Cw Test Final

Introduction

• Operationalized in September 2007, with its Head Office in Mumbai. • Comprises of a resource pool of 350+ Engineers who have worked with all Tier 1 OEMs across India. They bring rich experience by working in companies such as WIPRO, Reliance Communications, Tata Tele Tele Service Services, s, Micro Technolo echnologies. gies.

A Telecom & IT Company

W W W . W www.netwing.in ATSONWYATT.COM

NETWING TECHNOLOGIES Pvt. Ltd. • Management comprises of members having over 10 years of experience in providing solutions over the wireless network. • Dedicated to achieve best in Software Development and getting you the most of innovative developed software’s.

Netwing Technologies Private Ltd.

1

Equipment Details

Frequency used

2300 - 2400 MHz

Activity

type

Transmission

Reception

NETWING Tool Discription reference

RF Synthesizer

Tortoise Multi-Band Transmitter (CW)

2.3 GHz, 2.5/25/50/200 kHz step 20 watt

Power Amplifier

Tortoise

20 watt

RF Cables set

1/2"

5-10 mtr

Power meter

Yellow Frog Coyat

150 Mhz -2.7 ghz for rms & CW both

Omni antenna

Jaybeam Wireles Wirelesss

7640240

Telescopic mast

Various

5 to 7meters with safety guides

Analog Receiver

Coyote modular receiver w/GPS 

Rx1: 2.3-2.4 GHz receiver module (25 kHz steps/25 kHz IF BW)

Magnetic antenna

Mount Antenna

UMB

Set of accessories

Coyote

GPS Wheel trigger

Rotary (Same Work)

PC laptop

various

Netwing Technologies Private Ltd.

Coyat

2

Equipment Details

Activity

Survey 

type

reference

Digital camera

Canon / Sony

with Zoom equiv 35mm above 105

Professional Compass

Topochaix

Universal

GPS handset

Trimble / Garmin…

various references

Decameter

various

Binocular

Olympus

Antenna line tester

Anritsu

site master

Spectrum analyzer

Anritsu

MS2721 or equiv.

digital multimeter

Flex

to test Volt, Amp, ohm

Complements

Tool box with divers wrench

Netwing Technologies Private Ltd.

3

Site Selection

The major criteria with which sites were selected for CW testing is: •The representation of clutters in the sites surroundings meeting the pretext of model for which it is being driven. •Any major obstacles which can badly affect the collection of data. •For the feasibility of installing antenna and safe upkeep of the CW equipments near to the antenna. •Adequacy of driving in the surroundings of the selected sites. •Ability to find cleaner frequency channel for data collection. •Existence of regular power supply for avoiding battery to discharge in case where the drive tests may prolong more than 3 hours.

Site Selection

•The planning area should be categorized into dense urban, mean urban, suburb and rural. •The testing site shall be free of visible obstructions around. around. the building where the testing site is located on shall be higher • than the average height of surrounding buildings. • In dense urban, the valid antenna height should be about 10m higher than the average height of surrounding buildings; In mean urban, it’s about 15m; in suburban or rural, it’s about 15 to 25m. •There should be enough clutters (from the digital map) around the site, and enough roads to be able to cover those clutters. •The building’s building’s rooftop should not be too large. The antenna must be raised when the building’s rooftop is too large to affect the t he radio propagation, especially when there is a parapet on rooftop. •The omni antenna is set on top of the building or tower, and the valid antenna height, above ground level (from the ground to the middle of antenna), is 4 to 30m.

CW Methodology

Measurements Procedures For CW Survey Measurements • CW test routes were planned carefully to avoid re running on the routes where ever it was possible and also following sections were not included in the data collection by using the pause facility of the equipment. 1) Elevated sections of roads. 2) Tunnels. 3) Bridges. • Sufficient measurements were made in each clutter type for the model to be reasonably accurate and thus valid.

CW Methodology

Precautions Precauti ons Taken Taken : • • • •

Measurement tape was used to verify the accurate height. Position of the site was recorded carefully with the help of GPS. Mostly antenna heights were selected considering the average height of the clutter. The power meter is used for checking the output power after the feeder. It is important to check the forward power as well as the reflected in the antenna connection to be able to calculate the EiRP.

CW Drive Route Definition

•

Distance : Must account for expected coverage propagation. Must account for expected interference propagation

•

Clutter : Sufficient measurement in all local clutter types ( >1000 )

•

Roads : Avoid street canyons, tunnels, elevated roads, cuttings etc..Mix of radial and tangential road roads with ground height above the transmitter antenna.

