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Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS (Satellite Data Link System) SYSTEM PRESENTATION ICAO ACP Working Group C - Toulouse.

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Presentation on theme: "Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS (Satellite Data Link System) SYSTEM PRESENTATION ICAO ACP Working Group C - Toulouse."— Presentation transcript:

1 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS (Satellite Data Link System) SYSTEM PRESENTATION ICAO ACP Working Group C - Toulouse October 2003 ACP WGC6/WP19

2 Reproduction interdite © Alcatel Espace Reproduction forbidden PRESENTATION PLAN PART I - INTRODUCTION & CONTEXT PART II - SDLS SYSTEM DESIGN PRESENTATION PART III - PROJECT STATUS AND WAY FORWARD

3 Reproduction interdite © Alcatel Espace Reproduction forbidden PART I - INTRODUCTION & CONTEXT

4 Reproduction interdite © Alcatel Espace Reproduction forbidden An Agreement of Co-operation has been signed and one task is to progress the definition of a Next Generation Satellite System The European Space Agency and Eurocontrol are co-ordinating their effort SDLS a CANDIDATE to NEXSAT INITIATIVE

5 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS AND NEXSAT CONTRIBUTIONS Eurocontrol and ESA associate their effort to develop a New Generation Aeronautical Satellite System

6 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS MISSIONS SDLS Definition SDLS is as a potential Next Generation Aeronautical Communication System SDLS Missions as specified in Eurocontrol Mission Requirement Document, in line with Nexsat initiative Complement the VHF communication system in Europe Support datalink applications deployment in dense Airspace World-wide coverage / Regional deployment capabilities Supports communications needs on remote and oceanic airspace Interoperable / Open architecture

7 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS GENERAL CONCEPT Safety dedicated system (ATS and AOC communication) Operation in protected radio-spectrum band ( L-band AMS(R)S ) Network security through clearly segregated system Controlled network with Guaranteed Performances Low cost infrastructure and operational cost Light and easy to install terminal Omnidirectional antenna Mono-Transmission Channel terminal Based on up-to-date communication technology Compatible to proven Bent-pipe Geostationary satellites Distributed network implementation capability (reduced ground network infrastructure) Capability for low cost GES implementation (in Ku band) Optimised network architecture (Spectrum efficiency)

8 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS SERVICES Services supported : ATM services (Services link2000+) AOC services (including support of ACARS) Critical Short data services Voice services (Point to Point, Party Line)

9 Reproduction interdite © Alcatel Espace Reproduction forbidden QUALITY OF SERVICE DATA SERVICES VOICE SERVICES

10 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS HIGH LEVEL SPECIFICATIONS Basic raw data rate 5.6kbps over dense areas (regional spot beams) Reduced raw data rate 3.2kbps over oceanic and remote airspace (global beams) BER : for data, for voice - Link availability % QoS management

11 Reproduction interdite © Alcatel Espace Reproduction forbidden PART II - SDLS DESIGN PRESENTATION

12 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS DESIGN PARADIGMS Direct Sequence Code Division Multiple Access System (DS-CDMA) + Geostationary bent-pipe satellites Advantages of this configuration : Cancellation of Near-Far limitation of terrestrial CDMA systems Cancellation of frequency guard bands due to AES Doppler Cancellation of time guard with TDMA/CDMA configuration Resistance to interference, multipath and fading (scintillation..) Other by-products of interest : Supports decentralised access scheme Security at radio transmission level

13 Reproduction interdite © Alcatel Espace Reproduction forbidden WAVEFORM (Results of optimisation studies) CDMA Access mode Similar waveform on forward and return links Synchronous/Quasi Synchronous CDMA scheme alignment spec.1/8 of a chip Reference carriers for synchronisation and power control Asynchronous transmissions limited to GES and AES network entries Modulation QPSK with pulse shaping Spreading : Gold codes with a spread factor of 127 (BW=1MHz) Single Data/Voice Channel Coding : Turbo code with rate 1/2 Eb/No=2.6dB (256 bits blocks)

