OLT (
Norwegian 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 a signal modulation technique used in electronic communication, originally for transmitting messages with a radio wave. In frequency modulation a carrier wave is varied in its instantaneous frequency in proporti ...
(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
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...
bands, incorporating
MTD, and allowing international roaming within
Scandinavia
Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...
n countries.
External links
Norwegian mobile phone historyfrom Norsk Telemuseum (Norwegian)
{{Mobile telecommunications standards
Mobile radio telephone systems