GOVERNMENT POLY TECHNIC COLLEGE

EZHUKONE

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

SEMINAR REPORT

ON

“4G MOBILE COMMUNICATIONS”

SUBMITTED BY

AKHIL.M

ROLL NO: 04

REG NO:10200518

FIFTH SEMESTER DIPLOMA IN ELECTRONIC AND COMMUNICATION

2011-2012

GOVERNMENT POLY TECHNIC COLLEGE

EZHUKONE

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

SEMINAR REPORT 2012-2013

CERTIFICATE

Certified that the seminar work entitled “4G MOBILE COMMUNICATIONS” is a

bonafide work presented by AKHIL.M bearing REG NO 10200518 in a partial

fulfillment for the award of the diploma in electronics and communication of the

government polytechnic college,ezhukone, during the year 2012-13. The

seminar report has been approved as it satisfies the academic requirements

with respect to seminar work presented for the diploma in Engineering.

Staff in charge Head of the

Department

ABSTRACT

The modern communication system is aimed to reach the real world one

environment from virtual world via connecting resources of one with another

through social network system. The communication process is aggravated

various infrastructural development to reach in their current level such as 3G

and 4G communication system. The user expectation also increased to meet

their personal and social application. The users are try to integrate the personal

and social network technology with real time operation for their personal and

business objectives. This pepper is provided technological features of an

existing 4G communication technological and its architecture

CONTENTS

1. ABSTRACT

2. INTRODUCTION

3. HISTORY

4. SYMBOLS:

5. 3G OR 3RD GENERATION MOBILE TELECOMMUNICATIONS

6. VISION OF 4G

7. TRANSMISSION

8. KEY 4G TECHNOLOGIES

9. QUALITY OF SERVICE

10. SECURITY

11. BENEFITS

12. WIRELESS SYSTEM DISCOVERY

13. RE-CONFIGURABLE TECHNOLOGY

14. RE-CONFIGURABLE TECHNOLOGY CHALLENGES:

15. IPv6 SUPPORT

16. RE-CONFIGURABLE TECHNOLOGY BENEFITS

17. PERSONAL MOBILITY:

18. CONCLUSION

19. REFERENCES

INTRODUCTION

In telecommunications, 4G is the fourth generation of cellular wireless

standards. It is a successor to the 3G and 2G families of standards. In 2008, the

ITU-R organization specified the IMT-Advanced (International Mobile

Telecommunications Advanced) requirements for 4G standards, setting peak

speed requirements for 4G service at 100 Mbit/s for high mobility

communication (such as from trains and cars) and 1 Gbit/s for low mobility

communication (such as pedestrians and stationary users).

A 4G system is expected to provide a comprehensive and secure all-IP

based mobile broadband solution to laptop computer wireless modems, smart

phones, and other mobile devices. Facilities such as ultra-broadband Internet

access, IP telephony, gaming services, and streamed multimedia may be

provided to users.

Pre-4G technologies such as mobile WiMAX and first-release 3G Long

term evolution (LTE) have been on the market since 2006 and 2009

respectively, and are often branded as 4G. The current versions of these

technologies did not fulfill the original ITU-R requirements of data rates

approximately up to 1 Gbit/s for 4G systems. Marketing materials use 4G as a

description for Mobile-WiMAX and LTE in their current forms.

IMT-Advanced compliant versions of the above two standards are under

development and called ―LTE Advanced‖ and ―WirelessMAN-Advanced‖

respectively. ITU has decided that ―LTE Advanced‖ and ―WirelessMAN-

Advanced‖ should be accorded the official designation of IMT-Advanced. On

December 6, 2010, ITU announced that current versions of LTE, WiMax and

other evolved 3G technologies that do not fulfill "IMT-Advanced" requirements

could be considered "4G", provided they represent forerunners to IMT-Advanced

and "a substantial level of improvement in performance and capabilities with

respect to the initial third generation systems now deployed."

The approaching 4G (fourth generation) mobile communication systems

are projected to solve still-remaining problems of 3G (third generation) systems

and to provide a wide variety of new services, from high-quality voice to high-

definition video to high-data-rate wireless channels.

