Utran description-3-days (1)

UMTS/
UTRAN
Introduction

© Alcatel University - 8AS 90171 0004 VT ZZA Ed. E.A.U

Page 1

Introduction to UMTS

Table of contents
1.

Introduction

2.

Services Provided

3.

UMTS system description

4.

WCDMA for UMTS

5.

UTRAN (Release 1999)

Appendix
Related Documentation
Abbreviations and acronyms

Page 2

1.
Introduction


Page 3

1.Introduction

Definition

Universal
Mobile
Telecommunication
System
“UM
TS is o ne o f the m a jo r ne w third g e ne ra tio n m o bile
c o m m unic a tio ns s y s te m s be ing d e ve lo p e d within the
fra m e wo rk whic h ha s be e n d e fine d by the I a nd kno wn a s
TU
I T-2 0 0 0 ”
M
UMTS Forum

Page 4

1. Introduction

1.1

Context

1.2

Standardization

1.3

UMTS goals

1.4

UMTS technical overview


Page 5

1.Introduction/1.1 Context

Past mobile systems (1)
First Generation (1G)
In the early 80’s, analog systems
e.g Radiocom 2000, C-Netz…
Service:
speech
Limitations of 1G:
•poor spectrum efficiency
•expensive and heavy user equipment
•mobility only in a small area
•no security of communications


Page 6


Past mobile systems (2)
Second Generation (2G)
In the early 90’s, digital systems
Europe : GSM
US
: IS-95 (also called cdmaOne), IS-136 (TDMA system)
Japan : PDC
Services: Speech and low data rate
Limitations of 2G:
• Congestion
more than 300 million wireless subscribers worldwide -->need to increase system
capacity
• Limited mobility around the world -->need for a global standardisation
• Limited offer of services
more than 200 million internet users--> Need for new multimedia services and
applications (video telephony, e-commerce...)


Page 7


Technical solutions

Two types of solutions were possible :
• enhancement of 2G system --> 2,5G
low cost but short term
e.g.: HSCSD, GPRS, EDGE for GSM evolution
• design of a complete new standard --> 3G
high cost, long term, but great amount of new potential services
e.g: UMTS


Page 8


GSM evolution (1)
HSCSD (High Speed Circuit Switched Data)
Principle: to enhance channel coding scheme and to bundle GSM time
slots on a circuit-switched basis.
Performance: up to 115,2 kbps
Already implemented but not all operators/manufacturers have made this
choice.
GPRS (General Packet Radio Service)
Principle: to enhance channel coding scheme and to bundle GSM time
slots on a packet-switched basis (the allocation of time slots is performed
dynamically at the initialisation and during the connection)
Performance: up to 171,2 kbps
1999/2000 : deployment phase
2002 : service offers for most operators

Page 9


GSM evolution (2)
EDGE (Enhancement Data rates for GSM evolution)
Principle: new modulation scheme (8PSK instead of GMSK)
Performance: up to 384 kbps
Implementation is yet to come (foreseen for 2003)
EDGE might be a good alternative to 3G systems in certain areas or for
operators who do not have 3G licences, although the 3G brings more in
terms of new multimedia services.


Page 10


Let’s take some examples!
Downloading a map (50
KBytes)
GSM 42 s
GPRS
8s
EDGE 3 s
UMTS 0.2 s

Downloading a Word document
(500 KBytes)
GSM 7 mn
GPRS 82 s
EDGE 27 s
UMTS
2s

A 2 1/2 minutes MP3 music
file
(2.4 MBytes)
GSM
GPRS
EDGE
UMTS

34 mn
7 mn
128 s
10 s

Audio and Video
streaming
Streaming with all
technologies
except with GSM

Page 11

1.Introduction

1.1

Context

1.2

Standardization

1.3

UMTS Goals

1.4



Page 12

1.Introduction/1.2 Standardization

IMT-2000: definition

IMT-2000 is a framework for third generation mobile systems (3G) which is
scheduled to start service worldwide around the year 2000 subject to
market considerations.
IMT-2000 should use the frequencies around 2 GHz all over the world.
IMT-2000 is defined by a set of interdependent ITU Recommendations*.
IMT-2000 main requirements are :
- wide range of high quality services
- capability for multimedia applications
- worldwide roaming capability
- compatibility of services within IMT-2000 and with the fixed networks


Page 13


IMT-2000: main participants

Europe: ETSI
Japan: ARIB
USA: TIA, T1
South Korea: TTA
China: CWTS
ITU: International
Telecommunication Union


Page 14


IMT-2000: terrestrial
radio interfaces

IMT-TC (Time Code)
TD-CDMA
UMTS TDD
IMT-DS (Direct Spread)
W-CDMA
UMTS FDD

Evolved GSM
Core Network

IMT-MC (Multi Carrier)
CDMA2000
FDD MC

Radio/Network
Connection

IMT-SC (Single Carrier)
TDMA Single Carrier
UWC-136
EDGE/ERAN
IMT-FT (Frequency Time)
TDMA Multi-Carrier
DECT

Evolved IS-41
Core Network
Page 15


2G terrestrial radio interfaces
China :

GSM
US & Canada :

W
estern Europe:

CDMA
(13%)

GSM

GSM
(12%)

(87%)

(100%)

CDMA
(49%)

TDMA

Japan:

(39%)

PDC

(64%)

(36%)

Rest of the W
orld :

GSM
(41%)

CDMA

CDMA
(35%)

TDMA
(24%)


1999 Market Share:
GSM
48 %
CDMA
28 %
TDMA
15 %
PDC
9%
Page 16


3G terrestrial radio interfaces
China :

GSM
US & Canada :

GSM

GSM
(12%)

EDGE

(87%)

UMTS

W
estern Europe:

CDMA
(49%)
CDM
A
2000

(100%)

UMTS
TDMA

CDMA
(13%)
CDM
A
2000
Japan:

(39%)

EDGE

PDC

(64%)

UMTS
Rest of the W
orld :

GSM
(41%)

UMTS

CDMA
(35%)
CDM
A
2000
UMTS

TDMA
(24%)

EDGE

IMT2000

CDMA
(36%)
CDM
A
2000
UMTS

1999 Market Share:
GSM
48 %
UMTS
CDMA
28 %
CDM
TDMA
15A
%
EDGE
PDC
9%

2000


Page 17


3GPP: joint organization
for UMTS standardization
Affiliated organizations:
ETSI (Europe)
ARIB/TTC (Japan)
T1 (USA)
TTA (South Korea)
CWTS (China)
Other members involved: manufacturers and operators
System Specification:
Access Network
WCDMA (UTRA FDD)
TD-CDMA (UTRA TDD)
Core Network
Evolved GSM
All-IP
Releases defined for the system specifications:
- Release 99 (called R3 as well)
- Release R4 and R5 (previously known as Release 2000 or R’00)

In the following material we will only refer to UMTS R99.

Page 18


3GPP: TSG organization
Project Co-ordination Group
(PCG)

TSG CN
Core Network

TSG RAN

TSG SA

Radio Access Networks Service and System

TSG T
Terminals

Aspects

TSG GERAN
GSM EDGE
Radio Access Network

CN WG1
Mobility Management,
Call Control,
Session Management

RAN WG1
Radio layer 1
specification

SA WG1
Services

T WG1
Mobile Terminal
Conformance Testing

GERAN WG1
Radio Aspects

CN WG2
CAMEL

RAN WG2
Radio Layer 2 &
Radio Layer 3 RR
specification

SA WG2
Architecture

T WG2
Mobile terminal
services & capabilities

GERAN WG2
Protocol Aspects

CN WG3
Interworking with
External Networks

RAN WG3
Iub, Iur, Iu specification &
UTRAN O&M requirements

SA WG3
Security

T WG3
Smart Card
Application aspects

GERAN WG3
Terminal Testing

CN WG4
MAP/GTP /BCH/SS

RAN WG4
Radio performance &
Protocol aspects

SA WG4
CODEC

CN WG5
OSA
Open Service Access


SA WG5
Telecom Management

Page 19


3GPP specifications

Series_Id
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.

Series_description
Requirements
Service Aspects
Technical Realization
Signaling Protocols (UE to network)
UTRA aspects
CODECs
Data
(reserved)
Signaling Protocols (intra-fixed network)
Program management
User Identity Module
O&M
m
Security Aspects
ecs.ht
ecs/sp
sp
Test specification
p.org/
p
Security algorithms
ww.3g
/w


http:/

Page 20


UMTS Roadmap

EDGE
Commercial
introduction

UMTS R99
commercial
System

UMTS R99
Field Trials
GPRS
implementation

2001

2002


UMTS R5

2003

2004

Page 21

1.Introduction

1.1

Context

1.2

Standardization

1.3

UMTS Goals

1.4



Page 22

1.Introduction/1.3 UMTS goals

W UMTS?
hy

“UM will be a m o bile c o m m unic a tio n s y s te m tha t o ffe rs s ig nific a nt us e r
TS
be ne fits inc lud ing hig h-q ua lity wire le s s m ultim e d ia s e rvic e s to a c o nv e rg e nt
ne two rk o f fix e d , c e llula r a nd s a te llite c o m p o ne nts . ”
I will d e liv e r info rm a tio n d ire c tly to us e rs a nd p ro v id e the m with a c c e s s to
t
ne w a nd inno v a tiv e s e rv ic e s a nd a p p lic a tio ns .
I will o ffe r m o bile p e rs o na liz e d c o m m unic a tio ns to the m a s s m a rke t
t
re g a rd le s s o f lo c a tio n, ne two rk a nd te rm ina l us e d . ”
UMTS Forum 1997


Page 23

1.Introduction/1.3 UMTS goals

UMTS vision

Zone 4: Global
Satellite
Zone 3: Suburban

Zone 2: Urban
Zone 1: In-Building

Macro-Cell

MSS

GSM


Micro-Cell

UTRA/ FDD

Pico-Cell

UTRA/ TDD

Page 24

1.Introduction

1.1

Context

1.2

Standardization

1.3

UMTS Goals

1.4



Page 25

1.Introduction/1.4 UMTS technical overview

UMTS general architecture

PS networks

CS networks

(Internet…)

(PSTN, ISDN..)

