Hi I think I understand your meaning.
Not Bandwidth, but working band, a bit like channel and protocol in use, Analogue -!=> Digital ->GSM - 2G 3G now 4G and others between basically everything after GSM is backward compatible
It used to be an issue years ago when new stuff didn't work on the old systems but since 99% of phone coms chips cover the majority of standards now it's not likely to be an issue.
Your phone will work in USA and other countries as long as you have paid for global roaming and vice a versa.
Just about anything designed in the last 5 years to use the mobile network will use global compatible chips.
Pretty much the only hassle now is making sure you get the right SIZE SIM card
Cavet:
It never hurts to ask the seller/manufacturer just in case.
1 in 1000 it could be a cheap Chinese bit of crap built to get rid of surplus obsolete components. But price should tell you that.
There's always room for at least one more gun in my safe.
There's always room for one more safe in my house.