面向MPEG-4流的交换机调度算法  

Switch Scheduling Algorithm for MPEG-4 Streams

作　　者：徐永华[1,2] 陈清华[3] 

机构地区：[1]金陵科技学院信息技术学院,江苏南京211169 [2]江苏省信息分析工程实验室,江苏南京211169 [3]南京理工大学计算机科学与技术学院,江苏南京210094

出　　处：《实验室研究与探索》2013年第7期71-75,143,共6页Research and Exploration In Laboratory

基　　金：江苏省教育厅高校自然科学研究项目(11KJD510002)

摘　　要：为解决MPEG-4流传输过程中传统的交换机调度算法导致的普通数据队列包丢失及增强层有较大的延时和延时抖动问题,采用了改进算法,首先,将到达每个输出端口的数据按照优先级分成3组;其次,根据每组的特性采用动态优先级算法实现,设计了一个动态的线性优先级计算函数,该函数的输入参数是每个队列的优先级和在每一队列中的待发送的数据包数,传输的优先级随之动态改变。实验证明,提出的算法能够保证MPEG-4基本层的传输,根据网络带宽状况允许更多的MPEG-4增强子层通过,比传统的交换机调度算法提高了MPEG-4流传输的服务质量,更好地支持了流传输。In this paper the improved algorithm was proposed to solve the problem of ordinary data queue packet loss,the delay in enhanced layer and the delay jitter in the traditional MPEG-4 streaming process.First,each output port data were classified into three groups.Second,dynamic priority scheduling was used between groups according to the characteristics of the group.The results show that the adopted algorithm can guarantee the transmission of the basic MPEG-4 layer,and can enable more MPEG-4 enhance layer pass according to the state of network bandwidth.The quality of service for the transmission of MPEG-4 streams is higher than the traditional algorithm,which better supports the MPEG-4 stream transmission.

关 键 词：交换机调度算法 虚拟输出队列 服务质量 动态优先级算法 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]