WCDMA Radio Network Planning and
Optimization

Song Pengpeng
Contents
>

WCDMA Fundamentals(including link budget fundamentals)

>

Radio Resource Utilization

>

Coverage and Capacit...
WCDMA Fundamentals
>

WCDMA network infrastructure

>

WCDMA radio interface protocol architecture

>

WCDMA link level ch...
WCDMA Fundamentals
>

WCDMA Network infrastructure
Data General

C
N

Data General

Data General

M
SC
Iu

Iu
RC
N
I ub

R...
WCDMA Fundamentals
>

WCDMA Radio Interface protocol architecture
R o Bear er s
adi

R o R
adi
esour ce C r ol
ont
Subl ay...
WCDMA Fundamentals
>

Mapping between Trch and PHY channels
Transport Channels

Physical Channels

DCH

Dedicated Physical...
WCDMA Fundamentals
WCDMA parameters
Parameters
Chip rate
Frame length
Modulation
Bandwidth
Vocoder
Base synchronization
Po...
WCDMA Radio Network Planning---Example of link budget
analysis
>

RF link budget components:

Presentation Title — 8

All ...
WCDMA Radio Network Planning---Example of link
budget analysis
Example of RLB for 12.2 kbps voice service(uplink,120km/h,i...
RADIO RESOURCE UTILIZATION
>

Radio Resource Management

Basic RRM functions
* Power Control

To adjust the transmit power...
RADIO RESOURCE UTILIZATION---power control(1)
>

UMTS Power Control(PC) summary

Presentation Title — 11

All rights reser...
RADIO RESOURCE UTILIZATION---power control(2)
>

Uplink/Downlink inner- and outer- loop power control
DP

MO
C_

DE

QE
nd...
RADIO RESOURCE UTILIZATION---handover control
Soft-Handover:Example of Soft Handover Algorithm
Addition window

Event 1A: ...
RADIO RESOURCE UTILIZATION---PC and SHO
conclusion
>

Bonding of SHO and PC(based on the fact that SHO gain is dependent o...
RADIO RESOURCE UTILIZATION---congestion
control
>

Air interface load definition(load control principles)
•

Uplink
• Wide...
RADIO RESOURCE UTILIZATION---congestion
control (cont’d)

>

Congestion control---keep the air interface load
under predef...
RADIO RESOURCE UTILIZATION---congestion
control (cont’d)
>

Packet scheduling
•
•

Packet schedul i ng al gor i t hm

Time...
RADIO RESOURCE UTILIZATION---Code Planning
>

Code planning
•
•

>

Code allocation is under the control of RNC.
Code tree...
RRM optimization --- SHO optimization(1)
>

Addition window optimization
Determines the relative difference of the cells
a...
RRM optimization --- SHO optimization(2)
>

Drop window optimization
•

Slightly larger than the addition window
D aded
eg...
RRM optimization --- SHO optimization(3)
>

Replacement window optimization
•

Determines the relative threshold for MS to...
RRM optimization --- SHO optimization(4)
>

Maximum active set size optimization
D aded
egr
per f or m
ance
due t o t oo
h...
RADIO RESOURCE UTILIZATION --- SHO
optimization conclusion
>

SHO overhead target level should be 30%~40%.
•
•
•
•
•

Addi...
Coverage and Capacity issues
>

Coverage-limited & Capacity-limited scenarios …

>

Coverage & Capacity enhancement method...
Coverage and Capacity issues---Coverage
>

How can coverage be deduced from link budget? link budget Max Path
Losscell r...
Coverage and Capacity issues---Capacity
>

An uplink-limited scenario --- when the maximum uplink load is reached prior
to...
Coverage and Capacity issues---Enhancement
methods

>

Coverage & Capacity enhancement methods
•

Additional carriers and ...
Coverage and Capacity issues---Enhancement
methods(cont’d)
>

Coverage & Capacity enhancement methods(cont’d)
•

Repeaters...
Coverage and Capacity issues---Enhancement
methods(cont’d)
>

Coverage & Capacity enhancement methods(cont’d)
•

Higher-or...
Coverage and Capacity issues---Enhancement
methods(cont’d)
>

Coverage & Capacity enhancement methods(cont’d)
•

Sectoriza...
CELL DEPLOYMENT
>

Hierarchical Cell Structure(HCS) with two or more (FDD) carriers
•
•
•

>

Continuous macro-cells to pr...
CELL DEPLOYMENT
>

Case study of frequency reuse in micro- and macro- networks
Reference scenario

f2
f1

f1

f1

f1

Reus...
WCDMA Radio Network Planning
>

overview

>

Dimensioning

>

Detailed planning

>

Optimization aspects

>

Adjacent carr...
WCDMA Radio Network Planning---Network planning
process overview
Definition

N w
et ork
Conf i gurat i on
and
Dm
i ensi on...
WCDMA Radio Network Planning ---Dimensioning(1)
>

What is Dimensioning?
--- to estimate the required site density and sit...
WCDMA Radio Network Planning ---Dimensioning(2)
>

Coverage analysis:
•

for the single-cell case*:

•

where a = σ ⋅ 2 b ...
WCDMA Radio Network Planning ---Dimensioning(3)
>

Capacity estimation
•
•
•
•

>

WCDMA capacity and coverage are connect...
WCDMA Radio Network Planning ---Dimensioning(4)
>

RNC dimensioning(cont’d)
•

The number of RNCs needed to connect a cert...
WCDMA Radio Network Planning ---Detailed
Planning(1)
>

Using Radio Network Planning(RNP) tools
•

•

>

To find an optimu...
WCDMA Radio Network Planning ---Detailed
Planning(2)
>

Example of RNP tool workflow
Defining service
requirements

Creati...
WCDMA Radio Network Planning ---Detailed
Planning(3)---UL/DL iteration steps
i ni t i al i zat i on

G obal i ni t i al i ...
>

WCDMA Radio Network Planning ---Adjacent Channel
Interference

Adjacent Channel Interference(ACI) situation
•

Adjacent...
WCDMA Radio Network Planning ---Adjacent Channel
Interference
Tx
0dB

0dB

BS AC
LR

DL adjacent channel
interference situ...
WCDMA Radio Network Planning ---Example of Worst
ACI case
>

Worst ACI case when sites of different operators not co-locat...
WCDMA Radio Network Planning ---Optimization
aspects(1)
>

Guidelines for Radio Network Planning to avoid ACI in multioper...
WCDMA Radio Network Planning ---Optimization
aspects(2)
>

Site locations and configurations
•
•
•

>

Antenna installatio...
WCDMA-GSM Co-Planning Issues
>

Examples of maximum path losses with existing GSM and WCDMA system
GSM900/ GSM1800/ WCDMA/...
WCDMA-GSM Co-Planning Issues---interference
issues
>

Interference between the two system is the main issue
•

Radio frequ...
WCDMA-GSM Co-Planning Issues ---interference
issues
•

Interference mechanisms from GSM system to WCDMA system
Adjacent Ch...
WCDMA-GSM Co-Planning Issues
Eval uat e t he qual i t y of
t he exi st i ng 2G net w k
or

Space avai l abl e f or onet o-...
Co-existing TDD & FDD modes ---UTRA TDD mode
>

Some key parameters for the UTRA FDD and TDD modes

Frame structure
Frame ...
Co-existing TDD & FDD modes---Example of TDD RLB
uplink/downlink

Voice
Voice
NRT data NRT data
Example TDD link budget fo...
Co-existing TDD & FDD modes--- TDD/TDD
interference
>

