A Distributed Multi-channel Cognitive MAC Protocol for IEEE 802.11s Wireless Mesh Networks

In this paper, we propose a novel distributed frequency agile medium access control (MAC) extension to the IEEE 802.11s amendment for the next generation wireless mesh networks (WMNs). The proposed scheme has complete backward compatibility with the legacy IEEE 802.11 and the emerging 802.11s while, it is perfectly capable of multi-channel deployment of available frequency opportunities in order to coordinate concurrent multiple data transmissions. The root concept of the proposed enhancement is mainly based on the deployment of well-known ISM frequency bands, where the existing 802.11-based wireless equipments nowadays operate, as the common control channel in order to establish concurrent data transmissions. Here, we apply the aforementioned key concept to the IEEE 802.11s common channel framework (CCF) to attain two important goals: on one hand, the proposed scheme improves the channel utilization and capacity using the concept of cognitive radio and on the other hand, using the same concept it leads to lower access delay due to smarter decision making procedures exploited for link layer connection establishment. Through extensive simulations, which also take into account primary user (PU) appearance in non-ISM frequency opportunities, performance of the proposed medium access control (MAC) enhancement is evaluated showing its remarkable efficiency and better wireless medium access management.