QoS-based adaptive error control for wireless networks

Wireless channels are highly affected by unpredictable factors such as cochannel interference, adjacent channel interference, propagation path loss, shadowing and multipath fading. The unreliability of media degrades the transmission quality seriously. Automatic Repeat reQuest (ARQ) and Forward Error Correction (FEC) schemes are frequently used in wireless environments to reduce the high bit error rate of the channel. In this paper, we propose an adaptive error control scheme for wireless networks based on dynamic variation of error control strategy as a function of the channel bit error rate, desired QoS and number of receivers. Reed-Solomon erasure codes are used throughout this study because of their appropriate characteristics in terms of powerful coding and implementation simplicity. Simulation results show that our adaptive error control protocol decreases the waste of bandwidth due to retransmissions or extra coding overheads while satisfying the QoS requirements of the receivers.