DEVICES AND WHAT TO CONSIDER WHEN ROAMING
When you plan a travel abroad, you should check in advance that your phone will work while roaming.
There are several aspects that you should bear in mind and check related to the coverage, your roaming tariff plan and the rates you will be charged while roaming (insert the links to “What to consider when roaming” and “Where can I roam?”)
However, you should also check what kind of device you have, and if it is compatible with the tecnhology used in the country you are going to roam onto.
In fact, some devices are compatible also with some specific technologies (i.e. GSM or CDMA) and with specific bands (i.e. 850, 900, 1800, 1900, 2100 bands)
Therefore, before leaving you should check what tecnology and band is used in the country you are going to, and be sure that your phone is compatible with them.
GSM world phones are devices that operate on international frequencies. These can include “tri-band” phones/devices (which operate on three of the four GSM frequencies) and “quad-band” phones/devices (which operate on all four of the GSM frequencies).
In telecommunications, a multi-band device (including dual-band, tri-band, quad-band and penta-band devices) is a communication device that supports multiple radio frequency bands. Multiple bands in mobile devices support roaming between different regions where different standards are used for mobile telephone services.
The term quad-band describes a device that supports four frequency bands: 850 and 1900 MHz, mostly used in the Americas (ITU region 2), and the 900 and 1800 MHz bands used elsewhere. Most GSM/UMTS phones support all four bands, while most CDMA/1xRTT phones do not, and so are considered only dual-band devices. A few phones support both of the domestic frequencies but only one foreign one for limited roaming, making them tri-band phones.
The term penta-band describes a device that supports a fifth frequency band, commonly the 2100 MHz band in much of the world. The Advanced Wireless Services (AWS) 1700 MHz band also seeing increased usage.