H04Q 1/453
In which m-out-of-n signalling frequencies are transmitted
Official title: in which m-out-of-n signalling frequencies are transmitted
H04Q1/453 (In which m-out-of-n signalling frequencies are transmitted) appears on 89 US grants and 9 published applications in this corpus.
Search patents in H04Q- Granted patents
- 89
- Published applications
- 9
- Assignees
- 55
- Inventors
- 130
- Latest grant
- 12 Sep 2017
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 6 | 0 |
| 1977 | 1 | 0 |
| 1978 | 3 | 0 |
| 1979 | 4 | 0 |
| 1980 | 2 | 0 |
| 1981 | 2 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 0 | 0 |
| 1985 | 2 | 0 |
| 1986 | 3 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 2 | 0 |
| 1991 | 1 | 0 |
| 1992 | 3 | 0 |
| 1993 | 3 | 0 |
| 1994 | 6 | 0 |
| 1995 | 6 | 0 |
| 1996 | 5 | 0 |
| 1997 | 4 | 0 |
| 1998 | 10 | 0 |
| 1999 | 8 | 0 |
| 2000 | 3 | 0 |
| 2001 | 0 | 0 |
| 2002 | 1 | 0 |
| 2003 | 0 | 1 |
| 2004 | 2 | 3 |
| 2005 | 0 | 0 |
| 2006 | 2 | 0 |
| 2007 | 0 | 1 |
| 2008 | 0 | 0 |
| 2009 | 2 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 2 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 1 | 1 |
| 2015 | 1 | 0 |
| 2016 | 1 | 1 |
| 2017 | 1 | 0 |
By publication year. Applications have been published since 2001.
Subgroups
Granted patents
Recent patents
- Robust DTMF detection in an unreliable voice-over-IP (VoIP) environment12 Sep 2017US 9,762,741 B2Genesys Telecommunications Laboratories, Inc.
- Robust DTMF detection in an unreliable voice-over-IP (VoIP) environment26 Jul 2016US 9,401,998 B2Genesys Telecommunications Laboratories, Inc.
- Recovery of DTMF tones in the presence of periodic interference and obstruction9 Jun 2015US 9,055,145 B1The United States of America as represented by the Secretary of the Army
- High-performance tone detection using a digital signal processor (DSP) having multiple arithmetic logic units (ALUs)24 Jun 2014US 8,761,916 B2LSI Corporation
- Method and apparatus for decoding DTMF tones13 Oct 2009US 7,602,902 B2Honeywell International Inc.
- Robust DTMF detection in an unreliable voice-over-IP (VoIP) environment17 Nov 2016US 2016/0337524 A1Genesys Telecommunications Laboratories, Inc.
- Robust DTMF detection in an unreliable voice-over-IP (VoIP) environment19 Jun 2014US 2014/0169550 A1Soundbite Communications, Inc.
- High-performance tone detection using a digital signal processor (dsp) having multiple arithmetic logic units (alus)18 Aug 2011US 2011/0200147 A1LSI Corporation
- Method and apparatus having echo cancellation and tone detection for a voice/tone composite signal20 Jan 2011US 2011/0013766 A1
- Method and apparatus for decoding dtmf tones24 May 2007US 2007/0116242 A1Honeywell International Inc.
Most cited
By later US patents
- Information storage device for storing personal identification information232US 5,825,871 ASmart Tone Authentication, Inc. · 1998
- System and method using personal identification numbers and associated prompts for controlling unauthorized use of a security device and unauthorized access to a resource230US 5,745,555 ASmart Tone Authentication, Inc. · 1998
- Method and apparatus for the secure communication of data178US 5,583,933 A1996
- Method and system for the secure communication of data175US 5,907,597 ASmart Tone Authentication, Inc. · 1999
- Method and device for decoding a sequence of signals56US 6,078,660 ASiemens Information and Communication Systems, Inc. · 2000