Performance Evaluation of MAC Layer Protocols for Ad Hoc WLAN

Ad hoc wireless networks provide infrastructure-free communication, an efficient MAC protocol through which mobile stations can share a common broadcast channel is essential. Present medium access mechanism used are Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), multiple access with collision avoidance (MACA) and CSMA/CA with RTS/CTS. These protocols are designed to reduce the collision probability between multiple stations accessing a medium. CSMA/CA with RTS/CTS and MACA use RTS/CTS exchange mechanism to reserve the channel. In this paper, First theoretical model of WLAN is developed and the maximum possible throughput is calculated. In later part of the paper, for the verification of theoretical mode, simulation environment is developed and detailed simulation is performed using GloMoSim simulator. Finally theoretical and simulation result are compared, which shows the variation of throughput with the variation of packet arrival rate and variation of average end to end delay with throughput.