Universal Mobile Telecommunication Systems

MOBILE COMMUNICATIONSThe API will allow the same application to be used
Mobile communication is the application of wirelesson a wide variety of terminals and will also
technology in the access network. It offers manyprovide a common method of interfacing
useful features,applications to UMTS networks. The API will
• Easy installation for rapid roll outsupport security, billing, subscriber information,
• Proven platform with scalabilityservice management, call management, SIM
• Future proofmanagement user interaction and content
• Reliable and securetranslation. It is expected that the API will build
• Mobilityupon and extend today's technologies (i.e. Java,
It is a very rapidly growing and popular serviceWireless Application Protocol (WAP), GSM SIM
which was revolutionised telecommunications. ItToolkit and Internet technologies) that exploit
has become a backbone for business success andconvergence with other emerging technologies for
efficiency. It connects subscribers to the publicconsumer products (such as digital televisions).
switched telephone network(PSTN) using radio8)Client server architecture:-
signals as a substitute for copper.it allows anyOne of the primary drivers for UMTS is service
body to communicate with any one while on thedifferentiation. UMTS allows network operators to
move.market products based on more than just
Different technologies emerged for differentcoverage andcapacity issues. The key to this
types of requirements-coverage, capacity,benefit is the ability to develop and offer new
mobility, bandwidth.products and features in short timescales, without
GSMrequiring modifications from infrastructure
CDMAsuppliers.figure shows client server architecture of
CORDECTUMTS.
PHSMany new developments in the IT industry are
AMPS,DAMPSbased on a client/server technology, which allows
EVOLUTIONS OF MOBILE COMMUNICATIONS:-intelligence to be downloaded transparently from a
FIRST GENERATION(1G):ANALOG CELLULAR:-server into the user's terminal. The technology
The introduction to cellular systems in the lateprovides direct and immediate high performance
1970s and early 1980s represented a quantumuser interaction and interpretation. On the other
leap in mobile communication(especially in capacityhand, tasks that must remain centralized, such as
and mobility). Semiconductor technology anddatabase residence, are held on central servers
microprocessors made smaller and lighter weight ,waiting to rapidly and efficiently respond to
and more sophisticated mobile systems a practicalqueries from the clients. However, in the mobile
reality for many more users. These 1G cellularindustry, intelligent terminals and USIM card will
systems still transmit only analog voiceallow personalization of the user interface and
information. The most prominent 1G systems areprovision of features not possible with basic
ANALOG MOBILE PHONE SYSTEM(AMPS),terminals in today's client/server networks. As
NORDIC MOBILE TELEPHONE(NMT) and TOTALroaming traffic continues to increase, the ability to
ACCESS COMMUNICATION SYSTEMS(TACS).provide such features independently of the
With the 1G mobile introduction, the mobileserving network will become increasingly
market showed annual growth rates of 30 to 50important. Existing and evolving GSM standards,
percent, rising to nearly 20 million subscribers bysuch as SIM Toolkit and Mobile Execution
1990.Environment, together with other initiatives such
SECOND GENERATION(2G):MOBILE DIGITALas WAP, provide the framework for delivering
SYSTEMS:-this enhanced client/server approach. The user of
The development of 2G cellular systems wasan object-oriented language such as Java is
driven by the need to improve transmissionattractive because it is platform and operating
quality, system capacity and coverage. Furthersystem independent, and optimizes the download .
advances in semiconductor technology and9)Customer Care and Billing Systems:-
microwave devices brought digital transmission toUMTS will operate in a very different environment
mobile communications.sppech transmission stillthan today's mobile systems. Customer care and
dominates the airways,but the demands forbilling are inextricably linked. These systems must
fax,short message and data transmissions arebe able to effectively operate with all UMTS users
growing rapidly. Supplementary services such asand providers in a customer-friendly manner. For
fraud prevention and encrypting of user dataUMTS, a bill will no longer be just a dun but,
have become standard features that areinstead, a key part of a highly sophisticated
compatible to those in fixed networks. 2G cellularapproach to customer care across all provider
systems include GSM, DIGITALservices. Convergence will not only require the
AMPS(D-AMPS),CDMA and PERSONAL DIGITALinteroperation of fixed, mobile, satellite, private
COMMUNICATION. Today multiple 1G and 2Gand public systems but also the integration of
standards are used in world wide mobileplayers from non-telecommunications fields such
communications. Different standards serveas finance, entertainment, and the news media.
