METHOD AND SYSTEM FOR MANAGING POWER DELIVERY FOR POWER OVER ETHERNET SYSTEMS

• US 20080288794A1
• Filed: 07/31/2008
• Published: 11/20/2008
• Est. Priority Date: 01/04/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Neal, Rachel C., Marshall, Robert A., Randall, Anthony L.
• Granted Patent: US 8,082,457 B2
• Time in Patent Office: Days
• US Class Current: 713/310
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method for managing the delivery of power for a plurality of devices includes allocating a power limit for each of the plurality of devices and providing power to at least one of the plurality of devices. The method also includes, in response to the providing of power, measuring the amount of power utilized by each of at least one of the at least one of the plurality of devices and determining that the amount of power exceeds the power limit for the device.

Claims

1. In a Power Source Equipment network device, a method comprising:

allocating a power limit for each of a plurality of powered devices;

providing power to each of the plurality of powered devices over network connections, the network connections also providing network data communication between each of the plurality of powered devices and the Power Source Equipment network device; and

in response to providing power over the network connection, measuring an amount of power utilized by each of the plurality of powered devices and comparing the amount of utilized power for each of the powered devices to the allocated power limit for that powered device;

in response to comparing the amount of utilized power for each of the powered devices to the allocated power limit for that powered device, if the utilized power exceeds the power limit for that powered device, increasing the power limit for that powered device.

2. The method of claim 1, wherein increasing the power limit for the powered device comprises:

determining a combined amount of power being utilized by the plurality of powered devices; and

allocating a new power limit for the powered device, the new power limit exceeding the previously allocated power limit, in response to determining that the combined amount of power does not exceed an overall limit for the amount of power utilized by the plurality of powered devices.

3. The method of claim 2, wherein determining the combined amount of power being utilized by the plurality of powered devices includes:

summing together the measured amounts of power utilized by each of the plurality of powered devices.

4. The method of claim 2, wherein determining the combined amount of power being utilized by the plurality of powered devices includes:

measuring an overall amount of power provided by the Power Source Equipment network device.

5. The method of claim 1, wherein

the method further comprises:

receiving a user-specified power limit for each powered device; and

allocating the power limit for each of a plurality of powered devices includes allocating the user-specified power limit for each powered device.

6. The method of claim 1 wherein:

measuring the amount of power utilized by each of the plurality of powered devices includes measuring both the current and the voltage provided over each network connection and multiplying the current by the voltage.

7. The method of claim 1 wherein:

measuring the amount of power utilized by each of the plurality of powered devices includes measuring the current provided over each network connection and multiplying the current by a constant pre-defined voltage.

8. A system comprising:

a plurality of powered devices;

a Power Source Equipment (PSE) network device, the PSE network device connecting to the plurality of powered devices over network connections and providing network data communication over the network connections, the PSE network device including;

a power supply operative to provide power to the plurality of powered devices over the network connections;

a power measurement system operative to determine an amount of power being utilized by each of the plurality of powered devices;

a power limit system operative to store a power limit associated with each of the plurality of powered devices; and

a control system operative to adjust the power limit of each of the plurality of powered devices in response to a determination that the power usage by one of the plurality of powered devices is exceeding its associated power limit.

9. The system of claim 8, wherein the control system is further operative to adjust the power limit of each of the plurality of powered devices only in response to a further determination that an overall limit for the amount of power utilized by the plurality of powered devices is not exceeded.

10. The system of claim 8, wherein the control system is further operable to adjust the power limit of each of the plurality of powered devices to a value other than 15.4 watts, 7.5 watts, and 4.0 watts.

11. The system of claim 8 wherein:

the PSE network device further includes a user interface system operative to receive a user-specified power limit for each powered device; and

the power limit system is further operative to receive the user-specified power limit for each powered device from the user interface system and store each received value as the power limit associated with each of the plurality of powered devices.

12. The system of claim 8 wherein:

the power measurement system includes;

voltage measurement circuitry; and

current measurement circuitry; and

the power measurement system is further operative to determine the amount of power being utilized by each of the plurality of powered devices by, for each network connection;

measuring the voltage over that network connection with the voltage measurement circuitry;

measuring the current over that network connection with the current measurement circuitry; and

multiplying the measured current by the measured voltage.

13. The system of claim 8 wherein:

the power measurement system includes current measurement circuitry;

the power measurement system stores a constant pre-defined voltage; and

the power measurement system is further operative to determine the amount of power being utilized by each of the plurality of powered devices by, for each network connection;

measuring the current over that network connection with the current measurement circuitry; and

multiplying the measured current by the stored constant pre-defined voltage.

14. A data communications device for communicating with and concurrently providing power to a set of powerable devices, the data communications device comprising:

a power supply having a predefined power capacity;

a set of communications ports constructed and arranged to exchange a set of digital communications signals with the set of powerable devices through a set of network cables; and

a controller coupled to the power supply and to the set of communications ports, the controller being constructed and arranged to (i) individually provide an amount of power to a particular powerable device of the set of powerable devices through a particular communications port of the set communications ports and a particular network cable of the set of network cables based on an individually assigned power range for the particular powerable device, (ii) modify the individually assigned power range for the particular powerable device when the amount individually provided to the particular powerable device falls outside the individually assigned power range and the power supply continues to operate below the predefined power capacity, and (iii) cut power to the particular powerable device when the amount individually provided to the particular powerable device falls outside the individually assigned power range and the power supply does not continues to operate below the predefined power capacity.

15. A data communications device as in claim 14, wherein:

the data communications device further includes a user interface system operative to receive a user-specified power limit for each powerable device; and

the controller is further constructed and arranged to receive the user-specified power limit for each powerable device from the user interface system and individually assign the individually assigned power range for each particular powerable device according to the received user-specified power limit for that powerable device.

16. A data communications device as in claim 14, further comprising:

a set of power monitoring sensors coupled to the set of communications ports and to the controller, each power monitoring sensor being constructed and arranged to individually measure an amount of power to a particular powerable device of the set of powerable devices from a particular communications port of the set communications ports and through a particular network cable of the set of network cables;

the power supply, the set of communications ports and the set of power monitoring sensors residing in a single enclosure to form a power sourcing equipment unit for operation within an Ethernet network.

17. A data communications device as in claim 16, wherein:

each power monitoring sensor includes;

voltage measurement circuitry; and

current measurement circuitry; and

each power monitoring sensor is further constructed and arranged to determine the amount of power to the particular powerable device from the particular communications port by, for each communications port;

measuring the voltage at that communications port with the voltage measurement circuitry;

measuring the current at that communications port with the with the current measurement circuitry; and

multiplying the measured current by the measured voltage.

18. A data communications device as in claim 16, wherein:

each power monitoring sensor includes current measurement circuitry; and

each power monitoring sensor is further constructed and arranged to determine the amount of power to the particular powerable device from the particular communications port by, for each communications port;

measuring the current at that communications port with the with the current measurement circuitry; and

multiplying the measured current by a stored constant pre-defined voltage.