Research And Application Of NTP Time Server Based On BDS & GPS

In order to meet the needs of the company's equipment and customers for the time synchronization of the various LAN terminals,the company has set up a BDS & GPSbased network time server pre-research project to provide synchronization timestamp services for each terminal in the same ecosystem.For the time of many closed LANs Synchronization requirements can be achieved through a small and medium-sized network time server chassis,but such equipment is often more expensive,complicated to install,and not suitable for flexible,miniaturized or even mobile use scenarios.Therefore,the goal of this project is to make a miniaturization,A low-cost and easy-to-install hardware platform,which is mainly composed of high-precision and high-sensitivity timing BDS,GPS receiving module,control board,antenna,and power supply,etc.,and adopts an efficient embedded development model to cooperate with satellite timing and network synchronization.Technology to provide precise standard time signal and time stamping services for other systems that require time services.This project focuses on the reference and practice of the timing service of BDS + GPS satellite positioning system and the NTP network time service theory based on the Lightweight Network Protocol Stack(LWIP).The final application prototype software is centered on the processor of the Cortex M3 core,and the LWIP network protocol stack is built on it,and the protocol stack is used to implement high-precision NTP network time services.At the same time,the LWIP-based HTTP protocol is used to implement Server web login and remote configuration.Through the research and implementation of BDS and GPS's NTP time server,it provides a miniaturized and low-cost LAN NTP network timing solution.Most of its cost is only a STM32F107 and BDS GPS dual mode.The positioning and navigation system is composed of timing modules,which greatly saves the cost of time synchronization requirements of the local area network.Moreover,it also provides users with a convenient embedded WEB management system,so that users no longer need to develop a control software for them,and further reduces the threshold and cost of use.This research addresses the use of a small,low-cost network server,but it has no great advantage over other products in timing and punctuality accuracy.You can consider using more advanced algorithms to make NTP time server timing the accuracy is further improved,not only is the scientific and rationalization of the processing of network delays,but also the timing accuracy of the satellite positioning and navigation system,which is the source of the timing time,needs to be further controlled.This requires the accuracy factors of various Further research to determine the stability of the timing source.In addition,further improvement of punctuality capability can be done.Once the existing NTP time server is separated from the real-time timing of the satellite positioning and navigation system,the punctuality capability depends entirely on the external RTC's own crystal frequency offset.This kind of real-time iterative statistics algorithm of external RTC frequency offset to give punctuality ability with time compensation is also a way to make up for hardware ability with software.