Umts Overwiewppt

1. Mobile Communication Technology Evolution 2. UMTS General Description3. UMTS Services4. WCDMA Principles5. OAM

UMTS Overview

February. 2010

WCDMA BSM TeamLai Tuan Dung

1. Mobile Communication Technology Evolution

Always Surpassing Customers Expectations

Mobile Communication Technology Evolution



ITU (International Telecommunication Union) defines Mobile Communication’s Generation.

1st Generation: 1G networks (NMT, C-Nets, AMPS, TACS) are considered to be

the first analog cellular systems, which started early 1980s.

Only supported voice service.

2nd Generation: 2G networks (GSM, CDMA IS-95A) are the first digital cellular

systems launched early 1990s.

More provided service than 1st generation. There are voice service, text message service, e-mail service and other data service.

2nd Generation systems have enhanced voice capability in comparison to analog systems, better spectrum management, wider coverage area, circuit switching and better mobility.



3rd Generation: By the end of 2000, wireless voice services were already

matured. The focus of wireless companies shifted to enhance data rate and make available the very same applications of wired networks to the wireless community.

By 2001, 2.5G technologies were introduced, HSCSD (High Speed Circuit Switched Data), GPRS, EDGE and cdma20001xRTT(Radio Transmission Technology) were introduced. 2.5G technologies offered services such as voice mail, e-mail, lBS (location-Based Service), WAP (web surfing using Wireless Application Protocol) and other e-commerce services.

IMT-2000 (International Mobile Telecommunications) defined by ITU. According to IMT-2000, the design of 3rd technologies should be based on the following objective:

• The main features of 3rd generation system are “Always-on connectivity”, all “IP network”, “Global roaming” and value added services.

• IMT-2000 system used 2GHz Frequency Band. That’s why, called IMT-2000.



4th Generation: 4G service is available to provide 1Gbps at slow moving and

100Mbps at high speed.

4G system support IP based on router.

Frequency band select one from 2GHz to 6GHz.

2 major standards: The GSM, developed by the European Telecommunications

Standardization Institute (ETSI), and the CDMA developed by the Telecommunications Industry Association (TIA).

Currently, there are two major partnership project groups: the 3G Partnership Project (3GPP) and 3G Partnership Project 2(3GPP2). 3GPP is a standardization GSM-based system, whereas 3GPP2 is standardizing CDMA-based system.


2. UMTS General Description


Introduction

The Universal Mobile Telecommunication System (UMTS) is a 3G wireless standard, incorporating mobile cellular and other functionality.

It is based on a WCDMA (Wide Band Code Division Multiple Access) Access Network and a MAP (Mobile Application Part) Core Network.

UMTS is one of the technologies which allow Internet services to be made easily available via wireless.

UMTS as the evolution step from GSM/GPRS

The UMTS Network Solution is a available as an Access Network, a Core Network or as a complete Network Solution.

The UMTS Network’s solution offers wireless Internet services with the same quality of service as that which is offered today for voice telephony services.


UMTS General characteristics

Multimedia services & high data rates: WCDMA radio access

Support of QoS mechanisms

Volume-based pricing scheme

Service flexibility, wide bit-rate range and granularity: Packet- and Circuit-oriented services

“always on” connectivity, multiple services on one connection

Additional requirements: Dual-mode/co-existence with GSM & inter-system Hand off

Channel characteristics negotiation

Data Rates of UMTS

Satellite and rural outdoor 144 Kbps

Urban outdoor 384 Kbps

Indoor and low range outdoor

2 Mbps


UMTS Release 3 architecture


From GSM to UMTS


Functional overview

The UMTS Release 3 (or R99) architecture is based on the following subsystems:

UTRAN (UMTS Terrestrial Radio Access Network): UMTS uses a new radio technology called WCDMA (Wide Band Code Division Multiple Access) for the access network. The introduction of a new radio technology led to the creation of a completely new radio access infrastructure. This infrastructure is known as the UTRAN.

