System for powering a switch over data communication cabling infrastructure

• US 7,466,819 B2
• Filed: 03/29/2005
• Issued: 12/16/2008
• Est. Priority Date: 01/12/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Analog Mixed Signal Group Limited, Microsemi Corporation (Microchip Technology Incorporated)
• Inventors: Lehr, Amir, Atias, Ilan
• Primary Examiner(s): ELAHEE, MD S
• Application Number:
  US11/091,675
• Publication Number:
  US 20050169297A1
• Time in Patent Office: 1,358 Days
• Field of Search: 379/399.01
• US Class Current: 379/399.01
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02G 3/00 Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles installations of bus-bars H02G5/00; overhead installations H02G7/00; installations in or on the ground H02G9/00
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system for generating, delivering and distributing electrical power to network elements over a data communication network infrastructure within a building, campus or enterprise. Consolidating power distribution and data communications over a single network simplifies and reduces the cost of network element installation and provides a means of supplying uninterrupted or backup power to critical network devices in the event of a power failure. The invention includes power/data combiners that combine a data communication signal with a low frequency power signal. The combined signal is transported over the LAN infrastructure where a power/data splitter extracts the data signal and the power signal and generates two separate outputs. The power over LAN system of the present invention operates with high bandwidth data communication networks, i.e., 10 Mbps, 100 Mbps, 1000 Mbps. The electrical power distributed over the LAN can be delivered as DC or low frequency AC voltages which in either case will not interfere with data communications signals. The electrical power delivered over data communications cable can be transmitted using one or more spare pairs in the cable or over the receive and transmit wires.

Claims

1. A local area network comprising:

a first plurality of local area network nodes;

a first power data combiner;

first communication cabling connecting said first plurality of local area network nodes to said first power data combiner for providing data communication;

a second power data combiner; and

second communication cabling connecting said first power data combiner to said second power data combiner,

said second power data combiner providing power to said first power data combiner via said second communication cabling,

said first power data combiner comprising;

line interface circuitry coupling at least some of said power provided via said second communication cabling into said first communication cabling substantially without interfering with data communication; and

first current limiting and sense circuitry connected to said line interface circuitry,

wherein said first power data combiner is operative to provide at least some power provided via said second communication cabling to at least some of said plurality of first local area network nodes via said first communication cabling, and

wherein said first current limiting and sense circuitry is operative to limit one of current and power of said provided power to each of said first plurality of local area network nodes to a maximum level and provide a minimum current threshold reference level for said provided power for each of first local area network nodes.

2. A local area network according to claim 1, wherein said second power data combiner provides said current limited power to said first power data combiner via said second communication cabling utilizing a combined power data signal.

3. A local area network according to claim 1, further comprising:

a second plurality of local area network nodes; and

third communication cabling connecting said second plurality of local area network nodes to said second power data combiner;

said second power data combiner operative to provide power to at least one of said second plurality of local area network nodes via said third communication cabling.

4. A local area network according to claim 1, further comprising:

a second plurality of local area network nodes; and

third communication cabling connecting said second plurality of local area network nodes to said second power data combiner,

said second power data combiner comprising second current limiting and sense circuitry operative to provide power to at least one of said second plurality of local area network nodes via said third communication cabling,

said second current limiting and sense circuitry operative to limit one of current and power of said provided power to each of said second plurality of local area network nodes to a maximum level and provide a minimum current threshold reference level for said provided power to each of said second plurality of local area network nodes.

5. A local area network according to claim 4, wherein said second current limiting and sense circuitry of said second power combiner is further operative to limit one of current and power of said power provided to said first power data combiner, and to provide a minimum current threshold reference level for said power provided power to said first power data combiner.

6. A local area network according to claim 1, wherein at least one of said first power data combiner and said second power data combiner is integrated with one of a hub and a switch.

7. A local area network comprising:

a first plurality of local area network nodes;

a switch assembly;

a power data combiner;

first communication cabling connecting said first plurality of local area network nodes to said first switch assembly for providing data communication; and

second communication cabling connecting said switch assembly to said power data combiner for providing data communication,

said power data combiner being operative to provide power to said switch assembly via said second communication cabling;

said switch assembly comprising;

first line interface circuitry operative to couple at least some of said provided power into said first communication cabling substantially without interfering with data communication; and

first current limiting and sense circuitry connected to said first line interface circuitry,

wherein said switch assembly is operative to provide at least some of said power provided from said power data combiner to at least some of said first plurality of local area network nodes via said first communication cabling,

said first current limiting and sense circuitry operative to limit one of current and power for each of said first plurality of local area network nodes for which power is provided to a maximum level and provide a minimum current threshold reference level for each of said first plurality of local area network nodes for which power is provided.

8. A local area network according to claim 7, wherein said power data combiner comprises:

second line interface circuitry coupling power into said second communication cabling substantially without interfering with data communication; and

second current limiting and sense circuitry connected to said second line interface circuitry, said second current limiting circuitry operative to limit one of current and power of said power provided to said switch assembly to a maximum level and provide a minimum threshold reference level for power provided to said switch assembly.

