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RD-72   R-72
Y2K emergency radio telephone · MNN

RD-72, also known as R-72, was a portable telephone set, released in 1996 by Nokia in Finland, for use in first generation analogue mobile telephone networks (1G) and in PMR trunking radio networks. The device featured here was used in the Duch Y2K backup system (MNN) 1 — a shadow network, in case the regular infrastructure would fail at the turn of the millenium.

The RD-72 measures 200 x 115 x 82 mm and weights 1.8 kg, including the 1.7 Ah battery pack. It is very similar to the Nokia Talkman 720, which was a popular mobile phone in countries with a 1G analogue NMT-450 mobile network.

At the time, many experts thought that, at the turn of the century – from 31 December 1999 to 1 January 2000 – computer systems, telephone exhanges, access control systems, elevators, etc. might fail due to the so-called millenium bug, also known as the Year 2000 (Y2K) problem, as clock chips used only two digits for the year [2].
RD-72 emergency network Y2K

Such critical systems had often been developed many years earlier, going back to the early days of the (personal) computer. They commonly contained a real-time clock chip (RTC) that was kept running on an internal battery when the device was powered down. As these chips used only two digits to identify the current year, 2000 might be interpreted as 1900, causing the device to fail.

As it was feared that the Y2K problem could potentially cause life threatening issues, the Dutch Government commissioned the largest telecom operator, former state-owned mono­polist KPN, 2 to build a closed mobile emergency telephone network with national coverage, that did not depend on existing infrastructure.

The network became known as Mobiel National Noodnet (MNN) – Mobile National Emergency Network – and had more than 1500 subscribers, including emergency services, police, hospitals, authorities and critical infrastructure operators.
Network provider KPN

Each subscriber had a 7-digit number, and calls could only be made between subscribers on the same network, although calls to the wired national emergency network (NN) were also possible. Furthermore, the duration of a call was limited to 4 minutes. Approx. 10 seconds before the end, the user heared a warning tone, indicating that the call was about to be terminated. Like a regular trunking network, KPN's Y2K emergency network was semi-duplex (simplex), which means that users had to press the push-to-talk (PTT) switchintegrated in the handset — when speaking.

The Dutch Y2K network became operational on 1 October 1999 and was active for six months. It was dismantled in April 2000, after which the equipment was recalled by KPN and disposed of. A small number of nodes was later re-established, when it dawned that the turn from 31 December 2000 to 1 January 2001 might also cause problems, but no big calamities were ever reported.

  1. Dutch: Mobile Nationaal Noodnet (MNN) — Mobile National Emergency Network.
  2. Previously known as PTT. In 1989 privatised and renamed KPN.
  3. Calls could also be made to the wired national emergency network.

RD-72 emergency network Y2K
Right angle view
With handset off-hook
Handset with push-to-talk button
Operating the push-to-talk button
Network provider KPN
The phone's own telephone number
1 / 8
RD-72 emergency network Y2K
2 / 8
Right angle view
3 / 8
With handset off-hook
4 / 8
Handset with push-to-talk button
5 / 8
Operating the push-to-talk button
6 / 8
Network provider KPN
7 / 8
8 / 8
The phone's own telephone number

The map below shows the position of the most important MNN subscribers in the Netherlands, and the penetration in that region, taken from the initial emergency directory of September 1999 [D]. The larger the dot, the more subscribers. The highest penetration of MNN subscribers was in the areas around the capital Amsterdam, and the seat of the Dutch government — The Hague.

Map of the Netherlands with MNN nodes

  • Device
    Radio telephone (analogue)
  • Purpose
    Emergency communication at the turn of the millenium
  • Manufacturer
    Nokia (Finland)
  • Model
  • Operator
    KPN (Netherlands)
  • Standards
    ETS 300086/113, MPT-1327, MPT-1343
  • System
    Trunking network (semi-duplex)
  • Purpose
    Y2K national emergency network
  • Bands
    3 (only one supported, see below)
  • Mode
  • Output
    8 Watt
  • Power
    12V DC
  • Temperature
    -25°C to +55°C (storage +35°C to +65°C)
  • Dimensions
    200 x 115 x 82 mm
  • Weight
    1.8 kg (including 1.7 Ah battery)
Frequency bands
  1. 300 - 366 MHz
  2. 400 - 500 MHz ← used in The Netherlands
  3. 806 - 869 MHz
  1. Nokia R72, Gebruikershandleiding voor het Mobiel Nationaal Noodnet
    KPN, September 1999. DIN A6 format (in Dutch language).

  2. Mobiel Nationaal Noodnet, Quick Reference Card
    KPN, September 1999. DIN A5 format (in Dutch language).

  3. ProRent Calamiteiten, Quick Reference Card
    KPN, October 1999. DIN A5 format (in Dutch language).

  4. Mobiel Nationaal Noodnet, Telefoongids (directory)
    KPN, September 1999. DIN A5 booklet (in Dutch language).

  5. Mobiel Nationaal Noodnet, Aandachtspunten voor het Millenium
    Date unknown. DIN A4 leaflet (in Dutch language).

  6. Nationaal Noodnet & Mobiel Nationaal Noodnet, Telefoongids (directory)
    KPN, December 1999. DIN A5 booklet (in Dutch language).
  1. Wikipedia (Dutch), Nationaal Noodnet
    Retrieved November 2020.

  2. Wikipedia, Year 2000 problem
    Retrieved November 2020.

  3. Medianieuws, KPN komt met mobiel nationaal noodnet, 12 July 1999.
Further information
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Crypto Museum. Created: Thursday 03 December 2020. Last changed: Tuesday, 22 August 2023 - 18:44 CET.
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