Before we start: 'G' for 'Generation'.....
Each Generation is defined as a set of telephone network standards, which detail the technological implementation of a particular mobile phone system.
1G - Analog
Introduced in 1987 by Telecom (known today as Telstra).
The technology behind 1G was the AMPS (Advanced Mobile Phone System) network. AMPS was a voice-only network operating on the 800MHz band.
It did have one advantage over later 2G networks - coverage. An AMPS user could connect to a cell tower as far as the signal could be transmitted (often >40km depending on terrain).
1G was the first generation of mobile networks. Here basically, radio signals were transmitted in ‘Analogue’ form and expectedly, one was not able to do much other than sending text messaging and making calls. But the biggest disadvantage, however came in the form of limited network availability, as in the network was available only within the country.
2G - Digital
Fast forward to 1993 Telecom, now known as Telstra, introduces the digital network.
Text messaging, multimedia messaging, internet access, etc, and also introduced us to the SIM card.
GSM - Global System for Mobile Communication
CDMA - Code Division Multiple Access. .
2G networks on the other hand, were based on narrow band digital networks. Signals were transmitted in the digital format and this dramatically improved the quality of calls and also reduced the complexity of data transmission. The other advantage of the 2G network came in the form of Semi Global Roaming System, which enabled the connectivity all over the world.
EDGE - Enhanced Data Rates for GSM Evolution.
Between 2G and 3G there was a short phase in between where mobile phones became sleeker and more ‘pocketable’ if we can call it that. This is popularly referred to as 2.5G where the quantity of radio waves to be transmitted was much lower. This in turn had an effect on the shape and structure of mobile phones. But most of all, 2.5G helped in the ushering of GPRS (General Pocket Radio Service).
3G - The Mobile Broadband Revolution
The 3rd generation of mobile networks has become popular largely thanks to the ability of users to access the Internet over devices like mobiles and tablets. The speed of data transmission oG network ranges between 384KBPS to 2MBPS. This means a 3G network actually allows for mn a 3ore data transmission and therefore the network enables voice and video calling, file transmission, internet surfing, online TV, view high definition videos, play games and much more. 3G is the best option for users who need to always stay connected to Internet.
The new network also employs a much more secure encryption algorithm when transmitting over the air. 3G uses a 128-bit A5/3 stream cipher which, unlike A5/1 used in GSM (which can be cracked in near real-time using a ciphertext-only attack), has no known practical weaknesses.
4G - LTE-Advanced
4th Generation mobile networks are believed to provide many value added features. In addition to all the 3G facilities, data transmission is believed to go through the roof with speeds ranging between 100MBPs to 1GBPS.