System for informing secondary users of which radio channels are usable in which geographic region

摘要

Radio frequency reuse between two or more radio frequency communications systems is facilitated by having a beacon transmitter broadcast information globally throughout an area, which information identifies to users of a second system, which radio frequency resources are already in use by a first communications system. The global broadcast of information as to what channels are in use, permits users in the second system to avoid interfering use of those frequencies.