Patent classifications
H
ELECTRICITY
Load children
H04
ELECTRIC COMMUNICATION TECHNIQUE
Load children
H04M
TELEPHONIC COMMUNICATION
Load children
1/00
Substation equipment, e.g. for use by subscribers
Load children Filter patents View analytics View as hierarchy
H04M1/64
Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
Load children Filter patents View analytics View as hierarchy
H04M1/642
storing speech in digital form
Load children Filter patents View analytics View as hierarchy