4G-MOBILE COMMUNICATION USING WIRELESS COMMUNICATION
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”
We 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
industry 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-
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
4G 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 :
2G: was based on digital signal processing
1G: This process began with the designs in the
techniques and regarded as a revolution from
1970s that have become known as 1G. The
analogy to digital technology These 2G systems
earliest systems were implemented based on
provided circuit- switched data communication
analog technology and the basic cellular
services at a low speed. of 9.6 kbps The
structure of mobile communication.
competitive rush to design and implement
digital systems led again to a variety of different multimedia services requirements, together with
and incompatible standards such as GSM the coexistence of different services needing
,TDMA,CDMA,PDC. different QoS and bandwidth.
Limitation of spectrum and its allocation.
2.5G: An interim step is being taken between Difficult to roam across distinct service
2G and 3G, the 2.5G. It is basically an environment in different frequency bands.
enhancement of the two major 2G technologies Lack of end-to-end seamless transport
to provide increased capacity on the 2G RF mechanism spanning a mobile sub-network and
(radio frequency) channels and to introduce a fixed one.
higher throughput for data service, up to 384
kbps. GSM system enhancements like GPRS
Thus the limitations lead to development of new
and EDGE are considered to be 2.5
generation of wireless technology i.e., 4G
technologies. GPRS is an attractive solution to
mobile communications .the 4G has wide range
mobile operators, because it does not require
of features compared to the different generations
the same degree of the investment as UMTS.
.and has much advantages and features
3G: 3G is deploying a new system with new
4G: Edge over 3G
services instead of only providing higher data It is commonly said that 4G is the super-
up to 2 Mbps and broader bandwidth. Based on enhanced version of 3G.4G systems will be
intelligent DSP techniques, various multimedia deployed with software –defined radios,
data communications services are transmitted by allowing equipment upgrades for new protocols
convergent 3G networks. The 3G system would and services via software upgrades. In addition,
have higher quality voice channels. The 3G 4G holds the promise of worldwide roaming
system will have features like fast internet using a single handheld device. To
surfing advanced value added service and video summarise,4G means fully converged services,
telephony .The technologies that are used to ubiquitous cellular access, diverse user devices,
boost the speed are UMTS and W-CDMA . autonomous networks and software
Problems associated with 3G: The main aim of 3G was to provide multimedia,
Difficulty in continuously increasing multirate, cellular communications any time and
bandwidth and high data rate to meet any where. It‟s uneconomical to meet this
requirement with only cellular radio.4G radio.4G systems will extend the scenario to an
systems will extend the scenario to an IP IP network that integrates broadcast ,cellular ,
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 computer will send a packet to the 4G-IP
networks, each node will be assigned a 4G-IP address of the cell phone targeting on its home
address (based on IPv6), which will be formed address. Then a directory server on the cell
by a permanent “home” IP address and a phone‟s home network will forward this packet
dynamic “care-of” address that represents its to the cell phone‟s care-of address through a
actual location . When a device (computer) in tunnel, mobile IP; moreover, the directory
the Internet wants to communicate with another server will also inform the computer that the cell
device (cell phone) in the wireless network, the 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
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
Unlike 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 protocol) as a common protocol so that users are
wireless is intended to complement and replace in control because they will be able to choose
the 3G systems, perhaps in 5 to 10 years. every application and environment. Based on
Accessing information anywhere, anytime, with the developing trends of mobile communication,
a seamless connection to a wide range of 4G will have broader bandwidth, higher data
information and services, and receiving a large rate, and smoother and quicker handoff and will
volume of information, data, pictures, video, focus on ensuring seamless service across a
and so on, are the keys of the 4G infrastructure. multitude of wireless systems and networks.
