Medium access control in wireless sensor networks

Limited energy, computational, and communication resources complicate protocol design within sensor networks and prevent the application of many techniques used within other networks. Constraints on sensor node cost further restrict which technologies sensor networks may utilize. Despite much attention in recent years, researchers have yet to achieve the goal of long term, independent operation of sensor network deployments under these constraints. One research direction considers the energy expended performing communication functionality. Medium access protocols provide the greatest influence over communication mechanisms and provide the most direct influence over the utilization of the transceiver, the largest energy consumer in most sensor nodes. We present a discussion of medium access control concepts in relation to sensor networks and examine previous wireless medium access control protocols to illustrate how they do not match the requirements and characteristics of sensor networks. We then present several protocols recently proposed in the literature specifically for sensor networks.