An adaptive multiple rendezvous control channel for Cognitive Radio wireless ad hoc networks

Cognitive Radio (CR) technology enables the opportunistic use of the portions of the licensed spectrum by the CR users, while ensuring that the performance of the primary users (PUs) of the licensed bands is not affected. The spectrum is sensed locally by the CR users, and a specific channel that is acceptable to both the end nodes of the communication link is chosen. However, this necessitates a common control channel (CCC) for exchanging the sensing information and reserving the channel before actual data transfer. The design of an adaptive frequency hopping CCC, called as adaptive multiple rendezvous control channel (AMRCC), is proposed for CR ad hoc networks in this work, that is scalable, and allows continuous connectivity between the CR users under dynamic PU activity. The contribution made in this paper is twofold: (i) A frequency hopping scheme is proposed that allows altering the hopping sequence based on the PU activity in the channels, and (ii) A simple and low-overhead procedure is developed to aid new node-join and leave events. Simulation results reveal that our solution achieves better performance than the other classic CCC solutions in terms of the time to coordinate a feasible channel for communication and the resulting throughput specifically in CR ad hoc networks.