1. TCP / IP and ATN in Europe Danny Van Roosbroek, EATM/DAS/CSM
ICAO Seminar - TCP/ IP and ATN in Europe
TCP / IP and ATN in
Europe
Danny Van Roosbroek, EATM/DAS/CSM
Bangkok, November, 2003

2. Overview TCP / IP ATN TCP/IP and ATN Coexistence
ECAC TCP / IP Strategy
iPAX Task Force
Flight Data Exchange
Radar Data Distribution
Message Handling
Ground/Ground voice
ATN
ECAC ATN Strategy
Link2000
TCP/IP and ATN Coexistence
Eurocontrol Communications Strategy

3. ECAC TCP/IP Strategy (1)
Applicable to ATM Ground/Ground communication
The Problem :
All international ATC data exchange applications such as OLDI, make use of X.25 technology
Key manufacturers have stopped selling X.25 equipment and will cease support after 2005
The Solution is IP :
IP is omnipresent and mature
IPv4 is implemented in States; different approaches
IP version 6 is supported by the European Commission (PR 29/01/02)
Since the advent of internet-related products and services, industry-wide support of X.25 products and services is rapidly diminishing. As a result, the European ATM community as a whole has to face a technology change from existing ground X.25 communication to internet-based communication protocols. This is mainly applicable to surveillance data exchange and flight data exchange. Voice applications and other services (e.g Air Traffic Flow Management) shall be also affected by this technology change but at a much later stage.
The essential component of the ground communications strategy is therefore, the planning and co-ordination of migration of international X.25 to IP which involves the deployment of:
an ECAC wide IP (version independent) network service
the migration of existing X.25 based applications and systems to IP (OLDI, Surveillance data distribution, meteorological data).

4. ECAC TCP/IP Strategy (2)
IP version 6 for international data exchange
Address translation for existing IPv4 islands
States are encouraged to migrate from IPv4 to IPv6
Institutional Issues for IP service provision
ECIP COM 09 : migration from X25 to IP is under development
Strategy : “To implement the transition from legacy CONS to high QoS COTS-based IP technology to support current and future application requirements for ground environment.”
The European network architecture will be developed to provide a topology-independent IP network service that encompasses existing IPv4 national network deployments. The network architecture envisaged involves the use of IPv6 in order to build an international IP network service. Robust institutional arrangements must be put in place between implementers and existing network operators in order to achieve the envisaged service.
IPv6 is the recommended technology to support the meshed international network federating the national IPv4 implementations. At the same time, states are encouraged to migrate to IPv6 for their national network. The key benefits of IPv6 are a scalable addressing and routing architecture and the provision of better support for voice and mobile applications.
The European direction to implement international IPv6 services will be co-ordinated with the international community as early as possible

5. iPAX Task Force IPAX Task Force established to: WAN Trials
modify aeronautical standards for the exchange of ATM/CNS data
migration from X.25 to TCP/IP protocol suite
focus on ground data communications
WAN Trials
14 European sites connected via IPv6
IP security (IPsec and firewalls)
OLDI, ASTERIX, AMHS over TCP/IP data exchange
The internet Protocol for Aeronautical eXchange Task Force (iPAX-TF) has been established in August 2001 by EUROCONTROL to address the need to evolve current ATSP X.25-based data network infrastructure and services to the internet-based protocol suite (TCP/IP). Currently, this task force involves some 25 experts from 15 EUROCONTROL Member States.
The objective of the iPAX-TF is to develop or modify guidelines, specifications and possibly standards related to the exchange of aeronautical data between ATS or CNS systems based on the TCP/IP protocol suite with the aim to propose an alternative for the eventual replacement of the X.25 protocol in ATS/CNS.
A full iPAX-TF website has been prepared to increase awareness of the task force activities. The public site is Specifications will be made publicly available once the iPAX-TF considers them mature.

