Abstract: Satellite communications systems include a base station configured to communicate messages to disadvantaged mobile radiotelephone terminals. A mobile radiotelephone terminal receives a communication from a base station via a first high power paging channel and, if disadvantaged, monitors a second high power forward-only radiotelephone channel identified in the communication. The base station, upon determining that the mobile radiotelephone is disadvantaged, broadcasts the pending message to the mobile radiotelephone terminal via the second forward-only radiotelephone channel.

Abstract: A method and apparatus for reducing power consumption in a mobile terminal having a receiver for receiving a time multiplexed message distributed over a plurality of time slots by receiving a first subset of the plurality of time slots so as to receive a first portion of the time multiplexed message corresponding to the first subset of the plurality of time slots. The mobile terminal then determines from the first portion of the time multiplexed message if additional time slots of the time multiplexed message need to be received by the mobile terminal. The mobile terminal receives a second subset of the plurality of time slots so as to receive a second portion of the time multiplexed message if the mobile terminal determines from the first portion that additional portions of the time multiplexed message are to be received by the mobile terminal. This first portion of the message is preferably independently decodeable from the remainder of the message.

Abstract: A method for increasing the control channel capacity of a control station in a communications system. According to the method, in an idle mode of operation, a mobile station receives and processes data during more than one time slot per frame. As a result, additional channel structures are made possible such that additional data can be broadcast to a mobile station without restructuring a conventional slot format.

Abstract: A method for distinguishing between in-band signaling and user data transmissions of a communication system. The method includes the assignment of separate training bit sequences, one for in-band signaling transmissions and another for user data transmissions. During transmission, the training bit sequence associated with the type of transmission being sent is used as the training bit sequence. The method further includes the correlation of the received training bit sequence with both the training bit sequence assigned to in-band signaling and the training bit sequence assigned to user data. The training bit sequence having the highest correlation energy indicates the type of data contained in the communication transmission.

Abstract: A power saving method for maintaining synchronization in a power-limited communication system, such as a satellite-based TDMA mobile radiocommunication system. According to exemplary embodiments, the satellite transmits abbreviated bursts containing only synchronization information during intervals when no other control information is required by the receiving mobile unit, reducing power consumption during these intervals.

Abstract: A method and apparatus for reducing the echo in a hands-free digital cellular communications system is presented. Acting upon speech signals being present in the downlink, uplink speech frames generated by the hands-free communication device are attenuated to prevent the downlink speech signals from being transmitted at full volume back on the uplink as an echo. Added to the attenutated uplink speech frame is a noise frame generated by the hands-free communication device, which provides a consistent level of background noise to the person at the other end of the call. The noise codeword is further randomly ordered to prevent any modulative effects from the process.