H04M 3/32
For lines between exchanges
Official title: for lines between exchanges
H04M3/32 (For lines between exchanges) appears on 294 US grants and 138 published applications in this corpus.
Search patents in H04M- Granted patents
- 294
- Published applications
- 138
- Assignees
- 158
- Inventors
- 565
- Latest grant
- 2 Jun 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 3 | 0 |
| 1978 | 2 | 0 |
| 1979 | 2 | 0 |
| 1980 | 3 | 0 |
| 1981 | 5 | 0 |
| 1982 | 5 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 2 | 0 |
| 1986 | 4 | 0 |
| 1987 | 3 | 0 |
| 1988 | 1 | 0 |
| 1989 | 4 | 0 |
| 1990 | 4 | 0 |
| 1991 | 2 | 0 |
| 1992 | 0 | 0 |
| 1993 | 2 | 0 |
| 1994 | 3 | 0 |
| 1995 | 7 | 0 |
| 1996 | 7 | 0 |
| 1997 | 5 | 0 |
| 1998 | 14 | 0 |
| 1999 | 14 | 0 |
| 2000 | 14 | 0 |
| 2001 | 16 | 1 |
| 2002 | 18 | 17 |
| 2003 | 11 | 9 |
| 2004 | 15 | 15 |
| 2005 | 12 | 9 |
| 2006 | 5 | 7 |
| 2007 | 15 | 5 |
| 2008 | 5 | 7 |
| 2009 | 6 | 6 |
| 2010 | 9 | 2 |
| 2011 | 4 | 1 |
| 2012 | 6 | 4 |
| 2013 | 5 | 5 |
| 2014 | 7 | 2 |
| 2015 | 2 | 4 |
| 2016 | 8 | 7 |
| 2017 | 3 | 3 |
| 2018 | 6 | 4 |
| 2019 | 5 | 2 |
| 2020 | 5 | 5 |
| 2021 | 4 | 6 |
| 2022 | 5 | 4 |
| 2023 | 4 | 4 |
| 2024 | 4 | 5 |
| 2025 | 3 | 3 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Modular technologies for servicing telephony systems2 Jun 2026US 12,647,468 B2Cdw LLC
- Inter-core transport audio quality testing remote from testing site10 Mar 2026US 12,574,766 B2Spirent Communications, Inc.
- Systems, methods, and storage media for testing local loops of telecommunications networks10 Jun 2025US 12,328,410 B2Level 3 Communications, LLC
- Simulation of automated telephone call(s)3 Jun 2025US 12,323,373 B2Google Inc.
- Telephone number monitoring11 Mar 2025US 12,250,341 B2Avoxi, Inc.
- Systems for call monitoring and associated methods using call arrival intervals23 Apr 2026US 2026/0113401 A1Avoxi, Inc.
- Simulation of automated telephone call(s)14 Aug 2025US 2025/0260657 A1Google Inc.
- Simulation of automated telephone call(s)24 Apr 2025US 2025/0133036 A1Google Inc.
- Emergency call record and address validation17 Apr 2025US 2025/0126195 A1Level 3 Communications, LLC
- Systems, methods, and storage media for testing local loops of telecommunications networks3 Oct 2024US 2024/0333833 A1Level 3 Communications, LLC
Most cited
By later US patents
- Skills-based scheduling for telephone call centers370US 6,044,355 AIEX Corporation · 2000
- Communications network state and topology monitor285US 5,049,873 ANetwork Equipment Technologies, Inc. · 1991
- System and method for determining the performance of a user responding to a call182US 6,038,544 ATeknekron Infoswitch Corporation · 2000
- Method and system for testing hardware and/or software applications179US 6,279,124 B1Qwest Communications International Inc. · 2001
- High-speed facility protection in a digital telecommunications system127US 5,329,520 AAlcatel Network Systems, Inc. · 1994