WCDMA Dimension Ing Workshop

WCDMA Introductionand Planning workshop

Ramneek Singh Bali

Agenda• WCDMA theory

– WCDMA Concepts– Spreading– WCDMA Channels– Cell Breathing– Design priorities

• WCDMA Planning and dimensioning– Overview & Requirements– Link budgets– Planning for Coverage and Capacity– Hardware Dimensioning– HSDPA Introduction– HSDPA Dimensioning

Multiple Access Approaches��

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• Separate users through different codes

• Large bandwidth

• Continuous transmission and reception

f

Code

t

MS 1MS 2MS 3

5 MHz

Direct Sequence Code Division Multiple Access (DS-CDMA)

• IS-95 (1.25 MHz)

• CDMA2000 (3.75 MHz)

• WCDMA (5 MHz)

Frequency re-use

TDMA / FDMA

12

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Averagere-use=7

re-use=1

W-CDMA

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1

Wideband Code Division Multiple Access Features

• High data rates in 5 MHz – 384 kbps with wide-area coverage

• High service flexibility – support for services with variable rate – Support for simultaneous services – packet and circuit switched services

• The wide bandwidth reduces sensitivity to muti-path fading• Common shared resource that makes WCDMA RAN flexible• Allocates power to each subscriber and ensures that each user and

service creates the minimum of interference

Radio Access Bearer

Mapping Of Applications to RAB ( Examples)

Spreading principle• User information bits are spread into a number of chips by multiplying them

with a spreading code

•The chip rate for the system is 3.84 Mchip/s and the signal is spread in 5 MHz

•The Spreading Factor (SF) is the ratio between the chip rate and the symbol rate

•The same code is used for de/spreading the information after it is sent over the • air interface

Information signal

Spreading signal

Transmission signal

Spread Spectrum Multiple Access

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�=Rate DataRate Code

Both signals combinedin the air interface

Code 1Frequency

Am

pli

tude

Signal 1

Code 2Frequency

Am

pli

tude

Signal 2

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Code 1 Signal 1 is reconstructedSignal 2 looks like noise

Both signals arereceived together

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Two Transmitters at the same frequency

Spreading & Scrambling• Spreading Operation transforms data symbols

into chips. Thus increasing the bandwidth of the signal. The number of chips per data symbol is called the “Spreading Factor”��SF��.The operation is done through multiplication with OVSF (Orthogonal Variable Spreading Factor) code.

• Scrambling Operation is applied to the spreading signal.

Data bit

OVSF code

Scrambling code

Chips after

spreading

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12

Spreading Factor Tree

Designation: cch, SF , code number

1

1 -1

1 1

1 1 1 1

1 1 -1 -1

1 -1 1 -1

1 -1 -1 1

C1,0

C2,0

C2,1

C4,0

C4,1

C4,2

C4,3

SF = 1 SF = 2 SF = 4

3GPP TS 25.2013GPP TS 25.201

Downlink = SF 4 ----------------> SF 512

Uplink= SF 4 -----------> 256

Spreading ExampleSymbols are spread to the chip rate by Channelization Code

Spreading Factor (SF) = Chip Rate/Symbol rate

1 -1 1 1 -1Symbols

@960 ksps

1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1chips

SF=4

1 -1 1 -1 1 -1 1 -1 -1 1 -1 1-1

1x -1=- 1

1

1x 1= 1

-1

1x -1=- 1

-1 1 -1 1

-1x 1= -1

-1x -1= 1

-1x 1= -1

-1x -1= 1

Result 1

1x 1= 1

X

Code Channels

Freq. 1

Freq. 1

Code A

Code B

Cod

e C

BS1

BS2

Code D

Code E

• Users are separated by codes (code channels), not by frequency or time(in some capacity/hierarchical cell structure cases, also different carrier frequencies may be used).

• signals of other users are seen as noise-like interference

• CDMA system is an interference limited system which averages the interference (ref. to GSM which is a frequency limited system)

Scrambling Codes

SC3 SC4

SC5 SC6

SC1 SC1

Cell “1” transmits using SC1

SC2 SC2

Cell “2” transmits using SC2

� In the Downlink, the Scrambling Codes are used to distinguish each cell (assigned by operator – SC planning)

� In the Uplink, the Scrambling Codes are used to distinguish each UE (assigned by network)

Uplink: 16,777,216 Scrambling codes used to distinguish each UE Downlink: 512 Scrambling codes used to distinguish each cell

Channelization Codes

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� In the Uplink Channelization Codes are used to distinguish between data (and control) channels from the same UE

� In the Downlink Channelization Codes are used to distinguish between data (and control) channels coming from the same RBS

Soft/Softer Handover• Soft/softer handover is important mobility of UE, Subscriber Quality and for

efficient power control.

• Soft Handover: UE connected to two or more RBSs at the same time• Softer Handover: UE connected to two or more sector of the same RBS

18

Physical Channel

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

3GPP TS 25.2113GPP TS 25.211

14 480 240 16 320 56 232 8 8* 16 1514A 480 240 16 320 56 224 8 16* 16 8-1414B 960 480 8 640 112 464 16 16* 32 8-1415 960 480 8 640 120 488 8 8* 16 15

15A 960 480 8 640 120 480 8 16* 16 8-1415B 1920 960 4 1280 240 976 16 16* 32 8-1416 1920 960 4 1280 248 1000 8 8* 16 15

16A 1920 960 4 1280 248 992 8 16* 16 8-14

D PD C HB its /S lot

D PC C HB its/S lo t

S lo tForm at

#i

C hannelB it R ate(kbps)

C hannelS ym bol

R ate(ksps)

SF B its /S lot

N D ata1 N D ata2 N T PC N TFCI N Pilot

T ransm ittedslo ts per

rad io fram eN T r

0 15 7.5 512 10 0 4 2 0 4 150A 15 7.5 512 10 0 4 2 0 4 8-140B 30 15 256 20 0 8 4 0 8 8-141 15 7.5 512 10 0 2 2 2 4 15

1B 30 15 256 20 0 4 4 4 8 8-142 30 15 256 20 2 14 2 0 2 15

2A 30 15 256 20 2 14 2 0 2 8-142B 60 30 128 40 4 28 4 0 4 8-143 30 15 256 20 2 12 2 2 2 15

3A 30 15 256 20 2 10 2 4 2 8-143B 60 30 128 40 4 24 4 4 4 8-14

3GPP TS 25.2113GPP TS 25.211

Downlink DPDCH/DPCCH Format

• 3GPP protocol defined WCDMA radio interface into three channels: Physical, transport and logical channel.

Logical channel: Logical channels can either belong to a specific mobile (dedicated channels) or shared access among many mobile stations (common channels).

