Abstract: -
In general, a generation is defined by the result of technology changes over a 10-15 year time frame. Thus, 4G would refer to whatever is deployed in the 2010-2015 period, assuming 3G deployment spans the 2000-2005 periods. Typically, this means a new air-interface with higher data rates in the least, and some see change in the way data transport is handled end-to-end.
In general, a generation is defined by the result of technology changes over a 10-15 year time frame. Thus, 4G would refer to whatever is deployed in the 2010-2015 period, assuming 3G deployment spans the 2000-2005 periods. Typically, this means a new air-interface with higher data rates in the least, and some see change in the way data transport is handled end-to-end.
There is no formal definition of 4G,
but what such technologies have in common, says Andy Fuertes, an analyst at
Visant Strategies, a research firm, is that they are high-speed wireless
networks covering a wide area, designed above all for carrying data, rather
than voice or a mixture of the two.
It has various
features such as low cost, scalability of mobile networks, wider bandwidths and
higher bit rates etc. Multiple Inputs and Outputs Antenna System (MIMO),
Orthogonal frequency division multiplexing (OFDM), Software Defined Radio (SDR)
are the key technologies of 4G.
4G digital IP-based high-speed cellular systems are anticipated to
account for 14% of total mobile wireless data revenues in 2007, with 4G
carriers realizing a total of 50 million subscribers by year-end 2007. Revenues
from 4G infrastructure sales are anticipated to reach $5.3 billion during 2007.
Pioneer of 4G are focusing on
creating a convergent network that offers seamless IP connectivity over several
interfaces and wireless network with very high data rates. In future, internet,
cellular systems intranet etc will merge into a whole seamless wireless
internet whose core network will be 4G IPV6 backbone architecture.
Introduction:-
4G (or 4-G) is short for fourth-generation the successor of 3G and is
a wireless access technology. It describes two different but overlapping ideas.
The IEEE (Institute of Electrical and Electronics Engineers) official name for
4G is "3G and beyond".4G technology stands to be the future standard
of wireless devices. Unlike the 3G networks which are a
jumble of circuit switched and packet switched networks, 4G will be based on
packet switching only. This will allow low-latency data transmission. The
original analog cellular systems are considered the first generation of
mobile telephony (1G).
In the early
1980s, 1G system was deployed. At the same time, the cellular industry began
developing the second generation of mobile telephony (2G). The difference
between 1G and 2G is in the signaling techniques used: 1G used analog signaling,
2G used digital signaling.
Primary
thinking and concept development on 3G generally began around 1991 as 2G
systems just started to roll out .Since the general model of 10 years to develop
a new mobile system is being followed, that timeline would suggest 4G should be
operational some time around 2011.Each generation consists of additional
features that are not present in the previous generation as shown:-
Features of 4G:-
Ø Entirely
packet-switched networks.
Ø All
network elements are digital.
Ø Higher
bandwidths to provide multimedia services at lower cost (up to 100Mbps).
Ø Tight
network security.
Ø Support
interactive multimedia services: teleconferencing, wireless Internet, etc.
Ø Scalability
of mobile networks.
Ø Security.
Ø An
IP multimedia domain.
Ø Enhanced
GPS Services:
a 4G version of GPS technology would be able to let people be
virtually present in a variety of places.
Ø Media-Rich
Apps: media-rich
content would also flow seamlessly between devices.
Architecture of 4G mobile communications:-
The overall 4G
architecture discussed in this paper is IPv6-based, supporting seamless
mobility between different access technologies. In our case, we targeted
Ethernet for wired access; Wi-Fi for
wireless LAN access; and W-CDMA - the radio interface of UMTS - for cellular
access.
An
"IPv6-based" mechanism has to be used for interworking, and no
technology-internal mechanisms for handover, neither on the wireless LAN nor on
other technology, can be used. So, in fact no mobility mechanisms are supported
in the W-CDMA cells, but instead the same IP supports the movement between
cells.The users/terminals may
handover between any of these technologies without breaking their network
connection, and sustaining voice connections. The users can further roam
between administrative domains, being able to use their contracted services
across domains if only appropriate agreements between those domains exist.
