Abstract: A satellite communication system includes satellite nodes moving in respective known orbits, and a controller configured to determine routing neighborhoods for each satellite node based upon the known orbits, each routing neighborhood comprising a group of adjacent satellite nodes; and assign a respective primary neighborhood egress node (NEN) from among the plurality of satellite nodes for each routing neighborhood. A given satellite node of a given satellite node routing neighborhood may be configured to reroute a failed path from a source satellite node to a destination satellite node through the given satellite neighborhood using a secondary NEN instead of a respective primary NEN.

Abstract: Method and apparatus for scheduling time division multiple access (TDMA) communications among a plurality of peer nodes arranged to form a wireless ad hoc mobile network. The peer nodes communicate with each other using directional antennas and a TDMA process. The method includes a scheduling process for scheduling at least one transmit time slot during which a first one of the plurality of peer nodes transmits wireless data to a second one of the plurality of peer nodes.

Abstract: Method and apparatus for scheduling time division multiple access (TDMA) communications among a plurality of peer nodes arranged to form a wireless ad hoc mobile network. The peer nodes communicate with each other using directional antennas and a TDMA process. The method includes a scheduling process for scheduling at least one transmit time slot during which a first one of the plurality of peer nodes transmits wireless data to a second one of the plurality of peer nodes.

Abstract: Transcoding needs and selection are performed by a central call control function (17, 35). Each transcoder (18, 23, 34, 36) registers with the appropriate call control (17, 35). The call control then determines whether a vocoder is required at all. If vocoding is required, call control (17, 35) selects the appropriate transcoder (18, 34) and inserts the appropriate transcoder into the bearer traffic stream (16).

Abstract: A transcoder (40) includes a method for assigning transcoder channel elements (43, 44). The transcoding assignment method selects a DSP (60-75) selects a DSP (channel element) of the required type which has available channel elements (98). Further, the transcoding assignment method may dynamically reassign (118) DSPs from one channel element type to another.

Abstract: A method for location determination using Bluetooth techniques is applicable within buildings, underground or within other structures. A mobile unit (10) seeks the location of a cell from location master (20). Location master (20) and a number of location subsidiaries (21-24) determine ranging information with regard to the mobile unit (10) using Bluetooth techniques. The location master (20) then determines the mobile unit location using least squares estimation or other triangulation methods (50). In an alternate embodiment, ranging information is fine tuned for noise and error measurements between the location master and the location subsidiaries (51, 53) are used.

Abstract: A method for location determination using Bluetooth techniques is applicable within buildings, underground or within other structures. A mobile unit (10) seeks the location of a cell from location master (20). Location master (20) and a number of location subsidiaries (21-24) determine ranging information with regard to the mobile unit (10) using Bluetooth techniques. The location master (20) then determines the mobile unit location using least squares estimation or other triangulation methods (50). In an alternate embodiment, ranging information is fine tuned for noise and error measurements between the location master and the location subsidiaries (51, 53) are used.

Abstract: A connectionless, wireless network (20) includes any number of subscriber units (24) and gateways (22). The subscriber units (24) and gateways (22) are configured to engage in wireless communications with preferably more than one other node. The gateways (22) provide portals through which communications may flow to and from the PSTN (26). A repeating subscriber unit (24) includes a router (34) to aid in routing data conveyances to various communication links (25). A routing table (76) provides intelligence which is independent of other routing tables (76) in other subscriber units (24) and gateways (22) and which indicates a variety of routes for data conveyances. Each repeating subscriber unit (24) makes its own decisions about where to route data conveyances based upon the destinations of the data conveyances and feedback received from neighbors of the repeating subscriber unit (24). Communication links (25) previously selected for routing data conveyances may be altered when conditions warrant.

Abstract: The methods (300, 900, and 1200), and apparatus (140 and 800) of the present invention employ demand assigned spatial multiplexing in a satellite communication system (100) to efficiently accommodate varying demand for high data rate service while minimizing satellite antenna and radio system complexity in a ubiquitous coverage satellite system optimized for transporting packet data. In a preferred embodiment, the methods (300, 900, 1000 and 1200) and apparatus (140 and 800) of the present invention use a first set of signaling beams (210) to establish signaling uplinks and then direct traffic spot beams (220) at particular UE devices to support traffic uplinks in accordance with demand assigned multiple access (DAMA) parameters when and only when the UE devices have traffic data to transmit to a satellite.

