Joint Spectrum Sharing and Fair Routing in Cognitive Radio Networks

In this paper, we propose a cross-layer optimization framework to jointly design the spectrum sharing and flow routing with the interference considerations in cognitive radio networks. Given multiple traffic demands from different source nodes to destination nodes, we formulate an optimization problem in the form of mixed integer linear programming (MILP) to provide a fair routing. Different from the existing work, we consider bi-directional links because we believe the link level acknowledgements in an ad-hoc network are a must. For traffic routing we allow multi-path for each traffic demand. Numerical results show that the spectrum sharing among the secondary users is interference-free and a fair routing is guaranteed for different traffic demands.