CN
Iu
RAN
Uu
UE
CN
RAN
UE

Core Network
User Equipment


Core network (CN)
it provides support for the network
features and telecommunication
services. It is connected to external
CS networks or PS networks.
Radio Access network (RAN)
it comprises roughly the functions
specific to the access technique.
3 different RANs are foreseen:
•UTRAN (UMTS Terrestrial RAN)
•MSS (Mobile Satellite component)
•BRAN (Broadband RAN)
User Equipment (UE)
It is the mobile phone.
Page 26


UMTS Cellular System

UMTS consists of a set of hierarchical cells, but the multiple access
technique is completely different from GSM.
GSM
Users are separated in frequency
(FDMA) and in time (TDMA)


UMTS
Users are separated with codes
(CDMA)

Page 27


UMTS duplex modes

5 MHz channel

FDD mode
Code and Frequency
orthogonality

f1

Up link

f2

Do wnlink

TDD mode
Code and Time
orthogonality


..
.

5 MHz channel

Up link & Do wnlink

..
.

15TS

Page 28


UMTS Frequency allocations

2110

2170

FDD
1900

1920

TDD

MSS
1980

FDD

2200

2010

MSS

2025

TDD
Uplink

Downlink

FDD: Frequency Division Duplex
TDD: Time Division Duplex
MSS: Mobile Satellite System


Page 29

1.Introduction

QUIZ! (1)
Mark the following answers to the questions A to E by True or False.
A. W
hat are the limits of 2G systems like GSM?
1/ No security of communications
2/ No dynamical allocation of radio resources
3/ Mobility only in a small area
4/ Heavy mobile phones
5/ Limited offer of data services
B. EDGE...
1/ is an evolution of GSM
2/ is sometimes considered as a 3G system
3/ is based on a new modulation scheme
4/ is supposed to reach a bit rate about 40 times greater than the GSM one


Page 30

1.Introduction

QUIZ! (2)
C. W
hich of these radio interfaces belongs to IMT-2000?
1/ CDMA One

2/ UMTS FDD

3/ UMTS TDD

4/ CDMA 2000

5/ EDGE

D. W
hat is the organisation responsible for UMTS standardization?
1/ 3GPP

2/ 3GPP2

3/ ETSI

4/ ARIB

5/ CWTS

E. W
hat is the bandwidth of a CDMA carrier in UMTS?
1/

200 kHz

2/

1 MHz

3/

5 MHz

F. Are the following statements about UTMS duplex modes True or False?
1/ FDD is similar to the GSM duplex mode
2/ TDD use the same frequencies as FDD
3/ FDD is better suited for asymmetric traffic
4/ TDD will come later

Page 31

2.
Services provided


Page 32

2. Services provided

2.1

UMTS service principles

2.2

UMTS Bearer services

2.3

Tele-services

2.4

UMTS Terminals


Page 33

2. Services provided/2.1 UMTS service principles

W is a service?
hat

E.g speech,
file transfer,
emails...

CN
Node

UTRAN

TE/MT

CN
Gateway

Teleservice
External Bearer
Service

UMTS Bearer Service

E.g data
transfer at
9,6 kbps, in
transparent
mode,
with turbocode
...

TE

Radio Access Bearer Service
(RAB)
Radio Bearer
Service
...

Iu Bearer
Service

CN Bearer
Service
Backbone
Bearer Service

...

Physical
Radio Physical
Bearer Service
Bearer Service
Uu


Iu
Page 34


Teleservices
Speech, emergency calls
SMS
Email
Internet Access
Mobile e-commerce
Video Postcards
Information and location
based services
New applications

Tele-services and
Bearer services

“Instinctive” service
Basic services

Enhanced services
New services to be provided
by service providers (third party)

Large toolkit for all kinds of services

Page 35


Third party: service provider

Tele-services will not be standardised so as to differentiate between
operators and providers of applications.
UMTS offer new opportunity for content and service providers
Today’s 1:1 customer-operator relationship
Tomorrow’s situation?
Contracted Content providers

Operator

Contracted Service providers

Contracted Service providers

Operator

Page 36


Virtual Home Environment (VHE)
The Virtual Home Environment (VHE) is an important portability concept of
the 3G mobile systems.
• it enables end users to bring with them their Personal Service
Environment (PSE) whilst roaming between networks,
• and also being independent of terminal used.
• "same look and feel" wherever you are
The PSE is defined in terms of one or more User Profiles (list of
subscriptions, associated preferences, terminal interface preferences, …)


Page 37


Service Architecture

Service Layer

Tele-services
(terminal equipment functions,
Operator transmission capabilities)

Standardized
interfaces
Service Capability Features
Service Capability Servers

GSM/GPRS/UMTS

Bearer Services

CAMEL

MExE

SAT

Network Layer
Fixed

VHE concept is based on the standard mechanisms of Service Capability
Servers which allow Service Capability Features. The latter are carried
through standard interfaces in order to support Tele-services adapted to
the Service Capabilities of the network and user equipment.

Page 38


Let’s Look for the nearest
restaurant

Choose your preferences:
- type of restaurant: Fre nc h
- type of payment: c re d it c a rd
...
Restaurant Paul Bocuse
69660 Collonges-au-Mont-d'or

This service is built from the following service capability features:
call set-up & authorisation (CAMEL for services in roaming after
authentication phase with SAT),
Map display on the phone : SAT and MExE
Call the restaurant by Push Service : MExE
Reservation with VISA card number : secured transaction with MExE
Billing of the service : CAMEL

Page 39


2.1


2.2


2.3

Tele-services

2.4

UMTS Terminals


Page 40

2. Services provided/2.2 UMTS Bearer Services

Bearer services characterization
Bearer services are characterized by a set of end-to-end characteristics
with requirements on QoS, always considered point-to-point.
Bearer services provide the capability for information transfer between
access points and involve only low layer functions.
Each bearer service is characterized by its requirements:
• transfer information: connection oriented or connectionless, traffic
type (guaranteed/constant bit rate, non guaranteed/variable…), traffic
characteristics (uni-directional, bi-directional, multicast…), priority
• quality characteristics: maximum transfer delay, delay variation, bit
error ratio, data rate.
This set of requirements are called QoS parameters.
Example : several active radio bearer services can be handled
simultaneously by the same terminal equipment.
Page 41



Bearer QoS requirements

• negotiable: QoS offer on demand
• provide a wide range of QoS levels
• dynamic behaviour: It shall be possible to negotiate (re-negotiate) the
characteristics of a bearer service at session or connection establishment
(during an on going session or connection).
• support of asymmetric nature between uplink and downlink
• supply of bearer services without wasting resources on the radio and
network interfaces.

Page 42


Bearer Supported bit rates

The only limiting factor for satisfying application requirements shall be the
cumulative bit rate per mobile termination at a given instant in each radio
environment:
•At least 144 kbps in rural outdoor radio environment (with a
maximum speed of 500 km/h)
•At least 384 kbps in urban or suburban outdoor radio
environments (with a maximum speed of 120 km/h)
•At least 2048 kbps in indoor or low range outdoor radio
environment (with a maximum speed of 10 km/h)
Theses performances decrease:
- when the speed of the user increases
- when the load of the network increases

Page 43


2.1


2.2


2.3

Tele-services

2.4

UMTS Terminals


Page 44

2. Services provided/2.3 Tele-services

Typology

Media

Always-on

•
•
•
•
•

Directories
Mobile Office
•
•
•
•
•
•

Voice (!)
E-mail
Agenda
IntraNet/InterNet
Corporate Applications
Database Access

• Yellow/White Pages
• I rna tio na l Dire c to rie s
nte
• Operator Services

Games (Hangman, Poker, Quiz, …)
Screen Saver
Ring Tone
Horoscope
Biorhythm

Music

• Downloading of
music files or
video clips

Transportation

• Flight/train Schedule
• reservation

Vertical
application
•
•
•
•

Fun

Traffic Management
Automation
Mobile branches
Health

News
(general/
specific)
•
•
•
•
•
•
•
•

International/National News
Local News
Sport News
Weather
Lottery Results
Finance News
Stock Quotes
Exchange Rates

Location services
• Traffic Conditions
• Itineraries
• Nearest Restaurant,
Cinema, Chemist,
Parking;, ATM ...

M-commerce
Non physical
•
•
•
•
•
•

on-line Banking
Ticketing
Auction
Gambling
Best Price
e-Book

Physical

• on-line shopping
• on-line food

Page 45


QoS classes

4 classes have been identified:
conversational

+
Delay
sensitive

-

• AMR speech service
• Video telephony
– CS:
H324
– PS:
H323

streaming
interactive
• Web-browsing
• location based services

background

Data
Integrity
sensitive

+

• e-mail delivery
• SMS ...


Page 46


Performance

QoS of teleservices depends not only on UMTS network, but also on
applications, terminals and external networks.
From a user’s perspective it is more relevant to speak of delay rather than
bit rate:

Error
tolerant

Conversational Streaming audio Voice messaging
and video
voice and video

FTP, still image, E-commerce,
Error
Telnet,
WWW browsing
paging
intolerant interactive games

Conversational
delay <<1 sec


Streaming
delay<1 sec

Interactive
delay <10 sec

Fax

E-mail arrival
notification

Background
delay >10 sec

Page 47


Defining charging principles
• How will billing be performed: by time? by volume? by number of
connections?
• If billing is performed by volume, what will be an easy way to explain to
the customer what a “1 Mbyte of data” is?
• What will happen in case of handover between GSM and UMTS?
• What about roaming? Prepaid services?
• QoS depends directly on the load of the network. A trade-off must be
found between users. Customers who pay more might have higher priority
or better QoS (depending of the operator’s strategies). Billing for a given
service might depend on the QoS.

Page 48

2. Services provided/2.3 Teleservices

Location based services

Teleservices will depend on the strategy and on the imagination of
operators and content providers.
The key point is likely to be a fast access to information and an appropriate
filtering of the user location data.
the UMTS killer application is likely be a location based service
Example of location based services : look for an hotel, consult yellow
pages, get local traffic situation or weather report,...
Limitation: location information could be a risk for privacy.


Page 49


2.1


2.2


2.3

Tele-services

2.4

UMTS Terminals


Page 50

2. Services provided/2.4 UMTS terminals

User Equipement (UE)

Cu
interface

UICC
USIM1

USIM2

GSM
access

SIM
Mobile
Equipment

GSM/GPR
S terminal

(ME)

User Equipment (UE)


Page 51

2. Services provided/2.4 UMTS terminals

Range of terminals

There will be a wide range of terminals depending of the type of application
(speech, video, games, dual...), the mode (UMTS/GSM, UMTS/DECT...)
Integrated approach:

1 handset able to perform all
functions. Most of the concept
phones today.

Distributed approach:

1 handset for voice & WAP, or voice only
and a Bluetooth connection to other
devices (headset, camera...).
New interfaces

Automotive / Telematics PS
G

Data / IT

E-Commerce
Consumer Electronics

Image

Domestic

Games Audio
Page 52


QUIZ!

