Wi-Wi Is Wireless Time Sync at 1 nanosecond
At NAB, I found a demo of Wi-Wi STAMP, a wireless time synchronization protocol that came out of Japan's NICT.
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).
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.
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