Analysis of Contention Based Medium Access Control Protocols for Wireless Sensor Networks

A wireless sensor network is an ad hoc network and consists of a number of sensor nodes spread across a geographical area. Each sensor node is a tiny battery operated device and has a processor for computing and transceiver for communication. Instead of conventional network measures such that throughput, latency and bandwidth utilization, energy consumption has great importance and radio part of the sensor node is the major source of energy consumption. So to minimize energy consumption, there is need to handle transceiver (radio) intelligently and this is preliminary purpose of medium access control (MAC) protocol. This thesis analysiss two types of contention based MAC protocols such as non-adaptive (fixed duty cycle S-MAC) and adaptive (variable duty cycle T-MAC and TEEM). The average energy consumption behavior of network is simulated in OMNeT++ under heavy traffic load that varies over time and results are evaluated for linear and grid topologies. The results from simulations show that adaptive MAC protocols T-MAC and TEEM consume 3.3 and 3.8 times less average energy of network for linear and grid topologies respectively in comparison to nonadaptive MAC protocol S-MAC. Furthermore, the variation in average energy consumption over the range of input traffic load is much smaller in TEEM as compared to T-MAC. Therefore TEEM protocol has stable behavior at heavy traffic load and outperforms T-MAC.