Most Probable Satellite Communications Operating Concept for ECAC and other regions of the world

1. Most Probable Satellite Communications Operating Concept for ECAC and other regions of the world Presented by Philippe Renaud Prepared by Phil Platt ICAO AMCP WG-C 27-30 May 2002

2. European Civil Aviation Conference (ECAC) Member States

3. Communications Problems • In certain parts of the world (e.g. Europe) air traffic growth will outstrip communication resource in the VHF band. • New technologies are being considered in the timeframe of 2010-2015 to complement VHF systems • Satellite communications could be a possibility but only with improved performance over current AMSS • A lower cost satellite communication system would benefit many other areas of the world too

4. Predicted Traffic growth in Europe

5. Worldwide air traffic

6. Inmarsat Global beams

7. MTSAT - Japan

8. European spot beam

9. Limitation of current AMSS • Designed to meet full range of users leading to more complex system design • Shared use of spectrum between safety and non-safety services • Cost of aircraft installation and avionics • Large GESs leading limited options for communications service provision • Quality of communication service - transfer delays • Communication costs

10. A new satellite system ? • Oh no not more technology ! • Haven’t we got enough satellite communications systems e.g. • Inmarsat Aero systems H, H+, I, L, C, Mini-Aero, Swift64 • MTSAT (Japan) • Boeing Connexion • Iridium • Globalstar • ……….

11. Safety related communications • Yes there are many satellite technologies around but they are designed to support shared use • Some support AAC, APC - some may support AOC and ATSC (e.g. Aero H) • No system supports only AMS(R)S • Previous experience has shown that reliance on a shared business case can cause problems • Where safety and regularity of flight communications are to be carried by a communications system specific measures must be put in place to safeguard them

12. Requirements • High levels of availability, reliability and continuity required for safety and regularity of flight communication • ATS • Voice • Data • AOC • Voice • Data • Ranked on priority basis

13. ATSC Voice • ATSC voice is main form for executive control today • There will be increased use of data link in the future but voice will be required at least in the foreseeable future • ATSC use of data link requires new investment in ATS system on ground - voice is already there. • VHF RT is the main means of communications in higher density airspace where there is a ground infrastructure

14. ATC Communications Management Service (ACM) Departure Clearance Service (DCL) ATC Clearances and Information Service (ACL) Controller Access Parameters Service (CAP) Downstream Clearances Service (DSC) Pilot Preferences Downlink Service (PPD) Flight Plan Consistency Service (FLIPCY) Dynamic Route Availability Service (DYNAV) Dynamic Route Availability Service (DYNAV) Data Link Operational Terminal Information Service (D-OTIS) Data Link Runway Visual Range (D-RVR) Data Link Logon (DLL) Common Trajectory Co-ordination (COTRAC) Data Link SIGMET Service (D-SIGMET) System Access Parameters Service (SAP) ATS Data Link Services

15. AOC Applications • Voice • assumed to be continued to be required although expected to decline • Data Link • Flight Operations - a few examples of safety and regularity of flight applications • Access to Flight Information services (Weather, NOTAM…) • Weight & Balance • Performance Data • Maintenance • Aircraft condition monitoring

16. New Satellite System (1/2) • Desirable Features • Those identified in NGSS SARPs including • Tailored requirements - safety and regularity traffic only i.e. priority 1 to 6 in Article 44 • dedicated AMS(R)S spectrum • Replicate and improve on existing systems • Voice - VHF RT like with party-line and quick access • Data - point-to-point and broadcast • Optimised channels • tailored to meet the AMS(R)S requirement only until at least 2020 and possibly longer • Designed to provide required level of performance • use redundancy in critical communications path

17. New Satellite System (2/2) • Desirable Features • Ground Earth Station • able to reuse existing AMSS infrastructure wherever possible • allows possibility to use GESs with smaller antennas • greater flexiblity in deployment e.g. at ATCC or airline sites • Aircraft Earth Station • smaller due to limited design goal • low power, cheaper • Spectrum Efficiency • maximise frequency reuse • specific protocol to carry short frequent data • efficient mapping of user data to satellite physical link

18. Satellite Data Link System • SDLS is attempting to meet the desirable features • a tool-box of good ideas • can pick any or all of the tools to for a new system • ESA has sponsored a considerable amount of design effort to match technology with perceived requirements • a lot of work by satellite system manufacturers • contribution to the input to a possible open standard for aviation use • Development of a ‘ demonstrator ’ underway

19. Key features of SDLS (1/2) • Multiple Access Scheme • Synchronous CDMA in the fixed to mobile direction • Quasi Synchronous CDMA in the mobile to fixed direction • Aircraft Earth Stations • New CDMA modems being developed • Low cost solutions • Space Segment • MSS geostationary satellites at L-Band have already been deployed worldwide and hence are fundemental building block • Ground Earth Stations • Ku or C-Band depending on satellite feeder links

