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Proprietary
Procedure of CDMA RF Engineering
(RF Network Design)
2002. 4. 5
Jeon Hyun Cheol
Proprietary2
1. Network Design Objective… … … … … … … ..4
2. RF Network Design Procedure… … ...… ...13
Stage 1: Preparations … ...… … … … … … … ...… 14
Stage 2: Wireless Environment Analysis … … ..44
Stage 3: Coverage Design … … … … … … … … ..72
Stage 4: Parameter Design … … … … … … … … .86
Stage 5: Dimensioning … … … … … … … … … ...106
? About CellPLAN® … … … … … … … … … ...… 109
Contents
Proprietary3
SK Telecom CellPLAN®
- Propagation Model(Modified Hata, Modified COST-231, Ray Tracing, Lee model)
- Measurement Data- Traffic Distribution(Uniform, Non-uniform, Density per sector)
- Site Information(location, sector type, Tx pwr, antenna, neighbor list, etc.)
- Analysis algorithm(CDMA, CDMA 2000, EV-DO, WCDMA)
GIS
- DEM : 1 m or 10m resolution
- Vector- Morphology
: 14 Layer
- Coverage- Capacity- Quality
Proprietary4
? Acceptable Coverage? Forward & Reverse Link Quality?Capacity
? To Resolve
? To Manage
? To Ensure
? Engineering Requirement vs.? Available Equipment?Customer Complaints
? Pilot Pollution ?Cell Overlap / Handoff Regions
1. Network Design Objectives
Proprietary5
The Cellular Concept
Introduction
•A major breakthrough in solving the problem of spectral congestion and user capacity.
• It offer very high capacity in a limited spectrum allocation without any major technological changes.
Frequency Reuse (or Frequency Planning)•The design process of selecting and allocating channel
groups for all of the cellular base station within a system.
1. Network Design Objectives
Proprietary6
The Cellular Frequency Reuse
N =7 pattern (AMPS,TDMA)
Frequency Reuse Factor = 1/N
Ctotal = CH# * Cluster# * N
N =1 pattern(CDMA,IMT-2000)
Frequency Reuse Efficiency =
Ctotal = Cell# * Cper cell
1
2
3
45
6
7
1
2
3
45
6
7
1
2
3
45
6
7
100%6%
0.2%
ocic
ic
III?
Cluster
1. Network Design Objectives
Proprietary7
Method of locating co-channel cellsThe geometry of hexagons is such that the number of cells per cluster, N, can only have values which satisfy :
N = i2 + ij + j2
where i and j are non-negative
numbers.
1
2
3
4
5
6
7
1
2
3
4
5
6
7
1
2
3
4
5
6
71
1
11
N = 7i = 2j = 1
1. Network Design Objectives
Proprietary8
Co-channel interference and System CapacityWhen the size of each cell is approximately the same, and the base stations transmit the same power, the co-channel interference ratio is independent of the transmitted power and becomes a function of the radius of the cell (R) and the distance between centers of the nearest co-channel cells (D).
The parameter Q, called the co-channel reuse ratio, is related to the cluster size.
A small value of Q provides larger capacity since the cluster size N is small, whereas a large value of Q improves the transmission quality, due to a smaller level of co-channel interference. A trade-off must be made between these two objectives in actual cellular system.
NRD
Q 3??
Cluster size (N) Co-channel Reuse Ratio (Q)
i=1, j=1 3 3i=1, j=2 7 4.58i=2, j=2 12 6i=1, j=3 13 6.24
1. Network Design Objectives
Proprietary9
Co-channel interference and System Capacity
where S is desired signal power from the desired base station and Ii is the interference power caused by the ith interfering co-channel cell base station.m is the number of co-channel interfering cells. n is the path loss exponent. n is typically range 2 and 4.
For example, AMPS require S/I ? 18dB for sufficient voice quality. Assuming a path loss exponent n=4, cluster size N should be at least 6.49. Thus a minimum cluster size of 7 is required.
? ?? ? ? ?
13/
1
?????
???
?
?
?
NN
mRD
D
R
I
SIS
nn
m
mi
ni
n
m
ii
D+R
D+R
D
D
D-R
D-R
R
D
1. Network Design Objectives
Proprietary10
Cell Splitting and Sectoring
Cell Splitting
• the process of subdividing a congested cell into small cells
with its own base station.
Sectoring
•The co-channel interference in a cellular system may be decreased by using several directional antennas.
1. Network Design Objectives
Proprietary11
Increase in capacity by cell site reconfiguration
VS
•Simulation results shows the capacity can be up to 7% increased.
