Distributed overlay formation in heterogeneous wireless sensor networks

The scale and functional complexity of future-generation wireless sensor networks will call for a non-homogeneous architecture, in which different sensors play different logical roles or functions, or have different physical capabilities in terms of energy, computing power, or network bandwidth. When sensors of the same group need to communicate with each other, their communications often have to pass through other sensors, thus forming an overlay on top of the wireless sensor network. The topology of the overlay is critical. It must have a low diameter to reduce the communication latency between those sensors. It also needs to avoid using other sensors for relaying the communications as much as possible, so as to preserve the energy of other sensors. In this paper, we propose a distributed overlay formation protocol taking account of the above factors. Through simulation, we compare our protocol with two overlay formation protocols, one that generates a fully connected topology and the other a minimum spanning tree. The results show that our protocol can achieve better performance both in message latency and energy consumption.