A study of data processing in Xlet-based Interactive Digital Television Applications.

The main goal of this dissertation is to study the Xlet-based interactive applications (such as advertisements, games, government services and early warning applications) in the digital television broadcasting environment and to improve their versatility, usability and interoperability through the simplification of their codes and content management methods. The EU had set an obligation for its member states to begin digital television broadcasting by 2012, therefore the development of such systems prior to this deadline had become a task of utmost importance in recent years. At present, there are two major systems of digital video broadcasting (DVB), which are DVB-HTML and DVB-J (DVB-Java). I decided to give more emphasis on DVB-J for my research, mainly because it’s more compatible with the interactive applications that are created with Java-based Xlets, and also because it’s easier to use, modify and update; hence the reason why DVB-J is the system that’s preferred by a larger number of television broadcasting corporations worldwide. DVB-J is also the digital video broadcasting standard that’s compatible with a larger number of MHP (Multimedia Home Platform, or DVB-MHP) systems that are utilized by the set-top-boxes for receiving interactive content (in the form of Xlets) during digital television broadcasts; as well as by handheld devices and web-based internet television networks. As of today, Italy (which has a large and expanding DVB-T network) is one of the leading countries in the world that extensively utilize DVB-MHP systems for sending and receiving interactive content during IDTV broadcasts. By 2009, several administrative regions in Italy had already completed the switch-off process of their analog broadcasting systems and had gone all-digital. Numerous interactive services are currently available in the IDTV broadcasting environment of Italy, ranging from IDTV-commerce and IDTV-government services to the use of a growing number of internet content. At present, the terrestrial antennas for sending the aerial digital signals of the DVB-T networks aren’t capable of receiving any return signals for interaction by mobile handsets like the DVB-H, therefore interactivity is currently limited to internet connection through DSL in stationary devices or to mobile telephone services in the outdoor environments. Internet connection, however, allows the interoperability between different types of stationary and mobile devices, such as television sets, PCs, notebook computers, mobile phones, DVB-H, BlackBerry and iPod. Due to the complexities which arise from the burden of having to provide an efficient and safe interoperability between an ever-increasing number of different device types, I based my research on developing a CMS that’s simple, flexible and easy to upgrade. Since Xlets are Java applets that are developed for digital television broadcasting, I have so far concentrated on the utilization of Java TV API in platforms that are capable of receiving digital and interactive content, such as TV set-top-boxes, DVB-H, and the latest generation of cell phones. In order to optimize the use of such digital and interactive content, which become more diffused and complex through constant innovations, it is necessary to develop an IESG (Integrated Electronic Service Guide) system, due to the ever-increasing traffic of digital and interactive content. The IESG is particularly effective in categorizing the contents and optimizing their availability to the users through a more sensitive search which yields better results, thus saving both bandwidth and user time. In the following chapters, I have explained the methods that I used for the creation of simple and quick (optimized in terms of downloading and running time) Xlets for the IDTV broadcasting environment; and the elaboration of a basic and versatile content management system to store and run these Xlet-based applications by a Set-Top-Box, the functions and properties of which are emulated by the XleTView software. The themes that I chose for the Xlets are the Earthquake and Tsunami Early Warning application, the Recent Seismic Activity Report application, and the Emergency Services application.