Abstract: A dynamic channel management method (100) determines which base station (14, 24, 26) is a least utilized base station for servicing a channel request made by a subscriber unit (40). The least utilized base station is based on what base station (14, 24, 26) is more available to handle the channel request. If the least utilized base station can handle the channel request, it assigns and grants a channel to the subscriber unit (40). Otherwise, the channel request is blocked or denied. The dynamic channel management method (100) provides a systematic way for dynamically matching the available channel resources with the actual demand as a function of time. This enables the system (10) to handle significantly more traffic than with pure static channel management schemes.

Abstract: A dispatch system (10) uses satellites (40) to broadcast simultaneously to an individual remote unit (30), to a select group of remote units (30) or to all the remote units (30). The dispatch system (10) may assign a remote unit (30) to a unique channel if there are enough available channels, or may assign the remote units (30) to a shared channel when the number of available channels is limited. The remote units (30) are given a unique control code or a shared control code. Based on the channel and the control code, the remote unit (30) will be able to listen to the broadcast or ignore it.

Abstract: A method and apparatus used by a communication system (100) to register communication system users which use service provider equipment. Multiple-user and special purpose single-user communication units (110) are provided and/or operated by service providers. MCUs (110) can be located on mobile vehicles or in fixed locations. The system along with MCUs (110) collect registration information and usage information for individual users (440) and individual MCUs (110). Service providers receive billing information concerning the usage of their MCUs (110) by communication system users. After communication system (100) registers each user whose registration information is contained within the at least one combined request message, communication system (100) provides communication services to each user and billing information services to the service provider for the communications service and the service provider furnishing the communications equipment.

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: A speech vocoder device and corresponding method synthesizes speech excitation waveforms. The method entails reconstructing (216) an excitation target from decoded speech data, creating (220) aligned excitation segments by normalizing (296), correlating (298), and aligning (300) a source segment and a target segment, reconstructing normalized intervening segments by ensemble interpolating (318) between the source segment and the target segment, denormalizing (320) the normalized intervening segments, and reconstructing (322) an excitation waveform from the denormalized intervening segments, the source segment, and the target segment.

Abstract: System (10) and methods (100) assign satellite link access bandwidth upon demand as requested by a number of subscriber units (30). After receiving the connection request, a number of time slots being requested is determined. Next, if the maximum number of available time slots is greater than or equal to the number of time slots being requested plus the number of time slots already in use, the connection request is accepted and the number of requested time slots are allocated before communication begins. Otherwise the connection request is rejected and the subscriber unit (30) must try later.

Abstract: A communications system (20) and method (100) learns and dynamically selects routes among a number of nodes (1-12) based on network state information. Each of the nodes (1-12) monitors its links and determines the state of each of its link. Each of the nodes (1-11) transmits their respective link state information to a designated node called a center node (12) by using forward propagation. After the link state information has been received from all of the nodes (1-11), the center node (12) aggregates them and forms a comprehensive state of the entire network. This network state information is subsequently distributed by the center node (12) to each of the nodes (1-11) in the network using reverse propagation. Each of the node (1-11) uses the network state information in making route selection decisions for connection requests that arrive after the node updates its network state information.

Abstract: An improved satellite cellular telephone and data communication system facilitates dual satellite coverage over at least eighty-five percent of the earth. This improved system permits communication with hand held and mobile mounted cellular telephones (120). The system permits two-way communications anywhere on or above the earth up to a particular height above the earth of several hundred nautical miles. The system employs a number of low-earth orbiting satellites (12) moving about the earth in orbit. The satellites (12) are inclined at an angle between 30 and 90 degrees. Links (102) are provided from the satellites directly to the users (120) and via the public switched telephone network (20) to other users. The satellites (12) are interconnected via links in a ring structure surrounding the earth. Switching is performed by each of the satellites (12).

Abstract: A communications network (20) includes any number of moving switching nodes (30) and a route-determining node (28). The route-determining node (28) performs an off-line procedure (58) to define a-priori routing for the entire network. This procedure (58) is performed repetitively to track switching node (30) movement and to define routing for numerous epochs included in a planning period. The procedure (58) includes a process (86) for determining all shortest path routes between all possible origination and destination switching nodes (30). Another process (84) matches predicted call traffic for a subject epoch with the shortest path routes. Another process (88) generates routing code tables (54) in response to the predicted call traffic matched to shortest path routes. This process (88) assigns logical routing IDs (52) to physically distinct, shortest path routes in proportion to the predicted call traffic allocated to the distinct routes.

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 vocoder device and corresponding method characterizes and reconstructs speech excitation. An excitation analysis portion performs a cyclic excitation transformation process on a target excitation segment by rotating a peak amplitude to a beginning buffer location. The excitation phase representation is dealiased using multiple dealiasing passes based on the phase slope variance. Both primary and secondary excitation components are characterized, where the secondary excitation is characterized based on a computation of the error between the characterized primary excitation and the original excitation. Alternatively, an excitation pulse compression filter is applied to the target, resulting in a symmetric target. The symmetric target is characterized by normalizing half the symmetric target. The synthesis portion performs reconstruction and synthesis of the characterized excitation based on the characterization method employed by the analysis portion.

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: A method and apparatus for controlling communication channel access in a communication system (10) determines channel allocations (106) which represent limits on communication channel access and conforms operations of the system (10) to the channel allocations. The channel allocations are determined by dividing a surface which emanates signals from communication units (26) into elemental areas, collecting past traffic data (102) describing past communication channel usage by the communication units (26) located in the elemental areas, generating a traffic model (104) for a future time interval based on the past traffic data, and determining the channel allocations (106) based on the traffic model.

Abstract: A method and apparatus for establishing communication links between communication units that travel in different, determinable directions. The method includes the steps of calculating communication link boundary corridors, generating operational plans that inform the communication units how to establish and maintain a communication link, transmitting the operational plans to the communication units, and establishing links according to the operational plans. The apparatus includes a control segment that generates the operational plans and transmits them to the communication units.

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: 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: An arbitrary repeating pattern detector (ARPD) detects short cycle patterns having a length of N or less, where N is an integer number. The ARPD obtains data symbols from a random number generator. ARPD may be implemented in a circuit or process which evaluates data symbols b.sub.1 -b.sub.2N. A mismatch detector compares symbols b.sub.I+J-1 with symbols b.sub.N+J for all combinations of I and J, where I and J are integer numbers in the range of 1-N, inclusive. For each value of I, an alternative detector determines whether at least one mismatch occurs at any value of J. If such a mismatch is detected, an alternative indication declares a mismatch at the corresponding value of I. A conjunction detector determines whether alternative indications for all values of I indicate mismatches. If a single match is found, a repeating pattern is declared.

Abstract: A ground plane interconnection system using multiple connector contacts interconnects ground planes between backplanes, between circuit boards or between backplanes and circuit boards. When a column or a portion of the column of contacts is allocated to the ground plane interconnect, the ground plane interconnects within the acceptable operational impedance range. These contacts behave as a plane in the direction of interest in a backplane system.

Abstract: A burst error scrubbing system and method consecutively detects and corrects errors in all of memory, beginning with data stored at the first address of memory and continuing until data stored at the last address of memory is read, corrected and written back to memory. Burst error scrubbing is not performed during a refresh cycle but instead is programmable so that the burst scrubbing can be performed at a specific time interval.