Communications satellite router-formatter

• US 5,930,708 A
• Filed: 03/21/1996
• Issued: 07/27/1999
• Est. Priority Date: 03/21/1996
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Stewart, Michael E., Linsky, Stuart T.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US08/620,068
• Time in Patent Office: 1,223 Days
• Field of Search: 455/428, 455/430, 455/427, 455/429, 455/422, 455/403, 455/11.1, 455/13.1, 455/13.2, 455/552, 455/517, 455/13.3, 455/432, 455/12.1, 455/445, 455/15, 455/16, 455/446 , 455/456, 455/561, 370/316, 370/315, 370/426
• US Class Current: 455/428
• CPC Class Codes: H04B 7/1856 for call routing
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00

Abstract

A local telecommunications network is provided for satellite based telecommunications. The network 10 includes multiple handsets 18-22, 50 and 54 which communicate directly with ground stations 14 and 16. The ground stations communicate with an overhead satellite 12 through a satellite telecommunications uplink. The ground stations include a router for determining whether outgoing calls are directed to a destination handset located within or outside a predefined local geographic cell 30 and 32 for the corresponding ground station 14 and 16. If the destination handset is located outside the local cell of the originating handset, the ground station passes the call to the overhead satellite 12 to establish a satellite telecommunications link. However, if the destination handset 50 is located within the same local cell 32 as the originating handset 22, then the router 16 establishes a direct link between the handsets 22 and 50 without establishing a satellite telecommunications link 26.

Claims

1. A local telecommunications network for use in satellite based telecommunications, said network comprising:

first and second handsets for receiving and transmitting telecommunications signals, at least said first handset being located geographically in a predefined local cell; and

a ground station, in said local cell, for controlling communications between said first and second handsets, said ground station relaying telecommunications signals between said first and second handsets through one of a direct link and a satellite based remote link, said ground station including;

a router for establishing said direct link between said first and second handsets, without establishing said satellite based remote link, when said first and second handsets are both located within said local cell, said router establishing said satellite based remote link between said first and second handsets when said second handset is located outside, and remote to, said local cell.

2. A local telecommunications network, according to claim 1, wherein said router includes a discriminator which receives outgoing calls initiated by said first handset, said discriminator determining whether said outgoing calls are directed to a destination handset inside or outside of said local cell, said router establishing one of said direct link and satellite based remote link based on said determination by said discriminator.

3. A local telecommunications network, according to claim 1, wherein said router includes a switching network for connecting said first and second handsets through said direct link when said second handset represents a destination handset and when said second handset is located in said local cell.

4. A local telecommunications network, according to claim 1, wherein said ground station further includes a formatter for converting an outgoing call from said first handset from a local format to a satellite telecommunications standard format, said formatter outputting said outgoing call in a synchronized manner with respect to time.

5. A local telecommunications network, according to claim 1, wherein said ground station further includes a deformatter for converting an incoming call to said first handset from a satellite telecommunications standard format to a local format.

6. A local telecommunications network, according to claim 1, wherein said ground station includes a transmitter for transmitting outgoing calls synchronously with respect to time.

7. A local telecommunications network, according to claim 1, wherein at least one of said first and second handsets communicates with said ground station through an RF cellular link.

8. A local telecommunications network, according to claim 1, wherein at least one of said first and second handsets communicate with said ground station through a hard wired telephone line.

9. A local telecommunications network, according to claim 1, wherein said ground station further comprises an antenna for outputting a steerable transmission beam directed toward an overhead satellite to establish said satellite based remote link for carrying telecommunications from said first handset to a remote destination handset.

10. A local telecommunications network, according to claim 1, wherein said ground station further comprises a phased array antenna for maintaining said satellite based remote link with an overhead satellite for carrying said telecommunications signals to and from said local handset when said local handset communicates with a remote handset.

11. A local telecommunications network, according to claim 1, further comprising first and second ground stations which communicate with one another through said satellite based remote link and further comprising a third handset located in a second predefined geographic local cell surrounding said second ground station, said first and third handsets communicating through a said satellite based remote link between said first and second ground stations through an overhead satellite.

12. A local telecommunications network, according to claim 1, wherein said ground station further includes a formatter for converting an outgoing call from said first handset from a local format to a satellite telecommunications standard format, said formatter outputting said outgoing call in an asynchronized manner with respect to time.

13. A ground station for use in satellite based telecommunications between two handsets, at least one of said handsets being a local handset located in a predefined geographic local cell surrounding said ground station, said ground station comprising:

local communications links for outputting and receiving calls to and from local handsets;

a discriminator, connected to said local communications links, for determining whether calls from a local initiating handset are directed to a destination handset which is located in said local cell;

a router, including said discriminator, for directly connecting local initiating and local destination handsets through a direct link through said router when said discriminator determines that said destination handset is located in said local cell; and

an antenna for establishing a satellite communications link between said ground station and an overhead satellite, said router connecting said local initiating handset to said antenna when said discriminator determines that said destination handset is remote from said local cell.

14. A ground station, according to claim 13, wherein said router comprises a switching network for connecting said local initiating handset to a local destination handset through said direct link when said discriminator determines that said destination handset is local.

15. A ground station, according to claim 13, further comprising a formatter for converting an outgoing call from said local initiating handset from a first format to a satellite telecommunications standard format, said formatter outputting said call in a synchronized manner with respect to time.

16. A ground station, according to claim 13, further comprising a deformatter for converting an incoming call to a destination local handset from a satellite telecommunications standard format to a local format.

17. A ground station, according to claim 13, further comprising a transmitter for transmitting outgoing calls synchronously with respect to time.

18. A ground station, according to claim 13, further comprising an RF antenna for maintaining an RF cellular communications link with at least one local handset.

19. A ground station, according to claim 13, further comprising wired telephone lines for establishing a telephone link with at least one local handset.

20. A ground station, according to claim 13, wherein said antenna outputs a steerable satellite telecommunications beam adjustable to track an overhead satellite.

21. A ground station, according to claim 13, wherein said antenna constitutes a phased array antenna for outputting a satellite telecommunications beam for transmitting communications data to an overhead satellite.