Streaming of continuous media over wireless links is a notoriously difficult problem. This is due to the stringent Quality of Service requirements of continuous media and the unreliability of wireless links. We develop a streaming protocol for the real-time delivery of gprerecorded continuous media from a central base station to multiple mobile clients within a wireless cell. Our protocol prefetches parts of the ongoing continuous media streams into prefetch buffers in the clients. Our protocol prefetches according to a Join-the-Shortest-Queue policy. By exploiting rate adaptation techniques of wireless data packet protocols, the Join-the-Shortest-Queue policy dynamically allocates more transmission capacity to clients with small prefetched reserves. Our protocol uses channel probing to handle the location-dependent, time-varying, and bursty errors of wireless links. We evaluate our prefetching protocol through extensive simulations with VBR MPEG encoded video traces. Our simulations indicate that for bursty VBR video with an average rate of 64 kbit/sec and typical wireless communication conditions our prefetching protocol achieves client starvation probabilities on the order of ¢ ¡ ¤ £ ¦ ¥ and a bandwidth efficiency of 90 % with client buffers of 128 kBytes.
We have recently developed a prefetching protocol for video streaming, which schedules the transmissions according to a join-the-shortest-queue (JSQ) policy and the current channel conditions REF .
A prefetching protocol for continuous media streaming in wireless environments
IEEE Journal on Selected Areas in Communications
Computer Science