(by using practical antennas : 84 ~ 110 deg. Attenuation factor : 4)
1. Network Design Objectives
Proprietary12
Design Value
Design Criteria
? %
FER(Frame Error Rate)
? %
GOS(Blocking Rate)
? %
CoverageProbability
- 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
Proprietary13
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 theMap Positioning
Site survey & Field measurementMeasurement data integrationPath loss calculation
RF Environment Analysis
Outdoor/UndergroundCoverage 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
Proprietary14
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 Volumeand 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: PreparationsOverview
Proprietary15
Trunking and Grade of Service
The concept of trunking allows a large number of users to share the relatively small number of channels in a cell by providing access to each user, on demand, from a pool of available channels.
The grade of service (GOS) is a measure of the ability of a user to access a trunked system during the busiest hour.
The traffic intensity offered by each user is equal to the call request rate multiplied by the holding time. That is, each user generates a traffic intensity of A erlangs given by
Au = ? H
where H is the average duration of a call and ? is the average number of call requests per unit time. For a system containing U users and an unspecified number of channels, the total offered traffic intensity A, is given by
A = UAu
In a C channel trunked system, if the traffic is equally distributed among the channels, then the traffic intensity per channel, Ac, is given as
Ac = UAu/C
Stage 1: Preparations
Proprietary16
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
ang
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Cap
acit
y In
crea
se R
atio
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
Proprietary17
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
Proprietary18
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
Proprietary19
Setup the Design CriteriaStage 1: Preparations
0.5
0.6
0.7
0.8
0.9
1
1.1
? /n
Fra
ctio
n o
f To
tal A
rea
wit
h S
ign
al a
bo
veT
hre
sho
ld. F
u
0 1 2 3 4 5 6 7 8
PX0(R) = 0.95
0.9
0.85
0.80.75
0.70.65
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)
Proprietary20
Setup the Design CriteriaStage 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
Fade
Mar
gin
in d
B12 dB1110
9876
StandardDeviation
Fade Margin -----> 10 dB
Proprietary21
Setup the Design Criteria
? Coverage Area and Contour Reliability(FADE MARGIN)
10 dB
Dense Urban
6 dB8 dB8 dBSlow Fading
RuralSuburbanUrbanItem
Slow FadingIt follows the log-normal distribution with standard deviationIt 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
Proprietary22
CDMA Capacity
1. Hard Capacity and Soft Capacity(1) Hard Capacity : Call limits due to insufficient of H/W or frequency resource
(2) Soft Capacity : Call limits due to other user’s high level interference
2. Reverse Link Capacity(1) Pole Capacity : Theoretical maximum capacity with ideal noise condition
(2) Erlang Capacity : Statistical capacity from blocking probability
3. Forward Link Capacity(1) Capacity limits are reached when available HPA power reaches 100% transmit
power to meet Eb/Io requirements in a specific sector
(2) When forward Ec/Io drops under threshold due to change of pilot channel power ratio in total power
Stage 1: Preparations
Proprietary23
Hard Blocking ModelThe maximum possible carried traffic is the total number of channels, C, in erlangs.This implies that the channel allocations for cell sites are designed so that 1 out of 100 calls will be blocked due to channel occupancy during the busiest hour.
Erlang B Model (blocked calls cleared formula)
If no channels are available, requesting user is blocked without access and is free to try again later. It is assumed that there are an infinite number of users as well as the following :(a) Call arrive according to the Poisson process. This implies that the time between call arrivals is exponentially distributed. For this to be strictly true, a user whose call is blocked cannot immediately retry.(b) the probability of a user occupying a channel is exponentially distributed, so that longer calls are less likely to occur as described by an exponential distribution.(c) there are a finite number of channels available in the trunking pool.
? ? GOS
kA
CA
blocking C
k
k
c
??
?? 0 !
!Pr
Stage 1: Preparations
Proprietary24
Hard Blocking ModelThe second kind of trunked system is one in which a queue is provided to hold calls which are blocked. If a channel is not available immediately, the call request may be delayded until a channel becomes available.
Erlang C Model (blocked calls delayed formula)
? ??
?
????
??? ??
?? 1
0 !1!
0Pr C
k
kc
c
kA
CA
CA
Adelay
Number of Capacity (erl.) for GOSChannels (C) 2% 1%
2 0.224 0.1535 1.657 1.361
10 5.084 4.46240 31.00 29.0190 78.31 74.69
Capacity of an Erang B system
Number of Capacity (erl.) for DelayChannels (C) 2% 1%
2 ? 0.21 ? 0.155 ? 1.6 ? 1.3
10 ? 4.5 ? 4.040 ? 28.0 ? 26.090 ? 71.0 ? 70.0
Capacity of an Erang C system
Stage 1: Preparations
Proprietary25
Hard Blocking ModelStage 1: Preparations
Proprietary26
Soft Blocking ModelAn analog base station blocks calls when there is no channel available. This form of blocking is called “hard blocking”. However, another blocking condition exists for a CDMA base station. Unlike AMPS and TDMA, CDMA does not impose a definite limit on blocking.As the number of users increase in CDMA system, the level of interference increases as well, and this increase in interference negatively affects the quality of service. Because all users share the same RF spectrum, the interference increase contributes the a higher FER and a higher drop-call rate.
