System and method of determining Power over Ethernet impairment

• US 8,588,705 B1
• Filed: 11/25/2008
• Issued: 11/19/2013
• 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): Ngo, Ricky
• Assistant Examiner(s): NGUYEN, PHUONGCHAU BA
• Application Number:
  US12/323,292
• Time in Patent Office: 1,820 Days
• Field of Search: 340/657, 340/539.27, 340/539.3, 340/545.4, 713/300, 713/324, 455/522, 455/69
• US Class Current: 455/69
• 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 by a tap monitor of an echo canceller associated with a physical device, the echo canceller configured to remove echo energy from a signal;

computing an integral of the echo energy over time;

determining that an unbalanced current condition is causing magnetic saturation when the integral of the echo energy over time is above a threshold; and

triggering an alert responsive to determining that the unbalanced current condition is causing magnetic saturation, the alert including a recommendation to remedy the unbalanced current condition.

2. The method of claim 1 wherein said monitoring comprises monitoring tap adaptations of the echo canceller to identify areas representative of the 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 that indicate that the unbalanced current condition is causing magnetic saturation.

4. The method of claim 1 wherein said triggering comprises generating a software interrupt that indicates that the unbalanced current condition is causing magnetic saturation.

5. The method of claim 1 wherein the alert comprises an audible alarm or a visual display that alerts a user that the unbalanced current condition is causing magnetic saturation.

6. The method of claim 5 wherein said providing an output comprises alerting a user of the unbalanced current condition causing magnetic saturation.

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

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

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

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

11. A power sourcing equipment device configured to perform the method of claim 1.

12. A data terminal equipment device configured to perform the method of claim 1.

13. The method of claim 1 wherein the recommendation comprises a recommendation to remedy the unbalanced current condition by cleaning contacts, replacing a network cable, or reducing current levels.

14. A device for use in a Power over Ethernet application, said device comprising:

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

a tap monitor to monitor operation of said echo canceller and to compute an integral of the echo energy over time, wherein output from said tap monitor is employed to trigger an alert responsive to a determination that the integral of the echo energy over time is above a threshold, the integral of the echo energy over time being above the threshold indicating that an unbalanced current condition is causing magnetic saturation, the alert including a recommendation to remedy the unbalanced current condition.

15. The device of claim 14 wherein said tap monitor is configured to monitor tap adaptations of said echo canceller to identify areas representative of echo energy above the threshold.

16. The device of claim 14 wherein the output from said tap monitor is employed to set one or more bits in a hardware register at the device, the one or more bits indicating that the unbalanced current condition is causing magnetic saturation.

17. The device of claim 14 wherein the output from said tap monitor is employed to generate a software interrupt at the device, the software interrupt indicating that the unbalanced current condition is causing magnetic saturation.

18. The device of claim 14 wherein the alert comprises audible or visual output alerting a user of the unbalanced current condition causing magnetic saturation.

19. The device of claim 14 wherein the threshold is predetermined based on theoretical or expected values of the echo energy.

20. The device of claim 14 wherein the threshold comprises a selectively or dynamically adjustable threshold.

21. The device of claim 20 wherein the threshold varies, in real time, in accordance with a communications parameter.

22. The device of claim 21 wherein the communications parameter comprises a bit error rate.

23. The device of claim 14 wherein the recommendation comprises a recommendation to remedy the unbalanced current condition by cleaning contacts, replacing a network cable, or reducing current levels.