An overview of DSA via multi-channel MAC protocols

Multi-channel MAC protocols have been proposed to improve spectrum utilization and to increase network throughput by allowing multiple transmissions in a set of frequency channels. The purpose of these multi-channel MAC protocols is to enhance the overall performance of Wi-Fi like protocols (using IEEE 802.11 based mechanisms) with Distributed Coordination Function (DCF) as Medium Access Control (MAC) technique. However, this technique was not designed to work in a multi-channel environment. In this paper, we present an overview of different multi-channel MAC protocols; we describe their access mechanisms and we make a comparison of key features of each protocol according to the number of transceivers (TRx), the need for synchronization, the need for a CCCH (Common Control Channel) and the different ways to make rendezvous. The aim of this paper is to show how each multi-channel MAC protocol confronts the numerous problems that arise in Dynamic Spectrum Access (DSA).