Soft blocking Model
Three assumptions are used in the simplified model :
(1) There is a constant number of users N in the cell.
(2) There is perfect power control.
(3) Each user requires the same Eb/Io.
Stage 1: Preparations
Proprietary27
Variables affect on CDMA Soft Capacity
1. Processing Gain (Gp) : Bandwidth/Data Rate = W/R
2. Required Eb/Nt (or Eb/Io) : It is determined by required FER. FER translates directly into perceived voice quality, the system must be optimized so that there is minimal and acceptable FER on both forward and reverse links. The FER is largely correlated to Eb/Nt. Thus we examine FER in terms of the Eb/Nt. The FER also depends on vehicle speed, local propagation conditions (fast fading profile ..), receiver algorithm, and distribution of other co-channel mobiles, .
3. Activity factor : typically 0.4 ~ 0.5 for voice, 1 for data
4. Frequency Reuse Factor : Typically 0.6 ~ 0.85
5. Sectorization Gain : approximately 2.6 times for 3 sector
6. Standard Deviation of Power Control : typically 2 dB
Stage 1: Preparations
Proprietary28
FER vs. Eb/NtFor the two-path case, 30 km/h is the worst-case speed, requiring Eb/Nt of 7 dB to obtain a FER of one percent. (simulated by Qualcomm)
The diversity gain is about 3 to 6 dB, depending on the mobile speed.
Stage 1: Preparations
Proprietary29
CDMA Pole Capacity
SNfWFNS
G
WSNf
FN
RSIE
thp
tho
b
)1)(1(
)1)(1(/
????
???
?
?
?
SWFN
ffd
GN thp
)1(1
1)1(
1?
???
???
1)1(
1max ?
??
fd
GN p
?
Eb = bit energy
Io = Nth + interference density
F = Noise figure
Nth = power spectral density of thermal noise
S = received signal strength
R = bit rate
? = activity factor (=0.4)
f = interference factor = Ioc/Iin (=0.66)
N = number of users
W = bandwidth
Gp = W/R = processing gain
Ptotal = total power
Prec = received power
Stage 1: Preparations
Proprietary30
Cell Loading
Total Received Power to Noise Ratio vs. CellLoading
0
5
10
15
20
0 10 20 30 40 50 60 70 80 90 99
Cell Loading (%)
Tota
l Rec
eive
d P
ower
to
Ther
mal
Nois
e Rat
io (dB)
Interference to Thermal Noise Ratio vs. Cell Loading
-20-15-10-505
101520
1 10 20 30 40 50 60 70 80 90 99
Cell Loading (%)
Inte
rfer
ence
to
Ther
mal
Nois
e Ra
tio (
dB)
???
?1WFN
P
th
rec
???
??
11
WFNWFNP
WFNP
th
threc
th
total
? ,? ,
Stage 1: Preparations
Proprietary31
Cell Breathing
total
rec
threc
rec
th
threc
th
total
PP
WFNPP
orWFN
WFNPWFN
P
NN
??
?
????
??
?
?
?
??
?
)1(log10 Margin ceInterferen 1
1
Factor Loading :
10
max
Interference Margin
Loading
0
5
10
15
20
25
0 0,2 0,4 0,6 0,8 1
Load factorL
os
s (
dB
)
Stage 1: Preparations
Proprietary32
CDMA Erlang CapacityIn reality, none of the three previout assumptions holds because of the followings :
Three assumptions are used in the simplified model :
(1) The number of active calls is Poisson distributed with mean ? /? .
(2) Due to voice activity, each user is on with probability v and off with probability (1-v).
(3) Each user requires a different Eb/Io to achieve a desired FER.
To calculate the Erlang capacity of a single cell in a CDMA system, we assume that the number of active users M can be modeled by Poisson distribution.
Where ? /? = offered average traffic load in erlang.
? = average arrival rate of users, and
1/? = average time per call.
The call service time ? per user is assumed to be exponentially distributed, so that the probability that ? exceeds T is given as
? ? ???? /
!/ ?? eM
pM
m
0 )( ??? ? TeTp Tr
??
Stage 1: Preparations
Proprietary33
CDMA Erlang Capacity
? ?? ?? ? ? ? ? ??
??
??
,1/
1/BF
fIERW
ob ??
?
Using previous assumptions,
? ? ? ?? ?? ?? ?
? ?
? ?
? ? ? ??
?
2/
411
21
1
230301010ln2exp
1
power. noise thermal topower noise thermal plus ceinterferen total of ratio the1/factor activity voice v
where
2/)(
3
3
22
21
2
???
????
??
???
?
???
????
????
?????
???
??
??
??
?
?
z
x
ob
dxeQ(z)
Ba
Baa
B,sF
.)/(ß/sßa
rW/R)P(blockingQ/IE
B
Stage 1: Preparations
Proprietary34
CDMA Erlang Capacity
? ?? ?? ? ? ?? ?
erlangs 21.20
5360.055.01)4.0(012.5
1.0121.130
??
