rf network design
DESCRIPTION
TRANSCRIPT
2
1. Network Design Objective……………….…..3P
2. RF Network Design Procedure……...……..5P
Stage 1: Preparations …...………………………...6P
Stage 2: Wireless Environment Analysis …….21P
Stage 3: Coverage Design ………………………36P
Stage 4: Parameter Design ……………………..50P
Stage 5: Dimensioning …………………………..59P
Contents
Acceptable CoverageForward & Reverse Link Quality
Capacity
To Resolve
To Manage
To Ensure
Engineering Requirement vs. Available EquipmentCustomer Complaints
Pilot Pollution Cell Overlap / Handoff Regions
1. Network Design Objectives
Design Value
Design Criteria
? %
FER
(Frame Error Rate)
? %
GOS
(Blocking Rate)
? %
Coverage
Probability
- Demand for Service Coverage? - Demand for Service Quality? - Demand Service Capacity? - Usable Frequency Bandwidth? - Service Criteria? - Call Completion Rate? - Handoff Success Rate?
Design Objectives
1. Network Design Objectives
5
2. Network Design Procedure
Basic Data Collection & analysisDesign Criteria SetupGIS Data Conversion
Preparations
Competition Coverage MeasurementPlan SetupRegion ClusteringSite Survey Plan
Site AcquisitionSite Coverage Simulation
Link Budget AnalysisBase Station Design On the Map Positioning
Site survey & Field measurementMeasurement data integrationPath loss calculation
RF Environment Analysis
Outdoor/Underground Coverage design In-building and underground
Coverage Design
Pilot AssignmentPaging Capacity & Paging zoneHandoff neighbor list, etc.
Parameter Design
Required BTSRequired FARequired CHC / CE
Dimension & Report
STAGE 1
STAGE 2
STAGE 3
STAGE 4
STAGE 5
6
Target Objective Setup Competitor’s Info. Analysis Sheet Detail Design Criteria - Service Target Area(In Building/In car) - Traffic & Coverage data - FER(Frame Error Rate) - Coverage hole(If possible) - GOS(Grade Of Service) - Coverage reliability
General Statistic Data forDesign Scope- Population and Area- Traffic and BTS info./ GIS MAP- Telecommunication regulation
Competitor’s Service Information - Service Area and Quality (GSM,CDMA) - BTS Info.(Lon/Lat, Traffic & antenna)
Design Objective - GOS/FER/Coverage Reliability - FA capacity - Cell coverage criteria - Soft Handoff region ratio, etc.
General Statistics Data gathering & Analysis - RF Engineering Scope Analysis (Area, Population, Building Density, etc) - Traffic Information(Traffic Distribution analysis) (Traffic volume, call success/completion rate) - BTS Information(Lon/Lat, coverage, etc)
Competition company Traffic Volume and Quality Analysis(If Possible) - BTS and antenna type, position - Traffic analysis per each cell/sector - Overall BTS coverage analysis
Detail DesignCriteria Setup
Required Data/Tool
Main Activity
Accomplishment
Stage 1: Preparations
Overview
7
Setup the Design Criteria
GOS vs. Capacity
0
10
20
30
40
50
60
70
80
90
0.0% 0.1% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5% 4.0% 4.5% 5.0% 5.5% 6.0% 6.5% 7.0% 7.5% 8.0% 8.5% 9.0% 9.5% 10.0%
GOS
Erl
an
g
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Ca
pa
cit
y I
nc
rea
se
Ra
tio
Erlang Capacity Increase Ratio
Traffic Model : Soft Blocking ModelBTS Type : 3 SectorChannel : 84Maximum User : 33Sector Load Ratio : 1.5
GOS(Grade of Service), Blocking Probability
Stage 1: Preparations
1
1.5
2
2.5
3
3.5
4
1 2 3 4 5 6 7 8 9 10 11 12 13
% FER
Mea
n O
pin
ion
Sco
re
MOS
PSTN = MOS 4 CDMA = 3.6 (FER 1%)
MOS Vs. FER Graph (8K Vocoder)
Setup the Design Criteria
Stage 1: Preparations
Setup the Design Criteria Coverage Area and Contour Reliability(FADE MARGIN)
95% Area Reliability 95% Contour Reliability
15% Contour failure
< 10%
< 5%
< 1%
Percent Failure 4-6% Contour failure
< 3%
< 2%
< 1%
Percent Failure
85% contour reliability 97% area reliability
Stage 1: Preparations
10
Setup the Design Criteria
Stage 1: Preparations
0.5
0.6
0.7
0.8
0.9
1
1.1
/n
Fra
cti
on
of
To
tal A
rea
wit
h S
ign
al a
bo
ve
Th
res
ho
ld. F
u
0 1 2 3 4 5 6 7 8
PX0(R) = 0.95
0.9
0.85
0.80.75
0.7
0.65
0.6
0.55
0.5
Area Reliability FuContour Reliability
= Standard deviation[dB]
n = Path slope
Path Loss varies as 1/rn,
