Quad band

Quad band (also known as "quad-band" or "quadband") literally means four bands. Most people come across the term when it is used to describe a mobile phone supporting four 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

The GSM standard originated in Europe, where mobile phones occupy two frequency bands: one in the 900 MHz range and one in the 1800 MHz range. When GSM technology crossed the Atlantic to the Americas, it was impossible to reuse the same European frequency bands since those had already been allocated to other devices by the FCC. Hence, a different pair of frequency bands were made available for GSM use: the 850 and 1900 MHz bands.

In summary, a quad-band mobile phone is used to designate a phone that can operate in the following GSM frequency bands:
* 850 MHz (U.S./Canada/Latin America/Brazil (Only the carrier Vivo))
* 900 MHz (Africa/Europe/Brazil/Australia/Asia (ex Japan and S. Korea))
* 1800 MHz (Africa/Europe/Australia/Asia/Brazil)
* 1900 MHz (U.S./Canada/Latin America)

Some companies refer to this feature as "World Phone", due to the variety of bands a quad-band phone supports.

Note that hardly any quad band phones cover GSM 400 (450 - 480 MHz), a band used in sparsely populated areas or in less developed countries due to its longer range. While a "quint band" phone [phone]/1900) is possible, none has yet been announced.

3G

UMTS / HSDPA / HSUPA devices operate in the UMTS frequency bands 800/850/1900/2100 or 850/1700/1900/2100 MHz:
*2100 (downlink) / 1900 (uplink) for Europe, Africa, Australia, Asia (including South Korea and Japan) and Brazil (usually referred simply as UMTS2100)
*1900 for North and South America
*2100 (downlink) / 1700 (uplink) for T-Mobile USA and others, called AWS Band (usually referred simply as UMTS1700)
*900 for Australia (Optus and Vodafone Australia in rural areas) and in countries that currently use GSM900 in the future
*850 for North and South America, Australia (NextG)
*800 for Japan (NTT DoCoMo in rural areas)

Note that being UMTS / HSDPA / HSUPA quad band doesn't mean that phone is a GSM / GPRS / EDGE quad band. However nearly all HSUPA quad band devices are EDGE quad band too.

Five and Six band phones (800/850/900/1700/1900/2100) are possible but none has been announced.

Devices

UMTS/HSDPA/HSUPA 800/850/1900/2100 devices:
*HTC - HTC Kaiser Fact|date=April 2008 (aka HTC TyTN II, aka HTC P4550, aka O2 XDA Stellar, aka AT&T Tilt), HTC Polaris Fact|date=April 2008 (aka HTC Touch Cruise, aka HTC P3650, aka O2 XDA Orbit II) sony ericsson k850i

UMTS/HSDPA/HSUPA 850/1700/1900/2100 devices:
*Sony Ericsson - Xperia X1 (also available in 900/1700/1900/2100)

UMTS/HSDPA/HSUPA 900/1700/1900/2100 devices:
*Option – GT Express 401

References

* cite web
last = [e-mail]
date = 8 May 2006
url = http://www.thetravelinsider.info/roadwarriorcontent/quadbandphones.htm
title = "Dual, Tri, or Quad Band GSM Phone?"
publisher = TheTravelInsider.com
accessdate = 2006-07-26

ee also

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

External links

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