EEH-MAC: Energy-Efficient Hybrid MAC Protocol in Wireless Sensor Networks

Abstract

In wireless sensor networks (WSNs), energy is a very scarce resource and has to be managed wisely in order to extend the life of the sensors. Therefore, to be energy-efficient, this paper is presented as hybrid protocol for MAC layer in Wireless Sensor Networks (WSNs). It combines contention and schedule-based methods. Time slot assignment is designed by semi-distributed manner. A base station is considered as a master only for its one-hop children because nodes are also memory (buffer)-constrained ones in real world. When a base station sends token to its neighboring nodes all the way through the largest-hop nodes and token is sent back to the base station, this may cause the overflow of buffer or the time slot assignment table may be damaged during token is passing through all the nodes. To avoid this problem, time slot assignment is only considered as the two-hop neighbors from each parent.