Abstract:
A communication system (10) includes a population of mobile units (24) which communicate with a control station (29). Communications take place between the control station (29) and the mobile units (24) so that the system (10) may gain knowledge about the mobile units' locations. The mobile units (24) occasionally initiate such communications automatically. The control station (29) sends data defining a target area (72, FIG. 5) to the mobile units. The mobile units (24) reside in the target areas (72) when the target areas (72) are first assigned, but the mobile units (24) are free to move. The control station (29) transmits broadcast signals to geographically spaced apart cells (36, FIG. 2). The broadcast signals convey current data identifying the service areas covered by the cells (36). The mobile units (24) automatically initiate communications when their assigned target areas (72) do not coincide with the service areas for the broadcast signals they can receive.
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. In a preferred embodiment, UE device (140) also executes a method (1200) that includes steps for determining appropriate steering angles for a servicing satellite (110) to use to direct a traffic spot beam (220) to the UE device's location when the UE has traffic data to transmit.
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:
A hybrid constellation satellite communication system (100) is established using two or more satellite types (110, 120) in different constellations. The two or more satellite types (110, 120) are connected to system control centers (140) via control links (105, 135) which provides a communication path from the satellite constellations to the system control centers (140). The two or more satellite types (110, 120) are also connected to subscriber equipment (150) via subscriber links (155, 145) which provides a communication path from the satellite constellations to the subscriber equipment (150). The first type of satellites (110) are interconnected using upper inter-satellite links (115). The second type of satellites (120) are interconnected using lower inter-satellite links (125). Control services and other time delay non-sensitive services are provided using communication channels established using the first type of satellites (110). Time delay sensitive services are provided using communication channels established using the second type of satellites (120). There are no inter-satellite links between satellites in the two different constellations.
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:
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:
Various embodiments are described to address the need for a method and apparatus of voice transcoding in a VoIP environment that effectively interconnects multiple voice encoding formats. In general, a packet-based tandem transcoder (201) receives (706) packets that include vocoder data frames in which source voice samples have been encoded according to a first vocoding format. The transcoder then decodes (708) the vocoder data frames to produce a sequence of linear speech samples. Using a non-circuit switched communication path, an encoder obtains (710) linear speech samples from the sequence of linear speech samples and encodes (712) groups of speech samples from the sequence of linear speech samples to produce vocoder data frames according to a second vocoding format.
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. In a preferred embodiment, UE device (140) also executes a method (1200) that includes steps for determining appropriate steering angles for a servicing satellite (110) to use to direct a traffic spot beam (220) to the UE device's location when the UE has traffic data to transmit.