WCDMA Radio Network Planning and Optimization
Song Pengpeng
Presentation Title — 2 All rights reserved © 2004
Contents
> WCDMA Fundamentals(including link budget fundamentals)
> Radio Resource Utilization
> Coverage and Capacity issues
> Cell deployment
> WCDMA Radio Network Planning(including WCDMA-GSM Co-planning issues )
> Co-existing TDD & FDD modes
Presentation Title — 3 All rights reserved © 2004
WCDMA Fundamentals
> WCDMA network infrastructure
> WCDMA radio interface protocol architecture
> WCDMA link level characteristics & indicators
> WCDMA link budget analysis
Presentation Title — 4 All rights reserved © 2004
WCDMA Fundamentals
> WCDMA Network infrastructure
I u
I ur
I ub I ub
Uu
MSC
RNCRNC
NodeB NodeB NodeB NodeB
UE
CN
UTRAN
I u
I ub I ub
UEUE UE
Data General Data GeneralData General
Presentation Title — 5 All rights reserved © 2004
WCDMA Fundamentals
> WCDMA Radio Interface protocol architecture
Radi o Resource ControlSubl ayer(RRC)
Medi a Access Control Subl ayer (MAC)
Physi cal l ayer (PHY)
Packet DataConvergence
Protocol (PDCP)
Radi o Li nkControl
Subl ayer(RLC)RLC RLC RLC RLC
Transport Channel s
Logi cal Channel s
Si gnal l i ngRadi o Bearers
Radi o Bearers
Layer 3
Layer 2
Layer 1
Presentation Title — 6 All rights reserved © 2004
WCDMA Fundamentals
> Mapping between Trch and PHY channelsTransport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Common Pilot Channel (CPICH)
Primary Common Control Physical Channel (P -CCPCH)
Secondary Common Control Physical Channel (S -CCPCH)
Synchronisation Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-Detection/Channel-Assignment Indicator
Channel (CD/CA-ICH)
DSCH Physical Downlink Shared Channel (PDSCH)
HS-DSCH-related Shared Control Channel (HS-SCCH)
HS-DSCH High Speed Physical Downlink Shared Channel (HS-PDSCH)
Dedicated Physical Control Channel (uplink) for HS-DSCH (HS-DPCCH)
NodeB
UE
Si gnal i ng and ControlChannel s, e. g.
BCH, PCH, FACH, RACH. . .
User data transmi ssi on, DCH, DSCH, HS-DSCH, CPCH. . .
Presentation Title — 7 All rights reserved © 2004
WCDMA Fundamentals
WCDMA link level indicators
indicators Formularization Comments
BLER Average block error rate calculated for the transport blocksBER
Information bit error rateR User information bit rate
Eb/No
Uplink:
Downlink:Energy per bit divided by noise spectral density(including interference
power density)
Ec/Io(Eb/No) divided by
processing gainThe received chip energy relative to the total power spectral density;
always used on CPICH,AICH and PICH.
Ec/IorThe transmitted energy per chip on a chosen channel relative to the
total transmitted power spectral density at the base station.
IOther-to-own-cell received power ratio
G(Geometry factor)
Mostly used in downlink, G reflects the distance of the MS from the BSantenna. Atypical range is from –3 dB to 20 dB, where –3 dB is for the
cell edge.
Average Power RiseThe difference between the average transmitted power and the average
received power in low multi-path diversity channelsNoise Rise The ratio of the total received wideband power to the noise power.
Power Controlheadroom
(Average requiredreceived Eb/Io without fast PC)-
(average required receivedEb/Io with fast PC) Also referred as “TPC headroom” or “multipath fading margin”
Macro DiversityCombining Gain
The reduction of the required Eb/No per link in soft or softer handoverwhen compared to the situation with one radio link only.
I
P
R
W
N
E rxb 0
Nothown
rxb
PII
P
R
W
N
E
)1(0
own
oth
I
Ii
Noth
own
PI
IG
Parameters WCDMAChip rate 3.84 Mcps
Frame length 10 or 2 ms
ModulationDownlink: QPSK;
Uplink: HPSKBandwidth 5 MHz
VocoderAlgebraic Code Excited
Linear Prediction Coder(ACELP)Base synchronization AsynchronizationPower control rate 1500 Hz
Cell identificationUnique scrambling code (Gold code)
Channelization codeOVSF code
WCDMA parameters
Presentation Title — 8 All rights reserved © 2004
WCDMA Radio Network Planning---Example of link budget analysis
> RF link budget components:
Presentation Title — 9 All rights reserved © 2004
WCDMA Radio Network Planning---Example of link budget analysis
Allowed propagation lossfor cell range[dB] 141.9 v=r-s+t-u
Transmitter(mobile)Max. Tx power[dBm] 21 aMobile antenna gain[dBi] 0 bBody loss[dB] 3 cEquivalent IsotropicRadiated power(EIRP)[dBm] 18 d=a+b-c
Receiver(base station)Thermal noise density[dBm/Hz] -174 eBase station receivernoise figure[dB] 5 fReceiver noise density[dBm/Hz] -169 g=e+fReceiver noise power[dBm] -103.2 h=g+10*log(3840000)
Interference margin[dB] 3 IReceiver interferencepower[dBm] -103.2 j=10*log(10^((h+i)/10)-10^(h/10))Total effectve noise +interference [dBm] -100.2 k=10*log(10^(h/10)+10^(j/10))Processing gain[dB] 25 l=10*log(3840/12.2)Required Eb/No[dB] 5 mReceiver sensitivity[dBm] -120.2 n=m-l+kBase station antennagain[dBi] 18 o
Max_path_loss=Ptx_EIRP - Prx_receiver_sensitivity -Lrx_cable+ Grx_antenna
Cable loss in the basestation[dB] 2 pFast fading margin[dB] 0 qMax.path loss[dB] 154.2 r=d-n+o-p-q
Allowed_propagation_loss=Max_path_loss -Log_normal_fading_margin +soft_handover_margin -in_car_loss
Example of RLB for 12.2 kbps voice service(uplink,120km/h,in-car users,VA channel with soft handover)Example of RLB for 12.2 kbps voice service(uplink,120km/h,in-car users,VA channel with soft handover)Example of RLB for 12.2 kbps voice service(uplink,120km/h,in-car users,VA channel with soft handover)Example of RLB for 12.2 kbps voice service(uplink,120km/h,in-car users,VA channel with soft handover)
Coverage probability[%] 95Log normal fadingconstant[dB] 7Propagation model exponent 3.52Log normal fading margin[dB] 7.3 sSoft handover gain[dB] 3 tIn-car loss[dB] 8 u
(*) *“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(*) *“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
A headroom for mobile station to maintainadequate closed loop fast power control. Thisapplies especially to slow-moving pedestrianmobiles.Typical values are 2.0-5.0 dB for slow-moving mobiles(*)
handovers give a gin against slow fading byreducing the required log-normal fading margin;italso gives an additional macro diversity gainagainst fast fading by reducing the requiredEb/No due to the effect of macro diversitycombining.
the margin required to provide a specifiedcoverage availability over the individual cells.For a 95% coverage with a standard shadowingdeviation of 6.0dB and path loss model withn=3.6 we need a shadowing margin ofapproximately 6.0dB
Closely related with the loading of the cell whichsubsequently affects the coverage. For coverage-limited cases a smaller interference margin issuggested,while in capacity-limited cases a largerinterference margin should be used. Typical valuefor the interference margin in the coverage-limitedcases are 1.0-3.0 dB corresponding to 20-50%loading.
Presentation Title — 10 All rights reserved © 2004
HandoverControl
Power Control
ResourceManager
Admissioncontrol
Load control
Packet datascheduling
Congestion Control
Radio Resource Management
RADIO RESOURCE UTILIZATION
To adjust the transmit powers in upilnk and downlink to the minimum level required to enshure the demanded QoS
To adjust the transmit powers in upilnk and downlink to the minimum level required to enshure the demanded QoS
Takes care that a connected user is handed over from one cell to another as he moves through the coverage area of a mobile network.
Takes care that a connected user is handed over from one cell to another as he moves through the coverage area of a mobile network.
To ensure that the network stays within the planned condition
To ensure that the network stays within the planned condition
Let users set up or reconfigure a radio access bearer(RAB) only if these would not overload the system and if the necessary resources are available.
Let users set up or reconfigure a radio access bearer(RAB) only if these would not overload the system and if the necessary resources are available.
Takes care that a system temporarily going into overload is returned to a non-overloaded situation.
Takes care that a system temporarily going into overload is returned to a non-overloaded situation.
To handle all non-realtime traffic,allocate optimum bit rates and schedule transmission of the packet data, keeping the required QoS in terms of throughput and delays.
To handle all non-realtime traffic,allocate optimum bit rates and schedule transmission of the packet data, keeping the required QoS in terms of throughput and delays.
To control the physical and logical radio resources under one RNC;to coordinate the usage of the available hardware resouces and to manage the code tree.
To control the physical and logical radio resources under one RNC;to coordinate the usage of the available hardware resouces and to manage the code tree.
> Basic RRM functions
* Power Control
* Handover Control
* Congestion Control
* Resource Management
Presentation Title — 11 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---power control(1)
> UMTS Power Control(PC) summary
Presentation Title — 12 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---power control(2)
> Uplink/Downlink inner- and outer- loop power control
NBAP: initia
l target SIR,DL initia
l/max/min
RL power, DL TPC_step,DPC_MODE
NodeB
UE
SRNC
RRC:DL target BLER, U
L gain factors, UL TPC_step, PC algorith
m, UL RM values, D
PC_MODE
RRC: actual BLER,P-CPICH Ec/Io,P-CPICH RSCP, path loss,
traffic+UE internal m
eans
PC on DPCCH + DPDCHs
UL/DL TPC command on DPCCH(Inner lo
op PC)
DCH-FP(10-100Hz):UL CRC and QE
UL actual target SIR
Iub
Uu
SIR estimates Vs target SirUL TPC commands
DL outer loop PCSIR_step=f(BLER or BER)
SIR target management
SIR estimate vs. target SIR DL TPC commands
UL outer loop PCSIR_step=f(BLER or BER)
SIR target management
MDC and splitting
Presentation Title — 13 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---handover control
> Soft-Handover:Example of Soft Handover Algorithm
Event 1A: A P-CPICH enters the reporting range Event 1A: A P-CPICH enters the reporting range
)2(log10)1(log10log10 11101
1010 aaBest
N
iinew HRMWMWM
A
Event 1B: A P-CPICH leaves the reporting range Event 1B: A P-CPICH leaves the reporting range
)2(log10)1(log10log10 11101
1010 bbBest
N
iiold HRMWMWM
A
Event 1C: A non-active PCPICH becomes better than 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.
Event 1C: A non-active PCPICH becomes better than 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.
Addition windowAddition window
drop windowdrop window
AS_Th – AS_Th_HystAs_Rep_Hyst
As_Th + As_Th_Hyst
Cell 1 Connected
Event 1A Add Cell 2
Event 1C Replace Cell 1 with Cell 3
Event 1B Remove Cell 3
CPICH 1
CPICH 2
CPICH 3
Time
MeasurementQuantity
T T T
NodeB 1
SRNC
I ub Macro Di versi tycombi ni ng
NodeB 2
I ub
TPC command1
transmi ssi on
l i nk 1
UE i n SHO
TPC
comm
and2
tran
smi s
sion
l ink
2
Presentation Title — 14 All rights reserved © 2004
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 — 15 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---congestion control
> Air interface load definition(load control principles)• Uplink
• Wideband power-based uplink loading where
• Throughput-based uplink loading• Downlink
• Wideband power-based downlink loading
• Throughput-based downlink loading
or
rxTotal
othownUL P
II
NothownrxTotal PIIp
k
kkk
UL i
RW
)1(1
1
maxtx
rxTotoalDL P
P
max
1
R
RN
kk
DL
N
k
kkkDLDL W
Ri
1
)(])1[(
Presentation Title — 16 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---congestion control (cont’d) > Congestion control---keep the air interface load
under predefined thresholds• 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-real-
time traffic
Admi ssi oncontrol
Load control
Packet dataschedul i ng
Congesti on Control
> Admission control• Wideband power-based admission control
– For uplink, an RT bearer will be admitted if where and
– For downlink, an RT bearer will be admitted if
• Throughput-based admission control– For uplink, it follows – For downlink, it follows
etrxTrxNC PIP arg
rxOffsetetrxTrxTotoal PPP argLP
I rxTotal
1
RW
L1
1
ettxTtxNC PPP argtxOffsetettxTtxTotal PPP arg
LthresholdUoldUL L LthresholdDoldDL L
Presentation Title — 17 All rights reserved © 2004
RADIO RESOURCE UTILIZATION---congestion control (cont’d)
> Packet scheduling• Time division scheduling• Code division scheduling
Packet schedul i ng al gori thm
Process Capaci ty requests
Cal cul ate l oad budget forpacket schedul i ng
Load bel ow targetl evel ?
Overl oad threshol dexceeded?
I ncrease l oadi ng Decrease l oadi ng
Al l ocate/ modi fy/ rel easeradi o resources
Yes No
Yes
No
Presentation Title — 18 All rights reserved © 2004
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 — 19 All rights reserved © 2004
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
• Optimized so that only the relevant cells are in the active set
Addi ti onwi ndow
Too wi deSHO area
Too smal lSHO area
Unnecessarybranch
addi t i on
MRC gai nreducti on
I ncreasedSHO
overhead
Reduced DLcapaci ty
Degradedperformancedue to toohi gh l evel
di ff erence ofthe si gnal s
i n AS
I ncreasedBS and MSTx Power
Reduced DLand UL
capaci ty
Frequent ASupdates
Rel evantcel l s removed
f rom AS
Reduced ULcapaci ty
I ncreasi ngsi gnal l i ngoverhead
I ncreasedTx powers
Reduced UL/DL capaci ty
too hi gh
too l ow
Presentation Title — 20 All rights reserved © 2004
RRM optimization --- SHO optimization(2)
> Drop window optimization• Slightly larger than the addition window
dropwi ndow
Unnecessarybranches
stay i n AS
FrequentHOs
Too l argeSHO
overhead
I ncreasedsi gnal i ngoverhead
Degradedperformancedue to toohi gh l evel
di ff erence ofthe si gnal s
i n AS
I ncreased BSand MS Tx
Power
I ncreased BSTx power
Rel evantcel l s removed
f rom AS
I ncreasedTx powers
Reduced UL/DL capaci ty
too hi gh
too l ow
Reduced DLcapaci ty
I ncreasedMS Tx power
Reduced ULcapaci ty
too l ow
Frequent and delayed Hos (cells ping-pong in the
active set)
Frequent and delayed Hos (cells ping-pong in the
active set)
Presentation Title — 21 All rights reserved © 2004
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
repl acmentwi ndow
Acti vesetsubopti mal
Exceuti on ofunnecessary
HOs
MS Tx poweri ncrease
I ncreasedsi gnal i ngoverhead
BS Tx poweri ncrease
DL l oadi ncrease
too hi gh
too l ow
Reduced cal lsetup success
rate
UL l oadi ncrease
I ncreasedcal l drop orbl ock rate Reduced DL/ UL
total cel ltraffi c
Presentation Title — 22 All rights reserved © 2004
RRM optimization --- SHO optimization(4)
> Maximum active set size optimization
Max ASsi ze
Possi bl eunnecessary
branch addi t i on
Preventnecessary sof t
HO branchaddi t i on
Requi rehi gher Tx
power to a MS
I ncreasedBS Tx power
Reduced DLcapaci ty
Degradedperformancedue to toohi gh l evel
di ff erence ofthe si gnal s
i n AS
Reduced ULcapaci ty
Requi re hi gherTx power f rom
a MS
Degraded DLBLER
performance
Degraded ULBLER
performance
I ncreasedcal l drop/bl ock rate
too bi g
too smal l
I ncreased SHOoverhead
I ncreasedMS Tx power
Presentation Title — 23 All rights reserved © 2004
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 — 24 All rights reserved © 2004
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 — 25 All rights reserved © 2004
Coverage and Capacity issues---Coverage
Different service type([email protected], data@64,144,384kbps)supported with different link budget and thus different coverage range!
> How can coverage be deduced from link budget? link budget Max Path Losscell rangecoverage
> Generally, service coverage is uplink limited but system capacity may be limited by either uplink or downlink.
Hint: It’s critical to decide whether a specific area
should be planned for high data rate service coverage
or not
Hint: It’s critical to decide whether a specific area
should be planned for high data rate service coverage
or not
Service type Speech Data Data DataUplink bit rate(kbps) 12. 2 64 144 384Maximum transmit power(dBm) 21 21 21 21Antenna gain(dB) 0 0 2 2Body loss(dB) 3 0 0 0Transmit EIRP(dBm) 18 21 23 23Processing gain 25 17. 8 14. 3 10Required Eb/No(dB) 4 2 1. 5 1Target loading (%) 50 50 50 50Rise over thermal noise(dB) 3 3 3 3Thermal noise density(dBm/Hz) - 174 - 174 - 174 - 174Receiver noise figure(dB) 3 3 3 3Interference floor(dBm/Hz) - 168 - 168 - 168 - 168Receiver sensitivity(dBm) - 123. 1 - 117. 9 - 115 - 111. 1Rx antenna gain(dBi) 18. 5 18. 5 18. 5 18. 5Cable loss(dB) 2 2 2 2Fast fading margin(dB) 3 3 3 3Soft handover gain(dB) 2 2 2 2Isotropic power required (dBm) - 138. 6 - 133. 4 - 130 126. 6Allowed propagation loss(dB) 156. 6 - 154. 4 153. 4 149. 6
Presentation Title — 26 All rights reserved © 2004
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 Downlink limited
Limiting factor Uplink cell load BTS transmit power
Common reasons
Planned to a low uplink cell loadHigh BTS transmit power capabilityRelatively symmetric traffic
Planned to a high uplink cell loadLow BTS transmit powercapabilityGreater traffic on the downlink
IndicationsBTS transmit power not at maximumUplink cell load at maximum
BTS transmit power at maximumUplink cell load not at maximum
Solution Improve uplink load equationImprove downlink load equationImprove downlink link budget
Presentation Title — 27 All rights reserved © 2004
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 — 28 All rights reserved © 2004
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 Repeater
Application
Locating the entire logicalcell at a locatio normallyrequiring a long feeder run
Extending the coverageof an existing logical cell
Hardware atremote location
Tranmit power amplifiersand receiver front ends
Complete Rx and Tx chain forboth uplink and downlinkdirections
Connection to BS Optical link Usually a radio linkFunction Normal RF functions of the BS Non-intelligent retransmission
Presentation Title — 29 All rights reserved © 2004
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. closed-
loop 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 — 30 All rights reserved © 2004
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 deployme
nt
for typical Micro- cell deployme
nt
Sectorisation level Application
1 sector Microcell or low-capcity macrocell
2 sectorSectored microcell or macrocellproviding roadside coverage
3 sectorStandard macrocell configurationproviding medium capacity
4 or 5 sectorNot commonly used but may bechosen to support a specific traffic scenario
6 sector High-capacity macrocell configuration
for typical macro-cell deploymen
t
for typical macro-cell deploymen
t
Presentation Title — 31 All rights reserved © 2004
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 three-
sectored macro BS and 1.5Mbps/carrier/cell for a micro BS.
f 1 f1 f1
f1 f1 f1
f2
f1 f1 f1
f2
f2 f2 f2 f2 f2 f2
f1, f2 f1, f2 f1, f2 f1, f2 f1, f2 f1, f2
Conti nuous macro l ayerwi th f requency f1
Conti nuous macro l ayerwi th f requency f1
Sel ected areas wi th mi crocel l s wi th f requency f2
Conti nuous macro l ayerwi th f requency f1
Conti nuous mi cro l ayerwi th f requency f2
Both f requenci esconti nuousl y f1, f2used i n mi cro l ayer
No macro l ayer
> Example of WCDMA network evolution
An “umbrella” macro cell is best suited for high-
mobility users
An “umbrella” macro cell is best suited for high-
mobility users
Micro layer provides a very high capacity in a
limited area
Micro layer provides a very high capacity in a
limited area
Capacity enhancement
Capacity enhancement
Presentation Title — 32 All rights reserved © 2004
CELL DEPLOYMENT
> Case study of frequency reuse in micro- and macro- networks
f 2
f2
f2
f1 f1, f2 f1, f2 f1
Continuous macro layer with frequency f2
Continuous micro layer with frequency f1 and f2
f 1, f2f1 f1 f1 f1
f1 f1 f1 f1
f1, f2 f1, f2 f1, f2 f1, f2
Reference scenario
Continuous macro layer with frequency f2
Continuous micro layer with frequency f1
Continuous macro layer with frequency f1 and f2
Continuous micro layer with frequency f1
Continuous macro layer with frequency f2Continuous micro layer with frequency f1
selected microcells reusing macro frequency f2
Reuse of micro frequency in macro layer
Reuse of macro frequency in micro layer
Reuse of macro frequency in selected micro cells
Reusing a micro carrier on all macro-cells does
not bring any improvements in network
performance!
Reusing a micro carrier on all macro-cells does
not bring any improvements in network
performance!
Reusing a macro carrier on all micro-cells can
support 10% more users than the reference scenario,but extra
Power Amplifier needed!
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!
Micro-cells do not benefit from the other carrier reused from macro-cells if they still have unused
capacity on their own carrier!
macro carrier reuse is not worth while when micro-cells
locates near macro-cells!
macro carrier reuse is not worth while when micro-cells
locates near macro-cells!
Presentation Title — 33 All rights reserved © 2004
WCDMA Radio Network Planning
> overview
> Dimensioning
> Detailed planning
> Optimization aspects
> Adjacent carrier interference
> WCDMA & GSM Co-Planning
Presentation Title — 34 All rights reserved © 2004
WCDMA Radio Network Planning---Network planning process overview
DefinitionDefinition Planning and ImplementationPlanning and Implementation O&MO&M
NetworkConfi gurati on
andDi mensi oni ng
Requi rementsand strategyfor coverage,qual i ty andcapaci ty per
servi ce
Coveragepl anni ngand si tesel ecti on
Propagati onmeasurements
coveragepredi cti on
Si teacqui si ti on
Coverageopti mi sati on
Capaci tyRequi rements
Traffi cdi stri buti on
al l owedbl ocki ng/
qeui ng Systemfeatures
ExternalInterference
Anal ysi s
Identi fi cati onAdaptati on
Parameterpl anni ng
Area/Cel lspeci fi csetti ng
HandoverStrategi es
Maxi muml oadi ng
Other RRM
NetworkOpti mi sati on
SurveyMeasurements
Stati sti calperformance
anal ysi s
Qual i tyEffi ci encyAvai l abl i ty
Presentation Title — 35 All rights reserved © 2004
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 — 36 All rights reserved © 2004
WCDMA Radio Network Planning ---Dimensioning(2)
> Coverage analysis:• for the single-cell case*:
where
where is the received level at the cell edge, is the propagation constant, is the average signal strength threshold and is the standard deviation of the field strength and is the error function.
• for a typical macro-cellular environment – 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:
where is the maximum cell range and is the max path loss.
))1
(1()21
exp()(12
12 b
aberf
b
abaerfFu
))1
(1()21
exp()(12
12 b
aberf
b
abaerfFu 2
0
rPxa
20
rPxa
2
log10 10
enb
2
log10 10
enb
rPrP nn0x0x
erferf
)(log7.355.138 10 rLp )(log7.355.138 10 rLp rr pLpL
* “ Microwave Mobile Communications”, Jakes,W.C, John Wiley& Sons, 1974,126pp * “ Microwave Mobile Communications”, Jakes,W.C, John Wiley& Sons, 1974,126pp
Presentation Title — 37 All rights reserved © 2004
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 — 38 All rights reserved © 2004
WCDMA Radio Network Planning ---Dimensioning(4)> RNC dimensioning(cont’d)
• The number of RNCs needed to connect a certain number of cells
• The number of RNCs needed according to the number of BTSs to be connected
• the number of RNCs to support the Iub throughput
> Supported traffic (upper limit of RNC processing ability)
> Required traffic(lower limit of RNC processing ability)
> RNC transmission interface to Iub
2fillratebtsRNC
numBTSsnumRNCs
1fillratecellsRNC
numCellsnumRNCs
numSubsfillratetpRNC
PSdataTPCSdataTPvoiceTPnumRNCs
3
Presentation Title — 39 All rights reserved © 2004
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.
> Using Static simulator *• Static simulator flow
* “Static simulator for studying WCDMA radio network planning issues”,Wacker.A, Laiho-steffens.J,Sipila.K and Jasberg.M,VTC99’Spring pp2436-2440 * “Static simulator for studying WCDMA radio network planning issues”,Wacker.A, Laiho-steffens.J,Sipila.K and Jasberg.M,VTC99’Spring pp2436-2440
Gl obal i ni t i al i zat i on
I ni t i al i ze i terat i ons
Upl i nk i terat i on step
Downl i nk i terat i on step
Post processi ng
Graphi cal outputs
Coverage anal ysi s
I ni t i al i sati on phase
Combi ned UL/ DL i terati on
Post Processi ng phase
Presentation Title — 40 All rights reserved © 2004
Creating a plan/load maps
Importing/creatingand editing sites and
cells
Link loss calculationPropagation model
tuning
Importingmeasurements
Importing/generating and
refining traffic layers
Defining servicerequirements
WCDMAcalculations
Analysis
Quality of Service
Neighbour cellgeneration
reporting
WCDMA Radio Network Planning ---Detailed Planning(2)> Example of RNP tool workflow
A plan usually includes parameter settings for the planned network elements such as:•Digital map& its properties•Target planning area propagation models•Antenna models•Selected radio access technology•BTS types and site/cell templates
A plan usually includes parameter settings for the planned network elements such as:•Digital map& its properties•Target planning area propagation models•Antenna models•Selected radio access technology•BTS types and site/cell templates
Site location,site ground height number of cells and antenna directionSite location,site ground height number of cells and antenna direction
Traffic planning:• Bearer service type and bit rate,• average packet call size and retransmission rate,• busy-hour traffic amount and traffic density for each service,• mobile list and WCDMA calculation
Traffic planning:• Bearer service type and bit rate,• average packet call size and retransmission rate,• busy-hour traffic amount and traffic density for each service,• mobile list and WCDMA calculation
Cite/BTS hardware template may include:•Maximum number of wideband signal processors•Maximum number of channel units •Noise figure•Available Tx/Rx diversity types
Cite/BTS hardware template may include:•Maximum number of wideband signal processors•Maximum number of channel units •Noise figure•Available Tx/Rx diversity types
A WCDMA cell template may include cell layer type,channel model,Tx/Rx diversity options,power settings, maximum acceptable load, propagation model,antenna infomation and cable losses
A WCDMA cell template may include cell layer type,channel model,Tx/Rx diversity options,power settings, maximum acceptable load, propagation model,antenna infomation and cable losses
To verify that the planned coverage, capacity and QoS criteria can be met with te current network deployment and parameter settings:• Run UL/DL iterations to calculate tx powers for MS and BS• Snapshot analysis for interference and coverage estimation• Optimizing dominance
To verify that the planned coverage, capacity and QoS criteria can be met with te current network deployment and parameter settings:• Run UL/DL iterations to calculate tx powers for MS and BS• Snapshot analysis for interference and coverage estimation• Optimizing dominance
Propagation models:•Macro cell---Okumura-Hata model•Micro cell---Walfisch-Ikegami model
Propagation models:•Macro cell---Okumura-Hata model•Micro cell---Walfisch-Ikegami model
Presentation Title — 41 All rights reserved © 2004
WCDMA Radio Network Planning ---Detailed Planning(3)---UL/DL iteration steps
Set ol dThreshol ds to thedefaul t/ new coverage threshol ds
Cal cul ate new coveragethreshol ds
Check UL l oadi ng and possi bl y moveMSs tonew/other carri er or outage
Eval uate UL break cri teri on
Connect MSs to best server, cal cul ateneeded MS TxPower and SHO gai ns
Cal cul ate adj usted MS Txpowers, check MSs for outage
convergence
Cal cul ate new I =I _oth/ I _own
DL i terati on step
Post processi ng
END
i ni t i al i zati on
If n
o co
nver
genc
e
I ni t i al i ze del ta_C/ I _ol d
Al l ocate the CPI CH powers
Cal cul ate the recei ved Perch l evel s anddetermi ne the best server i n DL
Cal cul ate the MS sensi t i vi t i es
Determi ne the SHO connecti ons
Cal cul ate target C/ I ’ s
ful fi l l ed
UL i terati on step
Check CPI CH Ec/ I o cal cul ate theC/ I for each connecti on
cal cul ate C/ I for each MS
Post processi ng
END
Gl obal i ni t i al i zati on
Cal cul ate i ni t i al TX powers for al l l i nks
Check UL and DL breakcri teri a
Adj ust TX powers ofeach remai ni ng l i nk
accordi ng to del ta_C/ I
Update del ta_C/ I _ol d
I f not ful fi l l ed
UL iteration stepsUL iteration steps DL iteration stepsDL iteration steps
Presentation Title — 42 All rights reserved © 2004
WCDMA Radio Network Planning ---Adjacent Channel Interference
> Adjacent Channel Interference(ACI) situation • Adjacent Channel Leakage Power Ratio(ACLR)
– the ratio of the transmitted power to the power measured in an adjacent channel
• Adjacent Channel Selectivity(ACS)– 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
channel interference power
NodeB@frequency1
0dB
BS ACP
Rx
0dB
MS ACLR
Tx
0dB
BS ACP
Rx
0dB
MS ACLR
Tx
f1
f1
f1f2
f2
f2
f1
wanted si gnal
f2
wanted si gnal
BS sel ecti vi ty
MS l eakage NodeB@frequency2
UL adjacent channel interference situationUL adjacent channel interference situation
Presentation Title — 43 All rights reserved © 2004
WCDMA Radio Network Planning ---Adjacent Channel Interference
> 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
NodeB@frequency1
0dB
BS ACLR
Rx
0dB
MS ACP
Tx
0dB
BS ACLR
Rx
0dB
MS ACP
Tx
f1
f1
f1f2
f2
f2
f1
wanted si gnal
f2
wanted si gnal
BS l eakage
MS sel ecti vi ty NodeB@frequency2
DL adjacent channel interference situationDL adjacent channel interference situation
Presentation Title — 44 All rights reserved © 2004
WCDMA Radio Network Planning ---Example of Worst ACI case> Worst ACI case when sites of different operators not co-
located
Dead Zonefor Operator 1
Operator 1 MSMax. TX power
si gnalsi gnal
ACIACI
Operator 1MS
Operator 2 Mi cro Cel lhi gh TX power
Operator 2 Mi cro Cel l
Operator 1 Macro Cel l
Assuming ACS and ACLR of values 33dB and 45dB respectively, the coupling C between the carriers can be calculated as:
Assuming ACS and ACLR of values 33dB and 45dB respectively, the coupling C between the carriers can be calculated as: dBC 7.32)1010(log10 10/4510/33
10
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 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.
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 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.
dBmdBdBdBm 7.647.325321
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
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
if we further consider a DL Tx Eb/No requirement of 8dB, the transmit power would need to be
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
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
if we further consider a DL Tx Eb/No requirement of 8dB, the transmit power would need to be
dBmACSdBMCLdBdBm 7.58)(7.32)(5327
dBdBdBmdBdBdBmLp 138)6103(25521
dBmdBdBdBdBmptx 3.621382587.58
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.
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.
Presentation Title — 45 All rights reserved © 2004
WCDMA Radio Network Planning ---Optimization aspects(1)> Guidelines for Radio Network Planning to avoid ACI in multi-
operator 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 — 46 All rights reserved © 2004
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 downlink-
limited 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
* “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 — 47 All rights reserved © 2004
> Examples of maximum path losses with existing GSM and WCDMA system
WCDMA-GSM Co-Planning Issues
GSM900/speech
GSM1800/speech
WCDMA/speech
WCDMA/144kbps
WCDMA/384kbps
Mobile transmission power[dBm] 33 30 21 21 21
Receiver sensitivity[dBm]1
-110 -110 -124 -117 -113
Interference margin[dB]2
1 0 2 2 2
Fast fading margin[dB]3
2 2 2 2 2
Base station antenna gain[dBi]4
16 18 18 18 18
Body loss[dB]5
3 3 3
Mobile antenna gain[dBi]6
0 0 0 2 2Relative gain from lowerfrequency compared to UMTS
frequency[dB]7
11 1
Maximum path loss[dB] 164 154 156 154 150
1WCDMA 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.
3The fast fading margin for WCDMA includes the macro diversity gain against fast fading.
4The atenna gain assumes three-sector configuration in both GSM and WCDMA.
5The body loss accounts for the loss when the terminal is close to the user's head.
6 A 2.0dBi antenna gain is assumed for the data terminal.
7The 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.
Presentation Title — 48 All rights reserved © 2004
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
GSM 900935~960MHz
UTRATDD
UTRA FDD1920~1980
1900~1920MHz
f GSM=950~960MHz
f
Second-order harmonic distortion from GSM900
falling into WCDMA band
Second-order harmonic distortion from GSM900
falling into WCDMA band
Presentation Title — 49 All rights reserved © 2004
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.– Inter-Modulation Distortion(IMD):caused by non-linearities of RF
components of transmitter or receiver.
XMD is proportional to the square of transmitting
power and very sensitive to the Tx power of the MS!
XMD is proportional to the square of transmitting
power and very sensitive to the Tx power of the MS!
Typically in micro-cells
and could be reduced by
guard band.
Typically in micro-cells
and could be reduced by
guard band.
WCDMA BS GSM BS
ACI to WCDMA BS
ACI f romGSM BS
I MD at theWCDMA MS
Crossmodul ati on(XMD)
WB emi ssi onf rom GSM BS
Third-order IMD with mixture of products of
the GSM carrier frequencies f1 and f2:
2f1-f2 or 2f2-f1
Third-order IMD with mixture of products of
the GSM carrier frequencies f1 and f2:
2f1-f2 or 2f2-f1
Presentation Title — 50 All rights reserved © 2004
GSM GSM GSM
WCDMA WCDMA WCDMA
GSM GSM
Urban area rural area
WCDMA-GSM Co-Planning Issues
Eval uate the qual i ty ofthe exi st i ng 2G network
Space avai l abl e for one-to-one reuse
Assure the coverage foral l WCDMA servi ces
Defi ne traffi cdi stri buti on rul es
between systems
Defi ne handover rul esbetween systems
Run combi ned 2G andWCDMA anal ysi s
Handover GSMWCDMA for capacity extension or service optimization
Handover GSMWCDMA for capacity extension or service optimization
Handover WCDMA-GSM for coverage extension
Handover WCDMA-GSM for coverage extension
Antenna sharing and co-located sites could be preferable.
