An energy-efficient mac protocol for wireless sensor networks for wide area large scale environmental monitoring

Abstract

Technical improvements in sensor networks have resulted in low cost sensor nodes that are suitable for a large number of applications. Environment monitoring, target tracking and border surveillance are just some of the many applications for today’s sensor networks. For different application areas, there are different technical issues that researchers are currently solving. Sensor nodes have various energy and computational constraints because of their inexpensive nature and ad-hoc method of deployment. Considerable research has been focused at overcoming these deficiencies through more energy efficient routing, localization algorithms and system design. Even though many issues of old sensor networks have been already solved, high energy consumption continues to be a hot topic in research papers. This is because it is hard and impractical to charge or replace exhausted batteries of nodes. Protocols that save more energy than its predecessors and at the same time comply with its computation and communication functions are desirable for wireless sensor networks. This Thesis presents a proposal for the development of a Medium Access Control (MAC) protocol for wireless sensor networks that is appropriate for environmental monitoring purposes. An energy aware MAC protocol is proposed for wireless sensor networks. This protocol saves energy by substantially reducing idle-listening. It is a reactive protocol which permits nodes to transmit packets every time they wake-up but at the same time proposes a mechanism to transmit packets that contain interesting data when nodes should not normally be awake. The proposed protocol uses two techniques to reduce energy consumption for wide area large scale environmental monitoring applications. First, it uses a sleep/listen schedule in which nodes awake when a sample from the environment is taken. Second, it uses a mechanism through which a node that has urgent packets to send wakes up other nodes to convey data to Base Station fur further processing. This Thesis presents simulation results comparing proposed protocol against another existing protocol. Results show that proposed protocol achieves less energy consumption than the other protocol.