RF Network Design

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Procedure of CDMA RF Engineering

(RF Network Design)

2002. 4. 5

Jeon Hyun Cheol

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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

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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

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? 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

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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.


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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


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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

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11

N = 7i = 2j = 1


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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


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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


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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.


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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)


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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


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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

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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

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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

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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


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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)



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? 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


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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)

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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

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? 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


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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


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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


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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


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Hard Blocking ModelStage 1: Preparations

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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.


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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


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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.


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CDMA Pole Capacity

SNfWFNS

G

WSNf

FN

RSIE

thp

tho

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)1)(1(/

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1max ?

??

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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


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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

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ence

to

Ther

mal

Nois

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dB)

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threc

th

total

? ,? ,


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Cell Breathing

total

rec

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rec

th

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total

PP

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orWFN

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)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

)


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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

??


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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

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Ba

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.)/(ß/sßa

rW/R)P(blockingQ/IE

B


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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

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-1

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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


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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.


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? 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


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? 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


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? 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


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? 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


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? 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


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? 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 %


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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 Microcells

? PN Increment and Allocation



? 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


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RegionClustering

Maximum Cell Radius,Minimum AntennaHeight Calculation

Site Survey and Field Measurement

Competitor’s CoverageAnalysis

Link BudgetAnalysis

Procedure OverviewStage 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 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

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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


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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”


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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)


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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


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Build-Up Areas : A Classification Problem - CellPLAN®Stage 2: RF Environment Analysis

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Site Survey and Field Measurement Procedure


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


?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 .:













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


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


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


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


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


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)(


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


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)


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


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


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


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


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)


Proprietary67

Model Correction (Measurement Integration) - CellPLAN®


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)


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


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


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


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


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


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


?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 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


?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


Proprietary85


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


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


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


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


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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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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


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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


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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


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Soft Handoff Gain (forward)Stage 4: Parameter Design

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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


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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 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

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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


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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 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


Documents

RF Network Design