Digital return path for hybrid fiber/coax network

• US 7,016,308 B1
• Filed: 03/19/1999
• Issued: 03/21/2006
• Est. Priority Date: 03/19/1999
• Status: Expired due to Fees

• Current Assignee: Broadband Royalty Corporation (CommScope Holding Company, Inc.)
• Original Assignee: Broadband Royalty Corporation (CommScope Holding Company, Inc.)
• Inventors: Gallagher, Robert T.
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): RYMAN, DANIEL J
• Application Number:
  US09/273,197
• Time in Patent Office: 2,559 Days
• Field of Search: 370/465, 370/541, 370/263, 370/395, 370/410, 370242-244, 370/248, 370/250, 359/180, 359/158, 359/140, 359/135
• US Class Current: 370/241
• 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 7/17309 Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission

Abstract

A hybrid fiber/coax network is provided. The network includes a head end with at least one optical distribution node coupled to the head end over at least one fiber optic link. A plurality of coaxial cable links are coupled to each of the at least one optical distribution node. Further, a transmitter is disposed at the optical distribution node. The transmitter is responsive to signals from the plurality of coaxial cable links. The transmitter converts analog signals to baseband digital signals and transmits the baseband digital signals to the head end over the at least one optical link. A receiver is disposed at the head end. The receiver is responsive to the digital signals from the transmitter and converts the digital signals to analog signals for the head end.

Claims

1. A hybrid fiber/coax network comprising:

an optical distribution node including a transmitter the transmitter including,

an analog-to-digital converter configured to convert a first analog signal into a baseband digital signal,

a status monitoring unit configured to generate status data representing an operational status of the optical distribution node,

a multiplexer configured to convert the baseband digital signal into a serial data stream, and configured to multiplex the serial data stream and the status data to create a combined digital signal, and

an optical transmitter configured to transmit the combined digital signal via a fiber optic link; and

a head end configured to be coupled to the optical distribution node via the fiber optic link, configured to control or monitor an operation of the optical distribution node based on the status data, and including a receiver, the receiver including,

an optical receiver configured to receive the combined digital signal via the fiber optic link,

a demultiplexer configured to demultiplex the combined digital signal into the baseband digital signal and the status data, and

a node status monitoring unit configured to receive the status data from the demultiplexer, and

a digital-to-analog converter configured to convert the baseband digital signal into a second analog signal, the second analog signal being a reconstructed signal corresponding to the first analog signal.

2. The hybrid fiber/coax network of claim 1,

wherein the multiplexer is further configured to multiplex framing data to create the combined digital signal.

3. The hybrid fiber/coax network of claim 2,

wherein the demultiplexer is further configured to demultiplex the combined digital signal into framing data.

4. The hybrid fiber/coax network of claim 1, wherein the analog-to-digital converter is configured convert the first analog signal to the baseband digital signal at least at 850 mega-bits second with a 10-bit data width.

5. The hybrid fiber/coax network of claim 1, wherein the optical transmitter is configured to transmit the combined digital signal at a bit rate of up to approximately 1 gigabit per second.

6. The hybrid fiber/coax network of claim 1, wherein the multiplexer is further configured to multiplex data for bit error rate link performance testing to create the combined digital signal.

7. The hybrid fiber/coax network of claim 1, wherein the receiver further includes:

a clock data recovery device configured to receive the combined digital signal from the optical receiver; and

a decode logic unit configured to receive the combined digital signal and a clock signal from the clock data recovery device.

