03-08-2011, 11:15 AM
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4G mobile communicationseminar presentation
4G
Objectives of 4G
Principle technology used in 4g
Parameters of 4G
advantages of 4G
Difference between 3G&4G
Introduction
Fourth generation wireless system with wide area coverage and high throughput.
Any where any time multimedia
4G is a successor to 3G and 2G standards
It is going to be launched in the year 2010.
1G Technology
1G
AMPS ( Advance mobile phone system ) was first launched by US in 1980’s
the radio signals that 1G networks use are analog
Up to 2.4Kbps
1G technology which allows users to make voice calls within one country.
Access technology used is fdma
FDMA
2G technology
2G
2G cellular telecom networks were commercially launched in 1991
Digital –consists of 1s and 0s
Digital signal: 1) Low level, 2) High level, 3) Rising edge, and 4) Falling edge
2G
Second Generation (2G): Digital voice systems
CDMA,
TDMA
GSM (Global System for Mobile communication), PDC (Japan) D-AMPS(Digital Advanced Mobile Phone System)
PCS Systems
Second Generation – advanced (2.5G): Combining voice and data communications
Providing enhanced data rate
GPRS (General Packet Radio Service)
email and web browsing
TDMA
CDMA
GSM
Global System for Mobile Communications Tdma based
900-1800 MHZ freq used
SIM(subscriber identity module) is used
GSM offers a variety of data services
2G
Advantages:
The lower powered radio signals require less battery power
The digital voice encoding allows digital error checking
- increase sound quality
- lowers the noise level
Introduction of digital data transfer
- SMS –“short message service”
2G
Disadvantages:
Cell towers had a limited coverage area
Low data transfer rate
3G
3G Technology
2.05 Mbits/second to stationary devices.
384 Kbits/second for slowly moving devices, such as a handset carried by a walking user.
128 Kbits/second for fast moving devices, such as handsets in moving vehicles.
A greater number of users that can be simultaneously supported by a radio frequency bandwidth
3G
Advantages
More bandwidth, security, and reliability
Fixed and variable data rates.
multimedia services.
Global roaming
Large capacity and broadband capabilities
3G
Disadvantages of 3G
3G phones are expensive
High input fees for the 3G service licenses
Lack of 2G mobile user buy-in for 3G wireless service
network deployment costs
Base stations need to be closer to each other(more cost)
4G Technology
4G
Difference between 3G&4G
4G
Objectives
4G is being developed to accommodate the quality of service
Improve applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, Digital Video Broadcasting (DVB), minimal services like voice and data
A data rate of at least 100 Mbps between any two points in the world
4G
Principal technologies
OFDM
MIMO: To attain ultra high spectral efficiency
OFDM
single channel utilizes multiple sub-carriers on adjacent frequencies.
sub-carriers in an OFDM system are precisely orthogonal to one another, thus they are able to overlap without interfering
It allows transfer of more data than other forms of multiplexing (time, frequency, code, etc)
OFDM
PARAMETERS OF OFDM IN 4G
MIMO
POSSIBLE 4G PARAMETERS
Advantages of 4G
High speed
low cost per bit
High quality of service
Variety of services
On connectivity
Telecom Companies Developing 4G
NTT DoCoMo (JAPAN)
DIGIWEB (IRELAND)
SPRINT (CHICAGO)
VERIZON WIRELESS
VODAFONE GROUP
AMERICAN WIRELESS PROVIDER CLEARWIRE ETC..