The term 4G is used broadly to include several types of broadband

wireless access communication systems, not only cellular telephone systems.

One of the terms used to describe 4G is MAGIC—Mobile multimedia, anytime

anywhere, Global mobility support, integrated wireless solution, and customized

personal service. As a promise for the future, 4G systems, that is, cellular

broadband wireless access systems have been attracting much interest in the

mobile communication arena. The 4G systems not only will support the next

generation of mobile service, but also will support the fixed wireless networks.

This article presents an overall vision of the 4G features, framework, and

integration of mobile communication.

The features of 4G systems might be summarized with one word-

Integration. The 4G systems are about seamlessly integrating terminals,

networks, and applications to satisfy increasing user demands. The continuous

expansion of mobile communication and wireless networks shows evidence of

exceptional growth in the areas of mobile subscriber, wireless network access,

mobile services, and applications. An estimate of 1 billion users by the end of

2013 justifies the study and research for 4G systems.

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 systems. 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.

Technology 1G 2G 2.5G 3G 4G

Design Began 1970 1980 1985 1990 2000

Implementati

on

1984 1991 1999 2002 2010?

Service Analog

voice,

synchron

-ous data

to 9.6

kbps

Digital

voice,

short

messages

Higher

capacity,

packetized

data

Higher

capacity,

broadband

data up to 2

Mbps

Higher

capacity,

completely

IP- Oriented,

multimedia,

data to

hundreds Of

megabits

Standards AMPS,

TAGS,

INMT,

etc.

TDMA,

CDMA,

GSM

PDC

GPRS,

EDGE,

1XRTT

WCDMA,

CDMA2000

Single

standard

Data 1.9 kbps 14.4 kbps 384 kbps 2 Mbps 200 Mbps

Bandwidth

Multiplexing FDMA TDMA,

CDMA

TDMA

CDMA

CDMA CDMA?

core Network PSTN PSTN P3TK,

packet

network

Packet

network

internet

SYMBOLS :

1xRTT = 2.5G CDMA data service up to 384 kbps

AMPS = Advanced Mobile Phone Service

CDMA = Code Division Multiple Access

EDGE = Enhanced Data for Global Evolution

FDMA = Frequency Division Multiple Access

GPRS = General Packet Radio System

GSM = Global System for Mobile

NMT = Nordic Mobile Telephone

PDC = Personal Digital Cellular

PSTN = Public Switched Telephone Network

TACS = Total Access Communications System

TDMA = Time Division Multiple Access

WCDMA = Wideband CDMA

Time division multiple access (TDMA)

TDMA is a channel access method for shared medium networks. It allows

several users to share the same frequency channel by dividing the signal into

different time slots. The users transmit in rapid succession, one after the other,

each using its own time slot. This allows multiple stations to share the same

transmission medium (e.g. radio frequency channel) while using only a part of

its channel capacity. TDMA is used in the digital 2G cellular systems such as

Global System for Mobile Communications (GSM), IS-136, Personal Digital

Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless

Telecommunications (DECT) standard for portable phones. It is also used

extensively in satellite systems, combat-net radio systems, and PON networks

for upstream traffic from premises to the operator. For usage of Dynamic TDMA

packet mode communication, see below.

TDMA frame structure showing a data stream divided into frames and those

frames divided into time slots.

TDMA is a type of Time-division multiplexing, with the special point that instead

of having one transmitter connected to one receiver, there are multiple

transmitters. In the case of the uplink from a mobile phone to a base station

this becomes particularly difficult because the mobile phone can move around

and vary the timing advance required to make its transmission match the gap

in transmission from its peers.

