Simulation/Optimization Modeling for Robust

Satellite Data Unit for Airborne Network

Joe Zambrano

École de technologie supérieure – LASSENA

AVIATION 2015, 22–26 June 2015, Hilton Anatole, Dallas, TX

2

Agenda

• Introduction

• Motivation

• Current Scenario

• Simulation Architecture

• Results

• Conclusion

• References

Introduction - Airborne Network (AN)

3

Tactical

Mission

Commercial Satellite Link

through ISP to SIPRNET or

NIPRNET

GES

Terrestrial Segment

NIPRNET Internet(ISP)

SIPRNET

Air Segment

Space Segment

Tactical

Mission

NIPRNET

SIPRNET

Airborne

Network

GES

DoD Satellite Link to

SIPRNET or NIPRNET

Figure 1. Network architecture of Global Information Grid (GIG)

Tactical

Mission

Airborne

Sub-Network

AES

AES

AES

• AN is born as part of the GIG project of the US DoD

• Backbones in-the-sky

AES: Aircraft Earth Station

GES: Ground Earth Station

NIPRNET: Non-secure Internet Protocol (IP) Router Network

SIPRNET: Secret Internet Protocol Router Network

Introduction - Satellite Data Unit (SDU)

• Avionics appliance installed in an AES that permits A/G AMSS

communication via an aeronautical SatCom system

4

GES

Service cloud

ATM

AES

AeronauticalSatComSystem

UplinkDownlink

Downlink

Uplink

Service provider network

Figure 2. Overall end-to-end aeronautical SatCom system

Aeronautical Mobile

Satellite Service (AMSS)

Infotainment

Office (in-flight)

Telemedicine

Flight security

Logistic & maintenance

Introduction - Satellite Data Unit (SDU)

• Actually, the typical AAC consists of an ARINC 781/791 SDU

• All SatCom signals like audio or data is treated by the SDU

• Essential part of an AES's SatCom system

5Figure 3. SDU into Airborne Avionic Configuration SatCom

SDU

Introduction - Aeronautical Mobile Satellite Service

6

• Safety AMSS, are communications services that require high integrity and quick

response, these include:

Safety-related communications carried out by the Air Traffic Services (ATS) for

ATC, flight information and alerting

Communications carried out by aircraft operators, which also affect air transport

safety, regularity and efficiency (Aeronautical Operational Control (AOC))

• Non-Safety AMSS, are communications services that do not compromise flight safety,

these include

Private correspondence of aeronautical operators (Aeronautical Administrative

Communications (AAC))

Public correspondence (Aeronautical Passenger Communications (APC) including

In-Flight Connectivity (IFC) ).

Motivation

Commercial aviation forecast

• Passengers/year: 5 billion 12 billion by 2031*

• Aircraft movements/year: 77 million nearly double by 2031**

7

Table 1. Number of passengers, minimum and maximum expected mean data rate per A/C type 2014/2020

* Airports Council International 2013

** Boeing 2014

A/C Number of passengers

Minimum mean

data rate (Mbps)

2014

Minimum expected mean data rate (Mbps)

2020

Maximum mean

data rate (Mbps)

2014

Maximum expected mean data rate (Mbps)

2020

A320 150 - 180 9.96 52.43 11.95 62.91

A350 270 - 550 17.93 94.37 36.52 192.23

A380 555 - 853 36.86 193.98 56.65 298.14

B737 85 - 215 5.64 29.71 14.28 75.15

B777 301 – 550 19.99 105.20 36.52 192.23

B747 467 - 605 31.01 163.22 40.18 211.46

Current scenario

Figure 4. Current and future scenario

A/C Earth Station (AES)

Ground Earth Station

(GES)

Service cloud

GES

AES

Air Traffic Management (ATM)

Wi-FiGSM

A/G BROADBAND

Terrestrial cellular network with

broadband backhaul links

Service Provider Network

AES

AES

AES

AES

GES

Service cloud

ATM

SATCOM

UplinkDownlink

Downlink

Uplink

Service provider network

AES

A/A

A/A

A/A

A/A

A/A

A/A

A/A

A/AA/AA/A

• Increase in air traffic density is expected in transoceanic flights

• The growing demand for high-speed Internet for airline passengers

• A/G not cover transoceanic flights

• The reducing of distances between aircraft (ADS-B)

• Ensure safety avionic communications

8

Airborne Network

Objective

9

• Simulate and modeling a robust SDU able to deliver safety and

non-safety AMSS communications based on ARINC 791

standard and including capabilities to operate into an AN

Safety AMSS

Aircraft Communications Addressing and Reporting System

(ACARS)

