TCP network coding with forward retransmission

Abstract

The performance of the transmission control protocol (TCP) with loss-based congestion control is considerably degraded in lossy networks (e.g., wireless networks). Implementing a network coding (NC) with TCP (TCP/NC) helps prevent this performance degradation by introducing lost packet recovery capability without retransmission at a sink by sending redundant combination packets encoded at the source. TCP/NC can recover random lost packets. However, TCP/NC is less effective when burst packet losses occur because it requires packet retransmission and the retransmission mechanism of the standard TCP/NC entirely relies on the TCP layer. To improve the goodput of a system, we propose a new mechanism in the NC layer called forward retransmission that can retransmit more than one lost packet simultaneously and efficiently. We simulated the proposed mechanism using Network Simulator 3. The results demonstrate that the proposed scheme improves the goodput of a system compared with the standard TCP/NC and TCP NewReno in a burst loss channel.