Enabling cisco legacy power to support IEEE 802.3 AF standard power

• US 7,778,409 B2
• Filed: 12/03/2004
• Issued: 08/17/2010
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Karam, Roger A.
• Primary Examiner(s): Pham; Tuan A
• Application Number:
  US11/004,169
• Publication Number:
  US 20050141698A1
• Time in Patent Office: 2,083 Days
• Field of Search: 379/413, 379/399.01, 379/401, 379/413.04, 379/403, 37941301-41303, 379/387.01, 379/388.06, 379/395, 379/423, 713/300, 713/310, 713/320, 713/323
• US Class Current: 379/413
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

An apparatus and method for enabling Cisco legacy power to support IEEE 802.3af standard power. A network power system capable of delivering data terminal equipment power via a media dependent interface (MDI) includes power source equipment according to a first power via MDI scheme such as Cisco legacy power and at least one powered device according to a second power via MDI scheme such as IEEE standard power. A power compatibility module is inserted between the power source equipment and the powered device to enable the power source equipment to appear according to the first power via MDI scheme and the powered device to appear according the second power via MDI scheme. In one embodiment, the module includes switches, a DC/DC converter, an IEEE power source equipment circuit, and an isolator. The module may optionally include a user signaling device for communicating operating conditions of the module to a user.

Claims

1. A method for providing, by a power compatibility module, compatibility to a network power system having equipment capable of at least two power via Media Dependent Interfaces (MDI) schemes for delivering data terminal equipment power via an MDI, the network power system including power source equipment (PSE) configured to deliver power via a first power via MDI scheme and a powered device (PD) coupled to the PSE and configured to receive power from the PSE via a second power via MDI scheme different from the first power via MDI scheme, the method comprising:

exchanging, by the power compatibility module, classification signals with the PD to classify a power class of the PD;

in response to classifying the PD as an IEEE PD configured to receive power according to an IEEE power classification, receiving, by the power compatibility module, a power signal from the PSE at a first power level according to the first power via MDI scheme and converting, by the power compatibility module, the power signal to a power level corresponding to the IEEE power classification of the PD, the power level corresponding to the IEEE power classification of the PD associated with the second power via MDI scheme;

facilitating, by the power compatibility module, the PSE to operate according to the first power via MDI scheme while appearing to the PD to be operating according to the second power via MDI scheme; and

facilitating, by the power compatibility module, the PD to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme;

wherein facilitating the PD to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme comprises forwarding, by the power compatibility module, the power signal to the PD via the second power via MDI scheme.

2. The method as defined in claim 1, wherein the first power via MDI scheme is Cisco legacy power.

3. The method as defined in claim 2, wherein the second power via MDI scheme is IEEE standard power.

4. The method as defined in claim 1, wherein the second power via MDI scheme is IEEE standard power.

13. The method of claim 1, wherein:

facilitating the PSE to operate according to the first power via MDI scheme while appearing to the PD to be operating according to the second power via MDI scheme comprises facilitating the PSE to deliver power according to the first power via MDI scheme while appearing to the PD to be delivering power according to the second power via MDI scheme; and

facilitating the PD to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme comprises facilitating the PD to receive power according to the second power via MDI scheme while appearing to the PSE to be receiving power according to the first power via MDI scheme.

14. The method of claim 13, comprising:

receiving power from the PSE according to the first power via MDI scheme, the power received from the PSE according to the first power via MDI scheme having a first voltage level; and

delivering power to the PD according to the second power via MDI scheme, the power delivered according to the second power via MDI scheme having a second voltage level, the second voltage level being different than the first voltage level.

15. The method of claim 14, comprising, in response to receiving power from the PSE according to the first power via MDI scheme, increasing a voltage level of the power received from the PSE to the second voltage level, the second voltage level being greater than the first voltage level.

19. The method of claim 1, wherein the PSE is configured to exchange data signals with the PD.

20. The method of claim 15, wherein, in response to receiving power from the PSE according to the first power via MDI scheme, detecting the voltage level of the power received from the PSE is lower than an amount of power required by the PD according to a power classification of the PD;

and

in response to detecting, delivering power to the PD wherein the power has the second voltage level, the second voltage level being greater than the first voltage level.

