Cognitive Radio Policy-Based Adaptive Blind Rendezvous Protocols for Disaster Response

Abstract

In disaster scenarios, with damaged network infrastructure, cognitive radio (CR) can be used to provide temporary network access in the first few hours. Since spectrum occupancy will be unknown, the radios must rely on spectrum sensing and opportunistic access. An initial goal is to establish rendezvous between CR nodes to set up the network. The unknown primary radio (PR) activity and CR node topology makes this a challenging task. Existing blind rendezvous strategies provide guarantees on time to rendezvous, but assume channels with no PR activity and no external interferers. To handle this problem of blind multi-node rendezvous in the presence of primary users, we propose an Extended Modular Clock Algorithm which abandons the guarantee on time to rendezvous, an information exchange mechanism for the multi-node problem, and various cognitive radio operating policies. We show that the adapted protocols can achieve up to 80% improvement in the expected time to rendezvous and reduce the harmful interference caused to the primary radio.