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3g
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3G FundamentalsINDOSAT- NOKIA 3G Demo
Jakarta, 05 Jan 2006Reji WarrierSystem Marketing ManagerRadio Access Networkreji.warrier@nokia.com
1 © NOKIA Reji Warrier
2 © NOKIA Reji Warrier
Vision of UMTS Specification• Worldwide specified• Clear added value to GSM and backward compatible with GSM/ISDN• Full support for multimedia and advanced services• Generic radio access• Services must not be limited by the network capability.
UMTS Release 99
new radio interface solution• more efficient• more flexible
WCDMA• FDD-mode• TDD-mode
network evolution• enhanced GSM core network• enhanced service infrastructure
International Mobile Telephone - 2000
Direct Spread(on paired frequency spectrum)
CDMA
Multi Carrier(on paired frequency spectrum)
Time Code(on unpaired
frequency spectrum)
Single Carrier(on paired frequency spectrum)
Time Code(on unpairedfrequency spectrum)
TDMA FDMA
cdma2000 UWC-136(EDGE)
(DECT)
Framework for 3G Systems
IMT-2000radio
interfaceoptions
UMTSFDD mode TDD mode
3G systems
3 © NOKIA Reji Warrier
4 © NOKIA Reji Warrier
HW/SW Changes
Network evolution
MSC&VLR
HLR & AC & EIR
PSTNBSC
BSC
BTS
BTS
TCSM
TCSM
ISDN
A GSM network is made from 3 Sub-Systems (BSS, NSS and OSS)
Value AddedService Platform(s):
SMSC, VMS
Even at the start, VAS (value added services) were part of GSM networks
TRX Change & Transmission Upgrade
HW/SW Changes
IN
IN was introduced for new services and differentiation (e.g. Pre-Paid)
IP Networks
Data Rates in GSM are increased by implementation of Features like HSCSD
SGSN
GGSNIP Networks
GPRS is added to existing networks to support Packed Data
UMTS Rel'3; new BTS, Radio Network Controller, Media Gateway, 3G-SGSN
RNCBTS
3G-SGSN
MGW
GPRS adds improved data services with a new Packets witched backbone Where SGSN and GGSN are two main elements
Higher data rates are obtained by introducing EDGE in the GSM network
The subsystems of UMTS
WCDMA
ATM
Iu
NMSNMS
CNCNRANRAN
O&M
Uu
UEUE
UE = User EquipmentRAN = Radio Acces NetworkCN = Core NetworkNMS = Network Management System
Service PlatformService Platform
5 © NOKIA Reji Warrier
UMTS Rel. 99: UTRANCN (Core Network)
circuit switched (cs) domain
packetswitched (ps) domain
3GMSC/VLR
3GSGSN
UTRAN (UMTS Terrestrial Radio Access Network)
RNC
Node B
Node B
RNC
Node B
Node BRadio Network Subsystem (RNS)
Radio Network Subsystem (RNS)
Iub
Iub
Iur
Iu-PS
Iu-CS
Uu
Uu
UE
UE
6 © NOKIA Reji Warrier
RNC Radio Network ControllerUE User Equipment = Mobile Equipment (ME) + Universal SIM (USIM)
Radio Network Controller Tasks & Functions
• WCDMA radio resource managementincl. Radio resource management of channel configurations,traffic and control channels, handovers, power control.
• Telecom functionalityincl. Location & connection management, ciphering, Iu and Iub channel management, ATM switching and multiplexing
• Maintenanceincl. Fault localisation and reconfiguration
• Operationincl. RNC and Node B parameter modification
7 © NOKIA Reji Warrier
Node B Tasks & Functions
101010010101010001Iub InterfaceATM
Uu InterfaceWCDMA
Cellular Transmission managementManaging ATM switching and multiplexing
over the Iub interface. Control of AAL2/AAL5 connections. Control of the
physical transmission interfaces – E1, PDH, SDH or microwave.
Air Interface management.Controlling Uplink and Downlink
radio paths on the Uu Air Interface. Baseband to RF conversion. Antenna multi-
coupling.
O&M Processing.Interfacing with NMS
and RNC for alarm and control (Operations and Maintenance) functions.
Radio Channel functions.Logical to physical channel
mappings. Encoding/Decoding –Spreading/Despreading user
traffic and signalling.
RNC
8 © NOKIA Reji Warrier
Network architecture of Rel 4
• Separation of control plane from user plane, simpler and more efficient
• Statistical multiplexing gain and convergence with PS core as ultimate aim
• More efficient transmission reduces costs this allowing more complex services to be offered
• Evolutionary phase towards Release 5 which in turn will offer even more advanced services
• GERAN implementation
9 © NOKIA Reji Warrier
HSDPA Release 5
• AMC, adaptative modulation and coding 16 QuadratureAmplitude Modulation used in good radio link conditions
• Automatic Retransmission Query (ARQ) as error detectionmechanism provides efficient retransmissons
• support for services requiring high data rates in downlink, e.g. Internet browsing and video on demand.
