K-Group Random Channel Hopping (K-RCH) Rendezvous for Cognitive Radio Networks

The channel-hopping (CH) based rendezvous is an important technique in next-generation wireless cognitive radio networks (CRNs) where spectrum efficiency is desired. It allows unlicensed secondary users (SUs) to dynamically schedule rendezvous channels using their assigned CH sequence. Rendezvous is an essential operation for radios in CRNs to meet and establish a communication link, or find a common channel. Thus, radios can exchange information and communicate on a channel.In this paper, we propose a rendezvous protocol called K-Group Random Channel Hopping (K-RCH) which is based on the symmetric-role model. K-RCH assigns nodes into groups. Each group contains at least two nodes, which means our model is general and can fit both pairwise or multi-user rendezvous. K-RCH increases the chance of rendezvous by synchronizing channel hopping patterns of nodes in the same group and allowing for multi-round rendezvous. K-RCH considers a heterogeneous channel availability model and is suitable for complicated communication environments. Our simulation results show that K-RCH achieves a much shorter rendezvous time than most existing rendezvous protocols. The expected time to rendezvous (ETTR) is reduced by more than 85% as compared to the Jump-Stay strategy and the TENOR protocol. The ETTR decreases with an increasing number of SUs.