I live in the United Kingdom, where I’ve found that the best comms network provider for mobile computing is the ‘3’ network, operated by Hutchison Whampoa Limited. As far as I can tell, the frequencies used by the UK ‘3’ network are as follows...
Table » http://en.wikipedia.org.advanc.io/wiki/Hutchison_3G#Radio_frequency_summary_7
Title: Frequencies used on the Three UK network
...although I’m betting theinformr may well know of a more authoritative and reliable source for global comms network provider frequency usage data.