Inline power for multiple devices in a wired data telecommunications network

• US 20060273661A1
• Filed: 06/02/2005
• Published: 12/07/2006
• Est. Priority Date: 06/02/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Li, Ping, Toebes, John Albert, Cham, Jack C.
• Granted Patent: US 7,664,136 B2
• Time in Patent Office: Days
• US Class Current: 307/106
• CPC Class Codes: G06F 1/266 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 Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 25/0278 Arrangements for impedance matching

Abstract

A power sourcing equipment-powered device (PSE-PD) combination unit requests inline power from a connected PSE or other PSE-PD combination unit by having the PD portion of the PD-PSE combination unit adapt its electrical characteristics, if necessary, to obtain the maximum power available. The PD-PSE combination device keeps track of available power less power consumed locally with a summation unit. A PSE manager unit grants PD power requests from downstream devices based upon the available power left (e.g., original PSE power less losses less local consumption).

Claims

1. An inline power device, comprising:

a first port configured as a powered device (PD) port for coupling power and data with a port of an external PSE;

a plurality of selectable electrical components for use in establishing a magnitude of a power request from the external PSE;

a summation unit configured to determine an amount of power available for use by a downstream coupled PD;

a second port configured as a PD port for coupling available power and data with a port of a downstream coupled PD; and

a PSE manager unit configured for receiving inline power requests from a downstream coupled PD and responsive to the summation unit for providing up to an available power level to the downstream coupled PD.

2. The device of claim 1, wherein the plurality of selectable electrical components are a plurality of selectable resistors.

3. The device of claim 1 wherein said first port and said second port are Ethernet ports.

4. The device of claim 2 wherein said first port and said second port are Ethernet ports.

5. The device of claim 1, further comprising:

circuitry for selecting one of the plurality of selectable electrical components, wherein said circuitry is configured to first select a component corresponding to a request for a maximum amount of power.

6. The device of claim 5, wherein said circuitry is configured to second select a component corresponding to a request for a less than maximum amount of power upon denial of the first request.

7. The device of claim 6, wherein the plurality of selectable electrical components are a plurality of selectable resistors.

8. The device of claim 7 wherein said first port and said second port are Ethernet ports.

9. A method for providing inline power, comprising:

coupling a first port configured as a PD port of a PD-PSE combination device to a PSE-configured port of a first external device;

coupling a second port configured as a PSE port of the PD-PSE combination device to a PD-configured port of a second external device;

requesting initially a maximum available power at the first port from the first external device; and

keeping track of power available for downstream PSE use.

10. The method of claim 9, further comprising:

receiving a request for inline power from a downstream-coupled PD at the second port; and

accepting the request for inline power from the downstream-coupled PD if the request is for an amount of power not exceeding the power available.

11. The method of claim 9, further comprising:

receiving a request for inline power from a downstream-coupled PD at the second port; and

denying the request for inline power from the downstream-coupled PD if the request is for an amount of power exceeding the power available.

12. The method of claim 9, further comprising:

receiving a request for inline power from a downstream-coupled PD at the second port;

accepting the request for inline power from the downstream-coupled PD if the request is for an amount of power not exceeding the power available; and

denying the request for inline power from the downstream-coupled PD if the request is for an amount of power exceeding the power available.

13. The method of claim 12, further comprising:

requesting subsequently, responsive to a denial of the initial request, a less than maximum available power at the first port from the first external device.

14. An apparatus for providing inline power, comprising:

means for coupling a first port configured as a PD port of a PD-PSE combination device to a PSE-configured port of a first external device;

means for coupling a second port configured as a PSE port of the PD-PSE combination device to a PD-configured port of a second external device;

means for requesting initially a maximum available power at the first port from the first external device; and

means for keeping track of power available for downstream PSE use.