Research Article
Energy-Efficient Medium Access for Wireless Sensor Networks under Slow Fading Conditions
@INPROCEEDINGS{10.4108/ICST.BROADNETS2009.7554, author={Changmian Wang and Liuguo Yin and Geir E. \`{U}ien}, title={Energy-Efficient Medium Access for Wireless Sensor Networks under Slow Fading Conditions}, proceedings={6th International ICST Conference on Broadband Communications, Networks, and Systems}, publisher={IEEE}, proceedings_a={BROADNETS}, year={2009}, month={11}, keywords={Access protocols Collision avoidance Energy efficiency Fading Media Access Protocol Multiaccess communication Wireless application protocol Wireless communication Wireless sensor networks ZigBee}, doi={10.4108/ICST.BROADNETS2009.7554} }- Changmian Wang
Liuguo Yin
Geir E. Øien
Year: 2009
Energy-Efficient Medium Access for Wireless Sensor Networks under Slow Fading Conditions
BROADNETS
IEEE
DOI: 10.4108/ICST.BROADNETS2009.7554
Abstract
In this work, we first study and then propose an optimal version on the medium access control mechanism known as carrier sense multiple access with collision avoidance (CSMA/CA). This protocol is adopted by many wireless communication standards, such as the IEEE 802.11 series and IEEE 802.15.4 (ZigBee). We first identify its drawbacks in a slow fading channel environment, and show that the CSMA/CA can be very energy-inefficient, especially in many wireless sensor network (WSN) applications where the traffic demand is low. In particular, we study communication over a Rayleigh fading channel, which we model by means of a time invariant Markov process. We then show that the decision regarding the optimal access time on such a channel can be formulated as an optimization problem, and that an optimal solution can be accurately derived. We also simulate a ZigBee node in a Rayleigh fading environment and the result shows that optimum channel access can save significant amount of energy compared to conventional CSMA/CA.