Abstract: Phased array components utilizing two or more different types of semiconductor in one monolithic device are provided. High quality epitaxil layers of monocrystalline materials (26) can be grown overlying monocrystalline substrates (22) such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer (24) comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer (28) of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxil growth of single crystal silicon onto single crystal oxidematerials.

Abstract: A satellite ground station (500) mitigates potential interference from a fixed service installation (130, 150) by scanning a field of view and logging potentially interfering transmitters in a data structure (400). The data structure includes fields for azimuth, elevation, and frequency channel, and when complete, forms a map of potentially interfering transmitters within the field of view of the ground station. When a satellite traverses the field of view such that the ground station may interfere with, or be interfered with by, a known potentially interfering transmitter as identified in the map, the ground station takes mitigation measures such as changing frequency channels or handing-off to a different satellite.

Abstract: Transmit, receive, and processing functions of a communication satellite are performed by two communication payload satellites. A transmit payload satellite (20) and a receive payload satellite (10) communicate via a crosslink (30,28) which provides the communication path between the two parts of the transmit and receive payload pair (50). The receive payload satellite (10) is optimized to perform substantially all of the receiving and processing functions required in space. The transmit payload satellite (20) is optimized to perform substantially all of the transmitting functions. The optimization process takes into account the location in space for the two separate payloads, where trade-offs are made with respect to electromagnetic signal interference issues, size, weight, power, and complexity.

Abstract: Methods efficiently assign user channels in a LEO (low-earth orbit) telecommunication system. These methods adapt the channel reuses based on system load or demand. These methods achieve high capacity and minimize interference for the particular situation. Since these methods are adaptive, they adjust to maintain efficient operation as the load conditions change.

Abstract: To obtain service from a satellite communication system, a mobile subscriber unit must acquire a TDMA communication channel. Because the satellites move with respect to the surface of the earth, propagation delays and Doppler shift affect the timing and frequency of received signals. A mobile subscriber unit synchronizes to the frequency and timing windows of a satellite communication station by receiving frequency and timing corrections during channel acquisition. The satellite initially estimates correction factors during initial acquisition requests and further estimates correction factors from synchronization bursts from the subscriber unit.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers. The messages are transmitted at unique times, on unique frequencies, and into uniquely identified cells according to a plan which is periodically revised and transmitted in advance to the pagers. Battery resources in the satellites and pagers are thereby conserved, and interference between transmissions to adjacent cells is minimized.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers. The messages are transmitted during a guard-band time-slot of a compatible world-wide cellular telephone system. In order to achieve better penetration, the satellites boost their transmit power for paging messages. One or more paging carrier frequencies may be used to accommodate differences in paging demand among different terrestrial cells.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers via multiple beams. A message unit monitors multiple beams, recording the visit information for each beam, and ultimately determines the optimum beam to monitor for messages. The message unit, which conserves battery resources by entering into a sleep mode, synchronizes quickly to its message block when it awakes.

Abstract: Handoff methods perform cell-to-cell handoff between cells of the same satellite and between cells of different satellites. Handoff is initiated by an individual subscriber unit (ISU) based on local conditions. Once handoff is needed, the ISU chooses a candidate cell to transfer its communication based on a dynamic handoff candidate list provided by the satellite. After selecting a candidate cell, the ISU requests handoff, the satellite or satellites perform the handoff and communication begins over a new channel in the candidate cell.

Abstract: In a satellite communication system, communication channels are dynamically assigned in real-time based on actual demand using a regionalized channel assignment and reuse scheme. The tradeoff between system capacity and channel interference:is optimized through the use of interlocking local regions. Satellite communication stations within a radio line-of-sight of each other make up each local region. The communication stations of a local region change as the communication stations move through orbital positions. Channel reuse rules are adapted to system load and demand for services. Each communication station establishes its local region and notifies the other communication stations within its local region whenever it assigns a communication channel to a subscriber unit. Channel assignments within each local region are maintained locally by the defining communication station.

Abstract: A constellation of satellites distributed around the earth serves as a communication network that supports global communication of subscriber units. Subscriber units may potentially transmit from any location on earth. Some locations such as radio astronomy sites may be interfered with by nearby transmissions from subscriber units. Subscriber units located within a potentially interfering proximity to radio astronomy sites are prohibited from transmitting potentially interfering signals by reception of a non-interfering beacon at radio astronomy sites. The beacon repeatedly transmits a synchronous control signal with a subscriber unit's servicing satellite's control signal. The beacon's control signal is compatible with a subscriber unit's communication receiver. Control signal information contained in a beacon control signal inhibits the subscriber unit from transmitting.