Emergency call facility for car telephones - has signal generator activated by single key with tuned receiver on land based station to establish communication channel

摘要

An emergency call channel allows direct communication between vehicles with car telephones and land based telephone exchanges. The receiver-transmitter of a car telephone system operates together with the handset and operating unit. An additional switching unit provides a facility for generating an emergency call signal that is activated by operation of single push button. The land based stations have a receiver-transmitter coupled to a converter connected to the normal telephone system. A turred receiver identifies the emergency call signal. A directional location unit with rotating antenna allows a fix to be made of the vehicle.