Determining power over ethernet impairment

• US 9,148,200 B1
• Filed: 11/18/2013
• Issued: 09/29/2015
• Est. Priority Date: 12/11/2007
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Tsui, Tak-Lap, He, Runsheng, Barkan, Ozdal, Wu, Dance
• Primary Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US14/082,981
• Time in Patent Office: 680 Days
• Field of Search: 379/406.08, 379/406.01, 379/3, 379/390.02, 379/392, 370/242, 370/248, 370/290, 370/201, 370/276, 370/287, 370/286, 375/224, 455/69
• US Class Current: 1/1
• CPC Class Codes: H04B 3/237 using two adaptive filters, e.g. for near end and for end echo cancelling
• CPC Class Codes: H04B 3/493 Testing echo effects or singing
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

A system and method of determining an unbalanced current condition in Power over Ethernet applications are disclosed. In some implementations, a user or network administrator may be notified of potential impairments due to unbalanced current.

Claims

1. A method of determining an impairment in a Power over Ethernet application, said method comprising:

monitoring operation of an echo canceller with a tap monitor, the echo canceller being associated with a physical device, the echo canceller configured to remove echo energy from a signal;

measuring the echo energy over time;

determining that the measured echo energy over time is above a threshold indicating a saturation condition; and

responsive to said determining that the measured echo energy over time is above the threshold, triggering an alert indicating that the saturation condition is caused by an unbalanced current.

2. The method of claim 1, wherein said monitoring comprises monitoring tap adaptations of the echo canceller to identify areas representative of the measured echo energy being above the threshold.

3. The method of claim 1, wherein said triggering comprises setting one or more bits in a hardware register.

4. The method of claim 1, wherein said triggering comprises generating a software interrupt.

5. The method of claim 1, wherein the alert comprises an audible alarm or a visual display.

6. The method of claim 1, wherein the threshold is predetermined based on theoretical or expected values of the echo energy.

7. The method of claim 1, wherein the threshold comprises a selectively or dynamically adjustable threshold.

8. The method of claim 1, further comprising adjusting the threshold in real time based on a communications parameter associated with the physical device.

9. The method of claim 8, wherein the communications parameter comprises a bit error rate.

10. The method of claim 1, wherein the alert includes a recommendation to clean contacts, replace a network cable, or reduce current levels.

11. A device for use in a Power over Ethernet application, the device comprising:

an echo canceller to remove echo energy from a signal received at a receiver; and

a tap monitor configured to;

monitor operation of said echo canceller;

compute a value of the echo energy over time; and

responsive to a determination that the computed value of the echo energy over time is above a threshold, which indicates a saturation condition, trigger an alert to indicate unbalanced current as a cause of the saturation condition.

12. The device of claim 11, wherein said tap monitor is configured to monitor tap adaptations of said echo canceller to identify areas representative of the computed value of the echo energy over time being above the threshold.

13. The device of claim 11, wherein the output from said tap monitor is employed to set one or more bits in a hardware register at the device.

14. The device of claim 11, wherein the output from said tap monitor is employed to generate a software interrupt at the device.

15. The device of claim 11, wherein the alert comprises an audible alarm or a visual display.

16. The device of claim 11, wherein the threshold is predetermined based on theoretical or expected values of the echo energy.

17. The device of claim 11, wherein the threshold comprises a selectively or dynamically adjustable threshold.

18. The device of claim 11, wherein the threshold varies, in real time, in accordance with a communications parameter.

19. The device of claim 18, wherein the communications parameter comprises a bit error rate.

20. The device of claim 11, wherein the alert comprises a recommendation to clean contacts, replace a network cable, or reduce current levels.