Globalstar, Inc.

Space Systems/loral, LLC

Qualcomm Incorporated

Robert A Wiedeman

Paul A Monte

Michael J Sites

Vijaya Korwar Gallagher

Kent A Penwarden

William G Ames

Stanley Canter

Stephen S Carter

John A Serri

Prashant V Waknis

Edward Hirschfield

Jamal Izadian

Philip J Bowman

Wing-Po Yung

Disclosed are methods and apparatus to control the actions of a user terminal (UT) located at a remote location, possibly far from a gateway (GW), which has an interface to the Public Switched Telephone Network (PSTN) and/or to the Internet. The methods and apparatus provide for operation of a mobile satellite communication system having at least one gateway (GW), at least one user terminal (UT), and a constellation of satellites. The methods and apparatus allow access to the communication satellites by specifying an exclusion zone having a confidence limit (CL) associated therewith. The methods and apparatus selectively provide service to a UT depending on a determined location of the UT relative to the exclusion zone and on an estimated error (E) of the determined UT location, wherein location of the UT is determined by the UT, and transmitted to the GW, or location of the UT is determined by the GW.

Method and apparatus providing suppression of system access by use of confidence polygons, volumes and surfaces in a mobile satellite system

A code division multiplexing system for a link between components of a satellite communications system is disclosed where, using spread spectrum techniques, channel blocks are each spread by a pre-assigned orthogonal chip-coded waveform. The pre-assigned orthogonal chip-coded waveforms are each preferably chosen according to the origin and destination of the channel block. The channel blocks are each spread over an intermediate frequency and then upconverted such that their spreading bandwidth is equal, or approximately equal, to the allocated bandwidth of the particular link through which they will be transmitted. The channel blocks are spread so they each have the same, or approximately the same, center frequency as the allocated frequency spectrum of the link. A system for de-multiplexing the channel blocks in a link as received by one of the components of a satellite communications system is also disclosed, where the de-multiplexed link signals are then used to generate commands for use within the receiving component or to generate communications in another link.

Spread spectrum code division destination access (SS-CDDA) for satellite communication system with distributed gateways

A mobile satellite telecommunications system is disclosed comprising at least a user terminal and a satellite which is in earth orbit and at least a gateway bidirectionally coupled to a data communications network. The user terminal comprises a controller responsive to at least one criterion having been met for activating an indicator to inform a user of a potential for reduced user terminal performance.

Low performance warning system and method for mobile satellite service user terminals

A satellite communication system includes a plurality of satellites, such as low earth orbit satellites, and a plurality of gateways. The satellite communication system is bidirectionally coupled to a terrestrial communication system through at least the plurality of gateways. The satellite communication system and the terrestrial communications system together form a data communication network having a plurality of nodes including source nodes, destination nodes and intermediate nodes. Multiple copies of a packet can coexist within the data communication network, and the packet and its one or more copies are routed, using at least in part satellite-resident routers and gateway-resident routers, over a plurality of different paths between a particular source node and a particular destination node. At least one duplicate copy of a given packet is simply not used during the execution of a packet reordering procedure in the destination node, or at an intermediate node. Certain of the paths are carried over satellite-to-satellite cross-links, while certain other ones of the paths are carried over satellite-to-gateway uplinks and downlinks, and at least one path exists between a user terminal and at least one satellite. In a preferred embodiment the packets are TCP/IP (or equivalent protocol) packets containing information for enabling the selective destruction of a duplicate packet to occur.

ISP system using non-geosynchronous orbit satellites

A satellite-based communications system and a method for operating a satellite-based communications system is disclosed. The system is of a type where communications between a user terminal and a gateway occur using an uplink band of frequencies between the user terminal to at least one satellite and in a downlink band of frequencies between the at least one satellite and the user terminal. The system includes first transceivers in the user terminal, referred to herein as a dual user terminal or dual terminal ( ), for transmitting and receiving voice and data in the first and second bands of frequencies using a maximum data rate (e.g., a conventional MSS maximum data rate of 9600 Baud); and further includes second transceivers in the user terminal for transmitting and receiving data in the first and second bands of frequencies using a second data rate that exceeds the maximum data rate. The gateway is a dual gateway ( ) that includes a first interface to voice and data signals and circuitry for transmitting and receiving the voice and data signals using the maximum data rate, and further includes a second interface to data signals and circuitry for transmitting and receiving the data signals using the data rate that exceeds the maximum data rate. The first and second interfaces and circuitry, and the first and second transceivers, may operate simultaneously. User terminal registration and control signals are transmitted and received using the first transceiver, for example, using the conventional MSS data rates and signaling protocols. The user terminal may include at least one pointable antenna, and in this case information used for pointing the at least one antenna is received from the gateway using the first transceiver, for example, using the conventional MSS data rates and signaling protocols. The first transceiver is a portion of a Mobile Satellite Service (MSS) terminal that is detachable from the user terminal for being operated as a stand-alone unit for transmitting and receiving voice and data signals in the first and second bands of frequencies using the maximum data rate.

