12/2/03 AERONAUTICAL MOBILE COMMUNICATIONS PANEL (AMCP) EIGHTH MEETING Montreal, 4 to 13 February 2003 AGENDA ITEM 5 The attached constitutes the report on Agenda Item 5 and should be inserted at the appropriate place in the yellow report folder. (10 pages)
Report on Agenda Item 5 5-1 Agenda Item 5: Review of existing ICAO material on air/ground communication systems 5.1 INTRODUCTION 5.1.1 Under this agenda item, the meeting reviewed the report of the activities of Working Group M since AMCP/7. The activities of Working Group M included the review of Standards and Recommended Practices (SARPs) and guidance material (incorporated in various ICAO Manuals) for the aeronautical mobile satellite service (AMSS), high frequency data link (HFDL), very high frequency (VHF) digital link (VDL) Mode 2, VDL Mode 3 and VDL Mode 4. In addition, the working group considered liaison statements from Working Group C on automatic dependent surveillance broadcast (ADS-B), and from the Aeronautical Telecommunication Network Panel (ATNP) on communication priorities. The working group also studied aspects related to the introduction of 8.33 khz channel spacing in Europe. 5.1.2 The working group held six meetings since AMCP/7: a) 12-19 December 2000, Malmo, Sweden; b) 25 April - 3 May, Jarvenpaa, Finland; c) 10-18 December 2001, Tianjin, China; d) 6-15 March 2002, Brussels, Belgium; e) 19-23 August, St. Petersburg, Russia; and f) 12-18 December 2002, Montreal, Canada. 5.1.3 The Rapporteur of Working Group M was Mr. L. Jónasson from Iceland. 5.1.4 Also the activities of Working Group B since AMCP/7 were considered under this agenda item. These activities included the development of test procedures in order to establish the protection requirements for the various systems in the VHF-band, a definition of the test parameters to be used in the test procedures and the development of geographical separation criteria on the basis of an agreed propagation model. 5.1.5 The working group held the following meetings: a) 1-13 July 2000, Bretigny, France; b) 16-23 January 2001, San Diego, United States; c) 29 August - 7 September 2001, Montreal, Canada; d) 6-8 March 2002, Brussels, Belgium; e) 26-30 August 2002, St. Petersburg, Russia; and f) 13-17 January 2003, Montreal, Canada.
5-2 Report on Agenda Item 5 5.1.6 The Rapporteur of the working group was Mr. John Mettrop from the United Kingdom. 5.2 AERONAUTICAL MOBILE SATELLITE SERVICE 5.2.1 The meeting agreed to the feasibility and the need of splitting the current AMSS SARPs (Annex 10, Volume III, Part I, Chapter 4), which contain typical core SARPs material and detailed technical specifications. The core SARPs section shall remain in Annex 10. The detailed technical specifications should be deleted from Annex 10 and be included in a Manual on detailed technical specification for AMSS. This activity should include consideration of the incorporation into this material of the alternative provisions for the aeronautical mobile satellite (R) service as agreed at AMCP/7, following the guidelines to ANC panels for the development of SARPs material. The meeting therefore developed the following recommendation: Recommendation 5/1 Reorganization of SARPs for AMSS That AMCP develops proposals for: a) the reorganization of the SARPs for AMSS (Annex 10, Volume III, Chapter 4) into a core section and a section containing detailed technical specifications, as required in the Guidelines for ANC Panels for the development of SARPs material ; and b) the incorporation of alternative provisions for the aeronautical mobile satellite (R) service as contained in Appendices A and B to the reports on Agenda Item 3 of AMCP/7. 5.2.2 The meeting noted that this task should not include any substantial change to the current AMSS SARPs and detailed technical specifications and clarified that geostationary AMSS systems need to comply with either the current SARPs or the alternative provisions for the aeronautical mobile satellite service. 5.2.3 The meeting considered proposed amendments to the AMSS SARPs on: a) aircraft earth station receiver interference susceptibility; b) the maximum harmonic, discrete spurious and noise density levels; c) the maximum intermodulation product levels (Tables 4.3 and 4.3bis of the AMSS SARPs); and d) the data terminal equipment (DTE) effect on DCE restart rates and the DTE effect on DCE flow control transfer rates (Tables 4-30 and 4-43 of the AMSS SARPs. 5.2.3.1 The meeting could not agree to the amendments under b) and c) above since these would not provide the required protection of GLObal NAvigation Satellite System (GLONASS) receivers. The meeting, further considering that the amendments under d) above address material that would be transferred to the AMSS Manual on detailed technical specifications, referred these proposal back to WG-M for further consideration.
