Unique-ID based channel hopping rendezvous algorithm for cognitive radio ad hoc networks

Abstract

Rendezvous of cognitive radios on commonly available channels is fundamental and crucial phenomena in the formation of cognitive radio networks (CRNs). Rendezvous enables secondary users (SUs) to detect the presence of each other and establish communication links between them. The diversity in free available channels sensed by the SUs and non-awareness of the presence of SUs before rendezvous make the rendezvous process a non-trivial task. Assigning a channel as a common control channel (CCC) for all SUs is not feasible in the dynamic environment of CRNs since SUs may have diverse available channels that change with time and location. Hence, channel hopping (CH) technique often referred as blind rendezvous is more preferred in CRNs. In this paper, we present a unique identity based channel hopping (UID-CH) rendezvous algorithm that dynamically manipulate the unique identity of SUs and constructs the CH sequence on the top of available channels rather than the total potential licensed channels. The gist of the algorithm lies on hopping and waiting phenomena of SUs in a circular manner such that if one SU hops on available channels and the other SU waits on a particular channel then rendezvous can be guaranteed by the time first SU completes a round. Theoretical analysis and simulation experiments show that the UID-CH algorithm provides rendezvous guarantee in finite time without explicit requirement of time synchronization and performs well in distributed dynamic environment of CRNs.