PX0(R) = Coverage Probability on area boundary (r = R)
11
Setup the Design Criteria
Stage 1: Preparations
0
5
10
15
20
25
0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95
Location Probability at Cell Edge
Fad
e M
arg
in in
dB
12 dB
1110
98
7
6
StandardDeviation
Fade Margin -----> 10 dB
Setup the Design Criteria Coverage Area and Contour Reliability(FADE MARGIN)
Item Dense Urban Urban Suburban Rural
Slow Fading 10 dB 8 dB 8 dB 6 dB
Slow Fading It follows the log-normal distribution with standard deviation It depends on a variety of morphology
To obtain the exact slow fading value,must perform the field measurement which consumes the high cost and time
Stage 1: Preparations
13
Setup the Design Criteria
FA Capacity(based on IS-95A reverse link) • Limited by Interference From Other users• Based on minimum required [Eb/It]minimum
• Relationship between [Eb/It]minimum and Number of user N based on Perfect Power Control, No Thermal Noise, and Isolated Single Cell
RSNRS
ItEb
/)1(/
1
// ItEbRWN
• S: Received signal at the base station(from power controlled mobiles)• R: Data rate• W: CDMA Bandwidth(1.2288 Mbps)• Eb: Bit energy, It: Spectral Density of the total interference• N: Number of active users
Stage 1: Preparations
14
Setup the Design Criteria
Pole(Maximum) Capacity(based on IS-95A reverse link)
NoW
IoIocvSNRS
ItEb
N
N
)/1()1(/
)1()1(1 fvNW
R
It
EbWR
ItEb
NoWSN
• Including the effects of Thermal Noise, Voice Activity and other cell interference
Io
Iocf ,where
Stage 1: Preparations
15
Setup the Design Criteria
Pole(Maximum) Capacity(based on IS-95A reverse link)
• Pole(Max) Capacity, where required
• Obviously, this capacity can never be exceed in any cell/station• Pole(Max) Capacity/Sector
1*1*min)(
max Fv
ItEbRW
N
1)3
55.2(*1*
min)(secmax/ F
vItEbRW
torNf
F
1
1,where
Stage 1: Preparations
16
FA Capacity(based on cdma2000 1x)
)%80%100max
,( )(_ 00
S
k k
kS
kk N
NWhenMbitsMbitsCapacityFA
• Because of difference in required Signal /Noise, Activity and Transmission velocity in each service Nmaxk can be defined follows
)/6.0
1 where,()1
/(max
IoIocFSG
NtEb
FPGN
kk
kk
• Base station FA capacity of service carrying number of S with various transmission velocity
Setup the Design Criteria
Stage 1: Preparations
17
Cell Coverage • Coverage Criteria in CDMA System - Forward Coverage : Design by the standard of Pilot CH Ec/Io - Reverse Coverage : Design by the standard of Traffic CH Eb/No • As higher Ec/Io and Eb/No criteria are arranged, better call quality can be supplied for customers but more cost is also expected. Therefore, criteria should be arranged to meet the customer satisfaction and cost efficiency
Required Ec/Io
Required Eb/No
Forward Coverage
Reverse Coverage
>= -14dB
>= 6dB
Setup the Design Criteria
Stage 1: Preparations
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Soft Handoff Region Ratio
Soft Handoff Region Ratio
0
10
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30
40
50
60
70
80
-22 -21 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11
T_ADD (dB)
Re
gio
n R
ati
o (
%)
2Way Soft Handoff 3Way Soft Handoff Total Soft Handoff
T_ADD is used to add new Active/Candidate set
T_DROP is used to reduce the Active pilot
Because the output power of a mobile station decreases in handoff,
the interference also decreases and the BTS capacity increases.
But required channel resource also increases.
30 ~ 40 %
Setup the Design Criteria
Stage 1: Preparations
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PILOT_INC parameter setting
PN offset reuse distance calculation
PN offset allocation - PILOT_INC selection
- Distance between the same PN cell sites
- Extra PN offsets for expansion of cell sites or Micro cells
PN Increment and Allocation
Setup the Design Criteria
Stage 1: Preparations
Paging channel Load and Paging zone design Paging channel load calculation
Paging zone design(1st, 2nd Paging zone)
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ХХХ
Tx/Rx-0 Tx/Rx-1
10=3.6m
10=3.6m0.3m(MIN)
Competitor - ANT.
ХХХ
0.3m(MIN)
Competitor-ANT.
