Full-Duplex for Multi-Channel Cognitive Radio Ad Hoc Networks

Abstract

Cognitive radio ad hoc network (CRAHN) has been considered an efficiently spectrum-aware communication paradigm in wireless networks because of its intrinsic properties of cognition and self-organization. In practice, because primary and secondary ad hoc networks are usually associated with two different types of wireless networks, the synchronization between primary users and secondary users is hardly guaranteed. The multi-channel asynchronous CRAHNs referred to as multi-channel non-time-slotted CRAHNs impose many challenging problems that severely degrade system performance. In this article, we review these challenging issues in multi-channel non-time-slotted CRAHNs, including reactivation- failure, frequently unexpected hand-offs, nonreal- time spectrum aggregation, inefficient power allocation, and frequent re-routing problems. Then, we develop a full-duplex based framework to resolve these issues. Future research directions are discussed to improve system performance of multi-channel non-time-slotted CRAHNs.