Transport channel: Exists between radio interface layer 2 and physical layer. Describes services provided by physical layer for MAC and higher layer.

Physical channel: It is the embodiment of all kinds of information when they are transmitted on radio interfaces. Each channel that uses dedicated carrier frequency, code (spreading code and scramble) and carrier phase can be regarded as a dedicated channel.

Channel Concepts

• Control logical Channels– BCCH (Broadcast Control Channel, DL)

• Continuous transmission of system and cell information– PCCH (Paging Control Channel, DL)

• Carries control information to UE when location is unknown– CCCH (Common Control Channel, UL/DL)

• used for transmitting control information between the network and UE

– DCCH (Dedicated Control Channel, UL/DL)• transmits dedicated control information between network and

UE. • Traffic Logical Channels

– CTCH (Common Traffic Channel)• Traffic channel for sending traffic to a group of UEsUsed for

BLER measurements– DTCH (Dedicated Traffic Channel)

• Traffic channel dedicated to one UE to transfer user information

Logical Channels

22

Transport Channels - Downlink

• Common Transport Channels– BCH (Broadcast Channel)

• Continuous transmission of system and cell information

– PCH (Paging Channel)• Carries control information to UE when location is unknown

– FACH (Forward Access Channel)• Used for transmission of idle-mode control information to a UE

• Dedicated Transport Channels– DCH (Dedicated Channel)

• Carries dedicated traffic and control data to one UE• Used for BLER measurements

23

Transport Channels (L2) - Uplink

• Common Transport Channels– RACH Random Access Channel

• Carries access requests, control information, short data

• Dedicated Transport Channels– DCH Dedicated Channel

• Carries dedicated traffic and control data from one UE• Used for BLER measurements

24

Physical Channels - Downlink• Common physical Channels

– CPICH (Common Pilot Channel)• used for cell identification and there is only one CPICH per cell.

– SCH (Synchronization Channel)• used by the UE to detect the presence of WCDMA carrier and

synchronize with radio frame– PCCPCH (Primary Common Control Physical Channel)

• broadcasts cell site information and Carries BCH transport channel

– SCCPCH (Secondary Common Control Physical Channel)• carries idle mode signaling and control information to UE’s. Also

carries PCH and FACCH channels– PICH (Paging Indicator Channel)

• used by the cell to inform a group of UE’s that a page message can be addressed to them. It is always associated with SCCPCH

– AICH (Acquisition Indicator Channel)• Physical channels used by the cell to acknowledge the

reception of RACH preambles.

25

Physical Channels - Downlink

• Downlink Dedicated Control Channels (DPCH):Within one Downlink DPCH, data and control information generated are transmitted in a time-multiplexed manner The channel consists of:

• DPDCH (Dedicated Physical Data Channel)• It is a physical channel used to carry DCH.

• DPCCH (Dedicated Physical Control Channel)• It is a physical channel used for carrying

information related to physical layer operation e.g. dedicated pilot or power control bits.

26

Physical Channels - Uplink

• Common Physical Channels– PRACH Physical Random Access Channel

• Carries access requests and carries RACH

• Dedicated Physical Channels– DPDCH Dedicated physical data Channel

• Carries dedicated traffic data (DCH)

– DPCCH Dedicated physical data Channel• Carries control information related to physical layer operation

27

WCDMA Physical Channels

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P-CCPCH- Primary Common Control Physical ChannelSCH - Synchronization Channel

CPICH - Common Pilot Channel

Channels broadcast to all UE in the cell

DPDCH - Dedicated Physical Data Channel

DPCCH - Dedicated Physical Control Channel

Dedicated Connection Channels

PICH - Page Indicator Channel

Paging Channels

S-CCPCH - Secondary Common Control Physical Channel

AP-AICH - Acquisition Preamble Indicator Channel

CD/CA-AICH - Collision Detection Indicator Channel

CSICH - CPCH Status Indicator Channel

PRACH - Physical Random Access Channel

AICH - Acquisition Indicator Channel

Random Access and Packet Access Channels

{XOR}

Transport Channels

(L1 Characteristics

Dependent)

PCH BCH FACH RACH DCH

S-CCPCHP-CCPCHPhysical

ChannelsPRACH DPDCH

Logical Channels

(Data Dependent)

PCCH

DCCH

DTCH

DecicatedLogicalChannelCipherOn

BCCH CCCH CTCH

Higher Layer data

PagingPagingSystem

InfoSystemInfo

SignalingSignalingCell

BroadcastService

CellBroadcast

Service

Signalingand

User data

Signalingand

User data

DTCHDTCH

Channel Mapping

BCCHBroadcast Control Ch.

PCCHPaging Control Ch.

CCCHCommon Control Ch.

DCCHDedicated Control Ch.

DTCHDedicated Traffic Ch. N

BCHBroadcast Ch.

PCHPaging Ch.

FACHForward Access Ch.

DCHDedicated Ch.

P-CCPCH(*)Primary Common Control Physical Ch.

S-CCPCHSecondary Common Control

Physical Ch.

DPDCH (one or more per UE) Dedicated Physical Data Ch.

DPCCH (one per UE)Dedicated Physical Control Ch.Pilot, TPC, TFCI bits

SSCi

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DownlinkRF Out

DPCH (Dedicated Physical Channel)One per UE

DSCHDownlink Shared Ch.

CTCHCommon Traffic Ch.

CPICHCommon Pilot ChannelNull Data

Data Encoding

Data Encoding

Data Encoding

Data Encoding

Data Encoding

PDSCHPhysical Downlink Shared Channel

AICH (Acquisition Indicator Channel)

PICH (Paging Indicator Channel )

Access Indication data

Paging Indication bits

AP-AICH(Access Preamble Indicator Channel )Access Preamble Indication bits

CSICH (CPCH Status Indicator Channel )CPCH Status Indication bits

CD/CA-ICH (Collision Detection/Channel

Assignment )

CPCH Status Indication bits

S/P

S/P

Cch

S/P

S/P

S/P

S/P

S/P

S/P

S/P

S/P

Cell-specificScrambling

Code

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ModulatorQ

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Cch

Cch

Cch

Cch

Cch

Cch

Cch

Cch 256,1

Cch 256,0

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GS

PSC

GP ΣΣΣΣ

Sync Codes(*)

ΣΣΣΣ Filter

Filter

Gain

Gain

Gain

Gain

Gain

Gain

Gain

Gain

Gain

Gain

SCH (Sync Channel)

DTCHDedicated Traffic Ch. 1

DCHDedicated Ch.

Data Encoding

MUX

MUX

CCTrCHDCHDedicated Ch.

Data Encoding

WCDMA Downlink Channels

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UplinkRF Out

UEScrambling

Code

I+jQ I/QMod.

