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2009 – 2010. UTTAR PRADESH TECHNICAL UNIVERSITY
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
MR. ROHIT TRIPATHI
Gaurav Bajaj
4G Technology 2009
Page 1
A SEMINAR REPORT
ON
4G TECHNOLOGY
Given By
Under The Guidance Of
Submitted To
(LECTURE, EC DEPTT)
MR. ROHIT TRIPATHI
2009-2010.
Final Year of Electronics & Communication
Gaurav Bajaj
CERTIFICATECERTIFICATECERTIFICATECERTIFICATE
This is to certify that
as a partial fulfillment of
(Dr. Mrs. Geeta S. Lathkar)
4G Technology
CERTIFICATECERTIFICATECERTIFICATECERTIFICATE
This is to certify that have delivered a seminar on the topic,
“4G Technology”
as a partial fulfillment of
4G Technology 2009
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have delivered a seminar on the topic,
for the year
Gaurav Bajaj
wards my seminar guide and Lecture
crete step in study of this seminar of EC Department Mr. ROHIT TRIPATHI who at very dis
4G Technology 2009
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ACKNOWLEDGMENT
I feel great pleasure in submitting this seminar report on “4444G Technology” .
I wish to express true sense of gratitude to
contributed his valuable guidance and help to solve every problem that arose and opening
the doors of the department towards the realization of the seminar report.
Most likely I would like to express my sincere gratitude towards my family for
always being there when I needed them the most. With all respect and gratitude, I would
like to thank all the people, who have helped us directly or indirectly, I owe my all success
to them.
4G Technology 2009
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ABSTRACT
The fourth generation of mobile networks will truly turn the current mobile phone
networks, in to end to end IP based networks, couple this with the arrival of IPv6, every device
in the world will have a unique IP address, which will allow full IP based communications from
a mobile device, right to the core of the internet, and back out again. If 4G is implemented
correctly, it will truly harmonize global roaming, super high speed connectivity, and transparent
end user performance on every mobile communications device in the world. 4G is set to deliver
100mbps to a roaming mobile device globally, and up to 1gbps to a stationary device. With this
in mind, it allows for video conferencing, streaming picture perfect video and much more. It
won’t be just the phone networks that need to evolve, the increased traffic load on the internet as
a whole (imagine having 1 billion 100mb nodes attached to a network over night) will need to
expand, with faster backbones and oceanic links requiring major upgrade. 4G won’t happen
overnight, it is estimated that it will be implemented by 2012, and if done correctly, should take
off rather quickly. 4G networks i.e. Next Generation Networks (NGNs) are becoming fast and
very cost-effective solutions for those wanting an IP built high-speed data capacities in the
mobile network. Some possible standards for the 4G system are 802.20, WiMAX (802.16),
HSDPA, TDD UMTS, UMTS and future versions of UMTS. The design is that 4G will be based
on OFDM (Orthogonal Frequency Division Multiplexing), which is the key enabler of 4G
technology. Other technological aspects of 4G are adaptive processing and smart antennas, both
of which will be used in 3G networks and enhance rates when used in with OFDM. Currently 3G
networks still send their data digitally over a single channel; OFDM is designed to send data over
hundreds of parallel streams, thus increasing the amount of information that can be sent at a time
over traditional CDMA networks.
10.7 Adaptive Modulation and Power Control...........………………………….
Mobile Management...........................…………………………………………... 47Issues....................................................………………………………………….. 44
48 13. Quality of service…………......…………………………………………………
17. References………………………………………………………………………...54
16. Conclusion……………………………………………………………………….. 53 51
14. Security…………………………………………………………………………...50
43 42
..38 41
.. 37
.. 34 .. 33
31
Wireless Technologies Used in 4G......…………………………………………...30
8. Basic model for 4G……………………………………………………………
Transmission........................................…………………………………………...28
….26
4 7.4 Overlay network….……………………..………...……………….……..... 2
...21
20
... 21
Architecture in prospects………………………………………………………...20
17
15
Features of 4G…...……………………………………………………………....14
What is 4G……………………………………………………………………....10
History of 4G…………………………………………………………………... 08
Introduction to 4G……………………………………………………………... 07
15. Applications……………………………………………………………………...
12.11.
4.
5.
Error Correcting..........................................................................10.1.1
6. Implementation Using 4G..................................
What is needed to build 4G network?................
7.3 Relay network architecture………………………….……………………
7.2 Middleware architecture………………..………………………………..
7.1 End to end architecture………………….………………………………….
7.
9.
10.6 Scheduling Among User......................................………………………….10.5 Long term Power Prediction................................………………………….10.4 Smart Antenna..............………………..………………………………..10.3 Millimeter wireless......………………..………………………………..10.2 Ultra Wide Band..........………………..………………………………..
10.1 Orthogonal Frequency Division Multiplexing....………………………….
10.
...................................................
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CONTENT
Chapter Page No.
1.
2.
3.
...................................................
MIMO......................………………………………………………………….....40 9.
OFDM Multiplexing.…………………………………………………………....32 8.
7. OFDM Modulation...…………………………………………………………....29
Basic model of 4G……………………………………………………………....27 6.
Overlay networks………………………………………………………………..25
Multihop architecture…………………………………………………………....23
5.
4.
Implementatian daigram of 4G… ……………………………………………...193.
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FIGURE INDEX
Figure Page No.
1. History of mobile networks……………………………………………………..9
2. 4G mobile communication……………………………………………………...13
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1. INTRODUCTION
4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used to
describe the next complete evolution in wireless communications. A 4G system will be able to
provide a comprehensive IP solution where voice, data and streamed multimedia can be given to
users on an "Anytime, Anywhere" basis, and at higher data rates than previous generations.
