System and method for controlling a power budget at a power source equipment using a PHY

• US 8,154,147 B2
• Filed: 07/06/2011
• Issued: 04/10/2012
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Diab, Wael William, Yousefi, Nariman, Brown, Kevin Clyde
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US13/176,861
• Publication Number:
  US 20110264298A1
• Time in Patent Office: 279 Days
• Field of Search: 307/2, 307/3, 307/103, 322/21, 340/538.15, 340/310.15
• US Class Current: 307/2
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

A system and method for controlling the delivery of power to a powered device in a Power over Ethernet Broad Reach (PoE-BR) application. Cabling power loss in a PoE-BR application is related to the resistance of the cable itself. A PHY can be designed to measure electrical characteristics (e.g., insertion loss, cross talk, length, etc.) of the Ethernet cable to enable determination of the cable resistance. The determined resistance in a broad reach cable can be used in increasing a power budget allocated to a power source equipment port.

Claims

1. A network powering method in a system that supplies power to a plurality of powered devices via a plurality of ports in a power source equipment, comprising:

obtaining one or more electrical measurements of a first network cable that couples a first powered device to a first power source equipment port, said first network cable being less than 100 meters;

,

determining a first individual power budget for said first power source equipment port using said one or more electrical measurements of said first network cable;

obtaining one or more electrical measurements of a second network cable that couples a second powered device to a second power source equipment port, said second network cable being between 300 and 500 meters;

determining a second individual power budget for said second power source equipment port using said one or more electrical measurements of said second network cable;

controlling an assignment of portions of a total power budget available to said power source equipment to said plurality of power source equipment ports, wherein said control includes an assignment of said first individual power budget to said first power source equipment port and an assignment of said second individual power budget to said second power source equipment port; and

powering said first powered device over said first Ethernet cable that is less than 100 meters and said second powered device over said second Ethernet cable that is between 300 and 500 meters.

2. The method of claim 1, wherein said determining said second individual power budget is based on an identified length of said second network cable.

3. The method of claim 1, wherein said determining said second individual power budget is based on an identified type of said second network cable.

4. The method of claim 1, wherein said determining said second individual power budget is based on a resistance of said second network cable.

5. The method of claim 1, wherein said controlling comprises setting a current limit for a power source equipment port.

6. A network powering method in a system that supplies power to a plurality of powered devices via a plurality of ports in a power source equipment, comprising:

obtaining one or more electrical measurements of a first network cable that couples a first powered device to a first power source equipment port, said first network cable being less than 100 meters;

obtaining one or more electrical measurements of a second network cable that couples a second powered device to a second power source equipment port, said second network cable being between 300 and 500 meters; and

controlling an assignment of portions of a total power budget available to said power source equipment to said plurality of power source equipment ports, wherein said control includes an assignment of a first individual power budget to said first power source equipment port and an assignment of said second individual power budget to said second power source equipment port, wherein said first individual power budget is determined based on said one or more electrical measurements of said first network cable and said second individual power budget is determined based on said one or more electrical measurements of said second network cable.

7. The method of claim 6, wherein said second individual power budget is based on an identified length of said second network cable.

8. The method of claim 6, wherein said second individual power budget is based on an identified type of said second network cable.

9. The method of claim 6, wherein said second individual power budget is based on a resistance of said second network cable.

10. The method of claim 6, wherein said controlling comprises setting a current limit for a power source equipment port.

11. A power source equipment system, comprising:

a first cable detection component that measures one or more electrical characteristics of a first Ethernet cable that couples a first powered device to a first power source equipment ports, said first Ethernet cable having a length that is less than 100 meters;

a second cable detection component that measures one or more electrical characteristics of a second Ethernet cable that couples a second powered device to a second power source equipment port, said second Ethernet cable having a length that is between 300 and 500 meters; and

a power controller that controls an allocation of a first individual power budget determined for said first powered device using said one or more measured electrical characteristics of said first network cable, and a second individual power budget determined for said second powered device using said one or more measured electrical characteristics of said second network cable.

12. The power source equipment system of claim 11, wherein said individual power budgets are determined using a network cable type.

13. The power source equipment system of claim 11, wherein said individual power budgets are determined using a network cable length.

14. The power source equipment system of claim 11, individual power budgets are determined using a calculated network cable resistance.

15. The power source equipment system of claim 11, wherein a power allocation is changed through an adjustment to a current limit.