different applications with different levels ofThis will require a harmonized solution to customer
mobility, capability and service area standards arecare and billing systems despite very different
used only in one country or region and most arelegacy practices.
in compatible.The competitive services market will demand
2G TO 3G GSM: EVOLUTION:-multiple flexible interconnections between players
Phase 1 of the standardization of GSM 900mhzand roles. Seamless delivery will require a
band was completed by the EUROPEANunification of management and a means to
TELECOMMUNICATION STANDARD INSTITUTEprovide interworking without a prior relationship.
(ETSI) in 1990 and included all necessarySignificantly higher levels of automation and
definitions for the GSM network operations.timeliness will be required to support the billing and
Several tele services and bearer services havecustomer care operations. In addition, fraud
been defined (including data transmission uptomanagement will need to be applied across the
9.6kbps), but only some very basicwhole value chain. Charging and billing will need to
supplementary services offered. As a result, GSMmature as concepts and practices.
standards were enhanced in phase 2 (1995) toBENEFITS OF UMTS: what it offers?:-
incorporate a large variety of supplementaryCorporate use of UMTS (including global mobile
services that were compatible to digital fixedaccess to Intranets) will be a key driver for
network integrated services digital network(ISDN)UMTS. Businesses will demand greater flexibility
standards. In 1996, ETSI decided to furtherfor customization and more devolved service
enhance gsm in annual phase 2 + releases thatcontrol to optimize productivity and operational
incorporate 3G capabilities.efficiencies within corporate networks. UMTS
LIMITATIONS IN 1G AND 2G SYSTEMS:-subscriber and network management capabilities
• No global standardswill offer enhanced capabilities to meet these new
• No common frequency bandand evolving requirements .
• Low information bit ratesThe body of literature on UMTS indicates that it
• Low voice qualityoffers the promise of being a significant
• No support of videoadvancement in mobile communications
• Various categories of systems totechnology. UMTS is being designed to ensure
meet specific requirementsfigure shows theflexibility is presented to users, network operators
architecture of GSM.and service developers. UMTS will offer significant
INTERNATIONAL MOBILEbenefits in communication abilities including:
TELECOMMUNICATIONS 2000:-• Ease of use and low cost;
IMT:-A future standard in which a single• New and better services;
inexpensive mobile terminal can truly provide• Packet transmission and data rates on
communications any time and any where. Thedemand; and
main characteristics of 3G systems, known• Improved mobility and coverage.
collectively as IMT-2000 are a single family of1)Ease of use and low costs:- Wireless customers
compatible standards that have followingwant useful services, easy-to-use terminals and
characteristicsgood value for money, UMTS is envisioned to
• Used world wideoffer services that are easy to use and
• Used for all mobile applicationscustomizable in order to address individual user
• Support both packet witched(PS) andneeds and preferences. Terminals and other
circuit switched(CS) data transmissioncustomized equipment will be available to allow
• Offer high data transfer rates 2MBPS.easy access to these services. A wide array of
• Offer high spectrum efficiencyinexpensive, available terminals and other
IMT standards has made 17 proposals to meetperiphery will be available. Costs for the actual
the requirements of 2G systems.The mostUMTS service are projected to be low enough to
important IMT-2000 proposals are the UMTSensure a mass market and provider competition.
(W-CDMA) as the successor to GSM,CDMA as2)New and better services:- Market studies show
the interim standard 95(IS 95) successor and timethat voice will remain the dominant service for
division synchronous(TD-SCDMA), UNIVERSALexisting fixed and mobile telephone networks,
WIRELESS COMMUNICATIONS-136(UWC 136including GSM, through 2005. Users will demand
EDGE) as TDMA based enhancements to DAMPSlow-cost, high-quality voice service from UMTS.
