Details

Introduced: September 1968

Full Title

Full titles differ between systems:

IPC:

Line transmission systems > Details

CPC:

Line transmission systems (combined with near-field transmission systems H04B5/00) > Details

IPC and CPC are identically structured here. All 12 subcodes exist in both systems.

2 shared codes have differing titles between IPC and CPC.

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H04B 3/03 Hybrid circuits (for transceivers H04B1/52, H04B1/58) since 1980 IPC+CPC Available in IPC and CPC
H04B 3/04 Control of transmission; Equalising IPC+CPC Available in IPC and CPC
H04B 3/20 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other IPC+CPC Available in IPC and CPC
H04B 3/26 Improving frequency characteristic by the use of loading coils IPC+CPC Available in IPC and CPC
H04B 3/28 Reducing interference caused by currents induced in cable sheathing or armouring IPC+CPC Available in IPC and CPC
H04B 3/30 Reducing interference caused by unbalanced currents in a normally balanced line IPC+CPC Available in IPC and CPC
H04B 3/32 Reducing cross-talk, e.g. by compensating IPC+CPC Available in IPC and CPC
H04B 3/36 Repeater circuits (H04B3/58 takes precedence) IPC+CPC Available in IPC and CPC
H04B 3/40 Artificial lines; Networks simulating a line of certain length IPC+CPC Available in IPC and CPC
H04B 3/42 Circuits for by-passing of ringing signals IPC+CPC Available in IPC and CPC
H04B 3/44 Arrangements for feeding power to a repeater along the transmission line IPC+CPC Available in IPC and CPC
H04B 3/46 Monitoring; Testing IPC+CPC Available in IPC and CPC

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

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