A. True or False? The tele-services...
1/ are used for example to make a call, to access yellow pages, on-line banking...
2/ are mapped on bearer services
3/ will be standardized by 3GPP
B. True of False? The VHE...
1/ is a portability concept of 3G mobile systems
2/ will enable to keep the same environment when roaming between mobile and fixed networks
3/ will be adapted to the terminal capabilities
4/ will use proprietary interfaces


Page 53


QUIZ!

C. True or False? A bearer service can support for one user:
1/ 2 Mbps at a speed of 120 km/h
2/ 2 Mbps in a high loaded cell
3/ 2 Mbps at 3 km away from the base station
4/ Asymmetric traffic
5/ Variable traffic
D. True or False? Location based services...
1/ are services only available in some areas (city centers...)
2/ are services related to the location of the user
3/ can locate the mobile phone with an accuracy of about 50 m


Page 54


QUIZ!

E. True or False? A UICC (UMTS integrated Circuit Card)...
1/ has the same size as a GSM SIM card
2/ can not be used in a GSM terminal
3/ can be used in an UMTS terminal and provide access to GSM network
4/ is linked with the UMTS terminal via a proprietary interface
5/ may provide access to UMTS networks of different operators

F. UMTS services have been announced to come later than initially scheduled because of non
availability of UMTS terminals in volume: can you find some reasons which makes it quite
complex to design UMTS terminals?


Page 55

3.
UMTS System Description


Page 56

3. UMTS System Description

3 views of the system

Protocol architecture

Logical architecture

Pro to c o l
s ta c ks

Entitie s

Be a re rs
Call scenario

Page 57


Pro to c o l
s ta c ks

Entitie s

3.1 Logical architecture

Be a re rs

3.2 Protocol architecture
3.3 Call scenario


Page 58

3. UMTS System Descript./3.1 UMTS logical
architecture

UMTS logical Architecture
CN

Core Network

CS-Service
Domain

PS-Service
Domain

Iu-CS

IU

Iu-PS
Iu-PS

RNS

RNS
Iur

RNC

UTRA
N

UU

Iu-CS

Iu-reference
point

Iub
Node_B
Node B

Iub
Node B

RNC
Iub
Node B

Iub
Node B

Uu-reference
point

UE


Page 59

architecture

CN logical architecture
UMTS Core Network for Release 99
2G/3G
MSC

PLM
N
PS TN / I DN
S

2G/3G
GMSC

A

GSM BSS
BSC

EIR

Gb

HLR

AuC

VHE

Iu (CS)

UTRAN
RNC

Iu (PS)


2G/3G
SGSN

I Ba c kbo ne 2G/3G
P
GGSN

Ex te rna l
I N two rk
P e
Page 60

architecture

RNS

UTRAN logical
Architecture
RNS

Iur

RNC
Iub
Node_B
Node B

Iub
Node B

RNC
Iub
Node B

Iub
Node B

RNC
It is the intelligent part of the UTRAN:
- radio resource management (code allocation, congestion control, admission
control)
- radio mobility management
- macro-diversity handling (soft HO)
- control of Node-Bs
Node-B
A Node-B can be composed of several cells and performs:
- radio transmission handling
- macro-diversity handling (softer HO)

Page 61

architecture

Soft Handover (1)

Core Network
I
u

I
u
I
ur

S RNC1

DRNC2
S

I
ub

I
ub

I
ub

NodeB1

1

I
ub

NodeB2

NodeB3

NodeB4

2

3

4

5
6


Page 62

architecture

Soft Handover (2)

The role of an RNC (Serving or Drift) is on a per connection basis between
a UE and the UTRAN:
Serving RNC: provide Iu UE-CN connection
Drift RNC: supports Serving RNC by providing radio resources
The recombination of the signal is performed in Serving RNC (in Node B for
softer HO) and in UE using a RAKE receiver.
Soft HO is highly recommended in UMTS system: about 30 to 40% of
mobiles are in macro-diversity mode in IS-95.


Page 63

architecture

UMTS logical Interfaces

Open Interfaces
The functional split for the UMTS components (UE, Node-B, RNC...) are
clearly specified, but the internal architecture and implementation issues
are left open (it is up to the manufacturer).
However all the interfaces (Cu, Uu, Iub, Iur, Iu-CS, Iu-Ps) have been
defined in such a detailed level that the equipment at the endpoints can be
from different manufacturers.
“Open Interfaces” aim at motivating competition between manufacturers.
Physical implementation of Iu interfaces
Each Iu Interface may be implemented on any physical connection using
any transport technology.
ATM will be provided in the R99 release and IP is foreseen in further
releases

Page 64


Pro to c o l
s ta c ks

Entitie s


Be a re rs

3.3 Call scenario


Page 65

3. UMTS System Descri./3.2 UMTS protocol

Access stratum and
Non Access Stratum

architecture

N n-A c e s s Stra tum (N S)
o
c
A
Iu
Radio
Protocols Protocols
(2)
(1)

Radio
Protocols
(1)

Iu
Protocols
(2)

A c e s s Stra tum
c
(A
S)

UE
Uu

UTRAN

CN

Iu

SAP

Interchanges between entities is applied on a peer-to-peer principle.
Each entity provides services to entities of upper layers through Service
Access Points (SAP).

Page 66

architecture

Non Access Stratum

CS traffic
CM/
MM
CS traffic

PS traffic

CM/
MM

SM/
GMM

Iu Protocols

NAS
A
S

Uu

Radio Protocols

UE

Radio
Protocols

Iu
Protocols

IuCS

MSC

SM/
GMM

UTRAN

PS traffic

Iu Protocols
Iu-PS

SGSN

Page 67

architecture

1

2

4

Access Stratum: radio
protocols

4. Us e r a uthe ntic a tio n (N S s ig na lling )
A
2 . We b bro ws ing (fro m /to I
u-PS)
3 . Lo c a l
we a the r
1 . Sp e e c h (fro m /to I
u-CS)
fo re c a s t
(SM
S
Ce ll

3

N NA
O
CCESS STRA
TUM(N S)
A

Bro a d c a s t

)

ACCE SS ATUM(AS
S TR
)

RRC

5. I
nitia l a c c e s s (RRC Co nne c tio n Es ta blis hm e nt)

RRC
PDCP BMC

RLC
MAC

RLC
MAC

Phys

Phys

UE

Uu


Iu
protocols

Node B

Iu
protocols
Iub

ne
pla
ol
ne
ntr
pla
Co
er
Us

PDCP BMC

RNC
Page 68

architecture

Node-B

Iub
N P
BA

Iu-CS

RNC
RN P
SA

Radio
Network
Layer

Application Protocol:
- N P for Iub
BA
- RN P for Iur
SA
- RA A for Iu-CS
N P
and Iu-PS

Transport

Iur

SGSN

Iu-PS
Control
Plane

User Plane

Application
Protocol
Transport Network
User Plane

Data
Stream(s)
Transport Network
Control Plane

Transport Network
User Plane

ALCAP

Network
Layer

MSC
RA A
N P

RNC

The same general
protocol model is applied
for all Iu interfaces:

Access Stratum: Iu
protocols

Signaling
Bearer(s)

Signaling
Bearer(s)

Data
Bearer(s)

Physical Layer

Page 69


Pro to c o l
s ta c ks

Entitie s


Be a re rs

3.3 Call scenario


Page 70

3. UMTS System Description/3.3 Call Scenario

Radio Access Bearer (RAB)

UMTS Bearers
CN-CS
A
R
B
R
B
A

UMTS Bearer

UTRAN
UE

UMTS Bearer

R
A
B
R
A
B

UMTS bearer
services

CN-PS
Radio Bearers

Iu Bearers

RABs (mapped on Radio & Iu Bearers)
“The RAB provides confidential transport of signaling and user data
between UE and CN with the appropriate QoS”.

Page 71


Establishment of a call

Inside the UTRAN
No more distinction between CS and PS part: all data are mapped on RAB.
But the RAB characteristics (delay, bit rate…) may not be the same for CS
and PS part.
UTRAN has the total freedom to configure the radio bearers according to
the required RAB attributes (ie QoS).


Page 72


Example : CS call establishment
UE

UTRAN

Uu

Iu

CN

Connection to UTRAN
(RRC Connection establishment)

Request for service
(RRC)

(RANAP)

Authentication and Ciphering / Integrity
Setup
Establishment of Resources (RAB + Radio Bearer)
Alert and Connect

Page 73


QUIZ!

A. Put the correct words in the spaces on the figure below

...

...

CS networks
(PSTN, ISDN)

...

...

...

...

...

...

...

...

PS networks
(internet)

...
...

...


...

...

Page 74


Quiz!

B. W
hich of the following statements concerning the soft(er) handover is true of false?
1/ a soft(er) HO consists of two or more simultaneous radio links between the UE and the
UTRAN
2/ a soft HO is under the control of the Drift RNC
3/ a softer HO is performed by Node-B
C. W
here is performed the radio mobility management?
1/ in the CN

2/ at the RNC

3/ at the Node-B

D. According to the norm, can the RNC from a given
manufacturer be compatible with:
1/ the CN of another manufacturer?
2/ the RNC of another manufacturer?
3/ the Node-B of another manufacturer?

Page 75

4.
WCDMA for UMTS


Page 76

4. WCDMA for UMTS

4.1

Context

4.2

Spread Spectrum modulation

4.3

Code Division Multiple Access

4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7

Typical coverage and capacity values


Page 77

4. WCDMA for UMTS/ 4.1 Context

From military to civil modern
radio-communications
Early 70’s
CDMA developed for military field for its great qualities of privacy (low
probability interception, interference rejection)
1996
CDMA commercial launch in the US
This system called IS-95 or cdmaOne was developed by Qualcomm and
has reached 50 million subscribers worldwide
2000
IMT-2000 has selected three CDMA radio interfaces:
- WCDMA (UTRA FDD)
- TD-CDMA (UTRA TDD)
- CDMA 2000
In the following material we will only refer to W
CDMA (UTRA FDD)

Page 78

4. WCDMA for UMTS/ 4.1 Context

W CDMA?
hy

CDMA is very attractive:
• Better spectrum efficiency than 2G systems
• Suitable for all type of services (circuit, packet) and for multi-services
• Enhanced privacy
• Evolutionary (linked with progress in signal processing field)
BUT:
• Complex system: not easy to configure and to manage
• Unstable in case of congestion

Page 79

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 80

4. WCDMA for UMTS/ 4.2 Spread Spectrum Modulation

A code as a shell
against noise
Noise

Spreading

Transmitter

Radio channel

Despreading

Receiver

The letter ‘A’ represents the signal to transmit over the radio interface.
At the transmitter the height (ie the power) of ‘A’ is spread, while a color (i.e
a code) is added to ‘A’.
At the receiver ‘A’ can be retrieved with knowledge of the code, even if the
power of the received signal is below the power of noise due to the radio
channel.