Global dual terminal low earth orbit communications system

A method is disclosed for operating a satellite communications system for coupling a user terminal to a data communications network. The method has steps of (a) establishing a connectionless packet data transmission link between the user terminal and a gateway that is coupled to the user terminal through at least one satellite via an inbound link and an outbound link, the gateway being further coupled to the data communications network and being associated with a gateway service provider; (b) deriving billing-related information by counting a number of units of data that comprise data packets that are transmitted over at least one of the inbound link and the outbound link; (c) aggregating the billing-related information with billing-related information for other user terminals; (d) transferring the aggregated billing-related information to a satellite communication system operator site; and (e) at the satellite communication system operator site, determining an amount to bill the gateway service provider based at least in part on the aggregated billing-related information. The step of establishing the connectionless packet data transmission link may include a step of varying a bandwidth of the link to accommodate different data rate requirements.

Method and apparatus for accounting for user terminal session-based connection to a satellite communication system

A method includes steps of (a) establishing a call connection between a terrestrial telecommunications network and a user terminal via a first gateway and at least one satellite, (b) while the call connection is established, selecting at least one further satellite, and (c) maintaining the call connection to the terrestrial telecommunications network via a second gateway, the least one further satellite, and the first gateway. The at least one further satellite is selected, at least in part, based on information transmitted from the second gateway to the first gateway through an inter-gateway communications link, and can be based on signal quality indications determined at the user terminal, signal quality indications determined at the gateway(s), or path gains calculated at the gateway(s).

Satellite communication system providing multi-gateway diversity and improved satellite loading

There is disclosed a method and an apparatus for extending the effective service regions of gateways and virtual gateways through a gateway-to-gateway diversity technique. The gateways are interconnected for providing user terminal traffic and signalling information between themselves at call setup and during a call.

Low earth orbit distributed gateway communication system

Disclosed herein is a method for operating a satellite communications system as well as a method for providing a larger effective gateway coverage area, and a system that operates in accordance with the methods. The methods include steps of (a) establishing a call connection between a terrestrial telecommunications network and a user terminal via a first gateway and at least one satellite; and (b) while the call connection is established, coupling the user terminal to the terrestrial telecommunications network via a second gateway and at least one further satellite. The step of coupling includes a step of conveying call speech or data information between the first gateway and the second gateway over an inter-gateway communications link. By so linking multiple gateways each gateway experiences an increase in its effective coverage area, as an on-going call can be continued even after a user terminal moves from a first gateway's coverage area into a second gateway's coverage area.

Satellite communication system providing multi-gateway diversity to a mobile user terminal

A satellite communications system ( ) has a controller for improving and optimizing the delivery of path diversity in a satellite repeater-based communication system, thereby conserving both FDM channels and satellite power utilization. The reception of communications is improved, when one or more orbiting satellite repeater ( ) transmitters is blocked or severely faded, by recognizing the need for satellite path diversity on a real-time or near real-time basis. A user terminal ( ) is thus enabled to receive sufficient signal strength to avoid having an ongoing call automatically terminated. The system optimizes satellite path diversity applied to (a) classes (types) of user terminals and/or (b) to individual user terminals as a function of location and also a local RF propagation environment of the user terminal. In addition, a consideration is made of the satellite resources that are available at any given point in time, and may restrict or limit the availability of satellite path diversity, thereby increasing overall system capacity.

Satellite repeater diversity resource management system

The teaching of this invention pertains particularly to satellite communications systems using GSO or NGSO satellites. This invention employs data derived from signals of various types to derive a mathematical model of propagation related attenuation-inducing events so as to plan system resource allocation to minimize an amount of power required to close communication links between user terminals and the satellites. Disclosed are methods for modelling gateway to satellite links, as well as methods for modeling the user terminal to satellite links. This invention overcomes the problems inherent in the prior art by providing a direct measurement of severe path attenuation potential. The use of the teaching of this invention enables preplanning of the allocation of satellites and satellite resources by calculating a potential for signal path interference based on an external measurement of where rain attenuation may be located, and the real-time or approximately real-time tracking of rain cell activity within storm cells. Optimization of a global system of satellites is made possible, particularly in the context of a system of LEO satellites.

