Research On The Reliability Of Real-time Multimedia Transport System Based On Embedded Operating System

With the fast development of telecommunications in recent years, allkinds of multimedia business, gloriously, provide subsribers with variousservices. The service of the network transmission of real time multimediadata is practiced more and more broadly, and becomes the mainstreamstep by step. The original design purpose of IP network is to deal withnon-realtime data, and just can provide "best effort" service. Therefore, itcannot provide the quality of service for multimedia services such asaudio and video playback. Moreover, the real time multimedia servicewith high bandwidth occupation is growing more, in the condition ofcertain total bandwidth, every user has no enough bandwidth to receivemultimedia service, so the playback performance is poor. One keyproblem in the research of real time multimedia service is how to increasethe reliability of real time multimedia data transmission, and how toensure QoS of telecommunications.This article introduces a practical proposal, which is based on theembedded operating system and can ensure the real time playbackperformance of multimedia service. Based on this proposal, this articleanalyses the method and progress of building embedded operating systemon M5249C3 development board, and analyses and compares the datarecovery method which is suitable for real time multimedia transmission.On the basis of the research on the technical background anddevelopment future of embedded operationg system and real timemultimedia applications, this article describes the internal modules andexternal interfaces of development board M5249C3, analysis thefundamentals of embedded operating system uClinux and its realizationon M5249C3, including the selection of kernel modules, the realization ofJFFS file system, kernel compilation and program debugging. And then,it introduces the real time transmission protocol RFC 1889, and then onits basis analysizes the factors which affect the playback performance ofreal time multimedia, and the balance of the performance of real timemultimedia. At last, this article brings up a method to use forward errorcorrection proposal (RFC 2733) to ensure the performance of real timemultimedia playback, and carries out practical test. The test shows thatthe FEC proposal introduced in this article can greatly decrease thepacket loss ratio, increase the performance of real time multimediaplayback, increase the reliability of real time multimedia datatransmission, and effectively deals with the performance problem of realtime multimedia playback.