Page 81

4. WCDMA for UMTS/ 4.2 Spread Spectrum
Modulation

P

P

f

Spreading

Radio channel

Spectrum spreading
P

P

N is e
o
le v e l

f

f

f

De-spreading

At the transmitter the signal is multiplied by a code which spreads the
signal over a wide bandwidth while decreasing the power (per unit of
spectrum).
At the receiver it is possible to retrieve the wanted signal by multiplying the
received signal by the same code: you get a peak of correlation, while the
noise level due to the radio channel remains the same, because this is not
correlated with the code.
The spectrum spreading permits transmission of a signal below the noise
level and makes the signal very hard to detect.
Spectrum spreading makes CDMA very secure.

Page 82

Modulation

Transmission Chain

Air Interface
NB-Signal

WB-Signal

WB-Signal

NB-Signal

Data

Data
Modulator
Code sequence

Demodulator
Code Sequence

The narrowband data signal is multiplied bit per bit by a code sequence: it
is known as “chipping”.
The chip rate of this code sequence is much higher than the bit rate of the
data signal: it produces a wideband signal, also called spread signal.
At the receiver the same code sequence in phase should be used to
retrieve the original data signal.

Page 83

Modulation

Signal
Spreading
Code
Tx signal

1
1111
0101
0101

0
0000
0101
1010

0
0000
0101
1010

Rx signal
Code
Despreading
Signal

0101
0101
1111
1

1010
0101
0000
0

Spreading factor

(bits)
(chips)

1010
0101
0000
0

Radio channel

(In this case, each bit of the signal is spread over 4 chips. The spreading
factor is 4)
Spreading makes CDMA adequate for services with variable bit rates.


Page 84

Modulation

Processing Gain

P

W 
Processing Gain = 10 Log 10 
 Rb 

Processing
Gain
De-spreading
W

Rb

f

The Processing Gain is the gain you have at the receiver by the
despreading of the signal (peak of correlation). It enables transmission of
the signal below the noise level.
A high bit rate signal needs more power to cross the noise level by despreading.

Page 85

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 86

4. WCDMA for UMTS/ 4.3 Code Division Multiple
Access

One-cell reuse

The area is divided into cells, but the entire
bandwidth is reused in each cell (frequency reuse
of one)
> Inter-cell interference
> Cell orthogonality is achieved by codes

The entire bandwidth is used by each user at the
same time
> Intra-cell interference
> User orthogonality is achieved by codes

Page 87

4. WCDMA for UMTS/ 4.3 Code Division Multiple
Access

Multiple access (1)

Spreading 1

Transmitter 1

Spreading 2

Radio Channel

Spreading1

Receiver
The receiver aims at receiving Transmitter 1 only.

Transmitter 2

All the users transmit on the same 5 MHz carrier at the same time and
interfere with each over.
At the receiver the users can be separated by means of (quasi-)orthogonal
codes.

Page 88

4. WCDMA for UMTS/ 4.3 Code Division Multiple Access

Multiple access (2)

Spreading 1

Transmitter 1

Spreading 2

Radio Channel

Spreading1

Receiver
The receiver aims at receiving Transmitter 1 only.

Transmitter 2

If a user transmits with a very high power, it will be impossible for the
receiver to decode the wanted signal (despite use of quasi-orthogonal
codes)
CDMA is unstable by nature and requires accurate power control.

Page 89


Spreading:
Channelization and scrambling
cch1
air
interface

cch 2

cscrambling

M d ula to r
o

cch 3
The channelization code (or spreading code) is signal-specific: the code
length is chosen according to the bit rate of the signal.
The scrambling code is equipment-specific.

Page 90


Channelization codes
(spreading codes)

C

C
ch,1,0

= (1,1,-1,-1)

ch,4,2

= (1,-1,1,-1)

C

C

ch,2,0

ch,4,1

C

C

ch,4,0

=(1,1,1,1)

ch,4,3

= (1,-1,-1,1)

= (1,1)

The code tree is shared by several
users (usually one code tree per
cell)

= (1)

C

SF = 1

ch,2,1

= (1,-1)

SF = 2

SF = 4

SF = 8

The channelization codes are OVSF (Orthogonal Variable Spreading Factor)
codes:
• their length is equal to the spreading factor of the signal: they can match
variable bit rates on a frame-by-frame basis.
• orthogonality enables to separate physical channels:
UL: separation of physical channels from the same terminal
DL: separation of physical channels to different users within one cell

Page 91


Scrambling codes
The scrambling codes provide separation between equipment:
• UL: separation of terminals
No need for code planning (millions of codes!)
There are 214 long and 214 short scrambling codes in uplink
• DL: separation of cells
Need for code planning between cells (but trivial task)
There are only long scrambling codes in downlink
(512 to limit the code identification during cell search procedure)
The long scrambling codes are truncated to the 10 ms frame length.
Only one DL scrambling code should be used within a cell.
Another scrambling code may be introduced in one cell if necessary
(example : shortage of channelization code), but orthogonality between
users will be degraded.

Page 92

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 93

4. WCDMA for UMTS/ 4.4 Rake Receiver

Rake Receiver principle (1)
In a CDMA system there is a single carrier which contains all user signals.

Decoding of all these signals by one receiver is only a question of signal
processing capacity.
A Rake receiver is capable to decode several signals simultaneously in the
so called “fingers” and to combine them in order to improve the quality of
the signal or to get several services at the same time.
A Rake receiver is implemented in mobile phones and in base stations.
A Rake receiver can provide:
- multi-service (via handling of multiple physical channels that are carrying
the services)
- soft handover
- path diversity

Page 94


Rake receiver principle (2)

Delay Adjustment

Multi-code
signal

1 st
Fing e r

Delay 1

2 nd
Fing e r

Delay 2

3 rd
Fing e r

Data 1
Code Sequence 1

Code Sequence 2

Data 2
Delay 3

Code Sequence 2 or 3

The components of the multi-code signal are demodulated in parallel each
in one “finger” of the Rake Receiver.
The outputs of the fingers:
• can provide independent data signals
• can be combined to provide a better data signal(s)

Page 95


Rake receiver
and multi-service

Despreading 1

Spreading 1

Spreading 2

Radio Channel

Transmitter

Despreading 2

Multimedia receiver

As a first approach, we can say:
One service, one code! (*)
>> Which codes make it possible to
separate the two signals at the receiver?

Page 96


Rake Receiver
and soft handover

Spreading 1

Base station 1

Spreading 2

Base Station 2

Radio Channel

Despreading 1&2

Mobile phone

>> Which codes make it possible to
separate the two signals
at the
receiver?

Soft handover is possible, because the two mobile stations use the same
frequency band. The mobile phone need only one transmission chain to
decode both simultaneously.

Page 97


Rake Receiver
and path diversity (1)

Natural obstacles (buildings, hills…) cause reflections, diffractions and
scattering and consequently multipath propagation.
The delay dispersion depends on the environment and is typically:
• 1 µs (300 m) in urban areas
• 20 µs (6000 m) in hilly areas
The delay dispersion should be compared with the chip duration 0,26 µs
(78 m) of the CDMA system.
If the delay dispersion is greater than the chip duration, the multipath
components of the signal can be separated by a Rake Receiver.
In this case, CDMA can take advantage of multipath propagation.

Page 98


Rake Receiver
and path diversity (2)

Direct path
Despreading

Spreading

Transmitter

Reflected path

Dispersion <Chip duration
The Rake Receiver cannot provide path diversity.

Receiver
>> Which codes make it
possible to separate the two
signals at the receiver?

Direct path
Spreading

Transmitter

Despreading

Reflected path

Receiver

Dispersion > Chip duration
The Rake Receiver can provide path diversity to improve the quality of the signal.

Page 99

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 100

4. WCDMA for UMTS/ 4.5 Power Control

W Power Control?
hy

MS2
MS1
Node
B

Near-Far Problem
on the uplink way an overpowered mobile phone near the base station can
jam any other mobile phones far from the base station.
> Need for very efficient and very fast Power Control on UL
> Power Control is also used in DL to reduce interference and
consequently to increase the system capacity.

Page 101


Open Loop

Open loop power control

1
Node
B
2

If UE receives a STRONG DL signal,
then UE will speak low.

1
Node
B
2

If UE receives a weak DL
signal,
then UE will speak LOUD.

Problem:
fading is not correlated on UL and DL due to separation of UL and DL band.
Open loop Power Control is inaccurate.


Page 102


Closed Loop

Closed loop power control

”Power down” SIR estimation

RNC

SIR
target

Node
B

SIR
estimation
SIR
estimation

”Power down”
”Power up”
”Power ...”

SIR
estimation

...

The Node-B controls the power of the UE (and vice versa) by performing a
SIR estimation (inner loop).
The RNC controls parameters of the SIR estimation (outer loop).
This SIR estimation is performed each 0,66 ms (1500 Hz command rate).
Closed loop Power Control is very fast.

Page 103

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 104

4. WCDMA for UMTS/ 4.6 Soft Handover

Soft Handover (1)

RNC

Node
B
Node
B

Node
B

Soft
HO

Softer HO
Page 105


Soft Handover (2)

Why do we need soft HO?
Imagine that a UE penetrates from one cell deeply into an adjacent cell:
> it may cause near-far problem
> hard HO is not a good solution, because of the need for the hysteresis
mechanism
Additional resources due to soft HO:
- Additional rake receiver in Node-B
- Additional Rake Fingers in UE
- Additional transmission links between Node-Bs and RNCs
Soft HO provides Diversity (also called Macro-Diversity), but requires
more network resource.


Page 106


Soft Handover (3)

Soft Handover execution:
Soft Handover is executed by means of the following procedures
• Radio Link Addition (FDD soft-add);
• Radio Link Removal (FDD soft-drop);
• Combined Radio Link Addition and Removal.

The cell to be added to the active set needs to have information
forwarded by the RNC:
• Connection parameters (coding scheme, layer 2 information, …)
• UE ID and uplink scrambling code,
• Timing information from UE

The UE needs to get the following information
• Channelization & scrambling codes to be used
• Relative timing information (Timing offset based on CPICH synchro)

Page 107

4. WCDMA for UMTS

4.1

Context

4.2


4.3


4.4

Rake Receiver

4.5

Power Control

4.6

Soft Handover

4.7



Page 108

4. WCDMA for UMTS/ 4.7 Typical coverage and capacity
values

Radio dimensioning process: W
hat’s
new?