Space Diversity Polarization Diversity
Single Site
JointSite
Tx/Rx-0Tx/Rx-1
Tx/Rx-0 Tx/Rx-1
Tx/Rx-0 Tx/Rx-1
Distance between Antennas
Setup the Design Criteria
Stage 1: Preparations
21
RegionClustering
Maximum Cell Radius,Minimum AntennaHeight Calculation
Site Survey and Field Measurement
Competitor’s CoverageAnalysis
Link BudgetAnalysis
Procedure Overview
Stage 2: RF Environment Analysis
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1. Site Survey Report2. Field Measurement Data and Analysis Result - Measurement Integration & Propagation Modeling3. Frequency Planning4. Competitor’s Coverage Analysis Result
MAP DATA - Digital Map for CellPLAN - 1:10,000 Traffic Map
Cell Planning ToolField Measurement Tool - Transmitter / Receiver - Spectrum Analyzer, etc
Competitor’s CoverageMeasurement Tool - AMPS/CDMA or GSM SystemCompetitor’s Cell Info.etc.
Region clustering - Dense Urban, Urban, Suburban, Rural. - Drive Survey for region clusteringSite Survey & Field Measurement - Make the Site Survey list - Drive Route establishment - Perform the Field Measurement
Spectrum Clearance Check (including Site Survey List)
Frequency Planning Review or Setup - FA Planning
Competitor’s CoverageMeasurement Tool - AMPS/CDMA or GSM System
Required Data/Tool
Main Activity
Accomplishment
Stage 2: RF Environment Analysis
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Region Clustering by the Geographical Configuration (Flat, Hilly, Mountain)
General Clustering by the Map Data
(Rural, Suburban, Dense, Urban)
Extraction of the Regional Parameter Values such as BAI(Building
Area Index), BSD(Building Size Distribution), BHD(Building Height
Distribution), VI(Vegetation Index) etc., using the Geometry Function
Applying the Extracted Parameters to the Target Area to Achieve
more Detail Region Clustering
Precisely Divided Region Clustering
Region Clustering
Stage 2: RF Environment Analysis
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Region Clustering(Quantitative)
Region Class BAI(%)BSD(m2) BHD(Floors)
VI(%)Avg. STD Avg. STD
Rural Flat, Hilly, Mountain < 12 - - - - -
Suburban
Residential(Open) 12 ~ 20 95 ~ 115 55 ~ 70 2 1 >= 2.5
Residential(no Open) 20 ~ 30 100 ~ 120 70 ~ 90 2 ~ 3 1 <= 5
High-rise residential > = 12 >= 500 >= 90 >= 4 1 <= 2
Urban
Shopping Area 45 ~ 50 200 ~ 250 >= 180 >= 4 1 0
Commercial Area 30 ~ 40 150 ~ 200 >= 160 3 1 0
Industrial Area 35 ~ 45 >= 250 >= 200 2 ~ 3 1 <= 1
Dense
Urban
Shopping Area >= 50 200 ~ 250 >= 180 >= 4 1 0
Commercial Area >= 40 150 ~ 200 >= 160 6 1 0
Industrial Area >= 45 >= 250 >= 200 7 ~ 8 1 <= 1
[Reference] David Parsons “ The mobile radio propagation channel”
Stage 2: RF Environment Analysis
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Site Survey and Field Measurement Procedure
Stage 2: RF Environment Analysis
Planning
1. Selection of target Building for site survey2. Scheduling for site survey and field measurement3. Planning for Drive route
Site Survey & F.M**
1. Check the test equipment and visit site(building)2. Take a a photograph and fill out the site survey report3. Install the transmitter on the roof of the building4. Install the receiver in a car5. Put the transmitter on6. Start the driving test7. Perform the Site survey & field measurement result analysis - Path loss analysis8. Perform the Competitor’s coverage measurement
Test Equip.* Verification
1. Check the spectrum analyzer self-generated noise level & accuracy2. Setup the Transmitter and check the output power level 3. check the Amplifier Gain by using signal generator and spectrum analyzer4. Measurement of Cable loss - between transmitter and AMP
- between AMP and Antenna
* Equip.: Equipment** F.M: Field Measurement
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Site Survey Planning
Stage 2: RF Environment Analysis
Candidate sites shall be selected in each morphology to represent the characteristics of that region and then team organization and scheduling for the site survey and the field measurement shall be made. And the drive route should be decided based on the main road and the road condition
make a plan for site surveying & field measuremnt select a variety of candidate site organize the team for site surveying decide the drive route
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Site Survey Report
4Date :
Site ID :
Visitor :
Bldg . Address :
Bldg . Height : Steel Tower Height : m
Latitude : Longitude :
Special Comment :
Department store,Government office,Competitor site,Hotel, University,Above the10th-story bldg .
