A wireless sensor network is composed of numerous nodes distributed over an area to collect information. The sensor nodes communicate among themselves through the wireless channel to self-organize into a multi-hop network and forward the collected data towards base stations. Each node has sensors, embedded processors and low-power radios, and is normally battery operated. As these nodes are placed in such conditions that charging or replacing their battery are almost impossible energy consumption becomes a major constraint. Low power capacities of sensor nodes result in very limited coverage and communication range compared to other mobile devices. Hence, to successfully cover the target area, sensor networks are composed of large number of nodes. Employing energy efficient, sensor-specific MAC protocols is of necessity for sensor nets. In this paper, we surveyed some existing MAC protocols for WSN. The goal is to study MAC design, and to identify important design issues that allow us to improve the overall performances.

1. Ye W, Heidemann J, Estrin D., “An energy-efficient MAC protocol for wireless sensor network”. In Proceedings of the INFOCOM 2002. San Francisco: IEEE Computer Society, 2002.
2. Zheng, T. Radhakrishnan, S. Sarangan, V., “PMAC: An adaptive energy-efficient MAC protocol for Wireless Sensor Networks.” In Parallel and Distributed Processing Symposium, 2005. Proceedings. 19th IEEE International.
3. Zhang, Lei, Ghosh, Somnath, Veeraraghavan, Prakash, Singh, Samar. “An Energy Efficient Wireless Sensor MAC Protocol with Global Sleeping Schedule.” In Computer Science and its Applications, 2008. CSA '08. International Symposiu, Oct. 2008
4. LAN MAN Standards Committee of the IEEE Computer Society. IEEE Std 802.11-2000, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications. IEEE, 2000.
5. V. Rajendran , K. Obraczka and J. J. Garcia-Luna-Aceves “Energy-efficient, collision-free medium access control for wireless sensor networks.” In Wireless Netw., vol. 12, pp. 63, 2006.
6. Polastre, J., Hill, J., AND Culler, D. “Versatile low power media access for wireless sensor networks.” In Second ACM Conference on Embedded Networked Sensor Systems (2004).
7. M. Buettner, G. V. Yee, E. Anderson, and R. Han. “X-mac: a short preamble mac protocol for duty-cycled wireless sensor networks.” In Proc. 2nd ACMConf. on Embedded Networked Sensor Systems (SenSys’06), pages 307–320, 2006.
8. Wei Ye, John Heidemann, Deborah Estrin, “Medium Access Control with Coordinated, Adaptive Sleeping for Wireless Sensor Networks”, Technical Report ISI-TR- 567, USC/Information Sciences Institute, January 2003. LAN
9. MAN Standards Committee of the IEEE Computer Society, Wireless LAN medium access control (MAC) and physical layer (PHY) specification, IEEE Std 802.11, IEEE, 1997.
10. V. Bharghavan, A. Demers, S. Shenker, and L. Zhang, MACAW: A Media Access Protocol for Wireless LANs, In Proc. SIGCOMM’ 94, pp. 212-225, London, U.K., September 1994.

Medium Access Control Wireless Sensor Network S-MAC