The future 4G infrastructures will consist of a The below figure describes the process included
set of various networks using IP (Internet in 4G mobile communications
The key concept is integrating to the personal preference of different users and
the 4G capabilities with all of the existing support the users' traffic, air interfaces, radio
mobile technologies through advanced environment, and quality of service. Connection
technologies. Application adaptability and being with the network applications can be transferred
highly dynamic are the main features of 4G into various forms and levels correctly and
services of interest to users. These features efficiently. The dominant methods of access to
mean services can be delivered and be available this pool of
information will be the mobile telephone, PDA, 4G systems will be fully IP-based wireless
and laptop to seamlessly access the voice Internet. This all-encompassing integrated
communication, high-speed information perspective shows the broad range of systems
services, and entertainment broadcast services. that the fourth generation intends to integrate,
from satellite broadband to high altitude
The fourth generation will platform to cellular 3G and 3G systems to WLL
encompass all systems from various networks, (wireless local loop) and FWA (fixed wireless
public to private; operator-driven broadband access) to WLAN (wireless local area network)
networks to personal areas; and ad hoc and PAN (personal area network), all with IP as
networks. The 4G systems will interoperate with the integrating mechanism. With 4G, a range of
2G and 3G systems, as well as with digital new services and models will be . examined for
(broadband) broadcasting systems. In addition, their interface with the design of 4G systems
signals are the subset of the main signal. In
Multiplexing: Method of sharing a OFDM first the signal itself is split into
bandwidth with other independent data independent channels, modulated by data and
OFDM is a combination of both modulation and then re-multiplexed to create the OFDM carrier.
multiplexing. Multiplexing generally refers to OFDM is a special case of Frequency Division
independent signals, those produced by different multiplex (FDM).As an analogy, a FDM
sources. So it is a question of how to share the channel is a flow out of a faucet, in contrast the
spectrum with these users. In OFDM the OFDM signal is like a shower. In a faucet all
question of multiplexing is applied to water comes in a big stream and cannot be
independent signals but these independent subdivided
Fig.9: OFDM Principles
As shown in the fig.5 the signal is split into OFDM can also be as a multiple access
orthogonal sub carriers, on each of which the signal technology (Orthogonal Frequency Division
is “narrowband” (a few KHz) and therefore immune Multiple Access; OFDMA). In this case, each
to multipath effects, Provided a guard interval is
OFDM symbol can transmit information to/from
guarded between each OFDM symbol. OFDM also
several users using a different set of subcarriers
provides a frequency diversity gain increasing the
(sub channels). This not only provides
physical layer performance. It is also compatible
additional flexibility for resource allocation
with other enhancement technologies, such as smart
antenna and MIMO.
(increasing the capacity), but also enables cross-
layer optimization of radio link usage.
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.
Robust against narrow-band interference.
Efficient for simulcasting.
Used for highest speed Applications.
Supports dynamic packet Access.
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 a large metropolitan area. This data base could
be accessed by subscribers in vehicles.
Location application. 4G location applications
Virtual navigation and telegeoprocessing.
will be based on visualized, virtual navigation
You will be able to see the internal layout of a
schemes that will support a remote database
building during an emergency rescue. This type
containing graphical representations of streets,
buildings and another physical characteristic of
of application is some time referred to as present for restoration of wire line
A remote database will contain the graphical Limitations
representation of streets, buildings and physical Although the concept of 4G communications
characteristics of a large metropolis. Blocks of shows much promise, there are still limitations
this database will be transmitted in rapid that must be addressed. A major concern is
sequence to a vehicle, where a rendering interoperability between the signaling
program will permit the occupants to visualize techniques that are planned for use in 4G
the environment ahead. They may also (3XRTT and WCDMA).
„virtually‟ see the internal layout of buildings to Cost is another factor that could hamper the
plan an emergency rescue or engage hostile progress of 4G technology. The equipment
elements hidden in the building. required to implement the next-generation
Telemedicine. A paramedic assisting a victim network are still very expensive.
of a traffic accident in a remote location could A Key challenge facing deployment of 4G
access medical records (X-rays) and establish a technologies is how to make the network
video conference so that a remotely based architectures compatible with each other. This
surgeon could provide „on-scene‟ assistance. was one of the unmet goals of 3G.
Crisis management application. In the event AS regards the operating area, rural areas and
of natural disasters where the entire many buildings in metropolitan areas are not
communications infrastructure is in disarray, being served well by existing wireless networks
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
“IT IS A REVOLUTION –NOT EVOLUTION”
Hui, Suk Yu, and Yeung, Kai Hau, “Challenges in the Migration to 4G Mobile Systems”, IEEE
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”.
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