An Energy-efficient Multi-channel MAC Protocol for Cluster Based Wireless Sensor Networks

Abstract The research on wireless multimedia sensor networks (WMSNs) becomes more popular recently because multimedia sensor nodes largely improve the capability of wireless sensor networks for event description. WMSNs need large bandwidth to deliver multimedia contents effectively using energy-constrained sensor nodes because transmitting multimedia contents, such as video or audio clips, involves a large amount of data. In this paper, we propose an energy efficient, scalable and collision free multichannel medium access control protocol for cluster-based WMSNs to achieve high throughput, low medium access delay and high energy efficiency. The proposed MAC integrates the merits of frequency and time division principles to effectively utilize channels and timeslots assigned to sensor nodes. The proposed MAC also uses energy efficient techniques to reduce the number of nodes needed to send data to the cluster head. The proposed MAC is based on clustered network topology, and the protocol employs a simple algorithm for assigning channels among clusters to enable simultaneous non-interfering data collection. Intra-cluster transmissions are scheduled by cluster head (CH) based on time slot. CHs aggregate the gathered data and forward it over inter-CH paths to the base-station based on minimum spanning tree routing. Distinct channels are adopted by the independent branches of the inter-CH routing tree. The proposed MAC minimizes energy consumption by allowing nodes to stay in sleeping mode for the longest duration. Simulation demonstrated superiority of proposed MAC in terms of convergent rate, throughput and delay performance when compared with well-known protocol MMSN. With the low MAC delay feature, our protocol is suitable for applications of real time multimedia traffic sensing and transmitting, such as remote monitoring of hospital patients and fire spots