Draft AgendaACP WGN04 (New Orleans, 10th-19th November 2004)
ACP – WGN04-IP09
2/11/2004
AERONAUTICAL COMMUNICATIONS PANEL (ACP)
Working Group N - Networking
New Orleans, 10th– 19th November2004 (fourth meeting)
Agenda Item 3 : Coordination / Inputs With / From other Bodies
ATN Implementation Planning in the Asia/Pacific Region
Presented by Craig Head
Summary
This Information Paper provides an update on the current ATN implementation planning within the Asia/Pacific Region.
WGN04-WP01page 104/11/04
ATN Implementation Planning in the Asia/Pacific RegionACP WGN04 (New Orleans, 10th-19th November 2004)
1.Introduction
This paper provides a brief overview of the current progress in the implementation of the ATN in the Asia Pacific Region.
The Asia Pacific Region is committed to implementing the ATN in accordance with ICAO’s Doc 9705 – Manual of Technical Provisions for the ATN.
ICAO’s Asia Pacific ATN Transition Task Force (ATNTTF) is the body responsible for advising the Asia/Pacific Air Navigation Planning and Implementation Regional Group (APANPIRG) on ATN planning and implementation matters in the region. The ATNTTF was formed in 1999, holding its first meeting in Canberra, Australia. Over the past five years the members of the Task Force have developed various plans and technical guidance documents to assist States in implementation of the ATN in the region. These plans and documents have been approved by APANPIRG and are readily available to Asia and Pacific State members from ICAO’s Asia and Pacific office.
2.ATN Implementation in the Asia Pacific Region
The Asia/Pacific region is currently working toward a 2005 timetable for the implementation of the regional ATN ground-to-ground network that will support ATN applications, initially AMHS, in the region.
A concern had been raised, which needed to be addressed by the Region, suggesting that Telecommunication Service Providers are increasingly unwilling to provide low bandwidth connections and are phasing out X.25 Packet switched network services. There is also additional anecdotal evidence to support this concern. This has the potential to affect the implementation of ATN in the Asia/Pacific region. .
However, through the work of the Asia/Pacific ATN Transition Task Force Working Group (ATNTTF WG), the Asia/Pacific Region has been advised that the regional ATN network is not dependent on X.25 packet switched networks, but will be a private network composed of point-to-point communication links between ATN routers which implement the necessary data relay functionality. In the majority of cases, the communication links will be “clear channel” links. The only X.25 equipment required will be the X.25 cards and software built into the ATN routers connected via aDigital Service Unit or Network Terminating Unit interface provided by a Telecommunication Service Provider.
The Asia/Pacific Region also has been advised that point-to-point X.25 links may theoretically be supported on top of other sub-networks using appropriate equipment (e.g.protocol converters), such as X.25 over IP, X.25 over Frame Relay, and X.25 over ISDN, allowing the use of X.25 where direct support for these sub-networks is not built into the ATN router.
The ATNTTF WG, investigating the availability of X.25 in the region, anticipate that X.25 boards will be readily available for at least the next five years, and probably at increasing cost and diminishing availability for some time after that. It is believed that this availability will still be adequate to allow the regional ATN network to be established and to operate in the short-to-medium term.
Progress in the implementation of AMHS in the region is showing that a majority of States plan to be ready by the end of 2005/early 2006. Several States are already well advanced in their implementation programs. Hong Kong, China and Japan have their systems implemented and operational. Other States, such as Singapore and Thailand, are trialing systems. Australia is in the process of releasing its tender for its AFTN Replacement program which will include an AMHS service. Fiji, Indonesia and Mongolia have outlined their plans to implement the service by 2005. All services will operate over direct X.25 links.
It is anticipated that by the next ATNTTF/7 meeting in Shanghai, China, in April 2005, States will be able to confirm whether the objective to have AMHS implemented by the required target date will be met.
As the deployment of AMHS continues go grow in the region, the ATNTTF WG has been working towards developing a MTA routing policy for the region which will be presented at the next ATNTTF/7 meeting. The WG will be recommending that the Asia and Pacific regions be regarded as a single region as far as MTA routing is concerned. The policy will allow direct MTA-to-MTA routing to occur between “end states” for Intra-Regional AMHS routing only. However, Inter-Regional AMHS routing will be via nominated gateway MTAs, similar to that adopted today with AFTN.
3.Introduction of WMO BUFR Codes
At the last Asia Pacific ATNTTF WG meeting the Regional Officer MET informed the meeting that the World Meteorological Organisation plans to migrate to Binary Universal Form for the Representation of meteorological data (BUFR) for Coded Aeronautical Meteorological Messages. The new BUFR codes will be used in parallel with alphanumeric codes from 2007, with phase-out of the alphanumeric codes from 2015. States that are ready to implement table-driven codes will be allowed to do so from November 2007. After 2015, all exchange will be in binary format. The ATN and AMHS have been proposed for the exchange of BUFR coded messages which will require some modification to AMHS and place further pressure on the region to implement the AMHS that will allow the carriage for this type of OPMET traffic. It has been proposed by APANPIRG that this matter be addressed by the ATNTTF and the OPMET Management Task Force to jointly develop a transition plan by the end of 2005.
4.The Use of TCP/IP in the Asia Pacific Region
The use of TCP/IP in the Asia Pacific Region was discussed at the last Asia/Pacific ATNTTF WG meeting in Bangkok. While it had been decided to maintain X.25 connectivity between States in the short to medium term the region is fully aware that support for a long term solution will need to be established. Whether this should be TCP/IP, or some other form of Industry accepted protocol, is a matter that the ATNTTF WG believes should be addressed by the ICAO ACP and its associated Working Groups.
Valuable time has already been spent and investments made, or planned to be made, in implementing the ATN by Air Traffic Service Providers in the Asia and Pacific regions. Implementation of the AMHS and ground-ground ATN is in progress to meet a 2005 target date and to introduce a possible change in protocols is not considered appropriate at this late stage.
The Asia/Pacific Region is anxious to avoid the problem of sporadic pockets of AFTN and AMHS scattered throughout the region. Therefore, an asserted push to have the region operating over AMHS will be the main driving force over the next couple of years.
The Asia/Pacific ATNTTF WG has recommended that, until further information is forthcoming from the ACP WGN, TCP/IP should only be used as an encapsulation sub-network of the ATN under bilateral agreements between States and that it should not be used as a direct service until it has been formally addressed by the ACP WGN.
Regardless of the decision by the ACP WGN to introduce TCP/IP as a protocol stack of the ATN, its implementation in the region will most likely be delayed as majority of States will have already made their investments and the need to change would only be considered in their upgrade plans some time in the distant future.
Therefore, any direction that the ACP WGN is likely to take in the promotion of TCP/IP as a protocol stack of the ATN should be decided in a timely manner, and a proposed time frame outlined regarding the release of details in the Technical Provisions of the ATN, so that the relevant Asia/Pacific Regional Task Force and working groups can assess the likely impact on the region as a whole.
5.Action By The Meeting
The meeting is invited to note the commitment of the Asia Pacific Region in implementing the ground-to-ground network of the ATN by the end of 2005.
The meeting is also invited to note the Asia Pacific Region’s interest regarding the likely use of TCP/IP, its adoption as part of the ATN, and its release in Doc 9705 – Manual of Technical Provisions for the ATN.
WGN04-IP??Page 1