MANETによるワンセグ難視聴端末救済手法  [in Japanese] MANET-based Video Quality Improvement Method for One-segment Broadcasting Service  [in Japanese]

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Abstract

本論文では,モバイルユーザが所持する無線通信可能なワンセグ携帯端末を対象に,ワンセグの受信品質が良い端末から悪い端末(難視聴端末)に対してマルチホップでビデオをストリーミング配信することで視聴品質を向上させる手法を提案する.まず,無線通信帯域や最大転送ホップ数などの制約を満たし,難視聴端末の救済数を最大化するビデオ中継パスの集合を求める問題を形式的に定義する.本問題はNP困難問題であり短時間に最適解を求めることは難しいため,各端末が近隣端末と定期的に交換した情報をもとにグリーディにビデオ中継パスを発見するアルゴリズムを提案する.また,本グリーディアルゴリズムを改良し,近隣端末に難視聴端末が要求するワンセグチャネルを代理受信させ中継することで救済数を増加させるアルゴリズムを提案する.3種類の典型的なフィールドモデルを用いた計算機シミュレーションの結果,提案手法は2ホップの中継により,難視聴エリアへの総滞在時間の60%以上において視聴品質を改善できた.In this paper, we propose a method for improving 1seg video playback quality of mobile terminals with weak 1seg radio area (WRA terminals) by wireless multihop video streaming from terminals in strong 1seg radio area (SRA terminals). First, we formulate the problem to derive the set of video forwarding paths that maximize the number of relieved WRA terminals under the constraints on the wireless bandwidth and the maximum number of hops. Since this problem is NP-hard and it is difficult to derive the optimal solution in real-time, we propose a greedy algorithm that each WRA terminal finds a video forwarding path from a SRA terminal receiving the required 1seg channel based on the information periodically exchanged among neighboring terminals. In order to increase the number of relieved terminals, we introduce a technique called the cascade video forwarding where a WRA terminal (say A) asks a neighboring SRA terminal (say B) to receive the A's requesting 1seg channel and forward the video to A, and the terminal B asks another terminal to forward the video of the B's requesting 1seg channel. Through computer simulations, we confirmed that the proposed algorithm with 2-hop relief paths improved the video playback quality in more than 60% of the total WRA staying time for three typical field models.

In this paper, we propose a method for improving 1seg video playback quality of mobile terminals with weak 1seg radio area (WRA terminals) by wireless multihop video streaming from terminals in strong 1seg radio area (SRA terminals). First, we formulate the problem to derive the set of video forwarding paths that maximize the number of relieved WRA terminals under the constraints on the wireless bandwidth and the maximum number of hops. Since this problem is NP-hard and it is difficult to derive the optimal solution in real-time, we propose a greedy algorithm that each WRA terminal finds a video forwarding path from a SRA terminal receiving the required 1seg channel based on the information periodically exchanged among neighboring terminals. In order to increase the number of relieved terminals, we introduce a technique called the cascade video forwarding where a WRA terminal (say A) asks a neighboring SRA terminal (say B) to receive the A's requesting 1seg channel and forward the video to A, and the terminal B asks another terminal to forward the video of the B's requesting 1seg channel. Through computer simulations, we confirmed that the proposed algorithm with 2-hop relief paths improved the video playback quality in more than 60% of the total WRA staying time for three typical field models.

Journal

  • 情報処理学会論文誌

    情報処理学会論文誌 52(2), 829-838, 2011-02-15

    一般社団法人情報処理学会

Keywords

Codes

  • NII Article ID (NAID)
    110008507922
  • NII NACSIS-CAT ID (NCID)
    AN00116647
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    1882-7764
  • NDL Article ID
    024167968
  • NDL Call No.
    YH247-743
  • Data Source
    NDL  NII-ELS  IR  IPSJ 
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