
Network Module

The basic function of the Network Module is to:

Provide a geographic representation of the network

Provide the interface to the intra system interference calculations

Provide access to the design modules for individual Pathloss data files

Sites and links can be entered in different layers that could define regions, frequency bands, etc. There are a maximum of six site layers and six link layers, a site and a link cannot exist on more than one layer.

To display the Network Module select Module – Network. A blank Network Worksheet is displayed.


Network Module (Cont’d)



Defaults:

How the network diagram is to be displayed can be set up using the Defaults option. Select Defaults and a list of settable

options will be displayed.

Select the parameter to be set and enter the desired settings



Opening an Existing Network Diagram:

If a network diagram already exists it can be opened the using File – Open option

Change the path to the directory containing the network files, select a file and press Open. The

file will be loaded into the network worksheet.



Creating a network diagram:

A network diagram can be created in two ways.

First Method :

The first is by importing existing PL 4 files. Select Site Data – Import, select the path to the directory where the files are kept, select the files required to the network diagram and press Open. The files will be inserted into the network diagram.



Second Method :

A second method is to enter the site details in the Site List file and connect the together to form the desired network. Select Site Data – Edit – Add. Type the site name, latitude and longitude and press OK. Do this for each site in the network..

Once all the sites have been entered close the Site List dialog box. The sites will be displayed on the network diagram. Connect the sites together to form the network



Layers:

Sites and link can be assigned to different layers to indicate different options, e.g. frequency, geographic regions, etc. Sites and links can only exist in one layer. Sites layers can be set in the Site List dialog box

Site Layers:

In the Layer Column double click the Site Layer to be changed and select the desired layer from the drop down box. Once you have completed changing the site layers close the Site List dialog box.



Site Layers:

Link layers can be changed in two ways. The first is from the Link List dialog box. Select Site Data – Link List.

In the Layer column double click the Link Layer to be changed and select the desired layer from the drop down box. Once you have completed changing the link layers close the Link List dialog box.



The second method is to place the cursor on the link to be changed – right click the mouse – select Link Layer from the displayed dialog box and select the link layer required from the dropdown list and Press OK.

To display or hide layers select Layers, the Layer selection box will be displayed. Tick or un-tick the layers to be displayed.

Close the Layer Selection box and the selected layers will be displayed on the network diagram.



Network Background:

If a DTM is available a background can be generated for the network display. Select Site Data – Generate Background. The background generation will start automatically.

Once the generation is completed a topographical map is displayed behind the network diagram.

A color legend can be displayed by Selecting Site Data and ticking Color Legend option. The background, once generated, can be switched ON and OFF by Selecting Site Data and ticking the Show Background option



Add and Move Site:

We can Add a dummy site on Network.

Select Site Data Add Site

Now put the cross where you want to add the site.

Click Add site from Add Site window, and Give name

We can Move site from the Grid Module.

Select Data Move site , select the site and Drag the site to desired location.

These option mainly use during repeater selection


Worksheet Module

The parameters of the equipment use for the link are entered in the worksheet module. Select Worksheet from the Modules dropdown menu and the Link Worksheet will be displayed. First it is necessary to set the work sheet up for the methods of calculation to be used when calculating the link

performance

Clicking on the various items displayed on the profile enters other dialog boxes, i.e. the Cloud enters the rain data, the Channel ID box enters the operating frequencies of the link, etc.


Worksheet Module (Cont’d)

Reliability Methods:

Select the Operations dropdown menu and select Reliability Methods.

Select the options applicable to your requirements. The Type can either be selected as PDH or SDH depending on the link. Click OK.



Reliability Methods:

Vigants’ North American/ITU-R Rep.338 multipath outage model provides an accurate estimate of performance worldwide in optimally configured and aligned digital microwave links.

However, the new ITU-R Rec. P.530 model is replacing Vigants’ Rep. 338 model in many international regions.



