Wedig User Manual 2.0 Rev.C

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Rev.Date Rev. Document no.99.08.31 CPrepared by Subject Responsible Approved byIngvar HenneVidar Bakke

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WEDIG 2.0cUser Manual

NERA Networks AS Page 1(85)

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Rev.Date Rev. Document no.99.08.31 C

WEDIG 2.0c

Page 2(85) NERA Networks AS

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2.1 REQUIREMENTS...................................................................................................................................................... 52.2 INSTALLATION ........................................................................................................................................................ 52.3 STARTING THE PROGRAM........................................................................................................................................ 52.4 USER SET-UP .......................................................................................................................................................... 62.5 ENTERING DATA ..................................................................................................................................................... 62.6 CLOSING APPLICATION............................................................................................................................................ 62.7 WHAT’S NEW.......................................................................................................................................................... 6

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3.1 WORKBOOK CONTENTS .......................................................................................................................................... 7�� 3DWKV�VKHHW �� 6\VWHPV�VKHHW�� ,QIR�VKHHW�� 5DLQ�VKHHW�� )XQFWLRQV�VKHHW �� 6LQJOH�VKHHW �� (TXLSPHQW�VKHHW�� :RUNERRN�SDVVZRUG��

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4.1 PROJECT ................................................................................................................................................................. 9�� 1HZ �� 2SHQ�� 6DYH�� 6DYH�$V�� ([SRUW�WR�ILOH �� ,QIR�� 3URMHFW�REMHFWLYHV�� 3URMHFW�SUHIHUHQFHV �� 9LHZ ��

4.1.9.1 Customize Paths .............................................................................................................................................. 144.1.9.2 Customize Systems ......................................................................................................................................... 14

�� &XVWRPL]H�6LQJOH �� 4.1.10.1 View pro-rata chart.............................................................................................................................................. 164.1.10.2 View absolute chart............................................................................................................................................. 164.1.10.3 View variation charts .......................................................................................................................................... 174.1.10.4 View paths........................................................................................................................................................... 174.1.10.5 View selected path .............................................................................................................................................. 174.1.10.6 View systems....................................................................................................................................................... 174.1.10.7 View info............................................................................................................................................................. 184.1.10.8 View equipment .................................................................................................................................................. 184.1.10.9 View radio database ............................................................................................................................................ 184.1.10.10 View antenna database ................................................................................................................................... 184.1.10.11 View feeder database...................................................................................................................................... 184.1.10.12 Enable menus ................................................................................................................................................. 18

�� 3ULQW�� 4.1.11.1 Print project......................................................................................................................................................... 194.1.11.2 Print paths ........................................................................................................................................................... 194.1.11.3 Print selected path ............................................................................................................................................... 194.1.11.4 Print all paths separately ..................................................................................................................................... 194.1.11.5 Print systems ....................................................................................................................................................... 194.1.11.6 Print info ............................................................................................................................................................. 194.1.11.7 Print equipment ................................................................................................................................................... 20



WEDIG 2.0c


4.1.11.8 Reset page set-ups................................................................................................................................................204.2 PATHS ...................................................................................................................................................................20�� $GG�1HZ�SDWK ��

4.2.1.1 Site parameters.....................................................................................................................................................244.2.1.2 Path parameters....................................................................................................................................................25

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4.2.7.1 Tune antennas ......................................................................................................................................................294.2.7.2 Tune radio............................................................................................................................................................324.2.7.3 Tune Threshold degradation ................................................................................................................................344.2.7.4 Tune diversity ......................................................................................................................................................34

4.2.7.4.1 Frequency diversity.........................................................................................................................................344.2.7.4.2 Space Diversity ...............................................................................................................................................34

4.2.7.5 Tune feeder length ...............................................................................................................................................354.2.7.6 Tune feeder type ..................................................................................................................................................364.2.7.7 Tune path length ..................................................................................................................................................36

�� 8SGDWH ��4.2.8.1 Update this path only ...........................................................................................................................................374.2.8.2 Update all parameters ..........................................................................................................................................384.2.8.3 Update radio only ................................................................................................................................................384.2.8.4 Update feeder only...............................................................................................................................................38

4.3 SYSTEMS...............................................................................................................................................................38�� &OHDU�DOO�V\VWHPV�� $GG�V\VWHP�� ,QVHUW�V\VWHP �� 'HOHWH�V\VWHP ��

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5.1 POWER BUDGET ....................................................................................................................................................405.2 FREE SPACE LOSS ..................................................................................................................................................405.3 ATTENUATION DUE TO ATMOSPHERIC GASES.........................................................................................................405.4 LINK BUDGET ........................................................................................................................................................41�� 3DVVLYH�UHSHDWHUV��

5.4.1.1 Plane reflectors ....................................................................................................................................................435.4.1.1.1 Gain of plane reflector ....................................................................................................................................44

5.4.1.2 Back-to-back antennas .........................................................................................................................................455.5 MULTIPATH FADING ..............................................................................................................................................45�� )ODW�)DGLQJ��

5.5.1.1 Inland links ..........................................................................................................................................................475.5.1.2 Coastal linksover/near large bodies of water .......................................................................................................485.5.1.3 Coastal links over/near medium-sized bodies of water ........................................................................................495.5.1.4 Inland links in regions with many lakes...............................................................................................................495.5.1.5 Coastal links over/near uncertain size of body of water.......................................................................................49

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5.6.1.1 Space diversity.....................................................................................................................................................515.6.1.2 Frequency diversity..............................................................................................................................................53

5.6.1.2.1 Redundant 1+1 system.................................................................................................. ..................................535.6.1.3 Redundant N+1 System .......................................................................................................................................555.6.1.4 Hot standby configuration....................................................................................................................................555.6.1.5 Hybrid diversity ...................................................................................................................................................56

�� &RPELQHG�GLYHUVLW\ ��5.7 CROSS-POLAR INTERFERENCE.....................................................................................................................58�� 2XWDJH�GXH�WR�FOHDU�DLU�HIIHFWV�IRU�FR�FKDQQHO�V\VWHPV�� 2XWDJH�GXH�WR�SUHFLSLWDWLRQ�HIIHFWV�IRU�FR�FKDQQHO�V\VWHPV ��



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5.8 UNAVAILABILITY DUE TO RAIN ............................................................................................................................. 60�� 6SHFLILF�$WWHQXDWLRQ �� (IIHFWLYH�SDWK�OHQJWK �� 8QDYDLODELOLW\�GXH�WR�UDLQ�DWWHQXDWLRQ��

5.9 OBJECTIVES.......................................................................................................................................................... 63�� *��

5.9.1.1 High grade objectives.......................................................................................................................................... 635.9.1.2 Medium grade objectives .................................................................................................................................... 635.9.1.3 Local grade objectives......................................................................................................................................... 65

�� *�� 5.9.2.1 International portion using radio-relay systems................................................................................................... 655.9.2.2 National portion using radio-relay systems ......................................................................................................... 67

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7.1 WORKBOOK STRUCTURE ...................................................................................................................................... 717.2 NERA RADIO DATABASE ....................................................................................................................................... 727.3 NERA ANTENNA DATA BASE ................................................................................................................................. 727.4 FEEDER DATABASE............................................................................................................................... ................ 737.5 ITU-R WORLD MAPS ............................................................................................................................................ 74�� 3/�FRQWRXU�PDSV��,78�5�UHF��[��]� �� 5DLQIDOO�FRQWRXU�PDSV��,78�5�UHF��31��>��@�� :DWHU�YDSRXU�DW�JURXQG�OHYHO��,78�5�UHF��3��>��@��

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This program carries out prediction of system performance and outage due to rain on digital line-of-sightradio relay systems. The prediction model is based on ITU-R recommendation 530-7 [17]. The program isbasically a customised Microsoft Excel workbook. It is not a self-standing program, but it must be run as aworkbook in Excel. The Excel version can be either Office 95 Excel 7.0 or Excel 97. The program isdesigned to be a useful design tool for system planning engineers. Knowledge of Excel worksheet is abenefit, but not a necessity.

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The program and associated files occupy about 3.2 Mb on your c:\ drive. Make sure that the decimalseparator is . (period) and not , (comma) in the Windows number format.

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Run the VHWXS�H[H program to install the main program, databases and help-files. A program groupcontaining program icons will be created. The main program is WEDIG20.XLS. In addition the antennadatabase, radio database, feeder database, the help-file and the rain fall intensity data may be accesseddirectly from program manager.

You may use the WEDIG20.ICO file as a program icon in the program manager.

The following files are installed:

WEDIG20.XLS, WEDIG20.ICO, WED-HELP.HLP, ANT-DATA.XLS, NL-DATA.XLS, WG-DATA.XLS,Rain_ITU.dat.

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Double-click the program icon for WEDIG 2.0 or double-click the WEDIG20.XLS in file manager or as ashort-cut in Windows ’95 / ‘98.

The program is also automatically started when the WEDIG20.XLS file is opened in Excel.

The help about window will be displayed during workbook configuration. The program should be openedas a “read-only” file unless you want to make changes to the program itself.



WEDIG 2.0c


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Default user information may be set using the following procedure (please make a back-up copy of theoriginal program first):

Open the program by entering the program password (WEDIG20) so the program can be saved when the set-up is completed.

Select the Project-View-Enable menus command to enable access to all commands.

Make the desired changes, like changing the default text in the General comments text box or changing theformulas.

Save the program when the modifications are completed. See also 4.1.8.

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The program will always activate the Paths window when started (when configuration is completed). Inorder to enter data for a new path, simply select the $GG�1HZ�� command in the 3DWKV menu. The Inputdialog box in Figure 12 will be displayed and path parameters may be entered. This command is repeateduntil the system is totally defined. The data may be save using the 6DYH�$V�� command in the 3URMHFWmenu. Project information must be entered in order to identify your project before it is saved. The savecommand in the file menu is blocked in order to prevent changes in the program itself (see 2.6, 3.1.8).

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The project information should be saved before exiting the program. The program however,(WEDIG20.XLS file) should normally not be changed, so don’t save the changes made in your applicationwhen you close the file or exit Excel. If however changes are saved accidentally, use the 1HZ command inthe 3URMHFW menu to clear all data and then save the program. Changes made in the antenna database (ANT-DATA.XLS), the radio database or the feeder database should not be saved unless you deliberately havemade changes to the parameters stored in these databases.

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There are several changes both to the program it self , but also to the database files. The main changes are:n attenuation due to atmospheric gasesn cross-polar interferencen different receiver threshold for objectives based on G.821 and G.826.n new tune antenna dialog boxn both RFS and Andrew feeder data in the WG-databasen new performance objectives (national and custom)n export functionn rain rate databasen results both presented in percent of time and in time (hour:min.:sec.)



WEDIG 2.0c


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The workspace is a customised Microsoft Excel workbook. You will find additional commands in the menulist as described in Chapter 4. These commands are supported by macros written in Microsoft Visual BasicProgramming System. You may use all standard Excel commands and functions, but this freedom maycause unpredictable effects on the program’s behaviour. It is recommended to use the customisedcommands as far as possible in order to reduce the risk of malfunction. The statusbar at the bottom of thescreen will give the status of the current operation.

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The program itself is one Excel workbook, but equipment parameters used in the program are located inseparate workbooks defined as equipment databases. These databases are automatically opened at programstart-up.

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The WEDIG20.XLS workbook contains several sheets. There are four types of sheets:

• Sheets where information is entered and displayed (Paths and Info sheets).• Sheets where information is displayed only (Systems, Equipment and Single sheets).• Visual basic macro modules• Dialog box definitions

The user will normally only enter data in the first category of sheets. It is also possible to modify the othertypes of sheets, and an overview is given in chapter 7.1, Workbook structure.

Only the three information sheets (Paths, Systems and Info) are saved using the 3URMHFW�6DYH�command. Ifchanges are made in other sheets in the workbook (for example modification of the prediction modelfunctions), WEDIG20.XLS must be saved (please make a back-up of the original program first).

3.1.1 Paths sheet

The 3DWKV sheet contains all path parameters for your radio relay system. The path parameters are arrangedin a spreadsheet rows and columns manner. One path is defined in one row with totally 130 columns. Noneof the columns should ever be deleted, but they may be hidden in order to get a display of the wantedparameters. The first row has a colour-code for each group of parameters. These colours help identifyingthe different groups more rapidly. The second row is the column headings. Additional information isavailable by selecting the 6KRZ�,QIR�:LQGRZ�EXWWRQ (or the 9LHZ�,QIR�:LQGRZ check box in 2SWLRQVmenu). A short description like Figure 1a is displayed for each column heading. In Excel the informationis displayed automatically when the cursor is placed in the column heading cell if the Note Indicator ischecked in 7RROVÂ2SWLRQV�dialog box. A typical info-box is shown in Figure 1b.



