Self-organized common control channel design for Cognitive Radio Ad Hoc Networks

Cognitive Radio Ad Hoc Network (CRAHN) is an emergent paradigm in wireless communications that brings the promise of mitigating the well-known scalability problems of classical Mobile Ad Hoc Networks (MANETs). By integrating in its architecture novel dynamic spectrum access algorithms, the CRAHN is expected to increase usage efficiency of available spectrum resources. However, the performance of such algorithms, distributed and cooperative in its nature, is tightly coupled with the existence of a signaling layer, or common control channel (CCC), that is established between neighboring Cognitive Radios (CRs). In this paper we propose a Distributed Consensus Algorithm to address the problem of distributed CCC allocation in CRAHNs. The proposed solution defines a token ring architecture for the CCC and introduces an additional feature, the token-embedded pilot-tone, used by the consensus algorithm to derive a channel quality metric. Through a simulation study of the Distributed Consensus Algorithm, we evaluate its performance for different network scenarios; the results show a significant increase of network capacity and spectrum efficiency when compared to a sequence-based rendezvous scheme.