TDMA CHARACTERISTICS

Shares single carrier frequency with multiple users

Non-continuous transmission makes handoff simpler

Slots can be assigned on demand in dynamic TDMA

Less stringent power control than CDMA due to reduced intra cell

interference

Higher synchronization overhead than CDMA

Advanced equalization may be necessary for high data rates if the

channel is "frequency selective" and creates Inter symbol interference

Cell breathing (borrowing resources from adjacent cells) is more

complicated than in CDMA

Frequency/slot allocation complexity

Pulsating power envelope: Interference with other devices

2G TECHNOLOGIES

2G technologies can be divided into TDMA-based and CDMA-based standards

depending on the type of multiplexing used. The main 2G standards are:

GSM (TDMA-based), originally from Europe but used in almost all

countries on all six inhabited continents. Today accounts for over 80% of

all subscribers around the world. Over 60 GSM operators are also using

CDMA2000 in the 450 MHz frequency band (CDMA450).[2]

IS-95 aka cdma One (CDMA-based, commonly referred as simply CDMA in

the US), used in the Americas and parts of Asia. Today accounts for about

17% of all subscribers globally. Over a dozen CDMA operators have

migrated to GSM including operators in Mexico, India, Australia and South

Korea.

PDC (TDMA-based), used exclusively in Japan

iDEN (TDMA-based), proprietary network used by Nextel in the United

States and Telus Mobility in Canada

IS-136 a.k.a. D-AMPS (TDMA-based, commonly referred as simply 'TDMA'

in the US), was once prevalent in the Americas but most have migrated to

GSM.

2G services are frequently referred as Personal Communications Service, or

PCS, in the United States.

CAPACITIES, ADVANTAGES, AND DISADVANTAGES

CAPACITY

Using digital signals between the handsets and the towers increases system

capacity in two key ways:

Digital voice data can be compressed and multiplexed much more

effectively than analog voice encodings through the use of various codes,

allowing more calls to be packed into the same amount of radio

bandwidth.

The digital systems were designed to emit less radio power from the

handsets. This meant that cells had to be smaller, so more cells had to be

placed in the same amount of space. This was made possible by cell

towers and related equipment getting less expensive.

ADVANTAGE

While digital calls tend to be free of static and background noise, the lossy

compression used by the codes takes a toll; the range of sound that they

convey is reduced. You will hear less of the tonality of someone's voice

talking on a digital cell phone, but you will hear it more clearly.

DISADVANTAGES

In less populous areas, the weaker digital signal may not be sufficient to

reach a cell tower. This tends to be a particular problem on 2G systems

deployed on higher frequencies, but is mostly not a problem on 2G

systems deployed on lower frequencies. National regulations differ greatly

among countries which dictate where 2G can be deployed.

Analog has a smooth decay curve, digital a jagged steppy one. This can

be both an advantage and a disadvantage. Under good conditions, digital

will sound better. Under slightly worse conditions, analog will experience

static, while digital has occasional dropouts. As conditions worsen,

though, digital will start to completely fail, by dropping calls or being

unintelligible, while analog slowly gets worse, generally holding a call

longer and allowing at least a few words to get through.

EVOLUTION

2G networks were built mainly for voice services and slow data transmission.

Some protocols, such as EDGE for GSM and 1x-RTT for CDMA2000, are defined

as "3G" services (because they are defined in IMT-2000 specification

documents), but are considered by the general public to be 2.5G or 2.75G

services because they are several times slower than present-day 3G service.

2.5G (GPRS)

2.5G ("second and a half generation") is used to describe 2G-systems that

have implemented a packet-switched domain in addition to the circuit-switched

domain. It does not necessarily provide faster services because bundling of

timeslots is used for circuit-switched data services (HSCSD) as well.

The first major step in the evolution of GSM networks to 3G occurred with the

introduction of General Packet Radio Service (GPRS). CDMA2000 networks

similarly evolved through the introduction of 1xRTT. The combination of these

capabilities came to be known as 2.5G.

GPRS could provide data rates from 56 kbit/s up to 115 Kbit/s. It can be used for

services such as Wireless Application Protocol (WAP) access, Multimedia

Messaging Service (MMS), and for Internet communication services such as

email and World Wide Web access. GPRS data transfer is typically charged per

megabyte of traffic transferred, while data communication via traditional circuit

switching is billed per minute of connection time, independent of whether the

user actually is utilizing the capacity or is in an idle state.

