Optimal On-demand Mobile Sensor Allocation

In many practical applications of sensor networks, the level of sensor coverage needed at different locations varies with time. Pre-computation of sensor deployment in such cases is inadequate; on-the-fly redistribution of nodes in the network, as the system evolves, becomes necessary. Reallocation of sensors consumes resources (e.g., energy). Thus it is desirable to do so while minimizing a global metric of cost. The contribution of this paper is a distributed sensor reallocation algorithm superior to existing algorithms that computes the set of sensor movement that satisfies the demand of sensors at each part of the network, if it is at all feasible, while optimizing a given metric of interest, such as the total distance traveled. In general such discrete problems are NP-hard. However, the proposed algorithm is polynomial-time computable as it exploits a special structure of the problem. We numerically establish its superiority over previous algorithms.