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FDPS Interfaces
The DL-FEP System provides an ATN-like interface to the FDPS including access to the CM, CPDLC and PM-CPDLC services as well as control commands and notifications. 2 FDPS interfaces have been developed (IMF Interface and FMTP over IP). The FDPS interface module can be customized to fit the curstomer's data link interface if needed.
Back To Top  Aircraft Management
The DL-FEP System provides data link services to 3 types of aircraft:
- LINK 2000+ aircraft operating the Doc 9705 Edition 2 application protocols Context Mangement (CM) and Standard CPDLC (STD-CPDLC)
- Data Link Implementing Rule compliant aircraft operating the Draft Doc 9880 application protocols Context Mangement (CM) and Protected Mode CPDLC (PM-CPDLC)
- EUROCAE ED-100A / RTCA 258A FANS1/A+ application protocols operating Aircraft Facility Notification (AFN) and CPDLC.
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Link 2000+ Services
The DL-FEP System provides the communication services associated with the EUROCAE ED-120 / RTCA DO-290 as profiled by the Link 2000+ program in Europe and the EUROCONTROL Data Link Service Specification supporting the SES Data Link Implementation Rule. These services comprise Data Link Initiation Service (DLIC), ATC Communications Management (ACM), ATC Clearance (ACL) and ATC Microphone Check (AMC). Development is current on-going on the development of ADS-C and D-FIS based services (e.g. 4DTRAD, D-OTIS).
Accommodation of FANS1/A+ Aircraft in ATN Environment
The DL-FEP System implements the accommodation rules defined in the EUROCAE ED-154 / RTCA DO-305 document in order to provide FANS1/A+ aircraft with the Link 2000+ services by translating ATN and FANS messages and emulating the CM and CPDLC connection-mode services over the connectionless ACARS services. This optional facility can be configured out for ATSUs not willing to operate FANS1/A+ aircraft in their airspace.
Local Diplay and Control Monitoring (LDCM)
The DL-FEP LDCM is the interface provided to the DL-FEP administrator. In addition to displaying information about current data link activity (e.g. number of ATN and/or FANS logged and CPDLC connected aircraft), the operator has access to direct informatin about the status of the DL-FEP modules and interfaces and can activate/desactivate the different components and functions of the system. Are also managed through the LDCM the versions and configurations of the system, as well as the user profiles.
Back To Top Data link High Availability Solution (Resiliency)
The DL-FEP Resilient Agent allows the building of a high availability redundant DL-FEP node, in order to meet the ED120 / DO290 performance requirements. Such node is composed of an operational system and a backup system. When the agent detects a software or hardware failure on the operational DL-FEP system, it automatically triggers a recovery procedure on the backup system in order to restore the DL-FEP service. Several redundant sub-network interfaces may be handled in order to increase service availability. The information maintained in the aircraft data bases and dynamically synchronized between the two systems is used by the FDPS to re-establish the CPDLC connections.
Interface to the Legal Recording System
The DL-FEP System sends to the Legal Recording System in real time a copy of all uplink and downlink messages transiting through the data link gateway. The recording of the data by the Legal Recording System is a EUROCAE ED-111 requirement put on the ATSU ground system for legal recording to allow post-analysis of the data link trafic. The Legal Recording facility can be removed by configuration.
SNMP-Based Resource Management
The DLFEP SNMP Agent offers remote administration capability. It permits to fully configure and/or monitor any of the DL-FEP stack resources. Alarms are sent to the manager when defined thresholds are reached (e.g. CPU usage, file disk usage, number of logged aircraft) or specific events occur (e.g. physical interface is down). It implements a dedicated DL-FEP MIB (MIB-II compatible). Its standardized interface (compliant with SNMP version 1, 2 and 3) permits to easily integrate the management of the DL-FEP System in a wider management infrastructure (NMS COTS).
Time Synchronization
The DL-FEP System is automatically synchronized with one or several external NTP server when available, or to the local clock.
Performances
The DL-FEP System is currently configured for use by 600 aircraft.
ED-109 Level 4 Assurance Level
The development of the DL-FEP System met the software development requirement specified by ED-109 AL 4 (equivalent to an DO178B airborne level between level C and D). Strong requirements have been put on the development team during the whole life-cycle of the DL-FEP software on multiple areas: full traceability from design requirements to test cases, coding and test standards, documentation, system and module tests, quality management, configuration management, etc...
Safety Assurance
A safety analysis (FHA, PSSA, SSA, SSC) is performed with any integration of the DL-FEP System within an overall ATC center to ensure that ED-120 Safety Requirements are effectively met by ther system in its target environment and identify any additional hazards specific to this environement that would jeopardize safety during operation of data link.
Overview of the Software Architure
The figure above illustrates the software architecture of the DL-FEP System.
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