CN (Core Network): The CN is split into

• CS (Circuit Switched) domain: The CS domain is an evolution of GSM. The CS domain uses 64 kbps TDM (Time Division Multiplexed) channels or ATM (Asynchronous Transfer Mode) transport. This domain provides a similar set of services to those provided by GSM.

• PS (Packet Switched) domain: The PS domain is based on GPRS. The most significant addition is a viable architecture for the QoS (Quality of Service). This is essential for the support of voice and other real--time media services on the PS domain.


Functional overview (cont’)

UE (User Equipment): The UE is a mobile equipment with one or several UMTS SIMs (Subscriber Identity Module). It allows a user access to network services. For the purpose of 3GPP specifications, the interface between the UE and the network is the radio interface. A user equipment can be subdivided into a number of domains, the domains being separated by reference points.

The interface between the UTRAN and the Core Network is the Iu interface. The Iu interface has two variants:

Iu-CS: This is used for circuit services. The Iu-CS is an evolution of the GSM A interface.

Iu-PS: This is used for packet services. The Iu-PS replaces the GPRS Gb interface for UMTS services.


UTRAN

The UTRAN uses the WCDMA radio technology.

The UTRAN is composed of several Radio Network Subsystems (RNS).

Each RNS is composed of one Radio Network Controller (RNC) and several node Bs. A node B is a logical node responsible for radio transmission/reception in one or more cells to/from the user equipment.


UTRAN architecture


RNC

The RNC (Radio Network Controller) is the central element in the UTRAN. The main functions of the RNC are to control and manage:

RAN (Radio Access Network)

signaling between the different CN (Core Network) components and the RNS (Radio Network System)

Node Bs and the corresponding radio resources.

The RNC supports the following interfaces, standardized by 3GPP:

Iub: Iub is the interface between an RNC and a node B.

Iu: Iu is the interface between the UTRAN and the CN. The Iu interface has two variants:

• Iu-CS for circuit services

• Iu-PS for packet services

Iur: Iur is the interface between two RNCs.

Uu: Uu is the radio interface between UTRAN and UEs.


iRNC

The iRNC houses the following cabinets:

the C-Node (Control Node): The C-Node is an ATM-based engine that support UMTS call processing and signaling as well as OAM of both the RNC and the node Bs.

the I-Node (Interface Node): It is a high-capacity ATM switch, in charge of the connectivity (User Plane) of the iRNC.

Access Node: This optional cabinet is used for a PCMx configuration. The main function of the Access Node is to convert the STM1 links into PCM links and vice versa.


Node B

A node B is a logical node responsible for radio transmission/reception in one or more cells to/from the user equipment.

A node B provides the following interfaces:

Iub interface towards the RNC

Uu interface towards the User Equipment (UE)


iBTS

The iBTS has the following characteristics:

one mode of operation: STSR1

Antenna configuration:

The iBTS has the following configuration: six antennae for three-sector configuration

Frequency carriers:

The iBTS supports multi-carriers configuration. In STSR1 configuration, the iBTS supports one frequency carrier and allows 5 MHz operation.


STSR1-6-3


Core Network

The Core Network is split into two domains:

PS (Packet Switched)

CS (Circuit Switched)

Core Network entities:

entities common to PS and CS domains

CS domain entities

PS domain entities


Core Network architecture (UMTS01)


Common entities to PS and CS domains

HLR (Home Location Register): The HLR is a database that holds information on subscribers. It performs the following functions: handling of permanent subscriber data (identification,

subscription information, service limitation)

handling of temporary subscriber data: current VLR, SGSN addresses where the subscriber roams, security information

dialogue with the AuC database

VLR (Visitor Location Register): The VLR contains all subscriber data required for call handling

and other purposes for mobile subscribers currently located in the area controlled by the VLR. The VLR supports a mobile paging and tracking subsystem in the local area where the mobile is presently roaming.

AuC (Authentication Center):

The AuC is a database that contains secret subscriber keys and security algorithms. It generates security information for authentication and ciphering.


CS domain entities

MSC (Mobile Switching Center): The MSC has mainly to provide the basic switching

functionality as known from ISDN with additional capabilities for handling mobile subscribers. The MSC coordinates the setup of calls to and from all UMTS subscribers operating in its area.

GMSC (Gateway MSC): If a network delivering a call to the PLMN cannot interrogate

the HLR, the call is routed to an MSC. This MSC will interrogate the appropriate HLR and then route the call to the MSC where the mobile station is located. The MSC that performs the routing function to the actual location of the MS is called the GMSC (Gateway MSC).

IWF (Interworking Function): The IWF is a functional entity associated with the MSC. The

IWF provides the functionality necessary to allow interworking between a PLMN (Public Land Mobile Network) and the fixed networks (ISDN, PSTN and PDNs).


PS domain entities

SGSN (Serving GPRS Support Node): The SGSN performs mobility management session management

state control: UE state

data packet routing on the downlink

Authentication

GGSN (Gateway GPRS Support Node): The GGSN is serving as the interconnection point between the

UMTS network and the external Packet Data Network (PDN). It requires special features to be able to provide secure communication between UMTS users and the IP world in addition to providing tunneling capabilities within the UMTS network system itself.

It is connected with SGSNs via an IP-based packet domain PLMN backbone network. The GGSN contains all the subscriber data required for UMTS mode transmission for mobile subscribers using any service provided by the GGSN.


3. UMTS Services


Services

New services The service and application capabilities of UMTS far exceed

those available with second-generation networks.

Multimedia In UMTS networks, it is possible for one mobile termination to

have several active bearer services simultaneously, each of which can be connection oriented or connectionless.

Multiple information sources are available using audio, text and video with a quality of service previously unavailable via wireless networks. The capability for simultaneous sessions for example, allows a customer to conduct a voice call while at the same time accessing information via a web--browser.


Services (cont’)

Global mobility The development of new information technologies beyond

plain voice services (Internet, multimedia) has led to an extension of the concept of mobility. With cordless systems, the mobility concept was restricted to a small geographical area (home).

With the development of cellular technologies, mobility was extended to large areas (countries) thanks to the roaming service. The satellite provided world-wide coverage, but with smaller capacity. Each time, the user had to choose the appropriate technology according to his service expectations and local constraints.

The idea behind the global mobility concept is to use all these technologies to offer the best service to the user according to the environmental constraints. It also offers a seamless continuity when moving from one zone to another (“anywhere-anytime” communication).


Global mobility

Internetwork roamingSeamless End-to-End

services


4. WCDMA Principles


Introduction

WCDMA (Wideband Code Division Multiple Access) builds on the experience of the past 10 years of CDMA being used as a multiple access technology for cellular systems. CDMA is fundamentally different from the access technologies used in 1st generation systems and other 2nd generation systems.

First generation analog systems used FDMA (Frequency Division Multiple Access), while second generation systems used Frequency and TDMA (Time Division Multiple Access), often referred to as FTDMA.

In CDMA systems such as IS95 and UMTS, the user is allocated a carrier frequency and a code known as a pseudo random noise code. The narrowband voice signal is spread over the wideband carrier using the pseudo noise code which spreads the energy of the transmitted signal over the carrier spectrum.


Multiple Access Concept

Multiple Access is the simultaneous use of a communication system by more than one user

Each user’s signal must be kept uniquely distinguishable from other user’s signals, to allow private communications on demand

Users can be separated many ways: Physically : on separate wires

by arbitrarily defined “channels” established in frequency, time, or any other variable imaginable


Multiple Access Concept – 3 methods


CDMA (IS95, 3G)


Different types of WCDMA system

Wideband CDMA differs from 2nd generation CDMA systems by the bandwidth of the carriers. The carrier bandwidth defined for UMTS is 5 MHz whereas the bandwidth used for 2nd generation systems such as IS95 is 1.25 MHz.

