Both T-Mobile and AT&T have recently entered into an Exchange Agreement according to FCC document filings, which will see both carriers pack up some of their PCS and AWS-1 spectrum licenses to swap hands with the other, if the FCC approves the deal. The biggest part of this depends on how you look at it. To some, this will convey two of the nation's largest carriers working together toward bettering or improving their own networks through a partnership with the other. This is almost monumental in itself, as you don't normally hear about the partnerships or agreements made by the number two and now number three carriers in the U.S. However unlikely an agreement like this between the two may have seemed though, it should result in a better network for everyone involved from the carrier level down to the consumer on either network.
The goal of the agreement is to allow for both carriers to enable "more efficient operations." To accomplish this task, each carrier is going to need to create a larger set/block of spectrum that align next to each other in sequence. Each carrier will also be swapping the exact same amount of spectrum, so neither is going to have more spectrum changing hands than the other, and this sort of equality also extends out to the types of spectrum each carrier is transferring to the other. In a simpler explanation, both carriers will be letting go of x amount of PCS and AWS-1 spectrum, for the equal amount back from the other.
This exchange allows each carrier to get the type and amount of spectrum they need for a specific market where they may not have it. So for example, while T-Mobile may be letting go of some AWS-1 spectrum in one market, they're doing so by swapping it out of a market where it isn't needed so they're able to get back some spectrum licenses in a market where they need AWS-1 licesnses. The same goes for AT&T. This exchange, if approved, is expected to take place across several different markets in the U.S. including Boston, Sacramento, Pheonix, Hartford, Tulsa, Austin, San Antonio, and Minneapolis-St.Paul among others. Following this swap, this should open up a number of possible Wideband AWS LTE locations for T-Mobile, which would allow them to continue toward bringing customers faster speeds in more markets which they hope to do by the end of this year. At the moment, there is no clear date as to when the spectrum swap would take place if approved, but possibilities are sometime after the middle of this month and well into next year.