WEDIG 2.0c


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3.1.2 Systems sheet

The 6\VWHPV sheet contains the predicted performance for radio relay systems of one or more paths. Alldata in this sheet is linked to the paths sheet. Any changes made in the paths sheet is thus reflected in thesystems sheet. The 6\VWHPV sheet is a read-only sheet where no changes should be made manually.

This sheet has a similar set-up as the paths sheet, but only columns relevant to the system performance areincluded.

3.1.3 Info sheet

The ,QIR sheet contains relevant project information as defined in Figure 3. Parameters are entered in thissheet using the Project Info command. Comments may also be entered in the text box (main body of the,QIR sheet). The second page contains an overview of ITU-R high grade objectives. See also 4.1.6 Info.

3.1.4 Rain sheet

The rain sheet contains regression coefficients for calculation of rain attenuation. The coefficients are basedon Table 4, using an interpolation technique to achieve coefficients in 100 MHz steps for the frequencyrange from 1 to 40 GHz.

3.1.5 Functions sheet

The functions described in the prediction model (chapter 5) are defined in the functions sheet. It is possibleto make changes to these functions in order to adapt the program to different prediction models.

3.1.6 Single sheet



WEDIG 2.0c


A single page set-up is available for displaying or printing all parameters for individual paths (see 4.1.10.5and 4.1.11.3). The data in the sheet is updated when the sheet is activated.

3.1.7 Equipment sheet

Specifications for applied radio equipment and a summary of antenna types and feeder lengths used in theproject is available.

3.1.8 Workbook password

If permanent changes should be made to the program, the workbook password “WEDIG20” must be enteredwhen the program is opened. This will make the file save command available. It is strongly recommendedto make a backup copy of the original program first.

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The commands in the different menus are described in the order they appear in the pull-down menus. Thereare three application specific menus: Project, Paths and Systems. In addition you will find WEDIG20 Helpas a sub-entry in the bottom of the Excel Help menu. Context sensitive help is also included in allapplication specific dialog boxes.

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This menu contains all commands relevant to input/output operations, including outputs to screen (View).

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View Customize PathsCustomize SystemsCustomize SinglePro-rata ChartAbsolute ChartVariation ChartsPathsSelected PathSystemsInfoEquipmentRadio databaseAntenna databaseFeeder databaseEnable menus

Print Project Paths... Selected Path... All Paths Separately Systems... Info... Equipment... Reset page set-ups

Project New Open... Save Save As... Export to file Info... Objectives… Preferences… View Print



WEDIG 2.0c


4.1.1 New

Starts a new project by clearing all paths and systems in the worksheet. The formulas are maintained. Awarning dialog box is displayed, and the command must be confirmed by the user before the worksheet iscleared. Any existing project in the program should be saved before New is executed.

4.1.2 Open

Projects that are saved previously may be opened using this command. All data in the worksheet will besubstituted by the loaded data, and a warning dialog box is displayed before the data is actually loaded.Both path and system data, as well as project information, will be loaded, and the custom view is updatedaccording to set-up in the loaded file. The standard Excel 2SHQ�)LOH dialog box is displayed in order toselect the wanted file, and both Find File and Network functions are available. If the selected file has anincorrect file format the loading command is aborted.

If the selected file is calculated using a previous version (only version 1.1) of the prediction model, the fileis converted to the current model. It is likely that the radio in the old file is not found in the new radiodatabase since the radio names has changed. The radio should be chosen manually.

4.1.3 Save

Path, system and info data is saved using the same filename and project information as defined in the Infosheet. Only the 3DWKV, 6\VWHPV and ,QIR sheets are saved by this command. If changes are made in othersheets, the program file (WEDIG20.XLS) must be saved as well (see 7.1 Workbook structure). The cellscontent is saved by values, not as formulas. If the saved project is opened as a stand-alone workbook,performance data is QRW updated if data is changed. The performance of systems defined in your project willbe updated automatically when the project is opened again. Warning for replacement of existing files withthe same name is not displayed.

4.1.4 Save As

Path, system and info data is saved using filename and file location defined by the user in the projectinformation dialog box (Figure 3). Project information is updated in all page set-ups during save operation.(See also 4.1.6 Info.) Warning for replacement of existing files with the same name is displayed.

4.1.5 Export to fileThis function exports the data to a new Excel file such the prediction calculations can be view for userswithout the WEDIG program. The functions and formulas are not exported, only the values. In additions tothe sheets Paths, Systems and Info is also the data for each path in the Single sheet exported to the sheetDetails in the new file.

4.1.6 Info

The 3URMHFW� LQIRUPDWLRQ dialog box is displayed (Figure 3), showing the current project reference data.Click the 7RGD\ check box to update the date field. The data will be inserted in the ,QIR sheet. If a filereference includes a non-existing directory, this directory will be created when the project is saved. Use theTab-key to move to the next input field. Pressing enter will activate the selected button (usually equivalent



WEDIG 2.0c


to pressing the OK button). If no directory is specified in the File reference box, the project will be saved inthe default directory used by Excel.

Automatic log reference and file reference is activated by checking the $XWR check-box. The program willidentify the first vacant project number in your project directory and suggest a new log reference and filelocation

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The information entered in the project information dialog box (Figure 3) is entered in the Info sheet in astandard Nera document set-up. The header looks like indicated in Figure 4. Select the main text-box toenter general comments added to your project information.

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99.02.03 A 99/P045Prepared by Subject Responsible Approved by

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Test of program

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WEDIG 2.0c


4.1.7 Project objectives

The predicted performance is compared to the performance objectives in columns showing the path orsystem performance as a percentage of the objective. 100% represents a performance exactly at the limit ofthe objective, 10% represents a system ten times better than the objective.

The objective may be changed by using the Project-Objectives command. The objectives are selected usingoption buttons in the dialog box shown in Figure 5. The heading of the respective columns will changeautomatically. The following objectives may be selected:

Objectives based on ITU-T Rec. G.821 [2]

High grade objectives based on ITU-R Rec. 634 [12] and 695 [13]Medium grade objectives based on ITU-R Rec. 696 [6] and Rep. 1052 [7]Local grade objectives based on ITU-R Rec. 697 [8] and Rep. 1053 [9]Custom objectives where the availability is entered.

Objectives based on ITU-T Rec. G.826 [3]

International portion (terminating and intermediate country) based on ITU-R Rec. F.1092 [19]National portion (long, short and access) based on ITU-R Rec. F.1189 [20]Custom objectives where the availability is entered.See also 5.9.

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WEDIG 2.0c


4.1.8 Project preferences

The project preferences command is used to change the references to file names and locations for thedatabases and external files used by WEDIG. Initially these files are installed in the same directory as theWEDIG program, but the program may interact with other files located on servers, etc. The dialog boxshown in Figure 6 is displayed. Press the default button to return to the standard file names and locations.The currently used files and databases will be closed, and the new files will be opened when OK is pressed.Make sure that the new files have the correct data format according to selected application (e.g. the radiodatabase file has the same database structure as the standard NL-data.xls file). Please observe that thelocation of the Userdata.xls file should not be changed.In the “Single view” area can a customized selection of the data on the single-sheet be enabled. The wantedparameters may be selected by clicking the check-boxes. The selections are stored in the Userdata.xls file.

The name of the user, organization and project responsible may also be changed.

See also chapter 7 for more details on configuration and database structures.

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WEDIG 2.0c


4.1.9 View

This menu has several sub-menus that are used to view the wantedpart of the workbook. When you click on the 9LHZ field, the sub-menu is displayed.

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This command works on the paths-sheet only. The entire 3DWKVsheet consists 130 columns. All these columns cannot be displayedsimultaneously on the screen, and many of the columns arenormally of no interest to the user. To enable a customizedselection of the columns, the wanted parameters may be selected byclicking the check-boxes in Figure 7.

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4.1.9.2 Customize Systems

This command works on the systems-sheet only. The entire 6\VWHPV sheet consists 23 columns. It is notalways convenient to display all these columns simultaneously on the screen. To enable a customizedselection of the columns, the wanted parameters may be selected by clicking the check-boxes in Figure 8.

View Customize PathsCustomize SystemsCustomize SinglePro-rata ChartAbsolute ChartVariation ChartsPathsSelected PathSystemsInfoEquipmentRadio databaseAntenna databaseFeeder databaseEnable menus



WEDIG 2.0c


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WEDIG 2.0c


4.1.10 Customize SingleThis command works on the single-sheet only. It is not always convenient to display the objectives and thepresent of objective data. To enable a customized selection of the data on the single-sheet, the wantedparameters may be selected by clicking the check-boxes in Figure 9.

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The predicted system performance is related to the down-scaled ITU-R objectives as defined in the3URMHFW⋅REMHFWLYHV menu. If the predicted performance exactly matches the objective, the performance isdefined as 100% of the objective. The 3UR�UDWD�&KDUW shows graphically using bars how the different pathsin the system get out of it compared to the ITU-R objective. Both outage due to multipath fading and outagedue to precipitation is shown. The 3UR�UDWD�&KDUW is toggled on and off by checking/unchecking the menu-field. The chart is automatically updated if changes are made in the worksheet while the chart is displayed.The 3UR�UDWD�&KDUW and the $EVROXWH�&KDUW may not be visible at the same time. (See also 4.1.10.2 Viewabsolute chart.)

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The $EVROXWH�&KDUW�shows graphically how much each path contributes to the overall system performance.The chart shows the predicted performance as the percentage of time that the BER (Bit-Error-Ratio) exceedsthe SES threshold. Both outage due to multipath fading and outage due to precipitation is shown. Theabsolute chart is toggled on and off by checking/unchecking the menu-field. The chart is automaticallyupdated if changes are made in the worksheet while the chart is displayed. The $EVROXWH�&KDUW and the3UR�UDWD�&KDUW�may not be visible at the same time. (See also 4.1.10.3 View variation charts)



WEDIG 2.0c


�� 9LHZ�YDULDWLRQ�FKDUWV

The 9DULDWLRQ�&KDUWV�show graphically the effect of net path loss variations. The path performance andunavailability due to rain are shown with original path data as well as with 1, 2 and 3 dB additional loss.This command may be used to check the paths’ sensitivity to net path loss variations. These charts are notautomatically updated if changes are made in the worksheet while the chart is displayed.

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Activates the 3DWKV worksheet. Equivalent to pressing the Paths tab.

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Shows all relevant data for the selected path in a single page set-up. Activates the 6LQJOH�worksheet. Theparameters are automatically updated when the menu command is used, but also when the Single tab ispressed to activate the sheet.

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Activates the 6\VWHPV worksheet. Equivalent to pressing the Systems tab.



WEDIG 2.0c


�� 9LHZ�LQIR

Activates the ,QIR worksheet. Equivalent to pressing the Info tab. (See also 4.1.6.)

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Displays a summary sheet of radio specifications for applied radio types as well as antenna types andantenna feeders used in the project. The sheet is automatically updated when the menu command is used,but not if the sheet tab is used to activate the Equipment sheet.

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Activates the Nera radio database workbook (NL-data.xls). The radio in the selected path is selected bydefault.

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Activates the Nera antenna database workbook. All available antennas in the frequency band for theselected path is displayed by default. Use the filter selection tools to display antennas in different frequencybands or for selection of only specific antenna types.

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Activates the feeder database workbook (WG-data.xls). The feeder type used for the selected path isselected by default.

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Only the relevant menus are enable at program start-up in order to limit the possibilities of user errors. The(QDEOH�PHQXV command allows the user to manually enable all menus if required.

4.1.11 Print

This menu has several sub-menus that are used to print the wanted partof the workbook. When you click on the 3ULQW field, the sub-menu isdisplayed as shown. The charts may be printed by double-clicking themand then select the File - Print command or press the printer button inthe toolbar. Make sure the project information is set properly beforeyou print in order to get the correct references on your hard-copy.

Print Project Paths... Selected Path... All Paths Separately Systems... Info... Equipment... Reset page set-ups



WEDIG 2.0c


�� 3ULQW�SURMHFW

In order to print all sheets for the project this command is available. The following sheets will be printed inorder without prompts:

Info The project information sheetSystems Defined systems in project (if any)Equipment Summary of radios, antennas and feedersPaths All paths in project

�� 3ULQW�SDWKV

Prints all paths defined in the 3DWKV worksheet. Only the visible columns will be printed. The path nameand the column headings will be printed on every page to identify the parameters. When the print set-up hasbeen arranged, the standard Excel print dialog box is displayed. Press 2. to get a paper copy, or use any ofthe options available in the dialog box (like Print Preview, Printer Set-up, etc.).

�� 3ULQW�VHOHFWHG�SDWK

Prints the selected path in a single page set-up. (See also 4.1.10.5 View selected path and 4.1.11.2 Printpaths.)

�� 3ULQW�DOO�SDWKV�VHSDUDWHO\

Prints all paths defined in the 3DWKV worksheet in a single page set-up (one page per path). This may be auseful print mode for small systems of only a few radio relay paths. (See also 4.1.10.5 View selected path,4.1.11.2 Print paths and 4.1.11.3 Print selected path.)