GSM all of which are leading previous standardsHowever, the opportunity for increased revenues
toward theultimate goal of IMT 2000. The goalsthrough UMTS comes from offering advanced
of the services to be provided in 3G systems bydata and information services. Long term, industry
IMT 200 is shown in figure The Global System forforecasts for UMTS show a strongly growing
Mobile Communications (GSM) is now the world'smultimedia subscriber base by the year 2010.
most successful wireless standard. Recent figures3)Fast access:- One factor, which clearly sets
indicate that GSM has more than 100 millionUMTS above the second-generation mobile
subscribers in 120 countries and attracts moresystems, is its potential to support 2Mb/s data
than five million new users every month. Thererates for users from the outset. This capability,
are nearly 300 GSM system operators worldwide.together with inherent Internet Protocol (IP)
Current wireless or mobile systems, despite theirsupport of UMTS, is a powerful combination to
evolution, are still constrained in terms of the datadeliver interactive multimedia services as well as
rate they can offer and their flexibility toother new wideband applications such as video
manipulate complex, yet user-friendly multimediatelephony and video conferencing.
services. This need presents the opportunity toAs the demand for user data rates increases in
the mobile radio, IT, and consumer electronicsthe long term, UMTS will be developed to support
communities to offer users a mobile systemeven higher data rates, perhaps one or two
capable of managing and delivering a much widerorders of magnitude greater. In later phases of
range of information services to the massUMTS development, there will be a convergence
market. Elements of this opportunity include:with even higher data rate systems using mobile
• An industry-wide and governmentwireless Local Area Network (LAN) technologies
commitment across the world;(microwave or infrared) providing data rates of
• A coordinated program includingfor example 155 Mb/s in indoor environments .
spectrum, standards, and technology; and4)Packet transmission and data rate on
• Synergy of communications, IT, anddemand.:-Most cellular systems in use today use
media workings to bring about global opportunitiescircuit-switched technology for wireless data
for businesses and consumers, while creating newtransmission. However, UMTS integrates packet
ways of doing business, entertaining and informing.and circuit data transmission. Packet data over
A new mobile system for worldwide use is nowthe airwaves provides the user several benefits:
being developed to enhance and supersede• Virtual connectivity to the network at
current systems. The Universal Mobileall times;
Telecommunications System (UMTS) will be an• Alternative ways of billing. For example,
enhanced digital communications system that willpay-per-bit, per session or flat rate per month;
provide universal communications to anyone,and
regardless of their whereabouts. UMTS will allow• Asymmetric bandwidth in the uplink
for wireless Internet access, video-conferencing,and downlink. As demanded by many emerging
and other bandwidth intensive applications. Benefitsdata services where one link direction carries
from this new system of wirelesssimple commands and the other carries and
communications are expected to be:content rich, bandwidth intensive traffic (for
• Support to existing mobile services andexample Web browsing or video transmission).
fixed telecommunications services up to 2Mb/s;UMTS is also being designed to offer data rate on
• Support to unique mobile services suchdemand, where the network reacts flexibly to a
as navigation, vehicle location, and road trafficuser's demands based upon his or her profile and
information services, which will becomethe current status of the network. The use of
increasingly important in world market;packet-oriented transport protocols such as
• The ability to enable the use of theInternet Protocol (IP) for UMTS is being studied
system terminal from multiple environments - innow. The combination of packet data and data
the home, the office, and in the publicrate on demand will remove technical barriers for
environments -in both rural areas and citythe user and make operation of the system
centers; andmuch cheaper. Simply put, there should be no
• Provision of a range of mobile terminalsworries about how and when to connect to the
- from a low cost pocket telephone tonetwork.
sophisticated terminals to provide advanced videoUMTS services are based on standardized service
and data services .capabilities, which are common throughout all
UNIVERSAL MOBILE TELECOMMUNICATIONUMTS user and radio environments. This means
SYSTEMS(UMTS):-that a user will experience a consistent set of
INTRODUCTION:-services even when he or she roams from his or
In January1998, the European Telecommunicationsher home network to other UMTS operators.