The approaching 4G (fourth generation) mobile communication systems are projected to
solve still-remaining problems of 3G (third generation) systems and to provide a wide variety of
new services, from high-quality voice to high-definition video to high-data-rate wireless
channels. The term 4G is used broadly to include several types of broadband wireless access
communication systems, not only cellular telephone systems. One of the terms used to describe
4G is MAGIC-Mobile multimedia, anytime anywhere, Global mobility support, integrated
wireless solution, and customized personal service. As a promise for the future, 4G systems, that
is, cellular broadband wireless access systems have been attracting much interest in the mobile
communication arena. The 4G systems not only will support the next generation of mobile
service, but also will support the fixed wireless networks.
Researchers and vendors are expressing a growing interest in 4G wireless networks that
support global roaming across multiple wireless and mobile networks—for example, from a
cellular network to a satellite-based network to a high-bandwidth wireless LAN. With this
feature, users will have access to different services, increased coverage, the convenience of a
single device, one bill with reduced total access cost, and more reliable wireless access even with
the failure or loss of one or more networks. 4G networks will also feature IP interoperability for
seamless mobile Internet access and bit rates of 50 Mbps or more.
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3G, or Third Generation 3G systems promise faster communications services, entailing voice, fax and Internet data
transfer capabilities, the aim of 3G are to provide these services anytime, anywhere throughout
the globe, with seamless roaming between standards. ITU’s IMT-2000 is a global standard for
3G and has opened new doors to enabling innovative services and application for instance,
multimedia entertainment, and location-based services, as well as a whole lot more. In 2001,
Japan saw the first 3G network launched. 3G technology supports around 144 Kbps, with high
speed movement, i.e. in a vehicle. 384Kbps locally, and upto 2Mbps for fixed stations, i.e. in a
building.
2. HISTORYAt the end of the 1940’s, the first radio telephone service was introduced, and was designed to
users in cars to the public land-line based telephone network. Then, in the sixties, a system
launched by Bell Systems, called IMTS, or, “Improved Mobile Telephone Service", brought
quite a few improvements such as direct dialing and more bandwidth. The very first analog
systems were based upon IMTS and were created in the late 60s and early 70s. The systems were
called "cellular" because large coverage areas were split into smaller areas or "cells", each cell is
served by a low power transmitter and receiver. The 1G or First Generation was an analog
system, and was developed in the seventies, 1G had two major improvements, this was the
invention of the microprocessor, and the digital transform of the control link between the phone
and the cell site. Advance mobile phone system (AMPS) was first launched by the US and is a
1G mobile system. Based on FDMA, it allows users to make voice calls in 1 country.
2G, or Second Generation 2G first appeared around the end of the 1980’s, the 2G system digitized the voice signal, as well as the control link. This new digital system gave a lot better quality and much more capacity (i.e. more people could use their phones at the same time), all at a lower cost to the end consumer. Based on TDMA, the first commercial network for use by the public was the Global system for mobile communication (GSM).
Fig 1: - History of Mobile Networks
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3. What is 4G?
Fourth generation (4G) wireless was originally conceived by the Defense Advanced
Research Projects Agency (DARPA), the same organization that developed the wired Internet. It
is not surprising, then, that DARPA chose the same distributed architecture for the wireless
Internet that had proven so successful in the wired Internet. Although experts and policymakers
have yet to agree on all the aspects of 4G wireless, two characteristics have emerged as all but
certain components of 4G: end-to-end Internet Protocol (IP), and peer-to-peer networking. An all
IP network makes sense because consumers will want to use the same data applications they are
used to in wired networks. A peer-to-peer network, where every device is both a transceiver and
a router/repeater for other devices in the network, eliminates this spoke-and-hub weakness of
cellular architectures, because the elimination of a single node does not disable the network. The
final definition of “4G” will have to include something as simple as this: if a consumer can do it
at home or in the office while wired to the Internet, that consumer must be able to do it
wirelessly in a fully mobile environment.
Let’s define “4G” as “wireless ad hoc peer-to-peer networking.” 4G technology is
significant because users joining the network add mobile routers to the network infrastructure.
Because users carry much of the network with them, network capacity and coverage is
dynamically shifted to accommodate changing user patterns. As people congregate and create
pockets of high demand, they also create additional routes for each other, thus enabling
additional access to network capacity. Users will automatically hop away from congested routes
to less congested routes. This permits the network to dynamically and automatically self-balance
capacity, and increase network utilization. What may not be obvious is that when user devices
act as routers, these devices are actually part of the network infrastructure. So instead of carriers
subsidizing the cost of user devices (e.g., handsets, PDAs, of laptop computers), consumers
actually subsidize and help deploy the network for the carrier. With a cellular infrastructure,
users contribute nothing to the network. They are just consumers competing for resources. But in
wireless ad hoc peer-to-peer networks, users cooperate – rather than compete – for network
resources.
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Thus, as the service gains popularity and the number of user increases, service likewise
improves for all users. And there is also the 80/20 rule. With traditional wireless networks, about
80% of the cost is for site acquisition and installation, and just 20% is for the technology. Rising
land and labor costs means installation costs tend to rise over time, subjecting the service
providers’ business models to some challenging issues in the out years. With wireless peer-to-
peer networking, however, about 80% of the cost is the technology and only 20% is the
installation. Because technology costs tend to decline over time, a current viable business model
should only become more profitable over time. The devices will get cheaper, and service
providers will reach economies of scale sooner because they will be able to pass on the
infrastructure savings to consumers, which will further increase the rate of penetration.
