Technical Information

Architecture

The pen client represents the start point for the user interaction if he is using the interactive paper interface. In fact, it is the component that receives the input coordinates from the digital pen over the serial port. The received coordinates are augmented with semantic value using the information stored in our cross-media information management platform called iServer that runs as web application in the Tomcat server. The pen client issues an HTTP request to XCM, our content management system, in order to retrieve the content bound to the current action. iPaper is the iServer plug-in that enables user interfaces based on digital enhanced paper. The request directed to XCM passes through the ClientController proxy, which can use the information stored in the state and context cache to augment the request with additional parameters. When the client controller receives the response from the server it is sent to the response handlers that are responsible to represent it on the appropriate output channel.

XCM supports two modes of operation for delivering content. The first one is called db mode, which is the default mode of operation. It works using the information stored in the XCM database, including templates and meta-information, and retrieves the content directly from the application database. The second mode is called file mode and it simply returns a file store in the XCM file repository. It is useful for testing and for binary files, which must not be stored in the database.

The Context Engine runs in a separate Java virtual machine and it is responsible to manage the sensors that gather the context information from the user environment, storing the collected information and keeping up to date the context cache in the state manager. Running in a separate process, it is possible to turn on and off the context engine independently of other components. In the client controller’s Java virtual machine we also hosts four services that are important for the system functionality. The previously mentioned state manager keeps the current parameter states of the current request, moreover it is used as cache for the context information.

The voice service provide an interface to the text-to-speech engine, so that the same instance can be shared and accessed by various components. The reminder service is used to remind selected events to the user, it uses the voice service and/or an external asynchronous service (e-mail/SMS) as communication channel. Finally, the navigation service is used to integrate a landmark navigation system in the system. In order to guarantee the flexibility and generality of the system, it is heavily based on databases. In fact, all the application specific information is stored in five database servers. OMS Pro 3.0 is used for the XCM, application, context and navigation databases and OMS Java for the iServer.

Some functionality needs access to external services. Therefore, in order to be able to offer these services, we need internet access. This is the case for the reminder service, which can send an SMS or an e-mail if the mail gateway is available. Some context sensors as well need access to the internet, for instance to retrieve weather forecast information. The system is so implemented that if the internet connection is not available, only this functionality is affected,
but the rest will work without problems.

The EdFest2005 system can be started as an EdFest kiosk in order to offer a graphical web interface to the user that allows him to select given event and prepare a personal programme. In this case we need to start the kiosk web application in Tomcat instead of XCM. The kiosk is able to update the iPaper information stored in iServer, this mechanism allows to dynamically create links between paper and digital information.

Interactive Paper Documents

The EdFest 2005 system is based around three interactive paper documents: a brochure, a map and a bookmark.
The three interactive documents are designed in such a way that beyond their use in the digital system, they can serve some useful purpose also without it.

The three documents were designed on the base of the official Fringe brochure. Interactivity like getting extra information about an event or reserve a ticket can be achieved by touching the blue pictograms.

Generating the interactive documents implies the consideration of the active areas defined by the blue pictograms. In order to be able to map the information stored on XCM on paper and link back from paper to the relative functionality on the system three main components play a fundamental role: XCM itselfs, iPublish and iServer. The interplay of the three components defines the publishing process.

Data stored in XCM are exported to iPublish in order to be printed on paper and mapped into active regions in the iServer database.
This is achieved by applying specific templates which generate a pdf to be printed out. During the generation of the document the position of the active areas is tagged and exported into the iServer, enabling it to link back the specific position to the right information.

Hardware Requirements

The hardware requirements includes Bluetooth for the connection of the digital pen and earpiece, Wi-Fi for network connections, one USB port for the GPS sensor, a mobile phone for the asynchronous communication with short messages (SMS). The systems was tested on laptops with at least 512 MB RAM and Pentium M 1.7 GHz processor. The full system require 1.6 GB of disk space, whereas 900 MB are needed by the AT&T Natural Voices voice synthesiser using unit selection synthesis technology. By using the diphone synthesis technology as in the case of FreeTTS, we can spare this disk space, but results in a worse voice quality. Additional information about speech synthesis technologies can be found here.