Standards Institute (ETSI) decided on a single airUsers will find the same interface, whether they
interface standard for the proposed Universalare in their home network or roaming. The Virtual
Mobile Telecommunications System (UMTS). TheHome Environment (VHE) will ensure the delivery
system is one of the major new third-generationof the service provider's total environment,
mobile systems being developed within theincluding for example, a corporate user's virtual
framework that has been defined by thework environment, independent of the user's
International Telecommunications Union (ITU) andlocation or mode of access (satellite or terrestrial).
is known as IMT-2000. UMTS has been theVHE will also enable terminals to negotiate
subject of intense worldwide efforts on researchfunctionality with the visited network, possibly
and development throughout the past decade.even downloading software so that it will provide
The system has the support of many major"home- like" service. The ultimate goal is that all
telecommunications operators and manufacturersnetworks, signaling, connection, registration and
because it represents a unique opportunity toany other technology should be transparent to
create a mass market for highly personalized andthe user so that mobile multimedia services are
user-friendly mobile access to today's informationsimple, user friendly and effective.
society. The system seeks to build on and extendMobility and Coverage:- UMTS has been designed
the capability of today's mobile, cordless, andfrom the outset to be a global system,
satellite technologies by providing increasedcomprising both national terrestrial and global
capacity and data capability as well as a farsatellite components. Through multi-mode,
greater range of services using an innovativemulti-band terminals it can use 2nd generation
radio access scheme and an enhanced, evolvingsystems to extend its coverage for basic
core network.The system will be a member of aservices. The overall goal of the system offering
new family of mobile telecommunications systemsis to achieve truly personal communications using
being developed by the ITU for deploymentterminals that are able to roam from a private
across the world. While using different radiocordless or fixed network (Figure 1). A second
frequencies in different countries, every systemgoal is to achieve this with a consistent delivery
will offer the same set of features to users. Thisof the services via VHE.
will allow handsets to be developed that can beFigure 1. UMTS Coverage is Universal (Leino,
carried from country to country as the user1999).
travels.The UMTS radio access system UTRA will
The key difference between this system andsupport operation with high spectral efficiency and
previous mobile (wireless) systems, such as GSM,service quality in all the physical environments in
is that the earlier systems were conceptuallywhich wireless and mobile communication take
separate from the fixed (wire line) telephoneplace. Today's users live in a multi-dimensional
network. The goal of this system is to integrateworld, moving between indoor, outdoor urban and
wire line and wireless systems to provide aoutdoor rural environments with a degree of
universal communications service, such that a usermobility ranging from stationary through
can move from place to place while maintainingpedestrian up to very high vehicular speeds.
access to the sum set of services .There are also different user density
The system is intended to allow users to sendenvironments, including three-dimensional situations
and receive data at much higher bandwidths thanin high-rise buildings. UTRA has been specified for
supported by today's GSM system. While on theall these environments.
move, users will be able to access remoteLimitations of UMTS:-
systems at up to 144Kbps. When stationary,In practical implementations of UMTS, some users
connections of up to 2Mbp/s will be supportedmay be unable to access the highest data rates
through wireless access to networks, with muchat all times. For example, the physical constraints
higher performance being possible by plugging theof radio propagation and the economics of
handset into a network socket .operating a network will mean that the system
ETSI has chosen aggressive timescales for theservices might only support lower data rates in
introduction of UMTS in order to meet theremote or heavily congested areas. Therefore, in
demands of customers. The target date for itsorder to ensure that the subscriber is always able
introduction has been set as the year 2002. figureto use their terminal, services will be adaptive to
shows the architecture of UMTS.different data rate availability and other Quality of
To meet the deadline, the ETSI is following aService parameters.
phased approach in hopes of allowing capabilitiesIn the early stages of UMTS deployment, traffic
to improve over time following the initial systemwill probably be generated predominantly in
introduction. At launch, terrestrial UMTS will havelocations such as airports and railway stations
the capability for data rates up to 2Mb/s.which operators will cover immediately following
However, UMTS is designed as an open systemnetwork launch. However, users will want full
that should allow for evolution to incorporate newcoverage so that they can access their services
technologies as they become standardized.wherever they are . To offer this, UMTS
UMTS CRITICAL TECHNOLOGIES:- Some of thetechnology is being defined to enable roaming with
critical technologies essential for the successfulother networks. For example a GSM system
introduction of UMTS are described below:operated by the same operator or alternatively
1)UMTS Terrestrial Radio Access (UTRA):-by roaming agreements with other networks
The ETSI decision in January 1998 on the radiosuch as other GSM based systems or other third
access technique for UMTS combined twogeneration systems including UMTS compatible
technologies. The W-CDMA for paired-spectrumsatellite networks, which will effectively be able to
bands and TD-CDMA for unpaired band². Theoffer global coverage.
