Network and erasure coding for improved packet delivery

Abstract

Network coding (NC) and erasure coding (EC) share a common principle of encoding incoming data packets at network intermediate nodes so that destination nodes can reconstruct the original data packets using a sufficient number of encoded data packets collected at the destinations. While NC in general reduces the number of packets sent through the network, EC introduces redundancy into the packet streams to recover from lost packets. Many research papers in NC assume loss-free packet transmission, and to address this issue, end-to-end packet loss recovery through EC has been proposed. In this paper, we investigate hop-by-hop packet loss recovery through EC so as to avoid the accumulation of lost packets throughout the network using flow oriented EC. Specifically, we explore combined NC and EC at intermediate nodes in the networks to allow for improved packet loss recovery compared to end-to-end EC. Different implementations trading the packet processing complexity at the intermediate and destination nodes are considered. This paper first examines the effects of data loss in NC and then the improvements achievable with the proposed method are presented.