Strategy and use of IP and ATN for Aeronautical Communications in Europe
Ref : ACP/SGN1/Malmo/
ACP WGN-SGN1/05-WP xx
24 March 2006
AERONAUTICAL COMMUNICATIONS PANEL (ACP)
SUBgroup N1
Malmö, 27– 31March 2006
Agenda Item 4
Strategy and use of IP and ATN for Aeronautical Communications in Europe
Presented by Danny Van Roosbroek
Summary
This paper informs the Sub-Group on the strategy for IPS and ATN in Europe.
TABLE OF CONTENTS
1.Introduction......
2.Strategy......
3.Ground-Ground Data Communications......
3.1OLDI Message Exchange......
3.2CNS/ATM Applications......
3.3AMHS......
3.4Surveillance Data distribution......
3.5Network Infrastructure - Pan-European Network (PEN)......
4.Ground-Ground Voice Communications......
5.Air-Ground Data Communications......
6.Air-Ground Voice Communications......
7.Summary......
Version: 1.0Date: 24 March 2006Page: 1
Strategy and use of IP and ATN for Aeronautical Communications in Europe
Ref : ACP/SGN1/Malmo/
1.Introduction
The objective of this paper is to provide the Strategy in Europe, regarding the IPS Protocol Suite and the ATN network and the applications using IPS and ATN network services.
2.Strategy
The Strategy below applies to the selected networking technologies in support of ATM applications.
For ground-to-ground communications the Internet Protocol suite (IPS) shall be used. IPv6 is the recommended technology to support the meshed international network federating the national IPv4 implementations.
For air-to-ground communicationsthe ATN protocols, as specified in ICAO Doc 9705, shall be used.
3.Ground-Ground Data Communications
There are a number of applications that use IPS for ground-ground communication networks; related to the scope of the ACP Panel.
3.1OLDI Message Exchange
OLDI messages have traditionally been exchanged between ATC Centres in Europe using the Flight Data Exchange protocol (FDE-ICD), which is based on X.25 packet switched networks or point-to-point connections. FDE-ICD Part 2 was developed to support similar interchanges over IP, using IPv6, and this has been validated in pre-operational trials.
Under the EC Single European Sky interoperability regulation, a draft implementing rule has been developed for the Flight Message Transfer Protocol (FMTP), which is functionally identical to FDE-ICD Part 2. FMTP will become a mandatory requirement for EU Member Statesfrom 1 January 2009 (for new systems); and by 20 April 2011 for all systems.
ATS Interfacility Data Communication (AIDC) as standardised in ICAO Annex 10 and Doc 9705 is not implemented in the EUR Region.
The LINK 2000+ programme plans to perform CM ground forwarding using OLDI. CM Ground Forwarding is used in the EUR Region to avoid the CM Logon overhead during Transfer of Communications between European states.
3.2CNS/ATM Applications
The air-ground CNS/ATM applications specified in ICAO Annex 10 and Doc 9705 (CPDLC, CM, ADSC, FIS) are specified to operate over the ATN TP4 transport layer. The communications path has a ground-ground component in support of air-ground datalink applications. Some applications also have a ground-ground forwarding component.
For these datalink applications, the ATN Internet Communication Service (ICS) can be used, as specified in Doc 9705, using the IP Subnetwork Dependent Convergence Function (IP-SNDCF) to operate over an IP subnetwork as specified in the standard.
3.3AMHS
The Aeronautical Message Handling Service (AMHS) as specified in ICAO Annex 10 and Doc 9705 operates over the ATN TP4 transport layer.
In the European region, AMHS is being deployed on TCP/IP following EANPG Conclusion 44/45: ‘That States in the EUR region use TCP/IP …for the initial implementation of AMHS, as a transition mechanism to enable AMHS operations to commence ahead of the full SARPs compliant data transmission system’
A EUR regional profile for AMHS over TCP/IP is developed which specifies that AMHS will use IPS services by means of RFC1006. The use of RFC2126 is being considered for a future version of the profile.
For integration with other regions, a dual-stack configuration would be deployed, with boundary MTAs able to communicate within EUR via RFC 1006 and TCP/IP, and externally via TP4/CLNP as per ATN SARPs.
