Advanced Mobile Phone System
Advanced Mobile Phone System (AMPS) was an analog mobile phone system standard originally developed by Bell Labs and later modified in a cooperative effort between Bell Labs and Motorola. It was officially introduced in the Americas on October 13, 1983, and was deployed in many other countries, including Israel in 1986, Australia in 1987, Singapore in 1988, and Pakistan in 1990.
Source: Wikipedia — Advanced Mobile Phone System (CC BY-SA 4.0)