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3GUMTS

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ABSTRACT

Third generation (3G) is an evolution of todays digital cellular systems. High-speed data

capabilities will provide an array of services not available to todays users. These services

should be available wherever subscribers roam not just in their home network. 3G willoffer mobile subscribers new high-speed and multimedia wireless data Services such as

video, file transfer, e-mail, web browsing, video-conferencing, and so on. One of the

main characteristics of the 3G evolution will be its integration with the Internet. Thehigher bandwidths will enable a wide variety of services. Universal MobileTelephone System: A 3G specification for mobile telephony, based onWCDMA technology, part of the ITUs IMT-2000 family of standards for3G mobile networks.

Cellular mobile telecommunications and the World Wide Web are growing at an exciting

pace. In the year 1999 both GSM and the Internet reached more than 200 million

registered users globally. Thus, it may be expected that users will demand thecombination of mobility and multi-media services in a foreseeable period. Multi-mediacontent increases and differentiates with the changing information society, and an even

richer variety of audio, visual, and text-based information will be required in the future.

UMTS, the Universal Mobile Telecommunications Sys-tem, a member of the IMT-2000family of third-generation systems, will provide these services. UMTS standardization

has set a new paradigm of timely market-driven standardization in a global partnership of

standardization bodies. In this paper, we have included UMTS architecture, interference,services, security etc.

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TABLE OF CONTENT1. BACKGROUND.....................................................................................................5

2. WHAT IS UMTS?...................................................................................................6

3. A Better Understanding of 3G UMTS.....................................................................6

4. Hierarchical cell structure........................................................................................95. UMTS Network Architecture .................................................................................9

6. UMTS Interfaces ..................................................................................................22

7. NETWORK DEVELOPMENT.............................................................................258. Data rate.................................................................................................................26

9. Spectrum................................................................................................................27

10. Operation modes....................................................................................................2711. Services..................................................................................................................31

12. UMTS Location Based Services

...............................................................................................................................3313. Conclusion.............................................................................................................40

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BACKGROUND

Current forecasts indicate that demand for wireless access to global telecommunication

will reach one billion users by year 2010. Exceeding the likely no. of wired or fixed

access lines further if internet access, which has been doubling every year since 1988continuous to grow at this level the existing fix network, will be eclipsed in the every

near future. The emerging internet environment urgently required support for symmetric

interactive multimedia traffic based on high-speed packet data transport such rapidlyservice requirements driven by global users of telecommunications would dramatically

change the telecommunication service and the underlying networks in the 21st century.

The underlying vision for emerging mobile and personal communication services for the

new century is to enable communication with the person at any time at any place and in

any form with a paradigm shift from current focus on voice and low speed data services

to high-speed data and multimedia services. The current second generation digital mobile

and personal communication system are based on national and regional standard that areoptimized for region or countrys specific regulatory and operating environment. They

are therefore enable to interoperate with each other and can provide mobility only withinthat radio environment as well as within geographical regions in which specific standard

is operational .

Efforts are therefore underway at international as well as regional\national levels to

define the so-called third generation telecommunication that will meet the coming needs

of telecommunications subscribers. It is well recognized that international and global

standard for mobile telecommunication are needed, not only to ensure seamless globalmobility and service delivery but also for integrating wire line and wireless networks to

provide telecommunication services to transparently to the users this global standardsmust be flexible enough to meet local needs and to allow current national\regionalsystems to evolve smoothly towards the third generation systems.

The international telecommunication union (ITU), the unite nation organizationsresponsible for global telecommunication standard has been working since 1986 toward

developing an international standard for wireless access to worldwide

telecommunication infrastructure this standard known as IMT2000 for internationalmobile telecommunication 2000 where 2000 indicates target availability date as well as

operational radio frequency band (2000MHz) range for standards.

IMT-2000 is intended to form the basis for third-generation (3G) wireless systems, whichwill consolidate todays diverse and incompatible mobile environments into a seamless

radio and network infrastructure capable to offering a wide range of telecommunication

services on a global scale. Within the ITU, the radio aspects for IMT-2000, especially theselection of radio transmission technology (radio interface) and spectrum usage, are

addressed in the radio communication sector (ITU-R), whereas the network aspects,

which include definition of network signaling interfaces, services, numbering andidentities, quality of service, security, and operations and management for IMT-2000, are

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addressed by the Telecommunications Standardization Sector (ITU-T). The specifications

are captured in the so-called ITU Recommendations (voluntary standards), which provide

the essential backbone for worldwide telecommunications. Work is also under way inregional\national standards forums like ETSI (Europe), the TIA and T1 committees

(North America), and TTC (Japan) on third-generation wireless systems that complement

and provide inputs and direction to the IMT-2000 activities in the ITU.

WHAT IS UMTS?

UMTS (Universal Mobile Telecommunications System) is the European vision of a third

generation mobile communication system. It is designed to continue the global success of

the European second-generation mobile communication system GSM (Global System forMobile communication) which had, in December 1998, about 100 million customers and

300 operators worldwide. UMTS is one of the Third Generation (3G) mobile systems

being developed within the ITU's IMT-2000 framework. It is a realization of a new

generation of broadband multi-media mobile telecommunications technology. Thecoverage area of service provision is to be world wide in the form of FLMTS (Future

Land Mobile Telecommunications Services and now called IMT2000). The coverage willbe provided by a combination of cell sizes ranging from 'in building' Pico Cells to Global

Cells provided by satellite, giving service to the remote regions of the world. The UMTS

is not a replacement of 2nd generation technologies (e.g. GSM, DCS1800, CDMA,

DECT etc.), which will continue to evolve to their full potential.

A Better Understanding of 3G UMTS

Third Generation (3G) cellular technology promises a mobile and fixed wirelessenvironment that allows international roaming and high speed access to a variety of

services including voice communication, multi-media information, commerce,

entertainment and basic computing. Building on earlier 2G technologies, telecomnetwork designers face a major challenge in understanding the myriad of industry

standards that underlie 3G today.

3G clearly marks an important a major step forward in the evolution of

telecommunications network technology. Taking evolution as the watchword and

recognizing that 3G has many roots in earlier technologies, one useful way to understand3G is to apply a concept from evolutionary biology called cladistics.

