Telephone communication system and method over local area network wiring
View Patent ↗A method and apparatus for enabling a local area network wiring structure to simultaneously carry digital data and analog telephone signals on the same transmission medium. It is particularly applicable to a network in star topology, in which remote data units (e.g. personal computers) are each connected to a hub through a cable comprising at least two pairs of conductors, providing a data communication path in each direction. Modules at each end of the cable provide a phantom path for telephony (voice band) signals between a telephone near the data set and a PBX, through both conductor pairs in a phantom circuit arrangement. All such communication paths function simultaneously and without mutual interference. The modules comprise simple and inexpensive passive circuit components.
1. A circuit arrangement for coupling an information device and a digital data device to a local area network cable having at least first and second twisted wire pairs in a building, and simultaneously carrying a full-duplex packet-based digital data signal and an information signal, the circuit arrangement comprising:
a first local area network connector connectable to the local area network cable;
a second local area network connector connectable to a digital data device for coupling the full-duplex packet-based digital data signal to the digital data device; and
an information port couplable to the information device for coupling the information signal to the information device,
wherein each of the first and second twisted pairs is operative to carry a packet-based digital data signal, and the at least two twisted pairs cooperatively form a phantom channel operative to carry the information signal.
2. The circuit arrangement according to claim 1 , further comprising:
a first signal transformer having a primary winding and a secondary winding, said first signal transformer being connected between said first local area network connector and said second local area network connector, said primary winding having a center-tap connection, and said first signal transformer being operative to pass the local area network packet-based digital data signal; and
a second signal transformer having a primary winding and a secondary winding, said second signal transformer being connected between said first local area network connector and said second local area network connector, said primary winding having a center-tap connection, and said second signal transformer being operative to pass local area network packet-based digital data signals;
wherein said center tap connections of said first and second signal transformers are connected to said information port.
3. The circuit arrangement according to claim 1 , wherein said first and second local area network connectors are RJ-45 type, and the local area network packet-based digital data signals are based on 10/100BaseT according to IEEE802.3 protocol.
4. The circuit arrangement according to claim 1 having the external dimensions of an outlet.
5. The circuit arrangement according to claim 1 configured as a plug-in to an outlet.
6. The circuit arrangement according to claim 1 further attachable to a surface of a building.
7. The circuit arrangement according to claim 1 wherein the information signal is an analog signal, and said information port is an analog connector.
8. The circuit arrangement according to claim 7 wherein the information signal is an analog voice signal, and the information port is an analog voice connector.
9. The circuit arrangement according to claim 8 wherein the analog voice signal is a telephone signal and the analog voice connector is a telephone connector.
10. The circuit arrangement according to claim 1 wherein a DC power signal is concurrently carried over said phantom channel.
11. The circuit arrangement according to claim 1 wherein the local area network cable comprises N twisted wire pairs cooperatively forming N-1 phantom channels, where N is equal or greater than 3.
12. The circuit arrangement according to claim 1 wherein the information signal is bi-directionally carried between the first local area network connector and the information port.
13. A kit comprising first and second circuit arrangements, each according to claim 1 , for use with a local area network cable connectable between first local area network connectors of said first and second circuit arrangements for simultaneously transporting information and digital data signals over a local area network comprising at least two twisted wire pairs, for transporting an information signal from a first information device connectable to the information port of said first circuit arrangement to a second information device connectable to the information port of said second circuit arrangement over the twisted wire pairs that form the phantom channel, simultaneously with transporting a full-duplex packet-based digital data signal from a first digital data device connectable to said second local area network connector of said first circuit arrangement to a second digital data device connectable to said second local area network connector of said second circuit arrangement over the twisted pairs.
14. A local area network in a building for simultaneously carrying a full-duplex packet-based digital data signal between first and second digital data units and an information signal between first and second information units, the network comprising:
a local area network cable at least in part in a wall of the building and accessed via outlets, having first and second ends and comprising at least two twisted wire pairs, each wire pair being operative to carry the packet-based digital data signal, and said at least two twisted wire pairs cooperatively forming a phantom channel simultaneously operative to carry the information signal;
a first device connected to said first end of said local area network cable, said first device being couplable to the first digital data unit for coupling the packet-based digital data signal to the first digital data unit, and being further couplable to the first information unit for coupling the information signal to the first information unit; and
a second device connected to said second end of said local area network cable, said second device being couplable to the second digital data unit for coupling the packet-based digital data signal to the second digital data unit, and being further couplable to the second information unit for coupling the information signal to the second information unit.
15. The network according to claim 14 , wherein at least one of said first and second devices comprises:
a first signal transformer having a primary winding and a secondary winding, said first signal transformer being connected between said local area network cable and the digital data unit, said primary winding having a center-tap connection, and said first signal transformer being operative to pass the local area network packet-based digital data signals; and
a second signal transformer having a primary winding and a secondary winding, said second signal transformer being connected between said local area network cable and the digital data unit, said primary winding having a center-tap connection, and said second signal transformer being operative to pass the local area network packet-based digital data signals;
wherein said center tap connections of said first and second signal transformers are coupled to the information unit.
16. The network according to claim 14 , wherein said first and second devices are connected to the local area network cable via RJ-45 type connectors, and the local area network packet-based digital data signals are based on 10/100BaseT according to IEEE802.3 protocol.
17. The network according to claim 14 wherein at least one of said first and second devices has the external dimensions of an outlet.
18. The network according to claim 14 wherein at least one of said first and second devices is configured as a plug-in to an outlet.
19. The network according to claim 14 wherein at least one of said first and second devices is further attachable to a surface of the building.
20. The network according to claim 14 wherein the information signal is an analog signal.
21. The network according to claim 14 wherein the information signal is an analog voice signal.
22. The network according to claim 21 wherein the analog voice signal is a telephone signal and at least one of the information units is an analog telephone device.
23. The network according to claim 14 wherein a DC power signal is concurrently carried over said phantom channel.
24. The network according to claim 14 wherein the local area network cable comprises N wire pairs cooperatively forming N-1 phantom channels, where N is equal or greater than 3.
25. The network according to claim 14 wherein the information signal is bi-directionally carried between the first and second information units.
26. The network according to claim 14 wherein said first device and the first digital data unit are housed in a single enclosure.