| Project/Area Number |
18500053
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Computer system/Network
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| Research Institution | Nara Institute of Science and Technology |
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Principal Investigator |
ITO Minoru Nara Institute of Science and Technology, Graduate School of Information Science, Professor (90127184)
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| Co-Investigator(Kenkyū-buntansha) |
YASUMOTO Keiichi Nara Institute of Science and Technology, Graduate Schcol of Information Science, Associate Professor (40273396)
SHIBATA Naoki Shiga University, Faculty of Economy, Associate Professor (40335477)
MURATA Yoshihiro Hiroshima City University, Faculty of Information Science, Associate Professor (40362834)
KITANI Tomoya Nara Institute of Science and Technology, Graduate School of Information Science, Assistant Professor (40418786)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥4,110,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Video Multicast / Network Application / Mobile Terminal / QoS Control |
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| Research Abstract |
In this research, we have considered a cost-efficient multicast method for video streaming to heterogeneous mobile terminals via a content delivery network (CDN). Based on the requirements such that each mobile terminal can specify the quality of receiving video under the constraints of display size, computation power, available battery power, and bandwidth and that each terminal can receive the video mostly satisfying the user's demand, we have the following results.
(1) The original video is converted in various qualities by letting proxies execute transcoding services based on the users' requirements. We have developed an algorithm for deciding connecting paths among a server, proxies, and mobile terminals so as to minimize the resource of CDN. Furthermore, we have designed a protocol for reconstructing the paths periodically according to users' requirements.
(2) We consider a method for constructing a multicast tree in a mobile ad hoc network. In general, it is NP-hard to construct the cost-minimum multicast tree under multiple constraints such as latency time and bandwidth, and thus we have developed an efficient algorithm for obtaining a semi-optimal solution using a genetic algorithm. In order to apply to a large scale network, we have designed an distributed algorithm with two stages, as follows: The set of mobile nodes is divided into clusters by gathering the nodes located near. After that, a semi-optimal multicast tree is constructed for each cluster, and then a semi-optimal multicast tree is constructed for the set of representative nodes of clusters.
We have confirmed the usefulness of the results above through simulations.
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