Abstract: In a dynamic communication system (90) wherein communication parameters vary between transmissions, subscriber units (200) are susceptible to intermittent link blockages. These blockages can result in a loss of successive feedback, instructing subscriber units (200) of adjustments to link parameters to be employed in a subsequent transmission on a communication link (105). Dynamic link parameters are predicted (240) continuously throughout intermittent link fades and these predictions are employed during link blockages in an attempt to re-establish communications. In addition, the subsequent resynchronization process resynchronizes the link parameter predicting model (240) based on how long the signal was interrupted.

Abstract: A communication satellite system (100) includes one or more satellite clusters (150). Each satellite cluster (150) includes synchronized payload processors which are interconnected and synchronized into a parallel processing system using at least one crosslink (208) between multiple processor payload satellites (204). One element in the synchronized payload processors acts as a primary processor and other processor elements act as secondary processors. The primary processor controls and synchronizes the secondary processors. Various services which can include communication services, imaging services, and navigational services are provided to communication units (130) using at least one processor payload satellite (204) in satellite cluster (150). Two or more satellite clusters (150) are connected via a crosslink (138) which provides a communication and synchronization path between the satellite clusters (150).

Abstract: A satellite-based, world-wide cellular messaging system (5) transmits paging messages to pagers (2) via multiple beams. A pager (2) monitors multiple beams, recording the schedules for each beam, and by combining the schedules for multiple beams, ultimately determines which frames in the message groups to monitor for messages. Pager (2), which conserves battery resources by entering into a sleep mode, synchronizes quickly to its message block when it awakes.

Abstract: A communication system (10) includes a population of mobile units (24) which communicate with a control station. Communications take place between the control station 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 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 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: 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).

Abstract: A channel management process (68) is performed by a parent base station (36) of a radio telecommunications system (20) that exchanges channel usage data with neighbor base stations (38) within its local group (34). When channel usage data indicates a channel assignment conflict, that conflict is resolved in the base station (22) having the lesser loading of the pair of conflicting base stations (22). Channel usage requests received by a base station (22) are prioritized and sequentially processed, channels (58) being assigned for inter-cell handoff requests, then intra-cell handoff requests after inter-cell handoff requests, even when that assignment creates a conflict, and then channels (58) being assigned to new call requests after handoff requests if that assignment does not create a conflict.

Abstract: The system (10) and method (100) adjust reuse units when nodes (e.g., satellites (20, 22)) move in a communication system (10), such as satellites (20,22) moving in their orbits around the earth in a space-based communication system (10). The method (100) and system (10) computes interference potentials between a reference reuse unit in a first reuse unit table of a first satellite (20) and reuse units being used in second reuse unit tables in second satellites (20) that are adjacent to the first satellite (20); and when the interference potentials is less than a predetermined threshold, then assigns the satellite a non-interfering reuse unit for the specific time interval.

Abstract: A method and apparatus for routing signals through a system (10) which has multiple destination nodes (12, 14) assigns one or more unique carrier frequencies to each destination node (12, 14). When a signal is received (502) by a transceiver (12), the transceiver (12) evaluates (504) the carrier frequency of the signal, and determines (506) to which destination node (12, 14) that carrier frequency is assigned. The determination (506) is made using a table (200) which associates carrier frequencies to destination nodes (12, 14). The table (200) is created (304) and updated by a control facility (20) which distributes (306) the table (200) to the transceivers (12). Once the transceiver (12) determines (506) the destination node (12, 14), the transceiver (12) can route the signal toward that destination node (12, 14).

Abstract: In a dynamic communication system (90) wherein communication parameters vary appreciably between transmissions, subscriber units (200) are susceptible to link blockages resulting in a loss of successive feedback instructing subscriber units (200) of adjustments to communication parameters to be employed in a subsequent transmission on a communication link (105). A method and system are employed to predict subsequent communication parameters and employ these predictions during link blockages in an attempt to reestablish communications and upon the removal of a link blockage, a subscriber unit (200) employs the predicted communication parameters in resuming communications without requiring complex reallocation of an additional communication link.

Abstract: In a communication system (10) having at least one control center (24) and multiple satellites (12), the satellites (12) operate according to tables (80), wherein each satellites table becomes obsolete at a known time referred to as the exhaustion time. The earliest exhaustion time of all satellites (12) is determined and sent to the satellites (12) in the form of a message or a time-tagged update table (150). When the earliest exhaustion time is reached without updating the satellite (12), the satellites (12) enter default operation at that earliest exhaustion time. The satellites (12) continue default operations until otherwise instructed by the control center (24).

