Twenty years ago , an historic agreement was signed 
in Copenhagen by 15 telecommunications operators from 13 countries that led to the development of the Global System for Mobile Communications (GSM). Today, more than 2.5 billion people across 218 countries and territories, are served by GSM.
According to the GSM Association,
- the GSM family of technologies makes up 85% of the global mobile services market, which accounts for about 1.6% of global GDP.
- each year, mobile users purchase more than one billion new handsets, make more than 7 trillion minutes of calls and send about 2.5 trillion text messages.
- mobile operators have spent more than $234 billion building GSM and 3GSM networks since 2002.
- the world’s biggest GSM markets are China (445 million), Russia (160 million), and India (137 million).
- 64% of mobile users are in emerging markets.
.
http://www.gsmworld.com
