radio network planning fundamentalsnew

Copyright 2002 AIRCOM International Ltd All rights reserved AIRCOM Training is committed to providing our customers with quality instructor led Telecommunications Training. This documentation is protected by copyright. No part of the contents of this documentation may be reproduced in any form, or by any means, without the prior written consent of AIRCOM International. Document Number: P/TR/003/G101/2.2a This manual prepared by: AIRCOM International

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Radio Network Planning Fundamentals

Radio Network Planning Fundamentals © AIRCOM International 2002 0-1

Table of Contents

1 Propagation Models

1.1 Introduction......................................................................................................1-1 1.2 The Plane Earth Model....................................................................................1-2 1.3 Diffraction Effects ............................................................................................1-3 1.4 Empirical Models.............................................................................................1-8 1.5 Okumura’s Measurements ...........................................................................1-10

2 CW Measurements and Model Tuning 2.1 Introduction......................................................................................................2-1 2.2 The Transmitter................................................................................................2-2 2.3 The Receiver .....................................................................................................2-3 2.4 CW Measurements. .........................................................................................2-4 2.5 Model Calibration Exercise. ...........................................................................2-7 2.6 Model Tuning.................................................................................................2-11

3 Link Budgets 3.1 Introduction to Power Budgets......................................................................3-1 3.2 The Downlink Power Budget.........................................................................3-4 3.3 Uplink Power Budget......................................................................................3-7 3.4 System Balance.................................................................................................3-8 Self-Assessment Exerecises ..........................................................................3-13

4 Network Dimensioning 4.1 Introduction to the Dimensioning Process...................................................4-1 4.2 Different Approaches to the Dimensioning Process ..................................4-4 Self-Assessment Exercises ............................................................................4-11

5 Traffic Analysis 5.1 Introduction to Traffic Analysis ....................................................................5-1 5.2 Trafic measurements - Erlangs ands Blocking ............................................5-2 5.3 The Traffic Analysis Process ..........................................................................5-4 5.4 Using Demographic Data ...............................................................................5-5 5.5 Market Projections and Traffic Maps............................................................5-7 5.6 Roll-out Strategy ..............................................................................................5-9 5.7 Capturing Traffic and Assessing Resource Requirements ......................5-11 Self-Assessment Exercises ............................................................................5-15

6 Nominal Planning 6.1 Introduction......................................................................................................6-1 6.2 The Nominal Planning Process......................................................................6-2 6.3 Creating a Nominal Plan using a Planning Tool.........................................6-7 6.4 Evaluating the Capacity of the Nominal Network. ..................................6-11 6.5 Mixing Packet and Circuit Switched Services. ..........................................6-15 6.6 Self-Assessment Exercises ............................................................................6-17

Appendix A - Solutions to Self Assessment Exercises Appendix B - Erlang B Tables

0-2 Radio Network Planning Fundamentals

© AIRCOM International 2002

Intentional Blank Page


Course Objectives and Structure

There are certain fundamental planning techniques that are applicable to all mobile radio systems. Likewise, there are certain elements of knowledge that can be regarded as an essential core for planning engineers. The objective of this course is to equip such engineers with sufficient knowledge to allow them to develop further and to understand and learn the techniques specific to a particular technology such as GSM or UMTS. Such generic topics include appreciating the need for being able to predict the signal strength throughout the proposed network coverage area. This must be done accurately and rapidly. We shall see that accuracy and rapidity are conflicting demands. The most popular mathematical “models” will be reviewed and compared. In general we will find that most mathematical models are not sufficiently accurate to be applicable throughout all environments. As a result they will need to be “tuned” to a particular area. The tuning of a model is a skill that is required by planning engineers in order to ensure that the path loss predictions are sufficiently accurate.

Aims of the CourseAims of the Course• To achieve a general understanding of planning techniques applicable to all

mobile communication systems.

• To understand the need for an accurate radio propagation model.

• To be able to use carrier wave measurements to tune a propagation model.

• To understand and be able to produce a link budget.

• To be able to carry out dimensioning exercises.

• To be able to spread traffic and assess capacity requirements.

• To be able to produce a nominal plan and appreciate site design procedures.



Once a model that is capable of predicting the path loss between a base station and a particular point on the ground has been obtained, it is obviously essential to be able to calculate what path loss can be tolerated. In order to do this it is necessary to develop what is known as a “link budget”. The Link Budget is a method of accounting for gains and losses in a system so that the received signal power can be determined in a consistently accurate manner. Being able to dimension a network is a crucial skill. This involves incorporating market forecasts and coverage and capacity prediction for each cell to develop an estimate of the resource requirements of a network. In particular, this will involve the number and approximate location and configuration of sites. Once the dimensioning exercise has been carried out, it is possible to use a software planning tool to undertake a preliminary exercise in order to establish how well the network will cope with traffic in a simulation. This involves spreading traffic across the network area and analysing reports in order to assess whether or not cells are appropriately loaded with traffic. These tasks lead to the development of what is known as a “Nominal Plan” which is a hypothetical network that would meet the objectives. The development of a nominal plan is a pre-requisite to being able to commence site acquisition and network “roll-out” procedures.

Course OutlineCourse Outline

Propagation Models

CW Measurements and Model Tuning

Link Budgets

Network Dimensioning

Traffic Analysis

Nominal Planning


1. Propagation Models ________________________________________________________________________________ 1.1 Introduction

Predicting the strength of a signal received by a mobile is not straightforward. Often the mobile receiver cannot see the base station and the signal strength is determined largely by reflection (also called “scattering”) and diffraction. The variety of possible environments encountered by the radio wave means that the distance between the base station and the mobile is not the only parameter that affects the path loss. A variety of possible methods exist that allow the engineer to predict the path loss with sufficient speed and accuracy. It is vital that a prediction method that engineers are confident in is adopted before the network is designed.

Why we need a Propagation ModelWhy we need a Propagation Model

• Mobile communication is made possible using multipath propagation

• The radio wave undergoes scattering, diffraction and attenuation

• Propagation model calculates the path loss between transmitter and receiver

• Required for calculating power budgets and system balance requirements

• Model used for setting up a network and subsequent optimisation

?

Section 1 - Propagation Models



________________________________________________________________________________ 1.2 Plane Earth Model

Plane Earth ModelPlane Earth Model

Tx Rx

Image Tx

Reflection at Earth’s surface

Antenna heights (h1, h2)

Link distance d

Wavelength

Reflection coefficient of Earth

Signals at Rx may interfere constructively or destructively to different degrees

This depends on:


The simplest model to consider reflections at all is known as the Plane Earth model which computes the received signal to be the sum of a direct signal and that reflected from a flat, smooth earth. The relevant input parameters include the antenna heights, the length of the path, the operating frequency and the reflection coefficient of the earth.

Plane Earth Model EquationPlane Earth Model Equation• Calculations on the plane earth model lead to the following equation

for path loss:

LPEL = 20 log (d2 / h1 h2) dB

LPEL = 40 log (d) - 20 log (h1) - 20 log (h2)

• d = path length in meters

• h1 and h2 are antenna heights

• Problems with using plane earth model in GSM:• Does not deal with multipath reflections• Mobile height is constantly changing



For a perfectly reflecting earth, the path loss L is expressed by:

( ) ( ) ( )21 log20log20log40 hhdL −−= where d is the path length in metres and h1 and h2 are the antenna heights at the base station and the mobile. The plane earth model is not really appropriate for mobile systems as it does not consider reflections from buildings, multiple reflections or diffraction effects. Further, if the mobile height changes (as it will in practice) then the predicted path loss will also change.

________________________________________________________________________________ 1.3 Diffraction Effects

Terrain obstacles will sometime obstruct the line of sight (LOS) path between the base station and the mobile. The effect of an obstruction depends on the amount by which it obstructs the line of sight path, the distance from the obstruction to both ends of the path and also the frequency of operation. These four parameters can be reduced to a single parameter by expressing the clearance in terms of the Fresnel Zone Radius. The Fresnel zone describes an ellipsoid in three dimensional space. If you add the distance to each end of the link from any point on the surface of this ellipsoid, the sum is half a wavelength more than the straight-line distance between the two ends. The radius of this ellipsoid is referred to as the radius of the First Fresnel Zone.

Non LOS Paths: Non LOS Paths: FresnelFresnel Zone ConceptZone Concept• First Fresnel zone: ellipsoid with major axis along line from Tx to Rx• Path length of wave reflected from Fresnel zone surface is λ/2 more than

direct path:a + b = d + λ/2

• Radius of ellipsoid at d1 from Tx is given by:

Tx Rx

d1 d2

d

F1a b

ddd F 1

1λ

= 2

F1




First Fresnel Zone ClearanceFirst Fresnel Zone Clearance• Fresnel zone clearance is mainly used to calculate antenna heights for fixed

line of sight microwave links

• The height is calculated to give 100% clearance with an Earth radius factor (K) of 4/3 and again for 60% clearance with K = 2/3. The greater of these two results is then used for the antenna height.

• It can be useful when placing a base station to consider Fresnel zone clearance using an average position for the mobile station

BTS

High concentration of subscribers

First Fresnel zone clear of obstacles


If the first Fresnel zone is clear of obstructions then the link can be regarded as if no obstructions existed. It is important to remember that the curvature of the earth must be considered when evaluating the degree of obstruction. Atmospheric effects can lead to the curvature being either exaggerated or diminished. This is accounted for by applying a “k-factor” to the actual radius of 6373 km when determining the curvature effect. Typically, the whole of the first Fresnel zone would be expected to be obstruction-free for a k-factor of 1.33 and 60% free when the k-factor is 0.67.

Knife Edge DiffractionKnife Edge Diffraction

• Objects protruding into the first Fresnel zone will cause significant diffraction effects

• A variety of models are available to calculate diffraction loss or gain at the receiver due to a series of knife edges

• The commonly used knife edge models are:

• Bullington

• Epstein-Peterson

• Deygout

• Japanese Atlas



If the clearance requirements are not met, then the amount of “diffraction loss” must be calculated. If there is a single “knife-edge” obstacle, the calculation is relatively straightforward. If there is, instead, a series of obstacles then the computation becomes extremely complex. A number of approximate methods of predicting the diffraction loss under such circumstances have been put forward.

BullingtonBullington ModelModel• Defines a new effective knife edge obstacle at the point where the line-of-

sight from the two antennas cross

• Advantage:• Simple method

• Disadvantage: • Significant obstacles may be ignored leading to an optimistic estimate of field

strength


Tx Rx1 2

Equivalent knife edge

1 2

Epstein Epstein -- Peterson ModelPeterson Model

• This finds the total loss as the sum of the diffraction losses at each obstacle• For obstacle 1, consider Rx to be at obstacle 2. Then for obstacle 2, consider

Tx to be at 1 and Rx to be at 3 and so on.• Advantage:

• does not ignore important obstacles as Bullington method may

• Disadvantages: • may overestimate path loss when the obstructions are close together

Tx Rx1 2 3


1 32

Tx2

Rx1Rx2

Tx2



• Effective Tx position for each obstacle is found by extending the line to the previous obstacle back to meet the vertical line through the actual Tx

• Advantage:• gives improved results when the obstructions are closely spaced

• Disadvantage:• still suffers from underestimating the path loss• Non-reciprocal

Japanese Atlas ModelJapanese Atlas Model

Tx Rx1

Loss for obstacle 2: Take transmitterat T and receiver at 3

T


2 3

• This calculates a V parameter for each obstacle• Obstacle with highest value of V is the ‘main obstacle’• Loss for this edge is calculated• Loss over next most significant obstacle is then found and added to loss and so on

• Advantages: • Accurate when there is a clearly dominant edge• For three or four obstructions, Deygout gives the best results of any of the

approximate methods• Disadvantages:

• Where there is no dominant edge, Deygout tends to overestimate the loss• Does not work well when there are two similar height edges such as ends of a

building

DeygoutDeygout ModelModelSection 1 - Propagation Models

Tx Rx11 2

main edge

3


________________________________________________________________________________ 1.4 Empirical Models

Models Based on Practical DataModels Based on Practical Data• Models dealt with so far are purely theoretical

• For correct predictions of propagation, we must account for the topography of the region (ground clutter)

• Procedure:

• Start with a standard model based on measured data

• Drive test region for various clutter types and different frequencies

• Repeat measurements to obtain consistent results• Use drive test data to tune the standard model

• Make predictions from the tuned model

• Carry out further drive testing to verify the model


Empirical models are mathematical equations that are based on the result of measurements made in typical, realistic situations. In general, such models are “tunable” that is, they contain coefficients that can be altered to make the model agree with measurements made in the location in which the network is being planned.

