• Title/Summary/Keyword: Distributed MAC protocol

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A DCF Throughput Analysis of the Ideal and Fading Channel in the Wireless LAN (무선 LAN에서 이상 및 페이딩 채널 환경의 DCF 처리율 비교 분석)

  • Lee, Yong-Sik;Lee, Ha-Cheol;Lee, Byung-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.7
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    • pp.741-753
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    • 2008
  • This paper explores the throughput performance of CSMA/CA-based DCF protocol over both ideal channels and fading channels with payload size at the MAC layer in the 802.11a wireless LAN. In the ideal channel, there are no errors and at the transmission cycle there is one and only one active station which always has a packet to send and other stations can only accept packets and provide acknowledgements. In the fading channel, bit errors appear in the channel randomly and the number of stations is assumed to be fixed. And each station always has packets for transmission. In other words, we operate in saturation conditions. Up to now conventional research work about DCF throughput analysis of IEEE 802.11 a wireless LAN has been done over the ideal channel, but this paper is done over the Rayleigh/Ricean fading channel. So, the ratio of received average energy per bit-to-noise power spectral density $E_b/N_o$ is set to 25 dB and the ratio of direct-to-diffuse signal power in each sub-channel $\xi$ is set to 6 for combined Rayleigh/Ricean fading channel. In conclusion, it is shown that the saturation throughput is always less than the maximum throughput at all the payload size and the higher the transmission rate be, the higher the decreasing rate of saturation throughput compared to the maximum throughput be.