Delivery of Pre-stored Videos for Mobile Clients with Insufficient Playback Buffer and Bounded Delay Guarantee

A deterministic service model assisted by a sufficiently large playback buffer space can provide bounded delay guarantees for video packets and simplify network resource management. However, many popular mobile terminals do not have sufficient memory capacity for deterministic video services since the embedded memory is limited and needs to be shared by numerous software programs and masses of personal data. This paper improves the traditional deterministic modeling approach for delivering pre-stored videos to mobile clients with QoS guarantees. The limitation of playback buffer space, the network delay jitter, the processing load of resource management, and the QoS guarantee are considered in the proposed mechanism. Some traffic smoothing operations are integrated into the proposed mechanism for reducing the playback buffer demand and data rate variation. This paper further proposes a smart video frame skip algorithm, originating at the sender for preventing possible overflow problems due to insufficient playback buffer space. The algorithm can determine the most suitable temporal range for skipping frames and prevent arbitrary discarding from inappropriate video frames such as I-frames on the client side. Simulation results reveal that the proposed mechanism can effectively remedy situations of insufficient playback buffer space while still maintaining the advantages of deterministic services.