Abstract: A radio communication control system for a lead unit and a plurality of remote units is disclosed. The system has a protocol for establishing a communication link between the lead unit and the one or more remote units in the system which prevents any of the units in that system from processing messages or commands from other units in other train systems or processing messages or commands originating from units within a train system which are addressed to other units within the system. The communication system also includes a communications channel contention system for minimizing the probability of multiple units transmitting on the common communication channel at the same time and for insuring that the highest priority communications in each train are transmitted first in time measured from the end of the latest transmission on the radio communications channel.

Abstract: A radio communication control system for a lead unit and a plurality of remote units is disclosed. The system has a protocol for establishing a communication link between the lead unit and the one or more remote units in the system which prevents any of the units in that system from processing messages or commands from other units in other train systems or processing messages or commands originating from units within a train system which are addressed to other units within the system. The communication system also includes a communications channel contention system for minimizing the probability of multiple units transmitting on the common communication channel at the same time and for insuring that the highest priority communications in each train are transmitted first in time measured from the end of the latest transmission on the radio communications channel.

Abstract: An adaptive transmitter power control for use in satellite communications systems. The power control provides real-time adjustment of satellite transponder power on the basis of received signal quality so as to overcome the effects of rapid onset signal attenuation occurring within the system, such as would be caused by a rainstorm. The communication system includes at least two ground stations communicating with one another via a satellite transponder whose power output is functionally dependent upon received signal strength. The level of transmitter power utilized by the satellite is adjusted by adjusting the power level of the signal transmitted to the satellite by at least one of the ground stations. At least another of the ground stations includes a quality monitor which responds to soft decisions generated by the ground station in demodulating the signal received from the power controlled ground station via the satellite repeater.

Abstract: An adaptive transmitter power control for use in satellite communications systems wherein at least two ground stations communicate serial streams of binary data via a satellite transponder whose power-output is functionally dependent upon received signal strength. At least one of the ground stations includes a quality monitor which makes a real-time determination of the quality of the received signal, and generates signal quality indications in accordance with this determination. These signal quality indications are continuously communicated back to the corresponding transmitting station along with the serial stream of binary data. An encoder multiplexes the normal binary data and the signal quality indications into single, combined signal for transmission over only a single communications channel. The normal binary data and the signal quality indications are reconstructed at the transmitting station, where the signal quality indications are used to control the power level of the transmitted signal.