Balanced data gathering in energy-constrained sensor networks

We consider the problem of gathering data from a wireless multi-hop network of energy-constrained sensor nodes to a common base station. Specifically, we aim to balance the total amount of data received from the sensor network during its lifetime against a requirement of sufficient coverage for all the sensor locations surveyed. Our main contribution lies in formulating this balanced data gathering task and in studying the effects of balancing. We give an LP network flow formulation and present experimental results on optimal data routing designs also with impenetrable obstacles between the nodes. We then proceed to consider the effect of augmenting the basic sensor network with a small number of auxiliary relay nodes with less stringent energy constraints. We present an algorithm for finding approximately optimal placements for the relay nodes, given a system of basic sensor locations, and compare it with a straightforwaxd grid arrangement of the relays.