GSM & W-CDMA: a Technology Overview

[Effendi]

There are several mobile phone technologies all around the World. On this site we concentrate on GSM and W-CDMA offers, so here is an overview about these technologies, their frequencies and so the kind of mobile phones you can use in the different parts of the World.


GSM

GSM (Global System for Mobile communications) is the dominant 2G digital mobile phone standard for most of the World.
It's available in 4 different frequencies:
- 900MHz -> Europe, Asia, Africa, Pacific
- 1800MHz -> Europe, Asia, Africa (very little), South America (Brazil), Pacific (very little)
- 1900MHz -> America (and 1 operator in Asia)
- 850MHz -> America

With 900MHz only you can go anywhere in Europe, Asia, Africa and Pacific.
With 1900MHz only you can go in most of America.
With 1800MHz only you can "survive" in most of Europe, Asia and Brazil.

Among phones you can find these different standards:
- monoband 900
- monoband 1900 (only in Americas)
- dual-band 900/1800
- dual-band 850/1900 (only in Americas)
- triband 900/1800/1900
- triband 850/1800/1900 (only in Americas)
- quad-band 850/900/1800/1900

A quad-band phone solves all the compatibility problems, it's the only "World-phone" for GSM available. A triband is anyway usually enough for a trip to the Americas.
Most Caraibic islands and central American small countries are upgrading to a double-standard network with both 1800 (or 900) and 1900.


W-CDMA (3G)

W-CDMA (often referred to as UMTS) is one of the 3G standards available in the World. It's the standard de-facto in Europe and Pacific, while in Asia and America it usually competes with CDMA2000 1x Ev Do. 3g W-CDMA will become in the future the most used 3G service since most GSM network operators are deplying a W-CDMA network as well.

W-CDMA is available in 2 different frequencies:
- 2100MHz -> Europe, Asia, Pacific, South Africa
- 1900MHz -> United States

By now, in 2006, W-CDMA is quite widespread in Western Europe, Hong Kong, South Korea, Japan Australia, New Zeland and South Africa. New networks are going live in these months in Eastern Europe and Asia.
In the American continent it's still under development and only Cingular has its W-CDMA 1900 network live, but mostly for data-only connection.

All phones sold in Europe, Africa and Pacific are dual-mode, which means they have both GSM and W-CDMA 2100. Some phones in Japan are W-CDMA only but they are not available on prepaid.

There are actually really few quad-band, dual-mode phones, the only 2 I can remember of are:
- Nokia E61
- Nokia N80
They are both very good phones, but rather pricey.

The main features of W-CDMA are the high-speed data (up to 381Kbps) and video-calls capability.
Most W-CDMA networks in Europe are being updated to the new higher-speed standard called HSDPA which permits download speed up to 1,8Mbps. By now no HSDPA phones are available in the market yet, except a couple of data-cards.