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Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : A study on the impact of AL-FEC techniques on TV over IP Quality of Experience | Battisti et al. EURASIP Journal on Advances in Signal Processing 2011 2011 86 http asp.eurasipjournals.eom content 2011 1 86 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access A study on the impact of AL-FEC techniques on TV over IP Quality of Experience 1 1 2 1 Federica Battisti Marco Carli Elena Mammi and Alessandro Neri Abstract In this contribution an evaluation of the effectiveness of Application Layer-Forward Error Correction AL-FEC scheme in video communications over unreliable channels is presented. In literature several AL-FEC techniques for reducing the effect of noisy transmission on multimedia communication have been adopted. Recently their use has been proposed for inclusion in TV over IP broadcasting international standards. The objective of the analysis performed in this paper is to verify the effectiveness of AL-FEC techniques in terms of perceived Quality of Service QoS and more in general of Quality of Experience QoE and to evaluate the trade-off between AL-FEC redundancy and video quality degradation for a given packet loss ratio. To this goal several channel error models are investigated random i.i.d. losses burst losses and network congestions on test sequences encoded at 2 and 4 Mbps. The perceived quality is evaluated by means of three quality metrics the full-reference objective quality metric NTIA-VQM combined with the ITU-T Rec. G.1070 the full-reference DMOS-KPN metric and the pixel-wise error comparison performed by using the PSNR distortion measure. A post-processing synchronization between the original and the reconstructed stream has also been designed for improving the fidelity of the performed quality measures. The experimental results show the effectiveness and the limits of the Application Layer protection schemes. Keywords Quality of Service AL-FEC Techniques IP Transmission Video Quality estimation 1 Introduction In the last years communication architectures based on TCP IP suite have