tailieunhanh - Báo cáo hóa học: " Research Article Fast and Accurate Video PQoS Estimation over Wireless Networks"

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: Research Article Fast and Accurate Video PQoS Estimation over Wireless Networks | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 548741 10 pages doi 2008 548741 Research Article Fast and Accurate Video PQoS Estimation over Wireless Networks Pasquale Pace and Emanuele Viterbo Department of DEIS University of Calabria 87036 Rende Italy Correspondence should be addressed to Pasquale Pace ppace@ Received 29 September 2007 Revised 10 February 2008 Accepted 9 April 2008 Recommended by F. Babich This paper proposes a curve fitting technique for fast and accurate estimation of the perceived quality of streaming media contents delivered within a wireless network. The model accounts for the effects of various network parameters such as congestion radio link power and video transmission bit rate. The evaluation of the perceived quality of service PQoS is based on the well-known VQM objective metric a powerful technique which is highly correlated to the more expensive and time consuming subjective metrics. Currently PQoS is used only for offline analysis after delivery of the entire video content. Thanks to the proposed simple model we can estimate in real time the video PQoS and we can rapidly adapt the content transmission through scalable video coding and bit rates in order to offer the best perceived quality to the end users. The designed model has been validated through many different measurements in realistic wireless environments using an ad hoc WiFi test bed. Copyright 2008 P. Pace and E. Viterbo. 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 It is well known that the goal of any QoS mechanism is to maintain a good level of user-perceived QoS even when the network conditions are changing unpredictably. Typical QoS provisioning solutions for multimedia video applications have been always based on