6. Flight Data Exchange - OLDI (1)
Inter-centre coordination is the process by which the control of a flight is passed over from control centre to the next as the flight progresses. As part of this process, flight plan updates need to be communicated to the downstream center. It is a crucial application that has been executed using voice-based procedures. Since the early 90s, the On Line Data Interchange (OLDI) protocol, is used as the standard way to exchange coordination messages between control centres in Europe. It is now been expanded to the whole ECAC area.
The status of the FDE (Flight Data Exchange) connections in Europe reflects the situation as of January 2002.
Even though the majority of the inter-centre connections respect the provision of the FDE ICD Part 1 (green and brown links), some implementations evidence deviations that are caused by legacy solutions (blue links). The status shows clearly that the core area of ECAC has adopted the FDE ICD Part 1 protocol to support OLDI exchanges. Its enforcement is currently further expanded towards North Africa, Greece and the Balkans, and Eastern Europe (purple links).

7. Flight Data Exchange (2)
FDE/ICD Part 1 implemented in 80 Civil/Mil centres based on X25
FDE/ICD Part 2 supports TCP / IP
No change to the OLDI application
Validation by iPAX
Procedure for publication as standard started
ECIP COM-04 Time scale : 1/ /2007
OLDI is a subset of AIDC
OLDI Application
OLDI Application
TCP/IP
FDE ICD
(communication
manager)
FDE ICD
(communication
manager)
FDE interface to X.25
FDE interface to TCP
Common rules and message formats are incorporated in the EUROCONTROL Standard for On-Line Data Interchange. This standard ( the Eurocontrol FDE ICD Part 1) defines a set of functionalities which can be implemented on top of X.25 networks and point-to-point links. The FDE ICD Part 1 standard identifies a protocol stack and determines the options that are part of these protocols, this is called a profile.
FDE-ICD Part 2 defines the exchange of data over TCP/IP and introduces a Management Information Base (MIB) for systems management.
In the ATN context, coordination is ensured by an application called ATS Interfacility Data Communications (AIDC, which is part of Inter Centre Communications - ICC). The ICAO ATN Panel produced a comprehensive manual explaining the operational context and the concept behind each ATN application ([CAMAL3]).
While more global and functionally richer than OLDI, the AIDC deployment is however conditional to the existence of ground/ground ATN communication services. As the OLDI standard in Europe continues to meet the operational requirements for flight data exchange and as IP is the strategy for the ground network environment , there is no need to migrate to AIDC within the ECAC area.
X.25

8. Radar Data Distribution (1)
RADNET - Germany / Benelux (4 States/EUROCONTROL)
RENAR - France
UK-RADNET - United Kingdom
CADIN - Czech Republic
REDAN - Spain
SACON - Slovak Republic
ACN - Austria
CANDI
etc.
Existing
Radar
Networks
based on
X25
The surveillance distribution domain encompasses a variety of systems that have been deployed on a national or regional basis to relay sensor data e.g. RMCDE, SCR/UAST SIR (Server Info Radar). Each have been designed on the basis of different objectives and may not be fully equivalent in terms of functionality. Surveillance distribution systems are networked for better service reliability and some are networked to possibly to exchange sensor data and service data.
As a result, the change in technology from X.25 to IP shall impact this data flow between surveillance distribution systems. This flow is not only a national issue as surveillance distribution systems are already networked on a regional basis.

9. Radar Data Distribution (2)
Debden
X.25
CAPSIN
Claxby
Gatwick
UK-RADNET
RADNET
Amsterdam
RAPNET
Boulogne
Chaumont
RENAR
Paris
X.75
RMCDE/S
DPN100
SIR

10. Radar Data Distribution (3)
Today’s radar network based on X.25 (e.g. RADNET)
Migration to TCP/IP
International Impact : 30 sensors & 60 radar systems
for RMCDE : IPv4 multicast profile for surveillance data distribution defined
The IPv4 multicast profile for surveillance data distribution has been released as an EUROCONTROL Guideline for Implementation Support (EGIS).

