Expert: DebiN - 4/7/2010

Question
I live in Asia most of the time (Cambodia), but make 6 month trips back to the US every couple of years.  I would like to purchase a cell phone that I can use both places.  I know that I need to look for an unlocked quad band GSM phone, but I am confused about what the 3G numbers I am seeing are about.  I see UMTS (or HSDPA) with numbers like 900/2100 or 850/1900.  What are these about?  Can I use 3G technology in US and Asia with these?  Do I need all of these to use the phone as 3G in both places?  If I get a phone that can't use 3G in one of the locations, could I still access the internet with a data plan, just slower access?  Thanks for your help!

Answer
The 3G Band in Asia is 2100. In the US, it is 1900 and 850 (mostly 1900, but more 850 starting). If you get a phone that has 5 bands (850/1900 for US and 1800/900/2100 for abroad), you will set for anywhere. You can use 3G technology anywhere and if there isn't 3G speeds available, the phone will default back to EDGE (yes, slower but not necessarily something that would cause you any problems - 3G is not available everywhere). UMTS is the download side of 3G, HSDPA is high speed download packet access (HSUPA is the upload side). Don't worry too much about that, just find a phone with all 5 bands and you will be set everywhere. There aren't a lot of phones like this today, but you may be able find a couple. I hope this helps. Thanks. DebiN