交换式实时以太网的实现方法

将简单实用的以太网应用到工业控制和航空航天领域,是人们关心的一个问题。然而,由于缺乏实时性服务,导致无法对已用网络进行改造。本文给出一种对全双工交换式以太网进行改造的方法,以保证网络的流量和延时要求。交换机和节点用EDF算法控制实时传输,从而在无需修改以太网标准的前提下支持实时和非实时传输。交换机通过对源节点和目的节点之间的链路进行可行性分析,最终确认RT通道是否可以建立(即准许控制)。交换机还定时广播以太网帧来同步所有节点。

Implementation of the Switched Real-time Ethernet

There is a strong interest in the cheap and simple Ethernet technology used for industrial and aeronautical system.However,it is difficult to innovate in the network technology in service,because of the lack of real-time services.An amelioration method of full-duplex switched Ethernet is given in this paper to satisfy requirements of throughput and delay.The switch and the end-nodes can control the real-time transmission with Earliest Deadline First(EDF) scheduling without modifying the Ethernet standard,and support both real-time and non-real-time transmission.The feasibility analysis proceeded by the switch for each link between source node and destination node,and finally,it confirmed whether the real-time channel can be established(i.e.timely control).Also the switch broadcasts Ethernet frames regularly to synchronize all end nodes.