ADS-B

Non-Safety AMSS

IFC

Simulation architecture - ACARS

10

Aircraft Communications Addressing

and Reporting System (ACARS)

message generator

Figure 5. Example of ACARS message• ARINC 618 / 619 / 620 and 724

• Msg.: 50 – 220 characters

• 2.4 Kbps

• Minimum-Shift Keying Modulation

• Characters from ISO alphabet No.5

Figure 6. ACARS MSK modulator outputs

0 2 4 6

x 10-4

0

0.2

0.4

0.6

0.8

1Zero-bit 1.2 KHz

Time

0 2 4 6

x 10-4

-1

-0.8

-0.6

-0.4

-0.2

0One-bit 1.2 KHz

Time

0 2 4 6

x 10-4

-1

-0.5

0

0.5

1Zero-bit 2.4 KHz

Time

0 2 4 6

x 10-4

-1

-0.5

0

0.5

1One-bit 2.4 KHz

Time

Simulation architecture - ACARS

11

ACARS message generator

50 55 60 65 70 75 80 85 90 95 100-2

-1

0

1

2ACARS Message

Time(ms)

AC

AR

S s

ignal

0.05 0.055 0.06 0.065 0.07 0.075 0.08 0.085 0.09 0.095 0.1-0.5

0

0.5

1

1.5

Time (seconds)

AC

AR

S m

essage

Bits from ACARS Message to the SDU

Figure 7. ACARS Message to transmit (signal and bits)

Simulation architecture – ADS-B

12

Automatic Dependent Surveillance – Broadcast

(ADS-B) message generator

• RTCA DO 260B

• 8 bits preamble and 112 bits data block.

• Pulse Position Modulation.

• 1090 MHz Extended Squitter format

1.38 1.4 1.42 1.44 1.46 1.48 1.5

x 10-3

0.5

1

ADS-B Message with PPM

1.38 1.4 1.42 1.44 1.46 1.48 1.5

x 10-3

-10

0

10

ADS-B Message with AM (Carrier = 1090 MHz)

1.38 1.4 1.42 1.44 1.46 1.48 1.5

x 10-3

-20

0

20ADS-B Message and noise added

Time (seconds)

Figure 8. Simulation architecture – ADS-B

Safety AMSS AES

Non-Safety AMSS AES

Non-Safety AMSS NAES

Safety AMSS NAES

Simulation architecture - Scenario

13

GES

Service cloud

ATM

AES

Aeronautical SatComSystem

ACARSADS-B

IFC

Service provider network

Safety andNon-Safety AMSS

NeighboringAES

Figure 9. Simulation architecture and scenario

0

5

10

15

20

25

Time

Ban

dw

idth

(M

b)

30

Safety AMSS AES

Non-Safety AMSS AES

Simulation architecture - Scenario

• How to distribute between various systems using a

single channel of communication via AMSS?

• Spread spectrum technology and a special coding

scheme (Gold sequences)

• Gold code BW significantly higher than data14

Figure 10. Simulation architecture

Simulation architecture - Inside SDUs

15Figure 11. SDU architectures (NAES and AES)

ADS-B Message

ACARS Message

IFC Message

Safety AMSS

Non-Safety AMSS

From NAES

Simulation architecture - Inside NAES SDU

16

ADS-B message from NAES

• ADS-B BW = 2 MHz

• Gold Code 4 BW = 512 MHz

• SF = 256

Figure 12. ADS-B message from NAES

Simulation architecture - Inside NAES SDU

17

ACARS message from NAES

• ACARS BW = 2.4 KHz

• Gold Code 5 BW = 614.4 KHz

• SF = 256

Figure 13. ACARS message from NAES

Simulation architecture - Inside NAES SDU

18

IFC data from NAES

• IFC BW = 30 MHz

• Gold Code 6 BW = 7.68 GHz

• SF = 256

Figure 14. IFC data from NAES

Simulation architecture - Inside NAES SDU

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Data signals from NAES to AES

Figure 15. Data waveforms into NAES SDU

20Figure 16. A/A block for SNR = -20, 0 and 20 dB

SNR = -20 dB

SNR = 0 dB

SNR = 20 dB

Spectral density of added noise

Simulation architecture – A/A Channel

A/A Channel

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Simulation architecture – Inside AES SDU

AES SDU Architecture

Figure 17. Spectral densities into AES SDU

Spectral density of Safety AMSS data signalSpectral density of Safety AMSS data signal with Gold code 1

Spectral density of Data signal amplified (Blue) to send to GES via SatCom

• Same internal architecture

as the NAES SDU

• Safety AMSS is multiplied

by the Code 1 block

• Non-Safety AMSS is

multiplied by the Code 2

block

• Rx from NAES is multiplied

by the Code 3

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Simulation architecture – Reciving and decoding

GES receiver architecture

Figure 18. GES receiver architecture

• Cross-correlation for AES

data signal

• Double cross-correlation

for NAES data signal

• Signal rejections

• Interferences rejection

• Gold codes to recovering

original signals

23

Simulation architecture – Reciving and decoding

Decoded signals at GES receiver

Figure 19. Decoded signals at GES receiver

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Results

Data rate error at GES

• SDU optimization suggests reducing the error rate in

communication channels

• communications of 2Mbps with a BW of 512 MHz.

