Yes, WiMax (or WiMAX for those that care).
I spent a few weeks, a long time ago, getting the Imagine WiMax Motorola USBw35200 dongle working under Linux using the Sprint 4G Developer software, but it was a nasty hack.
A Hack that stopped working recently. Or at least, when I tried to use it this week it didn’t work.
Linux Kernel 3.0.0 has the right kernel module.
You need to build the Spring 4G package to get the firmware out, copy it to /lib/firmware
Imagine uses EAP-TLS
You can get the WiMAX and Imagine server certs from the CD-ROM partition on the dongle (disable usb modeswitch before you insert it)
You need a Device Private Key to connect, which is stored in a memory location on the dongle itself. I have no idea how to get it out, or how to point the wimax userspace agents to that memory.