Report on Agenda Item 5 5-3 5.3 RADIOTELEPHONY PROCEDURES 5.3.1 The meeting reviewed a report on the work conducted by Working Group C on potential amendments to Annex 10 radiotelephony procedures following the introduction of AMS(R)S and other digital voice communication systems. 5.3.2 Working Group C had reached the conclusion that no immediate requirements arose to amend Annex 10 radiotelephony procedures and that therefore the WG-C activity referred to in AMCP/7 Report, paragraph 7.3.1.1 g) had been completed. Working Group C, however, concluded that the Manual of Radiotelephony (Doc 9432) would need to be reviewed and possibly updated, and recognized that updates of the manual required air traffic management (ATM) operational expertise. 5.3.3 The meeting was informed that the Secretary had brought the need for the review to the attention of the appropriate operational entity within ICAO (the ATM Section), for consideration in the framework of ongoing work on update of guidance material on radiotelephony. 5.3.4 The outcome of the consultation, as reported to the meeting by the Secretariat, indicated that it might be premature to conclude that no modification to radiotelephony procedures would be necessary to support satellite voice communication. In particular, it was recognized that the experience gained so far in the use of satellite communications for non-routine and emergency situations was limited, and that work was ongoing in some States to investigate how satellite communications can best be integrated into the overall communications infrastructure. 5.3.5 On the basis of the information provided to the meeting, the panel concluded that, while there was no immediate requirement for direct involvement by AMCP, potential requirement for amendments to radiotelephony procedures should be monitored by appropriate ICAO bodies and further AMCP activities might be required in the future. 5.4 HIGH FREQUENCY DATA LINK (HFDL) 5.4.1 The meeting reviewed proposals for amending the SARPs for HFDL, addressing the signal-in-space specifications of the radio-frequency signal. These amendments are editorial in nature and bring the SARPs in line with the relevant provisions of the International Telecommunication Union (ITU) Radio Regulations (Appendix 27 to the Radio Regulations). The meeting agreed to these amendments, which are contained in Appendix A. 5.4.2 Accordingly, the meeting developed the following recommendation: RSPP Recommendation 5/2 Amendment to Annex 10, Volume III, Part I, HF data link That Annex 10, Volume III, Part I, Chapter 11, be amended as shown in Appendix A to the Report on Agenda Item 5.
5-4 Report on Agenda Item 5 5.4.3 In addition proposals for amending the Manual on HFDL (Doc 9741) were discussed. These amendments are the results of the ongoing implementation of HFDL. These are contained in Appendix B and the meeting developed the following recommendation: Recommendation 5/3 Amendment to the Manual on HF data link (Doc 9741) That the Manual on HF data link (Doc 9741) be amended as shown in Appendix B to the Report on Agenda Item 5. 5.4.4 The meeting was informed that, pending the publication of the amendments to Doc 9741 these amendments will be made available in a special section on the AMCP website so as to allow the industry to closely follow that latest developments. The meeting noted that the SARPs and the Manual for HFDL are now complete and any future amendments are expected to be very minor in nature. 5.5 VHF DIGITAL LINK (VDL) MODE 2 5.5.1 The meeting reviewed and agreed to proposed amendments to the Manual on the VHF digital link (VDL) Mode 2 (Doc 9776). These amendments are the result of operational experience gained when implementing VDL Mode 2 in Asia, Europe and North-America. These amendments are contained in Appendix C. Accordingly, the meeting developed the following recommendation: Recommendation 5/4 Amendment to the Manual on VDL Mode 2 (Doc 9776) That the Manual on VDL Mode 2 (Doc 9776) be amended as shown in Appendix C to the Report on Agenda Item 5. 5.5.2 The meeting noted that further work in Working Group M is ongoing on additional amendments. The meeting was informed that, pending the publication of the amendments to Doc 9776 these amendments will be made available in a special section on the AMCP website so as to allow the industry to closely follow that latest developments. The Manual for VDL Mode 2 is now relatively complete and it is expected that future amendments are expected to be minor in nature. 5.6 VDL MODE 3 5.6.1 The meeting reviewed and agreed to proposed amendments to the Manual on the VHF digital link (VDL) Mode 3 (Doc 9805). These amendments are the result of ongoing testing and implementation of VDL Mode 3 in the United States and are contained in Appendix D. Accordingly the meeting developed the following Recommendation:
