Technical Assistance for Iris Communication Standards Evaluation - University of Salzburg

Status date

Air traffic management via satellite offers many benefits for the future aeronautical communications infrastructure. Satellites can provide seamless and nearly global coverage over land masses, oceans and remote areas. This gives air traffic controllers enhanced possibilities to guide aircraft efficiently even under adverse conditions.

The Future Communications Infrastructure (FCI), initiated by EUROCONTROL and the FAA will be the key enabler for new ATM services and applications that will bring operational benefits in terms of capacity, efficiency and safety. Currently, great effort is taken in order to enable the transition to the FCI, i. e. the paradigm shift from mainly voice-based communications to mainly data-based communications.

The task of the Iris programme is to develop the satellite infrastructure suitable to support the expected data and voice load. In order to dimension this satellite system appropriately, a qualified idea of the magnitude of the communication load is required.

The University of Salzburg assistance to the Iris project focuses on developing as well as simulating models of the air traffic situation with respect to the timeframe of 2013 and 2025. Thus, the resulting information provided will be of essential value for the dimensioning of the satellite communications system.

click for larger image

  • Establish an accurate prediction of air traffic to expect,
  • Determine the data services destined for the Future Radio System (FRS) most suitable for the Iris satellite communications system,
  • Carry out simulations based on the resulting figures of the air traffic estimation simulations as well as the defined data services. As substantial data exchange with an ESA Iris simulator is to be carried out, the exact exchange format has to be specified.,
  • After processing by the Iris simulator, the overall results are evaluated.

The approach taken by University of Salzburg consists of carrying out simulations of future air traffic based on estimations of peak values as well as on actual traffic data. This approach ensures an appropriate degree of accuracy for the estimation of the data volume to expect which will come along with several benefits:

  • Qualified data traffic estimation will prove a high quality basis for decisions on the dimensioning of the Iris satellite system. This, in turn, will lead to a minimization of various kinds of overhead costs and consequently, hold the potential for economic advantage.
  • The Iris satellite system contributes to a great extent to the transition towards data-based communications services in aeronautical communications. The aimed at Future Radio System will mark a key element in the improvements in security, safety and efficiency in the overall aviation industry.

In order to reflect a realistic view of the data traffic to expect in the Future Radio System (FRS) defined in the COCRv2 document, it is not only sufficient to provide accurate estimations of the traffic situation in terms of airborne movements and the distribution of co-ordinating ground-based stations among countries. In fact it is necessary to deeply investigate the interrelations of flight movements and the data and voice communications associated with these.

The following approach was chosen to provide a forecast of the actual workload of the future satellite system:

Based on detailed air traffic predictions, voice and data messages are generated for each aircraft. The COCR defines triggers for each message exchange with regard to the flight phase (departure or arrival), ATC-sector and domain (airport, TMA, en-route, or oceanic/polar/remote). Within phase 1 of the COCR (before the year 2020) a considerable amount of air traffic services are still performed via voice. These voice exchanges are generated for each aircraft according to its flight phase, sector and domain, and are characterized with their duration. In addition to the message duration the position and properties of the concerned aircraft are recorded, too. In phase 2 of the COCR most voice exchanges are replaced by data communication. Analogue to the previous case, each data message is characterized by its size, associated aircraft, and position of generation.

The University of Salzburg simulations thoroughly consider the defined data services and connect them to the flight movements predicted. Using this approach, a realistic view of the data traffic to expect is generated.

click for larger image


The University of Salzburg assistance rendered to ESA consists of several tasks:

  • PIAC Estimation,
  • Information Volume Simulation,
  • Support to Communication Standard Assessment.

The project started in December 2007 and is scheduled for a duration of 9 months.

click for larger image

Current status

The following tasks have been achieved:

  • Estimation of PIAC values,
  • Identification of relevant FRS data services,
  • Specification of a data exchange format ,
  • Completion of the final version of Deliverable 1: PIAC Analysis Report,
  • Completion of the final version of Deliverable 2: Volume Analysis Report ,
  • Completion of the final version of Deliverable 3: Simulation Tool ICD,
  • Extensive generations/simulations of FRS data communications,
  • Statistical evaluation of the simulation results as well as the expected flight movements,
  • Visualization of performance statistics,
  • Evaluation of ICOS and Phoenix projects simulation results.

The project is completed.