Welcome to all of you
to world of “TELECOM "by
Welcome to all of you
to world of “TELECOM "by
•
•
•
•
•
•
Detailed Tropic discussed in this chapter
CW Testing
Model Tuning
Antenna
1. Isotropic Antenna
2. Dipole Antenna
•
•
•
•
•
•
•
RF Planning
1. Coverage planning
2. Capacity planning
3. Highway Planning
4. City planning
Planning Tool
Asset Planning Tool
•
•
•
•
•
•
•
•
•
•
•
Please introduce yourself as per guidelines below:
Name
Qualification
Professional Experience in years/months (if
applicable)
Name of the previous company (if applicable)
Tenure in previous company (if applicable)
Name of the Institute/University
Year of passing
What is your AIM in life
Expectations from this company
Expectations from this course
• Decorum of the course to be maintained by:
• Keeping your mobiles in Switched-off or Silent
mode.
• Doing one discussion at a time.
• Following the timings strictly as per schedule for
Breaks.
• Making the course interactive by asking questions
and by giving suggestions.
INTRODUCTION TO RF
PLANNING

Designing a cellular system - particularly one that incorporates both Macro
cellular and Microcellular networks is a delicate balancing exercise.

The goal is to achieve optimum use of resources and maximum revenue
potential whilst maintaining a high level of system quality.

Full consideration must also be given to cost and spectrum allocation
limitations.
INTRODUCTION TO RF PLANNING
•
A properly planned system should
allow capacity to be added
economically when traffic demand
increases.
•
As every urban environment is
different, so is every macro cell
and micro cell network. Hence
accurate planning is essential in
order to ensure that the system
will provide both the increased
capacity and the improvement in
network quality where required,
especially when deploying
Microcellular systems.
INTRODUCTION TO RF
PLANNING

RF planning plays a critical role in the Cellular design process.

By doing a proper RF Planning by keeping the future growth plan in mind we
can reduce a lot of problems that we may encounter in the future and also
reduce substantially the cost of optimization.

On the other hand a poorly planned network not only leads to many Network
problems but it also increases the optimization costs and still may not ensure
the desired quality.
INTRODUCTION TO RF PLANNING
•
The high level life cycle of the RF network planning process can be
summarised as follows :-
• To help the operator
to identify their RF
design requirement
• Optional
Comparative
Analysis
• Discuss and agree RF
design parameters,
assumptions and
objectives with the
customer
RF Design
requirement
• Coverage requirement
• Traffic requirement
• Various level of design
(ROM to detail RF
design)
RF Design
Site
Realization
RF Design
Implementation
• Issuing of search ring
• Cand. assessment
• Site survey, design,
approval
• Drive test (optional)
•
•
•
•
Frequency plan
Neighbour list
RF OMC data
Optimisation
INTRODUCTION TO RF PLANNING
•
This is an optional step
•
This is intended to :– Help an existing operator in building/expanding their network
– Help a new operator in identifying their RF network requirement,
e.g. where their network should be built
•
For the comparative analysis, we would need to :-
– Identify all network that are competitors to the customer
– Design drive routes that take in the high density traffic areas of
interest
– Include areas where the customer has no or poor service and the
competitors have service
INTRODUCTION TO RF PLANNING
•
The result of the analysis should include :-
•
For an existing operator
– All problems encountered in the customer’s network
– All areas where the customer has no service and a competitor
does
– Recommendations for solving any coverage and quality problems
•
For a new operator
– Strengths and weaknesses in the competitors network
– Problem encountered in the competitors network
INTRODUCTION TO RF PLANNING
•
The RF design inputs can be divided into :– Coverage requirements
• Target coverage areas
• Service types for the target coverage areas. These should be
marked geographically
• Coverage area probability
• Penetration Loss of buildings and in-cars
– Capacity requirements
• Erlang per subscriber during the busy hour
• Quality of service for the air interface, in terms GoS
• Network capacity
– Growth plan - Coverage and Capacity
INTRODUCTION TO RF PLANNING
– Available spectrum and frequency usage restriction, if any
– List of available, existing and/or friendly sites that should be
included in the RF design
– Limitation of the quantity of sites and radios, if any
– Quality of Network (C/I values)
– Related network features (FH, DTX, etc.)
INTRODUCTION TO RF PLANNING
RF Network Design
•
There are 2 parts to the RF network design to meet the :– Capacity requirement
– Coverage requirement
•
For the RF Coverage Design
CW Drive
Testing
Propagation
Model
Digitized
Databases
RF
Coverage
Design
Customer
Requirements
Link
Budget
TOOLS USED FOR RF
PLANNING

Network Planning Tool

CW Propagation Tool
DRIVE TEST FOR C.W. TESTING
DRIVE TEST
FOR C.W. TESTING
INTRODUCTION
Drive test types
Predesign drive test
Post design drive test
•
Predesign drive test for measurement integration
•
This is at beginning of design when no site has been built or even selected.
All test sites are temporary.
DRIVE TEST FOR C.W. TESTING
•
Drive test is performed mostly for characterization of propagation
and fading effects in the channel. The object is to collect field data to
optimize and adjust the prediction model for preliminary
simulations.
•
Post design drive test for site verification / optimization
•
Drive test is performed to verify if they meet the coverage objectives.
•
Overlaps are checked for hand-offs.
DRIVE TEST FOR C.W. TESTING
INTRODUCTION
 In field measurement we have to collect variations due to propagation and
slow fading.
 The received signals are typically sampled and averaged over spatial
windows called bins.
 There are several sampling issues to be considered like
Sampling rate
Averaging window
Number of bins to be measured
DRIVE TEST FOR C.W. TESTING
SAMPLING CRITEREA

When measuring the RF signal strength certain sampling criteria must be met
to eliminate the short-term fading components from the long-term component (
I.e. log normal fading )

The RF signal strength measurements must be taken over a radio path or
mobile path distance interval of 40, where  is the wavelength of the RF signal.