??
??
? ?? ?? ?? ?
? ?
? ?
0.5360
)2322.0()0874.1(
411
2)2322.0()0874.1(
10874.11
,
0874.12/)778.1()2322.0(exp
2322.01.0121.130
33.2012.5B
2.33(0.01)Q
3
3
22
2
-1
????
?
???
????
????
?????
??
??
?
?
?
?
BF
Example, W=1.25 MHz, R=9.6 kbps ,1/? =10 therefore n=0.1, ? =2.5dB or 1.778, f=0.55, blocking rate 1%, Eb/Io=7dB or 5.0, v=0.4
The number of users from the erlang B table at 1% blocking about 30 channel
Stage 1: Preparations
Proprietary35
CDMA Hard Blocking
Example,
When Offered traffic per cell = 11 erlang, Blocking rate = 1 % 2 way-Handoff area = 30 %, 3 way-Handoff area = 10 %
Load factor = 1 + 0.3 + 0.1= 1.4
Thus real offered load = 1.4 x 11 = 15.4 elang
From Erlang B Table, we obtain 24 traffic channel.
Stage 1: Preparations
Proprietary36
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 Nbased on Perfect Power Control, No Thermal Noise, andIsolated 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
Proprietary37
Setup the Design Criteria
? Pole(Maximum) Capacity(based on IS-95A reverse link)
NoW
IoIocvSNRS
ItEb
N
N
????
)/1()1(/
)1()1(1 fvNWR
ItEb
WR
ItEb
NoWSN
????
• Including the effects of Thermal Noise, Voice Activity and othercell interference
IoIocf ?,where
Stage 1: Preparations
Proprietary38
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 ?? FvIt
EbR
WN
1)355.2(*1*
min)(secmax/ ?? Fv
ItEb
RW
torNf
F?
?1
1,where
Stage 1: Preparations
Proprietary39
? 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
NtEbFPG
Nkk
kk ?
????
???
•Base station FA capacity of service carrying number of S with various transmission velocity
Setup the Design CriteriaStage 1: Preparations
Proprietary40
? 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 CriteriaStage 1: Preparations
Proprietary41
? Soft Handoff Region Ratio
Soft Handoff Region Ratio
0
10
20
30
40
50
60
70
80
-22 -21 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11T_ADD (dB)
Reg
ion
Rat
io (%
)
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 CriteriaStage 1: Preparations
Proprietary42
?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 Microcells
? 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)
Proprietary43
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 CriteriaStage 1: Preparations
Proprietary44
RegionClustering
Maximum Cell Radius,Minimum AntennaHeight Calculation
Site Survey and Field Measurement
Competitor’s CoverageAnalysis
Link BudgetAnalysis
Procedure OverviewStage 2: RF Environment Analysis
Proprietary45
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 clustering
Site 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
Proprietary46
?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
Proprietary47
Region Clustering(Quantitative)
016>= 160150 ~ 200>= 40Commercial Area
<= 117 ~ 8>= 200>= 250>= 45Industrial Area
01>= 4>= 180200 ~ 250>= 50Shopping AreaDenseUrban
<= 112 ~ 3>= 200>= 25035 ~ 45Industrial Area
013>= 160150 ~ 20030 ~ 40Commercial Area
01>= 4>= 180200 ~ 25045 ~ 50Shopping Area
Urban
<= 21>= 4>= 90>= 500> = 12High-rise residential
<= 512 ~ 370 ~ 90100 ~ 12020 ~ 30Residential(no Open)
>= 2.51255 ~ 7095 ~ 11512 ~ 20Residential(Open)
Suburban
-----< 12Flat, Hilly, MountainRural
STDAvg.STDAvg.VI(%)
BHD(Floors)BSD(m2)BAI(%)ClassRegion
[Reference] David Parsons “ The mobile radio propagation channel”
Stage 2: RF Environment Analysis
Proprietary48
Build-Up Areas : A Classification SampleBritish Telecom categories of land usage :
Category Description
0 River, lakes and seas
1 Open rural areas : e.g. fields and heathlands with few trees
2 Rural areas, similar to the above, but with some wooded areas, e.g. parkland Wooed or
forested rural areas
3 Wooded or forested rural areas
4 Hilly or mountainous rural areas
5 Suburban area, low density dwellings, e.g. council estates
6 Suburban area, higher density dwellings, e.g. council estates
7 Urban areas with buildings of up to four storeys, but with some open space between
8 Highter density urban areas in areas in which some buildings have more than four storeys
9 Dense urban areas in which most of the buildings have more than four storeys and some
