Abstract
The transmission of multimedia over Internet has its quality of service (QoS) requirements. The Internet is a best-effort network and cannot guarantee the QoS of multimedia transmission. Several approaches are proposed for the purpose of improving the QoS of multimedia transmission and ensuring secured multimedia transmission.An adaptive rate control approach for end-to-end multimedia transmission is proposed. An optimal transmission rate is obtained to maximize the utilization of the client buffer with a minimal bandwidth allocation. Less underflow will occur at the client buffer, which is favorable to providing a continuous presentation. More concurrent client presentations can be supported under the same bandwidth. It also provides a fair bandwidth competition with the dominant TCP traffic over Internet. An adaptive rate control approach is proposed for multimedia multicast. The rate is optimized in a way so the buffer occupancies of all clients can be improved to support quality of service. Fairness is provided among the member clients in the group with this extended rate control approach. An adaptive packet dropping algorithm for per-class queue management is proposed for the improvement of QoS of multimedia flows. The packet dropping rate can achieve a small delay for multimedia streams and protect the TCP flows from the unresponsive UDP flows. A video streaming approach is proposed based on the rate control algorithm. To improve the quality of delivered video streams under the constraint of bandwidth, selective dropping of frame packets is adopted. A packet scheduling algorithm is proposed to decide the transmission of video packets. Simulation results demonstrate it provides a better quality of the decoded frames at the client side.Network attacks like denial of service and probing consume a considerable amount of network resources and threaten reliable multimedia transmission. A secured and adaptive transmission rate control framework is proposed. Intrusion detection and transmission management are integrated into the design of the server. Intrusion detection examines the inbound network traffic to detect the hostile activities, while the transmission management provides the resource management. This design enhances the security and guarantees the resource for transmission even when there are attacks.