Coexistence-aware dynamic channel allocation for 3.5 GHz shared spectrum systems

The paradigm of shared spectrum allows secondary devices to opportunistically access spectrum bands underutilized by primary owners. As the first step, the FCC targeted sharing the 3.5 GHz (3550–3700 MHz) federal spectrum with commercial systems. The proposed rules require a Spectrum Access System to implement a three-tiered spectrum management framework, and one of its key functions is dynamic channel allocation (CA) for secondary devices. In this paper, we introduce coexistence-aware radio-channel-pair conflict graphs to capture pairwise interference, spatial channel availability variations, channel contiguity, and coexistence opportunities. We develop a super-radio formation algorithm to identify valid super-radios, i.e., a set of radios that can coexist on the same channel(s) via WiFi-like carrier-sensing mechanisms. With the proposed generic graph representation, we formulate CA as conflict-free max-demand CA with a min-demand constraint, and develop algorithms based on maximum weighted independent set. Preliminary results demonstrate good performance of proposed algorithms and benefits of coexistence.