1xRTT supports bi-directional (up and downlink) peak data rates up to

153.6 kbit/s, delivering an average user data throughput of 80-100 kbit/s in

commercial networks.[3] It can also be used for WAP, SMS & MMS services, as

well as Internet access.

2.75G (EDGE)

GPRS1 networks evolved to EDGE networks with the introduction of 8PSK

encoding. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS

(EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile

phone technology that allows improved data transmission rates, as an

extension on top of standard GSM. EDGE was deployed on GSM networks

beginning in 2003—initially by Cingular (now AT&T) in the United States.

EDGE is standardized by 3GPP as part of the GSM family and it is an upgrade

that provides a potential three-fold increase in capacity of GSM/GPRS networks.

The specification achieves higher data-rates (up to 236.8 kbit/s) by switching to

more sophisticated methods of coding (8PSK), within existing GSM timeslots.

3G OR 3RD GENERATION MOBILE TELECOMMUNICATIONS

3G or 3rd generation mobile telecommunications is a generation of

standards for mobile phones and mobile telecommunication services fulfilling

the International Mobile Telecommunications-2000 (IMT-2000)

specifications by the International Telecommunication Union.[1] Application

services include wide-area wireless voice telephone, mobile Internet access,

video calls and mobile TV, all in a mobile environment.

Several telecommunications companies market wireless mobile Internet

services as 3G, indicating that the advertised service is provided over a 3G

wireless network. Services advertised as 3G are required to meet IMT-2000

technical standards, including standards for reliability and speed (data transfer

rates). To meet the IMT-2000 standards, a system is required to provide peak

data rates of at least 200 kbit/s (about 0.2 Mbit/s). However, many services

advertised as 3G provide higher speed than the minimum technical

requirements for a 3G service. Recent 3G releases, often denoted 3.5G and

3.75G, also provide mobile broadband access of several Mbit/s to smart phones

and mobile modems in laptop computers.

The following standards are typically branded 3G:

The UMTS system, first offered in 2001, standardized by 3GPP, used

primarily in Europe, Japan, China (however with a different radio interface)

and other regions predominated by GSM 2G system infrastructure. The

cell phones are typically UMTS and GSM hybrids. Several radio interfaces

are offered, sharing the same infrastructure:

o The original and most widespread radio interface is called W-CDMA.

o The TD-SCDMA radio interface was commercialised in 2009 and is

only offered in China.

o The latest UMTS release, HSPA+, can provide peak data rates up to

56 Mbit/s in the downlink in theory (28 Mbit/s in existing services)

and 22 Mbit/s in the uplink.

The CDMA2000 system, first offered in 2002, standardized by 3GPP2,

used especially in North America and South Korea, sharing infrastructure

with the IS-95 2G standard. The cell phones are typically CDMA2000 and

IS-95 hybrids. The latest release EVDO Rev B offers peak rates of 14.7

Mbit/s downstream.00000000000000000

APPLICATIONS OF 3G

The bandwidth and location information available to 3G devices gives rise to

applications not previously available to mobile phone users. Some of the

applications are:

Mobile TV

Video on demand

Video Conferencing

Telemedicine

Location-based services

ADVANTAGE

1. The customers will get a high speed network for their communication which

is far better than the 2G technology, particularly in data communication.

2. The customer will get wireless broadband.

3. Customer can see video or satellite based programs like TV programs using

this technology.

4. Customers can use all the facilities at same time.

5. It may also be cheap than the other traditional media we are using, as a

result of price war.

6. The many in one service will be available at the same network. Due to use of

the DTH & the 3G technology, everyone will use these multi-purpose services to

avoid time loss and keeping records for different service providers.

DISADVANTAGE

1. Since in telecom sector, there is much competition, so the companies have a

very marginal price for their facilities.

2. The companies who will not get license from the spectrum distribution

authorities will suffer to use only 2G, which will badly affect their business. In

this situation these companies will either disappear from this sector or will run

with losses. Because of the customers will start to use the services of the

companies having 3G technology.

