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Wi-Wi is wireless time sync at 1 nanosecond

137 pointsby Brajeshwarlast Wednesday at 3:06 PM36 commentsview on HN

Comments

ProllyInfamoustoday at 6:07 PM

When you drive through the Texas Pandhandle at night, squaremiles of electric windmills blink together – like fireflies stirring across flatlines of [L]one-star horizon.

They've been simultaneous for decades... and remains a breathtaking detour (if you're out there, schedule night-travel).

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I like the similar project which uses GPS signal offsets, captured on a RaspberryPi, to then broadcast (e.g:) a local-network-timeserver.

MiracleRabbittoday at 7:29 AM

With GNSS+PPS and a hardware timer latch you can easily sync internal microcontroller timers to 2 to 3-digits nanoseconds against the global standard with a tightly controlled loop. But cannot get better than the PPS signal itself (roughly 30-100nS).

Everything below needs that a huge amount of engineering. CERN&friends developed the "White Rabbit" (https://ohwr.org/projects/white-rabbit/) system for this. This allows sub-Nanoseconds syncing of netwoked devices.

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jmpmantoday at 5:28 PM

I've wondered if you could have an array of "firecrackers", each timed very precisely, with perfect spatial knowledge of each, and synchronize their ignition to produce arbitrary shaped pressure waves.

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NkVczPkybiXICGyesterday at 10:53 PM

Why does the title say 1ns but the body of the article says 30ns (with hopes to eventually get it down to 5)?

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ectosphenolast Wednesday at 3:50 PM

That is cool. I use a gps NTP server on my home network and live with sub-millisecond time sync. I’d go PTP but the equipment is a bit too expensive if the only value add is better time sync and I don’t need additional bandwidth. Prices coming down would be nice.

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Lammyyesterday at 11:31 PM

> Wi-Wi stands for Wireless 2Way interferometry

> 2Way

Does that mean you won't get to know the time unless you let them spy on your physical location too? That's what the diagram implies: https://www.gps.gov/sites/default/files/2025-06/CGSICMeeting...

GNSS time is still cooler because you can have extremely accurate time and a reading of your position without the broadcasting satellites knowing you're there.

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CyborgCabbagetoday at 11:29 AM

I've wondered if something like this could ever be used for VR tracking, though it seems it is much bulkier in than IR methods.

wiradikusumatoday at 5:46 AM

Maybe silly question, why we care about nanosecond speed, don't we only need to sync once and the other system can count the time by itself?

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rkagerertoday at 2:08 AM

Most important question: Is it pronounced Why-Why, or Wee-Wee?

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simulator5gyesterday at 9:31 PM

Better signal penetration with Wi-Wi could be a game changer for battery life.

chrisallicktoday at 12:49 AM

thats insane