Reliability of ADS-B communications

Abstract

The Automatic Dependent Surveillance - Broadcast (ADS-B) technology promises to enhance the safety of civil avionics by diffusing flight data in a more efficient, timely, and easy to access fashion. Moreover, its adoption is mandatory by 2020. However, the quality of the communication is not completely satisfactory. Indeed, packets are lost for a number of reasons, such as obstacles, weather conditions, and by the fact that the frequency band on which ADS-B is intended to work in is the same shared by other legacy communication technologies used by the aircraft. Leveraging some previous work in the area providing preliminary study of packet loss issues in this specific context, in this paper we analyze the Opensky-network public database to provide more hints and real statistics on both the packet loss characterizing aircraft communications and the overall reliability of the ADS-B technology. Analyzing more than 21 GB of real aircraft-generated traces, we show that models introduced in the last years have severe limitations. This is imputable to several reasons, including the increased throughput and density of the network, as well as --- as discovered by our analysis --- that there is a not negligible portion of ADS-B implementations that do not follow the standard recommendation. Overall, this contribution intends to: (i) shed some lights on the current gap in the literature; (ii) provide a new, updated packet loss model for ADS-B communications; and, (iii) motivate further research efforts in the field, toward a precise characterization of the reliability of aircraft communications.