Standard Propagation ModelsStandard Propagation Models

• Models based on published data• Main models available are:

• Okumura - Hata

• COST 231 - Hata

• COST 231 Walfisch - Ikegami

• Sakagami - Kuboi

• Different models are more appropriate depending on:• Location• Frequency range• Clutter type




Typically, more than one model will be used in any given network in order to predict the changes in topography (land use; also known as “clutter category”). A few models are now widely used as they have been shown to produce reliable predictions in a wide variety of circumstances. Further they produce predictions very rapidly. Remember that a prediction will be made over a grid that will have a resolution of, say, 20 metres. That means 2500 predictions must be made for every base station for every square kilometre. Speed of calculation of the propagation model is vital. Some “traditional” models (such as the Okumura-Hata) have been modified to extend their range of applicability. One very active group in this field has been the COST 231 project; a collaborative affair involving engineers and scientists from universities and industry throughout Europe.

________________________________________________________________________________ 1.5 Okumura’s Measurements

A lot of current mobile propagation models have at their heart the measurements made by a Japanese engineer named Okumura.

Okumura’s MeasurementsOkumura’s Measurements

• Okumura, a Japanese engineer, carried out extensive drive test measurements, with a range of:

• clutter type

• frequency

• transmitter height

• transmitter power

• Main conclusion from Okumura field tests:• Signal strength decreases at a much greater rate with distance than that

predicted by free space loss



• Typical curves for different base station antenna heights with fixed mobileheight (1.5m) and frequency (900 MHz)

• Field strength drops off more rapidly than free space line, particularly closerto the base station

Okumura’s ResultsOkumura’s Results

Fiel

d S

treng

th (

d B)

Log Distance (km)

Free space loss

Increasing base station antenna height


From the graphs of lines of best fit for a number of situations it was possible to quantify the effect of link length and base station height on the received signal strength. Hata took Okumura’s results and set about converting them into a mathematical model. It must be remembered that the model should be regarded as applicable only over the ranges for which measurements were made. Hata developed three models: one for urban; one for suburban environments and one for open country. The coefficients can generally be changed as part of a “tuning” process.

Hata’s Propagation ModelHata’s Propagation Model

• Hata based the model on Okumura’s field test results

• Predicted various equations for path loss with different types of clutter

• Limitations on Hata model due to range of test results:

• Carrier Frequency: 150 MHz to 1500 MHz

• Distance from the base station (d): 1km to 20 km

• Height of base station antenna (hb): 30m to 200m

• Height of mobile antenna (hm): 1m to 10m




Hata’s EquationsHata’s Equations• Path loss for urban clutter:

Lp(urban) = 69.55 + 26.16 log(f) - 13.82 log(hb) - a(hm) + (44.9 - 6.55 log(hb)) log(d)

• Path loss for suburban clutter:Lp(suburban) = Lp(urban) - 2{log(f / 28)}2 - 5.4

• Path loss for open country:Lp(open country) = Lp(urban) - 4.78 {log(f)}2 + 18.33 log(f) - 40.94


Limitations on Limitations on HataHata Model for GSMModel for GSM

• Maximum carrier frequency = 1500 MHz

• Not valid for 1800 MHz or 1900 MHz systems

• Assumes base station antenna is above surrounding clutter

• Not suitable for microcell planning where antenna is below roof height

hb

hm

d

microcell


The upper frequency limit of 1500 MHz with regard to the Okumura-Hata model posed a serious problem when GSM systems commenced operation in the 1800 MHz band. One of the major objectives of the COST 231 project was to establish an appropriate macrocell model, or models, for frequencies up to 2000 MHz.


Cost 231 Cost 231 -- HataHata ModelModel• COST : European Co-operation in the Field of Scientific and Technical Research

• COST 231 - Hata extends the Okumura-Hata model for medium to small cities to cover the 1500 to 2000 MHz band

• Path loss equation is:

Lp= 46.3 + 33.9 log(f) - 13.82 log(hb) - a(hm) + {44.9 -6.55 log(hb)}log(d) + Cm

Cm = 3 dB for metropolitan centers

Cm = 0 dB for medium sized cities and suburban areas

• The model is not valid for hb <= hroof (i.e. base station below roof height) so it is not suitable for microcell planning


COST 231 COST 231 WalfischWalfisch--Ikegami ModelIkegami Model

• Combination of theoretical models (Walfisch / Ikegami)

• Includes some correction factors from measurements

• Deals with diffraction effects down to street level




SakagamiSakagami KuboiKuboi ModelModel• General model based on detailed analysis of Okumura’s results

• Valid over wide frequency range: 450 to 2200 MHz

• Processes a large number of parameters relating to the urban environment

• Claims validity for base antennas below roof top making it useful in planning microcells

Tx

Ø

W


Sakagami Kuboi FormulaSakagami Kuboi Formula• Path loss in dB:Lp = 100 - 7.1 log(W) + 0.023 Ø + 1.4 log(hs) + 6.1 log<H> - {24.37-3.7(H / hb)2} log(hb)

+ {43.42 - 3.1 log(hb)} log(d) + 20 log(f) + e[13 {log(f)-3.23}]

W = width of the road at the receiving point (5 - 50 m)Ø = orientation of road relative to base station direction

(0 to 90 degrees)hs= height of the building on the base station side of the receiving point (20 -

100 m)<H> = average height of the buildings near the receiving point

(5 - 50 m)H = average height of the buildings around the base station



The Sakagami-Kuboi formula is a level of sophistication above that of the Okumura-Hata or COST 231-Hata models. Its claim to be valid for base station heights below the building height makes it suitable for microcell and well as macrocells. However, it requires information regarding street width and orientation as well as building heights. This sort of information may not be readily obtainable for the mapping data to hand. Even if such data were available, the time taken to run the model may be prohibitive.

Which Model to Use?Which Model to Use?• Cell planners using various planning

tools have their favourite models

• No one model is accurate in every situation

• Model must be tuned or calibrated according to the local situation

• Before using a model to predict coverage it must be verified by drive testing

Asset’s model is based on COST 231-Hata and is tuned by v arying a combination of parameters k1 - k7




SummarySummary

• Need for propagation models: predictions, power budgets, optimisation

• Theoretical approaches: • plane Earth, Fresnel zone, diffraction models: Epstein - Peterson,

Bullington, Japanese Atlas, Deygout

• Practical measurements and models: • Okumura’s results, Hata model, COST 231 Hata, Sakagami - Kuboi,

need for model tuning



2. CW Measurements and Model Tuning

________________________________________________________________________________

2.1 Introduction

The gathering of Carrier Wave (CW) measurements involves what is known as “drive testing”; that is, covering an extensive part of the proposed coverage area measuring the signal strength received from a particular base station that is transmitting an unmodulated carrier. The measurements obtained are compared against those predicted by the mathematical model. This allows the coefficients of the various terms contained in the model to be altered so as to produce a “best-fit” curve to the measured data. The equation for this curve is then used as the propagation model.



________________________________________________________________________________

2.2 The Transmitter

It is usually necessary to establish a temporary transmitter in order to conduct a drive-test. The transmitter could utilise its own mobile mast or, alternatively, make use of existing buildings. It is, of course, vital that either the transmitter is battery powered or there is ready access to a mains power supply.

• Temporary Transmitter Arrangement:

• Roof top or crane mounted

• Access to AC power source

• Low gain omni-directional antenna

Temporary mastBATTERY

RADIOTRANSMITTER

C W Analysis C W Analysis -- TransmitterTransmitterSection 2 – CW Measurements & Model Tuning

________________________________________________________________________________ 2.3 The Receiver

The equipment must be capable of recording both the signal strength and the location of the mobile at the measurement instant. This is so that the measurement can be compared with the prediction for the signal strength at that position. The measurement equipment must include a sensitive, narrow band, receiver; usually including a spectrum analyser. The location information is provided by a GPS receiver. As a considerable distance may be travelled between one GPS reading and the next, the position information may be supported by speed and direction information provided by in-car equipment.


Wheel pulser

PC

GPSReceiver

PositionalInformation

DirectionalInformationSpeed

Information

C W Analysis C W Analysis -- ReceiverReceiver

RadioReceiver Disk

Storage

Gyro

Section 2 – CW Measurements & Model Tuning

________________________________________________________________________________ 2.4 CW Measurement

CW Test ProcessCW Test Process

• Drive testing should be performed on radial and circumferential (azimuthal) routes

• Radial routes show variationin signal strength with distancefrom base station

• Circumferential routes provide predictions for signal strength in different directions from the base station




It is important that as much variety as possible is incorporated into the measurements. It is not very useful if the mobile is just moved in a circle at a constant distance from the base station as no data would be gathered regarding the variation of signal strength with distance from the mobile. Similarly moving the mobile along one radial line from the base station would render the results likely to be unrepresentative due to some particular characteristic of the terrain in the direction chosen.

CW Analysis CW Analysis -- Transmitter SitingTransmitter Siting

• Select sites which are good representatives of your network

• Use a range of antenna heights

• Ensure there are no immediate obstructions near the test transmitter

• Do not place the test transmitter on a building having long roof

Long roof obstructs transmission in this direction


• Test drive in the main vertical lobe of the omni antenna - low gain antenna - large main lobe - consistent good coverage over wide area

• Do not test drive in the shadow regions

• Take panoramic photographs around the test site to relate measurements to actual ground features

CW Analysis CW Analysis -- Drive TestingDrive Testing

X

Omni antenna



When comparing results with the model it is important that the validity of any assumptions made by the model is maintained. One of these assumptions will concern the gain of the antenna. It is therefore very important that the mobile remains within the main lobe of the base station antenna. This entails ensuring that the mobile does not get too close to the antenna such that it is “under” the main lobe.

• Cover all clutter types equally throughout the test

• Be aware of man-made features such as bridges or tunnels

Most models assume a mobile height of 1.5m, bridges can affect the actual height above ground:

Clutter and ManClutter and Man--made Featuresmade Features

Actual position of mobile

Model assumes mobile is here

Bridge

Ground level - given by map data


Further, it is essential that, when the positional information gathered is translated onto a map of the test route, the mobile is calculated to be where it actually is. This may sound obvious but there are situations where discrepancies can occur. One such situation is when the mobile is on a bridge over a valley. The model may well assume that the mobile is on the valley floor when, in fact, it would be many metres above this point. An additional case to be avoided is placing the mobile in a tunnel when the mapping data would lead to the assumption that it was on the land surface vertically above.



CW Measurement EquipmentCW Measurement Equipment• Measurements should be distance based.

Take readings no closer than 0.38 wavelengths apart.

• Equipment can be:Distance triggeredTime triggered

• GPS outputs position every second.Position interpolation is required for each measurement.

• Test mobile measurements are NOT suitable.


Measurements should be taken at regular intervals. If the equipment is distance-triggered, care must be taken to ensure that the speed of the drive test vehicle is not so large that the equipment cannot complete a measurement before the next trigger pulse arrives. If the equipment is time triggered, a slow moving vehicle will produce the desired small distances between measurements. In this situation, the speed of the vehicle should be maintained constant. It is tempting to economise on the measurement equipment by using a test mobile instead of a professional measuring receiver. Test mobile receivers are inadequate for a number of reasons:

• They record signal levels to the nearest 2 dB. • They are wideband (200 kHz) devices and hence not sufficiently

sensitive.

________________________________________________________________________________ 2.5 Model Calibration Exercise

Firstly, we have to check that a propagation model exists. In the tools menu, click on “Propagation Model Editor”. The “900 MHz” model should already exist. Ensure that all categories on the Clutter tab are set to zero; Diffraction is set to “Epstein-Peterson”; Effective Antenna Height is set to “relative”. Finally click on the Path Loss tab and set the values to correspond with those given on the slide.


Model Calibration ExerciseModel Calibration Exercise• In this exercise you will calibrate an empirical propagation model at 900

MHz.The model calibration process is the same for any frequency.

• Procedure:• Start Enterprise

• Log into the “G101_01” database:User Id = “demouser”Password = “demouser”

• Start the “CW Analysis” Project.


Create a Propagation ModelCreate a Propagation Model

• Add a new propagation model.• Type - Standard macrocell• Name 900MHz

• Set up a propagation model with the default parameters.

Parameter SettingModel Type Standard MacrocellFrequency 900

Mobile Rx Height 1.5Effective Earth Radius 8491.2

K1 135K2 38K3 -2.55K4 0K5 -13.82K6 -6.55K7 0.7

Eff. Ant. Height RelativeDiffraction Epstein Peterson

Merge knife edges 0




Load a CW Measurement FileLoad a CW Measurement File

• Open the CW measurement analysis window.• Use the Add button to load the CW file.• Use the options button to check the CW measurement options.

• Model20m resolution.900 MHz prediction model.

• FilterDeselect all clutter types.Radius 0 » 100000m.Signal -110dBm » -40dBm.Visibility: Check both boxes.

• DisplayCheck the “Overall Summary” and “Clutter Summary” boxes.


The “CW Measurement Analysis” window is found under the Tools menu. Click on options and select the model and set the resolution as indicated in the slide above. Similarly check that the “Filter” and “Display” options are correctly set. Then click on “Add” to load the CW file. The file can be found in the D:\G101db\Ex1\CW folder. It will be necessary to change the “file type” to “Signia” in order to see the required file: “cw.hd”. Open this file (its name should now appear in the CW Meas Analysis window).

