Mobile satellite system and method for implementing a single-hop terminal-to-terminal call

• US 6,314,290 B1
• Filed: 02/11/1999
• Issued: 11/06/2001
• Est. Priority Date: 07/13/1998
• Status: Expired due to Term

• Current Assignee: Hughes Network Systems LLC (Echostar Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Roos, Dave, Noerpel, Anthony, Su, Chi-Jiun, Joshi, Chandra
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Woldetatios, Yemane
• Application Number:
  US09/247,847
• Time in Patent Office: 999 Days
• Field of Search: 320/360, 320/323, 320/522, 455/427, 455/428, 455/430, 455/432, 455/433, 455/435, 455/445, 455/456, 455/12.1, 455/13.1, 455/13.2, 455/515
• 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

Abstract

A mobile satellite (MSAT) system is provided for establishing a single-hop terminal-to-terminal call between two terminals. The MSAT system maintains a signaling path between each terminal and a gateway station during the terminal-to-terminal call although a call path between the mobile switching center and the originating terminal is blocked by the satellite. During single-hop call establishment, satellite channels for the terminal-to-terminal call path and for signaling are allocated. The allocated channels are assigned when a direct satellite link for the terminal-to-terminal call is established; otherwise, the call can proceed as a double-hop call using previously assigned satellite channels. A verification signal is sent on the direct satellite link which is for processing by the terminals and which contains information that causes the signal to be ignored by a gateway station. During a single-hop terminal-to-terminal call, signaling from a destination gateway station to an originating terminal at another gateway station is sent via an intranetwork communication system connecting traffic control subsystems in different gateway stations and the satellite channels allocated to the originating terminal

Claims

1. A first gateway station in a mobile satellite system for establishing a single-hop, terminal-to-terminal call between an originating terminal and a destination terminal using assigned channels at a satellite, the first gateway station comprising:

a transceiver and controller device for establishing a radio communication link with said originating terminal; and

traffic control system connected to said transceiver and controller device for performing at least one of a plurality of operations comprising;

managing the allocation of said satellite channels to said first gateway station;

assigning said originating terminal with at least one of said channels and a reserved one of said channels for a call path in response to data provided by said originating terminal indicating that said terminal-to-terminal call to another terminal in said system is desired, validating said originating terminal position, determining the mobile switching center identity corresponding to said destination terminal, and reserving one of said channels for signaling to said originating terminal during said terminal-to-terminal call.

2. A first gateway station as claims in claim 1, further comprising:

a second transceiver and controller device for establishing a radio communication link with said destination terminal, said traffic control system being connected to said second transceiver and controller device for performing at least one of a plurality of operations comprising assigning said destination terminal with at least one of said channels and a reserved one of said channels for said call path, and reserving one of said channels for signaling to said destination terminal during said terminal-to-terminal call.

3. A first gateway station as claimed in claim 2, wherein said system has a mobile switching center, said transceiver and controller device and said second transceiver and controller device each being operable to establish a mobility management connection with said mobile switching center.

4. A first gateway station as claimed in claim 2, wherein one of said transceiver and controller device and said second transceiver and controller device is operable to request cross-connection of said reserved ones of said channels for said call path for said originating terminal and said destination terminal.

5. A first gateway station as claimed in claim 4, wherein one of said originating terminal and said destination terminal transmits a service access point identifier signal having a value indicating that said signal is a terminal-to-terminal signal to be ignored be said first gateway station and processed only by said originating terminal and said destination terminal.

6. A first gateway station as claimed in claim 4, wherein said transceiver and controller device and said second transceiver and controller device each use said reserved ones of said channels for said terminal-to-terminal call if said cross-connection is established, and use previously assigned said at least one of said channels to establish a double-hop call if said cross-connection was not successful.

7. A first gateway station as claimed in claim 1, wherein said originating terminal has established a radio communication link with a second gateway station having a second traffic control system for managing the allocation of said satellite channels to said second gateway station, said second gateway station being operable to register with said gateway station, said second traffic control system being operable to transfer data relating to said channels for said call path and for said signaling to said traffic control system.

8. A data signal embodied in a carrier wave comprising a segment having a first value if said data signal is to be processed by a gateway station in a mobile satellite communication system, said segment having a second value to indicate that two terminals participating in a single-hop, terminal-to-terminal call are to process said data signal and that said gateway station is to ignore said data signal.

9. A data signal embodied in a carrier wave having at least one of a plurality of segments comprising a segment for indicating that said terminal-to-terminal call is desired, a segment identifying at least one satellite channel for establishing a signaling channel between a gateway station and one of two terminals during a single-hop, terminal-to-terminal call, and a segment identifying at least one satellite channel for a call path between said two terminals during said terminal-to-terminal call.

10. A mobile satellite communication system for allowing single-hop calls between terminals in the system, each of the terminals from which a call originates being an originating terminal and the selected one of the terminals for which the call is intended being a destination terminal, the satellite having satellite resources comprising channels for call traffic comprising single-hop calls and for control signaling, the satellite resources being managed by an operations center, a mobile switching center and a home location register maintain data relating to the location of the terminals, the system comprising:

a gateway station comprising a plurality of satellite transceivers for communicating with said originating terminal and said destination terminal, respectively, a gateway controller connected to each of said satellite transceivers and operable to control satellite communication with said originating terminal and said destination terminal, and a traffic control subsystem, said gateway controller and said traffic control subsystem each being operable communicate with said mobile switching center, said traffic control subsystem being operable to communicate with said operations center to request establishment of a single-hop satellite link between said originating terminal and said destination terminal by cross-connecting selected ones of said channels for a terminal-to-terminal call; and

a Global System for Mobile communications (GSM)-compatible interface between said mobile switching center and said gateway controller;

wherein said traffic control subsystem is operable to assign at least one of said channels to establish a signaling channel on which said gateway controller transmits control signals to at least one of said originating terminal and said destination terminal during said terminal-to-terminal call.

