T-Mobile boosts its 1900 network in three cities to support unlocked iPhones on its network
T-Mobile still doesn't offer the iPhone but the carrier is beefing up its network to support unlocked iPhones and these will now get a speed boost in Baltimore, Houston and Washington, D.C.
Apple sells its recent iPhones with a multi-mode chip which can work on GSM and CDMA but these don't support the radios which would have given you T-Mobile 4G. Under its network modernization plan, T-Mobile is repurposing some of its spectrum in the 1900 Mhz band to work well with unlocked iPhones (and other smartphones).
While it's not going to be as fast as the iPhone 5 with 4G LTE, T-Mobile is saying that unlocked iPhone 4S devices running on its 1900 Mhz band had an average of 70 percent faster download speeds than on AT&T's network. You can now get high speeds on T-Mobile for your unlocked iPhone in Baltimore, Kansas City, Las Vegas and Washington D.C. but if you're in another market, you'll be stuck on EDGE speeds.
Why would you want to take an unlocked iPhone to T-Mobile? T-Mobile does offer much cheaper plans and it also has unlimited access to its 4G. If you're in one of these markets and don't travel that often, an unlocked iPhone on T-Mobile may be a nice solution.