This is the information I have found about their network: Source
1.) The network is a "CDMA2000 1x-EvDO".
2.) However they call it a"3G standard" but I was under the impression that 3G & HSDPA where part of the UMTS network structure?
3.) Their current quoted speeds are 400-600Kb/s, however they do say something about a new version of 1x-EvDO which could increase speeds to 15Mb/s followed by 70Mb/s