A network

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A-network radio telephone type B72 (manufacturer: TeKaDe Nürnberg, 1963). Above the control unit with handset ; in the trunk was the transmitter / receiver unit (below) equipped with electron tubes and a 12-volt transistor DC converter.

The A-Netz was the first mobile radio system for telephony in the Federal Republic of Germany .

history

The A network was introduced from 1958 by the Deutsche Bundespost as a public mobile land radio service (öbL) and was in operation until 1977. It was an analog network with manual switching ( manual switching ). If the radio range of a land radio station was left, the call was broken off and had to be set up again. Forerunners from 1950 onwards were the port radio in Bremen, Cuxhaven, Hamburg and Kiel; the Rhine radio service in Dusseldorf and Mannheim and the car radio in Berlin (West) .

The first devices still equipped with tubes were extremely expensive and bulky, so that they were usually only installed in large sedans. Depending on the design and manufacturer, they cost between DM 5,000 and DM 6,000. The technology was essentially housed in a VHF transmitter / receiver unit and the selective call set in the trunk. Only a control unit with the telephone receiver was installed in the passenger compartment . With the triumphant advance of the transistor in the early 1960s, the devices shrank to the size of a shoebox.

A-Netz B-Netz C-Netz D-Netz E-Netz Universal Mobile Telecommunications System Long Term Evolution LTE-Advanced 5G

The network was continuously expanded until around 80% area coverage (West Germany) was achieved in 1968. The capacity limit of just under 11,000 participants was reached in 1971. In order to curb demand, the monthly basic fee was increased in 1972 from 65 DM (45 DM in the A2 and A3 networks) to 270 DM. In today's currency and adjusted for inflation, this corresponds to 110, 70 and 440 euros. The reason given by the Post for this measure was: “The previous fee structure had a test character and has now been checked for the first time.” In reality, however, the nationwide expansion of the new B-network required very large sums of money. In 1972, the technically better B-Netz was put into operation in Germany and most A-Netz users switched to the new network due to the extreme increase in basic charges. When the A-Netz was shut down in 1977, it still had 787 participants.

In 1980, after the A network was shut down, the frequencies were used for an expanded B network, the B2 network.

Technical specifications

  • Frequency range between 156 MHz and 174 MHz ( 2-meter band ), transmission power 10 W, hand-switched call setup
  • 17 manually switched channels (channels 30 to 46) in the A1 network
  • 19 manually switched channels (channels 47 to 63, 86, 87) in the A2 network
  • 5 partially automated channels (channels 65, 66, 68, 72, 75) in the A3 network (only Hamburg)
  • In the final stage: 136 radio communication areas with a total of over 317 radio channels
  • 50 kHz channel spacing (A3 network 20 kHz)
  • 10,784 participants
  • Frequency modulation

See also

literature

  • Christel Jörges and Helmut Gold : Telephones 1863 until today; From the collections of the Museums for Communication; Edition Braus, 2001; ISBN 3-926318-89-9 ; Pp. 284-285

Web links

Individual evidence

  1. ↑ Reachable everywhere - the development of the mobile phone , Rüdiger Gräve, Post- und Telekommunikationsgeschichte Regionalbereich West, issue 1999 p. 81ff, ISSN  1430-4589
  2. The amounts were determined with the template: Inflation , have been rounded to a full 10 euros and refer to the previous January.