4g-mobile communication using wireless communication
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4G-MOBILE COMMUNICATION USING WIRELESS COMMUNICATION
Abstract :
This paper aims to identify and explore the different issues and challenges related to fourth
generation networks. It starts with a brief Introduction, and then explains the edge of 4G technology
over 3G, and defines 4G. , . It also provides a detailed insight on the vision of 4G, and also discusses
about the advantages and applications of 4G technology. It also compares the 4G technology with all
other technologies. and explains all its ,characteristics.
This paper also focuses on key technologies to implement 4G technology. and also provide a technical
Platform for implementing the technology as it provides a basic idea on OFDM since with its natural
resistance to multipath fading and its ability to support extremely high data rates, orthogonal frequency
division multiplexing (OFDM) is a major candidate for fourth-generation air interfaces. ,it consists
characteristics and benefits’ of OFDM.
it mainly explains the use of 4G having possessed “3G”
.
IntroductionWe are seeing a massive demand for data, audio, image and video services on mobile phones.
These require a faster rate of data transfer.
Though the projected data rate of 3G is around 2 Mbps, the actual data rate is much slower, especially in
crowded areas or when the network is congested. Further, data rates also depend on the user’s activity
(moving or steady state) and location (indoor/outdoor).
As expected data services like multimedia are going to play an increasing role and will dominate the
cellular traffic instead of voice in future.
In such a scenario, the present 2G and 3G systems will saturate and have no room to survive. Also, the
demand for increasing data rates leads to higher bandwidth requirements. These factors force the cellular
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comindustry to develop a common standard or system that over comes almost all limitations imposed by
previous cellular technologies.
4G services hold out the promise of end-to-end, totally IP (Internet protocol), packet-switched networks
that will be able to handle growing loads of wireless voice, data, video and audio transmissions more
efficiently, at lower cost and at higher performance levels i.e., 4G systems are expected to allow much
higher data rates of around 100 Mbps, higher bandwidth of the order of hundreds of megahertz, plenty
of services like data, audio and video(as shown in fig1),seamless connectivity and improved quality of
service keeping in mind that all existing networks can be merged or interconnected to form an all-in-
one.
What is 4G?
Fig 2 shows the concept of 4G cellular network. The future 4G infrastructure will consist of various
networks using Internet Protocol (IP) as a common protocol. So the users will be in control as they can choose
every application and environment. Accessing information any where, in time with seamless connections to a
wide range of information, data, pictures, video and so on will be the benefits of 4G infrastructure.
One of the terms popularly used to describe 4G is ‘MAGIC’, which stands for ‘Mobile
multimedia, anytime any where, Global mobility support, Integrated Wireless solutions and customized
personal services.’
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.com4G services will be dynamic and adaptable to the application. Faster response and quality are the
prerequisites for full-motion video, home entertainment and advance location-based services. The
expected data rate is 2 Mbps for vehicular applications. Such high data rates obviously require a high
bandwidth of the order of several hundreds of megahertz.
COMPARISIONS OF DIFFERENT GENERATIONS :
1G: This process began with the designs in the
1970s that have become known as 1G. The
earliest systems were implemented based on
analog technology and the basic cellular
structure of mobile communication.
2G: was based on digital signal processing
techniques and regarded as a revolution from
analogy to digital technology These 2G systems
provided circuit- switched data communication
services at a low speed. of 9.6 kbps The
competitive rush to design and implement
digital systems led again to a variety of different
and incompatible standards such as
GSM ,TDMA,CDMA,PDC.
2.5G: An interim step is being taken between
2G and 3G, the 2.5G. It is basically an
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comenhancement of the two major 2G technologies
to provide increased capacity on the 2G RF
(radio frequency) channels and to introduce
higher throughput for data service, up to 384
kbps. GSM system enhancements like GPRS
and EDGE are considered to be 2.5
technologies. GPRS is an attractive solution to
mobile operators, because it does not require
the same degree of the investment as UMTS.
3G: 3G is deploying a new system with new
services instead of only providing higher data
up to 2 Mbps and broader bandwidth. Based
on intelligent DSP techniques, various
multimedia data communications services are
transmitted by convergent 3G networks. The 3G
system would have higher quality voice
channels. The 3G system will have features like
fast internet surfing advanced value added
service and video telephony .The technologies
that are used to boost the speed are UMTS and
W-CDMA .