Q

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Chc

ΣΣΣΣ

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Filter

Filter

CCCHCommon Control Ch.

DTCH (packet mode)Dedicated Traffic Ch.

RACHRandom Access Ch.

PRACHPhysical Random Access Ch.

DPDCH #1Dedicated Physical Data Ch.

CPCHCommon Packet Ch.

PCPCHPhysical Common Packet Ch.

Data Coding

Data Coding

DPDCH #3 (optional)Dedicated Physical Data Ch.

DPDCH #5 (optional) Dedicated Physical Data Ch.




ΣΣΣΣ6

DPCCHDedicated Physical Control Ch.

Pilot, TPC, TFCI bits

Chd

Gc

Gd

j

Chd,1 Gd

Chd,3 Gd

Chd,5 Gd

Chd,2 Gd

Chd,4 Gd

Chd,6 Gd

Chc Gd

Chc

ΣΣΣΣ

Chd

Gc

Gd

j

RACH Control Part

PCPCH Control Part

ΣΣΣΣ

j

ΣΣΣΣ

DCCHDedicated Control Ch.

DTCHDedicated Traffic Ch. N

DCHDedicated Ch.

Data Encoding

DTCHDedicated Traffic Ch. 1

DCHDedicated Ch.

Data Encoding M

UX

CCTrCH

DCHDedicated Ch.

Data Encoding

WCDMA Uplink Channels

• Qqualmeas

• Qrxlev meas

CPICH

P-CCPCH

• qQualmin

• qRxLevMin

• UE max transm pwr Ul

Cell Selection - I

•qQualmin is sent in the broadcast information and indicates the minimum required quality value. The UE measures the received quality, “Qqualmeas”; on the CPICH (CPICH Ec/N0) and calculates Squal.•qRxLevMin is also sent in the system information and indicates the minimum required signal strength. The UE measures the received signal Code Power (CPICH RSCP) and obtains Srxlev•maxTxPowerul is the maximum transmission power during random access on the RACH and that value is also sent in the system information. •P is the UE maximum output power according to its class.

•For cell selection criteria the UE calculates

Squal = Qqualmeas - qQualMin (for WCDMA cells) > 0

Srxlev = Qrxlevmeas - qRxLevMin – Pcompensation (for all cells) > 0

Where Pcompensation = max(maxTxPowerUL – P,0)

P is output power of UE according to class

Cell Selection - II

Power Control Types• 2. Outer-Loop Power Control (slow)

– maintains the required Block Error Rate (BLER) for a service by modifying the SIR target

– Dedicated channels– If the BLER measured (DL@UE, UL@RNC) is below/ above

the minimum acceptable BLER, • UE/RNC increase/reduce SIR target.• Use the new SIR target for the Inner-loop PC.

• 3. Inner-Loop Power Control UL/DL (fast)– minimizes the power and interference of ongoing

connections by maintaining a minimum SIR.– Dedicated channels– Performed 1500 times per second, – Adjust (up or down) the Tx power to reach the SIR target.

Uplink Outer & Inner Loop Power Control

1 Calculate initial UL SIR target

2 Power control command (1,500 / s)

3 Estimate UL quality

4Calculate new SIR target(using Macro Diversity)

Combatsfast fading

Combatsslow fading

Coverage in WCDMA• Cell extension (border) in DL is defined by its DL coverage

• DL coverage is provided by CPICH channel and is measured by RSCP. RSCP (Received Signal Code Power) is the received power on one SC measured on the CPICH at the UE antenna connector.

• Radio Network Design (RND) specifies the minimum RSCP level for an area to be considered as “WCDMA covered”

• The network parameter primaryCpichPower controls the power used by the CPICH channel.

• UL coverage is reached at the maximum transmitted power from theUE while connected to UTRAN

Quality in WCDMA• Quality in WCDMA can be measured in terms ofEc/No and

Pilot Pollution

� Ec/No is the ratio between the useful received signal and the interference generated from other SCs or external sources.

� The UE in the example receives useful signal (Ec) from the serving cell and interference (No) from the other cells

�Pilot Pollution is a measure of interference generated by one or more SCs with good RSCP that can’t be actively used by the UE during the service

NoNo

No

NoNo

NoEc

Cell Breathing

• Noise Rise is cell breathing• Interference increases with load in the network causing

network quality to degrade and WCDMA coverage to shrink

BS 1 BS 2

Fully loaded systemUnloaded system

Coverage – Relation RSCP and EC/N0 - I

Ec=RSCP = -75 dBm

Constant

N0= -65 dBm

Ec/N0 = -10 dB, OK

Ec + N0 Own N0 Other

Ec/N0 OK

Coverage – Relation RSCP and EC/N0 - II

Ec=RSCP = -75 dBm

Constant

N0= -55 dBm

Ec/N0 = -20 dB, Not OK

Ec + N0 Own N0 Other

Ec/N0 OK

Coverage not constant – Cell Breathing

• Cell coverage defined by Ec/N0.• Ec/N0 below target => No channel estimation, no call setup• Interference increases when traffic increases.• RSCP = Ec – always constant. • Cell coverage smaller when traffic increases. • Cell Breathes.

• WCDMA Planning and Dimensioning

Design Priorities

� Establish sufficient CPICH RSCP.� Establish good CPICH Ec/Io under load.� Ensure high probability of service coverage under

load on both links.� Which service?

CPICH RSCP

CPICH Ec/Io

Service Coverage

Design is built up by covering the basics first.

Antenna Down tilt Requirement� Power is a shared resource in UMTS.� As load increases in a cell, total transmitted power

increases also.� Max transmit power cannot be used to control

interference.

A B

C

D

E

A B

C

D

E

Unloaded Loaded

Important design requirements� UE needs to decode the CPICH to get service.� Good CPICH RSCP (Ec) does not mean that the

CPICH can be camped on. � Good CPICH Ec/Io is needed to camp on the

system.� Networks should be designed for good CPICH Ec/Io.

A B

E

FC

A B

E

FC

Sufficient RSCP

Bad Ec/Io

Coverage Overlap

� Overshooting sites should be lowered, downtilted or removed from the UMTS plan if possible.

� For neighboring cells, some optimum coverage overlap is needed.

Too much overlap results in loss of capacity

Too little overlap results in increased interference

Optimum Overlap

Air Interface DimensioningAssume an

uplink loading

Calculate uplinkcoverage/Lmax

Calculate uplink capacity

Estimate sitecountfor coverage

Estimate sitecountfor capacity

Balanced?

Yes

No

Calculate PCPICH, refbased on UL Lmax

CalculateDL Capacity

Calculate PDCH

Calculate PCCH, ref

DL Capacityfulfill req.