Perform a Preliminary Analysis (1)Perform a Preliminary Analysis (1)

• Press the Analyse button.• Identify which clutter types are

invalid due to insufficient measurements.

• In this case assume clutter types with fewer than 100 samples are invalid.

• In practice the actual threshold would be much higher than this.



Note that you will not get as many clutter categories reported on as shown in the slide above. They may all have more than 100 readings in which case the next slide can be ignored.


• Open the “CW measurement options” window. Highlight all the invalid clutter types on the “Filter” tab.

• These clutter types will be excluded from further analysis.

• The final propagation model will not be valid for these clutter types.

• This is one reason why careful selection of the drive route is important.

• Perform the analysis a second time to check that only valid clutter types remain.



• Use the “Graph” button to plot:• Received Level vs log(distance)• Error vs log(distance)

• These can be used to spot potential problems with CW measurement files.

• The example here shows a potential problem possibly causedby collecting data in underpasses and road cuttings. Such measurements should be removed prior to calibration.




________________________________________________________________________________ 2.6 Model Tuning

Examining the report we can see that the Mean and Standard Deviation of the error is reported. The objective of a tuning exercise is to reduce the mean to zero and make the Standard Deviation as small as possible. Note that, if the mean is zero, the standard deviation of the error will equal the rms error. The model used in the tool is summarised below.

Path Loss (dB) = k1 + k2log(d) + k3Hms + k4 log(Hms) + k5 log (Heff) +k6log(Heff)log(d) + k7(Diffraction Loss) + Clutter Loss

k1 is simply an offset, so reducing the mean error to zero is a trivial matter. Do this by altering k1 by an amount equal to the mean error reported. Check that the error is now zero. Now we must try and reduce the standard deviation by tuning the other parameters. k2 affects the slope of the graph with distance. At first it is set to 38. Vary this between 38 and 58 to see that the SD reaches a minimum. Notice that when k2 has been changed, the mean error is no longer zero. For this reason, adjusting the mean error is usually one of the last operations. Examining the other terms; k3 and k4 govern the affect of mobile height which was kept constant for the measurements shown here and are therefore not tunable. The process would involve tuning k5 then k6 followed by k2 and so on until the standard deviation is minimised.

Model Calibration (1)Model Calibration (1)

• The propagation model can now be calibrated.• Mostly a trial and error process.

• Change one model parameter at a time.• Re-analyse the modified propagation model and see if the model improves or

deteriorates.• Repeat the previous two steps until the error has been minimised for that

parameter.• Moving on to another parameter.• Changing one parameter might affect the optimum value of another parameter

so when all parameters have been calibrated the process might need repeating until convergence has been reached.



Model Calibration (2)Model Calibration (2)• There are different approaches to

model calibration.• Here, k3 and k4 are not altered,

because they relate to mobile height. In a typical cellular system, mobile height is constant making these coefficients redundant.

• This process can be extremely laborious. Some shortcuts are possible:

• k1 can be derived from the overall mean error

• Clutter offsets can be derived from the mean error of each clutter type.

• A good propagation model will have a standard deviation of error of 6 - 8 dB.

Repeat calibration of k factors

k2

k1

Effective Antenna Height Algorithm

k6

k7

k5

Diffraction Algorithm

Clutter Offsets

Start

Finish

Flowchart of typical model tuning process


It is possible, however, to tune the parameter k7. This is a factor that reduces the diffraction loss predicted. This can be appropriate when the field strength in the shadow of an obstacle is enhanced by either reflections or diffraction around the side of the obstacle.



SummarySummary• The practicalities of drive testing: Tx / Rx equipment,

siting of Tx, planning of routes• Analysing results: loading CW file, analysing for

clutter types, filtering of unrepresentative clutter• Tuning a model: trial and error process, change

k values one at a time, re-analyse to find standard deviation, minimise standard deviationand mean error



3. Link Budgets ________________________________________________________________________________

3.1 Introduction

One essential part of the system planning procedure is to establish the signal strength that a mobile will receive in a particular area and, further, to ensure that wherever coverage is provided on the “downlink” (from the base station to the mobile) then system balance is maintained by engineering the sites so that there is sufficient signal power received on the uplink.

• Calculations to allow for losses and gains in signal strength to ensure level is acceptable throughout service area

• Minimum level must be greater than sensitivity of mobile, with amargin for fading and penetration loss

• Decibel calculations allow simple tracking of losses and gains

• Power input to mobile = Tx output - Losses + Gains

Power BudgetsPower Budgets

Tx

Section 3 – Link Budgets



When assessing downlink coverage, it is important that due attention is paid to the threshold level (or “sensitivity”) of the mobile. This is the minimum signal level for which a service of acceptable quality will be provided. In practice, the signal strength will suffer fades due to multipath propagation. A margin should be allowed for this fading. Further, the propagation model will predict the signal strength in the street rather than inside buildings. If coverage is to be provided within buildings, an additional “penetration loss” must be accounted for. These margins will be added to the path loss and other losses to give a total loss. The antennas will provide some gain to offset against this. A net loss can then be calculated as the difference between the total losses and the total gains. This loss is subtracted from the transmit power to give an estimate of the power level received at any point.

________________________________________________________________________________

3.2 Review of Decibel Scale

Review of Decibel ScaleReview of Decibel Scale

• Logarithmic scale for comparing power levels• Gain = Pout / Pin as a ratio• In decibels: Gain = 10 log (Pout / Pin )• Using logarithms allows a sequence of gains and losses to be found by adding and

subtracting decibel values rather than multiplying and dividing

• Decibel scale can be used to measure an actual power level by using a reference level

• Power in dBm is compared to a power of 1 milliwatt (1 mW = 1/1000 W)• Example, convert 2 watts to dBm :

P = 10 log ( 2 W / 1 mW) = 10 log (2000 / 1 ) = 10 x 3.3 = 33 dBm

• Note: 1 mW = 0 dBm (since log(1) = 0)


The use of the decibel scale allows the result of combining losses and gains within a system to be determined by means of addition and subtraction rather than multiplication and division. A gain or a loss is expressed in decibels (dB) in accordance with the equation given in the above slide. It is possible to express an absolute power, rather than a gain, using the decibel scale by adopting 1 milliwatt as a reference power. The absolute power is then quoted in dBm, the “m” referring to a milliwatt. Certain commonly-encountered gains and losses are tabulated below.


Gain as a ratio Gain in dB

(= 10 log10[gain as ratio]) 2 3 dB 4 6 dB 10 10 dB 50 17 dB 100 20 dB 1000 30 dB 0.5 (a loss of a factor of 2) -3 dB 0.1 (a loss of a factor of 10) -10 dB

Power in milliwatts Power in dBm (= 10 log10[power in mW])

2 3 dBm 10 mW 10 dBm 100 mW 20 dBm 1000 mW 30 dBm 20 W = 20000 mW 43 dBm 1 µW -30 dBm 1 nW -60 dBm 1 pW -90 dBm

Antenna GainAntenna Gain

• Antenna gain is quoted relative to an isotropic radiator• Units : dBi• Gain is achieved because the output power is concentrated

into a smaller region

Isotropic pattern

Omni-directional dipole pattern

Typical antenna gains

Omni: 8 to 12 dBi

Sector: 10 to 18 dBi




Antenna gains are also quoted using a decibel scale. The gain of an antenna refers to its ability to concentrate the radiated energy into a narrow beam rather than spread it equally in all directions. A theoretical antenna (known as an “isotropic radiator”), that does radiate power equally in all directions, is usually chosen as a reference against which to compare the field strength produced by a practical antenna. In order to make it clear that an isotropic antenna has been adopted as a reference, the gain is quoted using the unit dBi (‘i’ being for isotropic).

________________________________________________________________________________

3.3 The Downlink Power Budget

Downlink Power BudgetDownlink Power Budget

BTS TxOutput Power

CombinerLoss

Duplex FilterLoss

Feeder Loss

Antenna Gain

Path LossMS Antenna Gain

Feeder Loss

Input to mobile

PoBS

Lc

Ld

Lfb

Gab

Lp

Gam

Lfm

PinMS

PinMS = PoBS - Lc - Ld - Lfb + Gab - Lp + Gam - Lfm


The above diagram highlights the contributing factors to gains and losses as the signal progresses from the Base Transceiver Station (BTS) to the mobile. A base station will probably transmit more than one carrier. These will share a common antenna. The combiner involved will introduce some loss. Additionally, in order to be able to use the same antenna for transmitting and receiving, it is necessary to use a device known as a duplexer. The duplexer will provide isolation between the transmitter and the receiver to prevent interference between the transmit and receive signals. In providing this isolation, it will inevitably insert a small loss into the wanted signal path.


In calculating the received signal power it is simply necessary to insert the appropriate numbers into the equation. This is demonstrated in the following slides.

Downlink Power Budget AnalysisDownlink Power Budget Analysis

• Power input to the mobile (dBm):PinMS = PoBS - Lc - Ld - Lfb + Gab - Lp + Gam - Lfm

PoBS = Power output from BTS TRX dBmLc = BTS combiner loss dBLd = BTS duplex filter loss dBLfb = BTS Feeder loss dBGab = BTS antenna gain dBiLp = Path loss dBGam = Mobile antenna gain dBiLfm = Mobile station feeder loss dB


Downlink Power Budget Downlink Power Budget -- ExampleExample• A class 4 mobile has a sensitivity of -102 dBm. Allowing a margin for fading,

we take the minimum signal strength at the cell boundary as - 90 dBm. This is to be 10 km from the base station.

• Find the BTS output power, PoBS , required given the following data:BTS combiner loss Lc = 6 dBBTS duplex filter loss Ld = 1 dB

BTS feeder loss Lfb = 7 dB

Omni antenna gain Gab = 12 dBiHata path loss for 10 km Lp = 132 dB

Mobile antenna gain Gam = 0 dBiMobile station feeder loss Lfm = 0 dB




Downlink Power Budget Downlink Power Budget -- SolutionSolution

Downlink power budget equation:

PinMS = PoBS - Lc - Ld - Lfb + Gab - Lp + Gam - Lfm

-90 = PoBS - 6 - 1 -7 + 12 -132 + 0 - 0

-90 = PoBS - 134

PoBS = 44 dBm


________________________________________________________________________________ 3.4 The Uplink Power Budget

Uplink Power BudgetUplink Power Budget

BTS Rx

Duplex FilterLoss

Feeder Loss

Antenna Gain

Path Loss

MS Antenna Gain

Feeder Loss

Output from mobile

PinBS

Ld

Lfb

Gab

Lp

Gam

Lfm

PoMS

Diversity Gain

GdBS

PinBS = PoMS - Lfm + Gam - Lp + GdBS + Gab - Lfb - Ld

Input to BTS Rx



The uplink power budget has two distinct differences when compared with the budget for the downlink.

1. There is no combiner in the base station on the downlink path, hence no combiner loss

2. Two receive antennas are often used at the base station (this is not feasible on the downlink as it is not possible to provide more than one antenna at the mobile).

This provides, what is known as a “diversity gain” due to the fact that, if the signal received from one antenna suffers a severe fade, the signal at the second antenna is unlikely to suffer from a fade. Thus the uplink has the advantage of no combiner loss and diversity gain. Additionally, the receiver in the base station is more sensitive than the receiver in the mobile. These three factors help compensate for the lower transmit power available on the uplink.

Uplink Power Budget Uplink Power Budget -- ExampleExample

• Using the data given earlier for downlink, find the input power to the base station if:

• Output power of mobile PoMS= 33 dBm (2 W class 4 mobile)• Diversity reception gain at base station GdBS= 5 dB

• Solution:PinBS = 33 - 0 + 0 - 132 + 5 + 12 - 7 - 1 = -90 dBm


________________________________________________________________________________

3.5 System Balance

There is no point in being able to communicate in one direction only on a mobile telephone system. The coverage area, and hence the maximum path loss tolerated, should be the same for the uplink and the downlink. If this is the case the system is said to be “balanced”.



System BalanceSystem Balance• Power budget calculations show the maximum distance of the mobile from

the base station at which uplink and downlink can be maintained• In a balanced system, the boundary for uplink and downlink must be the

same

• An unbalanced system would drop many calls in the fringe region

Uplink limitDownlink limit

Unbalanced system

Uplink limitDownlink limit

Balanced system


By considering the asymmetries between the uplink and the downlink it is possible to derive an equation that will allow the required base station transmit power to be calculated in terms of the mobile transmit power, the combiner loss, the diversity gain and the threshold levels of the base station and mobile receivers.

