| dc.description.abstract | Today s most advanced mobile devices support communication through a variety of network technologies; GSM (including GPRS and EDGE), UMTS, WLAN, Bluetooth, and IR. This master thesis characterizes different network technologies and protocols available to mobile devices, phones in particular. In addition, service provisioning capabilities over different types of networks are identified. Internet access till now has been provided over GSM or UMTS, often via a WAP Gateway. With a WAP Gateway, service providers can offer services to 3rd party content providers, enabling these to differentiate their content according to GSM/UMTS connectivity and type of client device. With the introduction of WAP 2.0, internet access for mobile devices does not depend on a WAP Gateway. The introduction of WLAN support in mobile devices enhances this effect. Internet access for mobile devices can also be provided through Bluetooth hotspots. A discussion concerning criteria for network selection when utilizing data services, distribution of responsibility when detecting available networks for the client and network selection, and different methods for service content differentiation follows. Possible solutions are suggested, and pros and cons are listed in order to provide a basis for the practical part of the thesis. Based on the discussion, a demonstrator is implemented, consisting of a client and server application. The client application is implemented using Java 2 Micro Edition (J2ME). The server application consists of three main parts; an HTTP server, a streaming server, and a Bluetooth server. The demonstrator allows the user to prioritize different criteria for network selection, and receive differentiated content from the content provider (server app.) according to type of client network. The service content offered by the demonstrator is information about movies and movie trailers. This type of content is chosen because multimedia like video is easy to differentiate in order to match different types of network s characteristics. The demonstrator also allows the user at any time to see the data rate (payload only) achieved during the last request. Limitations in J2ME prevented the implementation of a fully functional real-life demonstrator, but as a proof of concept it works well. The thesis concludes with the need for enhanced user preferences support concerning network selection when utilizing data services, and HTTP protocol support for service content differentiation in built-in mini-browsers on mobile devices. | nb_NO |
