Optically crosslinked communication system (OCCS)

• US 5,552,920 A
• Filed: 06/07/1995
• Issued: 09/03/1996
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: Geo Licensing Company LLP
• Original Assignee: Geo Licensing Company LLP
• Inventors: Glynn, Thomas W.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/480,743
• Time in Patent Office: 454 Days
• Field of Search: 359/172, 359/117, 359/128, 359/157, 455/109, 455/12.1, 455/13.3, 455/25, 342/352, 342/354, 342/359
• US Class Current: 398/126
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays

Abstract

An optically-based communication system hosted on an elevated platform (e.g., a satellite a tower, or other platform having a substantial vantage point) that uses multiple spatially diverse transmit and receive beams that are optically cross coupled to fully reuse the spectrum and which will create a fully interactive, high bandwidth, high capacity, fully switched communication system. The elevated platform (i.e., satellite, orbiting or tethered vehicles, airborne platforms, towers, etc.) reuses its assigned bandwidth in each of (N) multiple beams (or sectors). The beams are formed by either RF or optical means. The specific users in each beam are then spatially separated in frequency by use of an optical "Bragg Cell." The separated signals are then duplicated through a half mirror and a full mirror and recombined optically to create outputs that are unique combinations of frequencies from each full set of input beams. The recombined signals are then shifted to the transmit band and retransmitted through the same (N) multiple beams. The entire communication system then becomes a single elevated platform which can fully switch a high bandwidth, high channel capacity network.

Claims

1. A two-way optical communications switch system useful for a single elevated platform, said optical communication switch system capable of switching a large number of wide bandwidth channels, comprising:

an elevated platform for hosting said optical communications switch system;

a receive antenna system for receiving a first set of N beams, each of said first set of N beams servicing M customers;

an electrical-to-optical modulator for forming a first set of N optical channels from respective ones of said N beams;

a frequency resolver for spreading each of said first set of N optical channels in one dimension for creating a first set of N×

M optical channel elements;

a beam splitter image concatenator for duplicating said first set of N×

M optical channel elements to create a substantially identical second set of N×

M optical channel elements, said first set of N×

M optical channel elements adjacent to said second set of N×

M optical channel elements to form a dual virtual array having N×

2M optical channel elements and M diagonals, each of said M diagonals comprising M optical channel elements;

a diagonal optical combiner for combining said M optical channel elements for each of said M diagonals into N optical outputs for forming a second set of N beams; and

a transmit antenna system for transmitting said second set of N beams, each servicing M customers simultaneously.

2. The system of claim 1 wherein said frequency resolver includes a Bragg Cell.

3. The system of claim 2 further comprising a source terminal and a destination terminal, said source terminal routing signals through said optical communication switch system for establishing communication with said destination terminal, said source terminal and said destination terminal including control electronics to route signals through said optical communication switch system.

4. The system of claim 3 wherein the signals are wide bandwidth signals.

5. The system of claim 3 wherein said signals includes a plurality of signals within each subband useful for servicing additional customers.

6. The system of claim 2 wherein said frequency resolver further comprises:

a collimating lens disposed between said Bragg Cell and said beam splitter image concatenator, said collimating lens for collimating said N×

M optical channel elements.

7. The system of claim 2 wherein said beam splitter image concatenator includes,

a beam splitter for splitting each of said first set of N×

M optical channel elements to form said second set of N×

M optical channel elements, and

a regular mirror disposed between said beam splitter and said dual virtual array, said regular mirror for reflecting said second set of N×

M optical channel elements to create a first N×

M virtual array adjacent to a second N×

M virtual array, said first N×

M virtual array and said second N×

M virtual array comprising said dual virtual array.

8. The system of claim 2 wherein said diagonal optical combiner includes a cylindrical focusing lens disposed between said dual virtual array and said transmit antenna system, said cylindrical focusing lens for combining said M optical channel elements of said M diagonals to form N optical output channels, said diagonal optical combiner further including a multiple beam former for converting said N optical output channels into said second set of N beams.

9. The system of claim 2 wherein said elevated platform is a satellite.

10. The system of claim 2 wherein said elevated platform is a ground-based tower.

11. The system of claim 2 further including a source terminal, a destination terminal, and an intermediate terminal, said source terminal re-coding a signal for routing via said intermediate terminal to said destination terminal in the event a particular channel that is selected in accordance with a predetermined encoding scheme is occupied.

12. The system of claim 11 wherein said source terminal includes detection circuitry for detecting an occupied channel and re-coding said signals with a predetermined code when said occupied channel is detected, and said intermediate terminal including detection means for detecting said predetermined code and re-routing said signals encoded with said predetermined code.

13. The system of claim 11 wherein said intermediate terminal is an elevated platform.

14. The system of claim 1 wherein said wide bandwidth channels are one-way distributed video services selectable by said M customers.

15. The system of claim 1 wherein said receive antenna system and said transmit antenna system include a set of directional antennas, said antennas employing alternating polarization to enhance isolation.

16. The system of claim 1 wherein said N beams are further isolated by employing frequency separation between adjacent of said N beams.

17. The system of claim 1 wherein said beams are further isolated by employing at least a second elevated platform, said elevated platform and said second elevated platform covering over lapping sectors, a source terminal and a destination terminal, the terminals each employing a directional antenna that spatially isolates one of said elevated platform or said second elevated platform.

