ANTARES: Communication System Design Figures of Merit

Iris Information Event - PragueMay 26-27th, 2010

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INDEX

01 Objectives02 Design drivers03 Figures of Merit Definition04 Communication System Technologies Overview05 Figures of Merit Assessment06 Verification Test Bed07 Conclusions

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Communication System Design ObjectivesANTARES

Specification of a new satellite-based Air-Ground Communication Standard To cope with the future Air Traffic Services (ATS) and Airline

Operational Control (AOC) communication needs

Based on the COCR requirements (Application definition, traffic profile).

Design of the Communication System consisting in: Communication Standard (CS) with the specification of physical

and link layers Address User (traffic), Control and Management plane, with the

signaling needs between the system elements.

Verification of the CS in the frame of the ANTARES project

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Communication System Design Drivers System requirements and traffic profiles from the COCR

requirements (and any refinement of COCR along the project) Flow down of requirements to the Communication System design Precise definition of Applications to consolidate the traffic profile

Implications from Aeronautical scenario Efficient use of limited L-band spectrum resources User terminal design (omni-directional aircraft antennas, limited

amplifier power)

Design for high system efficiency and availability (> 5 nines) Flexibility to support decentralized service provision

Preferably technologies free of IPR (Intellectual property rights) CS specification aimed for a global standardization process

ANTARES

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CS Design: Figures of Merit Definition

Figures of merit to identify the communications system technologies that better fulfil the requirements

Identification of figures of merit related to:

System efficiency, maximize bit/s / bandwidth System capacity, technologies that better support the requested

traffic

Increase system availability, taking into account the propagation channel and the aeronautical mobile scenario Compliance with applications latency requirements

Optimize power needs in the User terminal and Payload Support the adequate level of information security and provide

robustness in front of interferences

ANTARES

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CS Design: Technologies OverviewANTARES

Redundancy Security Measures Handover Procedures Diversity Techniques

All techniques related to the physical and link layers and to the control and management planes, as for example:

Forward / Return Link Modulation and Channel Coding Adaptive Coding Modulation for the forward link Forward and Return Link Medium Access Control

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CS Design: Figures of Merit Assessment

System efficiency ( bit / sec / Hz )

Forward Link Modulation and Channel Coding based on MPSK and with adaptability to channel variations

Maximize capacity using Adaptive Coding & Modulation, but increasing the signalling overhead

Forward / Return Medium Access Control with an efficient use ofscarce radio resources

Frequency reuse among beams to increase efficiency Overhead due to synchronization, guard time, guard bands and

detection needs

Impact on efficiency due to signalling overheads from: Redundancy mechanism Handover procedures to assure service continuity Security mechanism Procedures for allocation of resources of the satellite network

ANTARES

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CS Design: Figures of Merit Assessment

Maximize the system capacity

Forward and Return Medium Access Control schemes

Evaluation of capacity of Demand based access (Time, Frequency or Code Multiplex) and Random Access schemes

Limitations caused by multiple access interference. Techniques based on frequency reuse among beams limited by

interferences from adjacent beams

ANTARES

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fR=3N=12 Beams=17dB

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CS Design: Figures of Merit Assessment Increase system availability

Modulation and coding exhibiting low Packet Error rate: Combined modulation (MPSK, OQPSK, CPM) and channel

coding (Turbo, LDPC, BCH) Performances with impairments from the mobile channel,

Satellite and User Terminal amplifier characteristics Optimize required signal-to-noise ratio for forward and return

links

Redundancy (Space and Ground segment) Avoid single points of failure and improve the system availability. Properly design of switch-over protocols (hot redundancy) Linked to ground segment architecture and interfaces

Handover mechanism Support of seamless mobility between beams, GES’s and

satellites. Performance as service continuity (minimise delay and

interruption) and signalling overheads

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CS Design: Figures of Merit Assessment Increase system availability (cont): applicability of Diversity

techniques Improve system availability by using different uncorrelated

communication channels Diversity techniques: satellite, GES site, polarization, space time

coding and UT antenna The use of the techniques is under evaluation, based on complexity

and performance (diversity gain)

ANTARES

Rain

(Feeder link ) (User link )

MultipathScintillationGeometric link

Rain

(Feeder link ) (User link )

MultipathScintillationGeometric link

Solar Outages

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CS Design: Figures of Merit Assessment

Optimize power needs in the User terminal

Return link Modulation and Coding: modulations (OQPSK, CPM) that minimises power requirements for the UT amplifier

Undesired out of band power: limited by regulation constraints and causing interferences to adjacent channels

Compliance with applications latency requirements

Forward and Return Multiple Access schemes, assuring delay requirements

Efficient synchronization and detection techniques Packet retransmission necessary after packet lost due to channel

propagation effects

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Verification Test Bed - Concept

Mapping between VTB and CS architecture

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Verification Test Bed - Architecture

VTB overall preliminary architecture

ANTARES

PTSPhysical Simulations

(SW based)

PTEPhysical Emulations

(HW based)

LTELogical Emulations

(SW based)

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Communication System Design - Conclusion

ANTARES Communication System Design activity

To specify a global communication standardMaximize system capacity, assuring reliability Adapted to the aeronautical scenario Efficient support of applications

Communication Standard validation

Development of a Verification Test Bed to validate the Communication Standard User Terminal to be prototyped and integrated in the Verification

Test Bed in the frame of ANTARES project

ANTARES

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Joan Manuel CebrianIndra Espacio, S.A.Telecommunication and Navigation Solutions

Roc Boronat, 133 08018 Barcelona, SPAINwww.indra.es/espacio

Thank you for your attention