8. A hybrid fiber/coax network comprising:

an optical distribution node configured to be coupled to a plurality of coaxial cable links of a predetermined quantity and including a transmitter, the transmitter including,

a plurality of analog-to-digital converters of the predetermined quantity, each configured to convert a corresponding first analog signal into a corresponding baseband digital signal,

a plurality of first multiplexers of the predetermined quantity, each configured to convert the corresponding baseband digital signal into a serial data stream,

a status monitoring unit configured to generate status data representing an operational status of the optical distribution node,

a second multiplexer configured to multiplex the serial data stream received from the plurality of first multiplexers and the status data to create a combined digital signal, and

an optical transmitter configured to transmit the combined digital signal via a fiber optic link; and

a head end configured to be coupled to the optical distribution node via the fiber optic link, configured to control or monitor an operation of the optical distribution node based on the status data, and including a receiver, the receiver including,

an optical receiver configured to receive the combined digital signal via the fiber optic link,

a first demultiplexer configured to demultiplex the combined digital signal into the baseband digital signals and the status data,

a plurality of second demultiplexers of the predetermined quantity, each configured to convert a corresponding one of the baseband digital signals received from the first demultiplexer into a non-serial data stream format,

a plurality of digital-to-analog converters of the predetermined quantity, each configured to convert the corresponding baseband digital signals into a corresponding second analog signal, each of the second analog signals being a reconstructed signal corresponding to a respective one of the first analog signals, and

a node status monitoring unit configured to receive the status data from the first demultiplexer.

9. The hybrid fiber/coax network of claim 8,

wherein the second multiplexer is further configured to multiplex framing data to create the combined digital signal.

10. The hybrid fiber/coax network of claim 9,

wherein the first demultiplexer is further configured to demultiplex the combined digital signal into framing data.

11. The hybrid fiber/coax network of claim 8, wherein the second multiplexer is further configured to multiplex data for bit error rate link performance testing to create the combined digital signal.

12. The hybrid fiber/coax network of claim 8, wherein the receiver further includes:

a clock data recovery device configured to receive the combined digital signal from the optical receiver; and

a decode logic unit configured to receive the combined digital signal and a clock signal from the clock data recovery device.

13. The hybrid fiber/coax network of claim 8, wherein the optical transmitter is configured to transmit the combined digital signal at a bit rate of up to approximately 5 gigabits per second.

14. A method for handling data in a return path of a hybrid fiber coax network, comprising:

processing an analog signal, by an optical distribution node, including,

receiving a first analog signal from at least one of a plurality of coaxial cable links,

converting the first analog signal into a baseband digital signal;

generating status data representing an operational status of the optical distribution node of the hybrid fiber coax network,

converting the baseband digital signal into a serial data stream,

multiplexing the serial data stream and the status data to create a combined digital signal, and

transmitting the combined digital signal via a fiber optic link from the optical distribution node; and

processing the combined digital signal, by a head end, including,

receiving the combined digital signal via the fiber optic link at the head end of the hybrid fiber coax network;

demultiplexing the combined digital signal into the baseband digital signal and the status data,

storing the status data in a node status monitoring unit of the head end, and

converting the baseband digital signal into a second analog signal, the second analog signal being a reconstructed signal corresponding to the first analog signal, and

controlling or monitoring an operation of the optical distribution node based on the status data.

15. The method of claim 14,

wherein the multiplexing further includes multiplexing framing data to create the combined digital signal.

16. The method of claim 15,

wherein the demultiplexing further includes demultiplexing the combined digital signal into framing data.

17. The method of claim 14, wherein the transmitting further includes transmitting the combined optical signal via the fiber optic link at a bit rate of up to approximately 5 gigabits per second.

18. The method of claim 14, wherein the multiplexing further includes multiplexing data for bit error rate link performance testing to create the combined digital signal.

19. The method of claim 14, further comprising:

inputting the combined digital signal to a clock data recovery device; and

transmitting the combined digital signal and a clock signal from the clock data recovery device to a decode logic unit.

20. An optical distribution node configured for use in a hybrid fiber/coax network, the optical distribution node comprising:

a coaxial input configured to input an analog signal from at least one of a plurality of coaxial cable links;

an analog-to-digital converter configured to convert the analog signal into a baseband digital signal;

a status monitoring unit configured to generate status data representing an operational status of the optical distribution node;

a multiplexer configured to convert the baseband digital signal into a serial data stream, and configured to multiplex the serial data stream and the status data to create a combined digital signal; and

an optical transmitter configured to transmit the combined digital signal to a head end via a fiber optic link,

wherein the optical distribution node is configured to have an operation controlled or monitored by the head end based on the status data.

