Actor Positioning in Wireless Sensor and Actor Networks Using Matching Theory

In most of the wireless sensor and actor network (WSAN) applications, the locations for the actors are determined autonomously by the collaboration of actors and/or sensors in order to eliminate human intervention as much as possible. Particularly, sensors can collaborate in a distributed manner and elect cluster-heads (CHs) among them based on certain criteria. The actors can then move to such CH locations by talking to nearby sensors/actors. Such movement, however, should be done wisely in order to minimize the movement distance of actors so that their lifetimes can be improved. Nevertheless, this may not be possible since not all the actor and CH locations will be known by each actor. In addition, the actors may not be reachable to each other and thus conflicts in assignments can easily occur. In this paper, we propose an actor-CH location matching algorithm which will assign the actors to appropriate CH locations in a distributed manner with minimized travel distance. We adapt the Gale-Shapley (G-S) stable matching algorithm from matching theory in order to prevent conflicts in matching and minimize the travel distance of actors. In this matching algorithm, actors are regarded as men and CHs are regarded as women. For distributed execution of the algorithm, subnetworks of actors and CHs are determined. Each subnetwork performs its own matching based on G-S algorithm.If there are unmatched actors after this process, a network wide search is used to detect such nodes and to perform the matching. We evaluated the performance of our approach through simulation and have shown that our approach can produce results very close to the brute force approach with minimal messaging overhead.