Nokia was one of the key developers of GSM (Global System for Mobile Communications), the second-generation mobile technology which could carry data as well as voice traffic. NMT (Nordic Mobile Telephony), the world's first mobile telephony standard that enabled international roaming, provided valuable experience for Nokia for its close participation in developing GSM, which was adopted in 1987 as the new European standard for digital mobile technology.
Nokia delivered its first GSM network to the Finnish operator Radiolinja in 1989. The world's first commercial GSM call was made on July 1, 1991 in Helsinki, Finland over a Nokia-supplied network, by then Prime Minister of Finland Harri Holkeri, using a prototype Nokia GSM phone. In 1992, the first GSM phone, the Nokia 1011, was launched. The model number refers to its launch date, 10 November. The Nokia 1011 did not yet employ Nokia's characteristic ringtone, the Nokia tune. It was introduced as a ringtone in 1994 with the Nokia 2100 series.
GSM's high-quality voice calls, easy international roaming and support for new services like text messaging (SMS) laid the foundations for a worldwide boom in mobile phone use. GSM came to dominate the world of mobile telephony in the 1990s, in mid-2008 accounting for about three billion mobile telephone subscribers in the world, with more than 700 mobile operators across 218 countries and territories. New connections are added at the rate of 15 per second, or 1.3 million per day.