20. Key features of SDLS (2/2) • Services • Voice service (point to point and “Party Line”)  • Data service including broadcast and polled • Network Architecture • Capability for decentralised satellite access • Satellite Diversity • Asumed to be required to meet availability requirements • Equipment Redundancy • For both airborne and ground is part of the design • Communication Resource Management • Fixed and demand assignment, handling of priority levels

21. Ground Earth Stations • Two main types of feeder links • C-band • currently used by Inmarsat GESs on global and spot beams. Requires large antennas but the infrastructure is there and will be for the foreseeable future to support maritime services • Ku-band • allows the use of smaller (cheaper) GESs. Could be deployed at or near ATC centres or airline operational control centre • Ku-band is more subject to atmospheric disturbance than C-band - has to be taken into account in design • Only Ku-Band VSATs practically allow highly decentralised access

22. CDMA channel structure Up to 255 CDMA channels per subband

23. Satellite Protocols • Reuse features of AMSS e.g. • Reliable Link- type service • AMSS strategy for priority, reference number… • Data rate determined by type of satellite beam size • Minimum data rate in global beam • Basic channel rate is 6.8kbps - in global beam (determined by vocoder) • Short message data throughput is 1.35kbps • Long message data throughput is 2.4kbps • Spot beams increases rate at least 4 times. • Broadcast capability - ground to air

24. Voice service • Vocoder rate of 4.8kbps - may be the same as AMSS • Full duplex circuit mode service for ‘normal’ use • suitable for AOC and some ATS applications • Special feature to emulate ATS RT • ‘party-line’ feature - allows rebroadcast of messages to other aircraft • requires dedicated channel per sector • synchronous CDMA - no signal acquisition time

25. Satellite diversity • Satellite diversity could be required due to - • shielding of the aircraft antenna by the structure of the aircraft • failure of the satellite system • This requires on the ground - • one antenna for each satellite in view by the GES, • one spare GES antenna to ensure the reliability • Pre-assigned spectrum for each satellites

26. Satellite diversity

27. Aircraft Earth Stations • Simple and cheap • isotropic antenna • low RF power - no forced air cooling requirements • single transmit channel per AES • need 2 AESs per aircraft to achieve redundancy requirements • Direct data inputs for Polling Services e.g. A429 • Interfaces to CMU/ATSU and voice distribution system

28. Aircraft Installation

29. Initial Deployment in ECAC

30. Ground architecture

31. Other deployment options • Whilst a solution based on global beams is a practical early solution (maybe preferred in ECAC area), other options are possible • Incremental flexible deployment can be provided through the use of spot beams where required • This could be an attractive first step in some areas of the world e.g. where there is not a well developed terrestrial infrastructure

32. Later deployment in ECAC

33. Ground Architecture

34. SDLS Demonstration Programme • SDLS Programme Phases • Key system performance demonstrator with AESs on ground (on-going with targeted completion third quarter 2002) • 2 AESs • 2 GESs - Ku band • ATS/AOC application emulation • EMS satellite • Evaluation with airborne avionics and the participation of ATSPs and airlines is in the planning stage

35. Institutional aspects • Standardisation • new satellite systems capability needs to be standardised for worldwide operation • confirm that NGSS SARPS are appropriate - seem so at initial review • Access control to space segment - who, how ? • Use of AMS(R)S spectrum with many service providers • GES operators • detailed technical standards • co-ordination between them e.g. use of codes, hand-overs, etc

36. Business Issues • Technically SDLS looks possible but there is a need to clarify business drivers • Targeted at AMS(R)S therefore has to be paid by ATSPs and airlines only e.g. no APC traffic • However it is not vulnerable to market failure • Benefits must come from cost saving • ‘do nothing’ cases must be considered • compare technology solutions • Cost must be minimised

37. Issues for further consideration • Data rate • Lowest rate assumed acceptable - need to confirm (e.g. AOC) • Use of Polling Service • How is it used in practice ? Who controls the service and shares the data ? • Efficient use of satellite physical link • need optimise the mapping of user data onto RF link • ATSC voice service • design of human interface for access • party line acceptance

38. Conclusions (1/3) • Satellite based communication system have advantages for aviation • wide coverage capability • could overcome need for terrestrial infrastructure development in some areas of the world • traditionally thought of as oceanic and remote areas only but with improved performance and lower cost can be considered for higher density airspace • Advanced design concepts seem to show that higher service quality levels than AMSS are achievable with proven technology • can draw on AMSS experience and institutional arrangements • ability to enable new service provision possibilities

39. Conclusions (2/3) • Technical design concepts are well advanced in SDLS but still open to refinement • Finalisation of design in consultation with aviation community • Institutional arrangements • standards development - SARPS, MASPS, MOPS, etc • can draw on NGSS work already undertaken • Business case • costs should be lower due to specific AMS(R)S goal • better define the benefits including ‘do nothing ’ option

40. Conclusions (3/3) • Recommendation on next steps in WG-C • Contribute to the production of a global operating concept to augment the ECAC Operational Concept • Contribute to the development of a design definition document • To liaise with AMCP WG-F to ensure the availability of adequate AMS(R)S spectrum • Address in due time the development of a Manual