This new generation of wireless is intended to complement and replace the 3G systems,
perhaps in 5 to 10 years. Accessing information anywhere, anytime, with a seamless connection
to a wide range of information and services, and receiving a large volume of information, data,
pictures, video, and so on, are the keys of the 4G infrastructures. The future 4G infrastructures
will consist of a set of various networks using IP (Internet protocol) as a common protocol so
that users are in control because they will be able to choose every application and environment.
Based on the developing trends of mobile communication, 4G will have broader bandwidth,
higher data rate, and smoother and quicker handoff and will focus on ensuring seamless service
across a multitude of wireless systems and networks. The key concept is integrating the 4G
capabilities with all of the existing mobile technologies through advanced technologies.
Application adaptability and being highly dynamic are the main features of 4G services of
interest to users.
These features mean services can be delivered and be available to the personal preference
of different users and support the users' traffic, air interfaces, radio environment, and quality of
service. Connection with the network applications can be transferred into various forms and
levels correctly and efficiently. The dominant methods of access to this pool of information will
be the mobile telephone, PDA, and laptop to seamlessly access the voice communication, high-
speed information services, and entertainment broadcast services. Figure 1 illustrates elements
and techniques to support the adaptability of the 4G domain. The fourth generation will
encompass all systems from various networks, public to private; operator-driven broadband
networks to personal areas; and ad hoc networks. The 4G systems will interoperate with 2G and
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3G systems, as well as with digital (broadband) broadcasting systems. In addition, 4G systems
will be fully IP-based wireless Internet. This all-encompassing integrated perspective shows
the broad range of systems that the fourth generation intends to integrate, from satellite
broadband to high altitude platform to cellular 3G and 3G systems to WLL (wireless local loop)
and FWA (fixed wireless access) to WLAN (wireless local area network) and PAN (personal
area network), all with IP as the integrating mechanism. With 4G, a range of new services and
models will be available. These services and models need to be further examined for their
interface with the design of 4G systems.
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Fig 2: - 4G Mobile Communication
4. FEATURES
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• Support for interactive multimedia, voice, streaming video, Internet, and
other broadband services
• IP based mobile system
• High speed, high capacity, and low cost‐per‐bit
• Global access, service portability, and scalable mobile services
• Seamless switching, and a variety of Quality of Service‐driven services
• Better scheduling and call‐admission‐control techniques
• Ad‐hoc and multi‐hop networks (the strict delay requirements of voice make
multi‐hop network service a difficult problem) • Better spectral efficiency
• Seamless network of multiple protocols and air interfaces (since 4G will be
all‐IP, look for 4G systems to be compatible with all common network
technologies, including 802.11, WCDMA, Bluetooth, and Hyper LAN).
• An infrastructure to handle pre‐existing 3G systems along with other wireless
technologies, some of which are currently under development.
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5. What is needed to Build 4G Networks of Future?
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A number of spectrum allocation decisions, spectrum standardization decisions, spectrum
availability decisions, technology innovations, component development, signal processing and
switching enhancements and inter-vendor cooperation have to take place before the vision of 4G
will materialize. We think that 3G experiences - good or bad, technological or business - will be
useful in guiding the industry in this effort. We are bringing to the attention of professionals in
telecommunications industry following issues and problems that must be analyzed and resolved:
* Lower Price Points Only Slightly Higher than Alternatives - The business visionaries
should do some economic modeling before they start 4G hype on the same lines as 3G hype.
They should understand that 4G data applications like streaming video must compete with very
low cost wireline applications. The users would pay only a delta premium (not a multiple) for
most wireless applications.
* More Coordination Among Spectrum Regulators Around the World - Spectrum
regulation bodies must get involved in guiding the researchers by indicating which frequency
band might be used for 4G. FCC in USA must cooperate more actively with International bodies
like ITU and perhaps modify its hands-off policy in guiding the industry. When public interest,
national security interest and economic interest (inter-industry a la TV versus
Telecommunications) are at stake, leadership must come from regulators. At appropriate time,
industry builds its own self-regulation mechanisms.
* More Academic Research: Universities must spend more effort in solving fundamental
problems in radio communications (especially multiband and wideband radios, intelligent
antennas and signal processing.
* Standardization of wireless networks in terms of modulation techniques, switching
schemes and roaming is an absolute necessity for 4G.
* A Voice-independent Business Justification Thinking: Business development and
technology executives should not bias their business models by using voice channels as
economic determinant for data applications. Voice has a built-in demand limit - data applications
do not.
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* Integration Across Different Network Topologies: Network architects must base their
architecture on hybrid network concepts that integrates wireless wide area networks, wireless
LANS (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.15 and IEEE 802.16, Bluetooth
with fiber-based Internet backbone. Broadband wireless networks must be a part of this
integrated network architecture.
* Non-disruptive Implementation: 4G must allow us to move from 3G to 4G.
6.IMPLEMENTATION USING 4G
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The
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goal of 4G is to replace the current proliferation of core
mobile networks with a single worldwide core network standard, based on IP
for control, video, packet data, and voice. This will provide uniform video, voice,
and data services to the mobile host, based entirely on IP.
The objective is to offer seamless multimedia services to users
accessing an all IP‐based infrastructure through heterogeneous access
technologies. IP is assumed to act as an adhesive for providing global
connectivity and mobility among networks.
An all IP‐based 4G wireless network has inherent advantages
over its predecessors. It is compatible with, and independent of the underlying
radio access technology. An IP wireless network replaces the old Signaling
System 7 (SS7) telecommunications protocol, which is considered massively
redundant. This is because SS7 signal transmission consumes a larger part of
network bandwidth even when there is no signaling traffic for the simple reason
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that it uses a call setup mechanism to reserve bandwidth, rather time/frequency
slots in the radio waves. IP networks, on the other hand, are connectionless and
use the slots only when they have data to send. Hence there is optimum usage of
the available bandwidth. Today, wireless communications are heavily biased
toward voice, even though studies indicate that growth in wireless data traffic is
rising exponentially relative to demand for voice traffic. Because an all IP core
layer is easily scalable, it is ideally suited to meet this challenge. The goal is a
merged data/voice/multimedia network.
