Research On Multimedia Transmission Technology In Differentiated Service Networks

The research on Quality of Service (QoS) has been an active area in telecommu-nication society since 1990s. In recent years, Di?erentiated Service (Di?Serv) networkhas been recognized as the main solution for the QoS problem for current Internet.The Assured Forwarding (AF) has been adopted to provide guaranteed subscribedbandwidth for multimedia services. However, with the deployment of more and moremultimedia applications over Internet, the multimedia tra?c represented by media-on-demand application takes the largest portion in the current Internet tra?c. This bringsnew challenges and pressures to networks in the following issues: ? The ability of network responding to burst tra?c. With the world becoming an earth village, the possibility of large-scale burst tra?c caused by a local event (such as Athens 2004 Olympic Games) increases. This calls for strict requirement on the robustness of network, which can be speci?ed by the queue robustness of in the view of routers. ? The ability of network to provide comprehensive QoS. The comprehensive QoS not only includes the measurable performance metrics (such as throughput, delay and loss ratio), but also includes the characteristics of availability, fairness and so on. Although current AF service can support guaranteed throughput, there is a lack of the quantitative di?erentiated guarantees in delay and loss ratio, also a lack of the support in the fairness of bandwidth allocation. ? The ability of network to provide edge service. With the deployment of more and more multimedia delivery applications, just providing QoS for backbone network cannot improve the scalability of information transmission system. The middle- boxs represented by Proxy Caching has been an important method to improve the data delivery performance between IP routers. To solve the above problems, this thesis addresses on the multimedia transmis-sion and delivery technologies in Di?Serv networks. The content of this thesis includesfour issues: (1) modeling and analysis of the queue robustness of Di?Serv router; (2)provision of quantitative guaranteed delay and loss ratio in Di?Serv network; (3) fair-ness of excess bandwidth allocation among multiple service classes; (4) delivery ofinteractive streaming content at the network edge. The works in this thesis has beensupported by the National Science Foundation of China "Investigation of WirelessMultimedia Techniques based on Multimedia Transmission Property"(No.60202005)and "Internet-based interactive streaming delivery technique"(No.60302004) respec-tively, and also supported by the Australian Research Council Foundation "Interactive IIIvideo-on-demand for e-Learning"(No.LX0240468) and the excellent Ph.D thesis foun-dation in Huazhong University of Science and Technology "QoS guarantees and Con-tent Delivery of Multimedia Services". The contributions of this thesis include: 1. The stability model of RIO queue in Di?Serv router: this thesis analyzes the steady queue performance of RIO queue in Di?Serv router. Based on ?uid model assumption, the steady working state of RIO queue system is given. Then the understanding model for the robustness problem of RIO queue is proposed as well as the fully discussion on its origin. 2. Adaptive queue management algorithm to provide quantitative guarantees in delay and loss ratio: Current AF service in Di?Serv can only provide qualitative service di?erentiation in delay and loss ratio. This thesis proposes two adaptive variants of RIO algorithm (ARIO-D and ARIO-L), which can provide stable and di?erentiated performances of delay and loss ratio as well as the guaranteed throughput. 3. Adaptive weighted scheduling scheme to provide fair excess bandwidth allocation among service classes: Current ?xed weighted scheduling in Di?Serv can not respond to the changes of tra?c load either provide fa...