Improving Network Coverage in CBRS Through Consensus Among PALs

This paper investigates strategies to extend the coverage of Citizens Broadband Radio Service (CBRS) on the system level. New Priority Access License (PAL) spectrum requests are handled by the Spectrum Access System (SAS) and in many instances, the requests are not granted due to violations with existing PAL protection contours. The process when a request is rejected is cumbersome, since manual coordination is required between the affected parties. A democratic consensus algorithm based on voting is proposed to automate the coordination process, allowing affected PALs to vote on the outcome of a new PAL Citizens Broadband Radio Service Device (CBSD) request. The behavior of the standardized SAS is compared with our consensus algorithm approach. The study reveals that substantial improvements in the CBRS system coverage area can be achieved, with an average observed increase of 104.30%. However, these gains come with certain tradeoffs. The expansion comes at the cost of increased encroach-ment on existing CBSDs protected contours and may dispro-portionately disadvantage some parties, particularly due to the operational characteristics of the selected consensus algorithm. Furthermore, some PAL licensees may experience an increase in the encroached area and interference. On average, the total encroached area saw an increase of 10.29%. Thus, while system coverage enhancements are possible, they often require a slight compromise from some licensees.