Tri-Band? Quad-Band?

Mobile phones are bit like walkie-talkies (or radios) in that they need to "tune in" to a special frequency.

In actual fact they tune into a range of frequencies also known as Bands and some mobile phone handsets are smart enough to tune into more than one band:

Dual-Band

Tri-Band

Quad-Band

Networks

To understand “Bands” we also have to understand “Networks”.  TravelSIM and most of the world’s mobile networks work on GSM including Australia, however there are also other types of networks available.

Network Band
GSM GSM 850
GSM 900
GSM 1800
GSM 1900
3G  
CDMA  
4G  

A simple way to think of this is comparing networks to language - if your phone speaks GSM it can't speak 3G and it won't understand the 3G network.

Hint:  See more on mobile frequencies to know what band or frequency your mobile handset can "pick up"?