If the distance interval is too short, the short term variation cannot be smoothed
out and will affect the local mean.
DRIVE TEST FOR C.W. TESTING
•
If the distance interval is too long, the averaged output cannot
represent the local mean since it washes out the detailed signal
changes due to the terrain variations.
•
The number of RF measurements taken within the 40 distance
should be greater than 50.
•
Depending on the speed of the vehicle during the drive test, the
sampling interval in time is selected.
•
Measurements have to be stopped whenever the vehicle is not
moving.
DRIVE TEST FOR C.W. TESTING
SAMPLING CRITEREA
•




If
f = 1900MHZ, then
 = 3 * 108 / 1900 * 106
= 0.158 m
 40  = 40 * 0.158
= 6.32 m
50 measurements must be recorded every 6.32m or 1 measurement every
0.1264m
The conversion from sampling distance to mobile velocity can be done as follows
minimum sampling rate ( per second ) = v / (0.1264 m/sample)
If velocity of vehicle is 50 kph then
Sampling rate( per second ) = (50000/ 3600) / 0.1264
= 110 samples / sec
TEMS kit cannot be used for this purpose as it can report RF signal strength
measurements at a maximum rate of 1 sample per second
DRIVE TEST FOR C.W. TESTING
WINDOW SIZE
•
In field measurements the interest is on local averages of received signals.
•
The size of averaging window have to be small enough to capture slow
variations due to shadowing and large enough to average out the fast
variations due to multipath.
•
A typical range is 20 to 1500 m.
•
The bin size is typically selected in 40 to 1500m, i.e. all measurements in this
size square are averaged to one value.
•
Normally the post processing tool takes care of averaging the collected data
over different bins.
DRIVE TEST FOR C.W. TESTING
NUMBER OF
BINS
Bin
•
•
•
•
The predicted and measured signal strengths for all bins within the drive route
is compared and the best set of correction factors to minimize the prediction
errors is determined.
All the bins within the coverage area cannot be drive tested. So a large enough
sample set should be considered.
The more the number of bins, the larger the confidence level of results.
Generally for acceptable confidence at least 300 to 400 bins have to be
considered.
DRIVE TEST FOR C.W. TESTING
PROPAGATION KIT
The propagation test kit consists of
– Test transmitter.
– Antenna ( generally Omni ).
– Receiver to scan the RSS (Received signal levels). The receiver scanning rate
should be settable so that it satisfies Lee’s law.
– A laptop to collect data.
– A GPS to get latitude and longitude.
– Cables and accessories.
– Wattmeter to check VSWR.
Receiver Antenna
Transmit Antenna
Transmitter
GPS Antenna
RECEIVER LAPTOP
DRIVE TEST FOR C.W. TESTING
The propagation test kit consists of
DRIVE TEST FOR C.W. TESTING
TRANSMITTER SETUP
•
•
•
•
•
•
If the propagation test is being done for model tuning to produce a generic
model for macro cells, then a high point in the particular area has to be
selected.
The transmitter and the transmit antenna will be placed at this point (say the
roof of the building ).
The transmit antenna is connected to the transmitter via a RF cable.
Check to see that the cable is connected properly and tight.
Loosely connected or faulty cable can increase the VSWR.
A test frequency has to selected from the frequency band allocated to the
operator. Set the transmitter to this test frequency.
TEST
TRANSMITTER
DRIVE TEST FOR C.W. TESTING
TEST SITE SELECTION
 Site selection is based on a number of criteria. It may not be possible to satisfy
all these criteria at the same time, but it is important to select the best sites
available.
 Drive test sites should be selected to give a good representative sample of the
system coverage area. The exact number of sites required will depend on the
size of the system coverage area and the variability of the characteristics of the
coverage area.
DRIVE TEST FOR C.W. TESTING
•
All terrain and clutter types in the area should be represented in the
drive test data for proper prediction tuning.
– Typical terrain types are: Flat, Rolling Hills, Large Hills, Mountains
– Typical clutter types are: Water, Open Land, Forest, Commercial /
Industrial, Low Density Urban, Medium Density Urban, High
Density Urban, City Center, Airport.
•
City maps, topographical maps and aerial photographs can be
useful in determining the terrain and clutter types for an area. It
may also be necessary to drive the area and observe building types
and density.
DRIVE TEST FOR C.W. TESTING
TEST SITE SELECTION
Site Availability

Test sites must be available for use during the drive test.

The site owner/supervisor should approve access to the site for as long as
needed to complete the testing. This may involve multiple visits to the site,
possibly on short notice.

