Low earth orbit distributed gateway communication system

• US 20020039900A1
• Filed: 04/06/2001
• Published: 04/04/2002
• Est. Priority Date: 07/08/1999
• Status: Active Grant

• Current Assignee: Globalstar Incorporated
• Original Assignee: Globalstar Incorporated
• Inventors: Wiedeman, Robert A., Monte, Paul A.
• Granted Patent: US 6,735,440 B2
• Time in Patent Office: Days
• US Class Current: 455/428
• CPC Class Codes: H04B 7/18558 Arrangements for managing communications, i.e. for setting up, maintaining or releasing a call between stations

Abstract

A method for operating a communication system includes steps of: (a) receiving a call for a user terminal at a satellite system gateway, the call originating from another user terminal; (b) examining a database to determine if the called user terminal is located within a coverage area of the satellite system gateway; and (c) if yes, formulating a paging message and transmitting the paging message to the called user terminal via at least one satellite. Upon the called user terminal responding to the page, the method further: (d) establishes the call using satellite system resources, (e) designates one of the calling or called user terminals as a call manager for the duration of the call, and (f) makes a temporary assignment of satellite system resources to the call manager user terminal for use in managing the remainder of the call. The step of establishing the call includes a step of assigning at least an initial channel/circuit pair to each of the user terminals. A call synopsis is transmitted from the call manager user terminal to the gateway at the completion of the call, and the gateway employs the call synopsis when transmitting billing-related information from the gateway to another gateway with which one or both of the user terminals has an affiliation. The other gateway could be a virtual gateway that serves a localized region within the service region of the gateway. At the completion of the call the assigned satellite system resources are relinquished. Also disclosed are methods and apparatus for extending the effective service regions of gateways and virtual gateways through a gateway-to-gateway diversity technique, wherein gateways are interconnected for providing user terminal traffic and signalling information between themselves at call setup and during a call.

Claims

1. A method for operating a communication system, comprising steps of:

providing a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one satellite system ground station that is bidirectionally coupled to the at least one satellite;

providing a terrestrial communication segment comprised of a plurality of satellite user terminals located within a service region of said ground station;

initiating a call from a first user terminal to a second user terminal, wherein a call initiation request is relayed to the ground station through at least one satellite;

setting up the call using the ground station; and

assigning satellite system resources to one of the user terminals that is designated a call manager for the call.

2. A method as in claim 1, and further comprising a step of operating the call manager user terminal to manage the call using the assigned satellite system resources and to transmit a call synopsis to the ground station at the completion of the call.

3. A method as in claim 2, wherein the step of relinquishing includes a further step of transmitting billing-related information from the ground station to another ground station.

4. A method as in claim 3, wherein the another ground station is a ground station with which the one or both of the user terminals has an affiliation.

5. A method as in claim 3, wherein the another ground station is a virtual gateway that serves a localized region within the service region of the ground station.

6. A method as in claim 1, and further comprising a step of operating the call manager user terminal to manage the call using the assigned satellite system resources;

and relinquishing the assigned satellite system resources at the completion of the call.

7. A method as in claim 1, wherein the step of setting up the call is comprised of steps of:

determining an availability of the called user terminal; and

sending a page message from the ground station to the called user terminal through at least one satellite.

8. A method as in claim 1, wherein the step of setting up the call is comprised of step of assigning at least a channel/circuit pair to each of the user terminals.

9. A method for operating a communication system, comprising steps of:

providing a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one satellite system ground station that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system;

providing a terrestrial communication segment comprised of at least one localized network (LN) base station capable of bidirectional communications with a plurality of LN user terminals within an associated LN service region, the terrestrial segment further being provided so as to comprise a LN ground station that is bidirectionally coupled to the at least one LN base station and to the at least one satellite for bidirectionally coupling communications to and from individual ones of the LN user terminals into and out of the LN service region;

receiving an allocation of a portion of satellite system resources at a LN ground station from a satellite system ground station having a coverage region within which the LN ground station is located;

reallocating some of the allocated satellite system resources to one or more LN user terminals requesting service; and

receiving at least one updated allocation of satellite system resources at the LN ground station from the satellite system ground station.

