A). Calls from the car were direct dial, whereas incoming calls required an operator to determine which base station the device was currently at. In 1962, an upgraded version called Mobile System B (MTB) was introduced. In 1971, the MTD version was launched, opening for several different brands of equipment and gaining commercial success. The network remained open until 1983 and still had 600 customers when it closed.

In 1958, development began on a similar service in the USSR, the Altay