What comes to my mind is that you could go to the phone testing mode and try to have a look at the phones capable network types and compare it to 3 network types
To go to test mode, you have to *#*#4636#*#* and there choose phone info.
Here is an example of what I see on my phone
Sent from my HTC One max using XDA Premium 4 mobile app
HTC One MAX ||| HTC ONE > HOX+ > Nexus 7 > HOX > Xperia Arc > Xperia X10 Mini > K810 > K550 > K750