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ABSTRACT
Currently 2G Technology (GSM), or second generation technology, is
widely used worldwide for cell phone networks. The problem with 2G
technology is that the data rates are limited. This makes it inefficient for data
transfer applications such as video conferencing, music or video downloads.
To increase the speed, various new technologies have been in development.
One of these, 4G technology, is mainly made up of high-speed wireless
networks designed to carry data, rather than voice or a mixture of the two.
4G transfers data to and from mobile devices at broadband speeds – up
to100 Mbps moving and 1Gbps while the phone is stationary. In addition to
high speeds, the technology is more robust against interference and tapping
guaranteeing higher security. This innovative technology functions with the
aid of VoIP, IPv6, and Orthogonal frequency division multiplexing
(OFDM).
To cater the growing needs of 4G, mobile data communication providers
will deploy multiple antennas at transmitters to increase the data rate. Unlike
the 3G networks, which are a mix of circuit switched and packet switched
networks, 4G will be based on packet switching only (TCP/IP). This will
allow low-latency data transmission. Furthermore, the use of IP to transfer
information will require IPv6 to facilitate the use of more cell phone devices.
During the presentation, an overview of the various generations of mobile
device technologies preceding 4G would be followed by technical aspects of
4G and how it functions, as well as the way it can lead to future innovations
in cellular and communication technology
INTRODUCTION
4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used
to describe the next complete evolution in wireless communications. A 4G system will be
able to provide a comprehensive IP solution where voice, data and streamed multimedia can
be given to users on an "Anytime, Anywhere" basis, and at higher data rates than previous
generations.
As the second generation was a total replacement of the first generation networks and
handsets; and the third generation was a total replacement of second generation networks and
handsets; so too the fourth generation cannot be an incremental evolution of current 3G
technologies, but rather the total replacement of the current 3G networks and handsets. The
international telecommunications regulatory and standardization bodies are working for
commercial deployment of 4G networks roughly in the 2012-2015 time scale. At that point it
is predicted that even with current evolutions of third generation 3G networks, these will tend
to be congested.
There is no formal definition for what 4G is; however, there are certain objectives
that are projected for 4G. These objectives include: that 4G will be a fully IP-based
integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds
both indoors and outdoors, with premium quality and high security. Many companies have
taken self-serving definitions and distortions about 4G to suggest they have 4G already in
existence today, such as several early trials and launches of WiMax, which is part of the
formal ITU standard for 3G. Other companies have made prototype systems calling those
4G. While it is possible that some currently demonstrated technologies may become part of
4G, until the 4G standard or standards have been defined, it is impossible for any company
currently to provide with any certainty wireless solutions that could be called 4G cellular
networks that would conform to the eventual international standards for 4G. These confusing
statements around "existing" 4G have served to confuse investors and analysts about the wireless industry
HISTORY
The history and evolution of mobile service from the 1G (first generation) to fourth
generation are discussed in this section. Table 1 presents a short history of mobile telephone
technologies. 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. Many fundamental problems were solved by
these early systems.
Numerous incompatible analog systems were placed in service around the world
during the 1980s.The 2G (second generation) systems designed in the 1980s were still used
mainly for voice applications but were based on digital technology, including digital signal
processing techniques. These 2G systems provided circuit-switched data communication
services at a low speed. The competitive rush to design and implement digital systems led
again to a variety of different and incompatible standards such as GSM (global system
mobile), mainly in Europe; TDMA (time division multiple access) (IS-54/IS-136) in the
U.S.; PDC (personal digital cellular) in Japan; and CDMA (code division multiple
access) (IS-95), another U.S. system. These systems operate nationwide or internationally
and are today's mainstream systems, although the data rate for users in these system is very
limited. During the 1990s, two organizations worked to define the next, or 3G, mobile
system, which would eliminate previous incompatibilities and become a truly global system.
The 3G system would have higher quality voice channels, as well as broadband data
capabilities, up to 2 Mbps. Unfortunately, the two groups could not reconcile their
differences, and this decade will see the introduction of two mobile standards for 3G. In
addition, China is on the verge of implementing a third 3G system.An interim step is being
taken between 2G and 3G, the 2.5G. It is basically an enhancement 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. A very important aspect of 2.5G
is that the data channels are optimized for packet data, which introduces access to
the Internet from mobile devices, whether telephone, PDA (personal digital assistant), or
laptop. However, the demand for higher access speed multimedia communication in today's
society, which greatly
depends on computer communication in digital format, seems unlimited. According to the
historical indication of a generation revolution occurring once a decade, the present appears
to be the right time to begin the
research on a 4G mobile communication system
VISION 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 infrastructures.
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 key concept is integrating the 4G capabilities with all of the existing mobile
technologies
through advanced technologies.Application adaptability and being highly 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. Figure 1 illustrates elements and techniques to support
the adaptability of the 4G domain. 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
available. These services and models need to be further examined for their interface with the
design of 4G systems. Figures 2 and 3 demonstrate the key elements and the seamless
connectivity of the networks.
