Sequence-Based Rendezvous for Dynamic Spectrum Access

In the context of dynamic spectrum access (DSA), rendezvous refers to the ability of two or more radios to meet and establish a link on a common channel. In decentralized networks, this is often accomplished by each radio visiting potential channels in random fashion, in a process that we call blind random rendezvous. In this work, we propose the use of sequences that determine the order with which radios visit potentially available channels. Through sequence-based rendezvous, it is possible to: (i) establish an upper bound to the time to rendezvous (TTR); (ii) establish a priority order for channels in which rendezvous occurs; (Hi) reduce the expected TTR as compared to random rendezvous. We provide an example of a family of sequences and derive the expected time-to- rendezvous using this method. We also describe how the method can be adopted when one or more primary users are detected in the channels of interest.