amcp wg c2 wp 21 7 to 11 may 2001 icao/amcp wg c 2nd meeting 1 satellite data link system (sdls) a...

7 to 11 May 20017 to 11 May 2001ICAO/AMCP WG C 2ndICAO/AMCP WG C 2nd meeting meeting

11AMCP WG C2 WP 21AMCP WG C2 WP 21

SATELLITE DATA LINK SYSTEMSATELLITE DATA LINK SYSTEM(SDLS)(SDLS)

A DEDICATED MOBILE SATELLITE A DEDICATED MOBILE SATELLITE COMMUNICATION SYSTEM COMMUNICATION SYSTEM

RESPONDING TO THE HIGHLY RESPONDING TO THE HIGHLY DEMANDING REQUIREMENTS OF DEMANDING REQUIREMENTS OF

CIVIL AVIATION CIVIL AVIATION

Claude Loisy Claude Loisy

European Space Agency (ESA)European Space Agency (ESA)

7 to 11 May 20017 to 11 May 2001ICAO/AMCP WG C 2nd meetiICAO/AMCP WG C 2nd meetingng


Satellite Data Link SystemSatellite Data Link System



The Air/Ground Communications of Civil AviationThe Air/Ground Communications of Civil Aviation

Two Categories of CommunicationsTwo Categories of Communications Safety related : ATS (Air Traffic Services) Safety related : ATS (Air Traffic Services)

AOC (Airline Operational Communications)AOC (Airline Operational Communications) Non Safety related : AAC and APC (passenger communication)Non Safety related : AAC and APC (passenger communication)

Technical Requirements for Safety Related Technical Requirements for Safety Related Specified by Specified by ICAOICAO (SARPs) (SARPs) Mandated by Mandated by StatesStates to Air Transport to Air Transport

Communication Systems Deployed at PresentCommunication Systems Deployed at Present Terrestrial Terrestrial “VHF”“VHF” : generally available in continental airspace : generally available in continental airspace Terrestrial Terrestrial “HF”“HF” : low capacity, slow response but worldwide coverage : low capacity, slow response but worldwide coverage Satellite Satellite “AMSS” “AMSS” : costly and deployed on only 2000 aircraft: costly and deployed on only 2000 aircraft



Meeting the Future Capacity Requirements of Safety Meeting the Future Capacity Requirements of Safety CommunicationsCommunications

Required Capacity is Steadily Required Capacity is Steadily IncreasingIncreasing Air Traffic volume displays an almost constantly Air Traffic volume displays an almost constantly expandingexpanding trend trend Anticipated reduction in aircraft geometrical separations will induce an Anticipated reduction in aircraft geometrical separations will induce an increaseincrease

in tactical exchanges and the per aircraft communication trafficin tactical exchanges and the per aircraft communication traffic

The VHF Aero Band is Nearing The VHF Aero Band is Nearing SaturationSaturation Frequency Re-use is severely limited by network Frequency Re-use is severely limited by network geometrygeometry Recent Introduction of higher efficiency modulation techniques for voice (Recent Introduction of higher efficiency modulation techniques for voice (8.33 8.33

KHz KHz instead of 25 KHz channels) is buying some extra timeinstead of 25 KHz channels) is buying some extra time Introduction of data services will initially increase spectrum demandIntroduction of data services will initially increase spectrum demand

Introduction of a Introduction of a new systemnew system is being studied is being studied SatelliteSatellite is among the options under consideration is among the options under consideration


55AMCP WG C2 WP 21AMCP WG C2 WP 21 ICAO Requirement Summary for theICAO Requirement Summary for theNext Generation Satellite SystemNext Generation Satellite System

Geographical CoverageGeographical Coverage WorldwideWorldwide coverage is needed coverage is needed Two types of scenario:Two types of scenario:

LEO or MEO constellationLEO or MEO constellation Interoperable GEO based networksInteroperable GEO based networks

Continuity of Service ProvisionContinuity of Service Provision Users expect high continuity based on a Users expect high continuity based on a stable technical standardstable technical standard Avionics lifetime should by far exceed that of aircraft Avionics lifetime should by far exceed that of aircraft (no retrofits)(no retrofits)

Services and Associated PerformancesServices and Associated Performances Voice and/or DataVoice and/or Data Fast response and high availabilityFast response and high availability

Affordable CostsAffordable Costs



SDLS Main System OptionsSDLS Main System Options

Safety Communication Safety Communication Dedicated SystemDedicated System Allows stable and Allows stable and less challengedless challenged access to radio frequency spectrum access to radio frequency spectrum Avoids the inherent Avoids the inherent risksrisks of sharing resources with a business venture of sharing resources with a business venture Highly simplifies the design and reduces Highly simplifies the design and reduces costscosts