can be classed as ‘skyscrapers’. (This category is restricted to the centre of a few largecities)
Stage 2: RF Environment Analysis
Proprietary49
Build-Up Areas : A Classification Sample
Comparison of BT and other land use categoriesBT(UK) Germany BBC(UK) Denmark Okumura(Japan) SK Telecom(Korea)
0 4 - - Land 0 No Data
1 2 1 0-2 - 1 Open areas 2 3 1 1-2 - 2 Inland Water3 2 1 4 - 3 Residential4 2-3 1 - Undulating 4 Mean Urban5 1 2 3 Suburban 5 Dense Urban6 1 2 6 Suburban 6 Buildings7 1 3 7 Urban 7 Village8 1 3 8 Urban 8 Industrial9 1 4 9 Urban 9 Open in Urban- - - - - 10 Forest- - - - - 11 Park- - - - - 12 Para Build High- - - - - 13 Para Build Low
Stage 2: RF Environment Analysis
Proprietary50
Build-Up Areas : A Classification Problem - CellPLAN®Stage 2: RF Environment Analysis
Proprietary51
Site Survey and Field Measurement Procedure
Stage 2: RF Environment Analysis
Planning
1. Selection of target Building for site survey
2. Scheduling for site survey and field measurement
3. Planning for Drive route
Site Survey & F.M**
1. Check the test equipmentand visit site(building)
2. Take a a photograph and fillout the site survey report
3. Install the transmitter onthe roof of the building
4. Install the receiver in a car5. Put the transmitter on6. Start the driving test7. Perform the Site survey &
field measurement result analysis- Path loss analysis
8. Perform the Competitor’scoverage measurement
Test Equip.* Verification
1. Check the spectrum analyzer self-generated noise level & accuracy
2. Setup the Transmitter andcheck the output powerlevel
3. check the Amplifier Gain byusing signal generator andspectrum analyzer
4. Measurement of Cable loss- between transmitter and AMP- between AMP and Antenna
* Equip.: Equipment** F.M: Field Measurement
Proprietary52
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 measurement? select a variety of candidate site?organize the team for site surveying?decide the drive route
Proprietary53
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
Proprietary54
Path loss calculation
For Analytical approach
For Macro cell (r>1km*note)
•Okumura’s model / Hata’s model
•COST-231 Model (Walfish-Ikegami model)
For Micro (100m<r<1km*note) & Pico (r<100m*note)cell
•COST-231 Model (Walfish-Ikegami model)
•Ray-Tracing model
ITU-R Recommendation
??? rnL log10
* Note : by ITU Recommendation
Stage 2: RF Environment Analysis
Proprietary55
Hata Model
CCIR
kmmbemrembeMHzurban dhhahfL log)log55.69.44()(log82.13log16.2655.69 ,,, ??????
4.5)]28/[log(2 2 ??? MHzurbansuburban fLL
94.40log33.18)(log78.4 2 ???? MHzMHzurbanopen ffLL
•Frequency : 150 MHz ~ 1.5 GHz (2.2 GHz)
•Distance : 1 km ~ 20 km ( 4 km)
•Tx antenna height (hb) : 30 m ~ 200 m
•RX antenna height (hr) : 1 m ~ 10 m
5.1h when 0)( mre,, ??mreha
Stage 2: RF Environment Analysis
Proprietary56
Smooth or Rough Terrain ? : Rayleigh Criterion
If , then a surface is rough and :
mean
Real Surface of the Earth
The Rayleigh Criterion
incidence of angle the :heigh terrain the of deviation stadard :
4)sin(4
??
?? ?
??? ?
the
C ??
Idealized Rough Surface
? ?? ? ? ????
sin22cos1sin
dd
L ????
? ??
?? sin4 dLko ??
The path length difference is :
The phase difference at receiver :
2?
?? Lko ? ? ??
??
8sin8??d
d
0.01 0.1 10 100C
smooth rough
Stage 2: RF Environment Analysis
Proprietary57
Path Loss by Hata Model
50.00
70.00
90.00
110.00
130.00
150.00
170.000.
1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
Distance (km)
Path
Loss
(dB
)
Urban_800M
Subur b a n _ 8 0 0 M
Open_800M
Urban_2G
Suburban _ 2 G
Open_2G
Hb = 30mHr = 1.5mf1 = 880MHzf2 = 2GHz
Path loss difference
between f1 and f2
Urban : 9.3dB
Subur : 6.9dB
Open : 5.2dB
Stage 2: RF Environment Analysis
Proprietary58
COST-231 Model
The European Co-operative for Science & Technical research
•Frequency : 800 MHz ~ 2 GHz
•Distance : 200 m ~ 5 km
•Tx antenna height : 30 m ~ 200 m
•RX antenna height : 1 m ~ 3 m
)log9loglog(L
)h20log10logf10logW-(-16.9
)44.32log20log20(
bsh
m
,,,
bfkdkk
L
fd
LLLL
fda
o
dBmsdBrtsdBFdB
??????????
???
???
