基于累积时延的流媒体传输模糊拥塞控制  

Fuzzy Congestion Control Algorithm Based on Accumulative Traffic Delay

作　　者：汪学舜[1,2] 余少华[2] 戴锦友[2] 罗婷[1,2] 

机构地区：[1]华中科技大学计算机学院,武汉430074 [2]武汉邮电科学研究院,武汉430074

出　　处：《计算机科学》2010年第7期57-61,90,共6页Computer Science

基　　金：863国家重点基金项目(2005AA121410)资助

摘　　要：为保证网络流媒体传输质量,在流媒体的传输中需要采用有效的拥塞控制策略。结合流媒体数据对时延敏感的特点,提出了一种基于累积时延的模糊拥塞控制算法,该算法在流媒体数据流传输过程中检测和跟踪其时延,在转发分组数据前,根据容忍时延阈值,丢弃超时数据包,减少不必要的带宽浪费,并且对所到达的数据流按照累积时延进行优先级分类,把全局性缓冲区和各队列的局部性缓冲区按照正常、拥塞避免和拥塞的规则划分为3个具有交叉过渡域的阶段,然后采用整体和局部相结合的拥塞控制方法,实现队列调度过程中的模糊处理,从而对网络拥塞进行有效的控制。理论分析和实验结果表明,使用基于累积时延的模糊拥塞控制算法,能有效改善流媒体的传输性能,是解决流媒体传输拥塞控制的有效途径,并能对提高网络性能起到重要作用。In order to guarantee the quantity of flow medium traffic delivered in the network,congestion control strategy is adopted in flow medium traffic. According to the delay sensitivity of flow medium data, this paper proposed a novel congestion control for multimedia transmission in networks known as Accumulative Delay Fuzzy Congestion Control （ADFCC）. ADFCC improves the QoS of multimedia stream in network by detecting and discarding these packets that accunaulated delay exceeds multimedia stream＇s delay tolerance so as to maintain high bandwidth utilization. All kinds of packets were firstly classified into queues according to their own priorities which calculated by aecumulative delay. Then the buffer state was divided into three phases, including normal, congestion avoidance, and congestion according to their buffer usage ratio. The three phases are crossover each other because of their fuzziness. Then by combining the whole congestion control, with the part congestion control, the fuzzy congestion control algorithm was carried out. Simulation results show that the proposed scheme can effectively reduce the average received packet delay than that of using traditional congestion eontrol algorithm. Moreover, it is suitable to be used in the ever-changing network environment and can improve utilization of the network resources.

关 键 词：流媒体 拥塞控制 动态队列管理 累积传输延时 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]