Each communication unit (112A through 112F) and talkgroup in a communication system (100) is assigned a priority at each site (106, 108, and 110) in the system. As communication units (112A through 112F) request resources, contention among requesters at a site is resolved by the priority of requesters at the site. System-wide resources are allocated equitably based on the geographical location of the communication unit using site-based priority.