THE LINK 2000+ DATALINK TEST FACILITY CPDLC GROUND AUTOMATED TOOL March 2007 By Isabelle HERAIL
TABLE OF CONTENTS Introduction...2 CPDLC Ground Automated Tool...3 Objectives...3 Automated Tool Accessibility...4 CMU/ATSU Addressing Database Pre-requisites...4 Before a Test session...4 Test session exercise...6 Logging CPDLC exchanges...9 Airlines feedback...9 Let s have a look at it!!!...10 Future development...11 Page 1
Introduction The LINK2000+ Datalink Test Facility is located at the Eurocontrol Experimental Center (EEC) in Bretigny-sur-Orge,France. The main objective of the LINK2000+ Test Facility is to support the validation of operational CPDLC services and ATN/VDL Mode2 infrastructure for both air and ground implementations before they are approved in an ATC operational environment. As introduced in Sept 2004 EEC Newsletter, the LINK2000+ Datalink Test Facility provides an inter-operability testing platform for the LINK 2000+ baseline and offers: Support to Avionics suppliers and Pioneer Airlines on CPDLC/ATN/VDL Mode2 interoperability testing, Support to ANSPs (Air Navigation Service Providers) implementations on CPDLC/ATN interoperability testing, Support in deployment of LINK2000+ ATN/VDL Mode2 Air-Ground and Ground-Ground infrastructure to ACSPs (Air-Ground Communication Service Providers). Page 2
CPDLC Ground Automated Tool As part of the LINK2000+ ATN/CPDLC deployment, a CPDLC Ground Automated Tool was requested by several Airlines equipped with LINK2000+ Baseline compliant ATN CMU or ATSU. Eurocontrol in the context of support to Pioneer Airlines decided to undertake the development of such a tool based on the existing EEC LINK2000+ Datalink Test Facility CM (Context Management) and CPDLC air and ground tools system architecture. GROUND CM/CPDLC AUTOMATED TOOL PM-CPDLC/CPDLC ASEs CM ASEs Airtel ATN Upper Layers Compaq EVO PC Linux OS Wanware X.25 boards Lan integrated interface ATN BIS/ES Airtel ATN Lower Layers Ethernet X.25 Access Access LINK2000+ Ground Automated Tool System Architecture Objectives The ground automated tool is intended to provide Airlines with support: To verify proper CM/CPDLC equipment installation and functioning. To verify new software avionics releases (from a test mock-up or a test aircraft in the hangar), before the software is installed on the first aircraft. To assist in aircrew CM/CPDLC familiarization. The main interest for the airlines is to have a ground tool available to allow them to exercise CPDLC from an aircraft, without any operator on the ground side. Page 3
Automated Tool Accessibility The ground automated tool supports CM/CPDLC end-to-end connectivity from any aircraft connected to the LINK2000+ ATN/VDL-Mode 2 operational infrastructure either via ARINC or SITA Air/Ground Communication Service Providers (ACSP). Airline Aircraft Grounded Avionics Airline Test Rig Avionics Simulation Avionics Laboratory LINK2000+ ATN/VDL-M2 Infrastructure X25 / ISDN/ FR EEC Datalink Test Facility LFPYTEST Ground Automated Tool LINK2000+ Ground Automated Tool Topology CMU/ATSU Addressing Database Pre-requisites The ground automated tool is identified as a ground ATC center with its own Ground Facility Designator (GFD): LFPYTEST. LFPYTEST GFD and CM ATN application address need to be part of the aircraft CMU or ATSU ATN addressing database to allow an Airline to exercise CM/CPDLC with the tool; the tool may upload this information dynamically. Before a Test session Some preliminary co-ordination is requested with the LINK2000+ Test Facility Manager in order to register in a filter list the 24bit ICAO address of any aircraft wishing to perform a test with the tool. The main objective is to control the access to the tool. When a Logon indication coming from an aircraft is received on the ground, the automated tool checks if the peer aircraft ID value is part of the positive filter list; otherwise the Logon indication is rejected. Page 4
LINK2000+ Ground Automated Tool Main Window Page 5