Test sites must also be physically accessible to allow setup of the transmitter
equipment and mounting of the antenna. For this reason building top sites are
preferred to tower sites.
DRIVE TEST FOR C.W. TESTING
Site Visit
•
Each site selected should be visited before testing to verify that is
suitable for use.
•
The inspection should be done by the same people who will be doing
the site setup for the actual drive test. Familiarity with the site
should speed up the site setup during the drive test.
DRIVE TEST FOR C.W. TESTING
BUILDING SITE SELECTION
•
•
•
When inspecting a building site the rooftop should be checked for any
obstructions that would interfere with signal propagation. This could include
objects on the rooftop itself or other nearby buildings or structures.
The antenna location should be selected and a sketch of the rooftop made to
identify this location relative to other objects nearby.
Photographs should be taken of the location where the antenna will be mounted
and in all directions looking away from the site.
DRIVE TEST FOR C.W. TESTING
BUILDING SITE SELECTION
DRIVE TEST FOR C.W. TESTING
TOWER SITE SELECTION
 When inspecting a tower site the best location to mount the antenna to the
tower must be deter-mined.
 This should be selected such that the tower doesn’t interfere with the
propagation pattern of the transmit antenna. This will usually require that the
antenna be above the tower or on an arm extending from the side of the tower.
 The area around the tower should be checked for any obstructions that would
interfere with signal propagation.
DRIVE TEST FOR C.W. TESTING
TEMPORARY STRUCTURE
•
•
•
Generally cranes are used for temporary structure.
When cranes are used power generators have to be arranged in
advance.
The location should be selected such that the antenna will be above
any nearby obstacles.
DRIVE TEST FOR C.W. TESTING
TEMPORARY STRUCTURE
DRIVE TEST FOR C.W. TESTING
DRIVE TEST PLAN

Each drive route should be marked on a
detailed road map showing the exact route to be
driven.

These maps should be used during the actual
drive for navigation of the test vehicle.

They can also be used during the drive test
DRIVE TEST FOR C.W. TESTING
•
verification to check that the positioning information in the drive
test file is correct.
•
A separate map should be prepared for each route.
•
Both line of site (LOS) and non-LOS points have to be included in
the drive test.
DRIVE TEST FOR C.W. TESTING
•
The data collected should represent typical coverage scenarios.
•
In urban area the effect of street orientations have to be considered.
•
The selection of drive test route should be based on the terrain
variations, Major highways and throughfares, potential shadowing
areas and handoff region.
DRIVE TEST FOR C.W. TESTING
DRIVE TEST PROCEDURE
•
The actual dive test must be performed carefully to insure that the data
collected is accurate.
•
It is important that all equipment used be tested and all setup
information be recorded.
•
If any of the procedures are not followed or any of the data is not
properly recorded then the drive test data will not be usable and the
drive will have to be repeated.
DRIVE TEST FOR C.W. TESTING
•
Engineer should study the drive test plan ahead of time and
highlight the intended drive test routes.
•
For each drive test a team of two people should get involved.
•
The measurement process should be stopped the car stops ( eg near
traffic lights) or whenever the sampling and measurements look
suspect.
DRIVE TEST FOR C.W. TESTING
DRIVE TEST OUTPUT
Lat
Long
RSSI
Freq
X1
Y1
M1
F
X2
Y2
M2
F
X3
Y3
M3
F
 The result of drive test is a collection of data files which has lat, long,
Received Signal Strength Indicator (RSSI) at that point and the
frequency.
 The location information ( lat, long ) is used by the post processing tools
as a reference of correlation between the measured vs. predicted signal
levels for measurement integration.
 This file has to be transferred onto the planning tool either by a floppy or
by data transfer using LAN.
DRIVE TEST FOR C.W. TESTING
DRIVE TESTOUTPUT
Model Tunning
Model Tunning
•Model Tuning On Asset version 6.1
Model Tunning
Model Tunning
 Models are used to predict path loss.
 Different models are used for different purpose. Eg:- Rural Macro-cell
-Okumura hata model, Micro cells - Ray tracing
 Models have to be tuned using data collected by drive testing.
 Good propagation tool + Sound engineering ingenuity = Sound RF
design.
 Some of the popular prediction models are Okumura hata, Walfisch
Ikegemi, COST231, Ray tracing etc.
Model Tunning
Okumura Hata Model
 This is used for Macro cell modeling.
 It has become the most popular propagation model for mobile
environments.
 It is best applicable for cell ranges of 5 to 20 kms.
Model Tunning
•
Below a range of 1 km it becomes very unreliable since obstacles in
the close vicinity of receiver and transmitter become the dominant
scattering influences which are not taken into account in the
formula.
•
Path loss = K1 + K2log(d) + K3log(Heff) + K4 * Diff + K5log(Heff)log(d)
+ K6log(Hmeff) +K7log(f) + Kmorphology
Model Tunning
•
•
K1 - 1Km intercept value. Upto this point model assumes free space
loss
K2 - Slope value
•
K3 - Effective height coefficient
•
K4 - Coefficient for diffraction calculation
•
K5 - Hata model multiplier
•
K6 - Multiplier for mobile height
•
K7 - factor for frequency
Model Tunning
•
model has four main parameters:
– Building separation (in meters) (b) : It is the distance between the
centre of two buildings.
– Average building height (h) : This is the average height of all
buildings in the cell’s coverage area.
– Road width (w)
– Road orientation angle ( )
Model Tunning
d
h
w
b
Walfish Ikegami Model
Model Tunning
MODEL TUNING

Propagation models use clutter and terrain data to predict cell
coverage at a site. However usually the terrain and clutter data
available from the maps are not perfect.

This means that the actual cell coverage could be different from the
predicted cell coverage. This could in turn result in wrong cell
designing.

