Mobile radio telephone systems were mobile telephony systems that preceded modern cellular network technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre-cellular (or sometimes zero generation, that is, 0G) systems. Technologies used in pre-cellular systems included the Push to Talk (PTT or manual), Mobile Telephone Service (MTS), Improved Mobile Telephone Service (IMTS), and Advanced Mobile Telephone System (AMTS) systems. These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatching system. These mobile telephones were usually mounted in cars or trucks (thus called car phones), although portable briefcase models were also made. Typically, the transceiver (transmitter-receiver) was mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver seat. They were sold through WCCs (Wireline Common Carriers, a.k.a. telephone companies), RCCs (Radio Common Carriers), and two-way radio dealers. Origins Early examples for this technology: Motorola, in conjunction with the Bell System, operated the first commercial mobile telephone service (MTS) in the US in 1946, as a service of the wireline telephone company. The A-Netz launched 1952 in West Germany as the country's first public commercial mobile phone network. System 1 launch in 1959 in the United Kingdom, the 'Post Office South Lancashire Radiophone Service', covering South Lancashire and operated from a telephone exchange in Manchester is cited as the country's first mobile phone network. However it was manual (needed to be connected via an operator) and with very little coverage for several decades. First automatic system was the Bell System's IMTS which became available in 1964, offering automatic dialing to and from the mobile. "Altai" mobile telephone system was launched into the experimental service in 1963 in the Soviet Union, becoming fully operational in 1965, a first automatic mobile phone system in Europe. Televerket opened its first manual mobile telephone system in Norway in 1966. Norway was later the first country in Europe to get an automatic mobile telephone system. The Autoradiopuhelin (ARP) launched in 1971 in Finland as the country's first public commercial mobile phone network The Automatizovaný městský radiotelefon (AMR) launched in 1978, fully operational in 1983, in