No

Finished

Yes

Input Data

System Reference Point

Energy per bit to Noise ratio (Eb/No)Transmitted Signal

Received Signal + Noise

Air Interface

1

-1Bit errors

Energy per bit (Eb)

Noise power density (No)

Eb

NoConceptual illustrationRealistic illustration

Eb/No and C/I (γγγγ)signal-to-noise ratio per bit: The ratio given by Eb/No, where Eb is the signal energy per bit and No is the noise energy per hertz of noise bandwidth.

Eb = S/Rinfo where S = signal energy and Rinfo is the bit rate

No = N/B where N = noise energy and B is the bandwidth

Eb/No = = S Rinfo

X B N

SN

X B Rinfo

Since B is proportional to chip rate B

Rinfo= Chip Rate

Rinfo= Processing gain (PG)

Therefore

In the uplink N will be predominately interference (I) from other UEs and S will be

the received carrier power (C) Eb/No = C/I PG = γγγγ.PG

Eb/No = γγγγ + 10log(PG)Since Eb/No and γγγγ are normally given in dB :

Uplink Dimensioning

Cell range and cell area can be calculatedCell range and cell area can be calculated

The number of sites required for meeting The number of sites required for meeting coverage requirement can be foundcoverage requirement can be found

Max path loss due to propagationMax path loss due to propagation

Uplink Link BudgetLpmax = PUE - SUL – BPC-BIUL-BLNF-LBL-LCPL-LBPL-Ga-LJ

whereLpmax is the maximum path loss due to propagation in the air. The cell range

can be calculated based upon this figure [dB].

PUE is the maximum UE output power, 21 or 24 [dBm].

SUL is the UL sensitivity. Depends on the RAB and channel model [dBm].

BIUL is the noise rise [dB].

BLNF is the log-normal fading margin [dB].

BPC is the power control margin, dependent on channel model [dB].

LBL is the body loss [dB].

LCPL is the car penetration loss [dB].

LBPL is the building penetration loss [dB].

Ga is the sum of RBS antenna gain and UE antenna gain [dBi].

LJ is the jumpers loss [dB].

Signal VariationsSS at Rx-antenna

DistanceVariations due to Shadowing (Local mean)

Received Signal Level from formulae (Global mean)

Variations due to

Rayleigh fading

Log Normal Fading Margin

SS at RX antenna

Prob

abili

ty

Derived Mean

Standard Deviation (�)

Measured Mean

Slow fading and Building Penetration Loss (BPL) are log normally distributed with standard deviations(�)

Uplink LNFmarg for 3 sector sites

Note: Handover gain is included in these margins

Power control margin PCmarg

Compensates for:-1) Increase in UE average power due to fast power control2) UE sensitivity degradation at cell border

TU= Typical Urban 3GPP channel Model

RA = Rural Area 3GPP channel Model

Link Budget losses

Environment Dense Urban Urban SuburbanBuilding Penetration loss (BPL) 18 18 12

Building Penetration Loss

Body and car penetration Losses

SRBS is the RBS sensitivity. When an ASC is used, it is measured at the ASC port, without ASC at the RBS

Eb/N0 is the bit energy divided by noise spectral density [dB]Nt is the thermal noise power density (.174 dBm/Hz),Nf is the noise figure (a typical cell planning value 2.3

dB with and 3.3 dB without ASC),Rinfo is the information bit rate [bps].LF is the feeder loss [dB]. The feeder loss becomes zero

in uplink calculations for installations with ASC.

SUL = SRBS + LF = Nt + Nf + 10logRinfo + Eb/N0 + LF [dBm]

UL System Sensitivity

RBS SensitivityMinimum RX signal (RBSsens)= Noise + Nf + γγγγwhere Nf Receiver noise figure and γ γ γ γ is the C/I for the service

RBSsens

C/I

Noise +Nf

However Eb/No = γγγγ + 10 log (B/Rinfo)

= γγγγ + 10 log (B) - 10 log (Rinfo)

To solve for γγγγ => γγγγ = Eb/No - 10 log (B) + 10 log (Rinfo)

If γγγγ is substituted into the equation for RBSsens it becomes:-

RBSsens = Nt + 10log(B) + Nf+ Eb/No - 10 log (B) + 10 log (Rinfo)

Noise = KTB W/Hz. If expressed as log values values:

Noise = KT + 10log(B) = Thermal noise (Nt) + 10 log (B)

Therefore RBSsens = Nt + 10log(B) + Nf + γγγγ

RBSsens = Nt + Nf + 10 log (Rinfo) +Eb/No dBm

BIUL - Noise Rise is referred as the increase in receiver noise floor when a system is more loaded.

0

2

4

6

8

10

12

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9Load

Inte

rfer

ence

incr

ease

∆∆ ∆∆I[

dB]

E.g. 20%=0,97dB, 50%=3dB

where Q is the uplink system loading

UL Noise Rise

dB Q1

110logBIUL �

�

�

�

−=

Maximum Cell Range (Rpathmax)

Cell Range (Rpathmax) is given by equation 21:-

Using Okumura-Hata propagation formula:

Lpath = A - 13.82logHb +(44.9-6.55logHb)logR - a(Hm) [[[[dB]]]]

R pathmax = 10αααα, where αααα = [Lpathmax - A + 13.82logHb + a(Hm)]/[44.9 - 6.55logHb]

Or using COST 231-Walfish-Ikegami formula we get equation 22:-

Lpath = 155.3 + 38logR – 18log(Hb – 17) [[[[dB]]]]

Rpathmax = 10αααα, where αααα = [Lpath – 155.3 + 18log(Hb – 17)]/38

Relation between coverage area and cell range.

2323

RArea = 2389

RArea =

RSitetoSite 3= RSitetoSite23= RSitetoSite 3=

2323

RArea =

R RR

4.53.264 Kbps PS

6.44.9Speech 12.2 Kbps

TU, 50km/hTU, 3Km/hService Type

Typical Eb/No values for UL

Uplink Example: 12.2 kbps, maximum, 95% probability of coverage

outdoor & indoor at 50% load

RBSsens(Speech,3km/h)= -171 + 10log(15600) + 4.9 =-124.2 dBmRBSsens(Speech,50km/h)= -171 + 10log(15600) + 6.4 =-122.7 dBmRBSsens (PS64,3km/h)= -171 + 10log(67400) + 3.2 =-119.5 dBm RBSsens (PS64,50km/h)= -171 + 10log(67400) + 4.5 =-118.2 dBm


Lpathmax = PUE – RBSsens – IUL – LNFmarg – PCmarg – BL – CPL – BPL +Gant – Lf+j





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LoadingIUL -1

1log10


PUE 21

RBSsens

Outdoor LNFmarg

PCmarg

IUL

BL

Gant 17.5

Lf+j 0

Lpathmax (outdoor)

CPL

Lpathmax (in-car)

BPL

Indoor LNFmarg

Lpathmax (indoor)

-124.2

0.7

3

4.1

6

7.518

3

151.9

145.9

130.5

α10R pathmax =]log55.69.44[)](log82.13[� bmbpath HHaHAL −++−=

mikm 47.075.0R pathmax ==



sqmi66.0R389

Area 2 ==

Sites needed to cover 100mi Sq Area = 66

Mpole is the number of simultaneous users that can notbe supported since the C/I can not be fulfilled for any

of them.

