An Energy Efficient Medium Access Protocol for Wireless Sensor Networks

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. This paper proposes a timeslot sharing medium access protocol for wireless sensor networks. The proposed scheme allows multiple sensor nodes to share a reserved or guaranteed timeslot for transmission. It allows more sensor nodes to transmit in the guaranteed timeslots and few sensor nodes to transmit in the contention slots. The goals of timeslot sharing protocol are to minimize the energy consumption of sensor nodes and to maximize the total number of nodes allowed in a network..