Aircraft call-up system to ground station - uses repeated signals in interference -detecting code

摘要

Signals in an interference-detecting code are repeatedly transmitted, and any properly received are accepted by the receiver, while the others are ignored. If the first signals are distorted the others if good are accepted. For traffic control clear determination of the order of channels is achieved by using a combination of call-up signals emitted alternately, and their configuration unequivocally indicates the channel in which the first transmission of a traffic signal and the second repeated transmission of the same signal is to take place. These call-up signals are not used for traffic information, and part of them are selected so that a particular ground station is indicated at the same time.