idea was to develop a common standard toThe limitations are,
ensure an optimum solution for all the different1)Risk of further regulation:- There is a certain
operating environments and service needs .anxiety that an attempt to achieve circulation by
The transmission rate capability of UTRA willmeans of administrative measures may lead to
provide at least 144 Kbit/s for full mobilityheavier regulation of UMTS (e.g. in the form of
applications in all environments, 384 Kb/s forcomplicated procedures or excessive marking).
limited mobility applications in the macro- andTherefore, current efforts are intended to take
micro-cellular environments, and 2.048 Mb/s forcare to aim to simplify regulation in all circulation
low mobility applications particularly in micro-cellularmeasures.
environments. The 2.048 Mb/s rate may also be2)Standardization:- Standardization will remain a
available for short range or packet applications inkey factor in providing quality services at an
the macro-cellular environment, depending onaffordable cost and enabling roaming between
deployment strategies, radio network planning, andsystems. The success of UMTS depends upon
spectrum availability.the flexibility of interfaces and the capacity to
2)Multi-mode Second Generation/UMTS Terminals:-evolve in parallel with technological development.
UMTS terminals will exist in a world of multipleContinued close co-operation between operators,
standards that will enable operators to offermanufacturers and regulators in the
maximum capacity and coverage to their userstandardization of UMTS/IMT 2000 is crucial for
base by combining UTRA with second- orsuccessful harmonization of standardization
third-generation standards. Therefore, operatorsproposals.
will need terminals that are able to interwork withUMTS in the Long Term:-
legacy infrastructures such as GSM/DCS2800 andIn order to ensure that UMTS flourishes in the
DECT, as well as other second-generation,long term, its capabilities must be progressively
worldwide standards (such as those based on theincreased by the addition of new technologies.
US AMPS standard) because these may initiallyThese technologies are discussed below.
have more complete coverage than UMTS. Many1)Re-configurable Terminals:- UMTS terminals will
UMTS terminals will therefore be multi-band andhave to exist in a world of multiple standards,
multi-mode. Building such terminals at a cost whichboth second-generation standards and other
is comparable to contemporary single-mode,members of the IMT-2000 family. In order to
second-generation terminals will become possibleprovide universal coverage, seamless roaming and
because of technological advances innon standardized services will no longer have fixed
semiconductor integration, radio architectures, andparameters, rather they will be in the form of a
software radio."toolbox" whereby the key parameters can be
3)Satellite Systems:-selected or negotiated to match the requirements
At initial service launch in 2002, the satelliteof the local radio channel.
component of UMTS will be able to provide aIn addition to the capability to adapt to different
global coverage capability. Implementation plans callstandards as described above, terminals will enable
for utilization of the S-band Mobile Satellite Servicenetwork operators to distribute new
(MSS) frequency allocations identified for satellitecommunications software via download over the
IMT2000 and will provide services compatible withair in order to improve the terminals' performance
the terrestrial UMTS system .in the network or to fix minor problems (e.g. an
4)SIM Cards/Smart cards:-improved handover algorithm). This aspect of
GSM introduced the Subscriber Identity Modulesoftware downloads will generally be invisible to
(SIM) or Smart Card. SIM technology incorporatesthe user.
enhanced security and a degree of user2)Application and Service Download:- When using
customization to the mobile terminal. SIMtoday's multimedia terminals (e.g. PCs), users have
requirements, security algorithms, card and siliconaccepted the idea that the capabilities of the
IC technology will continue to evolve up to andterminal can be modified over time through a
during the period of UMTS deployment . Thesoftware download. It is now commonplace for a
smart card industry anticipates being able to offeruser to download a new "plug in" (for example a
cards with greater memory capacity, faster CPUvideo or audio code) to access new types of
performance, contactless operation, and greatercontent. The introduction of multimedia services
capability for encryption. These advances will allowon UMTS will take this concept into the mobile
the UMTS Subscriber Identity Module (USIM) todomain. UMTS "plug ins" will come from a variety
add to the UMTS service package by providingof sources, for example:
portable high security data storage and• Pre-installed on the users' terminal by
transmission for users. In addition, the users willthe network operator or service provider;
be able to store, down or upload images,• Downloaded over the air, at the user's
signatures, personal files, fingerprint or otherrequest or automatically by the network - much
biometrics data through the card. Contactlessas today, where many Internet service providers
cards will allow the users to perform businessupgrade one's software or databases during a
transactions such as electronic commerce orsession; and
electronic ticketing without having to be removed• Supplied on media such as DVD or
from a wallet or phone .Electronic commerce andCD-ROM.
