ZULFIQAR ALI MIRANI

CNS/ATMEVOLUTION

July 19, 2012

What’s CNS/ATM

CNS/ATM stands for

Communication

Navigation

Surveillance/

Air Traffic Management

Current Communication Environment

Air TrafficServices Unit

VHF Voice

NeighboringAir Traffic ServicesUnit

HF Voice

VHF Radio

HF Radio

Voice and Data

HF communication is not restricted by line-of-sight , but HF radiotelephony is noisy, uncertain and inefficient

Voice communication has slow rate of information transfer. Voice communication problems arise due to language skill or accent of controllers and pilots. Possibility of errors under transmission or comprehension High workload of a controller.

Limitations of the present communication systems

The lack of digital air-ground data interchange systems to support automated systems in the air and on the ground. Existing ground voice/ data network is performing poorly

VHF radiotelephony has interference problems VHF radiotelephony coverage is poor VHF frequency and channel congestion.

Voice

Data

VHF

HF

Current Air Navigation Environment

• The propagation limitations of current ground-based navigation systems.• No full coverage of VOR/DME beacons and others as well in many regions of the world

Limitations Of The Present Navigation Systems

En-route

• Accuracy limitations, that does not allow to use flexible routes and area navigationArea Navigation

• Limited capabilities of existing system ( ILS) concerning coverage, stability and accuracy Landing

Current SurveillanceEnvironment

Secondary surveillance radar mode A/C

Primary surveillance radar

VHF ground direction finder

Air Traffic Control

Voice positionreport

RadarSurveillance

• Overload of transponder under overlapped coverage of SSR (A and C modes).• Possibility of false interrogations and answers.

• Accuracy limitations connected with:- different errors of time delay estimation;- limited range and angle resolution.

Limitations of the present surveillance systems

Accuracy

SSR

• The propagation limitations of current line-of-sight primary and secondary radars.• No full coverage in many areas of the world.

Coverage

Current Environment of Communication, Navigation and Surveillance

Communication Navigation Surveillance

Ground-to -Ground Enroute Radars

Voice VHF, HF NDBVORDME

PSRSSR (Mode A/C)Data Telephone

Wire, AFTN

Air-Ground Landing Voice Reporting

Voice VHF, HF ILS VHF

Data Very limited

EVOLUTION OF CNS/ATM CONCEPT

In 1983, Special Committee on Future Air Navigation Systems (FANS) was established by ICAO Council

Task: to study, identify and assess new technologies, including satellite technology; and to make recommendations for the future development of navigation systems for civil aviation.

FANS committee submitted its report in May 1988.

FANS (Future Air Navigation System) - Initiative

The limitations of voice communications and the lack of digital air-ground data interchange systems to support automatedsystems in the air and on the ground

The difficulty of implementing present CNS systems and of operating them in a consistent manner in large partsof the world

The propagation limitations of current line-of-sight systems

Shortcomings into the current air navigation system

CNS/ATM Concept Approval

The concept of CNS/ATM, as suggested by FANS Committee, was adopted at the 10th Air Navigation Meeting held in September 1991 at Montreal, Canada.

The concept is a mix of the best use of satellite technology and the line-of-sight systems to achieve the desired goal of organized Air Traffic Management.

Air Traffic Management Structure

Air Traffic Management

Airspace Management

Air Traffic Services• Air Traffic Control• Flight Information Service• Alerting Service

Air Traffic Flow Management

Components

Communication

Navigation

Surveillance

Functions

Transition to CNS/ATM

Major elements of change

• from ground-based to satellite based systems;• from limited coverage to global coverage; and • from analog to digital (data) communication.

There will be a great change in the pilot-controller interaction.

Transition to the new system will be one of the largest undertaking ever carried out by the aviation community.

Key Technologies Involve

Data Communication Links• VDL, HFDL, Mode-S, SATCOM

Satellite Navigation • Global Navigation Satellite System

Automatic Dependence SurveillanceADS-B

• Satellite Communication, Navigation and Surveillance; and

• Data Communication

INSIGHT INTO CNS/ATM SYSTEM

Air Traffic Management

Elements of ATM

• Air Traffic Services (ATS)• Air Space Management (ASM)• Flight Operations (ATM related aspects)• Air Traffic Flow Management (ATFM)

Air Traffic Services

ATS is the prime element of ATM.

ATS Sub-elements:

• Alerting Services;• Flight Information Service (FIS); and• Air Traffic Control.

The main objectives of ATC services are to prevent collisions between aircrafts and between aircraft and obstructions on the maneuvering area and to expedite and maintain an orderly flow of air traffic.

Air Space Management

ASM is recognized as dynamic sharing of airspace by civil and military users.

Flight Operations

The ATM-related aspects of flight operations are an integral part of ATM in CNS/ATM systems.

Air Traffic Flow Management

The objective of ATFM is to ensure an optimum flow of air traffic.

ATFM should reduce delays to aircraft both in flight and on the ground and prevent system overload.

ATFM assists ATC in meeting its objectives and achieving the most efficient utilization of available airspace and airport capacity .

ATFM is to ensure that safety is not compromised by the development of unacceptable levels of traffic congestion and traffic is managed efficiently without unnecessary flow of restrictions being applied.

Communication

Air-Ground Communications

Most of the routine communications in the en-route phase of flight will be via data interchange.

Data transfers will also take place between automated airborne and ground systems without the need for manual intervention.

A special communication arrangement between controller and pilot is introduced that is named as Controller-Pilot Digital Link Communication abbreviated as CPDLC.

Controller Pilot Data Link Communications (CPDLC)

CPDLC will be part of the Aeronautical Data Link system and provide an additional digital communications channel to supplement the voice frequencies.

Multiple controllers will have the capability to send Data Link messages from any given sector to any or all Data Link equipped aircraft in that sector, and transmissions will take place simultaneously over multiple media.

A defined set of (pre-formatted) message elements is used, that correspond to existing phraseology employed by current ATC procedures.

A ‘free text’ capability is also provided to exchange information not conforming to defined formats.

Radio Links

Transmission of air-ground messages is carried out over one of the following radio links:

– Aeronautical Mobile Satellite Service (AMSS) – a new standard introduced in CNS/ATM

– VHF (analog) – traditional communication link– HF (analog) - traditional communication link– VHF digital link (VDL) – a new standard introduced in

CNS/ATM– SSR Mode-S data link – a new standard introduced in

CNS/ATM– HF data link – a new standard introduced in CNS/ATM

VHF Digital Link (VDL)

VHF Digital Link (VDL) is a mobile sub-network of the Aeronautical Telecommunication Network (ATN), operating in the aeronautical mobile VHF frequency band.

Modes of VDL

– VDL Mode - 2– VDL Mode - 4

HF Data Link System

The HFDL service allows aircraft to send and receive packet data via a network of HFDL ground stations.

HFDL can provide very significant improvements over current HF Voice Communications in terms of system availability, system capacity, ease of use, and information integrity.

Mode-S Data Link

Mode-S can be used to exchange longer and more varied data.

Mode-S transmissions between the station and the transponder use 56 or 112 bit formats called frames.

There are 24 formats. First five bits in each format define the Uplink Format No.

There are two types of Mode-S data link– Specific– Interoperable

Mode-S : Interoperable data link

The interoperable data link was designed to allow ground-to-aircraft exchanges using Mode S as a packet switching data transmission network.

The messages (data packets) transmitted are then cut into pieces and distributed around the data fields in the frames, which are sent from the station to the transponder (or vice-versa) where the data fields are extracted and reconstituted a little further on at the exit from the Mode S " world ", for routing to the addressee.

The interoperable services will enable the integration of Mode S sub-networks in the Aeronautical Telecommunication Network (ATN). It can, truly, be used as a data communication link.

Mode-S : Specific data link

The specific data link is more closely linked to the Mode S surveillance system. In particular there is a highly optimized "aircraft data collection" protocol using the COMM-B frames.

It is based on the following principle :

In the transponder, there is a series of 256 buffers of 56 bits each, in which information concerning the flight and aircraft status are stored and permanently refreshed. Each buffer, identified by an order number, contains data of a precise nature formatted according to a predetermined code.

Ground-Ground Communications

Means of Communications between and within ATS units:

• AFTN/AMHS, • Voice, or • ATS Inter-facility Data Communications (AIDC).

The use of AIDC significantly reduces the need for voice coordination.

The AIDC message sets and procedures are designed for use over any ground-to-ground circuit, including the AFTN and ATN.

Future CommunicationEnvironment

SSR mode S Air Traffic Services Unit

SSR mode SData link

VHF Data link

AeronauticalTelecommunicationNetwork

SatelliteData link

Satellite

SatelliteStation

Neighboring Air Traffic Services unit

HFData link

VHF Radio

HF Radio

Voice in non-routine and emergency situations

Voice

Navigation

Navigation

Improvements in navigation include the progressive introduction of area navigation (RNAV) capabilities along with the global navigation satellite system (GNSS). These systems provide for worldwide navigational coverage and are being used for worldwide en-route navigation and for non-precision approaches. With appropriate augmentation systems and related procedures, it is expected that these systems will also support most precision approaches.