The service
providers are be able to keep track of the services being used by their
costumers, both inside their own network, and while roaming. Due to the
requirements of full service control by the provider, all the handovers are
explicitly handled by the management infrastructure through IP-based protocols,
even when they are intratechnology, such as between two different Access Points
in, or between two different Radio Network Controllers in WCDMA.
All network resources
are managed by the network provider, while the user only controls its local
network, terminal, and applications. Summarizing the key entities is:
·
A user - a person or company with a service
level agreement (SLA) contracted with an operator for a specific set of
services. Architecture is for user mobility, so access is granted to users, not
to specific terminals.
·
A MT (Mobile Terminal) - a terminal from where
the user accesses services. It supports terminal portability, i.e. a terminal
may be shared among several users, although not at the same time.
·
AR (Access Router) - the point of attachment to
the network, which takes the name of RG (Radio Gateway) - for wireless access
(WCDMA).
·
PA (Paging Agent) - responsible for locating the
MT entity when it is in "idle mode" while there are packets to be
delivered to it.
·
QoS Broker - entity responsible of managing one
or more ARs/AGs, controlling user access and access rights, provided by the
AAAC System.
·
AAAC System - the Authentication, Authorization,
Accounting and Charging System, responsible for service level management
(accounting, charging), Metering entities are also considered an integral part
of this AAAC system.
·
NMS
(Network Management System) - the entity responsible for managing and
guaranteeing availability of resources in the Core Network, and control.
Major Technologies of 4G:-
New,
powerful technologies that emerged recently promise a tenfold improvement in
spectral efficiency over existing solutions. Some of the major technologies of
4G are:-
1. Software Defined Radio (SDR):-
SDR is defined as “radio
that provide software control of a variety of modulation techniques, wide-band
or narrow band operations ,communication security functions and wave form requirements
of current and evolving standards over a broad frequency range” .
The principle defining
characteristics of SDR is that the most important
operational functionality of radio can be configured when it is in use rather
than when it is actually manufactured. This is the
original concept of SDR. Flexible radio receivers are also called Software
Defined Radios (SDRs). Although dedicated receivers (for one standard) will
always consume less power (a factor 10 or more)
SDR is mainly a combination of
wireless network, mobile telephone and wireless headset which is as shown in
the fig. Using SDR new radio functionality can be implemented in network
equipments and handsets as software modules running on a common hardware
platforms.
SDR mainly aims at providing a
common platform of air-interfaces, protocols and applications thereby
increasing network and terminal capability and versatility by software
modifications.
SDR system architecture brings
together the evolution of cellular RAN architecture, IP-based mobile networks
and network planning concepts yielding network functions to support
reconfigurable entities and potential architectures for appropriate network
deployment.
Benefits of SDR:-
For
operators:-They will provide the operators: Greater spectral efficiency,
reduced operational expenditure, reduced capital expenditure, faster time to
market for new services and applications, optimization of their network
resources.
For
Manufacturers:-Equipment manufacturer will benefit from SDR through a
reduction in the number of separate platforms that will be needed for different
technologies. This in turn will significantly reduce their research and
development costs and speed up their time for market new products
.
For
Subscribers:-SDR will provide users with greatly improved connectivity so
that they will be able, through a single terminal, to communicate through a
range of different access networks. It will also increase users roaming options
with SDR handsets could be loaded with software modules to allow user to
communicate regardless of wireless technology in use.
2. Orthogonal Frequency Division Multiplexing (OFDM):-
Orthogonal
frequency-division multiplexing (OFDM), also sometimes
called discrete multitone modulation
(DMT), is a transmission
technique based upon the idea of frequency-division multiplexing (FDM).
OFDM, with many technical variants, is endorsed by Nokia, Cisco, Lucent,
and Philips Semiconductor, and is represented as the successor to frequency
hopping and direct sequence CDMA. It
is also positioned as the technique of choice for next generation wireless LANs
and metropolitan networks. The capability of OFDM to cancel multipath
distortion in a spectrally efficient manner without requiring multiple local
oscillators has won adherents in the IEEE 802.11a and 802.16 working groups. However, despite the
support of many key industry players, OFDM is not actually deployed in
mainstream wireless systems. OFDM is fundamentally different
from other modulation schemes. In fact, it should probably not be considered a
modulation scheme at all, because it may be transmitted via AM, FM, QAM and so
on. OFDM
is properly defined as a mathematically elegant technique for the generation
and demodulation of radio waves. Although its origins date back to the Second
World War, its application to wireless communications is new.
