Aggregation vs. Load Balancing in WSNs

We consider the interplay between data aggregation and workload balancing in a Wireless Sensor Network (WSN). In particular, we formulate the problem of deciding where to forward traffic, in order to benefit the most from potential aggregation, while also splitting the resulting traffic (once aggregated) on the way to the Sink for the sake of load balancing. Load balancing across multiple paths results in a corresponding balanced energy consumption and therefore prolongs the lifetime of WSNs. The optimization formulation leads to an IP/LP model where the objective is that of maximizing the lifetime of the WSN. Heuristics are proposed for assigning an efficient data aggregation node for each sensor source. Simulation results show that our schemes significantly improve performance both in terms of longer system lifetime and less total data received (indicating more aggressive aggregation) at the Sink.