Performance Study of 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 who not only have to make sure that they do not cause harmful interference to the higher tier users but also must cooperate with each other to minimize potential interference among themselves. Thus, efficient GAA coexistence scheme is essential for operation of GAA users and to obtain high spectrum utilization. Towards this goal, the Wireless Innovation Forum (WInnForum) has recommended three schemes to facilitate coexistence among the GAA users. To the best of our knowledge, there is no performance study on any of these schemes available in the public domain. In this paper, we study performance of one of these schemes (called Approach 1). We choose two actual locations in the USA around which our study is conducted 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 and with different mix of CBRS devices (CBSDs) at those two locations. We provide some interesting insights into the bandwidth allocation process and performance of Approach 1 in terms of mutual interference.