The operator gives a SIM card to the customer who inserts it into the mobile device to gain access to the service.
In 1971, the MTD version was launched, opening for several different brands of equipment and gaining commercial success.
In 1966, Bulgaria presented the pocket mobile automatic telephone RAT-0,5 combined with a base station RATZ-10 (RATC-10) on Interorgtechnika-66 international exhibition.
On April 3, 1973, Martin Cooper, a Motorola researcher and executive, made the first analog mobile phone call using a heavy prototype model.
American and Canadian wireless providers tend to subsidize phones for consumers but tend to require 2 or 3-year contracts, while Asian and European providers sell the phone at full cost while the monthly fees charged are lower.