[Cowland]

I switched from Cricket to Project Fi - after I spent a while talking with Project Fi tech support to make sure I'd be able to get a cell signal at my house. Got my phone, set it up, and everything worked fine.

Then the power went out. I realized I'd been sending/receiving calls through Wi-Fi. Without power, I couldn't contact anybody.

I'm old, and I've gone to the hospital by ambulance 5 times in the last 3 years. But when the power is out, with Project Fi, I can't call 911.

Worked with Tech Support for several days, doing a whole series of tests and sending logs to Project Fi. Result: There's no problem with signal strength, but I'm in between "2 strong towers" so "your phone can't lock into either one of them."

Really? Is that a thing? When I use Open Signal or Network Cell Info, they show a signal at -122 to -118 dB.

[Rukbat]

Really, it's a thing. (I'm old too - 76, but I used to design these things back in the day.)

And never depend on a cell phone for 911. If the power at the tower goes out, so does your cellphone service. (During hurricane Florence [I hate that name] T-Mobile was down for 48 hours, and our power was out, and I have no landline, so no phone service at all for about 24 hours. Even the emergency pendants will go out when that happens. You need a "copper to the office" landline "red-ringed" as a medically needed line.) Project Fi is okay, but not perfect - if you're sitting right between 2 towers, it can't select one. (And Mint, if you don't need much data, is a lot cheaper.)

[hallux]

Except Mint will have the same issue if both those towers were T-Mobile, as Mint runs on T-Mobile.

Project Fi actually has some dialer codes you can use to force the phone to use one carrier. It's not ideal for emergency situations since it requires thought (it reverts to automatic again after 2 hours) but it can certainly help.

*#*#FINEXT#*#* switches to the next carrier
*#*#FITMO#*#* forces usage of T-Mobile
*#*#FISPR#*#* forces usage of Sprint
*#*#FIUSC#*#* forces use of USCC
*#*#FIAUTO#*#* reverts to automatic switching
*#*#FIXME#*#* attempts to perform an automatic repair (not certain on the usage here)
*#*#FIINFO#*#* provides info on the current network.

The app Signal Spy can automate some of this as well.