Sprint is actually in the process of rolling out some awesome updates to its network, like LTE throughout the United States. They expect to offer 4G LTE in the coming months to cities such as Chicago, Boston, Los Angeles, New York, San Francisco, and Washington, DC.
On top of that, Sprint is upgrading its cell tower technology to improve network coverage, call quality, and data speeds nationwide. This new technology works with multiple spectrum bands, whereas Sprint used to need separate equipment for each frequency. See how this works in the video below: