An Efficient TCP Algorithm for Differentiating Random Packet Losses from Spurious Retransmission Timeouts in Multi-hop Wireless Networks

TCP Retransmission Timeouts (RTOs) related to non-congestion have been reported as one of the main reasons of the performance degradation of TCP in multi-hop wireless networks. In this paper, we introduce an efficient algorithm called TCP NRT (Non-congestion Retransmission Timeouts) which is capable of recovering packets by detecting, differentiating and reacting to congestion as well as non-congestion RTOs. TCP NRT is able to reduce the unnecessary reduction of congestion window size and needless retransmissions. We implemented the algorithm in Qualnet network simulator and compared its performance to existing TCP versions such as Eifel, F-RTO, DSACK and EQRTO. The results from experiments show that our algorithm achieves significant performance improvement in multi-hop wireless networks.