移动节点多数据项实时广播调度算法的研究

Research on real-time broadcast scheduling algorithm of multiple data items for mobile nodes

随着物联网技术的广泛应用,如何高效、准确的向大量移动节点传递信息是数据广播研究的热点。由于广播数据具有时效性且GPRS网络的不稳定,移动节点常会出现获取的数据已失效。如何保证移动节点获取的数据有效,同时降低移动节点的能耗,缩短请求的访问时间是个很重要的研究课题。分析了适用于多数据项请求的QEM算法、改进型QEM算法等在该实时模型中的适用性,针对On-demand广播模式下的两个子问题,即请求选择问题和广播调度问题,提出了最小延迟时间优先请求和最大数据项访问频率优先调度的算法。理论分析仿真、实验测试显示,提出的广播调度算法相对于原有算法在实时模型下可以有效缩短请求的平均访问时间,改进系统的平均性能。

With the increasing of Internet of Things technology,mechanisms to efficiently and accurately to a large number of mobile notes are of interest.Data failover occur due to the unstable of GPRS and the timeliness of broadcast data items.How to ensure the timeliness of broadcast data,lower power consumption and reduce the access time is a fatal problem.Some major broadcast scheduling algorithms of multiple data items including QEM,improvement QEM as well as in on-demand broadcast mode their adaptive are briefly introduced.For the two sub-problem in on-demand broadcast mode,the query selection problem and the broadcast scheduling problem,we also propose minimum delay time preference algorithm and maximum data access frequency preference algorithm for both them respectively.The results of theoretical analysis,simulation and spot tests show that the algorithm aroused in this article reduces the access time,improve the system performance.