Padded-Dyck-Path-Based Rendezvous Algorithms for Heterogeneous Cognitive Radio Networks

Rendezvous is a vital step for secondary users who want to initiate a communication in cognitive radio networks. In this paper, we propose a novel Padded-Dyck-Path-based (PDP) rendezvous algorithm that generates channel hopping sequences utilizing global channels. PDP is designed according to the roundabout Dyck path so as to increase rendezvous opportunities. As the global channels may not be shared in distributed environments, we also propose a local PDP (L-PDP) heterogeneous rendezvous algorithm that generates channel hopping sequences utilizing only local available channels. L-PDP can significantly reduce rendezvous latency and allow for distributed implementations. We prove that both PDP and L-PDP can provide guaranteed rendezvous and derive their upper bounds of rendezvous latency. Analytical and simulation results show that PDP and L-PDP outperform existing algorithms in terms of time-to-rendezvous in global and local scenarios, respectively.