As part of the BEST project { a collaborative research effort under the Single European Sky ATM Research (SESAR) initiative { we developed the concept of the semantic container, aiming to facilitate information sharing and reuse in air tra c management (ATM) and air tra c operations, enabled by semantic technologies. In this context, a semantic container is a package of ATM information with an ontology-based description of the contents. The description serves for the management of semantic containers: The formal de nition of the contents of a semantic container allows to automatically match existing semantic containers with an application's information need. This demonstration showcases a proof-of-concept implementation of a system for the distributed and versioned storage of semantic containers.
Air tra c management (ATM) aims to ensure safe and e cient ight operations through the timely provisioning of relevant information to stakeholders such as pilots, air tra c controllers and others. Among the most common types of information exchanged in ATM, are messages such as Digital Notices to Airmen (DNOTAMs), which notify stakeholders of important events like runway closures and malfunctioning airport equipment, and Meteorological Terminal Air Reports (METARs), which report current weather conditions at airports. Other types of messages report on weather in regions of airspace, weather forecasts at airports or in regions of airspace, and signi cant meteorological events.
Di erent tasks in ATM and air tra c operations have di erent information needs. For example, planning of air tra c ow requires di erent types of information than piloting a ight. Furthermore, piloting a ight from Vienna (VIE) to Frankfurt (FRA) requires di erent information content-wise than a ight from Frankfurt (FRA) to Rio de Janeiro (GIG). While pilot brie ngs for both routes contain, among other message types, DNOTAMs and METARs, the brie ng for the VIE-FRA ight contains DNOTAMs and METARs relevant for VIE and FRA airports as well as messages relevant for en-route segments of the ight; messages for GIG airport will not be part of the VIE-FRA brie ng.
The System Wide Information Management (SWIM) concept, which is
currently being developed as part of the Single European Sky ATM Research
(SESAR) initiative, stipulates a service-oriented architecture and standard
exchange models for sharing ATM information (see [
In this demonstration4, we present a proof-of-concept implementation of a
semantic container management system (SCMS) for the distributed, versioned
storage of semantic containers in ATM. We refer to Deliverables 3.1 [
A semantic container has a semantic description, which de nes the membership
condition for data items [
For more information, visit the project website: https://project-best.eu/ 4 A demonstration video of the implementation is available on the website of the BEST project: http://project-best.eu/video/best_180604_final.mp4
Client Browser Frontend
REST REST
Node 1 Backend
...
Node n Backend «XML DB» Data Item Store «RDF DB» Local Registry «RDF DB» Global Registry «XML DB» Data Item Store «RDF DB» Local Registry
In order to separate the semantics from the storage concerns, i.e.,
distribution and versioning, we distinguish between logical and physical semantic
containers [
Figure 1 illustrates the architecture of the distributed semantic container management system (SCMS). For demonstration purposes, we provide a web frontend that allows to create and allocate containers at multiple server nodes. The frontend accesses via REST API multiple backend nodes at di erent locations, e.g., in Vienna, Frankfurt or even on an aircraft. Each backend node maintains an XML database for the storage of the actual data and an RDF database that serves as a local registry of physical containers. The di erent backend nodes share a global registry of logical containers, which may be (fully) replicated for increased availability. Thus, the SCMS comprises both a knowledge base for metadata and a database that contains the actual data items.
Using the presented proof-of-concept prototype, we demonstrate potential integration of semantic containers from the BEST project into the SWIM network { a BEST-enabled SWIM. In this scenario, an adapted Frequentis SWIM Registry provides not only information about SWIM services but also about semantic containers. The SCMS is used to de ne and create containers that are then visible in the SWIM registry. On an organizational level, the Frequentis
SWIM Integration platform (MosaiX) is used to con gure the SWIM information for the speci c SWIM applications. Finally, the information is accessed by the SWIM applications. To show BEST integration on an application level, we used an existing prototype { the Integrated Digital Brie ng { which was developed in SESAR 1.
In a BEST-enabled SWIM, semantic containers would facilitate reuse and caching of information as well as redundant allocation of safety-critical information, in addition to tracking changes of the relevant information over time. Consider, for example, that there are several main routes of air tra c. For each of these most frequent routes, a semantic container could package the static information that does not change very often and many ights on that route require. When collecting the relevant information for a speci c ight on such a route, rather than starting from scratch, the application could start with the already existing container. An application could then customize the container by creating a new container, based on the existing container, that adds additional information relevant for the speci c ight. Redundant allocation of semantic containers is important for safety reasons. Important information could be stored in multiple locations, including the aircraft. Tracking changes in the actual data set of a physical container over time is important to ensure auditability in case of accidents. That way, the version of a physical container in a particular location at a particular point in time can be reconstructed.
Acknowledgments. This project has received funding from the SESAR Joint Undertaking under grant agreement No 699298 under the European Union's Horizon 2020 research and innovation program. The views expressed in this paper are those of the authors.