An approach for using adaptive error control schemes in wireless LAN with CSMA/CA MAC protocol

Communication in high-speed wireless local area networks such as IEEE 802.11a are known to suffer from location-dependent, time-varying, and burst errors. It is usual to implement Forward Error Correction and Automatic Repeat reQuest mechanisms in the physical and data link layer to combat this errors. In this paper we evaluate the system performance of a WLAN with CSMA/MAC protocol with different ARQ protocols. We have implement three different schemes 1) Selective repeat ARQ, 2) ARQ with majority voting and 3) Type II Hybrid ARQ. The simulation results show that all three scheme performs well when the channel is in good condition but when the bit error rate (BER) increases the type II hybrid ARQ is superior the other two schemes.