Diversity Operation

If a diversity link is being planned reselect the Operations menu and select Diversity Calculations. Set up the Diversity Operation as shown.

Base band Switching is normally used on PDH links such as the Ericsson mini-link, while IF Combining is used on SDH trunk radios such as the Nera NL2006A equipment. The Maximum Diversity Improvement should be limited to 20.



Options Select the Operations dropdown

menu and select Options.

Tick the Call Sign and Station Code boxes, this will put the Call Sign and Station Code on the report sheet when it is generated.



Rain Data

Click on the Cloud and the Rain dialog box opens.

Select Horizontal Polarization, as this rain attenuation is greater using horizontal polarization than using vertical polarization. Check the ITU-R P.530-8 option.

Select Load Rain File. Change the directory path to the directory where the rain files are stored and select the appropriate rain file for the region that the link will operate in. Close the dialog box.



Path Profile Information Click on the Profile and the Path

Profile Data dialog box opens.

Click on the two Calculate buttons, once the calculation has been completed close the dialog box. Close the Path Profile Data dialog box



Click on Geo Clim and the Geoclimatic Factor ITU-R P.530-9 dialog box opens

Click on the two Calculate buttons, once the calculation has been completed close the dialog box.

Close the Path Profile Data dialog box



Radio Equipment Selection

Click on the TR symbol and the Radio Equipment dialog box will be displayed

To enter the microwave radio information, select the Code Index option. Use the New Index button to select the directory where the radio information is stored. Highlight the equipment used by the link and click the Both button. Close the Radio Code Index form.

The information entered in the Radio Equipment form can be edited, e.g. the TX Power can be reduced if the link is short and does not require it to operate at full power. Once you have completed

the data entry close the dialog box



Antenna Data Entry Antenna data is entered by clicking on the

Antenna symbol; this will open the Antenna TR-TR dialog box.

To enter the antenna information, select the Code Index option. Use the New Index button to select the directory where the antenna information is stored. Highlight the antennas used by the link and click the Both or the Site 1 or Site 2 button. Close the Antenna Code Index form.

If diversity antennas are used on the link repeat the above procedure for the diversity antennas.

Close the Antenna TR-TR dialog box



Transmission Line Data Entry

The Ericsson Mini-link and the Nera City Link are split indoor/outdoor microwave terminals and therefore do not require RF transmission lines as they us an IF cable to communicate between the indoor and outdoor units. However if the outdoor unit is connected to an antenna by Flex Twist waveguide the data for the waveguide has to be entered into the worksheet. The Nera NL2006A microwave radio uses elliptical waveguide to connect the terminal to the antenna and this data must be entered into the worksheet.

Click on the Transmission Line symbol and the Transmission Line TR-TR dialog box will be displayed.

Select Lookup and the Transmission Line selection box will be shown. Use the Files – Open command to select the directory where the transmission line files are stored. Highlight the transmission line to be used on the link and click the button for the side of the link the transmission line is to be used. This will enter the transmission line data in to the Transmission Line TR-TR dialog box. Close the Transmission Line Data form. Enter the Length of the transmission line and the calculation to be carried out. Enter 0.25 as connector losses for both sides of the link.

If the link uses diversity antennas repeat the above procedure for the diversity transmission line. Close the Transmission Line TR-TR dialog box.



Branching Network Data Entry Click on the Circulator picture and the

Branching Network TR-TR dialog box will be displayed. The filter losses, TX switch, RX hybrid and any other losses associated with the microwave radio transmission and reception paths are entered in this form.

Once data entry has been completed, close the form.



Frequency Selection Select the Channel ID symbol and the TX Channels

dialog box will be displayed.

