H04Q 2213/13405
Dual frequency signaling, dtmf
Official title: Dual frequency signaling, DTMF
H04Q2213/13405 (Dual frequency signaling, dtmf) appears on 410 US grants and 186 published applications in this corpus.
Search patents in H04Q- Granted patents
- 410
- Published applications
- 186
- Assignees
- 155
- Inventors
- 584
- Latest grant
- 5 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1988 | 1 | 0 |
| 1989 | 1 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 1 | 0 |
| 1993 | 4 | 0 |
| 1994 | 3 | 0 |
| 1995 | 4 | 0 |
| 1996 | 6 | 0 |
| 1997 | 27 | 0 |
| 1998 | 41 | 0 |
| 1999 | 42 | 0 |
| 2000 | 35 | 0 |
| 2001 | 37 | 26 |
| 2002 | 40 | 34 |
| 2003 | 16 | 14 |
| 2004 | 17 | 8 |
| 2005 | 11 | 9 |
| 2006 | 13 | 5 |
| 2007 | 15 | 16 |
| 2008 | 7 | 3 |
| 2009 | 2 | 2 |
| 2010 | 7 | 6 |
| 2011 | 6 | 6 |
| 2012 | 9 | 6 |
| 2013 | 8 | 5 |
| 2014 | 4 | 1 |
| 2015 | 7 | 6 |
| 2016 | 3 | 2 |
| 2017 | 3 | 4 |
| 2018 | 5 | 6 |
| 2019 | 7 | 6 |
| 2020 | 5 | 9 |
| 2021 | 6 | 3 |
| 2022 | 5 | 5 |
| 2023 | 2 | 1 |
| 2024 | 4 | 2 |
| 2025 | 2 | 0 |
| 2026 | 1 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Call classification through analysis of DTMF events5 May 2026US 12,621,382 B2Pindrop Security, Inc.
- Systems and methods for tone to token telecommunications platform21 Oct 2025US 12,450,587 B2Worldpay, LLC
- Calling line/name identification of enterprise subscribers in mobile calls23 Sep 2025US 12,425,814 B2Tango Networks, Inc.
- System and method for executing originating services in a terminating network for IMS and non-IMS applications27 Aug 2024US 12,075,327 B2Tango Networks, Inc.
- Call classification through analysis of DTMF events18 Jun 2024US 12,015,731 B2Pindrop Security, Inc.
- Call classification through analysis of dtmf events17 Sep 2026US 2026/0281227 A1Pindrop Security, Inc.
- Call classification through analysis of dtmf events26 Sep 2024US 2024/0323270 A1Pindrop Security, Inc.
- Systems and methods for tone to token telecommunications platform2 May 2024US 2024/0144230 A1Worldpay, LLC
- Calling line/name identification of enterprise subscribers in mobile calls3 Aug 2023US 2023/0247515 A1Tango Networks, Inc.
- System and method for executing originating services in a terminating network for ims and non-ims applications1 Dec 2022US 2022/0386213 A1Tango Networks, Inc.
Most cited
By later US patents
- PSTN architecture for video-on-demand services963US 5,247,347 ABell Atlantic Network Services, Inc. · 1993
- Video-on-demand services using public switched telephone network900US 5,410,343 ABell Atlantic Network Services, Inc. · 1995
- Message storage and delivery system854US 5,675,507 A1997
- Systems and methods for storing, delivering, and managing messages422US 5,870,549 A1999
- Network based distributed PBX system407US 5,742,596 APhonet Communication Ltd. · 1998