)G(1�

11

F11

M DTXpole +��

��

�+⋅�

�

��

�

+=

��

� �� !�"�� #$�� %��%��&��

'(�) (�)�'� �

�$*��%�"+,��-��.� ��

Uplink Capacity (Mpole)

γγγγ = Eb/No - 10log(PG)

57*25.076*75.0M Pole +=

72≈

Uplink CapacityNumber of Simultaneous Users in UL

poleM.QM =

• Uplink MPole for Speech for a 3 sector urban site: at 3 km/hr is 76 and at 50 km/hr is 57.

• Example

For a traffic distribution of 75% and 25% respectively in above case:

• For a multi-service system where the system utilizes different types of RABs, e.g. RAB 1, RAB 2 etc.

...M

MM

MM

MQ

3pole,

3

2pole,

2

pole,1

1max +++=

• UL noise rise is related to the UL loading. System cannot be loaded up to 100% as this would lead to infinite noise rise.

Recommended Maximum UL Load: Q = 60%

Number of Simultaneous Users

......QQQQ 321max +++=

Suppose Q = 50 % = MSpeech / Mpole Speech

MSpeech = 50%*72= 36 simultaneous users or channels

Erlang B, 2% GoS 36 channels give 27.34 Erl. offered traffic.

27.34/30 mE = 911 users (actual users in the network) per cell

Divide total user by user per cell to get no. of cells needed.

= 53180/911 = 55cells = 19sites

Site Count for Capacity

Balancing Coverage and Capacity

Data Services dimensioning• After finding number of sites (based on voice capacity and coverage); calculation for data i.e. Best Effort Traffic is done.

• First step is to find out data required to be supported based on BH requirements

Eg: For 12KB/h in UL and 230KB/h in DL data per user during BH;

PoleC M / MQ =

DLhKB

ULhKB

−===−===/151800KB/h Y X*230 sector supported/ be toData

/2640KB/h Y X*12 sector supported/ be toData

/��)�001�� &#��%� ��#��.��

��

• With 220 sites, subscribers per sector would be:= 50,000/660 = 75

•Offered Traffic would therefore be:= 75 * 25m = 1.875 Erlangs

•Actual Traffic = Offered Traffic (1-GOS) = 1.83Erlangs

.025401.83/72QC ==

Data Services dimensioning• Next step is to find out, whether that data can be supported by remaining available Uplink load, for this Qc is calculated.

PoleC M / MQ =

Data Services dimensioning

• In order to find out number of data sessions that can be supported by available best effort load:

poleBEdata M*Q*0.7M =

BEcmax QQQ +=

��-��#��.2� ��#��%�.��%% �3

4�� 5��.

4�� 5�#��%%��.BE

C

max

Q

Q

Q

• QBE is found from total load and speech load

cmax QQ =

474.00254.05.0Q BE =−=

5.3016*0.474*0.7Mdata ==

• Busy hour data traffic that can be supported is found out10

data 2*8/3600)*kbps)64 .g.RAB(e*M(=

Data Services dimensioning

�� .�� 6,$�

• If data that can be supported is greater than required data transfer during BH; number of sites remain same

• In case data cannot be supported:

• No of sites is increased

• Subscribers per sector, offered and actual traffic is found out

• Whole process is repeated, starting from QBE calculation to find out if increased number of sites support required data

hKB /5.1490622*8/)3600*10*64*5.30( 103 ==

• Transmitter (RBS) is in a single point, Receivers (Terminals) are distributed in the cell

• DL coverage and capacity are not only dependent on the number of terminals, but also on their distribution in a cell and their relative position towards other cells

Downlink Dimensioning

DL Capacity versus Cell Range

Downlink Margin DLmargBefore we can use this curve we must calculate the downlink margin DLmarg with equation 26:-

DLmarg = BL + CPL + BPL +∆Gant + Lf+j + LASC +∆Nf + ∆A0

BL is the body loss.

CPL is the car penetration loss. Since this is an urban area car loss will not be considered.

BPL is the building penetration loss.

∆Gant is the difference in antenna gain compared to the value used in the curves. ∆Gant= 17.5 – Gant

Lf+J is the loss in feeders and jumpers.

∆Nf is the difference in UE noise figure compared to the value used in the curves∆Nf = Nf –7

LASC is the insertion loss of the ASC (if used). ∆A0 is the difference of the distance independent term, in Okumura Hata, compared to the ………… value used in the curves

∆A0 = A0 – A0curves, where A0 = A – 13.82 logHb and A0curves is 134.68 or approx. 134.7

Downlink ExampleWhat load could a 40m, 3-sector Urban Cell cope with at a range of 1.5 km to outdoor services with the gains and losses below?

D Lm arg = B L + C PL + BPL +∆G ant + Lf+j + L A SC +∆N f + ∆A 0

BL =CPL =BPL =∆∆∆∆Gant= Lf+J =∆∆∆∆Nf =LASC =∆∆∆∆A0 =

3 dBUrban speech => TU 3 km/h => CPL = 0 dB18 dB�Gant= 17.5 – Gant, Gant = 17.5 => �Gant = 0 dB

5 dB

�Nf= Nf - 7, Nf = 7 => �Nf= 0 dB

0.4 dB�A0= A0 - 134.7 but A0 = 155.1 – 13.82 log(40)= 133 => �A0 = 133 - 134.7 = -1.7 dB

Dlmarg = 3 + 0 + 18 + 0 + 5 + 0 + 0.4 -1.7 = 24.7 approx 25 dB

2. Find possible cell loading where the 25 dB Dlmarg curve crosses the 1.5 km range:-

1.5 km

Lpmax = PTX,ref – SUE – BPC – BIDL – BLNF – LBL – LCPL – LBPL +Ga – LJ

Lpmax is the maximum path loss due to propagation in the air [dB].PTX,ref is the transmitter power at the system reference point [dBm]SUE is the UE sensitivity [dBm]BPC is the power control margin [dB]BLNF is the log-normal fading margin [dB]BIDL is the noise rise or the downlink interference margin [dB]LBL is the body loss [dB]LCPL is the car penetration loss [dB]LBPL is the building penetration loss [dB]Ga is the sum of RBS antenna gain and UE antenna gain [dBi]LJ is the jumper loss [dB]

•The Link Budget has to be calculated for •Common Primary Channel (CPICH)•For every Service RAB (DCH)

Downlink Link Budget

SUE = Nt + Nf + 10logRinfo + Eb/N0

Eb/N0 is the bit energy divided by noise spectral density [dB]. DownlinkEb/N0 values depend on the RAB and the channel model.