Cladistics is a method of analyzing evolutionary relationships to construct a family tree.

The objective is to discover key relationships by determining primitive and derivedcharacteristics. Primitive characteristics are inherited from a common ancestor and are

the attributes that belong to all members of a group. Derived characteristics are the

advanced traits that can be found only in some members of a group. The study ofcladistics may also give clues to future evolutionary relationships.

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Figure 1 is a simple cladistics diagram that shows the evolution of the transportation

industry. In this diagram, the primitive characteristic is wheels; a characteristic that all

members of the group share. There are two derived or advanced characteristics in thisgroup; three members (the automobile, airplane and space shuttle) have engines while

two members (the airplane and space shuttle) have wings.

The focus of cladistics is to determine differentiating (or derived) features. For 3Gtechnology however, we must also be concerned about how the common (or primitive)

features are changing over time. Accordingly, we might note that wheels, engines and

wings have undergone improvements over time:

Wings > cloth > metal> composites

Engine > internal combustion > jet. Chemical Wheels > wood > rubber > belted > radial

When we look at 3G UMTS technology, we can see origins from 2G (GSM) and 2.5G

(GPRS and EDGE). In Figure 2, the primitive characteristic is GSM; a common base oftechnology that all members of the group support. There are three derived characteristics

GPRS, EDGE and UMTS , which are progressively supported by 2.5G, 2.5G+, and

3G as shown.

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If we focus on just the 3G-UMTS world as in Figure 3, we can see how the technical

specifications and standards are evolving. It should be noted that the 3GPP organization

has the primary responsibility for setting standards for 3G UMTS and that newtechnical standards and revisions are being issued every 3 months!

On a much more detailed level, the important primitive characteristics for Release 99,

Release 4 and Release 5, as well, as how some of the derived characteristics have been

improved from 3GPP release to 3GPP release.

Unlike the evolutionary patterns and processes spanning billions of years revealed in

biological cladistics, todays telecommunications technologies are evolving at anexplosive and ever faster rate. The specifications for 3G network technologies are

complex and subject to revision several times a year. 3G networks must comply with

these rapidly evolving standards while supporting the legacy infrastructures. By taking acladistics approach, network designers have a valuable intellectual tool for making sense

of the complexity of the emerging 3G environment, and meeting the challenge ofdesigning, building and testing the 3G networks for tomorrow.

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Hierarchical cell structure

UMTS will offer global radio coverage and worldwide roaming. For that purpose, theURAN will be built in a hierarchical way in layers of varying coverage. A higher layer

will cover a larger geographical area than a lower layer. In the highest layer there will be

satellites covering the whole planet, the lower layers form the UMTS terrestrial radio

access network UTRAN. They are divided into macro-, micro- and Pico layer. Each layeris divided into cells. The lower the hierarchical level, the smaller the cells. Smaller cells

allow for a higher user-density. Therefore macro cells are used for land-wide coverage,additional micro cells are installed in areas with higher population density and Pico cellsin buildings and for so called "hot spots" (e.g. airports, railway stations

UMTS Network Architecture

UMTS is a network consisting of two main elements connected over a standard interface,called Iu. These two elements are:

UTRAN(UMTS Terrestrial Radio Access Network). This is composed of Node B,

which is equivalent to the GSM BTS and the Radio Network Controller (RNC),

which is equivalent to the GSM BSC. A novelty with the UTRAN concept is theexistence of a new modulation scheme: the Frequency Division Duplex (FDD)

and W-CDMA. This mode offers the highest efficiency within a single systemwhatever the conditionswide area, urban, indoor coverage from outdoor,

indoor, and so on. One carrier use 5 MHz.

The Core Network. This is the equivalent of the GSM NSS. There are two

options for the implementation of 3G and the evolution of the GSM Core

Network:

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ATM based architecture: this R'99 architecture may reuses in some cases the two-

domain architecture of GSM/GPRS, with:

Iu-PS (Packet Switched) interface instead of Gb on the packet domain

Iu-CS (Circuit Switched) interface instead of A on the circuit domain

Transport Independent and multimedia architecture: this R'00 architecture is in

line with the Next Generation Networks architecture and introduces separation ofcontrol and user planes. It also integrates multimedia capabilities.

UMTS Incorporates enhanced GSM Phase 2+ Core Networks with GPRS and CAMEL.

This enables network operators to enjoy the improved cost-efficiency of UMTS while

protecting their 2G investments and reducing the risks of implementation.

In UMTS release 1 a new radio access network UMTS terrestrial radio access network(UTRAN) is introduced. UTRAN, the UMTS radio access network (RAN), is connected

via the Iu to the GSM Phase 2+ core network (CN). The Iu is the UTRAN interface

between the radio network controller (RNC) and CN; the UTRAN interface betweenRNC and the packet-switched domain of the CN (IuPS) is used for PS data and the

UTRAN interface between RNC and the circuit-switched domain of the CN (IuCS) is

used for CS data.

"GSMonly" mobile stations (MSs) will be connected to the network via the GSM air(radio) interface (Um). UMTS/GSM dual-mode user equipment (UE) will be connected

to the network via UMTS air (radio) interface (Uu) at very high data rates (up to almost 2

Mbps). Outside the UMTS service area, UMTS/GSM UE will be connected to thenetwork at reduced data rates via the Um.

Maximum data rates are 115 kbps for CS data by HSCSD, 171 kbps for PS data by

GPRS, and 553 kbps by EDGE. Handover between UMTS and GSM is supported, and

handover between UMTS and other 3G systems (e.g., multicarrier CDMA [MCCDMA]) will be supported to achieve true worldwide access.