Select Lookup and the TX Channels selection box will be shown. Use the Files – Open command to select the directory where the frequency files are stored. Highlight the frequency required and select which site is to transmit high. Close the frequency selection box. If the polarization requires changing, double click the position of the frequency in the POL column the polarization will toggle between V and H. Once the settings are complete close the TX channels dialog box. If the terminal uses ATPC the

value is also entered in this form



Make sure of either our Path Calculation is correct or we need to revise again. To do that please check the followings

Make sure that your worksheet page has Green Correct sign in Right Bottom of screen. If it is wrong sign that's mean there are some data mistake

Have a look to RX Signal, Fade Margin & (Annual Availability with rain) Percentage as per shown in Fig.



Report Generation

Click Report on the Worksheet screen, then click Full Report, a Report Sheet is generated listing all the equipment and its parameters used in the link. It also provides a performance report on how well the link is expected to perform once installed.

This performance report needs to be checked to make sure that the link performance meets the standard for quality and availability. If it does not meet these requirements close the form and edit the equipment and/or change the frequency of operation until the standards are met.

Under the Files option on the Report Form, the report can be Copied, Saved or Printed. Page Setup and Printer Setup options are also found here.

Once you are satisfied with the link performance and the equipment used close the Report Form.



MNI TOIMNI N-TOI-8091

Elevation (m) 351.83 348.95Latitude 34 04 30.19 N 34 04 05.38 N

Longitude 072 35 19.38 E 072 37 45.61 ETrue azimuth (°) 101.51 281.54Vertical angle (°) -0.36 0.33

Antenna model ML23-0.6HP ML23-0.6HPAntenna height (m) 35.00 15.00Antenna gain (dBi) 39.50 39.50

Frequency (MHz) 23000.00Polarization Vertical

Path length (km) 3.83Free space loss (dB) 131.36

Atmospheric absorption loss (dB) 0.73Field margin (dB) 1.00

Net path loss (dB) 54.09 54.09

Radio model ML23E St 17E1.raf ML23E St 17E1.rafTX power (watts) 5.01e-03 5.01e-03TX power (dBm) 7.00 7.00

EIRP (dBm) 46.50 46.50Emission designator 28M6G7W 28M6G7W

TX Channels F23/1H 23030.0000V F23/1L 21798.0000VRX threshold criteria BER 10-6 BER 10-6

RX threshold level (dBm) -79.00 -79.00

RX signal (dBm) -47.09 -47.09Thermal fade margin (dB) 31.91 31.91

Geoclimatic factor 1.19E-04Path inclination (mr) 5.98

Fade occurrence factor (Po) 3.54E-05Average annual temperature (°C) 10.00

Worst month - multipath (%) 100.00000 100.00000(sec) 0.06 0.06

Annual - multipath (%) 100.00000 100.00000(sec) 0.18 0.18

(% - sec) 100.00000 - 0.36

Rain region ITU Region K0.01% rain rate (mm/hr) 42.00

Flat fade margin - rain (dB) 31.91Rain rate (mm/hr) 101.22

Rain attenuation (dB) 31.91Annual rain (%-sec) 99.99904 - 301.56

Annual multipath + rain (%-sec) 99.99904 - 301.92

Sat, Nov 10 2007MNI-TOI.pl4Reliability Method - ITU-R P.530-9Rain - ITU-R P.530-8


Diffraction Module

This module should never have to be used as links should not be designed that are obstructed. If however, there is no alternative a link can be designed that is obstructed, provided that the diffraction loss does not exceed 25% of the fade margin at Kmin.

Select Module – Diffraction Loss. The Diffraction Loss Module is displayed.

To draw the Fresnel zones press F2, the Fresnel Zone option box is displayed. Select how you want the Fresnel zones to be displayed and press Draw. Close the Fresnel Zone option box when you are finished.


Diffraction Module (Cont’d)

Calculating Diffraction Loss Set the value of K to 1.33 using the K dropdown menu at

the top of the screen. If the path is obstructed then the link should be rejected and an alternative route found.

Set the value of K to Kmin using the K dropdown menu at the top of the screen. To do this you may have to edit the K list. Click on Configure – Edit K List, a list of default K values is displayed. Edit this list to include the Kmin value for the link. Close list when done.

