Multi-interface rendezvous in self-organizing cognitive radio networks

Cognitive radio (CR) technology enables the opportunistic use of a portion of the licensed spectrum by CR users, while ensuring low interference to the primary user activity in a licensed band. It is very crucial for the CR user to rendezvous with another user on a certain channel and establish a communication link. The main focus of this paper is to design such an algorithm for blind rendezvous, i.e. rendezvous without any coordinator or common control channel, as is the case with jump-and-stay (JS) algorithm. Channels to jump have been assumed to be homogeneous in prior work; however, in the real world, channels exhibit different conditions. Therefore, by extending the JS algorithm, we designed an adaptive jumping pattern such that a better channel is jumped more often and users have a higher possibility to rendezvous on such a channel. Moreover, when multiple radio interfaces are available for CR users, the possibility of rendezvous increases but the number of channels to jump for each interface might not be the same as other users' interfaces. Consequently, we propose an enhanced adaptive rendezvous (EAR) algorithm that can work for multiple interfaces and different sizes of the channel list, and an adaptive jumping pattern for different channel conditions. Through extensive simulation, EAR is verified to work for these environments and further reduce the time-to-rendezvous compared to JS.