Challenges of medium access control (MAC) protocols in ad hoc mobile networks

Wireless mobile ad hoc networks, or MANETs, are networks that do not have any fixed infrastructure. Unlike cellular networks where mobile nodes communication with each other through the wired base stations, nodes in the ad hoc environment must discover communication routes dynamically. In such an environment, the medium access performance plays a pivotal role. The medium access control (MAC) protocol coordinates the wireless channel access. Without coordination, confusion would result from multiple nodes attempting to transmit on the wireless channel at the same time, causing transmission collisions.; In this dissertation, we focus on the challenges of the MAC layer in mobile ad hoc networks, examining both the unicast and multicast/broadcast aspects. Research in the area of unicast MAC includes decomposing the components of random access protocols to determine each individual component's effect on the network and studying the interaction between MAC and TCP in ad hoc networks. Work in the multicast/broadcast arena comprises of examining MAC layer reliable data broadcast support, achieving reliable multicast in ad hoc networks at the transport layer by using the reliable broadcast MAC principles, and analyzing the effects when utilizing a reliable multicast transport protocol on top of a reliable broadcast MAC protocol.