Market perspective
Mobile data market forecast
Marketing inputs
Multi-service environment
Voice+data
Variable bit rate
Different QoS
Asymmetric traffic
New radio technology
W-CDMA

Capacity

Coverage


Quality

Page 109

4. WCDMA for UMTS/ 4.7 Typical coverage and capacity
values

Concentric coverage

The coverage is determined by the uplink range, because the transmission
power of the terminal is much lower than that of the base station.
R1
R2

UE Transmit Power

R3

21 dBm (126 mW)
24 dBm (251 mW)

Service
in suburban area
Cell radius
(uplink limited)


Speech
12 kbps
R1 ≈ 3 km

Packet data
144 kbps
R2 ≈ 2 km

Packet data
384 kbps
R3 ≈ 1,5 km

Page 110

4. WCDMA for UMTS/ 4.7 Typical coverage and capacity values

W of improving coverage
ays

AMR speech Codec
it enables to switch to a lower bit rate if the mobile is moving out of the cell
coverage area: it is a trade-off between quality and coverage.
Multipath diversity
it consists of combining the different paths of a signal (due to reflections,
diffractions or scattering) by using a Rake Receiver.
Multipath diversity is very efficient with W
-CDMA.
Soft(er) handover
the transmission from the mobile is received by two or more base stations.
Receive antenna diversity
the base station collects the signal on two uncorrelated branches. It can be
obtained by space or polarization diversity.
Base stations algorithms
e.g. accuracy of SIR estimation in power control process

Page 111


Soft capacity
The capacity is determined by the downlink direction, because:
- better receiver techniques can be used in the base station than in the
mobile station (but requiring more CPU power).
- the downlink capacity is expected to be more important than the uplink
capacity because of asymmetric traffic.
The downlink capacity has two limitations:
- the amount of interference in the air interface
Adjacent cells share part of the same interference: there is an additional
capacity in a cell, if the number of users in the neighboring cells is smaller.
- the loss of code orthogonality
The downlink codes originate from a single point and can be synchronized.
But, after transmission over multipath channel, part of orthogonality is lost.
It is a soft capacity, because it is not limited by the hardware equipment.

Page 112


Parameters influencing capacity
The capacity depends on:
- the radio environment (rural, suburban, indoor)
- the terminal speeds
- the distribution of the terminals
- the load of the cell: trade-off capacity/coverage (breathing cells)

High loaded cell
High DL interference level
DL data throughput
660 kbps
(per carrier per sector)

High loaded cell
Low DL interference level
DL data throughput
1440 kbps
(per carrier per sector)
Page 113

4. WCDMA for UMTS

QUIZ!

A. True or False? Spreading...
1/ consists of increasing the power while decreasing the frequency bandwidth
2/ allows to transmit a signal with a S/N (Signal-to-Noise ratio) smaller than one
3/ enables to retrieve the coded signal at the receiver by using the same code in phase
4/ is used in FDMA system
B. Signal 1 has a bit rate of 12 kbps and a coding rate of 1/ signal 2 has a bit rate of 384 kbps
3,
and a coding rate of 1/
2:
1/ Which spreading factor should be chosen for each of these signals?
2/ What is the processing gain for each of these signals?


Page 114

4. WCDMA for UMTS

QUIZ!

C. True of false? W
CDMA...
1/ is also called UMTS FDD or UTRA FDD
2/ uses a 1 MHz bandwidth carrier
3/ has a chip rate of 3,84 Mchips/s
D. How many carriers are there per operator for W
CDMA?
1/ 124 carriers

2/ 62 carriers

3/ 1 to 3 according to the country

E. True or false? A Rake Receiver
1/ can separate simultaneously two signals only if their codes are perfectly orthogonal
2/ can separate simultaneously several signals of 2 different WCDMA carriers
3/ can take advantage of multipath propagation


Page 115

4. WCDMA for UMTS

QUIZ!

F. True or false? In W
CDMA, power control
1/ is used in uplink and in downlink
2/ is crucial in downlink because of near-far problem
3/ is composed of the open loop and the closed loop
4/ may be performed each WCDMA time slot (1500 Hz command rate)
G. True or false? Soft handover...
1/ is highly desirable in WCDMA
2/ require use of more frequencies
3/ require use of more power in uplink
4/ require additional signal processing equipment such as Rake Receiver
5/ require additional transmission links

Page 116

5.
UMTS Terrestrial
(FDD mode, Release 1999)

Page 117

5. UTRAN

UTRAN role and principles
Layer 3
Layer 2
Layer 1
UE

Uu

Node B

I
ub

RNC

CN

• To transfer traffic and control channels between UE and CN
- Common handling of packet-switched and circuit-switched data
- Protection of the user data on the air interface (providing of ciphering)
- Independence from the applied transport technology on the Iu interface
• To manage the radio mobility of the user
Full control of UE radio mobility with the use of the Iur interface which makes it
possible to perform soft HO even with 2 cells/Node-Bs belonging to different RNCs.
• To make efficient use of limited radio resources
Support of WCDMA specific Radio Resource Management (RRM) algorithms.

Page 118

5. UTRAN

Layer 3
Layer 2
Layer 1

UE

5.1

From Radio Bearers to transport channels

5.2

Iu Protocols

5.4

UE identifiers and UE states

5.5

Signalling procedures

5.6

The Physical Layer (on the air interface)

5.7

Radio Resource Management (RRM)

5.8

RNC

Radio Protocols

5.3

Node B

Mobility management


Page 119

5. UTRAN/5.1 From Radio Bearers to transport
channels

Situation

CN
Node

UTRAN

UE

CN
Gateway

UE

Teleservice
External Bearer
Service

UMTS Bearer Service
Radio Access Bearer Service
(RAB)
Radio Bearer
Service

...
Radio Physical
Bearer Service
Uu

Iu Bearer
Service

CN Bearer
Service
Backbone
Bearer Service

...
Physical
Bearer Service
Iu
Page 120

5. UTRAN/5.1 From Radio Bearers to transport channels

Radio Bearers, logical and transport
channels

Control plane

NAS signalling
RRC
Sig na lling
Ra d io
Be a re rs

User plane

W browsing
eb
Telephony
speech

RRC connection
establishment

SMS Cell
Broadcast

PDCP

Us e r p la ne
Ra d io
BMCBe a re rs

RLC
Co ntro l
Lo g ic a l
Cha nne l
s

MAC
Tra ns p o rt Cha nne ls
Phys.
UTRAN


Tra ffic
Lo g ic a l
Cha nne ls

(Iur)/Iub/Uu

...
MAC
Phys.
UE
Page 121

channels

Radio Bearers

Signalling Radio Bearers (SRB)
SRBs can carry:
- layer 3 signalling (e.g. RRC connection establishment)
- NAS signalling (e.g location update)
There can be up to 4 SRBs per RRC connection (one UE has one RRC
connection when connected to the UTRAN).
User Plane Radio Bearers
RABs are mapped on user plane RBs.
One RAB can be divided on RAB sub-flows and each sub-flow is mapped on
one user plane RB.
e.g the AMR codec encodes/decodes speech into/from three sub-flows; each
sub-flow can have its own channel coding.

Page 122

channels

Logical Channels (1)

Control Channels (CCH)
Broadcast Control Channel (BCCH)
Paging Control Channel (PCCH)

UTRAN

Common Control Channel (CCCH)
Dedicated Control Channel (DCCH)

Traffic Channels (TCH)
Dedicated Traffic Channel (DTCH)
Common Traffic Channel (CTCH)


Page 123

channels Logical

UL ( )
/
DL ( )

Channels (2)

Wha t typ e of inform a tion ?

BCCH

System control information
e.g cell identity, uplink interference level

PCCH

P
aging information
e.g CN originated call when the network does not know the
location cell of the UE

CCCH

Control information
e.g initial access (RRC connection request), cell update

D CCH

Control information (but the UE must have a RRC connection)
e.g radio bearer setup, measurement reports, HO

D TCH

T
raffic information dedicated to one UE
e.g speech, fax, web browsing

CTCH

T
raffic information to all or a group of UEs
e.g SMS-Cell Broadcast


Page 124


channels W
hy

Transport Channels?

A transport channel offers a flexible pattern to arrange information on any
service-specific rate, delay or coding before mapping it on a physical
channel:
• it provides flexibility in traffic variation
• it enables multiplexing of transport channels on the same physical channel
Transport channels provide an efficient and fast flexibility in radio
resource management.


Page 125


Structure of a Transport Channel (1)
Transport Block: basic
unit exchanged over
transport channels.

Transport Format (TF): it may be changed every TTI.
Each TF must belong to the Transport Format Set (TFS) of
the transport channel

168
360 bits

168

168

168

360

168

168

168

10 ms

10 ms

Time Transmission
Interval (TTI): periodicity
at which a Transport Block
Set is transferred by the
physical layer on the radio
interface

10 ms

10 ms

>> The system delivers one Transport Block Set to the
physical layer every TTI: what is the delivery bit rate of the
transport blocks to the physical layer during the first TTI?

Page 126


Structure of a Transport Channel (2)

Transport Format (TF)
• Semi-static part (can be changed, but long process)
Transmission Time Interval (TTI),
Coding scheme...
• Dynamic part (may be changed easily)
Size of transport block,
Number of transport blocks per TTI
Transport Format Set (TFS)
It is the set of allowed Transport Formats for a transport channel, which is
assigned by RRC protocol entity to MAC protocol entity.
MAC chooses TF among TFS.
MAC may choose another TF every TTI without interchanging with RRC
protocol (fast radio resource control).

Page 127


Example

576 bits
576

576
576

576

576

576

576

576

40 ms
Sta tic Pa rt
TTI
Coding scheme
CRC

?
T
urbo coding, coding rate= 1/ 3
16 bits

D yna m ic Pa rt
T
ransport Block Size
T
ransport Block Size Set

?
576*B (B= 0,1,2,3,4)

1. Complete the table
2. What is the delivery
bit rate of the transport
blocks to the physical
layer during the first
TTI?

3. How many Transport Format(s) may be chosen for this transport channel?
4. Can you imagine why the transfer has been interrupted during the third TTI?

