CHAPTER -8

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8 CHAPTER

COMPARISON OF 2G AND 3G MOBILE NETWORKS 8.1 An Introduction Mobile phones are available in first to fifth generation. Now in the mobile industry we can find the first to the fourth generation devices. The most vital thing to be noted is that when two devices connect or "talk" to each other without any physical device or cable between them, they use radio frequencies to transmit information. This is important because different vendors use different frequencies, cover different areas and have a wide range of signal strengths. During the first generation (1G) microprocessor and digitization of control links were invented, digitization of control signals and voice signal were developed during the second generation which is 2G. This system provided better quality and higher capacity with lower cost. The Third generation (3G) systems promise faster communications services which include voice, fax and Internet with seamless global roaming. This technology enables cell phones to offer high-speed Internet access, data, video and CD-quality music.

8.2

Overlook on Predecessor

Looking down towards its predecessors,1G provided only analog voice services (with the technology named as AMPS (Advanced Mobile Phone Service), 2G with digital voice service and data service with data rate of 9.6K to 14.4Kbit/sec (with technologies such as CDMA-code division multiple access, TDMA-time division multiple access, GSM-Global System for Mobile Communications, PDC-Personal digital cellular)and 94

enhanced calling features like caller ID but suffered serious drawbacks like no alwayson data connection which brought in the need for the next generation of mobile phones called 3G with Superior voice quality and up to 2M bit/second always-on data(involving

W-CDMA-Wide-band

2000,TDSCDMA-Time-division

Code

synchronous

Division

Multiple

Access,CDMA-

code

division

multiple-access

technologies.

Development of the Market Share of Mobile Standards This graphic compares the market shares of the different mobile standards.

Cellphone subscribers by technology (left Y axis) and total number of subscribers globally (right Y axis)

Fig 8.1 In (Figure8.1) a fast growing market, GSM/3GSM (red) grows faster than the market and is gaining market share, the CDMA family (blue) grows at about the same rate as the market, while other technologies (grey) are being phased out. Faster communication and internet are available over these generations of mobile phones. In 4G networks data is transferred at a faster pace, multimedia newspapers and television programs with clarity are available. The following chart provides a high level look of the evolution of the cellular networks.

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Table 8.1 Evolutions of cellular networks

Specifications

Protocol

Data Bandwidth

Voice service only (analog)

AMPS

No data service

Data TAC 1G analog

FDMA

network

NMT

Features

1.9 kbps

Mobitex TACS CDMA

Digital voice service

GSM

Push-to-talk(PTT)

iDEN

Short

PCS

service(SMS) Upto 20kbps

2G

messaging

Conference calling Caller ID Voicemail

TDMA

Simple data applications like email messaging and web browsing.

CDMA2000 1*RTT

Up to 144kbps (typical 60-80kbps)

All 2G features plus: Web Browsing MMS(Multimedia Message

Up to 144kbps 2.5G

2.75G

GPRS

(typical 30-40kbps)

HSCSD

Up to 64kbps

EDGE

Up to 384kbps

WiDEN

Up to 100kbps

EGPRS 2

Service) Real-time

location-based

services such as directions Basic multimedia including audio and video clips,games and images.

473kbps (uplink)to

Better performance for all 2/2.5g

1.2Mbps(downlink)

service.

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CDMA

Support for all 2G and 2.5G

2000 EVDO

features plus:

(data

Full motion video

only)Rev 0

Streaming music

CDMA2000

3D gaming

EVDV

3G (DSL speeds)

Upto 2.4 Mbps

Upto 2.4 Mbps

Faster web browsing

(simultaneous voice and data) Upto 2.4 Mbps

WCDMA CDMA2000/

Upto 3.1 Mbps

EVDO-RevA

3.5G (cable speeds)

UMTS

Upto 2 Mbps

HSDPA

Up to 14.4Mbps

CDMA2000/

Up to 46Mbps

EVDO Rev B

Support for all 2/2.5/3G features -demand video g (especially graphics intensive sites)