3.4Surveillance Data distribution
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). urveillance distribution systems are networked for better service reliability and are networked to exchange sensor data and service data.
As a result, of the strategic move from X.25 to IP this data flows between surveillance distribution systems shall run on the IPS .
More information on the migration of surveillance data is application is provided in a separate presentation.
3.5Network Infrastructure - Pan-European Network (PEN)
The concept of a Pan-European Network (PEN) providing a European-wide ground-ground communications infrastructure has been agreed by ANSPs as a strategic approach necessary to support future international ATM system developments. Recent work conducted has established that a managed IP network is essential to guarantee operational service continuity and to provide the required services for future applications.
The COM-T has requested EUROCONTROL to support the planning and co-ordination of implementation of the PEN through the development of a Programme/Service leading to a contract for service provision.
The PEN initiative has been triggered by the results of the Internet Protocol for Aeronautical eXchange (iPAX) Task Force. The objective was to develop or modify guidelines, specifications and possibly aeronautical standards related to the exchange of 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. In view of the existing IPv4 national or regional deployments and their non-interoperability, the iPAX-TF developed a solution combining both IPv4 and IPv6. The iPAX-TF concluded it's work in 2004.
Further information is provided in a separate presentation.
4.Ground-Ground Voice Communications
It is envisaged that voice communication will migrate to Voice Over IP (VoIP) applications. This is formalised in the EUROCONTROL COM Strategy and EUROCAE WG-67 terms of reference.
5.Air-Ground Data Communications
The CNS/ATM applications specified in ICAO Annex 10 and Doc 9705 are specified to operate over the ATN TP4 transport layer and ISO Connectionless Network Protocol (CLNP).
The LINK 2000+ Programme is now deploying operational CPDLC services in an area of the busy core European airspace. The LINK 2000+ data link services (ACL, ACM, AMC and DLIC) have been operational at Maastricht UAC for some time, and several hundred aircraft are benefiting from the data link services. With the introduction of PM-CPDLC, the need for voice read-back of profile-changing messages is being removed. The LINK 2000+ Baseline is well established and is solidly based on ATN protocols operating over a VDL Mode 2 network infrastructure operated by several interconnected aeronautical communication service providers.
A further European programme – CASCADE – will build on the achievements of LINK 2000+ and deploy additional services, using the CPDLC infrastructure and ADS-B.
Under the EC Single European Sky interoperability Regulation, a draft implementing rule on the provision and use of data link services supported by air-ground communications is currently being developed. The only specified Means of Compliance to the implementing rule is ATN with a VDL Mode 2 air-ground subnetwork. Widespread consultations are currently being undertaken on the proposed regulatory approach, after which the implementing rule itself will be drafted. It is expected to come into force from 2009 for new A/C and ATS Ground Service Providers; with implementation of ATN-based services over VDL-2 to become a mandatory legal requirement for EU Member States in specified airspace regions for specified aircraft classes. By 2014 all A/C are expected to be retrofitted in the selected airspace.
In the context of the Future Communications Study, investigations are being undertaken to define the air-ground data link and supported applications and services beyond the year 2020. New applications such as COTRAC are being evaluated, and it seems likely that IP will play an important role in supporting network communications over a future data link technology. With this in mind, studiesare under way to investigate the use of IP in air-ground ATS communications, as part of the future environment for air-ground networking.
6.Air-Ground Voice Communications
At present, there are no plans to change the existing VHF/UHF analogue voice infrastructure (other than 8.33 kHz channel spacing expansion activities).
7.Summary
Ground-Ground / Air-GroundData / (OLDI): IP – FMTP implementing rule.
(CPDLC g-g): IP subnet with SNDCF.
(AMHS)
Intra-EUR: EUR AMHS/TCP profile
Extra-EUR: ICAO SARPs - TP4 over a subnet (IP or X.25)
PEN / ( CPDLC/FIS/CM/DLIC ) ATN over VDL-2 - Data Link Implementing Rule
(Future Communications Study- all applications ) – target IP - to be confirmed by IPS studies
Voice / VoIP migration. / No plans
Version: 1.0Date: 24 March 2006Page: 1