�� 3ULQW�V\VWHPV

Prints all defined systems in the 6\VWHPV�worksheet. (See also 4.1.11.2 Print paths.)

�� 3ULQW�LQIR

Print the project info as given in the Info sheet. (See also 4.1.6.)



WEDIG 2.0c


�� 3ULQW�HTXLSPHQW

Prints a summary sheet of radio specifications for applied radio types as well as antenna types and antennafeeders used in the project. The sheet is automatically updated when the Project/Print/Equipment commandis used, but not if the File/Print command is used to print the Equipment sheet.

�� 5HVHW�SDJH�VHW�XSV

This command resets all page set-ups to the default values (as they are configured at program start).

�� 3DWKV

This menu contains all commands relevant to path parameters.

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4.2.1 Add New path

Use this command to enter data for a new path in your system. The path data will be added after the lastexisting path in your system (bottom row). Data for site B in the last existing path will be default data forboth site A and site B in the new path. This will reduce the typing work in most situations. The dialog boxshown in Figure 12 will show up.

A short description of the path parameters is given in Table 1. A more detailed description of the predictionmodel is given in chapter 5.

Tune Antennas... Radio… Threshold degradation Diversity... Feeder length... Feeder type... Path length...

Update This path only All parameters Radio only Feeder only Rain only

Paths Add new... Add selected ... Insert... Edit... Delete Move Tune Update



WEDIG 2.0c


3DUDPHWHU 'HVFULSWLRQ 8QLW1DPH Name of site none3RVLWLRQ Site geographical co-ordinates degrees/DWLWXGH Site latitude (leading zeros must be included; 06.04.09) degrees/RQJLWXGH Site longitude (leading zeros must be included) degrees6LWH�OHYHO Site level above mean sea level meters)HHGHU�OHQJWK Antenna feeder length meters$QWHQQD�KHLJKW Antenna height above ground level meters$QWHQQD�W\SH Description of antenna type none$QWHQQD�JDLQ Antenna gain for selected antenna dB3DWK�W\SH Classification of the path type (see Path type),QODQG Inland links are those in which either the entire path profile is

above 100 m altitude (with respect to mean sea level) or beyond50 km from the nearest coastline, or in which part or all of thepath profile is below 100 m altitude for a link entirely within 50km of the coastline, but there is an intervening height of landhigher than 100 m between this part of the link and the coastline.Links passing over a river or a small lake should normally beclassed as passing over land. See Figure 13

,QODQG��PDQ\ODNHV

Regions (not otherwise in coastal areas) in which there are manylakes over a fairly large area are believed to behave somewhatlike coastal areas. The region of lakes in southern Finlandprovides the best known example.

&RDVWDO��PHGLXP�VL]H�RI�ZDWHU

The size of a body of water can be chosen on the basis of severalknown examples: Medium-sized bodies of water include the Bayof Fundy (east coast of Canada) and the Strait of Georgia (westcoast of Canada), the Gulf of Finland, and other bodies of waterof similar size. See Figure 13

&RDVWDO��ODUJH�VL]HRI�ZDWHU

The size of a body of water can be chosen on the basis of severalknown examples: Large bodies of water include the EnglishChannel, the North Sea, the larger reaches of the Baltic andMediterranean Seas, Hudson Strait, and other bodies of water ofsimilar size or larger. See Figure 13

&RDVWDO��XQFHUWDLQVL]H�RI�ZDWHU

In cases of uncertainty as to whether the size of body of watershould be classed as medium or large. See Figure 13

7HUUDLQ�W\SH Classification of the terrain type.3ODLQV The path is in a largely plain area.+LOOV The path is in a largely hilly area.0RXQWDLQV The path is in a largely mountainous area with lower-antenna

altitude more than 700m above the mean sea level.8QNQRZQ The terrain is not known.3DWK�OHQJWK Distance between sites (optionally automatic) km$XWR Check this to activate automatic calculation of path length from

site positions (if site positions are given)3/�IDFWRU Percentage of time gradient ≤ -100 N/km %5DLQ�UDWH Rain intensity exceeded for 0.01% of the time mm/h:DWHU�YDSRXU Water vapour density g/m3

7HPSHUDWXUH Temperature in the surroundings. °C



WEDIG 2.0c


$XWR Check this to activate automatic lookup of the rain rate in therainfall intensity database file. The co-ordinates are input data forthis lookup (if site positions are given). The rain rate for both sites iscalculated, the largest rain rate is returned.

5DWLR�LQ�FRDVWDODUHD

The fraction of the path profile below 100 m altitude above themean level of the body of water in question and within 50 km of thecoastline, but without an intervening height of land above 100 maltitude. See Figure 14

%

5DGLR�W\SH Code referring to radio in radio sheet2WKHU�ORVV Addition loss (radome loss, diffraction loss, etc.) dB3ODQH�SDVVLYHUHSHDWHU

Selected if a plane reflector is used at passive repeater

%DFN�SDVVLYHUHSHDWHU

Selected if back-to-back antennas are used at passive repeater

'LVWDQFH��!�$ Distance from site A to passive repeater km$UHD�SODQH Geometrical area of plane reflector m2

$QJOH Reflection angle at plane reflector degrees

*DLQ�EDFN Net gain of back-to-back antennas repeater dB7H[W A short description of the repeater site. For information only3DWK�SRVLWLRQ Select geographical area (optionally automatic)/DWLWXGH Approximate latitude for selected path (optionally automatic) degree

s$XWR Check auto to activate automatic calculation of path position from

site positions (if site positions are given)

7DEOH��3DWK�SDUDPHWHUV



WEDIG 2.0c


)LJXUH��3DWK�SDUDPHWHUV�GLDORJ�ER[

Pressing the Help-button will open a help-file containing the information given in this user manual. Therelevant help topic will be selected automatically (context sensitive help). This applies to all applicationdefined dialog boxes in the program.

Use the move buttons to move between the paths.



WEDIG 2.0c


�� 6LWH�SDUDPHWHUV

Name: Enter the name of the site using any combination of characters, numbers and symbols.The site name is used to identify the paths and systems.

Position: The site positions may be given as geographical co-ordinates (latitude and longitude)in the format degrees, minutes, seconds (dd.mmss). Leading zeros should be included(06.0409 is 6 degrees, 4 minutes and 6 seconds. Press the appropriate option button toselect North/South and East/West.

Site level: Site level in meters above mean sea level is used to calculate the path inclination.This inclination is an input parameter to the prediction model (larger inclination ⇒less fading activity).

Feeder length: Antenna feeder length in meters. This value is used to calculate the feeder loss fromradio to antenna. The specific feeder loss (dB/100m) is automatically retrieved fromthe Feeder loss database sheet when the radio type is selected.

Antenna height: Antenna height in meters above ground level. This parameter is used to calculate theantenna height above sea level which in turn gives the path inclination. The parameteris also vital information to the installation team.

Antenna type: Used to identify the antenna type. This parameter is also used to create a summary ofused antennas in the total system. Use the Tune antenna menu to pick antenna typefrom Nera data base (see 4.2.7.1). The antenna type will be entered as Nera antennacode.

Antenna gain: Net antenna gain for specified antenna type in dB. Used to calculate the fadingmargin of the path.

Diversity help: Press the Diversity help button to quickly add space diversity antennas to the givenpath. The dialog box in Figure 20 will appear. Check none to remove existing spacediversity antenna. Select above existing to move main antenna up and place spacediversity antenna at the original height of the main antenna. Select below existing toplace diversity antenna below original height of main antenna. The vertical antennaseparation is given in meters. The Apply button is disabled when this dialog box iscalled from the path parameters dialog box. Hybrid space diversity (three antennasonly) may be selected by checking the hybrid diversity field. Check site A or site B toplace the diversity antenna at the site you want.

Feeder help: Press the Feeder help button to automatically set the feeder length equal to the antennaheight plus a horizontal feeder length as specified in the dialog box in Figure 21. Thefeeder lengths are not dynamically adjusted if the antenna heights are changed.Dynamic updating is achieved by using the Feeder length command in the Paths Tunemenu (See also 4.2.7.5).



WEDIG 2.0c


�� 3DWK�SDUDPHWHUV

Path type : Select correct path type according to the classification below.

Inland: Inland links are those in which either the entire path profile is above 100 m altitude(with respect to mean sea level) or beyond 50 km from the nearest coastline, or inwhich part or all of the path profile is below 100 m altitude for a link entirely within50 km of the coastline, but there is an intervening height of land higher than 100 mbetween this part of the link and the coastline. Links passing over a river or a smalllake should normally be classed as passing over land. See Figure 13

Inland, many lakes: Regions (not otherwise in coastal areas) in which there are many lakes over a fairlylarge area are believed to behave somewhat like coastal areas. The region of lakes insouthern Finland provides the best known example. See Figure 13

Coastal, medium-size of water

The size of a body of water can be chosen on the basis of several known examples:Medium-sized bodies of water include the Bay of Fundy (east coast of Canada) andthe Strait of Georgia (west coast of Canada), the Gulf of Finland, and other bodies ofwater of similar size. See Figure 13

Coastal, large sizeof water

The size of a body of water can be chosen on the basis of several known examples:Large bodies of water include the English Channel, the North Sea, the larger reachesof the Baltic and Mediterranean Seas, Hudson Strait, and other bodies of water ofsimilar size or larger. See Figure 13

Coastal, uncertainsize of water

In cases of uncertainty as to whether the size of body of water should be classed asmedium or large. See Figure 13

Terrain type Classification of the terrain type

Plains The path is in a largely plain area.

Mountains The path is in a largely mountainous area with lower-antenna altitude more than 700mabove the mean sea level.

Unknown The terrain is not known.Path length: Distance between site A and site B given in km.

PL-factor: The percentage of time PL that the average refractivity gradient in the lowest 100m ofthe atmosphere is less than -100 N units/km (see maps in 7.5.1). Used to determinethe geoclimatic factor.

Rain rate: Rain intensity exceeded for 0.01% of the time (1 minute integration time) (see maps in7.5.2). Use to determine the outage probability due to rain. The rain coefficients givenin the 5DLQ sheet are automatically updated according to the radio frequency.

Water vapour Water vapour density. ( see map in 7.5.3 )Temperature: Temperature in the surroundings.Ratio in coastalarea

The fraction of the path profile below 100 m altitude above the mean level of the bodyof water in question and within 50 km of the coastline, but without an interveningheight of land above 100 m altitude. See Figure 14

Radio type: The label on the macro button is the code of the selected radio. Pressing the Radio



WEDIG 2.0c


type button gives access to the radio type dialog box in Figure 15. Select the wantedradio and press OK.

Other loss: Additional loss may be entered in dB. This loss may be radome losses, diffractionloss, reduced output power, etc.

Passive repeater:

None: Used to remove definition of passive repeater (default).

Plane: Selected if a plane reflector is used at the passive repeater.

Back: Selected if back-to-back antennas are used at the passive repeater.

Distance -> A: The distance from Site A to the passive repeater in km. This distance should be keptas small as possible or as close to the total path length as possible in order to make oneof the legs as short as possible. Placing the passive repeater halfway between Site Aand B results in minimum fading margin.

Area plane: Geometrical area of the plane reflector in square meters. This field is only enabled ifa plane reflector type is selected. This parameter is used to calculate the gain of theplane reflector as given in equation.

Angle: Reflection angle at the plane reflector as indicated in figure 27. This field is onlyenabled if a plane reflector type is selected. Used to calculate the gain of the planereflector.

Gain back: Net gain of the back-to-back antennas repeater in dB. This field is disabled if a planereflector is selected, but the calculated gain of the plane reflector will be shown (noteditable) in this field.

Text: A short description of the repeater site. For information onlyPath position: Geographical area of the path. This information is used to determine the CLon

coefficient used in calculation of the geoclimatic factor.

Latitude: Approximate latitude of the path location. This information is used to determine theCLat coefficient used in calculation of the geoclimatic factor.



WEDIG 2.0c


/DUJH�VL]H��RI��ZDWHU�

English Channel, theNorth Sea, the largerreaches of the Baltic andMediterranean Sea,Hudson Strait, and otherbodies of similar size orlarger.

0HGLXP�VL]H��RI��ZDWHU�

The Bay of Fundy (eastcoast of Canada) and theStrait of Georgia (westcoast of Canada), theGulf of Finland, andother bodies of similarsize.

Terrain height 100mabove mean sea level

Distance > 0 km

Distance > 50 km

Terrain height less than 100mabove mean sea level

Entire path profileabove 100m altitude

Distance > 0 km

,QODQG

,QODQG

,QODQG

Distance < 50 km

Terrain heightless than 100mabove mean sealevel

&RVWDO��PHGLXPRU�ODUJH�VL]H�RIZDWHU

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0 km 10 km7 km

0 m a.s.l.

100 m a.s.l.

Ratio of path in coastal region = 70%

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WEDIG 2.0c


)LJXUH��5DGLR�W\SH�GLDORJ�ER[

4.2.2 Add Selected path

This command is similar to the Add New command, but in this case the default site and path parameters willbe identical to the parameters of the selected path. This command is useful if the new path is a spur-link.The new path will be added at the bottom of the list.

4.2.3 Insert

This command may be used if you want to insert a path somewhere in your list of existing paths. Defaultparameters for site A will equal site B for the path above the selected path, and parameters for site B willequal site A for the selected path. The new path will be inserted above the selected path.

4.2.4 Edit path

This command is used if you want to edit some path parameters in your list of existing paths. If the radiotype is changed without using this command (editing directly in cells), remember to run the Updatecommand in the Paths menu.



WEDIG 2.0c


4.2.5 Delete path

The selected path will be permanently removed from the list. Confirmation is required.

4.2.6 Move pathThe selected path will be moved to the row before the selected path in the dialog box. See Figure 16.

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4.2.7 Tune

This menu has several sub-menus that are used to tune pathparameters. When you click on the tune-field, the sub-menu isdisplayed.

�� 7XQH�DQWHQQDV

In order to match the performance objectives, tuning of the antennas is essential. This command enableseasy tuning of the antennas in order to meet the objectives.

Tune Antennas... Radio… Threshold degradation Diversity... Feeder length... Feeder type... Path length...



WEDIG 2.0c


)LJXUH��7XQH�DQWHQQDV�GLDORJ�ER[

Press the &DOFXODWH button to see the effect of changes in the antenna gain. Press 2. to use the selectedantenna parameters and close the dialog box. Press &DQFHO to close the dialog box without affecting theantenna parameters for the selected path. If you want to change both antennas simultaneously, use the autocouple function to reduce typing.

Press the 2SWLPLVH� VHOHFWHG button to find the minimum needed antenna gain to match the ITU-Robjectives. The antenna gain is tuned to match the path pro-rata objective with a margin as given in theoptimize criteria performance limit. A limitation in the fading margin may be added to the optimisationcriteria. If the frequency is above ∼ 10 GHz the wanted polarization should be selected in order todetermine antenna gain based on outage due to rain. Press 2SWLPLVH�DOO to repeat the optimisation for allpaths in your system. The path being optimised is shown in the statusbar at the bottom of the screen. Keepthe Esc-button pressed a few seconds to stop the optimisation. If the required antenna gain exceeds 50 dB,the antenna type is set to “failed” and the antenna gain equal to 50 dB. If the required antenna gain is lessthan 20 dB, the antenna type is set to “limited” and the antenna gain is set to 20 dB.

Press $SSO\� VHOHFWHG� �!1H[W�SDWK to tune antennas for the next path in your system without closing thedialog box. The Cancel button will only cancel changes in the last selected path when the Next path buttonis used.



WEDIG 2.0c


The 6DPH�DV�SUHYLRXV command button may be used to apply the same antenna type to the selected path aswas used for the previous path in your system. This command increases the tuning speed in systems wherethe same antenna types can be used for most of the paths. The standard Excel copy and paste commandsmay also be used to apply the same parameters to several paths in your system. The Replace function is alsoconvenient to make global changes to your system without using the edit path command.

Use the 6ZDS�DQWHQQDV�button to exchange the antennas from site A to site B and vice versa.

The 'LYHUVLW\� button is equivalent to selecting the Tune Diversity command, and a short-cut to changediversity parameters if tuning of antennas is insufficient to make the path match the performance objectives.

If the 8VH�1HUD�DQWHQQDV box is checked, the Nera antenna specifications group will be enabled and all theavailable antennas in the band will be shown in the list box. The available antennas in the list box can belimited by selecting the type of performance.

The antennas may be selected manually from the Nera antenna data base by first selecting antenna in theavailable antennas list box and then pressing the <- button beside the antenna data for the wanted site.



WEDIG 2.0c


�� 7XQH�UDGLR

The radio type or radio parameters may be changed using this command. All radio parameters are stored ina separate workbook as a Nera radio database.

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Press the 6HOHFW� UDGLR button in order to pick any radio type defined in the radio database by typing theradio code or by selecting the capacity, frequency and configuration. The dialog box shown in Figure 15will be displayed.

Press the $SSO\�WR�VHOHFWHG�SDWK button to update radio parameters for the selected path according to thecontents of the dialog box.

Press the $SSO\�WR�VHOHFWHG�UDGLR button to change radio parameters for all paths using the selected radiotype.

Press the 6WRUH� FKDQJHV� LQ�GDWDEDVH button to make permanent changes to the radio database. You areasked to confirm saving of changes in the radio database NL-DATA.XLS when you close the program.

A short description of the radio parameters is given in Table 2.



WEDIG 2.0c


Radio family: Radio family. (eg. CelLink, NL290,CityLink)Radio type: Nera radio-relay code. (example: NL290-1)Lower frequency: Lower frequency of radio frequency band in GHz.Centre frequency: Centre frequency of radio frequency band in GHz.Upper frequency: Upper frequency of radio frequency band in GHz.Data rate: Transmission capacity in Mb/s.Configuration: Radio channel arrangement.

HSB: Hot standby, 1+0, 1+1 and so on.BER 1 Bit error ratio (Eg. 1E-3)BER 2 Block error ratio (Eg. 5E-5)BER 3 Bit error ratio (Eg. 1E-6)Threshold level 1: Receiver threshold level 1 in point B given in dBm.Threshold level 2: Receiver threshold level 2 in point B given in dBm.Threshold level 3: Receiver threshold level 3 in point B given in dBm.C0/I 1: Carrier-to-Interference 1 in dB. Only for radios with co-channel.C0/I 2: Carrier-to-Interference 2 in dB. Only for radios with co-channel.C0/I 3: Carrier-to-Interference 3 in dB. Only for radios with co-channel.Signature 1: Receiver signature factor for threshold 1 given in /GHz.Signature 2: Receiver signature factor for threshold 2 given in /GHz.Signature 3: Receiver signature factor for threshold 3 given in /GHz.Calculate Check this to calculate the signature factor from the data in the “Data

for calculating signature factor” area.Tx power: Transmitter output power referred to point B’ given in dBm.High power: Additional transmitter power when high power is optional in dBBranching loss: Total branching loss point B to B’ in dB (excluding RF-filters).Freq. Div.: Minimum frequency separation regular to protection channel. Used to

calculate frequency diversity improvement.Modulation: Modulation method.XPIC.: Cross-polarized improvement factor in dB. Only for radios with co-

channel.

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WEDIG 2.0c


�� 7XQH�7KUHVKROG�GHJUDGDWLRQ

The receiver threshold can be degraded due to interference. The given threshold degradation will reduce thenominal threshold and therefore also the fading margin of the hop.

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The diversity parameters are altered by selecting this command. You may include or remove frequencydiversity or space diversity, or you could change the diversity parameters like system configuration,frequency separation and antenna separation.

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The system configuration may be changed by choosing 1+0 system or Hot Standby configuration (nofrequency diversity) or by selecting a redundant n+1 system. In the latter case the frequency separation maybe set manually to override the default value defined in the radio database. This can be done by changingthe “Freq.div.” parameter in the radio parameters dialog box, see Figure 18.

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Space diversity antennas may be added easily using this command. The dialog box in Figure 20 will appear.

None: Space diversity antennas are removed (if existing). Select the Above existing field if you want themain antenna to be lowered by the distance defined as vertical antenna separation.

Above existing: The existing main antennas will be moved upwards and the diversity antennas will beplaced at the original height of the main antennas on both sites.

Below existing: The diversity antennas will be placed below the existing main antennas.

Vertical antenna separation gives the distance between main and space diversity antennas. Press Apply tosee the effect of space diversity to the path performance.



WEDIG 2.0c


Hybrid diversity: Check this field to add diversity antenna on one site only. Select site A or site B in orderto place the diversity antenna on the wanted site.

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The exact feeder lengths are often unknown during initial planning. If the antenna heights are known, thefeeder lengths may be automatically set equal to the antenna height + a given horizontal feeder length. Thedialog box in Figure 21 shows the principle.

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WEDIG 2.0c


Press the $OO�SDWKV button to apply the given horizontal feeder length to all paths in your system.

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WEDIG automatically selects the optimum feeder type based on the selected radio type and the selected WGproducer. If however the user wants to override this selection, the feeder type may be selected manually bythis command. A list of all feeder types available for the selected frequency band in the Feeder sheet islisted in the dialog box. Select the wanted feeder type and press OK to change feeder type for selected pathor press $OO�SDWKV to apply the selected feeder type for all paths operating in the same frequency band as theselected path.

The wave guide producers that WEDIG are selecting data from can be set in the list box “WG producer”.

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The maximum usable path length that matches the tuning criteria given in Figure 23 may be found using thisTune Path length command. This function is useful in the initial planning stage where the maximum usablepath lengths with various antennas and system configurations is evaluated.

Start by adding one typical path in the area of interest. Make a number of copies of the corresponding rowand vary any parameters (antenna diameter, diversity type, radio type (radio frequency), etc.). Run theUpdate all command before the path length tuning is started. Press the Tune all button in Figure 23 andcreate a chart showing the maximum path length as a function of the varying parameters. Two examples areshown in Figure 24.



WEDIG 2.0c


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4.2.8 Update

Radio data, feeder data (see 7.1 Workbook structure) and raincoefficients (see 5.8 Unavailability due to rain) are given in database sheets in the workbook. This structure makes updating of datamore convenient in most cases. If changes are made manually(without using menu commands), the parameters given in these database sheets must be updated using one of the update commandsdescribed here.

This menu has several sub-menus. When you click on the update-field, the sub-menu is displayed as shown.

�� 8SGDWH�WKLV�SDWK�RQO\Only the selected path’s parameters will be updated. The radio code, radio family, capacity, modulation,configuration, high power option, lower and upper frequencies and the XPIC parameters are used to identifythe radio and feeder data as well as rain coefficients. These data are copied from the data sheets Radio,Feeder Loss and Rain. If the radio type or frequency has been changed manually (without using menucommands) this update command should be executed in order to get correct parameters for the calculation.

Update This path only All parameters Radio only Feeder only



WEDIG 2.0c


�� 8SGDWH�DOO�SDUDPHWHUV

All parameters for all path in your system will be updated by this command. Do not use this command ifany of the radio or feeder data has been changed intentionally for any of the paths. These changes will bereplaced by the data given in the sheets Radio, Feeder Loss and Rain when this command is executed. Thiscommand is useful in order to update all parameters after global changes of radio codes using standard Excelcommands (like Replace).

�� 8SGDWH�UDGLR�RQO\

This command updates radio parameters for all paths in the system. The feeder data and rain coefficientsare not updated. Observe that changes made manually to feeder data may cause inconsistency with theupdated radio parameters.

�� 8SGDWH�IHHGHU�RQO\

The feeder data (type and specific loss) will be updated according to the given frequency for all paths in thesystem. Feeder types selected in the 7XQH�)HHGHU�7\SH�menu will be discarded.

�� 6\VWHPV

This menu contains all commands relevant to definition of systems. A system is oneor several radio relay paths for which the total performance is calculated. The data forthe systems are automatically updated according to changes in the corresponding pathparameters. The performance objectives are defined for systems rather thanindividual paths. Define your systems using the $GG� V\VWHP command in order toverify the total system performance. The system sheet may also be used to comparethe performance of alternative routes from one site to another.

4.3.1 Clear all systems

This command clears all defined systems in the Systems sheet.

4.3.2 Add system

A new system is added at the bottom of the system list. The system is defined by selecting first and last siteusing the dialog box in Figure 25. If alternative routes are possible, alternative sites are given in nodalpoint, and the user must select the wanted routing.

Systems Clear all Add... Insert... Delete...



WEDIG 2.0c


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4.3.3 Insert system

Similar to Add New System, but the new system will be inserted above the selected system.

4.3.4 Delete system

The selected system will be permanently removed. Confirmation is required. The corresponding paths inthe “Paths”-sheet are not deleted by this command.



WEDIG 2.0c


�� 3UHGLFWLRQ�PRGHO

The prediction model used in WEDIG ver. 2.0 is based on ITU-R recommendation 530 [17].

�� 3RZHU�EXGJHW

In order to estimate the performance of a radio link system, a link power budget has to be prepared. Thedifference between nominal input level and the radio threshold level, the fading margin, is the main inputparameter in the performance prediction model.

�� )UHH�VSDFH�ORVV

The receiver power at the receiver is proportional to

�� Pf d

∝⋅1

2 2

This relation gives the free space formula (expressed in dB)

�� / G% G IIV( ) . log ( )= + ⋅ ⋅92 45 20 10 [dB]

�� $WWHQXDWLRQ�GXH�WR�DWPRVSKHULF�JDVHVAt higher frequencies, above about 15GHz, the attenuation due to atmospheric gases will add to the totalpropagation loss of a radio relay path. The attenuation on a path is given by:

�� $ GD 2 :

= + ⋅( )γ γwhere

G - path length in km

γR - specific attenuation [dB/km] for dry air

γW - specific attenuation [dB/km] for water vapour

The attenuation due to dry air and water vapour can be estimated using the simplified algorithms given inITU-R Rec. P.676 [21] Section 5.3 are valid for frequencies below 57GHz.

