Method and apparatus for considering user terminal transmitted power during operation in a plurality of different communication systems

• US 6,272,325 B1
• Filed: 09/18/1998
• Issued: 08/07/2001
• Est. Priority Date: 07/13/1995
• Status: Expired due to Term

• Current Assignee: Globalstar Incorporated
• Original Assignee: Globalstar Incorporated
• Inventors: Sites, Michael J, Wiedeman, Robert A, Monte, Paul A
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US09/154,671
• Time in Patent Office: 1,054 Days
• Field of Search: 455/12.1, 455/13.4, 455/26.1, 455/117, 455/115, 455/67.1, 455/69, 455/427, 455/430, 455/522, 455/405, 370/347, 340/600
• US Class Current: 455/117
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]

Abstract

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.

Claims

1. A method for operating a communications system, comprising the 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 of the user terminal at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein

the step of determining includes a step of considering an amount of power radiated by the user terminal in a satellite communications system as well as in another communications system; and

wherein the step of determining includes a preliminary step of receiving information from the other communications system for indicating an amount of power radiated by the user terminal in the other communications system.

2. A method as in claim 1, wherein the step of taking action includes a step of terminating the connection, and further including the step of, in response to the user terminal attempting to establish a second connection within an interval of time after executing the step of terminating, refusing to establish the second connection.

3. A method as in claim 1, wherein the step of taking action includes a step of terminating the connection, and further including the steps of, in response to the user terminal attempting to establish a second connection within an interval of time after executing the step of terminating, comparing a telephone number sent with a connection request with telephone numbers belonging to a predetermined set of telephone numbers, and if the telephone number matches one of the telephone numbers of the set, connecting the user terminal for placing the call to the telephone number.

4. A method as in claim 1, wherein the step of determining includes the steps of sampling a signal received from the user terminal over the return link;

transmitting a power control signal to the user terminal over the forward link to establish the transmitter power of the user terminal at a predetermined level; and

converting an expected transmitter power of the user terminal to a power density value relative to the user'"'"'s body.

5. A method as in claim 1, wherein the step of establishing includes the steps of:

identifying, from information received from the user terminal over the return link, a type of user terminal; and

executing the step of determining only if the user terminal type is identified to be one of a predetermined one or more types.

6. A method as in claim 1, wherein the step of taking action includes a step of reducing the transmitter 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.

7. A method as in claim 1, wherein the step of taking action includes a step of terminating the connection, wherein the step of terminating includes the initial steps of:

transmitting a message to the user terminal on the forward link; and

, in response to receiving the transmitted message, presenting an indication to the user of the user terminal that the connection will soon be terminated.

8. A method as in claim 1, wherein the step of establishing a wireless connection establishes the connection through at least one satellite.

9. A method for operating a communications system, comprising the 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 of the user terminal at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein

the step of determining includes a step of considering an amount of power radiated by the user terminal in a satellite communications system as well as in another communications system; and

wherein 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.

10. A method as in claim 9, wherein the at least one communications system parameter that is assigned is comprised of at least one of a frequency channel, a time slot, a number of satellites through which the user terminal is to communicate, or a data rate at which the user terminal is to communicate.

11. A method for operating a communications system, comprising the 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 of the user terminal at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein

the step of determining includes a step of considering an amount of power radiated by the user terminal in a satellite communications system as well as in another communications system; and

wherein the step of determining includes a preliminary step of receiving information from the other communications system for indicating an amount of transmitted power radiated by the user terminal in the other communications system, and wherein the step of determining weights the information received from the other communications system differently than information that is derived by a system that performs the step of determining.

12. A method for operating a communications system, comprising the 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 of the user terminal at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein

the step of determining includes a step of considering an amount of power radiated by the user terminal in a satellite communications system as well as in another communications system; and

wherein the step of determining includes a preliminary step of receiving information from the other communications system, via the user terminal, for indicating an amount of power radiated by the user terminal when operating in the other communications system.

13. A communication system, comprising:

a satellite communication system comprising at least one gateway and at least one earth orbiting satellite;

a terrestrial communication system comprising at least one base station;

at least one user terminal comprising circuitry for communicating with either said satellite communication system or with said terrestrial communication system;

said at least one gateway and said at least one base station each comprising means for establishing and conveying a bidirectional, power controlled RF communication connection between one or more terrestrial telecommunications systems and said at least one user terminal; and

a controller for determining, based at least in part on information derived from user terminal power control information in said satellite communications system as well as in said terrestrial communications system, if an averaged transmitted power density associated with an antenna of said user terminal will equal or exceed, relative to a user of said user terminal, at least one of a predetermined threshold level, within a specified unit of time, or an absolute threshold level, said controller being operable for taking action to reduce or eliminate an amount of user terminal transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein said controller is coupled to a controller of said terrestrial communication system, via a communications networks, for receiving information from said controller of said terrestrial communication system, the information indicating an amount of transmitted power radiated by the user terminal when operating in said terrestrial communications system.

14. A system as in claim 13, wherein said controller is responsive to a determination that the averaged transmitted power density will equal or exceed the at least one threshold level, to terminate the connection, and is further responsive to said user terminal attempting to establish a second connection within an interval of time after terminating the connection, for refusing to establish the second connection.

15. A system as in claim 13, wherein said controller is responsive to a determination that the averaged transmitted power density will equal or exceed the at least one threshold level, to terminate the connection, and is further responsive to said user terminal attempting to establish a second connection within an interval of time after terminating the connection, for comparing a telephone number sent with a connection request with telephone numbers belonging to a predetermined set of telephone numbers, and if the telephone number matches one of the telephone numbers of the set, for connecting said user terminal for placing the call to the telephone number.

