So let's assume that you already have a phone that was unlocked prior to Saturday. To take advantage of the trial, you fill out a form online and receive a confirmation code. You then proceed to the nearest T-Mobile store with the unlocked phone and the code, and the seven days will begin. The carrier says it has recently upgraded its HSPA+ 4G service in those two cities and it is now "faster and more dependable".
Las Vegas is expected to be the carrier's first LTE market and the service could debut soon.
T-Mobile is offering residents of Las Vegas and Seattle a chance to test its 4G service free for one week