and Infrastructure for Mobile Multimedia Applications
EPSRC GR/L64140 &GR/L64157
Alan Dix, 21/2/2002
Prototype Application Development
In order to evaluate the infrastructure we have developed a number of test applications including:
(i) An adaptive video streaming tool based on the RealPlayer video client. This application allows the platform to request specific streaming adaptations such as: switching to different stream qualities or changing the bit rate that the stream delivered.
(ii) An adaptive email client. This provides status information about all its activities (polling the pop server for new emails, down-loading emails, showing emails, etc.). All these activities can become triggers for adaptation of other applications in the system, or can be coordinated by the platform according to the user policies.
(iii) An adaptive web browser that can perform simple network adaptations. Specifically, the web browser utilises an intermediate proxy in order to perform network specific adaptation, e.g. it can alter images from web pages in order to speed up the download of web pages and it can control the transfer rate of data over the network.
In order to be able to monitor the system resources we also developed simple monitor applications for network bandwidth and available energy (from the end-systems internal battery). A snapshot of the operation of the prototype is shown in Fig. 3. In this figure the video player is triggered to reduce the use of bandwidth in order to allow the email client to download a large email within the timely requirements specified by the user.
Figure 3: Screen shot of prototype video player and email client (full size screen)