Survey on multi-channel access methods for wireless LANs

Abstract

The last decade has seen great progress in the field of wireless LANs. Their deployment is manifested in several areas of applications. However, these applications face many obstacles due to the complexity of managing the medium access. This shortcoming usually leads to some problems such as numerous collisions, throughput degradation and increased delays. To overcome these challenges, research works have focused on new multi-channel access methods that reduce contention as well as collision probability. Several transmissions can occur simultaneously in the same transmission area, thus considerably improving throughput and reducing delays to access the medium. However, the idea of using multiple channels arouses various problems such as the multi-channel hidden terminal, deafness and the logical partition. We present in this paper main multi-channel access methods generally discussed in the work of the scientific community. They are classified into two main categories: (1) the single rendezvous approach such as the split-phase, the dedicated channel and the common hopping; (2) the parallel rendezvous such as SSCH (Slotted Seeded Channel Hopping) and McMAC (Parallel Rendezvous Multi-Channel MAC Protocol). We can then deduce that for a multi-hop topology that we envision to achieve with a very reduced radio cost, some of these methods are not suitable for the desired single interface prototyping.