CW Drive Route Definition

•All directions from the testing site should be included. • Different distances should be reached; • All the clutters in coverage area must be tested. • Roads should be reached as much as possible. • Common and narrow roads are the main targets to be chosen. •Avoid of Drive test in the same route. • Don’t record the data when the car stops. s tops. •The testing radius should be large enough so that the received signal’s strength could be weaker than 110dBm;adjust the testing route according to the received signal in the practical drive

CW Equipment Set up



Transmitter setup

Antenna Tortoise Transmitter

To Power Supply 12V DC@5A

Power Meter

CW Equipment Set up 

Receiver setup

Antenna

Coyote :The signal received from the Omni-directional antenna (no gain) is

fed to the receiver and is again fed to the laptop PC through the parallel port extender. Output of the GPS is also fed to the laptop with the same cable. The transmitted test frequency is monitored using a laptop connected to the receiver. The data is processed using the Forecaster  software

Data Post processing Depends on customer requirements: •

Averaged Measurements – post processing involves simple conversion into Signia format supported by Enterprise

•

Signia data file ( .dat ) contains longitude, latitude latitude (decimal degrees) and received received level (dBm)

•

Every data file must have header file with identical name but with extension .hd.

•

Header file must have antenna type (identical name to one in Asset3g), Tx power, Tx antenna height, coordinates.

•

It is common practice to include all gains and losses under Tx power value and leave other fields relevant to gain/losses in the header blank. Therefore in a Tx field usually is put: •

Tx – Ct +Atg –Arg+Crl where

•

Tx-Tx power(dBm),

•

Ct-cable loss between transmitter and antenna (dB),

•

Atg-transmitting antenna gain (dBi)

•

Arg-receiving antenna gain (dBi)

•

Crl-cable loss between receiver and receiving antenna (dB)

CW Data Validation

•

Compare the site data (photographs, surrounding clutter and terrain profile) to the Clutter and DTM layer of the map data provided.

•

Check the driven routes against vectors within the map data.

•

Filter out any invalid data that may cause anomalies in the calibration process

•

Make sure that details relating to a site (EIRP (EIRP,, Location, Height, Antenna Antenna file) correspond to reports from f rom CW Survey.

•

Use Asset Asset utilities utili ties to get visual representation of the received signal vs distance.

Data filtering

•

Filter clutter types that have less than 500 bins. Clutter offsets or them will be estimated later in the model tuning process.

•

Filter out any file which shows extreme in signal level.

•

Unusually high signal level at far distance can be caused by reflection over big water surface, or driving along route which is higher than antenna.

•

Unusually weak signal level can be caused by driving driving behind blocking object.

•

Okumura –Hata can’t model above situations, therefore these data must be filtered out.

•

With careful route planning filtering can be avoided.

•

Having more than one file per site makes filtering during post processing proces sing much easier

Filtering example-Driving above Tx antenna

Filtering example-Blocking object

Displaying CW measurements in Asset

 –  –

 –

Data Types-CW Measurements-CW Signal To set up thresholds double click on CW Signal and specify thresholds under Categories tab The same goes for other options inside CW Measurements

Okumura-Hata in Asset

•

Asset uses slightly modified Okumura-Hata:



Ploss =K1 + K2*log(d) + K3*Hms + K4*log(Hms) + K5*log(Heff) + K6*log(Heff)*log(d) + K7*Ldiff + Lclutter



d is distance in km between Tx antenna and mobile station



Hms is mobile station height



Heff is effective antenna height in metres



Ldiff is a loss due to diffraction



Lclutter is a clutter loss

•

Asset has 4 algorithms for calculating effective effective antenna height

•

Asset has 4 algorithms for calculating diffraction diffraction

Asset improvements



K1 near and k2 near are designed to overcome Okumura-Hata limitation limitation for close distances.



Through Clutter Loss – takes into the account clutter profile along distance d from mobile station to base station.



Advantages in improved accuracy/reduced standard deviation error and more realistic calculated predictions.

Through Clutter Model Definition





Each clutter category is given Through Clutter Loss (dB/km) on the path between transmitter and receiver. Through clutter losses are linearly weighted. The clutter nearest the mobile station has highest effect

Overview of Model Calibration

•

There must be project set up (map data, antennas, sites, propagation model) in order to start tuning

•

Load CW data

•

Make appropriate filtering, usually: • -110dBm to -40dBm • 125m to 10000 Start with the default values for k parameters Do Auto Tune Try all combination of effective antenna height and diffraction algorithms and determine which one gives the lowest standard deviation

• • • •

Take note of second and third best

Model setting

•

Tools-Model Tuning-Options

•

Select the resolution of mapping data

•

Select the model as a start tuning model. It is recommended to use default model

Filter Setting

•

Tools-Model Tuning-Options-Fil Tuning-Options-Filter ter

•

Set up distance filtering

•

Set up signal level filtering

•

Filter out clutter types with insufficient data by highlighting them

•

If you tune k7 click just NLOS

•

Click antenna button if directional antennas were used

Auto Tune

•

Tools-Model Tuning-Auto Tune

• • •

Set up deltas

•

Click Auto Tune under Tools tab

•

Wait for results

•

You can apply new parameters by clicking apply new parameters

•

Through clutter offsets and clutter offsets are under Clutter tab

Click fix box next to the k factor you don’t want to tune

K parameters

•

K3 and K4 are not altered. This is because they relate to mobile height which in a typical cellular system is constant making these coefficients redundant.

•

K7 is the diffraction parameter. It can be determined by tuning just NLOS data.

•

All K parameters must keep the same polarity as in the original Okumura Hata model • K1, K2, K7 >0 • K3, K5, K6