Generalized-Bi-Connectivity for Fault Tolerant Cognitive Radio Networks
Bi-connectivity is a basic requirement for designing fault tolerant topologies in wireless networks. In Cognitive Radio Networks (CRNs), available channels of cognitive users dynamically change since a channel becomes unavailable whenever the channel is reclaimed by primary users. Therefore, fault tolerance of CRNs highly depends on the status of channel availability. However, traditional definition of bi-connectivity concerns only node/link failure and thus is not suitable to CRNs. In this paper, the authors introduce a new definition of generalized-biconnectivity (g-bi-connectivity) where a CRN is said to be g-biconnected if the remaining network is still connected when any one of the two events occurs: any node fails and any channel becomes unavailable.