3. Due to use of the DTH & the 3G technology, everyone will use these multi-

purpose services to avoid time loss and keeping records for different service

providers. So the traditional cable business will badly affected by implementing

this new technology.

4. The radiation of magnetic waves generated with the heavily use of the

wireless system will affect our life also. More uses of the services will have more

effect on us. The radiations of the magnetic waves are danger for our life. A

long use can affect our brains.

5. The mobile are not suitable devices to see TV or web browsing. So, initially

this service may be used in mass but in future, mobile can not be used to see

the TV or for Internet surfing. This will affect the business of 3G.

Thus we see here that the disadvantages are more than the advantages of the

3G technology from the service providers as well as from customer point of

view. Also, it will cause to damage the existence of some businesses like cable

operator business or 2G service. So, some of these may be kept in mind while

we implement the 3G technology.

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 2 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 3 and4 demonstrate the key elements and the seamless

connectivity of the networks.

Figure 2 4G Mobile Communication Visions

Figure 3. Seamless Connections of Networks

Figure 4. Key Elements of 4G Vision

TRANSMISSION

An OFDM transmitter accepts data from an IP network, converting and encoding

the data prior to modulation. An IFFT (inverse fast Fourier transform) transforms

the OFDM signal into an IF analog signal, which is sent to the RF transceiver.

The receiver circuit reconstructs the data by reversing this process. With

orthogonal sub‐carriers, the receiver can separate and process

IP NETWORK

OFDM

TRANSMITTER

MODULATION

IFFT making

IF analog

RF TRANSMITTER

ODFM provides better link and communication quality.

KEY 4G TECHNOLOGIES

Some of the key technologies required for 4G are briefly described below:

ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDMA)

Orthogonal Frequency Division Multiplexing (OFDM) not only provides clear

advantages for physical layer performance, but also a framework for improving

layer 2 performance by proposing an additional degree of free- dom. Using

OFDM, it is possible to exploit the time domain, the space domain, the

frequency domain and even the code domain to optimize radio channel usage.

It ensures very robust transmission in multi-path 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 (multiple-input and multiple-

output)radar antenna .OFDM modulation can also be employed as a multiple

access technology (Orthogonal Frequency Division Multiple Access). In this

case, each OFDM symbol can transmit information to/from several users using a

different set of sub carriers (sub channels). This not only provides additional

flexibility for resource allocation (increasing the capacity), but also enables

cross-layer optimization of radio link usage.

SOFTWARE DEFINED RADIO

Software Defined Radio (SDR) benefits from today's high processing

power to develop multi-band, multi-standard base stations and terminals.

Although in future the terminals will adapt the air interface to the available

radio access technology, at present this is done by the infrastructure. Several

infrastructure gains are expected from SDR. For example, to increase network

capacity at a specific time (e.g. during a sports event), an operator will

reconfigure its network adding several modems at a given Base Transceiver

Station (BTS). SDR makes this reconfiguration easy. In the context of 4G

systems, SDR will become an enabler for the aggregation of multi-standard Pico

/micro cells. For a manufacturer, this can be a powerful aid to providing multi-

standard, multi-band equipment with reduced development effort and costs

through simultaneous multi-channel processing.

Figure 6. An Ideal Software Radio Receiver

MULTIPLE-INPUT MULTIPLE -OUTPUT

MIMO uses signal multiplexing between multiple transmitting antennas (space

multiplex) and time or frequency. It is well suited to OFDM, as it is possible to

process independent time symbols as soon as the OFDM waveform is correctly

designed for the channel. This aspect of OFDM greatly simplifies processing.

The signal transmitted by m antennas is received by n antennas. Processing of

the received signals may deliver several performance improvements range,

quality of received signal and spectrum efficiency. In principle, MIMO is more

efficient when many multiple path signals are received. The performance in

cellular deployments is still subject to research and simulations. However, it is

generally admitted that the gain in spectrum efficiency is directly related to the

minimum number of antennas in the link.

