Cross-network spectrum sensing for mission-critical cognitive radio networks: Collaboration through gateways

In this paper, the cross-network spectrum sensing is considered for future mission-critical wireless networks employing cognitive radio technology. In military operations and disaster relief efforts, multiple cognitive radio networks may be deployed in the same geographical area for different organizations to access the spectrum collaboratively and provide much needed interoperability enabled by a software radio platform. In this context, cross-network collaboration based spectrum sensing in cognitive radio is studied. Because of security requirements among different organizations, different co-existing networks can only communicate through certain gateway nodes. The limited communication capability of gateway nodes incurs significant challenges for the collaboration. We propose to apply the technique of Belief Propagation for the cross-network collaboration with the assumption of Markov random field for the spectrum occupancies. The cross-network information is embedded into the Belief Propagation framework as a priori probabilities. The cross-network messages are also compressed due to the limited communication bandwidth. The effectiveness of the proposed algorithm is demonstrated by extensive simulations.