1

Study into IPS Suitability for Air-Ground ATM Communication

Carsten Underbjerg, Ericsson Member of Helios Study Consortium

European Organisation for the Safety of Air Navigation 18th September 2006

2

Introduction

The Future Communication Infrastructure (FCI) will support both ATS and AOC data communication applications between aircraft and ground systems for 2020+

This presentation describes a study into the use of the Internet Protocol Suite (IPS) for future air-ground communication supporting critical Air Traffic Services (ATS)

The study is being undertaken by a Helios led consortium of industrial partners on behalf of Eurocontrol

3

Study objectives

Assess the feasibility of using IP to support the next generation of collaborative ATS air-ground applications

Taking advantage of COTS components, where possible Identify a representative sample of Data Link Services that will be deployed

in the 2020+ timeframe Derive a common set of application requirements that an IPS

implementation must satisfy if it is to be deployed Investigate the use of the IPS over a representative sample of air-ground,

ground-ground and air-air networks This phase of work will result in a set of “top down” application

requirements, and “bottom up” information on how the IPS is expected to be implemented and what it can provide.

4

Study team

The study team has wide experience both of the aviation and wider industrial applications of the IPS

It will explore the potential of a future IPS system, using lessons learnt from current ATN-based implementations.

The team is led by Helios Technology (UK), and supported by: Ericsson (Sweden) Sofréavia (France) Luftfartsverket LFV (Sweden) Rockwell Collins (France) DLR (Germany) SITA (Multinational)

5

What is the Problem?

ATN has already demonstrated that packet mode communications air/ground works The IPS is simply the industry standard means of achieving the same thing

Downlinking IP packets is straightforward Aircraft may consider ground station to be a “default router” Properly addressed IP packets can be forwarded from Ground Station into the

ground Internet for delivery However, Uplink is a problem

IP Addresses are Network Relative An Aircraft will have a different IP Address on each air/ground network it is

attached to Assigned statically or dynamically

How can seamless uplink communications be achieved if the air/ground network changes in flight?

6

Options Available

Network Assigned IP Address

May changeIn Flight

ApplicationMust be

Resilient toChange

Send IP AddressAdvisories

To Ground Peer

Remains ConstantIn Flight

Same NetworkUsed throughout

Flight

No Problem!

Network Changes In Flight

IP AddressTransferred

Between Networks(micromobility)

No Problem!

Manage IP AddressChange in Internet

(macromobilty)

UseMobile IP

UseRouting Protocols

7

Choice of Options

Cannot assume same network always available during a Flight Resilience issues Denial of Service Issues

Micromobility is attractive but Relies on network providers to co-ordinate Does not permit operations where network providers do not or are

unable to co-operate Concern over transition when need to upgrade technology

The above solutions may be used wherever possible, but Study needs to address a full Solution

8

IP Study will Investigate

The design of Applications that are tolerant to IP Address Change

Mobile IP based solutions including NEMO Routing Protocol based solutions

Building on experience with existing ATN approach A different team will look at each approach

A competitive approach will be used to either Select Best Solution Determine when a given solution is appropriate

The Study will investigate three scenarios

9

Scenario 1

Mobility Management using Standard Routing Protocols A simple translation of the current ATN specification to the IPS Similar to the current ATN mobility support, but using the IPS

protocol BGP-4 (RFC 1771 Border Gateway Protocol) instead of ISO standard IDRP (ISO/IEC 10747 Inter-domain Routing Protocol)

The applications and ATN Upper Layer Communications Service are otherwise unchanged

If this scenario is to be successful then it will be important to demonstrate that the known problems can be solved without a radical change of approach

10

Scenario 2

Mobility Management using Mobile IP to manage mobility An IPS ATN based on RFC specified Mobile IP The study will investigate whether such scenarios result in a

reduced level of functionality (e.g. by not supporting more than one mobile network simultaneously), and if so how significant this is

There is also a concern over COTS support of Mobile IP, and this issue will need investigation.

Is NEMO relevant?

11

Scenario 3

Mobility Management using the Application Message Server Application managed mobility A “three layer approach”, where

The lowest layer is standard TCP/IP with no special requirements including no mobility support requirements

The middle layer is an ATN message server and provides a common message exchange and mobility management. It encapsulates what is ATN specific functionality that is common to all Data Link Services, but which is not subject to safety requirements

The top layer is the user layer that supports the user exchange of messages and is subject to safety requirements.

The separation of top and middle layers follows PM-CPDLC approach The proposed Message Server is resilent to IP Address change but can be used

with other Mobility Solutions

12

Work breakdown structure

WP1: Application requirement analysis WP2: IPS Analysis WP3: Assessment of Candidate Future Comm Infrastructures WP4: Security Threat and Vulnerability Analysis WP5: Review and Recommendation of the Candidate IPS

Architecture WP6: Use Cases WP7: Trials and Simulations

13

Study Deliverables

Application Requirements Report – 2020+ Timeframe IPS Analysis – a survey of the IPS today and how it is

implemented over many different networks Analysis of Mobility Options Security Threat and Vulnerability Analysis Recommended Future Comm Architecture “Use Cases” Proposals for Trials and Prototypes

14

Consultation – Forthcoming Workshop

To obtain a wide involvement from stakeholders when assessing the candidate scenarios, the assessment will include a workshop on 8th November 2006 at Eurocontrol HQ

The workshop will present: the Data Link Service requirements, the IPS implementation options,

and the three candidate scenarios the assessment criteria and the security report Recommendations on the Future Comm Architecture

Consensus will be sought as to which is the preferred scenario

15

Questions

For further information concerning the study, please contact:Danny Van RoosbroekEATM – DAS/CSMEurocontrol HQdanny.van-roosbroek@eurocontrol.intTel: +32-2-729 3471