RF Return Optical Transmission

• US 20070083909A1
• Filed: 09/01/2006
• Published: 04/12/2007
• Est. Priority Date: 05/11/1999
• Status: Abandoned Application

• Current Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Original Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Inventors: Buabbud, George
• Application Number:
  US11/469,739
• Publication Number:
  US 20070083909A1
• Time in Patent Office: Days
• US Class Current: 725/129
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04N 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission

Abstract

A method of transmitting TV signals and bidirectional telephone communication signals on a single optical fiber, existing telephone twisted pair infrastructure, and existing coaxial cable infrastructure. In addition to allowing the downstream transmission of television channels as well as bidirectional telephone communication, the single optical fibers also provides for the upstream travel of television related signals while requiring minimal changes of the existing infrastructure.

Claims

1. A method for processing communication signals from customer premises equipment, comprising:

receiving an optical signal at a first wavelength, the optical signal being modulated with telephony signals and an RF return signals;

separating the telephony signals from the RF return signals;

sampling the telephony signals;

attenuating the telephony signals;

attenuating the RF return signals based on attenuation of the telephony signals.

2. The method of claim 1, further comprising:

comparing the RF return signals to a pre-determined threshold level;

preventing processing of the RF return signals in response to the RF return signals being below the pre-determined threshold level.

3. The method of claim 2, further comprising:

processing the RF return signals in response to the RF return signals being above the pre-determined threshold level.

4. The method of claim 2, further comprising:

generating a control signal in response to the RF return signals being below the pre-determined threshold level.

5. The method of claim 2, wherein the RF return signals are periodically compared to the pre-determined threshold level.

6. The method of claim 1, wherein the telephony signals are individually attenuated.

12. The system of claim 1, wherein the control circuit is operable to individually attenuate the telephony signals.

7. A system for processing communication signals from customer premises equipment, comprising:

a photodetector operable to receive an optical signal at a first wavelength, the optical signal being modulated with telephony signals and an RF return signals, the photodetector operable to separate the telephony signals from the RF return signals;

a control circuit operable to sample the telephony signals, the control circuit operable to attenuate the telephony signals, the control circuit operable to attenuate the RF return signals based on attenuation of the telephony signals.

8. The system of claim 7, further comprising:

a comparator operable to compare the RF return signals to a pre-determined threshold level;

a squelch circuit operable to prevent processing of the RF return signals by the control circuit in response to the RF return signals being below the pre-determined threshold level.

9. The system of claim 8, wherein the squelch circuit allows the control circuit to process the RF return signals in response to the RF return signals being above the pre-determined threshold level.

10. The system of claim 8, wherein the squelch circuit is operable to generate a control signal in response to the RF return signals being below the pre-determined threshold level.

11. The system of claim 8, wherein the comparator is operable to periodically compare the RF return signals to the pre-determined threshold level.

13. A method for processing signals from customer premises equipment, comprising:

receiving telephony signals from the customer premises equipment;

receiving RF return signals from the customer premises equipment;

combining the telephony signals and the RF return signals;

generating an optical signal to carry the combined telephony signals and RF return signals.

14. The method of claim 13, further comprising:

shaping a frequency content of the telephony signals to avoid interference with the RF return signals.

15. The method of claim 13, further comprising:

separately amplifying the telephony signals and the RF return signals.

16. The method of claim 15, further comprising:

monitoring a signal strength of the telephony signals;

controlling an amplification of both the telephony signals and the RF return signals in response to the signal strength of the telephony signals.

17. The method of claim 13, further comprising:

maintaining a proportional signal strength between the telephony signals and the RF return signals.

18. A system for processing signals from customer premises equipment, comprising:

a controller operable to receive telephony signals from the customer premises equipment;

a diplexer operable to receive RF return signals from the customer premises equipment;

a laser driver operable to combine the telephony signals and the RF return signals, the laser driver operable to generate an optical signal to carry the combined telephony signals and RF return signals.

19. The system of claim 18, further comprising:

a filter operable to shape a frequency content of the telephony signals to avoid interference with the RF return signals.

20. The system of claim 18, further comprising:

a first amplifier operable to amplify the telephony signals;

a second amplifier operable to amplify the RF return signals.

21. The system of claim 20, further comprising:

a monitor operable to monitor a signal strength of the telephony signals, the monitor operable to generate a control signal to control amplification of both the telephony signals and the RF return signals in response to the signal strength of the telephony signals.

22. The method of claim 18, wherein the controller is operable to maintain a proportional signal strength between the telephony signals and the RF return signals.