To determine compatible networks the customer will need to verify the compatibility of the frequency band from their handset and desired network. GSM networks operate in a number of different carrier frequency ranges with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands and 3G networks 850 MHz and 1900 MHz bands. In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems. Most 3G networks in Europe operate in the 2100 MHz frequency band. – Africa, Asia, & Middle East 900 MHz {Most widely used} & 1800 MHz – Europe 900 MHz {Most widely used}, 1800 MHz, & 2100 MHz {3G} – North America: USA 850 MHz & 1900 MHz Canada 850 MHz {Backup / Rural Areas}, 1900 MHz {Urban Areas} – South America: Brazil 850 MHz, 900 MHz, 1800/1900 MHz Costa Rica 1800 MHz Ecuador & Panama 850 MHz (Exclusively) Guatemala, El Salvador, & Venezuela 850 MHz and 900/1900 MHz Peru 1900 MHz