What is  Analogue 1G first Generation Cellular System

In the late 1970s and early 1980s, various First Generation 1G cellular mobile Communication Systems were introduced, characterized by analogue frequency modulation, voice transmission and limited flexibility. The 1st such system Advanced Mobile Phone System AMPS was introduced in US in late 70s. Other First Generation 1G Systems include the Nordic Mobile Telephone System (NMT).

While these systems provide good voice quality, they provide limited spectral efficiency. They have been increasingly put aside by 2G Systems in most parts of the world.