Adaptive TCP receiver window control on channel conditions for wireless systems

Abstract

Wireless networks are quickly becoming an integral part of the Internet. But, the TCP does not work well in wireless networks. Considerable research has tried to improve TCP performance in wireless networks, especially in the face of the wireless link loss problem. However, TCP performance is also deeply influenced by channel conditions, and the performance in variable channel conditions has not been studied widely. In this paper, we observe the behavior of the traditional standard TCP performance in the face of variable channel conditions. Then, we propose a new simple TCP flow control scheme. The traditional standard TCP performs poorly because it does not reflect current channel conditions. Our adaptive TCP receiver window control scheme, however, performs well on variable channel conditions. Our scheme efficiently improves TCP performance with minimum modification of TCP module on the wireless terminal. It adaptively adjusts the TCP receiver window size depending on the dynamic channel conditions. Thus, our scheme maintains network conditions properly and has good TCP performance over all wireless channel conditions. In addition, since our scheme is simple and the only the TCP receiver module on the wireless terminal needs to be changed, it is feasible. Through the simulation and analysis, we found that our scheme has good TCP throughput and short end-to-end delay over all variable channel conditions.