8- wcdma principles&planning v3.0

WCDMA Principles andPlanning

16-19/05/2007Yüksel,Ülgen,Uğur,Ardıç

WCDMA Principles and Planning• Introduction – Mobile Technologies• WCDMA

– Basics– System Architecture

• WCDMA Principles– Codes– Modulation– Processing Gain– Eb/No– RAB

• System Overview– Physical Channels– Idle Mode Behaviour– HO– Power Control– Cell Breathing– Rake Receiver

WCDMA Principles and Planning• Radio Resource Management

– Admission Control– Congestion Control– RRC States

• Propagation Models• Linkbudgets (UMTS vs GSM)• Npole• General Dimensioning

– Dimensioning Example– 8 Parameter

• Turkcell UMTS planning strategy– Cell Detailed Planning

• Planning Tips• Analysing with Asset

– Static Analysis– Monte Carlo

• HSDPA Basics• HSUPA Basics

Mobile Technologies

CDMA OneCDMA20001x EV-DO

W-CDMA

TD-SCDMA

CDMA20001x RTT

CDMA20001x EV-DV

TD-CDMA

3G/UMTS5%

90%+9%

Mobile Technology Evaluation

3GPP Evaluation

• HSDPA

• Enh UL• HSDPA

• MBMS• Enh UL

• 3G LTE

2004-5 2006

2007 2008-9

RADIO ACCESS TECHNOLOGIES

f1 f2 f3 f4

PBand Genişliği

f1 f2 f3 f4t1

PBand Genişliği

kod1kod2kod3kod4kod5

Band Genişliği

FDMAFrequency Division Multiple Access

FrequencyFrequency

TimeTime

PowerPower

UserUser

FDMAFDMA

• Each user is assigned to one frequency within the spectrum

• Applications– Analog Cellular Systems

• AMPS• NMT• TACS

– Analog Satellite Communication

TDMATime Division Multiple Access

TDMATDMA • Each user is assigned to one time slot from a frequency

• Applications– Digital Cellular Systems

• GSM,• D-AMPS

PowerPower

FrequencyFrequency

TimeTime

UserUser

CDMACode Division Multiple Access

• Each user can use the whole frequency band every time– “Spread Spectrum”

technology– 1 user = 1 pseudo random code– Other users = Interference

• Applications– Digital Cellular Systems– Stallite Communications

FrequencyFrequency

TimeTime

PowerPower

UserUser

WCDMA BASICS

Introduction to W-CDMA

ishTurkish

French

They will all be ableto communicate intheir own language(code) if their voicelevels (received power)are about the same.

If someone speaks tooloud, the others willnot be able to understandand communicateat the same levels anymore

GSM vs. UMTSThe major differences

• Wider channel bandwidth 200 kHz -> 5000 kHz– Thermal noise will be higher

• Different users in the cell will have an effect upon each other.– The resources are shared in the system. If one user consumes a

lot of resources, the other users will suffer.• Fast power control (2 Hz for GSM and 1500 Hz for

UMTS)– The fast power control in UMTS is required in order to make sure

that no user consumes more recourses than absolutely necessary.

• An interference margin in the link budget is introduced in order to make the design for a loaded scenario.

• It’s more fun

UMTS Standards

UTRA-FDD (W-CDMA); wide area coverage, up to 384 kbit/s

Band Width is 60 Mhz.12 sub band with 5 Mhz. Band width were defined.2 frequency bands are used for uplink and downlink

separately. (60 Mhz. * 2)

UTRA-TDD (TD-CDMA); for indoor coverage and interactive applications, up to 2 Mbit/s

There are 2 frequency bands with total 35 Mhz. Band Width

TDD FDD uplink TDD1900 1980 2010 20251920

FDD downlink2110 2170 2200

FDD- Frequency Division Duplex

2 carriers are used for one connection as uplink and downlink. Carrier band width is 5 Mhz.Total Band width were defined as 60 Mhz. FDD are used for wide area coverage, because it’s designed to serve high number of subscribers rather than high throughput.It’s not suitable for high speed internet application because band widths used for downlink and uplink are fixed.

TDD- Time Division Duplex1 carrier is used for one connection.Carrier band width is 5 Mhz.2 frequency bands were defined with 20 Mhz. and 15 Mhz.TDD is suitable for high speed internet application, uplink and downlink data are transferred in one frequency band and according to required data rate band widths can change.TDD is designed for indoor coverage, it’s not very resilient to inteference so it cannot be used for wide area coverage

WCDMA Frequency Band in Europe

1900 202520101920 1980FDD- UL 21702110 FDD- DL

60MHz 60MHz20MHz 15MHz

1 Carrier = 5 MHz

60/5 = 12Total number of FDD carriers

Total number of TDD carriers (20+15)/5 = 7

Turkey 3G Licenses

WCDMA System Architecture

UMTS System Architecture

PacketPacketCoreCore

NetworkNetwork

Node B

CircuitCircuitSwitchedSwitchedNetworkNetwork

Iu (PS)

Iu (CS)

RNCIub

Node B

Iub RNC

UMTS together with GSMPSTN/ISDN

Internet/Intranet

GSM/UMTS Core NetwokA-Interface Iu-Interface

ISUP TCP/IP

UMTS Access (UTRAN)

GSM Access (BSS)

GSM UMTSGSM/UMTS

• Node B or BTS (Base Transceiver Station)

Node B(BTS)

Iub (ATM)

Main Node B functions:• Call Processing• Radio access• Performance Monitoring• Random Access detection• Air Interface Transmission/Reception• Modulation/Demodulation• W-CDMA Physical Channel Coding• Micro Diversity• Error Handling• Closed Loop Power Control

• RNC (Radio Network Controller)

ATMBackbone

Node B(BTS)

Iu ATMBackbone

Iub (ATM)

Core Network

Main RNC functions:• Radio Resource Management• User Mobility Handling• Interfaces • Macro Diversity

• Channel Allocation• Power Control• Handover Control• Ciphering• Open Loop Power Control

User Equipment

USIMCu

User Equipment

Maximum Tx Power:• 33 dBm = 2 W• 27 dBm = 0.5 W• 24 dBm = 0.25 W• 21 dBm = 0.125 W

Mobile Equipment

Mobile Termination

Radio Transmission

Terminal Equipment

End to End Application

WCDMA Principles

WCDMA BASIC PRINCIPLES

Spread signal by means of codes

12,2 KHZVoice service

3,84MhzBandwith of coded signal

code x

Spread Spectrum

Frequency

Data Modulation

Spreading Despreading

Demodulation

Spread Spectrum

Interference Rejection

Processing Gain

{ } dB 10384

3840Log10kbps 384 =⎥⎦⎤

⎢⎣⎡==pG{ } dB 25

2.123840Log10VoiceLog10 =⎥⎦

⎤⎢⎣⎡==

⎥⎥⎦

⎢⎢⎣

Modulation schemes

Z = I +jQ

Uplink Downlink

Quadrature Phase Shift KeyingQPSK

Dual Binary Phase Shift KeyingBPSK

WCDMA CODES

WHICH BTS ?WHICH MS ?WHICH DATA RATE?HOW MANY APPLICATIONS?

•PN (SCRAMBLING) CODE• -(LONG CODE)

•ORTHOGONAL CODE -Spreading-(SHORT CODE)

Data (1)„chipped“ „chipped“ (2)

Bit rate Chip rate Chip rate

BitrateChiprateFactor Spreading =

Channelization and scrambling codes

Spreading Factor Gain-1

W=3,84MHz

SF= W/Rb

Unspread signal

Spread signal

Power density

Frequency

Background Noise

Rb Change by serviceSF= W/Rb

W 3,84Mbit (fix)

User bit rate Kbit W=3840Kbit

SF SF gaindB

15 3840 256 24

30 3840 128 21

60 3840 64 18

120 3840 32 15

240 3840 16 12

480 3840 8 9

960 3840 4 6

1920 3840 2 3

3840 3840 1 0

ORTHOGONALVARIABLE CODE

SF= ? 4

SF GAIN DEPEND ON USER DATA RATE

ORTHOGONAL VARIABLE SPREADING FACTOR (OVSF)

•SF Gain depend on OVSF codes.

Chip Rate = 3.840 Mcps

480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s

1111 1100 1010 1001

11111111 11110000 11001100 11000011 10101010 10100101 10011001 10010110

OVSF Code Tree

960 kb/s

1920 kb/s

User data

480 kb/s 480 kb/s 480 kb/s 480 kb/s

1.92 Mb/s

Chip Rate = 3.840 Mcps1

1111 1100 1010 1001

11111111 11110000 11001100 11000011 10101010 10100101 10011001 10010110

= Unusable Code Space

SCRAMBLING CODES

USAGE•UL: Separation of Terminals

•DL: Separation of Cells

NUMBER OF CODES

•UL: Several Millions

•DL: 512

CODE FAMILY

•Long 10 ms Code: Gold Code

Downlink Scrambling Codes• Possibility of 262,143 different downlink scrambling codes • Only 8192 different scrambling codes have been defined

Primary scrambling code

8192 ...

Cell #1

Cell #512

Secondary scrambling code #1Secondary scrambling code #2

Secondary scrambling code #15

8192 scrambling

512 sets of 1 primary and 15

secondary codes

512 primary codes divided into 64 groups

SCRAMBLING CODE

CODE USING

Uplink : Distinquish Mobil Terminal.Downlink: Distinquish each cell.

PN3 PN4

PN5 PN6

PN1 PN1

NodeB Cell “1” PN code 1

PN2 PN2

NodeB cell “2” PN code 2

ORTHOGONALITY

Orthoganality = 0 Orthoganality = 0,5 Orthoganality = 1Orthoganality = 0 Orthoganality = 0,5 Orthoganality = 1

Uplink Downlink

•UL scrambling codes has not got orthogonality

•DL scrambling codes has got orthogonality

Radio Access Bearer (RAB)

UMTS and Radio Access BearerServices

UMTS Network

TETE MTMT WCDMA RAN

WCDMA RAN CN Iu

edgenode

CN Iuedgenode

CNGateway

End-to-End Service

TE/MT Local Bearer Service

External Bearer ServiceUMTS Bearer Service

RAB CN Bearer Service

Bearer Service Classes

Streaming class: preserve time relation between entities of the stream e.g. video streaming

Real time applications:

Conversational class: preserve time relation of the entities with low delay e.g. voice call, video call

Background class: destination is not expecting data, preserve payload e.g. email

Interactive class: request/response pattern with preserved payload e.g. Internet browsing

Non-real time applications:

RABs supportedConversational Speech 12.2 kbps Circuit switched

Conversational CS Data 64 kbps Circuit switched

Streaming 57.7 kbps Circuit switched

Interactive Variable rate Packet Switched

RACH/FACH, 64/64, 64/128, 64/384

Combination of Conversational AMR and Interactive 64/384Multi-RAB

Mapping of UMTS Services to RABs

• Eb/NoW-CDMATDMA-GSM

CEb/NoC

Power spectrum

Eb/N0 what is it ?• Eb/N0 is the ratio of the energy/bit (Eb) to the spectral

noise density (N0)– Simplified, the Eb/N0 can be seen as a basic measure

of how strong the signal is at the receivers input.Suppose we are going to design a digitalcommunication system where the BER notcan be more than 10-3. The modulation method used is DBPSK.