To avoid this model tuning is done.
Model Tunning
•
In model tuning data collected from the propagation test is loaded
on the planning tool.
•
This data represents the real life condition cell coverage.
•
The prediction for that cell is then done using the same conditions
as were for the propagation tests (i.e. using the same antenna type,
same height of the antenna at the site, same downtilts, same
transmit power etc.
Model Tunning
MODEL TUNING
•
Ideally both the propagation test cell coverage and the predicted cell
coverage should match.
•
If they match then the model does not require to be tuned.
•
If the models do not match then the certain parameters in the
propagation model equation are altered so that they both match.
Model Tunning
•
Once both the cell coverage match the model is then said to be
tuned.
•
Now the actual antenna type, height of antenna, transmit power are
used and prediction done.
•
This prediction can then be assumed to be correct.
•
Cell designing is then done using this prediction.
Model Tunning
MODEL TUNING

Ideally model tuning needs to be done for all the sites.

However in many cases , the Network is divided into different clutter
types (around 7 to 8) (e.g. urban, dense urban, semi urban, rural etc.)
and models are tuned for each clutter types.

The sites are then categorized in these clutter types and then fitted in
the model tuned for that clutter type.

This method though not perfect is widely accepted and saves lot of
time and money for the operator.
You must have an existing project with map data and with CW
sites. In the below mentioned slide there are total three sites for
tuning.
Import the antenna file and see the pattern
of Omni antenna.
Make the Feeder cable
from Equipment > Click on Feeder
Right click on the specific project > click
New Feeder
Give feeder Name (Say XYZ) in Part ID
and click on close
Update the site database for antenna ,
model and feeder type
Making a reference Model
From Configuration > Propagation Model
Propagation Model Window will pop up > click
Add > select any reference model(Say standard
Macrocell 3) > Click Add
Give the propagation model name (Say
1900)> click View/Edit Model Parameter
Fill the relative information (say
Frequency) in general tab
Fill K-values information from user guide
Choose Effective antenna height algorithm
(say Relative)
Choose Diffraction calculation Method
(say Epstein Peterson)
Initial through clutter losses and clutter offsets
will be 0. No need to fill the value in this tab
Importing the CW Drive test file
From Tools > Click Measurements
Measurement toolbox will open > Click “Add” in
cell associate measurement > Browse Header(.hd)
file > click open
Importing of drive file will take few
minutes
If header file and site database information are
same then loading will ask for the association of
drive data with cell > Click OK
Click on Load Associated
Similarly Import the other drive (Signia) files
Model Analysis Select the particular measurements>click
Individual > Model Analysis Tool Box will pop up > In Model
tab, Fill the required information > Select the Model
In filter tab > Give distance filtering > Rx Level
Filtering > Clutter filtering > Polygon Filtering
For Polygon Filtering you must have measurement analysis > Check
Measurement Signal > View the drive data in 2D view with sites >
Click on Create new vector from 2D menu > Give vector name (Say
1900)> Select polygon shape > make polygon for the bad drive
samples > Save all vectors
Now if you want to use polygon filtering > Check Use
Exclusion Polygons box > Click Select polygons > check
the specific polygon > click on Apply
Polygon Selected will show you the no of
Exclusion polygons > click OK
Model Analysis box will pop up > Select all the measurement >
click Composite. This will give combine values. You can also do
the analysis for individual drive data
After the completion of composite analysis this
will give you the values as slide is showing
You can also view the analysis report from here >
Click View Report > Analysis will run
After the completion of analysis an option box will
pop up > choose the desired options > Click OK
Analysis report will generate (See the below mentioned specimen) In this case You can see that mean
error & Std. Dev is not matching with exact criteria.Actually mean value should be 0 and Std. Dev
should be less or equal to 8
Analysis report will generate (See the below mentioned specimen) In this case You can see that mean
error & Std. Dev is not matching with exact criteria. Actually mean value should be 0 and Std. Dev
should be less or equal to 8. After tuning the value of K1, K2 and K7 we will get the exact report as
given
Auto Tuning
After Analysis you need to do the tuning for improved
results. Select the measurements > Click Auto Tune
Initialization of Auto tuning will take few
minutes
Model Calibration Utility box will pop up. This will show you the reference
model K-value. Also at the moment Through clutter losses are 0. You can see
the same from; Clutter > View/set Through clutter parameters
Initial Through clutter losses. Before going to auto tuning
you can fix or open the clutter losses values. In the below
mentioned slide all clutter loss values are open.
Before going to Auto tuning you can also fix or open the Kvalues. For eg. In the below mentioned slide K2 is open while
