The Citizen Band Radio Service (CBRS) Spectrum Access System
(SAS) is a three-tier service model that regulates access to CBRS services. The SAS system consists of Incumbent Access, Priority Access and General Authorized Access (GAA). Incumbent Access is the predominant access to Connectionless Broadband Data Services (CBDS) and provides protection against interference. The Priority Access below this level is regulated by the Priority Access Licenses (PAL), which are allocated via auctions. The lowest level is General Authorized Access (GAA).