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Class Information
Number: 379/235
Name: Telephonic communications > Plural exchange network or interconnection > Interexchange signalling > Voice frequency signalling over trunk
Description: Subject matter wherein control or supervisory signals are transmitted as tones within the audible frequency range.
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 7231211 |
Apparatus and method for monitoring a trunked radio communications system |
Jun. 12, 2007 |
| 7103674 |
Apparatus and method of reducing dataflow distruption when detecting path maximum transmission unit (PMTU) |
Sep. 5, 2006 |
| 6744880 |
Method for creating a telephone digital switching platform |
Jun. 1, 2004 |
| 6574661 |
Integrated proxy interface for web based telecommunication toll-free network management using a network manager for downloading a call routing tree to client |
Jun. 3, 2003 |
| 6366664 |
Method and system for translating call processing requests |
Apr. 2, 2002 |
| 6275578 |
Method and apparatus for providing back-up, in-band signaling in a communications network |
Aug. 14, 2001 |
| 5572578 |
Exchange of information between interconnected voice mail systems |
Nov. 5, 1996 |
| 5533111 |
System for originating and receiving telephone calls over a virtual piped connection, and specialized customer premise equipment for use in the system |
Jul. 2, 1996 |
| 5274696 |
Protocol for transmitting messages in a network |
Dec. 28, 1993 |
| 5222129 |
Telephone charging signalling detector suitable for central office line interface circuits |
Jun. 22, 1993 |
| 5206902 |
Network signaling arrangement for controlling tandem network functions |
Apr. 27, 1993 |
| 5052038 |
Apparatus and method for obtaining information in a wide-area telephone system with digital data transmission between a local exchange and an information storage site |
Sep. 24, 1991 |
| 5020099 |
Private branch exchange |
May. 28, 1991 |
| 4930153 |
PBX voice mail interface |
May. 29, 1990 |
| 4879743 |
PBX and adjunct using multi-frequency tones for communication therebetween |
Nov. 7, 1989 |
| 4868861 |
Trunk dialing converter |
Sep. 19, 1989 |
| 4829562 |
Receiver for detecting different fixed frequency signals on a telephone trunkline |
May. 9, 1989 |
| 4782509 |
Apparatus and method for obtaining information in a wide-area telephone system with multiple local exchanges and multiple information storage sites |
Nov. 1, 1988 |
| 4751696 |
CENTREX attendant console interface |
Jun. 14, 1988 |
| RE32263 |
Charge time start control for interconnect PABX |
Oct. 7, 1986 |
| 4555594 |
Telephone interexchange signaling protocol |
Nov. 26, 1985 |
| 4479188 |
Digital detector for a multi-frequency code in an analog signal |
Oct. 23, 1984 |
| 4385208 |
Multifrequency receiver |
May. 24, 1983 |
| 4311879 |
AC Supervisory signal detector circuit |
Jan. 19, 1982 |
| 4254304 |
Signal processor for use with a telephone system and a digital transmission line |
Mar. 3, 1981 |
| 4159402 |
Means for identifying subscriber lines |
Jun. 26, 1979 |
| 4153818 |
Telephone multiline signaling using common signal pair |
May. 8, 1979 |
| 4153819 |
Telephone tone signalling receiver with up-conversion of frequency of tones controlled by word instructions |
May. 8, 1979 |
| 4133982 |
AC supervisory signal detector circuit |
Jan. 9, 1979 |
| 4076965 |
Universal receiver/sender |
Feb. 28, 1978 |
| 4053709 |
Telephone connector |
Oct. 11, 1977 |
| 4048451 |
Arrangement for monitoring live call disposition signals |
Sep. 13, 1977 |
| 4048450 |
Trunk circuit traffic analyzer |
Sep. 13, 1977 |
| 4002848 |
Toll fraud eliminator for telephone systems |
Jan. 11, 1977 |
| 4001513 |
Method and apparatus for the detection of fraudulent toll telephone calls |
Jan. 4, 1977 |
| 3997736 |
Parallel control of a telephone switching network |
Dec. 14, 1976 |
| 3931476 |
Method and system for automatically controlling the connection of inter-city telephone calls at a users facility |
Jan. 6, 1976 |
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