�� ( )

γ2

W

SW

S W

S W

U

I U U I U UI U U=

++

− +

⋅ −7 27

0 351

7 5

57 2 4410

2 2 2 2 2 5

2 2 2 3.

.

.

.



WEDIG 2.0c


�� ( )

( ) ( )

γ

ρ

ρ:

W

W

S S W

W

S W

W

S W

S W

UU

U I U UU

I U U

U

I U U

I U U=⋅ + ⋅ + ⋅ +

− +

+− +

+− +

⋅

− − −

−

3 27 10 1 67 10 7 7 103 79

22 235 9 8111 73

183 31 1185

4 01

325153 10 44

10

2 37

42 2

2 2 2 2

2 4

. . ..

. ..

. .

.

. .

whereI - frequency in GHz

US = p/1013

UW = 288/(273+t)

S - pressure is set to 1013 hPa

W - temperature in C°

ρ - water vapour density in g/m3 . The figure in 7.5.3 from ITU-R Rec. P. 836 [22] gives theannual surface water vapour density.

�� /LQN�EXGJHW

Figure 26 shows a transmit/receive system that may be used as a simplified model of a radio link system. Ifthe transmitter output power is defined excluding the channel filter loss, this loss should be subtracted in thecalculations. The same applies at the receiver. The branching loss is defined as total branching loss for thehop. The difference between nominal input level and the receiver threshold level is known as the fadingmargin. This is a key parameter to the prediction model described in chapter 5.5.

The net path loss (13/) level for a normal path is given by:

�� 13/ G% / $ / / / * * /IV D I I E R

( ) = + + + + − − +1 2 1 2

and the received signal level is

�� 3 G%P 3 13/U W( ) = −

where3U� - received power in dBm

13/ - net path loss in dB

3W�� - transmitted power in dBm

*��*� - gain of antennas in dB over isotropic

/I��/I� - feeder loss in dB

/E - branching loss in dB (circulators, filters)



WEDIG 2.0c


$D - attenuation due to atmospheric gases

/R - other loss in dB (e.g. attenuators , degradation of threshold)

/IV�� - free space loss in dB

The difference between normal received signal level and the receiver threshold level is called the fadingmargin:

�� ) G% 3 3 /U 7KU 7KU 'HJ

( ) _= − −

where3U - normal received signal level in dBm

37KU - receiver threshold level in dBm

/7KUB'HJ - receiver threshold degradation due in interference in dB

This fading margin is a critical parameter in prediction of system performance.

Rx

Receiver threshold

Fading margin

feeder feeder

60

30

0

-30

-60

-90

)LJXUH��7UDQVPLW�UHFHLYH�V\VWHP



WEDIG 2.0c


CALCULATION EXAMPLE

3DUDPHWHU 9DOXH 8QLWTransmitter output power + 26.0 dBmFeeder loss transmitter 1.6 dBBranching loss (Tx/Rx) 1.2 dBTransmitter antenna gain 42.8 dBFree space loss and attenuation due to gases 145.5 dBReceiver antenna gain 42.8 dBFeeder loss receiver 1.2 dBNominal input level - 37.9 dBReceiver threshold - 82.0 dBmReceiver threshold degradation 0 dBFading margin 44.1 dB

5.4.1 Passive repeaters

Two types of passive repeaters will be introduced:

� plane reflectors � back-to-back antennas

The plane reflector reflects microwave signals in the same way as a mirror reflects light. The same lawsapply. Back-to-back antennas work just like an ordinary repeater station, but without radio frequencytransposition or amplification of the signal.

The receiver level at the active sites is thus given by:

�� ( )3 G%P 3 / / $ $ * / / / * * /U W IV IV D D S I I E R

= − − − − + ⋅ − − − + + −1 2 1 2 1 2 1 22

�� 3ODQH�UHIOHFWRUV

Plane reflectors are more popular than back-to-back antennas due to an efficiency close to 100% (50-60%for antennas). Plane reflectors may also be produced with much larger dimensions than parabolic antennas.



WEDIG 2.0c


�� *DLQ�RI�SODQH�UHIOHFWRU

The far field gain of a plane reflector is given by:

�� * G% I $S( ) . log ( ) log cos= + + ⋅

2145 20 10210 10

Ψ [dB]

where$ - area (in square meters) of the reflector

ψ - the angle between the incident and the reflected ray at the reflector

$ %

5

dAdB

θ

)LJXUH��3ODQH�SDVVLYH�UHIOHFWRU�JHRPHWU\�

11)( ) ( )( )

( )( ) ( )( )ψ

θ=

− + ⋅ ⋅ ⋅ − − −

⋅ + − ⋅ + −

−coscos1

2 6

2 6 2 2 6 2

10

10 10

K K G G K K K K

G K K G K K

5 $ $ % 5 $ % $

$ 5 $ % 5 %

where

hA is the antenna height above sea level at site A in m

hB is the antenna height above sea level at site B in m

hR is the height above sea level at the centre of the reflector in m

dA is the distance from site A to the reflector point in km

dB is the distance from site B to the reflector point in km

θ is the angle at the reflection point in plane projection in degrees

Unless the legs in figure 27 are extremely steep, θ may be used in place of ψ in equation 10) with goodaccuracy.



WEDIG 2.0c


It should be checked whether the passive repeater is in the far-field of the nearest antenna using the formula:

�� δπ

ψV

V

5

G

I $=

⋅

⋅ ⋅

75

2cos

where ds is the shortest of the two legs ( )G G$ % and in figure 27.

If δs > 2 5. the passive repeater is in the far-field of the nearest antenna, and formula 10) is valid.

�� %DFN�WR�EDFN�DQWHQQDV

Use of back-to-back antennas are practical when the reflection angle is large. The gain of a repeater withback-to-back antennas is given by:

�� * G% * * /S U U F( ) = + −1 2

where*U��*U� - gain of back-to-back antennas in dB

/F

- coupling loss between antennas in dB

�� 0XOWLSDWK�IDGLQJ

Fading due to layering of the atmosphere is the dominating factor of degradation of radio-relays.

Meteorological conditions in the space separating the transmitter and the receiver, may sometimes causedetrimental effects to the received signal. Rays that normally would have been lost in the troposphere maybe refracted into the receiving antenna where they are added to the wanted signal. The phase- and amplituderelationship between signals thus received determines the resulting output from the receiver.

This affects the transmission of digital signals in two ways. In some occasions, all components of the usefulsignal spectrum will be equally reduced. This is called non-selective or "flat" fading.

Other times only some of the spectral components will be reduced, causing the spectrum to be distorted.This is called frequency selective fading.

The cross-polarization discrimination (XPD) can deteriorate sufficiently to cause co-channel interference.This outage due to clear-air cross-polarization will only contribute to the total outage when the radio-relaysystem is utilising both polarizations on the same RF-channel to transmit two traffic channels. The outage isnegligible for other radio-relay system.These three effects will be treated separately.



WEDIG 2.0c


The total outage due to multipath fading is calculated from:

�� ( )33 3 3

3 3 3WRW

QV V ;3

GQV

��

GV

��

��

;3

LI�GLYHUVLW\ LV XVHG=

+ ++ +

where

3QV

- non-selective (flat) outage

3GQV

- non-selective outage with diversity

3V

- selective outage

3GV

- selective outage with diversity

3;3

- outage due to clear-air cross-polarization for co-channel systems

5.5.1 Flat FadingThe percentage of time that fade depth ) is exceeded in the average worst month can be calculated from:

�� 3 3QV

)

= ⋅−

01010 %

When using ) equal to the fading margin found using �� 3QV�

gives the percentage of time when the receiversignal is fading below threshold.The parameter 30, the fading occurrence factor, has been related to well-defined path parameters.

The methods are based on statistical analysis of paths in different parts of the world. The paths used havepath lengths ranging from 7 to 95 km, frequencies ranging from 2 to 37 GHz, path inclinations for the range0-24 mrad, and grazing angles in the range 1-12 mrad. Checks using several other sets of data for paths up to237 km in length and frequencies as low as 500 MHz suggest, however, that the method is valid for largerranges of path length and frequency

The fading occurrence factor for the average worst month:

�� 3 . G IS0

3 6 0 89 1 41= ⋅ ⋅ ⋅ + −. . .( )ε

where

. - Geoclimatic factor

G - Path length (km)

I - Frequency (GHz)

εS

K K

G=

−1 2 - Path inclination (millirad)

K��K� - antenna heights (m)



WEDIG 2.0c


The geoclimatic factor may be estimated for the average worst month from fading data. In absence of suchdata the following empirical relations must be used

�� ,QODQG�OLQNVInland links are those in which either the entire path profile is above 100 m altitude (with respect to meansea level) or beyond 50 km from the nearest coastline, or in which part or all of the path profile is below 100m altitude for a link entirely within 50 km of the coastline, but there is an intervening height of land higherthan 100 m between this part of the link and the coastline. Links passing over a river or a small lake shouldnormally be classed as passing over land.

�� ( ). 3/

& & &/DW /RQ= ⋅ ⋅ ⋅− − ⋅ − −5 0 10 107 1 5 0 1 0. . .

The coefficient CLat of latitude ξ is given by

�� [ ]&/DW

= 0 dB 53 oS ≥ ξ ≤ 53 oN

�� [ ]&/DW

= − +53 ξ dB 53 oN or oS < ξ < 60 oN or oS

�� [ ]&/DW

= 7 dB ξ ≥ 60 oN or oS

The longitude coefficient CLon is given by

�� [ ]&/RQ

= 3 dB Longitudes of Europe and Africa

�� [ ]&/RQ

= −3 dB Longitudes of North and South America

�� [ ]&/RQ

= 0 dB All other longitudes

The value of the coefficient &0 is given in Table 1 for three ranges of altitude of the lower of thetransmitting and receiving antennas and three types of terrain (plains, hills, or mountains). In cases ofuncertainty as to whether a link should be classified as being in a plain or hilly area, the mean value of thecoefficients &0 for these two types of area should be employed. Similarly, in cases of uncertainty as towhether a link should be classified as being in a hilly or mountainous area, the mean value of thecoefficients &0 for these two types of area should be employed. Links traversing plains at one end andmountains at the other should be classified as being in hilly areas. For the purposes of deciding whether apartially overwater path is in a largely plain, hilly, or mountainous area, the water surface should beconsidered as a plain.For planning purposes where the type of terrain is not known, the following values of the coefficient &0

should be employed:

&0 = 1.7 for lower-altitude antenna in the range 0-400 m above mean sea level;

&0 = 4.2 for lower-altitude antenna in the range 400-700 m above mean sea level;

&0 = 8 for lower-altitude antenna more than 700 m above mean sea level.



WEDIG 2.0c


Table 3 Values of C0 for various types of inland links

3/ is the percentage of time that the average refractivity gradient in the lowest 100 metre of the atmosphere

is less than -100 Nunits/km.

The figures in 7.5.1 from ITU-R Rec. P.453 [14] give 3/ for four different months. The month that has the

highest value should be chosen. An exception to this is that only the maps for May and August should beused for latitudes greater than 60 oN or 60 oS. These figures are given in 7.5.1.

�� &RDVWDO�OLQNVRYHU�QHDU�ODUJH�ERGLHV�RI�ZDWHU The size of a body of water can be chosen on the basis of several known examples: Large bodies of waterinclude the English Channel, the North Sea, the larger reaches of the Baltic and Mediterranean Seas, HudsonStrait, and other bodies of water of similar size or larger.

�� . = . U . .

. . .

O F

U . U .

FO L

L FO L

F L F FO( ) ( – ) log log= ≥

<

+10 1 for

for

where UF�is the fraction of the path profile below 100 m altitude above the mean level of the body of water in

question and within 50 km of the coastline, but without an intervening height of land above 100 m altitude,.L is given by the expression for . for inland links in equation ��, and:

�� .FO

&= ⋅ ⋅− − ⋅ − ⋅2 3 10 104 0 1 0 0110. . . ξ

Altitude of lower antenna and type of link terrain &0(dB)

/RZ�DOWLWXGH�DQWHQQD��P��±�3ODLQV�

Overland or partially overland links, with lower-antenna altitude less than 400 m above mean sea level,located in largely plains areas

0

/RZ�DOWLWXGH�DQWHQQD��P��±�+LOOV�

Overland or partially overland links, with lower-antenna altitude less than 400 m above mean sea level,located in largely hilly areas

3.5

0HGLXP�DOWLWXGH�DQWHQQD��P��±�3ODLQV�

Overland or partially overland links, with lower-antenna altitude in the range 400-700 m above mean sealevel, located in largely plains areas

2.5

0HGLXP�DOWLWXGH�DQWHQQD��P��±�+LOOV�

Overland or partially overland links, with lower-antenna altitude in the range 400-700 m above mean sealevel, located in largely hilly areas

6

+LJK�DOWLWXGH�DQWHQQD�� >��P��±�3ODLQV�

Overland or partially overland links, with lower-antenna altitude more than 700 m above mean sea level,located in largely plains areas

5.5

+LJK�DOWLWXGH�DQWHQQD�� >��P��±�+LOOV�

Overland or partially overland links, with lower-antenna altitude more than 700 m above mean sea level,located in largely hilly areas

8

+LJK�DOWLWXGH�DQWHQQD�� >��P��±�0RXQWDLQV�

Overland or partially overland links, with lower-antenna altitude more than 700 m above mean sea level,located in largely mountainous areas

10.5



WEDIG 2.0c


where ξ is the latitude in degrees.