Interference scenarios

>

TDD-TDD Interference scenarios/solutions...
Co-existing TDD & FDD modes --- TDD/FDD
interference
>

TDD-FDD Interference scenarios/solutions
U A TD
TR
D
U A FD / U
TR...
Co-existing TDD & FDD modes
>

UTRA TDD
•
•
•
•
•
•
•

Advantage in the unpaired spectrum operation
Better utilized for as...
Thanks!
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    1. 1. WCDMA Radio Network Planning and Optimization Song Pengpeng
    2. 2. Contents > WCDMA Fundamentals(including link budget fundamentals) > Radio Resource Utilization > Coverage and Capacity issues > Cell deployment > WCDMA Radio Network Planning(including WCDMA-GSM Coplanning issues ) > Co-existing TDD & FDD modes Presentation Title — 2 All rights reserved © 2004
    3. 3. WCDMA Fundamentals > WCDMA network infrastructure > WCDMA radio interface protocol architecture > WCDMA link level characteristics & indicators > WCDMA link budget analysis Presentation Title — 3 All rights reserved © 2004
    4. 4. WCDMA Fundamentals > WCDMA Network infrastructure Data General C N Data General Data General M SC Iu Iu RC N I ub RC N I ur I ub I ub I ub U AN TR U u U E Presentation Title — 4 N odeB N odeB U E N odeB N odeB U E All rights reserved © 2004 U E
    5. 5. WCDMA Fundamentals > WCDMA Radio Interface protocol architecture R o Bear er s adi R o R adi esour ce C r ol ont Subl ayer ( R C R) Layer 3 Packet D a at C onver gence Pr ot ocol ( PD P) C Si gnal l i ng R o Bear er s adi R o Li nk adi C r ol ont R LC Subl ayer ( R ) LC R LC R LC R LC Layer 2 Logi cal C hannel s M a Access C r ol Subl ayer ( M ) edi ont AC Tr anspor t C hannel s Physi cal l ayer ( PH Y) Presentation Title — 5 All rights reserved © 2004 Layer 1
    6. 6. WCDMA Fundamentals > Mapping between Trch and PHY channels Transport Channels Physical Channels DCH Dedicated Physical Data Channel (DPDCH) Dedicated Physical Control Channel (DPCCH) RACH Physical Random Access Channel (PRACH) CPCH Physical Common Packet Channel (PCPCH) Common Pilot Channel (CPICH) BCH Primary Common Control Physical Channel (P -CCPCH) FACH Secondary Common Control Physical Channel (S -CCPCH) U ser dat a t r ansm ssi on, i DH D HH D HC H.. C , SC , S- SC , PC . PCH Synchronisation Channel (SCH) DSCH Physical Downlink Shared Channel (PDSCH) Acquisition Indicator Channel (AICH) Access Preamble Acquisition Indicator Channel (AP-AICH) N odeB Paging Indicator Channel (PICH) Si gnal i ng and C r ol ont C hannel s, e. g. BC , PC , FAC , R H . . H H H AC . CPCH Status Indicator Channel (CSICH) Collision-Detection/Channel-Assignment Indicator Channel (CD/CA-ICH) HS-DSCH High Speed Physical Downlink Shared Channel (HS-PDSCH) HS-DSCH-related Shared Control Channel (HS-SCCH) Dedicated Physical Control Channel (uplink) for HS-DSCH (HS-DPCCH) Presentation Title — 6 All rights reserved © 2004 U E
    7. 7. WCDMA Fundamentals WCDMA parameters Parameters Chip rate Frame length Modulation Bandwidth Vocoder Base synchronization Power control rate WCDMA 3.84 Mcps 10 or 2 ms Downlink: QPSK; Uplink: HPSK 5 MHz Algebraic Code Excited Linear Prediction Coder(ACELP) Asynchronization 1500 Hz Unique scrambling code (Gold code) Cell identification WCDMA link level indicators indicators Formularization BLER BER Average block error rate calculated for the transport blocks Information bit error rate R User information bit rate Eb W Prx = ⋅ Uplink: N0 R I Energy per bit divided by noise spectral density(including interference Eb W Prx Downlink: N = R ⋅ I ⋅ (1 − α ) + I + P power density) 0 own oth N Eb/No (Eb/No) divided by processing gain Ec/Io Ec/Ior OVSF code Channelization code i= I G= G(Geometry factor) I oth I own I own I oth + PN Average Power Rise Noise Rise Power Control headroom (Average required received Eb/Io without fast PC)(average required received Eb/Io with fast PC) Macro Diversity Combining Gain Presentation Title — 7 Comments All rights reserved © 2004 The received chip energy relative to the total power spectral density; always used on CPICH,AICH and PICH. The transmitted energy per chip on a chosen channel relative to the total transmitted power spectral density at the base station. Other-to-own-cell received power ratio Mostly used in downlink, G reflects the distance of the MS from the BS antenna. Atypical range is from –3 dB to 20 dB, where –3 dB is for the cell edge. The difference between the average transmitted power and the average received power in low multi-path diversity channels The ratio of the total received wideband power to the noise power. Also referred as “TPC headroom” or “multipath fading margin” The reduction of the required Eb/No per link in soft or softer handover when compared to the situation with one radio link only.
    8. 8. WCDMA Radio Network Planning---Example of link budget analysis > RF link budget components: Presentation Title — 8 All rights reserved © 2004
    9. 9. WCDMA Radio Network Planning---Example of link budget analysis Example of RLB for 12.2 kbps voice service(uplink,120km/h,in-car users,VA channel with soft handover) Transmitter(mobile) Max. Tx power[dBm] Mobile antenna gain[dBi] Body loss[dB] Equivalent Isotropic Radiated power (EIRP)[dBm] Receiver(base station) Thermal noise density [dBm/Hz] Base station receiver noise figure[dB] Receiver noise density [dBm/Hz] Receiver noise power [dBm] Max_path_loss=Ptx_EIRP - Prx_receiver_sensitivity -Lrx_cable+ Grx_antenna Allowed_propagation_loss=Max_path_loss -Log_normal_fading_margin +soft_handover_margin -in_car_loss Presentation Title — 9 Interference margin[dB] Receiver interference power[dBm] Total effectve noise + interference [dBm] Processing gain[dB] Required Eb/No[dB] Receiver sensitivity[dBm] Base station antenna gain[dBi] Cable loss in the base station[dB] Fast fading margin[dB] Max.path loss[dB] 21 0 3 a b c 18 d=a+b-c -174 e 5 f -169 -103.2 3 g=e+f h=g+10*log(3840000) I -103.2 j=10*log(10^((h+i)/10)-10^(h/10)) -100.2 25 5 -120.2 k=10*log(10^(h/10)+10^(j/10)) l=10*log(3840/12.2) m n=m-l+k 18 2 0 154.2 Coverage probability[%] 95 Log normal fading constant[dB] 7 Propagation model exponent 3.52 Log normal fading margin [dB] 7.3 Soft handover gain[dB] 3 In-car loss[dB] 8 Allowed propagation loss for cell range[dB] All rights reserved 141.9 o p q r=d-n+o-p-q s t u © 2004 v=r-s+t-u Closely related with the loading of the cell which subsequently affects the coverage. For coveragelimited cases a smaller interference margin is suggested,while in capacity-limited cases a larger interference margin should be used. Typical value for the interference margin in the coverage-limited cases are 1.0-3.0 dB corresponding to 20-50% loading. A headroom for mobile station to maintain adequate closed loop fast power control. This applies especially to slow-moving pedestrian mobiles.Typical values are 2.0-5.0 dB for slowmoving mobiles(*) the margin required to provide a specified coverage availability over the individual cells. For a 95% coverage with a standard shadowing deviation of 6.0dB and path loss model with n=3.6 we need a shadowing margin of approximately 6.0dB handovers give a gin against slow fading by reducing the required log-normal fading margin;it also gives an additional macro diversity gain against fast fading by reducing the required Eb/No due to the effect of macro diversity combining. (*) *“modeling the impact of the fast power control on the WCDMA uplink”, sipila,K., Laiho-Steffens,J.,Jasberg,M. and Wacker.A, Proc VTC99’ Spring Huston,Texas,May 1999 pp.1266-1270
