On the Optimal Block Length for Joint Channel and Network Coding
Channel coding alone is not sufficient to reliably transmit a message of finite length from a source to one or more destinations. To ensure that no data is lost, channel coding on the physical layer needs to be combined with rateless erasure correcting schemes such as Automatic Repeat reQuest (ARQ) or Random Linear Network Coding (RLNC) on a higher layer. In this paper, the authors consider channel coding on a binary symmetric channel and random linear network coding for erasure correction. Given a message of length K and network coding over a finite Galois field of size q, they obtain the optimal number of blocks for network coding that minimizes the expected number of transmissions.