Apparatus and method for delivering key information of a channel request message from a user terminal to a network

• US 6,249,677 B1
• Filed: 02/11/1999
• Issued: 06/19/2001
• Est. Priority Date: 11/30/1998
• Status: Expired due to Term

• Current Assignee: Hughes Network Systems LLC (Echostar Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Demers, Stephanie, Noerpel, Anthony, Joshi, Chandra
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Tran, Congvan
• Application Number:
  US09/247,849
• Time in Patent Office: 859 Days
• Field of Search: 455/427, 455/12.1, 455/13.2, 455/434, 455/515, 455/3.2, 370/316, 370/318, 370/321, 370/337, 370/341, 375/356, 375/357, 375/368
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18558 Arrangements for managing communications, i.e. for setting up, maintaining or releasing a call between stations
• CPC Class Codes: H04B 7/2125 Synchronisation

Abstract

An apparatus and method, for use with the satellite-based communications network, for improving the reliability and speed at which communication between a user terminal and the network is established. The apparatus and method arranges data of a channel request message transmitted from a user terminal to a satellite in the satellite-based network to insure that the most critical data for establishing communication between the user terminal and the satellite-based network is received at the satellite during the appropriate receiving time frame window. The channel request message includes a first data group necessary for establishing a communication link for which information is transmitted between the apparatus and the network, and a second data group including information for decreasing the amount time necessary to establish the communication link. The first data group is positioned at the center of the channel request message, with portions of the second data group at opposite ends of the channel request message. The time at which the user terminal transmits the channel request message is set based on a location of the apparatus within a spot beam, to take into account the appropriate propagation delay time for the message to travel from the apparatus to the satellite in the network, thus assuring that at least the first data group of the channel request message is received at the satellite during an appropriate receiving time frame window.

Claims

1. An apparatus, for use in a satellite-based communications network, for generating and transmitting a channel request message, comprising:

a channel request message generator which generates a channel request message including a first data group for establishing a communication link through which information is transmitted between said apparatus and said network, and a second data group; and

a transmitter which transmits said channel request message to said network within a time period, such that an initial portion of said second data group is transmitted before any of said first data group, and a remaining portion of said second data group is transmitted after all of said first data group.

2. An apparatus as claimed in claim 1, wherein:

said transmitter sets the starting time of said time period such that at least all of said first data group of said transmitted channel request message is received at a satellite of said communications network during a channel request message receiving period established at said satellite.

3. An apparatus as claimed in claim 2, wherein:

said transmitter sets said starting time of said time period such that all of said first and second data groups of said transmitted channel request message are received at said satellite during said channel request message receiving period.

4. An apparatus as claimed in claim 1, wherein:

said transmitter transmits all data in said first data group sequentially during a portion of said time period during which none of said second data group is transmitted.

5. An apparatus as claimed in claim 1, wherein:

said transmitter sets the starting time of said time period for transmission of said channel request message based on a location of said apparatus within a spot beam generated by a satellite in said network.

6. An apparatus as claimed in claim 5, wherein:

said transmitter sets said starting time of said time period based on a distance of said apparatus from the center of said spot beam.

7. An apparatus as claimed in claim 5, wherein:

said transmitter selects one of a plurality of correction data based on said location of said apparatus within said spot beam, and sets said starting time based on said selected correction data.

8. An apparatus as claimed in claim 7, wherein:

said channel request message generator includes said selected correction data in said channel request message.

9. An apparatus as claimed in claim 1, wherein:

said first data group includes at least one of contention resolution data and synchronization pattern data.

10. An apparatus as claimed in claim 1, wherein:

said second data group includes data for accelerating establishment of said communication link by said first data group.

11. An apparatus as claimed in claim 10, wherein:

said second data group includes at least one of position data representing a position of said apparatus, identifier data identifying said apparatus, service provider data representing a service provider of said apparatus, second identifier data identifying a second apparatus with which said apparatus is attempting to communicate through said network, and call purpose data representing a cause for which said apparatus is attempting to establish communication with said second apparatus.

12. An apparatus as claimed in claim 1, wherein:

said transmitter transmits said channel request message within said time period at a transmission frequency defined by a spot beam generated by a satellite in said network.

13. A satellite-based communications network, comprising:

a satellite comprising;

a satellite transmitter which generates at least one spot beam; and

a satellite receiver which establishes a period of time, specific for each said spot beam, during which said receiver permits signal reception, and

a terminal unit, separate from said satellite, comprising;

a signal generator which generates a channel request message including first data, for establishing a communication link between said terminal unit and said satellite, and second data; and

a signal transmitter which transmits said channel request message to said satellite at a transmission frequency designated by a selected said spot beam, such that at least all of said first data is received at said satellite receiver during said period of time established for said selected spot beam,

wherein said terminal unit further comprises a terminal unit receiver which receives said at least one said spot beam and selects as said selected spot beam the spot beam being received at the greatest power level of any received spot beam; and

said transmitter transmits said channel request message to said satellite at a frequency defined by said spot beam received at said greatest power level.

14. A satellite-based communications network as claimed in claim 13, wherein:

said signal transmitter transmits said channel request message to said satellite such that all of said first and second data are received at said satellite receiver during said period of time established for said selected spot beam.

15. A satellite-based communications network as claimed in claim 13, wherein:

if said terminal unit fails to establish said communication link with said satellite after said transmitter transmits said channel request message to said satellite at said frequency, said transmitter transmits said channel request message to said satellite at another frequency defined by a spot beam being received by said terminal unit receiver at a different power level.

