The next stage in the development of automatic telephone exchanges in Russia began in 1947: Russian specialists developed a new PaBX, the decadic (ATC-47). Its launch was held in 1949.
Some years later, the Soviet Union started producing better and more comfortable to use coordinate exchanges.
The first experimental coordinate substation with a capacity of 100 rooms (SS-ISS-100) was developed by NIITS (LONIIS) and the Red Dawn factory in the Leningrad City Telephone Network in 1957.
In the early 1960s, together with the Red Dawn factory and other enterprises, the communications industry began developing NIITS coordinate exchanges for urban telephone networks, which culminated in the establishment of the ATSC.