IPC Main Group
H04B 11/00 Transmission systems employing ultrasonic, sonic or infrasonic waves
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- TRANSMISSION
Related Keywords
TRANSMISSION of information-carrying signals, using sonic, ultrasonic or infrasonic waves