others are fix. For Auto Tuning Go to Tools> Auto Tune
Auto Tuning will take Few Minutes time
Auto Tuning will give you new k and clutter values. If you want
to apply the new values go to Tools > Apply New parameters
You also can see the new clutter losses values
This will complete the Auto Tuning Process. Now
From File > Click Exit
See the tuned values from Configuration >Propagation
Model> Select Specific Model > View/Edit model
Parameters > Path loss tab and then > Clutter tab
Antenna
BASIC INTRODUCTION TO ANTENNA
•What is antenna?
•An antenna is the converter between cable bounded electromagnetic waves
and free space waves.
ANTENNA INSTALLATION
 Antenna installation configurations depend on the operators preferences.
 It is important to keep sufficient decoupling distances between antennas.
 If TX and RX direction use separated antennas, it is advisable to keep a horizontal
separation between the antennas in order to reduce the TX signal power at the RX
input stages.
Antennas for GSM System
Antennas for GSM System
Antennas for GSM System
• Base station antenna specification
and meanings
• Antenna types and trends
(Technical Data)
Blah blah
blah bl ah
Electrical properties
Mechanical properties
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Operation Frequency Band
Input impedance
VSWR
Polarization
Gain
Radiation Pattern
Horizontal/Vertical beamwidth
Downtilt
Front/back ratio
Sidelobe suppression and null filling
Power capability
3rd order Intermodulation
Insulation
Size
Weight
Radome material
Appearance and color
Working temperature
Storage termperature
Windload
Connector types
Package Size
Lightening
Electrical properties
Dipoles
Wavelength
1/4 Wavelength
1/2 Wavelength
1/4 Wavelength
1/2 Wavelength
Dipole
1800MHz ：166mm
900MHz ：333mm
1个 dipole
Multiple dipole matrix
接收功率(received power)：1mW
Received power：4 mW
GAIN= 10log(4mW/1mW) = 6dBd
Antenna
(Overlook
“Omnidirectional array”
Received power：1mW
“Sector antenna”
Received power：8mW
Gain=10log(8mW/1mW) = 9dBi
Frequency Range
•
•
•
•
GSM 900 : 890-960MHz
GSM 1800 : 1710-1880MHz
GSM dual band : 890-960MHz & 1710-1880MHz
eg.824-960MHz，1710-1900MHz
Optimum 1/2 wavelength
for dipole at 925MHz
at
890
MHz
at
960
MHz
Antenna
Dipole
BANDWIDTH = 960 - 890 = 70MHz
Impedance
•
50
Antenna
Cable
50 ohms
50 ohms
VSWR
Forward: 10W
50 ohms
Backward: 0.5W
80
ohms
Return Loss： 10log(10/0.5) = 13dB
VSWR (Voltage Standing Wave Ratio)
9.5 W
•
•
•
1.5
=(VSWR-1)/(VSWR+1)
RL=-20lg 
Polarization
Vertical
+ 45degree slant
Horizontal
- 45degree slant
V/H (Vertical/Horizontal)
Slant (+/- 45°)
•
•
Linear, vertical
45 dual linear 45 slant
dBd and dBi
Ideal radiating dot source
(lossless radiator)
2.15dB
eg:
Dipole
0dBd = 2.15dBi
Pattern :-
Beamwidth
3dB Beamwidth
10dB Beamwidth
Peak - 3dB
60° (eg)
Peak
Peak - 3dB
Peak - 10dB
120°
(eg)
Peak
Peak - 10dB
3dB
3dB Beam width Horizontal
•
Directional Antenna：65°/90°/105°/120 °Omni：360°
3dB
3dB Beam width Horizontal
Directional：
Omni-directional：
Down Tilt
•
Mechanical down tilt
•
Fixed electronic down
tilt
•
Adjustable electronic
down tilt
Demonstration of Electronic Down-tilt
不下倾
Non down tilt
电调下倾
Electronic downtilt
机械下倾
Mechanical
downtilt
(Electronic and mechanical down tilt)
Front to Back Ratio
•
Ratio of maximum main lobe to
maximum side lobe
后向功率
Back power
前向功率
Front power
F/B = 10 log(FP/BP)
typically ： 25dB
Upper Side lobes Suppression & Null Fill
Side lobe
In (dB)
In (dB)
Mechanical properties
Mast
•
Mast diameter 45-90mm
(Antenna Types and Development )
(Antenna Types)
By frequency band: GSM900, GSM1800, GSM900/1800
By polarization: Vertical, Horizontal, ±45º linear
polarization, circle polarization
By pattern:
Omni-directional, directional
By down-tilt:
Non, mechanical, electronic
adjustment, remote control
By function:
Transmission, receiving, transceiving
ONE ANTENNA FOR MULTIPLE BANDS
– 870-960MHz and 1710-1880MHz
– Extended band option with 806-960MHz
– Dual slant ±45º polarisation
– 65º horizontal beamwidth
– Band independent Teletilt™ control
– 17dBi gain in both bands
– Diplexed or Non-Diplexed versions
– Mechanical downtilt mounting option
7/8” MAIN FEEDER
1/2” JUMPER CABLE
Planning
Coverage Planning Strategies
Coverage Planning Strategies
•
The selection of site
configurations, antennas and
cables is the core of the coverage
planning strategy. The right choice
will provide cost savings and
guarantees smooth network
evolution.
3
2
3
4
7
1
2
3
1
2
4
7
4
7
6
5
4
6
5
7
1
3
4
6
2
7
1
3
4
6
2
5
1
3
5
1
6
2
7
7
Some typical configurations are:
– 3-sector sites for (sub) urban
areas
– 2-sector sites for road
coverage
4
6
5
3
5
1
2
•
6
5
•
These are not the ultimate solutions, decisions should be based on a
careful analysis
•
Cell Range and Coverage Area
•
For any site configuration, the cell ranges can be determined given
the equipment losses and gains. The site coverage areas can be
calculated then and these will lead to the required number of sites
for a given coverage region. This makes it possible to estimate the
cost, e.g. per km2, to be used for strategic decisions.
Network Planning Tool:Network Planning Tool:
Planning tool is used to assist engineers in designing and optimizing wireless
networks by providing an accurate and reliable prediction of coverage, doing
frequency planning automatically, creating neighbor lists etc.

