An Efficient Network Coding Scheme with Symbol Combining: Performance Evaluation, Optimization and Comparisons

In this paper, we investigate the performance advantages achieved by using a symbol combining (SC) approach in a random linear network coding (RLNC) scheme for broadcast communications over lossy channels. In particular, the focus is on a modified RLNC scheme that makes use of the repeated transmissions of each data symbol belonging to the same coded packet to implement the SC approach at the receiving ends. By considering the mean number of transmissions and energy consumption for each coded packet as objective metrics, two optimization procedures are proposed and compared in this paper. We consider a broadcast network model where an access point (AP) has to broadcast coded packets to a set of receiving nodes. In addition, the analysis presented in this paper is extended to broadcast communications in butterfly topology networks. For all the considered scenarios, the better behavior of the SC RLNC scheme results is clearly evident in comparison with the basic RLNC, without requiring additional implementation complexity at each receiving end.