Method and system for distributing power to networked devices

• US 20050136989A1
• Filed: 12/12/2003
• Published: 06/23/2005
• Est. Priority Date: 12/12/2003
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Dove, Daniel J.
• Granted Patent: US 7,203,849 B2
• Time in Patent Office: Days
• US Class Current: 455/572
• 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: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

One embodiment disclosed relates to a system for power distribution to network devices. The system includes a plurality of network switches each having an internal power supply and a plurality of ports for connecting to the network devices and an external power supply having a plurality of output ports for connecting to the network switches. The external power supply communicates power available to the network switches. Each network switch determines amounts and priority levels of power for the network devices connected thereto, sums together the amounts at each priority level, determines additional amounts and priority levels of power required beyond the is internal power supply capability, and sends a power request to the external power supply. The external power supply allocates power to the network switches depending on the power requests received.

Claims

1. A system for power distribution to network devices, the system comprising:

a plurality of network switches each having an internal power supply and a plurality of ports for connecting to the network devices;

an external power supply having a plurality of output ports for connecting to the network switches,

wherein the external power supply communicates power available to the network switches,

wherein each network switch determines amounts and priority levels of power for the network devices connected thereto, sums together the amounts at each priority level, determines additional amounts and priority levels of power required beyond the internal power supply capability, and sends a power request to the external power supply, and

wherein the external power supply allocates power to the network switches depending on the power requests received.

2. The system of claim 1, wherein cabling connecting the external power supply and the network switches includes a digital communications channel to communicate the power available and the power requests.

3. The system of claim 2, wherein the digital communications channel comprises a serial communications channel.

4. The system of claim 1, further comprising:

a programmable current sense and control unit coupled to power output for each port of the external power supply.

5. The system of claim 4, further comprising:

a controller in the external power supply configured to determine the allocation of power to the network switches; and

a control bus coupling the controller to each of the programmable current sense and control units in the external power supply.

6. The system of claim 1, further comprising:

a programmable current sense and control unit coupled to power output for each port of each network switch.

7. The system of claim 6, further comprising:

a controller in each network switch configured to determine the allocation of available power to the network devices; and

a control bus coupling the controller to each of the programmable current sense and control units in the network switch.

8. The system of claim 1, further comprising:

a power multiplexer in each network switch coupled to receive power both from the internal power supply of the network switch and from the external power supply,

wherein the power multiplexer is controllable to switch available power to the ports of the network switch.

9. The system of claim 8, wherein the power multiplexer is controllable to switch power from the internal power supply to a first bank of ports, to a second bank of ports, or to both the first and second bank of ports.

10. The system of claim 9, the power multiplexer is further controllable to switch power from the external power supply to the first bank of ports, to the second bank of ports, or to both the first and second bank of ports.

11. The system of claim 1, Wherein the power requests are determined by arbitration between the network switches.

12. The system of claim 11, wherein the arbitration comprises a master-slave arbitration procedure.

13. The system of claim 11, wherein the arbitration comprises a peer-to-peer arbitration procedure.

30. The system of claim 1, wherein the external power supply and the plurality of switches are integrated into a same unit.

14. A method of power distribution to network devices, the method comprising:

determining amounts and priority levels of power for the network devices connected to each power distributor of a plurality of power distributors;

summing together the amounts at each priority level at each power distributor; and

determining additional amounts and priority levels of power required beyond an internal power supply capability of each power distributor.

15. The method of claim 14,

communicating a power request to an external power supply;

and

allocating power by the external power supply to the power distributors depending on the communicated power requests.

16. The method of claim 14, wherein the power distributors comprise network switches, and wherein the available power and power requests are communicated using a serial data connection between the external power supply and each power distributor.

17. The method of claim 14, further comprising:

arbitration between the network switches to determine the power requests.

18. The method of claim 17, wherein the arbitration comprises a master-slave arbitration procedure.

19. The method of claim 17, wherein the arbitration comprises a peer-to-peer arbitration procedure.

20. A method of distributing power to network devices, the method comprising:

associating an amount and priority level of power for each device connected to a port of a network switch;

maintaining in the switch a table of the amount and priority level for each switch port; and

using the table to allocate available power to higher priority devices when insufficient power is available to fully power all of the connected devices.

21. The method of claim 20, wherein the allocation of power is controlled using current control switches connected to the switch ports.

22. The method of claim 21, wherein the allocation of power is further controlled using a power multiplexer circuit which is configured to connect to an internal power supply within the switch and to an external power supply.

23. The method of claim 22, wherein the power multiplexer circuit is controllable to switch power from each said power supply to a first bank of ports, to a second bank of ports, or to both the first and second bank of ports.

24. The method of claim 21, further comprising:

detecting actual power amounts drawn by the network devices using current sensors coupled to the switch ports.

25. The method of claim 24, wherein if an actual power drawn from a specific port exceeds the authorized power to that port, then the current switch associated with the port is open to halt the power drawn therefrom.

26. The method of claim 20, wherein the priority level of power for a switch port depends on which type of network device is connected to the port.

27. The method of claim 26, wherein the higher priority devices include IP-enabled telephone devices.

28. The method of claim 26, wherein the higher priority devices include at least one wireless access point.

29. The method of claim 20, wherein the priority levels of power for switch ports are manually configurable into the table by a network administrator.