IPC Subgroup
H04Q 1/3 Signalling arrangements; Manipulation of signalling currents
Introduced: September 1968
Last revised: January 2006
Full Title
Details of selecting apparatus or arrangements > Electrical details > Signalling arrangements; Manipulation of signalling currents
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- SELECTING
7 direct subcodes
Child Classifications
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- H04Q 1/32 using trains of DC pulses
- H04Q 1/38 using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors
- H04Q 1/39 using coded pulse groups
- H04Q 1/4 whereby duration of pulse or interval between two pulses is variable
- H04Q 1/44 using AC
- H04Q 1/48 Induced-current signalling arrangements
- H04Q 1/5 Conversion between different kinds of signals
Top Applicants
Top 10 applicants by patent filingsfor class H04, 2013–2023, worldwide · Source: EPO PATSTAT
- QUALCOMM US 97,396
- HUAWEI TECHNOLOGIES COMPANY CN 96,502
- SAMSUNG ELECTRONICS COMPANY KR 86,981
- TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 55,869
- HUAWEI TECHNOLOGIES COMPANY 55,349
- LG ELECTRONICS KR 53,649
- CANON 33,341
- SONY CORPORATION JP 32,761
- ZTE CORPORATION CN 32,274
- GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION 28,327