WCDMA Principles and Planning 16-19/05/2007 Yüksel,Ülgen,Uğur,Ardıç
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WCDMA Principles andPlanning
16-19/05/2007Yüksel,Ülgen,Uğur,Ardıç
WCDMA Principles and Planning• Introduction – Mobile Technologies• WCDMA
– Basics– System Architecture
• WCDMA Principles– Codes– Modulation– Processing Gain– Eb/No– RAB
• System Overview– Physical Channels– Idle Mode Behaviour– HO– Power Control– Cell Breathing– Rake Receiver
WCDMA Principles and Planning• Radio Resource Management
– Admission Control– Congestion Control– RRC States
• Propagation Models• Linkbudgets (UMTS vs GSM)• Npole• General Dimensioning
– Dimensioning Example– 8 Parameter
• Turkcell UMTS planning strategy– Cell Detailed Planning
• Planning Tips• Analysing with Asset
– Static Analysis– Monte Carlo
• HSDPA Basics• HSUPA Basics
Mobile Technologies
PDC
GSM
TDMA
CDMA OneCDMA20001x EV-DO
W-CDMA
EDGE
TD-SCDMA
CDMA20001x RTT
GPRS
CDMA20001x EV-DV
HSDPA
TD-CDMA
3G/UMTS5%
90%+9%
13%
73%
Mobile Technology Evaluation
3GPP Evaluation
• HSDPA
• Enh UL• HSDPA
Ph2
• MBMS• Enh UL
Ph2
• 3G LTE
2004-5 2006
R99
2007 2008-9
RADIO ACCESS TECHNOLOGIES
HOW?
RADIO ACCESS TECHNOLOGIES
f1 f2 f3 f4
PBand Genişliği
f1 f2 f3 f4t1
t2t3
PBand Genişliği
FDMA
TDMA
CDMA
f1 f2
kod1kod2kod3kod4kod5
kod1kod2kod3kod4kod5
Band Genişliği
kod x
t
P
t
P
FDMAFrequency Division Multiple Access
FrequencyFrequency
TimeTime
PowerPower
UserUser
FDMAFDMA
• Each user is assigned to one frequency within the spectrum
• Applications– Analog Cellular Systems
• AMPS• NMT• TACS
– Analog Satellite Communication
TDMATime Division Multiple Access
TDMATDMA • Each user is assigned to one time slot from a frequency
• Applications– Digital Cellular Systems
• GSM,• D-AMPS
PowerPower
FrequencyFrequency
TimeTime
UserUser
CDMACode Division Multiple Access
• Each user can use the whole frequency band every time– “Spread Spectrum”
technology– 1 user = 1 pseudo random code– Other users = Interference
• Applications– Digital Cellular Systems– Stallite Communications
FrequencyFrequency
TimeTime
PowerPower
UserUser
WCDMA
WCDMA BASICS
Introduction to W-CDMA
Engl
ishTurkish
French
They will all be ableto communicate intheir own language(code) if their voicelevels (received power)are about the same.
If someone speaks tooloud, the others willnot be able to understandand communicateat the same levels anymore
GSM vs. UMTSThe major differences
• Wider channel bandwidth 200 kHz -> 5000 kHz– Thermal noise will be higher
• Different users in the cell will have an effect upon each other.– The resources are shared in the system. If one user consumes a
lot of resources, the other users will suffer.• Fast power control (2 Hz for GSM and 1500 Hz for
UMTS)– The fast power control in UMTS is required in order to make sure
that no user consumes more recourses than absolutely necessary.
• An interference margin in the link budget is introduced in order to make the design for a loaded scenario.
• It’s more fun
UMTS Standards
UTRA-FDD (W-CDMA); wide area coverage, up to 384 kbit/s
Band Width is 60 Mhz.12 sub band with 5 Mhz. Band width were defined.2 frequency bands are used for uplink and downlink
separately. (60 Mhz. * 2)
UTRA-TDD (TD-CDMA); for indoor coverage and interactive applications, up to 2 Mbit/s
There are 2 frequency bands with total 35 Mhz. Band Width
TDD FDD uplink TDD1900 1980 2010 20251920
FDD downlink2110 2170 2200
FDD- Frequency Division Duplex
2 carriers are used for one connection as uplink and downlink. Carrier band width is 5 Mhz.Total Band width were defined as 60 Mhz. FDD are used for wide area coverage, because it’s designed to serve high number of subscribers rather than high throughput.It’s not suitable for high speed internet application because band widths used for downlink and uplink are fixed.
TDD- Time Division Duplex1 carrier is used for one connection.Carrier band width is 5 Mhz.2 frequency bands were defined with 20 Mhz. and 15 Mhz.TDD is suitable for high speed internet application, uplink and downlink data are transferred in one frequency band and according to required data rate band widths can change.TDD is designed for indoor coverage, it’s not very resilient to inteference so it cannot be used for wide area coverage
WCDMA Frequency Band in Europe
1900 202520101920 1980FDD- UL 21702110 FDD- DL
60MHz 60MHz20MHz 15MHz
1 Carrier = 5 MHz
60/5 = 12Total number of FDD carriers
Total number of TDD carriers (20+15)/5 = 7
Turkey 3G Licenses
WCDMA System Architecture
UMTS System Architecture
PacketPacketCoreCore
NetworkNetwork
Node B
Node B
Node B
CircuitCircuitSwitchedSwitchedNetworkNetwork
Iu (PS)
Iu (CS)
RNCIub
Iur
Node B
Node B
SGSN
Iub RNC
MSC
UMTS together with GSMPSTN/ISDN
Internet/Intranet
GSM/UMTS Core NetwokA-Interface Iu-Interface
ISUP TCP/IP
UMTS Access (UTRAN)
GSM Access (BSS)
GSM UMTSGSM/UMTS
• Node B or BTS (Base Transceiver Station)
Node B(BTS)
Uu
Iub (ATM)
UERNC
Main Node B functions:• Call Processing• Radio access• Performance Monitoring• Random Access detection• Air Interface Transmission/Reception• Modulation/Demodulation• W-CDMA Physical Channel Coding• Micro Diversity• Error Handling• Closed Loop Power Control
• RNC (Radio Network Controller)
RNC
ATMBackbone
Node B(BTS)
Iu ATMBackbone
Iub (ATM)
Iur
Core Network
Main RNC functions:• Radio Resource Management• User Mobility Handling• Interfaces • Macro Diversity
• Channel Allocation• Power Control• Handover Control• Ciphering• Open Loop Power Control
User Equipment
USIMCu
User Equipment
Maximum Tx Power:• 33 dBm = 2 W• 27 dBm = 0.5 W• 24 dBm = 0.25 W• 21 dBm = 0.125 W
Mobile Equipment
Mobile Termination
Radio Transmission
Terminal Equipment
End to End Application
WCDMA Principles
WCDMA BASIC PRINCIPLES
Spread signal by means of codes
12,2 KHZVoice service
CODE
3,84MhzBandwith of coded signal
code x
t
P
tP
Spread Spectrum
Pow
er
Frequency
Data Modulation
Spreading Despreading
Demodulation
Spread Spectrum
Interference Rejection
Processing Gain
Gp Gp
{ } dB 10384
3840Log10kbps 384 =⎥⎦⎤
⎢⎣⎡==pG{ } dB 25
2.123840Log10VoiceLog10 =⎥⎦
⎤⎢⎣⎡==
⎥⎥⎦
⎤
⎢⎢⎣
⎡=
jp R
WG
Modulation schemes
jQ
I
XX
X X
0001
11 10
Z = I +jQ
jQ
I
XX
X
X
1
0
1
0X
X
X
X
Uplink Downlink
Quadrature Phase Shift KeyingQPSK
Dual Binary Phase Shift KeyingBPSK
CODES
WCDMA CODES
WHICH BTS ?WHICH MS ?WHICH DATA RATE?HOW MANY APPLICATIONS?
WHICH BTS ?WHICH MS ?WHICH DATA RATE?HOW MANY APPLICATIONS?
•PN (SCRAMBLING) CODE• -(LONG CODE)
•ORTHOGONAL CODE -Spreading-(SHORT CODE)
Data (1)„chipped“ „chipped“ (2)
Bit rate Chip rate Chip rate
Cha
nnel
izat
ion
code
Scra
mbl
ing
code
(1)
(2)
BitrateChiprateFactor Spreading =
Channelization and scrambling codes
Spreading Factor Gain-1
Rb
W=3,84MHz
SF= W/Rb
Unspread signal
Spread signal
Power density
Frequency
Background Noise
Spreading Factor Gain-2
Rb Change by serviceSF= W/Rb
W 3,84Mbit (fix)
User bit rate Kbit W=3840Kbit
SF SF gaindB
15 3840 256 24
30 3840 128 21
60 3840 64 18
120 3840 32 15
240 3840 16 12
480 3840 8 9
960 3840 4 6
1920 3840 2 3
3840 3840 1 0
ORTHOGONALVARIABLE CODE
Spreading Factor Gain-3
SF= ? 4
SF GAIN DEPEND ON USER DATA RATE
ORTHOGONAL VARIABLE SPREADING FACTOR (OVSF)
•SF Gain depend on OVSF codes.
Chip Rate = 3.840 Mcps
480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s 480 kb/s
1
11 10
1111 1100 1010 1001
11111111 11110000 11001100 11000011 10101010 10100101 10011001 10010110
OVSF Code Tree
SF=8
SF=4
SF=2
SF=1
960 kb/s
1920 kb/s
User data
480 kb/s 480 kb/s 480 kb/s 480 kb/s
1.92 Mb/s
Chip Rate = 3.840 Mcps1
11 10
1111 1100 1010 1001
11111111 11110000 11001100 11000011 10101010 10100101 10011001 10010110
= Unusable Code Space
SCRAMBLING CODES
USAGE•UL: Separation of Terminals
•DL: Separation of Cells
NUMBER OF CODES
•UL: Several Millions
•DL: 512
CODE FAMILY
•Long 10 ms Code: Gold Code
Downlink Scrambling Codes• Possibility of 262,143 different downlink scrambling codes • Only 8192 different scrambling codes have been defined
Primary scrambling code
8192 ...
Cell #1
Cell #512
...
Secondary scrambling code #1Secondary scrambling code #2
Secondary scrambling code #15
8192 scrambling
codes
512 sets of 1 primary and 15
secondary codes
512 primary codes divided into 64 groups
SCRAMBLING CODE
CODE USING
Uplink : Distinquish Mobil Terminal.Downlink: Distinquish each cell.
PN3 PN4
PN5 PN6
PN1 PN1
NodeB Cell “1” PN code 1
PN2 PN2
NodeB cell “2” PN code 2
ORTHOGONALITY
Orthoganality = 0 Orthoganality = 0,5 Orthoganality = 1Orthoganality = 0 Orthoganality = 0,5 Orthoganality = 1
Uplink Downlink
•UL scrambling codes has not got orthogonality
•DL scrambling codes has got orthogonality
Radio Access Bearer (RAB)
UMTS and Radio Access BearerServices
UMTS Network
TETE MTMT WCDMA RAN
WCDMA RAN CN Iu
edgenode
CN Iuedgenode
CNGateway
CNGateway
TETE
End-to-End Service
TE/MT Local Bearer Service
External Bearer ServiceUMTS Bearer Service
RAB CN Bearer Service
Bearer Service Classes
Streaming class: preserve time relation between entities of the stream e.g. video streaming
Real time applications:
Conversational class: preserve time relation of the entities with low delay e.g. voice call, video call
Background class: destination is not expecting data, preserve payload e.g. email
Interactive class: request/response pattern with preserved payload e.g. Internet browsing
Non-real time applications:
RABs supportedConversational Speech 12.2 kbps Circuit switched
Conversational CS Data 64 kbps Circuit switched
Streaming 57.7 kbps Circuit switched
Interactive Variable rate Packet Switched
RACH/FACH, 64/64, 64/128, 64/384
Combination of Conversational AMR and Interactive 64/384Multi-RAB
Mapping of UMTS Services to RABs
Eb/No
• Eb/NoW-CDMATDMA-GSM
NC
CEb/NoC
I
1
1
11
11
1
2
2
2
2
3
3
3
3
32
4
4
4
4
4
Power spectrum
Eb/N0 what is it ?• Eb/N0 is the ratio of the energy/bit (Eb) to the spectral
noise density (N0)– Simplified, the Eb/N0 can be seen as a basic measure
of how strong the signal is at the receivers input.Suppose we are going to design a digitalcommunication system where the BER notcan be more than 10-3. The modulation method used is DBPSK.