•LF : free space path loss •Lrts : roof-to-street diffraction loss•Lms : multi-screen loss
Stage 2: RF Environment Analysis
Proprietary59
ITU-R Recommendation Model
For indoor office test environment
For outdoor to indoor and pedestrian test
environment
For vehicular test environment
????
?? ?
??
????460
12
3183037.
.log nn
nRL
493040 ??? fRL loglog
? ? 802118104140 3 ???????? ? fhRhL bb logloglog)(
Stage 2: RF Environment Analysis
Proprietary60
Knife Edge Diffraction Loss
Tx
Tx
d1 d2
h
d1 d2
h
Case I
Rx
Rx
Case II
???
????
??
??
21
112
dd
h?
?
????
?
????
?
?
?
???
??
????
?
-2.4v )v
0.22520log(-
-1v2.4- 0.38)(0.1v-0.1184-20log(0.4
0v1- )20log(0.5e
1v0 0.62v)20log(0.5 1v 0dB
2
0.45vF
Fresnel-kirchhoffDiffraction Parameter
Diffraction Loss
Stage 2: RF Environment Analysis
Proprietary61
Multiple Knife Edge Model
Bullington ModelBullington Model
h
A BC
T
R
C
Epstein-Peterson ModelEpstein-Peterson Model
A
BhA
hB
T
R
Japanese Atlas ModelJapanese Atlas Model
A
BhAT
T
R
hB
Deygout ModelDeygout Model
1947 Year1953 Year
1957 Year 1966 Yearh1
A CB
T
R
B
h2
h3
L=L(TBR)+L(TAB)+L(BCR)
L=L(TAB)+L(TAR)L=L(TCR)
L=L(TAB)+L(ABR)
Stage 2: RF Environment Analysis
Proprietary62
Build-Up Areas : A Classification Problem
Considering the relevance and effects of the environment on radio propagation, it is clear that the following characteristics could be used in classifying land usage types :
(1) Building density (percentage of area covered by buildings)
(2) Building size (area covered by a building)
(3) Building height
(4) Building location
(5) Vegetation density
(6) Terrain undulations
Stage 2: RF Environment Analysis
Proprietary63
Field Measurement- Drive Test: All roads 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
Proprietary64
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 Lossa. Between Transmitter and AMP b. Between AMP. and Antenna
Stage 2: RF Environment Analysis
Proprietary65
Field Measurement- Measurement Data Analysis
? 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 tocalculate the exact Propagation model
By using the Cell Planning tool,It will be easy to perform the MI
Stage 2: RF Environment Analysis
Proprietary66
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
Proprietary67
Model Correction (Measurement Integration) - CellPLAN®
Stage 2: RF Environment Analysis
Proprietary68
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
Proprietary69
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
Proprietary70
Link Budget Analysis(Reverse Link) Stage 2: RF Environment Analysis
Reverse LinkMAPLLBA
Operating Parameters:System % Loading, SHO gain
Subscriber Parameters:Maximum PowerCable lossAntenna GainNoise Figure
Noise FigureBS Parameters:
Antenna GainLosses
Voice Activity & Reuse FactorTechnology Parameters:
Bandwidth, Data Rate ( Proc. Gain)Required Eb/It
Propagation Parameters:Fade Margin, Penetration Loss
Proprietary71
Link Budget Table(Example: SK Telecom) Unit Value Remark
Frequency MHz 877 CustomerBandwidth MHz 1.2288 Spec.Data Rate bps 9600 CustomerProcessing Gain dB 21 Calculated%Loading % 50% CustomerRequired Area Reliability % 95% Customer
Morhpology Class D.Urban Urban S.Urban Rural Open Remark
At Mobile Station (TX)Mobile Tx Power dBm 23.0 23.0 23.0 23.0 23.0 Spec.(ClassIII)Antenna Gain 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 Station (RX)Noise Density(KT) dBm/Hz -174.0 -174.0 -174.0 -174.0 -174.0 Spec.Noise Figure(F) dB 5.0 5.0 5.0 5.0 5.0 Vendor Spec.Noise Bandwidth dB 60.9 60.9 60.9 60.9 60.9 Spec.Noise(KTBF) dBm -108.1 -108.1 -108.1 -108.1 -108.1 CalculatedRequired Eb/Nt dB 6.0 6.0 6.0 6.0 7.0 Vendor Spec. for 1% FERLoading Correction (1-x) dB 0.0 0.0 0.0 0.0 0.0Sensitivity dBm -123.2 -123.2 -123.2 -123.2 -122.2 CalculatedReceive Antenna Gain dBi 18.0 18.0 14.1 14.1 14.1 CustomerCable & Diplexer Loss dB 3.0 3.0 3.0 3.0 3.0 CustomerSHO Gain dB 3.0 3.0 3.0 3.0 3.0 Customer
At Radio ChannelSlow Fading dB 10.0 8.0 8.0 6.0 3.0 CustomerAtten. Factor of Propagation dB/dec 3.5 3.5 3.5 3.5 3.5 CalculatedS.F/A.F 2.9 2.3 2.3 1.7 0.9 CalculatedFade Margin dB 11.0 8.5 8.5 6.0 3.5 Calculated
At Service ConditionRequired Contour Reliability % 87.0 86.0 86.0 83.0 75.0 CalculatedPenetration Loss (in car) dB 5.0 5.0 5.0 5.0 5.0 CustomerPenetration Loss (in building) dB 18.0 15.0 10.0 10.0 10.0 Customer
OutputMax. Allow. PL (on street) dB 150.2 152.7 148.8 151.3 152.8 CalculatedMax. Allow. PL (in car) dB 145.2 147.7 143.8 146.3 147.8 CalculatedMax. Allow. PL (in building) dB 132.2 137.7 138.8 141.3 142.8 CalculatedMS Antenna Height 1.5 1.5 1.5 1.5 1.5BS Antenna Hegiht 21.0 25.0 30.0 45.0 45.0Max. Allow. Distance(on street) km 6.2 8.0 6.9 10.2 11.3 CalculatedMax. Allow. Distance(in car) km 4.5 5.8 4.9 7.3 8.1 CalculatedMax. Allow. Distance(in building) km 1.97 3.0 3.6 5.2 5.8 Calculated
Stage 2: RF Environment Analysis
Proprietary72
• 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 ProcedureStage 3: Coverage Design Ⅰ
Proprietary73
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 plotMobile 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
Proprietary74
Design on the MAPStage 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
Proprietary75
? 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 AnalysisStage 3: Coverage Design Ⅰ
Proprietary76
•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 AnalysisStage 3: Coverage Design Ⅰ
Proprietary77
•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 AnalysisStage 3: Coverage Design Ⅰ
Proprietary78
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
Proprietary79
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
Proprietary80
Site AcquisitionStage 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.
Proprietary81
Site AcquisitionStage 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 cellsite 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
Proprietary82
Site AcquisitionStage 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.
Proprietary83
Site AcquisitionStage 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.
Proprietary84
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
Proprietary85
Stage 3: Coverage Design Ⅱ
Coverage Simulation
? Main Activities?Forward Coverage Analysis
Forward Pilot Ec/Io PlotForward Pilot Best Server plotForward Pilot Eb/Nt plot
?Reverse Coverage AnalysisReverse Traffic Eb/Nt plotReverse Mobile ERP Plot
?Soft Handoff region ratio and Analysis?CDMA Forward/Reverse Link Coverage Analysis? 2D/3D profile for LOS check, etc
Proprietary86
PN Offset Allocation Result Paging zone Decision H/O Neighbor list s imulation- 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
Proprietary87
- 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 DesignStage 4: Parameter Design
Proprietary88
Pilot Assignment
Each sector of a base station is assigned a specific time (or phase) offset of Pilot PN sequences : this specific time offset distinguishes the transmissions from different sectors.
Short PN code is generated using 15-stage shift register. The length of such a PN sequence is about 215=32,768 bit. If we shift a PN sequence by one chip, then we have effectively generated a different PN sequence. Therefore, we could theoretically generate and use about 32,768 different PN sequences available to assign to different base stations.
488m
244m
2 chip
1 chip
A B
PN offset 0
PN offset 1
1 chip
1 chip
A B
time
Proprietary89
64chips
■ Pilot PN offset
Pilot PN Offset Allocation
■ PILOT offset increment (Pilot_INC)
PN offset 0
PN offset 1
PN offset 511
Pilot PN offset 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 508
509
510
511
Pilot_INC = 2 2 4 6 8 10 12 14 16 18 20 508
510
4 8 12 16 20 508
Pilot_INC = 4
Pilot_INC = 6 6 12 18 510
PN Sequence (215 chips)
Total available#of PN offset
256
128
86
32
215 chips / 64 chips = 512
0
0
0
Proprietary90
Pilot Offset Reuse
Minimum required distance between same PN offset
y > x + W/2 where W = SRCH_WIN_A size
D > 2x + W/2 where D = distance between base stations
Dmin > { 2R+(122 x W) } where R = cell radius (m)
y chips x chips
A B
PN offset 0
PN offset 0 x chip
delay
AB
time
SRCH_WIN_A
y chip delay
R
Proprietary91
Pilot Offset Reuse
Minimum required PN offset between adjacent base station
When PILOT_INC = N,
y < ( PILOT_INC x 64 ) + x - W/2
D < ( PILOT_INC x 64 ) + 2x - W/2
y chips x chips
A B
PN offset 0
PN offset N*64
x chip delay
A
time
SRCH_WIN_A
y chip delay
B
N*64 chips
Proprietary92
Pilot Search Window
Pilot Search Window Parameters• SRCH_WIN_A : Search window size for the active and candidate cell for handoff• SRCH_WIN_N : Search window size for the neighbor cell • SRCH_WIN_R : Search window size for remaining cell
SRCH_WIN_A
2 km (8.2 chips)
4 km (16.4 chips)
8.2 chips
SRCH_WIN_A < SRCH_WIN_N < SRCH_WIN_R
Proprietary93
Pilot Search Window (cont’)
3 km
A B
PN 1 PN 2