OpenOpen Technical Standard Technical Standard

GeosynchronousGeosynchronous Orbit (HEIO for the N polar cap)Orbit (HEIO for the N polar cap)

Capability for Highly Capability for Highly DistributedDistributed Satellite AccessSatellite Access

Aircraft Earth Station CharacteristicsAircraft Earth Station Characteristics Low cost Low cost isotropicisotropic antenna antenna

Low cost Low cost single channelsingle channel and medium transmit power level and medium transmit power level



SDLS Main Design CharacteristicsSDLS Main Design Characteristics (1) (1)

ServicesServices Voice service (point to point and Voice service (point to point and “Party Line”“Party Line”)) Data service including Data service including broadcastbroadcast and and polledpolled on-board parameter retrieval on-board parameter retrieval

Network ArchitectureNetwork Architecture Capability for Capability for decentraliseddecentralised satellite access satellite access

Satellite DiversitySatellite Diversity Dictated by service Dictated by service availabilityavailability requirements requirements

Equipment RedundancyEquipment Redundancy For both airborne and ground is part of the designFor both airborne and ground is part of the design

Communication Resource ManagementCommunication Resource Management Fixed and demand assignment, handling of priority levels Fixed and demand assignment, handling of priority levels



SDLS Main Design CharacteristicsSDLS Main Design Characteristics (2) (2)

Multiple Access SchemeMultiple Access Scheme Synchronous CDMASynchronous CDMA in the fixed to mobile direction in the fixed to mobile direction Quasi Synchronous CDMAQuasi Synchronous CDMA in the mobile to fixed direction in the mobile to fixed direction

Fixed Earth StationsFixed Earth Stations Ku or C-Band depending on satellite feeder linksKu or C-Band depending on satellite feeder links Only Ku-Band Only Ku-Band VSATsVSATs practically allow highly decentralised access practically allow highly decentralised access

Aircraft Earth StationsAircraft Earth Stations Low cost solutions meeting Low cost solutions meeting avionics standardsavionics standards are readily are readily availableavailable Only the CDMA modems require a specific developmentOnly the CDMA modems require a specific development

Space SegmentSpace Segment MSS GEO satellites at L-Band have MSS GEO satellites at L-Band have alreadyalready been deployed been deployed worldwideworldwide



The SDLS DemonstratorThe SDLS Demonstrator

ObjectivesObjectives Provide evidence to the prospective Aviation users that a Provide evidence to the prospective Aviation users that a satellitesatellite based Air / based Air /

Ground communication system Ground communication system cancan meet their most stringent requirements meet their most stringent requirements

provided the correct design options are selectedprovided the correct design options are selected

SDLS Programme PhasesSDLS Programme Phases Key system performance demonstrator with Key system performance demonstrator with AESs on groundAESs on ground (on-going with (on-going with

targeted completion third quarter 2002)targeted completion third quarter 2002)

A full scale validation with A full scale validation with airborne avionicsairborne avionics and the participation of CAAs and the participation of CAAs

and airlines is in the planning stageand airlines is in the planning stage

Industrialisation could immediately follow a Industrialisation could immediately follow a decisiondecision by aviation to take by aviation to take

advantage of SDLS to build an advantage of SDLS to build an ICAO standardICAO standard



Conclusion So FarConclusion So Far

SatelliteSatellite appears to be very well suited for the Safety appears to be very well suited for the Safety Communications of Communications of AviationAviation Extended geographical Extended geographical coveragecoverage capability capability High High service qualityservice quality levels are achievable with proven technology levels are achievable with proven technology Affordable Affordable costscosts

Difficulties Inherent to the Difficulties Inherent to the AviationAviation Environment Environment Decisions tend to be taken only when forced by external constraintsDecisions tend to be taken only when forced by external constraints Trial and error often takes precedence over theoretical analysisTrial and error often takes precedence over theoretical analysis Long term planning appears to be almost incompatible with the Long term planning appears to be almost incompatible with the

fundamentally political nature of international decision making processesfundamentally political nature of international decision making processes

HoweverHowever



SATELLITE DATA LINK SYSTEMSATELLITE DATA LINK SYSTEM

SDLSSDLS

It May Well Happen !

amcp wg c2 wp 21 7 to 11 may 2001 icao/amcp wg c 2nd meeting 1 satellite data link system (sdls) a...

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