Rendezvous with Utilities in Cognitive Radio Networks

In constructing the cognitive radio networks, a fundamental process is to establish a communication link on a same channel for every two users, which is referred to as rendezvous. Most studies focus on minimizing the time to rendezvous after they start the process synchronously or asynchronously. However, to the best of our knowledge, no work has considered the possibility that the users may achieve different utilities when they rendezvous on different channels for communication. The utility originates from the quality of the specific channel that two users rendezvous on, and it is influenced by the channel's bandwidth, transmission rate, stability, etc. In this paper, we formally formulate the problem of maximizing rendezvous utilities and propose a novel method by extending the channels to promote the users to achieve higher rendezvous utilities. We propose channel extension algorithms for both symmetric and asymmetric rendezvous scenarios, where the users may have the same or different sets of rendezvous channels respectively. These algorithms are built on the construction of Disjoint Relaxed Difference Set (DRDS) in [5], and we show the efficiency of achieving rendezvous on the channel with high utility theoretically. Moreover, we conduct thorough simulations to evaluate our algorithms and the results also corroborate our theoretical analyses.