Abstract: A communication system qualifies access to the services it provides to subscriber units based upon the locations of the subscriber units. Subscriber unit location data are routed through a satellite to a gateway where a home subscriber information manager for the subscriber unit resides. This home gateway selects a service control area and corresponding serving gateway to use in establishing calls to and from the subscriber unit. When an area of uncertainty for the subscriber unit's location overlies a boundary between service control areas, additional location data may be obtained to shrink the area of uncertainty. If the area still overlies a boundary, a serving gateway is selected based upon the current serving gateway, the home gateway, and the service control area where the center of the area of uncertainty resides.

Abstract: A communication network (10) includes a constellation (12) of mobile satellites (14) in low earth orbits and stationary gateways (24) near the surface of the earth. Data packets are routed through the network (10) using communication paths that change from moment to moment due to satellite movement. The routing paths are scheduled in advance (58) in response to predictable orbital satellite movement. The constellation (12) is configured so that only a minor amount of overlap in radio range exists between adjacent satellites (14). Gateways (24) include multiple, spaced apart antennas (30) that may be used to acquire arriving satellites (14'). When a gateway (24) has trouble quickly acquiring an arriving satellite (14'), an exception handoff time may be substituted for the scheduled normal handoff time at the gateway (24), departing satellite (14), and arriving satellite (14') involved.

Abstract: A network includes a system and a population of subscriber units. System satellites move in low earth orbits and form moving cells on the surface of the earth. A pattern of static areas that covers the service area of the system is defined in a map. The system discovers the static areas for the subscriber units. When an incoming call needs to be directed to a subscriber unit, the subscriber unit's static area is converted into identities of beams that form the cells that coincide with the static area. A ring signal is transmitted in only these cells. Subscriber units monitor area identification signals that identify the static areas coincident with the cells where the signals are transmitted. When the static area known by the system is not among the identified static areas, a subscriber unit engages in re-registration communications.

Abstract: A communication network (10) includes a constellation of satellites (12) in orbit around the earth. Gateways (14) communicate with the satellites (12), reside on the surface of the earth, and interface the network (10) to the local PSTN (18). User units (16) communicate with satellites (12) and provide communication services to users. A gateway (14) includes a mobile switching center (22), which connects half-calls, and an earth terminal controller (20), which occasionally overrides connections defined in the mobile switching center (22). When possible, communication paths connected at the mobile switching center (22) are intraswitched at a satellite (12) rather than being routed through the mobile switching center. However, when supplementary services are requested, the communication path is reconfigured back to the mobile switching center (22) so that additional signals may be inserted into the communication path.

Abstract: A radio telecommunication system includes a number of satellites in low earth orbits. Any number of subscriber units communicates with the satellites. A single subscriber unit communicates with a single satellite using electromagnetic signals so that a measurement processor can obtain Doppler component, propagation duration, and real time measurements of the signals. A location processor converts these measurements into a geographic location with respect to the earth. A service processor determines which qualifications to apply to communication services offered by the system. These qualifications are based on the subscriber unit's location. A call processor carries out the qualifications when requests to setup calls involving the subscriber unit are received by the system and during calls involving the subscriber unit.

Abstract: A hand-portable position locating radio has a geolocation (e.g. GPS) receiver providing local position and timing information from geolocation means (e.g. GPS or IRIDIUM satellites) and a local transceiver for sending local position and other information to a communication system (e.g., an IRIDIUM or MILSAT satellite). A data processor coupled to the local transceiver and receiver controls operation of the device, including storing local position information and separating signals broadcast by the communication system into those intended or not intended for the device. The radio prepares an emergency access message which it sends to the satellite communication system in a manner to insure rapid detection of the emergency signal and allocation of a clear channel and time slot for further communication.

Abstract: A radio telecommunications system includes a number of locator satellites in low earth orbits. Locatable subscriber units communicate with the satellites. A single subscriber unit communicates with a single satellite using electromagnetic signals so that a measurement processor can obtain Doppler component, propagation duration, and real time measurements of the signals. A location processor converts these measurements into a two-position location solution. The two-position solution includes an actual position and an image position. The actual position may be detected in some situations by identifying a cell within which communications take place. In other situations, the actual position may be distinguished from the image position by detecting the eastward rotation of the earth. A service processor determines which qualifications to apply to communication services offered by the system. These qualifications are based on the subscriber unit's location.

Abstract: A radio telecommunications/location system includes a number of locator satellites in low earth orbits. The satellites include multibeam antennas. Locatable subscriber units communicate with the satellites. A single subscriber unit communicates with a single satellite using electromagnetic signals so that measurement processors can obtain Doppler component, and propagation duration measurements of the signals. A location processor converts these measurements into a two-position location solution. The two-position solution includes an actual position and an image position. The actual position may be detected in some situations by identifying a cell within which communications take place.