Optical fiber communications method and system without a remote electrical power supply

• US 7,469,105 B2
• Filed: 04/09/2004
• Issued: 12/23/2008
• Est. Priority Date: 04/09/2004
• Status: Active Grant

• Current Assignee: NextG Networks
• Original Assignee: NextG Networks
• Inventors: Webster, Matthew, Wake, David
• Primary Examiner(s): Chan; Jason
• Assistant Examiner(s): Curs; Nathan M
• Application Number:
  US10/821,590
• Publication Number:
  US 20050226625A1
• Time in Patent Office: 1,719 Days
• Field of Search: 398/171, 398/113, 398/115
• US Class Current: 398/171
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/806 Arrangements for feeding power
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

The present invention allows remote antenna units for radio frequency signal transmission and receipt to operate without the requirement for remote electrical power supplies or for connecting cables that incorporate electrical conductors. According to an aspect of the present invention, an optical communications system employing radio frequency signals comprises a central unit; at least one remote unit having at least one optoelectronic transducer for converting optical data signals to radio frequency signals and converting radio signals to optical signals and at least one antenna to receive and send radio frequency signals; at least one optical fiber data link between the central unit and the remote unit for transmitting optical data signals therebetween; and at least one optical fiber power link between the central unit and the remote unit for providing electrical power at the remote unit.

Claims

1. An optical communications system employing radio frequency signals, the system comprising:

a plurality of optical transceiver units including at least one optical transceiver unit in communication with at least one base station of a plurality of base stations in a cellular wireless communications network, the at least one optical transceiver unit communicates reverse link radio frequency signals to the at least one base station and receives forward link radio frequency signals from the at least one base station;

at least one remote unit which is remote from the at least one optical transceiver unit, the at least one remote unit provides a radio connection point for mobile terminals in an associated coverage area, the at least one remote unit comprising at least one optoelectronic transducer for converting optical data signals to radio frequency signals and converting radio signals to optical signals, and at least one antenna to receive and send radio frequency signals;

at least one optical fiber data link between the at least one optical transceiver unit and the at least one remote unit for transmitting optical data signals therebetween;

at least one optical fiber power link between the at least one optical transceiver unit and the at least one remote unit for providing electrical power at the at least one remote unit;

a radio frequency combiner between the plurality of optical transceiver units and the plurality of base stations which combines reverse link radio frequency signals which are received from the plurality of optical transceiver units; and

a radio frequency splitter which splits the combined reverse link radio frequency signals, the radio frequency splitter is in communication with the plurality of base stations and is associated with the radio frequency combiner.

2. The optical communications system according to claim 1 wherein the at least one optoelectronic transducer comprises an electroabsorption transceiver.

3. The optical communications system according to claim 1 wherein the at least one optoelectronic transducer comprises a first optoelectronic transducer for converting optical data signals to radio frequency signals and a second optoelectronic transducer for converting radio frequency signals to optical signals.

4. The optical communications system according to claim 3 wherein the first and second optoelectronic transducers are low power consumption devices.

5. The optical communications system according to claim 4 wherein the second optoelectronic transducer comprises a VCSEL laser.

6. The optical communications system according to claim 3 wherein the second optoelectronic transducer comprises an edge-emitting laser.

7. The optical communications system according to claim 1, further comprising:

the radio frequency combiner combines forward link radio frequency signals which are received from the plurality of base stations.

8. The optical communications system according to claim 1 wherein an optical fiber provides both the at least one optical fiber data link and the at least one optical fiber power link using wavelength division multiplexing.

9. The optical communications system according to claim 1, wherein the radio frequency signals comprise multiple radio carriers within multiple frequency bands with multiple protocols.

10. The optical communications system according to claim 1, wherein:

the at least one remote unit comprises a photovoltaic converter for converting optical power from the at least one optical fiber power link into electrical power, and an amplifier coupled between the at least one optoelectronic transducer and the at least one antenna, the amplifier amplifies the radio frequency signals obtained by the converting of the optical data signals for transmission to the mobile terminals, the amplifier is coupled to the photovoltaic converter for receiving the electrical power.

11. The optical communications system according to claim 1, wherein:

the at least one remote unit comprises at least one active component, a photovoltaic converter for converting optical power from the at least one optical fiber power link into electrical power, and a regulator for converting the electrical power into a constant voltage or a constant current form that is required to power the at least one active component.