Page 128


Transport Channels

Common Channels
Broadcast Channel (BCH)
Paging Channel (PCH)

UTRAN

Forward Access Channel (FACH)
Downlink Shared Channel (DSCH)
Random Access Channel (RACH)
Common Packet Channel (CPCH)

Dedicated Channels
Dedicated Channel (DCH)


Page 129


Common Transport Channels (1)

BCH:

Broadcast Channel

A downlink transport channel that is used to carry BCCH. The BCH is
always transmitted with high power over the entire cell with a low fixed bit
rate.
>> The BCH is the only transport channel with a single transport format (no
flexibility). Can you explain why?
PCH:

Paging Channel

A downlink transport channel that is used to carry PCCH. It is always
transmitted over the entire cell.
>> Is it possible to carry all types of information on the PCH?


Page 130



FACH:

Forward Access Channel

A downlink transport channel that is used to carry control information. It may also
carry short users packets. The FACH is transmitted over the entire cell or over only
a part of the cell using beam-forming antennas. The FACH uses open loop power
control (slow power control).
>> In which case is it interesting to use beam-forming antennas? would it also be
relevant to implement this feature for PCH?
RACH: Random Access Channel
An uplink transport channel that is used to carry control information from the mobile
especially at the initial access. It may also carry short user packets. The RACH is
always received from the entire cell and is characterized by a limited size data field,
a collision risk and by the use of open loop power control (slow power control).
>> Why is it interesting to carry short user packets on RACH in spite of limited data
field and collision risk (instead of using a dedicated channel)?

Page 131


DSCH: Downlink Shared Channel
A downlink transport channel shared by several UEs to carry dedicated
control or user information. When a UE is using the DSCH, it always has
an associated DCH, which provides power control.
CPCH: Common Packet Channel
An uplink transport channel that is used to carry long user data packets
and control packets. It is a contention based random access channel. It is
always associated with a dedicated channel on the downlink, which
provides power control.

⇒ Tra ns fe r o f s ig na lling a nd tra ffic o n a s ha re d ba s is


Page 132


Dedicated Transport Channels

DCH:

Dedicated Channel

A downlink or uplink transport channel that is used to carry user or control
information. It is characterized by features such as fast rate change (on a
frame-by-frame basis), fast power control, use of beam-forming and
support of soft HO.
> > Two fe a ture s a re o nly a p p lie d o n DCH: c a n y o u g ue s s whic h?


Page 133


Mapping
Logical⇔Transport Channels

Control Logical Channels
BCCH

BCH

PCCH

PCH

CCCH

RACH

Traffic Logical Channels

DCCH

FACH

DTCH

DSCH

Common Transport Channels


CPCH

CTCH

DCH
Dedicated
Transport
Channels
Page 134


Mapping
Logical ⇔ Transport Channels
Control Logical Channels
BCCH

BCH

PCCH

PCH

CCCH

RACH

Traffic Logical Channels

DCCH

FACH

DTCH

DSCH

Common Transport Channels


CPCH

CTCH

DCH
Dedicated
Transport
Channels
Page 135


Complete the gaps!

(1 ) … c ha nne ls
are defined by what type of information (e.g user data, signalling, system
information...) is transported over the radio interface.
are defined by how and with what characteristics (e.g type of coding,
required transfer delay, required BER... ) data are transferred over the radio
interface.
are defined by the mechanisms (e.g frequency, code, power, framing...) with
which the data are transferred over the physical resources of the airinterface.

Page 136


Complete the table!
Tra ffic
cla ss
Sig na lling
1. …
2. …
3. …
4. …

-

Log ica l
Cha nne l

Tra nsp ort
Ch a nn el

BCCH
PCCH
CCCH
DCCH

BCH, FACH
PCH
UL: RACH, DL: FACH
RACH, DCH

UL: 3 coordinated DCHs
DL: 3 coordinated DCHs
UL: RACH, DL: FACH
UL: CPCH, DCH
DL: DSCH,DCH
UL: CPCH, DCH
DL: DSCH,DCH
UL: CPCH, DCH
DL: DSCH,DCH
FACH

Use r inform a tion
5. …

Conversational

6. …

Interactive

3
DTCHs
DTCH

7. …

Interactive

DTCH

8. …

Streaming

DTCH

9. …

Background

DTCH

10. …

Background

CTCH


Page 137

5. UTRAN

Layer 3
Layer 2
Layer 1

UE

5.1


5.2

Iu Protocols

5.4


5.5


5.6


5.7


5.8

RNC

Radio Protocols

5.3

Node B

Mobility management


Page 138

5. UTRAN/5.2 Radio Protocols

Radio protocol stack
Non Access Stratum

Control plane

User plane
Be a re rs (c a lle d
RA in us e r p la ne )
B

Access Stratum
control

control
control

Layer 2/
PDCP
Layer 2/
BMC
control

control

RRC

Layer 3

PDCP
PDCP

SAP
BMC

Ra d io Be a re rs

Layer 2/
RLC
RLC

RLC
RLC
RLC
RLC

RLC
RLC
RLC

Lo g ic a l Cha nne ls
Layer 2/
MAC

MAC

Layer 1

PHY
Phy s ic a l Cha nne ls


Page 139


Radio Resource Control (RRC)
Be a re rs
RRC
Ra d io Be a re rs
(c o ntro l p la ne )

Radio mobility management
Measurement control and reporting

control
control

control
control
control

Layer 3

Call management

Outer loop power control
PDCP
BMC

RLC
MAC
PHY

RRC is the brain of the radio interface protocol stack.

Page 140


PDCP and BMC protocols
PDCP (Packet Data Convergence Protocol)
- in the user plane, only for services from the PS domain
- it contains compression methods
In R99 only a header compression method is mentioned (RFC2507).
Why is header compression valuable?
e.g a combined RTP/UDP/IP headers is at least 60 bytes for IPv6, when IP
voice service header can be about 20 bytes or less.
BMC (Broadcast/
Multicast Services)
- in the user plane
- to adapt broadcast and multicast services from NAS on the radio interface
In R99 the only service using this protocol is SMS Cell Broadcast Service
(directly taken from GSM).

Page 141


Radio Link Control (RLC)

Segmentation
Ra d io Be a re rs
(us e r p la ne )

Ra d io Be a re rs
(c o ntro l p la ne )
Layer 2/
upper part

RLC

RLC
RLC
RLC

Co ntro l
Lo g ic a l
Cha nne ls

RLC
RLC
RLC
RLC
Tra ffic
Lo g ic a l
Cha nne ls

Buffering
Data transfer with 3
configuration modes:
- Transparent (TM)
- Unacknowledged (UM)
- Acknowledged (AM)
Ciphering

RLC provides segmentation and (in AM mode) reliable data transfer.

Page 142


Medium Access Control (MAC)
Tra ffic
Lo g ic a l
Cha nne ls

Co ntro l
Lo g ic a l
Cha nne ls
Layer 2/
lower part

Basic data transfer
Multiplexing of logical channels
Priority handling/Scheduling
(TFC selection)

MAC
Tra ns p o rt
Cha nne ls
(c o m m o n a nd
d e d ic a te d )

Reporting of measurements
Ciphering

MAC can switch a common channel into a dedicated channel if higher bit rate
is required (on request of L3-level).
MAC can change dynamically Transport Format (bit rate…) of each transport
channel on a frame basis (each 10 ms) without interchanging with L3-level.
MAC provides flexible data transfer.

Page 143


TFC selection in MAC protocol
Several transport channels can be time-coordinated to
be multiplexed on a CCTrCH before mapping on one
physical channel (or more if necessary).
Transport Format (TF)

e.g.

DCH1 = {244}
DCH2 = {0 ; 148}
DCH3 = {0 ; 148}

Transport Format Set (TFS)
Transport Format Combination (TFC)

MAC
TFC selection
DCH1 DCH2 DCH3
TrCH multiplexing

TFCS = { {244 ; 0 ; 0} , {244 ; 148 ; 0} , {244 ; 0 ; 148} }
Transport Format Combination Set (TFCS)

MAC selects TFC inside TFCS.
There is one TFCS per CCTrCH.
>> Why is the combination {244 ; 148 ; 148} not possible?

CCTrCH
Physical channel
Mapping

L1
Physical Channel(s)
Page 144


The Physical Layer

Co m m o n
Tra ns p o rt
Cha nne ls

De d ic a te d
Tra ns p o rt
Cha nne ls

Physical layer

Layer 1

Co m m o n
Phy s ic a l
Cha nne ls

Air Interface

Multiplexing of transport ch.
Spreading/modulation
RF processing

De d ic a te d
Phy s ic a l
Cha nne ls

Power control
Measurements

The physical layer provides multiplexing and radio frequency processing
with a CDMA method.

Page 145


Exercise: MAC protocol (1)
BCCH

PCCH

BCCH

CCCH

CTCH

DCCH DTCH DTCH

MAC
Control

MAC-d

MAC-b

BCH

MAC-c/sh

PCH FACH FACH RACH CPCH

DSCH DSCH

DCH DCH

Iur or local

Look at this figure and answer the questions on the following pages.

Page 146


1. On which logical/transport channels will be mapped:
- system information broadcasting
- paging
- telephony speech
- internet browsing at a high bit rate
- internet browsing at a low bit rate
Can you imagine a situation where the UE will use 2 DTCHs (or more) at the same time?
2. Guess the meaning of “MAC-b” “MAC-c/ and “MAC-d”.
sh”
3. Why is there one MAC-d entity on the UE side and several MAC-d entities on the UTRAN
side?
4. What is the link between MAC-c/sh and MAC-d for?
5. What are the 4 main functions of MAC protocol?
6. MAC can multiplex logical channels only if they require the same QoS: true or false?


Page 147


7. RNTI (Radio Network Temporary Identity) is an UE identity assigned by UTRAN, when the
UE is connected to the UTRAN . The parameter RNTI is included in the header of each
transport blocks in MAC-c/sh, but not in MAC-d : can you explain the reason?
8. The system can also multiplex transport channels: where does that take place?
9. What is the name of the channel on which several time-coordinated transport channels can
be multiplexed?
10. Which entity is responsible for TFC selection? TFCS allocation?
11. Is it possible to multiplex 2 FACHs (or more)? 2 DCHs (or more)? a FACH and a DCH?
12. Will the physical channel configuration be changed (e.g modification of spreading factor)
when MAC selects a new TFC inside TFCS?
13. MAC makes measurement reports to RRC: why is it necessary?


Page 148

5. UTRAN

Layer 3
Layer 2
Layer 1

UE

5.1


5.2

Iu Protocols

5.4


5.5

Signaling procedures

5.6


5.7


5.8

RNC

Radio Protocols

5.3

Node B

Mobility management


Page 149

5. UTRAN/ 5.3 Iu protocols

General model

The same general protocol model is applied for all Iu interfaces:
Radio
Network
Layer
Transport

Control
Plane

Application
Protocol
Transport Network
User Plane

Data
Stream(s)
Transport Network
Control Plane

Transport Network
User Plane

ALCAP

Network
Layer

User Plane

Signaling
Bearer(s)

Signaling
Bearer(s)
Physical Layer

Application Protocols:


Data
Bearer(s)

1. What is the
purpose of the
separation between
the Radio Network
Layer and the
Transport Network
Layer?
2. Why is ALCAP
protocol
necessary?

