System and method for facilitating fiber access transport using pluggable radio frequency optics

• US 8,750,710 B1
• Filed: 07/15/2011
• Issued: 06/10/2014
• Est. Priority Date: 07/15/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Villarruel, Fernando X., Wu, Kuang-Yi, Hirt, Fred S.
• Primary Examiner(s): PASCAL, LESLIE C
• Application Number:
  US13/184,302
• Time in Patent Office: 1,061 Days
• Field of Search: 398/9, 398/135
• US Class Current: 398/135
• CPC Class Codes: H04B 10/25751 Optical arrangements for CATV or video distribution adaptations of television systems for optical transmission H04N7/22
• CPC Class Codes: H04B 10/25759 Details of the reception of RF signal or the optical conversion before the optical fibre

Abstract

An example method includes receiving radio frequency (RF) signals from a cable modem termination system (CMTS) in a small form factor pluggable optical transmitter; converting the RF signals to optical signals in the small form factor pluggable optical transmitter; and transmitting, by the small form factor pluggable optical transmitter, the optical signals on a network. More specific embodiments can include RF signals that are modulated, where a modulation error ratio (MER) of the RF signal varies substantially linearly with Carrier to Composite Noise (CCN), and the converting is implemented by a laser transmitter. Other, more specific, embodiments include routing the RF signals through a pre-distortion RF amplifier RF variable attenuator, and coupling the optical transmitter to a chassis of the CMTS.

Claims

1. A method comprising:

receiving radio frequency (RF) signals from a cable modem termination system (CMTS) in a small form factor pluggable optical transmitter;

converting the RF signals to optical signals in the small form factor pluggable optical transmitter, wherein a modulation error ratio (MER) of the RF signal varies in a substantially linear fashion with Carrier to Composite Noise (CCN); and

transmitting, by the small form factor pluggable optical transmitter, the optical signals on a network.

2. The method of claim 1, wherein the pluggable optical transmitter is provisioned in a chassis of the CMTS.

3. The method of claim 1, wherein the RF signals are modulated.

4. The method of claim 1, wherein the converting is facilitated by a laser transmitter, the laser transmitter being a selected one of an externally modulated laser (EML) transmitter and a directly modulated laser transmitter.

5. The method of claim 1, wherein the RF signals are received by a pre-distortion RF amplifier RF variable attenuator.

6. The method of claim 1, wherein the small form factor pluggable optical transmitter is compliant to an XFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.72 inches, 3.1 inches, respectively.

7. The method of claim 1, wherein the small form factor pluggable optical transmitter is compliant to an SFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.53 inches, and 2.22 inches, respectively.

8. The method of claim 1, wherein direct current power consumption savings attributable to activities associated with the small form factor pluggable optical transmitter are in a range from 5 W to 16 W when compared with a content generation device that does not use the small form factor pluggable optical transmitter.

9. An apparatus, comprising:

a pre-distortion radio frequency (RF) amplifier RF variable attenuator;

a memory element configured to store data;

an optical transmitter; and

a processor operable to execute instructions associated with the data, wherein the pre-distortion RF amplifier RF variable attenuator, the optical transmitter, the computing processor, and the memory element are provisioned in a small form factor pluggable optical transmitter, wherein a single communication line is provisioned for control and calibration of the small form factor pluggable optical transmitter.

10. The apparatus of claim 9, further comprising:

an edge QAM modulator.

11. The apparatus of claim 9, wherein the apparatus is configured for:

receiving RF signals;

converting the RF signals to optical signals; and

transmitting the optical signals on a network.

12. The apparatus of claim 9, wherein the RF signals are modulated.

13. The apparatus of claim 9, wherein an automatic gain control of the RF signals is performed.

14. The apparatus of claim 9, wherein the apparatus is a cable modem termination system (CMTS).

15. The apparatus of claim 14, wherein the single communication line is provisioned within a chassis of the CMTS.

16. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is compliant to an XFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.72 inches, 3.1 inches, respectively.

17. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is compliant to an SFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.53 inches, and 2.22 inches, respectively.

18. The apparatus of claim 9, further comprising:

a plurality of small form factor pluggable optical transmitters configured to provide direct current power consumption savings in a range from 5 W to 16 W for each of the small form factor pluggable optical transmitters, when compared with a content generation device that does not use the small form factor pluggable optical transmitters.

19. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter generates a plurality of optical signals spanning multiple wavelengths for transmission over a single optical fiber.

20. The apparatus of claim 9, wherein the optical transmitter is a laser transmitter that is a selected one of an externally modulated laser (EML) transmitter and a directly modulated laser transmitter.

21. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is coupled to a content generation device.

22. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is mounted on a physical interface card (PIC) with a differential connection to an up-convertor digital to analog convertor located in a line card within the apparatus.

23. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is mounted on a PIC, with a single-ended connection to a buffer amplifier.

24. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is mounted on a rear of a line card through a blind mate connection.

25. The apparatus of claim 9, wherein the small form factor pluggable optical transmitter is mounted on a front of a line card with optical jumper cables connecting from the front of the line card to a rear of the line card.

26. Logic encoded in non-transitory media that includes code for execution and when executed by a processor is operable to perform operations in a small form factor pluggable optical transmitter, comprising:

receiving radio frequency (RF) signals from a cable modem termination system (CMTS);

converting the RF signals to optical signals, wherein a MER of the RF signal varies in a substantially linear fashion with CCN; and

transmitting the optical signals on a network.

27. The logic of claim 26, wherein the RF signals are modulated.

28. The logic of claim 26, wherein the small form factor pluggable optical transmitter is compliant to an XFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.72 inches, 3.1 inches, respectively.

29. The logic of claim 26, wherein the small form factor pluggable optical transmitter is compliant to an SFP form factor comprising height, width, and depth dimensions of substantially 0.33 inches, 0.53 inches, and 2.22 inches, respectively.