I have an unlocked iPhone 5, the non T-mobile version on T-Mobile. At this one building at school, I'm getting not 4G, not E. I'm getting an o. I'm pretty sure I used to have an E before in this building, but thats gone now. Strangely enough I walk outside I get 4G. I know the o is even slower than E which sucks, as it is more or less unusable, thankfully there's wifi in the building. I'm just wondering if anyone has experienced this with T-mobile, and if anyone has any idea whats going on. Thanks!