Sprint's LTE service was turned on nearly a month ago and already there have been complaints of spotty reception and the carrier explained that it is currently focusing on "street-level service" and its LTE signal is expected to be available inside, eventually. There is a question of whether Sprint will have enough unused spectrum to compete with Verizon and LTE.
As the video shows, putting up the necessary towers is not a quick or easy job and Sprint has a lot of ground to cover if it is going to be a major player in he LTE market. T-Mobile, currently testing LTE service, is expected to launch its LTE network in 2013.
source: YouTube via SprintUSERS