摘要
以太网是目前应用最广泛的局域网技术,应用于众多工业领域的实时以太网都面临着数据传输的实时性和确定性的需求。目前在分组网络中应用最广泛的是由IEEE 1588定义的精确时钟同步协议(Precision Time Protocol,PTP),其主要原理是通过一个同步信号周期性地对网络中所有节点的时钟进行校正同步,使分布式网络内的所有时钟与最精确的时钟同步,可以达到亚微米级别的时间同步精度。ISO/IEC/IEEE 8802-1AS基于IEEE1588定义的精确时钟同步协议提出了一种广义精确时间同步协议(generalized precision time protocol,gPTP),用于时间敏感网络中设备时钟的定时和同步,其同步原理与PTP一致。本文通过建立仿真模型对比验证gPTP的同步精度更高。本文首先分析了广义精确时间同步协议的消息同步、传播和转发过程,其次提出了一种对广义精确时间同步协议进行时间同步仿真的方案。通过INET架构和分析gPTP时钟同步协议的基础上,在OMNeT++上对PTP和gPTP协议进行了物理层和MAC层上的信息建模与系统建模,从而仿真了PTP和gPTP的时钟同步过程,实验结果表明gPTP的时钟同步误差范围更小,验证了gPTP相对于PTP在时钟同步方面的优越性。
Ethernet is the most widely used LAN technology currently.The real-time Ethernet applied in many industrial fields is faced with the demand of real-time and certainty of data transmission.At present,the most widely used in packet networks is the Precision Time Protocol defined by IEEE 1588.The main principle is to periodically synchronize the clocks of all nodes in the network through a synchronization signal,so that all clocks in the distributed network are synchronized with the most accurate clock,and sub-micron level time synchronization accuracy can be achieved.ISO/IEC/IEEE 8802-1 AS proposes a generalized precise time protocol(gPTP)based on the precision time protocol defined by IEEE1588,which is used for timing and synchronization of device clocks in time sensitive network.It’s synchronization principle is consistent with that of PTP.In this paper,we establish a simulation model to verify that the gptp synchronization accuracy is higher.Firstly,the paper analyses the message synchronization,propagation and forwarding process of gPTP.Secondly,the paper proposes a time synchronization simulation method for gPTP.Based on the INET architecture and analysis of the gPTP clock synchronization protocol,the information modeling and system modeling of PTP and gPTP on the physical layer and MAC layer are performed on OMNeT++,thereby simulating the clock synchronization process of PTP and gPTP.The experimental results show that gptp has a smaller error range in clock synchronization.It is verified the superiority of gPTP over clock synchronization in terms of PTP.
作者
卓兰
张弛
韩丽
Zhuo Lan;Zhang Chi;Han Li(China Electronics Standardization institute,Beijing 100007,China)
出处
《电子测量技术》
2020年第8期129-137,142,共10页
Electronic Measurement Technology
基金
十三五“国家重点研发计划重点专项”国家质量基础的共性技术研究与应用-智能制造共性技术标准研究16NQI0B02
