On the Vulnerability of Random Access Channels in Aeronautical Communications

Kurzfassung

In the last years, digitization of wireless communications has also reached the field of aviation. Furthermore, unmanned aircraft are entering the skies. The absence of a crew onboard these aircrafts requires a reliable data connection between the remote pilots and the air vehicle to allow a controlled operation under any circumstances. One critical part of all digital communication systems is the initial login of a new user. In many communication systems, also in aviation, this is realized by a Random Access Channel (RACH), that unregistered aircraft can use to inform the base station about their presence. In case the base station never successfully receives a new users registration message on the random access channel, no information exchange between this user and the base station is possible and the new user is never considered for resource assignment. Therefore, the random access channel is an attractive target for an attacker: it is sufficient to only attack the random access channel, a small fraction of the overall communications systems, to disturb communications inside the whole network. In this paper, we analyze the effect several targeted jamming attack on the random access channel can have on the network performance in a terrestrial-based communications system designed for air-ground/ground-air communications in aviation. We show, that pulsed jammers with very low duty cycles can achieve similar jamming performance as simple Continouous Wave (CW) jamming attacks, by outperforming the CW jammers by far in terms of energy efficiency.