    10. 10. RADIO RESOURCE UTILIZATION > Radio Resource Management Basic RRM functions * Power Control To adjust the transmit powers in upilnk and To adjust the transmit powers in upilnk and downlink to the minimum level required to downlink to the minimum level required to enshure the demanded QoS enshure the demanded QoS Power Control Takes care that a connected user is handed Takes care that a connected user is handed over from one cell to another as he moves over from one cell to another as he moves through the coverage area of a mobile through the coverage area of a mobile network. network. Handover Control * Handover Control * Congestion Control * Resource Management Let users set up or reconfigure a radio Let users set up or reconfigure a radio access bearer(RAB) only if these would not access bearer(RAB) only if these would not overload the system and if the necessary overload the system and if the necessary resources are available. resources are available. Takes care that a system temporarily going Takes care that a system temporarily going into overload is returned to a noninto overload is returned to a nonoverloaded situation. overloaded situation. To handle all non-realtime traffic,allocate To handle all non-realtime traffic,allocate optimum bit rates and schedule optimum bit rates and schedule transmission of the packet data, keeping the transmission of the packet data, keeping the required QoS in terms of throughput and required QoS in terms of throughput and delays. delays. Presentation Title — 10 To control the physical and logical radio To control the physical and logical radio resources under one RNC;to coordinate the resources under one RNC;to coordinate the usage of the available hardware resouces usage of the available hardware resouces and to manage the code tree. and to manage the code tree. All rights reserved © 2004 Admission control Load control Packet data scheduling Congestion Control Resource Manager To ensure To ensure that the that the network stays network stays within the within the planned planned condition condition
    11. 11. RADIO RESOURCE UTILIZATION---power control(1) > UMTS Power Control(PC) summary Presentation Title — 11 All rights reserved © 2004
    12. 12. RADIO RESOURCE UTILIZATION---power control(2) > Uplink/Downlink inner- and outer- loop power control DP MO C_ DE QE nd C a e t S IR n mi RM CR al rg ax/ UL ern UL al ta , E /m nt i a l OD ): actu Ei thm nit Hz ori +U L i PC_M UL 00 fic alg f -1 ,D  tra PC IR ep,D (1 0 ss, t tS ep , FP h lo rge PC_s _st Ht C ta DC , pa TP ial L T t L CP ini er, D ,U RS P: or s BA pow ICH a ct N RL nf -CP gai o ,P c/I UL E , ER ICH BL -CP ge t ,P C) tar ER pP BL :DL l oo C u al n er RR act (In C: CH Hs C RR DC DP DP on nd H+ ma CC co m DP C on TP PC /DL L u v al es, an me s Iub U Uu NodeB UE SIR estimates Vs target Sir UL TPC commands DL outer loop PC SIR_step=f(BLER or BER) SIR target management SIR estimate vs. target SIR  DL TPC commands Presentation Title — 12 All rights reserved © 2004 SRNC UL outer loop PC SIR_step=f(BLER or BER) SIR target management MDC and splitting
    13. 13. RADIO RESOURCE UTILIZATION---handover control Soft-Handover:Example of Soft Handover Algorithm Addition window Event 1A: A P-CPICH enters the reporting range SR C N I ub Event 1B: A P-CPICH leaves the reporting range  NA  10 ⋅ log10 M old ≤ W ⋅ 10 ⋅ log10  ∑ M i  + (1 − W ) ⋅ 10 ⋅ log10 M Best − ( R1b − H 1b 2)    i =1  N odeB 1 Event 1C: A non-active PCPICH becomes better than drop window an active one Event 1D: change of best cell. Reporting event is triggered when any P-CPICH in the reporting range becomes better than the current bet one plus an optional hysteresis value. Event 1E: A P-CPICH becomes better than an absolute threshold plus an optional hysteresis value. Event 1F: A P-CPICH becomes worse than an absolute threshold minus an optional hysteresis value. Presentation Title — 13 Measurement Quantity I ub M o D ver si t y acr i com ni ng bi d1 an n m m io co i ss C m 1 TP ans nk tr li  NA  10 ⋅ log10 M new ≥ W ⋅ 10 ⋅ log10  ∑ M i  + (1 − W ) ⋅ 10 ⋅ log10 M Best − ( R1a − H 1a 2)    i =1  T ∆ CPICH 1 TP tr Cc an om s m l i m s and i nk si 2 2 on > U i n SH E O N odeB 2 T ∆ T ∆ As_Th + As_Th_Hyst AS_Th – AS_Th_Hyst As_Rep_Hyst CPICH 2 CPICH 3 All rights reserved © 2004 Time Cell 1 Connected Event 1A Add ⇒ Cell 2 Event 1C ⇒ Replace Cell 1 with Cell 3 Event 1B ⇒ Remove Cell 3
    14. 14. RADIO RESOURCE UTILIZATION---PC and SHO conclusion > Bonding of SHO and PC(based on the fact that SHO gain is dependent on the PC efficiency) • SHO gain depends on the type of channel and the degree of PC imperfection.It is usually higher with imperfect PC. • SHO diversity can reduce the PC headroom,thus improving the coverage. • The transmit and receive power differences as a result of SHO measurement errors and SHO windows can affect the PC error rate in uplink,reducing the uplink SHO gains. • In uplink, SHO gain is translated into a decrease in the outer-loop PC’s Eb/No target. Presentation Title — 14 All rights reserved © 2004
    15. 15. RADIO RESOURCE UTILIZATION---congestion control > Air interface load definition(load control principles) • Uplink • Wideband power-based uplink loading ηUL = prxTotal = I own + I oth + PN 1 ηUL = ∑ Throughput-based uplink loading W k 1+ ρ k ⋅ Rk ⋅ν k Downlink • Wideband power-based downlink loading • • I own + I oth where PrxTotal ηDL = • PrxTotoal Ptx max Throughput-based downlink loading N η DL = Presentation Title — 15 ∑R k =1 N k Rmax or ηDL = [(1 − α ) + iDL ] ⋅ ∑ ( k =1 All rights reserved © 2004 ρ k ⋅ Rk ⋅ν k ) W ⋅ (1 + i )
    16. 16. RADIO RESOURCE UTILIZATION---congestion control (cont’d) > Congestion control---keep the air interface load under predefined thresholds • • • > C ongest i on C r ol ont Adm ssi on i cont r ol Admission control---handling all the new traffic Load control---managing the situation when system load has exceeded the threshold Packet scheduling---handling all the non-realtime traffic Load cont r ol Packet dat a schedul i ng Admission control • Wideband power-based admission control For uplink, an RT bearer will be admitted1if P where ∆I ≈ rxTotal ⋅ ∆L and ∆L = W 1+ 1 −η ρ ⋅ R ⋅ν – For downlink, an RT bearer will be admitted if – • Throughput-based admission control PrxNC + ∆I ≤ PrxT arg et PrxTotoal ≤ PrxT arg et + PrxOffset PtxNC + ∆P ≤ PtxT arg et PtxTotal ≤ PtxT arg et + PtxOffset For uplink, it follows ηoldUL + ∆L ≤ ηthresholdUL – For downlink, it follows ηoldDL + ∆L ≤ ηthresholdDL – Presentation Title — 16 All rights reserved © 2004
