With the advancement of mobile technologies, more and more mobile devices are designed for multimedia streaming services. A server-proxy-client network architecture is usually adopted to improve the quality of multimedia streaming services. However, proxy servers not only cache data for reducing the waiting time, but also tackle the user mobility in the IPv6 mobile networks. We assume that a mobile client is moving from subnet to subnet. If the mobile client connects to the same proxy all the way, then the transmission quality will become worse gradually. Thus, the mobile client should switch to a new proxy when it moves to a new subnet. In this paper, the procedure of switching the served proxies dynamically is defined as "proxy handoff". In order to make proxy handoff smoothly, a Layered Video Forwarding Mechanism (LVFM) based on IPv6 multicast and scalable MPEG-4 streaming is proposed and implemented. LVFM can analyze the situation of cached data in the original proxy and the new proxy and then decide whether the original proxy needs to forward the cached data to the new proxy or not. Once the forwarding procedure is required, LVFM can forward the cached video frames according to the priority of each layer. LVFM forwards these layers as long as the forwarding time can be done before the corresponding layers' presentation time is due. In order to verify the proposed LVFM, three experiments are designed and the experiment results are also presented in this paper.
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications