Blockchain-Assisted Dynamic Spectrum Sharing in the CBRS Band

As a frontier in dynamic spectrum sharing, the citizens broadband radio service (CBRS) system has been proposed by FCC, where three-tiered users are allowed to share the same spectrum. To manage the interference among different layered users, a centralized spectrum access system (SAS) combined with a central database is utilized to coordinate the spectrum access of lower-tiered users. Therefore, the centralized management architecture of the CBRS system cannot efficiently manage very large scale and large quantity of users, and may also suffer severe security and privacy issues. To address these problems, in this paper, we propose a new blockchain-assisted dynamic spectrum management model based on existing CBRS model, where the blockchain technology is leveraged to improve the spectrum management efficiency and quality-of-service of the GAA users. Furthermore, we design a detailed flow of the spectrum management of GAA users, where a dedicated graph coloring algorithm is proposed to obtain the optimal channel assignment strategy. Simulation results have increased the ratio of GAA users licensed and improved spectrum utilization under the proposed algorithm.