A directional-antenna based MAC protocol for wireless sensor networks

Directional antennas have been extensively used in designing MAC protocols for wireless ad hoc networks in recent years. Directional antennas provide many advantages over the classical antennas which are onmidirectional. These advantages include spatial reuse and increase in coverage range. One of the main considerations in designing MAC protocols for static wireless networks is to reduce power consumption at the sensor nodes. This is usually done by imposing transmission and receiving schedules on the sensor nodes. Since it is desirable for a sensor network to be self managed, these schedules need to be worked out by individual nodes in a distributed fashion. In this paper, we show that directional antennas can be used effectively to design an energy efficient MAC protocol for wireless sensor networks. Our MAC protocol conserves energy at the nodes by calculating a scheduling strategy at individual nodes and by avoiding packet collisions almost completely.