Conditions for System BalanceConditions for System Balance

• The conditions for system balance depend on the asymmetries between the uplink and downlink power budgets

• The asymmetries are:• Maximum output power from MS and

BTS are not the same• MS has less sensitive receiver than BTS• Diversity reception can be used at the

BTS but not at the MS• Combiner loss occurs at the BTS on

the downlink only



System Balance EquationSystem Balance Equation• Power budget equations:

Downlink: PinMS = PoBS - Lc - Ld - Lfb + Gab - Lp + Gam - Lfm

Uplink: PinBS = PoMS - Lfm + Gam - Lp + GdBS + Gab - Lfb - Ld

• When the mobile is at the extreme boundary of the cell:PinMS = PrefMS

PinBS = PrefBS

These are the reference sensitivities of the MS and BTS The output levels PoBS and PoMS are the maximum allowed values

• If the boundaries for uplink and downlink are the same, the path loss Lp will be the same in each direction

• Subtracting the uplink equation from the downlink gives the system balance equation:

PoBS = PoMS + Lc + GdBS + ( PrefMS - PrefBS )


When making modifications to a network design, it is important to consider the impact on the system balance of any changes. For example, if it is required to increase coverage, simply increasing the BTS tranmit power will not help as it will upset the system balance. However, utilising a higher gain antenna will provide increased coverage whilst maintaining balance . Similarly, adjusting the tilt of the antenna will affect coverage without upsetting the system balance.

Field Implications of System BalanceField Implications of System Balance

• When changing cell size to alter coverage, consider whether the change will affect the system balance, for example:

• Increasing BTS Tx power (PoBS ) to increase coverage would upset the balance

• Ways of altering coverage without affecting balance include:• Decreasing BTS Tx power - the BSS can force the MS to use dynamic

output power control (adjusting PoMS to maintain balance)

• Altering the gain of the base station antenna - Gab is a symmetrical term in the power budgets

• Antenna down tilting changes coverage area without affecting balance




System Balance ExampleSystem Balance Example• A downlink power budget calculation leads to a requirement that:

PoBS + Gab = 56 dBm

• Find PoBS using the system balance equation, with the following data:GdBS = 3dB , Lc = 6 dB , PrefBS = -105 dBm , PrefMS = -102 dBmPoMS = 33 dBm ( GSM Class 4 mobile)

• Solution:PoBS = 33 + 6 + 3 + ( -102 - (-105 )) = 45 dBm

• This is the maximum value for PoBS as balance can be maintained with reduced power

• The downlink power budget now gives the antenna gain as 11 dBi• If the antenna gain is greater than 11 dBi, it can be down tilted to adjust

coverage.


As an example consider the case where a downlink power budget is conducted using the following figures

Minimum mobile receive power -90 dBm Maximum Path loss 131 dB Feeder Loss 8 dB Combiner Loss 6 dB Duplexer Loss 1 dB Mobile antenna gain 0 dB Mobile feeder loss 0 dB

Using the equation

dBm560013181690

GLLLLLPGP

LGLGLLLPP

amfmpfbdcinMSaboBS

fmampabfbdcoBSinMS

=−+++++−=

−+++++=+

−+−+−−−=

Notice that, as no information is given regarding the base station antenna gain, it is possible only to state the sum of the transmit power and the gain.


We are now required to determine conditions for system balance using the following additional information.

Diversity Gain 3 dB Receive threshold for mobile -102 dBm Receive threshold for base station -105 dBm Mobile transmit power 33 dBm

Now we can determine a required figure for the base station transmit power.

dBm451051023633

)P(PGLPP refBSrefMSdBScoMSoBS

=+−++=

−+++=

This value is the maximum possible value for base station transmit power at which system balance can be maintained. It is possible to maintain balance at lower power levels by relying on the power control features within the mobile station. However, if this value was adopted, it is simple to calculate the required antenna gain to be 11 dBi. If a transmit power of 45 dBm is adopted and an antenna of higher gain is used, coverage can be restricted to the nominal value of 131 dB path loss by means of controlling the tilt of the antenna.

SummarySummary• Review of decibel scale: dB (gain or loss), dBm (absolute measure

of power input or output), dBi (antenna gain)• Uplink and downlink power budget calculations:

equations tracking gains and losses in up or downlink directions, final results for power inputs in dBm

• Concept of system balance: cell boundary for uplink and downlink power budgets should be the same

• Calculations for system balance: equations relating asymmetric terms in power budgets

• Practical implications: ways of altering coverage without upsetting system balance



Section 3 Self-Assessment Exercises 1. A particular radio link has a path loss of 146 dB. In one direction the sensitivity of the

receiver is –102 dBm. The receiving antenna has a gain of 2 dBi and the transmitting antenna has a gain of 17 dBi. Miscellaneous feeder, combiner and filter losses amount to 7 dB. Determine the required transmitter power.

Answer:

2. In a GSM system, the mobile terminal receiver has a sensitivity of –102 dBm and the Base Station receiver has a sensitivity of –105 dBm. The uplink generates an additional space diversity gain of 2 dB. The downlink suffers from a combiner loss of 4 dB. If the maximum mobile terminal transmit power is 33 dBm, what must the downlink transmit power be to maintain balance?

Answer


4. Network Dimensioning ________________________________________________________________________________ 4.1 Introduction Network Dimensioning is the process by which the size of the network is established. The dimensioning process takes market forecasts licence requirements and geographical data in order to produce an estimate of the resources required to implement a network.

The Network Dimensioning ProcessThe Network Dimensioning Process

CoverageRequirements

CapacityRequirements

QualityRequirements

DimensioningProcess

Rough estimateof Number

of Base Stations

Rough estimateof Configurationof Base Stations

Area Type&

Radio Propagation Data

Section 4 – Network Dimensioning



The main inputs required are: 1. Area Type and Radio Propagation Data: the link budget will provide

details regarding the maximum path loss that can be tolerated by a mobile-base station link. It is necessary to convert this path loss to a maximum range. This will require information regarding the environment in which the mobile will be located and, preferably, measurements made using test transmitters in the area of interest, thus allowing a “tuned model” to be produced.

2. Coverage Requirements: when a licence is awarded, it will be required that a certain percentage of the population and/or land area should be covered by a particular date. This will influence the dimensioning process as priority must be given to fulfilling the licence requirements.

3. Capacity Requirements: a market forecast will suggest the user demand for the network. As well as providing coverage from a particular base station, it is essential that the base station can service the traffic that it is likely to “capture”.

4. Quality Requirements: no mobile phone network is perfect. It is an economic imperative to ensure that the network is not “over-engineered” to the extent that high costs will never allow the potential profitability to be realised. This entails establishing target levels of the quality of service that customers will experience. Basically, the higher the quality of service required, the more resources that will be needed.

Network Dimensioning InputsNetwork Dimensioning Inputs• Network dimensioning is carried out at the start a project.• It is a process through which an initial estimate of the amount of network

equipment and possible configurations are determined.• The inputs to the process can be:

• Spectrum availability.• License conditions.• Equipment characteristics.• Link budget.• Geographic/Demographic data.• Market projections



The outputs from the dimensioning process include an estimate of the number of base stations together with approximate locations and, additionally, information regarding the configuration of these base stations. Details of the configuration will include, in GSM systems, an estimate of the number of carriers required at a particular base station and, also, whether it will be omni-directional or have three separate cells served by sectored antennas.

Network Dimensioning OutputsNetwork Dimensioning Outputs• The outputs of network dimensioning are used for:

• Budgetary purposes:Negotiations with vendors.Manpower resource estimations.Business plans.Network rollout plans.Negotiations with financial backers.

• Licence applications:Auction price.Spectrum requirement / license preference.

• Implementation:Rollout Timetable and Resource RequirementsCoverage strategy.




_______________________________________________________________________________

4.2 Different Approaches to the Dimensioning Process

Network Dimensioning MethodsNetwork Dimensioning Methods

• There are two main methods of dimensioning a network:• Spreadsheet based

• Benchmark planning

• Many companies use a sophisticated spreadsheet approach to model the combination of network coverage and capacity.

• Alternatively it is possible to dimension the network by benchmark, or first-pass, planning. This entails placing sites and predicting performance.

• AIRCOM is currently developing an GIS based dimensioning tool to combine the advantages of these two methods when dimensioning a UMTS system.


Spreadsheet DimensioningSpreadsheet Dimensioning

• We shall look at three scenarios:

• A simple coverage driven spreadsheet

• A simple capacity driven spreadsheet

• A simple combined approach



• Link budgets are used to calculate max path losses.• Path loss is converted into cell radii for different environments.• Cell radii are used to estimate typical site coverage areas.• Estimate the average site coverage area for each environment.

• No. sites (per environment) = Environment Area

• Add together the number of sites per environment required for each zone.• Assumptions on cell loading and services offered are made in the link

budget process.

Spreadsheet Dimensioning Spreadsheet Dimensioning --Simple Coverage Simple Coverage

Average Site Coverage Area


Spreadsheet Dimensioning Spreadsheet Dimensioning -- Urban Area Urban Area

Number of BTSs per site 3Max Path Loss 155 dB

Indoor correction 15 dBLog-normal fading correction 5 dB

Modified Path Loss 135 dBMast Height 25 m

Coverage Radius for 135 dB loss 1.1 kmCoverage Area 3.8 km2

Total Urban Area 4000 km2

Number of Sites Requred 1052Number of BTSs 3156




The inclusion of a “log-normal fading correction” in the above table acknowledges the fact that the propagation model is not perfect and, further, the signal will vary by considerable amounts for very small positional movements of the mobile. The error follows a “log-normal” distribution and will have a particular standard deviation. The result is that, at a distance corresponding to the maximum tolerated pathloss (as predicted by the propagation model), the error has a 50% chance of making the actual pathloss greater than the maximum, thus making it impossible to make a connection. Over the coverage area, as a whole, the probability will be only 76% of making a connection. The favoured technique is to make the probability of failure at the cell limit 25%. This has the effect of making the probability over the cell as a whole equal to 90%. In order to achieve this, it is necessary to build in a “log-normal fade margin”.

Cell boundary for 50%probability of coverageat edge

Cell boundary for75% probability ofcoverage at edge.


• Considering different environments such as rural and suburban will entail:

• Using different propagation models

• Using masts with different antenna heights

• This will lead to different coverage areas per site.

• Lightly loaded sites (those that do not serve much traffic, such as in rural areas) will probably have omni-directional antennas with one BTS per site.

Spreadsheet Dimensioning Spreadsheet Dimensioning --Different EnvironmentsDifferent Environments


Note that the choice of omni-directional or sectored antenna will influence the maximum pathloss that can be tolerated and, hence, the site range.

Spreadsheet Dimensioning Spreadsheet Dimensioning Site Parameters

Type 1 Type 2 Type 3Frequency 2000 2000 2000 M HzTransmitter Height 25 15 30 mReceiver Height 1.5 1.5 1.5 mSite Location urban suburban ruralNo. BT's 3 3 1

MAPL 155 155 153 dBReliability in coverage area 90 90 90 %Log Normal fade margin 5 5 5 dBBuilding Penetration Margin 13 9 0 dBMAPL w / Log Norm. fade margin 137 141 148 dB

Typical Cell Radiiurban 1.03 kmsuburban 2.32 kmrural 9.25 km

Typical Cell AreasUrban 3.33 km 2Suburban 4.35 km 2Rural 268.64 km 2

Geographic DataCoverage Area 151207 km 2Urban Area 5000 km 2Suburban Area 20632 km 2Rural Area 111156 km 2

Site DataNo. of sites 1500 4747 414No. of BTSs 4499 14240 414

Total Sites 6660Total BTSs 19153

The final spreadsheet will combine many different environments to give the total number of sites and BTSs required.




In the above spreadsheet it is interesting to note that the maximum pathloss is different for the different environments as the antenna gain will be different (omni for the rural area and sectored for the urban and suburban areas). This difference has a further impact when the conversion from the number of sites to the number of BTS’s is made.

Spreadsheet Dimensioning Spreadsheet Dimensioning --Simple CapacitySimple Capacity

• Given an estimate of the traffic profile per subscriber we can calculate the offered traffic per km2 in each environment

• Given the capacity of a cell we can estimate the average site capacity area in each environment

• This is the area containing the number of subscribers served by one cell• We may take into account factors such the uneven distribution of traffic

between sectors

• No. sites (per environment) =

• To find the total requirement, add together the number of sites needed per environment for each zone.

Average Site Capacity AreaEnvironment Area


Capacity dimensioning takes as its main input the likely user demands of the different environments and then assesses how much demand a single cell can satisfy. This then gives a predicted cell requirement for the particular environment. Naturally, it will be necessary in practice to ensure that both coverage and capacity requirements are satisfied. The simplest way to achieve this is to carry out both exercises for well-defined areas and take the higher resulting requirement for cell numbers. It is possible to identify any particular area as coverage constrained (that is it can accommodate higher traffic throughput within the given area) or capacity constrained as appropriate.


