RES426 – 325 – noting that the concept of operations and requirements for GADSS is general, its components and applications currently provide only scenarios, and it is being developed in an evolutionary manner in ICAO, resolves to invite the 2019 World Radiocommunication Conference 1 to take appropriate actions, taking into account the results of ITU-R studies; 2 to analyse the necessity for further studies, and consider whether this matter should be brought to the attention of a future competent conference, invites ITU-R 1 to conduct the relevant studies, taking into account information and requirements provided by ICAO for both the terrestrial and satellite components, including: a) quantification and characterization of radiocommunication requirements related to GADSS, such as: – data traffic requirements for different system components of GADSS (such as the aircraft tracking, autonomous distress and flight data recovery systems) and their terrestrial and satellite components at each phase of the operation; – information on the radiocommunication requirement related to safety-of-life applications; – performance criteria for terrestrial and satellite systems; b) analysis of the existing allocations to the relevant aeronautical services and determining whether any additional spectrum is required; c) studies on sharing and/or compatibility with the existing services; 2 to undertake studies of the existing regulatory provisions to determine whether it might be necessary to apply additional regulatory measures, invites the International Civil Aviation Organization to participate actively in the studies by providing requirements and information that should be taken into account in ITU-R studies, in particular those mentioned in invites ITU-R 1a), instructs the Secretary-General to bring this Resolution to the attention of the ICAO, the International Air Transport Association (IATA) and the International Maritime Organization (IMO).