Delay performance of the new explicit loss notification TCP technique for wireless networks

Abstract

TCP performs at an acceptable efficiency over the traditional wired networks where packet losses are usually caused by network congestion. However, in networks with wireless links in addition to wired segments this assumption would be insufficient, as the high wireless bit error rate could become the dominant cause of packet loss and thus TCP performs sub-optimum under these new conditions. As the main reason of this poor performance for TCP we may raise the fact that TCP cannot distinguish between packet losses due to wireless errors from those due to congestion. Moreover, TCP sender cannot keep the size of its congestion window at optimum level and always has to retransmit packets after waiting for timeout, which significantly degrades end-to-end delay performance of TCP. We evaluate the delay and loss recovery performance of a new algorithm named explicit loss notification with acknowledgement. Experimental results show that the proposed scheme improves both throughput and delay performance of TCP in wireless environment significantly.