[Cryptography] phantom 3g service?

[Jon Callas]

> On Oct 14, 2022, at 16:14, Ray Dillinger <bear at sonic.net> wrote:
> 
> 
> On 10/13/22 14:09, Jon Callas wrote:
>> 	• Verizon's 3G network will shut off on December 31, 2022. The carrier has made it clear that "the date will not be extended again."
>> 
>> So it's possible that there is some Verizon tower you're picking up.
> 
> Hmm.  'kay.  I went and found the Verizon coverage map, but they're not talking about anything save 4g and 5g service.

As the aphorism goes, the map is not the territory. 

On the customer pages, they're showing a customer what sort of service they can expect if they subscribe, and that's not 3G. They're shutting it down. They're going to tell you they don't have 3G because they don't want to sell it to you.

> 
> So I went to something I just barely remembered but I managed to find it again - a site where they collect coverage information while driving around.  So naturally the coverage info is limited to highways but they haven't detected any 3g Verizon towers local to me (san francisco bay area) EXCEPT for one small spot out on Treasure Island - which is probably coast guard or city government or a marina or something.
> 
> https://www.nperf.com/en/map/US/-/3255.Verizon-Wireless/signal/?ll=37.82897184890619&lg=-122.3361110687256&zoom=14

Interesting. Alas, I couldn't turn off what they showed for 4G and 5G, which is really what we want. And I bet they also show the max on all those measurements. Particularly if it's coming from phones themselves, the phone isn't going to attach to a 3G net if there is better service. Again, here, the map is not the territory. 

> 
> It would be pretty remarkable if that's what I'm picking up though because that's a good eighteen miles from here.
> 

Yeah, highly unlikely. 

What you really need is a device that connects only on that and reports on the network handshake, so it can tell you what you connected to.

	Jon