System for power delivery over data communication cabling infrastructure

• US 6,643,566 B1
• Filed: 04/16/1999
• Issued: 11/04/2003
• Est. Priority Date: 01/12/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: PowerDsine Limited (Microchip Technology Incorporated)
• Inventors: Lehr, Amir, Atias, Ilan
• Primary Examiner(s): Picard, Leo
• Assistant Examiner(s): CABRERA, ZOILA E
• Application Number:
  US09/293,343
• Time in Patent Office: 1,663 Days
• Field of Search: 700/286, 713/300-340
• 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. a plurality of local area network nodes;

b. an LAN switch assembly;

c. a communication cabling connecting said plurality of nodes to said switch assembly for providing data communication, said communication cabling comprising LAN cabling in one of categories meeting an EIA/TIA cabling standard, comprising twisted wire pairs simultaneously carrying both data and power; and

,

d. said LAN switch assembly comprising;

(1) line interface circuitry coupling power into said twisted wire pairs of the communication cabling substantially without interfering with data communication on said twisted wire pairs;

(2) a controller governing the supply of power to at least some of the plurality of local area network nodes via said twisted wire pairs of the communication cabling;

(3) current limiting circuitry connected to the line interface circuitry and controlling current delivered by the line interface circuitry into said twisted wire pairs of the communication cabling; and

,

(4) wherein said LAN switch assembly is operative to provide at least some power to at least some of said plurality of nodes via said twisted wire pairs of said communication cabling so as to yield a combined power/data signal, said current limiting circuitry being operative to provide a current limit level for each node.

2. A 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. A 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. A network according to claim 3, wherein said at least one maximum current threshold level is fixed.

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

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

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

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

9. A 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. A network according to claim 3, and operative to disconnect faulty nodes.