International Civil Aviation Organization 5/4/13 WORKING PAPER SATELLITE DISTRIBUTION SYSTEM OPERATIONS GROUP (SADISOPSG) EIGHTEENTH MEETING Dakar, Senegal, 29 to 31 May 2013 Agenda Item 10: Any other business ICAO PROVISIONS RELATING TO WAFS SATELLITE DISTRIBUTION SYSTEMS AND INTERNET-BASED SERVICES (Presented by the Secretary) SUMMARY This working paper invites the group to consider whether amendment to or clarification of references to the world area forecast system (WAFS) satellite distribution systems and Internet-based services is required in ICAO provisions, taking account recent developments (such as the cessation of the ISCS G2 satellite broadcasts) and their intended use in time-critical or nontime critical aeronautical applications. Action by the SADISOPSG is in paragraph 4. 1. INTRODUCTION 1.1 The group will be aware that ICAO Annex 3 Meteorological Service for International Air Navigation provisions ensure that a range of aeronautical meteorological products are made available to the centres designated by regional air navigation agreement for the operation of aeronautical fixed service satellite distribution systems. These provisions, in the form of Standards and Recommended Practices, are intended to ensure the necessary supply of meteorological service to the users listed in Annex 3, 2.1.2. In accordance with regional air navigation agreement, the centres designated to operate the ICAO aeronautical fixed service (AFS) satellite distribution systems are world area forecast centre (WAFC) London and WAFC Washington operating satellite distribution system for information relating to air navigation (SADIS) and international satellite communications system (ISCS) respectively 1. 1 Satellite Distribution System for information relating to air navigation (SADIS) and International Satellite Communication System (ISCS) (5 pages) SADISOPSG.18.WP.027.10.en.docx
- 2-1.2 In the 1990s, the satellite distribution components of the AFS SADIS and ISCS were implemented by the WAFC Provider States (the United Kingdom and United States), providing service to States/users worldwide through the use of three strategically located geostationary satellites overhead the Atlantic Ocean (at 34.5W), the Indian Ocean (at 63E), and the Pacific Ocean (at 177W). Over subsequent years, SADIS and ISCS were enhanced in line with the evolving requirements of users and advances in technology. In more recent years, the Internet-based components of SADIS and ISCS emerged to become operationally-accepted systems implemented by the WAFC Provider States, specifically to provide a backup to the satellite distribution system (SADIS 2G) or, in the case of WAFC Washington, as a replacement to the satellite distribution system (ISCS G2) 2. 1.3 The satellite distribution systems (SADIS 2G and the now decommissioned ISCS G2) and the more recent Internet-based services (Secure SADIS file transfer protocol (FTP) and WIFS 3 ) have fully met the evolving requirements of States/users over the past several decades, harnessing advances in technology in the process. 1.4 In recent years, noting the worldwide advances in Internet capability, including capacity and security, and noting that since 2010 (as part of Amendment 75 to Annex 3) ICAO Contracting States have been permitted to use the public Internet for non-time critical aeronautical applications, many States/users have elected to make sole use of Secure SADIS FTP (in place of using the SADIS 2G satellite broadcast) or, in the case of ISCS, been required to make sole use of the WIFS (due to the withdrawal of ISCS G2 satellite broadcast). 1.5 This working paper invites the group to consider whether amendment to or clarification of references to the world area forecast system (WAFS) satellite distribution systems and Internet-based services is required in ICAO provisions, taking into account the referred recent developments and the intended use of such systems in time-critical or non-time critical aeronautical applications. 2. DISCUSSION ICAO AFS and the public Internet 2.1 The AFS is defined by ICAO as follows: Aeronautical fixed service (AFS). A telecommunication service between specified fixed points provided primarily for the safety of air navigation and for the regular, efficient and economical operation of air services. 2.2 Collectively, SADIS and ISCS were the three AFS satellite distribution systems providing for global coverage used to support the global exchanges of operational meteorological information, conforming to Annex 3 and Annex 10 Aeronautical Telecommunications provisions. 2.3 The group may concur that in view of the decommissioning of the ISCS G2 satellite broadcasts covering the Americas and the Asia/Pacific Region in July 2012, there is now a need to amend Note 1 to Annex 3, 11.1.9, since the three aeronautical fixed service satellite distribution systems are referred as follows: 2 The ISCS G2 satellite broadcast was withdrawn by the WAFC Washington Provider State on 5 July 2012. 3 WAFS Internet File Service (WIFS).