OFDM
Feature:-
- No intercarrier guard bands.
- Maximum spectral efficiency (Nyquist rate).
- Easy
implementation by FFTs.
- Controlled overlapping of bands.
- Very sensitive time-freq. synchronization.
Fig: - OFDM allows for greater special
efficiency There are various systems based on OFDM such
as BST-OFDM, FLASH-OFDM, and COFDM. FLASH-OFDM:- Flash-OFDM
is a system that is based on OFDM and specifies also higher protocol layers. It
has been developed and is marketed by Flarion. Flash-OFDM has generated
interest as a packet-switched cellular bearer, on which area it would compete
with GSM and 3G networks. Flarion's core product - the Radio
Router base station - is a combination of a wireless base station and IP access
router .The autonomy of the Radio Router base stations is one of the more
critical attributes of the FLASH-OFDM network layer as shown:-
3. Multiple
Inputs and Multiple Output Antenna System (MIMO):- Multiple-input multiple-output, or MIMO,
is an abstract mathematical model for some communications systems. In radio
communications if multiple antennas are employed, the MIMO model naturally
arises. The
concept of MIMO was first introduced by Jack winter in1987 for two basic
communication system .The first was for communication between multiple mobiles
and base stations with multiple antennas and the second for communication
between mobiles each with multiple antennas. Multiple
antennas can be used on transmitter or receiver or on both sides. MIMO
architecture can be used for combined transmit and receive diversity as well as
parallel transmission of data and spatial multiplexing. It promises high bit
rates in narrow band widths. MIMO aims to separate data streams occupying the
same bandwidths relaying on the de-correlations of the multiple received
signals in the presence of multipath. Adaptive
can give higher channel capacity its practical application needs proper
estimation of the coherent time of the channel particularly in the outdoor
environments. MIMO can also be used in conjunction with OFDM, and it will be
part of the IEEE 802.11n High-Throughput standard, which is expected to be
finalized in mid 2006. MIMO,
as used by the expected 802.11n standard, will offer up to eight times the
coverage, and up to six times the speed, of current 802.11g networks. A few
wireless networking manufacturers have released "pre-N" hardware in
anticipation of an eventual standard. On January 19, 2006, the IEEE 802.11n
Working Group approved the EWC's specification as the draft approval of 802.11n.
Other
new enhancements will include the arrival of 802.11e and 802.11i. 802.11e will
prioritize important information on the network (e.g. voice message takes
precedence over email or a webpage). 802.11i will increase security by using WPA2.
MIMO has just been added to the latest draft version of Mobile WiMAX (802.16e). The typical MIMO system consists of several
transmit and receive antennas as shown in fig. It can be considered as a
network with transmission paths connecting each input with each output. Major
limiting MIMO system channels capacity factor are:-
Ø
Correlation
of the received signal by the different antenna elements.
Ø
The
number of multi-path components where it has been shown that the number if independent
channels is determine by number of smaller scatterers.
Fig: - MIMO Architecture
4G Applications:-
- 4g for public safety:-
Public safety
users will be able to provide faster incident response because of the accuracy
provided by the pinpoint identification of the physical location of users in
the 4G environment. Telegeoprocessing (a combination of Geographical
Information Systems [GIS] and GPS working in concert over a high capacity
wireless mobile system) will make
several public safety applications a reality.
Another
benefit to public safety that can be realized in the enhanced 4G environment is
the ability to locate people in need of assistance. For example, if a user
makes an emergency call from a wireless device and is unable to give an address
or location to the emergency operator, the emergency operator can pinpoint the
user’s position via the wireless network’s built-in functionality. This type of
service will offer users peace of mind and will help the public safety
communities do its job more effectively.
Application developers and service providers are paying
close attention to user expectations to determine what services to develop and
offer. Wireless users can be categorized into generalized segments. The
wireless industry must understand these segments and what drives each segment’s
requirements and expectations for the next generation of wireless technology.
