2. 1.Introduction
Universal Mobile Telecommunications System (UMTS) is a voice and high-speed data technology part of
the International Telecommunication Union’s (ITU ). UMTS is component of International
telecommunication network IMT2000 UMTS is Developed and Maintained by 3GPP 3rd generation
partnership project. Wideband CDMA (WCDMA) is the radio technology used in UMTS.UMTS
deployment offers stable network infrastructures and attractive, reliable mobile devices that have rich
capabilities with the addition of HSPA for high-speed packet data services. UMTS employs wideband
CDMA radio-access technology. UMTS is worldwide standard and available from service providers.
UMTS developed in 2000 and it is similar as CDMA2000 European Standard. UMTS is efficient
Telecommunication Model for CAPEX and OPEX(capital and operational expenditure .The primary
benefits of UMTS include high spectral efficiency for voice and data, simultaneous voice and data
capability for users, high user densities that can be supported with low infrastructure costs, support for
high-bandwidth data applications, and a clean migration to VoIP in the future. Operators can also use
their entire available spectrum for both voice and high-speed data services. UMTS is evolution of 2G
(GPRS) and 2.5G (EDGE) technology for enhance service quality and data transmission rate for next
generation data demand growth. UMTS builds on GSM, which is the world most widely used wireless
technology. UMTS enjoys a global cost structure, equipment selection and user adoption that is
unmatched by any other 3G technology.
3. 2.UMTS Technology
UMTS Network (3G Network) is based on next generation air interface technology based upon
orthogonal frequency-division multiplexing OFDM, allow multiple Channel in same frequency and
provide dedicated bandwidth to all users. UMTS-HSPA is quickly emerging as the dominant global
mobile-broadband network.
HSPA: High Speed Packet Access. HSPA is a 3rd Generation (3G) technology based on UMTS standards
offering faster data download speeds at the cost of upload speeds. The HSPA family of technologies is
quite large, covering High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access
(HSUPA), and Evolved High Speed Packet Access (HSPA+). UMTS supports maximum theoretical data
transfer rates of 42 Mbit/s when HSPA+ is implemented in the network. Users in deployed networks can
expect a transfer rate of up to 384 Kbit/s and 7.2 Mbit/s for HSDPA handsets in the downlink
connection. These speeds are significantly faster than the 9.6 Kbit/s of a single GSM error-corrected
circuit switched data channel, multiple 9.6 Kbit/s channels in HSCSD and 14.4 Kbit/s for CDMAOne
channels.
UMTS networks in many countries have been or are in the process of being upgraded with High Speed
Downlink Packet Access (HSDPA), sometimes known as 3.5G. HSDPA enables downlink transfer speeds
of up to 21 Mbit/s. Work is also progressing on improving the uplink transfer speed with the High-Speed
Uplink Packet Access (HSUPA). Longer term, the 3GPP Long Term Evolution (LTE) project plans to move
UMTS to 4G speeds of 100 Mbit/s down and 50 Mbit/s up...
UMTS works in a variety of spectrum bands offering operators more flexibility and is currently available
worldwide for use in the 450, 700, 850, 900, 1700, 1800, 1900, 2100 and 2600 MHz bands. Currently,
UMTS TDD equipment is available for the 450 MHz spectrum band. Because signals travel farther at
lower frequencies, UMTS networks at 850 or 900 MHz are a good fit for covering sparsely populated
rural areas.
UMTS operators can use a common core network that supports multiple radio-access networks,
including GSM, EDGE, WCDMA, HSPA and evolutions of these technologies. This is called the UMTS
multi-radio network and it gives operators maximum flexibility in providing different services across
their coverage areas.
4. 3.UMTS Architecture
A UMTS network consist of three interacting domains; Core Network (CN), UMTS Terrestrial Radio
Access Network (UTRAN) and User Equipment (UE). The main function of the core network is to provide
switching, routing and transit for user traffic. Core network also contains the databases and network
management functions.
The basic Core Network architecture for UMTS is based on GSM network with GPRS.
Core Network
The Core Network is divided in circuit switched and packet switched domains. Some of the circuit
switched elements are Mobile services Switching Centre (MSC), Visitor location register (VLR) and
Gateway MSC. Packet switched elements are Serving GPRS Support Node (SGSN) and Gateway GPRS
Support Node (GGSN). Some network elements, like EIR, HLR, VLR and AUC are shared by both domains.
5. Radio Access
Wide band CDMA technology was selected to for UTRAN air interface. UMTS WCDMA is a Direct
Sequence CDMA system where user data is multiplied with quasi-random bits derived from WCDMA
Spreading codes. In UMTS, in addition to channelization, Codes are used for synchronization and
scrambling. WCDMA has two basic modes of operation: Frequency Division Duplex (FDD) and Time
Division Duplex (TDD).
User Equipment
the UMTS standard does not restrict the functionality of the User Equipment in any way. Terminals work
as an air interface counterpart for Node-B and have many different types of identities. Most of these
UMTS identity types are taken directly from GSM specifications.
International Mobile Subscriber Identity (IMSI)
Temporary Mobile Subscriber Identity (TMSI)
Mobile station ISDN (MSISDN)
International Mobile Station Equipment Identity (IMEI)
UMTS Wireless Network Infrastructure
Voice and data transport is performed by the transport layer nodes, colored blue:
• Node B = base transceiver station
• RNC = radio network controller or base station controller (BSC)
• SGSN = serving GPRS support node
• GGSN = gateway GPRS support node
• MGW = media gateway
The call control function is mainly performed by the call control layer nodes, colored yellow:
• CSCF = call state control function
• MGCF = Media Gateway Control Function
• HSS = home subscriber server
6. 4.UMTS Protocol Model
UMTS Protocol Model have two plane
1. Horizontal Plane- The horizontal layers depict the protocol interworking across multiple interfaces and
protocol Terminations function of plane specific mobile networking .Horizontal plane d divided into
control and user plane.
2. Vertical Plane- planes illustrate the system control and user data flow in the UMTS system. Network
control aspect from the user data transfer aspect
UMTS protocol model is divided into three layers,
1. Transport network layer provides transport services for all UMTS network elements thus making them
able to communicate across different interfaces.
2 Radio network layer is responsible for the interworking between UE and CN on all radio bearer related
aspects.
3 System network layer system network layer protocols extend from UE to the transit network edge of
the UMTS CN and take care of the interworking of UMTS communication service related aspects.
7. 5.UMTS Services
1.UMTS offers tele services (like speech or SMS) and bearer services, which provide the capability for
information transfer between access points.
2. Connection oriented and connectionless services are offered for Point-to-Point and Point-to-
Multipoint communication.
3. Bearer services have different QoS parameters for maximum transfer delay, delay variation and bit
error rate. Offered data rate targets are:
(1)144 Kbits/s satellite and rural outdoor
(2)384 Kbits/s urban outdoor
(3)2048 Kbits/s indoor and low range outdoor
UMTS network services have different QoS classes for four types of traffic:
F Conversational class (voice, video telephony, video gaming)
F Streaming class (multimedia, video on demand, webcast)
F Interactive class (web browsing, network gaming, database access)
F Background class (email, SMS, downloading)
UMTS will also have a Virtual Home Environment (VHE). It is a concept for personal service environment
portability across network boundaries and between terminals. UMTS also has improved network
security and location based services.
UMTS is based on Internet Protocol (IP) technology with user achievable peak data rates of 350
kbps and more typical speeds for both the uplink and the downlink at 200 to 300 kbps.