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Picture No :Avg . Bldg . Height :Major Bldg .:
Stage 2: RF Environment Analysis
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Field Measurement - Test Equipment Verification
Checking of the spectrum analyzerSelf-generated Noise level & accuracy
Setting up the Transmitter andChecking Tx Output Power level
by using Spectrum Analyzer
Checking the LPA Gain by using Signal Generator and Spectrum Analyzer
Measurement of Cable Loss a. Between Transmitter and AMP b. Between AMP. and Antenna
Stage 2: RF Environment Analysis
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Field Measurement - Drive Test: All road test as possible as can go
FA “A” (Central Channel# A)
FA “B” (Central Channel# B)
Team A
Team B
MS_1 MS_2
MS_3 MS_4
10Km
10Km
Site A
Site BMeasurement Radius
Stage 2: RF Environment Analysis
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Field Measurement - Measurement Data Analysis(1)
Perform the Data Gathering and Analysis
Calculate the distance for each measurement point Calculate the average Rx level for unit area (30m * 30m) Calculate the average Rx level for distance
Path Loss Calculation
Path Loss = Transmit signal Power – Received signal power [dBm]
Path Loss data is used to perform the Measurement integration to calculate the exact Propagation model
By using the Cell Planning tool, It will be easy to perform the MI
Stage 2: RF Environment Analysis
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Field Measurement - Measurement Data Analysis(2)
PropagationPrediction Model
Measurement Data
Signal Strength
Distance
Propagation Prediction Model
Measurement Data
δ
Signal Strength
Distance
-δ
MEASUREMENT INTEGRATION(MI)
Stage 2: RF Environment Analysis
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Competitor’s Coverage Measurement / Analysis
Collecting Information about the Specification of the Competitor’s System
• The site location
• The height of the building and the tower
• Antenna type
• The direction and the angle of the antenna
• Control channel number and the output power by each sector
Measuring the Service Quality• GPS data(altitude & logitude)
• Cell ID (best sever / neighbor cell)
• Rx power (best sever / neighbor cell)
• BCCH (best sever / neighbor cell)
Stage 2: RF Environment Analysis
33
Link Budget Analysis
OBJECTIVES OF LBA
To estimate the Maximum Allowable Path Loss for the Reverse Link
To estimate Maximum Allowable Path Loss for the Pilot, Sync, and Paging Channels, including the appropriate path imbalance
To compute the required percentages of Base Station transmit power for the Pilot, Sync, Paging and Traffic Channel
To estimate cell coverage and count
Stage 2: RF Environment Analysis
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Link Budget Analysis(Reverse Link)
Stage 2: RF Environment Analysis
Reverse LinkMAPL
LBA
Operating Parameters:System % Loading, SHO gain
Subscriber Parameters: Maximum PowerCable lossAntenna GainNoise Figure
Noise FigureBS Parameters:
Antenna GainLosses
Voice Activity & Reuse Factor
Technology Parameters:Bandwidth, Data Rate ( Proc. Gain)Required Eb/It
Propagation Parameters:Fade Margin, Penetration Loss
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Link Budget Table(Example: SKTelecom)
Uni t Val ue RemarkFrequency MHz 877 CustomerBandwi dth MHz 1. 2288 Spec.Data Rate bps 9600 CustomerProcessi ng Gai n dB 21 Cal cul ated%Loadi ng % 50%CustomerRequi red Area Rel i abi l i ty % 95%Customer
Morhpol ogy Cl ass D. Urban Urban S. Urban Rural Open Remark
At Mobi l e Stati on (TX)Mobi l e Tx Power dBm 23. 0 23. 0 23. 0 23. 0 23. 0 Spec. (Cl assI I I )Antenna Gai n dBi 0. 0 0. 0 0. 0 0. 0 0. 0 CustomerBody Loss dB 3. 0 3. 0 3. 0 3. 0 3. 0 Customer
At Base Stati on (RX)Noi se Densi ty(KT) dBm/ Hz -174. 0 -174. 0 -174. 0 -174. 0 -174. 0 Spec.Noi se Fi gure(F) dB 5. 0 5. 0 5. 0 5. 0 5. 0 Vendor Spec.Noi se Bandwi dth dB 60. 9 60. 9 60. 9 60. 9 60. 9 Spec.Noi se(KTBF) dBm -108. 1 -108. 1 -108. 1 -108. 1 -108. 1 Cal cul atedRequi red Eb/ Nt dB 6. 0 6. 0 6. 0 6. 0 7. 0 Vendor Spec. f or 1% FERLoadi ng Correct i on (1-x) dB 0. 0 0. 0 0. 0 0. 0 0. 0Sensi t i vi ty dBm -123. 2 -123. 2 -123. 2 -123. 2 -122. 2 Cal cul atedRecei ve Antenna Gai n dBi 18. 0 18. 0 14. 1 14. 1 14. 1 CustomerCabl e & Di pl exer Loss dB 3. 0 3. 0 3. 0 3. 0 3. 0 CustomerSHO Gai n dB 3. 0 3. 0 3. 0 3. 0 3. 0 Customer
At Radi o ChannelSl ow Fadi ng dB 10. 0 8. 0 8. 0 6. 0 3. 0 CustomerAtten. Factor of Propagati on dB/ dec 3. 5 3. 5 3. 5 3. 5 3. 5 Cal cul atedS. F/ A. F 2. 9 2. 3 2. 3 1. 7 0. 9 Cal cul atedFade Margi n dB 11. 0 8. 5 8. 5 6. 0 3. 5 Cal cul ated
