7/31/2019 1g 2g

1/1

GSM means GlobalSystem for Mobile

Communications

In 1982 1G

First Generation

was introduced where

network signals were

analogue and used

Frequency Division Multiple Access (FDMA)

2G

Second Generation waslaunched in 1992 in which

signals and speech

channels were digitally

encrypted. 2G used Time

Division Multiple Access (TDMA)

2.5G

Deployed in 2003

which implemented High

Speed Circuit Switched Domain(HSCSD) Data rate

236.8kbps to 384kbps by using Enhanced Data Rate

for GSM Evolution (EDGE)

3G

has very different

functions like it allows

simultaneous use of speech

and data services at higher

rates and better spectral

efficiency.

3G Standard International Mobile

Telecommunications

IMT-2000 which is

popularly known as 3G

or 3rd Generation standard for mobile phones and

telecommunications services to make 3G globally applicable.

3G UMTS Universal Mobile

Telecommunications

System uses W-CDMA

WideBand-Code Division

Multiple Access as main

interface. Also known with other names. In

Japan called FOMA

Freedom OfMobile

Multimedia Access. In

China known as TD-

SCDMA Time Division- Synchronous Code

Division Multiple Access.

Basically all these arevariants which uses

different radio

interface. W-CDMA networks can

give speed upto

384kbps maximum.

3.5G

HSUPA upgrades the uplink for higher

data transfer speed and

capacity of 1.4 ,1.9 ,5.8

Mbps.

HSUPA name is given by Nokia and used in its phones only

but 3GPP does not

support this name.

HSDPA High-Speed

Downlink Packet Access

having faster speed from 1.8 ,3.6 ,7.2 to 14

Mbps.

3.75G

HSPA High Speed Packet Access is a

combination of HSUPAand HSDPA that

improves the

performance of W-

CDMA and can attain speed 21Mbps to

28Mbps. HSDPA High-Speed Downlink Packet Access

having faster speed

from 1.8 ,3.6 ,7.2 to 14

Mbps.

3.9G

HSOPA Some networks dubbed it as

4G. This project is

known as Long Term

Evolution and uses OF-DMA Orthogonal

Frequency-Division Multiplexing which will

offer data rate at

170Mbps for up-link

and 320Mbps for down-

link.

4G

Constitute of 4G has not been standardized

yet.It is non-backward

compatible with new

higher frequencies

bands. It is defined to

be comprehensive and secure for the users. 4Gwill only be packet-

based (all-IP) switched

network. Facilities like

IP-telephony (IP-based

voice data), Ultra- broadband internet Access 1GBps (Gigabit

speed) Support for IPV6

protocol, Gaming

Services, High Definition

HDTV, Streamed

Multimedia and many more new services are

added!!! UMTS operates on

frequencies of

850/900/1700/1900/2100

MHz. Most 3G phonessupport at least 2

frequencies. No 3G phone available which supports all 3G

frequencies.

It depends on service

provider what speed

and frequency it adopts

for its 3G network and what type of 3G

compatible phone you

have to fully

exploit ,utilize and

enjoy the services.