Apparatus for selectively enabling subscriber device to respond to ringing signal in dependence upon ringing cadence

An apparatus comprising:

• a telephone line connection port for receiving incoming ringing signals from a telephone line, said incoming ringing signals being any of a plurality of ringing signals having respectively different cadences in association with respectively different subscriber numbers as a special service by a telephone company;
• a subscriber line device connection port for connection to a subscriber line device, said subscriber line device having one of said respectively different subscriber numbers, so that an incoming ringing signal for said subscriber line device has a cadence associated with said one of said respectively different subscriber numbers;
• a controlled switching circuit for providing a communication path between said telephone line connection port an said subscriber line device connection port;
• and
• a plurality of ringing signal cadence detection circuits, each of which monitors the cadence of an incoming ringing signal presented from said telephone line to said telephone line connection port and produces a respective output signal for controllably causing said switching circuit to establish a communication path from said telephone line connection port to said subscriber line device connection port in dependence upon the cadence of said incoming ringing signal, respectively different ones of said cadence detection circuits being responsive to incoming ringing signals of respectively different cadences, and wherein said controlled switching circuit establishes said communication path in response to an output signal produced by that one of said plurality of cadence detection circuits which is associated with said one of said respectively different subscriber numbers, but prevents said communication path from being established for an output signal produced by another ringing signal cadence detection circuit.

For use with a telephone link over which plural ringing signals having respectively different cadences in association with respectively different subscriber numbers may be supplied as a special service by a telephone company, an apparatus for coupling said telephone line to a respective one of a plurality of subscriber line devices, so that said respective subscriber line device may receive ringing signals associated with its subscriber number, comprising:

• a telephone line connection port arranged to be coupled to said telephone line;
• a subscriber line device connection port arranged to be coupled to said subscriber line device;
• a controlled communication path having a first port coupled to said telephone line connection port, a second port coupled to said subscriber line device connection port, and a control port;
• and
• a plurality of ringing signal cadence detection circuits, each of which monitors the cadence of an incoming ringing signal presented from said telephone line to said telephone line connection port and produces a respective output signal for application to said control port of said controlled communication path in response to detecting a respectively different one of said plurality of ringing signals;
• and wherein
• only that ringing signal cadence detection circuit which is associated with said one of said respectively different subscribers numbers has its output coupled to the control port of said controlled communication path, so that any incoming ringing signal other than one having a cadence associated with said one of said respectively different subscriber numbers is prevented from being passed to said subscriber line device, and only those ringing signals whose cadence is associated with said one of said respectively different subscriber numbers are passed through said communication path to said subscriber line device.

For use with a telephone link over which plural ringing signals having respectively different cadences in association with respectively different subscriber numbers may be supplied as a special service by a telephone company, an apparatus for coupling said telephone link to a respective one of a plurality of subscriber line device, so that said respective subscriber line device may receive an incoming call associated with its subscriber number, comprising:

• a switching circuit having a first port arranged to be coupled to said telephone line, a second port arranged to be coupled to said subscriber line device, a normally interrupted communication path between said first and second ports, and a control port through which said switch is controllably actuated to terminate the normal interruption of said communication path and thereby effectively interconnect said first and second ports so as to enable said respective subscriber line device to receive an incoming call;
• and
• a plurality of ringing signal cadence detection circuits, each of which monitors the cadence of an incoming ringing signal presented from said telephone line to said telephone line connection port and produces a respective output signal for application to said control port of said controlled switching circuit in response to detecting a respectively different one of said plurality of ringing signals;
• and wherein
• only that ringing signal cadence detection circuit which is associated with said one of said respectively different subscriber numbers has its output coupled to the control port of said controlled switching circuit, so that any incoming ringing signal other than one having a cadence associated with said one of said respectively different subscriber numbers is prevented from being passed to said subscriber line device, and only those ringing signals whose cadence is associated with said one of said respectively different subscriber numbers are passed through said controlled switching circuit to said subscriber line device.

For use with a telephone line by way of which a multi-cadence ringing service is provided by a telephone company to identify plural telephone numbers, a method of coupling said telephone line to a line device, so that said line device may receive an incoming call associated with its telephone number, comprising the steps of:

• (a) connecting a first port of a switching circuit to said telephone line and a second port of said switching circuit said line device, said switching circuit being configured to normally interrupt a communication path between its first and second ports, and having a control port through which said switching circuit is controllably actuated, so as to terminate the normal interruption of said communication path and thereby effectively interconnect said first and second ports and thereby enable said respective line device to receive an incoming call;
• (b) coupling an incoming ringing signal from said telephone line to a plurality of ringing signal cadence detection circuits, each of which monitors the cadence of said incoming ringing signal and produces a respective output signal that is capable of controllably actuating said switching circuit in response to detecting a respectively different one of said plurality of ringing cadences;
• and
• (c) in response to any of said plurality of ringing signal cadence detection circuits detecting a ringing signal cadence other than a cadence that is representative of said one telephone number, maintaining the interruption of said communication path through said controlled switching circuit, so that telephone line is prevented from being coupled to said line device.