tailieunhanh - Báo cáo hóa học: " Cross-Layer QoS Support for Multimedia Delivery over Wireless Internet"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Cross-Layer QoS Support for Multimedia Delivery over Wireless Internet | EURASIP Journal on Applied Signal Processing 2005 2 207-219 2005 Hindawi Publishing Corporation Cross-Layer QoS Support for Multimedia Delivery over Wireless Internet Qian Zhang Microsoft Research Asia 3F Beijing Sigma Center 49 Zhichun Road Haidian District Beijing 100080 China Email qianz@ Fan Yang Microsoft Research Asia 3F Beijing Sigma Center 49 Zhichun Road Haidian District Beijing 100080 China Email t-fanyan@ Wenwu Zhu Microsoft Research Asia 3F Beijing Sigma Center 49 Zhichun Road Haidian District Beijing 100080 China Email wwzhu@ Received 17 August 2003 Revised 13 June 2004 Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service QoS requirement on bandwidth delay and delay jitter. However the current Internet can only support best-effort service which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet QoS supports can be addressed in different layers including application layer transport layer link layer and so forth. This paper presents a framework which provides QoS support for multimedia delivery over wireless Internet across different layers. To provide efficient QoS support for different types of media over the best-effort networks we first propose a cross-layer architecture which combines the application-level transport-layer as well as link-layer controls and then review recent advances in each individual component. Specifically dynamic estimation of varying channel and network adaptive and energy-efficient application and link-level error control efficient congestion control header compression adaptive automatic repeat request ARQ and priority-based scheduling as well as QoS-adaptive proxy caching technologies .