基于自相似流的星上虚拟信道调度算法研究  

Satellite virtual channel scheduling algorithms based on self-similar traffic

作　　者：底晓强[1,2] 刘永霞 Di Xiaoqiang;Liu Yongxia(School of Computer Science and Technology Changchun University of Science and Technology,Changchun,130022,China;NUERC of Space and Optoelectronics Technology,Changchun University of Science and Technology,Changchun,130022,Jilin,China)

机构地区：[1]长春理工大学计算机科学技术学院,长春130022 [2]长春理工大学空间光电技术国家地方联合工程研究中心,长春130022

出　　处：《南京大学学报（自然科学版）》2018年第3期515-521,共7页Journal of Nanjing University（Natural Science）

基　　金：国家863计划(2015AA015701);吉林省教育厅科研项目(JJKH20170630KJ)

摘　　要：以高级在轨系统(Advanced Orbit Systems,AOS)空间数据链路协议为基础,建立了CCSDS AOS协议信源模型,对比分析了自相似流量模型下先来先服务(first-come-first-served,FCFS)和时间片轮询(round-robin,RR)虚拟信道调度算法的性能.根据网络流量具有自相似性的特点,采用时间间隔服从正态分布的分形布朗运动流量模型描述AOS虚拟信道中数据流的自相似特性,并使用快速傅立叶变换方法生成了不同自相似系数的分形布朗运动流量,获取了数据包的到达时间、到达时间间隔和数量;之后通过仿真实验对比了FCFS和RR两种虚拟信道(VC)调度算法的时延和积压性能.实验结果表明,当到达数据量较小时,两种调度算法性能相当;当到达数据量较大时,RR调度算法的时延和积压性能明显优于FCFS调度算法.研究结果可为AOS虚拟信道调度算法的研究和设计提供参考.On the basis of the advanced orbit systems（AOS）spatial data link protocol,a CCSDS AOS protocol source model is established,and the first-come-first-served（FCFS）and round-robin（RR）virtual channel scheduling algorithms are compared and analyzed under the self-similar traffic model.According to the characteristics of selfsimilarity of network traffic,the fractional Brownian motion（fBm）traffic model whose time interval follows normal distribution is used to describe the self-similar characteristics of data flow in AOS virtual channel,moreover,using fast Fourier transform（FFT）approach to generate fBm traffic with different self-similar coefficients for obtaining the arrival time,the arrival time interval and the number of arrival packets.Afterwards,the delay and backlog ofFCFS and RR VC scheduling algorithms are compared by simulation experiments.The experiment results show that when the simulation time is short and the amount of arrived data is small,the performances of the two kinds of scheduling algorithms are equivalent in AOS design;but if the amount of data arrived is large and simulation time is long enough,the delay and backlog of RR scheduling algorithm are significantly better than FCFS＇s.It illustrates that the results of this study can serve as a reference for the selection of spatial network traffic model.Furthermore,it can provide reference for the research and design of AOS virtual channel scheduling algorithms.

关 键 词：高级在轨系统 虚拟信道调度 自相似 快速傅立叶变换 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]