Evolution of Wireless Communication Technologies

0 G	1946	Mobile radio telephone	These systems preceded modern cellular mobile telephony technology. Technologies included the Push to Talk (PTT or manual), Mobile Telephone System (MTS), Improved Mobile Telephone Service (IMTS), and Advanced Mobile Telephone System (AMTS) systems.
1G	1981	Analog	Network used analog radio signals. Fully automated on the carrier's end without requiring any human operator intervention, and used electronics that could be miniaturized enough to fit into smallish packages AMPS in the US & TACS and NMT in Europe Problems not very scalable security was very poor
2G	1991	GSM IS-95 CDMA/ cdmaOne	Network used digital radio signals. 2G cellular telecom networks were commercially launched on the GSM standard in Finland. Three primary benefits of 2G networks over their predecessors Phone conversations were digitally encrypted Significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels Introduced data services for mobile like SMS, MMS. Supported CSD that allowed you to place a dial-up data call digitally. Main 2G Standards GSM (TDMA-based) IS-95 aka cdmaOne (CDMA-based) Limitations Spectrum limitations Low data rates
2.5G	1997	GPRS	Permitted "always-on" data services. No dial-up. Operators could effectively bill by the kilobyte, rather than by the minute. Virtually every GSM operator in the world deployed it Wasn’t fast enough to meet 3G required speeds, hence the term 2.5G.
2.75G	1999	EDGE	Allowed more speed without investing a lot on UMTS hardware upgrades and spectrum. With an EDGE-compatible phone, you could get speeds over double what you got on GPRS ITU refer EDGE as an ITU-2000 Narrowband technology
3G	2003	UMTS	Component of IMT-2000 Standard  by ITU Developed and maintained by the 3GPP Uses W-CDMA
		IS 2000 CDMA 2000
3.5G	2008	HSPA	Improved 3G using W-CDMA protocols. Amalgamation of two mobile telephony protocols, HSDPA: 14.4Mbps HSUPA: 5.76Mbps
3.75G	2010	HSPA+ DC-HSPA+ HSPA+ Evolution	14Mbps 28Mbps
4G	2011	LTE Mobile WiMAX LTE Advanced	IMT-Advanced Standard  by ITU calls for 4G technologies to deliver downlink speeds of 1Gbps when stationary and 100Mbps when mobile, roughly 500-fold and 250-fold improvements over IMT-2000, respectively. LTE doesn’t meet it, LTE advanced does(only 1 network in the world) Use OFDMA Lack a dedicated voice network -- 100 percent of their spectrum is used for data services, voice calls are treated as VoIP.