Figure 1 Transmission Rate

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The public land mobile network (PLMN) described in UMTS incorporates three major

categories of network elements:

GSM Phase 1/2 core network elements: mobile services switching center (MSC),

visitor location register (VLR), home location register (HLR), authenticationcenter (AC), and equipment identity register (EIR)

GSM Phase 2+ enhancements: GPRS (serving GPRS support node [SGSN] and

gateway GPRS support node [GGSN]) and CAMEL (CAMEL serviceenvironment [CSE])

UMTS specific modifications and enhancements, particularly UTRAN

Network Elements from GSM Phase 1/2

The GSM Phase 1/2 PLMN consists of three subsystems: the base station subsystem

(BSS), the network and switching subsystem (NSS), and the operations support system(OSS). The BSS consists of the functional units: base station controller (BSC), base

transceiver station (BTS), transcoder, and rate adapter unit (TRAU). The NSS consists of

the functional units: MSC, VLR, HLR, EIR, and the AC. The MSC provides functionssuch as switching, signaling, paging, and interMSC handover. The OSS consists of

operation and maintenance centers (OMCs), which are used for remote and centralized

operation, administration, and maintenance (OAM) tasks.

Figure 2 UMTS Phase 1 Network

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Network Elements from GSM Phase 2+

GPRS

The most important evolutionary step of GSM toward UMTS is GPRS. GPRS introduces

PS into the GSM CN and allows direct access to packet data networks (PDNs). Thisenables highdata rate PS transmission well beyond the 64 kbps limit of ISDN through

the GSM CN, a necessity for UMTS data transmission rates of up to 2 Mbps. GPRSprepares and optimizes the CN for highdata rate PS transmission, as does UMTS with

UTRAN over the RAN. Thus, GPRS is a prerequisite for the UMTS introduction.

Two functional units extend the GSM NSS architecture for GPRS PS services: the GGSN

and the SGSN. The GGSN has functions comparable to a gateway MSC (GMSC). TheSGSN resides at the same hierarchical level as a visited MSC (VMSC)/VLR and

therefore performs comparable functions such as routing and mobility management.

CAMEL

CAMEL enables worldwide access to operator-specific IN applications such as prepaid,call screening, and supervision. CAMEL is the primary GSM Phase 2+ enhancement for

the introduction of the UMTS virtual home environment (VHE) concept. VHE is a

platform for flexible service definition (collection of service creation tools) that enables

the operator to modify or enhance existing services and/or define new services.Furthermore, VHE enables worldwide access to these operator-specific services in every

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GSM and UMTS PLMN and introduces location-based services (by interaction with

GSM/UMTS mobility management). A CSE and a new common control signaling system

7 (SS7) (CCS7) protocol, the CAMEL application part (CAP), are required on the CN tointroduce CAMEL.

Network Elements from UMTS Phase 1

As mentioned above, UMTS differs from GSM Phase 2+ mostly in the new principles for

air interface transmission (WCDMA instead of time division multiple access[TDMA]/frequency division multiple access [FDMA]). Therefore, a new RAN called

UTRAN must be introduced with UMTS. Only minor modifications, such as allocation of

the transcoder (TC) function for speech compression to the CN, are needed in the CN toaccommodate the change. The TC function is used together with an interworking

function (IWF) for protocol conversion between the A and the IuCS interfaces.

UTRAN

The UMTS standard can be seen as an extension of existing networks. Two new network

elements are introduced in UTRAN, RNC, and Node B. UTRAN is subdivided intoindividual radio network systems (RNSs), where each RNS is controlled by an RNC. The

RNC is connected to a set of Node B elements, each of which can serve one or several

cells.

Figure 3 UMTS Phase 1: UTRAN

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Existing network elements, such as MSC, SGSN, and HLR, can be extended to adopt the

UMTS requirements, but RNC, Node B, and the handsets must be completely new

designs. RNC will become the replacement for BSC, and Node B fulfills nearly the samefunctionality as BTS. GSM and GPRS networks will be extended, and new services will

be integrated into an overall network that contains both existing interfaces such as A, Gb,

and Abis, and new interfaces that include Iu, UTRAN interface between Node B andRNC (Iub), and UTRAN interface between two RNCs (Iur). UMTS defines four new

open interfaces:

Uu: UE to Node B (UTRA, the UMTS WCDMA air interface

Iu: RNC to GSM Phase 2+ CN interface (MSC/VLR or SGSN)o Iu-CS for circuit-switched data

o Iu-PS for packet-switched data

Iub: RNC to Node B interface

Iur: RNC to RNC interface, not comparable to any interface in GSM

The Iu, Iub, and Iur interfaces are based on ATM transmission principles.

The RNC enables autonomous radio resource management (RRM) by UTRAN. It

performs the same functions as the GSM BSC, providing central control for the RNSelements (RNC and Node Bs).

The RNC handles protocol exchanges between Iu, Iur, and Iub interfaces and is

responsible for centralized operation and maintenance (O&M) of the entire RNS with

access to the OSS. Because the interfaces are ATMbased, the RNC switches ATM cellsbetween them. The users circuit-switched and packet-switched data coming from IuCS

and IuPS interfaces are multiplexed together for multimedia transmission via Iur, Iub,

and Uu interfaces to and from the UE.

The RNC uses the Iur interface, which has no equivalent in GSM BSS, to autonomouslyhandle 100 percent of the RRM, eliminating that burden from the CN. Serving control

functions such as admission, RRC connection to the UE, congestion and handover/macro

diversity are managed entirely by a single serving RNC (SRNC).

If another RNC is involved in the active connection through an interRNC soft handover,it is declared a drift RNC (DRNC). The DRNC is only responsible for the allocation of

code resources. A reallocation of the SRNC functionality to the former DRNC is possible

(serving radio network subsystem [SRNS] relocation). The term controlling RNC

(CRNC) is used to define the RNC that controls the logical resources of its UTRANaccess points.

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Figure 4 RNC Functions

Node B

Node B is the physical unit for radio transmission/reception with cells. Depending on

sectoring (omni/sector cells), one or more cells may be served by a Node B. A single

Node B can support both FDD and TDD modes, and it can be co-located with a GSMBTS to reduce implementation costs. Node B connects with the UE via the WCDMA

Uu radio interface and with the RNC via the Iub asynchronous transfer mode (ATM)

based interface. Node B is the ATM termination point.

The main task of Node B is the conversion of data to and from the Uu radio interface,

including forward error correction (FEC), rate adaptation, WCDMA

spreading/dispreading, and quadrature phase shift keying (QPSK) modulation on the air

interface. It measures quality and strength of the connection and determines the frameerror rate (FER), transmitting these data to the RNC as a measurement report for

handover and macro diversity combining. The Node B is also responsible for the FDD

softer handover. This micro diversity combining is carried out independently, eliminatingthe need for additional transmission capacity in the Iub.