At Servi ce Condi ti onRequi red Contour Rel i abi l i ty % 87. 0 86. 0 86. 0 83. 0 75. 0 Cal cul atedPenetrat i on Loss ( i n car) dB 5. 0 5. 0 5. 0 5. 0 5. 0 CustomerPenetrat i on Loss ( i n bui l di ng) dB 18. 0 15. 0 10. 0 10. 0 10. 0 Customer
OutputMax. Al l ow. PL (on street) dB 150. 2 152. 7 148. 8 151. 3 152. 8 Cal cul atedMax. Al l ow. PL ( i n car) dB 145. 2 147. 7 143. 8 146. 3 147. 8 Cal cul atedMax. Al l ow. PL ( i n bui l di ng) dB 132. 2 137. 7 138. 8 141. 3 142. 8 Cal cul atedMS Antenna Hei ght 1. 5 1. 5 1. 5 1. 5 1. 5BS Antenna Hegi ht 21. 0 25. 0 30. 0 45. 0 45. 0Max. Al l ow. Di stance(on street) km 6. 2 8. 0 6. 9 10. 2 11. 3 Cal cul atedMax. Al l ow. Di stance(i n car) km 4. 5 5. 8 4. 9 7. 3 8. 1 Cal cul atedMax. Al l ow. Di stance(i n bui l di ng) km 1. 97 3. 0 3. 6 5. 2 5. 8 Cal cul ated
Stage 2: RF Environment Analysis
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• Outputs - Sites location - Antenna type - Antenna tower height - Antenna orientation / tilt - O/H Output power
- Candidate site location- Site acquisition report
- Coverage Plot- Recommendation on next candidate sites
• Considering Factors - Maximum cell radius - Traffic distribution - Competitor’s coverage
Designing onthe Map
Finding-out Sites Location and
Initial Parameter Value
Site Acquisition
CoverageSimulation
Coverage Design Procedure
Stage 3: Coverage Design Ⅰ
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Design on the Map result CellPLAN simulation Plot Equp. Type Decision(Initial)
- Anchor site position result - Initial coverage design map - Initial Capacity analysis
- Cell site Position(Morphology) FWD Ec/Io, REV Eb/Nt Plot - Traffic estimation per cell site
H/O region analysis plot
Mobile ERP Plot
MAP DATA - Digital Map for CellPLAN - 1:10,000 Traffic Map
CellPLAN Tool - SKTelecom Design Tool - Initial coverage simulation)Map Info S/W - Design on the Map(Note PC based)
LBA Result - Maximum cell radius - Minimum antenna height - Minimum cell site no
Design on the Map with MAP INFO Tool
- Anchor site selection
(In Dense Urban area, high traffic density)
- Site positioning through the anchor site
CellPLAN Coverage Simulation
- Initial Coverage design by using
CellPLAN Tool(FWD/REV Coverage)
- Initial Capacity analysis based on
the traffic prediction
Equip. Type Decision(Initial)
- BTS, Small BTS, pico BTS
- Fiber optic Micro cell
- RF Repeater
Required Data/Tool
Main Activity
Accomplishment
Stage 3: Coverage Design Ⅰ
38
Design on the MAP
Stage 3: Coverage Design Ⅰ
Coverage design consists of designing on the map, site acquisition and coverage simulation. Especially, site acquisition and coverage simulation is verified and modified repeatedly to achieve optimal coverage design(Iterative)
Cell site location is decided on the map by means of using the maximum cell radius, competitor’s site location and the result of the coverage analysis with consideration of estimated traffic in future
Initial Coverage Simulation After designing on the map, it must qualify the cell site location through the coverage simulation by using RF planning Tool(In case of SKTelecom, there is a cell planning tool named CellPLAN) - Forward / Reverse Coverage simulation - Soft handoff region, etc
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Existing Network Traffic Analysis Procedure
PEG Data Collection and Validity Check
Site/Sector’s Representative Carried Traffic and
Blocking Rate Calculation
• PEG count data collection for 2 Weeks • Abnormal data deletion (Beyond the limit of Avg Traffic 50%) - Too small traffic by an obstacle of BTS - Excessive traffic by PEG counting errors
• Representative Carried Traffic = Avg Carried Traffic + 1.28 * Std (Range of 90% reliability)
• Blocking rate calculating for each sector and site
• Offered Traffic = Carried Traffic * (1+Blocking Rate) Site/Sector’s Offered
Traffic Calculation
Traffic Distribution Analysis
Stage 3: Coverage Design Ⅰ
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• Divide total area into unit area(Aij)• Decide weighting factor each unit area (Wij)
• Wij = 1
Traffic Distribution
1
2
3
j
n
1 2 3 i m
Wij
W11 W12 W13
W21 W22 W23
W32 W33W31
Wnm
Traffic Weighting Map(Mobile Telecom Introduction Stage)
- Traffic Volume - Population Density - Land Usage Shape - Resident Living Standard
Traffic Distribution Analysis
Stage 3: Coverage Design Ⅰ
41
• Divide total area into unit area(Aij)• Calculate occurred traffic each BTS/Sector • Distribute traffic uniformly within BTS/Sector coverage • Decide weighting factor each unit area (Wij) ( Wij = 1)• Distribute the traffic of target year to unit area with weighting factor
Coverage Design and Dimensioning
