Abstract: A hybrid satellite communications system provides communications, particularly Internet access, to computer users. The hybrid satellite communications system includes a satellite system and a terrestrial communications system. The satellite system includes two transceivers. The first transceiver receives and transmits a first set of signals received from the terrestrial communications system to a plurality of user units. In reverse fashion, the satellite systems second transceiver receives a second set of signals in a second frequency band from the user units and transmits those signals back to the terrestrial communications system. The first set of signals (downlink signals) are of much higher frequency than the second set of signals (uplink signals). Preferably, the first set of signals are relayed by a Direct Broadcast System (DBS) satellite in a frequency band between 12.2 GHz and 12.9 GHz, while the second set of signals are relayed by a Mobile Satellite System (MSS) satellite operating between 1.

Abstract: A mobile terminal is configured to receive wireless communications including GPS data from a terrestrial and/or satellite wireless network, and to perform pseudo-range measurements using the GPS data that is received. The mobile terminal may be configured to perform pseudo-range measurements by receiving GPS coarse/acquisition (C/A) signals from GPS satellites, estimating Doppler shifts in the received GPS C/A signals, and estimating received code phases of the GPS C/A signals using the Doppler shifts that are estimated. The estimated code phases and/or the estimated Doppler shifts of the GPS C/A signals can provide the pseudo-range measurements. By removing the Doppler shift from the received signal samples prior to performing the code phase measurement, reduced computational complexity and/or processing time may be obtained.

Abstract: A system and method of operation for efficiently reusing and/or sharing at least a portion of the frequency spectrum between a first satellite spot beam and a second satellite spot beam, and/or an underlay terrestrial network associated with a second satellite spot beam. The spectrum is efficiently reused and/or shared between respective spot beams and/or associated underlay terrestrial systems in a manner minimizes interference between the respective satellite and terrestrial systems.

Abstract: A satellite radiotelephone system includes a space-based component that is configured to communicate with multiple radiotelephones over multiple frequency bands and/or multiple air interfaces. An ancillary terrestrial network is configured to communicate terrestrially with the multiple radiotelephones over substantially the multiple frequency bands and/or substantially the multiple air interfaces. An aggregate radiated power controller is configured to limit an aggregate radiated power by the multiple radiotelephones to a maximum aggregate radiated power.

Abstract: Two satellite communications systems can use the same frequency or frequencies in geographically overlapping footprints, without creating undue interference in a given system that is caused by the same frequency signal(s) that is/are used by the other system. In particular, an aggregate Effective Isotropic Radiated Power (EIRP) of the radioterminals and/or ancillary terrestrial components of a second satellite communications system in the common footprint is sufficiently low, and/or the receive antenna gain of a first satellite communications system is sufficiently low compared to the receive antenna gain of the second satellite communications system, so as to increase an aggregate receiver noise that is seen by the first satellite system receivers by an amount that does not substantially change a Quality of Service (QoS) of the first satellite communications system.

Abstract: The capacity of a terrestrial wireless communications system that uses a terrestrial frequency band for communications with wireless terminals is expanded by utilizing a satellite frequency band for terrestrially receiving terrestrial communications from the wireless terminals. Since the wireless terminals are configured to transmit communications to a space-based component such as a satellite via a satellite frequency band, these transmissions also may be picked up (received) terrestrially. Thus, terrestrial base stations can be equipped with satellite frequency band receivers that can receive communications from the wireless terminals over a satellite frequency band. By using the satellite frequency band receiver in a terrestrial base station, additional capacity and/or quality of service may be provided for a terrestrial and/or satellite communications system.

Abstract: Space-based wireless radiotelephone communications are provided in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. At least one of the satellite radiotelephone frequencies that is assigned to a given satellite cell in the satellite footprint is terrestrially reused outside the given satellite cell. A radiation pattern of at least the given satellite cell is modified to reduce interference with the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the given satellite cell.

Abstract: Radiation by an ancillary terrestrial network, and/or satellite radiotelephones that communicate therewith are monitored and controlled, to reduce and preferably prevent intra-system interference and/or interference with other satellite radiotelephone systems. In particular, a satellite radiotelephone system includes a space-based component that is configured to wirelessly communicate with first radiotelephones in a satellite footprint over a satellite radiotelephone frequency band, and an ancillary terrestrial network that is configured to wirelessly communicate with second radiotelephones in the satellite footprint over at least some of the satellite radiotelephone frequency band, to thereby terrestrially reuse the at least some of the satellite radiotelephone frequency band.

Abstract: A satellite radiotelephone system includes a space-based component, an ancillary terrestrial network, a monitor and a controller. The space-based component is configured to wirelessly communicate with radiotelephones in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into satellite cells in which subsets of the satellite radiotelephone frequency band are spatially reused in a spatial reuse pattern. The ancillary terrestrial network is configured to wirelessly communicate with radiotelephones in the satellite footprint over at least some of the satellite radiotelephone frequency band, to thereby terrestrially reuse the at least some of the satellite radiotelephone frequency band.

Abstract: A space-based network for a satellite radiotelephone system includes at least one receive-only satellite and at least one transmit satellite. The transmit satellite can be a transmit-only satellite or a transmit and receive satellite. The receive-only satellite(s) are configured to receive wireless communications from a radiotelephone at a location over a satellite frequency band. The transmit satellite(s) are configured to transmit wireless communications to the radiotelephone at the location over the satellite frequency band. By providing at least one receive-only satellite and at least one transmit satellite, space-based networks can offer a significant link margin, without the need to undesirably burden the radiotelephones themselves to achieve this link margin.

Abstract: Satellite radiotelephone systems include a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into a plurality of satellite cells, in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. An ancillary terrestrial network is configured to terrestrially reuse at least one of the ancillary radiotelephone frequencies that is used in a satellite cell in the satellite footprint, outside the cell and in some embodiments separated therefrom by a spatial guardband.

Abstract: A mobile communications system transporting messages between mobile terminals and a central control center using a satellite communications system. The central control center and the mobile terminals each store a plurality of message display forms each having a form identifier and a predetermimed display format. The message display forms are selected as templates for generating user messages including message data supplied at the originating station. The satellite messages transmit the user message by transmitting the message data and the form identifier of the corresponding selected message display form. The receiving station, upon receiving the satellite message, accesses the message display form from memory in response to the supplied form identifier, and combines the accessed message display form with the message data to recreate the user message. The mobile terminals are designed as low-cost data terminals requiring a minimum amount of memory.