• High data rates up to 10Mbit/s
10 © NOKIA Reji Warrier
Wireless Principle
• Transmission Type
• Simplex Transmission• Half Duplex Transmission• Duplex Transmission
• Radio Communication
• Analogue :- Voice over the air• Digital :- 0s & 1s are transmitted over the air
11 © NOKIA Reji Warrier
FDD and TDD
Duplex Transmission
Time Division DuplexFrequency Division Duplex
12 © NOKIA Reji Warrier
frequency
time
frequencytim
e
Uplin
k
Uplink
Uplink
UplinkDown
link
Downlink
Downlink
Downlink
With FDMA, the users transmit simultaneously using separate frequencies
frequency
13 © NOKIA Reji Warrier
time
mobile
phon
e 1
mobile
phon
e 4
mobile
phon
e 2mob
ile ph
one 3
carrier band
Used for broadcast. Different broadcasts in the same region. FDMA is used in cellular communications. Used higher power and lower frequencies
Space Division Multiple Access
Growing customer demand.Geographical region intosmaller areas called “cells.”Each cell would use a frequency different than those ofits nearest neighbours.Same frequency can be used multiple times in the same geographical region.Two freq in one cell.Basic limit of one call per frequency.
14 © NOKIA Reji Warrier
15 © NOKIA Reji Warrier
TDMA frame
frequency
time
TDMA frame
Mobile Phone 1
Mobile Phone 1
Mobile Phone 1
Mobile Phone 2
Mobile Phone 2
Mobile Phone 2
Mobile Phone 3
Mobile Phone 3
Mobile Phone 3
Mobile Phone 4
Mobile Phone 4
carrier band
TDMA divides the frequency into multiple time slices
Dividing the frequency into multiple time slices so that multiple users can access the same frequency at the same time.
Code Division Multiple Access
The user data is combined at the transmitter’s side with a code, then transmitted. On air, all transmission get mixed. At the receiver’sside, the same code is used as in the transmitter’s side.
16 © NOKIA Reji Warrier
Sharing the frequency by using different codes
Codes
Power (P)
Time
Frequency
17 © NOKIA Reji Warrier
WCDMA air interface properties
FrequencyBand
Duration(spreading factor)
Power
WCDMAOriginating Bit Received Bit
18 © NOKIA Reji Warrier
Spreading and sharing the same space
ff
User AUser A
DataData
PP P
P P
DespreadDespreadUser A signalUser B signalat the receiverat the receiver
ff
ff
ff
19 © NOKIA Reji Warrier
ff
User BUser BPP
Data afterData afterspreadingspreading
TransmissionTransmissionover the airover the air
ffP
Managing interference in CDMA
DespreadDespreadsignal at signal at the receiverthe receiver
Transm issionTransm issionover the airover the air
signalsignal
interferenceinterference
ff ff
pppp signalsignal
interferenceinterference
20 © NOKIA Reji Warrier
3G Access Rate targets
Environment RT Service Peak Rate(Delay fixedfixed 20 – 300 ms)
NRT Service Peak Rate(Delay variesvaries 20 – 300 ms)
Rural Outdoor(Speed < 250 km/h)
144 – 384 kb/s 144 – 384 kb/s
Urban/Suburban(Speed < 150 km/h)
384 – 512 kb/s 384 – 512 kb/s
Indoor/Low Range Outdoor(Speed < 10 km/h)
- 2 Mb/s(Special conditions)
- 2 Mb/s (Special conditions)
Pedestrian & Office (<10 km/h):bit rate <= 2 Mb/s
Outdoor (< 150 km/h):bit rate 384 kb/s, target 512 kb/s
Outdoor (<250 km/h):bit rate 144 kb/s, preferably more
3G Radio Access
21 © NOKIA Reji Warrier
CDMA theory
22 © NOKIA Reji Warrier
Differences between WCDMA & GSM
WCDMA GSM
Carrier spacing 5 MHz 200 kHzFrequency reuse factor 1 1–18Power controlfrequency
1500 Hz 2 Hz or lower
Quality control Radio resourcemanagement algorithms
Network planning(frequency planning)
Frequency diversity 5 MHz bandwidth givesmultipath diversity with
Rake receiver
Frequency hopping
Packet data Load-based packetscheduling
Timeslot basedscheduling with GPRS
Downlink transmitdiversity
Supported forimproving downlink
capacity
Not supported by thestandard, but can be
applied
High bit rates
Spectral efficiency
Different quality
requirements
Efficient packet data
23 © NOKIA Reji Warrier
WCDMA Capacity
f1
128 kbps
64 kbps
8 kbps
f1
144 kbps
64 kbps
24 © NOKIA Reji Warrier
NOTE!WCDMA capacity is a function of radio environment, user mobility/location and propagation conditions. Examples above are just examples of WCDMA cell capacities of a 3 sector macro cell BS configuration.