According to the graph we need an Eb/N0of at least 7.9 dB in order to fulfill the criteria

This 7.9 dB will then be our “coverage level”for this quality.

• Eb/No

Maximum noise level

Eb/No required

Power spectrum

Unwanted power from other sources

Eb/No = C / I x processing gain

Available power to share between users

• Eb/No & Power ControlPower spectrum

Maximum noise level

Eb/No required

Unwanted power from other sources

Power control

Power , Interference , Capacity .

Ec/N0, Ec/I0• CPICH Ec/I0, CPICH Ec/N0

• The Ec/I0 denotes the received chip energy relative to the total power spectral energy

• Ec/I0 is often used to indicate the quality of digital signals that do not carry any “user data” - like the CPICH for example.

System Overview

Physical Channels

Channels and Layers

Duplication Avoidance

BMCPDCP

PHYLayer 1

Layer 2

Layer 3

LogicalChannels

TransportChannels

Non Access Stratum (NAS)

Access Stratum (AS)

Control plane (C-plane)

User plane (U-plane)

Core Network

UTRAN Protocols• RRC – Radio Resource Control

– Main functions:• Responsible for establishing, reconfigure and releasing connections between the mobile and the network.• Routes the higher layer SDU (Service data units) to RLC, PDCP or BMC depending on its content.

• PDCP - Packet Data Convergence Protocol– Main functions

• Compress the packet data received from higher layers• etc.

• BMC - Broadcast/Multicast Control– Main functions:

• Responsible for handling the broadcasting/multicasting messages – SMS etc.• RLC – Radio Link Control

– Main functions (three different operation modes)• Transparent mode

– Segmentation and reassembly– Transfer of user data

• Un-acknowledged mode– As in transparent mode– Ciphering– Etc.

• Acknowledged mode– As in Unacknowledged– Flow control– etc

• MAC – Media Access Control– Main functions

• Mapping between logical channels/transport channels and transport channel selection• Multiplexing of PDUs Packet Data Unit) to/from common and dedicated channels• etc.

Channels and their mapping

RLC Layer(Radio Link Control)

MAC Layer(Media Access Control)

PHY(Physical Layer)

Air Interface

CHLogical Channels

Transport Channels

Physical Layer Structure• UMTS Frame Format

Slot = 0.667 ms = 2560 chips

Slot #0 Slot #1 Slot #j Slot #14

Frame #0 Frame #1 Frame #i Frame #4095

Frame = 15 slots = 10 ms = 38400 chips

Super frame = 4096 frames = 40.96 seconds

Common Pilot Channel (CPICH)

Pilot Symbol Data (10 symbols per slot)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

1 Frame = 15 slots = 10 mSec

1 timeslot = 2560 Chips = 10 symbols = 20 bits = 666.667 uSec

Primary Common Control Physical Channel (P_CCPCH)

Spreading Factor = 2561 Slot = 0.666 mSec = 18 broadcast data bits / slot

Broadcast Data (18 bits)S-SCH

2304 Chips256 ChipsSCH

1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSec

Secondary Common Control Physical Channel (S_CCPCH)

Spreading Factor = 256 to 41 Slot = 0.666 mSec = 2560 chips = 20 * 2k data bits; k = [0..6]

20 to 1256 bits0, 2, or 8 bits 0, 8, or 16 bits

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

DataTFCI or DTX Pilot

Page Indication Channel (PICH)– Spread with SF=256 Channelization code– Each UE looks for a particular PICH time slot– A paging indicator set to “1” indicates that the UE

should read the S-CCPCH of the corresponding frame.

288 bits for paging indication 12 bits (undefined)

b1b0 b287b288 b299

One radio frame (10 ms)

Acquisition Indicator Channel (AICH)Transmits Acquisition Indicators in response to UE Access AttemptsAI’s are derived from the UE’s Access Preamble Signature

Identifies the UE which is the target of the AICH response

1024 chips

AS #0 AS #1 AS #i AS #14

a1 a2a0 a31a30

AI part

(Transmission Off)∑=

sjssj bAIa

AS #14 AS #0

Downlink Dedicated Physical Data Channel (DPDCH)

Downlink Dedicated Physical Control Channel (DPCCH)

1 Slot = 0.666 mSec = 2560 chips = 10 x 2^k bits, k = [0...7]SF = 512/2k = [512, 256, 128, 64, 32, 16, 8, 4]

DPDCH DPCCHDPDCH DPCCH

Data 2TFCIData 1 TPC Pilot

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

SUMMARY FOR PHYSICAL CHANNELS

Common Pilot Channel (CPICH): The CPICH continuously sends the SC for the cell. It also aids channel estimation for cellselection/reselection and handover for the UE.

Primary Common Control Physical Channel (P_CCPCH): This channel is used to carry broadcast data and thesynchronization channels. The Channelization Code CP_CCPCH,256,1 is always used for this channel since it needs to be decoded by all UEs.

The Secondary Common Control Physical Channel(S_CCPCH): Uses a different Channelization Code depending on weather it is carrying a paging, signaling or user data.

Paging Indicator Channel (PICH): This channel is used in conjunction with the paging that is carried by S_CCPCH

The Acquisition Indicator Channel (AICH): Acknowledges that the RBS has acquired the RACH preamble by echoing theUE’s Random Access signature.

Physical Random Access Channel (PRACH): The PRACH is used to carry the 20 msec Random Access message on the I branch of the modulator and L1 control (Pilot and TFCI) on the Q branch

Dedicated Physical Data/Control Channel (DPDCH/DPCCH): The DPDCH carries user traffic, Layer 2 overhead bits andLayer 3 signaling data. The DPCCH carries Layer 1 control bits, which are as follows:

• Pilot bits, which are used by the receiver to measure the channel quality• Transmission Power Control (TPC) bits, which are used to adjust the power of the UE• Transport Format Combination Indicator (TFCI) bits,which are used to tell the receiver what is being carried by thisphysical channel.

The DPDCH and DPCCH are not time multiplexed, as they are in the downlink, but instead are fed into the I and Q inputs of a complex spreader

Downlink Data RatesVariable Data Rates on the Downlink:

ExamplesBits/Frame Bits/ Slot

Channel BitRate

(kbps)

ChannelSymbol

Rate(ksps)

TOTAL DPDCH DPCCH TOTAL DPDCH

TFCI TPC PILOT

15 7.5 512 150 60 90 10 4 0 2 4

120 60 64 1200 900 300 80 60 8 4 8

1920 960 4 19,200 18,720 480 1280 1248 8 8 16

Coded Data 1.920 Mb/sec

(19,200 bits per 10 mSec frame)S/P

Converter

Channel Coding(OVSF codes at 3.84 Mcps)

960 kbps/sec

Downlink Spreading

S→ P Cch Cscramb

cos(wt)

sin(wt)

DPDCH&

One radio frame, T f = 10 ms

TPCN TPC bits

Slot #0 Slot #1 Slot #i Slot #14

T slot = 2560 chips, 10*2 k bits (k=0..7)

Data2N data2 bits

DPDCHTFCI

N TFCI bitsPilot

N pilot bitsData1

N data1 bits

DPDCH DPCCH DPCCH

The same channelization code is applied to both I and Q!

Uplink Spreading

*j p(t)

I + jQ

Scramb

cos (w t)

sin (wt)

PilotN pilot bits

TPCN TPC bits

DataN data bits

Slot #0 Slot #1 Slot # i Slot #14

T slot = 2560 chips, 10 bits

1 radio frame: T f = 10 ms

DPCCHFBI

N FBI bitsTFCI

N TFCI bits

T slot = 2560 chips, N data = 10*2 k bits (k=0..6)

Different channelization codes areapplied to DPDCH and DPCCH

Idle Mode Behaviour

Paging in UMTS• There are 2 paging procedures in UMTS

– One procedure for the mobiles in Idle.– One procedure for the mobiles in Cell_DCH

(i.e. The mobile has a dedicated channel)

Common Channel Connected

PAGING TYPE2(sent from the RNC)

PAGING TYPE1(sent from the RNCafter reception ofA PAGING from core)

Cell re-selectionThere are 3 criterions (intra frequency and non HCS) that must be fulfilled in order for a intra cell reselection to take place:

– The S-criteria must be fulfilled– The cell should be ranked as the best– The new cell is better ranked than the serving cell during a time period of

Treselections and at least 1 second has elapsed since the mobile camped on the current serving cell.

S-criterionThe mobile measures the CPICH Ec/I0 and CPICH RSCP of the serving celland evaluates the cell selection criterion S for the serving cell at least every DRX cycle.

FDD cells: Srxlev > 0 AND Squal > 0GSM cells: Srxlev > 0

where:

Squal = Qqualmeas - QqualminSrxlev = Qrxlevmeas - Qrxlevmin - Pcompensation

Pcompensation = max(UE_TXPWR_MAX_RACH – P_MAX, 0)

Squal -> CPICH Ec/I0Srxlev -> CPICH RSCP

Cell ranking criterion - R

Rs = Qmeas,s + QhystsRn = Qmeas,n - Qoffsets,n

Re-selected cell: 1. Fulfills the S criterion2. Is the highest ranked

Qmeas = CPICH RSCP (RxLev) : Qhyst1s & Qoffset1s,n

Qmeas = CPICH Ec/I0 : Qhyst2s & Qoffset2s,n

Squal Cell selection quality value (dB).

Srxlev Cell selection RX level value (dB)

QqualmeasMeasured cell quality value. The quality in the received signal expressed in CPICH Ec/I0 (dB).

