China Wholesale Quad Band Cellphones

GSM-900 and GSM-1800 are used in most parts of the world: Europe, Middle East, Africa and most of Asia. In south Americas it is in Costa Rica (GSM-1800), Brazil (GSM-850, 900 and 1800), Guatemala (GSM-850, GSM-900 and 1900), El Salvador (GSM-850, GSM-900 and 1900).GSM-850 and GSM-1900 are used in the United States, Canada, and many other countries in the Americas.
In North America, GSM operates on the primary mobile communication bands-850 MHz and 1900 MHz. Initial implementations were exclusively 1900 MHz, with 850 MHz being added in 2001. In Canada, GSM-1900 is the primary band used in urban areas with 850 as a backup, and GSM-850 being the primary rural band. In the United States, regulatory requirements determine which area can use which band.
GSM-1900 and GSM-850 are also used in most of South and Central America, and both Ecuador and Panama use GSM-850 exclusively. Venezuela and Brazil use GSM-850 and GSM-900/1800 mixing the European and American bands.
Today, most cell phones support multiple bands as used in different countries. These are typically referred to as multi-band phones. Dual-band phones can cover GSM networks in pairs such as 900 and 1800 MHz frequencies (Europe, Asia, Australia and Brazil) or 850 and 1900 (North America and Brazil). European tri-band phones typically cover the 900, 1800 and 1900 bands giving good coverage in Europe and allowing limited use in North America, while North American tri-band phones utilize 850, 1800 and 1900 for wide-spread North American service but limited world-wide use. A new addition has been the quad band phone, supporting all four major GSM bands, allowing for global use.
There are also multi-mode mobile phones which can operate on GSM as well as on other cellular phone systems using other technical standards or proprietary technologies. Often these phones use multiple frequency bands as well.

Quad-Band Cell Phones Wholesale from China