Coexistence management for heterogeneous networks in white spaces

Certain spectrum bands originally occupied by legacy systems such as TV transmission have been opened up for free and unlicensed access in many countries provided no interference to the incumbents. It is envisioned that heterogeneous networks will coexist in these white space bands sharing the available unlicensed spectra. Therefore, an efficient coexistence management scheme is needed to coordinate access from different networks such that spectrum utilization is maximized while harmful interference is avoided. In this paper, we develop a two-stage coexistence management algorithm that efficiently coordinates spectrum sharing among heterogeneous networks operating over spectrum white spaces. The first stage allocates bandwidth to the networks such that fairness is achieved while maximizing spectrum reuse. Then, in the second stage, the available bandwidth is divided into channel slots and assigned to different networks according to the allocation from the first stage. The proposed scheme can be implemented at the white space database manager where the regulations require networks to contact in order to get the list of available spectrum for their location. Simulation results show that our proposed scheme provides significant performance gains owing to orthogonal channel assignment with coordinated spectrum re-use.