Wi-Wi:1纳秒级无线时间同步技术
Wi-Wi is wireless time sync at 1 nanosecond

原始链接: https://www.jeffgeerling.com/blog/2026/wi-wi-is-wireless-time-sync-less-than-5ns/

在 2026 年美国广播电视展(NAB 2026)上,精密授时领域最突出的创新是日本国家信息通信技术研究所(NICT)开发的无线同步协议——Wi-Wi STAMP。该技术运行在 900 MHz 频段,实现了卓越的皮秒级相位同步和毫米级定位精度。 目前的原型机展示了 20ps 的抖动和 30ns 的时间同步精度,未来版本的目标是达到 5ns。与全球导航卫星系统(GNSS)不同,Wi-Wi STAMP 具有更强的室内信号穿透能力,使其成为复杂环境下的一种可行的无线替代方案。展会上的演示突显了其多功能性,应用范围涵盖专业广播摄像机的无线黑场同步以及移动物体的实时追踪。 随着广播行业向 SMPTE 2110 和 AES67 等标准转型,高精度授时变得至关重要。对于传统的有线基础设施或 GNSS 覆盖不可行或成本过高的行业,Wi-Wi STAMP 提供了一种突破性的解决方案。随着行业向更加集成化的网络授时方向发展,这项技术代表了无线同步领域的重大飞跃。

最近 Hacker News 上的一场讨论聚焦于“Wi-Wi”(无线双向干涉测量技术),这是一种能够实现纳秒级时间同步的技术。尽管标题声称精度可达 1 纳秒,但创造者 Jeff Geerling 澄清说,1 纳秒仅在模拟环境中可实现,早期的硬件原型目前在 30 纳秒左右,未来的目标是在实际条件下达到 5 纳秒。 此次讨论引发了关于该技术隐私影响的争论,特别是信号交换是否需要暴露用户的物理位置。用户还将 Wi-Wi 与 GPS(提供隐私保护但需要卫星接收)和 PTP(精密时间协议)等现有的时间同步方法进行了比较。 尽管一些评论者指出,PTP 在商用硬件上的普及度越来越高,但也有人认为,由于真正支持透明时钟或边界时钟的交换机成本高昂,实现真正的亚微秒级同步仍然代价不菲。最终,参与者对 Wi-Wi 相比传统方法在提升信号穿透力和电池效率方面的潜力表示了兴趣。
相关文章

原文

At NAB, I found a demo of Wi-Wi STAMP, a wireless time synchronization protocol that came out of Japan's NICT.

Wi-Wi STAMP time synchronization hardware

Wi-Wi stands for Wireless 2Way interferometry, and it uses the 900 MHz band for picosecond-level time sync, and mm-level distance accuracy, in a tiny box, currently the size of a smartphone.

The system is still in development, but existing prototypes have 20ps of phase synchronization jitter, and time synchronization down to 30ns. The next generation will have time down to 5ns in real-world use.

I recorded a video on the tech with Nobu (one of Wi-Wi STAMP's co-founders) at Meinberg's booth:

I witnessed two practical applications:

  • Meinberg used the devices for wireless black burst time synchronization for two remote video cameras.
  • Nobu and Ahmad demonstrated the mm-level position accuracy with a set of three Wi-Wi units, and a transmitter in a cup, playing the shell game (pictured below).
Wi-Wi STAMP playing the cup game

The graph on the laptop (to the left in the picture above) showed the X-Y position of the cup with the Wi-Wi transmitter, updating 20 times per second. The wireless range of the current system seems to be between 0.2-5 km, depending on the RF power.

Using the 900 MHz band (920 MHz in North America), signal penetration can be much better than GNSS indoors, or in spaces where running wires may be prohibitively expensive. For some other practical applications, check out this 2024 presentation.

There was a lot to see at NAB this year, and my Dad and I covered it on the Geerling Engineering channel: The broadcast industry is changing in 2026.

But me being the time-nut I am, I was scanning the floor for timing-related tech, and now it's ubiquitous with the adoption of SMPTE 2110 and protocols like Ravenna, Livewire, and AES67 everywhere in broadcast tech.

It's even ubiquitous enough Ubiquiti themselves are getting into the game; they had a full booth, though I didn't get hands-on with their new PTP-aware Enterprise AV switches.

But if you're interested in nanosecond-level wireless time sync, or want to learn why commodity WiFi setups can't support it, watch the video above!

Note: My trip to NAB 2026 was entirely self-funded. I can work on these posts thanks to the support of readers like you!

联系我们 contact @ memedata.com