A study on combined routing and source coding with explicit side information in sensor networks

This paper studies the problem of combining tree routing and data compression with explicit side information in wireless sensor networks. We first present our network flow and data rate model based on the observation that in many practical situations, side information providing the most coding gain comes from a few nearby sensors. An optimization problem is then formulated and shown to be NP hard. It is subsequently cast as a mixed integer program. For our particular model, we examine several approximation algorithms, and compare their performances through simulations. Improvement over shortest path trees, which completely ignore the source correlation, is achieved only by judiciously merging flows of correlated data based on the coding gain information.