ORT issues - Alan Schuster Bruce- rev a 17 May 2005

NexSAT Steering Group - 31 May 2005

AeroBGAN Feasibility Study

WP3: Airborne Architectures for SwiftBroadband Services

Alan Schuster Bruce, Thales Avionics, 31 May 2005

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

2

Contents

Todays Satcom Architectures Key Questions on Architecture Key Performance Metric Packaging Locations Interfaces Conclusions

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

3

Today’s Arinc 741 Satcom Architecture(Plus changes introduced by Arinc 781)

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

4

Airborne Architecture Questions

What performance is needed? What are satcom functions?

How could they be packaged? Where would they be placed on aircraft?

What are satcom cockpit user interfaces? Same functional interfaces will be needed

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

5

Performance

Key metrics are G/T and EIRP. Inmarsat SDM figures are:

Antenna Terminal Class

EIRP (dBW) G/T (db/K)

LGA 4 11 -24.5 IGA 7 15 -19 HGA 6 20.5 nominal -13 minimum

An LGA will be required on smaller aircraft and hence this is the dimensioning service. Will the LGA system deliver the required service?

Will depend on required data rate and QoS, and these will depend on end-user applications. Being considered in WP1 LGA G/T implies 0dBic antenna and state of the art DLNA, and <0.3dB cable loss.

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

6

HPA Power vs EIRP

Inmarsat SDM sets EIRP for a LGA Terminal as provisionally 11dBW

Figure shows required HPA power to meet this Between 16 and 22W of RF power at HPA output will

be required EIRP vs HPA power (Ant gain 0dBi)

048

1216202428323640

5 6 7 8 9 10 11 12 13 14 15

EIRP (dBW)

HP

A p

ow

er

(Wa

tts

)

0.8dB loss betwen HPA and antenna

2.5dB loss between HPA and antenna

SDM value (11dBW)

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

7

Arinc 781 Satcom Architectures (with and without external HPA)

Arinc 781IGA orHGA

(containsBSU

functions)

HPASDU

Arinc 429 (BITE from Antenna)

Arinc 429 (Multicontrol)

DLNA BITE /Control

RF

Arinc 429

(BITE from HPA)

RF TxRF Tx

RF Rx

Arinc 781IGA orHGA

(containsBSU

functions)

SDU

Arinc 429 (BITE from Antenna)

Arinc 429 (Multicontrol)

DLNA BITE /Control

RF

RF Tx

RF Rx

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

8

Architecture Packaging Question

Basic functions are: SDU function - Modem and interface to aircraft HPA function - power amplification DLNA function - diplexer to combine Tx and Rx, plus

receiver low noise amplifier Antenna function

How can they be packaged?

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

9

Possible Satcom Packaging

1 SDU HPA DLNA Antenna Arinc 781 Default (internal HPA)2 SDU HPA DLNA Antenna Arinc 781 External HPA3 SDU HPA DLNA Antenna Combine HPA and DLNA4 SDU HPA DLNA Antenna All avionics in one unit

5 SDU HPA DLNA Antenna Avionics incorportaed in antenna6 SDU HPA DLNA Antenna DLNA incorportaed in antenna

Satcom functions

Satcom functionsScenarios With Other Functions Integrated Into Antenna (Less likely)

Scenarios With Standalone Antenna (Likely)

Same colour indicates functions combined into one LRU

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

10

Arinc 741 and 781

Arinc 781 Specification activity considers future ATS over

SwiftBroadband, although issues not currently being worked.

Certification level may rise to Level C Reasonable to assume that safety services will be

supported by Arinc 781 equipments (but not from all manufacturers).

Arinc 741 Equipment could be upgraded to support safety services - time will tell if this happens not least since basic designs are ‘old’, and will be ‘very old’ when the new system is rolled out.

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

11

Satcom Architecture Locations-1

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

12

Satcom Architecture Locations-2 Module/LRU location

Architecture Option

Forward of cockpit

(Un-pressurised)

EE bay or below cabin

floor (Pressurised)

Above cabin roof

Rear of aircraft

(Un-pressurised)

External to aircraft skin

1a*4

ARINC 781 SDU + DLNA

Antenna

1b*4 ARINC 741 SDU + HPA, D/LNA

2a*4 ARINC 781 SDU D/LNA Antenna

2b*4 ARINC 741 SDU

+ HPA D/LNA

3*4 ARINC 741 SDU HPA, D/LNA

Antenna

4a*4 ARINC 781

SDU +DLNA

Antenna

4b*4 ARINC 741

SDU + HPA + D/LNA

4c*4 SDU, HPA,

DLNA

5 SDU, HPA D/LNA,

Antenna

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

13

Satcom Architecture Locations-3

Module/LRU location

Architecture Option

Forward of cockpit

(Un-pressurised)

EE bay or below cabin

floor (Pressurised)

Above cabin roof

Rear of aircraft

(Un-pressurised)

External to aircraft skin

6a *4 ARINC 781

SDU

Tx Antenna, RX Antenna+ LNA

6b *4 ARINC 741 SDU + HPA

7a*3,4 ARINC 781 SDU + DLNA

Antenna

7b*3,4 SDU , HPA, DLNA

7c*3,4 ARINC 741 SDU + HPA D/LNA

8a ARINC 781

SDU +DLNA Antenna

8b

ARINC 741 SDU + HPA +

D/LNA

8c SDU, HPA,

DLNA

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

14

Satcom Architecture Locations-4

Option COMMENT BENEFITS WRT INSTALLATION DRAWBACKS WRT INSTALLATION 1 Option 1b is used by Thales

Jetsat, Arinc 761 Aero I system

Benign environment for SDU, HPA & DLNA. Cooling air available for SDU & HPA on air transport aircraft. SDU well located for other avionics interfaces, eg nav data. Easy access to SDU, HPA & DLNA.