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IMPLEMENTATION DIAGRAM OF 4G
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7.1 End-to-end Service Architectures for 4G Mobile
7. Architectures in Prospects
• Trust management. Mechanisms for managing trust r
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Systems:-
A characteristic of the transition towards 3G systems and beyond is that highly integrated
telecommunications service suppliers fail to provide effective economies of scale. This is
primarily due to deterioration of vertical integration scalability with innovation speed up. Thus,
the new rule for success in 4G telecommunications markets will be to provide one part of the
puzzle and to cooperate with other suppliers to create the complete solutions that end customers
require.
A direct consequence of these facts is that a radically new end-to-end service architecture
will emerge during the deployment of 3G mobile networks and will became prominent as the
operating model of choice for the Fourth Generation (4G) Mobile Telecommunications
Networks. This novel end-to-end service architecture is inseparable from an equally radical
transformation of the role of the telecommunications network operator role in the new value
chain of end service provision. In fact, 4G systems will be organized not as monolithic structures
deployed by a single business entity, but rather as a dynamic confederation of multiple—
sometimes cooperating and sometimes competing—service providers.
End-to-end service architectures should have the following desirable properties:
• Open service and resource allocation model.
• Open capability negotiation and pricing model.
elationships among clients
and service providers, and between service providers, based on trusted third
party monitors.
• Collaborative service constellations.
• Service fault tolerance.
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7.3
7.2
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Middleware Architecture:-
The service middleware is decomposed into three layers; i.e. user support layer, service
support layer and network support layer. The criterion for using a layered approach is to reuse
the existing subsystems in the traditional middleware. The user support layer has autonomous
agent aspects that traditional service middleware lacks. It consists of 4 sub-systems:
‘Personalization’, ‘Adaptation’, ‘Community’ and ‘Coordination’, to provide mechanisms for
context awareness and support for communities and coordination. Introduction of this functional
layer enables
the reduction of unnecessary user interaction with the system and the provision of user-centric
services realized by applying agent concepts, to support analysis of the current context,
personalization depending on the user’s situation, and negotiation for service usage.
The middle layer, the service support layer, contains most functionality of traditional
middleware. The bottom layer, the network layer supports connectivity for all-IP networks. The
dynamic service delivery pattern defines a powerful interaction model to negotiate the conditions
of service delivery by using three subsystems: ‘Discovery & Advertisement’, ‘Contract Notary’
and ‘Authentication & Authorization’.
Cellular Multihop Communications: Infrastructure-Ba sed Relay
Network Architecture:-
It is clear that more fundamental enhancements are necessary for the very ambitious
throughput and coverage requirements of future networks. Towards that end, in addition to
advanced transmission techniques and antenna technologies, some major modifications in the
wireless network architecture itself, which will enable effective distribution and collection of
signals to and from wireless users, are sought. The integration of “multihop” capability into the
conventional wireless networks is perhaps the most promising architectural upgrade.
In a Multihop network, a signal from a source may reach its destination in multiple hops
(whenever necessary) through the use of “relays”. Since we are here concerned with
infrastructure-based networks, either the source or destination is a common point in the network
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- base station (or, access point, in the context of WLANs). The potential advantage of relaying is
that it allows substituting a poor-quality (due to high path loss) single-hop wireless link with a
composite, two- or more hop, better-quality link whenever possible. Relaying is not only
efficient in eliminating black spots throughout the coverage region, but more importantly, it may
extend the high data rate coverage range of a single BS; therefore cost-effective high data rate
coverage may be possible through the augmentation of the relaying capability in conventional
cellular networks.
Advantages:-
• Property owners can install their own access points.
– Spreads infrastructure cost.
• Reduced network access operational cost.
– Backbone access through wireless.
– Wired access through DSL at aggregation points.
• Ad hoc-like characteristics:
– Access points configure into access network.
– Some access points may be moving (bus, train).
• Multihop also could reduce costs in heterogeneous 3G networks.
– 802.11 to GPRS for example.
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Fig.3: - Example of Heterogeneous Network Multihop Architecture
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5.4 Overlay network:-
In this architecture, a user accesses an overlay network consisting of several universal
access points. These UAPs in turn select a wireless network based on availability, QoS
specifications, and user defined choices. A UAP performs protocol and frequency translation,
content adaptation, and QoS negotiation-renegotiation on behalf of users. The overlay network,
rather than the user or device, performs handoffs as the user moves from one UAP to another. A
UAP stores user, network, and device information, capabilities, and preferences. Because UAPs
can keep track of the various resources a caller uses, this architecture supports single billing and
subscription.
Figure1. Possible 4G wireless network architectures. (a) A multimode device lets the
user, device, or network initiate handoff between networks without the need for network
modification or interworking devices. (b) An overlay network—consisting of several universal
access points (UAPs) that store user, network, and device information—performs a handoff as
the user moves from one UAP to another. (c) A device capable of automatically switching
between networks is possible if wireless networks can support a common protocol to access a
satellite-based network and another protocol for terrestrial networks.
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Viral N. Patel Page 21
Fig 4: -Overlay Networks
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8. A Basic Model for 4G Networks
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QoS, security and mobility can be viewed as three different, indispensable aspects in 4G
networks; however all are related to network nodes involving the controlling or the processing of
IP packets for end-to-end flows between an MN and the CN. I show in this section how we view
the 4G network infrastructure.