- NBAP for Iub interface
- RNSAP for Iur interface
- RANAP for Iu-CS and Iu-PS interfaces
Page 150


Iub protocols

Ra d io Link
Es ta blis hm e nt

RNC

Radio
Network
Layer
Transport

RA *
Bs

RRC Co nne c tio n
Es ta blis hm e nt*
N S s ig na lling *
A

Control Plane

User Plane

NBAP

Frame
Protocols
(IubFP)

Transport Network
User Plane

Transport Network
Control Plane

ALCAP

Network
Layer

Transport Network User
Plane

AAL5

AAL5

AAL2

ATM
Physical Layer
* a t this s ta g e the s e d a ta s tre a m s ha v e be e n m a p p e d o n
tra ns p o rt c ha nne ls by M C p ro to c o l
A

Node B
Page 151


Iur protocols

SRNC

Es ta blis hm e nt o f
a n a d d itio na l ra d io
link to a n UE
(fo r s o ft HO )
Radio
Network
Layer
Transport

RA *
Bs

RRC Co nne c tio n
Es ta blis hm e nt*
N S s ig na lling *
A

Control Plane

User Plane

RNSAP

Frame
Protocols
(Iur FP)

Transport Network
User Plane

Network

Transport Network User
Plane

ALCAP

...

Layer

Transport Network
Control Plane

AAL5

AAL5

AAL2

ATM
Physical Layer
* a t this s ta g e the s e d a ta s tre a m s ha v e be e n m a p p e d o n
tra ns p o rt c ha nne ls by M C p ro to c o l
A

DRNC
Page 152


UTRAN protocols:
general recap
RRC PDCPBMC
RLC
MAC

RRC PDCPBMC
Uu

RLC

Iub

SRNC
Softer
combining

UE

Phy.
(air)

Soft combining

...
...
AAL5 AAL5 AAL2

NBAP ALCAP Iub-FP Iur-FP ALCAPRNSAP
...
...
...
...
AAL5 AAL5 AAL2 AAL2 AAL5 AAL5

ATM/Physical layer

Soft(er) combining

Phy.
(air)

MAC

ATM/Physical layer

NBAP ALCAP Iub-FP

Node-B

Iur

RRC PDCPBMC

Radio Protocols
Iu Protocols (Radio Network Layer)
Iu protocols (Transport Network Layer)

RLC

DRNC

MAC

NBAP ALCAP Iub-FP Iur-FP ALCAPRNSAP
...
...
...
...
AAL5 AAL5 AAL2 AAL2 AAL5 AAL5
ATM/Physical layer
Page 153

5. UTRAN

5.1


5.2

Radio Protocols

5.3

Iu Protocols

5.4


5.5


5.6


5.7


5.8

?

Mobility management


?

Page 154

5. UTRAN/5.4 UE identifiers and UE states

UE identifiers

2 types of UE identification on the radio interface:
• NAS identifiers
- IMSI: International Mobile Subscriber Identity
- TMSI: Temporary Mobile Station Identity
They are used in the initial access CCCH message
• UTRAN identifier
- RNTI: Radio Network Temporary Identity
This is allocated by the UTRAN for each UE in connected mode and used
for inband identification in common transport channels (e.g FACH). The
RNTI is not used outside the UTRAN.


Page 155


UE states (1)

RRC Connection Release

out of coverage

UE

UE

UE

detached

in idle mode

in connected
mode

“just after switch on” process
Including Ce ll s e a rc h p ro c e d ure

RRC Connection Establishment

Why is the idle mode necessary?

Page 156


UE states (2)
RRC Connection Release

out of coverage

R C Connection E
R
stablishm procedure
ent

UE
UE

UE

in connected

detached

in idle mode

mode

“just after switch on” process

CCCH

RNC

1

RRC Connection Establishment

- UE in idle mode,
- a Common Control Channel (CCCH) is
used to initiate the procedure

CCCH
DCCH

DCCH

RNC

RNC

2

- Setup of a Dedicated Control Channel
(DCCH)

3

- UE in connected mode
- The DCCH is used during the whole
time of the RRC connection to carry
signalling dedicated to this particular UE

Which type of transport channel are used
to carry CCCH? DCCH?

Page 157


UE states (3)

Cell_DCH state
Signalling and traffic data
dedicated to the UE (mapped
on DCCH and DTCH
respectively) are carried on
DCH transport channel

UE

UEin connected
Cell DCH
m
ode
Cell PCH

in id le
m o de

Cell FACH
URA PCH

Cell_FACH state
Signalling and traffic data
dedicated to the UE (mapped
on DCCH and DTCH
respectively) are carried on
RACH (uplink) and FACH
(downlink) transport channels


Cell_DCH ⇒Cell_FACH
No traffic UL/ at expiry of timer 1
DL
Cell_FACH ⇒Cell_DCH
Traffic volume UL/ too large
DL

Page 158


UE states (4)

Cell_PCH state
No transmission of signalling and
traffic data dedicated to the UE (no
DCCH and no DTCH)
But the RRC connection is still
active (UTRAN keeps RNTI for UE)
and UE location at a cell level.

UE

URA_PCH state
Very similar to cell_PCH state
UTRAN keeps the location of the UE at
the URA level (set of UMTS cells)

m o de

UEin connected
m
ode
Cell PCH

in id le

- a DCCH (and possibly a DTCH)
can be reestablished very quickly
(this procedure is initiated by
sending a paging signal PCH)


Cell DCH

Cell FACH
URA PCH

Cell_FACH ⇒Cell_PCH
No traffic UL/ at expiry of timer 2
DL
Cell_PCH ⇒ Cell_FACH ⇒URA_PCH
Too many cell reselections
Cell/
URA_PCH ⇒ Cell_FACH
Incoming DL or UL traffic
Page 159


UE identifiers and UE states:
complete the table!

UE Sta te s

CN
UTRAN
UE Id e ntifie rs UE Loca tion UE Id e ntifie r UE Loca tion

id le m od e

IMSI, TMSI

LA, RA

ce ll_DCH
conn e cte d
m ode

ce ll_FACH
ce ll_PCH
URA_PCH


Page 160

5. UTRAN

Layer 3
Layer 2
Layer 1

UE

5.1

Radio Protocols

5.3

Iu Protocols

5.4


5.5

Signaling procedures

5.6


5.7


5.8

RNC


5.2

Node B

Mobility management


Page 161

5. UTRAN/5.5 Signaling procedures

List of basic signaling procedures
A. Broadcast of system information
B. Paging
B1. Paging Type 1 (in idle mode or in cell_PCH or in URA_PCH states)
B2. Paging Type 2 (in cell_FACH or cell_DCH states)
C. RRC Connection
C1. RRC Connection Establishment (to cell_FACH and to cell_DCH states)
C2. RRC Connection Release (in cell_DCH states)
D. Radio Link establishment
E. Direct Transfer
F. Control of RAB, RB, Transport Channel and Physical Channel
F1. RAB Establishment
F2. Physical Channel Reconfiguration
G. Soft HO (Radio Link Addition)

Page 162


How to read call scenario diagrams

Name of the message

Logical channel
Transport channel
RNC

UE
RRC

1. RRC Co nne c tio n Re q ue s t (CCCH:RACH)
Initial UE identity, Establishment cause, Initial
UE capability

RRC

Network entity

Protocol entity
Parameters of the message

Page 163


A. System Information Broadcasting
(1)
The broadcast system information:
- may come from CN, RNC or Node-B.
- contains static parameters (Cell identity, supported PLMN types...) and
dynamic parameters (UL interference level...).
- is arranged in System Information Blocks (SIB), which group together
elements of the same nature.
- can be carried on BCH which is transmitted permanently over the entire
cell.
>> Do you think the UE needs to read all the SIBs each time a broadcast is
repeated?


Page 164


A. System Information
Broadcasting (2)

UE

RNC

Node-B
NBAP

NBAP
RRC

Sy s te m I rm a tio n (BCCH:BCH)
nfo
RRC
Master/Segment Info Block(s)

Sy s te m I rm a tio n
nfo
Up d a te Re q ue s t
NBAP
Master/Segment Info
Block(s), BCCH
modification time
Sy s te m I rm a tio n
nfo
Up d a te Re s p o ns e

NBAP

nfo
RRC

RRC

CN

RRC

nfo
RRC


>> Why does RRC protocol
terminate at Node-B for BCH
(not at RNC)?
Page 165


B. Paging

Paging is typically used at core network-originated call.
UE in idle mode
The network will page the UE in LA (CS domain) or RA (PS domain)
UE is in connected mode
The network will page the UE:
- in the cell (in cell_PCH, cell_FACH, cell_DCH states)
- in the URA (in URA_PCH state)
Pa g ing Ty p e 1 : mapped on PCCH/PCH
Pa g ing Ty p e 2 : mapped on DCCH/FACH or DCCH/DCH
>> Can you guess which Paging Type will be use in idle mode? in cell_PCH
state? in cell_FACH state? in cell_DCH state? in URA_PCH state?

Page 166


B1. Paging Type 1

UE 1

UE 2

Node-B
1

Node-B
2

R 1
NC

RANAP

1 . Pa g ing

CN Domain Indicator, UE
identity, Paging cause

RANAP

RRC

2 . Pa g ing Ty p e 1 (PCCH:PCH)

RRC

1 . Pa g ing
Idem

RANAP

RANAP

RRC

2 . Pa g ing Ty p e 1 (PCCH:PCH)


CN

RNC 2

RRC

Page 167


B2. Paging Type 2

UE

Node-B

RANAP

RRC

2 . Pa g ing Ty p e 2 (DCCH:FACH or
DCH)


CN

SRNC

1 . Pa g ing

CN Domain Indicator, UE
identity, Paging cause

RANAP

RRC

Page 168


C. RRC connection

RRC connection is established at the initial access
(after cell search procedure when the UE is camping on a cell).
After RRC connection establishment:
- UE will switch from idle mode to cell_FACH or cell_DCH states.
- UE will have a signalling link with UTRAN (on DCCH)
UE needs to establish a RRC connection prior to making :
- voice call
- location update
- measurement reporting
...

