tailieunhanh - Báo cáo toán học: " An occupancy-based and channel-aware multilevel adaptive scheme for video communications over wireless channels"

Tuyển tập các báo cáo nghiên cứu khoa học ngành toán học được đăng trên tạp chí toán học quốc tế đề tài: An occupancy-based and channel-aware multilevel adaptive scheme for video communications over wireless channels | Mukhtar et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 199 EURASIP Journal on . http content 2011 1 199 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access An occupancy-based and channel-aware multilevel adaptive scheme for video communications over wireless channels Husameldin Mukhtar1 Mohamed Hassan2 and Taha Landolsi2 Abstract Video streaming over wireless channels is challenged with the time-varying nature of the underlying channels and the stringent requirements of video applications. In particular video streaming has strict requirements on bandwidth delay and loss rate while wireless channels are dynamic and error-prone by nature. In this article we propose a novel multilevel adaptive scheme that is designed to mitigate the challenges facing video streaming over unreliable channels. This is done while preventing potential playback discontinuities and guaranteeing a graceful degradation of the rendered video quality. Scalable video coding adaptive modulation and adaptive channel coding are integrated to achieve the objectives of the proposed scheme. If adaptive modulation and channel coding are not enough to guarantee the on-time delivery of decodable video frames we adopt scalable coding. Simulation results show that the proposed adaptive scheme achieves an improvement of about dB in the peak signal-to-noise ratio over a nonadaptive one. In addition the proposed scheme reduces the number of starvation instances by 50 and 90 in the cases of Stop-and-Wait and Go-Back-N automatic repeat requests respectively. Keywords adaptive modulation channel coding error control source rate control wire-less channels 1 Introduction Delivery of multimedia contents over wireless channels is becoming increasingly popular. Recent advances in wireless access networks provide a promising solution for the delivery of multimedia services to end-user premises. In contrast to wired networks .