RARE: A Spectrum Aware Cross-Layer MAC Protocol for Cognitive Radio Ad-Hoc Networks

Abstract

This paper proposes a spectrum-aware cross-layer (RARE) medium access control protocol for cognitive radio ad-hoc networks. The RARE protocol initially splits the network into clusters, where cluster formation is defined as the maximum edge biclique problem. Besides, in order to maintain the integrity of the cluster-based network, super-frame structure, and topology maintenance protocols are also presented in this paper. Moreover, RARE also integrates a delay-aware routing protocol, where the routing protocol is defined as a weighted graph problem. It is anticipated that clusters in RARE adapt themselves dynamically with respect to spectrum availability and node mobility. Furthermore, the routing protocol in RARE is expected to select stable paths while ensuring faster data delivery from a source node to the destination. A simulation is conducted to evaluate the performance of the proposed RARE protocol, where it is found that RARE outperforms existing approaches by maintaining a smaller number of clusters and a steady number of common channels. The simulation results also show that route selection in RARE proves to be more stable, with the lowest packet transmission delay compared with the other approaches.