摘要
提出一种用于无线实时流媒体传输的数据链路层自适应SR-ARQ控制策略,以显著提高接收方的播放质量.该策略采用跨层设计的方法,基于增强型GM(1,1)模型预测当前的网络状态,自适应地调整SR-ARQ参数N_(max)(最大重传次数),同时依据逻辑链路控制子层(LLC layer)不同的操作类型为MPEG三种视频帧(I,P和B帧)提供不同优先级的服务;另一方面,在应用层采用自适应FEC策略,在视频源数据和冗余数据之间动态分配网络带宽.数学分析与仿真实验的统计结果对比表明,该策略能使接收方获得最大的可播放帧率,有效地提高了流媒体传输的可靠性.
The real-time delivery of multimedia data over wireless links with QoS-Guarantee is a big challenge due to the unreliable and dynamic characteristics of wireless networks, limited bandwidth and high QoS requirements for multimedia applications. This paper proposes an adaptive link-layer selective repeat automatic repeat request （SR-ARQ） algorithm at the data link layer for wireless media streaming, in the hope that the media could be played on receivers with high quality. The algorithm, based on cross-layer optimization design, predicts the packet loss rate using the enhanced GM （1,1） model, and adjusts the SR-ARQ parameter N Additionally, according to the different types of operation for data communication between service access points at logical link control layer （LLC）, the paper provides differentiated services for three types of MEPG video frame （I, P and B frame）. On the other hand, the paper employs an adaptive FEC at the application layer to adjust the sending rate of MPEG video frame adaptively and to allocate the network bandwidth resource between the MPEG video source data and the redundant data dynamical!y. Both the mathematical analyses and NS simulation demonstrate that the proposed mechanism can significantly improve quality of media streaming, in terms of playable frame rate and reliability performance on the receiving side.
出处
《常熟理工学院学报》
2010年第2期87-94,共8页
Journal of Changshu Institute of Technology
基金
常熟理工学院青年教师科研启动基金项目(QZ0911)
