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4G TECHNOLOGY
Presenting by :
Purnima.K
Btech III year- ECE
P Indra Reddy Memorial Engg. College
Email id : [email protected]
Contact no. : 8019101682
ABSTRACT :
Mobile communication systems revolutionized the
way people communicate. Evolution of wireless
access technologies is about to reach its fourth
generation. Looking past, wireless access
technologies have followed different evolutionary
paths aimed at unified target : Performance and
Efficiency in high mobile environment. The first
generation (1G) has fulfilled the basic mobile
voice, while the second generation (2G) has
introduced capacity and coverage, later the third
generation (3G) which has a quest for data at
higher speeds to open the gates for truly “Mobile
Broadband” experience which will be further
realized by the fourth generation. The fourth
generation (4G) will provide access to wide range
of telecommunication services, advanced mobile
services, supported by fixed networks, along with
support of low to high mobility services and wide
range of data rates.
INTRODUCTION :
The fourth generation of mobile networks will truly
turn the current mobile phone networks in to end to
end IP based networks. If 4G is implemented
correctly, it will truly harmonise global roaming,
super high speed connectivity on every mobile
communication device in the world. 4G is set to
deliver 100mbps to a roaming mobile device
globally and up to 1gbps to a stationary device.
Bhuvaneshwari Reddy.S
Btech III year -ECE
P Indra Reddy Memorial Engg. College
Email id : [email protected]
Contact no. : 8790650078
It wont be just the phone networks that need to
evolve, the increased traffic load on the internet as
a whole will need to expand, with faster backbones
and oceanic links requiring major upgrade.
Bandwidth will always be the limiting factor in the
development of applications and devices. Hence
the short fall of 3G networks is clear, its just not
fast enough, offering 384kbps doesn’t meet the
requirements of what the users expects now a days.
The evolution from 3G to 4G will be driven by
services that offer better quality (video or sound)
i.e greater bandwidth, more sophistication in the
association of a large quantity of information.
Technology companies with 4G networks are
knocking the door and mobile operators are
beginning to answer. 4G networks and 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, HSDPA, UMTS and proprietary
networks from Arraycomm Inc., Navini Networks,
Flarion Technologies and 4G efforts in India,
China, and Japan.
KEY 4G TECHNOLOGIES :
The design is such that the 4G will be based on
OFDM ( Orthogonal Frequency Division
Multiplexing ), which is the key enabler of 4G
Technology. Other technology 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. 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. 4G
data rates will vary depending on the number of
channels that are available. 4G networks will also
use smart antenna technology.
OFDM :
Orthogonal frequency division multiplexing not
only provides clear advantages for physical layer
performance, but also a framework for improving
layer performance by proposing an additional
degree of free-dom. Using OFDM, it is possible to
exploit the time, space domain, frequency domain
and even the code domain to optimize radio
channel usage. It ensures very robust transmission
in multipath environments with reduced receiver
complexity. OFDM also provides a frequency
diversity gain, improving the physical layer
performance, It is also compatible with other
enhancement technologies, such as smart antennas
and MIMO. OFDM modulation can also be
employed as a multiple access technology. In this
case, each OFDM symbol can transmit information
to several users using a different set of subcarriers.
This not provides additional flexibility for resource
allocation, but also enables cross layer optimization
of radio link usage.
ASSUMED FEATURES OF 4G :
The 4G system was originally envisioned by the
Defence Advanced Research Projects Agency
(DARPA). The DARPA selected the distributed
architecture and end-to-end Internet protocol, and
believed at an earlier stage in peer-to-peer
networking in which every mobile device would be
both a transceiver and a router for other devices in
the network, eliminating the spoke and hub
weakness of 2G and 3G cellular systems. In 4G
systems, the circuit switched infrastructure is
abandoned and only a packet switched network is
provided, while 2.5G and 3G systems require both
packet switched and circuit switched network
nodes, i.e. two infrastructures in parallel. This
means that in 4G, traditional voice calls are
replaced by IP telephony. Cellular systems such as
4G allow seamless mobility, thus a file transfer is
not interrupted in case a terminal moves from one
cell to another. Hence 4G is described as MAGIC:
mobile multimedia, anytime anywhere, global
mobility support, integrated wireless solution, and
customized personal service.
Some key features of 4G mobile networks are :
(a).High usability : anytime, anywhere, and with
any technology.
(b).Support for multimedia services at low
transmission cost.
(c).Personalization.
(d).Integrated services.
CONCLUSION :
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.
The provision of megabit/s data rates to thousands
of radio and mobile terminals per square kilometer
presents several challenges. The key enablers are:
• Sufficient spectrum, with associated sharing
mechanisms.
• Coverage with two technologies: parent (2G, 3G,
and WiMAX) for real-time delivery, and
discontinuous Pico cell for high data rate delivery.
• Fixed-mobile convergence (for indoor service).
• Network selection mechanisms.
REFERENCES :
[1] http://www.four-g.net/index.html
[2] http://en.wikipedia.org/wiki/4G
[3] Advanced Wireless Communications: 4G Technologies
by Savo G.Glisic