Two Planes: Functional Decomposition
Noting that an IP network element (such as a router) comprises of numerous functional
components that cooperate to provide such desired service (such as, mobility, QoS and/or AAA –
Authentication, Authorization and Accounting), we identify these components in the SeaSoS
architecture into two planes, namely the control plane and the data plane.
Fig. 5 illustrates this method of flexible functional composition in 4G networks. As we
are mainly concerned with network elements effectively at the network layer, we do not show a
whole end-to-end communication picture through a whole OSI or TCP/IP stack. The control
plane performs control related actions such as AAA, MIP registration, QoS signaling,
installation/maintenance of traffic selectors and security associations, etc., while the data plane is
responsible for data traffic behaviors (such as classification, scheduling and forwarding) for end-
to-end traffic flows. Some components located in the control plane interact, through installing
and maintaining certain control states for data plane, with data plane components in some
network elements, such as access routers (ARs), IntServ nodes or DiffServ edge routers.
However, not all control plane components need to exist in all network elements, and also not all
network elements (e.g., AAA server) are involved with data plane functionalities.
I refer these cases as path-decoupled control and other cases as path coupled control. We
argue the separation and coordination of control plane and data plane is critical for seamless
mobility with QoS and security support in 4G networks, with the reasons as follows. Per-flow or
per-user level actions occur much less frequent than per-packet actions, while per-packet actions
are part of critical forwarding behavior, which involves very few control actions (which are
typically simply to read and enforce according the install state during forwarding data). Actually,
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this separation concept is not new – routing protocols have the similar abstraction together used
with the traditional IP packet delivery, this abstraction is recently being investigated in the IETF
ForCES working group. However, we emphasize the three critical dimensions of future 4G
networks: mobility, QoS and security, as well as other new emerging or replacement components
might appear, integrated into a unified framework and allowing more extensibility for 4G
networks design.
Fig.5: - The decomposition of control plane and data plane
functionalities
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9.TRANSMISSION
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An OFDM transmitter accepts data from an IP network,
converting and encoding the data prior to modulation. An IFFT (inverse fast
Fourier transform) transforms the OFDM signal into an IF analog signal, which is
sent to the RF transceiver. The receiver circuit reconstructs the data by reversing
this process. With orthogonal sub‐carriers, the receiver can separate and process
each sub‐carrier without interference from other sub‐carriers. More impervious to
fading and multi‐path delays than other wireless transmission techniques, ODFM
provides better link and communication quality.
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IP NETWORK
OFDM TRANSMITTER
MODULATION
IFFT making IF analog
RF TRANSMITTER
OFDM MODULATION
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10.
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Wireless Technologies Used In 4G
1. OFDM
2. UWB
3. MILLIMETER WIRELESS
4. SMART ANTENNAS
5. LONG TERM POWER PREDICTION
6. SHEDULING AMONG USERS
7. ADAPTIVE MODULATION AND POWER CONTROL
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10.1 Orthogonal Frequency Division Multiplexing:
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OFDM, a form of multi‐carrier modulation, works by dividing the
data stream for transmission at a bandwidth B into N multiple and parallel bit
streams, spaced B/N apart (Figure ). Each of the parallel bit streams has a much
lower bit rate than the original bit stream, but their summation can provide very
high data rates. N orthogonal sub‐carriers modulate the parallel bit streams,
which are then summed prior to transmission.
An OFDM transmitter accepts data from an IP network, converting
and encoding the data prior to modulation. An IFFT (inverse fast Fourier
transform) transforms the OFDM signal into an IF analog signal, which is sent to
the RF transceiver. The receiver circuit reconstructs the data by reversing this
process. With orthogonal sub‐carriers, the receiver can separate and process each
sub‐carrier without interference from other sub‐carriers. More impervious to
fading and multi‐path delays than other wireless transmission techniques,
ODFM provides better link and communication quality.
8
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Fig 8: :Orthogonal Frequency Division Multiplexing:
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10.1.1Error Correcting:
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4Gʹs error‐correction will most likely use some type of concatenated
coding and will provide multiple Quality of Service (QoS) levels. Forward
error‐correction (FEC) coding adds redundancy to a transmitted message through encoding prior to transmission. The advantages of concatenated
coding (Viterbi/Reed‐Solomon) over convolutional coding (Viterbi) are
enhanced system performance through the combining of two or more
constituent codes (such as a Reed‐Solomon and a convolutional code) into one
concatenated code. The combination can improve error correction or combine
error correction with error detection (useful, for example, for implementing an
Automatic Repeat Request if an error is found). FEC using concatenated
coding allows a communications system to send larger block sizes while
reducing bit‐error rates.
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10.2 Ultra Wide Band :
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A UWB transmitter spreads its signal over a wide portion of the RF
spectrum, generally 1 GHz wide or more, above 3.1GHz. The FCC has chosen
UWB frequencies to minimize interference to other commonly used equipment,
such as televisions and radios. This frequency range also puts UWB equipment
above the 2.4 GHz range of microwave ovens and modern cordless phones, but
below 802.11a wireless Ethernet, which operates at 5 GHz.
UWB equipment transmits very narrow RF pulses—low power and
short pulse period means the signal, although of wide bandwidth, falls below
the threshold detection of most RF receivers. Traditional RF equipment uses an
RF carrier to transmit a modulated signal in the frequency domain, moving the
signal from a base band to the carrier frequency the transmitter uses. UWB is
ʺcarrier‐freeʺ, since the technology works by modulating a pulse, on the order of tens of microwatts, resulting in a waveform occupying a very wide frequency
domain. The wide bandwidth of a UWB signal is a two‐edged sword. The signal
is relatively secure against interference and has the potential for very high‐rate
wireless broadband access and speed. On the other hand, the signal also has the
potential to interfere with other wireless transmissions. In addition, the low‐
constraints on UWB the FCC, due to its interference potentialplaced
bypower
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4G Technology 2009
with other RF signals, significantly limits the range of UWB equipment (but still
makes it a viable LAN technology).
