SATURN - Satellite Assured Time service supporting UK Resilience

即使在今天，准确和可靠的时间信息的传播也是一个挑战。使用的主要方法是GNSS(非常准确和便宜，但基于接收非常弱的信号容易受到干扰)，以及基于网络的协议，如PTP或白兔(需要点对点网络工程和专用硬件支持)。为了克服这些限制，我们的项目探索了两个创新的想法：1.生成当地UTC时标，将GNSS和原子钟结合在一起。2.利用两种协议通过低成本的商业网络服务(特别是家庭互联网)传播UTC：DTM和NTP的增强版本(ENTP)。系统将生成自己的独立时标，与UTC(NPL)一致，并通过原子钟减少其对全球导航卫星系统的依赖。GNSS和原子钟的结合提供了一个同步源，它提供了今天和下一代电信、银行、数据中心和能源分配网络所需的必要的精度、健壮性和可靠性。关于网络协议，GMVNSL近年来一直在试验专有协议DTM和NTP(增强型NTP或ENTP)的修改版本。这两个协议已经在商业电信提供商提供的低成本网络链路上进行了测试，结果令人振奋。该项目的目的是进一步改进和证明ENTP的准确性与数字地面模型相当。

The dissemination of accurate and robust time information is a challenge even nowadays. The main methods in use are GNSS (very accurate and inexpensive, but based on the reception of very weak signals susceptible to jamming), and network-based protocols such as PTP or White Rabbit (which require point-to-point network engineering and dedicated hardware support). To overcome these limitations our project explores two innovative ideas:1. The generation of a local UTC time scale, combining GNSS and atomic clocks. 2. The dissemination of UTC over low-cost, commercially available network services (in particular home Internet) using two protocols: DTM, and an enhanced version of NTP (eNTP).The system will generate its own independent time scale that is aligned to UTC(NPL) and reduces its dependency on GNSS by means of an atomic clock. The combination of GNSS and atomic clocks provides a synchronization source, which provides the necessary precision, robustness and reliability required by todays and next-generation telecom, banking, data centres and energy distribution networks.Regarding network protocols, GMVNSL has been experimenting in recent years with the proprietary protocol DTM, and with a modified version of NTP (enhanced NTP or eNTP). These two protocols have been tested over low cost network links offered by commercial telecom providers with promising results. This project will aim to improve further and demonstrate the accuracy of eNTP on a par with DTM.