CogMesh: A cluster based cognitive radio mesh network

As the radio spectrum usage paradigm shifting from the traditional command and control allocation scheme to the open spectrum allocation scheme, wireless ad-hoc networks meet new opportunities and challenges. The open spectrum allocation scheme has potential to provide those networks more flexibility, reliability, availability and capacity. However, the freedom brought by the new spectrum allocation scheme introduces spectrum management and network coordination challenges. For instance, wireless ad-hoc networks usually rely on a global common control channel for coordination. Such a control channel may, however, not always available in an open spectrum allocation scheme due to the interference and the need for coexistence with primary users of the spectrum. In this chapter, we propose a cluster-based framework to form a wireless mesh network in the context of open spectrum sharing. Clusters are constructed by neighbor nodes sharing common channels, and the network is formed by interconnecting the clusters gradually. We identify issues in such a network and provide mechanisms for neighbor discovery, cluster construction, network formation, and network topology management. The unique feature of this type of networks is its capability to intelligently adapt to the network and radio environment change.