CPC Subgroup
H04M 3/42 Systems providing special services or facilities to subscribers (specially adapted for wireless communication networks H04W4/00)
Full Title
Automatic or semi-automatic exchanges > Systems providing special services or facilities to subscribers (specially adapted for wireless communication networks H04W4/00)
29 direct subcodes
Child Classifications
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- H04M 3/424 Arrangements for automatic redialling (at the subscriber's set H04M1/27)
- H04M 3/428 Arrangements for placing incoming calls on hold
- H04M 3/432 Arrangements for calling a subscriber at a specific time, e.g. morning call service