The "G" in wireless networks refers to the "generation" of the unique wireless network technology. Technically, generations are distinct and explained below.
1G (1970 – 1980)
1G stands for first-generation wireless telephone technology. This generation of phones and networks is represented by the brick-sized analog phones . Subsequent numbers refer to newer and upcoming technology. Its speed is 14.4 Kbps (peak). It is used in AMPS,NMT,TACS. 1G Wireless phones are used for voice only.
2G (1990 to 2000)
It is a second - generation Digital Narrow band circuit data . 2G phones use digital networks. Going all-digital allowed for the introduction of digital data services, such as SMS and email. 2G networks and their digital nature have also made it more difficult to eavesdrop on mobile phone calls. Its speed is 9.6/14.4 Kbps. It is used in TDMA,CDMA. 2G capabilities are achieved by allowing multiple users on a single channel via multiplexing. 2G Cellular phones are used for data and data with voice.
It is a third –generation Digital Broadband Packet Data. 3G networks are in between standard. 3G is seen more as pre4G instead of a standard of its own. The advantage of 3G networks over 2G networks is speed. 3G networks are built to handle the needs of today’s wireless users. These wireless networks increases the speed of internet browsing, picture and video messaging, and hand-held GPS use. 3.1 Mbps (peak) 500-700 Kbps. It is used in TD-SCDMA, CDMA 2000 (1xRTT, EVDO) UMTS, EDGE. 3G has Multimedia services support along with streaming are more popular. In 3G, Universal access and portability across different device types are made possible. (Telephones, PDA’s, etc.)
4G (At present)
It is a fourth - generation Digital Broadband Packet All IP. It has very high throughput 4G (AKA Beyond 3G) like the other generations and additional advantage of increased speed of data transmission. There is currently no formal definition for 4G, but there are objectives. One of the objectives of 4G is to become a fully IP-based system, much like modern computer networks. 4 G technology is mainly a marketing buzzword at the moment. The supposed speeds for 4G will be between 100-300 Mbps (peak) 3-5 Mbps 100 Mbps (Wi-Fi). It is used in WiMax, LTE, Wi-Fi. During Speeds for 4G are further increased to keep up with data access demand used by various services.High definition streaming is now supported in 4G. New phones with HD capabilities surface. It gets pretty cool. In 4G, Portability is increased further. World-wide roaming is not a distant dream.
Probably it will start in the year 2020 with gigabits Currently there is no 5G technology deployed. When this becomes available it will provide very high speeds to the consumers. It would also provide efficient use of available bandwidth as seen throughout the development of each new technology.