多跳无线网络中具有时间意识的视频流控制协议

Time-aware control protocol for video streaming in multihop wireless networks

为了在多跳无线网络中对实时视频流提供高效的端到端服务质量支持,提出了一种具有时间意识的视频流控制协议(TACP).首先在网络层增加了独立的TACP子层,采用跨层设计方法将各协议层的参数映射至该子层.在此基础上,源节点通告视频同步信息,使中间节点形成时间意识;中间节点通过分布式时延估计方法限制超时视频数据的转发.随后,为了对高优先级视频数据提供保护,研究了一种基于GOP的路径探测机制,并将其与视频流控制协议协同工作.利用仿真实验,对TACP视频通信性能进行分析和评价.结果表明:TACP能够显著改善实时视频流质量,包括可解码帧率、端到端时延和时延抖动等性能指标;该协议极大地提高了网络带宽利用率,并能够有效适应实时性需求的变化.

To provide efficient end-to-end quality of service （QoS） support for video streaming in multihop wireless networks, a time-aware control protocol （TACP） is proposed. First, a new TACP sub-layer is introduced into the network layer. The parameters of all protocol layers are mapped to the sub-layer by using the cross-layer design approach. On this basis, a source node notifies video synchronization information to deploy a time-aware characteristic for each intermediate node. An in- termediate node limits the forwarding of scale video data through the method of distributed delay esti- mation. Then, a GOP（ group of picture）-based protect strategy working together with video stream- ing control protocol is studied to protect video packets with high-priority. Finally, simulation experi- ments are carded out to evaluate and analyze the video communication performance. The results show that the TACP can significantly improve the quality of real-time video streaming such as decod- able frame ratio, end-to-end delay, delay jitter and so on. In addition, the TACP can greatly im- prove network bandwidth utilization and effectively adapt various delay requirements.