An adaptive medium access control for energy efficiency in wireless sensor networks

Wireless sensor networks are usually a collection of sensor nodes deployed remotely with limited energy resources. Therefore, conservation of energy is one of the highest priorities in a wireless sensor network design. In this paper we present enhancements at medium access control (MAC) layer to improve energy efficiency. The MAC employs a variable frame size instead of using a fixed frame size, which improves energy conservation. A new approach called extended Kalman Filter is used to predict the optimal frame size. The variable frame size keeps the system degradation caused by a time varying wireless channel to minimum. These enhancements are designed to optimize the MAC layer without losing its fairness while increasing throughput. Simulations have been conducted with different network scenarios and the results suggest that our approach improves energy efficiency by 5 to 15%.