This class covers electrical communication systems with propagation paths employing light (optical communication), infra-red, ultrasonic, sonic, or infrasonic waves.
distribution of entertainment or informative matter simultaneously to a number of receiving stations over transmission lines or over radio waves;
recording of the use made of the broadcast service.
H04H 1/00
Broadcast distribution systems
H04H 1/02
·
Wired systems
H04H 1/04
· ·
using carrier waves
H04H 1/06
· · ·
having frequencies in two or more frequency bands, e.g. medium wave and VHF
H04H 1/08
· · ·
combined with telephone network over which the broadcast is continuously available (telephone systems in general Fulltext... Hierarchy... Expanded...H04M)
H04H 1/10
· ·
using signals not modulated on a carrier
H04H 1/12
· · ·
not sharing the network with any other service
H04H 1/14
· ·
combined with power distribution network
H04H 3/00
Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency