Among the most important command locations during the Winter War, the Headquarters (Päämaja) was placed in Mikkeli, the Headquarters of the Karelian Army in Imatra, and the Headquarters of the IV Army Corps in Suistamo. The headquarters of the Air Defense and Naval Forces operated in Helsinki.
The Chief Signal Officer of theHeadquarters was Lieutenant Colonel Leo Ekberg.
During the extra exercises, a central company for the Headquarters was formed from telephone professionals in the Helsinki area, which began preparing communication connections in Mikkeli.
To construct long-distance connections for the Headquarters, four work detachments were formed from personnel of the postal and telegraph service.
From the signal units established for the Headquarters, Signal Battalion 18 was formed in December 1939. It eventually consisted of six companies. Signal depots and warehouses were established to handle signal logistics.
The storage facilities of the postal and telegraph service were allocated for the use of the Headquarters. To provide reinforcements for signal personnel, a Signal Training Center was established in Riihimäki.
