TCP with network coding meets loss burstiness estimation for lossy networks.

Although Transmission Control Protocol (TCP) is still dominant in both wired and wireless networks, TCP in lossy networks suffers from goodput reduction because it considers any packet loss as a network congestion signal and decreases its sending rate even if the loss is not due to congestion. TCP with network coding (TCP/NC) had been proposed to overcome this problem. It is expected to recover the lost packets without retransmission at the sink by proactively sending the redundant combination packets encoded at the source. However, the original TCP/NC is ineffective in burst loss channels because it does not provide any means to determine appropriate values of the network coding parameters, e.g., redundancy factor and coding window size, to adapt burst loss channels. We propose the new scheme called TCP/NC with loss rate and loss burstiness estimation (TCP/NCwLRLBE), which periodically estimates not only the loss rate but also the loss burstiness based on observation of the past communications and adaptively determines appropriate network coding parameters based on computation of the necessary recovery capability. We implemented and validated our proposal in Network Simulator 3. The results show that the TCP/NCwLRLBE can improve the TCP goodput in the burst loss channels.