The Node B also participates in power control, as it enables the UE to adjust its power

using downlink (DL) transmission power control (TPC) commands via the inner-loop

power control based on uplink (UL) TPC information. The predefined values for inner-loop power control are derived from the RNC via outer-loop power control.

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Figure5. Node B Overview

UMTS UE

The UMTS UE is based on the same principles as the GSM MSthe separation betweenmobile equipment (ME) and the UMTS subscriber identity module (SIM) card (USIM).

Figure 6 shows the user equipment functions. The UE is the counterpart to the various

network elements in many functions and procedures.

Figure 6 UE Functions

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w-cdma

The mainprinciple

of Spread

Spectrum

communication is that the bandwidth

occupancy is much higher than usual.Because of this much larger bandwidth

the power spectral density is lower, in

the channel the signal just looks like noise. The Spreading is done by combining the datasignal with a code (code division multiple access) which is independent of the transmitted

data message.

A number of advantages are:

As the signal is spread over a large frequency-band, the Power Spectral Density is

getting very small, so other communications systems do not suffer from this kind of

communications. However the Gaussian Noise level is increasing.Random Access can be dealt with, as a large number of codes can be generated a large

number of users can be permitted.

The maximal number of users is interference limited.

Security: without knowing the spreading code, it is (nearly) impossible to recover thetransmitted data.

Fading rejection: as a large bandwidth is used the system is less susceptible to

distortions.

There are a couple of Spread Spectrum Techniques which can be used. The most famous

one is Direct-Sequence (DS) also well-known is Frequency-Hopping (FH). Acombination of these two (DS/FH) offers a lot of advantages over the other two and will

be the basis of the proposed system.

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Direct Sequence

Direct Sequence is the most famous Spread Spectrum Technique. The data signal is

multiplied by a Pseudo Random Noise Code (PN-code).

A PN-code is a sequence of chips valued -1 and 1 (polar) or 0 and 1 (non-polar). Thenumber of chips within one code is called the period of this code. A PN-code is a noise-

like code with certain properties.

Several classes of binary (2-phase) PN-codes exist: M-sequences (base), Gold-codes and

Kasami-codes. There exists also 4-phase codes , these aren't taken into account yet. APN-code can be created by means of one or more shiftregisters. When the length of such

a shiftregister is , in general the following can be said about the period N

N = 2^n -1

In the most simple case a complete PN-code is multiplied with a single data bit (seefigure, in this example N=7). The bandwidth of the data signal is now multiplied by a

factor N this factor is said to be the processing gain.

So the resulting bandwidth is large, The Power Spectral Density has the shape of a

SINc^2-function in case of using a m-sequence as PN-code. When using another PN-code (such as a Kasami-code) the shape of the PSD is different. As the total power

doesn't change during spreading, the Power Spectral Density decreases, it is evenpossible that the resulting PSD sinks below the noise level. Direct Sequence spreading

can be seen as a form of BPSK-modulation, just multiplying a signal by +1or-1.

In the receiver, the received signal is again multiplied by the same (synchronized) PN-

code, since this operation removes the PN-code we are left with the initial data-signal.

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As despreading is the same operation as spreading a possible jammer-signal in the radio

channel is spread before the data-detection is done. Also this jammer won't cause us any

problems, see figure:

The main Problem with Direct Sequence is the Near-Far effect. If there are more then oneusers active, the transmitted power of non-reference users is suppressed by a factor

dependent on the (partial) cross correlation between the code of the reference user and the

code of a non-reference user. However when a non-reference user is closer to the receiver

then the reference-user, it is possible that the interference caused by this non-referenceuser (however suppressed) has more power the reference user. Now only the non-

reference user will be received, this nasty property is called the near-far effect.

One way to beat the near-far effect can be exploited in cellular systems. In such systemsthe base station takes care that all users have such a power that the received power at the

base station is equal for all users.

In non-cellular systems the influence of the near-far effect can be reduced by using the

frequency-hopping spread spectrum technique.

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Frequency Hopping

When using Frequency Hopping, the carrier frequency is 'hopping' according to a knownsequence (of length Nfh). In this way the bandwidth is also increased. If the channels are

non-overlapping the factor of spreading is, Nfh). this factor is equal to the Processing

Gain. The process of frequency hopping is shown below:

There are two kinds of Frequency Hopping Techniques.

Slow Frequency Hopping (SFH)In this case one or more data bits are transmitted within one Frequency Hop. An

advantage is that coherent data detection is possible. A disadvantage is that if one

frequency hop channel is jammed, one or more data bits are lost. So we are forced touse error correcting codes.

Fast Frequency Hopping (FFH)

In this technique one data bit is divided over more Frequency Hops. Now errorcorrecting codes are not needed. An other advantage is that diversity can be applied.

Every frequency hop a decision is made whether a -1 or a 1 is transmitted, at the end of

each data bit a majority decision is made. A disadvantage is that coherent data

detection is not possible because of phase discontinuities. The applied modulationtechnique should be FSK or MFSK.

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As nearby non-reference users are not constantly in the same frequency slot a the

reference user, the near-far effect has less influence.

Hybrid System: DS/(F)FH

The DS/FFH Spread Spectrum technique is a combination of direct-sequence and

frequency-hopping. One data bit is divided over frequency-hop channels (carrier

frequencies). In each frequency-hop channel one complete PN-code of length is added tothe data signal (see figure, where Nfh is taken to be 5). Using the FFH scheme in stead of

the SFH scheme causes the bandwidth to increase, this increase however is neglectable

with regard to the enormous bandwidth already in use.

As the FH-sequence and the PN-codes are coupled, an address is a combination of an FH-sequence and NfhPN-codes. To bound the hit-chance (the chance that two users share the

same frequency channel in the same time) the frequency-hop sequences are chosen in

such a way that two transmitters with different FH-sequences share at most twofrequencies at the same time (timeshift is random). From Jack P.F. Glas

Difference between regular CDMA and W-CDMA

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UMTS Interfaces

Many new protocols have been developed for the four new interfaces specified in UMTS:Uu, Iub, Iur, and Iu.

