| Project/Area Number |
16560344
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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 |
Communication/Network engineering
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| Research Institution | Okayama Prefectural University |
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Principal Investigator |
SAKAKIBARA Katsumi Okayama Prefectural University, Faculty of Computer Science & System Engineering, Associate Professor, 情報工学部, 助教授 (10235137)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAKITA Jiro Okayama Prefectural University, Faculty of Computer Science & System Engineering, Professor, 情報工学部, 教授 (20145816)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2004: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Wireless Sensor Networks / Wireless LAN / IEEE 802.11 DCF / Markov Model / アドホックネットワーク / センサーネットワーク / MACプロトコル / エネルギー効率 / バックオフ・アルゴリズム / スループット |
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| Research Abstract |
Most of analytical models proposed so far for the IEEE 802.11 distributed coordination function (DCF) focus on saturation performance. In this research, we develop an analytic model for unsaturation performance evaluation of the IEEE 802.11 DCF with and without slow contention window decrease (SCWD). The model explicitly takes into account the carrier sensing mechanism and an additional backoff interval after successful frame transmission, both of which can be ignored under saturation conditions. Expressions are derived for throughput and delay characteristics by means of the equilibrium point analysis. The accuracy of our model is validated through computer simulation. Numerical results based on the IEEE 802.11b with CCK show that the SCWD can stably achieve approximately 20% performance gain over the normal 802.11 DCF under unsaturation conditions as well as saturation ones. We develop an analytic model to evaluate non-saturation energy consumption of IEEE 802.11 DCF, based on the model by Cantieni. The model explicitly takes into account both the carrier sensing mechanism and an additional backoff interval after successful frame transmission, which can be ignored under saturation conditions. The probability generating function with respect to energy consumed between consecutive frame generations is derived. Numerical example shows that most of energy is wasted in carrier sensing when the frame generation probability is smaller than some critical value and that the energy consumed in overhearing a frame destined to another user occupies the major part otherwise.
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