Abstract: A constellation (12) of satellites (14) distributed around the earth supports satellite-based communication system (10) involved in global communication of subscriber units (24). Subscriber units (24) may potentially transmit from any location on earth. Some locations such as radio astronomy sites (28) may be interfered with by nearby transmissions from subscriber units (24) or transmissions from satellites (14). Subscriber units (24) located within a potentially interfering proximity to radio astronomy sites are prohibited from transmitting potentially interfering signals by reception of a non-interfering control signal transmitted by a radio astronomy special equipment located at radio astronomy sites. A radio astronomy special equipment (44) repeatedly transmits to a subscriber unit (24) a control signal synchronous with a control signal of a servicing satellite. The radio astronomy special equipment control signal (46), (48), and (54) is compatible with a subscriber unit's communication receiver.

Abstract: A method for a radio frequency communication unit (110) (CU) to hand off from a losing node (120) to a gaining node (122) estimates a gaining node uplink time (210) and a gaining node uplink frequency (212), which the gaining node uplink signal comprises. During handoff, the CU (110) ceases communications with the losing node (120) and immediately begins communications with the gaining node (122) using the uplink time and uplink frequency. A CU apparatus (300) uses a processor (302) for carrying out calculations necessary for estimating the gaining node uplink time and frequency. Information necessary for the calculations, such as a downlink signal time-of-arrival and Doppler offset, are collected by a CU receiver (306). The CU receiver (306) and a CU transmitter (304) are used to support downlink signals (142) and uplink signals (140), respectively, between the CU (110) and a node (120, 122).

Abstract: A communication system (10), having dynamic nodes such as satellites (12), require narrow-tolerance communication parameters such as timing and frequency. A voice subscriber unit (26) establishes a traffic channel (17) by negotiating communication parameters. A user of voice subscriber unit (26) generates inherent voice pauses in communications. A data subscriber unit (31) possess a datagram for delivery through communication system (10). Instead of negotiating a dedicated traffic channel for delivery of the datagram, data subscriber unit (31) monitors an active voice subscriber unit (26) and determines if the communication parameters used by voice subscriber unit (26) are compatible for data subscriber unit (31). Data subscriber unit (31), upon detecting a voice pause by voice subscriber unit (26), transmits the datagram to satellite (12) using the negotiated communication parameters of voice subscriber unit (26).

Abstract: In a satellite communication system (10), a subscriber unit (26) is assigned a communication channel (17). The channel is used in the present cell (54) as well as subsequent cells (54) as the cells move relative to the earth. The channel is assigned using a cost function which includes a distance factor and an isolation factor. The distance factor which is based on a geographic distance between the nearest use of an interfering channel and the subscriber unit's cell. The isolation factor includes an interference potential between two channels. As a result of this channel assignment process, channels become associated with the geographic location of the subscriber unit. Accordingly, subscriber unit communications on the same satellite are handed-off between cells using the same channel making hand-offs invisible to the subscriber unit (26). When a hand-off is needed to another satellite, the same channel may also be used, or a new channel assigned using the cost function.

Abstract: A satellite-based, world-wide cellular messaging system (5) transmits paging messages to pagers (2) via multiple beams. A pager (2) monitors multiple beams, recording the schedules for each beam, and by combining the schedules for multiple beams, ultimately determines which frames in the message groups to monitor for messages. As propagation characteristics degrade, an adaptive method refines the criteria for including frames into a monitoring schedule.

Abstract: A satellite cellular communication system includes satellites in motion that project cells upon the surface of the Earth. These cells are in motion and pass over individual subscriber units (26) engaged in communications, thus requiring individual subscriber units (26) to perform handoffs as an active current cell (300) currently servicing them advances. Selection of a subsequent servicing cell requires evaluation of active neighboring cells. A pre-computation of candidate cells is performed in advance according to a cell activation schedule. Active neighboring cells of an active current cell (300) are evaluated and prioritized in advance of individual subscriber unit's need for them. A candidate handoff cell list is then delivered to a satellite (12). A candidate handoff cell list is broadcast to all individual subscriber units (26) located within active current cell (300) for use in handoff decisions.

Abstract: A subscriber unit (30) operates in a synchronous communication system having dynamic nodes such as satellites (12). Satellites (12) employ a strict transmit and receive time window and all transmissions directed to satellites (12) must fall within the receive window to be recognized. In a dynamic communication system where low earth orbit satellites (12) continuously orbit, propagation timing between a satellite (12) and a subscriber unit (30) vary rapidly over a wide range. Subscriber unit (30) must approximate a transmit timing advance for use in inaugurating a transmission to satellite (12). Subscriber unit (30) utilizes a valid geolocation position when available but when a position is unavailable or stale, relies on configuration characteristics of the constellation for generating an initial approximation of propagation delay.