16. A system as in claim 13, wherein said controller is responsive to information received from said user terminal over said return link for determining a type of user terminal, and takes said action to reduce or eliminate the transmitted power density only if the user terminal type is identified to be one of a predetermined one or more types.

17. A communication system, comprising:

a satellite communication system comprising at least one gateway and at least one earth orbiting satellite;

a terrestrial communication system comprising at least one base station;

at least one user terminal comprising circuitry for communicating with either said satellite communication system or with said terrestrial communication system;

said at least one gateway and said at least one base station each comprising means for establishing and conveying a bidirectional, power controlled RF communication connection between one or more terrestrial telecommunications systems and said at least one user terminal; and

a controller associated with one of said satellite communication system or said terrestrial communication system, said controller operating for determining, based at least in part on information derived from user terminal power control information in said satellite communications system as well as in said terrestrial

communications system, if an averaged transmitted power density associated with an antenna of said user terminal will equal or exceed, relative to a user of said user terminal, at least one of a predetermined threshold level, within a specified unit of time, or an absolute threshold level, said controller being operable for taking action to reduce or eliminate an amount of user terminal transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein said controller associated with said one of said satellite communication system or said terrestrial communication system is coupled to a controller of the other communication system, via said user terminal, for receiving information from the other controller, the information indicating an amount of transmitted power radiated by the user terminal when operating in the other communications system.

18. A communication system, comprising:

a satellite communication system comprising at least one gateway and at least one earth orbiting satellite;

a terrestrial communication system comprising at least one base station;

at least one user terminal comprising circuitry for communicating with either said satellite communication system or with said terrestrial communication system;

said at least one gateway and said at least one base station each comprising means for establishing and conveying a bidirectional, power controlled RF communication connection between one or more terrestrial telecommunications systems and said at least one user terminal; and

a controller for determining, based at least in part on information derived from user terminal power control information in said satellite communications system as well as in said terrestrial communications system, if an averaged transmitted power density associated with an antenna of said user terminal will equal or exceed, relative to a user of said user terminal, at least one of a predetermined threshold level, within a specified unit of time, or an absolute threshold level, said controller being operable for taking action to reduce or eliminate an amount of user terminal transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein said controller takes action to reduce the transmitted power of said user terminal by at least one of assigning said user terminal to another frequency channel, assigning said user terminal to another time slot, changing a number of satellites through which said user terminal is communicating, or by changing a data rate at which said user terminal is transmitting.

19. A communication system, comprising:

a satellite communication system comprising at least one gateway and at least one earth orbiting satellite;

a terrestrial communication system comprising at least one base station;

at least one user terminal comprising circuitry for communicating with either said satellite communication system or with said terrestrial communication system;

said at least one gateway and said at least one base station each comprising means for establishing and conveying a bidirectional, power controlled RF communication connection between one or more terrestrial telecommunications systems and said at least one user terminal; and

a controller for determining, based at least in part on information derived from user terminal power control information in said satellite communications system as well as in said terrestrial communications system, if an averaged transmitted power density associated with an antenna of said user terminal will equal or exceed, relative to a user of said user terminal, at least one of a predetermined threshold level, within a specified unit of time, or an absolute threshold level, said controller being operable for taking action to reduce or eliminate an amount of user terminal transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein said controller establishes a wireless connection with said user terminal by assigning at least one communications system parameter to said user terminal based at least in part on a historical record of how quickly said user terminal approaches the threshold.

20. A system as in claim 19, wherein the at least one communications system parameter that is assigned is comprised of a frequency channel, a time slot, a number of satellites through which said user terminal is to communicate, or a data rate at which said user terminal is to communicate.

21. A communication system, comprising:

a satellite communication system comprising at least one gateway and at least one earth orbiting satellite;

a terrestrial communication system comprising at least one base station;

at least one user terminal comprising circuitry for communicating with either said satellite communication system or with said terrestrial communication system;

said at least one gateway and said at least one base station each comprising means for establishing and conveying a bidirectional, power controlled RF communication connection between one or more terrestrial telecommunications systems and said at least one user terminal; and

a controller associated with one of said satellite communication system or said terrestrial communication system, said controller operating for determining, based at least in part on information derived from user terminal power control information in said satellite communications system as well as in said terrestrial communications system, if an averaged transmitted power density associated with an antenna of said user terminal will equal or exceed, relative to a user of said user terminal, at least one of a predetermined threshold level, within a specified unit of time, or an absolute threshold level, said controller being operable for taking action to reduce or eliminate an amount of user terminal transmitted power at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein said controller associated with said one of said satellite communication system or said terrestrial communication system receives and stores information from the other communication system for indicating an amount of transmitted power radiated by the user terminal in the other communications system, and weights the information received from the other communication system differently than information derived by the controller.

22. A method for conducting wireless communications, comprising the 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 of the user terminal at a time prior to or when the averaged transmitted power density level equals or exceeds the threshold level;

wherein

the step of determining includes a step of considering an amount of power radiated by the user terminal in a first wireless communications system with which the user terminal currently has an established wireless connection, as well as power radiated by the user terminal in a second wireless communications system with which the user terminal previously had an established wireless connection, the step of determining including a step of sending, from the second wireless communication system to the first wireless communication system, information that is descriptive of an amount of power that was radiated by the user terminal when the user terminal previously had an established wireless connection with the second wireless communication system.

23. A method as in claim 22, wherein the first wireless communication system is comprised of a satellite communication system and wherein said second wireless communication system is comprised of a terrestrial communication system.

24. A method as in claim 22, wherein the first wireless communication system is comprised of a first satellite communication system and wherein said second wireless communication system is comprised of a second satellite communication system.

25. A method as in claim 22, wherein the first wireless communication system is comprised of a first terrestrial communication system and wherein said second wireless communication system is comprised of a second terrestrial communication system.