Abstract: In today’s mobile era, multimedia applications need to communicate in real-time and are sensitive to the Quality of Service (QoS) they receive from the mobile network environment. For these applications to perform adequately and be widely used, QoS must be quantified and managed. Proxies can improve the quality of service of clients when the server proxy client networking architecture is applied to mobile networking environment. Since the mobile clients keep moving in the mobile networking environment, they should be able to switch to a new proxy dynamically in order to get the quality in multimedia streaming. In this paper, Application-layer Proxy Handoff (APH) is proposed to have applications be executed smoothly when mobile clients move in the server-proxy-client architecture. First, APH employs application-layer anycast to select one of the candidate proxies as the next proxy. Second, APH utilizes IPv6 multicast to switch the session from the original proxy to the next proxy smoothly. In order to meet the requirements of clients with multiple resolutions, transcoding enabled proxies are employed in this system. The transcoding enabled proxies perform transcoding as well as caching for efficient rich media delivery to mobile network users and also it optimizes the bandwidth requirement.

Keywords: Proxy handoff, Transcoding, Application Layer any cast, Quos.