Page 169


C1. RRC Connection Establishment
UE
RRC

Node-B
1. RRC Co nne c tio n Re q ue s t (CCCH:RACH)
Initial UE identity, Establishment cause, Initial UE capability

RNC
RRC

2. Allocate RNTI, Select
Level 1 and Level 2
parameters (e.g. TFCS,
scrambling code)
3. Radio Link Establishment (see Pro c e d ure
D)
RRC

RRC

4. RRC Co nne c tio n Se tup (CCCH:FACH)
Initial UE identity, RNTI, capability update requirement, TFS, TFCS, frequency, UL
scrambling code, power control info

5. RRC Co nne c tio n Se tup Co m p le te (DCCH:RACH or DCH)
Integrity information, ciphering information

RRC

RRC

>> Can the UE send user information (e.g voice call) after completing this stage?

Page 170


C2. RRC Connection Release
(in cell_DCH state)
UE

Node-B
of DRNC

DRNC

Node-B
of SRNC

CN

SRNC
RANAP

1 . I Re le a s e
u
Co m m a nd
Cause

RANAP

2 . I Re le a s e
u
Co m p le te
RANAP
RANAP
-

3. ALCAP Iu Bearer Release
RRC
RRC

4. RRC Co nne c tio n Re le a s e (DCCH:DCH )
Cause

5. RRC Co nne c tio n Re le a s e Co m p le te (DCCH:DCH )
-

RRC
RRC

6. Radio Link Deletion

Page 171


D. Radio Link (RL) Establishment
for a DCH
RNC

Node-B
NBAP
Start RX

Ra d io Link Se tup Re q ue s t

Cell id, TFS, TFCS, frequency, UL scrambling
code, power control info

NBAP

ALCAP Iub Data Transport Bearer Setup
Ra d io Link Se tup Re s p o ns e

NBAP

Iub-FP

Do wnlink s y nc hro nis a tio n

Iub-FP

Iub-FP

Up link s y nc hro nis a tio n

Iub-FP

NBAP

Signalling link termination, transport layer
addressing info

Start TX
>> Are NBAP, ALCAP and RRC messages carried on the same transport bearers on Iub?

Page 172


E. Direct Transfer

The mechanism to transfer signalling from higher layers (NAS signaling)
through messages of RRC protocol is called Dire c t Tra ns fe r.
UE

Node-B

RANAP
RRC

RRC

2 . Do wnlink Dire c t Tra ns fe r
(DCCH:FACH or DCH)
NAS message

1 ’. Up link Dire c t Tra ns fe r
(DCCH:RACH or DCH)
CN node indicator, NAS message

1. Dire c t Tra ns fe r

CN Domain Indicator,
NAS PDU

RANAP

RRC

>> Can you mention some
examples of use of
Dire c t Tra ns fe r?
RRC
RANAP


CN

SRNC

2’. Dire c t Tra ns fe r

CN Domain Indicator,
NAS PDU

RANAP
Page 173


F. Control of RAB, RB, Transport
and Physical Channels
These procedures take place after RRC connection establishment: the UE
is either on cell_FACH or cell_DCH state.
A RAB is mapped on one or more RB(s).
A RB establishment consists of:
- performing admission control (see RRM: Radio Resource Management)
- setting parameters describing RB processing in layer 2 (e.g TFS, TFCS)
and in layer 1 (codes, power control)
RAB and RB can be reconfigured during an active connection.
The transport channels and physical channels parameters are included in
the RB but can also be reconfigured separately with transport and physical
channel dedicated procedures (Tra ns p o rt Cha nne l Re c o nfig ura tio n and
Phy s ic a l Cha nne l Re c o nfig ura tio n).

Page 174


F1. RAB Establishment

UE

RNC

Node-B

RANAP

1. RA A s ig nm e nt
B s
Re q ue s t
RAB parameters, User plane
mode, Transport Address, Iu
Transport association

CN
RANAP

2. ALCAP Iu Data Transport Bearer Setup
3. Radio Link
Establishment
(see Pro c e d ure D)
RRC

4. RB Se tup (DCCH:FACH or DCH )
TFS, TFCS...

RRC

5. RB Se tup Co m p le te (DCCH:RACH or DCH )
RRC
RRC
-

RANAP

6. RA A s ig nm e nt
B s
Re s p o ns e
-

RANAP

>> Can the UE send user information (e.g voice call) after completing this stage?

Page 175


F2. Physical Channel
Reconfiguration

UE

Node-B
of DRNC

DR
NC
1. RL Re c o nfig . Pre p a re

NBAP

NBAP

DL scrambling code

2. RL Re c o nfig . Re a d y

NBAP

NBAP

-

RNSAP
RNSAP
NBAP
RRC
RRC

5. RL Re c o nfig . Co m m it

SRNC

3.

DL scrambling
code

4.

RNSAP

NBAP

6. Phy s ic a l Cha nne l Re c o nfig ura tio n (DCCH:DCH )
DL scrambling code

7. Phy s ic a l Cha nne l Re c o nfig ura tio n Co m p le te (DCCH:DCH )
-

RNSAP

RRC
RRC

>> What is the difference between NBAP and RNSAP?

Page 176


G. Soft HO
(Radio Link Addition)

UE

Node-B
of DRNC

DR
NC

SRNC
1. Decision to setup
new RL

RNSAP

2 . RL Se tup Re q ue s t
-

RNSAP

3. Radio Link Establishment
(see Pro c e d ure D)
4. ALCAP Iur Data Transport Bearer Setup
RNSAP
RRC

RRC

5 . RL Se tup Re s p o ns e

6. A tiv e Se t Up d a te (DCCH:DCH )
c
-

7. A tive Se t Up d a te Co m p le te (DCCH:DCH )
c


-

-

RNSAP
RRC

RRC
Page 177


EXERCICE

Please complete the procedure diagrams on the following
slides by using the elementary procedure previously
described

Duration :
10 minutes


Page 178

5. UTRAN/5.5 Signalling procedures

Location Update

Find the missing procedure names!
UE

UE d e ta c he d

RNC

Node-B

CN

0. “Just after switch on” process
UE in id le m o d e

1. ...
UE in c o nne c te d m o d e

MM: Lo c a tio n Up d a ting Re q ue s t

2. ...
MM: A
uthe ntic a tio n Re q ue s t

MM: A
uthe ntic a tio n Re s p o ns e
3. Security procedures
4. ...

MM: Lo c a tio n Up d a ting A c e p t
c

5. ...
UE in id le m o d e

Page 179

5. UTRAN/5.5 Signalling procedures

Mobile terminated call

Find the missing procedure names!
UE

RNC

Node-B

CN

0. “Just after switch on” process

1. ...
2. ...
RR: Pa g ing Re s p o ns e

3. ...
MM: A
uthe ntic a tio n Re q ue s t

MM: A
uthe ntic a tio n Re s p o ns e
4. Security procedures
5. ...
CC: Ca ll Co nfirm

CC: A rting
le
CC: Co nne c t


CC: Se tup

6. ...
7. ...
CC: Co nne c t A kno wle d g e
c
Page 180

5. UTRAN

Layer 3
Layer 2
Layer 1

5.1

UE

5.2

Radio Protocols

5.3

Iu Protocols

5.4


5.5


5.6


5.7

Radio Resource management (RRM)

5.8

Mobility management


Node B

RNC

Page 181

5. UTRAN/5.6 The Physical Layer

Physical Layer Process
Transport Channels

Channel Coding

Convolutional coding,
Turbo coding

Radio Frame Segmentation

10 ms frame duration
15 time slots

Transport Channel Multiplexing
Physical Channel Mapping

CCtrCH
DPDCH, DPCCH, PRACH...

Spreading
Layer 1

Channelization codes
Scrambling codes

Modulation

QPSK

Physical Channels
spread over 5 MHz bandwidth

Page 182


Radio Frame Structure
…

1 Radio Frame :

= 15 Time Slots

10ms

….

1 Time slot :

= N bits

(according to the bit rate after channel coding)
0.6666 ms

1 Bit :

..

= M chips

(M is equal to the spreading factor)

The bit rate may be changed for each frame (10 ms).
Fast power control may be performed for each time slot (0,666 ms).

Page 183


DCH 1

DCH 2

Channel Coding

Channel Coding

CCTrCH
Physical Channel Mapping
One Physical Channel (or more if necessary)
Two transport channels can be mapped onto the same physical channel
(for one user).

Page 184


Physical channels

Phy s ic a l c ha nne ls
are defined by the mechanisms (e.g frequency, code, power, framing...) with which
the data are transferred over the physical resources of the air-interface.

• Physical channels are defined mainly by:
- a specific carrier frequency
- a scrambling code
- a channelization code
- start & stop instants (giving a time duration, measured in integer multiples
of chips)
• Physical channels are sent continuously on the air interface between start
and stop instants.
• Physical channels are separated by means of quasi-orthogonal codes (2
physical channels shall not have the same channelization code / scrambling
code combination).

Page 185


Uplink Physical Channels
Common Channels
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)

Node
B

Associated with
Transport Channels

Dedicated Channels
Dedicated Physical Data Channel (DPDCH)

Associated with
Transport Channels

Dedicated Physical Control Channel (DPCCH)

NOT associated with
Transport Channels


Page 186


e.g. Uplink DPDCH/
DPCCH
Data

DPDCH
DPCCH

Ndata bits

Pilot

TFCI

Npilot bits

NTFCI bits

FBI

NFBI bits

TPC

NTPC bits

Tslot = 2560 chips, 10*2k bits (k=0..6)

1 Radio Frame Slot #0

Slot #1

Slot #i

Slot #14

T = 10 ms

DPDCH carries the dedicated data generated at layer 2 (ie the Dedicated
Transport Channel DCH).
f

DPCCH carries the dedicated signalling of the physical layer, which is
required to convey DPDCH. DPCCH is not visible above the physical layer,
it is not carried by any transport channels.
Under long scrambling code.

Page 187


e.g. Uplink PRACH

When attempting to access the network, the mobile has no dedicated code
yet and must choose randomly a code in a set of codes.
Collisions may occur between two mobiles.
radio frame: 10 ms

radio frame: 10 ms

5120 chips
#0
Access slot #0
Access slot #1

#1

#2

#3

#4

#5

#6

#7

#8

#9

#10 #11 #12 #13 #14

Random Access Transmission

Access slot #7
Access slot #8


A mobile can only begin to
transmit at a certain access slot
(slotted ALOHA).
15 access slots have been
defined (nothing to do with the
time slots of the radio frame!).


Access slot #14

The PRACH has a Random Access Transmission to limit risk of collision.
It is based on a Slotted ALOHA approach with fast acquisition indication.

Page 188

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