A Review on Medium Access Control Protocols for Wireless Sensor Networks

Wireless sensor networks (WSNs) have become an active research area for the researchers due to their widely used range of application potential in areas such as target detection and tracking, environmental monitoring, industrial process monitoring, and tactical systems. Usually, after the deployment of sensor nodes in the hazardous, hostile or remote areas, these sensor nodes work on their own. These sensor nodes will have to work with their limited and none replenish able energy resources. 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. Therefore, to ensure a long-lived network of wireless communicating sensors, we are in need of a MAC protocol that is able to improve energy efficiency by maximizing sleep duration, minimizing idle listening and overhearing, and eliminating collision of packets. This paper presents a review of the most recent works regarding with MAC protocols for applications of wireless sensor networks. First we present discussions on radio energy model, energy consumption measuring and the sensor network properties that are crucial for the design of MAC layer protocols. Second we describe the several available energy-efficient MAC protocols for sensor networks emphasizing their energy saving methods. These energyefficient MAC protocols are mainly divided into two groups, i.e. synchronous and asynchronous MAC protocols. Finally, we discuss some future research issues in the design of MAC protocol for WSNs. Keywords-Energy Efficiency; Radio Energy Model; MAC Protocols; Wireless Sensor Network