�� &RDVWDO�OLQNV�RYHU�QHDU�PHGLXP�VL]HG�ERGLHV�RI�ZDWHUThe size of a body of water can be chosen on the basis of several known examples: Medium-sized bodies ofwater include the Bay of Fundy (east coast of Canada) and the Strait of Georgia (west coast of Canada), theGulf of Finland, and other bodies of water of similar size.

�� . = . U . .

. . .O F

U . U .FP

FP L

L FP L

F L F( ) ( – ) log log= ≥<

+10 1 for

for

where UF�is the fraction of the path profile below 100 m altitude above the mean level of the body of water in

question and within 50 km of the coastline, but without an intervening height of land above 100 m altitude,.L is given by the expression for . for inland links in equation ��, and:

�� .FP

. .L FO= ⋅ +100 5. (log log )

with .FO

given by equation �� Note that the condition .FP

< .L �occurs in a few regions at low and mid

latitudes.

�� ,QODQG�OLQNV�LQ�UHJLRQV�ZLWK�PDQ\�ODNHVRegions (not otherwise in coastal areas) in which there are many lakes over a fairly large area are believedto behave somewhat like coastal areas. The region of lakes in southern Finland provides the best knownexample. Until such regions can be better defined, . should be calculated from:

�� . U . U .F L F FP= − +100 5 2. [( ) log log ]

with .FP

given by equation ��, .L given by equation ��and where U

F� is the fraction of the path profile

below 100 m altitude above the mean level of the body of water in question and within 50 km of thecoastline, but without an intervening height of land above 100 m altitude.

�� &RDVWDO�OLQNV�RYHU�QHDU�XQFHUWDLQ�VL]H�RI�ERG\�RI�ZDWHUIn cases of uncertainty as to whether the size of body of water should be classed as medium or large, .should be calculated from:

�� . U . U . .F L F FP FO= − + +10 1 0 5( ) log . (log log )

with .FP

given by equation ��.L given by equation ��Kcl given by equation �� and where U

F� is the

fraction of the path profile below 100 m altitude above the mean level of the body of water in question andwithin 50 km of the coastline, but without an intervening height of land above 100 m altitude.

5.5.2 Frequency Selective FadingThere are a number of different methods for predicting outages due to frequency selective fading. Themethod using the signature curve is described in ITU-R recommendation 530 [17].This method agreesreasonably well with measured results and clearly shows the radio’s ability to withstand the selective fading.



WEDIG 2.0c


�� 3 VIV

P= ⋅ ⋅ ⋅4302

0

η ττ

in %

where η is related to the fading occurrence factor 30. η is often called the fading activity factor:

�� η = −− ⋅

1

0 2100

00 75

H3

..

where P0 is the multipath occurrence factor corresponding in %, given in equation ��.

τP

is the typical path echo delay given by :

�� τP

G= ⋅

0 750

1 3

..

G is the path length in km and VI is called the equipment signature factor.

τ� is the echo delay time used during measurement of the signature curves. A much used value (also used by

Nera) is:

τ0�= 6.3 ns

The signature factor VI is derived from the signature curve of the equipment, using the formula:

�� ( )VI : :0

%

10

%0 10= ⋅ × + ×− −1

210 1020 20/ /

where::0 : minimum phase signature width (GHz)%0 : minimum phase signature depth (dB):10 : non-minimum phase signature width (GHz)%10 : non-minimum phase signature depth (dB)

�� 'LYHUVLW\

The performance of line-of-sight (LOS) digital radio links can be seriously impaired by frequency selectivefading, due to in-band amplitude and phase distortions. This multipath (or selective) fading can be a resultof surface reflections, or induced by atmospheric anomalies such as strong ducting gradients. One principalmethod of overcoming the effects of multipath fading is to use a form of diversity transmission andreception. The common forms of diversity in LOS links are IUHTXHQF\ and VSDFH, or combinations of both.

By switching or combining the different channels carrying the same signal, it is possible to attain animprovement relative to a single channel given by the factor:

34) IP

P= Single channel

Diversity



WEDIG 2.0c


5.6.1 Single diversity

The degree of improvement afforded by all of the diversity techniques depends on the extent to which thesignals in the diversity branches of the system are uncorrected. For narrow-band analogue systems, it issufficient to determine the improvement in the statistics of fade depth at a single frequency. For widebanddigital systems, the diversity improvement also depends on the statistics of in-band distortion.

�� 6SDFH�GLYHUVLW\

The system performance may be significantly improved by use of space diversity. Identical information istransmitted over separate paths as indicated in Figure 28.

)LJXUH��6SDFH�GLYHUVLW\�SULQFLSOH

The vertical space diversity improvement factor on overland paths can be estimated from

35) ( ), 6 I G3

VG

) 9= − − ⋅ ⋅ ⋅ ⋅ ⋅

⋅− −−

−1 3 34 10100

104 0 87 0 12 0 48 01 04

10exp . . . ..

where

G - path length (km)

) - fade depth (dB) for the unprotected path

I - frequency (GHz)

*V��*V� - gains of the two space diversity antennas (dB)

30 ��fading occurrence factor in %

6 ��vertical separation (centre-to-centre) of receiving antennas (m)

9 * *V V

= −1 2

The relation for ,VG applies only when the following conditions are met:



WEDIG 2.0c


2 GHz < �I < 11 GHz43 km < G��< 240 km 3 m < 6 < 23 m

ITU-R recommendation 530 [17] indicates that ,VG can be used with reasonable accuracy for path lengths

down to 25 km. In cases where any of these boundaries have been exceeded (within reasonable limits), theparameters have been set equal to the boundary value in the program. E.g. for 13 or 15 GHz links, theimprovement factor for 11 GHz will be calculated.

The following procedure is used to calculate the selective and non-selective outages:

Calculate the square of the non-selective correlation coefficient, NQV

, from:

36� N,

3

QV

VG

QV

2 1 100= −⋅

ηwhere 3QV in % is the outage due to the non-selective component of the fading that is given by equation ��and η is the fading activity factor that is given by equation ��.

Calculate the square of the selective correlation coefficient, NV, from:

37� ( )( )

N

U

U U

U U

V

Z

ZU

Z

Z Z

Z2 0 109 0 13 1

0 5136

0 8238 05

1 0195 1 0 5 0 9628

1 0 3957 1 0 9628

=

≤

− − < ≤

− − >

− −

. .

. . .

. .

. . log ( )

.

for

for

for

where the correlation coefficient, UZ, of the relative amplitudes is given by:

38� ( )( )

UN N

N NZ

QV QV

QV QV

=− − ≤

− − >

1 0 9746 1 0 26

1 0 6921 1 0 26

2 2 170 2

2 1034 2

. .

. .

.

.

for

for

Calculate the non-selective outage, 3GQV

, from:

�� 33

,GQV

QV

VG

= in %

where 3QV in % is the outage due to the non-selective component of the fading given by equation ��

Calculate the selective outage, 3GV

, from:

�� ( )33

NGV

V

V

=⋅ −

2

2100 1ηin %

where�3V in % is the non-protected selective outage given by equation ��



WEDIG 2.0c


�� )UHTXHQF\�GLYHUVLW\

�� 5HGXQGDQW��V\VWHP

1 1

2 2

)LJXUH��)UHTXHQF\�GLYHUVLW\�SULQFLSOH�

The following procedure is used to calculate the selective and non-selective outages:

Calculate the improvement factor for frequency diversity from:

�� { },I G

II

,IG

)

IG=⋅

⋅ ⋅ ≥8010 510∆

∆I� - frequency spacing between rf-channels in GHz

I - carrier frequency in GHz

G - distance in km

) - fading margin in dB

The equation is considered valid only for values of ,IG ≥ 5. The relation for ,IG applies only when the

following conditions are met :

1.7 GHz < I��< 13 GHz 20 km < G < 75 km

∆I�/I < 0.05

In cases where these boundaries are exceeded (within reasonable limits), the ,IG is calculated with

boundary values. E.g. if the distance is 15 km, then ,IG is calculated with G = 30 km.

Calculate the square of the non-selective correlation coefficient, NQV

, from:



WEDIG 2.0c


�� N,

3

QV

IG

QV

2 1 100= −⋅

ηwhere 3QV in % is the outage due to the non-selective component of the fading that is given in formula ��and η is the fading activity factor that is given in formula ��


�� ( )( )

N

U

U U

U U

V

Z

ZU

Z

Z Z

Z2 0 109 0 13 1

0 5136

0 8238 05

1 0195 1 0 5 0 9628

1 0 3957 1 0 9628

=

≤

− − < ≤

− − >

− −

. .

. . .

. .

. . log ( )

.

for

for

for


��( )( )

UN N

N NZ

QV QV

QV QV

=− − ≤

− − >

1 0 9746 1 0 26

1 0 6921 1 0 26

2 2 170 2

2 1034 2

. .

. .

.

.

for

for


, from:

�� 33,GQV

QV

IG

= in %



, from:

�� ( )33

NGV

V

V

=⋅ −

2

2100 1ηin %




WEDIG 2.0c


�� 5HGXQGDQW�1��6\VWHPIf frequency diversity is used in n+1 operation, n>1, the diversity improvement factor will be reduced sincethere are more than one channel sharing the same diversity channel.

If it is assumed that no more than two of the rf-channels are simultaneously afflicted by equal fading, andboth have the same priority, the reduced diversity improvement factors are given by:

�� { }, ,IG IG2 1 0 67+ = ⋅. { }, ,IG IG5 1 0 49+ = ⋅.

{ }, ,IG IG3 1 057+ = ⋅. { }, ,IG IG6 1 0 47+ = ⋅.

{ }, ,IG IG4 1 052+ = ⋅. { }, ,IG IG7 1 0 45+ = ⋅.

∆I� - frequency spacing between rf-channels in GHz

�� +RW�VWDQGE\�FRQILJXUDWLRQ

The hot standby configuration is often used to give equipment diversity (protection) on paths wherepropagation conditions are non-critical to system performance. This configuration gives no improvement ofsystem performance, but reduces the system outage due to equipment failures.

The transmitters and receivers in Figure 30 operate at the same frequency. Consequently no frequencydiversity improvement could be expected.

1

1

1

1

)LJXUH��+RW�VWDQGE\�SULQFLSOH�



WEDIG 2.0c


�� +\EULG�GLYHUVLW\

Hybrid diversity is an arrangement where a 1+1 system has two antennas at one of the radio sites only. Thefollowing procedure is used to calculate the selective and non-selective outages:

1

2

1

2

1

2

1

2

)LJXUH��+\EULG�GLYHUVLW\�SULQFLSOH�

The non-selective correlation coefficient, NQV

, is found from:

�� N N NQV QV V QV I

= ⋅, ,

where NQV,V and N

QV, I are the non-selective correlation coefficients computed for space diversity equation ��and frequency diversity equation ��, respectively.


�� ( )( )

N

U

U U

U U

V

Z

ZU

Z

Z Z

Z2 0 109 0 13 1

0 5136

0 8238 05

1 0195 1 0 5 0 9628

1 0 3957 1 0 9628

=

≤

− − < ≤

− − >

− −

. .

. . .

. .

. . log ( )

.

for

for

for


��( )( )

UN N

N NZ

QV QV

QV QV

=− − ≤

− − >

1 0 9746 1 0 26

1 0 6921 1 0 26

2 2 170 2

2 1034 2

. .

. .

.

.

for

for


, from:

�� 33

,GQV

QV

VG

= in %




WEDIG 2.0c



, from:

�� ( )33

NGV

V

V

=⋅ −

2

2100 1ηin %


5.6.2 Combined diversity

When using frequency and space diversity at the same time, common practice is to use the product of theimprovement factors.

)LJXUH��&RPELQHG�IUHTXHQF\�DQG�VSDFH�GLYHUVLW\


, from:

�� 33

, ,GQV

QV

VG IG

=+

in %

where 3QV in % is the outage due to the non-selective component of the fading given by equation ��,IG isthe improvement factor for frequency diversity given by equation �� and ,VG is the vertical space diversityimprovement factor given by equation ��).


