A practical self-adaptive rendezvous protocol in cognitive radio ad hoc networks

In cognitive radio ad-hoc networks, two users rendezvous on a common available channel to realize communications. Most existing rendezvous papers focus on success-guaranteed channel-hopping sequence design. However, the theoretical rendezvous successful rate may suffer from the available channel status changing, collisions on channels, congestion at users, and target users unavailability in practical scenarios. Thus, a practical rendezvous framework that can address these issues is highly demanded. In this paper, we develop analytical models for each possible factor which may influence the performance of rendezvous. Then, based on the analysis of each factor, we propose corresponding schemes and integrate them into a self-adaptive protocol which can adjust its reaction and optimize system parameters to adapt to the dynamic network. Simulation results demonstrate that our proposed protocol gains better performance in terms of true rendezvous successful rate, short rendezvous delay, and low congestion. To the best of our knowledge, this is the first rendezvous protocol that addresses practical issues in realistic communication scenarios in cognitive radio networks.