According to the graph we need an Eb/N0of at least 7.9 dB in order to fulfill the criteria
This 7.9 dB will then be our “coverage level”for this quality.
• Eb/No
Maximum noise level
Eb/No required
Power spectrum
Ebit
gain
Unwanted power from other sources
Echip
Eb/No = C / I x processing gain
Available power to share between users
• Eb/No & Power ControlPower spectrum
Ebit
Maximum noise level
Eb/No required
Unwanted power from other sources
Eb/No
Power control
Power , Interference , Capacity .
Ec/N0, Ec/I0• CPICH Ec/I0, CPICH Ec/N0
• The Ec/I0 denotes the received chip energy relative to the total power spectral energy
• Ec/I0 is often used to indicate the quality of digital signals that do not carry any “user data” - like the CPICH for example.
System Overview
Physical Channels
Channels and Layers
MAC
MM
Duplication Avoidance
RRC
BMCPDCP
RLC
PHYLayer 1
Layer 2
Layer 3
CC
LogicalChannels
TransportChannels
Non Access Stratum (NAS)
Access Stratum (AS)
Control plane (C-plane)
User plane (U-plane)
Core Network
UTRAN Protocols• RRC – Radio Resource Control
– Main functions:• Responsible for establishing, reconfigure and releasing connections between the mobile and the network.• Routes the higher layer SDU (Service data units) to RLC, PDCP or BMC depending on its content.
• PDCP - Packet Data Convergence Protocol– Main functions
• Compress the packet data received from higher layers• etc.
• BMC - Broadcast/Multicast Control– Main functions:
• Responsible for handling the broadcasting/multicasting messages – SMS etc.• RLC – Radio Link Control
– Main functions (three different operation modes)• Transparent mode
– Segmentation and reassembly– Transfer of user data
• Un-acknowledged mode– As in transparent mode– Ciphering– Etc.
• Acknowledged mode– As in Unacknowledged– Flow control– etc
• MAC – Media Access Control– Main functions
• Mapping between logical channels/transport channels and transport channel selection• Multiplexing of PDUs Packet Data Unit) to/from common and dedicated channels• etc.
Channels and their mapping
BC
H
RLC Layer(Radio Link Control)
MAC Layer(Media Access Control)
PHY(Physical Layer)
Air Interface
BC
CH
CP
ICH
CC
CH
PC
CH
FAC
H
PC
H
P-CC
PCH
S-CC
PCH
SC
H
AIC
H
PIC
H
DP
CH
PR
AC
H
DP
CC
H
DP
DC
H
DC
HD
TCH
DC
CH
RA
CH
CC
CH
DC
HD
TCH
DC
CHLogical Channels
Transport Channels
Physical Layer Structure• UMTS Frame Format
Slot = 0.667 ms = 2560 chips
Slot #0 Slot #1 Slot #j Slot #14
Frame #0 Frame #1 Frame #i Frame #4095
Frame = 15 slots = 10 ms = 38400 chips
Super frame = 4096 frames = 40.96 seconds
62
Common Pilot Channel (CPICH)
Pilot Symbol Data (10 symbols per slot)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
1 timeslot = 2560 Chips = 10 symbols = 20 bits = 666.667 uSec
63
Primary Common Control Physical Channel (P_CCPCH)
Spreading Factor = 2561 Slot = 0.666 mSec = 18 broadcast data bits / slot
Broadcast Data (18 bits)S-SCH
2304 Chips256 ChipsSCH
P-SCH
1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSec
64
Secondary Common Control Physical Channel (S_CCPCH)
Spreading Factor = 256 to 41 Slot = 0.666 mSec = 2560 chips = 20 * 2k data bits; k = [0..6]
20 to 1256 bits0, 2, or 8 bits 0, 8, or 16 bits
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
DataTFCI or DTX Pilot
1 Frame = 15 slots = 10 mSec
65
Page Indication Channel (PICH)– Spread with SF=256 Channelization code– Each UE looks for a particular PICH time slot– A paging indicator set to “1” indicates that the UE
should read the S-CCPCH of the corresponding frame.
288 bits for paging indication 12 bits (undefined)
b1b0 b287b288 b299
One radio frame (10 ms)
66
Acquisition Indicator Channel (AICH)Transmits Acquisition Indicators in response to UE Access AttemptsAI’s are derived from the UE’s Access Preamble Signature
Identifies the UE which is the target of the AICH response
1024 chips
AS #0 AS #1 AS #i AS #14
a1 a2a0 a31a30
AI part
(Transmission Off)∑=
=15
0,
sjssj bAIa
AS #14 AS #0
20 ms
67
Downlink Dedicated Physical Data Channel (DPDCH)
Downlink Dedicated Physical Control Channel (DPCCH)
1 Slot = 0.666 mSec = 2560 chips = 10 x 2^k bits, k = [0...7]SF = 512/2k = [512, 256, 128, 64, 32, 16, 8, 4]
DPDCH DPCCHDPDCH DPCCH
Data 2TFCIData 1 TPC Pilot
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
SUMMARY FOR PHYSICAL CHANNELS
Common Pilot Channel (CPICH): The CPICH continuously sends the SC for the cell. It also aids channel estimation for cellselection/reselection and handover for the UE.
Primary Common Control Physical Channel (P_CCPCH): This channel is used to carry broadcast data and thesynchronization channels. The Channelization Code CP_CCPCH,256,1 is always used for this channel since it needs to be decoded by all UEs.
The Secondary Common Control Physical Channel(S_CCPCH): Uses a different Channelization Code depending on weather it is carrying a paging, signaling or user data.
Paging Indicator Channel (PICH): This channel is used in conjunction with the paging that is carried by S_CCPCH
The Acquisition Indicator Channel (AICH): Acknowledges that the RBS has acquired the RACH preamble by echoing theUE’s Random Access signature.
Physical Random Access Channel (PRACH): The PRACH is used to carry the 20 msec Random Access message on the I branch of the modulator and L1 control (Pilot and TFCI) on the Q branch
Dedicated Physical Data/Control Channel (DPDCH/DPCCH): The DPDCH carries user traffic, Layer 2 overhead bits andLayer 3 signaling data. The DPCCH carries Layer 1 control bits, which are as follows:
• Pilot bits, which are used by the receiver to measure the channel quality• Transmission Power Control (TPC) bits, which are used to adjust the power of the UE• Transport Format Combination Indicator (TFCI) bits,which are used to tell the receiver what is being carried by thisphysical channel.
The DPDCH and DPCCH are not time multiplexed, as they are in the downlink, but instead are fed into the I and Q inputs of a complex spreader
69
Downlink Data RatesVariable Data Rates on the Downlink:
ExamplesBits/Frame Bits/ Slot
DPCCH
Channel BitRate
(kbps)
ChannelSymbol
Rate(ksps)
SF
TOTAL DPDCH DPCCH TOTAL DPDCH
TFCI TPC PILOT
15 7.5 512 150 60 90 10 4 0 2 4
120 60 64 1200 900 300 80 60 8 4 8
1920 960 4 19,200 18,720 480 1280 1248 8 8 16
Coded Data 1.920 Mb/sec
(19,200 bits per 10 mSec frame)S/P
Converter
Channel Coding(OVSF codes at 3.84 Mcps)
960 kbps/sec
Downlink Spreading
S→ P Cch Cscramb
p(t)
p(t)
cos(wt)
sin(wt)
I
DPDCH&
DPCCH
Q
One radio frame, T f = 10 ms
TPCN TPC bits
Slot #0 Slot #1 Slot #i Slot #14
T slot = 2560 chips, 10*2 k bits (k=0..7)
Data2N data2 bits
DPDCHTFCI
N TFCI bitsPilot
N pilot bitsData1
N data1 bits
DPDCH DPCCH DPCCH
The same channelization code is applied to both I and Q!
Uplink Spreading
*j p(t)
p(t)
DPDCH
DPCCH
Chc
ChD
I + jQ
Scramb
cos (w t)
sin (wt)
PilotN pilot bits
TPCN TPC bits
DataN data bits
Slot #0 Slot #1 Slot # i Slot #14
T slot = 2560 chips, 10 bits
1 radio frame: T f = 10 ms
DPDCH
DPCCHFBI
N FBI bitsTFCI
N TFCI bits
T slot = 2560 chips, N data = 10*2 k bits (k=0..6)
Different channelization codes areapplied to DPDCH and DPCCH
Idle Mode Behaviour
Paging in UMTS• There are 2 paging procedures in UMTS
– One procedure for the mobiles in Idle.– One procedure for the mobiles in Cell_DCH
(i.e. The mobile has a dedicated channel)
Common Channel Connected
PAGING TYPE2(sent from the RNC)
PAGING TYPE1(sent from the RNCafter reception ofA PAGING from core)
Cell re-selectionThere are 3 criterions (intra frequency and non HCS) that must be fulfilled in order for a intra cell reselection to take place:
– The S-criteria must be fulfilled– The cell should be ranked as the best– The new cell is better ranked than the serving cell during a time period of
Treselections and at least 1 second has elapsed since the mobile camped on the current serving cell.
S-criterionThe mobile measures the CPICH Ec/I0 and CPICH RSCP of the serving celland evaluates the cell selection criterion S for the serving cell at least every DRX cycle.
FDD cells: Srxlev > 0 AND Squal > 0GSM cells: Srxlev > 0
where:
Squal = Qqualmeas - QqualminSrxlev = Qrxlevmeas - Qrxlevmin - Pcompensation
Pcompensation = max(UE_TXPWR_MAX_RACH – P_MAX, 0)
Squal -> CPICH Ec/I0Srxlev -> CPICH RSCP
Cell ranking criterion - R
Rs = Qmeas,s + QhystsRn = Qmeas,n - Qoffsets,n
Re-selected cell: 1. Fulfills the S criterion2. Is the highest ranked
Qmeas = CPICH RSCP (RxLev) : Qhyst1s & Qoffset1s,n
Qmeas = CPICH Ec/I0 : Qhyst2s & Qoffset2s,n
Squal Cell selection quality value (dB).
Srxlev Cell selection RX level value (dB)
QqualmeasMeasured cell quality value. The quality in the received signal expressed in CPICH Ec/I0 (dB).
QrxlevmeasMeasured cell RX level value. The level in the received signal is expressen in CPICH RSCP (dBm)
Qqualmin Minimum required quality in the cell
Qrxlevmin Minimum required RX level in the cell
PcompensationMax(UE_TXPWR_MAX_RACH - P_MAX,0)
UE_TXPWR_MAX_RACH Maximum TX power level a mobile may use when accessing the cell on the RACH.
P_MAX Maximum RF output power of the mobile
Neighbour cell measurements (in Idle mode)The measurements are started when:
Intra frequency: Squal ≤ SintrasearchOR Sintrasearch is not sent in SIB
Inter frequency: Squal ≤ SintersearchORSintersearch is not sent in SIB
Inter RAT (GSM): Squal ≤ SsearchRATORSsearchRAT is not sent in SIB*
* This is equal to the case when SsearchRAT = 20 dB
Cell re-selection (UMTS)
Thisrange is decidedby QSI parameter valueh
Qqualmin
QhystsQoffsets,n
Re-selectionMeasurementsSuitable
Qqualmeas
timeRe-selection
Treselections
Mea
sure
men
tsar
e pe
rform
ed
No measurements areperformed on neighbours
No measurements areperformed on neighbours
Srxlev > 0 AND Squal > 0
Cell re-selection (UMTS-GSM)
SsearchRAT
Qrxlevmin
QhystsQoffsets,n
Re-selectionMeasurementsSuitable
Qrxlevmeas
timeRe-selection
Treselections
Mea
sure
men
tsar
e pe
rform
ed
Srxlev > 0
No measurements areperformed on neighbours
Measurements areperformed on GSM neighbours
Cell re-selection (GSM-UMTS)
FDDQmin
Qhysts
FDDQOFF
Re-selectionSuitable
FDDRCPMIN > 0-15 (-114 to -84 dBm)Qqualmeas
FDDQMINOFF
No cell reselection areperformed on neighbours
No cell reselection areperformed on neighbours
This range is decided byQSI parameter value
time
Cell re-selection (GSM - UMTS)
-98-94-90-86-82-78-74-70-66-62-58-54
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 QSI
dBm
XAlways measure UMTS
Measure UMTS whenRxLev is below
Measure UMTS whenRxLev is above
Cell Re-selection• A threshold on the serving cell defines below (or above) which levels inter-
system measurements are initiated (Trigger)• A threshold on the target cell defines below which level re-selection is not
possible (Capture)• Serving and target cells are compared, possibly with added offsets (Ranking)
Trigger Capture Ranking
Measure CPICH Ec/I0 RxLev CPICH RSCP and RxLev
Parameters Qqualmin
SsearchRAT
Qrxlevmin Qhyst1
Qoffset
Measure RxLev CPICH Ec/I0 CPICH RSCP and RxLev
Parameters QSI FDDQMIN FDDQOFF
GSM
to
UMTS
UMTS
to
GSM
Cell re-selection rules to avoid “ping pong”
Qqualmin + SsearchRAT < FDDQMINFDDQOFF < -Qhyst1 – Qoffset1
Trigger Capture Ranking
Measure CPICH Ec/I0 RxLev CPICH RSCP and RxLev
Parameters Qqualmin
SsearchRAT
Qrxlevmin Qhyst1
Qoffset
Measure RxLev CPICH Ec/I0 CPICH RSCP and RxLev
Parameters QSI FDDQMIN FDDQOFF
GSM
to
UMTS
UMTS
to
GSM
5
Region Condition Neighbour cells to be measured in idle mode
1 Squal > Sintrasearch None2 Sintersearch < Squal ≤ Sintrasearch Intra frequency adjacencies3 SsearchRAT < Squal ≤ Sintersearch Intra & Inter frequency adjacencies4 Squal ≤ SsearchRAT Intra, Inter and inter system adjacencies5 Squal < 0 Full scan of 3G and 2G frequencies
(initial selection mode)
Cell re-selection
Handover
Handovers in UMTS
• Intra frequency handover (f1 to f1)– Softer Handover– Soft Handover– Soft/Softer Handover– Core Network Hard Handover
• Inter frequency handover(f1 to f2)– Hard Handover
• Inter system handover (UMTS to GSM)– Hard Handover
Handovers in UMTS
Node B Node B
Intra frequency handover
• An intra frequency handover is a handover between to cells using the same frequency.
• An intra frequency handover decision is in 99% of the cases decided by the RNC.
• The UE performs measurements and reports to the RNC when a certain criteria has been fulfilled. This is referred to as event based reporting.
HANDOVER
Node BNode B
RNC
Iub
• SOFTER HANDOVER
UMTS COVERAGE
MSC/VLRIn a softer handover the active set contains at least 2 cells from the same Node-B
UMTS COVERAGE
Node BNode B
DRIFTRNC
Iur
IubIub
SERVINGRNC
HANDOVER• SOFT HANDOVER
MSC/VLRIn a soft handover the active set contains cells from different Node-Bs
Soft/Softer Handover
• In soft/softer handover the active set contains 2 cells from the same Node-B and one cell from a different Node-B.
Active set update “procedure”UE Node-B RNC
Decision to setupNew RL
Event Measurement reports
Radio Link Setup Request
Radio Link Setup Response
Iub Bearer Setup
Downlink Synchronization
Uplink Synchronization
Active Set Update
Active Set Update Complete
X seconds
1 ~ 2 seconds
Power Control&SoftHO
time
Trouble zone: Prior to Hard Handover, the UE causes excessive interference to BS2
BS2 Receive Power Target
UE responding to BS1power control bits
UE responding to BS2power control bits
time
BS1 Receive Power Target
time
BS2 Receive Power Target
1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 1 1 1 12 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
UE responding to BS1power control commands
UE responding to BS2power control commands
time
BS1 Receive Power Target
1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 12 2 2 2 2 2
1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
BS1 BS2 Action0 0 Reduce power0 1 Reduce power1 0 Reduce power1 1 Increase power
UE responds to power control commandsfrom both BS1 and BS2
SoftHO Gain
SRNC CNGood block
Block in error
Macro Diversity Combining
BER =10-1
BER =10-2
BER =10-1
BER =10-3
BER =10-1
BER =10-5
BER =10-1
BER =10-5
BER =10-3
BER =10-4
BER =10-2
BER =10-3
BER =10-1
BER =10-6
BER =10-1
BER =10-2
BER =10-1
BER =10-3
BER =10-4
BER =10-5
BER =10-2
BER =10-5
BER =10-6
BER =10-2
RL 1 RL 2 RL 3
21014,5 −⋅=BER 21078,2 −⋅=BER 21064,2 −⋅=BER
With MDCin the RNC:
31028,1 −⋅=BER
RNC
Iub
• HARD HANDOVER
UMTS COVERAGE
BSC
GSM COVERAGE
Abis
Node B
MSC/VLR
BTS
HANDOVER
Hard handover is defined as a handover where the old connection is released before the new connection is established (like in GSM)
Hard handover takes place at an inter frequency handover or an inter system handover.
Filtering of measurements
-105
-100
-95
-90
-85
-80
-75
Sign
al s
tren
gth
(dB
m)
Original signal K=2 K=6 K=8 K=11 K=19
( ) nnn MaFaF ⋅+⋅−= − 11Fn = Updated filtered measurement resultFn-1 = Old filtered measurement resultMn = Latest received measurement resulta = (½) (k/2)
Not supported by all mobiles
Event-triggeredreport
(Event 1A)CPICH 3
CPICH 1
CPICH 2
Periodicreport
Periodicreport
Reportingrange
Reportingterminated
)2/(10)1(1010 111
aaBest
N
iiNew HRLogMWMLogWLogM
A
−−⋅⋅−+⎟⎟⎠
⎞⎜⎜⎝
⎛⋅⋅≥⋅ ∑
=
Mea
sure
men
t Qua
ntity
Time
1X type of reporting events in FDD
• Event 1A (called E1A): A primary CPICH enters the reporting range
• Event 1B (called E1B): A primary CPICH leaves the reporting range
• Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active set
• Event 1D (called E1D): Change of best cell in active set• Event 1E (called E1E): A primary CPICH becomes
better than an absolute threshold• Event 1F (called E1F): A primary CPICH becomes
worse than an absolute threshold
Event-triggeredreport
(Event 1B)
CPICH 3
CPICH 1
CPICH 2
Reportingrange
)2/(10)1(1010 111
aaBest
N
iiNew HRLogMWMLogWLogM
A
−−⋅⋅−+⎟⎟⎠
⎞⎜⎜⎝
⎛⋅⋅≤⋅ ∑
=
Event 1B (called E1B): A primary CPICH leaves the reporting range
Mea
sure
men
t Qua
ntity
Time
2/1cInASNew HMM +≥
CPICH 2
CPICH 1
CPICH 3
CPICH 4
Mea
sure
men
t Qua
ntity
TimeEvent-triggeredreport
(Event 1C)
•Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active set
CPICH 2
CPICH 1
CPICH 3
CPICH 4
Mea
sure
men
t Qua
ntity
Event-triggeredreport
Event-triggeredreport
(Event 1D)
Event-triggeredreport
Event 1C (called E1C): A non active primary CPICH (not in active set) becomes better than an active primary CPICH (in the active setEvent 1D (called E1D): Change of best cell in active set
Time
Intra frequency handover example
R1A
-H1A
/2 H1C
/2
R1B
+H1B
/2
Cell 1Connected
Event 1AAdd Cell 2
Event 1CReplace Cell 1
with Cell 3
Event 1BRemoveCell 3
CPICH 1
CPICH 2
CPICH 3Time
MeasurementQuantity
∆T ∆T ∆T
Ec /I0
Time to trigger
Soft Handover Overhead (SHO)• In a GSM network the soft handover overhead is always 0%• The soft handover overhead is a measure on how many connections on
average exceeding 1 a mobile has got to the network.• A large soft handover overhead indicates that each mobile has got many
connections on average to the network (>1) -> Average AS size is high.• A low soft handover overhead indicates that each mobile has got few
connections on average to the network (~1) -> Average AS size is low.• A large SHO could indicate that too many resources are used by the mobile.• A low SHO could indicate that there could be more gain achieved in having
several connections to the network and that the mobile does use too much transmit power on average.
• A well balanced SHO is about 30-40% (1.3 – 1.4 connections on average)
⎟⎟⎠
⎞⎜⎜⎝
⎛−
≠⋅= 1
0__________100(%)_
ASwithUEsofNumbernetworktheinradiolinksactiveofNumberOverheadSHO
Compressed Mode
Radio frame(10 ms)
Normal mode
Compressed mode
UE performsmeasurements
on another frequencyor another system
SP=256 SP<<256 normally SF/2
DownlinkPower
DownlinkPower
UE only has got one receiverand one transmitter
SF SF
Intersystem HandoverUMTS -> GSM (voice)
WCDMA
COMPRESSEDMODE
GSM
Contains the orderto verify the BSIC
Contains the verificationof the BSIC
Intersystem HandoverGSM -> UMTS (voice)
GSM
WCDMA
Power Control
Power Control
SIRerror
SIRtarget
Up/Down
Outer closed loop power controlInner closed loop power control
Power Control
B2 B1
M2
M1
N1 P1 N2 P2
Power Control• There are three different power control mechanisms in
UMTS– Open loop power control
• Takes place at initial access in order to set the initial transmit power. (Is based on the pathloss measured by the mobile)
– Inner closed loop power control• This is the fast power control (1.5 kHz) and is controlled by the
Node-B/mobile based on the SIRtargets sent from the RNC/mobile. The aim of the Inner closed loop power control is to control thetransmitted power (UL and DL) on the air interface so that the SIR targets can be fulfilled.
– Outer closed loop power control• The outer closed loop power control sets SIR target for the Inner
closed loop power. The rate is 10-100 Hz typically.
RACH transmission (preamble)1. The mobile decodes the BCH to find out which RACH’s that are available2. The downlink power is measured and the mobile calculates how much power that is
required in order to reach the Node-B (Open loop power control)3. A 1 ms RACH preamble is sent from the mobile using the calculated transmission
power.4. If the mobile does not get any response from the Node-B (AICH) it send another
preamble with increased power.5. This procedure is repeated until the mobile receives a response from the Node-B
AIC
H
DL
RA
CH
RA
CH
RA
CH
RA
CH
UL
Power Control
Uplink Open Loop Power Control
RBS
UE 1
Dedicated channel at just enough power
1) UE measures Pilot
UE 2
3) Transmits
at calculated power
4) The power is ramped up until a response is heard or maximum number of re-attempts is reached
Connection established with minimum interference to other users
2) Reads interference level from Broadcast channel
Downlink Open Loop Power Control
RBS
UE 1
Minimum downlink power used to setup a connection thus maximizing downlink capacity
UE 2
2) Transmits
at calculated power
3) The power is ramped up until a response is heard or until a certain maximum power is reached
1) Uses parameters to calculate required power
Dedicated channel at just enough power
UE 2
Uplink Inner Loop Power Control
UE 2
RBS
UE 1
‘Increase power’
‘reduce power’
Uplink Signal to Interference (SIR) target is maintained for all services
Commands are fast enough (1500 times per second) to compensate for ‘Rayleigh’ fading
UE 2
Downlink Inner Loop Power Control
UE 2
RBS
UE 1
‘Increase power’
‘reduce power’
Minimum power for each connection is maintained, thus maximizing downlink capacity
Commands are fast enough (1500 times per second) to compensate for ‘Rayleigh’ fading
RBS
Uplink Outer Loop Power Control
UE SRNC
Inner loop commands based on SIR measured
SIR target = x dB
SRNC measures the BLER for the service and creates a new SIR target
SIR target = y dB
Uplink BLER for the service is maintained, regardless of UE environment
Downlink Outer Loop Power Control
RBSUE
Inner loop commands based on SIR measuredSIR target
= x dB
UE measures the BLER for the service and creates a new SIR target
SIR target = y dB
Downlink BLER for the service is maintained, regardless of UE environment
Cell Breathing
Cell breathing due to loading
Thermal Noise
6 dB
Thermal Noise
Cell Loading = 75%
Cell Loading = 50%
3 dB
3 dB
3dB
Cell Breathing
Cell radius depends on traffic load
$3$
Rake Receiver
RAKE Receiver Block Diagram• WCDMA Mobile Station RAKE Receiver Architecture
Each finger tracks a single multipath reflection• Also be used to track other base station’s signal during soft
handoverOne finger used as a “Searcher” to identify other base stations
Finger #1
Finger #2
Finger #N
Searcher Finger
Combiner
Sum ofindividual multipath components
Power measurement of Neighboring Base Stations
RAKE Receiver Example
0 50 100 150 200 250 300 350 400-2
0
2
4
6
8
10
12
14
16
18
0 50 100 150 200 250 300 350 400-2
0
2
4
6
8
10
12
14
16
18
0 50 100 150 200 250 300 350 400-202468
1012141618
n ⋅1/2-chip delay
∑
To Viterbi Decoder
Composite Received Signal
PN, Channelization Codes
m ⋅1/2-chip delay
k ⋅1/2-chip delay
Ai
Ai
Ai
Correlator
Correlator
Correlator
Equal Combining, ML Combining,or Select Strongest
time
0 50 100 150 200 250 300 350 400-2
0
2
4
6
8
10
12
14
16
18
1
23
1
23
1
23
1
23 1
2
3 + Interference
+ Interference
+ Interference
Radio Resource Management
RADIO RESOURCE MANAGEMENT-1
CellCoverage
CellCapacity
ServiceQuality
Optimization
NodeB
RNC
RRM
RADIO RESOURCE MANAGEMENT-2
Admission ControlAdmission Control
PAKETSCHEDULING
LOAD (Congestion)
CONTROL
HANDOVERCONTROL
Powercontrol
RRM
RADIO RESOURCE MANAGEMENT-3
Admission Control
Admission Control
• The purpose of the admission control is to maintain the stability of the network by ensuring that if the loading becomes too high, no additional mobiles are admitted to the network
• Admission control typically allows the operator to limit (vendor dependent):– The uplink noise rise– The downlink transmit power– The maximum transmit power per user– The allocated radio bearer
Before assigning new carrier, cell load is checked:New RAB EstablishmentHandoverChannel Switching
Cell load contains two part:Uplink InterferenceDownlink Power
Admission Control
Admission Control Thresholds
Admission Control
Load (Congestion) Control
Congestion Control
Congestiondetection
Congestionhandling
RB drop
Bit rate adaptation
Dedicated to common
Load
Cong_thr
Cong_OK
Congestion Control Actions
StartreleaseAseDl
RADIO RESOURCE MANAGEMENT-3
384128 64 FACH 64 128
384
Power or Load Limit
dB
Kbps
128384
Congestion Control handling- DL
= pwrHyst
100ms
StartreleaseAseDl
Time
DL Power
pwrAdm +pwrAdmOffset
pwrOffset
75ms
< pwrHyst
StartreleaseAseDl
= tmCongAction
200ms
Congestion
100ms
= pwrHyst
StoppreleaseAseDl
Congestionsolved
Congestion Control handling - UL
= ifHyst
100ms
StartreleaseAseDl
Time
RSSI
iFCong
iFOffset
75ms
< ifHyst
StartreleaseAseDl
= tmCongAction
300ms
Congestion
100ms
= ifHyst
StoppreleaseAseDl
Congestionsolved
RRC States
UE RRC states
„IDLE State“
Used for transportationof small data volumes
Used for transportationof big data volumes
Connected to the Network
Not connected to the Network
Stand by mode(ready for transport)
Wake me up whenyou need me“I am still in the office”
RRC statesNot supported by many UEs Bad performance
in many UEs
URA_PCH Cell_PCH
Cell_FACHCell_DCH
Idle
Does not consume so much battery
Transmissionstate
Nontransmission
state
Common channel shared by all users in the cell
Idle Cell_FACH Cell_DCH Cell_FACH Cell_PCH
TimerTimer expiredexpired
(RLC (RLC bufferbuffer stillstill emptyempty))
RRC states
Data Transfer Data Transfer startsstarts
(RLC (RLC bufferbuffer fullfull))
HighHigh data data transfer transfer demand
LowLow data data transfer transfer demand
Data transfer Data transfer finishedfinished
(RLC (RLC bufferbufferemptyempty))
demand demand
Channel type switching (CTS)Traffic volume
Event 4Ais sent
CELL_FACHState
CELL_DCHState
Uplink upper transport channel traffic volume threshold
Uplink lower transport channel traffic volume threshold
Downlink lower transport channel traffic volume threshold
Downlink upper transport channel traffic volume threshold
time
FACH stateDownlink
E4A
E4A
E4B
E4B
Event 4Bis sent
Uplink
Channel type switching (CTS)
Cell_DCH 64/384
Cell_DCH 64/64
Cell_FACH
Cell_DCH 64/128
Idle Mode
No activityNo activityCommon to Dedicated based on
buffer size
Common to Dedicated based on
buffer size
Soft Congestion
Soft Congestion
SHO can initiate a
switch if it fails to add
a RL
SHO can initiate a
switch if it fails to add
a RL
Coverage triggered downswitch
Coverage triggered downswitch
Upswitchbased on
bandwidth
Upswitchbased on
bandwidth
Dedicated to common based on throughput
Channel type switching (CTS)
DCH
TTime -out
User 1 User 2
RACHSwitch to common
Switch to dedicated
Release dedicated channel
PacketPacket Packet
Packet Packet Packet
User 3
Data Buffers
Bit Rate Adaptation
Bit Rate can be increased via reason mentioned below
High channel utilization (radio quality must be high)
Bit Rate can be decreased via reason mentioned below
Low channel utilizationBad radio qualityHigh Load (congestion control)
Overflow in RLC Buffer: Event 4AUnderflow in RLC Buffer: Event 4B
Bit Rate Adaptation
WCDMA Planning
Radio Propagation Models
Cell ConceptsMacro Cell
Cell Range > 1km, mostly Rural areas, andUrban
Mini CellCell Range 500m-1km, Urban areas
Micro CellCell Range 200m-500m, DenseUrban areas
Pico Cellİnbuilding cells
Cell Concepts
Macro Cell
d > 1 km
Mini Cell500 m < d < 1 km
RF Propagation Basics
Fast FadingRayleigh distributed
Slow FadingLog normal distribution with standart deviation
Path LossDecrease of the global mean value withdistance
Fast Fading (Rayleigh)
Slow Fading (Log-normal)
Shadowing
Fast and Slow Fading
Simple Radio Propagation Models
Propagation in Free Space
Simple Radio Propagation Models
Plane Earth Propagation
Knife-edge Diffraction
E0
Okumura-Hata Related Models
1 km < d < 100 kmhb>30m
Okumura Model – empiricalHata Model - <1.500 MHz.Cost - 231 Hata Model - >1.500 MHz.
Okumura-Hata Model forDimensioning
A constant for 2GHz
Walfish Ikegami Model
Flat ground
Uniform building height and building seperations
Propagation Model in Asset
[ ] [ ]
)log(
)log()log(
)log()log()log()log()log(
)log()log()log()log()log(
)(
62
75431
6275431
7654321
eff
effmsms
effeffmsms
effeffmsms
HKKB
clutterdııfKHKhKhKKAwhere
dBAdHKKclutterdııfKHKhKhKK
clutterdııfKdHKHKhKhKdKK
dBPathloss
+=
+++++=
+=+++++++
=+++++++
=
Rec
eive
dle
vel
log(d)
“A”
“B”
K1 is used to model the intercept – will be directly related to the clutter factorsK2 is used to model the pure distance dependenceK3 should always be -2.96 as the mobile antenna height is assumed to always be 1.5 mK4 should always be 0 because mobile antenna height is assumed to always be 1.5 mK5 is used to model the relation between the site antenna height and the intercept – will have an impact on the clutter factorsK6 is used to model the relation between the site antenna height and the distance from the siteK7 is used to model the influence of diffraction
Example: K6 – is always negative in a correct model
-10
-8
-6
-4
-2
0
2
4
6
8
10
1 17 33 49 65 81 97 113
15 meter (-K6)20 meter (-K6)25 meter (-K6)30 meter(-K6)35 meter (-K6)15 meter (+K6)20 meter (+K6)25 meter (+K6)30 meter (+K6)35 meter (+K6)
K6 < 0As the antenna height increasesthe “signal strength” also increases
K6 > 0As the antenna height increasesthe “signal strength” decreases
The same apply to K5 !!!
Linkbudgets (UMTS vs GSM)
Linkbudgets
• In GSM there is a linkbudget for one service only. But in UMTS there are several different services available…
• Which one should be dimensioned for ?
128/
384
kbps
64/384 kbps
128/384 kbps8/8 kbps
VideoVoice
HSDPA
PS Radio Bearer AllocationLoad in DL
Allocated Radio Bearer
64/6
4 kb
ps
64/1
28 k
bps
64/3
84 k
bps
8/8
kbps
30%
50%
70%
80%0/0 kbps is used for multi RABs
CS 12.2 kbps + PS 0/0 kbps
UMTS supported Radio Bearers (Vendor dependant)
Circuit Switched
• AMR 12.2 kbps (Voice)• UDI 64 kbps (Video)
•Streaming
Packet Switched
Interactive/Background• 8/8 kbps• 64/64 kbps• 64/128 kbps• 64/384 kbps• 128/128 kbps• 128/384 kbps
Streaming• ..Conversational• ..
Multi Radio BearersAMR 12.2 kbps + Interactive/Background
Asymmetric Services
DownlinkPower
UplinkPower
CPICHCoverage
UL: 64 kbpsDL: 384 kbps
DownlinkPower CPICH
CoverageUplinkPower
Linkbudget (GSM and UMTS)• A link budget is made in order to find the cell range for
different environments• The link budget will give you the maximum allowed
pathloss (MAPL) in order to meet the requirements for that environment– The cell range could then found by a simple calculation:
Maximum output power – MAPL → cell range (and coverage level)
Maximum Pathloss (MAPL)
Linkbudget (GSM)
• In GSM one user consume “all” the available power in the base station during a timeslot
timeslotMaxPower
Use
r 1
Use
r 2
Use
r 3
Use
r 4
Use
r 5
Use
r 6
time
Linkbudget (UMTS)• In UMTS one user consume the power he requires in order to keep
the connection• The available power in UMTS is shared between different users in
the downlink
time
MaxPower User 1
User 2User 3
Total output power =User 1 + User 2 + User 3
Linkbudget (UMTS)
• The available power in the downlink is 43 dBm.
• The available power in the uplink is 21 dBm (maximum output power of the mobile)
• This means:– The limiting link in terms of coverage is the
uplink in UMTS !
LinkbudgetsGSM UMTSUplink and downlink are balanced Uplink and downlink are not balanced
GSM 900 Downlink Uplink
TX
42.5
3.0
0.0
18.0
57.5
RX Sensitivity -102.0 -104.0
Penetration Loss 22
Fading Margin 12.8
Maximum Pathloss 122.7 122.7
Feeder Loss 0.0 3.0
Body Loss 2.0 0.0
Antenna Gain 0.0 18.0
Diversity Gain 0.0 1.5
Sigma Total 8
Probability Area 95.0 %
Probability Edge 89.1%
RBS TX Power 33
Feeder Loss 0.0
Body Loss 2.0
Antenna Gain 0.0
Total Max EIRP 28.0
RX
19Penetration Loss
18.2Fading Margin
127.1?Maximum Pathloss
-124.8?RX Sensitivity
3.00.0Feeder Loss
0.02.0Body Loss
18.00.0Antenna Gain
2.00.0Diversity Gain
8Sigma Total
95.0 %Probability Area
90.0%Probability Edge
?
18.0
0.0
3.0
?
Downlink
RX
19.0Total Max EIRP
0.0Antenna Gain
2.0Body Loss
0.0Feeder Loss
21Node-B TX Power
TX
UplinkW-CDMA
Service and environmentaldependant entries
MAPL GSM Voice122.7 dB
MAPL UMTS Voice127.1 dB
LinkbudgetAlternative approachTurkcell approach
Assume a load for the uplinkCheck if its OK in downlink
If not, decrease/increase the load andcheck again.
Make the design for VideoIndoor with 50% load in uplink.
Will always be OK in the downlinkas we are limited by coverage in thisscenario
MAPL
LOAD
Coveragelimited(uplink)
Capacitylimited(downlink)
Uplink
Downlink
Coverage Capacity?
Downlink/Uplinkcoverage dimensioning
Assume a path loss of 127 dB (Dense Urban environment)
“Signal strength” from CPICH (Pilot)
33 – 127 = -92 dBm
“Signal strength” from mobile
21-127 = -106 dBmMobile coverage
Pow
er for traffic (for all users)
Power for coverage(Pilot power)
33 dBm(2 Watt)
43 dBm(20 Watt)
Pow
er fo
r Upl
ink
cove
rage
21 dBm(0.126 Watt)
2 Watt for CCH
42 dBm(16 Watt)
→ The “coverage” is limited by theavailable power in the mobile
What is Npole?
Uplink or Downlink?
Uplink Npole• The uplink pole capacity, Npole, is the theoretical limit for the number of UEs that a
cell can support. It is service (RAB) dependent. At this limit the interference level in the system is infinite and thus the coverage reduced to zero.
⎟⎟⎟⎟
⎠
⎞
⎜⎜⎜⎜
⎝
⎛
+⋅+
=j
bpole
RNEW
iN
0
1)1(
1υ
Downlink Npole
General Dimensioning
Mobile coverage
Downlink/Uplinkcoverage dimensioning
Pow
er for traffic (for all users)Power for coverage
(Pilot power)
33 dBm(2 Watt)
42 dBm(16 Watt)
43 dBm(20 Watt)
Pow
er fo
r Upl
ink
cove
rage
21 dBm(0.126 Watt)
33 dBm(2 Watt)
Uplink coverage dimensioning
Noise Rise Loading Factor
3 dB 50%
6 dB 75%
10 dB 90 %
20 dB 99 %
∞ dB 100 %Thermal Noise No
Noi
se Terminal X
Terminal X
Terminal 1
Terminal 2
Terminal 1
∑=
X
njL
1
Uplink dimensioningSuppose our wanted signal is Pj and the total received power in the Node-B (all other users + noise) is Itotal, our achieved Eb/Nb can then be written:
where:
is the processing gain
is the bandwidth of the received signal, 3.84 MHz
is the datarate of our channel (i.e. Voice 12.2 kHz)
j
jtotal
j
jjb
b
RW
PIP
RW
NE
−=⎟⎟
⎠
⎞⎜⎜⎝
⎛
W
jR
Uplink dimensioningSolving for Pj yields:
totalj
jjb
b
totalj
j
jb
b
j
jb
btotal
j
j
jb
b
jtotal
j
IL
RW
ENIP
WR
NE
WR
NEI
P
WR
NE
PIP
=
⎟⎟⎠
⎞⎜⎜⎝
⎛+
=⇒
⎟⎟⎠
⎞⎜⎜⎝
⎛+
⎟⎟⎠
⎞⎜⎜⎝
⎛
=
⎟⎟⎠
⎞⎜⎜⎝
⎛=
−
1
1
Uplink dimensioningInserting typical values yields:
This can be interpreted as this user will be responsible for a part of the total received power at the Node-B
1271
1220038400004.01
1
12200 3840000 4.0
≈⋅+
=
===
j
jb
b
L
RWEN
1271
Uplink dimensioningItotal includes the other users in the cell (N) and the thermal noise and can be written as:
All the users in the cell will cause the received power to rise over the “unloaded” received power (thermal noise). This rise is normally referred to as the noise rise in the cell. It can be written as:
∑=
+=N
jntotaljtotal PILI
1
ULN
jj
N
jjtotal
totalN
jtotaljtotal
total
n
total
LLI
I
ILI
IP
Iη−
=−
=
⎟⎟⎠
⎞⎜⎜⎝
⎛−
=−
=
∑∑∑===
11
1
1
1111
This term is normally referred to as the loading factor
Interference in Uplink
0
5
10
15
20
25
1 10 19 28 37 46 55 64 73 82 91 100
Load (%)
Inte
rfere
nce
(dB
)
MAPL
LOAD
Coveragelimited(uplink)
Capacitylimited(downlink)
3 dB
Gain for 2 x P
out
Output Power vs. Capacity
Uplink
Downlink
Available power in the UE = 21 dBmor 126 mW
Available power in the Node-B = 43 dBmor 20000 mW
Dimensioning Samples
Sample City - Environment• City İstanbul• Environment Denseurban• Area 187,84 km2• Coverage Indoor• Coverage Prob. %90• UL Case• Limiting Service Video• Subs/km2 3.000
%10 Load, Coverage Case
%30 Load, Coverage Case
%50 Load, Coverage Case
%50 Load, Incar CoverageCase
%50 Load, %95 Coverage Case
%50 Load, %95 VoiceCoverage Case
%50 Load, Cov&Cap Case
INCREASE
or
DECREASE
LOAD?
%40 Load, Cov&Cap Case
INCREASE
or
DECREASE
LOAD?
%45 Load, Cov&Cap Case
INCREASE
or
DECREASE
LOAD?
%47 Load, Cov&Cap Case
INCREASE
or
DECREASE
LOAD?
%49 Load, Cov&Cap Case
INCREASE
or
DECREASE
LOAD?
%48 Load, Cov&Cap Case
RESULT:
DIMENSIONING LOAD %49
# OF SITE 211
%50 Load, Cov&Cap, 4000 sub/km2
%50 Load, Incar Cov&Cap, 4000 sub/km2
8 Parameter Analysis in Dimensioning
Base Line Values and 8 Parameters
Area (km2) 206PA (W) 20 Subscriber# 228000Noise Rise (dB) 3Orthogonality 0,5 Site # 536CPICH Pwr (dBm) 33 UL Load % 16,95Antenna height (m) 20 DL Load % 26,92Coverage probability% 90Building Loss (dB) 18SHO% 30
Baseline values
1. Power Amplifier Values: 20 – 40 Watt2. Noise Rise Values : 0,97 - 1,55 – 2,2 – 3 – 4 dB3. Orthogonality Values : 0,67 – 0,5 – 0,3 – 0,154. CPICH Power Values : 36 – 33 – 30 – 27 dB5. Antenna Height Values : 15 – 20 – 25 - 306. Coverage Prob. Values : %85 - %90 - %95 - %997. Building Loss Values : 16 – 18 – 19 – 20 – 22 dB8. SHO % Values : %20 - %25 - %30 - %35 - %40
Power AmplifierValues: 20 – 40 Watt
PA (W) UL Load % DL Load % Site#20 16,95 26,92 53640 16,95 26,92 536
0
5
10
15
20
25
30
20 40
PA (W)
Load
(%)
0
100
200
300
400
500
600
Site
Num
bers
UL Load %DL Load %Site#
Noise RiseValues : 0,97 - 1,55 – 2,2 – 3 – 4 dB
Noise Rise (dB) UL Load % DL Load % Site# %0,97 18,75 29,37 414 -1,55 17,73 27,88 445 7,49%2,2 16,7 26,38 485 8,99%3 16,95 26,92 536 10,52%4 15,93 25,45 606 13,06%
0
5
10
15
20
25
30
35
0,97 1,55 2,2 3 4
Noise Rise
Load
(%)
0
100
200
300
400
500
600
700
Site
num
bers
UL Load %DL Load %Site#
OrthogonalityValues : 0,67 – 0,5 – 0,3 – 0,15
Orthogonality UL Load % DL Load % Site# % changes0,15 16,95 35,12 5360,3 16,95 31,61 536 -9,99%0,5 16,95 26,92 536 -14,84%
0,67 16,95 22,94 536 -14,78%
0
5
10
15
20
25
30
35
40
0,15 0,3 0,5 0,67
Orthogonality
Load
(%)
0
100
200
300
400
500
600
Site
num
bers
UL Load %DL Load %Site#
CPICH PowerValues : 36 – 33 – 30 – 27 dB
CPICH Pwr (dBm) UL Load % DL Load % Site#27 16,95 26,92 53630 16,95 26,92 53633 16,95 26,92 53636 16,95 26,92 536
0
5
10
15
20
25
30
27 30 33 36
CPICH Power (dBm)
Load
(%)
0
100
200
300
400
500
600
Site
num
bers
UL Load %DL Load %Site#
Antenna HeightValues : 15 – 20 – 25 - 30
Antenna height (m) UL Load % DL Load % Site# % changes15 14,6 23,33 64120 16,95 26,92 536 -16,38%25 17,72 27,87 464 -13,43%30 18,76 29,37 410 -11,64%
0
5
10
15
20
25
30
35
15 20 25 30
Antenna Height (m)
Load
(%)
0
100
200
300
400
500
600
700
Site
num
bers
UL Load %DL Load %Site#
Coverage ProbabilityValues : %85 - %90 - %95 - %99
S. D. LNF Coverage Prob (%) UL Load % DL Load % Site# %changes12 6,9 85 22,77 36,42 35912 10,1 90 16,95 26,92 536 49,30%12 14,7 95 12,83 20,96 967 80,41%12 23,4 99 8,05 13,58 2890 198,86%
0
5
10
15
20
25
30
35
40
85 90 95 99
Coverage Probability (%)
Load
(%)
0
500
1000
1500
2000
2500
3000
3500
Site
num
bers
UL Load %DL Load %Site#
Building LossValues : 16 – 18 – 19 – 20 – 22 dB
Building Loss (dB) UL Load % DL Load % Site# % changes16 18,75 29,37 41618 16,95 26,92 536 28,85%19 15,93 25,45 608 13,43%20 14,9 23,96 690 13,49%22 12,49 20,22 889 28,84%
0
5
10
15
20
25
30
35
16 18 19 20 22
Building Loss (dB)
Load
(%)
0
100
200
300
400
500
600
700
800
900
1000
Site
num
bers
UL Load %DL Load %Site#
SHO %Values : %20 - %25 - %30 - %35 - %40
SHO Gain SHO (%) UL Load % DL Load % Site#2 dB 20 16,95 24,85 5362 dB 25 16,95 25,89 5362 dB 30 16,95 26,92 5362 dB 35 16,95 27,96 5362 dB 40 16,95 28,99 536
0
5
10
15
20
25
30
35
20 25 30 35 40
SHO (%)
Load
(%)
0
100
200
300
400
500
600
Site
num
bers
UL Load %DL Load %Site#
Turkcell UMTS Planning Strategy
Turkcell UMTS planning strategy
• Use as much as possible of the existing infrastructure (where possible).
• Deploy UMTS where there are 3G terminals available (the VİP sites)
• Take some traffic load from the 2G network.
• Support indoor video calls in DU areas (under certain coverage conditions)
Initial deployment procedure(Overview)
Nominal PlanningCell detailed
& Capacity Planning
Initial tuningOf
pre defined clusters
Initial networkOptimization
on a City level
3G coverage methodology
• Determine the service to make the design for.
• Calculate the uplink link budget for this service in DU, U, SU etc.
• Find the maximum allowable path loss for each environment.
• Calculate the required pilot field strength for this MAPL (i.e. “33 dBm – MAPL”)
Target of the 3G coverage methodology
• Create clear CPICH dominance– Minimizes pilot pollution– Maximizes the initial available capacity
• Plan for sufficient signal strength (not to much) in order to prepare for good network performance and quality.
Good UMTS site•The ideal UMTS site would cover it’s intended coverage area and very little else
• A practical site would be located so it’semissions were contained by the terrainand clutter
• The site would be located no higherthan absolutely necessary.
• In an urban area, the antennas would be high enough to clear surrounding buildingsand no higher.
Bad UMTS site• A nightmare UMTS site would be locatedon very high ground overlooking a largecity
• Such a site would provide little or no servicein the city but would reduce the capacity of all the cells in the area
• Another bad example of a site would be asite positioned on a building in an urbanarea significantly higher that all the othersurrounding buildings.
• The emissions from such a site would travel much further than the intended service area and reduce the capacity.
RSCP and Ec/I0• RSCP (Received Signal Code Power) is the
received power of the common pilot (CPICH) -dBm
• Ec/I0 indicates the quality of the common pilot -dB
• The mobile will only be able to maintain a connection if the quality of the signal is good enough (i.e. -5 to -18 dB).
• The level of the RSCP is of “secondary importance”. See example on next slide
RSCP and Ec/I0 (II)Ec/I0 = - 8 dBRSCP = - 93 dBmOK
Ec/I0 = - 20 dBRSCP = - 93 dBmNO
Ec/I0 = - 5 dBRSCP= -104 dBmOK
Ec/I0 = - 20 dBRSCP = - 75 dBmNO
RSCP and Ec/I0 (III)
-80 dBmPilot coverage
“Interferer” 1: -73dBm
“Interferer” 2: -73dBm
4 signals are received at cell edge:Wanted signal, Ec (RSCP): -80 dBm (1*10-11
Watt)Interferer 1 I1: -73 dBm (5.01*10-11 Watt)Interferer 2 I2: -73 dBm (5.01*10-11 Watt)Interferer 3 I3: -73 dBm (5.01*10-11 Watt)Total “interference”: -68 dBm (1.5*10-10 Watt)
“Ec/I0” = -80 – (-68) = - 12 dB=++ 321 IIIEc
“Interferer” 3: -73dBm
Main activities in the nominal planning stage
• Identify and confirm candidate sites• Make the initial design in terms of antenna
configurations, initial tilts, initial heights etc• Confirm the coverage and quality in the
Asset 3G tool.• Identify the requirements on additional 3G
sites.
Electrical down tilting
A lot of interferenceNo or very little interference – A new site herewill give very good quality
.....654321 ++++++ IIIIIIEc
0
5
10
15
20
25
30
35
40
45
50
0 2 4 6 8 10 12 14
Downtilt (degrees)
Num
ber o
f voi
ce c
onne
ctio
ns
Increases the qualityin the area (Ec/I0)
Decreases the coveragein the area.
In this particular case 6 degrees electricaldown tilt was the optimum tilt.
Cell Detailed Planning
Cell detailed planning process• Finalize the RF design of the site
– Antenna, feeder lengths, tilts, heights, pollution etc.• Define the 3G neighbours• Assign scrambling codes according to the scrambling code
planning strategy• Define 2G neighbours (could physically be max 32)
– 1st priority are the once existing in GSM– 2nd priority are 2G sites that later will be 3G as well– 3rd priority are all the other 2G sites
• Make Static/Monte Carlo simulations with traffic in order to confirm the design.– Use the voice traffic from the existing GSM network as starting input.– Add different amounts of CS64 and PS traffic– Find out if the design is limited by capacity or coverage for the different
scenarios.
Scrambling Code Planning
Primary and Secondary Scrambling Codes
Scrambling C
ode 1
Scrambling C
ode 2
Scrambling C
ode 3
Scrambling C
ode 4
Scrambling C
ode 5
Scrambling C
ode 6
Scrambling C
ode 7
Scrambling C
ode 8
Scrambling C
ode 9
Scrambling C
ode 10
Scrambling C
ode 11
Scrambling C
ode 12
Scrambling C
ode 13
Scrambling C
ode 14
Scrambling C
ode 15
Primary Scrambling Code 0
Scrambling C
ode 17
Scrambling C
ode 18
Scrambling C
ode 19
Scrambling C
ode 20
Scrambling C
ode 21
Scrambling C
ode 22
Scrambling C
ode 23
Scrambling C
ode 24
Scrambling C
ode 25
Scrambling C
ode 26
Scrambling C
ode 27
Scrambling C
ode 28
Scrambling C
ode 29
Scrambling C
ode 30
Scrambling C
ode 31
Primary Scrambling Code 16
Scrambling C
ode 33
Scrambling C
ode 34
Scrambling C
ode 35
Scrambling C
ode 36
Scrambling C
ode 37
Scrambling C
ode 38
Scrambling C
ode 39
Scrambling C
ode 40
Scrambling C
ode 41
Scrambling C
ode 42
Scrambling C
ode 43
Scrambling C
ode 44
Scrambling C
ode 45
Scrambling C
ode 46
Scrambling C
ode 47
Primary Scrambling Code 32
Scrambling C
ode 49
Scrambling C
ode 50
Scrambling C
ode 51
Scrambling C
ode 52
Scrambling C
ode 53
Scrambling C
ode 54
Scrambling C
ode 55
Scrambling C
ode 56
Scrambling C
ode 57
Scrambling C
ode 58
Scrambling C
ode 59
Scrambling C
ode 60
Scrambling C
ode 61
Scrambling C
ode 62
Scrambling C
ode 63Primary Scrambling Code 48
Scrambling Code Groups
There are in total 64 scrambling code groups each containing 8 primary scrambling codes
The j:th scrambling code group consists of primary scrambling code 8j + k, where j = 0....63 and k = 0....7
Scrambling C
ode 1
Scrambling C
ode 2
Scrambling C
ode 3
Scrambling C
ode 4
Scrambling C
ode 5
Scrambling C
ode 6
Scrambling C
ode 7
Scrambling C
ode 8
Scrambling C
ode 9
Scrambling C
ode 10
Scrambling C
ode 11
Scrambling C
ode 12
Scrambling C
ode 13
Scrambling C
ode 14
Scrambling C
ode 15
Primary Scrambling Code 0k=0 k=7
j=0
j=63
Group number
Scrambling Code Groupsk=0 k=7
j=0
j=63
Scrambling C
ode 1
Scrambling C
ode 2
Scrambling C
ode 3
Scrambling C
ode 4
Scrambling C
ode 5
Scrambling C
ode 6
Scrambling C
ode 7
Scrambling C
ode 8
Scrambling C
ode 9
Scrambling C
ode 10
Scrambling C
ode 11
Scrambling C
ode 12
Scrambling C
ode 13
Scrambling C
ode 14
Scrambling C
ode 15
Primary Scrambling Code 0
Scrambling C
ode 49
Scrambling C
ode 50
Scrambling C
ode 51
Scrambling C
ode 52
Scrambling C
ode 53
Scrambling C
ode 54
Scrambling C
ode 55
Scrambling C
ode 56
Scrambling C
ode 57
Scrambling C
ode 58
Scrambling C
ode 59
Scrambling C
ode 60
Scrambling C
ode 61
Scrambling C
ode 62
Scrambling C
ode 63
Primary Scrambling Code 3
The codes assigned to aNode-B should come fromthe same group.
Scrambling Codes in Asset 3G
Scrambling code number(within the group) 0-7
Scrambling code group 0-63
Scrambling code 0-511(calculated automaticallybased on number and group)
Scrambling code allocation
k=0 k=7
j=0
j=63
Group number
SC=0
SC=1SC=2
SC=3
SC=4SC=5
SC=16
SC=17SC=18
Reserved for indoor, test etc.
Scrambling Code Planning Wizard in Asset 3G
Scrambling Code Planning Wizard in Asset 3G
Note that before the Wizard is launched neighbours must have been defined !
Scrambling Code Planning – Alert!
• Remember that the mobile can be connected to 3 sectors (3 RLs) at the same time.
• The mobile can not have different connections to Node-Bs that have the same scrambling code defined !
• You can plan the scrambling codes with the help of the Wizard but planning them manually is also an alternative – and quite easy.
Neighbour Planning
UMTS to GSM handover procedure(Voice) – Vendor dependant
Criteria to leave theUMTS network
is fulfilled(RSCP, Ec/I0, UE TX)
etc
Make measurementson GSM network
defined neighbours
Verify BSICof the suitable
GSM neighbour
Perform Handoverto GSM
Go to/from
compressedmode
Neighbour Definition Strategy• Plan all UMTS <-> UMTS neighbours• Plan all UMTS -> GSM neighbours
– If the UMTS site is a co-site with GSM consider to define the same neighbours to GSM as the existing GSM site
– Run the 3G to 2G Neighbour definition Wizard in Asset to find additional definitions or neighbour deletions
• Plan all GSM -> UMTS neighbours– Make the above plan mutual and include the Ec/I0
threshold using the Wizard
Defining initial neighbours in 3G
• All definitions must be mutual• The first ring of cells should
be defined as default (~20)• In special cases cells from
the outer ring could be added
2G3G
2G3G
2G
• All existing 2G definitions shouldbe defined as 3G to 2G neighbours
Defining NeighboursUMTS <-> UMTS
UMTS sites
The first “ring”of sites
Defining NeighboursUMTS <-> UMTS
• Scrambling codes should be defined after the neighbours are planned and stored in the site database.
• All UMTS neighbours must be mutual• Always include the first ring of UMTS sites.• Start off with the Neighbour Wizard in Asset 3G
to find the first set of neighbour relations.• Edit then these by hand by displaying the
relations graphically
Neighbour Wizard in Asset 3G
Setup of the Wizard in Asset 3GOnly the sites includedin the filter(s) will beplanned
These parameters will be defined
Good to create an xml file forbackup and data build purposes
Neighbour Wizard resultsIn order to see which neighbours that have beenplanned you need to mark the cell
Outgoing
Incoming
UMTS Neighbour Planning Results in Detail
All neighbours should be mutualwhich could be done easilyby clicking – Make All Mutual
UMTS Neighbours in the graphical view
Displays theneighbours
UMTS <-> GSM Neighbours
• In order to plan the UMTS <-> GSM neighbours with the Wizard there must be a best array prediction available in GSM.
• Also - all the defined GSM neighbours in the network should be available in the site database.
Planning GSM NeighboursGSM sites
Planning GSM Neighbours
Planning vs. Site Database
These are neighbour relations that alreadyexisted in the database and that the Wizardalso wants to add.
This is a neighbour relation that is new (did not existin the database) and that the Wizard wants to add.
Planning Results GSM
Planning Results GSM- Graphical View
Using the Wizard for creating initial GSM <-> UMTS neighbours
GSM and UMTS
2 filters enabledOne GSM andOne UMTS
Will be definedlater
GSM <-> UMTS neighboursDetailed Results
Mutual UMTS <-> GSM neighbours
Graphical Display of GSM <-> UMTS neighbours
Planning Tips
Cell structures
• Very difficult to avoid excessive overlap• Very difficult to create dominance • Very difficult to avoid pilot pollution
“Corner of death”Antenna
~ 20 m
Drop !!!
Active set update “procedure”UE Node-B RNC
Decision to setupNew RL
Event Measurement reports
Radio Link Setup Request
Radio Link Setup Response
Iub Bearer Setup
Downlink Synchronization
Uplink Synchronization
Active Set Update
Active Set Update Complete
X seconds
1 ~ 2 seconds
Clutter heights
! !These two cases give very different results in the predictions !
If you place an antenna below the clutter height in Asset 3G database -make sure that this also is the case for the real site. If not, you should consider to move the antenna to “1-2 meters” over the clutter in Asset in order to be able
to produce more accurate predictions.20
m
17 m
20 m
22 m
Increasing Capacity in UMTS
The capacity in UMTS can be increased by increasing the number ofsectors on sites. However, the sectors must be narrow beam as thecapacity increase comes as a result of better dominance (Ec/I0).
• Node B Supports,
– 6x1 20/40W or
– 6x2 20W
in one cabinet
• More Feeders, ASCs/W-TMAs & Antennas• Going from 3 sector sites to 6 sector sites
provides– 85% Capacity gain– 40% Coverage gain (30% less sites)
6 ASCsor
W-TMAs
6antennas
12 feeders• 6 Radio Units
• 6 Filter Units
6 sector solutions
Antenna Site Design
3 deg3 deg
Areas of poor dominance
Antenna design - Electrical downtiltand mechanical uptilt
Mechanical up tilt&
Electrical down tiltMain lobeBack lobe
Effective Antenna Height AlgorithmsRelative algorithm
Heff = Hbase+ Hob – Hom if H0b > Hom
Heff = Hb if Hob ≤ Hom
20 m 20 mA
B15 m
The effective antenna height for site A 20 metersThe effective antenna height for site B 35 meters
Sea Level
50 m
Hob > Hom
Hob = Hom
30 m
Planning Tips
The nominal site is an old GSMsite. The antennas areplaced on the nominal height of20 meters
In the dense urban area thereare a few “coverage” holes
Planning Tips
• But the GSM site have the antennas at 22 meter height.
Planning Tips
• Moving the UMTS antennas to the same height as GSM (i.e from 20 to 22 meter) will remove parts of the coverage hole
Antenna Isolation
GSM/UMTS GSM/UMTS CoCo--SitingSiting SolutionsSolutions
Three possibilities exist when co-siting
1) Seperate Antennas
2) Diplexed to Shared Feeder
3) Shared Antennas
Each site may have a different solution according torequirements.
1) Seperate Antenna Configuration
RBS2000 series BTS
GSM 900
RBS3000
Series BTS
UMTS
ASC
Isolation >=30 dB
Four Feeders arerequired per sector
2) Shared Feeder for GSM/UMTS
GSM
Antenna
UMTS
Antenna
Isolation >=30 dB
ASCDIPLEXShared feeders
RBS 2000 series BTS
GSM 900
RBS3000
Series BTS
UMTS
DIPLEX
3) Shared AntennaIsolation >=30 dB
RBS 2000 series BTS
GSM 900
RBS3000
Series BTS
UMTS
ASC
GSM/UMTS
Antenna
Isolation = A_cableloss-A_gain+Lpattloss_ab-B_gain+Lpattloss_ba
Isolation
GSM 900 UMTS
Isolation ?
A_gain B_gain
A_cableloss B_cablelossPropogation Loss
Lpattloss_abLpattloss_ba
Horizontal Seperation
I h(dB)≈22+20log(d/λ), d> λd
d>83 cm to achieve 30 dBisolation
Turkcell, for safety, it is 2m Vertical Seperation
I v (dB) ≈28+40 log(d/λ), d> λ
d> 37 cm to achieve 30 dBisolation
Turkcell, for safety, it is 1m
d
λ coming from Tx system33cm for 900Mhz15cm for 2000Mhz
FeedersFeeders usedused in in TURKCELLTURKCELL’’ss GSM GSM RadioRadio Network Network andand theirtheir characteristicscharacteristics at 2 at 2 GHzGHz
DiameterMinimum bending
450 900 1500 1800 2000 2200 (mm) radius (mm)
MHz MHz MHz MHz MHz MHz
1/2" LDF4 4,8 6,9 9,1 10,1 10,7 11,2 16 1251/2" FSJ4
(flex) 7,6 11,1 14,9 16,6 17,6 18,6 13,2 32
7/8" LDF5 2,7 3,9 5,2 5,8 6,1 6,5 28 250
Andrew
Insertion loss dB/100m at 20°C
Sharing of feeders between GSM and WCDMA is possible andwill be used to reduce cost and visual effects.
Analysing with Asset
Static Analysis
Static Analysis•
- Uses a deterministic algorithm in order to calculate the load. Whenthe load has been calculated, pilot coverage and quality, handover regions, downlink powers etc can be calculated as well. The cellloading parameters (uplink noise rise, downlink traffic power) can be written into the site database.
Static Analysis - Outputs• Pilot Strength, RSCP (dBm)
• Handover Type (No handover, Soft, Softer & Both)
• Pilot Quality, Ec/I0 (dB)
• Number of pilot polluters (Any cell that provides an Ec/I0 level higher than the “pilot pollution” threshold), are pilots that are flagged as a polluters.
• Nth Best Ec/I0, server 1-6 (dB)
• DL FRE (Total received power from the best serving cell divided by the total received power from all cells) (%)
• DL i (Total received power from other cells divided by the totalreceived power from the best serving cell)
Monte Carlo Analysis
Analysis in Monte Carlo
Useful studies:
• DL Achieved Eb/N0• Mean number of soft handover cells• Mean number of softer handover cells• Mean size of active set• Path balance• Probability of noise rise failure• Probability of UL Eb/N0 failure• Reason for failure• UL required TX power• Cell uplink load• DL Loss
Downlink lossfor video
according the linkbudget
DU: 127 dBU: 133 dB
SU: 146 dB
Downlink achieved
Eb/N0
Displays theservice required
Eb/N0 (4.8 dB) as maximum and not
what is “achievable”
Cell Uplinkload (%)
Displays theload in the uplink.
The maximumallowable load inthe uplink is 50%according to our
linkbudget
NOTE: When a mobile fails to connect in the simulationsİt is “turned off” and does not generate any interference
UL required TX power
Displays theaverage mobilerequired output
power. Maximumpower is 21 dBm.
Minimum is -50 dBm
Reason forfailure
Displays theThe reason for failure in each
pixel.
Note: 6 dB for noise raise
For some analyses it is very important to check thethreshold parameters as they will have a great
impact on the results
Path balance
Displays failing link
in each pixel
Probability of Noise Rise Failure
Displays the probability thatthe Noise Rise
limit (set for each cell) is exceeded
Shows the meannumber of
soft handovercells
Shows the meannumber of
softer handovercells
Shows the meansize of theActive set
HSDPA Basics
What is High Speed Downlink Packet Access (HSDPA)?