Mobile Station
64 kbps
144 kbps
Base Station
"Cell breathing"
The size of cell variesaccording the traffic load
144 kbps
64 kbps
64 kbps
High load 800 kbps-> smaller coverage
Low load 200 kbps-> large coverage
Where are codes used?
In the Uplink (UE → Node B), the user's data and
signalling information is separated by
Channelisation Codes
datasignalling
In the Downlink (Node B→UE), cells are seperated by Scrambling Codes
In the Uplink (UE → Node B), terminals are separated by
Scrambling Codes
In the Downlink (Node B → UE), user connections are separated by
Channelisation Codes
Dedicated User Channel
Channel Coding
TxRAKE Air interface
Signalling Data
Call set-up,SMS etc.messages
Voice, videoand other user data
Channels
Radio Framing
Spreading &Channelisation
Scrambling
Modulation
25 © NOKIA Reji Warrier
Interference in CDMA• Interference is
caused by mobiles in the neighbouring cells as well as by mobiles in the same cell area (uplink)
• Total interference experienced by BTS is summary of all those
• If interference increases the needed output power from MS needs to be increased as well.
Signal
Interference
26 © NOKIA Reji Warrier
Power control in WCDMA
• Fast, accurate power control is of utmost importance – particularly in UL;• UEs transmit continuously• WCMDA often uses 1 frequency• Poor PC leads to increase interference > reduced capacity
• From BTS perspective every UE accessing network increase interference
• WCMDA capacity is proportional to interference level > minimise interference
• PC maintains link quality by adjusting UE (UL) and BTS (DL) powers every slot
• Mitigates 'near far effect', by providing minimum required power for each connection
• UEs and BTSs should always be at the lowest possible transmission power
• PC utilises Signal-to-Interference Ratio (SIR) – independently for each connection
• Provides protection against shadowing and fast fading
27 © NOKIA Reji Warrier
Power control
Node BP1 P2
Node B RNC
Open Loop Power Control (Initial Access)
Closed Loop Power Control
Outer Loop Power Control
28 © NOKIA Reji Warrier
Open Loop Power Control• Controlled by UE• Determines how much power UE should use during random access procedure (UL)• Network informs UE of current network status;
• CPICH power (RNP parameter)• UL required C/I ratio (RNP parameter)• UL interference
• UE uses these parameters to calculate initial power of RACH preamble• If access request is not detected power of preamble is increased in steps• After detection of MS signal, the initial SIR is calculated in RNC
Preamble PreamblePreamble
Preamble
MS
Out
put
Pow
er AICH
Mesage Part
RACH
29 © NOKIA Reji Warrier
Fast Loop Power Control• Located in BTS and UE• Controls the power of the dedicated physical channels• Power control changes can occur every slot (i.e. 1500 times per second)• BTS and UE continuously compare recevied SIR with SIR target and inform each other
to either increase or decrease its power (using TPC commands)
WithoutPower Control
With OptimumPower Control
MS1
MS2
MS3
MS4
Rec
eive
d po
wer
at B
S
MS1MS2
MS3MS4
MS1 MS2 MS3 MS4
Rec
eive
d po
wer
at B
S30 © NOKIA Reji Warrier
Closed Loop Power Control• Adjusts the SIR for every user based on BER/FER observation. Initial, max. and min.
SIR values are set by AC• Needed to track changes in radio environment• Aims to provide required quality• UL quality evaluation is made after MDC• RNP parameters control the threshold comparison process for SIR target and the
reporting of these results• If SIR target reaches its maximum (I.e. radio conditions deteriorate even though SIR
target is inceased, system has to take action;• inter-frequency / inter-system handover• RRC connnection release
31 © NOKIA Reji Warrier
Handover types
32 © NOKIA Reji Warrier
CNRNC
MSCBSC
GSM900/1800GSM900/1800
WCDMA FDDWCDMA FDD
Inter-SystemInter-System
Intra-SystemIntra-System
WCDMA TDDWCDMA TDD
Inter-SystemInter-System
Active cells and soft handovers
CNRNC
frame reliability info
frame reliability infoframe
selection /duplication
BS1 BS2
Soft handover windowP
2) Add BS2
1) Connection to BS1
3) Drop BS1
4) Connection to BS2
33 © NOKIA Reji Warrier
Handover types
Soft Handover
34 © NOKIA Reji Warrier
4
Hard/Inter-Frequency Handover
Softer Handover
Inter-System Handover
Node B
Frequencyf1
Frequencyf1
Frequencyf1
Frequencyf2
UMTS GSM900/1800
Sector 1f1
Sector 2f1
Sector 3f1
Multipath Signalthrough Sector 1
Multipath Signalthrough Sector 3
Frequencyf1
Frequencyf1
RNC RNCIur
Iub Iub
Node B
Node B Node B
Node BNode B
Node B
Node B BTS
Load Control
Estimated capacity for NRT traffic.
Measured load caused by non-controllable load (RT)
Overloadthreshold x
Load Targetthreshold y
Pow
er
Time
Preventive Load Control
Overload Control
35 © NOKIA Reji Warrier
Admission Control
Planned uplink interference margin; defines the optimum operating poit up to which the AC can operate.
Defines the limit (the first UL overload threshold) for the UL interference margin, after which the BS starts its load control actions to prevent overload.
Offset
25
Inte
rfer
ence
Mar
gin
(dB)
20
15
10
5
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Load
36 © NOKIA Reji Warrier
AdmissionControl
LoadControl
PacketScheduler
PrxTarget orPtxTarget
PrxTarget+PrxOffset orPtxTarget+PtxOffset
PrxThreshold orPtxThreshold
P_CellMax
No actionsPS increases theamount of NRT
bearersAC admits RT
bearers normally
No actions
Load preventive LCactions
Overload actions
AC does not admitnew bearers
AC does not admitnew bearers
PS decreases thebitrates and drops
NRT bearers
PS decreases thebitrates of NRT
bearers
PS does notincrease NRT load,
but can changeNRT bitrates
Power
Load
Summary
37 © NOKIA Reji Warrier
Features of WCDMA
• Efficient use of spectrum
• Limited frequency management
• Low mobile station transmit power
• Uplink and downlink resource utilisation independent
• Wide variety of data rates
• Improvement of multi-path resolution
• Statistical multiplexing advantage
• Increased standby-time from higher rate control channels.
38 © NOKIA Reji Warrier
Features of WCDMA
• Efficient use of spectrum ( disco trans – dec inter, incr cap “ NRT data when not enough RT..)
• Limited frequency management
• Low mobile station transmit power
• Uplink and downlink resource utilisation independent ( Diff bit rates in UL/DL)
• Wide variety of data rates
• Improvement of multi-path resolution
• Statistical multiplexing advantage ( More channels/user in one carrier)
• Increased standby-time from higher rate control channels. ( wideband spectrum, ms listens only part of the time )
39 © NOKIA Reji Warrier
Key operator benefits
• New service capabilities means new business opportunities for operators, (further differentiation)
• Revenue opportunity with increased data/voice traffic
• New frequency spectrum
• The path towards IP mobility
40 © NOKIA Reji Warrier
Key end-user benefits
• Integrated customised services
• Simplified service provisioning and service upgrades
• Wireless personal Internet
• Multimedia messaging
• Enhanced e-mail
• Telecommuting
• Improved quality of service
• Support for video/audio clips
41 © NOKIA Reji Warrier
Thank You
Jakarta, 05 Jan 2006
42 © NOKIA Reji Warrier
Review Questions
1. In UMTS, there are two methods used for transport through the air interface.
The first is UMTS-FDD. What is the second one?
a. TDD, Time Doubled Division
b. CDD, Code Division Duplex
c. TDD, Time Division Duplex
d. CDD, Code Divided Data
43 © NOKIA Reji Warrier
Review Questions
2. Which of the following sentences best describes the phenomenon called cell breathing?
a. When more capacity is used, the cell spreads in size.
b. When more capacity is used, the cell shrinks in size.
c. The cell will adjust its size in line with the furthest users.
For example, if the user is 5 km away, the cell is 5 km.
If the user is 2 km away, the cell is 2 km.
d. Cell breathing is the height of the cell: from 2 - 3 km towards
the atmosphere.
44 © NOKIA Reji Warrier
Review Questions
3. There are two types of codes used in UMTS. These are the channelisation and scrambling codes.
Why are the scrambling codes used?
a. To separate downlink physical channels in a cell.
b. To separate user data and signalling in the network.
c. As security to check if the User Equipment (UE) is not stolen.
d. To separate different cells in the downlink direction.
45 © NOKIA Reji Warrier
Review Questions
4. The Iur-interface is used between two RNCs. What is the purpose of this interface?
a. There is no use for this interface.
b. It is used for soft handovers.
c. It is used to transfer software files.
d. It is used when a RNC has a hardware failure.
46 © NOKIA Reji Warrier
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