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DIFF Main Group
H04L 51/00

User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail

Introduced: January 2022

Additional Content IPC

Social network Social networks Websites and applications for the informal communication and sharing of information with other users. Store and forward A telecommunications technique in which information is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station Instant messaging (IM) Instant messaging IM Real-time transmission and exchange of short messages between two parties

IPC and CPC are identically structured here. All 10 subcodes exist in both systems.

IPC defines codes here since 2022.

Child Classifications

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  • H04L 51/02 using automatic reactions or user delegation, e.g. automatic replies or chatbot-generated messages since 2022 IPC+CPC Available in IPC and CPC
  • H04L 51/42 Mailbox-related aspects, e.g. synchronisation of mailboxes since 2022 IPC+CPC Available in IPC and CPC
  • H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases since 2022 IPC+CPC Available in IPC and CPC
  • H04L 51/52 for supporting social networking services since 2022 IPC+CPC Available in IPC and CPC
  • H04L 51/56 Unified messaging, e.g. interactions between e-mail, instant messaging or converged IP messaging [CPM] since 2022 IPC+CPC Available in IPC and CPC
  • H04L 51/58 Message adaptation for wireless communication since 2022 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class H04,2013–2023, worldwide · Source: EPO PATSTAT

  1. QUALCOMM US 97,396
  2. HUAWEI TECHNOLOGIES COMPANY CN 96,502
  3. SAMSUNG ELECTRONICS COMPANY KR 86,981
  4. TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 55,869
  5. HUAWEI TECHNOLOGIES COMPANY 55,349
  6. LG ELECTRONICS KR 53,649
  7. CANON 33,341
  8. SONY CORPORATION JP 32,761
  9. ZTE CORPORATION CN 32,274
  10. GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION 28,327

Top Applicants (CPC)

Class H04,2013–2023, worldwide · Source: EPO PATSTAT

  1. HUAWEI TECHNOLOGIES COMPANY CN 101,476
  2. QUALCOMM US 101,139
  3. SAMSUNG ELECTRONICS COMPANY KR 96,655
  4. TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 57,744
  5. LG ELECTRONICS KR 55,253
  6. HUAWEI TECHNOLOGIES COMPANY 54,181
  7. SONY CORPORATION JP 35,309
  8. ZTE CORPORATION CN 32,950
  9. INTEL CORPORATION US 27,533
  10. GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION CN 27,498