Energy Efficient Hybrid MAC Protocol for Cluster-Based Wireless Sensor Network

Abstract

Wireless sensor networks consist of large number of nodes often battery operated, which have ad hoc topology and variable traffic rates. The medium access control (MAC) protocol designed for the network must be stable and should consume less energy. This paper presents a novel hybrid MAC protocol that uses the information of clusters to divide the MAC layer functionality into two types, namely, bit map assisted (BMA) protocol and nanoMAC protocol for the intra and inter-cluster communication respectively. Performance of the hybrid MAC protocol is evaluated in terms of energy, delay and offered traffic load and compared with the conventional MAC schemes. Simulation results show that the hybrid MAC protocol considerably reduces the energy consumption and delay to maximize the lifetime of the sensor network. is proposed for this high contention resolution. It incorporates dynamic scheduling of non-cluster head nodes and when utilized for intra-cluster communication (5), it can significantly reduce the idle listening of nodes and conserve energy. With low contention, TDMA based MAC protocols give much lower channel utilization, higher delay and energy consumption compared with CSMA (5), (6). In inter-cluster communication, channel contention is less, hence a CSMA based MAC protocol called nanoMAC is proposed. NanoMAC protocol incorporates sophisticated sleep algorithm and collision avoidance techniques with CSMA to minimize energy consumption. Hence this paper suggests a novel hybrid MAC approach with BMA and nanoMAC and utilizes clustering scheme to reduce energy consumption. The main feature of the hybrid MAC protocol is that it can adapt to the level of contention in the network either high or low. The analysis of the proposed hybrid MAC protocol is evaluated to maximize the lifetime of the network and compared with np-CSMA and conventional TDMA schemes. The reminder of the paper is organized as follows. Section II describes the system model. Section III presents the hybrid MAC protocol scheme and its energy model for the intra and inter-cluster domain. The simulation framework and results are discussed in section IV and finally section V presents the conclusion of the suggested method.