GPRS (General Packet Radio Service) GPRS stands for General Packet Radio Service. 2G + GPRS = 2.5G .This technology is used for the transfer of information (data) over wireless (cellular) networks. It also enables cellular phones,

Personal Digital Assistants) and mini computers to

access web sites, e-mail and other data related information sources. The class of a GPRS phone determines the speed at which data can be transferred. Class A - Operates in GSM and GPRS modes at the same time, and hold simultaneous voice and data sessions. Class B - Operates in GSM and GPRS modes at the same time, and but cannot hold simultaneous calls. In other words devices support one type at a time, and switch automatically between data and voice.

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Class C

Can be active in either GSM or GPRS mode, but not at the same time. In

other words devices support one type at a time, and require user intervention to switch between data and voice. Technically the classes available are related to timeslots of the phone. The timeslots in turn are used for data upload and download and this is apart from the reserved slots available in the phone. Greater the number of slots faster is the transmission.

8.3

Difference between 3G and GPRS

The main difference between these two technologies is that 3G enables much faster data transfer rates and this helps to work faster.3G offers speed of up to 384 kilobits per second which is up to 7 times faster than a standard dial up connection.

EDGE & 3G networks

Are the same or related?

EDGE provides data transfer rates significantly faster than GPRS. EDGE can use upto 8 timeslots and each of 48Kbps and so the maximum data transfer rate is 48*8 = 384 kbps. It is a further step towards the capacities and capabilities of 3G.It offers data speeds that are required for music and videos; however EDGE does not offer Video telephony. EDGE acts as an compliment to the 3G networks.

8.4

Difference between 2G and 3G Technology 1) Cost: The license fee to be paid for 3G network is much higher as compared to 2G networks. The network construction and maintenance of 3G is much costlier than 2G networks. Also from the customers point of view the expenditure for 3G network will be excessively high if they make use of the various applications of 3G.

2) Data Transmission: The main difference between 2G and 3G networks is seen by the mobile users who download data and browse the Internet on the mobile phones. They find much faster download speeds, faster access to the data and applications in 3G networks as compared to 2G networks. 2G networks are less compatible with the functions of smart phone. The speed of data

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transmission in 2G network is less than 50,000 bits per sec while in 3G it can be more than 4 million bits per sec.

3) Function: The main function of 2G technology is the transmission of information via voice signals while that of 3G technologies is data transfer via video conferencing, MMS etc.

4) Features: The features like mobile TV, video transfers and GPS systems are the additional features of 3G technology that are not available with 2G technologies.

5) Frequencies: 2G technology uses a broad range of frequencies in both upper and lower bands, under which the transmission depends on conditions such as weather. A drawback of 3G is that it is simply not available in certain regions.

6) Implication: 3G technology offers a high level of security as compared to 2G technology

because

3G

networks

permit

validation

measures

when

communicating with other devices.

7) Making Calls: Calls can be made easily on both 2G and 3G networks with no real noticeable differences except that in 3G network video calls can also be made. The transmission of text messages and photos is available in both the networks but 2G networks have data limit and the speed of the data transmission is also very slow as compared to 3G.

8) Speed: The downloading and uploading speeds available in 2G technologies are up to 236 Kbps. While in 3G technology the downloading and uploading speeds are up to 21 Mbps and 5.7 Mbps respectively.

3G services will add invaluable dimension for the integral part of the modern world. Flexible working practices can be incorporated where employees need access to a wide range of information and services via their corporate intranets, whether they are at their own desk or anywhere else. In the near future, mobility will not be considered as an add-on: it will become a fundamental aspect. As the penetration for using Mobile 99

phones continues to rise the handset manufacturers divert their attention towards manufacturing new and wide variety of styles and sizes of handsets to meet the individual needs of users. Development of 3G networks will continue and pick up pace in the near future, the 2nd generation networks will keep evolving in terms of continuous enhancements and towards convergence of existing 2G standards. People will be getting same quality of service from a next generation phone as they would get from their PCs today.

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