Multiple satellite fade attenuation control system

A method for operating a mobile satellite telecommunications system has steps of (a) providing a user terminal that is operable to simultaneously receive a communication signal from a gateway via a plurality of satellites; and, (b) at the gateway, selectively transmitting the communication to one satellite or a plurality of satellites each having a coverage area that includes a current location of the user terminal. The step of selectively transmitting includes a step of considering a plurality of factors, including a current reception state of the user terminal, a current state of satellite power of at least one of the plurality of satellites, and a predicted required state of satellite power of the at least one satellite. The current reception state of the user terminal is indicated by a received signal quality indicator, which in the preferred embodiment is expressed as the Frame Error Rate (FER). If the value of the FER increases above a threshold level the number of selected satellites is increased, thereby increasing satellite diversity, and if the FER decreases below the threshold level the number of selected satellites is decreased, thereby decreasing satellite diversity. In addition, when a plurality of satellites are selected, the power through each selected satellite is controlled proportionally. The overall effect is conserve satellite power and optimize satellite power consumption, so as to satisfy future demand for the satellite's circuits.

Multiple satellite repeater management system using frame error rate for diversity selection

A user terminal ( ) includes an RF transceiver ( ) for transmitting modulated RF signals to a gateway ( ) and for receiving modulated RF signals from the gateway via at least one satellite ( ). The satellite may be a GEO or a non-GEO satellite. The user terminal further includes a signal processor ( ) coupled to the RF transceiver for demodulating received RF signals to digital signals, an audio unit ( ) for transponding speech signals with a user, and a plurality of encoders/decoders ( A, B) and/or vocoders ( ) between the signal processor and the audio unit for encoding and decoding speech signals passing to and from the audio unit. A first vocoder can be a variable rate vocoder, a second vocoder can be a fixed rate vocoder, where the fixed rate vocoder operates at an average data rate that differs from, e.g., is less than, an average data rate of the variable rate vocoder. The encoder/decoder or vocoder selection is made in the gateway based on one or more criterion such as a presence of an RF signal impairment or RF interference, a predicted and/or actual communications system, a user-selected voice quality, and/or a signal quality received from the user terminal. In one embodiment the vocoder selection command is generated in the terrestrial gateway in response to a request from the user terminal, and in this case the criterion is based on a quality of a signal received from the terrestrial gateway at the user terminal. The selection can be made on the fly on a frame or multi-frame basis.

Multiple vocoder mobile satellite telephone system

A communications system (,) includes at least one satellite (,), at least one terrestrial gateway (,) capable of being bidirectionally coupled to the at least one satellite, at least one terrestrial paging system (,), and at least one user unit (,) capable of being wirelessly coupled to the terrestrial gateway, through the at least one satellite, or to the terrestrial paging system. The gateway includes a paging system (,) for receiving a page message for the user unit, for storing the received page message, and for selectively delivering the received page message to the user unit through the satellite system or through the terrestrial paging system. The gateway is bidirectionally coupled to the terrestrial paging system through the at least one satellite, a virtual gateway (,), and a pager interface unit (,). The pager interface unit includes a pager message and retrieval system (,) for storing a page message until it is determined that the page message can be one of successfully delivered or not successfully delivered to the user unit via the terrestrial paging system. Stored page messages can be later recalled and delivered to the user.

Global mobile paging system

A method includes steps of establishing a wireless connection with a user terminal through a forward link and a return link; determining, during the connection, if an averaged transmitted power density associated with an antenna of the user terminal will equal or exceed, relative to a user of the terminal, at least one of a predetermined threshold level, within a specified unit of time, and an absolute threshold level; and taking action to reduce or eliminate the transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level. The step of determining includes a step of considering the operation of the user terminal in a satellite communications system as well as in a terrestrial communications system. The step of taking action includes a step of reducing the transmitted power of the user terminal by at least one of: assigning the user terminal to another frequency channel, assigning the user terminal to another time slot, changing a number of satellites through which the user terminal is communicating, or changing a data rate at which the user terminal is transmitting. The step of establishing a wireless connection includes a step of assigning at least one communications system parameter to the user terminal based at least in part on a historical record of how quickly the user terminal approaches the threshold.

Growing community of inventors

Los Altos, CA, United States of America

Robert A Wiedeman