QrxlevmeasMeasured cell RX level value. The level in the received signal is expressen in CPICH RSCP (dBm)

Qqualmin Minimum required quality in the cell

Qrxlevmin Minimum required RX level in the cell

PcompensationMax(UE_TXPWR_MAX_RACH - P_MAX,0)

UE_TXPWR_MAX_RACH Maximum TX power level a mobile may use when accessing the cell on the RACH.

P_MAX Maximum RF output power of the mobile

Neighbour cell measurements (in Idle mode)The measurements are started when:

Intra frequency: Squal ≤ SintrasearchOR Sintrasearch is not sent in SIB

Inter frequency: Squal ≤ SintersearchORSintersearch is not sent in SIB

Inter RAT (GSM): Squal ≤ SsearchRATORSsearchRAT is not sent in SIB*

* This is equal to the case when SsearchRAT = 20 dB

Cell re-selection (UMTS)

Thisrange is decidedby QSI parameter valueh

Qqualmin

QhystsQoffsets,n

Re-selectionMeasurementsSuitable

Qqualmeas

timeRe-selection

Treselections

No measurements areperformed on neighbours

Srxlev > 0 AND Squal > 0

Cell re-selection (UMTS-GSM)

SsearchRAT

Qrxlevmin

QhystsQoffsets,n

Re-selectionMeasurementsSuitable

Qrxlevmeas

timeRe-selection

Treselections

Srxlev > 0

No measurements areperformed on neighbours

Measurements areperformed on GSM neighbours

Cell re-selection (GSM-UMTS)

FDDQmin

Qhysts

FDDQOFF

Re-selectionSuitable

FDDRCPMIN > 0-15 (-114 to -84 dBm)Qqualmeas

FDDQMINOFF

No cell reselection areperformed on neighbours

This range is decided byQSI parameter value

Cell re-selection (GSM - UMTS)

-98-94-90-86-82-78-74-70-66-62-58-54

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 QSI

XAlways measure UMTS

Measure UMTS whenRxLev is below

Measure UMTS whenRxLev is above

Cell Re-selection• A threshold on the serving cell defines below (or above) which levels inter-

system measurements are initiated (Trigger)• A threshold on the target cell defines below which level re-selection is not

possible (Capture)• Serving and target cells are compared, possibly with added offsets (Ranking)

Trigger Capture Ranking

Measure CPICH Ec/I0 RxLev CPICH RSCP and RxLev

Parameters Qqualmin

SsearchRAT

Qrxlevmin Qhyst1

Qoffset

Measure RxLev CPICH Ec/I0 CPICH RSCP and RxLev

Parameters QSI FDDQMIN FDDQOFF

Cell re-selection rules to avoid “ping pong”

Qqualmin + SsearchRAT < FDDQMINFDDQOFF < -Qhyst1 – Qoffset1

Trigger Capture Ranking

Measure CPICH Ec/I0 RxLev CPICH RSCP and RxLev

Parameters Qqualmin

SsearchRAT

Qrxlevmin Qhyst1

Qoffset

Measure RxLev CPICH Ec/I0 CPICH RSCP and RxLev

Parameters QSI FDDQMIN FDDQOFF

Region Condition Neighbour cells to be measured in idle mode

1 Squal > Sintrasearch None2 Sintersearch < Squal ≤ Sintrasearch Intra frequency adjacencies3 SsearchRAT < Squal ≤ Sintersearch Intra & Inter frequency adjacencies4 Squal ≤ SsearchRAT Intra, Inter and inter system adjacencies5 Squal < 0 Full scan of 3G and 2G frequencies

(initial selection mode)

Cell re-selection

Handover

Handovers in UMTS

• Intra frequency handover (f1 to f1)– Softer Handover– Soft Handover– Soft/Softer Handover– Core Network Hard Handover

• Inter frequency handover(f1 to f2)– Hard Handover

• Inter system handover (UMTS to GSM)– Hard Handover

Handovers in UMTS

Node B Node B

Intra frequency handover

• An intra frequency handover is a handover between to cells using the same frequency.

• An intra frequency handover decision is in 99% of the cases decided by the RNC.

• The UE performs measurements and reports to the RNC when a certain criteria has been fulfilled. This is referred to as event based reporting.

HANDOVER

Node BNode B

• SOFTER HANDOVER

UMTS COVERAGE

MSC/VLRIn a softer handover the active set contains at least 2 cells from the same Node-B

UMTS COVERAGE

Node BNode B

DRIFTRNC

IubIub

SERVINGRNC

HANDOVER• SOFT HANDOVER

MSC/VLRIn a soft handover the active set contains cells from different Node-Bs

Soft/Softer Handover

• In soft/softer handover the active set contains 2 cells from the same Node-B and one cell from a different Node-B.

Active set update “procedure”UE Node-B RNC

Decision to setupNew RL

Event Measurement reports

Radio Link Setup Request

Radio Link Setup Response

Iub Bearer Setup

Downlink Synchronization

Uplink Synchronization

Active Set Update

Active Set Update Complete

X seconds

1 ~ 2 seconds

Power Control&SoftHO

Trouble zone: Prior to Hard Handover, the UE causes excessive interference to BS2

BS2 Receive Power Target

UE responding to BS1power control bits

UE responding to BS2power control bits

1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 1 1 1 12 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

UE responding to BS1power control commands

UE responding to BS2power control commands

1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 12 2 2 2 2 2

1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

BS1 BS2 Action0 0 Reduce power0 1 Reduce power1 0 Reduce power1 1 Increase power

UE responds to power control commandsfrom both BS1 and BS2

SoftHO Gain

SRNC CNGood block

Block in error

Macro Diversity Combining

BER =10-1

BER =10-2

BER =10-1

BER =10-3

BER =10-1

BER =10-5

BER =10-1

BER =10-5

BER =10-3

BER =10-4

BER =10-2

BER =10-3

BER =10-1

BER =10-6

BER =10-1

BER =10-2

BER =10-1

BER =10-3

BER =10-4

BER =10-5

BER =10-2

BER =10-5

BER =10-6

BER =10-2

RL 1 RL 2 RL 3

21014,5 −⋅=BER 21078,2 −⋅=BER 21064,2 −⋅=BER

With MDCin the RNC:

31028,1 −⋅=BER

• HARD HANDOVER

UMTS COVERAGE

GSM COVERAGE

Node B

MSC/VLR

HANDOVER

Hard handover is defined as a handover where the old connection is released before the new connection is established (like in GSM)

Hard handover takes place at an inter frequency handover or an inter system handover.

Filtering of measurements

Original signal K=2 K=6 K=8 K=11 K=19

( ) nnn MaFaF ⋅+⋅−= − 11Fn = Updated filtered measurement resultFn-1 = Old filtered measurement resultMn = Latest received measurement resulta = (½) (k/2)

Not supported by all mobiles

Event-triggeredreport

(Event 1A)CPICH 3

CPICH 1

CPICH 2

Periodicreport

Reportingrange

Reportingterminated

)2/(10)1(1010 111

aaBest

iiNew HRLogMWMLogWLogM

−−⋅⋅−+⎟⎟⎠

⎞⎜⎜⎝

⎛⋅⋅≥⋅ ∑

1X type of reporting events in FDD

• Event 1A (called E1A): A primary CPICH enters the reporting range

• Event 1B (called E1B): A primary CPICH leaves the reporting range

• Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active set

• Event 1D (called E1D): Change of best cell in active set• Event 1E (called E1E): A primary CPICH becomes

better than an absolute threshold• Event 1F (called E1F): A primary CPICH becomes

worse than an absolute threshold

(Event 1B)

CPICH 3

CPICH 1

CPICH 2

Reportingrange

)2/(10)1(1010 111

aaBest

iiNew HRLogMWMLogWLogM

−−⋅⋅−+⎟⎟⎠

⎞⎜⎜⎝

⎛⋅⋅≤⋅ ∑

Event 1B (called E1B): A primary CPICH leaves the reporting range

2/1cInASNew HMM +≥

CPICH 2

CPICH 1

CPICH 3

CPICH 4

TimeEvent-triggeredreport

(Event 1C)

•Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active set

CPICH 2

CPICH 1

CPICH 3

CPICH 4

(Event 1D)

Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active setEvent 1D (called E1D): Change of best cell in active set

Intra frequency handover example

/2 H1C

Cell 1Connected

Event 1AAdd Cell 2

Event 1CReplace Cell 1

with Cell 3

Event 1BRemoveCell 3

CPICH 1

CPICH 2

CPICH 3Time

MeasurementQuantity

∆T ∆T ∆T

Ec /I0

Time to trigger

Soft Handover Overhead (SHO)• In a GSM network the soft handover overhead is always 0%• The soft handover overhead is a measure on how many connections on

average exceeding 1 a mobile has got to the network.• A large soft handover overhead indicates that each mobile has got many

connections on average to the network (>1) -> Average AS size is high.• A low soft handover overhead indicates that each mobile has got few

connections on average to the network (~1) -> Average AS size is low.• A large SHO could indicate that too many resources are used by the mobile.• A low SHO could indicate that there could be more gain achieved in having

several connections to the network and that the mobile does use too much transmit power on average.

• A well balanced SHO is about 30-40% (1.3 – 1.4 connections on average)

⎟⎟⎠

⎞⎜⎜⎝

⎛−

≠⋅= 1

0__________100(%)_

ASwithUEsofNumbernetworktheinradiolinksactiveofNumberOverheadSHO

Compressed Mode

Radio frame(10 ms)

Normal mode

Compressed mode

UE performsmeasurements

on another frequencyor another system

SP=256 SP<<256 normally SF/2

DownlinkPower

UE only has got one receiverand one transmitter

Intersystem HandoverUMTS -> GSM (voice)

COMPRESSEDMODE

Contains the orderto verify the BSIC

Contains the verificationof the BSIC

Intersystem HandoverGSM -> UMTS (voice)

Power Control

SIRerror

SIRtarget

Up/Down

Outer closed loop power controlInner closed loop power control

Power Control

N1 P1 N2 P2

Power Control• There are three different power control mechanisms in

UMTS– Open loop power control

• Takes place at initial access in order to set the initial transmit power. (Is based on the pathloss measured by the mobile)

– Inner closed loop power control• This is the fast power control (1.5 kHz) and is controlled by the

Node-B/mobile based on the SIRtargets sent from the RNC/mobile. The aim of the Inner closed loop power control is to control thetransmitted power (UL and DL) on the air interface so that the SIR targets can be fulfilled.

