China has the most GSM cell phone users

This represents over 16 percent of the world's GSM population of 500 million, according to figures released today by the GSM Association, a worldwide body for the mobile/wireless industry, and EMC World Cellular Database, a wireless research organization.

GSM is a set of standards widely used in Europe for cellular communications.

By region, Europe holds the largest GSM population, or over 300 million users. However, adoption rates outside of Europe, such as in the Americas, is increasing at an exponential rate, the organizations said in a statement.

Specifically, it noted that "AT&T Wireless, Rogers Wireless and other major operators' recent decision to overlay digital TDMA (Time Division Multiple Access) network with GSM services (in the US) is expected to lead to a surge in GSM usage across the (country)".

TDMA is a method of digital wireless communications transmission allowing a large number of users to access a single radio-frequency channel without interference.

At present, there are said to be more than 10 million GSM phones in North America.

Meanwhile, for Latin America, "decisions by countries such as Brazil, Argentina, Peru and Mexico to adopt GSM are predicted to see a tenfold increase in GSM users in (the region) during the next 12 to 18 months", GSM Association and EMC World Cellular Database noted.

Both organizations added that GSM, a technology which allows mobile phone users to roam in more than 168 countries, now accounts for more than 70 percent of the world's mobile phones. The remaining 30 percent is made up of phones based on other technologies such as Code Division Multiple Access (CDMA).

CDMA is a digital spread-spectrum modulation technique used mainly with personal communications devices such as mobile phones.