1
2
3
j
n
1 2 3 i m
WijSite B Site D
W11 W12 W13
W21 W22 W23
W32 W33W31
Wnm
Site C
Traffic Weighting Map(Competitor In Service) • Additional Factor to be
Considered• BTS / Sector Traffic
Traffic Distribution Analysis
Stage 3: Coverage Design Ⅰ
42
Site Acquisition result CellPLAN simulation Result Plot Antenna azimuth & Tilt Degree
- Detail Cell site position - Forward Coverage Plot
- No. of Site Acquisition - Reverse Coverage Plot Initial Overhead Power setup
- Cell site type Decision (Including FMC & RF Repeater)
(BTS, FMC, RF Repeater)
MAP DATA - Digital Map for CellPLAN - 1:10,000 Traffic Map
CellPLAN Tool - SKTelecom Design Tool - Detail coverage simulation (Iterative coverage Simulation)
Result of Design on the MAP - Anchor site position result - each site position, etc
Site Acquisition & Simulation(Iterative) - Search area ring setup for each cell site (SAR: one of fourth area per cell radius) - Making the candidate site list survey - Visit the candidate site
Site Acquisition & Simulation(Iterative) - Check the cell site qualification (LOS, Building Rent or room, etc) - Antenna azimuth & tilt degree decision
CellPLAN Simulation (Iterative & Detail)
- Forward Ec/Io plo
- Reverse Eb/Nt plot
- H/O Region analysis plot
- Mobile ERP plot, etc
Required Data/Tool
Main Activity
Accomplishment
Stage 3: Coverage Design Ⅱ
43
Site Acquisition Site Acquisition Procedure
Pre-visit Analysis and Rank Candidate Sites
All SitesUnacceptable
Visit Sites
Perform and EvaluateDrive Test
Notify Real Estate
Visit Search Area
Revise Objectives
Redesign System
Release SAMs for Site Search
YES
NO
Stage 3: Coverage Design Ⅱ
44
Site Acquisition
Stage 3: Coverage Design Ⅱ
Pre-visit analysis and rank the candidate sites The first of the site acquisition is to identify multiple candidates for each site location, evaluate them on various criteria and rank them accordingly. This procedure results in identification of the best suited candidates for all sites. If all the candidates for any site are rejected for any reason(s), alternatives have to be found, or the objectives revised and candidates reevaluated, and,if all else fails, redesign the system/partial system.
The ranking of the candidate is done in two steps - A preliminary ranking and visit to the top three candidates,followed by the final ranking. Approval is then given to up to three Candidates and the first site that passes the drive test, if required, is accepted.
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Site Acquisition
Stage 3: Coverage Design Ⅱ
Select the Anchor Sites(initial design stage) Anchor sites dictates the overall RF network design. They determine the rest of the search rings. Generate an initial cell site layout, starting with anchor cells and using the preferred/desired locations and the pre-qualified site candidates.
Setup the Search Area Ring Search rings define the areas where a need for antenna placement has been determined. Search rings are not precise cell site locations.
Prepare a list of candidates to visit Since it is not possible, nor necessary, to visit all the candidate sites, the top two or three candidates from the first part of the ranking matrix are to be visited. Since a site cannot be acquired unti11 it is visited, it is in the interest of speedy acquisition that the best potential candidates be visited
46
Site Acquisition
Stage 3: Coverage Design Ⅱ
Site Visit Activities CHECK LOCATION DATA, using the maps or GPS. And record it CHECK OBSTRUCTIONS in all directions, e.g. tall building, unobstructed line of sight for microwave propagation, airports, other antennas, AM stations, etc. ORIENT THE ANTENNA using a compass. Getting an orientation degree is important to evaluate the coverage effectiveness of this site TAKE MEASUREMENT of distance between equipment shelter and antennas (cable run), dimensions of the equipment shelter and compared to the dimensions of the vendor equipment. TAKE PICTURES to document intervening structures/unusual topography of the site.
47
Site Acquisition
Stage 3: Coverage Design Ⅱ
Redesign of the system In the event that all sites initially recommended by Real Estate are unacceptable, reevaluation of rejected sites is not feasible and no alternatives can be identified, the recourse is to revise objectives and redesign the system if needed. This process is initiated by forwarding the Redesign Request to RF Engineering, identifying the reason(s) why this situation arose, and, upfront, making some suggestions or issues to bear in mind while redesigning the system. This facilitates a successful redesign, with less chances of again yielding unacceptable candidates.
