Globalstar, Inc.

Kent A Penwarden

Robert A Wiedeman

Paul A Monte

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 method in accordance with this invention for operating a satellite communications system of a type that has a plurality of earth orbiting satellites, at least one terrestrial user terminal, and at least one terrestrial gateway, includes steps of determining a location and an azimuthal orientation of the user terminal; determining locations of one or more satellites co-visible to the user terminal and to the gateway; determining a signal quality of paths to each satellite co-visible with the gateway; displaying a representation to an operator of the user terminal, the representation depicting at least the orientation of the user terminal, the determined locations of the one or more satellites, and the determined signal qualities for satellites that are in use and those that are not in use; and changing the location of the user terminal in response to the displayed representation. Also, an unattended user terminal located a desired geographical position can generate a map of the sky over a period of time, the map indicating satellite availability at the desired position. The map can subsequently be used by the user terminal and/or the gateway to schedule communications, thereby conserving one or both of system capacity and user terminal battery power.

Mobile satellite user information request system and methods

Disclosed are methods and apparatus for use in a satellite communications system (10) that enable a user to gain knowledge of a direction to one or more 'best' satellites available to the user. This information enables the user to alter his or her position to take advantage of the one or more 'best' satellites at any particular time in order to facilitate the ability to log-on, initiate and receive calls, and complete calls. The information can be supplied by the user terminal (13) itself, or by a gateway (14). The information can be employed by the user to select for a period of time, by example, a position on an east side of a building, to move to a south-east facing window, or to take some other action that enhances the user's connectivity to one or more of the satellites.

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Los Altos, CA, United States of America

Kent A Penwarden