2G is an acronym for second-generation wireless telephone technology. While its predecessor 1G, made use of analog radio signals, 2G uses digital radio signals. Based on what type of multiplexing (the process of combining multiple digital data streams into one signal) is employed, 2G technologies may be categorized by whether they are based on time division multiple access (TDMA) or code division multiple access (CDMA).
2G makes use of a CODEC (compression-decompression algorithm) to compress and multiplex digital voice data. Through this technology, a 2G network can pack more calls per amount of bandwidth as a 1G network. 2G cellphone units were generally smaller than 1G units, since they emitted less radio power.
The battery life of a 2G handset lasts longer, again due to the lower-powered radio signals.
3G International Mobile Telecommunications-2000 (IMT-2000), better known as 3G or 3rd Generation, is a family of standards for mobile telecommunications fulfilling specifications by the International Telecommunication Union. 3G allows simultaneous use of speech and data services and higher data rates it comes with enhancements over previous wireless technologies, like high-speed transmission, advanced multimedia access and global roaming. 3G helps to simultaneously transfer both voice data (a telephone call) and non-voice data (such as downloading information, exchanging e-mail, and instant messaging.
1) Several times higher data speed
2) Enhanced audio and video streaming
3) Video-conferencing support
4) Web and WAP browsing at higher speeds
5) IPTV (TV through the Internet) support.
4G 4G refers to the fourth generation of cellular wireless standards successor to 3G and 2G families of standards. A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and streamed multimedia may be provided to users.
4G would be offering internet data rates up to what is being called as ‘ultra-broadband’, i.e speed in Gigabytes.
It is expected to use available radio spectrum more efficiently and as a result, provide end users with cable-modem transmission speeds which will support high-quality streaming video.
4G services also have in the offing promises of a minimum of 100 Mbit/s data rate between any two points in the world. Another facility which it will provide is global roaming across multiple networks and interoperability with existing wireless standards.