Sprint packs WiMAX and LTE into latest hotspot

Sprint(s s) is cramming an awful lot of radios into its latest hotspot. On May 18, Sprint will begin selling the Sierra Wireless Tri-Fi hotspot, which customers can immediately connect to its 3G and WiMAX networks and eventually use Sprint’s new LTE network when it goes live this summer.

Sprint first unveiled the device at CES as part of its initial LTE portfolio, but the May launch shows it planning to follow the same seeding strategy it’s pursuing with its smartphones: By pre-selling LTE devices, its customers can take immediate advantage of the new 4G service when it launches.

Customers will have to put up with limited mobile broadband coverage initially – its Clearwire-run(s clwr) WiMAX network covers only 130 million people, while LTE will launch in 10 markets. But Sprint plans to ramp up quickly, building an LTE footprint covering 250 million people in 260 markets by the end of 2013. Once LTE is live, Tri-Fi customers will get to choose between two 4G options where they are available and fall back on Sprint’s CDMA EV-DO networks where they aren’t.

While Sprint’s smartphone data plans remain unlimited, its capped hotspot plans could definitely use some work. It doesn’t appear to changing its pricing policies for LTE, which could cause careless customers to run up enormous data bills. While Sprint’s plan of tier pricing undercuts most of its competitors, the carrier still engages in the medieval practice of charging punitive overage fees. If you exceed your data cap, charges of 5 cents per minute kick in, which works out to be $50 a gigabyte.

The plans for the device start at $34.99 for 3 GB a month, but it also offers several big bucket options: $49.99 for 6GB of combined 3G/4G data or $79.99 for 12GB of 3G/4G data. While at CTIA Wireless in New Orleans on Wednesday, Sprint announced that the new HTC EVO 4G LTE would be available on May 18 as well.