Navigation satellites or Global Navigation Satellite System are alternative to NDB, VOR and ILS provided they meet the required standard.

GNSS (Global Navigation Satellite System)

Though GNSS is being used today for en-route navigation, but it requires augmentation systems to monitor signal reliability and enhance accuracy to make them suitable for Air Navigation Use.

GNSS, as specified in Annex 10, will provide a high-integrity, high-accuracy and all-weather worldwide navigation service.

The successful implementation of GNSS would enable aircraft to navigate in all types of airspace, in any part of the world, offering the possibility to dismantle some or all of their existing ground-based navigation infrastructure.

Augmentation Systems

• Ground based augmentation systems• Satellite based augmentation systems• Aircraft based augmentation systems

Ground based augmentation systems

• DGPS (USA)

• LAAS (Local Area Augmentation System)

• GRAS Ground-Based regional Augmentation System (Australia)

• European GBAS

• Korean GBAS

Satellite Based Augmentation Systems

• WAAS (Wide Area Augmentation System )

• EGNOS (European Geostationary Navigation Overlay Service)

• MSAS (Multi Satellite-based Augmentation System)

• GAGAN (GPS aided geo augmented navigation)

• Canada's CDGPS• K-SBAS (Korea)• SNAS (China)

Aircraft-Based Augmentation System

Aircraft-based augmentation system (ABAS - ICAO definition) augments and/or integrates the information obtained from the GNSS elements with other information available on board the aircraft.

GNSS +

Airborne Sensors

More accuratePositionInformation

ABAS

- RAIM (Receiver autonomous integrity monitoring

system)

- FDE (Fault Detection and Exclusion)- AAIM (Aircraft Autonomous Integrity Monitoring)

technique (GPS + other sensor)

Future Air Navigation Environment

Satellite Navigation Systems

Operational

• GPS• GLONASS

In development

• GALILEO• BeiDou-2 Compass• IRSS• QZSS

GPS (Global Positioning System)]

GPS was developed in 1973 by the United States Department of Defense for position fix coordination of the inertial navigation systems (INS) on board military aircraft and cruise missiles. It became fully operational in 1994.

In 1996, recognizing the importance of GPS to civilian users as well as military users, U.S. President issued a policy directive declaring GPS to be a dual-use system.

On May 2, 2000 "Selective Availability" was discontinued as a result of the 1996 executive order, allowing users to receive a non-degraded signal globally.

GLONASS

GLONASS is a Soviet space-based navigation system comparable to the US GPS system. Development of GLONASS began in the Soviet Union in 1976

Formally declared operational in December 1995 with constellation of 24 operational satellites.

Galileo

Galileo is a satellite navigation system currently being built by the European Union (EU) and European Space Agency (ESA).

Launched in 2011

Initial Operational Capability (IOC) to be completed around mid-decade.

Full completion of the 30 satellites Galileo system (27 operational + 3 active spares) is expected by 2019

BeiDou-2 or Compass

The BeiDou Navigation Satellite System or Compass) is a project by China.

It will be a global satellite navigation system consisting of 35 satellites

• Launched in 2007

• Planned to offer services to customers in the Asia-Pacific region by 2012 (with 10 satellites), and to global customers upon its completion in 2020.

IRSS

Indian Regional Navigational Satellite System (IRNSS) is an autonomous regional satellite navigation system being developed by the Indian Space Research Organization.

The first satellite of total seven satellites constellation is expected to be launched during 2012-2013. While the full constellation is planned to be realized around 2014

QZSS

Quasi-Zenith Satellite System (QZSS), is a proposed three-satellite regional time transfer system and Satellite Based Augmentation System for the GPS, that would be receivable within Japan.

QZSS can enhance GPS services in two ways: first, availability enhancement, whereby the availability of GPS signals is improved, second, performance enhancement whereby the accuracy and reliability of GPS derived navigation solutions is increased.

Surveillance

• Traditional SSR modes will continue to be used, along with the gradual introduction of Mode S in both terminal areas and high-density continental airspace. The major breakthrough, however, is with the implementation of automatic dependent surveillance (ADS).

Surveillance Types

• Independent Surveillance (IS)• Co-operative Independent Surveillance (CIS)• Automatic Dependent Surveillance (ADS)

Automatic Dependent Surveillance

• ADS-B (Automatic Dependent Surveillance-Broadcast)

• ADS-C (Automatic Dependent Surveillance-Contract)

ADS-A

ADS-Addressed (ADS-A) also known as ADS-Contract (ADS-C), is based on a negotiated one-to-one peer relationship between an aircraft providing ADS information and a ground facility requiring receipt of ADS messages.

