杨志军 孙洋洋

摘 要：针对提高轮询控制模型工作效率和区分网络优先级的问题，提出了区分站点忙闲状态的完全门限两级轮询控制模型（ETTPSS）。模型以两级优先级为基础，依据站点的忙闲状态采用并行处理方式只对忙站点进行信息分组发送服务。模型既能区分传输服务优先级又能避开对无信息分组的空闲站点的查询，从而提高了模型资源利用率和工作效率。运用概率母函数与马尔可夫链相结合的方法对该模型进行理论分析研究，精确解析了模型各个重要性能参数。仿真实验结果表明，仿真值与理论值近似相等，说明理论分析正确合理。与普通轮询模型相比，该模型性能大幅度提高。

关键词：优先级;忙站点;轮询模型;利用率;工作效率

中图分类号：TN911

文献标志码：A

Abstract： To improve the work efficiency of polling control model and distinguish network priorities， an ExhaustiveThreshold Twostage Polling control model based on Site Status （ETTPSS） was proposed. Based on two levels of priority， parallel processing was used to only send information to busy sites according to busy and idle states of sites. The model could not only distinguish the priorities of transmission services but also avoid the queries to the idle sites without information packets， thereby improving model resource utilization and work efficiency. The method of probabilistic generating function and Markov chain was used to analyze the model theoretically， and the important performance parameters of the model were analyzed accurately. The simulation results show that the simulation values and the theoretical values are approximately equal， indicating that the theoretical analysis is correct and reasonable. Compared with normal polling model， the model performance is greatly improved.

英文关键词Key words： priority; busy site; polling model; utilization; work efficiency

0 引言

轮询控制模型具有服务质量保障的优点，一直是通信网络中媒体访问控制（Media Access Control， MAC）一种重要的调度方式，使其在现代网络中应用非常普遍[1]。文献[2]分析研究了轮询控制模型在大数据流式计算平台Apache Storm中的应用;文献[3-5]分析研究了轮询控制模型在计算机网络异构无线网络以及信息采集的应用。

轮询控制模型中，对无信息分组的空闲站点的查询会浪费模型资源。文献[6]通过对有信息分组发送需求的忙站点分配信道避免空闲查询，且服务器完成对当前站点的信息发送后需要经过一个转换查询时间才能对下一个需要信息发送的站点进行服务，而采用并行调度控制方式[7]，就是把查询和服务过程进行并行处理，不再消耗模型的转换查询时间。……