, from:

�� 33

, ,GV

V

VG IG

=+

in %


127(� 7KLV�PHWKRG�GLIIHUV�IURP�WKH�PHWKRG�GHVFULEHG�LQ�,78�5�UHF��[��]



WEDIG 2.0c


�� &5266�32/$5�,17(5)(5(1&(Co-channel operation of radio relay systems will double the capacity compared to conventional radio relaysystems. In co-channel systems transmission of two separate traffic channels is performed on the same radiofrequency but on orthogonal polarisation. This works well as long as the discrimination between the twopolarisations called Cross Polar Discrimination (XPD), is sufficient to ensure interference-free operation.The nominal value of XPD is termed XPD0 and is governed by the cross-polarisation patterns of theantennas.Both multipath- and rainfading can result in severe degradation of the XPD level. As the XPD decreases, theinterference level in the channel will rise and may cause threshold degradation and errors in the data traffic.Procedures for predicting both the outage due to clear-air effects and due to precipitation conditions is givenITU-R rec. 530 [17]

5.7.1 Outage due to clear-air effects for co-channel systemsThe following procedure is used to calculate the outage due reduction of XPD in clear-air:

�� ;3';3' ;3'

;3'J J

J0

5 35

40 35=

+ ≤

>

for

for

;3'J is the manufacturer’s guaranteed minimum XPD at boresight for both the transmitting and receiving

antennas, i.e., the minimum of the transmitting and receiving antenna boresight XPDs.

�� 4N

3[S= −

⋅

10

100

0

logη

whereη is the fading activity factor given by equation �� and P0 in % is the fading occurrence factor givenby equation �� and:

�� N V[S W= − − ×

−

0 7

1 0 3 4 10 62

.

. exp

one transmit antenna

two transmit antennasλ

In the case where two orthogonally polarized transmissions are from different antennas, the verticalseparation is V

W (m) and the carrier wavelength is λ (m).

Derive the parameter &�from:

�� & ;3' 4= +0

Calculate the outage 3[S

due to clear-air cross-polarization from:

�� 3 3[S

0;3'

= × −0

1010 in %

where P0 in % is the fading occurrence factor given by equation �� and 0;3'

(dB) is the equivalent XPDmargin for a reference BER given by:



WEDIG 2.0c


�� 0&

&

,

&&

,;3,)

;3' =−

− +

0

0

without XPIC

with XPIC

Here, C0 /, is the carrier-to-interference ratio for a reference BER, which is measurements.XPIF is a laboratory-measured cross-polarization improvement factor that gives the difference in cross-polarisolation XPI at sufficiently large carrier-to-noise ratio and at a specific BER for systems with and withoutcross polar interference canceller (XPIC).

5.7.2 Outage due to precipitation effects for co-channel systemsIn addition to the usual attenuation of microwave signals due to rain, there will also be a depolarisationeffect. This depolarisation may be substantial even at frequencies where the attenuation is insignificant(below 10 GHz). The following procedure is used to calculate the outage:

Calculate the coefficients U and V.

�� 8 = 80 + 30 log I

where 80 is set to equal 15 dB and I is the frequency in GHz.

�� 9 I

IRU I *+]

I IRU I *+]

IRU I *+]

( )

.

.

.

.=

<

≤ ≤< ≤

19 002 8

12 8 8 20

22 6 20 35

0 19

127(��7KH�IRUPXOD�IRU�9�I��KDV�LQ�,78�5�UHF��[��]�D�ORZHU�OLPLW�RI��*+]��7KH�YDOXH�9�I� ��LVXVHG�IRU�IUHTXHQFLHV�EHORZ��*+]�

Determine the path attenuation, $0,01 (dB), exceeded for 0.01% of the time from :

�� $U0 01. = ⋅ψ γ

where ψ is the effective path length given by equation �� and γr is the specific attenuation given byequation ��

Determine the equivalent path attenuation, $S (dB):

�� $S8 & , ;3,) 9= − +10 0(( / ) / ) in dB

where &0��, (dB) is the carrier-to-interference ratio defined for the reference BER without XPIC, and�XPIF

(dB) is the cross-polarized improvement factor for the reference BER. If an XPIC device is not used, setXPIF = 0.



WEDIG 2.0c


Determine the following parameters:

�� [ ]P$ $ PS=

≤2326 012

40

400 01. log . .

if

otherwise

and:

�� ( )Q P= − + −12 7 16123 4 2. . /

Determine the outage due to precipitation effects for co-channel systems from:

�� 3;35

Q= ⋅ −100 10 2( ) in %

The total outage probability due to rain is calculated from taking the largest value of 3UDLQ

and 3;35

.

�� 8QDYDLODELOLW\�GXH�WR�UDLQ

On any path there is a possibility of additional attenuation of the radio signal due to absorption andscattering by rain and sleet. This can be ignored at frequencies below 5 GHz. At higher frequencies, inparticular above 10 GHz, it can be quite significant.

The model described in ITU-R rec. 530 [17] is used to calculate the unavailability due to rain. The rainfallcontour maps in appendix 3 may be used if specific rainfall data for the region of interest is not available.



WEDIG 2.0c


5.8.1 Specific AttenuationThe specific attenuation γU (dB/km) for the frequency, polarization and rain rate is given by

�� γ αU

N 5= ⋅

5 - the rain intensity in mm/h not exceeded for more than 0.01% of the worst month. See 7.5.2

N and α are regression coefficients that have been calculated for oblate spheroid raindrops for a range offrequencies. These parameters are appropriate to the polarization. These regression coefficients are given inITU-R Rec. 838 [23]. It should be noted that the specific attenuation is lowest for the vertical polarization.

Frequency[GHz]

kh kv αh αv

1 0.0000387 0.0000352 0.912 0.8802 0.0001540 0.0001380 0.963 0.9234 0.0006500 0.0005910 1.121 1.0756 0.0017500 0.0015500 1.308 1.2657 0.0030100 0.0026500 1.332 1.3128 0.0045400 0.0039500 1.327 1.310

10 0.0101000 0.0088700 1.276 1.26412 0.0188000 0.0168000 1.217 1.20015 0.0367000 0.0335000 1.154 1.12820 0.0751 0.0691 1.099 1.06525 0.124 0.113 1.061 1.03030 0.187 0.167 1.021 1.00035 0.263 0.233 0.979 0.96340 0.350 0.310 0.939 0.929

7DEOH��5HJUHVVLRQ�FRHIILFLHQWV�IRU�HVWLPDWLQJ�VSHFLILF�DWWHQXDWLRQ��,78�5�5HF��[��]��Y��YHUWLFDO�SRODUL]DWLRQ��K��KRUL]RQWDO�SRODUL]DWLRQ�

The coefficients given in Table 4 are given for every 100 MHz from (1 GHz to 40 GHz) in the Rain sheet inWEDIG20.XLS.

5.8.2 Effective path length

Since rain has a tendency to cluster (especially at high rain rates), only parts of a typical radio link path willbe affected by rain. The effective path length containing rain cells is given by

�� ψ =+

⋅

− ⋅

GGH 5

135 0 015.

for R R> =100 100 mm / h: mm / h

where G�is the path length in km

5�is the rain intensity in mm/h (integration time 1 minute).



WEDIG 2.0c


5.8.3 Unavailability due to rain attenuation

The unavailability (in percent) due to rain is given by:

�� ( )) 3U UDLQ

3UDLQ= ⋅ ⋅ ⋅ − + ⋅012 0 546 0 043 10. ( . . log )Ψ γ

3UDLQ�� - unavailability in percent

) - fading margin in dB

The unavailability may be found by solving equation �� with respect to 3UDLQ�

��( )( )3

UDLQ

)U=

⋅ − + + ⋅ ⋅ ⋅10

11 628 0 546 0 29812 0 172 0 12. . . . log . /ψ γin %

To avoid imaginary values, use ψ�⋅�γU��)� �� in case where ψ�⋅�γ

U��)��

The prediction procedure outlined above is considered to be valid in all parts of the world at least forfrequencies up to 40 GHz and path lengths up to 60 km.

The total outage probability due to rain is calculated from taking the largest value of 3UDLQ

and 3;35

.

�� 33 3 3

3 3 35DLQ WRW

UDLQ UDLQ ;3'

;35 UDLQ ;3'

, =><

if

if in %

The outage due to precipitation effects for co-channel systems is set to zero, 3;35

= 0, for radio relaysystems without a co-channel arrangement.



WEDIG 2.0c


�� 2EMHFWLYHV

Several objectives may be used as design goals in the program (see 4.1.7).

5.9.1 G.821

G.821 is measuring bit errors.SES - BER should not exceed 10-3

DM - BER should not exceed 10-6

�� +LJK�JUDGH�REMHFWLYHV

The ITU-R objectives for real circuits describe system lengths between 280 km and 2500 km. See ITU-RRec. 594 [5] and ITU-R Rec. 695 [13]. They are referred to the HRDP and the objectives are scaled down toa minimum of 280 km. See ITU-R Rec. 634 [12]. Performance objectives for shorter distance than 280 kmare still under study.

7KH�REMHFWLYHV�DUH�

SES BER>10-3 for no more than (L/2500).0.054% of any month,integration time 1 s.

DM BER>10-6 for no more than (L/2500).0.4% of any month, integrationtime 1 min.

Availability A = 100 - (0.3.L/2500) %

Availability due to rain AR = 100 - (0.1.L/2500) %

The objectives are valid for systems only.The objectives for each hop are pro rata objectives that should be treated as information only since the hoplength is less than 280km. When each hop complies with these pro rata objectives, can such hops later beincorporated in a larger system without any negative influence on the total system performance. Hops withhigher outage than the pro rata objectives can be accepted.

�� 0HGLXP�JUDGH�REMHFWLYHV

Medium grade objectives are supposed to be used for national networks, normally between the localexchange and the international switching centre. However, this depends very much on the size of the countryand the size of the networks in the country.

According to ITU-T Rec. G.821 [2] the local grade and medium grade portions are permitted to cover up tothe first 1250 km of the circuit from the T - reference point extending into the network. Since the length ofthe local grade portion is usually negligible, the maximum length of the medium grade portion isapproximately 1250 km.



WEDIG 2.0c


The medium grade portion has 4 quality classifications. Class 1 corresponds to high grade classification butcan also be used for medium grade classification. The other three apply to medium grade only. Themedium grade objectives for a total medium grade portion at each end of an HRX can be found in ITU-RRec. 696 [6]. Comments are found in ITU-R Report 1052 [7].

For SES the objective was 0.015% with an additional allowance of 0.05%. That is 0.025% for each side.The total is 0.04%

For DM and ES there are no additional allowances. The objectives are:

BER not to exceed 10-3 for more than 0.04% of any month with integration time of1 s.

BER not to exceed 10-6 for more than 1.5% of any month with an integration timeof 1 min.

For an HRDS the ITU-R Rec. 696 [6] has made a table for the different classifications and objectives. Thesefigures shall be used for lengths less than these distances.

Percentage of any month

Performance parameter Class 1 Class 2 Class 3 Class 4280 km 280 km 50 km 50 km

BER>10-3 0.006 0.0075 0.002 0.005

BER>10-6 0.045 0.2 0.2 0.5

Unavailability 0.033 0.05 0.05 0.1

7DEOH��0HGLXP�JUDGH�REMHFWLYHV

If a system is a mixture of different classifications it must be ensured that the overall objective for themedium grade portion is not exceeded.

2EMHFWLYHV�XVHG�LQ�:(',*:

Percentage of any month

Performance parameter &ODVV�� &ODVV�� &ODVV�� &ODVV��0<L<280 km 0<L<280 km 0<L<50

km0<L<50

kmpro rata pro rata block

allowanceblock

allowance

BER>10-3 [%] 0.006*L/280 0.0075*L/280 0.002 0.005

BER>10-6 [%] 0.045*L/280 0.2*L/280 0.2 0.5

Unavailability for SES due to

rain (1/3 of total allowance) [%]0.011*L/280 0.017*L/280 0.017 0.033



WEDIG 2.0c


�� /RFDO�JUDGH�REMHFWLYHV

The local grade portion of the HRX represents the part between the subscriber and the local exchange. Thismay be a point-to-point or point-to-multipoint system, often of simple and cost-effective design.

The error performance objectives for the local grade portion can be found in ITU-R Rec. 697 [8] andcomments in ITU-R Report 1053 [9].

The objectives for performance are as follows:

n BER should not exceed 10-3 for more than 0.015% of any month with an integration time of 1 s.

n BER should not exceed 10-6 for more than 1.5% of any month with an integration time of 1 min.

