1G mobile communication system was introduced in Japan in 1979 by Nippon Telegraph and Telephone (NTT) . Initially, it started in Tokyo and within next five years expanded to cover the whole of Japan.28 Eyl 2018
1G mobile communication system was introduced in Japan in 1979 by Nippon Telegraph and Telephone (NTT) . Initially, it started in Tokyo and within next five years expanded to cover the whole of Japan.28 Eyl 2018