The Wireless communication is the transfer of information over a distance without the use of enhanced electrical conductors or "wires”. The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications). The technologies have been classified according to their generation, which largely specifies the type of services and the data transfer speeds of each class of technologies.
o It was wireless Telephone technology and mobile Telecommunication introduced in 1980's. 1G networks used analog signals, as opposed to digital signals used by all the successive generations of mobile technologies.
o In 1G networks, voice calls were simply modulated to a higher frequency, typically to 150 MHZ and up.
o The first commercially available cellular network using 1G standard was introduced by NTT in the year 1979 in Japan.
2G - The Second Generation
o It was commercially launched for the GSM standard in 1991 by Radiolinja, currently known as Elisa Oyj in Finland.
o 2G allowed for enhanced data services and also introduced the Short Messaging Services (SMSs). Since, the introduction of 2G, voice communication were digitally encrypted.
o Two revisions or additions to this generation are referred to as 2.5 G and 2.75 G. The combined usage of GPRS and CDMA networks collectively came to be known as 2.5G. WAP (Wireless Application Protocol) and MMS (Multi Media Messaging) were introduced, along with Internet services.
3G - The Third Generation
o The third generation was introduced by NTT DoCoMo in Japan in 2001. Although Limited in scope, initially it was a leap forward.
o 3G data transfer rattes are 384 k bits to 2 M bits, so it allows for never before services like video calls, video conferencing, mobile TV, online gaming etc.
4G-The Fourth Generation
o The next generation, 4G mobile phones are all set to provide data transfer rates of 100 Mb/sec to 1Gb sec, which is mind boggling.
o It is a successor to 3G and 2Gfamilies of standards. The nomenclature of the generations generally refers to a change in the fundamental nature of the service, non-backwards compatible transmission technology and new frequency bands. The first was the move from 1981 analogue (1G) to digital (2G) transmission in1992. This was followed, in 2002, by 3G multi-media support, spread spectrum transmission and at least 200 kbit/s, soon expected to be followed by 4G, which refers to all-IP packet-switchednetworks, mobile ultra-broadband (gigabit speed) access and multi-carrier transmission. Pre-4Gtechnologies such as mobile WiMAX and first-release 3G Long Term Evolution (LTE) have been available on the market since 2006and 2009 respectively.
5G-The 5th Generation
o It is a term used in some research papers and projects to denote the next major phase of mobile telecommunication standards beyond the current 4G/IMT-Advanced Standards.
Who made India's first cell-phone call ?
In August 1995, Chief Minister of West Bengal, Shri Jyoti Basu ushered in the cellphone revolution in India by making the first call to Union Telecom MinisterSukhram (this call was made between Writer's Building in Kolkata and Sanchar Bhavan in Delhi). This call was carried on the network of Mobile Net. The day also saw the introduction of Internet in the country, starting with Mumbai, Calcutta, Chennai and Pune.