Telephone extension system utilizing power line carrier signals

• US 4,495,386 A
• Filed: 11/07/1983
• Issued: 01/22/1985
• Est. Priority Date: 03/29/1982
• Status: Expired due to Term

• Current Assignee: Phonex Broadband Corp.
• Original Assignee: Astech, Inc. (Melrose Industries Plc)
• Inventors: Brown, William M., Dunn, Robert T.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Brady, W. J.
• Application Number:
  US06/549,598
• Time in Patent Office: 442 Days
• Field of Search: 179/2.51, 179/2 A, 179/2 AM, 179/3, 179/4, 179/2 EA, 370/69-71, 370/76, 340/310 R, 340/310 A, 340/310 CP
• US Class Current: 455/402
• CPC Class Codes: H04B 2203/5437 Wired telephone
• CPC Class Codes: H04B 2203/5454 Adapter and plugs
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04M 1/71 Substation extension arrangements
• CPC Class Codes: H04M 11/00 Telephonic communication systems specially adapted for combination with other electrical systems

Abstract

A power line telephone extension system for carrying electrical signals between a subscriber'"'"'s telephone line of a conventional telephone communication system and the subscriber'"'"'s remote transmit-receiver device, (such as a conventional extension telephone), over the AC electric power wires available to the subscriber which includes: master linking circuits for processing signals between the subscriber'"'"'s telephone line and the AC power wires; extension linking circuits for processing signals between the AC power wires and the subscriber'"'"'s remote transmit-receive device, such as a conventional extension telephone; and a directional coupler circuit electrically coupling the remote transmit-receive device and the telephone line. The extension system is quite suitable for use with the presently available, well known, conventional extension telephone that plugs in by the plug (modular or 4 prong) provided therewith, to the directional coupler. Thus, the extension phone can then be used along with the extension linking circuits at any location at the subscriber'"'"'s premises where there is access to the AC power wires.

Claims

1. A method of electrically coupling telephone signals on a telephone line to a conventional extension telephone having four or less wires, three of which are the tip, ring, or ground wires utilizing available electrical power lines having power outlets along the power lines comprising the steps of:

(a) coupling the tip and ring wires from the telephone line to a master linking circuit;

(b) coupling the master linking circuit to a first power line outlet;

(c) coupling an extension linking circuit to a second power line outlet;

(d) coupling a conventional extension telephone having tip and ring lines to the extension linking circuit;

(e) said master linking circuits performing the following steps;

(i) coupling telephone signals on the tip line to a transmitter for transmission in a first direction over said power line to said extension linking circuits;

(ii) receiving signals in a receiver from the extension linking circuits for transmission in a second direction to the telephone line;

(f) said extension linking circuits performing the following steps;

(i) coupling telephone signals on the tip line of the extension telephone to a transmitter for transmission in said second direction over said power line to said receiver in said master linking circuits;

(ii) receiving signals in a receiver from the transmitter in the master linking circuits for transmission in said first direction to the extension telephone over the tip and ring lines.

2. The method of claim 1 wherein a hybrid coupler is provided in each master linking circuit and extension linking circuit for communication in both first and second directions.

3. A method of carrying electrical telephone signals between a subscriber'"'"'s telephone line of a conventional telephone communication system and the subscriber'"'"'s conventional extension telephone, wherein said conventional telephone line has four or less wires connected to it of which one is a tip wire, one a ring wire and one a ground wire, over available electric power wires, comprising the steps of:

(a) providing a master location including master linking circuits for processing the telephone signals by electrically coupling the telephone signals from the subscriber'"'"'s telephone line to the power wires;

(b) providing an extension location along said power wires including said conventional extension telephone and extension linking circuits for processing the telephone signals, by electrically coupling the extension telephone to the power wires;

(c) originating an extension telephone off-cradle signal at the extension telephone;

(d) at the master location detecting the edges of said cradle-off signal and producing a signal level representative thereof and switching the master linking circuits to the telephone line in response to said signal level representative of cradle-off;

(e) at said extension location generating pulses that define, make or break intervals; and

(f) detecting both the leading and trailing edges of the the dial pulses and

(i) generating pulses shorter than the break interval between said edges of the dial pulse,

(ii) generating pulses longer than said break interval between said edges of the dial pulse,

(iii) producing pulses coincident with said shorter and longer pulses, and

(iv) applying aid coincident pulses to a monostable multivibrator.

4. In a power line telephone extension system for carrying electrical signals including ring signals between a subscriber'"'"'s telephone line of a conventional telephone communication system and the subscriber'"'"'s extension telephone over available electric power wires, wherein there is a master location including master linking circuits for processing the signals, electrically coupled between the subscriber'"'"'s telephone line and power wires and an extension location along said power wires including an extension telephone and extension ringer and extension linking circuits for processing the signals, electrically coupled between the extension telephone and power wires, the method of:

(a) at the master location generating and transmitting master carrier frequency signals to the extension location and detecting said ring signals and turning on the master transmitter during the interval of each ring signal;

(b) coupling all signals carried to the extension location from the master location onto a master carrier frequency;

(c) at the extension location, detecting the occurrence of the master carrier frequency originating from the master transmitter;

(d) in response thereto generating an oscillating signal substantially coincident with said occurrence, the frequency of said oscillating signal and the power thereof being suitable for driving the extension ringer, and

(e) coupling said oscillating signal to the extension ringer.