– Outer closed loop power control• The outer closed loop power control sets SIR target for the Inner

closed loop power. The rate is 10-100 Hz typically.

RACH transmission (preamble)1. The mobile decodes the BCH to find out which RACH’s that are available2. The downlink power is measured and the mobile calculates how much power that is

required in order to reach the Node-B (Open loop power control)3. A 1 ms RACH preamble is sent from the mobile using the calculated transmission

power.4. If the mobile does not get any response from the Node-B (AICH) it send another

preamble with increased power.5. This procedure is repeated until the mobile receives a response from the Node-B

Power Control

Uplink Open Loop Power Control

Dedicated channel at just enough power

1) UE measures Pilot

3) Transmits

at calculated power

4) The power is ramped up until a response is heard or maximum number of re-attempts is reached

Connection established with minimum interference to other users

2) Reads interference level from Broadcast channel

Downlink Open Loop Power Control

Minimum downlink power used to setup a connection thus maximizing downlink capacity

2) Transmits

at calculated power

3) The power is ramped up until a response is heard or until a certain maximum power is reached

1) Uses parameters to calculate required power

Dedicated channel at just enough power

Uplink Inner Loop Power Control

‘Increase power’

‘reduce power’

Uplink Signal to Interference (SIR) target is maintained for all services

Commands are fast enough (1500 times per second) to compensate for ‘Rayleigh’ fading

Downlink Inner Loop Power Control

‘Increase power’

‘reduce power’

Minimum power for each connection is maintained, thus maximizing downlink capacity

Commands are fast enough (1500 times per second) to compensate for ‘Rayleigh’ fading

Uplink Outer Loop Power Control

UE SRNC

Inner loop commands based on SIR measured

SIR target = x dB

SRNC measures the BLER for the service and creates a new SIR target

SIR target = y dB

Uplink BLER for the service is maintained, regardless of UE environment

Downlink Outer Loop Power Control

Inner loop commands based on SIR measuredSIR target

= x dB

UE measures the BLER for the service and creates a new SIR target

SIR target = y dB

Downlink BLER for the service is maintained, regardless of UE environment

Cell Breathing

Cell breathing due to loading

Thermal Noise

Cell Loading = 75%

Cell Loading = 50%

Cell Breathing

Cell radius depends on traffic load

Rake Receiver

RAKE Receiver Block Diagram• WCDMA Mobile Station RAKE Receiver Architecture

Each finger tracks a single multipath reflection• Also be used to track other base station’s signal during soft

handoverOne finger used as a “Searcher” to identify other base stations

Finger #1

Finger #2

Finger #N

Searcher Finger

Combiner

Sum ofindividual multipath components

Power measurement of Neighboring Base Stations

RAKE Receiver Example

0 50 100 150 200 250 300 350 400-2

0 50 100 150 200 250 300 350 400-202468

1012141618

n ⋅1/2-chip delay

To Viterbi Decoder

Composite Received Signal

PN, Channelization Codes

m ⋅1/2-chip delay

k ⋅1/2-chip delay

Correlator

Equal Combining, ML Combining,or Select Strongest

0 50 100 150 200 250 300 350 400-2

3 + Interference

+ Interference

Radio Resource Management

RADIO RESOURCE MANAGEMENT-1

CellCoverage

CellCapacity

ServiceQuality

Optimization

Admission ControlAdmission Control

PAKETSCHEDULING

LOAD (Congestion)

CONTROL

HANDOVERCONTROL

Powercontrol

Admission Control

• The purpose of the admission control is to maintain the stability of the network by ensuring that if the loading becomes too high, no additional mobiles are admitted to the network

• Admission control typically allows the operator to limit (vendor dependent):– The uplink noise rise– The downlink transmit power– The maximum transmit power per user– The allocated radio bearer

Before assigning new carrier, cell load is checked:New RAB EstablishmentHandoverChannel Switching

Cell load contains two part:Uplink InterferenceDownlink Power

Admission Control

Admission Control Thresholds

Admission Control

Load (Congestion) Control

Congestion Control

Congestiondetection

Congestionhandling

RB drop

Bit rate adaptation

Dedicated to common

Cong_thr

Cong_OK

Congestion Control Actions

StartreleaseAseDl

384128 64 FACH 64 128

Power or Load Limit

128384

Congestion Control handling- DL

= pwrHyst

StartreleaseAseDl

DL Power

pwrAdm +pwrAdmOffset

pwrOffset

< pwrHyst

StartreleaseAseDl

= tmCongAction

Congestion

= pwrHyst

StoppreleaseAseDl

Congestionsolved

Congestion Control handling - UL

= ifHyst

StartreleaseAseDl

iFCong

iFOffset

< ifHyst

StartreleaseAseDl

= tmCongAction

Congestion

= ifHyst

StoppreleaseAseDl

Congestionsolved

RRC States

UE RRC states

„IDLE State“

Used for transportationof small data volumes

Used for transportationof big data volumes

Connected to the Network

Not connected to the Network

Stand by mode(ready for transport)

Wake me up whenyou need me“I am still in the office”

RRC statesNot supported by many UEs Bad performance

in many UEs

URA_PCH Cell_PCH

Cell_FACHCell_DCH

Does not consume so much battery

Transmissionstate

Nontransmission

Common channel shared by all users in the cell

Idle Cell_FACH Cell_DCH Cell_FACH Cell_PCH

TimerTimer expiredexpired

(RLC (RLC bufferbuffer stillstill emptyempty))

RRC states

Data Transfer Data Transfer startsstarts

(RLC (RLC bufferbuffer fullfull))

HighHigh data data transfer transfer demand

LowLow data data transfer transfer demand

Data transfer Data transfer finishedfinished

(RLC (RLC bufferbufferemptyempty))

demand demand

Channel type switching (CTS)Traffic volume

Event 4Ais sent

CELL_FACHState

CELL_DCHState

Uplink upper transport channel traffic volume threshold

Uplink lower transport channel traffic volume threshold

Downlink lower transport channel traffic volume threshold

Downlink upper transport channel traffic volume threshold

FACH stateDownlink

Event 4Bis sent

Uplink

Channel type switching (CTS)

Cell_DCH 64/384

Cell_DCH 64/64

Cell_FACH

Cell_DCH 64/128

Idle Mode

No activityNo activityCommon to Dedicated based on

buffer size

Common to Dedicated based on

buffer size

Soft Congestion

SHO can initiate a

switch if it fails to add

SHO can initiate a

switch if it fails to add

Coverage triggered downswitch

Upswitchbased on

bandwidth

Upswitchbased on

bandwidth

Dedicated to common based on throughput

Channel type switching (CTS)

TTime -out

User 1 User 2

RACHSwitch to common

Switch to dedicated

Release dedicated channel

PacketPacket Packet

Packet Packet Packet

User 3

Data Buffers

Bit Rate Adaptation

Bit Rate can be increased via reason mentioned below

High channel utilization (radio quality must be high)

Bit Rate can be decreased via reason mentioned below

Low channel utilizationBad radio qualityHigh Load (congestion control)

Overflow in RLC Buffer: Event 4AUnderflow in RLC Buffer: Event 4B

Bit Rate Adaptation

WCDMA Planning

Radio Propagation Models

Cell ConceptsMacro Cell

Cell Range > 1km, mostly Rural areas, andUrban

Mini CellCell Range 500m-1km, Urban areas

Micro CellCell Range 200m-500m, DenseUrban areas

Pico Cellİnbuilding cells

Cell Concepts

Macro Cell

d > 1 km

Mini Cell500 m < d < 1 km

RF Propagation Basics

Fast FadingRayleigh distributed

Slow FadingLog normal distribution with standart deviation

Path LossDecrease of the global mean value withdistance

Fast Fading (Rayleigh)

Slow Fading (Log-normal)

Shadowing

Fast and Slow Fading

Simple Radio Propagation Models

Propagation in Free Space

Simple Radio Propagation Models

Plane Earth Propagation

Knife-edge Diffraction

Okumura-Hata Related Models

1 km < d < 100 kmhb>30m

Okumura Model – empiricalHata Model - <1.500 MHz.Cost - 231 Hata Model - >1.500 MHz.

Okumura-Hata Model forDimensioning

A constant for 2GHz

Walfish Ikegami Model

Flat ground

Uniform building height and building seperations

Propagation Model in Asset

[ ] [ ]

)log()log(

)log()log()log()log()log(

6275431

7654321

effmsms

effeffmsms

clutterdııfKHKhKhKKAwhere

dBAdHKKclutterdııfKHKhKhKK

clutterdııfKdHKHKhKhKdKK

dBPathloss

+++++=

+=+++++++

=+++++++

log(d)

“A”

“B”

K1 is used to model the intercept – will be directly related to the clutter factorsK2 is used to model the pure distance dependenceK3 should always be -2.96 as the mobile antenna height is assumed to always be 1.5 mK4 should always be 0 because mobile antenna height is assumed to always be 1.5 mK5 is used to model the relation between the site antenna height and the intercept – will have an impact on the clutter factorsK6 is used to model the relation between the site antenna height and the distance from the siteK7 is used to model the influence of diffraction

Example: K6 – is always negative in a correct model

1 17 33 49 65 81 97 113

15 meter (-K6)20 meter (-K6)25 meter (-K6)30 meter(-K6)35 meter (-K6)15 meter (+K6)20 meter (+K6)25 meter (+K6)30 meter (+K6)35 meter (+K6)

K6 < 0As the antenna height increasesthe “signal strength” also increases

K6 > 0As the antenna height increasesthe “signal strength” decreases

The same apply to K5 !!!

Linkbudgets (UMTS vs GSM)

Linkbudgets

• In GSM there is a linkbudget for one service only. But in UMTS there are several different services available…

• Which one should be dimensioned for ?

64/384 kbps

128/384 kbps8/8 kbps

VideoVoice

PS Radio Bearer AllocationLoad in DL

Allocated Radio Bearer

80%0/0 kbps is used for multi RABs

CS 12.2 kbps + PS 0/0 kbps

UMTS supported Radio Bearers (Vendor dependant)

Circuit Switched

• AMR 12.2 kbps (Voice)• UDI 64 kbps (Video)

•Streaming

Packet Switched

Interactive/Background• 8/8 kbps• 64/64 kbps• 64/128 kbps• 64/384 kbps• 128/128 kbps• 128/384 kbps

Streaming• ..Conversational• ..