Nt is the thermal noise power density (�174 dBm/Hz),Nf is the noise figure (a typical cell planning value is 7 dB),Rinfo is the information bit rate [cps].

• For the dedicated channels

• For CPICH

SUE, CPICH = Nt + Nf + 10logRchip + Ec/N0

Rchip is the system chip rate 3.84 McpsEc/N0 is the chip energy divided by noise spectral density [dB]

UE Sensitivity

Downlink nominal power• The nominal output power at the system reference point is calculated by subtracting the feeder and ASC insertion losses from the nominal output power at RBS.

LLPP ASCFRBSnom,refnom, −−= [dBm]

Total Power• Average downlink total output power depends on the loading and the maximum pathless at the cell border.

Q1L*HP

P sarefCCH,reftot,

−+=

where:is the average power allocated to all common control channels at the system reference point

H is a factor related to the path loss distribution of the UE’sLsa is the signal attenuation from system reference point

to a UE at cell borderQ is the DL system loading

ref CCH,P

•Downlink noise rise depends on the output power ofthe transmitter and the location of the users

�c is the non-orthogonality factor at the cell border,

is the average ratio between the received inter-cell and intra-cell interference at the cell border

Downlink Noise Rise

sa

reftot,IDL L

PK1B += where

chiptf

cc

RNNF

K+= α

cF

JaCPLBPLBLLNFPCpmaxsa LGLLLBBLL +−+++++=

IDLUEreftot,sa BSPL −−=

• Downlink dimensioning method is iterative and it comes from the fact that the noise rise, BIDL is required to find out power. This in turn depends on signal attenuation, Lsa, which a function of the noise rise.

Downlink Noise Rise (Example)Input Output

DL Noise Rise = 12dB Signal Attenuation = 131dB

Signal Attenuation = 131dB DL Noise Rise = 11.3dB

DL Noise Rise = 11.3dB Signal Attenuation = 131.8dB

Signal Attenuation = 131.8dB DL Noise Rise = 10.7dB


……………… ………………

……………… ………………

……………… ………………





Arbitrary value chosen

Iteration does not need to proceed further

Entering a high DL Noise Rise Value

Downlink Noise Rise (Example)Input Output


Signal Attenuation = 140dB DL Noise Rise = 6dB


Signal Attenuation = 137dB DL Noise Rise = 7.2dB


……………… ………………

……………… ………………

……………… ………………





Arbitrary value chosen

Iteration does not need to proceed further

Entering a low DL Noise Rise Value

Downlink CPICH Link Budget

jaBPLCPLBLLNFIDLPCUECPICHpathmax LGL-LL-B-BBSPL −+−−−−=

Equation is similar to DL link budget except for following:

• UE sensitivity is calculated using different equation• There is no power control margin.• Log Normal Fading (LNF) margin doesn’t take into account, gain due to SHO.

• The CPICH power at the system reference point should be less than or equal to 10% of total output power at the system reference point.• The average DCH power at the system reference point for the traffic channel of a single user should not exceed 30% of the total output power at the system reference point.

Downlink Power calculations

refnom,reftot, 0.75PP < [W] refCPICH,refCCH, P5.2P ≈

refnom,refCPICH, P1.0P ≤

[W]

[W]refnom,reflink,DCH, P30.0P ≤ [W]

Downlink Power Distribution

CCH 25%

Mobility Headroom

25% (DCH)

DCH50%

+��- &��. �� # � ��

*

Downlink Capacity

)G(1

(b)G1(b))G1(bSHO

1F)�(�

1M DTXAS

1b SHO

SHO(b)pole +⋅

��

�

�

+−−++

=

�=

Whereαααα non orthogonality factorMpole is the downlink pole capacity.F is the system average downlink F factor.SHO(b) is the fraction of users that are in soft/softer handover

with b base stations [%].b indicates the number of BSs in soft handover.GSHO(b) is the system average of the soft handover gain ∆∆∆∆k

for UEs in soft handover with b BSs.GDTX is the DTX gain,AS Typical Active Set size

(Pilot) 0CchipftUE /NE10logRNNS +++=

2.11716)10*84.3log(107174 6 −=−++−=

jaBPLCPLBLLNFIDLUEPilotpathmax LGL-LL-B-BSPL −+−−−=

ajASCfBPLLNFIDLUEpathmaxPilot GLLLLBBSLP −+++++++=

��*�7� �5�, .��

5.182.02.08.2189.49.42.1172.137P(Pilot) −++++++−= 5.32=

LLPP ASCFRBSnom,ref(Pilot)nom, −−=

8��9�: ��: 1��

8��;�9�.,&�� 1�;1�/

(Pilot)P

�8��<��=��,��: ��9�� =�1��> &��=��

��;��?��&��

8��.,

CPICH Link Budget Lsa is the signal attenuation (used for DL noise rise calculation) between the antenna/ASC reference point and the terminal

refCPICH,refCCH, P5.2P ≈ 25.2= Average CCh Power

0chipftUE Eb/N10logRNNS +++=

6.1111.7)10*84.3log(107174 6 −=−++−=


ajASCfBPLLNFIDLUEpathmaxDCH GLLLLBBSLP −+++++++=

(�7� �5�, .��

5.182.02.08.2189.49.46.1112.137PDCH −++++++−= 5.37=

LLPP ASCFRBSnom,ref(DCH)nom, −−=

8��<�9�: ��: 1��

8��9�.,&�� /

(Pilot)P

(�7� �5�, .��

Q1L*HP

P sarefCCH,reftot,

−+=

w80.7=

��#�� &&��.�

��&&��.�.�� *�7�

"��&&��.�.�"�� &&��@��

��

� ��

� ��

� ��

��

��

� ��

� ��

� ��

��

��*��7�

A.,B

��5��

A.,&B

��5��

A/B

+��

A/B��

CPICH Link Budget

Node B HW Dimensioning

Node B HW Capacity • Hardware resources capacity in a WCDMA RBS (Node B)

capacity is defined by channel element and are mostly shared between all users.