5. An apparatus for providing compatibility to a network power system having equipment capable of at least two power via Media Dependent Interfaces (MDI) schemes for delivering data terminal equipment power via an MDI, the network power system including power source equipment (PSE) configured to deliver power via a first power via MDI scheme and a powered device (PD) coupled to the PSE and configured to receive power from the PSE via a second power via MDI scheme different from the first power via MDI scheme, the apparatus comprising:

means for exchanging classification signals with the PD to classify a power class of the PD;

in response to classifying the PD as an IEEE PD configured to receive power according to an IEEE power classification, means for receiving a power signal from the PSE at a first power level according to the first power via MDI scheme and means for converting the power signal to a power level corresponding to the IEEE power classification of the PD, the power level corresponding to the IEEE power classification of the PD associated with the second power via MDI scheme;

means for operating the PSE according to the first power via MDI scheme while appearing to the PD to be operating according to the second power via MDI scheme; and

means for operating the PD according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme;

wherein means for operating the PD to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme comprises means for forwarding the power signal to the PD via the second power via MDI scheme.

6. The apparatus as defined in claim 5, wherein the first power via MDI scheme is Cisco legacy power.

7. The apparatus as defined in claim 6, wherein the second power via MDI scheme is IEEE standard power.

8. The apparatus as defined in claim 5, wherein the second power via MDI scheme is IEEE standard power.

9. A network power system for delivering data terminal equipment (DTE) power via a media dependent interface (MDI), the system comprising:

a power source equipment (PSE) configured to deliver power via a first power via MDI scheme;

a DTE adapted to receive power from the PSE via a second power via MDI scheme different from the first power via MDI scheme; and

a power compatibility module coupled to the PSE and the DTE, wherein the power compatibility module is configured to;

exchange classification signals with the PD to classify a power class of the PD;

in response to classifying the PD as an IEEE PD configured to receive power according to an IEEE power classification, receive a power signal from the PSE at a first power level according to the first power via MDI scheme and convert the power signal to a power level corresponding to the IEEE power classification of the PD, the power level corresponding to the IEEE power classification of the PD associated with the second power via MDI scheme;

facilitate the PSE to operate according to the first power via MDI scheme while appearing to the DTE to be operating according to the second power via MDI scheme; and

facilitate the DTE to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme;

wherein when facilitating the PD to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme the power compatibility module is configured to forward the power signal to the PD via the second power via MDI scheme.

10. The system as defined in claim 9, wherein the first power via MDI scheme is Cisco legacy power.

11. The system as defined in claim 10, wherein the second power via MDI scheme is IEEE standard power.

12. The system as defined in claim 9, wherein the second power via MDI scheme is IEEE standard power.

16. The network power system of claim 9, wherein the power compatibility module is configured to:

when facilitating the PSE to operate according to the first power via MDI scheme while appearing to the DTE to be operating according to the second power via MDI scheme, facilitating the PSE to deliver power according to the first power via MDI scheme while appearing to the DTE to be delivering power according to the second power via MDI scheme; and

When facilitating the DTE to operate according to the second power via MDI scheme while appearing to the PSE to be operating according to the first power via MDI scheme, facilitating the DTE to receive power according to the second power via MDI scheme while appearing to the PSE to be receiving power according to the first power via MDI scheme.

17. The network power system of claim 16, wherein the power compatibility module is configured to:

receive power from the PSE according to the first power via MDI scheme, the power received from the PSE according to the first power via MDI scheme having a first voltage level; and

deliver power to the DTE according to the second power via MDI scheme, the power delivered according to the second power via MDI scheme having a second voltage level, the second voltage level being different than the first voltage level.

18. The network power system of claim 17, wherein the power compatibility module is configured to, in response to receiving power from the PSE according to the first power via MDI scheme, increase a voltage level of the power received from the PSE to the second voltage level, the second voltage level being greater than the first voltage level.