10. A method as in claim 9, and further comprising a step of:

while providing service to a LN user terminal, employing at least a portion of the updated allocation of satellite system resources to make a change in the satellite system resources being used to provide the service to the LN user terminal.

11. A method as in claim 10, wherein the change is made to a satellite diversity level so as to increase or decrease a number of satellites through which the service is being provided.

13. A method as in claim 12, and further comprising a step of transmitting a call synopsis from the call manager user terminal to the gateway at the completion of the call.

14. A method as in claim 13, and further comprising a step of transmitting billing-related information from the gateway to another gateway with which one or both of the user terminals has an affiliation.

15. A method as in claim 14, wherein the another gateway is a virtual gateway that serves a localized region within the service region of the gateway.

16. A method as in claim 12, and further comprising a step of relinquishing the assigned satellite system resources at the completion of the call.

17. A method as in claim 12, wherein the step of establishing the call is comprised of step of assigning at least an initial channel/circuit pair to each of the user terminals.

18. A method as in claim 12, and further comprising a step of, during the call, updating the temporary assignment of satellite system resources to the call manager user terminal

19. A method as in claim 18, and further comprising a step of, during the call, employing at least a portion of the updated allocation of satellite system resources to make a change in the satellite system resources being used to support the call.

20. A method as in claim 19, wherein the change is made to a satellite diversity level so as to increase or decrease a number of satellites through which the call is being made.

12. A method for operating a communication system, comprising steps of:

receiving a call for a user terminal at a satellite system gateway, the call originating from another user terminal;

examining a database to determine if the called user terminal is located within a coverage area of the satellite system gateway;

if yes, formulating a paging message and transmitting the paging message to the called user terminal, the paging message being transmitted via at least one satellite;

upon the called user terminal responding to the page, establishing the call using satellite system resources;

designating one of the calling or called user terminals as a call manager for the duration of the call; and

making a temporary assignment of satellite system resources to the call manager user terminal for use in managing the remainder of the call.

21. A communication system, comprising:

a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one satellite system ground station that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system; and

a terrestrial communication segment comprised of at least one localized network (LN) base station capable of bidirectional communications with a plurality of LN user terminals within a LN service region, said terrestrial segment further comprising a LN ground station that is bidirectionally coupled to said LN base station and to said at least one satellite for bidirectionally coupling communications to and from individual ones of said LN user terminals into and out of said LN service region, wherein

one or more beams from one or more of said satellites at the surface of the earth cover a regional service area (RSA) within which said LN service region is located, and wherein said communication system further comprises at least one database that stores information for associating individual ones of said LN user terminals with said RSA; and

wherein an individual one of said LN user terminals is enabled to complete a call to another individual one of said LN user terminals, where one of the LN user terminals is designated as a call manager for the call.

22. A communication system as set forth in claim 21, and further comprising a plurality of other user terminals that are located within said RSA but not within said LN service region, and wherein said database further stores information for associating individual ones of said other user terminals with said RSA.

23. A communication system as set forth in claim 21, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from a terminal connected to said terrestrial communications network, via said LN base station, said LN ground station, said at least one satellite, and said at least one satellite system ground station.

24. A communication system as set forth in claim 22, wherein individual ones of said other user terminals include a transceiver operable for transmitting a call to and receiving a call from a terminal connected to said terrestrial communications network, via said at least one satellite and said at least one satellite system ground station.

25. A communication system as set forth in claim 22, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said other user terminals, via said LN base station, said LN ground station, and said at least one satellite.

26. A communication system as set forth in claim 22, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said other user terminals, via said LN base station, said LN ground station, said at least one satellite, and said at least one satellite system ground station.

27. A communication system as set forth in claim 21, and further comprising a second plurality of LN terminals that are located within a second LN service region that is contained within said RSA, and wherein said database further stores information for associating individual ones of said second plurality of LN user terminals with said RSA.

