Joseph wrote about Re: Cell Phone Use Coming for Airbus Fliers on Sat, 19 Feb 2005 02:13:30 -0800
Some phones are "Tri-band" and include the 1800 band. The ancient Motorola Timeport is an example. Most of the more advanced phones sold for use by international travelers are triband, and every seller will have one or two. I believe most older US phones cannot do 850, but rather do 1900 or 900/1800/1900, which is the official definition of "tri-band". Those that include 850 are quad-band
The official definition, found atthat 850 and 900 are different:
Global System for Mobile communications, the second generation digital technology originally developed for Europe but which now has in excess of 71 per cent of the world market. Initially developed for operation in the 900MHz band and subsequently modified for the 850, 1800 and1900MHz bands. GSM originally stood for Groupe Speciale Mobile, the CEPT committee which began the GSM standardisation process
Refers to a mobile phone able to operate on the three internationally designated GSM frequencies- 900, 1800 and 1900MHz
I believe they are using different parts of the 800-900 band.
See:In principle the GSM system can be implemented in any frequency band. However there are several bands where GSM terminals are, or will shortly be available. Furthermore, GSM terminals may incorporate one or more of the GSM frequency bands listed below to facilitate roaming on a global basis.
Frequency Range GSM400 450.4 - 457.6 MHz paired with 460.4 - 467.6 MHz or 478.8 - 486 MHz paired with 488.8 - 496 MHz
GSM 850 824 - 849 MHz paired with 869 - 894 MHz
GSM900 880 - 915 MHz paired with 925 - 960 MHz
GSM1800 1710 - 1785 MHz paired with 1805 - 1880 MHz
GSM1900 1850 - 1910 MHz paired with 1930 - 1990 MHz
In the above bands mobile stations transmit in the lower frequency sub-band and base stations transmit in the higher frequency sub-band.
In any event, some of the latest phones (such as the new Motorola Razr V3) claim to be "quad-band."
To see which companies use which bands, see the following.
GSM Worldwide Live Networks illustrates the spread of live GSM networks worldwide. Included is the operating frequency (e.g. GSM 900, GSM 1800 or GSM 1900) and the date the service went live. At present, Tanzania is the only country with GSM 400, and it also has GSM900/1800. TANZANIA Celtel Tanzania Limited celtel TANZANIA GSM 900/1800/400 Nov 2001
The file is available to view as a Acrobat PDF file or in HTML.
Download GSM Global Networks on Air (829k PDF).OR
View GSM Global Networks on Air as an HTML page. (This page is large (675k) and may take a while to completely load.)United States Networks are identifed as GSM 850/1900, 1900 or as 850. The 850s or 850/1900s are mostly small companies (often with Farmer or Coop or Rural in their name) and the 1900s include the larger companies.
Those in the UK are identified as GSM 900/1800 or as GSM 1800. Most of the tri-band phones Many European phones are dual band:
Mobile phones which support transmission and reception of calls on the900MHz and 1800MHz bands with seamless handover between the two frequency bands.