Multi Radio BearersAMR 12.2 kbps + Interactive/Background

Asymmetric Services

DownlinkPower

UplinkPower

CPICHCoverage

UL: 64 kbpsDL: 384 kbps

DownlinkPower CPICH

CoverageUplinkPower

Linkbudget (GSM and UMTS)• A link budget is made in order to find the cell range for

different environments• The link budget will give you the maximum allowed

pathloss (MAPL) in order to meet the requirements for that environment– The cell range could then found by a simple calculation:

Maximum output power – MAPL → cell range (and coverage level)

Maximum Pathloss (MAPL)

Linkbudget (GSM)

• In GSM one user consume “all” the available power in the base station during a timeslot

timeslotMaxPower

Linkbudget (UMTS)• In UMTS one user consume the power he requires in order to keep

the connection• The available power in UMTS is shared between different users in

the downlink

MaxPower User 1

User 2User 3

Total output power =User 1 + User 2 + User 3

Linkbudget (UMTS)

• The available power in the downlink is 43 dBm.

• The available power in the uplink is 21 dBm (maximum output power of the mobile)

• This means:– The limiting link in terms of coverage is the

uplink in UMTS !

LinkbudgetsGSM UMTSUplink and downlink are balanced Uplink and downlink are not balanced

GSM 900 Downlink Uplink

RX Sensitivity -102.0 -104.0

Penetration Loss 22

Fading Margin 12.8

Maximum Pathloss 122.7 122.7

Feeder Loss 0.0 3.0

Body Loss 2.0 0.0

Antenna Gain 0.0 18.0

Diversity Gain 0.0 1.5

Sigma Total 8

Probability Area 95.0 %

Probability Edge 89.1%

RBS TX Power 33

Feeder Loss 0.0

Body Loss 2.0

Antenna Gain 0.0

Total Max EIRP 28.0

19Penetration Loss

18.2Fading Margin

127.1?Maximum Pathloss

-124.8?RX Sensitivity

3.00.0Feeder Loss

0.02.0Body Loss

18.00.0Antenna Gain

2.00.0Diversity Gain

8Sigma Total

95.0 %Probability Area

90.0%Probability Edge

Downlink

19.0Total Max EIRP

0.0Antenna Gain

2.0Body Loss

0.0Feeder Loss

21Node-B TX Power

UplinkW-CDMA

Service and environmentaldependant entries

MAPL GSM Voice122.7 dB

MAPL UMTS Voice127.1 dB

LinkbudgetAlternative approachTurkcell approach

Assume a load for the uplinkCheck if its OK in downlink

If not, decrease/increase the load andcheck again.

Make the design for VideoIndoor with 50% load in uplink.

Will always be OK in the downlinkas we are limited by coverage in thisscenario

Coveragelimited(uplink)

Capacitylimited(downlink)

Uplink

Downlink

Coverage Capacity?

Downlink/Uplinkcoverage dimensioning

Assume a path loss of 127 dB (Dense Urban environment)

“Signal strength” from CPICH (Pilot)

33 – 127 = -92 dBm

“Signal strength” from mobile

21-127 = -106 dBmMobile coverage

er for traffic (for all users)

Power for coverage(Pilot power)

33 dBm(2 Watt)

43 dBm(20 Watt)

21 dBm(0.126 Watt)

2 Watt for CCH

42 dBm(16 Watt)

→ The “coverage” is limited by theavailable power in the mobile

What is Npole?

Uplink or Downlink?

Uplink Npole• The uplink pole capacity, Npole, is the theoretical limit for the number of UEs that a

cell can support. It is service (RAB) dependent. At this limit the interference level in the system is infinite and thus the coverage reduced to zero.

⎟⎟⎟⎟

⎜⎜⎜⎜

Downlink Npole

General Dimensioning

Mobile coverage

Downlink/Uplinkcoverage dimensioning

er for traffic (for all users)Power for coverage

(Pilot power)

33 dBm(2 Watt)

42 dBm(16 Watt)

43 dBm(20 Watt)

21 dBm(0.126 Watt)

33 dBm(2 Watt)

Uplink coverage dimensioning

Noise Rise Loading Factor

3 dB 50%

6 dB 75%

10 dB 90 %

20 dB 99 %

∞ dB 100 %Thermal Noise No

se Terminal X

Terminal X

Terminal 1

Terminal 2

Terminal 1

Uplink dimensioningSuppose our wanted signal is Pj and the total received power in the Node-B (all other users + noise) is Itotal, our achieved Eb/Nb can then be written:

where:

is the processing gain

is the bandwidth of the received signal, 3.84 MHz

is the datarate of our channel (i.e. Voice 12.2 kHz)

jtotal

−=⎟⎟

⎞⎜⎜⎝

Uplink dimensioningSolving for Pj yields:

totalj

btotal

jtotal

⎟⎟⎠

⎞⎜⎜⎝

⎟⎟⎠

⎞⎜⎜⎝

⎟⎟⎠

⎞⎜⎜⎝

⎟⎟⎠

⎞⎜⎜⎝

Uplink dimensioningInserting typical values yields:

This can be interpreted as this user will be responsible for a part of the total received power at the Node-B

1220038400004.01

12200 3840000 4.0

≈⋅+

Uplink dimensioningItotal includes the other users in the cell (N) and the thermal noise and can be written as:

All the users in the cell will cause the received power to rise over the “unloaded” received power (thermal noise). This rise is normally referred to as the noise rise in the cell. It can be written as:

jntotaljtotal PILI

jjtotal

totalN

jtotaljtotal

Iη−

⎟⎟⎠

⎞⎜⎜⎝

⎛−

∑∑∑===

This term is normally referred to as the loading factor

Interference in Uplink

1 10 19 28 37 46 55 64 73 82 91 100

Load (%)

Coveragelimited(uplink)

Capacitylimited(downlink)

Gain for 2 x P

Output Power vs. Capacity

Uplink

Downlink

Available power in the UE = 21 dBmor 126 mW

Available power in the Node-B = 43 dBmor 20000 mW

Dimensioning Samples

Sample City - Environment• City İstanbul• Environment Denseurban• Area 187,84 km2• Coverage Indoor• Coverage Prob. %90• UL Case• Limiting Service Video• Subs/km2 3.000

%10 Load, Coverage Case

%50 Load, Incar CoverageCase

%50 Load, %95 Coverage Case

%50 Load, %95 VoiceCoverage Case

%50 Load, Cov&Cap Case

INCREASE

DECREASE

INCREASE

DECREASE

INCREASE

DECREASE

INCREASE

DECREASE

INCREASE

DECREASE

RESULT:

DIMENSIONING LOAD %49

# OF SITE 211

%50 Load, Cov&Cap, 4000 sub/km2

%50 Load, Incar Cov&Cap, 4000 sub/km2

8 Parameter Analysis in Dimensioning

Base Line Values and 8 Parameters

Area (km2) 206PA (W) 20 Subscriber# 228000Noise Rise (dB) 3Orthogonality 0,5 Site # 536CPICH Pwr (dBm) 33 UL Load % 16,95Antenna height (m) 20 DL Load % 26,92Coverage probability% 90Building Loss (dB) 18SHO% 30

Baseline values

1. Power Amplifier Values: 20 – 40 Watt2. Noise Rise Values : 0,97 - 1,55 – 2,2 – 3 – 4 dB3. Orthogonality Values : 0,67 – 0,5 – 0,3 – 0,154. CPICH Power Values : 36 – 33 – 30 – 27 dB5. Antenna Height Values : 15 – 20 – 25 - 306. Coverage Prob. Values : %85 - %90 - %95 - %997. Building Loss Values : 16 – 18 – 19 – 20 – 22 dB8. SHO % Values : %20 - %25 - %30 - %35 - %40

Power AmplifierValues: 20 – 40 Watt

PA (W) UL Load % DL Load % Site#20 16,95 26,92 53640 16,95 26,92 536

PA (W)

UL Load %DL Load %Site#

Noise RiseValues : 0,97 - 1,55 – 2,2 – 3 – 4 dB

Noise Rise (dB) UL Load % DL Load % Site# %0,97 18,75 29,37 414 -1,55 17,73 27,88 445 7,49%2,2 16,7 26,38 485 8,99%3 16,95 26,92 536 10,52%4 15,93 25,45 606 13,06%

0,97 1,55 2,2 3 4

Noise Rise

OrthogonalityValues : 0,67 – 0,5 – 0,3 – 0,15

Orthogonality UL Load % DL Load % Site# % changes0,15 16,95 35,12 5360,3 16,95 31,61 536 -9,99%0,5 16,95 26,92 536 -14,84%

0,67 16,95 22,94 536 -14,78%

0,15 0,3 0,5 0,67

Orthogonality

CPICH PowerValues : 36 – 33 – 30 – 27 dB

CPICH Pwr (dBm) UL Load % DL Load % Site#27 16,95 26,92 53630 16,95 26,92 53633 16,95 26,92 53636 16,95 26,92 536

27 30 33 36

CPICH Power (dBm)

Antenna HeightValues : 15 – 20 – 25 - 30

Antenna height (m) UL Load % DL Load % Site# % changes15 14,6 23,33 64120 16,95 26,92 536 -16,38%25 17,72 27,87 464 -13,43%30 18,76 29,37 410 -11,64%

15 20 25 30

Antenna Height (m)

Coverage ProbabilityValues : %85 - %90 - %95 - %99

S. D. LNF Coverage Prob (%) UL Load % DL Load % Site# %changes12 6,9 85 22,77 36,42 35912 10,1 90 16,95 26,92 536 49,30%12 14,7 95 12,83 20,96 967 80,41%12 23,4 99 8,05 13,58 2890 198,86%

85 90 95 99

Coverage Probability (%)

Building LossValues : 16 – 18 – 19 – 20 – 22 dB

Building Loss (dB) UL Load % DL Load % Site# % changes16 18,75 29,37 41618 16,95 26,92 536 28,85%19 15,93 25,45 608 13,43%20 14,9 23,96 690 13,49%22 12,49 20,22 889 28,84%

16 18 19 20 22

Building Loss (dB)

SHO %Values : %20 - %25 - %30 - %35 - %40

SHO Gain SHO (%) UL Load % DL Load % Site#2 dB 20 16,95 24,85 5362 dB 25 16,95 25,89 5362 dB 30 16,95 26,92 5362 dB 35 16,95 27,96 5362 dB 40 16,95 28,99 536

20 25 30 35 40

SHO (%)

Turkcell UMTS Planning Strategy

Turkcell UMTS planning strategy

• Use as much as possible of the existing infrastructure (where possible).