Objectives of 4G
4G is being developed to accommodate the quality of service (QoS) and rate
requirements set by forthcoming applications like wireless broadband access, Multimedia
Messaging Service (MMS), video chat, mobile TV, HDTV content, Digital Video
Broadcasting (DVB), minimal service like voice and data, and other streaming services for "anytime-anywhere". The 4G working group has defined the following as objectives of the
4G wireless communication standard:
A spectrally efficient system (in bits/s/Hz and bits/s/Hz/site),
High network capacity: more simultaneous users per cell,
A nominal data rate of 100 Mbit/s while the client physically moves at high speeds
relative to the station, and 1 Gbit/s while client and station are in relatively fixed
positions as defined by the ITU-R,
A data rate of at least 100 Mbit/s between any two points in the world,
Smooth handoff across heterogeneous networks,
Seamless connectivity and global roaming across multiple networks,
High quality of service for next generation multimedia support (real time audio, high
speed data, HDTV video content, mobile TV, etc)
Interoperability with existing wireless standards,and
An all IP, packet switched network.
In summary, the 4G system should dynamically share and utilise network resources to meet
the minimal requirements of all the 4G enabled users.
3.2. An "All IP Network" (AIPN)
A characteristic of so-called "4G" networks such as LTE is that they are
fundamentally based upon TCP/IP, the core protocol of the Internet, with higher level
services such as voice, video, and messaging, built on top of this. In 2004, the 3GPP
proposed this as the future of UMTS and began feasibility studies into the so-called All IP
Network (AIPN.) These proposals, which included recommendations in 2005 for 3GPP
Release 7 (though some aspects were in releases as early as 4), form the basis of the effort to
build the higher level protocols of evolved UMTS. The LTE part of this effort is called the
3GPP System Architecture Evolution.
At a glance, the UMTS back-end becomes accessible via a variety of means, such as
GSM's/UMTS's own radio network (GERAN, UTRAN, and E-UTRAN), WiFi, and even
competing legacy systems such as CDMA2000 and WiMAX. Users of non-UMTS radio
networks would be provided with an entry-point into the IP network, with different levels of
security depending on the trustworthiness of the network being used to make the connection.
Users of GSM/UMTS networks would use an integrated system where all authentication at
every level of the system is covered by a single system, while users accessing the UMTS
network via WiMAX and other similar technologies would handle the WiMAX connection
one way (for example, authenticating themselves via a MAC or ESN address) and the UMTS
link-up another way.
3.3. Developments
The Japanese company NTT DoCoMo has been testing a 4G communication system
prototype with 4x4 MIMO called VSF-OFCDM at 100 Mbit/s while moving, and 1 Gbit/s
while stationary. NTT DoCoMo recently reached 5 Gbit/s with 12x12 MIMO while moving
at 10 km/h,and is planning on releasing the first commercial network in 2010.
Digiweb, an Irish fixed and wireless broadband company, has announced that they
have received a mobile communications license from the Irish Telecoms regulator, ComReg.
This service will be issued the mobile code 088 in Ireland and will be used for the provision
of 4G Mobile communications.
Pervasive networks are an amorphous and at present entirely hypothetical concept
where the user can be simultaneously connected to several wireless access technologies and
can seamlessly move between them. These access technologies can be Wi-Fi, UMTS, EDGE,
or any other future access technology. Included in this concept is also smart-radio (also
known as cognitive radio technology) to efficiently manage spectrum use and transmission
power as well as the use of mesh routing protocols to create a pervasive network.
Sprint plans to launch 4G services in trial markets by the end of 2007 with plans to
deploy a network that reaches as many as 100 million people in 2008.. and has announced
WiMax service called Xohm. Tested in Chicago, this speed was clocked at 100 Mbit/s.
Verizon Wireless announced on September 20, 2007 that it plans a joint effort with the
Vodafone Group to transition its networks to the 4G standard LTE. The time of this transition
has yet to be announced.
The German WiMAX operator Deutsche Breitband Dienste (DBD) has launched
WiMAX services (DSLonair) in Magdeburg and Dessau. The subscribers are offered a tariff
plan costing 9.95 euros per month offering 2 Mbit/s download / 300 kbit/s upload connection
speeds and 1.5 GB monthly traffic. The subscribers are also charged a 16.99 euro one-time
fee and 69.90 euro for the equipment and installation. DBD received additional national
licenses for WiMAX in December 2006 and have already launched the services in Berlin,
Leipzig and Dresden.
American WiMAX services provider Clearwire made its debut on Nasdaq in New
York on March 8, 2007. The IPO was underwritten by Merrill Lynch, Morgan Stanley and JP
Morgan. Clearwire sold 24 million shares at a price of $25 per share. This adds $600 million
in cash to Clearwire, and gives the company a market valuation of just over $3.9 billion.