11. Message Handling (1) AFTN/CIDIN will be replaced by AMHS
AMHS in ECAC will use TCP / IP
An AMHS/IP specification is under development and submitted to ICAO/ACP/WGN
Communication between AMHS/IP and AMHS/ATN or AFTN systems will be ensured via double stacks
The ECG (Eatm Communications gateway) implements the AFTN/AMHS gateway as specified in Doc 9705; and provides dual stack underlying network (ATN and TCP/IP)
ECIP COM-05:
Migration of AMHS to an IP COTS-based messaging (long term)
The AFTN has been the cornerstone for aeronautical message interchange for the last 30 years. Both the technology and the specifications are out-dated, and ICAO has specified the Aeronautical Message Handling Service (AMHS) for future message handling applications. Some ATSPs ( Air Traffic Service Providers) are already deploying or plan to deploy AMHS technology for international messaging applications to replace the current AFTN. In the ECAC area, the rollout of AMHS-based systems is governed by the ECIP (European Convergence and Implementation Programme) COM05.
AMHS will be deployed over TCP/IP in the EUR region. A “Fast Track” AMHS/IP spec for Europe will be developed, and the content contributed to ICAO ACP.
The migration from AFTN/CIDIN to AMHS has been defined in ECIP COM05
Such implementations must coexist with, and where necessary interoperate with AMHS/ATN-based applications, via appropriate gateways for international messaging.
Initial deployment of AMHS technology has already begun, but coexistence with legacy (AFTN and CIDIN) technology will be necessary for the medium-to-long term.
The EATMP Communications Gateway offers portable software components necessary to implement a gateway between the AFTN message switching world and AMHS.

12. Message Handling (2) National IP Messaging 2000 2005 2010 2015 2020
Bilateral
ECAC AMHS/IP
AMHS / IP Messaging Gateway
AMHS/CIDIN/AFTN Gateway (ECG)
(External)
AFTN / CIDIN
(External)
National IP Messaging
Bilateral / International
Internet-based COTS messaging products are already in use on a national basis, and are expected to be used internationally subject to bilateral agreements. In the long term, an IP-based messaging system, not necessarily SMTP, is expected to gradually replace AMHS, such messaging system will still need to interoperate with AMHS via an appropriate gateway to ensure when so needed, a seamless store and forward messaging environment across the ECAC area. A study in this area needs to be undertaken.
2000
2005
2010
2015
2020

13. Ground / Ground Voice
International Voice over IP
National Voice Over IP
ATS-QSIG based Voice Network
Analogue Voice Network
(External)
1.1 MFC/R2
Analogue voice networks based on MFC/R2 are widely deployed in the ATSP community. These will continue to be operated in the medium term, with a gradual phasing out in accordance with technology evolution in the public telecomms service in the short and medium term.
1.2 ATS-QSIG Voice Services
The short term strategy is that most states should complete the move from legacy analogue systems to a QSIG based digital voice infrastructure which provides the technical base for the improved end-to-end voice services, in accordance with ECIP objectives.
1.3 Voice over IP
In view of the anticipated widespread commercial adoption of Internet technology, it is envisaged that these protocol sets will be the basis for voice over Asynchronous Transfer Mode, and future switching fabric and bearers, for the ATSP community. Adoption of IP as the common enabler for future fixed and mobile network services will allow for the introduction of voice over IP, based on ITU H.323 and/or IETF SIP, as a more cost advantageous goal for seamless voice services over multiple concatenated sub-network technologies. These protocol sets are also enablers for multi-media communications services such as videoconferencing.
2000
2005
2010
2015
2020

