Cross-layer optimization for performance trade-off in network code-based wireless multi-hop networks

Maximizing network lifetime and optimizing aggregate system utility are important but usually conflict goals in wireless multi-hop networks. For the trade-off particularly for such networks equipped with the capability of network coding, we introduce a cross-layer optimization approach that can seamlessly accommodate routing, scheduling and stream control to simultaneously meet the diverse objectives with the aid of network utility maximization. Specifically, by taking into account both intra- and inter-session network coding and cross-layer formalization, the algorithms resulted are considered to be more general than those obtained from, e.g., poison-remedy based methods that focus on the methodology of network coding itself. In particular, along with a Markov Chain Monte Carlo method and a CSMA approximation, these algorithms can dynamically approach the optimal solution while solving the scheduling subproblem involved, which is NP-hard in general, in a distributed manner. Finally, we present numerical results for the insight that can be gained from the cross-layer optimization and show that this work is capable on achieving an optimal trade-off between the lifetime and utility.