The Nordic Mobile Telephone (NMT) was introduced from 1981 in the Nordic countries, Denmark, Finland, Norway, Sweden and Iceland, and was part of the first generation of mobile telephony. It operated in the 450 MHz range (NMT-450), and later, in 1986, also in the 900 MHz range. The original NMT concept had a channel bandwidth of 25 kHz and used Frequency Division Multiple Access (FDMA) as the access method.
The exact frequency bands, the exact channel numbers and the channel widths varied from country to country. For example, there were also countries that operated with 20 kHz channel bandwidths.