Increasing the safety of the ATC voice communications by using in-band messaging

While the legacy ATC (Air Traffic Control) R/T (Radio Telephony) system provides important services to the aeronautical community, there is a common understanding that it is used in a very inefficient manner. However, new solutions like digital voice introduce significant changes across the whole communications chain and require many years to become available on a worldwide basis. The authors believe that adding a new "digital" feature - aeronautical messaging service - to the legacy analogue system would significantly improve the safety and security of the currently deployed system. This can technically be done without modifying legacy ATC radios by implementing an in-band modem within each existing voice AF (Audio Frequency) channel. The corresponding concept has been called Data in Voice (DiV). The benefits are not expected from the DiV technology itself, but rather from the new applications that become possible with DiV. As an example, the identification of the current user of the communications channel (Talker ID) would immediately improve the system safety. The new messaging service is also capable to provide support for advanced security concepts. As with any other new concept, there are many architectural, procedural and institutional issues to be solved prior to the DiV operational usage. The preliminary tests with the demonstration system are encouraging. As the legacy R/T system - with all its deficiencies - have to remain in use during the next ten years or even longer, the authors propose to the aeronautical community to consider systematic validation of the DiV technology.