Test session exercise The different steps of a test session between a LINK2000+ Baseline compliant CMU/ATSU and the ground automated tool are described below. PHASE DESCRIPTION LOGON - From CMU/ATSU the aircrew sends a LOGON request to LFPYTEST - If the LOGON is accepted (the aircraft ID is in the ground tool filter list, the aircraft is not logged on yet and a maximum of five aircraft are not connected yet), the tool sends a positive LOGON response back. CURRENT DATA AUTHORITY - Shortly after the LOGON response has been sent, the ground tool initiates the CPDLC connection and waits for the CURRENT DATA AUTHORITY message from the aircraft. - A CPDLC session timer of 20 minutes is started on the ground. The main objective of the session timer is to limit the CPDLC connection duration of an aircraft and allow concurrent pending test aircraft to connect. - A free text message is uploaded to announce LFPYTEST as the Current ATC Unit. ACCEPTANCE - Once the Current ATC Unit message has been notified, the ground tool notifies the aircrew that they are connected to a test system and waits for the crew to accept the test conditions. - The crew has to select ROGER message to further continue exercising CPDLC with the test tool. If an UNABLE response is received or the response timer expires, the CPDLC connection is aborted by the ground side. Page 6
PHASE CPDLC DOWNLINK MESSAGES PROCESS DESCRIPTION - When the ROGER response is received on the ground, the tool sends a free text message inviting the crew to send downlink requests; it also indicates how to proceed to trigger the uplink clearances sequence. - When a downlink request is received, the tool automatically returns an operational response. The response is taken from a list of four pre-configured responses. If the same downlink request is received several times during a same CPDLC session, the tool rotates on the potential responses. - When the crew wants to move to the uplink messages sequence, they downlink a REQUEST DIRECT TO UP000 (fixname) as indicated in previous freetext message. - The tools replies with an AFFIRM message and starts uplinking the ground clearances. Page 7
PHASE CPDLC UPLINK MESSAGES PROCESS DESCRIPTION - The tool sends the uplink messages taken from a list of predefined uplink clearances. The list includes the most common messages currently used at Maastricht UAC. - When a clearance is received on the CMU/ATSU, the aircrew selects the appropriate response (or leaves the response timer to expire). - When the response from the air side is received on the ground, the automated tool moves to the next clearance in the table after a 10 seconds delay. - Once the uplink sequence is completed a relevant freetext message is sent to the crew. CPDLC connection TERMINATION The air side may terminate a CPDLC connection by sending a LOGOFF/TERMINATE from the CMU/ATSU at any convenient time. The ground tool may terminate the CPDLC connection for several reasons: - The aircraft does not accept the conditions at the acceptance phase. - The CPDLC session timeout expires. A free text message is sent to the crew before the ground disconnects. Page 8
Logging CPDLC exchanges All CM/CPDLC exchanges performed with an aircraft during a test session with the ground automated tool are logged for further analysis. An Airline may request the relevant logs related to a test session from the LINK2000+ Test Facility manager. Airlines feedback LINK2000+ Ground Automated Tool CPDLC Log Example The ground automated tool already received very positive feedback from the pioneer Airlines who had the opportunity to try it from test rigs or equipped aircraft. Lufthansa Lufthansa CityLine Page 9
Let s have a look at it!!! Please feel free to have a look at the short video showing an example of a test session against the CPDLC ground automated tool exercised from a Rockwell Collins CMU 900 interface. The video was taken in the EEC LINK2000+ Datalink Test Facility equipped with an ATN/VDL Mode2 Rockwell Collins avionics test rig. Just try CPDLC now!!! Page 10
Future development Based on the same system architecture as the LINK2000+ Ground Automated Tool, an Air Automated tool is planned to be developed in the course of 2007 in order to support Air Navigation Service Providers implementation and interoperability testing. Page 11