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Class Information
Number: 379/251
Name: Telephonic communications > Centralized switching system > With generating of call associated substation signal
Description: Subject matter which generates and transmits a signal to a substation which indicates the presence of, or result of, a call attempt.
Sub-classes under this class:
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 7587031 |
Forced hold call handling in a VoP environment |
Sep. 8, 2009 |
| 7587040 |
Systems and methods for detecting false signals on an outbound call |
Sep. 8, 2009 |
| 7257222 |
Ring voltage generation circuit and method for generating a ring voltage |
Aug. 14, 2007 |
| 7046755 |
Digital access arrangement circuitry and method for connecting to phone lines having a DC holding circuit with switchable time constants |
May. 16, 2006 |
| 6917681 |
Peak power management and active decoupling arrangement for span-powered remote terminal access platforms |
Jul. 12, 2005 |
| 6714644 |
Ringing scheduling for FXS ports on platforms with limited power supply |
Mar. 30, 2004 |
| 6697482 |
Method and system for transmitting messages to subscribers during the set-up stage of incoming telephone calls |
Feb. 24, 2004 |
| 6671370 |
Method and apparatus enabling a calling telephone handset to choose a ringing indication(s) to be played and/or shown at a receiving telephone handset |
Dec. 30, 2003 |
| 6522668 |
System and method for special signaling with customer premises equipment |
Feb. 18, 2003 |
| 6088440 |
Method and apparatus for operating a telephone exchange having selectable audio sources |
Jul. 11, 2000 |
| 5949873 |
Method of providing centrex type operation using a PBX and a central switching office |
Sep. 7, 1999 |
| 5920610 |
System and method for updating database of customers' telephone numbers |
Jul. 6, 1999 |
| 5881147 |
Ring varying technique for a telephone |
Mar. 9, 1999 |
| 5699419 |
Analog multibutton telephone keysets |
Dec. 16, 1997 |
| 5655012 |
Private branch exchange apparatus |
Aug. 5, 1997 |
| 5627884 |
Method for returning inbound calls |
May. 6, 1997 |
| 5579386 |
Telephone network alerting cadence control system |
Nov. 26, 1996 |
| 5544235 |
Identification of called directory number at multiple directory number per line premises prior to ringing signal reception |
Aug. 6, 1996 |
| 5490214 |
Method and apparatus for selectively generating control signals in a telephone system |
Feb. 6, 1996 |
| 5452345 |
Metering signal level control circuit |
Sep. 19, 1995 |
| 5408527 |
Exchange system and method of connecting calls in said exchange system |
Apr. 18, 1995 |
| 5406623 |
Method and apparatus for ringing telephone stations |
Apr. 11, 1995 |
| 5335271 |
Ring trip detection circuit |
Aug. 2, 1994 |
| 5335270 |
Bell signal generating circuit |
Aug. 2, 1994 |
| 5172407 |
Circuit for generating metering pulses intended for presentation to a telecommunication subscriber |
Dec. 15, 1992 |
| 5161180 |
Call interceptor for emergency systems |
Nov. 3, 1992 |
| 4995111 |
Ring trip circuit for subscriber telephone |
Feb. 19, 1991 |
| 4750200 |
Call meter signal receiver for subscriber's private metering of telephone system |
Jun. 7, 1988 |
| 4602128 |
Automatic redialing arrangement for multi-line telephone station sets |
Jul. 22, 1986 |
| 4264786 |
A.C. Signal current transmission trunk circuit for telephone exchange systems |
Apr. 28, 1981 |
| 4204094 |
Tone applying line circuit |
May. 20, 1980 |
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