48
Coverage Simulation
• Measurement Integration• Forward Link Analysis - RSSI - Pilot Ec/Io - Soft Handoff•Reverse Link Analysis - Mobile ERP - Traffic Eb/Nt
• GIS DB - Terrain - Morphology - Vector - Building
• Propagation Prediction Model • Field Measurement Data• Cell Site Parameters • Traffic Distribution
CDMA Cellular Wireless Network
Analysis
Personal ComputerWindow 95
CellPLAN
CellPLAN Structure
Stage 3: Coverage Design Ⅱ
49
Stage 3: Coverage Design Ⅱ
Coverage Simulation Main Activities
Forward Coverage Analysis Forward Pilot Ec/Io Plot Forward Pilot Best Server plot Forward Pilot Eb/Nt plot Reverse Coverage Analysis Reverse Traffic Eb/Nt plot Reverse Mobile ERP Plot Soft Handoff region ratio and Analysis CDMA Forward/Reverse Link Coverage Analysis 2D/3D profile for LOS check, etc
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PN Offset Allocation Result Paging zone Decision H/O Neighbor list simulation - PILOT_INC Decision - Paging channel capacity calc. - make the H/O neighbor list - PN Offset Reuse Distance Calculation - Paging zone decision - Cell site PN Offset Allocation BTS O/H Power Simulation
Design Criteria - PILOT Assignment - Soft Handoff Region ratio - Paging channel capacity - Paging zone
Cell Plan Tool - Handoff simulation - coverage simulation, etc
PN Offset Allocation - PILOT_INC Calculation (Lower/Upper Limit) - PN Offset Reuse Distance Calculation - Base Station PN Offset Allocation
Paging Zone Decision - Paging Channel Capacity Calc. - Paging Zone Decision
Handoff Neighbor List Simulation - Handoff neighbor list
BTS Overhead Power Simulation
Required Data/Tool
Main Activity
Accomplishment
Stage 4: Parameter Design
51
- PN offset allocation
- Paging zone
- Handoff neighbor list
- Overhead power
• Use coverage design result and design criteria• Design results are used the initial operation value of system
parameters• Adjust the system parameters according to optimization after
system in-service• Designed parameters
Parameter Design
Stage 4: Parameter Design
52
Parameter Design (Pilot offset allocation)
Stage 4: Parameter Design
Lower Limit for PILOT_INC
No interference Condition between δ1 and δ2
1. To prevent the presence of a pilot signal with
a different PN offset in the active search window
due to a large differential delay
2. To prevent the presence of a pilot signal with
an undesired PN offset in the neighbor search
window due to a large differential delay
ri : Cell radiusδi : Pilot PN Phase offsetτi : Time delay between Cell site and Mobile stationSA : active search window size (one sided)SN : neighbor search window size(one sided)
PILOT Interference between sites
p1
p2
Interference
p
r1 chips
r2 chips
PN Offset = δ2 chips
PN Offset = δ1 chips
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δ1 δ2
α1+τ1 δ2 +τ2
sA
Cell Tx PN timing
Mobile Rx PN timing
Active SearchWindowEarliest arriving
multipath of a pilot
Condition 1
(δ2 + τ2) - (δ1 + τ1) >SA
δ12 = δ2 - δ1 > SA + max{τ1 - τ2} max{τ1 - τ2} = r1
δ1+τ0 δ2 +τ0
sN
Mobile Rx PN timing
Earliest arriving multipath of a pilot
Condition 2
δ0+τ0 δ1+τ1δ2 +τ2
sA
sN
Neighbor SearchWindow
δ2 + τ0 - SN > δ1 + τ0 + SN
δ12 = δ2 - δ1 > 2SN
δ12 = δ2 - δ1 > max{SA + r1, 2SN}
δ12 = PILOT_INC * 64 PILOT_INC * 64 > 2 SN
(SN > SA ,SN > r1)
sN sN
Parameter Design (Pilot offset allocation)
Stage 4: Parameter Design
54
Pilot PN Offset Reuse
Pi : cell site Tx Powerdi : Distance between Cell site and MSi : Pathloss exponentdi : Distance between cell sitesT : Threshold value
Parameter Design (Pilot offset allocation)
Stage 4: Parameter Design
PILOT PN OFFSET REUSE
Cell 3
r3 chips
Cell 1
r1 chips
Phase Offset = δ1 chips Phase Offset = δ1 chips
Cell 2
r2 chips
D chips
Phase Offset = δ2 chips
No interference Condition between δ1 and δ2
1. To prevent undesired finger output for the pilot
signal from distant reuse cell
2. To guarantee the absence of the undesired finger
output for the pilot signal from distant reuse cell
3. To prevent indistinguish ability of sectors with the
same offset in other’s neighbor search window
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Condition 1
D > 6.8r
Condition 2
If d1=r1, d3=D-r1 (Worst case)
edd
PP b
T
)(
1
3
3
1 31
β
1
)(
3
11
