A performance comparison of hybrid and conventional MAC protocols for wireless networks

Ad hoc networks consist of a group of wireless nodes that dynamically form a multihop network via shared communication channels. For each node, channel access is managed by a media access control (MAC) protocol. MAC protocols can be classified into three broad categories: contention, allocation, and hybrid protocols that combine the contention and allocation access schemes. ADAPT is a hybrid protocol comprised of two component protocols-an allocation protocol that provides stable operation under strenuous network conditions (e.g., high load and nodal degree), and a contention protocol that dynamically manages the available bandwidth. This paper presents a simulation study that compares the performance of several conventional and hybrid MAC protocols. We examine the relative performance of each protocol under equivalent network conditions, and show that the overall performance of the ADAPT protocol is superior. We also discuss the ability of each protocol to support delay sensitive applications, such as voice, video, and multimedia transmission.