Spreadsheet Analysis Spreadsheet Analysis -- Simple Combined Simple Combined Coverage/Capacity ApproachCoverage/Capacity Approach

• Compare the number of sites required per zone derived from the capacity approach and the coverage approach

• The output of the dimensioning is the larger number of sites per zone• The zone is said to be either:

Coverage ConstrainedorCapacity Constrained

• To appreciate capacity constraints requires a traffic analysis - the subject of the next section




SummarySummary

• The Network Dimensioning Process: inputs, outputs,

• Methods of Network Dimensioning: spreadsheet, benchmark

• Spreadsheet dimensioning: simple coverage, simple capacity, combined approach

Cover ageRequirements

CapacityRequirements

QualityRequirements

Dimen sion ingProcess

Rough es ti mateof N umber

of Base Stations

Rough es ti mateof C onfigurati onof Base Stations

Area T ype&

Radi o Pr opagati on Data



Section 4 Self-Assessment Exercise

For the purposes of dimensioning, a coverage area is divided into to categories: rural and urban. Of the total coverage area of 8000 km2 2500 km2 is urban and 5500 km2 is rural. Different propagation models are used for the two areas giving due consideration to the antenna heights that are permitted. For the urban model the path loss L (dB) is linked to the range R kilometres by the formula:

RL 10log36143+= For the rural model the equivalent equation is

RL 10log30137 += Giving due consideration to margins appropriate for in-building coverage and shadow fading a maximum path loss of 139 dB is considered suitable for the urban area and a path loss of 142 dB for the rural area. Determine the total number of sites required for the coverage area.

Answer: Urban area Rural area Range: Range: Area: Area: Number of cells required:

Number of cells required:

Total number of cells


5. Traffic Analysis ________________________________________________________________________________

5.1 Introduction

The traffic analysis process involves collating data regarding the location and numbers of potential customers and combining this information with a marketing forecast that will estimate the likely usage of the services offered to such potential customers. The usage is estimated from projections for both market penetration (what percentage of the population will become customers?) and the service usage per individual subscriber. One significant contributor to these inputs is the demographics of a country.



________________________________________________________________________________ 5.2 Traffic Measurements – Erlangs and Blocking

• Unit of traffic measurement: erlang (E)

• Traffic in erlangs is the number of call-hours per hour:

A = C T / 3600

A = Traffic in ErlangC = number of calls during the hourT = mean holding time per call in seconds

• One channel in continuous use is carrying a traffic of 1 erlang

• Typical traffic per subscriber during the busy hour is 25 mE

which corresponds to a mean call holding time of 90 s

Traffic MeasurementTraffic MeasurementSection 5 – Traffic Analysis

Another traffic unit, used mostly in the USA, is the Call Centum Second (CCS): 1 CCS = 100 call seconds per hour 1 Erlang = 3600 call seconds per hour 1 Erlang = 36 CCS

BlockingBlocking

Offered Traffic : Total traffic offered to channel by all users

Carried Traffic : Traffic successfully carried by the channel

Blocked Traffic: Traffic which is blocked at call setup

Call Setup

ProcessOffered Traffic

Blocked Traffic

Carried Traffic

Offered Traffic = Carried Traffic + Blocked Traffic

Section 5 – Traffic Analysis


Grade of Service (Grade of Service (GoSGoS))

• Typical Grade of Service is 0.02 (2%)

• Grade of Service is also called blocking probability or loss probability

• Grade of Service is the fraction of incoming calls (offered traffic) allowed to beblocked due to congestion in the channel

Offered Traffic

Blocked Traffic

Carried Traffic

A

A x GoS

A x (1 - GoS)Call Setup

Process


A good grade of service is a low value. This implies low channel utilization. If a poorer grade of service is accepted, more traffic can be offered to the same number of traffic channels.

Erlang Models of TrafficErlang Models of Traffic• Two commonly used models are Erlang B and Erlang C• Erlang B - blocked calls are lost or cleared• Erlang C - calls that cannot be handled are put in a queue until a

channel becomes available

A A(1-GoS)

A (GoS)

QueueErlang BErlang C

• GSM uses the Erlang B model not Erlang C


For GSM we are concerned with circuit switched voice traffic which must be handled in real time. Thus the Erlang B model with no queuing is appropriate.



Erlang B CalculationsErlang B Calculations• Tables based on the Erlang B model allow calculations to be

made relating:• Offered traffic• Grade of Service• Number of channels

• Structure of Erlang B table:

• Example: at 2% blocking (0.02 GoS), 2 traffic channels can carry 0.22347 erlangs of traffic

0.01 0.02 0.03

123

.01010 .02041 .03093

.15259 .22347 .28155

.45549 .60221 .71513

Grade of Service

n

Offered trafficNumber of channels


________________________________________________________________________________ 5.3 The Traffic Analysis Process

What is Traffic Analysis?What is Traffic Analysis?• By traffic analysis we mean:

• Examining the demographic spread within a country• Identifying subscriber distribution from market projections• Calculating the traffic offered to the network per subscriber• Creating a traffic ‘map’ describing the spread of traffic in the network

• Marketing or engineering?• Data about demographic trends and subscribers’ potential use of the network

comes from marketing surveys• Engineers need traffic maps to:

Carry out network dimensioningCarry out a first pass network capacity analysis of the nominal planSimulate the performance of the final network plan



Traffic Analysis ProcessTraffic Analysis Process

Calculate distribution of subscribers

Demographic Data

Business Data

Marketing

Offered Traffic Map per Service

Service Definitions

Market

Penetr

ation

Service Usage Per Subscriber

Offered Services


________________________________________________________________________________ 5.4 Using Demographic Data

DemographicsDemographics

• Demography is the study of population in a country• This can be our first step into our analysis of traffic in the network• The demographic data describing a country can typically be purchased

from:• National Statistics Office• GIS data suppliers• Marketing organisations

• It is usually based upon census data• Most EU countries have a census every 10 years, most scheduled

for 2000/2001• This is updated yearly based on births/deaths /immigration




Resolution of Demographic DataResolution of Demographic Data

• It is possible purchase demographic data describing a number of sizes of areas:

• Postcode/Zip• Municipality/Commune (NUTS 5 - about 98 000 throughout EU)• Electoral Areas• Regions/Provinces• Telephone Code Areas

• Nomenclature of Territorial Units (NUTS) is an EU wide classification for categorising the size of administrative areas, up to national level (NUTS 1)

• Typically we would use commune level data initially, some operators take this analysis to a household level


Using Demographic DataUsing Demographic Data

• Typically people analyse demographic data using a GIS• Creating a traffic map requires the number of subscribers per commune

• Not just people who live there - include commuters etc.• May need separate daytime and evening analysis to account for the

movement of subscribers to suburban areas in the evening• Business data can be acquired over administrative regions


It is important to gather details not just of people’s residences but also their workin g locations. The location of peak demand will move over a 24-hour, weekly and annual cycle. Further, the fact that people may live a considerable distance from their places of work may lead to considerable demand from areas in between the residential and industrial/business centres during the peak travel times.


________________________________________________________________________________ 5.5 Market Projections and Traffic Maps

Market Projections Market Projections

• Market Penetration• Number of subscribers per head of population/business employee• % penetration for different target groups

• Service Offerings• What types of services will be offered• What data rates and quality of service (QoS) these will require

• Service usage per subscriber• For circuit switched services in Erlangs or calls per busy hour• For packet switched services in Mb/h or sessions per busy hour


It should be noted that the demand of a subscriber to digital services is best measured by the amount of data transferred rather than by the length of time that the subscriber was connected to the network. Some packet based services will be offered on an “always on” basis.

SubscribersSubscribers

• We can calculate the number of subscribers in an area from the market penetration and the demographic/business data we are using

• However, this will just give us a table of communes with the number of subscribers

• We must take different land usage categories into account to create a subscriber map suitable for network capacity analysis or simulation

Town Clutter

Commune Border

Very HighHighMediumLow

Subscriber Density

Spread by boundary Spread by Boundary and Clutter




Once the number of likely subscribers within a particular commune border has been identified, it is important to realise that the demand will not be distributed evenly throughout the commune area. Within a commune border, there is likely to be open areas from which little demand can be expected. The different types of land usage must be considered within the area.

Traffic MapsTraffic Maps

• If we then apply the service usage per subscriber then we can create a traffic map for each service

• This can then be imported into the planning tool or used for network dimensioning


The likely traffic from each different land usage (or “clutter”) category can be combined with a data base that divides the entire network coverage area into different categories. It is then possible to use a computer to spread the traffic over the network and produce a traffic map. This traffic map will be a key factor in deciding on the roll-out strategy. In the more advanced systems, certain new services will initially be available only in a restricted area. A further use of the traffic map is that it allows decisions to be made regarding where new services should be targeted in order to maximise revenue for a minimum investment.


________________________________________________________________________________ 5.6 Roll-Out Strategy

Target Rollout AreasTarget Rollout Areas• Typically a licence is issued subject to a population coverage requirement• We can use the demographic data to calculate which towns or regions we

must cover to meet these conditions • Deciding the target regions is a major strategic decision to be taken at board

level


Target CoverageTarget Coverage

• The environment that a user is in forces a change in the required coverage levels due to building penetration and model accuracy

• We also need the service availability required• We can determine what these coverage levels are using the link

budget• But we need to know where to target coverage to these levels




Specifying Coverage Areas Specifying Coverage Areas --Coverage PolygonsCoverage Polygons

• Coverage polygons can be used to describe the areas to be covered to a certain level

• To give guidance to planners• To provide the basis for

acceptance testing for turnkey/outsourced planning

• Just because the clutter type suggests a certain type of land usage does not mean that it exists there

• Coverage polygons should not be generated purely from clutter data Dense Urban

UrbanSuburban


Specifying Coverage Areas Specifying Coverage Areas -- RoadsRoads• Road and Rail does not lend itself to coverage polygons

• Dense urban, urban and suburban coverage levels will typically form concentric rings around a town, and do not overlap between towns

• Roads link towns and using polygons may result in very long and spindly shapes which all overlap with each other

• A better way to specify road coverage is using a list or schedule of roads to be covered.


The spreading of traffic is normally undertaken on a “subscribers per unit area” basis. That approach makes the use of polygons that are assumed to enclose a certain amount of subscribers appropriate. However, when roads and railway lines are expected to contain significant numbers of subscribers, describing the density in terms of subscribers per kilometer rather than per square kilometer is more appropriate. The activity is known as spreading traffic “along a vector” rather than over an area.


________________________________________________________________________________ 5.7 Capturing Traffic and Assessing Resource Requirements

Capturing TrafficCapturing Traffic• Each cell will be the “best server” for a particular area.• “Best server” means that it will deliver the largest signal at a particular point.• By overlaying the “Best Server” information on top of the traffic map it is

possible to estimate how much traffic a cell will “capture”.• This can identify overloaded cells and provide information regarding

resource requirements.


Providing the ServiceProviding the Service• Once the likely amount of traffic per cell has been established, it is

possible to decide on the number of channels (timeslots in GSM, a nominal provision in UMTS) that should be made available.

• The traffic forecast is in Erlangs. If a traffic of 3 Erlangs is forecast then, on average, 3 channels will be in use.

• However, simply providing 3 channels will not be sufficient as the users do not co-ordinate their demands but, rather, make them randomly.




Providing the ServiceProviding the Service• The random manner in which users access and use the service usually

follows what is known as a “Poisson” distribution.• This allows the number of channels required to be predicted for a given

“blocking ratio” or “grade of service”. • A “blocking ratio” of 2% means that 2% of calls made will not be able to

access a channel because they will all be in use.

Call setup

processOffered Traffic

Blocked Traffic

Carried Traffic

100 %

2 %

98 %


Providing the ServiceProviding the Service• Example:

Blocking ratio = 2% Offered Traffic = 3 Erlangs Number of channels required = 7

• Trunking Efficiency: measure of usage of the channels • In the example: Trunking Efficiency = 3 / 7 = 43%• Trunking Efficiency increases with the number of trunks

• Number of channels found using Erlang B tables or calculator• Examples for 2% blocking:

10 channels required for 5 Erlangs30 channels required for 22 Erlangs50 channels required for 40 Erlangs



SummarySummary• The Meaning of Traffic Analysis: marketing data, services required by

users, traffic offered, traffic map• The Traffic Analysis Process: offered traffic map for each service,

service definitions• Demographics and Business Data: sources of statistics, resolution of

data, interpretation of data• Market Projections: market penetration, service offerings, service

usage • Target Coverage: specifying coverage areas, capturing traffic• Providing the Service: Erlang B model, blocking, grade of service,

channels required



Section 5 Self-Assessment Exercise Analysing the traffic captured by cells. Log into the Data Source G101_01 using the password “demouser”. Then start the project “Traffic Analysis” and check that you can see the coastline of Jersey by clicking on the 2D view and checking the coastline polygon.

. Select Site Filter and All Sites to view the sites.

2D view

Data Types



In order to establish which site provides the best server at all locations within the coverage area, it is necessary to carry out a coverage prediction using the Tools>Coverage/Interference>Predictor menu.

