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: Impact of Video Coding on Delay and Jitter in 3G Wireless Video Multicast Services | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 24616 Pages 1-7 DOI WCN 2006 24616 Impact of Video Coding on Delay and Jitter in 3G Wireless Video Multicast Services Kostas E. Psannisand Yutaka Ishibashi Department of Computer Science and Engineering Graduate School of Engineering Nagoya Institute of Technology Nagoya 466-8555 Japan Received 29 September 2005 Revised 14 February 2006 Accepted 26 May 2006 We present an efficient method for supporting wireless video multicast services. One of the main goals of wireless video multicast services is to provide priority including dedicated bandwidth controlled jitter required by some real-time and interactive traffic and improved loss characteristics. The proposed methodis based on storing multiple differently encoded versions of the video stream at the server. The corresponding video streams are obtained by encoding the original uncompressed video file as a sequence of I-P I -frames using a different GOP pattern. Mechanisms for controlling the multicast service request are also presented and their effectiveness is assessed through extensive simulations. Wireless multicast video services are supported with considerably reduced additional delay and acceptable visual quality at the wireless client-end. Copyright 2006 K. E. Psannis and Y. Ishibashi. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Multimedia transport typically requires stringent QoS metrics bandwidth and delay and jitter guarantees . However in addition to unreliable wireless channel effects it is very hard to maintain an end-to-end route which is both stable and has enough bandwidth in an ad hoc network. The rapid growth of wireless communications and networking protocols will ultimately bring video to our .