Because I was interviewing as an internal employee, for a position under the same Sr. Manager, the interview process was shortened considerably. They were quite considerate, making sure that I was one of the first interviewed. I did have to wait several weeks to hear back from them, and obviously I would have wished it was shorter.
In all of my interviews that I have had a T-Mobile, I have found that the process can take a very long time, even when you do end up being offered the position. From others who interview at other companies I frequently hear that they will hear back within a week, sometimes much sooner, as to whether or not they will be continuing through the process. Unfortunately that isn't the case with T-Mobile. They are also not extremely communicative.
But don't assume that just because you don't hear that you definitely will or won't get the job, in my experience.