Frequency re-used and time-shared cellular communication system having

Abstract

A method and apparatus for multiplexing time-shared base stations between a plurality of radio communication systems in a cellular communication system. Each radio communication system in the cellular system is assigned a limited unique set of frequencies for communication therein. Base stations in the cellular system are synchronized to a common time base and frequency reuse is achieved by time-sharing the frequencies via allocated time slots. Base stations activated to communicate in a first radio communication system and using the same frequencies that may interfere with each other are activated in the first system only during selected time intervals while same-frequency base stations nearby are deactivated in the first system. The deactivated base stations are then in turn activated in the first system while previously activated same-frequency base stations nearby are deactivated. Enhanced base station efficiency is achieved using the present inventive method by activating the time sharing base stations to communicate in one or more additional radio communication systems during periods when the base stations are deactivated in the first system. The radio communication systems can use differing numbers of assigned frequencies having differing time slot durations. The transmission periods used by each system may be mutually exclusive, or may overlap.