• Deploy UMTS where there are 3G terminals available (the VİP sites)

• Take some traffic load from the 2G network.

• Support indoor video calls in DU areas (under certain coverage conditions)

Initial deployment procedure(Overview)

Nominal PlanningCell detailed

& Capacity Planning

Initial tuningOf

pre defined clusters

Initial networkOptimization

on a City level

3G coverage methodology

• Determine the service to make the design for.

• Calculate the uplink link budget for this service in DU, U, SU etc.

• Find the maximum allowable path loss for each environment.

• Calculate the required pilot field strength for this MAPL (i.e. “33 dBm – MAPL”)

Target of the 3G coverage methodology

• Create clear CPICH dominance– Minimizes pilot pollution– Maximizes the initial available capacity

• Plan for sufficient signal strength (not to much) in order to prepare for good network performance and quality.

Good UMTS site•The ideal UMTS site would cover it’s intended coverage area and very little else

• A practical site would be located so it’semissions were contained by the terrainand clutter

• The site would be located no higherthan absolutely necessary.

• In an urban area, the antennas would be high enough to clear surrounding buildingsand no higher.

Bad UMTS site• A nightmare UMTS site would be locatedon very high ground overlooking a largecity

• Such a site would provide little or no servicein the city but would reduce the capacity of all the cells in the area

• Another bad example of a site would be asite positioned on a building in an urbanarea significantly higher that all the othersurrounding buildings.

• The emissions from such a site would travel much further than the intended service area and reduce the capacity.

RSCP and Ec/I0• RSCP (Received Signal Code Power) is the

received power of the common pilot (CPICH) -dBm

• Ec/I0 indicates the quality of the common pilot -dB

• The mobile will only be able to maintain a connection if the quality of the signal is good enough (i.e. -5 to -18 dB).

• The level of the RSCP is of “secondary importance”. See example on next slide

RSCP and Ec/I0 (II)Ec/I0 = - 8 dBRSCP = - 93 dBmOK

Ec/I0 = - 20 dBRSCP = - 93 dBmNO

Ec/I0 = - 5 dBRSCP= -104 dBmOK

Ec/I0 = - 20 dBRSCP = - 75 dBmNO

RSCP and Ec/I0 (III)

-80 dBmPilot coverage

“Interferer” 1: -73dBm

4 signals are received at cell edge:Wanted signal, Ec (RSCP): -80 dBm (1*10-11

Watt)Interferer 1 I1: -73 dBm (5.01*10-11 Watt)Interferer 2 I2: -73 dBm (5.01*10-11 Watt)Interferer 3 I3: -73 dBm (5.01*10-11 Watt)Total “interference”: -68 dBm (1.5*10-10 Watt)

“Ec/I0” = -80 – (-68) = - 12 dB=++ 321 IIIEc

Main activities in the nominal planning stage

• Identify and confirm candidate sites• Make the initial design in terms of antenna

configurations, initial tilts, initial heights etc• Confirm the coverage and quality in the

Asset 3G tool.• Identify the requirements on additional 3G

sites.

Electrical down tilting

A lot of interferenceNo or very little interference – A new site herewill give very good quality

.....654321 ++++++ IIIIIIEc

0 2 4 6 8 10 12 14

Downtilt (degrees)

Increases the qualityin the area (Ec/I0)

Decreases the coveragein the area.

In this particular case 6 degrees electricaldown tilt was the optimum tilt.

Cell Detailed Planning

Cell detailed planning process• Finalize the RF design of the site

– Antenna, feeder lengths, tilts, heights, pollution etc.• Define the 3G neighbours• Assign scrambling codes according to the scrambling code

planning strategy• Define 2G neighbours (could physically be max 32)

– 1st priority are the once existing in GSM– 2nd priority are 2G sites that later will be 3G as well– 3rd priority are all the other 2G sites

• Make Static/Monte Carlo simulations with traffic in order to confirm the design.– Use the voice traffic from the existing GSM network as starting input.– Add different amounts of CS64 and PS traffic– Find out if the design is limited by capacity or coverage for the different

scenarios.

Scrambling Code Planning

Primary and Secondary Scrambling Codes

Scrambling C

ode 10

Scrambling C

ode 11

Scrambling C

ode 12

Scrambling C

ode 13

Scrambling C

ode 14

Scrambling C

ode 15

Primary Scrambling Code 0

Scrambling C

ode 17

Scrambling C

ode 18

Scrambling C

ode 19

Scrambling C

ode 20

Scrambling C

ode 21

Scrambling C

ode 22

Scrambling C

ode 23

Scrambling C

ode 24

Scrambling C

ode 25

Scrambling C

ode 26

Scrambling C

ode 27

Scrambling C

ode 28

Scrambling C

ode 29

Scrambling C

ode 30

Scrambling C

ode 31

Scrambling C

ode 33

Scrambling C

ode 34

Scrambling C

ode 35

Scrambling C

ode 36

Scrambling C

ode 37

Scrambling C

ode 38

Scrambling C

ode 39

Scrambling C

ode 40

Scrambling C

ode 41

Scrambling C

ode 42

Scrambling C

ode 43

Scrambling C

ode 44

Scrambling C

ode 45

Scrambling C

ode 46

Scrambling C

ode 47

Scrambling C

ode 49

Scrambling C

ode 50

Scrambling C

ode 51

Scrambling C

ode 52

Scrambling C

ode 53

Scrambling C

ode 54

Scrambling C

ode 55

Scrambling C

ode 56

Scrambling C

ode 57

Scrambling C

ode 58

Scrambling C

ode 59

Scrambling C

ode 60

Scrambling C

ode 61

Scrambling C

ode 62

Scrambling C

ode 63Primary Scrambling Code 48

Scrambling Code Groups

There are in total 64 scrambling code groups each containing 8 primary scrambling codes

The j:th scrambling code group consists of primary scrambling code 8j + k, where j = 0....63 and k = 0....7

Scrambling C

ode 10

Scrambling C

ode 11

Scrambling C

ode 12

Scrambling C

ode 13

Scrambling C

ode 14

Scrambling C

ode 15

Primary Scrambling Code 0k=0 k=7

Group number

Scrambling Code Groupsk=0 k=7

Scrambling C

ode 10

Scrambling C

ode 11

Scrambling C

ode 12

Scrambling C

ode 13

Scrambling C

ode 14

Scrambling C

ode 15

Scrambling C

ode 49

Scrambling C

ode 50

Scrambling C

ode 51

Scrambling C

ode 52

Scrambling C

ode 53

Scrambling C

ode 54

Scrambling C

ode 55

Scrambling C

ode 56

Scrambling C

ode 57

Scrambling C

ode 58

Scrambling C

ode 59

Scrambling C

ode 60

Scrambling C

ode 61

Scrambling C

ode 62

Scrambling C

ode 63

The codes assigned to aNode-B should come fromthe same group.

Scrambling Codes in Asset 3G

Scrambling code number(within the group) 0-7

Scrambling code group 0-63

Scrambling code 0-511(calculated automaticallybased on number and group)

Scrambling code allocation

k=0 k=7

Group number

SC=1SC=2

SC=4SC=5

SC=17SC=18

Reserved for indoor, test etc.

Scrambling Code Planning Wizard in Asset 3G

Note that before the Wizard is launched neighbours must have been defined !

Scrambling Code Planning – Alert!

• Remember that the mobile can be connected to 3 sectors (3 RLs) at the same time.

• The mobile can not have different connections to Node-Bs that have the same scrambling code defined !

• You can plan the scrambling codes with the help of the Wizard but planning them manually is also an alternative – and quite easy.

Neighbour Planning

UMTS to GSM handover procedure(Voice) – Vendor dependant

Criteria to leave theUMTS network

is fulfilled(RSCP, Ec/I0, UE TX)

Make measurementson GSM network

defined neighbours

Verify BSICof the suitable

GSM neighbour

Perform Handoverto GSM

Go to/from

compressedmode

Neighbour Definition Strategy• Plan all UMTS <-> UMTS neighbours• Plan all UMTS -> GSM neighbours

– If the UMTS site is a co-site with GSM consider to define the same neighbours to GSM as the existing GSM site

– Run the 3G to 2G Neighbour definition Wizard in Asset to find additional definitions or neighbour deletions

• Plan all GSM -> UMTS neighbours– Make the above plan mutual and include the Ec/I0

threshold using the Wizard

Defining initial neighbours in 3G

• All definitions must be mutual• The first ring of cells should

be defined as default (~20)• In special cases cells from

the outer ring could be added

• All existing 2G definitions shouldbe defined as 3G to 2G neighbours

Defining NeighboursUMTS <-> UMTS

UMTS sites

The first “ring”of sites

Defining NeighboursUMTS <-> UMTS

• Scrambling codes should be defined after the neighbours are planned and stored in the site database.

• All UMTS neighbours must be mutual• Always include the first ring of UMTS sites.• Start off with the Neighbour Wizard in Asset 3G

to find the first set of neighbour relations.• Edit then these by hand by displaying the

relations graphically

Neighbour Wizard in Asset 3G

Setup of the Wizard in Asset 3GOnly the sites includedin the filter(s) will beplanned

These parameters will be defined

Good to create an xml file forbackup and data build purposes

Neighbour Wizard resultsIn order to see which neighbours that have beenplanned you need to mark the cell

Outgoing

Incoming

UMTS Neighbour Planning Results in Detail

All neighbours should be mutualwhich could be done easilyby clicking – Make All Mutual

UMTS Neighbours in the graphical view

Displays theneighbours

UMTS <-> GSM Neighbours

• In order to plan the UMTS <-> GSM neighbours with the Wizard there must be a best array prediction available in GSM.

• Also - all the defined GSM neighbours in the network should be available in the site database.

Planning GSM NeighboursGSM sites

Planning GSM Neighbours

Planning vs. Site Database

These are neighbour relations that alreadyexisted in the database and that the Wizardalso wants to add.

This is a neighbour relation that is new (did not existin the database) and that the Wizard wants to add.

Planning Results GSM

Planning Results GSM- Graphical View

Using the Wizard for creating initial GSM <-> UMTS neighbours

GSM and UMTS

2 filters enabledOne GSM andOne UMTS

Will be definedlater

GSM <-> UMTS neighboursDetailed Results

Mutual UMTS <-> GSM neighbours

Graphical Display of GSM <-> UMTS neighbours

Planning Tips

Cell structures

• Very difficult to avoid excessive overlap• Very difficult to create dominance • Very difficult to avoid pilot pollution

“Corner of death”Antenna

~ 20 m

Drop !!!