18. The system of claim 1 further comprising:

by-pass circuitry for extracting a set of selected ones of intra-beam signals from said first set of N beams, said intra-beam signals routed directly to said second set of N beams for transmission by said transmit antenna system.

19. The system of claim 1 wherein alternating ones of said N beams alternate a transmit frequency and a receive frequency for enhancing beam isolation.

20. A two-way communications switch system useful for a single elevated platform, said communication switch system capable of switching a large number of wide bandwidth channels, comprising:

a receive antenna system for receiving a first set of N beams, each of said first set of N beams servicing M customers;

an elevated platform for hosting said communication switch system;

a bank of frequency selective filters for forming a first set of N channels from respective ones of said N beams, each of said first set of N channels having M signals, each of said M signals separated by frequency;

a set of summation devices for forming a second set of N channels, each of the channels comprising M signals, each of said M signals from a separate one of said first set of N channels;

routing means for routing said M signals from each of said first set of N channels to said summation means; and

a transmit antenna system for converting said N channels into said second set of N beams and transmitting said second set of N beams servicing M customers simultaneously.

21. The system of claim 20 further comprising a source terminal and a destination terminal, said source terminal routing signals through said communication switch system for establishing communication with said destination terminal, said source terminal and said destination terminal including control electronics to route signals through said communication switch system.

22. The system of claim 21 wherein the signals are wide bandwidth signals.

23. The system of claim 21 wherein said receive antenna system and transmit antenna system comprise a set of directional antennas, each of the antennas having beams oriented to service a distinct geographical sector.

24. The system of claim 21 wherein said signals includes a plurality of signals within each subband useful for servicing additional customers.

25. The system of claim 21 wherein said source terminal includes detection circuitry for detecting an occupied channel and re-coding said signals with a predetermined code when said occupied channel is detected, and said intermediate terminal including detection means for detecting said predetermined code and re-routing said signals encoded with said predetermined code.

26. The system of claim 21 wherein said elevated platform is a satellite.

27. The system of claim 21 wherein said elevated platform is a ground-based tower.

28. The system of claim 21 wherein said beams are further isolated by employing at least a second elevated platform, said elevated platform and said second elevated platform having over lapping sectors, a source terminal and a destination terminal, the terminals each employing a directional antenna that spatially isolated one of said elevated platform or said elevated platform.

29. The system of claim 20 wherein said beams are further isolated by alternating polarized energy employed in alternating ones of said beams.

30. The system of claim 20 wherein said beams are further isolated by employing frequency separation between adjacent ones of said beams.

31. The system of claim 20 wherein said wide bandwidth channels are one-way distributed video services selectable by said M customers.

32. The system of claim 20 further including a source terminal, a destination terminal, and an intermediate terminal, said source terminal re-coding a signal for routing via said intermediate terminal to said destination terminal in the event a particular channel that is selected in accordance with a predetermined encoding scheme is occupied.

33. The system of claim 32 wherein said intermediate terminal is an elevated platform.

34. The system of claim 20 further comprising:

by-pass circuitry for extracting a set of selected ones of intra-beam signals from said first set of N beams, said intra-beam signals routed directly to said second set of N beams for transmission by said transmit antenna system.

35. A two-way optical communications switch system useful for a single elevated platform, said optical communication switch system capable of switching a large number of wide bandwidth channels, comprising:

an elevated platform for hosting said optical communications switch system;

means for receiving a first set of N beams, each of said first set of N beams servicing M customers;

optical channel forming means for forming a first set of N optical channels from respective ones of said N beams;

spreading means for spreading each of said first set of N optical channels in one dimension for creating a first set of N×

M optical channel elements;

N×

M optical channel element duplicating means for duplicating said first set of N×

M optical channel elements to create a substantially identical second set of N×

M optical channel elements, said first set of N×

M optical channel elements and said second set of N×

M optical channel elements positioned to form a dual virtual array having N×

2M optical channel elements and M diagonals, each of said M diagonals comprising M optical channel elements;

selective focusing means for combining said M optical channel elements for each of said M diagonals into a second set of N beams; and

transmitting means for transmitting said second set of N beams, each servicing M customers simultaneously.

36. The system of claim 35 wherein said spreading means includes a Bragg Cell.

37. The system of claim 36 further comprising a source terminal and a destination terminal, said source terminal routing signals through said optical communication switch system for establishing communication with said destination terminal, and said source terminal and said destination terminal including control electronics to route signals through said optical communication switch system.

38. A method for simultaneously switching wideband signals of a first set of M users in each of a first set of N beams to any of a second set of M users each in of a second set of N beams, comprising the steps of:

receiving a first set of N beams, each of said N beams servicing M customers;

converting each of said N beams from electromagnetic energy into N electrical channels;

converting said N electrical channels to a first set of N optical channels;

focusing said N optical channels;

collimating said first set of N optical channels;

focusing said N optical channels on a Bragg Cell;

converting said N optical channels into N×

M optical channels;

collimating said N×

M optical channels;

duplicating said N×

M optical channels for forming a dual virtual array having N×

2M optical channel elements and M diagonals, each of said M diagonals having M optical channel elements;

combining said M optical channel elements of each of said M diagonals;

forming a second set of N beams from the combined M optical channel elements of said M diagonals; and

transmitting said second set of N beams to service a second set of M customers in each of said N beams.