DIFF Subgroup
H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
Introduced: September 1968
Full Title
Arrangements for detecting or preventing errors in the information received > by using return channel > in which the return channel carries supervisory signals, e.g. repetition request signals > Automatic repetition systems, e.g. Van Duuren systems
IPC and CPC are identically structured here. All 8 subcodes exist in both systems.
IPC defines codes here since 2023.
Child Classifications
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- H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ] since 2023 +2 CPC IPC+CPC Available in IPC and CPC
- H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes since 2023 IPC+CPC Available in IPC and CPC
- H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions since 2023 IPC+CPC Available in IPC and CPC
- H04L 1/1829 Arrangements specially adapted for the receiver end since 2023 +7 CPC IPC+CPC Available in IPC and CPC
- H04L 1/1867 Arrangements specially adapted for the transmitter end since 2023 +7 CPC IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
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
Top Applicants (CPC)
Class H04,2013–2023, worldwide · Source: EPO PATSTAT
- HUAWEI TECHNOLOGIES COMPANY CN 101,476
- QUALCOMM US 101,139
- SAMSUNG ELECTRONICS COMPANY KR 96,655
- TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 57,744
- LG ELECTRONICS KR 55,253
- HUAWEI TECHNOLOGIES COMPANY 54,181
- SONY CORPORATION JP 35,309
- ZTE CORPORATION CN 32,950
- INTEL CORPORATION US 27,533
- GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION CN 27,498