General Protocol Model [3G TS 25.401]

UTRAN interface consists of a set of horizontal and vertical layers (see Figure1). The

UTRAN requirements are addressed in the horizontal radio network layer across differenttypes of control and user planes. Control planes are used to control a link or a connection;

user planes are used to transparently transmit user data from the higher layers. Standardtransmission issues, which are independent of UTRAN requirements, are applied in the

horizontal transport network layer.

Figure 1 UTRAN InterfaceGeneral Protocol Model

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Five major protocol blocks are shown in Figure 1

i. Signaling bearers are used to transmit higher layers signaling and control

information. They are set up by O&M activities.

ii. Data bearers are the frame protocols used to transport user data (data streams).The transport networkcontrol plane (TNCP) sets them up.

iii. Application protocols are used to provide UMTSspecific signaling and control

within UTRAN, such as to set up bearers in the radio network layer.

iv. Data streams contain the user data that is transparently transmitted between the

network elements. User data is comprised of the subscribers personal data and

mobility management information that are exchanged between the peer entitiesMSC and UE.

v. Access link control application part (ALCAP) protocol layers are provided in the

TNCP. They react to the radio network layers demands to set up, maintain, andrelease data bearers. The primary objective of introducing the TNCP was to

totally separate the selection of the data bearer technology from the control plane

(where the UTRANspecific application protocols are located). The TNCP is

present in the IuCS, Iur, and Iub interfaces. In the remaining interfaces wherethere is no ALCAP signaling, preconfigured data bearers are activated.

Simplified UMTS coding process

This is a short overview how data stream is modified during processing in layer 2 and 1

in downlink direction. Uplink coding is done in a similar way.

Ciphering happens in RCL or MAC-d part of the layer 2. f8 algorithm gets five inputs to

generate a keystream block that is ciphered by binary addition to a data stream. Channel

coding separates different down link connection to users within a cell. In the uplink

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direction Channel coding is used for separation of physical data and control channels.

Half-rate and 1/3-rate convolutional coding is used for low data rates, turbo coding is

used for higher bit rates. Channel coding includes the spreading.

Rate matching is dynamic frame-by-frame operation and done either by puncturing or by

repetition of the data stream. Interleaving is done in two stages. It is first done by inter-frame and then by intra-frame. Scrambling is used to separate base stations in downlink

direction and user terminal is uplink direction. After scrambling down link channels are

summarised, synchronisation code is added and signal is QSPK modulated.

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Main UMTS Codes

Here us a summary of the main UMTS codes:

Synchronisation

CodesChannelisation

CodesScrambling

Codes, ULScrambling

Codes, DL

Type

Gold Codes

Primary

Synchronization

Codes (PSC) and

SecondarySynchronization

Codes (SSC)

OrthogonalVariable Spreading

Factor (OVSF)

codes

sometimes calledWalsh Codes

Complex-Valued

Gold CodeSegments (long)

or Complex-

Valued S(2)Codes (short)

Pseudo Noise

(PN) codes

Complex-

Valued Gold

Code Segments

Pseudo Noise(PN) codes

Length 256 chips 4-512 chips38400 chips /

256 chips38400 chips

Duration 66.67 s1.04 s -

133.34 s10 ms / 66.67 s 10 ms

Number of

codes

1 primary code / 16

secondary codes

= spreading factor4 ... 256 UL,

4 ... 512 DL

16,777,216

512 primary /15 secondary

for each

primary code

SpreadingNo, does not change

bandwidthYes, increasesbandwidth

No, does not

changebandwidth

No, does not

changebandwidth

Usage

To enable terminals tolocate and

synchronise to the

cells' main control

channels

UL: to separate

physical data and

control data fromsame terminal

DL: to separate

connection to

different terminalsin a same cell

Separation of

terminal

Separation of

sectors

NETWORK DEVELOPMENT

The development of UMTS has got two aspects, the radio access network and the corenetwork. The radio access network comprises the mobile station (handy), the base station

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(transceiver, antenna, controller) and the radio interface between them. The core network

consists of nodes (switches) with connecting lines. This core network does not only

connect the base stations with each other but offers also gateways to other networks(ISDN, Internet,..)

The core network of UMTS is an evolution of the present GSM-core network. The radioaccess network of UMTS, especially the method of radio transmission (radio interface), is

revolutionary new. The UMTS radio access network URAN will not be an evolution ofthe GSM radio access network. However, the GSM radio acces network will be in use

and also under development even after the introduction of UMTS. This means that there

will be a common core network but two independent radio access networks for UMTSand for GSM. The UMTS radio access network will allow for multimedia applications

because of the larger bandwith of the radio channels (5 MHz instead of 200 kHz in GSM)

and the new access method CDMA (Code division multiple access). Multimedia inUMTS means that the simultaneous transfer of speech, data, text, pictures, audio and

video with a maximum data rate of 2 Mbit/s will be possible. Transmission of speech and

low data rate applications will go on to be carried out by GSM (lower price); at leastduring the first years after the introduction of UMTS around 2002.

Data rate

The maximum data rate and the maximum speed of the user are different in each

hierarchical layer. In the macro layer at least 144 kbit/s with maximum speed of 500

km/h shall be possible. In the micro layer 384 kbit/s with maximum speed of 120 km/hshall be supported. The Pico layer offers up to 2 Mbit/s with a maximum speed of 10

km/h. It shall be possible for the user to trade off bit error rate versus delay in certain

limits. For real-time applications with constant delay (speech, video) the bit error rate canbe in the range of 10-3 to 10-7, the maximum delay can be in the range of 20 ms to 300

ms. For non-real-time applications (e-mail, SMS) with variable delay the bit error rate

can be in the range of 10-5 and 10-8. The maximum delay can be 150 ms and more

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Spectrum

The spectrum for UMTS lies between 1900 MHz to 2025 MHz and 2110 MHz to 2200

MHz. For the satellite service an own sub band in the UMTS spectrum is reserved (uplink1980 MHz to 2010 MHz, downlink 2170 MHz to 2200 MHz). The remaining spectrum

for terrestrial use is divided between two modes of operation. In the FDD (FrequencyDivision Duplex) mode, there are two equal bands for the uplink (1920 MHz to 1980MHz) and for the downlink (2110 MHz to 2170 MHz). In the operation mode, TDD

(Time division duplex) uplink and downlink are not divided by use of different frequency

carriers but by using different timeslots on the same carrier. Therefore, there is no needfor a symmetrical spectrum but the remaining unpaired spectrum can be used.

