Detection, classification and mutual recognition of 4 pair power over Ethernet

Patent metadata

Field	Value
Publication number	US-9369176-B2
Application number	US-201314076553-A
Country	US
Kind code	B2
Filing date	Nov 11, 2013
Priority date	Nov 11, 2013
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A method for verifying interconnection of a PSE and PD with 4-pair PoE capabilities includes performing a first classification event on first and second pairs, respectively, and detecting a first predetermined class current on first and second sets of twisted pairs, respectively. The method includes performing a second classification event on first and second pairs, respectively, and detecting first and second predetermined class currents on first and second pairs, respectively. After expiration of a first variable delay period related to a first pseudo-random variable of the PSE, the method includes performing a third classification event on the first pair and detecting a first derived class current on the first pair. After expiration of a second variable delay period related to a second pseudo-random variable of the PD, the method includes performing the third classification event on the second pair and detecting a second derived class current on the second pair.

First claim

What is claimed:

1. A method for verifying interconnection of a power sourcing equipment (“PSE”) and a powered device (“PD”) with 4 pair power over Ethernet (“PoE”) capabilities using the PSE, comprising:
performing a first classification event on a first plurality of twisted pairs and detecting a first predetermined class current on the first twisted pairs in response to the first classification event;
performing the first classification event on a second plurality of twisted pairs and detecting the first predetermined class current on the second twisted pairs in response to the first classification event;
performing a second classification event on the first twisted pairs and detecting the first predetermined class current on the first twisted pairs in response to the second classification event;
performing the second classification event on the second twisted pairs and detecting a second predetermined class current on the second twisted pairs in response to the second classification event, wherein the second predetermined class current is different than the first predetermined class current;
assigning a first pseudo-random variable to the PSE;
after expiration of a first variable delay period that is related to the first pseudo-random variable, performing a third classification event on the first twisted pairs and detecting a first derived class current on the first twisted pairs in response to the third classification event; and
after expiration of a second variable delay period that is related to a second pseudo-random variable assigned to the PD, performing the third classification event on the second twisted pairs and detecting a second derived class current on the second twisted pairs in response to the third classification event.

2. The method of claim 1 , wherein the first and second pseudo-random variables are integers and values of the respective integers determine lengths of the first and second variable delay periods, respectively.

3. The method of claim 1 , further comprising:
decoding the first derived class current to determine the second pseudo-random variable assigned to the PD; and
using the second pseudo-random variable to determine a length of the second variable delay period.

4. The method of claim 1 , further comprising decoding the second derived class current to confirm the first pseudo-random variable assigned to the PSE.

5. The method of claim 4 , further comprising supplying power to the first twisted pairs and second twisted pairs if the decoded second derived class current matches the first pseudo-random variable.

6. The method of claim 4 , further comprising entering an error state if the decoded second derived class current does not match the first pseudo-random variable.

7. The method of claim 1 , further comprising waiting for a first predetermined delay period to expire between sequentially performing the first classification event on the first twisted pairs and second twisted pairs or sequentially performing the second classification event on the first twisted pairs and second twisted pairs.

8. The method of claim 1 , further comprising waiting for a second predetermined delay period to expire between sequentially performing the first classification event on the second twisted pairs and the second classification event on the first twisted pairs.

9. The method of claim 1 , further comprising:
decoding the first variable delay period at the PD to determine the first pseudo-random variable assigned to the PSE; and
using the first pseudo-random variable to provide the second derived class current on the second twisted pairs in response to the third classification event.

10. A method for verifying interconnection of a power sourcing equipment (“PSE”) and a powered device (“PD”) with 4 pair power over Ethernet (“PoE”) capabilities using the PSE, comprising:
performing a first classification event on a first plurality of twisted pairs and detecting a first predetermined class current on the first twisted pairs in response to the first classification event;
performing the first classification event on a second plurality of twisted pairs and detecting the first predetermined class current on the second twisted pairs in response to the first classification event;
performing a second classification event on the first twisted pairs and detecting the first predetermined class current on the first twisted pairs in response to the second classification event;
performing the second classification event on the second twisted pairs and detecting a second predetermined class current on the second twisted pairs in response to the second classification event, wherein the second predetermined class current is different than the first predetermined class current;
assigning a first pseudo-random variable to the PSE;
performing a third classification event on the first twisted pairs and detecting a first derived class current on the first twisted pairs in response to the third classification event, wherein the third classification event comprises a first variable number of detection cycles related to the first pseudo-random variable; and
performing a fourth classification event on the second twisted pairs and detecting a second derived class current on the second twisted pairs in response to the fourth classification event, wherein the fourth classification event comprises a second variable number of detection cycles related to a second pseudo-random variable assigned to the PD.

11. The method of claim 10 , wherein the first and second pseudo-random variables are integers and values of the respective integers determine the first and second variable numbers of detection cycles, respectively.

12. The method of claim 10 , further comprising:
decoding the first derived class current to determine the second pseudo-random variable assigned to the PD; and
using the second pseudo-random variable to determine the second variable number of detection cycles.

13. The method of claim 10 , further comprising decoding the second derived class current to confirm the first pseudo-random variable assigned to the PSE.

14. The method of claim 13 , further comprising supplying power to the first twisted pairs and second twisted pairs using the PSE if the decoded second derived class current matches the first pseudo-random variable.

15. The method of claim 10 , further comprising:
decoding the first variable number of detection cycles at the PD to determine the first pseudo-random variable assigned to the PSE; and
using the first pseudo-random variable to provide the second derived class current on the second twisted pairs in response to the fourth classification event.

16. A method for verifying interconnection of a power sourcing equipment (“PSE”) and a powered device (“PD”) with 4 pair power over Ethernet (“PoE”) capabilities, comprising:
assigning a first pseudo-random variable to the PSE;
assigning a second pseudo-random variable to the PD;
communicating the first pseudo-random variable from the PSE to the PD using a first plurality of twisted pairs;
in response to communicating the first pseudo-random variable from the PSE to the PD, communicating the first pseudo-random variable back to the PSE from the PD using a second plurality of twisted pairs;
communicating the second pseudo-random variable from the PD to the PSE using the second twisted pairs; and
in response to communicating the second pseudo-random variable from the PD to the PSE, communicating the second pseudo-random variable back to the PD from the PSE using the first twisted pairs.

17. T

Assignees

• Cisco Tech Inc

Inventors

• Barrass Hugh
• Vetteth Anoop

Classifications

• G01R31/67

  Testing the correctness of wire connections in electric apparatus or circuits · CPC title

• G06F1/26

  Power supply means, e.g. regulation thereof (for memories G11C) · CPC title

• G06F1/266 Primary

  Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips · CPC title

• H04B3/02 Primary

  Details · CPC title

• H04L12/40045

  Details regarding the feeding of energy to the node from the bus · CPC title