• 1000 bits per signal

• SNR and SF variable

25

Results

Error rate values for different SNR values

0.0000000.0010000.0020000.0030000.0040000.005000

SafetyAMSS

Non-SafetyAMSS

NAESADS-B

NAESACARS

NAESIFC

ErrorRate

ErrorrateforSNR=-10dB

4

8

32

64

0.0000000.0005000.0010000.0015000.0020000.0025000.0030000.0035000.004000

SafetyAMSS

Non-SafetyAMSS

NAESADS-B

NAESACARS

NAESIFC

ErrorRate

ErrorrateforSNR=0dB

4

8

32

64

0.0000000.0005000.0010000.0015000.0020000.0025000.0030000.0035000.004000

SafetyAMSS

Non-SafetyAMSS

NAESADS-B

NAESACARS

NAESIFC

ErrorRate

ErrorrateforSNR=10dB

4

8

32

64

0.0000000.0005000.0010000.0015000.0020000.002500

SafetyAMSS

Non-SafetyAMSS

NAESADS-B

NAESACARS

NAESIFC

ErrorRate

ErrorrateforSNR=40dB

4

8

32

64

Figure 20. Error rate values for different SNR values

Conclusion

• We have presented the simulation/optimization modeling for robust

SDU for AN integrating different simulation models on avionics systems

such ADS-B, ACARS and IFC.

• We have also provided a review of the main elements in an AN

presenting a SDU architecture based on spread spectrum technology .

• The development of this solution in a physical platform could support

an aircraft tracking system channel that works anywhere under all

conditions .

• SDU can fit a Global Aeronautical Distress and Safety System

(GADSS) because it sends a large amount of data for the same

channel, by sending information from a AES not only to a satellite but

also to others nearby AES.

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References

• Zambrano, J., Yeste-Ojeda, O. Landry, R., “Requirements for Communication Systems in Future Passenger Air Transportation” in

14th AIAA Aviation Technology, Integration, and Operations Conference, Atlanta, GA, USA, 2014.

• Kwak, K., et al, “Airborne Network, Evaluation: Challenge and High Fidelity Emulation Solution”, Presented at Airborne’12, June

11, 2012, Hilton Head, South California, USA.

• USAF Airborne Network Special Interest Group, “AIRBORNE NETWORK ARCHITECTURE” - System Communications

Description & Technical Architecture Profile, Version 1.1, Prepared by HQ ESC/NI17, October 2004

• National Security Agency NSA, “Global Information Grid” - The GIG Vision - Enabled by Information Assurance, NSA web site,

URL: https://www.nsa.gov/ia/programs/global_information_grid/ [cited 3 December 2014].

• Aeronautical Radio, Incorporated, ARINC 781-6 “Mark 3 Aviation Satellite Communication Systems”, December, 2012.

• Aeronautical Radio, Incorporated, ARINC 791P1-2 Mark I Aviation Ku-Band and Ka-Band Satellite Communication System, Part 1,

Physical Installation and Aircraft Interfaces, August, 2014

• Aeronautical Radio, Incorporated, ARINC 791P2-1 Mark I Aviation Ku-Band and Ka-Band Satellite Communication System, Part 2,

Electrical Interfaces and Functional Equipment Description, July, 2014.

• Aeronautical Radio, Incorporated, ARINC 741P1-14 Aviation Satellite Communication System, Part 1, Aircraft Installation

Provisions, June, 2012.

• Aeronautical Radio, Incorporated, ARINC 741P2-11 Aviation Satellite Communication System, Part 2, System Design and

Equipment Functional Description, June, 2012.

• Radio Technical Commission for Aeronautics, RTCA DO-260B. 2009. “Minimum Operational Performance Standards for 1090 MHz

Extended Squitter Automatic Dependent Surveillance – Broadcast (ADS-B) and Traffic Information Services – Broadcast (TIS-B)”.

Washington, DC 20036: RTCA.

• International Civil Aviation Organization, ICAO Ad-hoc Working Group on Aircraft Tracking, “Global Aeronautical Distress & Safety

System (GADSS)” – Concept of operations SECOND HIGH-LEVEL SAFETY CONFERENCE 2015 (HLSC 2015) PLANNING FOR

GLOBAL AVIATION SAFETY IMPROVEMENT, Montréal from 12 to 13 May 2014.Montréal, 2 to 5 February 2015.27

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