    17. 17. RADIO RESOURCE UTILIZATION---congestion control (cont’d) > Packet scheduling • • Packet schedul i ng al gor i t hm Time division scheduling Code division scheduling Pr ocess C apaci t y r equest s C cul at e l oad budget f or al packet schedul i ng Yes N o N o Load bel ow t ar get l evel ? O l oad t hr eshol d ver exceeded? Yes I ncr ease l oadi ng D ease l oadi ng ecr Al l ocat e/ m f y/ r el ease odi r adi o r esour ces Presentation Title — 17 All rights reserved © 2004
    18. 18. RADIO RESOURCE UTILIZATION---Code Planning > Code planning • • > Code allocation is under the control of RNC. Code tree may become “fragmented” and code reshuffling is needed(arranged by RNC). Code allocation • • Scrambling and spreading code allocation for uplink(by UTRAN) Scrambling and spreading code allocation for downlink • Downlink channelisation code allocation (by UTRAN) • Downlink scrambling code planning • 512 scrambling codes subdivided into 64 groups each of eight codes Presentation Title — 18 All rights reserved © 2004
    19. 19. RRM optimization --- SHO optimization(1) > Addition window optimization Determines the relative difference of the cells at the MS end that are to be included in the active set D aded egr per f or m ance • Optimized so that only the relevant cells are due t o t oo hi gh l evel in the active set • di f f er ence of t he si gnal s i n AS Too w de i SH ar ea O U nnecessar y br anch addi t i on I ncr eased SH O over head Too sm l al SH ar ea O M C gai n R r educt i on R educed U L capaci t y Fr equent AS updat es t oo hi gh I ncr easi ng si gnal l i ng over head R evant el cel l s r em oved f r om AS I ncr eased Tx pow s er Addi t i on w ndow i t oo l ow Presentation Title — 19 I ncr eased BS and M S Tx Pow er All rights reserved © 2004 R educed D L capaci t y R educed U L/ D capaci t y L R educed D L and U L capaci t y
    20. 20. RRM optimization --- SHO optimization(2) > Drop window optimization • Slightly larger than the addition window D aded egr per f or m ance due t o t oo hi gh l evel di f f er ence of t he si gnal s i n AS R educed U L capaci t y I ncr eased BS and M Tx S Pow er Frequent and delayed Hos (cells ping-pong in the active set) I ncr eased M Tx pow S er I ncr eased BS Tx pow er R educed D L capaci t y U nnecessar y br anches st ay i n AS Too l ar ge SH O over head t oo l ow Fr equent Hs O I ncr eased si gnal i ng over head t oo l ow R evant el cel l s r em oved f r om AS I ncr eased Tx pow s er t oo hi gh dr op w ndow i Presentation Title — 20 All rights reserved © 2004 R educed U L/ D capaci t y L
    21. 21. RRM optimization --- SHO optimization(3) > Replacement window optimization • Determines the relative threshold for MS to trigger the reporting Event 1C. Too high: slow branch replacement and thus non-optimal active set – Too low: ping-pong effect with unnecessary SHOs – t oo hi gh Act i veset subopt i m al r epl acm ent w ndow i t oo l ow Exceut i on of unnecessar y Hs O Presentation Title — 21 M Tx pow S er i ncr ease U l oad L i ncr ease I ncr eased cal l dr op or bl ock r at e BS Tx pow er i ncr ease D l oad L i ncr ease R educed cal l set up success r at e I ncr eased si gnal i ng over head All rights reserved © 2004 R educed D U L/ L t ot al cel l t r af f i c
    22. 22. RRM optimization --- SHO optimization(4) > Maximum active set size optimization D aded egr per f or m ance due t o t oo hi gh l evel di f f er ence of t he si gnal s i n AS t oo bi g M AS ax si ze Possi bl e unnecessar y br anch addi t i on Pr event necessar y sof t H br anch O addi t i on I ncr eased M Tx pow S er I ncr eased BS Tx pow er I ncr eased SH O over head R educed U L capaci t y R educed D L capaci t y Presentation Title — 22 R equi r e hi gher Tx pow t o a M er S D aded D egr L BLER per f or m ance R equi r e hi gher Tx pow f r om er a M S t oo sm l al D aded U egr L BLER per f or m ance All rights reserved © 2004 I ncr eased cal l dr op/ bl ock r at e
    23. 23. RADIO RESOURCE UTILIZATION --- SHO optimization conclusion > SHO overhead target level should be 30%~40%. • • • • • Addition window & Drop window optimization should be tuned first Change the active set size if needed Drop timer value is secondary P-CPICH power could be the final parameter for SHO optimization(not recommended!) Optimization of active set weighting coefficient to give a stable SHO performance Presentation Title — 23 All rights reserved © 2004
    24. 24. Coverage and Capacity issues > Coverage-limited & Capacity-limited scenarios … > Coverage & Capacity enhancement methods • • • • • • • • Additional carriers and Scrambling codes Mast Head Amplifiers Remote RF Head Amplifiers Repeaters Higher-order Receiver Diversity Transmit Diversity Beam-forming Sectorization Presentation Title — 24 All rights reserved © 2004
    25. 25. Coverage and Capacity issues---Coverage > How can coverage be deduced from link budget? link budget Max Path Losscell rangecoverage > Generally, service coverage is uplink limited but system capacity may be limited by either uplink or downlink. Service type Speech Data Data Uplink bit rate(kbps) 12. 2 64 144 Maximum transmit power(dBm) 21 21 21 Antenna gain(dB) 0 0 2 Body loss(dB) 3 0 0 Transmit EIRP(dBm) 18 21 23 Processing gain 25 17. 8 14. 3 Required Eb/No(dB) 4 2 1. 5 Target loading (%) 50 50 50 Rise over thermal noise(dB) 3 3 3 Thermal noise density(dBm/Hz) - 174 - 174 - 174 Receiver noise figure(dB) 3 3 3 Interference floor(dBm/Hz) - 168 - 168 - 168 Receiver sensitivity(dBm) - 123. 1 - 117. 9 - 115 Rx antenna gain(dBi) 18. 5 18. 5 18. 5 Cable loss(dB) 2 2 2 Fast fading margin(dB) 3 3 3 Soft handover gain(dB) 2 2 2 Isotropic power required (dBm) - 138. 6 - 133. 4 - 130 Allowed propagation loss(dB) 156. 6 - 154. 4 153. 4 Presentation Title — 25 Data 384 21 2 0 23 10 1 50 3 - 174 3 - 168 - 111. 1 18. 5 2 3 2 126. 6 149. 6 All rights reserved © 2004 Hint: It’s critical to decide whether a specific area should be planned for high data rate service coverage or not Different service type(voice@12.2kbps, data@64,144,384kbps )supported with different link budget and thus different coverage range!
    26. 26. Coverage and Capacity issues---Capacity > An uplink-limited scenario --- when the maximum uplink load is reached prior to the base station running out of transmit power. > An downlink-limited scenario --- when the base station runs out of transmit power and additional users cannot be added without modifying the site configuration. Identifying the limited link: > Uplink limited Limiting factor Downlink limited Uplink cell load BTS transmit power Planned to a high uplink cell load Low BTS transmit power capability Greater traffic on the downlink BTS transmit power at maximum Uplink cell load not at maximum Improve downlink load equation Improve downlink link budget Planned to a low uplink cell load High BTS transmit power capability Common reasons Relatively symmetric traffic BTS transmit power not at maximum Indications Uplink cell load at maximum Solution Presentation Title — 26 Improve uplink load equation All rights reserved © 2004
