A Dynamic Contention Window MAC Protocol for Wireless Sensor Networks

Abstract

Wireless Sensor Networks are used in various fields. Sensor nodes have a constraint in getting the required resources as they are in distant places. The primary goal indesigning a wireless sensor network is to reduce the energy expenditure for a better lifetime. Medium Access Control (MAC) Protocols, are at the lower layer of WSNs’ protocol. They have a greater influence on performance and energy consumption of the network.There is various contention-based MAC protocol.SMAC is one of the most widely used contention-based MAC protocol for WSN networks.SMAC uses periodic sleep and listens to the mechanism. SMAC cannot adjust to the traffic as the contention window is fixed.We here develop an improved algorithm that adjusts the contention window as per requirement instead of fixed one. We here also ensure thatthe contention window is not changed drastically.Two different methods are used for calculating it, and equal weight is given to both when contention window is calculated.The contention window remains within the range defined. NS-2(2.35) is used for simulation Different traffic levels, and topologies are simulated. The results show that the improved protocol has a better throughput, lesser delay, and better energy efficiency.