• CHANNEL ELEMENT:Channel Element is the required baseband processing capacity to handle one Speech RAB(12.2kbps)– TXB handles CRC, channel coding, interleaving, spreading, rate

matching - Downlink.– RXB handles demodulation, rake receiving, despreading, de-

interleaving, decoding, CRC evaluation - Uplink

More base-band processing is required in UL

How Channel Elements work

• Channel Element is linked to Dedicated Channel (DCH) resources of the RBS (dedicated data channels and dedicated signaling channels ).

• Each time a DCH allocated, HW resources consumed in UL and DL (even if one link is under utilised)

• If HW limit is exceeded then Admission/Congestion Control kicks in.

• If user is not transmitting (in PS case), HW will still be reserved until switchdown occurs. Hence more CEs need to be allowed for this reservation scheme.

Ericsson CE Advantages

• CEs pooled per site (gain approx 10%)• No additional CEs needed for Softer Handover

(up to 20% supported)• No additional CEs needed for signaling (CCH)

channels (sufficient capacity supported on boards)

• Fewer CEs needed for high bit rate services compared to other vendors

• Scalable, can buy UL and DL independently

CE Mapping/Ladder

RAB UL DLSpeech 12.2 1 1CS 64 4 2CS 57.6 (Str) 4 2PS 64/64 4 2PS 64/128 4 4PS 64/384 4 8

NodeB Capacity

768512384256CEs DL

76825612816CEs UL

R2 Max site capacity

R1 Max site capacity

R2 Max board capacity

R1 Max board capacity

• Ensures NodeB HW does not become limiting factor for capacity

• Software key enables/disables more CEs

( )

( ) �

�

Γ⋅+=

Γ⋅+=

iidlidlce

iiuliulce

MKn

MKn

,,

,,

1

1

CE Dimensioning- conversational

K

iM

iΓ

Number of Channel elements is given by equationcen

Fraction of soft handover margin, depends on activesetMaximum number of simultaneous users per site for radio bearer (i)Channel element factor per radio bearer (i)

( )

( ) �

�

Γ⋅+=

Γ⋅+=

jjsessionjdlbece

ulululbece

MKn

MKn

,,,

6464,,

1

1

CE Dimensioning- interactive

K

jM

jΓ

Number of Channel elements is given by equationbecen ,

Fraction of soft handover margin, depends on activesetMaximum number of simultaneous users per site for radio bearer (i)Channel element factor per radio bearer (i)

Mixing Conversational and Best Effort

Occ

upie

d C

E

Time

CE used bycircuit switched traffic

CE_peak

CE_be

CE_av

CE = Max (CE_peak, CE_av + CE_be)

What is HSDPA ?• High Speed Downlink Packet Access• Can get up to 14 Mbps in the downlink• In P4, 4.32 Mbps is possible• Best effort service• HSDPA P4 is time shared• HSDPA has

– Link Adaptation• QPSK• 16 QAM

– Hybrid ARQ– Scheduling– Short TT1 (2 msec)

HS-DSCH

Common channels (not power controlled)

Dedicated channels (power controlled)

Tota

l ava

ilabl

e ce

ll po

wer

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

HSDPA Basic Features

• 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

• Shared Channel Transmission– Dynamically shared code resource

• Fast Channel-Dependent Scheduling– 2 ms time basis

2 ms

• Short TTI (2 ms)– Reduced delays

HSDPAUE capabilities

3.36

3.36

User data throughput –P4 (Mbps)

QPSK1.85Category 12

QPSK0.95Category 11

Both14.015Category 10

Both10.215Category 9

Both7.310Category 8

Both7.310Category 7

Both3.65Category 6

Both3.65Category 5

Both1.85Category 4

Both1.85Category 3

Both1.25Category 2

Both1.25Category 1

QPSK / 16 QAM

L1 peak rates (Mbps)

Maximum number of HS-DSCH codes received

HS-DSCH category

P4 time frame

Short 2 ms Transmission Time Interval (TTI)

• Reduced round trip delay on the air interface • Enables HSDPA features to operate at 500 times

per second!– Fast Link Adaptation– Fast Radio Channel-dependent Scheduling– Fast hybrid ARQ with soft combining

10 ms20 ms40 ms80 ms

Earlier releases

2 msRel 5 (HS-DSCH)

2 ms

Shared Channel Transmission• New transport channel type, using multicode

transmission

• Radio resources dynamically shared among multiple users in time & code domain

• Efficient code utilization

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

Channelization codes allocatedfor HS-DSCH transmission

8 codes (example)SF=16

SF=8

SF=4

SF=2

SF=1

TTI

Shared channelization

codes

Fast Hybrid ARQ• If NACK is received Node B retransmits data• UE combines the faulty block with retransmission

(soft combining)• MAC-hs RTT=12 ms• 6 HARQ processes needed to transmit in every TTI

HSDPA 16QAMNew optional feature

• 16QAM may be used as a complement to QPSK• 16QAM allows for twice the peak data rate

compared to QPSK• 16QAM more sensitive to interference

16QAM

2 bits/symbol 4 bits/symbol

QPSK

Fast Link Adaptation

• Adjust transmission parameters to match instantaneous radio channel conditions– Path loss and shadowing– Interference variations– Fast multi-path fading

• HS-DSCH is rate controlled– Encoding rate, number of channelization codes &

modulation type adapted based on available power

– Adaptation on 2 ms TTI basis 500 times/sec!

High data rate

Low data rate

Fast Channel Dependent Scheduling• Scheduling = which UE to transmit to at a given time instant• Basic idea: transmit at fading peaks

– May lead to large variations in data rate between users– Tradeoff: fairness vs cell throughput

• HSDPA scheduler is implemented in Node B• Scheduler determines the UE to which data should be transmitted in

the next 2 msec TTI• It considers channel conditions experienced by the UE• Scheduler can assign HS-DSCH to the UE with better channel quality

(CQI)• Short term improvements in radio conditions can mean higher

throughput

high data rate

low data rate

Time

#2#1 #2 #2#1 #1 #1

User 2

User 1

Scheduled user

• Two different algorithms available in P4 by combination of factors (queueSelectAlgorithm)– Round Robin

• Considers only f(delay). Longer the wait, higher the probability of selection

• Fairness of time allocation– Proportional Fair

• Combination of all the three factors• Increases system throughput by prioritizing users with

good quality• Some fairness of time and rate allocation is also

considered

Scheduling Algorithm

high data rate

low data rateTime

#2#1 #2 #2#1 #1 #1

User 2

User 1

Scheduled user

HSDPA Channel overview– HS-DSCH: High speed downlink shared channel

• “Fat pipe”: Carrying high speed downlink traffic– A-DCH DL: Associated dedicated

channel 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

RNC

Iub Iub

Iu

Associated Dedicated channelsHS-DSCHHS-SCCH

HS-DPCCH

RNC

Iub Iub

Iu

Associated Dedicated channelsHS-DSCHHS-SCCH

HS-DPCCH

HSDPA Available Power

Common Channel Power (Ex: 14% for 40 W RBS)

R’99 DCH Power

MaxTransmissionPower

MaxTransmissionPower - hsPowerMargin-5%

Available HS Power

Time

• Not all the available HS power is always used for transmission.