Active set update “procedure”UE Node-B RNC

Decision to setupNew RL

Event Measurement reports

Radio Link Setup Request

Radio Link Setup Response

Iub Bearer Setup

Downlink Synchronization

Uplink Synchronization

Active Set Update

Active Set Update Complete

X seconds

1 ~ 2 seconds

Clutter heights

! !These two cases give very different results in the predictions !

If you place an antenna below the clutter height in Asset 3G database -make sure that this also is the case for the real site. If not, you should consider to move the antenna to “1-2 meters” over the clutter in Asset in order to be able

to produce more accurate predictions.20

Increasing Capacity in UMTS

The capacity in UMTS can be increased by increasing the number ofsectors on sites. However, the sectors must be narrow beam as thecapacity increase comes as a result of better dominance (Ec/I0).

• Node B Supports,

– 6x1 20/40W or

– 6x2 20W

in one cabinet

• More Feeders, ASCs/W-TMAs & Antennas• Going from 3 sector sites to 6 sector sites

provides– 85% Capacity gain– 40% Coverage gain (30% less sites)

6 ASCsor

W-TMAs

6antennas

12 feeders• 6 Radio Units

• 6 Filter Units

6 sector solutions

Antenna Site Design

3 deg3 deg

Areas of poor dominance

Antenna design - Electrical downtiltand mechanical uptilt

Mechanical up tilt&

Electrical down tiltMain lobeBack lobe

Effective Antenna Height AlgorithmsRelative algorithm

Heff = Hbase+ Hob – Hom if H0b > Hom

Heff = Hb if Hob ≤ Hom

20 m 20 mA

The effective antenna height for site A 20 metersThe effective antenna height for site B 35 meters

Sea Level

Hob > Hom

Hob = Hom

Planning Tips

The nominal site is an old GSMsite. The antennas areplaced on the nominal height of20 meters

In the dense urban area thereare a few “coverage” holes

Planning Tips

• But the GSM site have the antennas at 22 meter height.

Planning Tips

• Moving the UMTS antennas to the same height as GSM (i.e from 20 to 22 meter) will remove parts of the coverage hole

Antenna Isolation

GSM/UMTS GSM/UMTS CoCo--SitingSiting SolutionsSolutions

Three possibilities exist when co-siting

1) Seperate Antennas

2) Diplexed to Shared Feeder

3) Shared Antennas

Each site may have a different solution according torequirements.

1) Seperate Antenna Configuration

RBS2000 series BTS

GSM 900

RBS3000

Series BTS

Isolation >=30 dB

Four Feeders arerequired per sector

2) Shared Feeder for GSM/UMTS

Antenna

Isolation >=30 dB

ASCDIPLEXShared feeders

RBS 2000 series BTS

GSM 900

RBS3000

Series BTS

DIPLEX

3) Shared AntennaIsolation >=30 dB

RBS 2000 series BTS

GSM 900

RBS3000

Series BTS

GSM/UMTS

Antenna

Isolation = A_cableloss-A_gain+Lpattloss_ab-B_gain+Lpattloss_ba

Isolation

GSM 900 UMTS

Isolation ?

A_gain B_gain

A_cableloss B_cablelossPropogation Loss

Lpattloss_abLpattloss_ba

Horizontal Seperation

I h(dB)≈22+20log(d/λ), d> λd

d>83 cm to achieve 30 dBisolation

Turkcell, for safety, it is 2m Vertical Seperation

I v (dB) ≈28+40 log(d/λ), d> λ

d> 37 cm to achieve 30 dBisolation

Turkcell, for safety, it is 1m

λ coming from Tx system33cm for 900Mhz15cm for 2000Mhz

FeedersFeeders usedused in in TURKCELLTURKCELL’’ss GSM GSM RadioRadio Network Network andand theirtheir characteristicscharacteristics at 2 at 2 GHzGHz

DiameterMinimum bending

450 900 1500 1800 2000 2200 (mm) radius (mm)

MHz MHz MHz MHz MHz MHz

1/2" LDF4 4,8 6,9 9,1 10,1 10,7 11,2 16 1251/2" FSJ4

(flex) 7,6 11,1 14,9 16,6 17,6 18,6 13,2 32

7/8" LDF5 2,7 3,9 5,2 5,8 6,1 6,5 28 250

Andrew

Insertion loss dB/100m at 20°C

Sharing of feeders between GSM and WCDMA is possible andwill be used to reduce cost and visual effects.

Analysing with Asset

Static Analysis

Static Analysis•

- Uses a deterministic algorithm in order to calculate the load. Whenthe load has been calculated, pilot coverage and quality, handover regions, downlink powers etc can be calculated as well. The cellloading parameters (uplink noise rise, downlink traffic power) can be written into the site database.

Static Analysis - Outputs• Pilot Strength, RSCP (dBm)

• Handover Type (No handover, Soft, Softer & Both)

• Pilot Quality, Ec/I0 (dB)

• Number of pilot polluters (Any cell that provides an Ec/I0 level higher than the “pilot pollution” threshold), are pilots that are flagged as a polluters.

• Nth Best Ec/I0, server 1-6 (dB)

• DL FRE (Total received power from the best serving cell divided by the total received power from all cells) (%)

• DL i (Total received power from other cells divided by the totalreceived power from the best serving cell)

Monte Carlo Analysis

Analysis in Monte Carlo

Useful studies:

• DL Achieved Eb/N0• Mean number of soft handover cells• Mean number of softer handover cells• Mean size of active set• Path balance• Probability of noise rise failure• Probability of UL Eb/N0 failure• Reason for failure• UL required TX power• Cell uplink load• DL Loss

Downlink lossfor video

according the linkbudget

DU: 127 dBU: 133 dB

SU: 146 dB

Downlink achieved

Displays theservice required

Eb/N0 (4.8 dB) as maximum and not

what is “achievable”

Cell Uplinkload (%)

Displays theload in the uplink.

The maximumallowable load inthe uplink is 50%according to our

linkbudget

NOTE: When a mobile fails to connect in the simulationsİt is “turned off” and does not generate any interference

UL required TX power

Displays theaverage mobilerequired output

power. Maximumpower is 21 dBm.

Minimum is -50 dBm

Reason forfailure

Displays theThe reason for failure in each

pixel.

Note: 6 dB for noise raise

For some analyses it is very important to check thethreshold parameters as they will have a great

impact on the results

Path balance

Displays failing link

in each pixel

Probability of Noise Rise Failure

Displays the probability thatthe Noise Rise

limit (set for each cell) is exceeded

Shows the meannumber of

soft handovercells

Shows the meannumber of

softer handovercells

Shows the meansize of theActive set

HSDPA Basics

What is High Speed Downlink Packet Access (HSDPA)?

SPEED Higher bit rates: up to 14 Mbps

CAPACITY 2 – 3 times improved system throughput

STANDARDIZED Integral part of WCDMA (3GPP Release 5)

REDUCED DELAY Reduced round trip time

Smooth Upgrade Short time to market with existing sites

Key Idea in HSDPA

Fast adaptation of transmission parameters to fast variations in radio conditions

Main functionality to support HSDPA•Fast link adaptation

•Fast Hybrid ARQ

•Fast channel-dependent scheduling

Basic Features

• Shared Channel Transmission– Dynamically shared code resource

• Short TTI (2 ms)– Reduced delays

• Fast Channel-Dependent Scheduling– 2 ms time basis

• Fast Link Adaptation and higher modulation– Data rate adapted to radio conditions– 2 ms time basis

• Fast Hybrid ARQ– Roundtrip time ~12 ms possible– Soft combination of multiple attempts

Short 2 ms TTI2 ms

• Reduced air-interface delay– Improved end-user performance– Required by TCP at high data rates

• Necessary to benefit from other HS-DSCH features– Fast Link Adaptation– Fast hybrid ARQ – Fast Channel-dependent Scheduling

10 ms20 ms40 ms80 ms

Earlier releases

2 msRel 5 (HS-DSCH)

Shared Channel Transmission

• A set of radio resources dynamically shared among multiple users, primarily in the time domain– Efficient code utilization– Efficient power utilization

Channelization codes allocatedfor HS-DSCH transmission

8 codes (example)SF=16

Shared channelization

User #1 User #2 User #3 User #4

Fast Channel-dependent Scheduling

• Scheduling = which UE to transmit to at a given time instant and at what rate– Formally part of MAC-hs (a new MAC sub-layer in RBS)

• Basic idea: transmit at fading peaks– May lead to large variations in data rate between users– Tradeoff: fairness vs cell throughput

high data rate

low data rate

User 1

User 2

Scheduled user

Time#1 #2 #1 #2 #1 #2 #1

Fast Channel-dependent Scheduling

• Examples of scheduling algorithms– Round Robin (RR)

• Cyclically assign the channel to users without taking channel conditions into account

• Simple but poor performance– Proportional Fair (PF)

• Assign the channel to the user with the best relative channel quality• High throughput, fair

– Max C/I Ratio• Assign the channel to the user with the best channel quality• High system throughput but not fair

Fast Link Adaptation and higher modulation

• Adjust transmission parameters to match instantaneous channel conditions

• HS DL Shared Channel: Rate control (no Fast Power control)– Adaptive coding– Adaptive modulation (QPSK or

16QAM)– Adapt on 2 ms TTI basis ⇒ fast

• R99: Power control (no Rate control ⇒constant data rate possible)

High data rate

Low data rate

Higher Modulation

• HS-DSCH supports both QPSK and 16QAM– 16QAM is mandatory in the UE, except for the 2 lowest UE categories– 16QAM gives approximately double data rates– 16QAM is mainly useful at good radio conditions– 16QAM typically requires more advanced receivers in the UE

QPSK 16QAM

2 bits 4 bits

Fast Hybrid ARQ with Soft Combining

• Rapid retransmissions of erroneous data– Hybrid ARQ protocol terminated in Node B⇒ short RTT (typical example: 12 ms)

– Soft combining in UE of multiple transmission attempts⇒ reduced error rates for retransmissions

P1,1 P2,1 P3,1+ +

Transmitter

Receiver

HS-DSCH – Power Allocation• HS-DSCH must share the transmission power with all other channels

• Dynamic power allocation– Allocate remaining power to HS-DSCH transmission– Best power utilization

HS-DSCH

Common channels (not power controlled)

Dedicated channels (power controlled)

