In an ideal world, the same radio frequencies would be used for wireless systems worldwide and a device bought on one continent would just work as well on another. Unfortunately, this is not quite the reality.
Countries in Europe, Asia and Africa use the 900 and 1800 MHz band for GSM while UMTS uses the 2100 MHz band. Consequently phones sold in these regions usually support these frequencies. Most phones also support GSM on 1900 MHz which is used in North America but lack the ability for GSM 850 and UMTS 1900 MHz which are also essential for this part of the world. So people visiting North America are always handicapped as in-house and rural coverage is sometimes a problem due to the missing 850 MHz band. UMTS does not work at all…
For people living in North America the situation is vice versa when they travel. Their phones support the 850 MHz band for GSM and the 1900 MHz for GSM and UMTS. These phones usually also support the 1800 MHz band which is one of the frequencies used for GSM in the rest of the world. However 900 MHz GSM and 2100 MHz UMTS is missing…
But hope is on the horizon. Sierra Wireless will launch a Quad Band GSM – Dual Band UMTS data card soon which will support GSM/GPRS/EDGE 850,900,1800 and 1900 as well as UMTS in both the 2100 MHz and 1900 MHz bands. Thus, such worries will be a thing of the past. Let’s hope the technology ends up in mobile phones soon. Nokia for example should have a great interest in this if they want to improve their position in the North America market. Even one of their latest flagship mobile, the N80 does not support both UMTS bands. There’s one for the world market with 2100 MHz UMTS support and another verison with 1900 MHz support for North America. Time to change this!
The question remains why mobile phone manufacturers are so reluctant to produce ‘world band’ phones!? Is the extra hardware cost so much higher than the overhead of producing and maintaining different hardware and software versions?
A side note: The story is about to be continued. UMTS for the 900 MHz and is already specified and it seems only a matter of time before some countries will start using it. Also, I wonder when UMTS will make it’s appearance in the 850 MHz band.