    27. 27. Coverage and Capacity issues---Enhancement methods > Coverage & Capacity enhancement methods • Additional carriers and Scrambling codes System capacity is maximized by sharing the power across the available carriers,e.g, two carriers configured with 10W can offer significantly greater capacity than a single carrier configured with 20W does. – In downlink-limited capacity scenario,the number of supported users depends on the downlink channelisation code orthogonality. It is especially true when higher data rate service is supported in micro-cell. – • Mast Head Amplifiers To reduce the composite noise figure of the bse station receiver subsystem. – But brings bad effects when in downlink-limited scenario. – • Remote RF Head Amplifiers To allow the physical separation of base station’s RF and baseband modules. – Maintaining the same service coverage performance while increasing cell capacity. – Difference between remote RF head amplifiers and repeaters . – Presentation Title — 27 All rights reserved © 2004
    28. 28. Coverage and Capacity issues---Enhancement methods(cont’d) > Coverage & Capacity enhancement methods(cont’d) • Repeaters Used for extending the coverage area of an existing cell, low-cost and ease of installation but introduces delay. – Slight capacity loss in uplink-limited scenario. – Applicable in scenarios where clear cell dominance can be achieved such as in rural areas or in tunnels. – Remote RF head amplifier Locating the entire logical cell at a locatio normally requiring a long feeder run Repeater Extending the coverage Application of an existing logical cell Complete Rx and Tx chain for Hardware at Tranmit power amplifiers both uplink and downlink remote location and receiver front ends directions Connection to BS Optical link Usually a radio link Function Normal RF functions of the BS Non-intelligent retransmission Presentation Title — 28 All rights reserved © 2004
    29. 29. Coverage and Capacity issues---Enhancement methods(cont’d) > Coverage & Capacity enhancement methods(cont’d) • Higher-order Receiver Diversity To overcome both the impact of fading across radio channel and increase the resulting signal-to-interference ratio. – Improves uplink performance,especially beneficial for low-speed mobile terminals. – • Transmit Diversity Downlink transmit diversity mandatory in 3GPP specifications,e.g. closedloop mode and open-loop mode. – Most effective when time- and multipath- diversity is inadequate,e.g. for capacity gain in micro-cell scenario. – • Beam-forming An effective technique for improving the downlink performance,especially in environment with a low transmit element. – High mobile terminal complexity requirement and non-standard functionality configuration. – Presentation Title — 29 All rights reserved © 2004
    30. 30. Coverage and Capacity issues---Enhancement methods(cont’d) > Coverage & Capacity enhancement methods(cont’d) • Sectorization A general technique to increase cell capacity where antenna selection is critical. – May require correspondingly high quantity of hardware with highly sectorisation. – Usage – for typical Micro- cell deployment Sectorisation level Application 1 sector Microcell or low-capcity macrocell Sectored microcell or macrocell 2 sector providing roadside coverage Standard macrocell configuration 3 sector providing medium capacity Not commonly used but may be 4 or 5 sector chosen to support a specific traffic scenario 6 sector High-capacity macrocell configuration Presentation Title — 30 All rights reserved © 2004 for typical macro-cell deploymen t
    31. 31. CELL DEPLOYMENT > Hierarchical Cell Structure(HCS) with two or more (FDD) carriers • • • > Continuous macro-cells to provide full coverage as an “umbrella” layer. Micro-cells to accommodate hot-spots with increased capacity and higher bit rates in limited areas. Typical air interface capacities are about 1Mbps/carrier/cell for a threesectored macro BS and 1.5Mbps/carrier/cell for a micro BS. Example of WCDMA network evolution An “umbrella” macro cell is best suited for highmobility users f1 f1 f1 f1 f1 f1 f2 Capacity enhancement f1 f2 Micro layer provides a very high capacity in a limited area Presentation Title — 31 f2 f1 f2 f2 f2 f2 f1 f2 f 1, f 2 f 1, f 2 f 1, f 2 f 1, f 2 f 1, f 2 f 1, f 2 All rights reserved © 2004 C i nuous m o l ayer ont acr w t h f r equency f 1 i C i nuous m o l ayer ont acr w t h f r equency f 1 i Sel ect ed ar eas w t h m cr o i i cel l s w t h f r equency f 2 i C i nuous m o l ayer ont acr w t h f r equency f 1 i C i nuous m cr o l ayer ont i w t h f r equency f 2 i N m o l ayer o acr Bot h f r equenci es cont i nuousl y f 1, f 2 used i n m cr o l ayer i
    32. 32. CELL DEPLOYMENT > Case study of frequency reuse in micro- and macro- networks Reference scenario f2 f1 f1 f1 f1 Reuse of micro frequency in macro layer f 1, f 2 f1 f1 f1 f1 macro carrier reuse is not worth while when micro-cells locates near macro-cells! Reusing a micro carrier Continuous macro layer with frequency f2 on all macro-cells does Continuous micro layer with frequency f1 not bring any improvements in network performance! Continuous macro layer with frequency f1 and f2 Continuous micro layer with frequency f1 Reuse of macro frequency in micro layer f2 Continuous macro layer with frequency f2 f 1, f 2 f 1, f 2 f 1, f 2 f 1, f 2 Continuous micro layer with frequency f1 and f2 Reuse of macro frequency in selected micro cells f2 f1 f 1, f 2 f 1, f 2 Presentation Title — 32 f1 Continuous macro layer with frequency f2 Continuous micro layer with frequency f1 selected microcells reusing macro frequency f2 All rights reserved © 2004 Reusing a macro carrier on all micro-cells can support 10% more users than the reference scenario,but extra Power Amplifier needed! Micro-cells do not benefit from the other carrier reused from macro-cells if they still have unused capacity on their own carrier!
    33. 33. WCDMA Radio Network Planning > overview > Dimensioning > Detailed planning > Optimization aspects > Adjacent carrier interference > WCDMA & GSM Co-Planning Presentation Title — 33 All rights reserved © 2004
    34. 34. WCDMA Radio Network Planning---Network planning process overview Definition N w et ork Conf i gurat i on and Dm i ensi oni ng R equi rem s ent and st rat egy f or coverage, qual i t y and capaci t y per servi ce Presentation Title — 34 Planning and Implementation Coverage pl anni ng and si t e sel ect i on P ropagat i on m easurem s ent coverage predi ct i on Capaci t y R equi rem s ent P aram er et pl anni ng N w et ork O i m sat i on pt i T fic raf di st ri but i on al l ow ed bl ocki ng/ qeui ng Syst em f eat ures A rea/Cel l speci f i c set t i ng Survey M easurem s ent E ernal xt Int erf erence A ysi s nal Si t e acqui si t i on Coverage opt i m sat i on i O&M Ident i f i cat i on A dapt at i on All rights reserved © 2004 H andover St rat egi es M m axi um l oadi ng O her R M t R St at i st i cal perf orm ance anal ysi s Q i ty ual E f i ci ency f A l abl i t y vai
