Comparison between 2.5 G & 3G

2.5 Generation:

• GPRS is a service comes under 2.5G.
• GPRS is based on GSM architecture.
• 2.5 G is up gradation of 2G.
• GPRS is a service which provides TDMA+FDMA access in radio access part but switching side it provide packet access.
• GPRS designed in GSM900 & GSM1800 band.
• GPRS is a service which enable to Internet access, Picture messaging.
• Theoretical speed is 53kbps in GPRS but practically it will be around 30 kbps because it depend upon your mobile class & coding technique As well as time when are you accessing service.
• If it is midnight then it may be possible that you will get speed of 53 kbps because traffic load will be less at that time.
• Channel bandwidth is 200 kHz in GPRS.
• If so many subscribers is trying to access Internet via GPRS then every subscriber will get different speed & quality of reception & transmission will be not guaranteed.
• In GPRS network authentication will perform by network only.
• 2G mobile can not be used over 3G network
• GPRS feature governed under ITU recommendation.

3^rd Generation (3G):

• 3G is new technology named as WCDMA.
• WCDMA is implementing over existing 2G architecture not by replacing.
• It is new technology not up gradation of GSM architecture.
• It support CDMA + FDMA access in radio part while in core network it support packet switching & circuit switching both.
• It supports MMS, internet browsing, Video conferencing etc.
• Theoretical speed is 2 Mbps while practical speed is around 1.3 Mbps.
• Channel bandwidth is 5 Mhz for every subscriber.
• Quality of service is guaranteed.
• If you get connected with 3G network then quality of service will be guaranteed until unless call get drop.
• Authentication will be performing by mobile phone as well as network.
• 11-2G mobile phone can not be used over 3G network but 3G network can be use      over 2G networks. But 2G mobile subscriber can make call to 3G & 2G can make call to 3G.
• 12- 3G feature governed under 3GPP recommendation.

CDMA 2000 is already satisfying 3G feature but operators are not using because it is not economical due to expensive phone & less number of data subscriber.

WCDMA technology will also use code division multiple access but over GSM architecture & WCDMA will use different type of coding technique not same as in CDMA 2000.

CDMA & GSM both are good technology but comparatively GSM is more economical for VOICE service & CDMA techniques are more economical for data (Picture, Internet, and MMS) service.