report of the action team on global navigation satellite systems (gnss)

include Special Implementation Projects, Technical Co-operation Projects and InternationalFinancial Facility for Aviation Safety. In addition, ICAO is undertaking periodical technical visitsto States, developing regional guidance material and conducting regional workshops.447. Trials are being carried out in <strong>the</strong> Caribbean, South American (CAR/SAM) and African(AFI) regions <strong>of</strong> ICAO at <strong>the</strong> regional and national levels to collect data for <strong>the</strong> definition <strong>of</strong> <strong>the</strong>GNSS architectures in <strong>the</strong>se regions. These trials involve WAAS and EGNOS testbeds in <strong>the</strong>CAR/SAM States and an EGNOS testbed in <strong>the</strong> AFI States.448. The lessons learnt and proposals stemming from <strong>the</strong> experiences gained with GNSSdevelopment and implementation were reviewed by <strong>the</strong> ICAO Eleventh Air NavigationConference (Montreal, Canada, 22 September – 3 October 2003). These concerned a broad range<strong>of</strong> issues, including human resources, regional training capabilities, and <strong>the</strong> need for integration<strong>of</strong> technical co-operation projects and financing aspects. Human resource training and financingissues were <strong>report</strong>ed as major challenges in implementing complex technology systems such asGNSS. The conference encouraged States and service providers that develop and introducesatellite-based augmentation systems to provide <strong>the</strong>ir technical and financial support andparticipation in <strong>the</strong> activities leading to <strong>the</strong> extension <strong>of</strong> <strong>the</strong>ir SBAS service areas intoneighbouring States and regions. States participating in SBAS implementation activities wouldco-ordinate with o<strong>the</strong>r participating States to optimize <strong>the</strong>ir effort, minimize duplication <strong>of</strong>service and facilitate participation <strong>of</strong> service providers.449. The goal <strong>of</strong> transition to GNSS to support aeronautical navigation for all phases <strong>of</strong> flightand remove <strong>the</strong> requirement for conventional ground-based navigation aids is maintained.However, when implementing GNSS-based operations, States are expected to assess <strong>the</strong>likelihood and effects <strong>of</strong> GNSS vulnerabilities in <strong>the</strong>ir airspace and utilize, as necessary, <strong>the</strong>mitigation methods including effective spectrum management and protection <strong>of</strong> GNSSfrequencies, on-board mitigation techniques and terrestrial navigation aids as a back-up during anevolutionary transition to GNSS. Therefore, <strong>the</strong> need for ground-based navigation aids or some <strong>of</strong><strong>the</strong>m will remain during <strong>the</strong> transition until such time when all requirements for safe and costeffectiveoperations using GNSS are met.450. Following a recommendation <strong>of</strong> <strong>the</strong> Worldwide CNS/ATM Systems ImplementationConference (Rio de Janeiro, Brazil, 11 - 15 May 1998), ICAO has addressed <strong>the</strong> issue <strong>of</strong> costallocation amongst all users <strong>of</strong> GNSS.451. The Conference on <strong>the</strong> Economics <strong>of</strong> Airports and Air Navigation Services (Montreal, 19to 28 June 2000) requested ICAO to continue its efforts in this area with a more comprehensivestudy, for which a broad-based coalition <strong>of</strong> civil aviation interests and non-aeronautical userswould need to be established in order to estimate acceptable and equitable cost allocation sharesfor each major user group.452. The “requirements-driven” approach was endorsed as one method that should be takeninto account in <strong>the</strong> fur<strong>the</strong>r work in two areas:• Allocation amongst civil aviation users; and• Allocation between civil aviation and o<strong>the</strong>r users.83