Ostrolenk, Faber, Gerb & Soffen
Service channel signal transmission system
 A service channel signal transmission system in which a service channel signal is constantly fed to at least two radio channels in parallel. Each intermediate repeater station has a service channel demodulator which is constantly connected to either one of the radio channels. A combining and switching circuit automatically switches over the service channel demodulation to the other radio channel in response to an alarm output which indicates an abnormality in a received signal at a receiver associated with the one radio channel. The service channel is completely switched from one to the other without resorting to line switchover control signals from terminal stations. 
Nippon Electric Company, Ltd.
H H H H H
H04B H04B H04B H04B H04B
inventional inventional inventional inventional inventional
Akira Hiromi Toshiyuki Koyo
Abe Hashimoto Takenaka Taniguchi