Wireless ad hoc networks has attracted extensive research interest for past 30 years. To meet the increasing demand of multimedia it is necessary to provide the quality of service in such networks. The QoS supporting components at upper layer such as signaling and routing assumes the existence of MAC protocol which solves the problem of medium contention, supports reliable communication and provides resource reservations, particularly bandwidth. The channel in wireless network is shared among the stations and one of the key challenges is estimating the usable bandwidth. It is equally important to evaluate the performance of MAC protocols proposed in literature. This books is a effort made to summarize the efforts of researchers who contributed towards the development of various aspects for estimating the available bandwidth in network.