When we mention 2G,3G,4G..etc. the 'G' there refers to a 'Generation". In technology a generation change is said to happen when there is a paradigm shift in the characteristics of the existing technology usage ,service etc.
Modern telecommunication using some technology started from the birth of telegraphy. It was followed by telephone. In early days these wren facilitated by wired connections. This later changed to 'wireless' telecommunication.
However the early use and service of wireless telecommunication was mostly for specific sectors like defence, law and order machinery ,scientific research etc.
A lot of innovation and technology migration happened once the wireless telecommunication came became available commercially and for use by common man for private communication.
Zero G and 1 G.
The notable changes were felt after the coming of Cell phones or cellular telecommunication. With the advent of cell phones, a caller could directly make a call to the receiver by dialing the prescribed number. The call could be continued in a larger geographic area seamlessly even when the caller or receiver is moving also. This was enabled by a network of low power transmitters set up in a large geographic are called 'cells'. The first commercial use of cellular technology came in 1979 in Tokyo, Japan. This is now taken to be the first generation of Cellular communication or Cell phones. (The pre-cellular mobile phone stage is also known to be Zero G.)
2G
As the popularity and usage of cellphones for private communication started becoming wider there came technological changes too. A global standardisation was brought in-known as GSM. This allowed short text messaging in addition to voice call. There was more privacy in communication compared to earl 1G phones.
The technological shift in 2G was that transmission became digital, where as it was analogous in the earlier generation. The 2 G was launched from 1981.
The sub improvements and changes within the same 2G generation may be subdivided as 2.5G where GPRS was enabled and .2.75 G when the higher speed EDGE-(Enhanced Digital Rates for GSM Evolution) came in.
3G
The 3G period is considered to be 2001-2009..With data speed increasing 3G brought more wide ranging facilities like video calls, streaming, broad band internet, gaming, GPs, mobile television etc. It helped higher speed and stability for moving devices too with reduction in call lags and became more convenient.
The sub generation are called 3.5G with HSDPA and HSUPA; 3.75 G with HSPA.
4G -2010-2019
There was a demand for more speed and need for less time for data transfer Hence the next generation, 4G was aimed to give a speed up to 1GBPS. LTE (Long Term Evoloution ) is the start of 4G. This mainly enabled VoLTE-Voice over LTE and voice over the internet the internet, IP telephony. It enabled HD mobile TV, cloud computing etc. Data transfer was many many times of that of 2G and 3G. It helped multimedia transmission at low costs. HD quality streaming became possible.
5G
5G was targeted to be introduced by 2010. 5G aimed at high speed and NIL latency. This was aimed at prevalent use of IoT-Internet of Things, unmanned vehicles etc.5G is not a single standard5G mobiles can access to different wireless technologies at the same time. 5 G can connect about one lakh devices in a square kilometer.
5G has ben launched only in a few countries as of now. In India too it is in the pre-launch stage. But some countries like South Korea the 5G is becoming more and more widely used. As of now the feedback from users is mixed .More use and stabilisation is awaited for a clear verdict.