Report on Agenda Item 5 5-5 Recommendation 5/5 Amendment to the Manual on VDL Mode 3 (Doc 9805) That the Manual on VDL Mode 3 (Doc 9805) be amended as shown in Appendix D to the Report on Agenda Item 5. 5.6.2 The meeting noted that further work in Working Group M is ongoing on additional amendments. The meeting was informed that, pending the publication of the amendments to Doc 9805 these amendments will be made available in a special section on the AMCP website so as to allow the industry to closely follow that latest developments. Further amendments to the manual are expected. 5.7 VDL MODE 4 5.7.1 The Manual on VDL Mode 4 was agreed at AMCP/7 but has not yet been published by ICAO. Amendments to this manual were considered by the meeting. These amendments include the introduction of a new data link service (DLS) protocol, which was necessary in order to correct errors, inconsistencies and inefficiencies in the current protocol and also improves the performance of VDL Mode 4. Also, as an editorial matter, references to material in the VDL Mode 2 manual were replaced with the full text of these references in order to make the manual self-contained. The amendments were validated according to the agreed validation plan and have been carried out by inspection and simulation. The meeting noted that further validation based on actual testing of equipment needs to be undertaken. Working Group M will consider the results of this further validation work. The amendments to the VDL Mode 4 Manual (Implementation Aspects and Detailed Technical Specifications) are contained in Appendices E and F respectively. The results of the validation activities are contained in Appendix G. Accordingly, the meeting developed the following recommendation: Recommendation 5/6 Amendment to the Manual on VDL Mode 4 That the Manual on VDL Mode 4 be amended as shown in Appendices E and F to the Report on Agenda Item 5. 5.7.2 With regard to the validation report, as contained in Appendix G, some members could not agree to the validation activities being completed without any flight testing. In this connection, the meeting recalled that AMCP/4, when recommending the inclusion in Annex 10 of VDL SARPs for VDL Mode 1 and Mode 2, had recognized that some further testing, including flight trials, was still ongoing and expected to be completed only five months after the end of the meeting. It was also recalled that when AMCP/7 had recommended the publication by ICAO of a Manual on VDL Mode 3, it had recognized that validation of some elements of those specifications could only be completed after implementation of the system. Subsequent work within AMCP had then led to extensive changes to the original material (including but not limited to those referred to in Section 5.6). The meeting recognized that a number of changes was virtually inevitable in the case of detailed technical specifications for complex systems subject to ongoing testing and implementation. 5.7.2.1 After a long discussion on this issue, the meeting decided to agree that the validation report could be accepted as complete under the following conditions: a) flight testing on the use of VDL Mode 4 as an ATN compatible air/ground data link should be completed by 20 March 2003;
5-6 Report on Agenda Item 5 b) WG-M will consider the results of the flight testing in the period 7-11 April 2003; c) the results of the WG-M review will be communicated to all panel members by 11 April 2003; and d) the Commission will consider the report of AMCP/8 after 22 April 2003 and will be informed on the results of the flight testing validation work. 5.7.2.2 Some members opposed this course of action and would have preferred to re-consider the validation activities after the results of the flight testing are available. 5.7.3 The meeting noted that further work in Working Group M is ongoing on additional amendments. The meeting was informed that it is expected that the Manual on VDL Mode 4 will be published during the second quarter of 2003. Pending the publication of this manual, the amendments will be made available in a special section on the AMCP website so as to allow the industry to closely follow that latest developments. 5.7.4 The meeting reviewed an analysis of compliance of VDL Mode 4 with generic data link requirements and desirable features, which were developed at the Special Communications/Operations Divisional Meeting (SP COM/OPS 95) in 1995 and amended at AMCP/4 in 1996. The analysis demonstrated that VDL Mode 4 data link could meet these requirements and desirable features. In addition, a comparative analysis of VHF data links (VDL Mode 2, Mode 3 and Mode 4) was considered which concluded that both VDL Mode 3 and Mode 4 could meet the future requirements for generic air-ground data transmission. 5.7.4.1 However, it was concluded that VDL Mode 4 would not offer any additional benefits over those requirements already satisfied by VDL Mode 3 and that using VDL Mode 4 as a communications data link would further proliferate VHF data links and would not follow the direction given by the SP COM/OPS 95 where the VDL Mode 3 system was considered as the data link that would provide long term improvements. 5.7.4.2 The meeting further considered a number of concerns that need to be addressed to update and validate the technical material for VDL Mode 4, as necessary. A number of future work items, are contained in Appendix H and will be further addressed by WG-M. 5.7.5 The meeting agreed to the future use of VDL Mode 4 as a communication data link, on the understanding that these concerns shall be addressed satisfactorily. 5.7.6 The amendments necessary to Annex 10 in relation to this development are contained in Appendix I (See also Recommendation 5/7 on the amendments to notes in Annex on the use of VDL Mode 4 as ADS data link). 5.7.7 In the ensuing discussions on this matter, the meeting addressed the urgency of guidance for ICAO on steps to be taken to avoid further proliferation of data links and possibly, in the future reduce the number of data links in order to ensure global implementation of an interoperable system. It was suggested that the 11th Air Navigation Conference could provide such guidance. 5.7.8 The meeting noted that further guidance was needed on the steps to be undertaken in the validation activities. The Secretary would inform the panel members on any work on this that was already completed in AMCP.
