A Model-Based Approach to Evaluation of the Efficacy of FEC Coding in Combating Network Packet Losses

摘要

We propose a model-based analytic approach for evaluating the overall efficacy of FEC coding combined with interleaving in combating packet losses in IP networks. In particular, by modeling the network path in terms of a single bottleneck node, described as a $G/M/1/K$ queue, we develop a recursive procedure for the exact evaluation of the packet-loss statistics for general arrival processes, based on the framework originally introduced by Cidon , 1993. To include the effects of interleaving, we incorporate a discrete-time Markov chain (DTMC) into our analytic framework. We study both single-session and multiple-session scenarios, and provide a simple algorithm for the more complicated multiple-session scenario. We show that the unified approach provides an integrated framework for exploring the tradeoffs between the key coding parameters; specifically, interleaving depths, channel coding rates and block lengths. The approach facilitates the selection of optimal coding strategies for different multimedia applications with various user quality-of-service (QoS) requirements and system constraints. We also provide an information-theoretic bound on the performance achievable with FEC coding in IP networks.