Scandinaviaa
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| Mobile phone system that was specified by the Nordic telecommunications administrations (PTTs) starting in 1970, and opened for service in 1981 as a response to the increasing congestion and heavy requirements of the manual mobile phone networks: ARP (150 MHz) in Finland and MTD (450 MHz) in Sweden, Norway and Denmark. NMT is based on analog technology (first generation) and two variants exist: NMT-450 and NMT-900. The numbers indicate the frequency bands uses. NMT-900 was introduced in 1986 because it carries more channels than the previous NMT-450 network.
The network was opened in Sweden and Norway in 1981, and in Denmark and Finland in 1982. Iceland joined in 1986. However, curiously for a mobile phone standard that has the word "Nordic" in it, the first commercial service was introduced in Saudi Arabia on September 1st 1981 to 1200 users, one month before Sweden The NMT network has mainly been used in the Nordic countries, Switzerland, the Netherlands, Slovenia, Croatia, Bosnia, Baltic countries and Russia but also in the Middle East and in Asia. The cell sizes in an NMT network range from 2 km to 30 km. With smaller ranges the network can service more simultaneous callers; for example in a city the range can be kept short for better service. NMT used full duplex transmission, allowing for simultaneous receiving and transmission of voice. Car phone versions of NMT used transmission power of up to 15 watt (NMT-450) and 6 watt (NMT-900), handsets up to 1 watt. NMT had automatic switching (dialling) 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. Additionally, the NMT standard specified billing as well as national and international roaming. NMT also supported a simple but robust integrated data transfer mode called DMS (Data and Messaging Service) or NMT-Text, which used the network's signalling channel for data transfer. Using DMS, also text messaging was possible between two NMT handsets before SMS service started in GSM, but this feature was never commercially available except in Russian and Polish NMT networks. Transmission Frequency :
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Data Tranmision Rates of Various Technology, NMT being at the bottom
A lady is using a NMT analog 1G Phone