The long-term growth of air traffic requires integrated audio and data services to improve the support of air traffic controllers in maintaining safety despite increased capacity. The use of an IP (Internet Protocol) based network for voice and data communication will ease this integration but on the other hand causes new challenges when facing the characteristics of packet based networks.

The presented software architecture combines audio services with basic data services and offers interfaces to integrate them with other air traffic control systems. Air traffic control uses radio based air/ground communication. We use the session initiation protocol (SIP) for setting up audio sessions and the SIP specific event notification to control radios. We implemented a prototype to measure notification delays. Compared with air traffic control requirements the concept is proven in general, but implementation details have to be improved to reach the performance requirements for large systems.