) 465 - 470   2016.03

パケットスケジューリングと無線アクセス優先制御の協調手法における送信機会優先度が与える影響と評価

馬場智也, ルアンサイコンシリ, 藤本章宏, 内尾文隆

電気学会 次世代産業システム研究会     2015.03

協調キャッシュ管理機能を有するSet Top Boxを用いたP2P型動画共有システムに関する一検討

古本敦大, 藤本章宏, 内尾文隆

電気学会 次世代作業システム研究会     2015.03

Open Flowネットワークにおける適応的なコントローラ冗長化手法の提案

高 尚昊, 藤本章宏, 内尾文隆

電気学会 次世代産業システム研究会     2015.03

BitTorrent型配信システムにおけるRateless Codingを用いた希少ピース拡散手法についての一検

藤本 章宏, 廣田 悠介, 戸出 英樹 （Part： Lead author )

情報処理学会研究報告   2014-DPS-161 ( 4 ) 1 - 7   2014.09

WLANにおけるQoSと公平性を考慮したパケットスケージュリングとアクセス優先制御の協調手法

ルアンサイ コンシリ, 藤本章宏, 内尾文隆

電子情報通信学会技術研究報告   113 ( 472 ) 567 - 572   2014.03

高機能プロキシサーバーを用いた携帯端末に低負荷かつセキュアな音声通信システム

金沢 真嗣, 藤本 章宏, 内尾 文隆

電子情報通信学会技術研究報告   113 ( 472 ) 307 - 311   2014.03

Video Streaming System Based on Overlapped Cluster-Trees with Various Attributes for Churn-Resistance and Low-Latency

MOTOHASHI Tomoki, FUJIMOTO Akihiro, HIROTA Yusuke, TODE Hideki, MURAKAMI Koso

The transactions of the Institute of Electronics, Information and Communication Engineers. B ( The Institute of Electronics, Information and Communication Engineers )  97 ( 2 ) 132 - 142   2014.02

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ネットワークへの負荷分散を考慮したライブストリーミングを実現するアプリケーションレベルマルチキャスト技術として,複数配信木方式が挙げられる.これまで著者らは,ノードの参加離脱に耐性のあり効率的な遅延低減ができる,重畳クラスタ木方式を提案してきた.しかしながら,先行研究は基本コンセプトの提案であり,重畳する各クラスタ木は単純なものにとどまっていた.本論文では,ノード性能が不均質な環境を考慮し,このような場合においても,重畳クラスタ木を基に適切な選出指標に基づきノード選択を行い,更にそれら指標を組み合わせることで,配信遅延の低減と離脱耐性の向上が実現される方式を提案する.配信性能を向上させた重畳クラスタ木方式の性能を計算機シミュレーションによって評価する.

High Quality Streaming using Disjoint Paths under Hierarchical Cache-servers Environment

FUJIMOTO Akihiro, HIROTA Yusuke, TODE Hideki, MURAKAMI Koso

IEICE technical report ( The Institute of Electronics, Information and Communication Engineers )  112 ( 463 ) 237 - 242   2013.03

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Video streaming using hierarchical cache servers is effective to provide high quality services to many users. However, when some videos are streamed from cache servers far from users, Quality of Experience (QoE)of the users is degraded due to relatively high packet loss rate. We have proposed Inter-Stream Forward Error Correction (FEC), which improves recovery capability utilizing path diversity. In this paper, we propose a high quality video streaming method using Inter-Stream FEC with multiple cache servers. This method aims to improve recovery capability and redundancy by adaptively selecting video streams protected by Inter-Stream FEC considering both of cache status of cache servers and the condition of transmission paths from cache servers.

Resilient Video Streaming System Based on Overlapped Cluster-trees with Tolerance to Massive Churn

MOTOHASHI Tomoki, FUJIMOTO Akihiro, HIROTA Yusuke, TODE HIDEKI, MURAKAMI Koso

IEICE technical report ( The Institute of Electronics, Information and Communication Engineers )  112 ( 463 ) 571 - 576   2013.03

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The multiple-tree Application Level Multicast (ALM)is expected for the video streaming to many users because of effectively improving the fairness of bandwidth consumption. However, the multiple-tree ALM has the demerit of low churn resilience and larger transmission delay caused by the gap between logically structured overlay and underlying physical network. We have proposed the construction method of overlapped cluster-trees which has the merits of decreasing delay and enhancing churn resilience. Nevertheless, the overlapped cluster-trees method may be unsustainable if leaving the massive number of nodes occurred. In this paper, we propose further extended video streaming system based on overlapped cluster-trees. The newly proposed video streaming system enhances the tolerance for the heavy node churn because of selecting high performance nodes and early detection and repair of massive node leavings. The performance of the proposed methods is evaluated through computer simulation.

B-6-109 P2P Live Streaming System with Fast Channel Switching and Category-based Recommendation Functions

Kondo Daishi, Fujimoto Akihiro, Hirota Yusuke, Tode Hideki, Murakami Koso

Proceedings of the IEICE General Conference ( The Institute of Electronics, Information and Communication Engineers )  2012 ( 2 ) 109 - 109   2012.03

Prototyping and Evaluation of a Multi-Server Video Streaming System with Inter-Stream FEC Function

FUJIMOTO Akihiro, HIROTA Yusuke, TODE Hideki, MURAKAMI Koso

IEICE technical report ( The Institute of Electronics, Information and Communication Engineers )  111 ( 277 ) 83 - 88   2011.11

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To establish seamless and highly robust contents distribution technology in the environment of so-called multi-server contents distribution network, we have proposed the new concept, Inter-Stream FEC, that means data recovery method between several streams using parity streams generated by inter-stream cooperation. Our previous research shows that the proposed method can significantly improve the recovery capability, especially in burst-loss occurrence environments, compared with traditional FEC method. However, we have only evaluated the performance under ideal environment. In this paper, we summarize the requirements of Inter-Stream FEC function and propose the practically-oriented parity stream construction method. We implemented and empirically evaluated the prototype of a simplified multi-server video streaming system with Inter-Stream FEC function. The results show the system can achieve high restoration performance.