Press F9 to calculate the Diffraction Loss of the link. Click on the Tick on the report to accept the values. If the value exceeds 25% of the fade margin the link should be rejected and an alternative route found.

Select Modules – Worksheet. You will be asked if you want to include the diffraction loss in the work sheet. If the link is to be implemented the value should be included in the worksheet.


Radio Refractivity Vs Height

Tx Rx

Primary Ray

Super Refractive Layer

Refracted Ray

Refraction or reflections can cause dynamic multipath fading which can severely affect

digital path performance

Fading typically increases with path distance

Relative Air Density

Warm-Cold Boundary

Layer

Reflected Ray

Path Fading


k = 4/3Water Reflections

Rm-m

For Ground & Water Reflections

Path Fading


Reflection Module

Reflections can cause the degradation of the received signal on a microwave link depending on the amplitude of the signal and the phase delay at which it arrives. If the reflected signal delay is greater than 20 – 40 nanoseconds, performance problems on high capacity systems can occur unless the reflected signal amplitude is at least 40 dB below the direct signal. Reflection analysis should be carried out in both direction of the link.

Select Module – Reflections, the Reflections Worksheet is displayed.


Reflection Module (Cont’d)

Defining the Reflective Plane

Select Define Plane and the Define Reflective Plane Worksheet will be displayed.

To define one end of the plane place the arrow to the desired position on one side of the profile and press F1 the arrow will change color. Next place the arrow at the desired position at the other end of the profile and press F1 the arrow will change color and reflection symbol will appear on the profile where the reflection will occur. Click the OK button to accept the reflective plan



Modifying Terrain Roughness

Select Modify –Roughness and the Terrain Roughness Worksheet is displayed.

Select Fresnel Zones and draw 100% Fresnel zone to the reflection point. Close the Fresnel Zone options box. Place the arrow at one end of the area covered by the Fresnel zone and press F1, move the arrow to the other end of the Fresnel zone and press F1 again. The terrain roughness of the area will be calculated. Press OK to

accept the value.



Modifying reflection Parameters The reflected signal will be attenuated by ground cover so this value should be included in

the calculation. Select Modify – Parameters, the Modify Reflection Parameters dialog box is displayed.

The terrain roughness previously calculated and the antenna 3 dB beam width has entered in the form ground Cover – Clearance Loss can be entered. This can vary between 0 to greater than 15 dB depending on the ground cover. The PL 4 manual suggests the following values:

0 to 1 dB Water, desert or salt flats

1 to 3 dB Fields with low vegetation or low grass

3 to 6 Db Sage bush, field with high vegetation or high grass

8 to 15 dB Partially wooded areas including trees along the road which are perpendicular to the path

>15 dB heavily wooded areas

.



Tick the Use Divergence box. Divergence is the scattering of a reflected signal due to the curvature of the earth. Click OK



Varying Parameters to see the Effect of reflections

Select Variable, a drop down menu is displayed and a number of parameters can be varied. For this example Earth Radius Factor (K) will be used.

Select Earth Radius Factor (K), a dialog box is displayed in which the parameters of the calculation can be edited. Once you have completed editing them press OK and a graph showing the effect of Earth radius Factor (K) will be displayed.



All other variable parameters work in the same manner



Dispersion ReportSelect Dispersion and the Dispersion Analysis Report will be displayed.

The two most important items on this report are: Reflection Loss and Reflection Delay. The Antenna Heights and Earth Radius Factor (K) can be edited and the result of the changes will be reflected in the report. Once you are finished editing the report press OK.


Multipath Module

Unless reliable atmospheric data is available this module cannot be used with any accuracy. The Multipath module displays ray traces for various atmospheric gradients.

Select Module – Multipath and the Multipath Worksheet is displayed.

The display above shows reflected ray as well as the ray trace for a constant gradient atmospheric scenario.

Pathloss 4.0 & MW Link Planning Part 2

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Transcript of Pathloss 4.0 & MW Link Planning Part 2