Abstract: A method and apparatus for establishing a high data rate high frequency data link (HDR-HFDL) between aircraft and ground stations enhances the aircraft HFDL data radio to transmit at an HDR frequency assigned by a ground station and transmitted to the aircraft via the HFDL frequency assigned to the ground station. The ground station may select and transmit an alternate HDR frequency if necessary. In Phase I, existing aircraft subsystems and ground stations will be configured for HDR downlink only, but an aircraft subsystem may additionally receive HDR data packets if propagation conditions allow. In Phase II, dedicated HDR ground stations and enhancements to existing aircraft subsystems will provide for full HDR uplink and downlink capability. Dedicated HDR ground stations may select an HDR frequency from the band including the assigned HFDL frequency or transmit at an assigned HDR frequency.

Abstract: The present invention is a radio communications system. The system includes a first Line-Replaceable Unit (LRU) and a second Line-Replaceable Unit (LRU). Each LRU includes two transmitters, a multi-channel receiver, a passive hybrid combiner-splitter, and a bypass relay. The first LRU and the second LRU are communicatively coupled via a crosslink connection, such as a coax cable connection. The system includes first and second antennas, which are communicatively coupled with the first and second LRUs respectively. The system includes a crosslink bus configured for communicatively coupling the first and second LRUs, thereby allowing the LRUs to coordinate operation of the relays via the crosslink bus. Still further, the system is configured for providing concurrent transmit and receive operation.