HANDOVER AND MOBILITY

Handover technologies based on mobile IP technology have been considered for

data and voice. Mobile IP techniques are slow but can be accelerated with classical

methods (hierarchical, fast mobile IP). These methods are applicable to data and probably

also voice. In single-frequency networks, it is necessary to reconsider the handover

methods. Several techniques can be used when the carrier to interference ratio is negative

(e.g. Variable Spreading Factor Orthogonal Frequency and code Division Multiplexing

(VSFOFDM), bit repetition), but the drawback of these techniques is capacity. In OFDM,

the same alternative exists as in CDMA, which is to use macro-diversity. In the case of

OFDM, MIMO allows macro-diversity processing with performance gains. However, the

implementation of macro-diversity implies that MIMO processing is centralized and

transmissions are synchronous. This is not as complex as in CDMA, but such a technique

should only be used in situations where spectrum is very scarce.

QUALITY OF SERVICE

What QoS does 4G provide to us they are as follows:-

(a) Traffic generated by the different services will not only increase traffic

loads on the networks, but will also require different quality of service (QoS)

requirements (e.g., cell loss rate, delay, and jitter) for different streams (e.g.,

video, voice, and data).

(b) Providing QoS guarantees in 4G networks is a non-trivial issue where

both QoS signaling across different networks and service differentiation

between mobile flows will have to be addressed.

(c) One of the most difficult problems that are to be solved, when it comes

to IP mobility, is how to insure the constant QoS level during the handover.

(d) Depending on whether the new access router is in the same or some

other sub network, we recognize the horizontal and vertical handover.

(e) However, the mobile terminal cannot receive IP packets while the

process of handover is finished. This time is called the handover latency.

(f) Handover latency has a great influence on the flow of multimedia

applications in real-time.

(g) Mobile IPv6 has been proposed to reduce the handover latency and

the number of lost packets.

(h) The field "Traffic Class" and "Flow Label" in IPv6 header enables the

routers to secure the special QoS for specific packet series with marked priority.

SECURITY

Security is a major issue in today’s convergence communication world what

securities does 4G provide to us they are as follows:-

(a) The heterogeneity of wireless networks complicates the security issue.

(b) Dynamic reconfigurable, adaptive, and lightweight security mechanisms

should be developed.

(c) Security in wireless networks mainly involves authentication, confidentiality,

integrity and authorization for the access of network connectivity and QoS

resources for the mobile nodes flow.

(d) AAA (Authentication Authorization Auditing) protocols provide a framework

for such suffered especially for control plane functions and installing security

policies in the mobile node such as encryption, decryption and filtering.

BENEFITS

(a) Convergence of cellular mobile networks and WLANs

(i) Benefits for Operators:

(aa) Higher bandwidths.

(ab) Lower cost of networks and equipment.

(ac) The use of license-exempt spectrum.

(ad) Higher capacity and QoS enhancement.

(ae) Higher revenue.

(ii) Benefits for Users:

(aa) Access to broadband multimedia services with lower cost and

where mostly needed.

(ab) Inter-network roaming.

(b) Convergence of mobile communications and broadcasting

(i) From broadcaster point of view:

Introducing interactivity to their unidirectional point-to multipoint

Broadcasting systems. That is, a broadband downlink based on DAB/DVB-T

(Digital Audio Broadcasting/Digital Video Broadcasting – Television) and a

narrowband uplink based on 3G cellular systems.

(ii) From the cellular mobile operator point of view:

Providing a complementary broadband downlink in vehicular

environments to support IP- based multi-media traffic which is inherently

asymmetrical.

(c) Convergence benefits

(i) Broadcasters will benefit from the use of cellular mobile systems to adapt the

content of their multi-media services more rapidly in response to the feedback from

customers.

(ii) Cellular operators will benefit from offering their customers a range of new

broadband multimedia services in vehicular environments.

(iii) Users will benefit from faster access to a range of broadband multi-media

services with reasonable Quality of Service (QoS) and lower cost.

WIRELESS SYSTEM DISCOVERY

(a) A multimode terminal attaches to the WLAN and scans the available

systems. It can download suitable software manually or automatically.