Antenna sharing and co-located sites could be preferable.
Presentation Title — 51 All rights reserved © 2004
Co-existing TDD & FDD modes ---UTRA TDD mode
> Some key parameters for the UTRA FDD and TDD modesRather 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.
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.
UTRA FDD UTRA TDDFrame structure 15 slots/frame 15 slots/frameFrame length 10 ms 10 msChip rate 3.84 Mcps 3.84 McpsUplink spreading factors 4~512 1~16Number of parallel ULcodes per user 1 or 2Downlink spreading factors 4~512 1~ 16Number of parallel DLcodes per user 1~6 1~16Modulation QPSK QPSK
Power control update rate 1500Hz
theretically up to 800Hz;inpractice, only 100Hz in DLand 100Hz or possibly 200Hzin UL
Handover soft and hard hard onlyDynamic channel allocation N/A slow and fastIntra-cell interferencecancellation
support for advancedreceivers at base station support for joint detection
Not as fast as to follow fast fading
pattern!
Not as fast as to follow fast fading
pattern!
Presentation Title — 52 All rights reserved © 2004
Co-existing TDD & FDD modes---Example of TDD RLB uplink/downlink
Example TDD link budget foruplink(RxD=receive diversity)
Voice12.2kbpsRxD
Voice12.2kbpsNo RxD
NRT data128kbpsRxD
NRT data128kbpsNo RxD
Transmitter(mobile)Max.Tx Power(dBm) 21 21 24 24MS antenna gain(dBi) 2 2 2 2Body loss(dB) 3 3 0 0EIRP(dBm) 20 20 26 26Receiver(base station)Number of used slots in TDD 1 1 1 1Thermal noise density(dBm/Hz) -174 -174 -174 -174Base station receiver noisefigure(dB) 5 5 5 5Desensitisation 0 0 0 0Receiver noise density(dBm/Hz) -169 -169 -169 -169Receiver noise power(dBm) -103.2 -103.2 -103.2 -103.2Interference margin(dB) 8 8 8 8Receiver interferencepower(dBm) -95.9 -95.9 -95.9 -95.9Total effective noise+interference(dBm) -95.2 -95.2 -95.2 -95.2Processing gain(dB) 12 12 2.4 2.4Required Eb/No(dB) 1.7 8.6 0.3 6.4Receiver sensitivity(dBm) -105.5 -98.6 -97.3 -91.2BS antenna gain(dBi) 4 4 4 4Cable loss in the basestation(dB) 0 0 0 0Fast fading margin(TPC headroom) (dB) 6.3 6.3 3.4 3.4Max.path loss(dB) 123.2 116.3 123.9 117.8
slotinchips
periodguardmidambleslotinchipsk
R
WGP __
___
15
Greater Eb/No difference between with or without RxD!
Greater Eb/No difference between with or without RxD!
Smaller Max path loss than that of FDD scenario TDD cells
have smaller radius!
Smaller Max path loss than that of FDD scenario TDD cells
have smaller radius!
Example TDD link budget fordownlink(No TxD)
Voice12.2kbps
NRT data128kbps
Transmitter(mobile)
Max.Tx Power(dBm) 24 24
BS antenna gain(dBi) 4 4
Cable loss in BS(dB) 0 0
EIRP(dBm) 28 28
Receiver(mobile)
Number of used slots in TDD 1 1
Thermal noise density(dBm/Hz) -174 -174Mobile station receiver noisefigure(dB) 9 9
Receiver noise density(dBm/Hz) -165 -165
Receiver noise power(dBm) -99.1 -99.1
Interference margin(dB) 8 8Receiver interferencepower(dBm) -91.9 -91.9Total effective noise+interference(dBm) -91.1 -91.1
Processing gain(dB) 12 2.4
Required Eb/No(dB) 9.4 6.7
Receiver sensitivity(dBm) -93.7 -86.8
Mobile antenna gain(dBi) 2 2
Body loss(dB) 3 0Fast fading margin(TPC headroom) (dB) 5.5 3.1
Max.path loss(dB) 115.2 113.7
Presentation Title — 53 All rights reserved © 2004
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
receiving, especially at cell borders.– Cannot be avoided by network planning,but may benefit from
– DCA and radio resource management– Power control
• BS to BS interference---when BS1 is transmitting while BS2 is receiving
– 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 — 54 All rights reserved © 2004
Co-existing TDD & FDD modes --- TDD/FDD interference> TDD-FDD Interference scenarios/solutions
• 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
UTRA TDDTx/ Rx
UTRA FDD/ UL Sate-l l i te
UTRATDD
Tx/Rx
1900 1920 1980 2010 2025 (MHz)
Interference mainly between TDD and FDD/UL
frequency bands!
Interference mainly between TDD and FDD/UL
frequency bands!
Presentation Title — 55 All rights reserved © 2004
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!
From the service point of view, UTRA TDD is most suited for small cells and high data rate services!
Thanks!