With a database that takes into account data such as terrain, clutter, and
antenna radiation patterns, as well as an intuitive graphical interface, the
Planning tool gives RF engineers a state-of-the-art tool to:
 Design wireless networks
 Plan network expansions
 Optimize network performance
 Diagnose system problems
•
The major tools available in the market are Planet, Asset, Net-Act,
Cell Cad.
•
Also many vendors have developed Planning tools of their own like
Net plan by Motorola, TCPU by Ericsson and so on.
Propagation Test Kit
Propagation Test Kit

The propagation test kit consists of
 Test transmitter.
 Antenna ( generally Omni ).
 Receiver to scan the RSS (Received signal levels). The receiver scanning
rate should be settable so that it satisfies Lee’s law.
 A laptop to collect data.
 A GPS to get latitude and longitude.
 Cables and accessories.
 Site Master to check VSWR.
•
A single frequency is transmitted a predetermined power level from
the candidate site.
•
These transmitted power levels are then measured and collected by
the Drive test kit. This data is then loaded on the Planning tool and
used for tuning models.
•
Commonly Graysons or BVS test kits are used.
RF Network Design
COVERAGE PLANNING
Frequency Bands
•
GSM-900
•
The term GSM-900 is used for any GSM system which operates in
any 900 MHz band.
•

P-GSM-900
P-GSM-900 band is the primary band for GSM-900 Frequency band
for primary GSM-900 (P-GSM-900) : 2 x 25 MHz
•
•
•

•
•
890 – 915 MHz for MS to BTS (uplink)
935 – 960 MHz for BTS to MS (downlink)
E-GSM-900
In some countries, GSM-900 is allowed to operate in part or in all of
the following extension band. E-GSM-900 (Extended GSM-900) band
includes the primary band (P-GSM-900) and the extension band :
880 – 890 MHz for MS to BTS (uplink)
925 – 935 MHz for BTS to MS (downlink)
Frequency Bands
•
R-GSM-900

R-GSM-900 (Railway GSM-900) band includes the primary band (P-GSM900) and the following extension band:
•
•
876 – 890 MHz for MS to BTS (uplink)
921 – 935 MHz for BTS to MS (downlink)
•
GSM-1800

Frequency band: 2 x 75 MHz
•
•
1710 – 1785 MHz for MS to BTs (uplink)
1805 – 1880 MHz for BTS to MS (downlink)
Carrier Spacing and Channel Structure
•
Channel number – the carrier frequency is designated by the absolute
radio frequency channel number (ARFCN). The frequency value of the
carrier n in the lower band is called FL (n) while FU (n) is the
corresponding frequency value in the upper band. Frequencies are in
MHz
•
P-GSM-900:
FL (n) = 890 + 0.2 n
with 1 < n < 124
FU (n) = FL (n) + 45
•
E-GSM-900:
FL (n) = 890 + 0.2 x n with 1 < n < 124
FL (n) = 890 + 0.2 x (n-1024)
with 975 < n < 1024
FU (n) = FL (n) + 45
Coverage, Capacity, and Quality
•
Providing coverage is usually considered as the first and most
important activity of a new cellular operator. For a while, every
network is indeed coverage driven. However, the coverage is not
the only thing. It provides the means of service and should meet
certain quality measures.
•
The starting point is a set of coverage quality requirements.
 To guarantee a good quality in both uplink and downlink
direction, the power levels of BTS and MS should be in balance
at the edge of a cell. Main output results of the power link
budgets are:
• Maximum path loss that can be tolerated between the MS and the
BTS
• Maximum output power level of the BTS transmitter.
Coverage, Capacity, and Quality
 These values are calculated as a function of
design constraints:
• BTS and MS receiver sensitivity levels
• MS output power level
• Antenna gain
• Diversity reception
• Losses in combiners, cables, etc.
Coverage, Capacity, and Quality
•
The cell ranges are derived with propagation loss formulas such as
Okumura-Hata, using inputs of maximum path loss, differences in the
operating environments and the quality targets in different cell ranges.
•
The traffic capacity requirements have to be combined with the
coverage requirements, by allocating frequencies. This also may have
impact on the cell range.
Coverage Planning Strategies
•
The selection of site configurations, antennas and cables is the core of
the coverage planning strategy. The right choice will provide cost
savings and guarantees smooth network evolution.
•
Some typical configurations are:
 3-sector sites for (sub)urban areas
 2-sector sites for road coverage
 omni sites for rural areas
Coverage Planning Strategies
•
These are not the ultimate solutions, decisions should be based
on a careful analysis
•
Cell Range and Coverage Area
•
For any site configuration, the cell ranges can be determined
given the equipment losses and gains. The site coverage areas
can be calculated then and these will lead to the required
number of sites for a given coverage region. This makes it
possible to estimate the cost, e.g. per km2, to be used for
strategic decisions.
Methodology
•
Define design rules and parameters




Identify design rules to meet coverage and capacity targets efficiently
Acquire software tools and databases
Calibrate propagation models from measurements
Set performance targets



Clear statement of coverage requirements (roll out and quality)
Forecast traffic demand and distribution
Test business plan for different roll out scenarios and quality levels
Methodology
•
Design nominal plan
 Use computer tool to place sites to meet coverage and capacity
targets
 Verify feasibility of meeting service requirements
 Ensure a frequency plan can be made for the design
 Estimate equipment requirements and costs
 Develop implementation and resource plans (including
personnel requirements)
 Radio plan will provide input to fixed network planning
Nominal RF Design
Link Budget
Propagation
model
Coverage
requirements
Site radius
Nominal RF
Design
(coverage)
Traffic
requirements
Maximum
path loss
Typical site
configuration
• Transmit Power
• Antenna configuration
(type, height, azimuth)
• Site type (sector, omni)
Traffic
requirements
• Standard hexagon site
layout
• Friendly, candidate sites
• Initial site survey inputs
• Recalculate the site
radius using the
number of sites from
the traffic requirement
• Repeat the nominal
RF design
Coverage site
count
Traffic site
count
Traffic > Cov.
Cov. > Traffic
Nominal site
count
Methodology