28. A communication system as set forth in claim 21, and further comprising a second plurality of LN terminals that are located within a second LN service region that is contained within a second RSA, and wherein said database further stores information for associating individual ones of said second plurality of LN user terminals with said second RSA.

29. A communication system as set forth in claim 21, and further comprising a plurality of other user terminals that are located within a second RSA, but not within a LN service region, and wherein said database further stores information for associating individual ones of said other user terminals with said second RSA.

30. A communication system as set forth in claim 27, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of LN user terminals, via said LN base station, said LN ground station, said at least one satellite, said at least one satellite system ground station, and a second LN ground station and a second LN base station associated with said second LN service region.

31. A communication system as set forth in claim 27, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of LN user terminals, via said LN base station, said LN ground station, said at least one satellite, and a second LN ground station and a second LN base station associated with said second LN service region.

32. A communication system as set forth in claim 28, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of LN user terminals, via said LN base station, said LN ground station, said at least one satellite, said at least one satellite system ground station, and a second LN ground station and a second LN base station associated with said second LN service region.

33. A communication system as set forth in claim 28, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of LN user terminals, via said LN base station, said LN ground station, said at least one satellite, and a second LN ground station and a second LN base station associated with said second LN service region.

34. A communication system as set forth in claim 29, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said other user terminals, via said LN base station, said LN ground station, and said at least one satellite.

35. A communication system as set forth in claim 29, wherein individual ones of said LN user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said other user terminals, via said LN base station, said LN ground station, said at least one satellite, and said at least one satellite system ground station.

36. A communication system as set forth in claim 22, and further comprising a second plurality of other user terminals that are located within a second RSA, but not within a LN service region, and wherein said database further stores information for associating individual ones of said other user terminals with said second RSA.

37. A communication system as set forth in claim 26, wherein individual ones of said other user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of other terminals, via said at least one satellite and said at least one satellite system ground station.

38. A communication system as set forth in claim 26, wherein individual ones of said other user terminals include a transceiver operable for transmitting a call to and receiving a call from one of said second plurality of other terminals, via said at least one satellite.

39. A communication system, comprising:

a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one terrestrial satellite gateway that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system;

wherein one or more beams from one or more satellites at the surface of the earth cover a Regional Service Area (RSA) within which at least one Wireless Local Loop (WLL) service region is located; and

a terrestrial communication segment comprised of at least one WLL base station capable of bidirectional communications with a plurality of WLL user terminals within said WLL service region, said terrestrial segment further comprising a virtual gateway that services said RSA and that is bidirectionally coupled to said WLL base station and to said at least one satellite, wherein said virtual gateway is responsive to information received from said terrestrial satellite gateway for temporarily assuming control of satellite system resources for bidirectionally coupling a communication to or from an individual one of said WLL user terminals into or out of said WLL service region, and wherein

said virtual gateway is bidirectionally coupled to another virtual gateway through traffic and signalling links for enlarging an effective coverage region of each.

40. A communication system, comprising:

a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one terrestrial satellite gateway that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system;

wherein one or more beams from one or more satellites at the surface of the earth cover a regional service area within which at least one Wireless Local Loop (WLL) service region is located; and

a terrestrial communication segment comprised of at least one WLL base station capable of bidirectional communications with a plurality of WLL user terminals within said WLL service region, said terrestrial segment further comprising a virtual gateway that is associated with said regional service area and that is bidirectionally coupled to said WLL base station and to said at least one satellite, wherein said virtual gateway is responsive to information received from said terrestrial satellite gateway for assuming local control of satellite system resources for bidirectionally coupling a communication to or from an individual one of said WLL user terminals into or out of said WLL service region;

wherein

said virtual gateway is further bidirectionally coupled to a transmitter used for transmitting at least one of paging and broadcast messages to one or more of said WLL user terminals, said paging and broadcast messages being received by said virtual gateway from said terrestrial satellite gateway via said at least one satellite, and wherein

said terrestrial satellite gateway is bidirectionally coupled to another terrestrial satellite gateway through traffic and signalling links for enlarging an effective coverage region of each.

