Tri band

Tri band phones (also known as "tri-band" or "triband") are mobile phones that support three frequency bands. Having more than one frequency in one device is useful to enable roaming between different countries that peg the allowed transmission frequency at different values or to allow a better coverage in the same country.

2G

Various countries use different frequency bands for their mobile networks and a triband phone can be used on three of these bands, generally speaking, chosen to favour two of the home country's bands, and one for roaming in other countries.

GSM frequency bands used around the world:
* 850 MHz (In America)
* 900 MHz (In Africa, Europe, and many parts of Asia and Latin America)
* 1800 MHz (In Africa, Europe, and Asia and many parts of Latin America)
* 1900 MHz (In America)

2G Triband phones are mobile phones that support the GSM 900/1800/1900 MHz bands commonly sold in Europe, Asia and Africa, (for example the LG KE820 is a triband mobile phone that is sold in Europe, but works in big cities of America but not so well in suburbs and rural areas).Or alternatively the 850/1800/1900 bands (commonly sold in the Americas). The Motorola V300 formerly carried by Rogers Wireless used a rare combination of 850/900/1900.A 2G Quad band (850/900/1800/1900) offers more coverage and is now quite common.

3G

UMTS / HSDPA devices operate in UMTS frequency bands 850/1900/2100 or 850/1700/2100 MHz:
*2100 (downlink) / 1900 (uplink) for Europe and Asia (usually referred simply as W-CDMA 2100)
*1900 / 850 (independently, for both the uplink and downlink) for America (e.g. AT&T)
*2100 (downlink) / 1700 (uplink) for America (e.g. T-Mobile)
*850 for Australia (Telstra NextG)

UMTS / HSDPA / HSUPA is a further evolution.

Note that being UMTS / HSDPA / HSUPA tri band doesn't mean that phone is a GSM / GPRS / EDGE tri band. An HSUPA tri band might not be a GSM at all. However nearly all HSDPA or HSUPA tri band are EDGE quad band too.

A 3G Quad band offers more coverage.

Devices

Some UMTS / HSDPA 850/1900/2100 tri band are already available:
*Apple - iPhone 3G
*ASUS -
*BandRich - BandLuxe C100
*Gigabyte - GSmart MS820, MS808, MS804, MD800
*Glofiish (E-Ten/Acer) - Glofiish V900
*HTC – HTC TyTN, HTC P3600, HTC Advantage X7500, HTC Shift (Ultra-Mobile PC), HTC S420, HTC S630, HTC P4550, HTC P6500, HTC Touch Cruise
*Huawei – E800 Data Card (ExpressCard)
*i-mate – JASJAM, Ultimate series 5150 6150 7150 8150 9150 (all five available alternatively in 850/1700/2100 bands)
*Nokia - E90? N85
*Motorola - Motorola Atila
*Palm - Treo 750 (UMTS only), Treo Pro
*RIM - Blackberry Bold
*Samsung - Samsung BlackJack II (UMTS only), Samsung BlackJack III?, Samsung i900 Omnia
*Sony Ericsson – PC300, Z750, K850i, W760i, C902, MD300
*UBiQUiO - 503G

Some UMTS / HSDPA / HSUPA 850/1900/2100 tri band are already available:
*HTC - HTC Omni
*Huawei – E270 Wireless modem (USB)
*Novatel Wireless – Merlin X950D ExpressCard
*Option – GlobeTrotter Express HSUPA, GlobeTrotter GT MAX HSUPA, GlobeSurfer iCON HSUPA, GTM380
*Sierra Wireless – AirCard 880 and the AirCard 881 (PC Card), AirCard 880E and the AirCard 881E (ExpressCard) and MC8780 and the MC8781 (PCI Express)
*Sony Ericsson – EC400g (plus GPS)

ee also

* 3GPP
* Cellular frequencies
* Dual band
* GSM frequency bands
* Quad band
* Roaming
* UMTS frequency bands

External links

* [http://www.coveragemaps.com/gsmposter.htm Frequency world map]
* [http://www.gsmworld.com/HSPA HSPA website]