11. A system as claimed in claim 10, wherein said signaling channel is a multiplexed, point-to-multipoint channel from said gateway station to a plurally of said terminals.

12. A system as claimed in claim 10, wherein said traffic control subsystem is operable to assign a first pair of said channels for signaling by said originating terminal and said destination terminal, respectively, with respect to said gateway station and prior to establishing said single hop satellite link and to reserve another pair of said channels to be the cross-connected said selected ones of said channels during said terminal-to-terminal call.

13. A system as claimed in claim 12, wherein said mobile switching center is operable to use said signaling channel to send a message indicating that establishment of said single-hop satellite link was unsuccessful to said at least one of said originating terminal and said destination terminal said mobile switching center being operable to maintain a double-hop call between originating terminal and said destination terminal using said first pair of said channels.

14. A system as claimed in claim 10, wherein said system operates in conjunction with cooperating networks that provide at least one of mobile satellite communications and terrestrial mobile communications to user devices, said home location register being operable to maintain data relating to the location of said user devices in said cooperating networks.

15. A system as claimed in claim 10, further comprising a second gateway station with which said originating terminal is registered, said second gateway station comprising at least one transceiver for communicating with said originating terminal, a second gateway controller connected to said at least one transceiver and operable to control satellite communication with said originating terminal, a second traffic control subsystem, and a second mobile switching center, said second gateway controller and said second traffic control subsystem each being operable communicate with said second mobile switching center, said second traffic control subsystem being operable to allocate selected said channels to establish a radio communication link via said satellite between said originating terminal and said second gateway station, said second mobile switching center being operable to determine the identity of said mobile switching center and to provide data relating to said mobile switching center to said originating terminal to reregister said originating terminal to said mobile switching center.

16. A system as claimed in claim 15, wherein said second mobile switching center provides said originating terminal with data comprising at least one of a location area identifier corresponding to said mobile switching center and different from said second mobile switching center, and a temporary mobile station identity to establish a mobility management connection between said originating terminal and said mobile switching center.

17. A system as claimed in claim 15, further comprising an intranetwork communication system for allowing said traffic control subsystem and said second traffic control subsystem to communicate with each other, said second traffic control subsystem being operable to transmit to said traffic control subsystem via said intranetwork communication system data identified a selected one of said channels allocated to establish a second signaling channel between said second gateway station and said originating terminal during said terminal-to-terminal call.

18. A system as claimed in claim 17, wherein said gateway station assigns said second signaling channel to said originating terminal after reregistration.

19. A system as claimed in claim 18, wherein said gateway controller is operable to send a message signal to said second gateway controller during said terminal-to-terminal call via said intranetwork communication system and said second signaling channel.

20. A method for establishing a single-hop terminal-to-terminal call via switched satellite channels between an originating terminals and a destination terminal in a mobile satellite system comprising the steps of:

establishing radio frequency links between said destination terminal and said originating terminal and a gateway station, respectively, using respective gateway station transceivers, said gateway station having a gateway station controller connected to said gateway station transceivers and to a mobile switching center for controlling the allocation and use of said satellite channels at said gateway station;

allocating selected said satellite channels for cross-connection for a single-hop call path between said originating terminal and said destination terminal, said mobile switching center being blocked from signaling said originating terminal and said destination terminal via said single-hop call path;

allocating selected said satellite channels for signaling between said gateway station and said originating terminal and between said gateway station and said destination terminal, during said single-hop call; and

sending signals via said links to said originating terminal and said destination terminal, respectively, assigning said selected satellite channels for cross-connection and said signaling.

21. A method as claimed in claim 20, further comprising the steps of:

establishing said single-hop call path using said selected satellite channels for said cross-connection; and

sending a verification signal between said original terminal and said destination terminal on said single-hop call path.

22. A method as claimed in claim 21, further comprising the step of establishing a double-hop call via said satellite between said destination terminal and said originating terminal using said links if said single-hop call path fails to be established.

24. A method as claimed in claim 20, wherein said destination terminal is registered with a second gateway station and further comprising the step of reregistering said originating terminal with said second gateway station.

25. A method as claimed in claim 24, further comprising a call progress message from a second mobile switching center connected to said second gateway station to said originating terminal.

26. A method as claimed in claim 24, wherein a second mobile switching center is connected to said second gateway station, said reregistering step comprises the steps of:

providing identification data relating to said mobile switching center to said originating terminal; and

updating the location of said originating station and providing data relating to the updated location to said gateway station.

27. A method as claimed in claim 24, wherein allocation of said selected satellite channels to said originating terminal and said destination terminal for said cross-connection and said signaling is accomplished at said second gateway station and said gateway station, respectively, and further comprising the step of transmitting said selected satellite channels allocated to said originating terminal for said cross-connection and for said signaling to said second gateway station.

23. A method as claimed in 20, further comprising the step of sending a signal to at least one of said original terminal and said destination terminal via said single-hop call path, said signal being a service access point identifier signal having a value indicating that said signal is a terminal-to-terminal signal to be ignored by said gateway station and processed only by said at least one of said original terminal and said destination terminal.