We propose a hybrid model to alleviate the notorious problem of premature battery depletion in sensor networks: in a first stage, simple sensors are deployed over an area of interest using any traditional method, in a second phase, more powerful relays are put in positions that allow them to off-load as much of the forwarding burden imposed on the simple sensors as possible. We introduce this model in detail, give a few theoretical results with respect to the optimal placement of the powerful sensors, propose various heuristic approaches for their placement, and present comparative simulation results for these heuristics.
Stephan Eidenbenz, Lukas Kroc, James P. Smith