private 5G networks?

Wed Dec 1 11:23:46 UTC 2021

On Tue, 30 Nov 2021 at 23:48, Shane Ronan <shane at ronan-online.com> wrote:

> Please provide details on public transit systems that are controlled via
> Wifi, I find that very interesting.
>

This should give a good overview:

https://backend.orbit.dtu.dk/ws/files/128950142/COMST2661384.pdf

It is in fact quite interesting.

And yes these are low bandwidth but on the other hand often stretch wifi to
the very limits on the distance between bases. I am not claiming this is
the same use case as a warehouse. I am pointing out that the argument that
a system critical implementation _must_ be based on licensed frequencies
does not hold as nothing could be more critical than a system that prevents
trains from colliding.

I do claim that the reason these metro train systems can boast of a very
high uptime is not that it would be especially hard to jam their wifi based
systems. No it is in fact probably quite easy to do so. It is just that
nobody does it. Because that way lies jail and there are also so many other
ways to stop the trains (rocks on the tracks etc). The same holds true for
the warehouse as someone trying to cause trouble could just as easily do
something to the power, cut a fiber cable, start a fire, call in a bomb
threat, etc.

Also having a licensed frequency only stops those that are law abiding and
it is never legal to cause harmful interference to sabotage the operations
of a warehouse.

That leaves the risk that the wifi frequencies are blocked by other legal
users of the frequencies. This risk is especially low on the new 6 GHz
frequencies because the range is not great and you do have full control of
what equipment enters your warehouse. The risk is essentially that the
neighbor is also a warehouse with a wifi based system. The physical
separation would in most cases be enough that this is not a problem and
otherwise it would not be too much trouble to talk to the neighbor to agree
on some frequency split on the bases at the border between the two systems.
No need to pay a third party or the government for that.

I did read about a use case for a private 5G network however. A system
covering the harbor. Wifi would be at a disadvantage here because it is a
large outside area with a lot of third parties entering, both ships and
trucks. I imagine there also exists similar such a large mining operation
etc.

Regards,

Baldur
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20211201/b38682cd/attachment.html>