For example, ADS-A reports are employed in the Future Air Navigation System (FANS) using the Aircraft Communication Addressing and Reporting System (ACARS) as the communication protocol. During flight over areas without radar coverage (e.g., oceanic and polar), reports are periodically sent by an aircraft to the controlling air traffic region

ADS-B

ADS-B periodically broadcasts information about each aircraft, such as identification, current position, altitude, and velocity, through an onboard transmitter.

ADS-B provides air traffic controllers with real-time position information that is, in most cases, more accurate than the information available with current radar-based systems.

ADS-B consists of two different services: ADS-B Out and ADS-B In.

ADS-B Principle of Operation

ADS-B: Physical Layer

Two link solutions are being used as the physical layer for relaying the ADS-B position reports.

• 1090 MHz Mode S Extended Squitter (ES)

• Universal Access Transceiver (UAT) 978 MHz

• VDL Mode-4

Traffic Information Service - Broadcast

TIS-B is a surveillance technique that broadcasts surveillance information from the ground for suitably equipped air or ground-based aircrafts, mobiles or objects of Interest .

TIS-B supplements ADS-B air-to-air services to provide complete situational awareness in the cockpit of all traffic known to the ATC system.

Future SurveillanceEnvironment GNSS

Secondary surveillance radar mode S

Air Traffic Control

SSR mode SData linkVHF or HF

Data link

ADS

RadarSurveillance

AeronauticalTelecommunicationNetwork

VHF or HF Radio

SatelliteData link

CommunicationSatellite

SatelliteStation

Air TrafficControl

Airborne Systems

• Cockpit Display of Traffic Information (CDTI)

• FMCS (Flight Management Computer System)

• Multi-Mode Receiver (MMR)

• Collision Avoidance Systems: ACAS (Airborne Collision Avoidance System) TCAS (Traffic Alert and Collision Avoidance

System)

• Automatic Dependant Surveillance – In & Out• Airline Operational Control Datalink• Air Traffic Control (ATC) Datalink• GNSS or Global Positioning System Receiver

Aeronautical Telecommunication

Network

ATN (Aeronautical Telecommunication Network)

ATN allows ground, air-ground and avionics data sub-networks to inter-operate for the specified aeronautical applications.

All the afore-mentioned data links are ATN-compatible and therefore constitute ATN sub-networks.

In ATN environment, sub-networks are connected to other sub-networks through ATN routers, which select the best route for transmission of each data message. As such, the choice of the air-ground data link is often transparent to the end-user.

CONCLUSION

Communication

a) Voice Air-Ground Communications: VHF, UHF, HF and SATVOICE (SATVOICE is a satellite telephone system that is available on suitably equipped aircraft through the Inmarsat Geostationary Satellite Network)

b) Data Link Air-Ground Communications: Controller Pilot Data Link Communications (CPDLC) application via data link utilising Satellite, VDL, HFDL and Mode-S sub networks

c) ATS Ground-Ground Communications: Voice communications; ATS Interfacility Data Communications (AIDC); AMHS and AFTN.

d) DSP (Data Link Service Providers} Internetworking.

e) Aeronautical Telecommunication Network

Navigation

The major technological changes in navigation are the adoption of Global Navigation Satellite Systems (GNSS).

The level of aircraft navigation capability required for particular operations is expressed by Performance Based Navigation (PBN) criteria.

Surveillance

Surveillance information will be obtained by – Automatic Dependent Surveillance (ADS)– SSR Mode – S

Traditional surveillance means such as Radar (both Primary and Mode A/C) will also be used.

Traffic information will be broadcasted from ground ATS centers via TIS-B.

Application of IT in CNS/ATM

Information Technology deals matters concerned with computer science and technology, design, development, installation and implementation of information systems and applications

Because of advantages such as Reliability, Flexibility, Multi Facility Integration, Expanded Operation, User convenience, Security (of information) IT is involved in all the three components of CNS/ATM; that is Communication, Navigation and Surveillance.

IT makes the future ATC/ATM systems and Voice/Data communication networks work efficiently at enormously high speeds.

Future Environment as foreseen by AIRBUS industriesCNS/ATMCNS/ATM overviewoverview

CommunicationSatellites (Satcom)

Space

Air

Ground

Ground Network for

Data Communications

SatcomGround-based radios

(VHF & HF) Transponder

NavigationSatellites (GNSS)

Airline Host Information Service ATC Center

DifferentialGNSS station

What’s the Future ?

FREE FLIGHT

Thank You

Questions ?