Definition - What does Tri-band mean?
Tri-band technology refers to mobile communications devices, usually cellphones that can operate on three, rather than just one, broadband frequency. These devices use two domestic frequencies available and one foreign frequency for limited roaming capability.
Tri-band phones are the most common kinds of phones because of their greater geographical range, gaining the title of world phones. The common frequencies used are GSM900, GSM1800 and GSM1900.
Techopedia explains Tri-band
There are two main types of tri-band phones: the American and European. The American tri-band phones cover the 850, 1800 and 1900 frequency bands, while the European covers 900, 1800 and 1900 frequency bands. Travelers, however, prefer the European models since the frequencies they use are also in wide use outside the US and Canada.
Tri-band phones operate using the Global System for Mobile Communications (GSM) standard, the second generation (2G) of digital networks technology used by mobile phones. 2G phones were a major development from the first mobile phones in the 80s which allowed for the switch into digital. However, with the newer 3G technology and the introduction of 4G in 2010, 2G tri-band technology became outdated and obsolete, but that doesn’t mean it is no longer in wide use.