If significant distance from EE bay to Antenna, then RF cable loss trade-off. High RF loss or heavy & expensive RF cable, which is difficult to install.

2 Benign environment for SDU and HPA. Cooling air available for SDU & HPA on air transport aircraft. SDU well located for other avionics interfaces, eg nav data. Easy access to SDU and HPA. D/LNA operating in a lower temperature environment which may help G/T during flight.

If significant distance from EE bay to DLNA, then RF Tx cable loss trade-off. Hi loss or heavy & expensive RF cable. Difficult access to DLNA.

3 Removes need for low loss cable. Option 3 used on A330/A340/A380 with Arinc 741 systems.

Benign environment for SDU. Cooling air available for SDU on air transport aircraft. SDU well located for other avionics interfaces, eg nav data. Removes need for low loss cable. Easy access to SDU.

Harsh environment for HPA. HPA cooling air only available on air transport aircraft. Difficult access to HPA and DLNA.

4 Option 4b used on B747/B777/B787. Option 4c is a single avionic unit mounted close to aircraft skin

No long RF cable runs could compensate for any lack of forced cooling.

Harsh environment for integrated unit. Space issues on smaller aircraft. Cooling air only available on air transport aircraft. Difficult access. Long cable runs to associated avionics interfaces, eg nav data.

5 Avionics on outside of aircraft. Integrated antenna plus avionics. Most optimistic architecture!

No long RF cable runs could compensate for any lack of forced cooling. Simple troubleshooting, ie only one unit to replace on failure.

Extremely harsh environment. Complex and expensive physical installation. Long cable runs to associated avionics interfaces, eg nav data. More volume externally, so higher drag and therefore aircraft performance penalty. Not considered a practical solution today.

6 Two separate antenna elements for Tx and RX.

Allows improved forward link since LNA is included in antenna.

Extremely harsh environment for LNA. If significant distance from HPA to Antenna, then RF Tx cable loss trade-off. Hi loss or heavy & expensive RF cable. Needs careful analysis of isolation and emissions requirements.

7 Avionics in front of cockpit bulkhead

May be most appropriate configuration for some small aircraft where space is at a premium.

Extremely harsh environment for avionics. Antenna needs to be at front of fuselage to minimse Tx RF cable loss.

8 Avionics in tail (top or bottom). GIV and other business jets use bottom tail configuration.

Useful when antenna can not be located on fuselage. Extremely harsh environment for avionics.

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

15

Interfaces To Cockpit-Voice

Expected that both current interfaces and new digital interfaces (eg AFDX) will be required in future.

New digital interfaces may be on single or multiple physical connections

Function Todays Interface Possible Future Interface Voice 4 wire analogue As today or new digital interface Control (PTT etc) Discretes As today or new digital interface Dialing info etc Arinc 429 to MCDU As today or new digital interface

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

16

Voice over SwiftBroadband PS

SwiftBroadband can support voice by circuit or packet services. If the latter - where will the function (e.g. VOIP, multicast) reside to convert to circuit user services be provided:

In SDU? In another unit? Industry will need to consider this issue

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

17

Interfaces To Cockpit-Data

Current interface is Data2/Williamsburg/Arinc 429 (FANS 1/A) Data3/Williamsburg/Arinc 429 (ATN compatible)

Key question is how this will migrate to the IP environment supported by SwiftBroadband

Tunnel existing Data2/3 over IP Migrate to pure IP environment ICAO ACP is considering accommodating IP

Where will this function reside In SDU? In another unit? Industry will need to consider this

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

18

Interfaces To Cockpit-Control and Maintenance

Todays Interfaces Control of satcom e.g. logging on, GES preferences etc

although these are typically automatic (uses MCDU) Display of BITE (uses CFDS) Upload of software/configuration data (uses ADL/PDL)

The above interfaces are expected to also be required for any future service.

These interfaces are not fundamentally dependent on whether the satcom uses classic or SwiftBroadband.

The current interfaces could be duplicated or a new generation of interfaces (e.g. AFDX) could be developed – the latter will depend on general trends in avionics.

It is expected that both existing Arinc 429 type interfaces and newer interfaces will be required for different aircraft

Nex

Sat

Ste

erin

g G

rou

p, A

ero

BG

AN

Stu

dy,

WP

3 -

Air

bo

rne

Arc

hit

ectu

res,

A

lan

Sch

ust

er B

ruce

- 31

May

200

5

19

Conclusions

LGA is expected to meet some ATS requirements Various packaging options are possible

Different options expected for different market segments Arinc 781 equipment should support safety services Arinc 741 could be upgraded to support new services but

equipment design is ageing. Installation locations reviewed Voice interfaces will have similar functions but may migrate to

digital How will IP be handled? VOIP/multicast in SDU or external unit