- 3-11.1.9 Recommendation. The telecommunications facilities used for the exchange of operational meteorological information should be the aeronautical fixed service or, for the exchange of non-time critical operational meteorological information, the public Internet, subject to availability, satisfactory operation and bilateral/multilateral and/or regional air navigation agreements. Note 1. Three aeronautical fixed service satellite distribution systems providing for global coverage are used to support the global exchanges of operational meteorological information. Provisions relating to the satellite distribution systems are given in Annex 10, Volume III, Part 1, 10.1 and 10.2. Note 2. Guidance material on non-time-critical operational meteorological information and relevant aspects of the public Internet is provided in the Guidelines on the Use of the Public Internet for Aeronautical Applications (Doc 9855). 2.4 In addition, Annex 3 contains six references 4 to the centres designated by regional air navigation agreement for the operation of aeronautical fixed service satellite distribution systems. The group may concur that there is a need to amend the pluralized reference to systems in Annex 3 and to also ensure that the WAFS Internet-based services that use the infrastructure of the public Internet are appropriately referenced. 2.5 In 2010, Amendment 75 to Annex 3 enabled the operational use of the public Internet in aeronautical (meteorological) applications. More specifically, as of November 2010 it has been permissible to use the public Internet for the exchange of non-time critical meteorological information. While Annex 3 and other Annexes to the Convention on International Civil Aviation do not provide a specific definition for the term public Internet, the Guidelines on the Use of the Public Internet for Aeronautical Applications (ICAO Doc 9855, First Edition, 2005) provides the following description 5 : The word Internet is a contraction of the phrase interconnected network. However, what is commonly referred to and is the subject of this document, i.e. the public Internet (or simply the Internet ), is a loosely organized international collaboration of autonomous interconnected networks that use the Transmission Control Protocol/Internet Protocol (TCP/IP) for inter-networking. [ ] Time-critical versus non-time critical 2.6 Doc 9855 provides guidelines on the use of the public Internet (vis-à-vis the Internet) for non-time critical aeronautical ground-to-ground applications. Doc 9855 determines that non-time-critical means that the messages and/or data that are being communicated have no immediate effect on an active flight. Such non-time critical applications generally involve the dissemination/exchange of information between: a) a State authority and users (within the State); b) two or more State authorities; or c) a third party (usually a commercial entity) and users (in the same or different State(s)). 4 At Annex 3, 3.5.1 c) 3), 3.7 b) 3), Appendix 3, 3.1.1, Appendix 5, 1.6, and Appendix 6, 1.2.2 and 2.2.2. 5 Doc 9855 (First Edition, 2005), Chapter 1 (Background), paragraph 1.1.
- 4-2.7 Meteorological information provided using the infrastructure of the public Internet should not be relied upon for time-critical operational decisions, either in-flight or immediately prior to departure. Meteorological information referred to as time-critical in this context includes SIGMET and AIRMET information, special air-reports, volcanic ash advisories, tropical cyclone advisories and amended aerodrome forecasts (TAF). Where such (Annex 3) products are to be used for time-critical operational decisions, they should be disseminated and sourced via the AFS including the aeronautical fixed telecommunication network (AFTN) since the characteristics of the AFS will ensure that the messages are received in a timely manner. a) owing to the dependence of Secure SADIS FTP and WIFS on the infrastructure of the public Internet, the (Annex 3) products made available and sourced from these services should only be used for non-time critical aeronautical applications. Moreover, as detailed in Doc 9855, 4.3.2, the services for operators and flight crew members for pre-flight planning under centralized operational control are considered non-time-critical. Meteorological information for pre-flight planning by operators includes: current and forecast upper winds, upper-air temperatures, tropopause heights, geopotential heights and maximum wind information and amendments thereto; b) existing and expected significant en-route weather phenomena and jetstream information and amendments thereto; c) forecast for take-off; d) METAR and, where available, SPECI for the aerodrome of departure, take-off and en-route alternate aerodromes, the aerodrome of intended landing and destination alternate aerodromes, as determined by regional air navigation agreement; e) TAF and amendments thereto for the aerodrome of departure and intended landing, and for take-off, en-route and destination alternate aerodromes, as determined by regional air navigation agreement; and f) SIGMET information and appropriate special air-reports relevant to the whole of the routes concerned, as determined by regional air navigation agreement. As the group will appreciate, with the exception of item c) above, all of the referred products are made available on Secure SADIS FTP and WIFS, as well as the SADIS 2G satellite broadcast. Therefore, when sourced from the WAFS Internet-based services and used in a pre-flight planning context, the referred meteorological information is considered non-time critical. 2.8 In respect of the WAFS Internet-based services (Secure SADIS FTP and WIFS), since the Internet cannot be assured for the provision of information for time-critical operational decisions, the services cannot be considered as part of the AFS. Instead, they are considered as part of the public Internet and can only be used for non-time critical aeronautical applications (e.g. pre-flight planning) in accordance with the guidelines contained in Doc 9855.
- 5-3. CONCLUSION 3.1 In view of the foregoing, the group may wish to formulate the following conclusion: Conclusion 18/xx Description of the WAFS satellite distribution systems and Internet-based services in Annex 3 That, the Secretariat develop, through the World Area Forecast System Operations Group (WAFSOPSG), a draft amendment proposal to Annex 3 Meteorological Service for International Air Navigation, to appropriately reference to the one remaining WAFS satellite distribution system and the two existing WAFS Internet-based services provided by the WAFC Provider States. Note. Specific attention should be paid to Annex 3, 3.5.1 c) 3), 3.7 b) 3), Note 1 to 11.1.19, Appendix 3, 3.1.1, Appendix 5, 1.6, and Appendix 6, 1.2.2 and 2.2.2. 4. ACTION BY THE SADISOPSG 4.1 The SADISOPSG is invited to: a) note the information contained in this paper; and b) decide on the conclusion proposed for the group's consideration. END