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DIFF Main Group
H04M 7/00

Arrangements for interconnection between switching centres

Introduced: September 1968

Of 15 combined children, 5 exist in both systems.

7 codes are CPC-only extensions, 3 exist only in IPC.

Child Classifications

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  • H04M 7/009 CPC only CPC only
  • H04M 7/0093 CPC only CPC only
  • H04M 7/0096 CPC only CPC only
  • H04M 7/02 for compensating differences of ground potential IPC only IPC only
  • H04M 7/04 for compensating differences of line impedance IPC only IPC only
  • H04M 7/08 for phantom working IPC+CPC Available in IPC and CPC
  • H04M 7/1 for two-way working, i.e. calls may be set-up in either direction over the same connection IPC only IPC only
  • H04M 7/14 in systems involving main and subordinate switching centres IPC+CPC Available in IPC and CPC
  • H04M 7/16 in systems employing carrier frequencies 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