Achieving High Lifetime and Low Delay in Very Large Sensors Networks Using Mobile Sinks

For smaller scale wireless sensor networks (WSN) it has been clearly shown that a single mobile sink can be very beneficial with respect to the network lifetime. Yet, how to plan the trajectories of many mobile sinks in very large WSNs in order to simultaneously achieve lifetime and delay goals has not been treated so far. In this paper, we delve into this difficult problem and propose a heuristic framework using multiple orbits for the sinks´ trajectories. The framework is carefully designed based on geometric arguments to achieve both, high lifetime and low delay. In simulations, we compare two different instances of our framework, one conceived based on a load balancing argument and one based on a distance minimization argument, with a set of different competitors spanning from statically placed sinks to battery-state aware strategies. We find our heuristics to perform very favorably: both instances outperform the competitors in both, lifetime and delay. Furthermore, and probably even more importantly, the heuristic, while keeping its good delay and lifetime performance, scales well with an increasing number of sinks.