9. A local area network according to claim 8, further comprising:

a second plurality of local area network nodes; and

third communication cabling connecting said second plurality of local area network nodes to said power data combiner,

said power data combiner further operative to provide power via said third communication cabling to at least one of said second plurality of local area network nodes.

10. A local area network according to claim 8, further comprising:

a second plurality of local area network nodes; and

third communication cabling connecting said second plurality of local area network nodes to said power data combiner,

said power data combiner further operative to provide power via said third communication cabling to at least one of said second plurality of local area network nodes,

said second current limiting and sense circuitry further operative to limit one of current and power of said power provided to each of said powered second plurality of local area network nodes to a maximum level and provide a minimum current threshold reference level for said power provided to each of said powered second plurality of local area network nodes.

11. A local area network according to claim 7, wherein said power data combiner is integrated within one of a hub and a switch.

12. A local area network comprising:

a plurality of first local area network nodes;

a first switch assembly;

a second switch assembly;

first communication cabling connecting said plurality of first local area network nodes to said first switch assembly for providing data communication; and

second communication cabling connecting said first switch assembly to said second switch assembly, said second switch assembly operative to provide at least some power via said second communication cabling to said first switch assembly;

said first switch assembly comprising;

first line interface circuitry coupling at least some of said power provided by said second switch assembly into said first communication cabling substantially without interfering with data communication; and

first current limiting and sense circuitry connected to said line interface circuitry,

wherein said first switch assembly is operative to provide at least some power to at least some of said plurality of first local area network nodes via said first communication cabling,

said first current limiting and sense circuitry operative to limit one of current and power of said provided power to each of said first local area network nodes beingprovided power via said first communication cabling to a maximum level and provide a minimum current threshold reference level for said provided power for each of plurality of first local area network nodes.

13. A local area network according to claim 12, further comprising:

a second plurality of local area network nodes; and

third communication cabling connecting said second plurality of local area network nodes to said second switch assembly,

said second switch assembly being farther operative to provide power via said third communication cabling to at least one of said second plurality of local area network nodes.

14. A local area network according to claim 13, wherein said second switch assembly comprises:

second line interface circuitry coupling power into said second communication cabling substantially without interfering with data communication; and

second current limiting and sense circuitry connected to said second line interface circuitry, said second current limiting and sense circuitry operative to limit one of current and power of said provided power to each of said second plurality of local area network nodes to a maximum level and provide a minimum current threshold reference level for said provided power for each of second plurality of local area network nodes.

15. A local area network according to claim 14, wherein said second current limiting and sense circuitry is further operative to limit one of current and power of said power provided to said first switch assembly and provide a minimum threshold reference level for power provided to said first switch assembly.

16. A method of powering a switch, the method comprising:

receiving a first plurality of data signals;

receiving a low frequency power signal;

combining said received plurality of data signals and said received low frequency power signal into a plurality of first combined power and data signals, said power substantially not interfering with said data signal, said plurality of first combined power and data signals being transmittable over data communication cabling to a first plurality of nodes, at least one of said first plurality of nodes comprising a switch assembly;

limiting one of current and power for each of said plurality of first combined power and data signals to a maximum level;

providing a minimum current threshold level for each of said plurality of first combined power and data signals;

transmitting at least one of said first combined power and data signals over communication cabling to said switch assembly;

splitting said at least one of said first combined power and data signal into separate power and data components at said switch assembly; and

powering said switch assembly with said power component.

17. A method according to claim 16, further comprising;

switching said data component to a second plurality of nodes;

combining said power component with said switched data component to provide at least one second combined power and data signal;

limiting one of current and power for each of said at least one second combined power and data signal to a maximum level;

providing a minimum current threshold level for each of said at least one second combined power and data signal; and

transmitting said second combined power and data signal to at least one of said second plurality of nodes.

18. A powered switch comprising:

means for receiving a combined power data signal at an input;

a splitter operative to split said received combined power data signal into separate power and data components; and

a power and data combiner operative to combine said power component into a plurality of combined power and data outputs, said power and data combiner comprising current limiting and sense circuitry operative to limit one of current and power for each of said plurality of combined power and data outputs to a maximum level and provide a minimum current threshold reference level for each of said plurality of combined power and data outputs.

19. A powered switch according to claim 18, wherein each of said plurality of combined power and data outputs are transmittable over communication cabling.

20. A powered switch according to claim 18, wherein said maximum level is one of fixed and controllable for each of said combined power and data outputs.

21. A powered switch according to claim 18, wherein said power and data combiner further comprises:

line interface circuitry coupling at least some of said power component into said plurality of combined power and data outputs substantially without interfering with data communication.

22. A method comprising:

receiving a combined power and data signal at an input;

splitting said received combined power and data signal into separate power and data components;

combining said power component into a plurality of combined power and data outputs; and

limiting one of current and power of each of said plurality of combined power and data outputs to an associated maximum level; and

providing a minimum current threshold level for each of said plurality of combined power and data outputs.