OLT (

Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe * Norwegians, both a nation and an ethnic group native to Norway * Demographics of Norway *The Norwegian language, including ...

for ''Offentlig Landmobil Telefoni'', Public Land Mobile Telephony), was the first land mobile telephone network in Norway. It was established December 1, 1966, and continued until it was obsoleted by NMT in 1990. In 1981, there were 30,000 mobile subscribers, which at the time made this network the largest in the world. The network operated in the 160 MHz VHF band, using

frequency modulation Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing. In analog fre ...

(FM) on 160-162 MHz for the mobile unit, and 168-170 MHz for the base station. Most mobile sets were semi-duplex, but some of the more expensive units were

full duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...

. Each subscriber was assigned a five digit phone number. In 1976, the OLT system was extended to include UHF bands, incorporating MTD, and allowing international roaming within

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

n countries.

External links

Norwegian mobile phone history
from Norsk Telemuseum (Norwegian) {{Mobile telecommunications standards Mobile radio telephone systems