One distinct advantage of UWB is its immunity to multi‐path
distortion and interference. Multi‐path propagation occurs when a transmitted
signal takes different paths when propagating from source to destination. The
various paths are caused by the signal bouncing off objects between the
transmitter and receiver—for example, furniture and walls in a house, or trees
and buildings in an outdoor environment. One part of the signal may go directly
the receiver will make mistakes when demodulating the information in the
signal. For long‐enough delays, bit errors in the packet will occur since the
receiver canʹt distinguish the symbols and correctly interpret the corresponding
bits.
to the receiver while another; deflected part will encounter delay and take longer
to reach the receiver. Multi‐path delay causes the information symbols in the
signal to overlap, confusing the receiver—this is known as inter‐symbol
interference (ISI). Because the signalʹs shape conveys transmitted information,
The short time‐span of UWB waveforms—typically hundreds of
picoseconds to a few nanoseconds—means that delays caused by the transmitted
signal bouncing off objects are much longer than the width of the original UWB
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4G Technology 2009
pulse, virtually eliminating ISI from overlapping signals. This makes UWB
technology particularly useful for intra‐structure and mobile communications
applications, minimizing S/N reduction and bit errors.
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10.3 Millimeter Wireless:
4G Technology 2009
Using the millimeter‐wave band (above 20 GHz) for wireless service
is particularly interesting, due to the availability in this region of bandwidth
resources committed by the governments of some countries to unlicensed
cellular and other wireless applications. If deployed in a 4G system, millimeter
wireless would constitute only one of several frequency bands, with the 5 GHz
band most likely dominant.
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10.4 Smart Antennas:
4G Technology 2009
A smart antenna system comprises multiple antenna elements with
signal processing to automatically optimize the antennasʹ radiation (transmitter)
and/or reception (receiver) patterns in response to the signal environment. One
smart‐antenna variation in particular, MIMO, shows promise in 4G systems,
particularly since the antenna systems at both transmitter and receiver are
usually a limiting factor when attempting to support increased data rates.
MIMO (Multi‐Input Multi‐Output) is a smart antenna system
where ʹsmartnessʹ is considered at both transmitter and the receiver. MIMO
represents space‐division multiplexing (SDM)—information signals are
multiplexed on spatially separated N multiple antennas and received on M
antennas. Figure shows a general block diagram of a MIMO system. Some
systems may not employ the signal‐processing block on the transmitter side.
Multiple antennas at both the transmitter and the receiver provide essentially multiple parallel channels that operate simultaneously on the same
frequency band and at the same time. This results in high spectral efficiencies in
9
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4G Technology 2009
a rich scattering environment (high multi‐path), since you can transmit multiple
data streams or signals over the channel simultaneously. Field experiments by
several organizations have shown that a MIMO system, combined with adaptive coding and modulation, interference cancellation, and beam‐forming
technologies, can boost useful channel capacity by at least an order of
magnitude.
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Fig 8 : Multiple Input Multiple Output
4G Technology 2009
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10.5 Long Term Power Prediction:
4G Technology 2009
Channels to different mobile users will fade independently. If the
channel properties of all users in a cell can be predicted a number of
milliseconds ahead, then it would be possible to distribute the transmission load
among the users in an optimal way while fulfilling certain specified constraints
on throughput and delays. The channel time‐frequency pattern will depend on
the scattering environment and on the velocity of the moving terminal.
In order to take the advantage the channel variability, we use OFDM
system with spacing between subcarrires such that no interchannel interface
occurs for the worst case channel scenario
(Low coherence bandwidth).A time‐frequency grid constituting of regions of
one time slot and several subcarriers is used such that the channel is fairly
constant over each region. These time‐frequency regions are then allocated to the
different users by a scheduling algorithm according to some criterion.
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6.2
6.1
10.6 Scheduling among Users:
4G Technology 2009
To optimize the system throughput, under specified QoS
requirements and delay constraints, scheduling will be used on different levels:
Among sectors:‐In order to cope with co‐channel interference
among neighboring sectors in adjacent cells, time slots are allocated according to
the traffic load in each sector .Information on the traffic load is exchanged
infrequently via an inquiry procedure. In this way the interference can be
minimized and higher capacity be obtained.
After an inquiry to adjacent cells, the involved base stations
determine the allocation of slots to be used by each base station in each sector.
The inquiry process can also include synchronization information to align the
transmission of packets at different base stations to further enhance
performance.
Among users:‐Based on the time slot allocation obtained
from inquiry process, the user scheduler will distribute time‐frequency regions
among the users of each sector based on their current channel predictions. Here
different degrees of sophistication can be used to achieve different transmission
goals.
10.7 Adaptive modulation and power control:
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In a fading environment and for a highly loaded system there will
almost exist users with good channel conditions. Regardless of the choice of
criterion, which could be either maximization of system throughput or
equalization to user satisfaction, the modulation format for the scheduled
user is selected according to the predicted signal to noise and interference ratio.
By using sufficiently small time‐frequency bins the channel can be
made approximately constant within bins. We can thus use a flat fading AWGN
channel assumption. Furthermore since we have already determined the time
slot allocation, via the inquiry process among adjacent cells described above we
may use an aggressive power control scheme, while keeping the interference on
an acceptable level.
For every timeslot, the time‐frequency bins in the grid represent
separate channels. For such channels the optimum rate and power allocation for
maximizing the throughput can be calculated under a total average power
constraint. The optimum strategy is to let one user, the one with best channel,
transmit in each of the parallel channels.