Operation modes

The operation in FDD mode is assigned for macro- and micro cells, the operation in TDD

mode is assigned for Pico cells. The TDD mode does not allow large propagation delays

between mobile station and base station, as this would cause a collision between transmit-and receive timeslots. Therefore this mode can only be used in environments where the

propagation delay is small (Pico cells). Yet the TDD mode has the advantage that a largeasymmetry of data transfer between uplink and downlink is possible. Many internetapplications are characterized by large asymmetry of data transfer as more data is

received (downlink) than transmitted (uplink). The FDD mode uses a different multiple

access method (W-CDMA) than the TDD mode (TD-CDMA Time Division CDMA).

This decision has not only technology reasons but it is a political compromise betweendifferent groups in ETSI (European Telecommunication Standards Institute).

Spectrumfor UMTS-

1920 MHz - 1980 MHz FDD Uplink

2110 MHz - 2170 MHz FDD Downlink1900 MHz - 1920 MHz

TDD2010 MHz - 2025 MHz

1980 MHz - 2010 MHz MSS (Mobile Satellite Service) Uplink

2170 MHz - 2200 MHz MSS Downlink

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THE SPREADING PROCESS

WCDMA uses Direct Sequence spreading, where spreading process is done by directlycombining the baseband information to high chip rate binary code. The Spreading Factor

is the ratio of the chips (UMTS = 3.84Mchips/s) to baseband information rate. Spreading

factors vary from 4 to 512 in FDD UMTS. Spreading process gain can in expressed indBs (Spreading factor 128 = 21dB gain).

HANDOVER

When a mobile phone is moving, it will be traveling through different cells. If the mobilephone is not engaged in a call, it will tell the network every now and then, that it has

moved to another cell. If the mobile phone is engaged in a call, the call of course needs to

be maintained while the phone is moving. The process of replacing communication withone cellular radio station with another is called handover.

Even while engaged in a call, the mobile phone is scanning the frequencies for other

cells, and reporting the signal strength received from those cells to the cellular network.When the cellular network sees the mobile phone moving closer and closer to another

cell, it will initiate the handover process, during which the call will be transferred from

one cellular radio station to another.

Handover occurs when a call has to be passed from one cell to another as the user movesbetween cells. In a traditional "hard" handover, the connection to the current cell isbroken, and then the connection to the new cell is made. This is known as a "break-

before-make" handover. Since all cells in CDMA use the same frequency, it is possible to

make the connection to the new cell before leaving the current cell. This is known as a"make-before-break" or "soft" handover. Soft handovers require less power, which

reduces interference and increases capacity. Mobile can be connected to more that two

BTS the handover. "Softer" handover is a special case of soft handover where the radio

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links that are added and removed belong to the same Node B.

CDMA soft handover

UMTS Power Control

Open loop power control is the ability of the UE transmitter to sets its outputpower to a specific value. It is used for setting initial uplink and downlink

transmission powers when a UE is accessing the network. The open loop powercontrol tolerance is 9 dB (normal conditions) or 12 dB (extreme conditions)

Inner loop power control (also called fast closed loop power control) in the

uplink is the ability of the UE transmitter to adjust its output power in accordance

with one or more Transmit Power Control (TPC) commands received in thedownlink, in order to keep the received uplink Signal-to-Interference Ratio (SIR)

at a given SIR target. The UE transmitter is capable of changing the output power

with a step size of 1, 2 and 3 dB, in the slot immediately after the TPC_cmd canbe derived. Inner loop power control frequency is 1500Hz.

The serving cells estimate SIR of the received uplink DPCH, generate TPCcommands (TPC_cmd) and transmit the commands once per slot according to the

following rule: if SIRest > SIRtarget then the TPC command to transmit is "0",

while if SIRest < SIRtarget then the TPC command to transmit is "1". Uponreception of one or more TPC commands in a slot, the UE derives a single TPC

command for each slot, combining multiple TPC commands if more than one is

received in a slot. Two algorithms are supported by the UE for deriving a

TPC_cmd. Which of these two algorithms is used, is determined by a UE-specific

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higher-layer parameter, "PowerControlAlgorithm".

Algorithm 1:

The power control step is the change in the UE transmitter output power in

response to a single TPC command

Algorithm 2:

If all five estimated TPC command are "down" the transmit power is reduced by

1 dB

If all five estimated TPC command are "up" the transmit power is increased by 1

dB

Otherwise the transmit power is not changed

Transmitter power control range

The transmit power of the downlinkchannels is determined by the network. The power

control step size can take four values: 0.5, 1, 1.5 or 2 dB. It is mandatory for UTRAN tosupport step size of 1 dB, while support of other step sizes is optional. The UE generates

TPC commands to control the network transmit power and send them in the TPC field ofthe uplink DPCCH. Upon receiving the TPC commands UTRAN adjusts its downlinkDPCCH/DPDCH power accordingly.

Outer loop power control is used to maintain the quality of communication at the levelof bearer service quality requirement, while using as low power as possible. The uplinkouter loop power control is responsible for setting a target SIR in the Node B for each

individual uplink inner loop power control. This target SIR is updated for each UEaccording to the estimated uplink quality (BLock Error Ration, Bit Error Ratio) for each

Radio Resource Control connection. The downlinkouter loop power control is the ability

of the UE receiver to converge to required link quality (BLER) set by the network (RNC)

in downlink.

Power control of the downlink common channels are determined by the network. In

general the ratio of the transmit power between different downlink channels is notspecified in 3GPP specifications and may change with time, even dynamically.

