Alright, T-Mobile's out then. My apartment building is from the 50s and it's built like a goddamn air raid bunker.Correct, they are in the range of 1700 and 2100 if I remember correctly so it doesn't really penetrate buildings very well. (lower frequency the better, for example Verizon uses 700 for heavy urban areas and Sprints old iDen 800 frequency will be theirs when Spark rolls out)