Abstract-Amovgh VBR coding is more efficient tiian CBR coding, the burstlness of VBR video traffic brings great difliculty to network resource management. To address this problem, we propose a novel wavelet-based trafflc smoothing (WTC) algorithm. Unlike existing algorithms, which only have one resolution, the WTS algorithm has the multiresolutional property that is preferable for smoothing VBR video traffic that exhibits a self-similar behavior, WTS allows traffic smoothing at multiple resolutions and the best transmission schedule is searched as a pruned subtree of a full binary tree, which corresponds to the original VBR video trafllc, WTS optimizes several metrics simultaneously for both the single and multipleflow case while traditional algorithm only optimize one or two metrics for a single flow. The computation complexity of the WTS algorithm is also lower.

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By carefully studying the characteristics of IPTV (Internet Protocol TeleVision) live streaming service supporting timeshift functions, we find the default disk I/O strategies of universal OS can not provide satisfactory performance. Based on these observations, this paper proposes a set of dedicated disk I/O strategies in the design and implementation of a live streaming server supporting timeshift functions. Our proposed strategies include asynchronous direct I/O, block-level data processing, media caching and media prefetching, which are implemented in a live streaming server (ClearServer) developed by ourselves. ClearServer has been successfully deployed in the Shanghai Zhabei IPTV test-bed. Based on the deployment, detailed performance evaluation and test results demonstrate that the proposed strategies significantly improve several major performance metrics of the IPTV live streaming servers.

Streaming services on wireless network is being popular since the bandwidth and QoS on wireless network has been improved. However, the dynamic fluctuated bandwidth, higher error rate and sharp delay jitter on wireless channel cause trouble to the real-time demand of streaming services. The wireless streaming media system aims at mobile users must also consider the large scale number of the potential users and the fast growth in the future. To solve these problems, we propose a scalable wireless video streaming system adopting TCP transmission mode in this paper. Our proposed system is compatible with the RTSP/RTP protocols. It adopts RTP-on-TCP transmission mode to improve the quality of service on wireless network. It takes a hybrid centralized-distributed architecture on the server side to support the growth of users. Streaming services such as VOD are supported by the system with a wide range of media bitrates and several highperformance compression standards such as H264 and AMR. 1． IntroductionStreaming Media is a way to transmit multimedia on networks as a stream. It first appeared on wired networks. The video is being played while it is being downloaded. In this way, users can watch the video before they download the whole file. So the initial delay is dramatically decreased. Furthermore, users can do the VCR operation, which provides a high level of interaction, dramatically improves the personal experience. Due to the above advantages, streaming media applications has been widely deployed on the broadband-wired network, such as Video on Demand, video live streaming, video conference, Distant Education, and Digital Library.Recently, streaming services also become popular on wireless networks when the bandwidth has grown and the quality of service has been improved. In addition to the traditional streaming services on wired networks, wireless streaming media can provide many unique services, such as cell-phone online games, mobile TV, MMS with video streaming, outdoor video telephone/meeting, and mobile positioning services, with the mobility of wireless terminal devices. In the near future, 3G network technology will provide a much higher bandwidth, which will surely make streaming service more popular.However, some characters of the wireless network such as dynamic fluctuated bandwidth, higher error rate and sharp delay jitter do harm to the streaming service, as the latter has significant demands on real-time and reliability. So wireless-streaming-media systems should take these problems into consideration.Besides, considering the fast growth of the mobile users, wireless-streaming-media systems must have good scalability. But traditional streaming media server architecture that is based on one single machine cannot meet the need of this demand.To solve these problems, we designed a high performance wireless-streaming-media system adopting TCP transmission mode. The server system has a hybrid centralized-distributed architecture to archive high scalability. It uses RTSP (Real Time Streaming Protocol) a...