Transmission-Distortion Tradeoffs in Network Channel Coding

Network channel coding (NCC) is a framework under which intermediate router/nodes employ encoding/decoding operations to facilitate an efficient multicast delivery of video. The network usage and video distortion is a function of the channel coding rates assigned to nodes in the network. In this paper, we investigate the tradeoff between the total bandwidth usage and a global distortion measure. We propose a dynamic programming based framework to identify the optimal transmission-distortion operating points. The proposed optimal allocation of coding rates is compared with an earlier version of NCC, network embedded FEC (NEF), which optimally places codecs of a fixed channel coding rate within the network. The proposed NCC scheme is shown to achieve significantly improved transmission distortion tradeoffs.