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4G WIRELESS
COMMUNICATIONS
By
K Arathi
096P1A0406
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Contents
Introduction
Features of 4G
Technology used in 4G
3G Vs 4G
Challenges in 4G
Conclusion
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Introduction
Abbreviation of fourth generation wirelesstechnology
It will provide a comprehensive IP solution wherevoice , data and multimedia can be given to user onan anytime , anywhere basis.
It includes several types of broadband wirelesscommunication system access including cellular
telephone system.
It will provide seamless mobility and internet accessat a rate of 100 Mbps.
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Features of 4G Networks
4G networks are all-IP(Internet Protocol) basedheterogeneous networks
This will allow users to:
Select any system atany time and any where
Use Multiple systems atthe same time (e.g.GPS and WLANs and
CDMA)
A wide range ofapplications using onlyone 4G integratedterminal
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Features of 4G (cont)
Support for multimedia services like teleconferencing andwireless internet.
Wider bandwidths and higher bitrates.
Entirely packet-switched network.
Global mobility and service portability.
Support for previous wireless technologies.
High internet speed.
tight network security.
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6
RNCBase
Station
Access
Gwy
BaseStation
RNCBaseStation
Access
Gwy
All IP Core
Network
4G Access Network
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Technology used in 4G
OFDM
UWB
Smart antennas
IPv6
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OFDM
IT transmits large amounts of digital data over a radio wave.
OFDM works by splitting the radio signal into multiplesmaller sub-signals that are then transmitted simultaneouslyat different frequencies to the receiver .
By inserting a cyclic prefix between adjacent OFDM signalinter signal interference is virtually eliminated if the max.channel delay spread is less than the time interval of cyclic
prefix.
In OFDM the subcarrier pulse used for transmission isrectangular.
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UWB
An advanced technology that can be used in 4G technology.
It is typically detected as noise.
It can use any part of the frequency spectrum, which means
that it can use frequencies that are currently in use by otherradio frequency devices .
It uses a frequency of 3.1 to 10.6 Hz.
It uses less power , since it transmits pulse instead ofcontinuous signal.
Special antennas are needed to tune and aim the signal.
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Smart Antennas
smart antenna can be employed to find tune ,and turn up signalinformation.
smart antenna can send signal back in the same direction that they comefrom.
There are two types of smart antennas-
switched beam antenna:- It has fixed beams of transmission, and switchfrom predefined beam to another when the user with the phone movesthroughout the sector.
Adaptive array antenna :- It represents the most advanced smart antennaapproach to data using a variety of new signal It represent the mostadvanced smart antenna approach to date using a variety of new signalprocessing algorithms to locate and track the user, minimize interference,and maximize intended signal reception.
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IPv6
IPv6 means Internet Protocol Version 6 .
The Internet Protocol (IP) is the method or protocol which data is
sent from one computer to another on the internet.
Each computer (known as a host) on the Internet has at least one IP
that uniquely identifies it from all other computers on the Internet.
It includes128 bits, which is 4 times more than 32bits IP address in
IPv4.
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3G Vs 4G
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Challenges in 4G
Multi-access interface, timing and recovery.
Higher frequency reuse leads to smaller cells that may causeintra-cell interference or higher noise figures due to reduced
power levels.
The Digital to analog conversions at high data rates,multiuser detection and estimation (at base stations), smartantennas and complex error control techniques as welldynamic routing will need sophisticated signal processing.
Issues in the interface with the ad hoc networks should besorted out.
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Challenges in 4G (cont)
Voice over multi-hop networks is likely to be an interestingproblem because of the strict delay requirements of voice.
Security will be an important issue.
A new IP protocol might be needed because of the variableQoS services and the network should do " better than best "effort.
Networking protocols that adapt dynamically to the changing
channel conditions.
Seamless roaming and seamless transfer of services.
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Conclusion
The work on 4G systems has begun in the industry as well theacademia.
In the USA, Motorola, Lucent, AT&T, Nortel and other majorcompanies are also working on 4G systems.
Multimedia traffic will be dominant in the future. It isestimated that voice would contribute to only 20-30 % oftotal traffic in the future.
A modified IP will be the universal network layer protocol inthe future.
The entire network would be digital and packet switched.
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References
Wikipedia
IEEE digital library
FAQs on 4G
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THANK
YOU
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