    35. 35. WCDMA Radio Network Planning ---Dimensioning(1) > What is Dimensioning? --- to estimate the required site density and site configurations for the area of interest • Radio Link Budget(RLB) and coverage analysis; • Capacity estimation • Estimation of the amount of base station hardware and sites,radio network controllers,equipment at different interfaces and core network elements • Knowledge of service distribution,traffic density, traffic growth estimates and QoS requirements are essential Presentation Title — 35 All rights reserved © 2004
    36. 36. WCDMA Radio Network Planning ---Dimensioning(2) > Coverage analysis: • for the single-cell case*: • where a = σ ⋅ 2 b = σ ⋅ 2 10 wherer is the received level at the cell edge,n is the propagation P constant, x0 is the average signal strength threshold and σ is the standard deviation of the field strength and erf is the error function. for a typical macro-cellular environment Fu = 1  1 − 2ab 1 − ab  ⋅ 1 − erf ( a ) + exp( ) ⋅ (1 − erf ( )) 2 2  b b  x0 − Pr 10 ⋅ n ⋅ log e using Okumura-Hata model, the following formular gives an example for an urban macro-cell with base station antenna height of 25m, mobile station antenna height of 1.5m and carrier frequency of 1950 MHz: – Lp = 138.5 + 35.7 ⋅ log10 ( r ) where r is the maximum cell range and Lp is the max path loss. * “Microwave Mobile Communications”, Jakes,W.C, John Wiley& Sons, 1974,126pp Presentation Title — 36 All rights reserved © 2004
    37. 37. WCDMA Radio Network Planning ---Dimensioning(3) > Capacity estimation • • • • > WCDMA capacity and coverage are connected in terms of interference margin. Knowledge and vision of subscriber distribution and growth is a must. Site configurations such as channel elements,sectors and carriers and site density can be determined. Capacity refinement may be obtained in late network optimization. RNC dimensioning • RNC dimensioning limited factors: Maximum number of cells(a cell is identified by a frequency and a scrambling code) – Maximum number of Node B under one RNC – Maximum Iub throughput – Amount and type of interfaces(e.g. STM-1,E1) – Presentation Title — 37 All rights reserved © 2004
    38. 38. WCDMA Radio Network Planning ---Dimensioning(4) > RNC dimensioning(cont’d) • The number of RNCs needed to connect a certain number of cells numRNCs = • The number of RNCs needed according to the number of BTSs to be connected numBTSs numRNCs = • numCells cellsRNC ⋅ fillrate1 btsRNC ⋅ fillrate2 the number of RNCs to support the Iub throughput numRNCs = voiceTP + CSdataTP + PSdataTP ⋅ numSubs tpRNC ⋅ fillrate3 > Supported traffic (upper limit of RNC processing ability) > Required traffic(lower limit of RNC processing ability) > RNC transmission interface to Iub Presentation Title — 38 All rights reserved © 2004
    39. 39. WCDMA Radio Network Planning ---Detailed Planning(1) > Using Radio Network Planning(RNP) tools • • > To find an optimum trade-off between quality,capacity and coverage criteria for all the services in an operator’s service portfolio. Integrated tools for dimensioning,network planning and optimization. I ni t i al i ze i t er at i ons I ni t i al i sat i on phase Upl i nk i t er at i on st ep Downl i nk i t er at i on st ep Using Static simulator * • G obal i ni t i al i zat i on l Com ned UL/ DL i t er at i on bi Static simulator flow Post pr ocessi ng G aphi cal out put s r Cover age anal ysi s Post Pr ocessi ng phase * “Static simulator for studying WCDMA radio network planning issues”,Wacker.A, Laiho-steffens.J,Sipila.K and Jasberg.M,VTC99’Spring pp2436-2440 Presentation Title — 39 All rights reserved © 2004
    40. 40. WCDMA Radio Network Planning ---Detailed Planning(2) > Example of RNP tool workflow Defining service requirements Creating a plan/ load maps Importing/creating and editing sites and cells A plan usually includes parameter settings for A plan usually includes parameter settings the planned network elements such as: the planned network •Digital map& its properties •Digital map& its properties •Target planning area propagation models •Target planning area propagation models •Antenna models •Antenna models •Selected radio access technology •Selected radio access technology •BTS types and site/cell templates •BTS types and site/cell templates Importing measurements Site location,site ground height number of cells and antenna direction Importing/ generating and refining traffic layers Traffic planning: Traffic planning: • Bearer service type and bit rate, • Bearer service type and bit rate, • average packet call size and retransmission rate, • average packet call size and retransmission rate, • busy-hour traffic amount and traffic density for • busy-hour traffic amount and traffic density for each service, each service, • mobile list and WCDMA calculation • mobile list and WCDMA calculation To verify that the planned coverage, capacity and QoS criteria To verify that can be met with te current network deployment and parameter can be met with te current network deployment and parameter settings: settings: • Run UL/DL iterations to calculate tx powers for MS and BS • Run UL/DL • Snapshot analysis for interference and coverage estimation • Snapshot analysis estimation • Optimizing dominance • Optimizing dominance Presentation Title — 40 Link loss calculation WCDMA calculations Analysis Propagation model tuning Propagation models: Propagation models: •Macro cell---Okumura-Hata model •Macro cell---Okumura-Hata model •Micro cell---Walfisch-Ikegami model •Micro cell---Walfisch-Ikegami model A WCDMA cell template may include cell A WCDMA cell template may include cell layer type,channel model,Tx/Rx diversity layer type,channel model,Tx/Rx diversity options,power settings, maximum acceptable options,power settings, load, propagation model,antenna infomation load, propagation model,antenna infomation and cable losses and cable losses Quality of Service Neighbour cell generation All rights reserved © 2004 reporting Cite/BTS hardware template may include: Cite/BTS hardware template may include: •Maximum number of wideband signal •Maximum number of wideband signal processors processors •Maximum number of channel units •Maximum number of channel units •Noise figure •Noise figure •Available Tx/Rx diversity types •Available Tx/Rx diversity types
    41. 41. WCDMA Radio Network Planning ---Detailed Planning(3)---UL/DL iteration steps i ni t i al i zat i on G obal i ni t i al i zat i on l S et ol dThr eshol ds t o t he def aul t / new cover age t hr eshol ds I ni t i al i ze del t a_C I _ol d / Al l ocat e t he C C pow s PI H er I f no convergence C cul at e new cover age al t hr eshol ds C cul at e t he r ecei ved Per ch l evel s and al det er m ne t he best ser ver i n D i L C heck U l oadi ng and possi bl y m L ove M t onew ot her car r i er or out age Ss / C cul at e t he M sensi t i vi t i es al S D er m ne t he SH connect i ons et i O E val uat e U br eak cr i t er i on L C cul at e i ni t i al TX pow s f or al l l i nks al er C onnect M s t o best ser ver , cal cul at e S needed M TxPow S er and SH gai ns O C cul at e t ar get C I ’ s al / C cul at e adj ust ed M Tx al S pow s, check M s f or out age er S U i t er at i on st ep L C cul at e new I =I _ot h/ I _ow al n C heck C C Ec/ I o cal cul at e t he PI H C I f or each connect i on / cal cul at e C I f or each M / S D i t er at i on st ep L C heck U and D br eak L L cr i t er i a I f not f ul f i l l ed conver gence UL iteration steps Adj ust TX pow s of er each r em ni ng l i nk ai accor di ng t o del t a_C I / f ul f i l l ed P ost pr ocessi ng D Presentation Title — 41EN U pdat e del t a_C I _ol d / Post pr ocessi ng All rights reserved © 2004 EN D DL iteration steps
