1G refers to analog cellular networks, while 2G and 3G refer to digital cellular networks providing improved voice quality and additional data capabilities. 2G networks such as CDMA and GSM were the first digital networks, providing low-speed data, while 3G networks such as WCDMA combined GSM and CDMA to offer higher speeds and support for multimedia applications. 4G networks such as LTE further increased speeds and were designed specifically for high-speed data and IP connectivity.

1. 1G refers to analog phone service, and 2G to digital service. 3G refers to voice, data and
streaming multimedia, including large packets of data such as PPT files.
IMT-Advanced label
2G – Technology - CDMA (Code Division Multiple Access)
3G – Wireless Communication
2G, 3G and 4G refer to the communication protocol between the mobile handset and the cell
phone tower
WCDMA (Wideband Code Division Multiple Access)
UMTS – Universal Mobile Telecommunication Services
ITU – International Telecommunication Union
GSM - Global System for Mobile Communication
CDMA - Code division multiple access
1G
Analog systems – Launched in 1981
Implemented in North America
AMPS- Analog Mobile Phone Systems
This one is based on circuit – switched technology and designed for voice, not data
Still widely used in US and many parts of the world.
2G: CDMA & GSM
Low band Digital data signaling
Circuit – switched technology
Improved for more advanced voice technology
Not suitable for web browsing and multimedia applications
CDMA
- Developed in 1989
- First Deployment in hong kong late 1994, But major success in korea 1996
- Followed communication access principle that used spectrum technology and special
coding scheme
- Not having multiband capability
- We cant able to readily to use multiple countries
- Conference call will support 2 simultaneously
- CDMA also does not require a SIM card. (Now some companies do provide SIM cards for
CDMA connections also, such as Reliance communications and TATA Indicomm in India.)
- All users can share same frequency band
-
GSM
- First Implemented in 1991 by finland
- Combination of FDMA(Frequency Division Multiple Access ) & TDMA (Time Division
Multiple Access)
- we can use multiple countries
- followed multiband capability
- High speed wireless data technology
- Conference call will support 5 simultaneously
- July 2001 survey 800 Million users for GSM

2. 2.75G :
EDGE – Enhanced Data for Global Evaluation – deployed in beginning of 2003
Radio based high-speed mobile data standards
Packet switched network
2.5G
GPRS – General Packed Radio Services
It uses radio spectrum
Worldwide roaming
Always connectivity and greater bandwith
covers 82% of market globally
3G
• First pre-commercial 3G network was launched by japan in may 2001
• Post commercial launch by japan in oct 2001
• The second network is SK Telecom of south korea in jan 2002
• The first commercial network Verizon wirless network in oct 2003 on CDMA 2000
WCDMA – Developed in North America
Spread Spectrum Technology to break up speech in to small, digitized segments and encodes to
identify each call
It providing clear voice with less background noice
3G technology which is combination of both GSM and CDMA (WCDMA) is compatible with both
GSM and CDMA. So a 3G mobile can serve for both GSM and CDMA radio signals.
WCDMA = CDMA+GSM -
In WCDMA systems the CDMA air interface is combined with GSM based networks.
As recently as mid-2010, the networks for most wireless carriers in the U.S. were 3G.
4G
LTE-Advanced, WirelessMAN-Advanced, WiMax
Upgrading to 4G networks allowed them to offer data transmission speeds up to four times faster
than their 3G networks.
Final:
Both 2G and 3G networks were designed primarily for voice communications rather than data, On
the other hand, 4G is designed especially for data transmission rather than voice
So 4G offers faster access to data using mobile phones
For example, streaming video works better with 4G, with less stuttering and a higher resolution.
Similarly, video conferencing and multi-player online games work better with the faster data
transmission offered by 4G.