Architecture
The SHARE system provides four services which are accessible over one single client main GUI application: PTS voice/video, digital message forms (DMF), map navigation and multimedia content indexing/retrieval. Each service can also be used as a separate application if the other components fail. The general idea is, however, that all services are interrelated to the others during the operation by connecting all of them to a common ontology-based knowledge base and a digital archive. The knowledge base is populated with instances of ontology concepts by all four application services. All modules can also query the knowledge base for new knowledge instances that were created by other applications before. In this way all knowledge generated during the operation by user interaction or by reasoning is stored in a central database and can be used for information retrieval and system control while the operation evolves.
- Complete software architecture of the SHARE system
Another important aspect of the data server is the integrated multimodal interface, which allows voice input by users. Command and control functionality is implemented by using a multimodal gateway on server side that passes incoming user input, like voice and text commands, to an automatic speech recognition or text-to-speech systems. For the first prototype only the multimedia retrieval service supports this multimodal interface. For the second project phase it is planed to extend it to the other data services. The multimodal client/server system is shown in the upper part of figure above which illustrates the complete software architecture of the SHARE system.
Integration of the various components of the system is done by following the concept of a service-oriented architecture (SOA). A service is in this context a functionality that can be accessed over a standardized interface. The most common access method is that of a Web service using SOAP (simple object access protocol) in connection with a Servlet container and HTTP server like Apache Tomcat. Other access methods for services are SIP/RTP (session initialization protocol / real-time transport protocol) and simple HTTP. All three of these methods are used for the first integrated prototype. Indexing/retrieval service, DMF and Ontology Data Service are implemented as Web services. PTS voice is implemented using a SIP/RTP interface. Finally, the map navigation service uses simple HTTP requests to a so called Web map server/Web feature server, which again provide a standardized interface.
Detailed View on one SHARE Service
The second version of the map application was released by end 2006. It supports 3D digital maps and location-based services. The following pictures show screenshots of the MAP3D client GUI with 2D/3D maps and pedestrian information.
- Screenshot of the SHARE MAP3D client with pedestrian information and a 3D view of Dortmund city
- SHARE MAP3D client with synchronized 2D/3D view of the Westfalen-Stadium and building blocks with texture information
When the user navigates through the map the 2D and 3D views are synchronized automatically. Full screen display for both 2D and 3D maps is possible. The 3D maps provide two different data objects. The first is a 2.5 dimensional model of building blocks where only the high was estimated during the capturing process. Additionally texture information of the cladding and roof type information is provided. Secondly, in detail modeled 3D objects are available for important buildings. The current data set contains a complex model of the Westfalenstadium in Dortmund.
Location-based services are integrated by adding a GPS receiver to every end-device. Geographical coordinates of all users are stored frequently on server side. The user can ask for point-of-interest in his neighborhood by specifying the desired POIs a radius which determines the area of interest. POIs like restaurants or hospitals are then shown on the map in the radius around the user’s position.
Finally, pedestrian information can be visualized as a new layer on the map. Walkways, crossings or non-crossable roads are examples of this type of imformation.