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Services

From the user point of view the main advantage of UMTS will be a broad offer of

services. Speed, variety and user-friendliness of the services will be significantlyimproved as compared with GSM. For example the download of a foto from the internet

that takes one minute in GSM with 9.6 kbit/s will last only half a second in UMTS with 2

Mbit/s. In order to increase the variety of services and the competition between operatorsETSI defines only a framework for the services. Only so-called bearer services will be

standardized specifying bit rate, bit error rate and delay time. The actual application (incl.

man-machine interface) from the users point of view is called teleservice. A teleservicecan make use of several bearer services. Teleservices can be created independently by

each service provider or network operator and offered in the network to the customers.

Exception: Four UMTS teleservices will be standardized completely by ETSI, these are

speech, fax, SMS and emergency call.

In the following some examples of UMTS (tele-) services are given:

Information services:-

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www-browsing interactive shopping on-line newspaper on-line translation

location based broadcasting services

intelligent search- and filtering facilities

Education

virtual schools

on-line science lab on-line library on-line language labs

training

Entertainment

audio on demand games video clips

virtual sightseeing

Business services

mobile office narrowcast business TV

virtual workgroups

Finance services

virtual banking on-line billing universal USIM card and credit card

Community services

emergency call administration services

democratic procedures

Telemetric

Road transport logistics Remote Control

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Terminal and USIM card

The user service identity module USIM stores the identity of the subscriber (user),operator and service provider and (at least one) user service profile. This service profile

defines the services that a customer is subscribed to, the time and the network where he

can use them. The USIM-card is a modular IC-card (integrated circuit card). It containsone or more USIMs and possibly other applications (e.g. credit card functionality). By

inserting the USIM-card into a UMTS terminal the user is recognised by the UMTS

network and can be addressed on this terminal either via his personal telephone numberor his personal email address.

In contrast to GSM there will be a multitude of different types of terminals in UMTS, e.g.multi-mode or multi-band handies, notebook-like communicators or UMTS-laptops with

camera, speakers and microphone all equipped with a USIM-card. There will be

terminals too where more than one USIM-card can be inserted. This means that someterminals (e.g. fax terminals) shall be used by several UMTS-customers simultaneously.

Convergence

UMTS stands also for the convergence of mobile and fixed line communicationnetworks. If the user is close to a fixed line network termination he will be registered

automatically in the fixed line network and will communicate via fixed line (with fixed

line tariff). His UMTS-handy works then as a cordless terminal. If he leaves the coverage

of the fixed line network termination he will be registered automatically in the mobile(cellular) network and will communicate via UTRAN (UMTS Terrestrial Radio Access

Network). His telephone number is always the same (UPT Universal Personal

Telecommunication). The term "convergence" is often used in another meaning too.During the next decades computing, telecommunication, broadcast and television will

merge together. UMTS is the mobile part of this scenario and a milestone towards its

realization.

UMTS Location Based Services

UMTS networks will support location service features, to allow new and innovative

location based services to be developed. It will be possible to identify and report in a

standard format (e.g. geographical co-ordinates) the current location of the user's terminal

and to make the information available to the user, ME, network operator, serviceprovider, value added service providers and for PLMN internal operations. The location

is provided to identify the likely location of specific MEs. This is meant to be used for

charging, location-based services, lawful interception, emergency calls, etc., as well asthe positioning services.

Location Information consists of:

Geographic Location

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Velocity (the combination of speed and heading)

Quality of Service information (horizontal & vertical accuracy and response

time)

3GPP specification also describes location based service reliability, priority,

security, privacy and other related aspects.

Location-

independentMost existing cellular services, stock prices, sports reports

PLMN orcountry

Services that are restricted to one country or one PLMN

Regional(up to 200km)

Weather reports, localized weather warnings, traffic information(pre-trip)

District

(up to 20km)Local news, traffic reports

Up to 1 km Vehicle asset management, targeted congestion avoidance advice

500m to 1kmRural and suburban emergency services, manpower planning,

information services (where are?)

100m (67%)

300m (95%)

U.S. FCC mandate (99-245) for wireless emergency calls using

network based positioning methods

75m-125mUrban SOS, localized advertising, home zone pricing, networkmaintenance, network demand monitoring, asset tracking,

information services (where is the nearest?)

50m (67%)

150m (95%)

U.S. FCC mandate (99-245) for wireless emergency calls using

handset based positioning methods

10m-50m Asset Location, route guidance, navigation

Example of location services

The table below lists the attributes of specific location based services as determined bythe GSM Alliance Services Working Group. It is possible for the network operator or

service provider to define additional, non-standardised service types.

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Location based servicescategories

Standardized Service Types

Public Safety ServicesEmergency Services

Emergency Alert Services

Location Sensitive Charging

Tracking Services

Person Tracking

Fleet Management

Asset Management

Traffic Monitoring Traffic Congestion Reporting

Enhanced Call RoutingRoadside AssistanceRouting to Nearest Commercial

Enterprise

Location Based InformationService

Navigation

City SightseeingLocalized Advertising

Mobile Yellow Pages

Service Provider Specific

Services

UE locations are reported periodically. The periodic reporting function is generallyapplicable for asset management services and exists as several variants, each applicable

to different value added services:

Location reporting only within predetermined period

e.g. commercial asset tracking and,subject to provision of privacy,manpower planning.

Periodic location reporting within specified

period and reporting triggered by a specific

event

e.g. high value asset security, stolen

vehicle monitoring, home zone charging.

Periodic location reporting triggered by a

specific event

e.g. 24hr depot management, transit

passenger information systems

A LCS Client is a logical functional entity that makes a request to the PLMN LCS serverfor the location information of one or more than one target UEs. A LCS server consists of

a number of location service components and bearers needed to serve the LCS clients.The LCS server shall provide a platform which will enable the support of location based

services in parallel to other telecommunication services such as speech, data, messaging,

other teleservices, user applications and supplementary services. Using the LocationService Request, an LCS client communicates with the LCS server to request the location

information for one or more target UEs within a specified set of quality of service

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parameters. As shown in below, a location service may be specified as immediate or

deferred.

Request

TypeResponse Time

Number of

Responses

Immediate Immediate Single

DeferredDelayed (event

driven)One or More

Location Service Requests

The LCS Server will provide, on request, the current or most recent Location

Information (if available) of the Target UE or, if positioning fails, an error indication plusoptional reason for the failure.

