Mobile Phone History

Mobile phones getting faster technology improvements, in the beginning it has been used to make wireless communication with each other, but now it is becoming a portable device with all functions of a computer. In this post i would like to share about my mobile evolving history, And the history somewhat bigger so i continue it in oncoming posts too.
1920: Police department of America used Dual way Radio communication, which seeds up the mobile phone technology
1947: A.T & T Bell Labs found out that it is possible to operate the transmission of signals at longer distance when network of small groups of Cells(a cell is limited region where a tower could receive and transmit signals) is connected with a short range transmitters.
1954: First time it is made possible to communicate a mobile inside a Car and conversation was made, thus improving signal strength.
1970:Rich people could make calls from inside the car(Car phones begin spreading through upper part of the society)
1973:Motorola corporations Dr.Martin Cooper proved that it is possible to commuicate while walking in the road without car phone, that is he introduced Handheld mobile phones.
1979: First commercial launch of Mobile phones usage began in Tokyo, Japan
1984: Even though the cost of the mobile phones are much higher, approximately over 300000 (3 Lakhs) people used mobile phone
1989:Motorola invented a complete Mobile Phone and assigned a name Micro Talk.
1990:2G technology and GSM Digital Mobile phone which opearates in 2G technology has come to usage.
The first conversation through Digital Mobile is the information communicated a by person who got into a train in America to another person who is far away from him.
Remaining mobile phone evolution can be seen on next post.