面向无线视频传输的内容感知AQM算法研究

Content-aware active queue management algorithm for video transmission over wireless networks

区分服务(DiffServ,Differentiated Services)在各种保障技术中能更好地满足视频流对服务的要求。在区分服务网络中,常用的主动队列管理算法由于对视频重要数据保护强度的不足,不能很好地满足用户的QoS的需求。针对H.264/MPEG-4视频编码的特性,在现有算法WRED的基础上,通过改变平均队长的计算方法,进一步加强对重要数据的保护能力,以提高视频传输的质量,同时,还考虑了延时对视频传输的影响,提出了超时早检测机制,避免了无效视频数据传输占用宝贵的网络资源。仿真结果显示该算法在原有算法的基础上进一步提高了视频传输质量。

Differentiated Services（DiffServ） can meet the requirements of video streaming service better among various guarantee technologies.In the DiffServ networks,the traditional active queue management algorithm usually can not fulfill user＇s QoS require-ments satisfactorily due to insufficient strength to protect the important data of video.In this paper,based on the video coding characteristics of H.264/MPEG-4,a further improvement is provided on the existing algorithm WRED to enhance the quality of video transmission by changing the way to calculate the average queue length,thus enhance the ability to protect the important data and provide a better quality of video transmission.Meanwhile,considering the effects of delay to the video transmission,the mechanism is provided for expiration early detection to prevent invalid transmission wasting network resources.Simulation results show that,compared to the existing algorithm,the algorithm provides a better quality of video transmission.