14. ECAC ATN Strategy (1)
The ATN internet is the strategic solution to support Air - Ground applications ( For G/G applications IP is the strategic solution).
ECIP ATC06 : Implement ATC A/G Data Link Services - 6/ /2007 ( Link2000 Programme)
The IP SNDCF allows COTS IP Networks to carry ATN A/G Traffic ( e.g. CPDLC messages)
Airborne IP (in the cabin) can coexist with ATN (in the cockpit)
1.1 ATN general
The ATN has been specified in international standards (ICAO SARPs). Those standards are mature having been validated through extensive prototyping and pre-operational trials programmes and the ATN is now being implemented for air/ground services providing safe and cost-effective data communications to meet the operational needs of the aeronautical community. The initial phase of the deployment consists of implementing ATN Internet service in support of the Link2000+ programme. The ATN Internet service will be the communications platform for the air-ground data communications services deployed for LINK2000+ from 2005 onwards.
1.2 ATN internet Service
The ATN internet service has been specified to deliver network services which have been identified as necessary to meet the data communications service requirements for air navigation applications that conform to the ICAO ATN SARPs. These requirements include specific characteristics such as policy based routing and mobile end systems. ATN Air-Ground end-to-end services will be carried over the underlying IP-based ground networks, using an appropriate SNDCF or tunnelling technology. In ATN technical terms, this means that the IP network is used as a ground-ground ATN subnetwork via an appropriate SNDCF

15. ECAC ATN Strategy (2) The LINK 2000+ Programme
Co-ordinating the implementation of en-route CPDLC (ACM, ACL, AMC, DLIC) over ATN/VDL2 by 2007.
Providing a migration path for legacy DCL and D-ATIS data link services to ATN/VDL2.
Programme Objectives
The LINK Programme

16. The current scope of the LINK Programme will provide 7 air-ground data link services for ATC, in the period 2003 to 2007, in the airspace of 11 European States. This will result in reduction of communication errors and pilot and controller fatigue (Safety); increased capacity through both reduction of voice congestion and increase in controller efficiency (Capacity) and reduction of flight costs generated by ATM delays, and of Airlines communication costs (Cost Effectiveness).
The implementation of the LINK Programme will require the completion of a wide range of activities by a number of stakeholders. These activities have been planned to enable implementation to be achieved in a safe and efficient manner.
The following data link services are included in the LINK Programme:
DLIC Data link Initiation Capability
ACM ATC Communications Management
ACL ATC Clearances
AMC ATC Microphone Check
DCL Departure Clearance
DSC Downstream Clearance
D-ATIS Data link ATIS

17. LINK2000 : Avionics + Pioneers
CMU
Rockwell Collins (now)
Teledyne (now)
Honeywell (mid 2004)
ATSU
Airbus (mid 2005 ?)
VDR (VDL Mode 2 radio)
Thales (now)
Honeywell (now)
Committed European PIONEERS
Lufthansa (Honeywell CMU/ Rockwell VDR)
SAS (Rockwell CMU/VDR)
AAL (Rockwell CMU/VDR)
ATI (Rockwell CMU/VDR)
Committed US PIONEERS
Continental (Rockwell CMU/VDR)
DELTA (Teledyne CMU/Thales VDR)
FEDEX (Rockwell CMU/VDR)
USAF (Rockwell CMU/VDR)

18. ATN and IP Co-Existence (1)
L2K
ATN
VDL2
ATC centre
The ATN internet service has been specified to deliver network services which have been identified as necessary to meet the data communications service requirements for air navigation applications that conform to the ICAO ATN SARPs. These requirements include specific characteristics such as policy based routing and mobile end systems. ATN Air-Ground end-to-end services will be carried over the underlying IP-based ground networks, using an appropriate SNDCF or tunnelling technology. In ATN technical terms, this means that the IP network is used as a ground-ground ATN subnetwork via an appropriate SNDCF.
X25 IP
L2K
Router
ATN
ATN data carried as user data over IP ground networks

19. ATN and IP Co-Existence (2)
Appl
AOC
ATN
Appl
IPP R
ATN R
Mobile IP
ATN Mobile
Subnetwork IP
ATN R
ATC centre
Ground IP
Network
ATN
Appl
Airline
ATN R
COM

20. ECAC Communications Strategy

21. Summary IP is the strategic solution for ground infrastructure
Migration and implementation of ground applications to IP underway has started
ATN is the strategic solution to support ATS air/ground applications
Implementation of ATN well underway
Coexistence of IP and ATN
ECAC Communications Strategy available at :

22. Thank You