3. 4G wireless in one view:
4g is the short name for 4th generation wireless, the stage of
mobile communication that will enable things like ip-based
voice, data, gaming services and high quality streamed
multimedia on portable devices with cable modem-like
transmission speed.
4. technology 1G 2G 2.5G 3G 4G
Design
began
1970 1980 1985 1990 2000
implementa
tion
1984 1991 1999 2002 2010
service Analog
voice,
synchronous
data to
9.6kbps
Digital
voice,
short
messages
Higher
capacity,
packetized
data
Higher
capacity
broadband
data up to
2mbps
Higher
capacity,
completely
ip oriented
standards AMPS,TACS,
NMT etc…
TDMA,CD
MA,GSM,P
DC
GPRS,EDGE,1
*RTT
WCD,CDMA
MA2000
Single
standard
Data
bandwidth
1.9 kbps 14.4 kbps 384 kbps 2 Mbps 200 Mbps
multiplexing FDMA TDMA,CD
MA
TDMA, CDMA CDMA CDMA
Core
network
PSTN PSTN PSTN packet
network
Packet
network
Internet
5. About 4G wireless systems
• 4g is the fourth generation wireless network communications
technology standard.
• This new generation of wireless is intended to complement
and replace the 3g systems.
• 4g infrastructures is consisting of a set of various networks
using IP(internet protocol) as a common protocol.
• Application adaptability and being highly dynamic are the
main features of 4g services .
• 4g systems are fully ip-based wireless internet
6. 1.Technologies that comprise 4g:
4g is based entirely on packet switched networks.
Standards such as 3g and Bluetooth are incorporated in to 4g
standards.
2.Need for 4g:
firstly 3g’s maximum data transfer rate 384kbps to 2mbps is
much slower than 20 to 100mbps of 4g.
With its use of existing technologies and communication
standards, 4g present a comparably inexpensive standard.
7. 3.Specifications of 4g:
4g can provide 10 times increase in data transfer over 3g.
This speed can be achieved through orthogonal frequency
division multiplexing(OFDM).
OFDM can not only transfer data at a speed of more than
100mbps, but it can also eliminate interference that impairs
high speed signals.
8. 4.Potential applications of 4g:
4g provides a seamless network for users who travel and
require uninterrupted voice/data connections.
Navigation menus is also present in 4g technology.
It provides a vast number of applications for mobile devices.
12. OFDM:
• It transmits a large amount of digital data in a radio wave
• OFDM works by splitting the radio signal into multiple smaller
sub-signals that are then transmitted simultaneously at
different frequencies to the receiver .
• By inserting a cyclic prefix between adjacent OFDM signal
inter signal interference is virtually eliminated if the max.
channel delay spread is less than the time interval of cyclic
prefix.
13. • In OFDM the subcarrier pulse used for transmission is
rectangular.
• Here modulation can performed by an IDFT ,which can be
generated very efficiently as an IFFT . so, receiver only needs a
FFT to reverse this process.
14. UWB:
An advanced technology that can be used in 4G technology
It is typically detected as noise.
It can use any part of the frequency spectrum, which means that
it can use frequencies that are currently in use by other radio
frequency devices .
It uses a frequency of 3.1 to 10.6 Hz.
It uses less power , since it transmits pulse instead of continuous
signal.
Special antennas are needed to tune and aim the signal
15. IPv6
IPv6 means Internet Protocol Version 6 .
The Internet Protocol (IP) is the method or protocol which data is
sent from one
computer to another on the internet.
Each computer (known as a host) on the Internet has at least one
IP that uniquely identifies it from all other computers on the
Internet.
It includes128 bits, which is 4 times more than 32bits IP address
in IPv4.
16. Quality of service
In wireless networks, Quality of Service (QOS) refers to the
measure of the performance for a system reflecting its
transmission quality and service availability.
4G is expected to have at least a reliability of 99.99%).
In 4G QOS may be divided in following ways-
Transaction-level QOS describes both the time it takes to
complete a transaction and the packet loss rate.
Circuit-level QOS includes call blocking for new as well as existing
calls .
User-level QoS depends on user mobility and application type .
17. Software defined ratio
A software defined radio is one that can be configured to any
radio or frequency standard
through the use of software.
The phone should automatically switch from operating on a
CDMA frequency to a TDMA frequency whenever it is
required.
Roaming can be an issue with different standards, but with a
software defined radio, users can just download the interface
upon entering new territory, or the software could just
download automatically.
18. Application
In traffic control.
Multimedia – video services
Telemedicine.
Crisis Management
Virtual Navigation
19. Limitations
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.
