Optical communication system for transmitting RF signals downstream and bidirectional telephony signals which also include RF control signals upstream

• US 7,058,966 B2
• Filed: 06/12/2001
• Issued: 06/06/2006
• Est. Priority Date: 05/11/1999
• Status: Expired due to Term

• Current Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Original Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Inventors: BuAbbud, George H.
• Primary Examiner(s): Srivastava, Vivek
• Application Number:
  US09/879,395
• Publication Number:
  US 20020015203A1
• Time in Patent Office: 1,820 Days
• Field of Search: 725/106, 725/122, 725/126, 725/129, 398135-139, 385/31
• US Class Current: 725/106
• 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: H04M 11/062 using different frequency bands for speech and other data
• CPC Class Codes: H04N 2007/1739 the upstream communication being transmitted via a separate link, e.g. telephone line
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• 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. An optical distribution terminal, comprising:

a transceiver coupled to an input fiber, the transceiver including;

a first photodiode for receiving optical video signals transmitted on the input fiber at a first wavelength;

a second photodiode for receiving optical telephony signals transmitted on the input fiber at a second wavelength; and

a laser diode for transmitting multiplexed return signals on the input fiber at the second wavelength, the multiplexed return signals including telephony return signals and video return signals;

distribution circuitry for transmitting the received video and telephony signals to a plurality of subscribers and for receiving the telephony return signals and the video return signals from the plurality of subscribers; and

a multiplexer for combining the telephony return signals and the video return signals to generate the multiplexed return signals.

2. The optical distribution terminal of claim 1, further comprising:

a diplexer coupled to the first photodiode and the multiplexer for routing the received video signals to the distribution circuitry, and also coupled to the multiplexer for routing the video return signals from the distribution circuitry.

3. The optical distribution terminal of claim 1, wherein the first wavelength is 1550 nm.

4. The optical distribution terminal of claim 1, wherein the second wavelength is 1310 nm.

5. The optical distribution terminal of claim 1, wherein the first photodiode converts the optical video signals into electrical video signals having a bandwidth between about 50 and 800 MHz.

6. The optical distribution terminal of claim 1, wherein the video return signals have a bandwidth between about 5 and 50 MHZ.

7. The optical distribution terminal of claim 1, wherein the second photodiode converts the optical telephony signals into electrical telephony signals.

8. A system for transmitting video and telephony signals between a central location and a plurality of subscribers, comprising:

a fiber optic network coupled between the central location and a plurality of optical distribution terminals, wherein downstream video signals are transmitted over the fiber optic network at a first frequency, and wherein downstream telephony signals and upstream return video and telephony signals are transmitted over the fiber optic network at a second frequency;

wherein the optical distribution terminals each include;

a first optical-to-electrical converter for receiving the downstream video signals at the first frequency and for generating downstream electrical video signals;

a second optical-to-electrical converter for receiving the downstream telephony signals at the second frequency and for generating downstream electrical telephony signals;

distribution circuitry for transmitting the downstream electrical video and telephony signals to the plurality of subscribers;

a multiplexer for receiving the upstream return video and telephony signals from the plurality of subscribers and for combining these signals into multiplexed upstream signals; and

an electro-optical transmitter for transmitting the multiplexed upstream signals at the second frequency to the central location.

9. The system of claim 8, wherein the first optical-to-electrical converter is a photodiode.

10. The system of claim 9, wherein the second optical-to-electrical converter is a photodiode.

11. The system of claim 8, wherein the electro-optical transmitter is a laser diode.

12. The system of claim 8, wherein the first optical-to-electrical converter is a photodiode, the second optical-to-electrical converter is a photodiode, and the electro-optical transmitter is a laser diode.

13. The system of claim 8, wherein the first and second optical-to-electrical converters and the electro-optical transmitter are configured in a single optical device.

14. The system of claim 8, wherein the first frequency is 1550 nm and the second frequency is 1310 nm.

15. The system of claim 14, wherein the downstream electrical video signals have a bandwidth of about 50 to 800 MHz.

16. The system of claim 15, wherein the downstream electrical video signals have a bandwidth of about 5 to 50 MHz.

17. The system of claim 8, wherein each optical distribution terminal services a single subscriber.

18. The system of claim 8, wherein each optical distribution terminal services a plurality of subscribers.

19. The system of claim 17, wherein the optical distribution terminal is located at the subscriber'"'"'s location.

20. The system of claim 18, wherein the optical distribution terminals are located remote from the subscribers'"'"' location.

21. The system of claim 8, further comprising:

a coaxial cable plant coupling the plurality of optical distribution terminals to the subscribers, wherein the downstream electrical video signals and the return video signals are transported on the coaxial cable plant.

22. The system of claim 21, further comprising:

a plurality of twisted pairs of wires coupling the plurality of optical distribution terminals to the subscribers, wherein the downstream electrical telephony signals and the upstream return telephony signals are transported on the plurality of twisted pairs of wires.

23. An electro-optical transceiver, comprising:

an optical coupler for connecting the electro-optical transceiver to an optical fiber;

a first photodiode for receiving optical signals from the optical fiber at a first frequency and for generating electrical signals having a first bandwidth;

a second photodiode f or receiving optical signals from the optical fiber at a second frequency and for generating electrical signals having a second bandwidth; and

a laser diode for transmitting multiplexed electrical signals at a third bandwidth onto the optical fiber at the second frequency.