I found the most interesting part of the NIST outage post [1] is NIST's special Time Over Fiber (TOF) program [2] that "provides high-precision time transfer by other service arrangements; some direct fiber-optic links were affected and users will be contacted separately."
I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom providers synchronizing 5G clocks for time-division duplexing [4]? Google/hyperscalers as input to Spanner or other global databases?
Seriously fascinating to me -- who would be a commercial consumer of NIST TOF?
I never saw a need for this in HFT. In my experience, GPS was used instead, but there was never any critical need for microsecond accuracy in live systems. Sub-microsecond latency, yes, but when that mattered it was in order to do something as soon as possible rather than as close as possible to Wall Clock Time X.
Still useful for post-trade analysis; perhaps you can determine that a competitor now has a faster connection than you.
The regulatory requirement you linked (and other typical requirements from regulators) allows a tolerance of one second, so it doesn't call for this kind of technology.
> I never saw a need for this in HFT. In my experience, GPS was used instead, but there was never any critical need for microsecond accuracy in live systems.
> The required accuracy (Tables 1 and 2 in that document)
no, Tables 1 and 2 say divergence, not accuracy
accuracy is a mix of both granularity and divergence
regardless, your statement before:
> The regulatory requirement you linked (and other typical requirements from regulators) allows a tolerance of one second, so it doesn't call for this kind of technology.
> accuracy is a mix of both granularity and divergence
I respectfully disagree.
In context, "granularity" is nothing more than a resolution constraint on reported timestamps. Its inclusion adjacent to the specified "divergence from UTC" is a function of market manipulation surveillance objectives as discussed in preamble item (2), and really doesn't have anything to do with accuracy proper.
any time i am certain of something i never capitalize and i do not end my sentences with periods or use any punctuation because i like people to believe i am an omniscient narrator who cannot be interrupted
My guess would be scientific experiments where they need to correlate or sequence data over large regions. Things like correlating gravitational waves with radio signals and gamma ray bursts.
Would the police actually try to investigate from where came the jammer? Might the competing firm possibly even finance an investigation themselves privately? And if so, would the police then accept the evidence?
The victim firm would definitely notice, they’d tell the FCC, and their investigators will show up with a device that literally points them to wherever the jammer is. If you do this for stupid, silly reasons you will get fined[1], if you do it in commission of another crime you will probably get made an example of. It doesn’t matter how evil you are, it’s hilariously easy to get caught doing this.
> “Mr. Bojczak claimed that he installed and operated the jamming device in his company-supplied vehicle to block the GPS … system that his employer installed in the vehicle,” the FCC decision stated.
I'm not surprised that somebody would try and do this. However it is just so stupid at every level.
Sorry, you are correct. As soon as the subject of HFT came up I was thinking about London and the things they do to reduce latency to the exchanges in North America. It's too late to edit or remove my previous message.
The parent was saying HFT firms would do this to other HFT firms. They would care about doing this kind of thing - it’s not a white collar crime. And foreign adversaries would care about doing this during peacetime, especially for very unclear benefit.
But they do not need absolute time, and internal rubidium clocks can keep the required accuracy for a few days. After that, sync can be transferred with a portable plug, which is completely viable in tactical/operational level EW systems.
Google doesn't use chrony specifically, just an algorithm that is somewhat chrony-like (but very different in other ways). It's called Google TrueTime.
I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom providers synchronizing 5G clocks for time-division duplexing [4]? Google/hyperscalers as input to Spanner or other global databases?
Seriously fascinating to me -- who would be a commercial consumer of NIST TOF?
[1] https://groups.google.com/a/list.nist.gov/g/internet-time-se...
[2] https://www.nist.gov/pml/time-and-frequency-division/time-se...
[3] https://www.finra.org/rules-guidance/rulebooks/finra-rules/4...
[4] https://www.ericsson.com/en/blog/2019/8/what-you-need-to-kno...