16. A method for generating and transmitting a channel request message from a user terminal to a satellite in a satellite-based communications network, comprising the steps of:

generating a channel request message including a first data group for establishing a communication link through which information is transmitted between said user terminal and said network, and a second data group; and

transmitting said channel request message to said network within a time period, such that an initial portion of said second data group is transmitted before any of said first data group, and a remaining portion of said second data group is transmitted after all of said first data group.

17. A method as claimed in claim 16, wherein:

said transmitting step transmits said channel request message such that at least all of said first data group of said transmitted channel request message is received at a satellite of said communications network during a channel request message receiving period established at said satellite.

18. A method as claimed in claim 16, wherein:

said transmitting step transmits said channel request message such that all of said first and second data groups of said transmitted channel request message are received at said satellite during said channel request message receiving period.

19. A method as claimed in claim 16, wherein:

said transmitting step transmits all data in said first data group sequentially during a portion of said time period during which none of said second data group is transmitted.

20. A method as claimed in claim 16, wherein:

said transmitting step sets the starting time of said time period for transmission of said channel request message based on a location of said apparatus within a spot beam generated by a satellite in said network.

21. A method as claimed in claim 20, wherein:

said transmitting step sets said starting time of said time period based on a distance of said apparatus from the center of said spot beam.

22. A method as claimed in claim 20, wherein said transmitting step comprises the steps of:

selecting one of a plurality of correction data based on said location of said apparatus within said spot beam; and

setting said starting time based on said selected correction data.

23. A method as claimed in claim 22, wherein:

said generating step includes said selected correction data in said channel request message.

24. A method as claimed in claim 16, wherein:

said transmitting step transmits said channel request message within said time period at a transmission frequency defined by a spot beam generated by a satellite in said network.

25. A method for establishing communication between a user terminal and a satellite, comprising the steps of:

generating at least one spot beam from the satellite,

establishing a period of time, specific for each said spot beam, during which said network permits signal reception at said satellite;

generating a channel request message including first data, for establishing a communication link between said terminal unit and said satellite, and second data;

transmitting said channel request message to said satellite at a transmission frequency designated by a selected said spot beam, such that at least all of said first data is received at said satellite during said period of time established for said selected spot beam,

receiving said at least one said spot beam at said user terminal;

selecting as said selected spot beam the spot beam being received at the highest power level of any received spot beam; and

wherein said transmitting step transmits said channel request message to said satellite at a frequency defined by said spot beam received at said highest power level.

26. A method as claimed in claim 25, wherein:

said transmitting step transmits channel request message to said satellite such that all of said first and second data are received at said satellite during said period of time established for said selected spot beam.

27. A method as claimed in claim 25, wherein:

if said terminal unit fails to establish said communication link with said satellite after transmitting said channel request message to said satellite at said frequency, transmitting said channel request message to said satellite at another frequency defined by a spot beam being received by said terminal unit at a different power level.

28. A data signal, embodied in a carrier wave, for establishing communication between a terminal and a satellite in a satellite-based communications network, said data signal comprising:

a first data segment comprising data for establishing a communication link through which information is transmitted between said terminal and said satellite; and

a plurality of second data segments, each comprising data for accelerating establishment of said communication link by said first data segment, said first data segment being disposed between said plurality of second data segments.

29. A data signal as claimed in claim 28, wherein:

said first data segment includes at least one of contention resolution data and synchronization pattern data.

30. A data signal as claimed in claim 28, wherein:

said second data segment includes at least one of position data representing a position of said terminal, identifier data identifying said terminal, service provider data representing a service provider of said terminal, second identifier data identifying a second terminal with which said terminal is attempting to communicate through said network, and call purpose data representing a cause for which said terminal is attempting to establish communication with said second terminal.

31. A satellite-based communications network, comprising:

a satellite comprising;

a satellite transmitter which generates at least one spot beam; and

a satellite receiver which establishes a period of time, specific for each said spot beam, during which said receiver permits signal reception; and

a terminal unit, separate from said satellite, comprising;

a signal generator which generates a channel request message including first data, for establishing a communication link between said terminal unit and said satellite, and second data;

a signal transmitter which transmits said channel request message to said satellite at a transmission frequency designated by a selected said spot beam, such that at least all of said first data is received at said satellite receiver during said period of time established for said selected spot beam; and

a terminal unit receiver which receives said at least one said spot beam and selects as said selected spot beam the spot beam being received at the greatest power level of any received spot beam;

wherein said transmitter transmits said channel request message to said satellite at a frequency defined by said spot beam received at said greatest power level.

32. A satellite-based communications network as claimed in claim 31, wherein:

if said terminal unit fails to establish said communication link with said satellite after said transmitter transmits said channel request message to said satellite at said frequency, said transmitter transmits said channel request message to said satellite at another frequency defined by a spot beam being received by said terminal unit receiver at a different power level.

33. A method for establishing communication between a user terminal and a satellite of a satellite-based communications network comprising the steps of:

generating at least one spot beam from the satellite;

establishing a period of time, specific for each said spot beam, during which said network permits signal reception at said satellite;

generating a channel request message including first data, for establishing a communication link between said terminal unit and said satellite, and second data;

transmitting said channel request message to said satellite at a transmission frequency designated by a selected said spot beam received at the highest power level, such that at least all of said first data is received at said satellite during said period of time established for said selected spot beam;

receiving at least one said spot beam at said user terminal;

selecting as selected spot beam the spot beam being received at said highest power level of any received spot beam.

34. A method as claimed in claim 33, wherein:

if said terminal unit fails to establish said communication link with said satellite after transmitting said channel request message to said satellite at said frequency, transmitting said channel request message to said satellite at another frequency defined by a spot beam being received by said terminal unit at a different power level.