IPC Subgroup
H04M 3/2 with means for interrupting existing connections; with means for breaking-in on conversations
Introduced: September 1968
Last revised: January 2006
Full Title
Automatic or semi-automatic exchanges > with means for interrupting existing connections; with means for breaking-in on conversations
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- TELEPHONIC COMMUNICATION