AERONAUTICAL COMMUNICATIONS PANEL (ACP) Working Group N - Networking Information Paper

1


WGN05
-
IP04





AERONAUTICAL COMMUNICATIONS PANEL (ACP)



Working Group N
-

Networking


Information Paper




Report on the European Organization for Civil Aviation Equipment (EUROCAE)
Working Group 67 Proceedings for Voice over Internet Protocol
in Air Traffic
Management





Prepared by: Leon Sayadian (FAA)









March 2005


SUMMARY

This information paper is a report on the proceedings of the 6
th

meeting of EUROCAE Working
Group 67 (WG
-
67) and their subgroups, held at Eurocontrol headquarters i
n Brussels, Belgium to
develop a technical specification for Voice over Internet Protocols (VoIP) implementations in Air
Traffic Management (ATM) systems.



2

1. Background


Current ATM Ground
-
to
-
Ground (G
-
G) voice communication systems use TDM
-
based, point
-
to
-
point,
analog technology, which has not been cost
-
effective. However, in recent years, newer advances have
enabled the integration of voice and data in a common medium, which is enabled with TCP/UDP/IP
networking. Adopting this VoIP technology for ATM w
ill achieve the following benefits:




Enhanced Quality of Services (QoS), security, and safety



Improved cost over the current systems



Enhanced system scalability and flexibility



Integrated management


To realize these benefits in ATM communications, EUROCAE

WG
-
67 developed the Terms of Reference
(ToRs) and working objectives for VoIP in ATM. The ToRs were approved by the EUROCAE Council on
July 7
th
, 2004.

2. Scope


This paper describes the on
-
going work effort of the EUROCAE WG
-
67 and subgroups. The purpose
of
these groups is to develop VoIP specification and guidance documents for use in the development of G
-
G
infrastructures for ATM voice communications.

3. Objectives


The WG
-
67 divided into three sub
-
working groups in charge of the following tasks
-

as de
scribed in section
2 of the ToR
-

to perform the following ATM Voice Communications tasks:


WG67
-
1: Requirement Sub Group
(led by Eurocontrol) will define VoIP ATM System operational and
technical requirements at the application and transport layers. Docum
ent deliverables include:


-

End
-
to
-
End delays and parameters for voice and signaling

-

Monitoring/Recording functions

-

General/Management functions

-

System availability

-

Network performance


Delivery of these documents to SG2 will be expected by mid 20
05.


WG67
-
2: Interoperability Sub Group (
led by CS
-
France) will define applicable standards/protocols for
VoIP (e.g., H.323 series, SIP, MGCP, IAX, and RTP/RTCP over TCP/UDP/IP), and interfaces between
VoIP components, to fulfill operational and technical
requirements of telephone and radio stations.
Document deliverables include:



-

Voice Coding/Encoding and MOS


-

Signaling standards


3


-

Recording Interfaces


-

Management standards

-

Protocols and Parameters for ES and IS (e.g., Routers, Servers, Gateways
, Adapters)


-

Radio interfaces for ground stations


-

End
-
to
-
End QoS standards


Final versions of these documents are expected by April 2006.


WG67
-
3: WAN Sub Group (
led by DFS of Germany) will write WAN/LAN performance requirements to
fulfill QoS, safety
, network security, availability, and functional requirements for Intra
-
and Inter
-
domain
networking, using IPv4 and IPv6 technology. Using data from
SG1

and
SG2,
the following documents will
be developed:



-

Network design guidelines regarding existing in
frastructure and transitioning to future technology


-

Network security policy and protocols (e.g., IPSec, VPN, and MPLS)


-

IP addressing plan and policy for IPv4 and IPv6


-

Network QoS monitoring and reporting


-

System redundancy and switch
-
over times


-

Any
-
cast and multicast services


A final comprehensive release of all WG
-
67 documentation is expected by May 2006.


The interrelationships and workflow among the WG
-
67 subgroups is shown in Figure 1 below.


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Figure 1
–

WG
-
67 Workflow


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4. Progress of WG
-
67


The sixth meeting of WG
-
67 on VoIP was conducted in Brussels, Belgium on January 25
–

26, 2005. At this
meeting, the subgroups convened and defined their tasks, schedules, and responsible participants. One
outstanding WG
-
67 issue is to originate a new subgroup SG
-
4 (Validation and Tests) to identify sponsorship
for validating and verifying the WG
-
67 deliverable documentation (e.g., technical specifications, guidance
materiel). The WG
-
67 Chairman will send a WP to the EUROC
AE Council to approve the creation of SG
-
4.


It was estimated that the final WG
-
67 deliverables document would be ready by the third quarter of 2006,
which will now include validation and verification findings of the recommended technologies.


Once the WG
-
67 deliverables are approved by appropriate European standards organization(s), they will be
presented to ICAO/ANC panel WG
-
N for consideration as a recommended basis for the integration of VoIP
services in the future ATN.


Upcoming WG
-
67 meetings are sche
duled as follows:

-

March 17
–

18, 2005, Place: Florence/Italy (OTE)

-

May 11
–

12, 2005, Place: Bucharest (ROMATSA)


5. Glossary


ATM


Air Traffic Management

ES


End System

EUROCAE

European Organization for Civil Aviation Equipment

FAA


Federal Aviation A
dministration

G
-
G


Ground
-
to
-
Ground

IP


Information Paper

IPv4 and 6

Internet Protocol versions 4 and 6

IS


Intermediate System

LAN


Local Area Network

MGCP


Media Gateway Control Protocol

MOS


Mean Opinion Score

QoS


Quality of Service

RTCP


Real
-
time Con
trol Protocol

RTP


Real
-
time Protocol

SG


Sub Group

SIP


Session Initiation Protocol

TCP


Transport Control Protocol

ToR


Terms of Reference

UDP


User Datagram Protocol

VoIP


Voice over Internet Protocol

WAN


Wide Area Network

WG


Working Group