Ensure that the “All Sites” filter is selected and press Start.


The next step is to create a Best Server array using the Coverage Wizard that can be accessed via the Tools>Coverage/Interference menu.

Ensure that the view of Jersey is selected and press on Next. Then select the All sites filter and create the Best Server Array.



Having established the coverage from each site, the next step is to spread the traffic in accordance with market forecasts. Traffic in the form of Terminal Types can be spread by accessing the appropriate dialogue box under the Options>Terminal Types menu.

Examine the GSM Handset Terminal and see how it is spread according to clutter category by clicking on the “Clutter” tab. You should see that a total of 200 Erlangs of traffic has been allocated to the coverage area. This has been spread in accordance to the predicted demand. It is seen that the Urban areas are very highly weighted.


A Traffic Raster must now be created. The dialog box is accessed under the Tools>Traffic menu.

After first checking that the view of Jersey is again displayed, ensure that the GSM Handset is selected. Then create the raster.



The final step is to analyse the traffic. The Traffic Analysis dialog box can be accessed under the Tools>Traffic>Analyse.. menu.

Select the All sites filter and press Capture Traffic.


The report generated will show how much of the traffic would be captured by each cell.


6. Nominal Planning ________________________________________________________________________________ 6.1 Introduction

What is a Nominal Plan?What is a Nominal Plan?

• A nominal plan is initially a hypothetical wireless network.

• The nominal plan is the starting point for the cell rollout process and will evolve into the final network design.

• As physical sites are identified and acquired, the nominal plan is amended.

Nominal Plan

Final Network Design

Rollout process

Section 6 – Nominal Planning



________________________________________________________________________________ 6.2 The Nominal Planning Process

Simplified Network Planning FlowchartSimplified Network Planning Flowchart

Create nominal plan

Define search areas

Site selection

Detailed site design

Site acquisition

Initial network dimensioning

Identify site options

Site construction


Initial Network DimensioningInitial Network Dimensioning

• Initial dimensioning is a major input to the nominal plan• Spreadsheet based analysis.• Used in the license application.• Identifies the approximate number of sites required.• Identifies the approximate site radii required for:

• Urban/Rural areas• Voice/Data services

Typical cell radius estimates

Service Urban Radius Rural RadiusVoice 1600 metres 4400 metres Data 1100 metres Not available



The above simplified spreadsheet has been produced assuming that the data service will only be made available in the Urban areas. Therefore, the nominal cell radii used in the initial coverage-based dimensioning exercise will be 1100 metres for the Urban areas and 4400 metres in the Rural areas.

Create Nominal PlanCreate Nominal Plan

• Position a hexagonal grid of sites over the desired coverage area.

• The radius of each hexagon can be determined from the initial dimensioning.

• The capacity of the network can then be analysed to detect:

• Hot spots that require cell splits.

• Under-used cells that could be removed from the plan.

Rural Cell

Urban Cell


Each cell can be set to have a nominal radius to aid in the placement of sites in both rural and urban areas.

Define Search AreasDefine Search Areas• The sites in a nominal plan are only imaginary.• To become a real network, physical sites are required.• A suitable physical site must be found for each nominal site.• A suitable physical site must among other things:

• Give adequate radio coverage.• Have connectivity into the transmission network.• Be aesthetically and politically acceptable to the local community.• Have power nearby, good access and a co-operative owner.

• A survey of each nominal site is normally carried out to identify possible site options which meet the above criteria.




Define Search AreasDefine Search Areas• Guidelines given to the surveyor should be based on the appropriate radio

coverage required from the site.• The guideline is given in the form of a search area, such as:

• Radius from the nominal site.• One or more polygons following height contours.

Or


It is desirable for a surveyor to be provided with as wide a range of acceptable alternatives as possible. In the situation described in the diagram, it has been determined that the site could be located either in the service area or, alternatively, overlooking the area from a surrounding hillside.

Identify Site OptionsIdentify Site Options

• Surveyor visits each search area and identifies potential site options.• The first sites to be considered should be

• Existing radio sites.• Sites offered from major site owners (MSOs) e.g. utilities and railways.

• All options should meet certain criteria to ensure that they are:• Technically acceptable.• Buildable

• A good idea to consult with the planning/zoning authority during the survey.

• Good training of surveyors will save time later in the building process.



Identify Site OptionsIdentify Site Options

• The surveyor will prepare a report listing the options.

• Report will include:• Accurate grid reference.• Accurate height of structures or

available antenna windows.• Photographs of the site.• 360º panoramic photos from site

or if obstructed from nearby location/structure.

A

D

C B


Site SelectionSite Selection

• Normally a desk study.• Evaluate radio coverage and

transmission. • Quickly eliminate unsuitable

options.• Rank the remaining sites in order

of preference.

• Nominate a preferred option and possibly a backup option.

A3rd

D1st

C2ndB - Unsuitable




Site AcquisitionSite Acquisition

• Run more than one site simultaneously.• Negotiate with site owners.• Prepare drawings.• Draw up leases.• Apply for planning permissions.• Apply for power wayleaves.• As soon as one option is ready to proceed:

• Sign the lease• Abandon the alternatives• Enter site into building program.


Detailed Site DesignDetailed Site Design

• Prior to starting construction work, a detailed site design is required.

• This includes• Antenna and feeder requirements.• Antenna azimuths and tilts.• Equipment capacity requirements

• Cannot be completed in isolation. Must take into account other sites.

60º

60º

180º180º

300º

300º

Ant 1

Ant 2

Ant 5

Ant 4

Ant 6

Ant 3


Providing coverage over a large area will necessitate accurate configuration of a large number of sites simultaneously. It is not possible to state the ideal configuration of any one site in isolation. The network of sites must work together in harmony to produce the desired results.


________________________________________________________________________________

6.3 Creating a Nominal Plan Using a Planning Tool

Using ASSET to Create a Nominal PlanUsing ASSET to Create a Nominal Plan

• At the start of the cell rollout program, the nominal plan is only a rough outline of the network.

• Static calculations will give fast adequate results at this stage, even if a UMTS system is being analysed.

• It is more appropriate to analyze a UMTS nominal plan with ASSETrather than 3G at this stage.

• The planning process is virtually identical in outline regardless of the system being implemented: the difference is in the detail.


Setting up ASSET for Nominal PlanningSetting up ASSET for Nominal Planning

Import suitable antenna patterns

Create cell layers

Create a propagation model

Create site templates

• Procedure for initialising parameters in ASSET before starting the nominal plan




When producing a Nominal Plan it is important to make the results of any simulation as realistic as possible. Accordingly, manufacturers data regarding the radiation pattern of a particular antenna is used. A template can be established of a “typical” site. This is the site configuration that will be adopted as a default, making the need for subsequent changes minimal.

Creating a Nominal PlanCreating a Nominal Plan

• From the link budgets, identify the cell radius for each environment to be planned.

• Select site from site template.• For each environment, position a

hexagonal grid of sites with the appropriate cell radii over the target coverage area.


The map shown here assumes three different types of environment are being planned for.

Locating Urban Nominal SitesLocating Urban Nominal Sites• Define mid hexagon radius as

1100m and select in the site template.

• Position a grid of sufficient sites to cover the urban areas.



Locating Rural Nominal SitesLocating Rural Nominal Sites• Select Hexagon Radius in the site

template to be 4400m.• Position a grid of sufficient sites to

cover the rural areas.


Evaluate Nominal Network CoverageEvaluate Nominal Network Coverage

• Run a coverage array for the nominal network.

• Check that the coverage is in line with your expectations.

• Adjust site locations and add additional sites if improvements to coverage is necessary.

• Check for excessively high sites.


Once the sites have been placed the signal strength can be predicted at all points within the network. This allows coverage gaps to be identified. Further, it will enable any sites that are covering too large an area to be identified. These so-called “high sites” will capture too much traffic becoming over full while neighbouring sites are lightly loaded.



________________________________________________________________________________ 6.4 Evaluating the Capacity of the Nominal Network

Evaluate Nominal Network CapacityEvaluate Nominal Network Capacity

• Create a traffic raster for each service:• Create a terminal type for each service.• Spread traffic for each terminal type to

simulate users.

• Analyse how much traffic each cell will capture.

• Evaluate whether each cell has sufficient capacity for the traffic it captures

• If a multi-service network is being planned, each service must be analysed and the combined requirement assessed.

Create Traffic Raster

Capture Traffic

Evaluate Each Cell’s Required Capacity

Re-Engineer Network (if required)


Create Terminal TypesCreate Terminal Types

• Create a circuit switched terminal type for each service.

• Allocate total traffic to simulate users, e.g.:

• Voice = 200 Erlangs• Data: 384 kb/s = 100 Erlangs

(simulating 100 terminals)

Clutter Type WeightUrban 500

Open in urban 30Suburban Residential 20

Industry 10Village 10Airport 5

Park Recreational 5Woodland Forest 2Agricultural land 1

Isolated Dwellings 1Open Rural 1

Pylons 1Rivers 0Sea 0

Unclassified 0Water 0



Spread Voice TrafficSpread Voice Traffic• Spread the traffic on the voice terminal type over the island.


Create Coverage Array (Voice)Create Coverage Array (Voice)

• Set the minimum service level in the Array Settings window to match the minimum threshold for speech services.

Here it is set at -114dBm

• Create coverage array as before.




AnalyseAnalyse Voice TrafficVoice Traffic• Use the traffic analysis tool to

estimate the voice traffic per cell.Cell: CS Traffic(E)Site0A: 1.27874Site0B: 18.989Site0C: 2.64128Site1A: 18.1042Site1B: 0.099755Site1C: 1.71587Site2A: 2.13376Site2B: 1.58312Site2C: 105.062Site3A: 11.8475Site3B: 2.43671Site3C: 12.1231Site4A: 2.06883Site4B: 1.76368Site4C: 1.87409Site5A: 1.58884Site5B: 3.31571Site5C: 3.13637


Spread Data Traffic (multiSpread Data Traffic (multi--service networks service networks only)only)

• Spread the traffic on the data terminal type over the island.



Create Coverage Array (Data)Create Coverage Array (Data)• Set the minimum service level in

the Array Settings window to match the minimum threshold for data services.

e.g. - 96 dBm

• Create coverage array as usual.• Notice that coverage for data

may not be as extensive as for voice.


AnalyseAnalyse Data TrafficData Traffic

• Use the traffic analysis tool to estimate the traffic per cell.

• This must be added to the requirements for voice traffic in order to assess the aggregate loading of the cell.

• The data traffic could be “packet” or “circuit” switched. This has an implication on network requirements.

Cell: Packet usersSite0A: 0.617848Site0B: 9.13428Site0C: 1.23677Site1A: 9.05208Site1B: 0.0498775Site1C: 0.769083Site2A: 0.732088Site2B: 0.687448Site2C: 52.4403Site3A: 5.71852Site3B: 0.963885Site3C: 5.90523Site4A: 0.496473Site4B: 0.396895Site4C: 0.889275Site5A: 0.337783Site5B: 0.733785




________________________________________________________________________________

6.5 Mixing Packet and Circuit Switched Traffic

Evaluating Traffic RequirementsEvaluating Traffic Requirements

Real time non-controllable load

Spare capacity for which can be allocated to non real time

applications

Peak traffic

Load

Time

Average circuit switched traffic

Data may be packet switched, in which case it can be made to “fill the gaps” in the demand for voice services.


Evaluating Traffic RequirementsEvaluating Traffic Requirements

• To evaluate the required cell capacity:

• First assume that the packet data can be scheduled to fill the spare real time capacity.

• When all the spare real time capacity has been exhausted we must convert the remaining capacity to an equivalent data capacity.

• One GSM timeslot can carry 13 kb/s of data.



Traffic Requirement ExampleTraffic Requirement Example

• A cell captures 2 Erlangs of voice traffic and is assigned a GSM carrier with 7 timeslots. The grade of service is 2%.Estimate the amount of data traffic that can be handled. How much of this must be packet data and how much can be circuitswitched?

• Solution:

Timeslots available on average = 7 - 2 = 5 This represents a total data rate of 5 x 13 = 65 kb/s

2 Erlangs voice traffic requires 6 trunks (timeslots) for 2% blocking.

1 timeslot can be dedicated (circuit switched) for data, i.e. 13 kb/sRemaining data must be packet switched = 65 - 13 = 52 kb/s.


Nominal Planning Nominal Planning -- SummarySummary

• The Nominal Plan may be regarded as the end product of a planning exercise.

• This plan will be modified as development work progresses.• Key inputs are:

• Propagation models derived from CW measurements• Coverage predictions for different environments• Traffic forecasts

• Output is the number, location and configuration of sites.



Section 6 Self-Assessment Exercise A particular cell in a network is predicted to capture 4 Erlangs of voice traffic. A 2% blocking ratio is required. As GSM timeslots cannot be allocated to cells individually it is necessary to devote 15 channels to this cell. Determine how much data traffic (in equivalent voice channels) that can be serviced by this cell. Additionally state how much of this data traffic can be real-time circuit switched as opposed to packet switched.