21. The optical distribution node of claim 20, wherein the multiplexer is further configured to multiplex framing data to create the combined digital signal.

22. The optical distribution node of claim 20, wherein the optical transmitter is configured to transmit the combined digital signal at a bit rate of up to approximately 1 gigabit per second.

23. The optical distribution node of claim 20, wherein the multiplexer is further configured to multiplex data for bit error rate link performance testing to create the combined digital signal.

24. A head end configured for use in a hybrid fiber/coax network, the head end comprising:

an optical receiver configured to receive a combined digital signal from an optical distribution node via a fiber optic link, the combined digital signal including status data representing an operational status of the optical distribution node and a baseband digital signal constructed from a first analog signal input to the optical distribution node;

a demultiplexer configured to demultiplex the combined digital signal into the baseband digital signal and the status data;

a node status monitoring unit configured to receive the status data from the demultiplexer; and

a digital-to-analog converter configured to convert the baseband digital signal into a second analog signal, the second analog signal being a reconstructed signal corresponding to the first analog signal,

wherein the head end is configured to control or monitor an operation of the optical distribution node based on the status data.

25. The head end of claim 24, wherein the demultiplexer is further configured to demultiplex the combined digital signal into framing data.

26. The head end of claim 24, wherein the optical receiver is configured to receive the combined digital signal at a bit rate of up to approximately 1 gigabit per second.

27. The head end of claim 24, wherein the demultiplexer is further configured to demultiplex the combined digital signal into data for bit error rate link performance testing.

28. The head end of claim 24, further comprising:

a clock data recovery device configured to receive the combined digital signal from the optical receiver; and

a decode logic unit configured to receive the combined digital signal and a clock signal from the clock data recovery device.

29. A method of operating an optical distribution node configured for use in a hybrid fiber/coax network, the method comprising:

receiving analog signals from at least one of a plurality of coaxial cable links;

converting the analog signals into baseband digital signals;

generating status data representing an operational status of the optical distribution node;

converting the baseband digital signals into a serial data streams;

multiplexing the serial data streams and the status data to create a combined digital signal;

transmitting the combined digital signal to a head end via a fiber optic link; and

controlling or monitoring an operation of the optical distribution node based on the status data,

wherein the receiving, converting the analog signals, generating, converting the baseband digital signals, multiplexing, and transmitting are performed by the optical distribution node, and

the controlling or monitoring is performed by the head end.

30. The method of claim 29, wherein the multiplexing further includes multiplexing framing data to create the combined digital signal.

31. The method of claim 29, wherein the transmitting further includes transmitting the combined digital signal at a bit rate of up to approximately 5 gigabits per second.

32. The method of claim 29, wherein the multiplexing further includes multiplexing data for bit error rate link performance testing to create the combined digital signal.

33. A method of operating a head end configured for use in a hybrid fiber/coax network, the method comprising:

receiving a combined digital signal from an optical distribution node via a fiber optic link, the combined digital signal including status data representing an operational status of the optical distribution node and a baseband digital signal constructed from a first analog signal input to the optical distribution node;

demultiplexing the combined digital signal into the baseband digital signal and the status data;

converting the baseband digital signal into a second analog signal, the second analog signal being a reconstructed signal corresponding to the first analog signal; and

controlling or monitoring an operation of the optical distribution node based on the status data,

wherein the receiving, demultiplexing, converting, and controlling or monitoring are performed by the head end.

34. The method of claim 33, wherein the demultiplexing further includes demultiplexing the combined digital signal into framing data.

35. The method of claim 33, wherein the receiving further includes receiving the combined digital signal at a bit rate of up to approximately 5 gigabits per second.

36. The method of claim 33, wherein the demultiplexing further includes demultiplexing the combined digital signal into data for bit error rate link performance testing.

37. The method of claim 33, further comprising:

inputting the combined digital signal to a clock data recovery device; and

transmitting the combined digital signal and a clock signal from the clock data recovery device to a decode logic unit.