DIFF Subgroup
H04J 1/14 Arrangements providing for calling or supervisory signals
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Frequency-division multiplex systems > Details > Arrangements providing for calling or supervisory signals
CPC:
Frequency-division multiplex systems (H04J14/00 takes precedence) > Details > Arrangements providing for calling or supervisory signals
No child classifications to compare. This is a leaf node in both IPC and CPC.