An Adaptive MAC Protocol for Efficient Group Communications in Sensor Networks

Abstract-This paper proposes a novel adaptive energy efficient MAC protocol for wireless sensor networks, referred to as TDMA-WA. The proposed protocol is contention free and is based on the well known time-division multiple access (TDMA) principle. However, the frame length is variable corresponding to the degree of 2-hop neighborhood for each node. This allows the frame length to adapt to the varying density of the network. Unlike most of the existing protocols that are based on the CSMA principle, the proposed protocol guarantees bounded end-to-end delay. Furthermore, unlike other TDMA based protocols, TDMA-WA does not require separate channel for signaling or slot reservation. The protocol is designed to facilitate efficient realization of group communication primitives that frequently arise in collaborative computations over sensor networks. The performance results of realizing group communication based on this protocol are presented and compared with adaptive S-MAC. Our proposed protocol provides significantly superior performance in terms of communication time and energy usage. For example, we show improvement in routing time between 25 % to 75% over 50%-SMAC for routing linear permutations