The Research Of Cross-layer Design For Video Transmission In WLAN

This paper makes a study of the cross-layer design for video business in the wireless local area network (WLAN) transmission. At application layer the video compression coding standard (H.264) is used , and the protocol of 802.11e is used at MAC layer. Comparing with other standards, H.264 enhances the compression efficiency and reduces the encoded bit rate. so it is suitable for WLAN more, while at MAC layer, by using 802.11e the quality-of-service can be guaranteed by distinguishing different priority to transmit the important information first.In this paper, at application layer a fuzzy measure theory and least square method are used to acquire the degree that how different parameter subsets affect the performance metric, then to confirm which is the key parameter. And some error recovery method are applied to optimize the video transmission in WLAN, such as parameter set, data partition, FMO, and at MAC layer, aiming at the idea of the parameter set and data partition in H.264, a large number of data partition analysis is done, to get the different effect degree that different partition have on decode, and to arrange the content of four queues more reasonably and meticulously. Finally, the cross-layer design considers the key parameters of application and MAC layers jointly, and the encoding parameters are adjusted according to the network conditions. The experiment and simulation results test the cross-layer design idea and show the cross-layer design can provide higher video quality.