A new link layer protocol for wireless correlated fading channels

Internet access is expected to be the main data service in future wireless networks. However, the typical wireless correlated fading channels are found very unfriendly to TCP performance in such networks. Further challenge comes from the variations in fading rate, which demands an efficient link layer protocol that can adapt to the variations and improve the TCP transmission performance. In this paper, we first study the performance of different RLP (radio link protocol) retransmission schemes in supporting TCP. Through simulation results, we show that a single retransmission scheme does not yield the best performance in terms of throughput with different rates of fading. Based on this observation, we propose an adaptive link layer protocol (ALLP) for the future wireless networks that has a fading rate detector to estimate the channel fading rate. Based on the estimated channel fading rate, ALLP adaptively adjusts its retransmission schemes to achieve the optimal data transmission performance. Simulation results show that ALLP can improve both the performance of a particular mobile host and the total throughput of wireless networks.