For emergency services (where required by local regulatory requirements), thegeographic location may be provided to an emergency services LCS Client either without

any request from the client at certain points in an emergency services call (e.g. followingreceipt of the emergency call request, when the call is answered, when the call is

released) or following an explicit request from the client. The former type of provision is

referred to as a push while the latter is known as a pull.

Type ofAccess

Information Items

Push

Current Geographic Location (if

available)

MSISDNIMSI

IMEI

NA-ESRK

NA-ESRDState of emergency call:

unanswered, answered, released

Pull

Geographic location, either:

- Current location- Initial location at start of emergency

call

Location information that may be provided

The specification Release '99 specifies the following LCS positioning methods:

Cell coverage based positioning method

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Observed Time Difference Of Arrival (OTDOA) method with network

configurable idle periods

Network assisted GPS methods

OTDOA Location Method

UMTS Security

the security functions of UMTS are based on what was implemented in GSM. Some of

the security functions have been added and some existing have been improved.Encryption algorithm is stronger and included in base station (NODE-B) to radio network

controller (RNC) interface , the application of authentication algorithms is stricter and

subscriber confidentially is tighter.

The main security elements that are from GSM:

Authentication of subscribers

Subscriber identity confidentially

Subscriber Identity Module (SIM) to be removable from terminal hardware

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Radio interface encryption

Additional UMTS security features:

Security against using false base stations with mutual authentication

Encryption extended from air interface only to include Node-B to RNC

connection Security data in the network will be protected in data storages and while

transmitting ciphering keys and authentication data in the system.

Mechanism for upgrading security features.

Core network traffic between RNCs, MSCs and other networks is not ciphered andoperators can to implement protections for their core network transmission links, but

that is unlike to happen. MSCs will have by design a lawful interception capabilities

and access to Call Data Records (SDR), so all switches will have to have securitymeasures against unlawful access.

UMTS specification has five security feature groups:

Network access security: the set of security features that provide users with secureaccess to 3G services, and which in particular protect against attacks on the (radio) access

link;

Network domain security: the set of security features that enable nodes in the

provider domain to securely exchange signalling data, and protect against attacks on the

wireline network;

User domain security: the set of security features that secure access to mobile

stations

Application domain security: the set of security features that enable applications in

the user and in the provider domain to securely exchange messages.

Visibility and configurability of security: the set of features that enables the user to

inform himself whether a security feature is in operation or not and whether the use and

provision of services should depend on the security feature.

UMTS specification has the following user identity confidentiality security features: User identity confidentiality: the property that the permanent user identity (IMSI) of

a user to whom a services is delivered cannot be eavesdropped on the radio access link;

User location confidentiality: the property that the presence or the arrival of a user in

a certain area cannot be determined by eavesdropping on the radio access link;

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User untraceability: the property that an intruder cannot deduce whether different

services are delivered to the same user by eavesdropping on the radio access link.

Air interface ciphering/deciphering in performed in RNC in the network side and in

mobile terminals. Ciphering in function of air interface protocol Radio Link Control

(RLC) layer or Medium Access control (MAC) layer.

Live 3G Networks, Updated 9th October 2002

Here is the list of officially launched WCDMA networks:

1. NTT DoCoMo, Japan, October 1, 20012. Telenor, Norway, December 1, 2001 *)

3. Manx Telecom, Isle of Man (UK), December 5, 2001 *)

4. Europolitan, Sweden, December 31, 2001 *)5. Sonera, Finland, January 1, 2002 *)

6. Radiolinja, Finland, January 3, 2002 *)

7. Mobilkom, Austria, September 25, 2002

*) Network started operation to satisfy licensing requirements, in limited areas;

beginning of commercial service depends on handset availability.

Other UMTS network that should have started operation to satisfy licensing

requirements:

Netcom, Norway, December 2001

Tele2, Norway, December 2001

Orange Sverige, Sweden, January 2002Hi3g, Sweden, January 2002

Tele2, Sweden, January 2002

Kolmegee, Finland, January 2002

Telia, Finland, January 2002

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Conclusion

Allowing operators to offer mass-market mobile multimedia services, UMTS provides a

route for the information technology and content industries to deliver new, innovative,

non-voice based services.

UMTS is a future-looking technology but one which recognizes and builds upon the

massive investments that have already been made in today's 2nd generation systems,

notably GSM . It takes a fresh approach to optimal use of valuable radio spectrum,

achieving greater spectrum efficiency and capacity compared to todays 2nd generationsystems.

Thanks to UMTS, mobile users will have access to pictures, graphics, video

communications and other wide-band information - as well as voice and data. UMTS will

build on and extend the capability of todays mobile technologies (like digital cellularand cordless) by providing increased capacity, data capability and a far greater range of

services using an innovative radio access scheme and an enhanced, evolving corenetwork.

UMTS will enable tomorrows wireless Information Society, delivering high-valuebroadband information, commerce and entertainment services to mobile users via fixed,

wireless and satellite networks. It will speed convergence between telecommunications,

IT, media and content industries to deliver new services and create fresh revenue-generating opportunities. UMTS will offer low-cost, high-capacity mobile

communication with global roaming and other advanced capabilities.

Never before has the telecommunications industry faced such an opportunity that is Third

Generation Mobile Telephony. 3G is the convergence of mobile, telephony andinformation systems which promises to change people's lives by enabling them to access

information when, where and how they want. This is the world of mobile multimedia. It

will be a revolution in communications that has the potential to change all our lives.However there are huge challenges for the players in the mobile telecommunications field

as they rollout and deploy 3G mobile networks and services, both from technological and

economical point of view.

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REFERENCE:-

WWW.UMTSWORLD.COM

WWW.UMTS-FOURM.NET

WWW.IBM.COM

WWW.3G.UK.ORG

BOOKS:-

COMMUNICATION SYSTEM

-by IYAN WILLY

PERSONAL MOBILE COMMUNICATION SERVICE & SYSTEM

-by RAJ PANDYA

http://www.umtsworld.com/http://www.umts-fourm.net/http://www.ibm.com/http://www.3g.uk.org/http://www.umtsworld.com/http://www.umts-fourm.net/http://www.ibm.com/http://www.3g.uk.org/