RE-CONFIGURABLE TECHNOLOGY

(a)In order to use the large variety of services and wireless networks, multimode user terminals are essential as they can adapt to different wireless networks by reconfiguring themselves

(b)This eliminates the need to use multiple terminals (or multiple hardware components in a terminal).

(c) The most promising way of implementing multimode user terminals is to

adopt the software radio approach.

Figure 5. 4G wireless: one view shown wireless system discovery

RE-CONFIGURABLE TECHNOLOGY CHALLENGES:

(a) Regulatory and Standardization issues

(b) Business models

(c) Flexible spectrum allocation and sharing between operators

(d) User preference profiles

(e) Inter-system handover mechanisms and criteria

(f) Software downloads mechanisms

IPv6 SUPPORT

Unlike 3G, which is based on two parallel infrastructures consisting of

circuit switched and packet switched network nodes respectively, 4G will be

based on packet switching only. This will require low-latency data transmission.

By the time that 4G was deployed, the process of IPv4 address

exhaustion was expected to be in its final stages. Therefore, in the context of

4G, IPv6 support is essential in order to support a large number of wireless-

enabled devices. By increasing the number of IP addresses, IPv6 removes the

need for network address translation (NAT), a method of sharing a limited

number of addresses among a larger group of devices, although NAT will still be

required to communicate with devices that are on existing IPv4 networks.

RE-CONFIGURABLE TECHNOLOGY BENEFITS FOR:

(a) USERS:

(i) Select network depending on service requirements and cost.

(ii) Connect to any network - Worldwide roaming.

(iii) Access to new services.

(b) OPERATORS:

(i) Respond to variations in traffic demand (load balancing).

(ii) Incorporate service enhancements and improvements.

(iii) Correction of software bugs and upgrade of terminals.

(iv) Rapid development of new personalized and customised services.

(c) MANUFACTURERS:

(i) Single platform for all markets.

(ii) Increased flexible and efficient production.

PERSONAL MOBILITY:

In addition to terminal mobility, personal mobility is a concern in

mobility management. Personal mobility concentrates on the movement of

users instead of users' terminals, and involves the provision of personal

communications and personalized operating environments. Once the caller's

agent identifies user's location, the caller's agent can directly communicate

with his agent.

APPLICATIONS

(a) VIRTUAL PRESENCE: This means that 4G provides user services at all

times, even if the user is off-site.

(b) VIRTUAL NAVIGATION: 4G provides users with virtual navigation

through which a user can access a database of the streets, buildings etc.

(c) TELE-GEOPROCESSING APPLICATIONS: This is a combination of GIS

(Geographical Information System) and GPS (Global Positioning System) in

which a user can get the location by querying.

(d) TELE-MEDICINE AND EDUCATION: 4G will support remote health

monitoring of patients. For people who are interested in lifelong

education, 4G provides a good opportunity.

(e) CRISIS MANAGEMENT: Natural disasters can cause breakdown in

communication systems. In today's world it might take days or 7 weeks to

restore the system. But in 4G it is expected to restore such crisis issues in

a few hours.

MULTIMEDIA - VIDEO SERVICES

4G wireless systems are expected to deliver efficient multimedia

services at very high data rates.

Basically there are two types of video services: bursting and

streaming video services.

Streaming is performed when a user requires real-time video

services, in which the server delivers data continuously at a

playback rate.

Bursting is basically file downloading using a buffer and this is

done at the highest data rate taking advantage of the whole

available bandwidth.

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. In few countries like South Korea and

Japan 4G was launched in 2010 and the world is looking forward for the most

intelligent technology that would connect the entire globe. In India, Mukesh

Ambani’s Reliance Communications conducted trial for 4G in India, got 80 Mbps

Download Speed.

In all suggestions for 4G, the CDMA spread spectrum radio

technology used in 3G systems and IS-95 is abandoned and replaced by OFDMA

and other frequency-domain equalization schemes. This is combined with MIMO

(Multiple in Multiple Out), e.g., multiple antennas, dynamic channel allocation

and channel-dependent scheduling.

REFERENCES

1) Communication Systems

2) www.comsoc.org

3) www.techonline.com

4) www.ieee.org