14 Reproduction interdite © Alcatel Espace Reproduction forbidden BASIC AES CHARACTERISTICS Design target : low cost SATCOM terminal (i.e. similar to a VHF radio). Basic Terminal Mono-transmit channel terminal with 30W HPA operated at saturation Omnidirectional antenna (0dBi at 5°, G/T -25dB/K) Include all the protocol stacks Supports Arinc 429 or Arinc 664 Interfaces Terminal Option AERO-I/H existing terminals supported (better EIRP-G/T figures) Up to 22kbps (4 times basic rate) could be provided

15 Reproduction interdite © Alcatel Espace Reproduction forbidden Current LINK BUDGET - MOBILE LINK

16 Reproduction interdite © Alcatel Espace Reproduction forbidden Possible Data Rate Improvement on future platforms

17 Reproduction interdite © Alcatel Espace Reproduction forbidden ACCESS - CARRIER DISTRIBUTION Forward CDMA carriers GES A Generic Distribution T CHANNEL TTTTT...T AES2 AES3 AES4 AES1 A Generic Distribution A CHANNEL Ad Ar Ad... Ad AES2 AES3 AES4 AES1 Collision AES1 and AES3 C Dedicated Return Carriers shared by several AES (Except voice multiplexed carriers) T T T A A C T A n 1 8 CDMA Codes 2 AES1 AES2 AES3 AES4 Common ASYNC CDMA shared by all AES (Spread-ALOHA). Log-on purpose (L channel) P and C AES AESx

18 Reproduction interdite © Alcatel Espace Reproduction forbidden ACCESS - CARRIER DEFINITION Typical payloads / bursts P, T, C : 150 bytes (Long Block Data Unit) A :Ar : 32 bytes (Short Block Data Unit) Ad : 8 bytes (Super Short Block Data Unit)

19 Reproduction interdite © Alcatel Espace Reproduction forbidden Network Architecture Paradigm Optimised Satellite Gateway

20 Reproduction interdite © Alcatel Espace Reproduction forbidden Gateway vs. Transparent Example SDLS Gateway Model Transparent Network Model Satellite Link Optimised Interface Network Dependent Interface Protocol Overhead reduction Minimal retransmissions Channel efficiency optimisation Flow control

21 Reproduction interdite © Alcatel Espace Reproduction forbidden QoS Management

22 Reproduction interdite © Alcatel Espace Reproduction forbidden Supported Diversity Schemes SDLS Design can be instantiated with diversity schemes at several levels : AES : Two patch antenna to avoid masking 2Rx / 1 Tx terminal 2Rx / 2 Tx terminals GES : GES site diversity in Ku band the feeder links to remove rain attenuation effect (up to 10dB) Satellite : Two satellites in hot redundancy

23 Reproduction interdite © Alcatel Espace Reproduction forbidden System Expandability SDLS is fully scalable. Minimal Configuration Operation in a single spot with one control and traffic station NMS/GES Multi GES Many GES can be instantiated in the system Transparent introduction allowed by the CDMA structure of the system Multi Frequency Slots Expandability by steps of 500/1000KHz on the same transponder Multi Spots On the same satellite, several spots can be used simultaneously Only one Network Master Station required for all spots Multi Satellite All system expansions are transparent to the Avionics

24 Reproduction interdite © Alcatel Espace Reproduction forbidden PERFORMANCE FIGURES (I) SDLS Traffic and capacity assumptions (from Eurocontrol ref.) Capacity assessment per aircraft

25 Reproduction interdite © Alcatel Espace Reproduction forbidden PERFORMANCE FIGURES (II) Initial Simulation Results Hypothesis & Modelling Queuing Analysis based on Markov models One GES configuration / One spot beam PIAC of 2000 aircrafts Preliminary Results Short Priority 2 (QoS3) Priority 3 (QoS4 & 5) Long* FD W RT Short Long* P P P P Ar T T PTPriority 1 (QoS1 & 2)4,41<4,5 s 3,30 6,71 7,65 12,29 <27 s <7,2 s Transit Delay (sec) * Long packets imply to make a reservation on A channel

