一种支持HFC网中QoS业务的调度方法

A SCHEDULING ALGORITHM WITH QoS SUPPORT SERVICES IN HFC

为了在HFC中支持不同QoS的业务,必须仔细研究CMTS的上行业务调度算法。但是在当前最重要的标准 MCNS DOCSIS1.1中,没有规定任何针对 QoS设计的调度算法,而很多文献都是以改进的先到先服务(FCFS)为基础讨论的。该文提出了一种可支持 QoS的调度算法,通过将业务分类,按照不同类型业务的带宽占用动态分配业务的优先级,同时还考虑了回带(piggyback)对网络吞吐量的影响,给出了仿真结果,并针对典型的时延敏感业务——IP Telephony提出了改善网络通道利用率的方法。

To support different QoS services in HFC, the CMTS scheduling algorithm should be analyzed carefully. However, in the most important standard-MCNS DOCSIS 1.1, no specific; scheduling is prescribed, and many papers have discussed it with modified First Come First Service(FCFS). In this paper, a scheduling algorithm with QoS support-PDBQ is introduced. It distributes the priority of services by the different used bandwidth of different services. The influence of piggyback to throughput is also discussed, the performance of this algorithm is illustrated by simulation results. A method of improving link bandwidth utilization is presented in the typical delay-sensitive service of IP telephony.