NMT (Nordic Mobile Telephone System) is a cellular phone system that was introduced in the Nordic countries of Denmark, Finland, Norway, and Sweden in 1981. It was the first commercial mobile telephone network to cover an entire country. NMT provided reliable communication services to customers across Scandinavia for over two decades before GSM networks replaced it.

The NMT system operated on a 450MHz frequency band with 30 channels and supported both analog voice calls as well as digital data transmission over its network. Each channel had a capacity of 2 x 8 kbit/s, allowing users to make simultaneous voice calls or send short messages using their phones’ built-in keyboards or external modems connected via cables or infrared ports. The range of coverage extended up to 50 km from base stations located throughout each country’s cities and towns, offering excellent reception even in rural areas where other systems could not reach customers due to their limited range capabilities.

In addition, NMT also featured advanced features like roaming between different countries within the region without changing SIM cards; call forwarding; conference calling; voicemail; caller ID; paging service, etc., making it one of the most sophisticated telecommunication systems available during its time period. In fact, some operators deployed additional technologies such as SMS messaging on top of existing infrastructure to provide enhanced services for subscribers.

By 1997 however, GSM networks began replacing traditional analog cellular systems like NMT across Europe which eventually led many Scandinavian carriers to switch over to newer technology too. Despite this, legacy components remain operational today, allowing some enthusiasts to still access these frequencies with specialized equipment – providing a unique opportunity to explore the history of telecommunications development firsthand!