Two different types of WCDMA system have been defined for UMTS: FDD (Frequency Division Duplex): WCDMA in frequency division

duplex mode

TDD (Time Division Duplex): WCDMA in time division duplex mode

FDD mode is the preferred mode for macro-cellular applications

TDD mode is the preferred mode for the unpaired part of the spectrum. In TDD, each time slot can be assigned a different direction. So the TDD mode offers a great flexibility to manage duplex and asymmetric traffic. The TDD spectrum will be used for low mobility coverage in urban areas.


WCDMA: FDD or TDD


FDD mode

FDD is a duplex method where by the uplink and the downlink transmissions use 2 separate frequency bands: Uplink: 1920 MHz - 1980 MHz

Downlink: 2110 MHz - 2170 MHz

Each carrier is 5-MHz wide and the uplink channel is 190 MHz away from the downlink. So, up to 12 pairs of carriers are available.

WCDMA in FDD mode shares many common characteristics with 1st and 2nd generation systems that used FDMA and FTDMA. As with those systems, separate frequency bands are reserved for uplink communications and downlink communications.

This separation obviously guarantees isolation between the two communication channels and perfect symmetry in capacity for both directions. Whereas this is efficient for voice communication, it can become inefficient as data services such as Internet browsing become more popular.


TDD mode

TDD is a duplex method whereby the uplink and the downlink transmissions are carried over the same frequency using synchronized time intervals. The carrier still uses a 5 MHz band.

In the IMT-2000 spectrum allocation, 35 MHz have been reserved for TDD services.

In TDD mode the uplink and downlink communications occur on the same carrier, without any fixed duplex separation. The allocation of codes and bandwidth is made as a function of demand in the uplink or downlink directions. In this way, WCDMA in TDD mode is more adapted for non-symmetrical data services.


Spread spectrum

CDMA falls into the family of transmission systems known as spread spectrum.

The main characteristics of spread spectrum systems are the following: The bandwidth of the transmitted signal, Bt, is much larger

than the bandwidth of the information-bearing signal, Bi.

The radio-frequency bandwidth of the transmitted signal is independent of any of the characteristics of the information-bearing signal.

The processing gain (Gp) in CDMA systems is defined by: GΡ= Bt/Bi


Code multiplexing

All WCDMA users occupy the same frequency at the same time. Frequency and time cannot be used as discriminators.

WCDMA operates by using codes to discriminate between users. Using the correct code sequence, the receiver can decipher the required transmission channel.

Users are discriminated thanks to the spreading codes.


Code multiplexing


Handover in UMTS


Different Types of Handover


5. OAM


OAM

What is OAM? Operation, Administration, and Maintenance.

It delivers an integrated UMTS management platform for the Access and the Core Network.

The management layer includes functions and tools in the following areas: Integrated Management Platform (NSP: Network Service

Platorm)

Fault Management

Configuration Management

Performance Management

Charging Gateway Function (CGF)

Policy Services Management

OSS Interfaces


OAM

The OAM system uses:

An IP network to interconnect the OAM components.

A client--server architecture to support processor and memory-intensive graphical user interfaces.

A distributed software architecture that integrates a number of existing OAM products into a single system, without particular regard to the physical boundaries of the hardware platforms that run the software.

stand-alone or semi-independent OAM systems for some components where the maturity of the technology does not permit full integration.


OAM functional architecture


OAM Connection


Acronyms

GSM: Global System for Mobile Communications

GPRS: General Packet Radio Service

EDGE: Enhanced Data rates for GSM Evolution

PSTN: Public Switched Telephone Network

ISDN: Integrated Services Digital Network

PLMN: Public Land Mobile Network

Node B is a term used in UMTS to denote the BTS (Base Transceiver Station)

PCM: Pulse-Code Modulation

STM-1: Synchronous Transport Module Level-1

REF:http://www.3gpp.org

http://www.3gpp2.org

http://www.wikipedia.org

http://www.google.com


END

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