Implement cell plan
 Identify physical site locations near to nominal or
theoretical locations, using search areas.
 Modify nominal design as theoretical sites are replaced
with physical sites
 Modify search areas in accordance with evolving network.
•
Produce frequency plan
 Fixed cluster configuration, can be done manually.
 Flexible, based on interference matrix using an automatic
tool.
Methodology
•
Optimizing the network
•
Expand the network




In line with the roll out requirement
In line with the forecasted traffic level
Improve the coverage quality
Maintain the blocking performance
Fade Margin
•
The concept of a fade margin is to reserve extra signal power to
overcome potential fading.
•
Assume :
 The mobile radio system needs an signal level of Pr dBm at the
receiver
 The maximum likely fade (loss) is calculated to be L(fade) dB
•
The a received signal level of Pr dBm can be ensured by transmitting
enough power for a normal received signal level of (Pr + L(fade)) dBm
Fade Margin
•
The fade margin is normally equal to the maximum expected
fade or to a smaller value. The value is chosen in such a way
that the threshold value is undershot in only a low percentage
of time.
•
For this purpose, it is necessary to know the probability density
function of the fading.
•
In RF planning, the impact of Rayleigh fading is taken into
account by implementing an extra fade margin of 8 dB.
Multipath Propagation
•
The radio wave may be reflected, from a hill, a building, a truck, an
aeroplane or a discontinuity in the atmosphere. In some cases, the
reflected signal is significantly attenuated, while in others almost all
the radio energy is reflected and very little absorbed. The result is that
not one but many different paths are followed between the transmitter
and receiver. This is known as Multipath Propagation
Multipath Propagation
Building
Building
Building
Multipath Propagation
•
Reflection and multipath propagation can cause positive and negative
effects :-
 Coverage extension
Multipath propagation allows radio signal to reach behind hills
and buildings and into tunnels
The latter effect is known as ducting
Multipath Propagation
 Constructive and destructive interference
The interference due to multipath propagation manifest
itself in the following 3 most important ways:• Random phase shift creates rapid fluctuations in the signal
strength known as Rayleigh fading
• A delay spread in the received signal causes each symbol
to overlap with adjacent symbols : intersymbol
interference
• Random frequency modulation due to different doppler
shifts on different paths
Propagation Modeling
 Statistical propagation models
 These calculate a median signal for each pixel. The level within
this pixel varies about the median in a way that can only be
analysed statistically.
 Local mean signal levels are distributed around the pixel median
with a log-normal probability distribution.
 Formulas derived from measurements (e.g. Okumura-Hata).
 No obstacles assumed to be close to the BTS antenna.
 Deterministic propagation models
 Take into account individual buildings and use ray tracing
techniques.
 Make use of high resolution map data (at least 10m).
Cellular Architecture
•
The essential principles of the cellular architectures are :-
 Low power transmitters with antenna heights between 20 – 50
m
 Small coverage zones (cells), typical macro cell radius 3 – 30 km
 Frequency reuse (factor n = 3, 4, 7 ... )
 Cell splitting to increase local capacity
 Micro and Pico cells act as patches for hot spots, tunnels and
buildings
•
Balance is to be found between conflicting requirements of :
 Coverage
 Traffic capacity
Cell Clustering
•
Frequency reuse is the core concept of the cellular mobile radio system,
given the fact that the number of allowed frequencies is fixed. A
frequency can be reused simultaneously in different cells, provided that
the cells using the same frequency set are far enough separated so that
co-channel interference is kept at an acceptable level most of the time.
•
The total frequency spectrum allocation can be divided into K
frequency reuse patterns.
Cell Types
•
The 2 main cell types are :-
 Omni cells :
– Coverage is in principle a
circle, but in reality a
rough pattern
 Sector cells :
– 2 sectors (e.g. for
highways)
– 3 sectors
•
Cell Coverage Area

