A system (10) and method (50 or 70) of dynamic allocation of spectrum for a communication device where a UHF band is currently unused for licensed television broadcasting involves determining (51) a location of a user device using GPS or other signals (such as television broadcast signals) received at the user device using signal strength or time distance of arrival of those signals. The method can determine (52) which UHF television broadcast channels are available for use by the user device and determine (53) a maximum allowed transmission power for a given channel based on signal strength for the given channel and on adjacent channels before transmitting (54) the maximum allowed transmission power and location by the user device to a remote server for sharing information. The method can receive (55) polygon endpoints from a television broadcast defining the location of usable reception of the television broadcast.