Performance Impact of Coexistence Groups in a GAA-GAA Coexistence Scheme in the CBRS Band

The General Authorized Access (GAA) users in the Citizens Broadband Radio Service (CBRS) band are the lowest priority users. They must make sure that they do not cause harmful interference to the higher tier users while cooperating with each other to minimize potential interference among themselves. Thus, efficient GAA coexistence scheme is essential for the operation of GAA users and to obtain high spectrum utilization. Towards this goal, the Wireless Innovation Forum (WInnForum) has recommended three schemes to facilitate GAA-GAA coexistence. We had reported a performance study of one of these schemes (called Approach 1), but that study did not have any Coexistence Group (CxG). A CxG is responsible for managing interference among its CBRS devices (CBSDs). In this paper, we study the performance of Approach 1 without CxGs as well as with different number of CxGs, in various configurations. We conduct our study around two locations in the USA using actual terrain and land cover data of the continental USA. We evaluate performance of the scheme at different deployment densities, using different propagation models at those two locations with different number of CxGs. We provide some interesting insights into the costs and benefits of having CxGs in the deployment.