Abstract: Handover in a wireless communications system from a first communications platform to a post-handover platform is implemented utilizing low-level synchronization mechanisms to enable at least some of a plurality of terminals to adjust timing and synchronize communications with the post-handover platform. Synchronization with the post-handover platform can be facilitated based on a comparison between an expected time to receive response data and the actual time that such data is received from the post-handover platform.

Abstract: Multiple bandwidth requestors (220), a bandwidth manager (420) and a forward link (410) from the bandwidth manager to the bandwidth requestors are used to allocate bandwidth in a return link beam (210). The uplink bandwidth allocation is preferably based on the information to be transmitted provided by the user Automatic Data Processing Equipment (ADPE) (300) and overall system data loading. The preferred method exercised by the bandwidth manager (420) allocates bandwidth on the return link (210) to individual user terminals in either a minimal rate required for the protocol being exercised (213), a committed information rate required for the services being requested, or a fair share rate (214) that allows maximum transfer of data from the user terminal (201) to the gateway (400).

Abstract: A communication system transmits groups of digital communication data from a plurality of sources over a communication network having a bandwidth varying in time. An input receives the communication data. A memory stores for each data group a bandwidth value indicative of a predetermined amount of bandwidth and a priority value indicative of priority. A processor at least estimates the data-carrying ability of at least a portion of the system, identifies the predetermined amount of bandwidth and priority assigned to current data groups presenting data for transmission over the network, identifies the amount of bandwidth requested by the current data groups, and determines eligible current data groups in response to at least the data-carrying ability, the predetermined amount of bandwidth and priority identified for the current data groups, and the amount of bandwidth requested by the current data groups. An output transmits data from the eligible current data groups.

Abstract: Handover in a wireless communications system from a first communications platform to a post-handover platform is implemented utilizing low-level synchronization mechanisms to enable at least some of a plurality of terminals to adjust timing and synchronize communications with the post-handover platform. Synchronization with the post-handover platform can be facilitated based on a comparison between an expected time to receive response data and the actual time that such data is received from the post-handover platform.

Abstract: The present method for allocating bandwidth in a satellite communication system includes determining an uplink assignment of uplinks to user terminals and a gateway. The uplink assignment is preferably based on input parameters including a gateway uplink efficiency, a user terminal uplink efficiency, and a traffic ratio between the user terminal and the gateway. The method also determines a downlink assignment of downlink to the user terminals and one or more gateways. The downlink assignment is preferably based on traffic offered to the user terminals and the gateways as dictated by the uplink assignment. Either of the uplink assignment and downlink assignment may be integer or non-integer assignments.

Abstract: The present method (300) for allocating bandwidth in a satellite communication system (500) includes determining (304) an uplink assignment of uplinks (512) to user terminals (506) and a gateway (504). The uplink assignment is preferably based on input parameters including a gateway uplink efficiency, a user terminal uplink efficiency, and a traffic ratio between the user terminal and the gateway. The method (300) also determines a downlink assignment of downlinks (516) to the user terminals (506) and one or more gateways (504). The downlink assignment is preferably based on traffic offered to the user terminals (506) and the gateways (504) as dictated by the uplink assignment. Either of the uplink assignment and downlink assignment may be integer or non-integer assignments.

Abstract: A method and computer program to configure feeds on a satellite (300, 310, 320) to provide for redundant coverage when a satellite (300, 310, 320) fails. Further, this method and computer program can enable the switching of feeds from commands from a ground station (30) to activate certain feeds and deactivate other feeds when demand for service changes. In addition, this method and computer program allow for repositioning of satellites so that when one satellite fails another satellite may take over its area of coverage by switching active feeds without the need for placing another satellite in orbit.

Abstract: A communications satellite system 100 is provided that comprises a communications satellite 101, at least one user terminal 204 and at least one gateway terminal 202. The communications satellite 101 conveys communication signals between the user terminal 204 and the gateway terminal 202. The communications satellite system 100 includes a forward communication path 200 and a return communication path 300 through the communications satellite 101 between the user terminal 204 and the gateway terminal 202. At least one equivalent signal component is located in both the forward communication path 200 and return communication path 300 and operates on the communication signals. The equivalent signal component has substantially the same operating range in both the forward communication path 200 and return communication path 300 for at least one operating characteristic.

Abstract: A system and method for allocating uplink and downlink bandwidth in a communication system is presented. The communication system includes a communication platform, a plurality of spokes and at least one hub. The plurality of spokes and at least one hub communicate through the communication platform. Each spoke includes spoke uplink bandwidth and spoke downlink bandwidth and each hub includes hub uplink bandwidth and hub downlink bandwidth. The allocation of bandwidth among the spokes and hub may be dynamically adjusted based on the present user demands. Additionally, if the communication system is a packet switched system, empty packets may be discarded at the communication platform and the bandwidth that was previously allocated to the packets may be reallocated.

Abstract: A method and computer program to configure feeds on a satellite (300, 310, 320) to provide for redundant coverage when a satellite (300, 310, 320) fails. Further, this method and computer program can enable the switching of feeds from commands from a ground station (30) to activate certain feeds and deactivate other feeds when demand for service changes. In addition, this method and computer program allow for repositioning of satellites so that when one satellite fails another satellite may take over its area of coverage by switching active feeds without the need for placing another satellite in orbit.

Abstract: Multiple bandwidth requestors (201), a bandwidth manager (401) and a forward link (410) from the bandwidth manager to the bandwidth requestors are used to allocate bandwidth in a return link beam (210). The uplink bandwidth allocation is preferably based on the information to be transmitted provided by the user ADPE (300) and overall system data loading. The preferred method exercised by the bandwidth manager (401) allocates bandwidth on the return link (210)to individual user terminals (200) in either a minimal rate required for the protocol being exercised (213), a committed information rate (214) required for the services being requested, or a fair share rate (214) that allows maximum transfer of data from the user terminal (200) to the gateway (400).

Abstract: An earth orbiting satellite communicates with ground-based communication terminals via a limited number of frequency channels. To maximize the amount of concurrent communication that can be accommodated, the satellite's effective service area is partitioned into cells. The position of each cell relative to nearby cells is established in support of a scheme to maximize channel reutilization. Based on knowledge of communication demand and inter-cell interference constraints, all available channels are associated with particular groups of cells having a common relative position. This establishes a preference for assigning channels to particular cell groups. As communication demand in the cells fluctuates and additional communication channels are required, the channel assignment preferences are consulted to determine which channels to assign to the requesting cells.

Abstract: A satellite based telecommunications system having a multiple registration location register which enables a terminal to register with more than one earth station simultaneously, without any particular one of the earth stations knowing that the terminal is registered elsewhere. The multiple registration location register receives the registration information from each of the earth stations and records the information. This information is used by the multiple registration location register to re-route calls to an earth station that is providing coverage for the terminal. The multiple registration location register may consider many system factors, including satellite to earth station connectivity and satellite to terminal connectivity, in determining to which earth station it should route calls.

Abstract: The present invention includes a satellite based telecommunications system having an earth station network which enables user terminals to remain registered with a single visitor location register independent of satellite movement so long as the terminal remains within a fixed geographic location area. The preferred embodiment includes multiple earth stations which communicate with user terminals via coverage satellites. Each user terminal is registered with a single visitor location register. As the user passes between location areas, the user terminal re-registers at a new associated visitor location register. Earth stations and mobile-services switching center/visitor location registers (MSC/VLRs) are interconnected along a dedicated earth station network link. Communications data is passed along the earth station network link between MSC/VLRs and earth stations in a compressed and/or encoded format.

Abstract: A satellite based telecommunications system having a multiple registration location register which enables a terminal to register with more than one earth station simultaneously, without any particular one of the earth stations knowing that the terminal is registered elsewhere. The multiple registration location register receives the registration information from each of the earth stations and records the information. This information is used by the multiple registration location register to re-route calls to an earth station that is providing coverage for the terminal. The multiple registration location register may consider many system factors, including satellite to earth station connectivity and satellite to terminal connectivity, in determining to which earth station it should route calls.

Abstract: A method is provided for optimally assigning power load demands between satellites in a satellite constellation for a telecommunications system. The method first obtains a satellite coverage snapshot at the satellite operations center. It then identifies the satellites with overlapping coverage areas. The user clusters are then identified which are located in the overlapping coverage areas and initially assigned to one of the covering satellites which requires the least amount of power to communicate with the user clusters or randomly. The processor then balances clusters (or portions thereof) to other satellites so as to efficiently balance the power load on the satellite constellation system. The method repeats the process at regular time intervals to maintain an efficient power balance.

Abstract: A method and apparatus for implementing a weighted voting scheme for reading and accurately recognizing characters in a scanned image. A plurality of optical character recognition processors scan the image and read the same image characters. Each OCR processor outputs a reported character corresponding to each character read. For a particular character read, the characters reported by each OCR processor are grouped into a set of character candidates. For each character candidate, a weight is generated in accordance with a confusion matrix which stores probabilities of a particular OCR to identify characters accurately. The weights are then compared to determine which character candidate to output.