1 research outputs found
Performance Evaluation of Varying Contention Window Size for Bandwidth Constrained Routing in Adhoc Networks
Providing bandwidth efficient routing in ad hoc networks is a challenging task. Available
bandwidth of nodes is accurately evaluated before finding route from source to destination.
Accuracy of available bandwidth is mainly affected by collision and overhead due to the execution of
backoff scheme. Existing bandwidth constrained routing uses binary exponential backoff which
follows serial transmission and causes unfair channel access. To overcome these, implicit pipelined
backoff procedure is proposed to improve the available bandwidth and reduce the overhead
associated with the backoff scheme employed in medium access control layer. In this, when two
nodes are sharing the channel, the remaining nodes start the channel contention procedure in
parallel to transmit next packet. Thus the channel waiting time is reduced. Each node maintains
separate contention window for each phase in pipelined backoff. Proper choice of contention
window size has great effect on performance of the network. This proposed algorithm is combined
with a reactive link disjoint multipath routing protocol called AOMDV (Adhoc Ondemand Multipath
Distance Vector) to find the best path based on bandwidth. Experimental results show that this
algorithm outperforms existing approach in terms of QoS metrics such as delay, throughput, packet delivery ratio and energy consumption for different contention window sizes