THE 'G' Family : 0G to 4G

1. The ‘G’ (0G,1G,2G,2.5G,2.75G,3G,4G) family that has now become, originally started with mobile telephone service MTS in the US in 1946 (ie 0G) followed by Analog Communication standards in 1980s(ie 1G). One of the largely used 1G based service in earlier 80s was NMT (Nordic Mobile Telephone) that was used in Nordic countries, Switzerland, Netherlands, Eastern Europe and Russia.

2. 2G (or 2-G) is short for second-generation wireless telephone technology and these were commercially launched on the GSM standard in Finland in early 90s. Three elemental benefits of 2G networks were :

(a) Phone conversations were digitally encrypted.

(b) More efficient on the spectrum allowing for far greater mobile phone penetration levels

(c) 2G introduced data services for mobile, starting with SMS text messages.

The main 2G standards are:

• GSM (TDMA-based)
• IS-95 aka cdmaOne , (CDMA-based, commonly referred as simply CDMA in the US
• PDC (TDMA-based), used exclusively in Japan
• iDEN (TDMA-based), proprietary network used by Nextel in the United States and Telus Mobility in Canada
• IS-136 aka D-AMPS, (TDMA-based, commonly referred as simply TDMA in the US

3. 2.5G is considered to be a way between 2G & 3G cellular wireless technologies. The term "second and a half generation" is used to describe 2G-systems that have implemented a packet switched domain (Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets.) in addition to the circuit switched domain(a circuit switching network is one that establishes a circuit between nodes and terminals before the users may communicate, as if the nodes were physically connected with an electrical circuit.) This got famously known as GPRS and was able to provide data rates from 56 kbit/s up to 114 kbit/s.

4. 2.75G actually meant to refer the EDGE technology ie Enhanced Data rates for GSM Evolution, as the name suggests allows improved data transmission rates as an extension on top of standard GSM. EDGE can carry data speeds up to 236.8 kbit/s. There is also something known as evolved EDGE which is a further extension over EDGE wherein Peak bit-rates of up to 1Mbit/s and typical bit-rates of 400kbit/s are supported.

5. 3G is the third generation of telecommunication hardware standards and general technology for mobile networking, superseding 2.75G. This would be able to provide even higher transmission rates that would range from a minimum speed of 2Mbit/s to a maximum of 14.4Mbit/s for stationary users, and 348 kbit/s in a moving vehicle.

6. 4G is the short term for fourth-generation wireless, the stage of broadband mobile communications that will supplant the third generation (3G). While neither standards bodies nor carriers have concretely defined or agreed upon what exactly 4G will be, it is expected that end-to-end IP and high-quality streaming video will be among 4G's distinguishing features. Fourth generation networks are likely to use a combination of WiMAX and WiFi.

7. I was curious to know about all the G’s and have written in brief of what I have understood very clearly and read from Wiki and other good sources.Thanks Wiki again!