17-06-2013, 01:01 PM
Latest Trends in Wireless Mobile Communication (3G to 4G Technologies)
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Abstract
Consumers demand more from their technology.
Whether it is a television, cellular phone, or refrigerator, the
latest technology purchase must have new features. With the
advent of the Internet, the most-wanted feature is better, faster
access to information. Cellular subscribers pay extra on top of
their basic bills for such features as instant messaging, stock
quotes, and even Internet access right on their phones. To
support such a powerful system, we need pervasive, high-speed
wireless connectivity. A number of technologies currently exist
to provide users with high-speed digital wireless connectivity;
Bluetooth and 802.11 are examples. These two standards
provide very high-speed network connections over short
distances, typically in the tens of meters. The goal is the same:
long-range, high-speed wireless, which for the purposes of this
report will be called 4G, for fourth-generation wireless system.
Fourth-generation wireless needs to be standardized due to its
enticing advantages to both users’ and providers. Each
generation is characterized by new frequency bands, higher
data rates and non backwards compatible transmission
technology.
INTRODUCTION
Until the controversial spectrum scams were brought up in the lime light
many were ignorant of what 1G, 2G or 3G stood for and all of a sudden
a hike was found out amongst laymen so as to be knowledgeable about
it. Still a number of people are unaware of 1G or 2G when the world has
moved on to 4G.The telecommunication service in World had a great
leap within a last few year. . 6 billion people own a mobile phones so
we are going to analyze the various generations of cellular systems as
studied in the evolution of mobile communications from 1st generation
to 5th generation .Now almost all the service provide as well as the
customers seek for availing these 3G and 4G services. We can analyze
that this could be due to increase in the telecoms customers day by day.
In the present time, there are four generations in the mobile industry.
These are respectively 1G the first generation, 2G the second
generation, 3G the third generation, and then the 4G the fourth
generation. Ericson a Swedish company is launching this high tech
featured mobile into the market. It is being first introduced in the
Swedish Capital city, Stockholm. The Brief description of the
generations of mobile communication is given in below.
CURRENT TECHNOLOGY
The two Technologies currently used are time-division multiple
access (TDMA) or code-division multiple access (CDMA) these
two technologies are collectively referred to as secondgeneration,
or 2G.
TDMA
TDMA, or Time Division Multiple Access, is a technique for
dividing the time domain up into sub channels for use by
multiple devices. Each device gets a single time slot in a
procession of devices on the network, as seen in Figure 3.
During that particular time slot, one device is allowed to utilize
the entire bandwidth of the spectrum, and every other device is
in the quiescent state.
CDMA
CDMA, or Code Division Multiple Access, allows every device
in a cell to transmit over the entire bandwidth at all times. Each
mobile device has a unique and orthogonal code that is used to
encode and recover the signal (Leon-Garcia and Widjaja 2000).
The mobile phone digitizes the voice data as it is received.
APPLICATIONS OF 4G
With the increase in the data rates, the mobile phones are made
to perform higher performance applications. In 4G the mobile
phone is not only for calling but it’s something extraordinary
device that can be used for variety of purposes. One such
application in 4G is context awareness. For example if the
mobile user is passing by an office where he/she is having an
appointment to meet someone and they have forgotten the
appointment. If the office location, address and geographical
location matches the one user has already stored in the phone,
he/she will receive information about the appointment and will
be reminded that you need to perform this activity. Telemedicine
is another application of 4G [8]. Using telemedicine a patient
can send general reading like temperature, glucose level and
blood pressure to the doctor online. Or if someone needs to
know about their family member’s health continuously they can
receive all the information through telemedicine by using 4G
technology.
SECURITY
Security in digital world means to protect the digital systems
from criminal and unauthorized usage. In terms of computers
and mobile communications the need for security has increased
overwhelmingly with the improvement in technology. In
attempting to avoid security problems like those that plagued the
first-generation cellular systems, engineers must design security
into any new technology it cannot be added as an afterthought.
Unfortunately, this is no easy task. Implementing good security
requires that security be designed into every aspect of the
system; otherwise, a security leak exists. There can be many
attacks on digital data some of them are eavesdropping, man in
the middle attack, denial of service (DOS) attack, spoofing and
lot more.Before seeking to design and implement wireless
security, however, one first needs to understand what this elusive
concept of security really means. In this case, wireless security is
really a combination of wireless channel security (security of the
radio transmission) and network security (security of the wired
network through which the data flows).
CONCLUSION
In this paper we are describing about the various wireless mobile
technologies, and various applications of 4G mobile
communication as well as the LTE (Long Term Evolution). And
also we describe about various networks we are used in 4G, such
as MIMO and OFDMA Evolution, in that we discus about
FDMA, CDMA, as well as TDMA. And also describes the
Security, Quality of Service in 4G. We present the challenges
that 4G faces and their up-to-date solutions. To improve the QoS
in 4G we propose our own scheme of combining mobility
protocol SMIP and application layer protocol SIP. With this
scheme the QoS level in 4G can be improved because both the
protocols provide support in handovers. Together they can
decrease the packet loss and can improve security during the
handover process. We can make sure the resource allocation
during the handover process by combining the two protocols and
mobility management can be optimized.