an Entity references as follows:
Aeronautical radionavigation-satellite (short: ARNSS) is – according to Article 1.47 of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as «A radionavigation service in which earth stations are located on board aircraft.» This service is a so-called safety-of-life service, must be protected for Interferences, and is essential part of navigation.