Users can be segmented in many ways. According to a recent presentation by
Lucent Technologies at the Supercomm 2001 conference in June, Lucent is considering
segmenting users into the following categories: Gender, Age, Internet Usage,
Income Brackets, and Mobile Professional.
- 4G in mobiles:-
Studies believed that
a new mobile phone network system, 4G will be in the market in the nearby
future. 4G, or known as the fourth generation mobile is a whole new radio
access network. Stronger and clearer signals and higher speed (broadband speed,
100 times faster than the 3G connection) connection through the internet are
the highlights of the 4G technology.
Although
the 3G technology had only been promoted no long ago, this new technology is
now under development stage and believed to be put out in the market in year
2010. It is believed that the 4G will be a big leap and a whole new revolution for
the mobile phone industry and the users.
A 4G device would act as a
simultaneous interpreter. The 4G
device should break down communication barriers by providing translation and
interpretation functions, Samsung president Lee Ki-tae wrote. He added that a
function for recognizing various sign languages and converting them into spoken
language will also be introduced.
...
"A mobile phone three years from now will become a portable doctor and
omnipotent medical device enabling the user to check his or her health
condition from home, work or anywhere around the world,’’ Lee said. The 4G
infrastructure operator will mix several technologies, each of which has its
optimal usage. The connection to one of them will result in a real-time
trade-off which will offer the user the best possible service. Some tools that
genuinely improve the user's multimedia quality of experience.
Garmin is showing off the Garmin Mobile 20 platform, essentially a car
mount with built-in GPS receiver that works with software available for most
Nokia and Windows Mobile phones, which uses the 4G technology.
It is a Windows Mobile 5 smartphone a 4G
product with a built-in GPS receiver that foregoes any external antenna. Using
a quad-band GSM radio—which means it should work just about everywhere in the
world—the G500 also supports Traffic Message Channel (TMC), a service that allows
updates regarding traffic congestion to be broadcast to the device.
4G wikipodLinux:-
IPod Linux is
currently in development for fourth generation, mini (first generation), U2 and
Photo iPods. Development for getting the second-generation mini to work is also
in progress. There has been no stable release for non-developers yet - you
cannot get your new iPod to load iPod Linux using the normal methods. The 4g,
mini (the 2G uses the PP5022 chipset), U2 and photo all use a
completely different chipset (the PP5020) to previous
iPods (the PP5002).
This means the kernel
has to be modified before it will successfully run - this requires a lot of
reverse engineering and therefore a lot of time and hard work. After the kernel
has been successfully modified, more tinkering will be required to ensure the
rest of the 4g's components work.
Fig:-Some
of the 4G ipods
Conclusions:-
Conclusions:-
·
4G (or 4-G) is short for fourth-generation
the successor of 3G and is a wireless access technology. It describes two
different but overlapping ideas. The IEEE (Institute of Electrical and
Electronics Engineers) official name for 4G is "3G and beyond".4G
technology stands to be the future standard of wireless devices.
- 4G's
goal is to "replace the current proliferation of core cellular
networks with a single worldwide cellular core network standard based on
IP (Internet protocol) for control, video, packet data, and Voice over IP
(VoIP).
- 4G's flexibility will allow the integration of several different LAN and WAN technologies. This will let the user apply one 4G appliance, most likely a cell-phone/PDA hybrid, for many different tasks—telephony, Internet access, gaming, real-time information, and personal networking control, to name a few.
- "A mobile phone three years from now will become a portable doctor and omnipotent medical device enabling the user to check his or her health condition from home, work or anywhere around the world,’’ Lee said.
- A 4G wireless phone would
give a user the capability of global roaming and access—the ability to use
a cell phone anywhere worldwide. At this point, the 4G wireless system
would truly go into a "one size fits all" category, having a
feature set that meets the needs of just about everyone.
Ø A article
Wireless Enters the 4th(G) Dimension Jim Lipman
Ø
Search
Engine Google.
Ø
‘Emerging
wireless technologies’ by Eiman Mohyeldin,
Dr. Egon Schulz.
Ø
Flarion
Technologies - Products and Technology - FLASH-OFDM Technology.htm.
Ø
‘4G
wireless technology’ by Jason Devaney.
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