The iPod Touches were connected to an ad hoc wireless network that had been created using a Nokia N95 mobile phone, as the iPhone OS does not support the creation of ad hoc networks. The video stream was sent from another iPod Touch that was running our application in server mode. Although the streaming server has been integrated into our application, unfortunately it cannot access the video and audio files stored on the iPhone due to Apple’s limitations. An application can only access files within its own application bundle. At the moment, the only solution is to store all media files we want to share in the application bundle.
In Fig. 5 we present the bandwidth usage of our streaming server compared to the unicast solutions mentioned earlier. All plots were generated by Wireshark during the playback of the same video file. As seen on these plots, the bandwidth usage is constant and never exceeds 100 kbytes/s, which is significantly lower than the others. Note that adding additional receivers will not have a negative impact on the performance of our application, since we only use minimal feedback from the clients.