    42. 42. > WCDMA Radio Network Planning ---Adjacent Channel Interference Adjacent Channel Interference(ACI) situation • Adjacent Channel Leakage Power Ratio(ACLR) – • Adjacent Channel Selectivity(ACS) – • the ratio of the transmitted power to the power measured in an adjacent channel the ratio of the receive filter attenuation on the assigned channel frequency to the receive filter attenuation on the adjacent channels Adjacent Channel Protection(ACP) – The ratio of adjacent channel power received by the base station as adjacent R x R x channel interference power 0dB 0dB BS AC P UL adjacent channel interference situation BS AC P f1 f2 BS sel ect i vi t y w ed si gnal ant Tx N odeB@r equency1 f f2 w ed si gnal ant Tx 0dB 0dB N odeB@r equency2 f M l eakage S M AC S LR M AC S LR f1 Presentation Title — 42 f1 All rights reserved © 2004 f2 f1 f2
    43. 43. WCDMA Radio Network Planning ---Adjacent Channel Interference Tx 0dB 0dB BS AC LR DL adjacent channel interference situation Tx BS AC LR f1 f2 BS l eakage w ed si gnal ant R x N odeB@r equency1 f f2 w ed si gnal ant R x 0dB 0dB N odeB@r equency2 f M sel ect i vi t y S M AC S P M AC S P f1 > f1 f2 f1 f2 Worst ACI cases---when a macro MS is coming too close to a micro BS • Minimum Coupling Loss(MCL) the smallest path loss between the transmitters and receivers – For a micro BS and MS, MCL is about 53dB – For a macro BS and MS, MCL is about 70dB – Presentation Title — 43 All rights reserved © 2004
    44. 44. WCDMA Radio Network Planning ---Example of Worst ACI case > Worst ACI case when sites of different operators not co-located For downlink scenario, supposing the micro BS is transmitting with a minimum power of 0.5W(27dBm); then the received interference at the MS in the adjacent channel is O at or 1 M o C l per acr el 27dBm − 53dB ( MCL) − 32.7dB ( ACS ) = −58.7dBm Assuming speech service (processing gain of Gp=25dB) with an Eb/No requirement at the Ms of 5dB and an allowed noise rise in the macro cell of 6 dB, the maximum allowed propagation loss Lp to keep the uplink connection working is L p = 21dBm − 5dB + 25dB − ( −103dBm + 6dB ) = 138dB if we further consider a DL Tx Eb/No requirement of 8dB, the transmit power would need to be p = −58.7dBm + 8dB − 25dB + 138dB tx O at or 2 M cr o C l per i el hi gh TX pow er For uplink scenario, with a maximum MS power of 21dBm, 53dB for MCL to the micro BS and coupoing between the carriers of C=32.7dB,the received level at the micro BS and be estimated as 21dBm − 53dB − 32.7dB = −64.7dBm if the background noise level is dBm, the micro BS would suffer a 38.4 dB noise rise form one macro user, which is located in the radio sense at the MCL distance form the micro BS, i.e. such a macro user would completely block the micro BS. O at or 2 M cr o C l per i el = 62.3dBm si gnal si gnal AC I D ead Zone f or O at or 1 per This simple example shows that clearly in these cases the DL is the weaker link, i.e. before coming too close to a micro BS, the connection of a macro BS will be dropped due to insufficient DL power and it cannot block the micro BS. O at or 1 per Assuming ACS and ACLR of values 33dB and 45dB M S respectively, the coupling C between the carriers can be calculated as: −33 / 10 Presentation Title — 44 C = −10 ⋅ log10 (10 All rights reserved © 2004 AC I O at or 1 M per S M TX pow ax. er + 10−45 / 10 ) = 32.7dB
    45. 45. WCDMA Radio Network Planning ---Optimization aspects(1) > Guidelines for Radio Network Planning to avoid ACI in multioperator environment • Base station and antenna locations Co-locate BSs – Deploy the antennas in a position as high as possible – • Base station configuration Optimum antenna beam-width – “desensitisation”---increasing the noise figure – • • • Inter-frequency handovers Inter-system handovers Guard bands Presentation Title — 45 All rights reserved © 2004
    46. 46. WCDMA Radio Network Planning ---Optimization aspects(2) > Site locations and configurations • • • > Antenna installations(cable losses) Optimum antenna tilting angle and correct antenna selection Optimum sectorisation regarding to number of users and SHO overhead.* Usage of mast head amplifier(MHA)** • • • Used in uplink direction to compensate for the cable losses Improved uplink coverage probability May have negative effect on downlink performance in case of downlinklimited scenario * “The impact of the base station sectorisation on WCDMA Radio Network Performance”,A.Wacker,J.Laiho-Steffens,K.Sipila,K.Heiska,VTC99’Amsterdam. ** “The impact of the Radio Network Planning and Site Configuration on the WCDMA Network Capacity and Quality of Service”,J.Laiho-Steffens,A.Wacker, P.Aikio,VTC2000 Presentation Title — 46 All rights reserved © 2004
    47. 47. WCDMA-GSM Co-Planning Issues > Examples of maximum path losses with existing GSM and WCDMA system GSM900/ GSM1800/ WCDMA/ WCDMA/ WCDMA/ speech speech speech 144kbps 384kbps Mobile transmission power[dBm] Interference margin[dB] Fast fading margin[dB] 4 Base station antenna gain[dBi] 5 Body loss[dB] 6 Mobile antenna gain[dBi] Relative gain from lower frequency compared to UMTS 7 frequency[dB] Maximum path loss[dB] 21 21 -110 -124 -117 -113 0 2 2 2 2 2 2 2 16 18 18 18 18 3 3 21 2 2 30 1 Receiver sensitivity[dBm] 33 -110 1 3 3 0 0 0 2 2 11 1 164 154 156 154 150 1 WCDMA sensitivity assuems 4.0dB base station noise figure and Eb/No of 5dB for 12.2kbps speech,1.5dB for 144kbps and 1.0dB for 384kbps data.GSM sensitivity is assumed to be -110dBm with receive antenna diversity. 2 WCDMA interference margin corresponds to 37% loading of the pole capacity.An interference margin of 1.0dB is reserved for GSM900 because the small amount of spectrum in 900MHz does not allow large reuse factors. 3 The fast fading margin for WCDMA includes the macro diversity gain against fast fading. 4 The atenna gain assumes three-sector configuration in both GSM and WCDMA. 5 The body loss accounts for the loss when the terminal is close to the user's head. 6 Presentation Title — 47 A 2.0dBi antenna gain is assumed for the data terminal. All rights reserved © 2004 7 The attenuation in 900MHz is assumed to be 11.0dB lower than in UMTS band and in GSM1800 band 1.0dB lower than in UMTS band.
    48. 48. WCDMA-GSM Co-Planning Issues---interference issues > Interference between the two system is the main issue • Radio frequency issue Second harmonics of GSM900 could probably fall into WCDMA uplink band – Third-order inter-modulation products of PCS 1800 could be problematic – Second-order harmonic distortion from GSM900 falling into WCDMA band f GSM=950~960M z H G 900 SM 935~960M z H U A U A FD TR TR D TD 1920~1980 D 1900~1920M z H Presentation Title — 48 All rights reserved © 2004 f
    49. 49. WCDMA-GSM Co-Planning Issues ---interference issues • Interference mechanisms from GSM system to WCDMA system Adjacent Channel Interference(ACI):depends on Tx/Rx filter and spatial and spectral distance between the own and adjacent carrier,the cell type and the power levels used. – Wideband Noise(WB):from all out-of-band emission components. – Cross-modulation(XMD): depends on non-linearity of the MS receiver,the duplex isolation and the transmitting mobile power. XMD is proportional to proportional to – Inter-Modulation Distortion(IMD):caused by non-linearities of RF the square of the square of transmitting components of transmitter or receiver. transmitting – W M B CD A S G B SM S W em ssi on B i f r om G BS SM Typically in Typically in micro-cells micro-cells and could be and could be reduced by reduced by guard band. guard band. C ossm r odul at i on ( XM ) D Third-order IMD with mixture of products of the GSM carrier frequencies f1 and f2: 2f1-f2 or 2f2-f1 AC f r om I G BS SM AC t o W D A BS I CM Presentation Title — 49 I M at t he D WD A M CM S All rights reserved © 2004 power and very power and very sensitive to the Tx sensitive to the Tx power of the MS! power of the MS!
    50. 50. WCDMA-GSM Co-Planning Issues Eval uat e t he qual i t y of t he exi st i ng 2G net w k or Space avai l abl e f or onet o- one r euse Antenna sharing and co-located sites could be preferable. Assur e t he cover age f or al l W D A ser vi ces CM U ban ar ea r D i ne t r af f i c ef di st r i but i on r ul es bet w een syst em s D i ne handover r ul es ef bet w een syst em s R com ned 2G and un bi W D A anal ysi s CM Presentation Title — 50 G SM WD A CM r ur al ar ea G SM WD A CM Handover GSM WCDMA for capacity extension or service optimization All rights reserved © 2004 G SM G SM G SM WD A CM Handover WCDMA-GSM for coverage extension
    51. 51. Co-existing TDD & FDD modes ---UTRA TDD mode > Some key parameters for the UTRA FDD and TDD modes Frame structure Frame length Chip rate Uplink spreading factors Number of parallel UL codes per user Downlink spreading factors Number of parallel DL codes per user Modulation Power control update rate Handover Dynamic channel allocation Intra-cell interference cancellation Presentation Title — 51 UTRA FDD 15 slots/frame 10 ms 3.84 Mcps 4~512 UTRA TDD 15 slots/frame 10 ms 3.84 Mcps 1~16 4~512 Rather low spreading factors makes it inadequate to reuse all the timeslots in all the cells.That is,network must control which slots and directions are used in which cells. 1 or 2 1~ 16 1~6 QPSK 1500Hz soft and hard N/A support for advanced receivers at base station 1~16 QPSK theretically up to 800Hz;in practice, only 100Hz in DL and 100Hz or possibly 200Hz in UL hard only slow and fast support for joint detection All rights reserved © 2004 Not as fast as to follow fast fading pattern!
    52. 52. Co-existing TDD & FDD modes---Example of TDD RLB uplink/downlink Voice Voice NRT data NRT data Example TDD link budget for 12.2kbps 12.2kbps 128kbps 128kbps uplink(RxD=receive diversity) RxD No RxD RxD No RxD Transmitter(mobile) Max.Tx Power(dBm) 21 21 24 24 MS antenna gain(dBi) 2 2 2 2 Body loss(dB) 3 3 0 0 EIRP(dBm) 20 20 26 26 Receiver(base station) Number of used slots in TDD 1 1 1 1 Thermal noise density(dBm/Hz) -174 -174 -174 -174 Base station receiver noise figure(dB) 5 5 5 5 Desensitisation 0 0 0 0 Receiver noise density (dBm/Hz) -169 -169 -169 -169 Receiver noise power(dBm) -103.2 -103.2 -103.2 -103.2 Interference margin(dB) 8 8 8 8 Receiver interference power(dBm) -95.9 -95.9 -95.9 -95.9 Total effective noise +interference(dBm) -95.2 -95.2 -95.2 -95.2 Processing gain(dB) 12 12 2.4 2.4 Required Eb/No(dB) 1.7 8.6 0.3 6.4 Receiver sensitivity(dBm) -105.5 -98.6 -97.3 -91.2 BS antenna gain(dBi) 4 4 4 4 Cable loss in the base station(dB) 0 0 0 0 Fast fading margin (TPC headroom) (dB) 6.3 6.3 3.4 3.4 Max.path loss(dB) 123.2 116.3 123.9 117.8 Presentation Title — 52 All rights reserved © 2004 Example TDD link budget for downlink(No TxD) Voice NRT data 12.2kbps 128kbps Transmitte r(mobile) Max.Tx Power(dBm) 24 24 BS antenna gain(dBi) 4 4 Cable loss in BS(dB) 0 0 28 28 1 1 EIRP(dBm) Receiver(mobile) Number of used slots in TDD GP = Thermal noise density(dBm/Hz) -174 -174 Mobile station receive r noise Wfigure(dB) _ in _ slot − midamble − guard _ period k chips 9 9 ⋅ ⋅ RReceiver noise density(dBm/Hz) _ slot -165 15 chips _ in -165 Receiver noise power(dBm) -99.1 -99.1 Interference margin(dB) Receiver interference power(dBm) Greatereffective difference Total Eb/No noise between with or without RxD! +interference(dBm) 8 8 -91.9 -91.9 -91.1 -91.1 Processing gain(dB) 12 2.4 Required Eb/No(dB) 9.4 6.7 -93.7 -86.8 2 2 3 0 5.5 3.1 115.2 113.7 Receiver sensitivity(dBm) Mobile antenna gain(dBi) Smaller Max path loss than that Body loss(dB) of FDD scenario TDD cells Fast fading margin have smaller radius! (TPC headroom) (dB) Max.path loss(dB)
    53. 53. Co-existing TDD & FDD modes--- TDD/TDD interference > Interference scenarios > TDD-TDD Interference scenarios/solutions • MS to MS interference---when MS1 is transmitting while MS2 is • BS to BS interference---when BS1 is transmitting while BS2 is receiving receiving, especially at cell borders. – Cannot be avoided by network planning,but may benefit from – DCA and radio resource management – Power control depends heavily on BS locations. – Could be avoided by providing sufficient coupling loss between base stations – BSs better be synchronized and of same asymmetry. – Presentation Title — 53 All rights reserved © 2004
    54. 54. Co-existing TDD & FDD modes --- TDD/FDD interference > TDD-FDD Interference scenarios/solutions U A TD TR D U A FD / U TR D L Tx/ R x 1900 • 1920 Sat ellite 1980 Interference mainly between TDD and FDD/UL frequency bands! U A TR TD D Tx/ R x 2010 H 2025 ( M z) TDD MS to FDD BS To make FDD/BS less sensitive,especially for small pico cells – To place BS antenna as high as possible from TDD MSs – • FDD MS to TDD BS – • Inter-frequency or inter-system may be helpful FDD MS to TDD MS Use downlink power control of TDD BS to compensate for the interference from FDD MS – Inter-system/inter-frequency handover – Presentation Title — 54 All rights reserved © 2004
    55. 55. Co-existing TDD & FDD modes > UTRA TDD • • • • • • • Advantage in the unpaired spectrum operation Better utilized for asymmetric service at high data rate Can build stand-alone wide-area TDD network(?) or serve as a separate capacity-enhancing layer in the network Lower Max. Path loss compared with FDD scenario Lower “cell breathing” and thus more stable service coverage Requires strict synchronization especially in uplink Low-rate services often goes to code-limited cases while high-rate services goes to interference-limited cases From the service point of view, UTRA TDD is most suited for small cells and high data rate services! Presentation Title — 55 All rights reserved © 2004
    56. 56. Thanks!

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