DETECTION OF SELFISH MISBEHAVIOR AT MAC LAYER IN WIRELESS NETWORK

Abstract

The IEEE 802.11 CSMA/CA protocol is most commonly used MAC protocol for wireless network. This protocol is used to access the media. But IEEE 802.11 works properly only if all the stations obey the MAC protocol. In public area wireless networks, it is possible that the participating hosts may deviate from the specified MAC protocol. Selfish hosts that do not obey to the MAC protocol may obtain an unfair media share. For example, IEEE 802.11 requires hosts competing for access to the channel to wait for a backoff interval, randomly selected from a specified range, before initiating a transmission. Selfish hosts may wait for smaller backoff intervals than well-behaved hosts. By this way some node can substantially increase his share of bandwidth by slightly changing the parameters of MAC protocol, in order to increase their throughput. This cause throughput degradation of all well behaved node. In this dissertation, we proposed the detection scheme for selfish misbehavior at MAC layer in wireless networks based on comparative study of Throughput, RTS retransmission rate and packet retransmission rate of nodes under well behaved and selfish attack.