AND: Asynchronous neighborhood discovery protocols for opportunistic cognitive wireless networks

A neighborhood discovery (ND), also referred to as a rendezvous (RDV), is a challenging and fundamental phase in opportunistic Cognitive Radio Networks (CRNs) due to changing network topology, the time and location varying spectrum availability and different channel qualities. Simplified solutions, such as, a central controller or common control channel are not feasible in opportunistic CRNs. Therefore, in order to be able to initiate a communication, there is a need of on-demand searching for a control traffic channel by cognitive radio (CR) users, usually working in an asynchronous manner. To meet these challenges we propose an asynchronous neighborhood discovery (AND) for opportunistic CRNs, which takes into account the asynchronous character of CRs, different channel ranks, as well as heterogeneous channel availability.