Thus begins the quest to try to get it to work in the US. I know that it can work, because when I was a Docomo subscriber and brought it here on visits it would get 3G/LTE roaming access.
However, I have no idea which network it was using to do that. My initial effort, which just consisted of going to the T-Mobile store and asking them for a SIM card to fit it, didn't work: it can make calls and it gets 2G access, but nothing faster. It can't even see the T-Mobile 3G network to be able to select it in the settings.
Investigating on the 'net, it appears that
- Actual 4G LTE is hopeless. The phone uses only band 1, which is not supported in North America. This doesn't match my roaming experience, but it's possible that the phone was displaying "LTE" as the connection type when it actually meant "3G plus some speed boost features."
- For 3G, the phone uses bands 1, 9, and 19. None of these are supported by anyone in North America.
- AT&T supports, in some places, band 5. Band 19 is entirely contained within band 5. I strongly suspect this is the one it was using when I was here before. As further evidence, "AT&T[3G]" shows up as a carrier I can select in the phone settings screen.
So my options seem to be
- Switch to AT&T. They have an equivalent plan to what I've got now, so it won't cost me any more. I'm not sure how to check if they have reasonable coverage since coverage maps don't show which bands are used where, but "some coverage" is better than the "no coverage" I've got now. The one catch is that my current T-Mobile plan is a grandfathered one that's $20/mo cheaper than anything else they offer currently, so if I leave them and then want to switch back later it'll cost.
- Buy a new phone. Arrrrggggghhhhhh.
- Give up and live with 2G access. It seems to be kinda-usable just for web browsing at least. Though apparently 2G networks are deprecated and getting shut down soon.