面向工业无线网络的动态TDMA系统设计与实现

Design and Implementation of Dynamic TDMA System for Industrial Wireless Networks

随着工业4.0的发展,不同种类的新型工业应用被部署到工厂中,这对现有工业无线技术提出了实时性和高速率的要求.为了同时满足这两种需求,本文在支持高速率的IEEE802.11的基础上,提出了基于软件定义的动态时分多址(Time division multiple access,TDMA)机制无线接入系统.首先,为了提供时延有界的传输服务,设计并实现了基于MAC(Medium access control)层的动态TDMA接入机制.然后,为了满足工业无线网络中的动态变化的带宽需求,考虑设备数据量的动态变化,在SDN(Software defined network)控制器上通过基于最小二乘法的线性回归算法预测设备时隙需求,再将动态时隙分配问题转化为优化问题以最大化网络中所有设备动态时隙需求.最后,通过仿真对比TDMA时隙分配算法的性能,并在实际网络环境中开展系统部署与测试.结果表明,相对于其他TDMA接入机制,动态TDMA机制在保障时延有界的同时能有效提升传输性能.

With the development of Industry 4.0,various types of new industrial applications are deployed in factories,which introduces real-time and high-rate requirements for existing industrial wireless technologies.To satisfy the two requirements simultaneously,we propose a software-defined based dynamic TDMA(time division multiple access)wireless access system with high-speed IEEE802.11.Firstly,to guarantee the transport service with bounded delay,we design a dynamic TDMA access mechanism based on MAC(medium access control)layer.Moreover,to meet the dynamic bandwidth requirements in industrial wireless networks,the linear time-regression algorithm based on the least square method on the SDN(software defined network)controller considering the dynamic changes in the amount of device data is used to predict the device time slot requirements,then the dynamic time slot allocation problem is translated into an optimization problem to maximize the dynamic slot requirements of all devices in the network.Finally,we conduct simulations to compare the performance of TDMA channel resources management algorithms,and implement them in real networks to evaluate the performance of dynamic TDMA system.The experimental results demonstrate that comparing with existing TDMA wireless access mechanisms,the dynamic TDMA mechanism can guarantee delay bound and improve the transmission performance efficiently.