caa a22 4500 44532242X CHVBK 20180317142708.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s00530-011-0236-y doi (NATIONALLICENCE)springer-10.1007/s00530-011-0236-y Channel adaptive video stream switching for broadband wireless links [Elektronische Daten] [Bahar Partov Poor, Martin Fleury, Muhammad Altaf, Mohammed Ghanbari] This paper exploits an H.264/Advanced Video Coding codec's smooth stream switching to achieve robust video delivery across an IEEE 802.16 (WiMAX) broadband wireless link. As the wireless channel conditions vary over time, dynamic selection of bitrate and corresponding video quality will reduce the risk of harmful packet loss. The paper investigates choice of stream-switching with Secondary SP-frames or SI-frames relative to the selection of quantization parameter (QP) values. To control the switching points at the WiMAX server, the proposed scheme applies a feedback mechanism that monitors packet loss. As an additional suggestion, the paper considers an adaptive ARQ scheme to protect switching frames against packet loss. In summary, the broadband wireless streaming system gives more protection to higher quality video, reduces delay and packet loss, and improves received video quality. In particular, for the QP values selected, results show that increased quality primary-switching frames together with SI frames bring a significant gain in video quality compared with other switching schemes with secondary SP-frames. The other schemes in turn show an improvement to using ‘no switching' when streaming takes place over a typical WiMAX channel with burst errors. Link delay is also reduced. Springer-Verlag, 2011 Broadband wireless nationallicence SP and SI switching frames nationallicence Video coding nationallicence Video streaming nationallicence WiMAX nationallicence Partov Poor Bahar University of Essex, Colchester, UK aut Fleury Martin University of Essex, Colchester, UK aut Altaf Muhammad University of Essex, Colchester, UK aut Ghanbari Mohammed University of Essex, Colchester, UK aut Multimedia Systems Springer-Verlag 17/5(2011-10-01), 449-463 0942-4962 17:5<449 2011 17 530 https://doi.org/10.1007/s00530-011-0236-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00530-011-0236-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Partov Poor Bahar University of Essex, Colchester, UK aut NATIONALLICENCE 700 1- Fleury Martin University of Essex, Colchester, UK aut NATIONALLICENCE 700 1- Altaf Muhammad University of Essex, Colchester, UK aut NATIONALLICENCE 700 1- Ghanbari Mohammed University of Essex, Colchester, UK aut NATIONALLICENCE 773 0- Multimedia Systems Springer-Verlag 17/5(2011-10-01), 449-463 0942-4962 17:5<449 2011 17 530 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer