The important issue of real-time video communication is end-to-end delay constraint. Therefore, UDP(User Datagram Protocol) is more suitable for transporting multimedia data than TCP(Transmission Control Protocol). But UDP does not control network congestion and guarantee QoS(Quality of Service). There are many research results to complement UDP. One of those results is RTP(Real-Time Transport Protocol) and RTCP(Real-Time Transport Protocol). RTP and RTCP is mainly designed for use with UDP(User Datagram Protocol) for multimedia transport over the Internet. It has the capability of media-synchronization and network’s QoS feedback to compensate for the weakness of UDP.
In this thesis, the RTP/ RTCP/ UDP protocol is implemented over a windows pc system, and integrate with a H.263 video codec system. The performance of two channel rate control algorithms for VBR(Variable Bit Rate) video transmission is compared by simulation and by the implemented test system. They are a TCP-Friendly rate control algorithm and a modified algorithm with a bounded minimum and maximum bit rate. It is shown that the modified algorithm provide a wider range of controlled bit rates depending on the packet loss ratio than the TCP-Friendly control algorithm.