Answer: Excess channels available

Channels required for 5 Erlangs:

Channels available for RT-CS

Channels available for PS.

Radio Network Planning Fundamentals © AIRCOM International 2002 A-1

Appendix A Solutions to Self-Assessment Exercises

Section 3: Link Budgets 1.

Summing the losses: 146 + 7 = 153 dB Summing the gains: 17 + 2 = 19 dBi Net loss = 153-19 = 134 dB Required Tx Power = -102 + 134 = 32 dBm

2.

Notice that all the differences are “in favour” of the uplink. Hence the downlink will require a bigger transmit power Difference in sensitivity = 3 dB Diversity gain = 2 dB Combiner loss = 4 dB Total of above = 9 dB Required downlink transmit power = 33 + 9 = 42 dBm.

A-2 Radio Network Planning Fundamentals


Section 4: System Dimensioning

Answer: Urban area Rural area

Range: 0.774 Range: 1.47 Area: 1.88 Area: 6.79

Number of cells required:

1330 Number of cells required:

810

Total number of cells 2140

For the urban area: ( ) km774.010 36143139 == −R Area = 1.88 km2

For the rural area: ( ) km47.110 30137142 == −R Area = 6.79 km2

Radio Network Planning Fundamentals © AIRCOM International 2002 A-3

Section 6: Network Planning and Analysis A particular cell in a network is predicted to capture 4 Erlangs of voice traffic. A 2% blocking ratio is required. As GSM timeslots cannot be allocated to cells individually it is necessary to devote 15 channels to this cell. Determine how much data traffic (in equivalent voice channels) that can be serviced by this cell. Additionally state how much of this data traffic can be real-time circuit switched as opposed to packet switched.

Answer: Excess channels available 15 – 4= 11

Channels required for 4Erlangs: From Erlang B table 9 trunks req’d.

Channels available for RT-CS 15 – 9 = 6

Channels available for PS. 11 – 6 = 5

A-4 Radio Network Planning Fundamentals



Advanced GSM Cell Planning © AIRCOM International 2002 B-1

APPENDIX B – ERLANG B TABLES

n Grade of Service n

0.00001 0.00005 0.0001 0.0005 0.001 0.002 0.003 0.004 0.005 0.006 1 .00001 .00005 .00010 .00050 .00100 .00200 .00301 .00402 .00503 .00604 1 2 .00448 .01005 .01425 .03213 .04576 .06534 .08064 .09373 .10540 .11608 2 3 .03980 .06849 .08683 .15170 .19384 .24872 .28851 .32099 .34900 .37395 3 4 .12855 .19554 .23471 .36236 .43927 .53503 .60209 .65568 .70120 .74124 4 5 .27584 .38851 .45195 .64857 .76212 .89986 .99446 1.0692 1.1320 1.1870 5 6 .47596 .63923 .72826 .99567 1.1459 1.3252 1.4468 1.5421 1.6218 1.6912 6 7 .72378 .93919 1.0541 1.3922 1.5786 1.7984 1.9463 2.0614 2.1575 2.2408 7 8 1.0133 1.2816 1.4219 1.8298 2.0513 2.3106 2.4837 2.6181 2.7299 2.8266 8 9 1.3391 1.6595 1.8256 2.3016 2.5575 2.8549 3.0526 3.2057 3.3326 3.4422 9 10 1.6970 2.0689 2.2601 2.8028 3.0920 3.4265 3.6480 3.8190 3.9607 4.0829 1011 2.0849 2.5059 2.7216 3.3294 3.6511 4.0215 4.2661 4.4545 4.6104 4.7447 1112 2.4958 2.9671 3.2072 3.8781 4.2314 4.6368 4.9038 5.1092 5.2789 5.4250 1213 2.9294 3.4500 3.7136 4.4465 4.8306 5.2700 5.5588 5.7807 5.9638 6.1214 1314 3.3834 3.9523 4.2388 5.0324 5.4464 5.9190 6.2291 6.4670 6.6632 6.8320 1415 3.8559 4.4721 4.7812 5.6339 6.0772 6.5822 6.9130 7.1665 7.3755 7.5552 1516 4.3453 5.0079 5.3390 6.2496 6.7215 7.2582 7.6091 7.8780 8.0995 8.2898 1617 4.8502 5.5583 5.9110 6.8782 7.3781 7.9457 8.3164 8.6003 8.8340 9.0347 1718 5.3693 6.1220 6.4959 7.5186 8.0459 8.6437 9.0339 9.3324 9.5780 9.7889 1819 5.9016 6.6980 7.0927 8.1698 8.7239 9.3515 9.7606 10.073 10.331 10.552 1920 6.4460 7.2854 7.7005 8.8310 9.4115 10.068 10.496 10.823 11.092 11.322 2021 7.0017 7.8834 8.3186 9.5014 10.108 10.793 11.239 11.580 11.860 12.100 2122 7.5680 8.4926 8.9462 10.180 10.812 11.525 11.989 12.344 12.635 12.885 2223 8.1443 9.1095 9.5826 10.868 11.524 12.265 12.746 13.114 13.416 13.676 2324 8.7298 9.7351 10.227 11.562 12.243 13.011 13.510 13.891 14.204 14.472 2425 9.3240 10.369 10.880 12.264 12.969 13.763 14.279 14.673 14.997 15.274 2526 9.9265 11.010 11.540 12.972 13.701 14.522 15.054 15.461 15.795 16.081 2627 10.537 11.659 12.207 13.686 14.439 15.285 15.835 16.254 16.598 16.893 2728 11.154 12.314 12.880 14.406 15.182 16.054 16.620 17.051 17.406 17.709 2829 11.779 12.976 13.560 15.132 15.930 16.828 17.410 17.853 18.218 18.530 2930 12.417 13.644 14.246 15.863 16.684 17.606 18.204 18.660 19.034 19.355 3031 13.054 14.318 14.937 16.599 17.442 18.389 19.002 19.470 19.854 20.183 3132 13.697 14.998 15.633 17.340 18.205 19.176 19.805 20.284 20.678 21.015 3233 14.346 15.682 16.335 18.085 18.972 19.966 20.611 21.102 21.505 21.850 3334 15.001 16.372 17.041 18.835 19.743 20.761 21.421 21.923 22.336 22.689 3435 15.660 17.067 17.752 19.589 20.517 21.559 22.234 22.748 23.169 23.531 3536 16.325 17.766 18.468 20.347 21.296 22.361 23.050 23.575 24.006 24.376 3637 16.995 18.470 19.188 21.108 22.078 23.166 23.870 24.406 24.846 25.223 3738 17.669 19.178 19.911 21.873 22.864 23.974 24.692 25.240 25.689 26.074 3839 18.348 19.890 20.640 22.642 23.652 24.785 25.518 26.076 26.534 26.926 3940 19.031 20.606 21.372 23.414 24.444 25.599 26.346 26.915 27.382 27.782 4041 19.718 21.326 22.107 24.189 25.239 26.416 27.177 27.756 28.232 28.640 4142 20.409 22.049 22.846 24.967 26.037 27.235 28.010 28.600 29.085 29.500 4243 21.104 22.776 23.587 25.748 26.837 28.057 28.846 29.447 29.940 30.362 4344 21.803 23.507 24.333 26.532 27.641 28.882 29.684 30.295 30.797 31.227 4445 22.505 24.240 25.081 27.319 28.447 29.708 30.525 31.146 31.656 32.093 4546 23.211 24.977 25.833 28.109 29.255 30.538 31.367 31.999 32.517 32.962 4647 23.921 25.717 26.587 28.901 30.066 31.369 32.212 32.854 33.381 33.832 4748 24.633 26.460 27.344 29.696 30.879 32.203 33.059 33.711 34.246 34.704 4849 25.349 27.206 28.104 30.493 31.694 33.039 33.908 34.570 35.113 35.578 4950 26.067 27.954 28.867 31.292 32.512 33.876 34.759 35.431 35.982 36.454 5051 26.789 28.706 29.632 32.094 33.332 34.716 35.611 36.293 36.852 37.331 51

0.00001 0.00005 0.0001 0.0005 0.001 0.002 0.003 0.004 0.005 0.006

B-2 Advanced GSM Cell Planning © AIRCOM International 2002


0.007 0.008 0.009 0.01 0.02 0.03 0.05 0.1 0.2 0.4 1 .00705 .00806 .00908 .01010 .02041 .03093 .05263 .11111 .25000 .66667 1 2 .12600 .13532 .14416 .15259 .22347 .28155 .38132 .59543 1.0000 2.0000 2 3 .39664 .41757 .43711 .45549 .60221 .71513 .89940 1.2708 1.9299 3.4798 3 4 .77729 .81029 .84085 .86942 1.0923 1.2589 1.5246 2.0454 2.9452 5.0210 4 5 1.2362 1.2810 1.3223 1.3608 1.6571 1.8752 2.2185 2.8811 4.0104 6.5955 5 6 1.7531 1.8093 1.8610 1.9090 2.2759 2.5431 2.9603 3.7584 5.1086 8.1907 6 7 2.3149 2.3820 2.4437 2.5009 2.9354 3.2497 3.7378 4.6662 6.2302 9.7998 7 8 2.9125 2.9902 3.0615 3.1276 3.6271 3.9865 4.5430 5.5971 7.3692 11.419 8 9 3.5395 3.6274 3.7080 3.7825 4.3447 4.7479 5.3702 6.5464 8.5217 13.045 9 10 4.1911 4.2889 4.3784 4.4612 5.0840 5.5294 6.2157 7.5106 9.6850 14.677 1011 4.8637 4.9709 5.0691 5.1599 5.8415 6.3280 7.0764 8.4871 10.857 16.314 1112 5.5543 5.6708 5.7774 5.8760 6.6147 7.1410 7.9501 9.4740 12.036 17.954 1213 6.2607 6.3863 6.5011 6.6072 7.4015 7.9667 8.8349 10.470 13.222 19.598 1314 6.9811 7.1155 7.2382 7.3517 8.2003 8.8035 9.7295 11.473 14.413 21.243 1415 7.7139 7.8568 7.9874 8.1080 9.0096 9.6500 10.633 12.484 15.608 22.891 1516 8.4579 8.6092 8.7474 8.8750 9.8284 10.505 11.544 13.500 16.807 24.541 1617 9.2119 9.3714 9.5171 9.6516 10.656 11.368 12.461 14.522 18.010 26.192 1718 9.9751 10.143 10.296 10.437 11.491 12.238 13.385 15.548 19.216 27.844 1819 10.747 10.922 11.082 11.230 12.333 13.115 14.315 16.579 20.424 29.498 1920 11.526 11.709 11.876 12.031 13.182 13.997 15.249 17.613 21.635 31.152 2021 12.312 12.503 12.677 12.838 14.036 14.885 16.189 18.651 22.848 32.808 2122 13.105 13.303 13.484 13.651 14.896 15.778 17.132 19.692 24.064 34.464 2223 13.904 14.110 14.297 14.470 15.761 16.675 18.080 20.737 25.281 36.121 2324 14.709 14.922 15.116 15.295 16.631 17.577 19.031 21.784 26.499 37.779 2425 15.519 15.739 15.939 16.125 17.505 18.483 19.985 22.833 27.720 39.437 2526 16.334 16.561 16.768 16.959 18.383 19.392 20.943 23.885 28.941 41.096 2627 17.153 17.387 17.601 17.797 19.265 20.305 21.904 24.939 30.164 42.755 2728 17.977 18.218 18.438 18.640 20.150 21.221 22.867 25.995 31.388 44.414 2829 18.805 19.053 19.279 19.487 21.039 22.140 23.833 27.053 32.614 46.074 2930 19.637 19.891 20.123 20.337 21.932 23.062 24.802 28.113 33.840 47.735 3031 20.473 20.734 20.972 21.191 22.827 23.987 25.773 29.174 35.067 49.395 3132 21.312 21.580 21.823 22.048 23.725 24.914 26.746 30.237 36.295 51.056 3233 22.155 22.429 22.678 22.909 24.626 25.844 27.721 31.301 37.524 52.718 3334 23.001 23.281 23.536 23.772 25.529 26.776 28.698 32.367 38.754 54.379 3435 23.849 24.136 24.397 24.638 26.435 27.711 29.677 33.434 39.985 56.041 3536 24.701 24.994 25.261 25.507 27.343 28.647 30.657 34.503 41.216 57.703 3637 25.556 25.854 26.127 26.378 28.254 29.585 31.640 35.572 42.448 59.365 3738 26.413 26.718 26.996 27.252 29.166 30.526 32.624 36.643 43.680 61.028 3839 27.272 27.583 27.867 28.129 30.081 31.468 33.609 37.715 44.913 62.690 3940 28.134 28.451 28.741 29.007 30.997 32.412 34.596 38.787 46.147 64.353 4041 28.999 29.322 29.616 29.888 31.916 33.357 35.584 39.861 47.381 66.016 4142 29.866 30.194 30.494 30.771 32.836 34.305 36.574 40.936 48.616 67.679 4243 30.734 31.069 31.374 31.656 33.758 35.253 37.565 42.011 49.851 69.342 4344 31.605 31.946 32.256 32.543 34.682 36.203 38.557 43.088 51.086 71.006 4445 32.478 32.824 33.140 33.432 35.607 37.155 39.550 44.165 52.322 72.669 4546 33.353 33.705 34.026 34.322 36.534 38.108 40.545 45.243 53.559 74.333 4647 34.230 34.587 34.913 35.215 37.462 39.062 41.540 46.322 54.796 75.997 4748 35.108 35.471 35.803 36.109 38.392 40.018 42.537 47.401 56.033 77.660 4849 35.988 36.357 36.694 37.004 39.323 40.975 43.534 48.481 57.270 79.324 4950 36.870 37.245 37.586 37.901 40.255 41.933 44.533 49.562 58.508 80.988 5051 37.754 38.134 38.480 38.800 41.189 42.892 45.533 50.644 59.746 82.652 51

