Mobile telephones – though still connected using cables – were first brought into serious use during the First World War. In the Second World War they were taken for granted and often played a decisive role in the outcome of events.

This was shown not least in military actions east of Sweden. On November 30, 1939, the Soviet Union attacked Finland; the Russian generals expected to be able to occupy the country in 10–12 days. The first campaign, the Winter War, came to an end 105 days later without achieving that objective. In the second conflict between the two countries, the Continuation War of 1941–1944, the outcome was the same.

Field telephones were enormously important for Finland’s resistance. They were supplied by Ericsson, something made easier by the company’s major operations in Finland and the fact that the head of Ericsson in Finland, Sven Weber, had an extremely good relationship with the Finnish general staff. Weber spent the mornings in meetings with the Finnish generals, and Ericsson’s deliveries arrived in the afternoons.

On April 9, 1940, Germany occupied Denmark and Norway. Here too telephones were important for the resistance movement – but this time the communication was mobile.

During the war, about 200 members of the Norwegian resistance acted as radio agents for Britain’s Secret Intelligence Service. Using small, portable radio transmitters, they sent information that helped the allies to act – one famous example is the sinking of the Tirpitz, an enormous German battleship, on November 12, 1944. The Germans monitored the airwaves intensively in an attempt to locate radio agents, and they were shown little mercy if caught. Hitler’s orders were that radio agents captured behind the front lines were to be executed without trial.

Author: Svenolof Karlsson & Anders Lugn


Pentti Myyryläinen, major-general of the engineering corps and a veteran of Finland’s wars with the Soviet Union, carried out a study during the 1950s of the significance of field telephones during war. He praises L.M. Ericsson’s equipment, which was delivered in great quantities during the war, and often without the company requiring payment.


With the military driving it, research into radio communication was intensive during the war years. The innovation that attracted the most attention was doubtless radar. Another was the walkie-talkie, a handheld two-way radio (with half-duplex channels, communication can take place in one direction at a time) which in 1940 was developed by the Galvin Manufacturing Company. The company later became known as Motorola.

Telephones from L.M Ericsson being used by the finnish army

© Telefonaktiebolaget LM Ericsson and Centre for Business History

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