12. The optical communications system according to claim 1, wherein:

the at least one optical transceiver unit comprises a first, high power laser diode coupled to the at least one optical fiber power link and a second laser diode coupled to the at least one optical fiber data link.

13. The optical communications system according to claim 12, wherein:

the high power laser diode provides radiation on the at least one optical fiber power link with a power of about 500 mW.

14. The optical communications system according to claim 12 wherein:

the high power laser diode provides radiation on the at least one optical fiber power link with a power of at least 2 W.

15. The optical communications system according to claim 1, further comprising:

a plurality of remote units, each providing a radio connection point for mobile terminals in associated coverage areas;

at least one optical fiber data link between the at least one optical transceiver unit and each of the remote units for transmitting optical data signals therebetween; and

at least one optical fiber power link between the at least one optical transceiver unit and each of the remote units for providing electrical power at each of the remote units.

16. An optical communications system employing radio frequency signals, the system comprising:

a central unit;

at least one remote unit, which is remote from the central unit, the at least one remote unit provides a radio connection point for mobile terminals in an associated coverage area, said at least one remote unit having first means for converting optical data signals to radio frequency signals and converting radio frequency signals to optical data signals, second means for converting optical data signals into baseband digital signals and converting baseband digital signals to optical data signals, and at least one antenna to receive and send radio frequency signals, the second means communicates with a local area network;

at least one optical fiber data link between the central unit and the at least one remote unit, and associated with the first means, for transmitting optical data signals;

at least one optical fiber data link between the central unit and the at least one remote unit, and associated with the second means, for transmitting optical data signals; and

at least one optical fiber power link between the central unit and the at least one remote unit for providing electrical power at the at least one remote unit.

17. The optical communications system according to claim 16 wherein the baseband digital signals are used in a protocol of the local area network.

18. The optical communications system according to claim 17 wherein the local area network protocol is Ethernet.

19. An optical communications system employing radio frequency signals, the system comprising:

a plurality of base stations in a cellular wireless communications network;

a central unit comprising a plurality of optical transceiver units and a radio frequency splitter-combiner, the radio frequency splitter-combiner is operatively provided between the plurality of optical transceiver units and the plurality of base stations;

a plurality of remote units which are remote from the central unit, each remote unit provides a radio connection point for mobile terminals in an associated coverage area, the plurality of remote units transmit forward link radio frequency signals to mobile terminals via respective antennas and receive reverse link radio frequency signals from mobile terminals via respective antennas, each remote unit is associated with a different one of the optical transceiver units; and

a different optical fiber data link and a different optical fiber power link between each remote unit and its associated optical transceiver unit.

20. The optical communications system according to claim 19, wherein:

the radio frequency splitter-combiner combines forward link radio frequency signals which are received from the plurality of base stations.

21. The optical communications system according to claim 19, wherein:

the radio frequency splitter-combiner combines reverse link radio frequency signals which are received from the plurality of optical transceiver units.

22. The optical communications system according to claim 21, wherein:

the radio frequency splitter-combiner splits the combined reverse link radio frequency signals.

23. An optical communications system employing radio frequency signals, the system comprising:

a plurality of optical transceiver units including at least one optical transceiver unit in communication with at least one base station of a plurality of base stations in a cellular wireless communications network, the at least one optical transceiver unit communicates reverse link radio frequency signals to the at least one base station and receives forward link radio frequency signals from the at least one base station;

a plurality of respective remote units including at least one remote unit which is remote from the at least one optical transceiver unit, the at least one remote unit provides a radio connection point for mobile terminals in an associated coverage area, the at least one remote unit comprising at least one optoelectronic transducer for converting optical data signals to radio frequency signals and converting radio signals to optical signals, and at least one antenna to receive and send radio frequency signals;

at least one optical fiber data link between the at least one optical transceiver unit and the at least one remote unit for transmitting optical data signals therebetween;

at least one optical fiber power link between the at least one optical transceiver unit and the at least one remote unit for providing electrical power at the at least one remote unit;

a radio frequency combiner between the plurality of optical transceiver units and the plurality of base stations which combines reverse link radio frequency signals which are received from the plurality of optical transceiver units;

the plurality of respective remote units provide respective radio connection points for mobile terminals in associated respective coverage areas, each respective remote unit is in communication with a different respective optical transceiver unit of the plurality of optical transceiver units;

a different optical fiber data link between each respective optical transceiver unit and its respective remote unit for transmitting optical data signals therebetween; and

a different optical fiber power link between each respective optical transceiver unit and its respective remote unit for providing electrical power at the respective remote unit.