any unlocked phone available in the US will operate on all carriers as long as LTE coverage is available, which is 100% of medium to large sized cities. the problem becomes when coverage downgrades to 3G or 2G..verizon and sprint are CDMA standard based; t-mobile and ATT are GSM based. Originally Posted by darkwaderAlso, signal can downgrade to 3G in the center of large buildings, or in weird topographic situations.
ATT and t-mobile are both GSM based, and operate in similar bands so any phone that works on ATT will also work on t-mobile.True and not true. Most iPhones sold since the 6 are the same device with all applicable bands for all carriers. We need the model number to be sure.
any unlocked phone available in the US will operate on all carriers as long as LTE coverage is available, which is 100% of medium to large sized cities. the problem becomes when coverage downgrades to 3G or 2G..verizon and sprint are CDMA standard based; t-mobile and ATT are GSM based.
tl;dr: unlocked phones sold by ATT will work 100% on t-mobile network and viceversa. same with verizon and sprint. if you never travel to areas without LTE coverage, you can buy phones sold by any carrier and use them on any others, as long as the device is unlocked. know you wont have access to emergency service e911 calling in some cases tho. Originally Posted by darkwader