26 Reproduction interdite © Alcatel Espace Reproduction forbidden PERFORMANCES (III) Summary Table : Total number of CDMA channels (PIAC 2000 aircrafts) Number of CDMA channels 1 GES configuration 15 GES configuration* Forward P channels 2730 Return A channel TBD Return T channel 1315 Total number TBD *Uniform PIAC AES distribution among 15 GES

27 Reproduction interdite © Alcatel Espace Reproduction forbidden COST FIGURES (I) SDLS Service Unit Costs: Results for Data Cost Hypothesis : Space capacity lease from 1 to 2M/year/MHz/39dBW

28 Reproduction interdite © Alcatel Espace Reproduction forbidden COST FIGURES (II) SDLS Service Unit Costs: Results for voice Cost Hypothesis : Space capacity lease from 1 to 2M/year/MHz/39dBW

29 Reproduction interdite © Alcatel Espace Reproduction forbidden PART III - PROJECT STATUS

30 Reproduction interdite © Alcatel Espace Reproduction forbidden EXPERIMENTATION STATUS Slide 1 : Initial Feasibility study Slice 2 : SDLS Demonstrator Baseline system qualified in July 2002, with : SDLS Network elements : NMS - GES - 2 AES SDLS Test Bed : set ATS and AOC applications SDLS Demonstrator Extension under completion : System Qualified on ESA Artemis Satellite (September 2003) Second Access Station deployed in Rome (November 2003) Slice 3 : SDLS Operational system study On-going SDLS Experimentation Plan for next phase include : Performance test bench development (transmission and network simulations) Real life test based on SDLS Demonstrator (with embarked tests)

31 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS SLICE 3 - WBS Experimentation Service Analysis Detailed Studies Economic Analysis System Consolidation

32 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS SLICE 3 : STUDY PHILOSOPHY Future SATCOM Solution SDLS feasibility analysis and technical solutions User needs Analysis, Service Requirements Making top-down and bottom-up approaches converge AccessProtocolsWaveform Solutions & Trade-Offs

33 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS SLICE 3 STUDY OVERVIEW Indra (SP) Schlumberger Sema (SP) Airtel (Ir) Skysoft (P) Vitrociset (I) Thales ATM (F) Alcatel Bell (B) AlcatelSpace

34 Reproduction interdite © Alcatel Espace Reproduction forbidden Slice 3 : Operational System Study Status Core studies have been conducted Services and QoS figures defined Baseline system architecture defined Studies currently on-going with short term results expected Transmission : Alternative spreading/scrambling schemes performance evaluation Envelope variation minimisation through complex scrambling Code reuse between spot using scrambling TCM-8PSK evaluation (bandwidth reduction) Reduced spreading option analysis in 500kHz bandwidth Network Architecture : Access performance refinement Gateway stack definition and performance refinement System consolidation activity on-going Outputs : System Design Concepts Justification File System Functional Specification

35 Reproduction interdite © Alcatel Espace Reproduction forbidden OPEN ISSUES & WAY FORWARD Consolidation of Mission Requirements with Eurocontrol Performances Verification Simulation models to be developed to confirm preliminary results network/protocol efficiency, capacity, QoS compliance system availability refinement (scintillation effects…) Safety assessment Safety analysis to be performed Security requirements Functions linked to security management could be included in the design if required (authentication / crypto /..) Experimentation Leverage existing system demonstrator to validate system key features (access diversity, gateway prototyping, environmental tests including in-flight demonstrations)

36 Reproduction interdite © Alcatel Espace Reproduction forbidden SDLS System Prototype SDLS Demonstrator Pre-Operational System SARPS/MOPS D Pre-Operation SDLS Phase B Completion SDLS Phase C Flight Test Experimentation SDLS Slice CDR PDR NexSat Initiative Contribution to ICAO MRD V1 Users Steering Group STANDARDISATION DEVELOPPEMENT EXPERIMENTATION MRD V2 System Specification


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