Abstract: A high capacity satellite communications system including a satellite with a beam for a forward downlink focused on a geographic area for which disproportionately higher capacity is desired, a hub located in a geographic area for which disproportionately lower capacity is desired, compared to the location of a VSAT, and the VSAT located in area where a beam for a forward downlink received by the VSAT from the satellite does not overlap with a beam for a return downlink received by the hub from a satellite.

Abstract: A triple use satellite system includes a VSAT population including a VSAT, and a satellite including a broadcast beam for a broadcast service and spot beams for a broadband service, where each of the spot beams provides broadband service to VSATs in separate coverage areas in a geographic region and the broadcast beam provides a broadcast service to the VSAT population in the geographic region.

Abstract: A method and system for acquiring a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Initially, the power level of the incoming signal is determined by locating the maximum power received in half time slot intervals. Next a series of frames are correlated against the expected unique word, each at one of a plurality of possible frequencies. The frequency generating the maximum correlation with the unique word is selected.

Abstract: A method and system for tracking a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Frequency variations of the incoming signal are tracked at the satellite terminal by correlating the PN sequence of the incoming signal against early and late locally generated versions of the PN sequence in a discriminate circuit. The output of the discriminate is provided to a delay locked loop circuit of at least third order. The output of the loop is used to adjust the frequency of the VCO, which clocks the A/D converter operating on the incoming signal.

Abstract: A satellite-based communications network employing at least one satellite and a plurality of user terminals adapted for use with the communications network. The network includes a transmitter for transmitting data to the plurality of user terminals, where the data includes a plurality of broadcast modes and/or services. The transmitter transmits data in a packetized format in which a predetermined number of data packets are transmitted in a frame, where the frame is defined as a predetermined period of time. Further, the transmitter transmits each of the plurality of broadcast modes utilizing a single carrier frequency. Each of the plurality of user terminals includes a receiver for receiving the transmitted data and for regenerating the data so that the data is made available to a device coupled to the user terminal.

Abstract: A method and system for acquiring a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Initially, the power level of the incoming signal is determined by locating the maximum power received in half time slot intervals. Next a series of frames are correlated against the expected unique word, each at one of a plurality of possible frequencies. The frequency generating the maximum correlation with the unique word is selected.

Abstract: A method and system for tracking a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Frequency variations of the incoming signal are tracked at the satellite terminal by correlating the PN sequence of the incoming signal against early and late locally generated versions of the PN sequence in a discriminate circuit. The output of the discriminate is provided to a delay locked loop circuit of at least third order. The output of the loop is used to adjust the frequency of the VCO, which clocks the A/D converter operating on the incoming signal.

Abstract: A dispatch system and a cellular interconnect system are combined to form a single system in which dispatch and interconnect communications are made with use of common system equipment. Different system configurations are employed according to the number of cells in the system to minimize loss of cellular interconnect capacity arising from dispatch communication operations.

Abstract: A cellular system supports dispatch and datagram operations. The architecture of a conventional cellular system, such as the GSM system, is modified by adding a local area network (TIL) where nodes on the network include various base switching controllers (BSC). The BSC has a Switching Interface Module (SIM) which provides an interface to the TIL. The TIL may also include one or more gateways (40) to landline based networks. The datagram operation uses an appropriate gateway to complete a data path which includes an RF segment to or from the BSC. Dispatch operations provide for switching by the BSC so that switching is at a level below the Mobile Switching Center (MSC). For example, compressed voice traffic received by the BSC may be transmitted over the TIL to another BSC from where it is sent over an RF segment to a mobile receiver (MS).

Abstract: A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. The system also supports multiple digital protocols so that a carrier can also be converted to operate in any one of several different digital modes. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to a request for a channel allocation or deallocation.

Abstract: Cellular handoff is improved by tailing or adapting the measurement time based on the characteristics of the received signal intensity or power. More particularly, base stations typically measure mobile signal power in order to determine the necessity for handoff and the identity of a new cell. The measurement time must be of a duration which is sufficient to characterize the environment of the mobile. In accordance with the invention, the duration of the measurement time is determined from the received signal itself. Once the duration of the measurement time is determined, that data may be passed to a target cell along with other handoff data.