1. A method of operating a Spectrum Access System (SAS), the method comprising:receiving, from a first Citizens Broadband Radio Service Device (CBSD), first user equipment (UE) information including at least one of timing advance or power headroom information for one or more UEs in communication with said first CBSD;
estimating, based on the received first UE information, a first CBSD coverage area;
making a first resource allocation to the first CBSD based on the estimated first CBSD coverage area, said first resource allocation including an allocation of at least one of a frequency bandwidth allocation or transmission power allocation to the first CBSD;
prior to estimating the first CBSD coverage area, identifying the UE with the largest timing advance in communication with the first CBSD; and
determining if the UE in communication with the first CBSD having the largest timing advance also has the lowest power headroom of the UEs for which power headroom information is provided in said first UE information.