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 device for coupling digital data signals and a DC signal to first and second Local Area Network (LAN) cables, each cable having at least first and second twisted wire pairs connected for carrying full-duplex packet-based digital data over the wire pairs and a signal over a phantom channel formed between the twisted wire pairs, said device comprising a single enclosure and, in said single enclosure:
a digital data packet-based component having first and second ports;
a first LAN connector for connecting to the first LAN cable;
a first signal transformer having a center tap and coupled between said first port and said first LAN connector for passing only digital data signals between said first port and the first twisted wire pair of the first LAN cable;
a second signal transformer having a center tap and coupled between said first port and said first LAN connector for passing only digital data signals between said first port and the second twisted wire pair of the first LAN cable;
a second LAN connector for connecting to the second LAN cable;
a third signal transformer having a center tap and coupled between said second port and said second LAN connector for passing only digital data signals between said second port and the first twisted wire pair of the second LAN cable;
a fourth signal transformer having a center tap and coupled between said second port and said second LAN connector for passing only digital data signals between said second port and the second twisted wire pair of the second LAN cable; and
a third connector connected for receiving a DC signals, wherein said third connector is coupled to the center taps of said first and second signal transformers, for passing the DC signal onto a phantom channel over the first cable; and said third connector is coupled to the center taps of said third and fourth signal transformers, for passing the DC signal onto a phantom channel over the second cable.
2. The device according to claim 1 , wherein said first and second LAN connectors are RJ-45 type connectors, and communication over said LAN cables is based on IEEE802.3 10BaseT or 100BaseTX standards.
3. The device according to claim 1 , wherein said digital data packet-based component is an Ethernet switch or a router.
4. The device according to claim 1 , wherein the DC signal is part of an analog telephone (POTS) signal and said connectors are connected for providing an analog telephone (POTS) path between said third connector and each of said first and second LAN connectors.
5. The device according to claim 4 wherein said third connector is an RJ-11 type connector.
6. The device according to claim 1 , in combination with an outlet in which at least a part of said device is housed.
7. The device according to claim 1 , wherein said device is pluggable into, or attachable to, an outlet.
8. The device according to claim 1 , wherein said single enclosure is wall mountable, or mountable into an outlet opening, or structured to at least in part replace an existing outlet.
9. The device according to claim 1 , wherein said single enclosure is constructed to have at least one of the following:
a form substantially similar to that of a standard outlet;
wall mounting elements substantially similar to those of a standard wall outlet;
a shape allowing direct mounting in an outlet opening or cavity; and
a form to at least in part substitute for a standard outlet.