This document discusses the key technologies, challenges, and trends related to the development of 4G wireless networks. It covers topics like network convergence, next generation networks using IP Multimedia Subsystem, the use of technologies like cognitive radio and MIMO to improve spectrum usage. It outlines challenges around seamless connectivity, latency, complexity, interference and discusses potential solutions. The conclusion is that 4G promises to revolutionize wireless communication but overcoming technical challenges will be difficult.

1. Presented by,
Dr. Vijay M. Wadhai

2. Trends
Convergence
Technology
NGN‐IMS
Challenges
Conclusion
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14. 4G
WCDMA FDD IPWireless TDD Flarion
WCDMA TDD InterDigital TDD
TD-SCDMA Navini
CDMA 1x licensed spectrum NextNet
EV-DO / DV ArrayComm
… Beamreach
… ….
802.20 AirGo
3GPP Family 802.16e
802.16-2004 (WiMax)
Proprietary 802.11b
technologies 802.11a / g / n / s
IEEE 802 Family … unlicensed spectrum
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17. Mobile Station
Multimode User Terminals
Wireless System Discovery
Wireless System Selection
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18. System
Terminal Mobility
Network Infrastructure and QoS Support
Security
Fault Tolerance and Survivability
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19. Service
Multi‐operators and Billing System
Personal Mobility
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20. 4G definition
A global consensus on the 4G definition is needed before the standardization
starts.
Despite efforts there still are too many diverging approached to 4G.
GISFI’s Efforts
Seamless connectivity
Inter‐ and intra‐network connectivity is fundamental to the provision of
temporally and spatially seamless services.
Vertical and horizontal handovers are critical for 4G. In the former case, the
heterogeneity and variety of networks exacerbate the problem.
IMS Network
Latency
Many 4G services are delay sensitive.
Guaranteeing short delays in networks with different access architecture and
coverage is far from straightforward.
IPV6 &IDMP based fast handover protocol
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21. Concealing complexity
4G networks would be undoubtedly complex, but this needs to be hidden from the user.
Server based solution‐IMS
Spectrum issues
It is difficult to design a wireless system without knowing the channel, in particular if exploit multi‐
antenna technology.
Cognitive Radio*, MIMO Technique.
Spectrum planning‐ 40 telecom services – Mobile TV, IM broadcasting, Satellite,Wimax
Spectrum management‐Dr Ashok Chandra
Complex resource allocation
Management of time, frequency and spatial resources in a multi‐network, multi‐user environment is
far from trivial.
Software Defined Radio
Interference
Multiple access interference control and mitigation in heterogeneous environments (coexisting air
interfaces, varied terminals and services) is an issue.
OFDM,CR
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22. Cognitive radio is an intelligent wireless communication
system that is aware of its surrounding environment (i.e., outside
world), and uses the methodology of understanding‐by‐building
to learn from the environment and adapt its internal states to
statistical variations in the incoming RF stimuli by making
corresponding changes in certain operating parameters (e.g.,
transmit‐power, carrier‐frequency, and modulation strategy) in
real‐time, with two primary objectives in mind:
• highly reliable communications whenever and wherever
needed;
• efficient utilization of the radio spectrum.
(Dr. Ramji Prasad)
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24. 1) Radio‐scene analysis, which encompasses the
following:
• estimation of interference temperature of the radio
environment;
• detection of spectrum holes.
2) Channel identification, which encompasses the
following:
• estimation of channel‐state information (CSI);
• prediction of channel capacity for use by the
transmitter
3) Transmit‐power control and dynamic spectrum
management.
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25. Power consumption
By any measure, power consumption in future multi‐function multi‐
standard 4G terminals will sharply increase.
Usability is seriously compromised, heat management becomes an
issue.
OFDM,WOFDM,OFDMA.
Cost
Cost of infrastructure is key for the success of 4G. However, new
access architectures may require a large number of access points.
Cost of terminal should be low enough to attract customers.
Services need to be attractively priced.
Rural –plastic terminal –very low cost
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26. From user driven perspective, the user has freedom and flexibility to select the service, at a
reasonable QoS and price, anytime, anywhere
Reconfigurability: Next-generation wireless network interfaces need to be able to switch
seamlessly between different communications standards, in order to provide the most suitable
level of service while the user moves across different environments.
Convergence:Network convergence is the key to the fourth generation
Convergence is what 4G is about
– Fixed, Celluar phone systems, WPANs,WLANs ,Broadcasting/Satellite Commnunication
Hierarchy of wireless networks: 4G will consist of a hierarchy of quality/bandwidth modes
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27. 4G is showing tremendous promise and has
the capacity to revolutionize our world.
Migration to 4G networks will be evolutionary
Before the realization of the 4G wireless
society, very difficult but interesting technical
challenges are waiting for us ...
4G, convergence of networks, technologies, applications and services, will offer
a personalized and pervasive network to the users.
Convergence is heading towards an advent of a really exciting and disruptive
concept of 4th generation mobile networks.
Scope of wireless networks is expanding 4G - The Next Generation
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28. Web Link
‘Wikipedia’ – title: 4G
http://en.wikipedia.org/wiki/4G
National Science Foundation
http://www.nsf.gov
Groups working on 4G : WWRF , projects funded by NSF , Lucent , AT&T, Motorola, etc.
http://www.wireless‐world‐research.org/
4G Wireless Systems
http://users.ece.gatech.edu/~jxie/4G
4G Wireless Standard
http://www.nd.edu/~mhaenggi/NET/wireless/4G/
IEEE:
http://www.ieee.org
IEEE Communications Society:
http://www.comsoc.org/index.html
International Telecommunications Union:
http://www.itu.org
Association of Computer Machinery:
http://www.acm.org
European Telecommunications Standard Institue:
http://ww.etsl.org
3Gpp partnership project:
http://www.3gpp.org
Internet Engineering Task Force:
http://www.ietf.orgB
Bluetooth official website:
http://www.bluetooth.com
WAP forum:
http://www.WAPForum.org
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