On Maintaining Sensor-Actor Connectivity in Wireless Sensor and Actor Networks

In wireless sensor and actor networks (WSANs), a group of sensors and actors are connected by a wireless medium to perform distributed sensing and acting tasks. Sensors usually gather information in an event area and pass it on to actors, which are resource-rich devices that make decisions and perform necessary actions. Therefore, it is vital to maintain connections between sensors and actors for effective sensor- actor coordination. In this paper, we first define several sensor- actor connection requirements, including weak and strong actor-connectivity, and then propose several local solutions that put as many sensors as possible to sleep for energy saving purposes, while meeting different actor-connectivity requirements. We also prove the relationship between the proposed actor-connectivity and the connectivity in regular graphs, which helps with the implementation of the proposed solutions. Comprehensive performance analysis is conducted through simulations.