New T-Mobile iPhone Carrier Bundle is Available for Download
The new iPhone carrier bundle update for T-Mobile that enables AWS LTE and additional features, is now available for download, according to TMONews.
Apple and T-Mobile have just now pushed the Carrier Bundle (ipcc) that enables T-Mobile LTE for the iPhone 5 (and just enables general service for all the other iPhones). If you have an iPhone 3GS/4/4S/5, this update will be available to you by going to the About Phone page in Settings.
A direct download to the iOS 6.1 ipcc is here.