Research On Streaming Media Transmission Technology In Wireless Environment

There are special QoS questions that streaming media transmission suffers high packet loss ratio and low throughput because of the high bit error ratio and mobility in wireless environment. Neither sole network QoS guarantee scheme nor adaptive transmission technology in end systems can entirely solve the QoS questions of streaming media transmission in wireless environment. After the QoS guidelines are systemically analyzed, a general layered frame for streaming media transmission in wireless environment as well as the QoS guarantee schemes adopted in each layer are proposed in this dissertation. These QoS guarantee schemes can be either individually or unitedly used. The merit of the proposed frame is that it is suitable for more instances, implemented easily and can provide a transmission platform with QoS guarantee, which reduces the difficulty of developing streaming media applications. Different schemes for improving the QoS of streaming media transmission is proposed respectively at transport layer, network layer and link layer in the dissertation:1) At the network layer, to satisfy the request of the delay and packet loss ratio of streaming media transmission, an admission-control method based on multiple-prior probing is proposed in DiffServ network to provide different kinds of application data streams with an end-to-end connection with guarantee of delay and packet loss ratio in the dissertation.2) At the transport layer, to guarantee the TCP friendliness, high smoothness and high responsiveness of streaming media transmission in dynamic network environment, a dynamic TCP friendly congestion control scheme based on dynamic TCP throughput model is proposed in the dissertation with the the flaw of Padhye's TCP throughput model being analyzed; An end-to-end packet loss differentiation algorithm based on (m, k) statistical measuring, which can maintain high precision of packet loss differentiation in different link error control scheme, is proposed in the dissertation so as to reduce the influence on streaming media transmission of high bit error ratio and handover in wireless environment and increase the throughput of streaming media transmission. Based on the algorithm, a streaming media congestion control suitable for wireless environment is...