Omni cell (Hexagon) = 2.6 R2

Sector cell (Hexagon) = 1.96 R2
Capacity Planning
•Capacity Planning
Capacity Planning
•
•
•
•
•
Capacity can be understood in simplest terms as the number of mobile
subscribers a BTS can cater for at a given time.
Capacity planning is a very important process in the network rollout as it
defines the number of base stations required and their respective capacities.
When the sector utilization more then 100% then we will go for a new
capacity site in the nearby area.
Capacity plans are made in the preplanning phase for initial estimations, as
well as later in a detailed manner.
The number of base stations required in an area comes from the coverage
planning, and the number of transceivers required is derived from capacity
planning as it is directly associated with the frequency re-use factor.
Capacity Planning
•
There are three essential parameters required for capacity planning:
estimated traffic, average antenna height, and frequency Re-use.
– Estimated Traffic:- Traffic in the network is dependent on the user
communication rate and user movement in the network. Traffic
estimation in the network is given in terms of ‘erlangs’. One erlang (1 Erl)
is defined as the amount of traffic generated by the user when he or she
uses one traffic channel for one hour (this one hour is usually the busy
hour of the network)
– Average Antenna Height:-The concept of the average antenna height is
the basis of the frequency re-use pattern determining capacity
calculations in a cellular network. If Antenna Height is low then the
covered area is small in an Urban Area, Exactly the opposite is the case
in micro cellular environment.
– Frequency Re-use:-Frequency re-use basically means how often a
frequency can be re-used in the network. If the average number of the
transreceivers and the total number of frequencies are known, the
frequency re-use factor can be calculated.
Capacity Enhancement Solutions
•
Conventional solutions
•
•
•
•
•
•
Cell splitting
Site distance reduction
Interference Reduction Features
New Site Plan
Optimize site properly
Extra Spectrum
• Extended GSM (10 MHz)
• Dual Band/ Dual Mode
•
•
Microcells (Hotspot, Continuous Layer)
Indoor Planning Solutions
City Planning
City Planning Enhancement Solutions
•
•
Conventional solutions
– New Site planned
– Building Height
– Tower Heights
Microcells (Hotspot, Continuous Layer)
City Planning
•
•
•
•
The whole land area is divided into three major classes – urban, suburban and
rural –based on human-made structures and natural terrains
City Is coming under Dense Urban, Urban & Suburban.
City Planning requires from the planners is generally a network design that covers
100% of the area. Fulfilling this requirement is usually impossible, so efforts are
made design a network that covers all the regions that may generate traffic and to
have ‘holes’ only in no-traffic zones.
The cells (sites) that are constructed in these areas can be classified as outdoor
and indoor cells. Outdoor cells can be further classified as macro-cellular, microcellular or pico-cellular.
– Macro Cells:- When the base station antennas are placed above the average
roof-top level, the cell is a known as a macro-cell. A macro-cell range may vary
from a couple of kilometers to 35 km So this concept is used for rural
Environment.
– Micro Cells:- When the base station antennas are below the average roof-top
level, then the cell is known as a micro-cell. The area that can be covered is
small, so this concept is applied in Dense urban and urban areas. The range
of micro-cells is from a few hundred meters to a couple of kilometers.
– Pico Cells:-Pico-cells are defined as the same layer as micro-cells and are
usually used for indoor coverage.
Highway Planning
•
•
•
In Highway planning needs High gain antenna as well as more
height.
This site is coming under clutter type Rural area.
This site is dedicated to highways & act as an backbone network for
those Rural area nearby the highway.
RF Planning on Asset
Tool
Creating a Project
•
•
•
•
Add a new project from the “Add Project”
Give a Project Name & Change the Following parameters as the Requirement:
Coordinate System:-The information is vital to locate the mapping
information on the earth’s surface. This information is obtained from the
data provided.
• Map Projection
• Ellipsoid
• UTM Zone
Then Click “Save” button and then press “OK”.
Creating a Project

–
Mapping data directory
Information relating to the location in the directory structure of
where the particular type of mapping data is held
–Line (vector) data
–Heights
–Clutter
–Text
Training On Asset Tool
Creating a Project
•
•
User data directory
Directory for storage of the user data types
–
–
–
–
–
–
User Preference
Prediction Directory
Max Disk Space (Default space 5 GB)
Colour Palette (C:\Program Files\AIRCOM International\Enterprise 6.0\Common)
Coverage Array Directory
User Line Vector (Data)
Creating a Project

•
•
Map data extents
Defined the overall area that the user will be able to move around in the
2-D view
Click on “Calculate” Button.
Asset Planning Tool
•
Now Project created & Select the project by click on the “Start” Button.
2D Views Window
3. Add
Sites
2. Add BSC
1. Add
MSC
4. Moving
•
5. Deleting
6. Moving antenna
7. Re-orientating
antenna
For a new project, the user will need to firstly lay down MSCs
and BSCs in hierarchical order.
Site Database Window
Site Database
Site Database
•
To get all information regarding a site, Like GSM Antenna
Height, type, power, Lat/Long.
Site Database
Site Database
Site Database
Analysis
•
Predictions for all sites to be analysed are required before any
analysis is done
Analysis - Array Creation
Create Array
Add site to
coverage
array
Display
coverag
Add cell to
e for a
coverage
cell
array
Create/display
Array
Coverag
e
Statistic
Display
coverage
for a site
Cell signal
difference
Analysis - Array Creation
Use to analysis network with frequency
hopping turn-on
Use to analysis network without
frequency hopping turn-on
Analysis - Array Creation
Minimum signal level at which a
cell is considered to be a serving
cell
Analysis - Array Creation
Analysis - Array Creation
Use when there are predictions of
different resolution, to interpolate
and smooth all the different
resolutions to the selected one to
give a continuous resolution
coverage array
Settings
•
Options - Carriers
Settings
•
Option - Group
Settings
•
Option - Carrier Layers
Settings
•
Option - Cell Layer
Settings
•
Option - Cell Layer
Settings
•
Coverage Thresholds and Types
Create Array
•
•
Select the filter in Create Array windows & Press “OK”.
Then Processing for the Create Array.
Asset Planning Tool
•
•
After Processing Prediction Plot of the Site.
For multiple Site we can select required Site the go for Prediction.
Single Site Prediction
Multiple Site Prediction
Report
Export
•
The project can be exported to the following format :–
–
–
–
–
–
–
–
–
–
Coverage (MapInfo bitmap)
Enterprise
Coverage (Coversoft/GSM Association V6)
Coverage (InterGraph)
Coverage (MapInfo Mif)
Coverage (MapInfo Tiff)
Neptune
NPS/10
NPS/X
PlaNet/EET
Import
•
Asset can import data from :-
– Enterprise
– Neptune
– NPS/X
– PlaNet/EET
!!!! END !!!!