In the 1970s, Nokia became more involved in the telecommunications industry by developing the Nokia DX 200, a digital switch for telephone exchanges. The DX 200 became the workhorse of the network equipment division. Its modular and flexible architecture enabled it to be developed into various switching products. In 1984, development of a version of the exchange for the Nordic Mobile Telephony network was started.
For a while in the 1970s, Nokia's network equipment production was separated into Telefenno, a company jointly owned by the parent corporation and by a company owned by the Finnish state. In 1987, the state sold its shares to Nokia and in 1992 the name was changed to Nokia Telecommunications.
In the 1970s and 1980s, Nokia developed the Sanomalaitejärjestelmä ("Message device system"), a digital, portable and encrypted text-based communications device for the Finnish Defence Forces. The current main unit used by the Defence Forces is the Sanomalaite M/90 (SANLA M/90).