0.007 0.008 0.009 0.01 0.02 0.03 0.05 0.1 0.2 0.4

Advanced GSM Cell Planning © AIRCOM International 2002 B-3


0.00001 0.00005 0.0001 0.0005 0.001 0.002 0.003 0.004 0.005 0.006 51 26.789 28.706 29.632 32.094 33.332 34.716 35.611 36.293 36.852 37.331 51 52 27.513 29.459 30.400 32.898 34.153 35.558 36.466 37.157 37.724 38.211 52 53 28.241 30.216 31.170 33.704 34.977 36.401 37.322 38.023 38.598 39.091 53 54 28.971 30.975 31.942 34.512 35.803 37.247 38.180 38.891 39.474 39.973 54 55 29.703 31.736 32.717 35.322 36.631 38.094 39.040 39.760 40.351 40.857 55 56 30.438 32.500 33.494 36.134 37.460 38.942 39.901 40.630 41.229 41.742 56 57 31.176 33.266 34.273 36.948 38.291 39.793 40.763 41.502 42.109 42.629 57 58 31.916 34.034 35.055 37.764 39.124 40.645 41.628 42.376 42.990 43.516 58 59 32.659 34.804 35.838 38.581 39.959 41.498 42.493 43.251 43.873 44.406 59 60 33.404 35.577 36.623 39.401 40.795 42.353 43.360 44.127 44.757 45.296 60 61 34.151 36.351 37.411 40.222 41.633 43.210 44.229 45.005 45.642 46.188 61 62 34.900 37.127 38.200 41.045 42.472 44.068 45.099 45.884 46.528 47.081 62 63 35.651 37.906 38.991 41.869 43.313 44.927 45.970 46.764 47.416 47.975 63 64 36.405 38.686 39.784 42.695 44.156 45.788 46.843 47.646 48.305 48.870 64 65 37.160 39.468 40.579 43.523 45.000 46.650 47.716 48.528 49.195 49.766 65 66 37.918 40.252 41.375 44.352 45.845 47.513 48.591 49.412 50.086 50.664 66 67 38.677 41.038 42.173 45.183 46.692 48.378 49.467 50.297 50.978 51.562 67 68 39.439 41.825 42.973 46.015 47.540 49.243 50.345 51.183 51.872 52.462 68 69 40.202 42.615 43.775 46.848 48.389 50.110 51.223 52.071 52.766 53.362 69 70 40.967 43.405 44.578 47.683 49.239 50.979 52.103 52.959 53.662 54.264 70 71 41.734 44.198 45.382 48.519 50.091 51.848 52.984 53.848 54.558 55.166 71 72 42.502 44.992 46.188 49.357 50.944 52.718 53.865 54.739 55.455 56.070 72 73 43.273 45.787 46.996 50.195 51.799 53.590 54.748 55.630 56.354 56.974 73 74 44.045 46.585 47.805 51.035 52.654 54.463 55.632 56.522 57.253 57.880 74 75 44.818 47.383 48.615 51.877 53.511 55.337 56.517 57.415 58.153 58.786 75 76 45.593 48.183 49.427 52.719 54.369 56.211 57.402 58.310 59.054 59.693 76 77 46.370 48.985 50.240 53.563 55.227 57.087 58.289 59.205 59.956 60.601 77 78 47.149 49.787 51.054 54.408 56.087 57.964 59.177 60.101 60.859 61.510 78 79 47.928 50.592 51.870 55.254 56.948 58.842 60.065 60.998 61.763 62.419 79 80 48.710 51.397 52.687 56.101 57.810 59.720 60.955 61.895 62.668 63.330 80 81 49.492 52.204 53.506 56.949 58.673 60.600 61.845 62.794 63.573 64.241 81 82 50.277 53.012 54.325 57.798 59.537 61.480 62.737 63.693 64.479 65.153 82 83 51.062 53.822 55.146 58.649 60.403 62.362 63.629 64.594 65.386 66.065 83 84 51.849 54.633 55.968 59.500 61.269 63.244 64.522 65.495 66.294 66.979 84 85 52.637 55.445 56.791 60.352 62.135 64.127 65.415 66.396 67.202 67.893 85 86 53.427 56.258 57.615 61.206 63.003 65.011 66.310 67.299 68.111 68.808 86 87 54.218 57.072 58.441 62.060 63.872 65.897 67.205 68.202 69.021 69.724 87 88 55.010 57.887 59.267 62.915 64.742 66.782 68.101 69.106 69.932 70.640 88 89 55.804 58.704 60.095 63.772 65.612 67.669 68.998 70.011 70.843 71.557 89 90 56.598 59.526 60.923 64.629 66.484 68.556 69.896 70.917 71.755 72.474 90 91 57.394 60.344 61.753 65.487 67.356 69.444 70.794 71.823 72.668 73.393 91 92 58.192 61.164 62.584 66.346 68.229 70.333 71.693 72.730 73.581 74.311 92 93 58.990 61.985 63.416 67.206 69.103 71.222 72.593 73.637 74.495 75.231 93 94 59.789 62.807 64.248 68.067 69.978 72.113 73.493 74.545 75.410 76.151 94 95 60.590 63.630 65.082 68.928 70.853 73.004 74.394 75.454 76.325 77.072 95 96 61.392 64.454 65.917 69.791 71.729 73.896 75.296 76.364 77.241 77.993 96 97 62.194 65.279 66.752 70.654 72.606 74.788 76.199 77.274 78.157 78.915 97 98 62.998 66.105 67.589 71.518 73.484 75.681 77.102 78.185 79.074 79.837 98 99 63.803 66.932 68.426 72.383 74.363 76.575 78.006 79.096 79.992 80.760 99 100 64.609 67.760 69.265 73.248 75.242 77.469 78.910 80.008 80.910 81.684 100101 65.416 68.589 70.104 74.115 76.122 78.364 79.815 80.920 81.829 82.608 101

0.00001 0.00005 0.0001 0.0005 0.001 0.002 0.003 0.004 0.005 0.006

B-4 Advanced GSM Cell Planning © AIRCOM International 2002

n Grade of Service n 0.007 0.008 0.009 0.01 0.02 0.03 0.05 0.1 0.2 0.4

51 37.754 38.134 38.480 38.800 41.189 42.892 45.533 50.644 59.746 82.652 51 52 38.639 39.024 39.376 39.700 42.124 43.852 46.533 51.726 60.985 84.317 52 53 39.526 39.916 40.273 40.602 43.060 44.813 47.534 52.808 62.224 85.981 53 54 40.414 40.810 41.171 41.505 43.997 45.776 48.536 53.891 63.463 87.645 54 55 41.303 41.705 42.071 42.409 44.936 46.739 49.539 54.975 64.702 89.310 55 56 42.194 42.601 42.972 43.315 45.875 47.703 50.543 56.059 65.942 90.974 56 57 43.087 43.499 43.875 44.222 46.816 48.669 51.548 57.144 67.181 92.639 57 58 43.980 44.398 44.778 45.130 47.758 49.635 52.553 58.229 68.421 94.303 58 59 44.875 45.298 45.683 46.039 48.700 50.602 53.559 59.315 69.662 95.968 59 60 45.771 46.199 46.589 46.950 49.644 51.570 54.566 60.401 70.902 97.633 60 61 46.669 47.102 47.497 47.861 50.589 52.539 55.573 61.488 72.143 99.297 61 62 47.567 48.005 48.405 48.774 51.534 53.508 56.581 62.575 73.384 100.96 62 63 48.467 48.910 49.314 49.688 52.481 54.478 57.590 63.663 74.625 102.63 63 64 49.368 49.816 50.225 50.603 53.428 55.450 58.599 64.750 75.866 104.29 64 65 50.270 50.723 51.137 51.518 54.376 56.421 59.609 65.839 77.108 105.96 65 66 51.173 51.631 52.049 52.435 55.325 57.394 60.619 66.927 78.350 107.62 66 67 52.077 52.540 52.963 53.353 56.275 58.367 61.630 68.016 79.592 109.29 67 68 52.982 53.450 53.877 54.272 57.226 59.341 62.642 69.106 80.834 110.95 68 69 53.888 54.361 54.793 55.191 58.177 60.316 63.654 70.196 82.076 112.62 69 70 54.795 55.273 55.709 56.112 59.129 61.291 64.667 71.286 83.318 114.28 70 71 55.703 56.186 56.626 57.033 60.082 62.267 65.680 72.376 84.561 115.95 71 72 56.612 57.099 57.545 57.956 61.036 63.244 66.694 73.467 85.803 117.61 72 73 57.522 58.014 58.464 58.879 61.990 64.221 67.708 74.558 87.046 119.28 73 74 58.432 58.930 59.384 59.803 62.945 65.199 68.723 75.649 88.289 120.94 74 75 59.344 59.846 60.304 60.728 63.900 66.177 69.738 76.741 89.532 122.61 75 76 60.256 60.763 61.226 61.653 64.857 67.156 70.753 77.833 90.776 124.27 76 77 61.169 61.681 62.148 62.579 65.814 68.136 71.769 78.925 92.019 125.94 77 78 62.083 62.600 63.071 63.506 66.771 69.116 72.786 80.018 93.262 127.61 78 79 62.998 63.519 63.995 64.434 67.729 70.096 73.803 81.110 94.506 129.27 79 80 63.914 64.439 64.919 65.363 68.688 71.077 74.820 82.203 95.750 130.94 80 81 64.830 65.360 65.845 66.292 69.647 72.059 75.838 83.297 96.993 132.60 81 82 65.747 66.282 66.771 67.222 70.607 73.041 76.856 84.390 98.237 134.27 82 83 66.665 67.204 67.697 68.152 71.568 74.024 77.874 85.484 99.481 135.93 83 84 67.583 68.128 68.625 69.084 72.529 75.007 78.893 86.578 100.73 137.60 84 85 68.503 69.051 69.553 70.016 73.490 75.990 79.912 87.672 101.97 139.26 85 86 69.423 69.976 70.481 70.948 74.452 76.974 80.932 88.767 103.21 140.93 86 87 70.343 70.901 71.410 71.881 75.415 77.959 81.952 89.861 104.46 142.60 87 88 71.264 71.827 72.340 72.815 76.378 78.944 82.972 90.956 105.70 144.26 88 89 72.186 72.753 73.271 73.749 77.342 79.929 83.993 92.051 106.95 145.93 89 90 73.109 73.680 74.202 74.684 78.306 80.915 85.014 93.146 108.19 147.59 90 91 74.032 74.608 75.134 75.620 79.271 81.901 86.035 94.242 109.44 149.26 91 92 74.956 75.536 76.066 76.556 80.236 82.888 87.057 95.338 110.68 150.92 92 93 75.880 76.465 76.999 77.493 81.201 83.875 88.079 96.434 111.93 152.59 93 94 76.805 77.394 77.932 78.430 82.167 84.862 89.101 97.530 113.17 154.26 94 95 77.731 78.324 78.866 79.368 83.134 85.850 90.123 98.626 114.42 155.92 95 96 78.657 79.255 79.801 80.306 84.100 86.838 91.146 99.722 115.66 157.59 96 97 79.584 80.186 80.736 81.245 85.068 87.826 92.169 100.82 116.91 159.25 97 98 80.511 81.117 81.672 82.184 86.035 88.815 93.193 101.92 118.15 160.92 98 99 81.439 82.050 82.608 83.124 87.003 89.804 94.216 103.01 119.40 162.59 99

100 82.367 82.982 83.545 84.064 87.972 90.794 95.240 104.11 120.64 164.25 100101 83.296 83.916 84.482 85.005 88.941 91.784 96.265 105.21 121.89 165.92 101

0.007 0.008 0.009 0.01 0.02 0.03 0.05 0.1 0.2 0.4

radio network planning fundamentalsnew

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