D-STAR MAC Protocol: A Cross Layer Solution for Wireless Sensor Networks Endowed with Directive Antennas

This paper deals with a novel MAC layer protocol, namely Directive synchronous transmission asynchronous reception (D-STAR), which is able to logically synchronize a Wireless sensor network (WSN). In this case both sleep and active states together with integrating directional antennas within the communications framework can be managed, according to a cross-layer design. D-STAR protocol has been characterized in terms of functional characteristics and the overall performance is presented in terms of network lifetime gain, set-up latency and collision probability. A remarkable gain is shown with respect to the basic approach endowed with omnidirectional antennas without increasing the signaling overhead nor affecting the set up latency, but achieving energy consumption reduction.