Telephone extension switch hook state detection system

Details Telephone extension switch hook state detection system Telephone extension switch hook state detection system

1998-04-30

2000-03-21

Loomis, Paul

Telephonic communications

Multi-line or key substation system with selective switching...

Line status indication or call alerting

379377, H04M 100

Patent

active

060411074

ABSTRACT:
A computer integrated telephony system embodied in a PC that includes a telephony interface connected to the local loop that detects whether one or more extension phones are off-hook by using the signal generating and detection capabilities found on a typical telephony interface card. In the preferred embodiment, the telephony interface is based on a programmable DSP that generates and injects onto the local loop a subsonic signal having a known shape and amplitude. If one or more extensions are off-hook, the amplitude of the subsonic signal detected on the line will be significantly attenuated. The amplitude of the detected signal is compared against a threshold value and an indication is made if the detected signal amplitude is below the threshold value.

REFERENCES:
patent: 4680783 (1987-07-01), Boeckmann
patent: 4760592 (1988-07-01), Hensley
patent: 4802207 (1989-01-01), Uchida
patent: 4817137 (1989-03-01), Rosenfeld et al.
patent: 4847896 (1989-07-01), Siligoni et al.
patent: 5388153 (1995-02-01), Burger et al.
patent: 5402482 (1995-03-01), Minohara et al.
patent: 5506891 (1996-04-01), Brown
patent: 5570418 (1996-10-01), Wu et al.
patent: 5592529 (1997-01-01), Linsker
patent: 5606593 (1997-02-01), Smith
patent: 5668870 (1997-09-01), Dahlquist
patent: 5706342 (1998-01-01), Baeder et al.
patent: 5768363 (1998-06-01), Daurtartas et al.
patent: 5809132 (1998-09-01), Sakamoto
patent: 5844977 (1998-12-01), McKinney et al.
patent: 5850436 (1998-12-01), Rosen et al.
patent: 5937058 (1999-08-01), Bleile et al.

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