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ISSUES:
The first issue deals with optimal choice of access technology, or how
to be best connected. Given that a user may be offered connectivity from more
than one technology at any one time, one has to consider how the terminal and
an overlay network choose the radio access technology suitable for services the
user is accessing.
There are several network technologies available today, which can be
viewed as complementary. For example, WLAN is best suited for high data
rate indoor coverage. GPRS or UMTS, on the other hand, are best suited for
nation wide coverage and can be regarded as wide area networks, providing a
4G Technology 2009
higher degree of mobility. Thus a user of the mobile terminal or the network
needs to make the optimal choice of radio access technology among all those
available. A handover algorithm should both determine which network to
connect to as well as when to perform a handover between the different
networks. Ideally, the handover algorithm would assure that the best overall
wireless link is chosen. The network selection strategy should take into
consideration the type of application being run by the user at the time of
handover. This ensures stability as well as optimal bandwidth for interactive and
background services.
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The second issue regards the design of a mobility enabled IP
networking architecture, which contains the functionality to deal with mobility
between access technologies. This includes fast, seamless vertical (between
heterogeneous technologies) handovers (IP micro‐mobility), quality of service
(QoS), security and accounting. Real‐time applications in the future will require
fast/seamless handovers for smooth operation.
Mobility in IPv6 is not optimized to take advantage of specific
mechanisms that may be deployed in different administrative domains. Instead,
IPv6 provides mobility in a manner that resembles only simple portability. To
enhance Mobility in IPv6, ‘micro‐mobility’ protocols (such as Hawaii[5], Cellular
IP[6] and Hierarchical Mobile IPv6[7]) have been developed
for seamless handovers i.e. handovers that result in minimal handover delay,
minimal packet loss, and minimal loss of communication state.
The third issue concerns the adaptation of multimedia transmission
across 4G networks. Indeed multimedia will be a main service feature of 4G
networks, and changing radio access networks may in particular result in drastic
changes in the network condition. Thus the framework for multimedia
transmission must be adaptive. In cellular networks such as UMTS, users
compete for scarce and expensive bandwidth.
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Variable bit rate services provide a way to ensure service
provisioning at lower costs. In addition the radio environment has dynamics that
renders it difficult to provide a guaranteed network service. This requires that
the services are adaptive and robust against varying radio conditions.
High variations in the network Quality of Service (QoS) leads to
significant variations of the multimedia quality. The result could sometimes be
unacceptable to the users. Avoiding this requires choosing an adaptive encoding
framework for multimedia transmission. The network should signal QoS
variations to allow the application to be aware in real time of the network
conditions. User interactions will help to ensure personalized adaptation of the
multimedia presentation.
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11.MOBILITY MANAGEMENT
4G Technology 2009
Features of mobility management in Ipv6:
128‐bit address space provides a sufficiently large number of addresses
High quality support for real‐time audio and video transmission,
short/bursty connections of web applications, peer‐to‐peer applications,
etc.
Faster packet delivery, decreased cost of processing – no header checksum
at each relay, fragmentation only at endpoints.
Smooth handoff when the mobile host travels from one subnet to another,
causing a change in its Care‐of Address.
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13. Quality of Service (QoS):-
4G Technology 2009
The Internet provides users with diverse and essential quality of service (QoS),
particularly given the increasing demand for a wide spectrum of network services.
Many services, previously only provided by traditional circuit-switched networks, can now be
provided on the Internet. These services, depending on their inherent characteristics, require
certain degrees of QoS guarantees. Many technologies are therefore being developed to enhance
the QoS capability of IP networks. Among these technologies, differentiated services (DiffServ)
and MPLS are paving the way for tomorrow’s QoS services portfolio.
DiffServ is based on a simple model where traffic entering a network is classified,
policed, and possibly conditioned at the edges of the network, and assigned to different behavior
aggregates. Each behavior aggregate is identified by a single DS code point (DSCP). At the core
of the network, packets are fast forwarded according to the per-hop behavior (PHB) associated
with the DSCP. By assigning traffic of different classes to different DSCPs, the DiffServ
network provides different forwarding treatments and thus different levels of QoS.
MPLS integrates the label swapping forwarding paradigm with network layer routing.
First, an explicit path, called a label switched path (LSP), is determined, and established using a
signaling protocol. A label in the packet header, rather than the IP destination address, is then
used for making forwarding decisions in the network. Routers that support MPLS are called label
switched routers (LSRs). The labels can be assigned to represent routes of various granularities,
ranging from as coarse as the destination network down to the level of each single flow.
Moreover, numerous traffic engineering functions have been effectively achieved by MPLS.
When MPLS is combined with DiffServ and constraint-based routing, they become powerful and
complementary abstractions for QoS provisioning in IP backbone networks.
Supporting QoS in 4G networks will be a major challenge due to varying bit
rates, channel characteristics, bandwidth allocation, fault-tolerance levels, and handoff support
among heterogeneous wireless networks. QoS support can occur at the packet, transaction,
circuit, user, and network levels.
• Packet-level QoS applies to jitter, throughput, and error rate. Network resources such as
buffer space and access protocol are likely influences.
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• Transaction-level QoS describes both the time it takes to complete a transaction and the
packet loss rate. Certain transactions may be time sensitive, while others cannot tolerate any
packet loss.
• Circuit-level QoS includes call blocking for new as well as existing calls. It depends
primarily on a network’s ability to establish and maintain the end-to-end circuit. Call routing and
location management are two important circuit-level attributes.