41. A communication system, comprising:

a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one satellite system ground station that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system; and

a terrestrial communication segment comprised of a plurality of localized network (LN) base stations each of which is capable of bidirectional communications with a plurality of LN user terminals within an associated LN service region, said terrestrial segment further comprising a LN ground station that is bidirectionally coupled to each of said LN base stations and to said at least one satellite for bidirectionally coupling communications to and from individual ones of said LN user terminals into and out of said LN service regions, wherein

one or more beams from one or more of said satellites at the surface of the earth cover a regional service area within which at least one of said LN service regions is located, wherein said communication system further comprises a system database coupled to said satellite system ground station and a LN database coupled to each of said plurality of LN base stations that store information for associating individual ones of said LN user terminals with a home LN service region;

wherein

LN user terminals that roam from one LN service region to another LN service region, or from one LN service region to a location outside of any LN service region, are authenticated and provided service based on information stored in said database of a home LN service region; and

wherein

for a call from a first LN user terminal to a second LN user terminal, a call initiation request is relayed to the LN ground station through at least one satellite and is set up using the LN ground station, and satellite system resources are assigned to one of the LN user terminals that is designated a call manager for the call.

42. A communication system, comprising:

a satellite communication system segment comprised of at least one satellite that projects a plurality of beams on the surface of the earth and at least one satellite system ground station that is bidirectionally coupled to the at least one satellite and also to a terrestrial communications system; and

a terrestrial communication segment comprised of a plurality of virtual gateways each comprised of a localized network (LN) base station capable of bidirectional communications with a plurality of LN user terminals within an associated virtual gateway service region, each of said virtual gateways further comprising a LN ground station that is bidirectionally coupled to each of said LN base stations and to said at least one satellite for bidirectionally coupling communications to and from individual ones of said LN user terminals into and out of said LN service regions, said terrestrial communication segment further comprising a regional virtual gateway that is bidirectionally coupled to each of said virtual gateways and to said satellite system ground station through at least one satellite, said regional virtual gateway allocating system resources amongst said virtual gateways based on resource assignments received from said satellite system ground station;

wherein

said satellite system ground station designates one of the calling or called LN user terminals as a call manager for the duration of the call, and makes a temporary assignment of satellite system resources to the call manager LN user terminal for use in managing the remainder of the call.

43. A communication system, comprising at least one virtual gateway comprised of a localized network (LN) base station capable of bidirectional wireless communications with a plurality of LN user terminals within an associated regional service region covered by one or more beams associated with one or more satellites, said at least one virtual gateway further comprising a LN satellite ground station that is bidirectionally coupled to said LN base station and to at least one satellite for bidirectionally coupling communications to and from individual ones of said LN user terminals into and out of said LN service regions, said virtual gateway allocating satellite system resources amongst said LN user terminals based on satellite system resource assignments received from a satellite system ground station;

wherein one of the calling or called LN user terminals is designated as a call manager for the duration of the call, and receives a temporary assignment of satellite system resources for use in managing the call.

44. A communications system as in claim 43, wherein said satellite system resources include frequency channels.

45. A communications system as in claim 43, wherein said satellite system resources include spreading codes.

46. A communications system as in claim 43, wherein at least some of said LN user terminals are mobile terminals.

47. A communications system as in claim 43, wherein at least some of said LN user terminals are fixed terminals.

48. A communications system as in claim 43, wherein said LN base station is coupled to a database that stores information for identifying individual ones of said plurality of LN user terminals and for associating individual ones of said LN user terminals with said regional service area.

49. A communications system as in claim 43, wherein said database can be queried via said at least one satellite for authenticating a LN user terminal that has roamed outside of a home LN service region and that is requesting service.

50. A communications system as in claim 43, wherein said one or more satellites are a portion of a constellation of low earth orbit satellites.