Problems associated with 3G:
Difficulty in continuously increasing
bandwidth and high data rate to meet
multimedia services requirements, together with
the coexistence of different services needing
different QoS and bandwidth.
Limitation of spectrum and its allocation.
Difficult to roam across distinct service
environment in different frequency bands.
Lack of end-to-end seamless transport
mechanism spanning a mobile sub-network and
a fixed one.
Thus the limitations lead to development of new
generation of wireless technology i.e., 4G
mobile communications .the 4G has wide range
of features compared to the different generations
.and has much advantages and features
4G: Edge over 3GIt is commonly said that 4G is the super-
enhanced version of 3G.4G systems will be
deployed with software –defined radios,
allowing equipment upgrades for new protocols
and services via software upgrades. In addition,
4G holds the promise of worldwide roaming
using a single handheld device. To
summarise,4G means fully converged services,
ubiquitous cellular access, diverse user devices,
autonomous networks and software
dependency.
The main aim of 3G was to provide multimedia,
multirate, cellular communications any time and
any where. It’s uneconomical to meet this
requirement with only cellular radio.4G
systems will extend the scenario to an IP
network that integrates broadcast, cellular
radio.4G systems will extend the scenario to an
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comIP network that integrates broadcast ,cellular , cordless ,WLAN/PAN and fixed wire.
“4G is a network of networks” with which users will be in control. They will be able to decide the right s As can be seen in the picture above, the main requirements for 4G are as follows:
Peak data rate of 100Mbps for high mobility applications such as mobile access
Approx. 1Gbps for low mobility applications such as nomadic/local wireless access
4G TECHNICAL PERSPECTIVES:
In the 4G wireless
networks, each node will be assigned a 4G-IP
address (based on IPv6), which will be formed
by a permanent “home” IP address and a www.1000projects.comwww.fullinterview.comwww.chetanasprojects.com
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comdynamic “care-of” address that represents its
actual location . When a device (computer) in
the Internet wants to communicate with another
device (cell phone) in the wireless network, the
computer will send a packet to the 4G-IP
address of the cell phone targeting on its home
address. Then a directory server on the cell
phone’s home network will forward this packet
to the cell phone’s care-of address through a
tunnel, mobile IP; moreover, the directory
server will also inform the computer that the cell
phone’s care-of address (real
location), so next packets can be sent to the cell phone directly. The idea is that the 4G-IP address (IPv6)
can carry more information than the IP address (IPv4) that we use right now. IPv6 means Internet
Protocol Version 6 including 128 bits, which is 4 times more than 32bits IP address in IPv4. 32 bits IP.
Moreover, in 4G wireless network, not only has it IPv6 transmission protocol, but also be supported by
OFDM, M
FEATURES OF 4G:
4G is the Fourth Generation Wireless Network Communications Technology standard. When
implemented, users of 4G devices will have the ability to access to applications ranging from
basic voice communications to seamless real-time streaming video. Although it is in the research
and development stage, 4G is expected to be globally available to the public between 2006 and
2010.
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comUnlike previous standards such as 3G (Third Generation), 4G is based entirely on packet switched
networks. In addition, all 4G networks will be digital and will provide higher bandwidths of up to
100Mbps. 4G is actually a collection of previous standards as opposed to an entirely new standard.
Standards such as 3G C-CDMA, LAS-CDMA, UWB *7 and Network-LMD
VISIONS OF 4G:
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 infrastructure.
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 below figure describes the process included
in 4G mobile communications
The key concept is integrating
the 4G capabilities with all of the existing
mobile technologies through advanced
technologies. Application adaptability and being www.1000projects.comwww.fullinterview.comwww.chetanasprojects.com
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comhighly 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.
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 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 . examined for
their interface with the design of 4G systems
Multiplexing: Method of sharing a bandwidth with other independent data channels.OFDM is a combination of both modulation and
multiplexing. Multiplexing generally refers to
independent signals, those produced by different
sources. So it is a question of how to share the
spectrum with these users. In OFDM the
question of multiplexing is applied to
independent signals but these independent
signals are the subset of the main signal. In
OFDM first the signal itself is split into
independent channels, modulated by data and
then re-multiplexed to create the OFDM carrier.
