Exploiting the capture effect opportunistically in MANETs

Abstract

Channel fading has been regarded as a negative factor for successful packet transmission. However, with deep fading, although collisions for a given transmission may exist, the capture effect can allow the transmission to succeed as long as the channel for the transmitted signal is strong enough and is weak enough for the interference signals. Accordingly, we propose an asynchronous medium access control (MAC) scheme that selects a packet with the highest success probability to be transmitted. We call this approach opportunistic interference management (OIM). The basic mechanism in OIM consists of probing the channel conditions for multiple neighbors concurrently, and then selecting to transmit those packets corresponding to the winners of the probing phase. OIM improves the probability of successful transmission and increases network throughput without adding extra delays for inter-nodal handshakes. Mathematical analysis and simulations are used to validate the advantages of OIM over the traditional packet-transmission scheme used in MAC protocols today.