Report on Agenda Item 5 5-7 5.8 TECHNICAL ISSUES RELATING TO 8.33 KHZ CHANNEL SPACING AND VDL MODE 3 5.8.1 The meeting discussed the listen before push to talk principle that is part of the VDL Mode 3 design. An override or anti-blocking feature is not deemed to be appropriate. Rather, when an aircraft must establish an emergency or distress communication link, this will be accomplished through priority management by the ground system. A link will then be established when the appropriate channel becomes free. 5.8.2 The meeting further discussed the inconsistent use of the words frequency and channel in the SARPs for VDL Mode 3 and 8.33 khz DSB-AM. The meeting noted that such confusion can arise from the current radiotelephony procedures, and that EUROCONTROL is studying this aspect. 5.9 FM BROADCAST IMMUNITY FOR VDL MODE 4 WHEN OPERATING IN THE BAND 108-117.975 MHZ 5.9.1 Proposals for amending Annex 10, Volume II, Part I, Chapter 6 (VDL Mode 4) to include FM immunity characteristics for VDL Mode 4 were agreed. These amendments are contained in Appendix I. Introduction of this material is necessary inn the light of the expected amendment to the ITU Radio Regulations at the ITU World Radiocommunication Conference that will be held in June/July 2003 where the band 108-117.957 MHz could be made available for data link systems providing air navigation and surveillance functions. These amendments are confirming that introduction of VDL Mode 4 will not place additional constraints on the FM broadcasting service and are similar as the relevant provision for GBAS. 5.9.2 Further work on potential interference from VDL Mode 4 into FM broadcasting is ongoing. WG-F will develop relevant material for ITU meeting. 5.9.3 Accordingly, the meeting developed the following recommendation: RSPP Recommendation 5/7 FM immunity characteristics for VDL Mode 4 That Annex 10 Volume III, Part I, Chapter 6, be amended as shown in Appendix I to include FM immunity characteristics for VDL Mode 4 and amend notes on the use of VDL Mode 4 as ADS data link. Note. See also paragraph 5.7.5. 5.10 FREQUENCY ASSIGNMENT PLANNING CRITERIA FOR VDL 5.10.1 The meeting reviewed the development of frequency assignment planning criteria for VDL Mode 2, Mode 3 and Mode 4. The meeting agreed to the assignment planning criteria for VDL Mode 2 as contained in Appendix J, and considered them as complete. Appendix J also contains signal parameters and testing principles. It was agreed to incorporate these criteria in the Manual on VDL Mode 2 (Doc 9776). Further work on frequency assignment planning criteria for VDL Modes 3 and 4 is necessary.
5-8 Report on Agenda Item 5 5.10.2 With regard to the frequency assignment planning criteria for VDL Mode 2, the meeting developed the following recommendation: Recommendation 5/8 Frequency assignment planning criteria for VDL Mode 2 That ICAO publishes in the Manual on VDL Mode 2 the frequency assignment planning criteria for VDL Mode 2, as contained in Appendix J to the Report on Agenda Item 5. Mode 2. Note. This recommendation refers only to the elements of Appendix J dealing with VDL