• It is only used the amount required to fullfill the maximum TF that can be transmitted according to channel conditions

Carrier Power

��

�� !�"�#��$�

�� %&"'�"�$�Done!

Lsa or PDCHtoo large

Lsa or PCCHtoo large

Average DL network load (Q)

- Link budget margins

- HW configuration

- Cell border params

Uplink PS & CS traffic

StartUL link budget

@��Lsa

CPICH link budget

@��

PCCH,Lsa

DL link budget

@��

PCCH, PDCH, Lsa,

HSDPA dimensioning

@��

Pcpich,ref ≤ 15%*Pnom,ref

�.��C� �5��≤≤≤≤ �1D�E��&2��%

HSDPA Dimensioning

(Pilot) 0CchipftUE /NE10logRNNS +++=

2.11716)10*84.3log(107174 6 −=−++−=


ajASCfBPLLNFIDLUEpathmaxPilot GLLLLBBSLP −+++++++=

��*�7� �5�, .��

5.182.02.08.2189.49.42.1172.137P(Pilot) −++++++−= 5.32=

LLPP ASCFRBSnom,ref(Pilot)nom, −−=

8��9�: ��: 1��

8��;�9�.,&�� 1�;1�/

(Pilot)P

�8��<��=��,��: ��9�� =�1��> &��=��

��;��?��&��

8��.,

CPICH Link Budget Lsa is the signal attenuation (used for DL noise rise calculation) between the antenna/ASC reference point and the terminal

refCPICH,refCCH, P1.2P ≈

89.1= Average CCh Power

%��7@(�+2��

��9�� &��*�7��

Example • CPICH dimensioning:

– Lsa = 141.8 dB, corresponding to PS 64 kbps in UL

– 8.7 W at Tx ref. Point (17.4W nominal power, 3dB f&j loss)

?��.�.��*�7��

1�;�/ �

��11D��5��.�

1�<��/

�<9D��5��.�0

0,5

1

1,5

2

2,5

3

120 125 130 135 140 145 150 155

Lsa [dB]

CP

ICH

pow

er [W

]

75% network load 100% network load

��*�7� �5�, .��

• CCH power

– If all UEs are using HSDPA, average CCH can be reduced since no data is sent on FACH-2

– It approximately becomes:

?��.�.��7��

��7 8��E�1�;�8��/

CPICH Link Budget

refCPICH,refCCH, P1.2P ≈ %��7@(�+2��

��9�� &��*�7��

-7��

-2��

-0.4��

1.5��

1.8��

-7��

-��

-3.1��

-3.5��

-1.8��

�� *��7�A.,B��

CPICH Link Budget• Relative HS-SCCH setting

Parameter values for peak power setting of DL common channels in HSDPA enabled cell are given as:

( F �� .��&��%��

��#�� &��&��

( (�� 5�� %��(�7�� .�#�� .�� & ��

�11D�",@��& ��)��%��

sareftot,refDCH, LHPQP ⋅+⋅=

refnom,refCCH,refDCH, 0.75PPP ≤+


refnom,refDCH, P4.0P ≤

• The average power available for HSDPA at the Tx reference point is calculated as:

��

=

=

−

++=++=

M

1m

M

1mmthhsdpacch

mhsdpacchreftot,Q1

LNPPPPPP

RBS power at Tx reference point= nominal power at Tx reference point with 100% network load

DL system loading (M/Mpole)Factor related to the path lossdistribution of the UEs within a cell

Signal Attenuation,average cell size

sacchreftot,hsdpa LHPPQ).(1P ⋅−−−=

Q1LH*PP sahsdpacch

−++=


7@C(@�7��

For both HSDPA coverage and capacity, it is important to find the amount of power left for HS-DSCH. The average HS-DSCH power at the TX reference point is calculated as:

refDCH,ArefSCCH,HSrefDCH,refCCH,refnom,refDSCH,HS PPPPPP −−− −−−−=

7@(�+��

?�& ��)��%�� A/B

+��7��)��%��

+�� .�#��";;�(�7��)��%��

+��7@C@��7��)��%�� A/B

+��.�� 5�+C(�7��)��%�� A/BDCHA

SCCHHS

DCH

CCH

nom

P

P

P

P

P

−

−

Power Settings for HSDPA channels(�7��

sareftot,refDCH, LHPQP ⋅+⋅=

7@C@��7��

2dBPP refCPICH,refSCCH,HS −=−

+C(�7��

0, =− refDCHAP

refCPICHrefDCHA PP ,, =−

��#��.��

��

System Capacity vs. HS-DSCH Power• HS-DSCH system capacity depends on HS-DSCH power

• HS-DSCH power is mainly determined by the amount of R99 traffic.

• HSDPA system capacity in presence of R99 traffic is calculated as:

��

�

�

−−′=

C

DCHHSHS

�100�

1TT

C

DCH

HST

ζζ

′ 7@(�+��&�� %��7@(�+

��%��& ��%��";;��)��%��

��%��& �� .�%��

�)��%��

C/I vs. HS-DSCH Throughput

( ��$*�%��7@C(@�7��#�� .�

� ��%�� -��

sanom

DSCHHS

NLP �)..F(�P

C/I++

= −

+�� #��.�� 5�7@C(@�7��A/B

?��C��

F�� %�� #��.��

?�& �� A/B

�� %��&��.�� 5

��&��?� ��A/BN�

PF�

P

nom

DSCHHS-

System Capacity vs. Signal attenuation Assmuptions: TU-3, 10W at RBS reference point, Proportional Fair gain included

System capacity vs signal attenuation

C/I vs Throughput

HSDPA system capacity when all power is available for HSDPA = 1160 kbps (from graph)

Average Power for Control Channels = 2.42 WPercentage of nominal power used for Control Channels, Yc = 2.42/10 = 24.2%Average DCH Power = 3.1 WPercentage of nominal power used for R99 traffic, Yb = 3.1/10 = 30.1%

HSDPA system capacity with R99= 1160[1-(0.31/1-0.242)] = 686 kbps

Average HSDPA throughput

Part

HSDPA Cell Border Throughput

Putting values and solving for C/I = 0.23 = -6.42 dBMapping it against the throughput using the table for Category 7 UE - 10 multi codes

C/I gives throughput = 320 Kbps

sanom

DSCHHS

NLP �)..F(�P

C/I++

= −

Cell border throughput

WCDMA Dimension Ing Workshop

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