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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: An Evaluation of Media-Oriented Rate Selection Algorithm for Multimedia Transmission in MANETs | EURASIP Journal on Wireless Communications and Networking 2005 5 757-773 2005 Mohammad Hossein Manshaei et al. An Evaluation of Media-Oriented Rate Selection Algorithm for Multimedia Transmission in MANETs Mohammad Hossein Manshaei Planete Project INRIA 2004 Route des Lucioles B.P 93 06902 Sophia Antipolis Cedex France Email manshaei@sophia.inria.fr Thierry Turletti Planete Project INRIA 2004 Route des Lucioles B.P 93 06902 Sophia Antipolis Cedex France Email turletti@sophia.inria.fr Thomas Guionnet Temics Project IRFSA-INRIA Campus de Beaulieu 35042 Rennes Cedex France Email thomas.guionnet@irisa.fr Received 15 June 2004 We focus on the optimization of real-time multimedia transmission over 802.11-based ad hoc networks. In particular we propose a simple and efficient cross-layer mechanism that considers both the channel conditions and characteristics of the media for dynamically selecting the transmission mode. This mechanism called media-oriented rate selection algorithm MORSA targets loss-tolerant applications such as VoD that do not require full reliable transmission. We provide an evaluation of this mechanism for MANETs using simulations with NS and analyze the video quality obtained with a fine-grain scalable video encoder based on a motion-compensated spatiotemporal wavelet transform. Our results show that MORSA achieves up to 4 Mbps increase in throughput and that the routing overhead decreases significantly. Transmission of a sample video flow over an 802.11a wireless channel has been evaluated with MORSA. Important improvement is observed in throughput latency and jitter while keeping a good level of video quality. Keywords and phrases ad hoc networks cross-layer optimization IEEE 802.11 wireless LAN MANETs mode selection algorithms. 1. INTRODUCTION With recent performance advancements in computer and wireless communications technologies mobile ad hoc networks MANETs are becoming an integral part of communication networks. The emerging widespread use of .
