Date Added: Dec 2012
Wireless sensor networks have been widely used in many important fields such as target detection and tracking, environmental monitoring, industrial process monitoring etc. Since the nodes in wireless sensor networks consist of a limited power source, energy efficient operations of the nodes are very important. Although energy conservation in communication can be performed in different layers of the TCP/IP protocol suit, energy conservation at MAC layer is found to be the most effective one due to its ability to control the radio directly. For sensor nodes that are battery operated, it is sometimes difficult or impractical to charge or replace exhausted battery. The Medium ACcess protocol (MAC) for wireless sensor network must be energy efficient.