Can you explain to me why cell phones operating on different frequency bands are usually needed for roaming overseas?
GSM wireless networks around the world operate on different frequencies or “bands.” Most GSM networks around the world operate on the 900 or 1800 MHz bands, while some operate on both. Most GSM networks in the Americas, however, including Primus’ network in Canada, operate on a different band—1900 MHz. Some networks in the Americas now also use the 850 MHz band. The table below outlines which type of cell phone will operate in which countries.
