Comparison of graph-based and hypergraph-based models for wireless network coexistence

Dynamic Spectrum Access (DSA) is regarded as a promising solution for efficient spectrum management. Regulators have also approved licence-exemption or general authorisation access (GAA) to further improve spectrum accessibility for DSA systems in the Television (TV) and 3.5 GHz bands. However, heterogeneous DSA radio standards have been developed and the gains in spectrum efficiency could be undermined by coexistence challenges. Hence, the IEEE 802.19.1 standard for wireless network coexistence methods was published, but it leaves algorithmic implementation of the methods to the industry. When the spectrum is not sufficient for exclusive channel allocation, the standard includes a method for co-channel sharing among coexistent neighbour networks. In previous work, channel sharing was introduced on top of the exclusive channel allocation. However, channel sharing options could be significantly limited by the outcome of the exclusive channel allocation. Alternatively, this paper proposes use of hypergraph theory to model the co-sharing strategy for coexistence management of heterogeneous radio systems. Results demonstrate that the hypergraph method achieves higher average spectrum utilisation by up to 8% and requires up to 5 fewer channels to achieve, on average, 100% operational networks than the previous method.