| ▲ | Wi-Wi is wireless time sync at 1 nanosecond(jeffgeerling.com) |
| 68 points by Brajeshwar 2 days ago | 9 comments |
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| ▲ | Lammy 22 minutes ago | parent | next [-] |
| > 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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| ▲ | NkVczPkybiXICG an hour ago | parent | prev | next [-] |
| 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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| ▲ | geerlingguy 19 minutes ago | parent | next [-] | | The 2nd revision of the hardware is 1ns in simulation, likely 5ns in real-world scenarios. The first revision of the hardware (which I saw at NAB) is more like 30ns (with 20ps jitter, I believe). 1ns is about the best you can do with the nearly 1 GHz carrier (as mentioned in a sibling comment). | |
| ▲ | larpingscholar 37 minutes ago | parent | prev [-] | | It's the period of the carrier wave (900MHz)? |
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| ▲ | ectospheno 2 days ago | parent | prev | next [-] |
| 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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| ▲ | Youden 2 hours ago | parent [-] | | What's expensive? PTP is widely supported on commodity hardware these days. I think most Intel NICs support it, quite a few Realtek and a lot of embedded stuff, down to even MCUs like STM32. Even if you want a NIC with a stable oscillator or GPS inputs to act as a grandmaster, you can buy an E810 with the necessary hardware from eBay etc. for a few hundred or DIY something yourself much cheaper. | | |
| ▲ | geerlingguy an hour ago | parent | next [-] | | Switches that properly support PTP are expensive, at least for now. You can achieve microsecond accuracy with a lot of non-timing-specific networking hardware, but it's around as good as you get with modern NTP... To get sub-microsecond, you need hardware that supports transparent/boundary clock and doesn't just 'say' it does, but actually does (vendors have stamped PTP support on things that definitely don't account for time correctly internally!). | |
| ▲ | jcelerier 44 minutes ago | parent | prev [-] | | out of dozens of laptops and computers we have where I work, we have maybe 3 that have a PTP-compatible NIC. |
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| ▲ | simulator5g 2 hours ago | parent | prev [-] |
| Better signal penetration with Wi-Wi could be a game changer for battery life. |
