What is a Tri- Band phone?
I think this link might help… http://www.wirelessreview.com/ar/wireless_gsms_world_phone/ Basically, as I understand it, a “tri-band” phone can be used abroad – i.e., if you call me on my U.S. phone number, it will still ring in the country I am in (not ALL countries, of course, I’m sure for each service there is a list, though I think it includes quite a few countries), you will pay for a call within the U.S., and I will pay the roaming charges. I hope this helps.
A tri-band phone is one that can be used around the world. If you travel frequently in Europe or Asia, you will find your cell phone won’t work overseas since Europe and Asia use a different digital frequency then we do in North America. So unless your cell phone has tri-band capabilities, you may just as well leave it home.
This is a phone you can use around the world, so you can take it with you on foreign vacations or business trips. A different digital frequency is used in Europe and Asia than is generally found in North America, so you won’t be able to take your cell phone with you to many countries around the world unless you have this Tri-Band capability.