HSDPA Channel structure• New data channel

– High Speed Downlink Shared Channel (HS-DSCH) mapped to High Speed Physical Downlink Shared Channel (HS-PDSCH)

• New control channels– High Speed Shared Control Channel(s) (HS-SCCH)– High Speed Dedicated Physical Control Channel (HS-DPCCH)

Associated Dedicated ChannelsHS-DSCHHS-SCCH

HS-DPCCH

HSDPA Channel StructureNew Channel overview

– HS-DSCH: High speed downlink shared channel• “Fat pipe”: Carrying high speed downlink traffic

– A-DCH DL: Associated dedicatedchannel downlink

• Voice/video (multi-RAB)• Release 99 signaling

– A-DCH UL: Associated dedicatedchannel uplink

• UL data transmission• TCP ACK/NACK• Voice/video (multi-RAB)• Release 99 signaling

– HS-SCCH: High speed shared control channel• HARQ signaling

– HS-DPCCH: High speed dedicated physical control channel• HARQ ACK/NACK• CQI: channel quality indicator

Iub Iub

Associated Dedicated channelsHS-DSCHHS-SCCH

HS-DPCCH

Iub Iub

Associated Dedicated channelsHS-DSCHHS-SCCH

HS-DPCCH

Channel structureHS-PDSCH

• Carries user plane data on downlink• 1 to 5 HS-PDSCH per cell• Spreading Factor = 16• Always associated with a DPDCH• Supports 16-QAM (optional) or QPSK

(mandatory)

Channel structureHS-DSCH

• Transport channel that carries the user data• Mapped to HS-PDSCHs• One transport block of dynamic size per 2 ms

TTI• Supports link adaptation, hybrid ARQ, radio

channel dependent scheduling• Never in soft or softer handover• Always associated with a DPCH

Channel structureHS-SCCH

• Carries control information to scheduled UE in a 2-ms interval– UE identity for which the HS-SCCH (and HS-DSCH)

is intended– Hybrid ARQ information– Modulation scheme and transport format selected by

link adaptation mechanism• One HS-SCCH per cell• Power controlled, never in soft handover• SF = 128• Similar to DPCCH

Channel structureHS-DPCCH

• Carries physical layer info sent in the uplink• One HS-DPCCH for each user in the cell• Feedback from the UE:

– ACK/NACK (positive or negative acknowledge)

– CQI (Channel Quality Indicator)• SF = 256• Timing relative to HS-PDSCH

Channel structureA-DCH

• One A-DCH per HSDPA enabled terminal in the cell• A-DCH UL

– 384 kbps (or 64 kbps) DCH (TCP ACK/NAK)– 3.4 kbps SRB (control signaling: RRC & NAS)– High-Speed Dedicated Physical Control Channel

(HS-DPCCH) • ACK/NACK for H-ARQ• Channel Quality Indicator (CQI)• Never in soft handover (softer is possible)

• A-DCH DL– 3.4 kbps SRB (control signaling: RRC & NAS)

HSDPA mobility

Serving HS-DSCH Cell Change– Direct UE to scheduling queue in chosen target cell– Stop transmission in source cell

Benefits– Maintains mobility for UEs using HSDPA– Reduces user data interrupt for HSDPA mobility,

thereby improving subscriber perceived quality– Supports networks where HSDPA is deployed on

separate frequency layers only, as well as networks in which not all UEs are capable of HSDPA

Without HSDPA mobilityCell reselection HS

Common

HS DCH

HSHSHS

IdleIdle

HSDPA/R99 HSDPA/R99 HSDPA/R99 R99 R99

UE movement

5-6 second impact on the disruption of user traffic

With HSDPA mobilityHS-DSCH Cell Change HS

Common

• Practically interruption-free user traffic– Intra-RNC

HSDPA/R99 HSDPA/R99 HSDPA/R99 R99 R99

UE movement

HSDPA admission control

Efficient and flexible allocation of power resources as well as selection of uplink Radio Bearers

– Applied in the system on cell level in both uplink and downlinkBenefits

– Enables HSDPA and regular services, such as voice, to co-exist in same cell

– Provides the possibility to reserve downlink output power for HSDPA, increasing HSDPA user bit rates & capacity

– Provides the possibility to trade the average throughput per HSDPA user versus accessibility

– Provides efficient allocation of Uplink 384 kbps Radio Bearer– Reduces dropped call probability

HSDPA admission controlAdvanced Radio Resource Management

DCH + CCH

Service differentiated Admission & Congestion Control (operator-controlled parameters)• R99 Packet users down switched or moved to Common channels• HSDPA users released -> Voice/video/streaming users released

Fast Congestion Control (every 0.67 ms)• No MCPA shut-down (Lost cell)• Enables aggressive

• Adm. & Cong. Control • HS-DSCH power allocation

HS-DSCH• Dynamic power allocation (every 2 ms)• “Reserve” HSDPA power with Padm & Pcong

Operator-configurable parameters• Max number of HSDPA users per cell• Max number of HSDPA users on uplink 384 kbps RAB per cell

R99+R5f1

f1 R99

Shared same carrier

Different carrier

HSDPA- Deployment

WCDMA- HSDPA

WCDMA HSDPAOVSFC YES NOFAST POWER CONTROL YES NO

TTI TIME 10ms 2msMAXIMUM THROUGHTPUT 384Kbps 14Mbps

VARIABLE MUDULATION NO YESFAST RE-TRANSMISION NO YESSOFT HANDOVER YES NOFAST SCHEDULING NO YES

Release 99 HSPA

Retransmission delay >100 ms 12 ms

Scheduling delay >200 ms 2 ms

Dynamic code allocation

• Dynamic Code Allocation – Based on Code Utilisation and Cell capacity/HW

capabilityCodes shared between DCH and HS 15 HS codes shared in 3 sectors

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

# Voice Users / cell

# HS codes

HSDPA uses fast feedback from mobile

Terminal sends fast L1 feedback to Node-B– Channel Quality Info (CQI) – Transmission period typically every 4 ms

CQI is used by HSDPA packet scheduling– Link adaptation– Multiuser scheduling decisions

L1 Feedback (CQI)

TTI 1 TTI 2 TTI 3 TTI 4

User 1 CQI

User 2 CQI

Scheduled userProportional fair scheduling principle : allocate resources to the best user leading to multi-user diversity gain

HSDPA UE categories• Theoretical peak bit rate up to 14 Mbps• Initially 1.8 Mbps and 3.6 Mbps capabilities with 5 codes

3.6Mbps

1.8Mbps

1.2Mbps

1.8Mbps

0.9Mbps --36302QPSK only

--36301QPSK only

QPSK/16QAM

14.0 Mbps

10.1 Mbps

-279521

-202511

7.2 Mbps144111

-72981

-72982

-72983

HSDPACategory 5 CodesModulation 15 Codes10 CodesTransport

Block sizeInter-TTI

10 and 15 codes for increased user bitrates and cell capacity

• Average cell HSDPA throughput increased • Peak datarate up to 7.2Mbps (10codes) and 10.7-

14Mbps (15codes)• 14.4Mbps is not in practice achieved (no channel

coding)• Increased cell peak data rate and capacity when most

of the power can be allocated to HSDPA• Gain in cell capacity from 10/15codes together with

code multiplexing is more important than max bitrateper user

User data rates in practical radio conditions15 Code Terminal with Equalizer Assumed

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

Distance from BTS [relative to cell radius, 1=cell edge]

3.6 Mbps available with 45% x cell radius

7.2 Mbps (10codes) available

with 20% x cell radius = 4% x cell area

10 Mbps (15codes)availability very limited 3-sector

macro cellassumed

BTS Cell edge

Code Shared HSDPA Scheduler• Peak rate of 10.8 Mbps is shared dynamically between sectors• Efficient utilization of resources since the peak rate of 10.8 Mbps is only

seldomly available in macro cells due to interference

Instantaneous adaptation according to throughput per sector

Throughput shared equallybetween all sectors

HSDPA mobiles onlyin single sector

Throughput sharedbetween two sectors

10.8 Mbps

7.2 Mbps

3.6 Mbps

0 Mbps (no HSDPA mobiles)

3.6 Mbps

HSUPA BasicsHSHSUUPA PA BasicsBasics

HSUPA provides high performance withsimple SW-upgrade

• HSUPA is a SW-upgrade and exitingbaseband in NodeB’s can be reused

• HSUPA availability follows marketneeds and terminal availability– Initially Max 1.5 Mbps user bitrate– Max 20 users per cell– Simultaneous HSUPA and

HSDPA– Soft/softer HO supported– Fast HSUPA scheduling

HSUPA enhances end-user experience• HSUPA provides

significantly improvedupload performance for e.g.– Email– Multimedia

• Lower latency enabled byHSUPA benefits mostservices, also downloads

• Combined HSDPA and HSUPA enables new services like mobile multiplayer gaming or highquality video conferencing

HSUPA supports full mobilityRNC 1RNC 1 RNC 2RNC 2

• For HSUPA user, the following HOs are supported

– Softer HO– Intra RNC soft HO– Inter RNC soft HO

• Active set for DCH and E-DCH can be different (e.g. cell not supporting E-DCH can be added to AS)

• Cell change algorithm will control that best cell • is the serving cell in E-DCH active set

• Event 1D for CPICH Ec/No will be used to monitor the best cell

• Switch to DCH is performed if– A cell under DRNC becomes the best cell– A cell not supporting E-DCH becomes the best cell– Compressed mode needs to be activated

E-DCH & DCHbranch

DCHbranch

RNC 1RNC 1

HSUPA supports more RAB combinations

fully featured HSPA – simultaneous HSUPA &

HSDPA + AMR voice since the first release

– Soft and softerhandover

– HSUPA DL physical channel power control

– Advanced Schedulerutilising both absoluteand relative grants

HSUPA Scheduling & RRM

• The user’s allocation is downgraded the utilization is low – throughput based optimization for Release 99 DCH

• The user’s allocation is upgraded when – A) the user is ‘unhappy’ and – B) there is room : power, hardware and transport resources

• No users are downgraded to make room for other users

• HSUPA RRM algorithm in the RNC performs combined power and throughput based packet scheduling for R99 DCH and HSUPA users

• RNC performs dynamic sharing of received interference between NRT DCH and HSUPA users.

Thank You

8- wcdma principles&planning v3.0

hsdpar99 hsdpar99

radio resource

bevent measurement

acquisition

effective

channel type

primary cpich

soft handover

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