311
ePPr
bTD
β
τ3 - τ1 >SA
If τ1=r1, τ3=D-r1
D > 2r + SA
Condition 3
To distinguish the cell1, cell 3 at the cell 2, must keep the distance above 2r2 + s2N
In case of straight line of three cell sites(worst case)
D > 2(2r2 + s2N)
Equal size sells & Power
= 3.84, T = 19dB
8dB stdev for the shadow fading
D > MAX(condition1, condition2, condition3)
> MAX(condition1, condition3)
Reuse Distance
Parameter Design (Pilot offset allocation)
Stage 4: Parameter Design
56
Parameter Design (Paging channel analysis)
Stage 4: Parameter Design
General AssumptionNumerical
ValueGeneral Assumption
Numerical Value
a. Paging Channel Capacity 9600 bps j. System Parameter Message 264 bits
b. Maximum allowable utilization 0.9(90%) k. Access Parameter Message 184 bits
c. Paging Strategy(No. of users) 2 l. Neighbor List Message 216 bits
d. Termination Rate 0.35 m. CDMA Channel List Message 88 bits
e. Busy Rate 0.03 n. Extended System Parameter Message 112 bits
f. BHCA per Subscriber 2 o. Channel Assignment Message 144 bits
g. Number of Sectors per MSC ----- p. Order Message
h. General Page 136 bitsVoice Mail Service
q. Voice Mail Notification 720 bits
i. Overhead Message I=j+k+l+m+nShort Message Servicer. Data Burst Message(x: No. of character) 7x+380 bits
s._DONE Message 72 bits
Assumption & Paging channel MSG Lengths
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Parameter Design (Paging channel analysis)
1 Pagi ng Capaci ty Anal ysi s Tabl e 2 Si ze3 Number Of Users 200000 Subscri bers4 Number of power Up/ Down per day 55 Ti mer based Regi strat i on peri od parameter 64 Ti me Based Regi strat i on Peri od
6 TI mer based Regi strat i on peri od val ue - Second 5242. 88 I F(POWER(2, (C5/ 4))*0. 08= 0. 08, 0, POWER(2, (C5/ 4))*0. 08) :Typi cal Val ue of Reg. Peri od
7 Another Regi strat i on 0 Zone-based Reg. Etc89 Number of Zones 1 1 zo ne As su m p ti o n10 Number of BTS per Zone 24. 0011 Number of Sectors per BTS 312 Number of BTS i n System 2413 Sectors i n System 72 C11*C1214 Regi strati on
15 Total Regi strat i on i n the System per Day 5295898 C3*(C4*2+3600*24/ C6+C7) : Power On/ Off , Ti me Based, Zonebased r e g .e t c
16 Concentrati on rate of BHCA 0. 098
Stage 4: Parameter Design
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Parameter Design (H/O neighbor list)
Stage 4: Parameter Design
• make the H/O neighbor list by using CellPLAN tool. (Maximum List: 20 EA / Cell Site)
• 1st, 2nd Cluster analysis(1,2 tier analysis)• Search Window Size decision - Active Search Window Size
- Neighbor Search Window Size
- Remaining Search Window Size
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Yearly based Dimensioning result
- Required BTS no. - Required FA no.
- Required CHC no.
- Required channel element no.)
Marketing Demand Analysis- Subscriber forecasting- MOU(Minute of Usage)- Traffic prediction
Equipment Type - capacity per equipment - coverage per equipment
Cell site trafficDistribution analysis
Engineering sheet Drawing Up - FA growth calculation - Channel Card quantity - Channel element quantity
Engineering sheet Drawing Up for yearly based dimensioning - No. of Required FA - No. of Required Channel Element - No. of Required CHC(Channel Card)
Required Data/Tool
Main Activity
Accomplishment
Stage 5: Dimensioning
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Dimensioning Procedure
Design Criteria - MAX. CE per FA - MIN. CC - GOS(Blocking Rate)
Estimated Traffic - Carried Traffic - Soft Handoff Traffic
Cell Site Configuration - Channel Card Type - BTS Type
FA DimensionBTS Dimensioning
Loading Calculation
Module
Required CE CalculateRequired CECalculation
Module
Required CC Calculate CE per CC
Stage 5: Dimensioning
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Predicted Traffic Calculation by Subscriber’s MOU Analysis
• Total Traffic and Traffic per Sub. Calculation
- Erlang / Sub. = MOU per Sub. / ACDM * BHDR / MH
- Total Erlang = Erlang / Sub. * Total Estimated Sub.
BHDR : Busy Hour Day Ratio
ACDM : Average Calling Days per Month(Use 26 or 27 days)
MH : Minutes per Hours(60 Minute)
• The Required BTS by the year• The Required FA No.• The Required CE and CHC calculation
Engineering Sheet Drawing up
Stage 5: Dimensioning