P&P protocol: Local coordination of mobile sensors for self-deployment

The use of mobile sensors is of great relevance for a num- ber of strategic applications devoted to monitoring critical areas where sensors can not be deployed manually. In these networks, each sensor adapts its position on the basis of a local evaluation of the coverage eciency, thus permitting an autonomous deployment. Several algorithms have been proposed to deploy mobile sensors over the area of interest. The applicability of these approaches largely depends on a proper formalization of rigorous rules to coordinate sensor movements, solve local con icts and manage possible fail- ures of communications and devices. In this paper we intro- duce P&P, a communication protocol that permits a correct and ecient coordination of sensor movements in agreement with the PUSH&PULL algorithm. We deeply investigate and solve the problems that may occur when coordinating asynchronous local decisions in the presence of an unreliable transmission medium and possibly faulty devices such as in the typical working scenario of mobile sensor networks. Sim- ulation results show the performance of our protocol under a range of operative settings, including con ict situations, irregularly shaped target areas, and node failures.