Seamless MPEG-4 Video Streaming over Mobile IP-enabled Wireless LAN

In the mobile IP-enabled wireless LAN (WLAN), packet transfer is interrupted due to the handoff of a mobile node at the link and network layers, which results in burst packet loss. This transient behavior is hurting time-critical streaming media applications. Many ideas mitigating the interruption have been suggested such as reducing handoff latency and minimizing packet losses. Also, in the applications perspective, it is known that extending the prebuffering at a streaming client can mitigates the playback disruption due to handoffs. However, in the empirical experiment, seamless streaming still cannot be achieved due to the packet loss during handoff period in mobile agents. Moreover, the lack of study on the relation of the pre-buffering size and the handoff methods causes the over estimated pre-buffering. In this paper, targeting seamless streaming over the mobile IP-enabled WLAN, we extend the mobile IPv4 protocol and experiment on the MPEG-4 video streaming with the implemented mobile IP system. A packet forwarding with buffering mechanism is implemented to reduce the packet loss during link-/IP-layer handoff. Pre-buffering adjustment is performed based on the handoff transient time analysis [11]. The experimental results show that the proposed approach can reduce packet losses during a handoff and provide the feasibility of seamless MPEG-4 video streaming.