Trw Limited

Northrop Grumman Systems Corporation

Hughes Electronics Corporation

Northrop Gumman Corporation

William F Courtney

Carl F Reisig

Richard L Vogel

Ray M Nuber

Michael S Munoz

Jeffrey E Outwater

Raymond M Nuber

Steven L Branscombe

Fritz B Mezger

Kuang-Yu Li

M'Lissa L Smith

Christian H Wiher

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.

Communications protocol to facilitate handover in a wireless communications network

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

Variable bandwidth satellite communication techniques

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 downlinks ( ) 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.

Asymmetric assignment of space-borne communication system resources

A method and computer program to configure feeds on a satellite ( ) to provide for redundant coverage when a satellite ( ) fails. Further, this method and computer program can enable the switching of feeds from commands from a ground station ( ) 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.

Method of configuring satellite constellation design using multiple discrete switchable spot beams

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.

Cellular communication system employing dynamic preferential channel allocation

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.

Satellite-based cellular telecommunications system utilizing a multiple

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. Each MSC/VLR is interconnected along a terrestrial network link with a gateway and the public switching telephone network. Communications data is passed along the terrestrial network link in a decompressed and/or decoded format. Optionally, MSC/VLRs may be located physically remote from earth stations. When MSC/VLRs and earth stations are provided at a common physical site, a modem switch is provided to selectively interconnect the earth station and MSC/VLR and the earth station network link. Earth stations and MSC/VLRs communicate along the earth station network through wide area network interfaces.

Satellite-based cellular telecommunications system utilizing an earth

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.

Method for balancing demand between satellites in a telecommunications

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.

Growing community of inventors

Long Beach, CA, United States of America

William F Courtney