• User-level QoS depends on user mobility and application type. The new location may
not support the minimum QoS needed, even with adaptive applications. In a complete wireless
solution, the end-to-end communication between two users will likely involve multiple wireless
networks. Because QoS will vary across different networks, the QoS for such users will likely be
the minimum level these networks support.
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14. Security
4G Technology 2009
Security in 4G networks mainly involves authentication, confidentiality, ntegrity, and
authorization for the access of network connectivity and QoS resources for the MN’s flows.
Firstly, the MN needs to prove authorization and authenticate itself while roaming to a new
provider’s network. AAA protocols (such as Radius, COPS or Diameter [10]) provide a
framework for such support especially for control plane functions (including key establishment
between the MN and AR, authenticating the MN with AAA server(s), and installing security
policies in the MN or ARs’ data plane such as encryption, encryption, and filtering), but they are
not well suited for mobility scenarios.
There needs to an efficient, scalable approach to address this. The Extensible
Authentication Protocol (EAP) [6], a recently developed IETF protocol, provides a flexible
framework for extensible network access authentication and potentially could be useful.
Secondly, when QoS is concerned, QoS requests needs to be integrity-protected, and moreover,
before allocating QoS resources for an MN’s flow, authorization needs to be performed to avoid
denial of service attacks. This requires a hop-by-hop way of dynamic key establishment between
QoS-aware entities to be signaled on. Finally, most security concerns in this paper lie in network
layer functions: although security can also be provided by higher layers above the network layer.
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15. Applications
4G Technology 2009
1) Application to Admission Control in Cellular Packet Networks:-
Based on the developing trends of mobile communication, 4G will have broader
bandwidth, higher data rate, and smoother and quicker handoff and will focus on ensuring
seamless service across a multitude of wireless systems and networks. The key concept is
integrating the 4G capabilities with all of the existing mobile technologies through advanced
technologies. Application adaptability and being highly dynamic are the main features of 4G
services of interest to users.
Emerging wireless technologies such as 4G tend to be packet-switched rather than
circuit-switched because the packet-based architecture allows for better sharing of limited
wireless resources. In a packet network, connections (packet flows) do not require dedicated
circuits for the entire duration of the connection. Unfortunately, this enhanced flexibility makes
it more difficult to effectively control the admission of connections into the network.
2) 4G in normal life:-
2.1 Traffic Control:-
Beijing is a challenging city for drivers, with or without an Olympics going on. The
growing middle class, and their new-found ability to purchase automobiles, is increasing the
number of passenger vehicles on the road at a staggering annual rate of 30%. 4G networks can
connect traffic control boxes to intelligent transportation management systems wirelessly. This
would create a traffic grid that could change light cycle times on demand, e.g., keeping some
lights green longer temporarily to improve traffic flow. It also could make vehicle-based on-
demand “all green” routes for emergency vehicles responding to traffic accidents, reducing the
likelihood that those vehicles will themselves be involved in an accident en route.
Using fiber to backhaul cameras means that the intelligence collected flows one way:
from the camera to the command center. Using a 4G network, those images can also be sent from
the command center back out to the streets. Ambulances and fire trucks facing congestion can
query various cameras to choose an alternate route. Police, stuck in traffic on major
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4G Technology 2009
thoroughfares, can look ahead and make a decision as to whether it would be faster to stay on the
main roads or exit to the side roads.
2.2 Sensors on Public Vehicles:-
Putting a chemical-biological-nuclear (CBN) warning sensor on every government-
owned vehicle instantly creates a mobile fleet that is the equivalent of an army of highly trained
dogs. As these vehicles go about their daily duties of law enforcement, garbage collection,
sewage and water maintenance, etc., municipalities get the added benefit of early detection of
CBN agents. The sensors on the vehicles can talk to fixed devices mounted on light poles
throughout the area, so positive detection can be reported in real time. And since 4G networks
can include inherent geo-location without GPS, first responders will know where the vehicle is
when it detects a CBN agent.
3) Security:-
Beijing has already deployed cameras throughout the city and sends those images back to
a central command center for the OLYMPIC games2008. This is generally done using fiber,
which limits where the cameras can be hung, i.e., no fiber, no camera. 4G networks allow
Beijing to deploy cameras and backhaul them wirelessly. And instead of having to backhaul
every camera, cities can backhaul every third or fifth or tenth camera, using the other cameras as
router/repeaters.
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16. Conclusion
4G Technology 2009
As the history of mobile communications shows, attempts have been made to reduce a
number of technologies to a single global standard. Projected 4G systems offer this promise of a
standard that can be embraced worldwide through its key concept of integration. Future wireless
networks will need to support diverse IP multimedia applications to allow sharing of resources
among multiple users. There must be a low complexity of implementation and an efficient means
of negotiation between the end users and the wireless infrastructure. The fourth generation
promises to fulfill the goal of PCC (personal computing and communication)—a vision that
affordably provides high data rates everywhere over a wireless network.
Although 4G wireless technology offers higher bit rates and the ability to roam across
multiple heterogeneous wireless networks, several issues require further research and
development. It is not clear if existing 1G and 2G providers would upgrade to 3G or wait for it to
evolve into 4G, completely bypassing 3G. The answer probably lies in the perceived demand for
3G and the ongoing improvement in 2G networks to meet user demands until 4G arrives.
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17. References
4G Technology 2009
1.” eMobility Technology Platform Whitepaper” edited by Didier Bourse (Motorola Labs) and
Rahim Tafazolli (University of Surrey, CCSR)
2.”Intuitive Guide to Principle of Communications” copyright 2004 Charan Langton
3.”Paper on 4g evolution” By Abhijit Hota
4. www.wikipedia.com
5. www.4g.co.uk
6. www.wiley.com
7. www.mobilecomms-technology.com