banking activities, utilizing smart cards, is expectedSmart Antennas:- Smart antennas react
to become widespread. Users will expect and beintelligently to the received radio signal, continually
able to use their cards on any terminal over anymodifying their parameters to optimize the
network. New memory technologies can betransmitted and received signal. This allows them
expected to increase card memory sizes makingto:
larger programs and more data storage feasible.• Increase coverage and capacity by
Several applications and service providers could bereducing interference between adjacent mobiles;
accommodated on one card. In theory, the users• Offer space division multiple access,
could decide which applications/services they wantwhere frequencies are assigned on a per-mobile
on their cards, much as they do for their desktoprather than a per-cell basis allowing vastly
computers' hard disks .increased capacity; and
5)Internet Protocol (IP) Compatibility:-• Enable user location in space, allowing
UMTS is a modular concept that takes advantagethe introduction of advanced location based
of the trend towards convergence of fixed andservices.
mobile networks and services, enabling a host ofBroadband Satellite Systems:- Several broadband
new applications. For example, a laptop with ansatellite systems are also planned for deployment
integrated UMTS communications modulein the post-2002 timeframe to offer data rates
becomes a general-purpose communications andbeyond 2Mb/s and into the Gigabits domain. Some
computing device for broadband Internet access,of these systems may offer compatibility with
voice, video telephony, and conferencing forUMTS service concepts using satellite frequency
either mobile, office, or residential use.UMTS mayallocations in the 20-30 GHz range. The
well become the most flexible broadband accessrequirements of the terminal equipment and
technology available, as it allows for mobile, officehigher power consumption will necessitate larger
and residential use in a wide range of public andsize transportable or fixed terminals or smaller
non-public networks. The system can supportelectronic components.
both IP and non-IP traffic in a variety of modesCONCLUSIONS:-
including packet circuit switched and virtualUMTS appears to offer significant benefits to
circuit². UMTS will be able to benefit frompersonal and commercial endeavors. Technologies
parallel work by the Internet Engineering Taskare being put in place to bring it into the mobile
Force (IETF) who is further extending its basiccommunity. A phased introduction of UMTS
set of IP standards for mobile communication .hardware and services with coverage, capability
New developments like IP version 6 allowsand number of operators growing over time. This
parameters such as quality of service, bit rate,phased introduction ensures early availability of
and bit error rate (BER), vital for mobile operation,services to users while reducing risks for UMTS
to be set by the operator or service provider.operators and manufacturers.
Developments on new domain name structuresUMTS must be capable of co-existing and working
are also taking place. These new structures willwith existing second-generation mobile
increase the usability and flexibility of the system,communications technologies so that operators
providing unique addressing for each user,can choose to reuse their existing infrastructure
independent of terminal application or location .assets and expertise. Global availability of UMTS
6)Cross platform interoperability:-servers will be ensured by providing for roaming
The need for the ability to transport multimediabetween members of the IMT-2000 family and
content over various types of networks requireshandover between GSM and UMTS. A number of
industry to develop cross-platform interoperabilitytechnologies are required, in addition to the radio
because the properties of the networks mayinterface on which so much focus has been
have an effect on the content of theplaced recently. Although most current attention is
transmission. In many cases several different kindfocused on the early years of deployment, UMTS
of networks will be cascaded (i.e. Ethernet, ATM,is being defined with a view to the long term.
X.25 and UMTS) .UMTS is a significant opportunity for
7)API and Development toolbox:-manufacturers, operators, and content providers
It is expected that rapid development andas a communications system and as a part of the
deployment of new and innovative services willgreater information society. The vision of UMTS is
drive the UMTS market. A key enabler in thisas a customer-focused system, where customers
area will be the standardization of the UMTSinclude both network operators and end users.
application-programming interface (API). API allowsThe challenge to the communications industry is
for abstraction of both the terminal and theto integrate the technologies needed for UMTS in
network. It will also provide a generic way fora way which supports this goal and thereby
applications to access terminals and networks.transforms the vision for UMTS into reality.