SPEED Higher bit rates: up to 14 Mbps
CAPACITY 2 – 3 times improved system throughput
STANDARDIZED Integral part of WCDMA (3GPP Release 5)
REDUCED DELAY Reduced round trip time
Smooth Upgrade Short time to market with existing sites
Key Idea in HSDPA
Fast adaptation of transmission parameters to fast variations in radio conditions
Main functionality to support HSDPA•Fast link adaptation
•Fast Hybrid ARQ
•Fast channel-dependent scheduling
Basic Features
• Shared Channel Transmission– Dynamically shared code resource
2 ms
• Short TTI (2 ms)– Reduced delays
• Fast Channel-Dependent Scheduling– 2 ms time basis
• Fast Link Adaptation and higher modulation– Data rate adapted to radio conditions– 2 ms time basis
• Fast Hybrid ARQ– Roundtrip time ~12 ms possible– Soft combination of multiple attempts
Short 2 ms TTI2 ms
• Reduced air-interface delay– Improved end-user performance– Required by TCP at high data rates
• Necessary to benefit from other HS-DSCH features– Fast Link Adaptation– Fast hybrid ARQ – Fast Channel-dependent Scheduling
10 ms20 ms40 ms80 ms
Earlier releases
2 msRel 5 (HS-DSCH)
Shared Channel Transmission
• A set of radio resources dynamically shared among multiple users, primarily in the time domain– Efficient code utilization– Efficient power utilization
Channelization codes allocatedfor HS-DSCH transmission
8 codes (example)SF=16
SF=8
SF=4
SF=2
SF=1
TTI
Shared channelization
codes
User #1 User #2 User #3 User #4
Fast Channel-dependent Scheduling
• Scheduling = which UE to transmit to at a given time instant and at what rate– Formally part of MAC-hs (a new MAC sub-layer in RBS)
• Basic idea: transmit at fading peaks– May lead to large variations in data rate between users– Tradeoff: fairness vs cell throughput
high data rate
low data rate
User 1
User 2
Scheduled user
Time#1 #2 #1 #2 #1 #2 #1
Fast Channel-dependent Scheduling
• Examples of scheduling algorithms– Round Robin (RR)
• Cyclically assign the channel to users without taking channel conditions into account
• Simple but poor performance– Proportional Fair (PF)
• Assign the channel to the user with the best relative channel quality• High throughput, fair
– Max C/I Ratio• Assign the channel to the user with the best channel quality• High system throughput but not fair
Fast Link Adaptation and higher modulation
• Adjust transmission parameters to match instantaneous channel conditions
• HS DL Shared Channel: Rate control (no Fast Power control)– Adaptive coding– Adaptive modulation (QPSK or
16QAM)– Adapt on 2 ms TTI basis ⇒ fast
• R99: Power control (no Rate control ⇒constant data rate possible)
High data rate
Low data rate
Higher Modulation
• HS-DSCH supports both QPSK and 16QAM– 16QAM is mandatory in the UE, except for the 2 lowest UE categories– 16QAM gives approximately double data rates– 16QAM is mainly useful at good radio conditions– 16QAM typically requires more advanced receivers in the UE
QPSK 16QAM
2 bits 4 bits
Fast Hybrid ARQ with Soft Combining
• Rapid retransmissions of erroneous data– Hybrid ARQ protocol terminated in Node B⇒ short RTT (typical example: 12 ms)
– Soft combining in UE of multiple transmission attempts⇒ reduced error rates for retransmissions
P1,1
P1,1
NACK
P1,2
P1,2
ACK
P2,1
P2,1
NACK
P2,2
P2,2
ACK
P3,1
ACK
P1,1 P2,1 P3,1+ +
Transmitter
Receiver
HS-DSCH – Power Allocation• HS-DSCH must share the transmission power with all other channels
• Dynamic power allocation– Allocate remaining power to HS-DSCH transmission– Best power utilization
HS-DSCH
Common channels (not power controlled)
Dedicated channels (power controlled)
Tota
l ava
ilabl
e ce
ll po
wer
HSDPA Channel structure• New data channel
– High Speed Downlink Shared Channel (HS-DSCH) mapped to High Speed Physical Downlink Shared Channel (HS-PDSCH)
• New control channels– High Speed Shared Control Channel(s) (HS-SCCH)– High Speed Dedicated Physical Control Channel (HS-DPCCH)
Associated Dedicated ChannelsHS-DSCHHS-SCCH
HS-DPCCH
HSDPA Channel StructureNew Channel overview
– HS-DSCH: High speed downlink shared channel• “Fat pipe”: Carrying high speed downlink traffic
– A-DCH DL: Associated dedicatedchannel downlink
• Voice/video (multi-RAB)• Release 99 signaling
– A-DCH UL: Associated dedicatedchannel uplink
• UL data transmission• TCP ACK/NACK• Voice/video (multi-RAB)• Release 99 signaling
– HS-SCCH: High speed shared control channel• HARQ signaling
– HS-DPCCH: High speed dedicated physical control channel• HARQ ACK/NACK• CQI: channel quality indicator
RNC
Iub Iub
Iu
Associated Dedicated channelsHS-DSCHHS-SCCH
HS-DPCCH
RNC
Iub Iub
Iu
Associated Dedicated channelsHS-DSCHHS-SCCH
HS-DPCCH
Channel structureHS-PDSCH
• Carries user plane data on downlink• 1 to 5 HS-PDSCH per cell• Spreading Factor = 16• Always associated with a DPDCH• Supports 16-QAM (optional) or QPSK
(mandatory)
Channel structureHS-DSCH
• Transport channel that carries the user data• Mapped to HS-PDSCHs• One transport block of dynamic size per 2 ms
TTI• Supports link adaptation, hybrid ARQ, radio
channel dependent scheduling• Never in soft or softer handover• Always associated with a DPCH
Channel structureHS-SCCH
• Carries control information to scheduled UE in a 2-ms interval– UE identity for which the HS-SCCH (and HS-DSCH)
is intended– Hybrid ARQ information– Modulation scheme and transport format selected by
link adaptation mechanism• One HS-SCCH per cell• Power controlled, never in soft handover• SF = 128• Similar to DPCCH
Channel structureHS-DPCCH
• Carries physical layer info sent in the uplink• One HS-DPCCH for each user in the cell• Feedback from the UE:
– ACK/NACK (positive or negative acknowledge)
– CQI (Channel Quality Indicator)• SF = 256• Timing relative to HS-PDSCH
Channel structureA-DCH
• One A-DCH per HSDPA enabled terminal in the cell• A-DCH UL
– 384 kbps (or 64 kbps) DCH (TCP ACK/NAK)– 3.4 kbps SRB (control signaling: RRC & NAS)– High-Speed Dedicated Physical Control Channel
(HS-DPCCH) • ACK/NACK for H-ARQ• Channel Quality Indicator (CQI)• Never in soft handover (softer is possible)
• A-DCH DL– 3.4 kbps SRB (control signaling: RRC & NAS)
HSDPA mobility
Serving HS-DSCH Cell Change– Direct UE to scheduling queue in chosen target cell– Stop transmission in source cell
Benefits– Maintains mobility for UEs using HSDPA– Reduces user data interrupt for HSDPA mobility,
thereby improving subscriber perceived quality– Supports networks where HSDPA is deployed on
separate frequency layers only, as well as networks in which not all UEs are capable of HSDPA
Without HSDPA mobilityCell reselection HS
SRB
DCH
Idle
Common
Idle
SRB
HS DCH
Idle
SRB
HSHSHS
IdleIdle
SRB
HSHS
Idle
SRB
HSDPA/R99 HSDPA/R99 HSDPA/R99 R99 R99
UE movement
5-6 second impact on the disruption of user traffic
With HSDPA mobilityHS-DSCH Cell Change HS
SRB
DCH
Idle
Common
Idle
SRB
HSHS
Idle
SRB
DCH
• Practically interruption-free user traffic– Intra-RNC
HSDPA/R99 HSDPA/R99 HSDPA/R99 R99 R99
UE movement
HSDPA admission control
Efficient and flexible allocation of power resources as well as selection of uplink Radio Bearers
– Applied in the system on cell level in both uplink and downlinkBenefits
– Enables HSDPA and regular services, such as voice, to co-exist in same cell
– Provides the possibility to reserve downlink output power for HSDPA, increasing HSDPA user bit rates & capacity
– Provides the possibility to trade the average throughput per HSDPA user versus accessibility
– Provides efficient allocation of Uplink 384 kbps Radio Bearer– Reduces dropped call probability
HSDPA admission controlAdvanced Radio Resource Management
t
PCCH
Pnom
DCH + CCH
Padm
Pcong
Service differentiated Admission & Congestion Control (operator-controlled parameters)• R99 Packet users down switched or moved to Common channels• HSDPA users released -> Voice/video/streaming users released
Fast Congestion Control (every 0.67 ms)• No MCPA shut-down (Lost cell)• Enables aggressive
• Adm. & Cong. Control • HS-DSCH power allocation
HS-DSCH• Dynamic power allocation (every 2 ms)• “Reserve” HSDPA power with Padm & Pcong
Operator-configurable parameters• Max number of HSDPA users per cell• Max number of HSDPA users on uplink 384 kbps RAB per cell
R99+R5f1
f1
f2
f1 R99
R5
Shared same carrier
Different carrier
WCDMA
HSDPA
WC
DM
A
HSD
PA
HSDPA- Deployment
WCDMA- HSDPA
WCDMA HSDPAOVSFC YES NOFAST POWER CONTROL YES NO
TTI TIME 10ms 2msMAXIMUM THROUGHTPUT 384Kbps 14Mbps
VARIABLE MUDULATION NO YESFAST RE-TRANSMISION NO YESSOFT HANDOVER YES NOFAST SCHEDULING NO YES
Release 99 HSPA
Retransmission delay >100 ms 12 ms
Scheduling delay >200 ms 2 ms
Dynamic code allocation
• Dynamic Code Allocation – Based on Code Utilisation and Cell capacity/HW
capabilityCodes shared between DCH and HS 15 HS codes shared in 3 sectors
0
10
20
30
40
50
60
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
8 3
4
# Voice Users / cell
# HS codes
# HS codes
HSDPA uses fast feedback from mobile
Terminal sends fast L1 feedback to Node-B– Channel Quality Info (CQI) – Transmission period typically every 4 ms
CQI is used by HSDPA packet scheduling– Link adaptation– Multiuser scheduling decisions
L1 Feedback (CQI)
Data
TTI 1 TTI 2 TTI 3 TTI 4
User 1 CQI
User 2 CQI
Scheduled userProportional fair scheduling principle : allocate resources to the best user leading to multi-user diversity gain
HSDPA UE categories• Theoretical peak bit rate up to 14 Mbps• Initially 1.8 Mbps and 3.6 Mbps capabilities with 5 codes
10
9
7/8
5/6
3/4
1/2
12
11
-
-
-
3.6Mbps
1.8Mbps
1.2Mbps
1.8Mbps
0.9Mbps --36302QPSK only
--36301QPSK only
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
14.0 Mbps
10.1 Mbps
-
-
-
-
-279521
-202511
7.2 Mbps144111
-72981
-72982
-72983
HSDPACategory 5 CodesModulation 15 Codes10 CodesTransport
Block sizeInter-TTI
10 and 15 codes for increased user bitrates and cell capacity
• Average cell HSDPA throughput increased • Peak datarate up to 7.2Mbps (10codes) and 10.7-
14Mbps (15codes)• 14.4Mbps is not in practice achieved (no channel
coding)• Increased cell peak data rate and capacity when most
of the power can be allocated to HSDPA• Gain in cell capacity from 10/15codes together with
code multiplexing is more important than max bitrateper user
User data rates in practical radio conditions15 Code Terminal with Equalizer Assumed
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Distance from BTS [relative to cell radius, 1=cell edge]
kbps
3.6 Mbps available with 45% x cell radius
7.2 Mbps (10codes) available
with 20% x cell radius = 4% x cell area
10 Mbps (15codes)availability very limited 3-sector
macro cellassumed
BTS Cell edge
Code Shared HSDPA Scheduler• Peak rate of 10.8 Mbps is shared dynamically between sectors• Efficient utilization of resources since the peak rate of 10.8 Mbps is only
seldomly available in macro cells due to interference
Instantaneous adaptation according to throughput per sector
Throughput shared equallybetween all sectors
HSDPA mobiles onlyin single sector
Throughput sharedbetween two sectors
10.8 Mbps
7.2 Mbps
3.6 Mbps
0 Mbps (no HSDPA mobiles)
0 Mbps (no HSDPA mobiles)
0 Mbps (no HSDPA mobiles)
3.6 Mbps
3.6 Mbps
3.6 Mbps
HSUPA BasicsHSHSUUPA PA BasicsBasics
HSUPA provides high performance withsimple SW-upgrade
• HSUPA is a SW-upgrade and exitingbaseband in NodeB’s can be reused
• HSUPA availability follows marketneeds and terminal availability– Initially Max 1.5 Mbps user bitrate– Max 20 users per cell– Simultaneous HSUPA and
HSDPA– Soft/softer HO supported– Fast HSUPA scheduling
HSUPA enhances end-user experience• HSUPA provides
significantly improvedupload performance for e.g.– Email– Multimedia
• Lower latency enabled byHSUPA benefits mostservices, also downloads
• Combined HSDPA and HSUPA enables new services like mobile multiplayer gaming or highquality video conferencing
HSUPA supports full mobilityRNC 1RNC 1 RNC 2RNC 2
• For HSUPA user, the following HOs are supported
– Softer HO– Intra RNC soft HO– Inter RNC soft HO
• Active set for DCH and E-DCH can be different (e.g. cell not supporting E-DCH can be added to AS)
• Cell change algorithm will control that best cell • is the serving cell in E-DCH active set
• Event 1D for CPICH Ec/No will be used to monitor the best cell
• Switch to DCH is performed if– A cell under DRNC becomes the best cell– A cell not supporting E-DCH becomes the best cell– Compressed mode needs to be activated
E-DCH & DCHbranch
E-DCH & DCHbranch
DCHbranch
RNC 1RNC 1
HSUPA supports more RAB combinations
fully featured HSPA – simultaneous HSUPA &
HSDPA + AMR voice since the first release
– Soft and softerhandover
– HSUPA DL physical channel power control
– Advanced Schedulerutilising both absoluteand relative grants
HSUPA Scheduling & RRM
• The user’s allocation is downgraded the utilization is low – throughput based optimization for Release 99 DCH
• The user’s allocation is upgraded when – A) the user is ‘unhappy’ and – B) there is room : power, hardware and transport resources
• No users are downgraded to make room for other users
• HSUPA RRM algorithm in the RNC performs combined power and throughput based packet scheduling for R99 DCH and HSUPA users
• RNC performs dynamic sharing of received interference between NRT DCH and HSUPA users.
Thank You
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