| Project/Area Number |
14550361
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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 |
情報通信工学
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| Research Institution | Kagawa University |
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Principal Investigator |
OGOSE Shigeaki Kagawa University, Faculty of Engineering, Professor, 工学部, 教授 (00304577)
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| Co-Investigator(Kenkyū-buntansha) |
HATA Masaharu Okayama University, Faculty of Engineering, Professor, 工学部, 教授 (50335577)
YOSHIDA Teruaki Hiroshima City University, Faculty of Information Sciences, Professor, 情報科学部, 教授 (50316139)
NISHI Masahiro Hiroshima City University, Faculty of Information Sciences, Assistant, 情報科学部, 助手 (30316137)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2002: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Communication broadcasting integration / Radio wave propagation Characteristics / UHF band / Mobile communication / Okumura-Hata formula / 通信放送融合型情報ネットワーク |
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| Research Abstract |
(1)Mobile propagation measurements
We have measured the receiving level of UHF bandbroadcasting radio wave from the existent TV stations in local cities such as Hiroshima, Okayama, and Takamatsu. From the measurement results, following are clarified :
(a)Urban area : Attenuation constant is about 3.1 and the path loss is lower than that of Okumura-Hata model by 10dB.
(b)Suburban area : Attenuation constant is around 6.5 and path loss is lower than that of Okumura-Hata model by 10dB.
(c)Hilly area : Attenuation constant is about 7 or more in Okayama and Takamatsu and 3 in Hiroshima, path loss fluctuates from 20 dB to 30 dB due to coexistent of both LOS and NLOS areas caused by complex terrain characteristics.
In the local cities, the urban structure changes rapidly from the downtown to the suburban. Fluctuation of path loss strongly depends on the terrain LOS. We should consider the urban structure and LOS effect in the system design of UHF band terrestrial TV broadcasting systems.
(2)System design related matters
(a)System aspects and condition : System aspects and conditions to realize information system operating in UHF band are considered. Characteristics of overlapped and superimposed cell layout methods were compared.
(b)Service-area estimation : Based on the path-loss measurement results, service area in mobile reception environment is estimated. It is clarified that the service area for digital TV broadcasting is decreased to be 35%-55% of analog broadcasting due to large fluctuation of reception level.
(c)Information distribution algorithm : New type of information distribution method adaptively using wireless multicast and unicast links is proposed in order to reduce the waiting time until users receive the requested data.
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