Sprint is sticking to its plans to cover 123 million PoPs covered with LTE by the end of the year and 250 million by the end of 2013. President of Network Operations Steve Elfman reiterated the company lines: that initial launches will come in mid-year in Atlanta, Baltimore, Dallas, Houston, Kansas City and San Antonio with the first devices -- out of 15 planned this year -- launching before that time, but he also noted that the LTE network will cover most of the WiMax footprint this year and subsume it next year.

Sprint's deployment strategy includes starting in small towns like Kankakee, Ill., its first cluster to go live, where it has the right zoning and leases and it's rural enough to not disrupt a lot of people in the testing phases. Then, Sprint VP of Development & Engineering Iyad Tarazi said, it will creep its way into the major city nearby, as with Waco working towards Dallas and Fort Worth and Kankakee moving into Chicago.

Sprint has Network Vision construction started in 17 markets and is working on LTE in all states except for Alaska.

Sprint reports its first-quarter earnings on April 25, so the carrier didn't divulge any financial updates on Network Vision. We'll have to wait a week to learn about vendor financing and acquisition targets (although, don't hold your breath on that one). SVP of Networks Bob Azzi said, however, that Sprint's built a lot of its future upgrades into its financials, so there won't be huge incremental investments necessary outside of the initial US$4 to $5 billion.

Azzi also said Sprint will have more information on its earnings call about how it's working with the Rural Cellular Association on LTE roaming and, in general, on how it will be "highly competitive to the big two," AT&T Inc. (NYSE: T) and Verizon Wireless .

Don't expect any WiMax/LTE/CDMA smartphones. Sprint will offer tri-mode hotspots for heavy data users, but doesn't plan on selling any phones that can cross all three networks. In fact, it won't be making any new WiMax smartphones, although it will continue to sell them through the end of the year. Handoff from LTE to CDMA will matter less going forward because LTE will become ubiquitous, Azzi said.

Sprint will start coordinating its small cell network, which Azzi said includes "several hundred thousand" small cells already, with its macro network in late 2012 to early 2013.

The carrier plans to stick with unlimited on LTE, but it's hoping to encourage more of its customers to use Wi-Fi with a network client it built with Smith Micro Software Inc. (Nasdaq: SMSI) and Birdstep Technology ASA (Oslo: BIRD) that automatically defaults to Wi-Fi when available or chooses the best network, WiMax or CDMA, on Android devices. (See Sprint: Still Unlimited on 4G LTE Smartphones.)

Sprint Chief Sales Officer Paget Alves doesn't believe Sprint will have any trouble marketing 4G LTE, because it's already established the value of 4G with its consumer customers through WiMax, and its enterprise customers are anxious for LTE to come online. Neither group necessarily understands or cares about the difference between WiMax and LTE, he said.