US Patent 7164660 Radio communication system and method of operating the system

A radio communication system comprises a primary station (100) for transmitting information signals on a downlink channel (122) and for receiving signals from one or more secondary stations (110) on an uplink random access packet channel (RACH) (124), the downlink and uplink channels being independent of each other. Power control is applied to the transmitted downlink signals by at least one of the secondary stations transmitting indicia indicating the prevailing radio channel characteristics of the uplink channel, the indicia being used by the primary station to apply power control to the downlink signals.