System for power delivery over data communication cabling infrastructure

• US 6,909,943 B2
• Filed: 09/09/2003
• Issued: 06/21/2005
• Est. Priority Date: 01/12/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Power Dsine Limited
• Inventors: Lehr, Amir, Atias, Ilan
• Primary Examiner(s): Picard, Leo
• Assistant Examiner(s): CABRERA, ZOILA E
• Application Number:
  US10/657,216
• Publication Number:
  US 20040049321A1
• Time in Patent Office: 651 Days
• Field of Search: 700/286, 713300-340, 340/310.01
• US Class Current: 700/286
• 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 plurality of local area network nodes;

an Ethernet switch assembly complying with the IEEE 802.3 standard; and

,

communication cabling connecting said plurality of nodes to said switch assembly for providing data communication;

said Ethernet switch assembly comprising;

line interface circuitry coupling power into the communication cabling, over pairs used for Ethernet communications, substantially without interfering with data communication;

a controller governing the supply of power to at least some of the plurality of local area network nodes via the communication cabling; and

,

current limiting circuitry connected to the line interface circuitry and controlling current delivered by the line interface circuitry into the communication cabling,

wherein said Ethernet switch assembly is operative to provide at least some power to at least sonic of said plurality of nodes via said communication cabling,

said current limiting circuitry being operative to provide a current limit level for each node.

2. The local area network according to claim 1, wherein the current limiting circuitry also comprises current sensing circuitry operative to perform current sensing for each wire pair within the communication cabling.

3. The local area network according to claim 1, wherein the current limiting circuitry also comprises maximum current level management circuitry operative to maintain at least one maximum current threshold level.

4. The local area network according to claim 3, wherein said at least one maximum current threshold level is fixed.

5. The local area network according to claim 3, wherein said at least one maximum current threshold level is system-controlled.

6. The local area network according to claim 3, wherein the controller is operative to perform status reporting.

7. The local area network according to claim 6, wherein the status reporting comprises reporting on power consumed by each channel within the communication cabling.

8. The local area network according to claim 6, wherein the status reporting comprises reporting on channel failures.

9. The local area network according to claim 3, and also comprising a management station wherein activation status of individual nodes can be programmed by a network administrator providing suitable commands via said management station.

10. The local area network according to claim 3, wherein the maximum current level management circuitry is further operative to disconnect faulty nodes.

11. The local area network according to claim 1, and also comprising a management unit via which minimum and maximum current threshold reference levels of power supplied to at least one of the nodes are set.

12. The local area network according to claim 1, wherein an LAN protocol is defined over the network, the LAN protocol comprising an IEEE 802.3 protocol operating at 10 Mbps and wherein said Ethernet switch assembly is 10 BaseT compatible.

13. The local area network according to claim 1, wherein an LAN protocol is defined over the network, the LAN protocol comprising an IEEE 802.3 protocol operating at 100 Mbps and wherein said Ethernet switch assembly is 100 BaseT compatible.

14. The local area network according to claim 1, wherein an LAN protocol is defined over the network, the LAN protocol comprising an IEEE 802.3 protocol operating at 1000 Mbps and wherein said Ethernet switch assembly is 1000 BaseT compatible.

15. The local area network according to claim 1, wherein an LAN protocol is defined over the network, the LAN protocol comprising an IEEE 802.3 protocol operating at one of the following bitrates:

10 Mbps, 100 Mbps, 1000 Mbps; and

wherein said Ethernet switch assembly is 10/100/1000 BaseT compatible.

16. An Ethernet switch assembly comprising:

line interface circuitry receiving a plurality of data connections and an electrical power signal, said line interface circuitry coupling power from said electrical power signal into attached communication cabling for transmission to a plurality of nodes substantially without interfering with data communication between the plurality of nodes and said plurality of data connections;

a controller governing the supply of power being coupled by said line interface circuitry for transmission to at least some of the plurality of nodes; and

current limiting circuitry connected to the line interface circuitry and controlling current coupled by said line interface circuitry for transmission to at some of the plurality of nodes,

said current limiting circuitry being operative to provide a current limit for each of the plurality of nodes.