Nordic Mobile Telephone

Initial NMT phones were designed to mount in the trunk of a car, with a keyboard/display unit at the driver's seat.

However, Ericsson introduced the first commercial service in Saudi Arabia on 1 September 1981 to 1,200 users, as a pilot test project, one month before they did the same in Sweden.

In Iceland, the GSM network reaches 98% of the country's population but only a small proportion of its land area.

The NMT system however reaches most of the country and a lot of the surrounding waters, thus the network was popular with fishermen and those traveling in the vast empty mainland.

In Denmark, Norway and Sweden the NMT-450 frequencies have been auctioned off to Swedish Nordisk Mobiltelefon which later became Ice.net and renamed to Net 1 that built a digital network using CDMA 450.

Skylink, subsidiary company of Tele2 Russia operates NMT-450 network as of 2016 in Arkhangelsk Oblast and Perm Krai.

NMT had automatic switching (dialing) and handover of the call built into the standard from the beginning, which was not the case with most preceding car phone services, such as the Finnish ARP.

This caused the periodic short noise bursts, e.g. during handover, that were uniquely characteristic to NMT sound.

In the original NMT specification the voice traffic was not encrypted; it was possible to listen to calls using e.g. a scanner or a cable ready TV.

Later versions of the NMT specifications defined optional analog scrambling which was based on two-band audio frequency inversion.

While the scrambling method was not at all as strong as encryption of current digital phones, such as GSM or CDMA, it did prevent casual listening with scanners.