A PROTOCOL TO IMPROVE THE DATA COMMUNICATION OVER WIRELESS NETWORK

Reliable transport protocols are tuned to perform well in traditional networks where packet losses occur mostly because of 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. The main reason of this poor performance for TCP is that TCP cannot distinguish between packets 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 throughput and end-to-end performance of TCP. In this work, a novel protocol, called DLN (Data Loss Notification), is be proposed. By changing the ACK format of TCP, we could successfully distinguish packet losses incurred by congestion and channel error which will improve both throughput and delay performance of TCP in wireless environment significantly. This mechanism has been demonstrated to provide performance improvements across a range of bit-error rates.