OFDM is a special case of Frequency Division
multiplex (FDM).As an analogy, a FDM
channel is a flow out of a faucet, in contrast the
OFDM signal is like a shower. In a faucet all
water comes in a big stream and cannot be
subdivided
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Fig.9: OFDM Principles
As shown in the fig.5 the signal is split into
orthogonal sub carriers, on each of which the signal
is “narrowband” (a few KHz) and therefore immune
to multipath effects, Provided a guard interval is
guarded between each OFDM symbol. OFDM also
provides a frequency diversity gain increasing the
physical layer performance. It is also compatible
with other enhancement technologies, such as smart
antenna and MIMO.
OFDM can also be as a multiple access
technology (Orthogonal Frequency Division
Multiple Access; OFDMA). In this case, each
OFDM symbol can transmit information to/from
several users using a different set of subcarriers
(sub channels). This not only provides
additional flexibility for resource allocation
(increasing the capacity), but also enables cross-
layer optimization of radio link usage.
OFDM Characteristics:
High peak-to-average power levels.
Preservation of orthogonality in severe multi-path.
Efficient FFT based receiver structures.
Enables efficient TX and RX diversity.
Adaptive antenna arrays without joint Equalization.
Support for adaptive modulation by sub carrier.
Frequency Diversity.
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.com Robust against narrow-band interference.
Efficient for simulcasting.
Variable/Dynamic Bandwidth.
Used for highest speed Applications.
Supports dynamic packet Access.
OFDM Benefits:
High-spectral efficiency.
Resistance to frequency selective fading.
. Advantages of 4G Support for interactive multimedia services like teleconferencing and wireless Internet.
Wider bandwidths and higher bitrates.
Global mobility and service portability.
Scalability of mobile network.
Entirely Packet-Switched networks.
Digital network elements.
Higher band widths to provide multimedia services at lower cost (up to 100 Mbps).
Tight network security.
Applications
Location application . 4G location applications
will be based on visualized, virtual navigation
schemes that will support a remote database
containing graphical representations of streets,
buildings and another physical characteristic of
a large metropolitan area. This data base could
be accessed by subscribers in vehicles.
Virtual navigation and telegeoprocessing.
You will be able to see the internal layout of a
building during an emergency rescue. This type
of application is some time referred to as
‘telegeoprocessing’.
A remote database will contain the graphical
representation of streets, buildings and physical
characteristics of a large metropolis. Blocks of
this database will be transmitted in rapid
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www.1000projects.comwww.fullinterview.comwww.chetanasprojects.comsequence to a vehicle, where a rendering
program will permit the occupants to visualize
the environment ahead. They may also
‘virtually’ see the internal layout of buildings to
plan an emergency rescue or engage hostile
elements hidden in the building.
Telemedicine. A paramedic assisting a victim
of a traffic accident in a remote location could
access medical records (X-rays) and establish a
video conference so that a remotely based
surgeon could provide ‘on-scene’ assistance.
Crisis management application. In the event
of natural disasters where the entire
communications infrastructure is in disarray,
restoring communications quickly is essential.
With wideband wireless mobile
communications, limited and even total
communication capability (including Internet
and video services) could be set up within hours
instead of days or even weeks required at
present for restoration of wire line
communications.
LimitationsAlthough the concept of 4G communications
shows much promise, there are still limitations
that must be addressed. A major concern is
interoperability between the signaling
techniques that are planned for use in 4G
(3XRTT and WCDMA).
Cost is another factor that could hamper the
progress of 4G technology. The equipment
required to implement the next-generation
network are still very expensive.
A Key challenge facing deployment of 4G
technologies is how to make the network
architectures compatible with each other. This
was one of the unmet goals of 3G.
AS regards the operating area, rural areas and
many buildings in metropolitan areas are not
being served well by existing wireless networks
CONCLUSION:
“IT IS A REVOLUTION –NOT EVOLUTION”
REFERENCES:
Hui, Suk Yu, and Yeung, Kai Hau, “Challenges in the Migration to 4G Mobile Systems”, IEEE
Communications
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Magazine, December 2003, pp. 54-59eamless handover and the additional data communications
Janny Hu,Willie W. Lu ,“Open Wireless Architecture - The Core to 4G Mobile Communications”. In Proceedings of ICCT, 2007
. Juuso Pesola, Sami Pönkänen,”Location-aided Handover in Heterogeneous Wireless Networks”.
In Wireless Personal Communications ,Volume 30 , Issue 2-4 ,September 2004
“2G – 3G Cellular Wireless data transport terminology”, Arc Electronics
www.arcelect.com/2G-3G_Cellular_Wireless.htm
Schiller, J., “Mobile Communications”, slides
http://www.jochenschiller.de/
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