ACP WGN/01 (Montreal, 20-23 May 2003
WGN01-WP-18
Page 1

Aeronautical Communications Panel (ACP)

Working Group N

Montreal, Canada
20-23 May 2003

Agenda Item: 6.1 – Technical discussion - ICS

Value of the NSAP address ADM field

Presented by
S. Tamalet
Airbus France

ICCAIA

Introduction

In the scope of the AFAS project, Airbus-France is experimenting a dual-stack ACARS+ATN airborne router. The router is a derived version of the ATSU equipment, the main difference being that an ATN communication stack has been added and runs in parallel to the ACARS communication stack.

In order to set up the router in an operational state, Airline specific parameters (e.g. addressing identifiers, contracted VHF DSPs, routing preferences) have to be initialized within the router. The initialization of these parameters is typically done by the Airline maintenance operator (or by the pilot), through the Router HMI, being accessible via an MCDU in the cockpit.

The addition of the ATN communication stack within the equipment, implies that additional Airline specific parameters needs to be set by the maintenance operator. One of such additional parameter is the ADM field, which within the airborne router NSAP addresses identifies the Airline Administrative domain.

In the ICAO Doc 9705, the values of the ADM field for ATN routers owned by airlines is left undefined. The definition of values for this field is left under the responsibility of IATA.

Because the format and allowed range of values for the ADM field is not yet known, it could be envisaged to add on the MCDU router initialization page, an input area where the ADM field can be keyed in hexadecimal characters. However, this approach is undesirable for the following reasons:

  1. There will be an additional field to be set by the maintenance operator or the pilot; this will increase the workload
  2. Input of an hexadecimal parameter is to be avoided because this is prone to errors, and because maintenance operators or pilots do not like to manipulate data they don’t understand.

These cumbersome points could be eliminated, if the ADM field was set equal to the 3-letters Airline code (Airline Id). This is because the 3 letters Airline code is already part of the set of parameters to be defined by the operator via the MCDU (it is used as ACARS addressing parameter) and because this code is well known by the maintenance operator or the pilot.

Recommendation

Airbus-France would like to invite IATA to consider the above proposal to fix the ADM field value so that it is defined as being equal to the 3-letters Airline code.

Airbus France would also like to invite the ACP/WG N to consider whether, depending on the IATA position on this point, an update of the ICAO Doc 9705 Subvolume V could be useful.