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Tham khảo tài liệu 'communications and networking part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Wireless Multimedia Communications and Networking Based on JPEG 2000 169 The selected size is never bigger than the wireless device s resolution. The clients connected to the server receive the highest images video quality achievable for the estimated available bandwidth. The available bandwidth estimation tool is launched every 10 frames but this frequency could be changed according to the application requirements. As recommended in Mairal Agueh 2010 we fix this frequency to 10 frames. The result is a smooth and robust video sequence for each receiver. It is worth noting that the original JPEG 2000 codestreams is copied and stored at the encoder so that new JPEG 2000 codestreams are generated for each client according to the parameters selected by the proposed scalability algorithm. An interesting extension to this work is to implement a real time system which is able to handle real time multiple JPEG 2000 source coding. Scenario The video streaming scenarios considered in this work are derived from wireless transmission trials used in the literature for bandwidth estimation purpose. WBest is the available bandwidth estimation tool implemented in our system. The video sequence is speedway.mj2 Speedway 2005 which is a 352x288 motion JPEG2000 sequence constituted of 200 JPEG 2000 frames with six resolutions and three layers each. In the considered scenario figure 11 an IEEE 802.11 based wireless network with two receivers and one sender connected to an access point is used to demonstrate the effectiveness of the proposed system. Fig. 11. Single server multiple wireless clients transmission scenario In Table 3 we present the results of the considered scenario where speedway.mj2 is transmitted to multiple wireless clients. The estimated available bandwidths along with the characteristics of the selected stream for each client are presented. In the first case the client receives a video composed of JPEG 2000 frames with all layers and which size is 176x144. In this .