4 km 3 km
16.4 chips
16.4 chips
Proprietary94
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
Proprietary95
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 arrivingmultipath 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
Proprietary96
Pilot PN Offset Reuse
Pi : cell site Tx Powerdi : Distance between Cell site and MS?i : 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
Proprietary97
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
Proprietary98
Parameter Design (Paging channel analysis)Stage 4: Parameter Design
7x+380 bitsShort Message Servicer. Data Burst Message(x: No. of character)
I=j+k+l+m+ni. Overhead Message
72 bitss._DONE Message
720 bitsVoice Mail Serviceq. Voice Mail Notification
136 bitsh. General Page
p. Order Message-----g. Number of Sectors per MSC
144 bitso. Channel Assignment Message2f. BHCA per Subscriber
112 bitsn. Extended System Parameter Message0.03e. Busy Rate
88 bitsm. CDMA Channel List Message0.35d. Termination Rate
216 bitsl. Neighbor List Message2c. Paging Strategy(No. of users)
184 bitsk. Access Parameter Message0.9(90%)b. Maximum allowable utilization
264 bitsj. System Parameter Message9600 bpsa. Paging Channel Capacity
Numerical Value
General AssumptionNumerical Value
General Assumption
Assumption & Paging channel MSG Lengths
Proprietary99
Parameter Design (Paging channel analysis)1 Paging Capacity Analysis Table 2 Size3 Number Of Users 200000 Subscribers4 Number of power Up/Down per day 55 Timer based Registration period parameter 64 Time Based Registration Period
6 TImer based Registration period value - Second 5242.88 IF(POWER(2,(C5/4))*0.08= 0.08,0,POWER(2,(C5/4))*0.08) :Typical Value of Reg. Period
7 Another Registration 0 Zone-based Reg. Etc89 Number of Zones 1 1 z o n e As s u m p t i o n10 Number of BTS per Zone 24.0011 Number of Sectors per BTS 312 Number of BTS in System 2413 Sectors in System 72 C11*C1214 Registration
15 Total Registration in the System per Day 5295898 C3*(C4*2+3600*24/C6+C7) : Power On/Off, Time Based, Zonebased r e g . e t c
16 Concentration rate of BHCA 0.098
Stage 4: Parameter Design
Proprietary100
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
Proprietary101
Definition & Types of HandoffsDefinition of Handoffs■ A process by which the BTS and mobile maintains the communication when the mobile
travels from coverage of site A to that of another site.■ Required handoff time is defined by system processing time.-> 300-400msec■ MAHO(Mobile Assisted Handoff) : Cell decides the handoff based on the report of
the mobile( PSMM : Pilot Strength Measurement Message )
Types of Handoffs■ Soft
- Cell to cell: between same frequency, mobile assisted, make before break,data receivedby cells passed on to switch, occupy multiple traffic channel
- MSC to MSC: between same frequency, new feature■ Softer
- Sector to sector within the same cell: between same frequency, data from multiples sectors is combined at cell, does not involve switch, occupy single traffic channel
■ Hard- Frequency to frequency
Stage 4: Parameter Design
Proprietary102
Soft Handoff
Ec/Io
Time
Cell A
Signal Margin
Soft Handoff RegionCell C
Cell B
Time Margin(T_TDROP)
ADD Threshold(T_ADD)
Drop Threshold(T_DROP)
Parameter Range Suggested ValueT_ADD -31.5 ~ 0 dB -13 dBT_COMP 0 ~ 7.5 dB 2.5 dBT_DROP -31.5 ~ 0 dB -15 dBT_TDROP 0 ~ 15 sec 2 sec
Stage 4: Parameter Design
Proprietary103
Soft Handoff Gain (reverse)
R0
R1
R0 =range without soft-handoff gain(@75%contour reliability )
R1 =range with soft-handoff gain(@75%contour reliability )
Switch
Selection Diversity
Power Control
Stage 4: Parameter Design
Proprietary104
Soft Handoff Gain (forward)Stage 4: Parameter Design
Proprietary105
Handoff channel allocation ratio & Problem
%Area in Handoff Overhead factorNo H/OSofterSoft
Soft-SofterSoft-Soft
TYPE35% (21.98%)20%(61.54%)25%(5.49%)10%(8.79%)10%(2.20%) 0.2
0.10.2500
※ Handoff Success rate : more than 98%
■Handoff channel allocation ratio in the field
■ Pilot Pollution
Stage 4: Parameter Design
Proprietary106
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 foryearly 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
Proprietary107
Dimensioning rocedure
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 CalculateCE per CC
Stage 5: Dimensioning
Proprietary108
? 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 RatioACDM : 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