Unavailability objectives for local grade circuits have not yet been established by the ITU-T or the ITU-R.The objectives for "Medium grade class 4" ITU-R Rec. 696 [6] is therefore used. Total unavailability forSES should not exceed 0.1 % for L<50 km. NERA has chosen to relate 1/3 of the total unavailability tounavailability due to rain.

n Unavailability for SES due to rain: less than 0.033%

5.9.2 G.826

The main difference between ITU-T Rec. G.826 [3] and ITU-T Rec. G.821 [2] is that G.826 uses EORFNVinstead of ELWV as in G.821.

�� ,QWHUQDWLRQDO�SRUWLRQ�XVLQJ�UDGLR�UHOD\�V\VWHPV The G.826 defines the Error Performance Parameters and Objectives for International, Constant Bit RateDigital Paths at or above the Primary Rate. The corresponding ITU-R Recommendation F.1092 [19] definesthe error performance objectives for constant bit rate digital path at or above the primary rate carried bydigital radio-relay systems which may form part of the international portion of a 27500 km hypotheticalreference path. In ITU-R Recommendation F.1397 [25] have the objectives in F.1092 been scaled down(pro-rata) to give engineers proper performance objectives for planing real digital radio links. The objectivesin F.1397 is given in Table 6.



WEDIG 2.0c


5DWH��0ELW�V� ��WR��6HYHUHO\�HUURUHGVHFRQGV�UDWLR 0.002 × (F

L + B

L ) × L

link /L

R

7DEOH��,78�5�5HF��)��LQWHUQDWLRQDO�SRUWLRQ��REMHFWLYHV

where:distance allocation factor: F

L = 0.01 × LR /500

block allowance factor, BL :– for intermediate countries: BL = BR × 0.02 × (LR / Lref ) for Lmin < LR ≤ Lref

BL = BR × 0.02 for LR > Lref

– for terminating countries: BL = BR × 0.01 × LR /( Lref /2) for Lmin < LR ≤ Lref /2BL = BR × 0.01 for LR > Lref /2

block allowance ratio, BR : (0 < BR ≤ 1)

reference length, Lref: Lref = 1 000 km (provisionally).LR is the rounded value of L rounded up to the nearest multiple of 500 km;The lower limit of Llink , used to scale the objectives to the real case, is Lmin. Provisionally Lmin is 50 km.


Unavailability objectives for international portion have not yet been established by the ITU-T or the ITU-R.The objectives for "High grade" ITU-R Rec. 695 [13] is therefore used.

7HUPLQDWLRQ�FRXQWU\pro rata

,QWHUPHGLDWH�FRXQWU\pro rata

L < 500km L > 500km L < 1000km L > 1000kmPerformance forSES [%] 0.002*2*(L/500) 0.002*(L/500+L/LR) 0.002*2*(L/500) 0.002*(L/500+2*L/LR)Unavailability dueto rain for SES [%] 0.1 * L / 2500 0.1 * L / 2500

7DEOH��2EMHFWLYHV�IRU�WKH�LQWHUQDWLRQDO�SRUWLRQ�XVHG�LQ�:(',*



WEDIG 2.0c


�� 1DWLRQDO�SRUWLRQ�XVLQJ�UDGLR�UHOD\�V\VWHPV

The ITU-R Recommendation F.1189 [20] defines the error performance objectives for constant bit ratedigital path at or above the primary rate carried by digital radio-relay systems which may form part or all ofthe national portion of a 27500 km hypothetical reference path.

Pathend-point

Localexchange

Note 1International

gateway

Access Short haul Long haul

1RWH � – In dependence of the country network architecture, this centre may coincide with a primary centre (PC),a secondary centre (SC) or a tertiary centre (TC) (see ITU-T Recommendation G.801).

7DEOH��%DVLF�VHFWLRQV�RI�QDWLRQDO�SRUWLRQ�RI�WKH�+53

5DWH��0ELW�V� ��WR�� !��WR�� !��WR�� !��WR�� !��WR��

(UURUHG�VHFRQGUDWLR

0.04xZ 0.05xZ 0.075xZ 0.16xZ Under study

6HYHUHO\�HUURUHGVHFRQGV�UDWLR

0.002xZ

%DFNJURXQG�EORFNHUURU�UDWLR

2x10-4x Z 2x10-4x Z 1x10-4x Z

/RQJ�KDXO�VHFWLRQ Z = A A = A1 + (LR/500) A1 = 1 - 2 %

6KRUW�KDXO�VHFWLRQ Z = A fixed block allocation only B = 7.5 - 8.5 %

$FFHVV�VHFWLRQ Z = A fixed block allocation only C = 7.5 - 8.5 %

$1% + % % + & % shall not exceed 17.5% and % % + & % are in the range 15.5% to 16.5%.LR is the rounded value of L rounded up to the nearest multiple of 500 km; where�/ is the actual

system length

7DEOH��,78�5�5HF��)��[��]��QDWLRQDO�SRUWLRQ��REMHFWLYHV



WEDIG 2.0c



Unavailability objectives for the national portion have not yet been established by the ITU-T or the ITU-R.The objectives for "High grade" ITU-R Rec. 695 [13] is therefore used for the long haul section and theobjectives for "Medium grade class 4" ITU-R Rec. 696 [6] is therefore used for the short haul and accesssections.

/RQJ�KDXO 6KRUW�KDXO $FFHVV

L < 500kmpro rata

block allowance block allowance

Performance for SES [%] 0.002*(L/LR + L/500) 0.015 0.017

Unavailability due to rainfor SES [%] 0.1*L/2500 0.033 0.033

LR is the rounded value of L rounded up to the nearest multiple of 500 km; where�/ is the actual systemlength.

7DEOH��2EMHFWLYHV�IRU�WKH�QDWLRQDO�SRUWLRQ�XVHG�LQ�:(',*



WEDIG 2.0c


�� 5HIHUHQFHV

[1] CCITT Rec. G.801. Digital Transmission models. CCITT Volume III - Fascicle III.5, Geneva1989.

[2] CCITT Rec. G.821. Error Performance of an International Digital connection forming part ofan Integrated Services Digital Network. CCITT Volume III - Fascicle III.5, Geneva 1989.

[3] CCITT draft Rec. G.826, "Error Performance Parameters and Objectives for International,Constant Bit Rate Digital Paths at or above the Primary Rate", January 1993.

[4] C.C.I.R. Rec. 557-2. Availability Objective for a Hypothetical Reference Circuit and aHypothetical Reference Digital Path. Recommendations of the C.C.I.R., Volume IX-Part 1,Geneva 1990.

[5] C.C.I.R. Rec. 594-2. Allowable Bit Error Ratios at the output of the Hypothetical ReferenceDigital Path for Radio-Relay Systems which may form part of an Integrated Services DigitalNetwork. Recommendations of the C.C.I.R., Volume IX-Part 1, Geneva 1990.

[6] C.C.I.R. Rec. 696. Error Performance and Availability Objectives for Hypothetical ReferenceDigital Sections utilizing Digital Radio-Relay Systems forming part of all of the MediumGrade Portion of an ISDN Connection. Recommendations of the C.C.I.R., Volume IX-Part 1,Geneva 1990.

[7] C.C.I.R. Report 1052-1. Error Performance and Availability Objectives for Digital Radio-Relay Systems used in the Medium Grade Portion of an ISDN Connection. Reports of theC.C.I.R., Annex to Volume IX-Part 1, Geneva 1990.

[8] C.C.I.R. Rec. 697. Error Performance Objectives for the Local Grade Portion at each end ofan ISDN Connection utilizing Digital Radio-Relay Systems. Recommendations of theC.C.I.R., Volume IX-Part 1, Geneva 1990.

[9] C.C.I.R. Report 1053-1. Error Performance and Availability Objectives for Digital Radio-Relay Systems used in the Local-Grade Portion of an ISDN Connection. Reports of theC.C.I.R., Annex to Volume IX-Part 1, Geneva 1990.

[10] "Prediction of Transmission Quality on Digital L.O.S. Radio Relays", ABB Nera, September9. 1992.

[11] Propagation data and prediction methods required for terrestrial line-of-sight systems. Report338-6. Reports of the C.C.I.R., 1990. Annex to volume V. Propagation in non-ionisedmedia. Geneva ISBN 92-61-04211-2.

[12] Error performance objectives for real digital radio-relay links forming part of a high-gradecircuit within an integrated services digital network. Recommendation 634-1.Recommendations of the C.C.I.R. 1990, Volume IX - part 1. Fixed service using radio-relaysystems. Geneva ISBN 92-61-04251-1.



WEDIG 2.0c


[13] Availability objectives for real digital radio-relay links forming part of a high-grade circuitwithin an integrated services digital network. Recommendation 695.Recommendations of theC.C.I.R. 1990, Volume IX - part 1. Fixed service using radio-relay systems. Geneva ISBN92-61-04251-1.

[14] The radio refraction index: Its formula and refractivity data..ITU-R Recommendations P.453-6 1997

[15] Effects of propagation on the design and operation of line-of-sight radio-relay systems.Report 784-3. Reports of the C.C.I.R., 1990. Annex to volume IX - part 1. Fixed serviceusing radio-relay systems. Geneva ISBN 92-61-04251-1.

[16] Attenuation by hydrometeors, in particular precipitation, and other atmospheric particles.Report 721-3. Reports of the C.C.I.R., 1990. Annex to volume V. Propagation in non-ionised media. Geneva ISBN 92-61-04211-2.

[17] Propagation data and prediction methods required for the design of terrestrial line-of-sightsystems. Recommendation P.530-7. ITU-R. Recommendations (1997)

[18] Ingvar Henne, Per Thorvaldsen “Planning of line-of-sight radio relay systems”, ABB Nera1994.

[19] Error performance objectives for constant bit rate digital path at or above the primary ratecarried by digital radio-relay systems which may form part of the international portion of a27500 km hypothetical reference path. ITU-R Recommendations F.1092-1 (1997 ).

[20] Error performance objectives for constant bit rate digital path at or above the primary ratecarried by digital radio-relay systems which may form part or all of he national portion of a27500 km hypothetical reference path. ITU-R Recommendations F.1189-1 (1997).

[21] Attenuation by atmospheric gases.ITU-R Recommendation P.676-3 1997

[22] Water vapour: Surface density and total columnar content.ITU-R Recommendation P.836-1 1997

[23] Specific attenuation model for rain for use in prediction methods.ITU-R Recommendation 838 1992

[24] Characteristics of precipitation for propagation modelling.ITU-R Recommendation PN.837-1 1994

[25] Error performance objectives for real digital links used in the international portion of a 27500km hypothetical reference path at or above the primary rate.ITU-R Recommendations F.1397 (1999 )



WEDIG 2.0c


�� $SSHQGL[

�� :RUNERRN�VWUXFWXUH

The workbook has been arranged in the following way:

6KHHW�QDPH )XQFWLRQ 7\SHPaths Main sheet for all path parameters WorksheetSystems Summary of system performance WorksheetInfo Project information and comments WorksheetRain Data base sheet containing rain coefficients (chapter 5.8) Worksheet databaseFunctions Macro sheet containing all user defined functions for the prediction

model.Macro module

General_c General commands macro sheet. Macro moduleProject_c Macro module for commands in the Project menu. Macro moduleProject_c_2 Macro module for commands in the Project menu. Macro modulePaths_c Macro module for commands in the Paths menu. Macro moduleAntenna_Feeder_Radio_c

Macro module for commands in the Paths menu. Macro module

Systems_c Macro module for commands in the Systems menu. Macro moduleAbout Information about the program Macro dialogPath_data Main input dialog box definition (Figure 12) Macro dialogTune Tune antennas dialog box (Figure 17) Macro dialogDiversity Selection of frequency or space diversity Macro dialogFreq_div Dialog box for frequency diversity parameters Macro dialogMax_D Dialog box for calculation of maximum path lengths (Figure 23) Macro dialogView Custom view dialog box for Paths (Figure 7) Macro dialogSpace Dialog box for space diversity antenna arrangement (Figure 20) Macro dialogFeeder type Dialog box for selection of feeder type (Figure 22) Macro dialogSelect_feeder

Dialog box for selection of feeder type. Macro dialog

Hor feeder Dialog box definition for feeder length calculation (Figure 21) Macro dialogSites Dialog box definition for site selection in system calculations (Figure

25)Macro dialog

Next Dialog box definition for route selection. Macro dialogCoax Dialog box definition for selection of coaxial cable type in the 2 GHz

band.Macro dialog

Log Dialog box definition for project information Macro dialogTune_degradation

Dialog box definition for adjusting the receiver threshold degradation Macro dialog

View_Single Custom view dialog box for Single Macro dialogView_Systems

Custom view dialog box for Systems Macro dialog

Move_path Dialog box definition for moving path up and down Macro dialogSelect radio Dialog box for selection of radio type (Figure 15) Macro dialog



WEDIG 2.0c


Edit radio Dialog box for editing radio parameters (Figure 18) Macro dialog

User dialog Dialog box definition for user preference data. Macro dialogSingle Page set-up for single page print-out of path parameters WorksheetEquipment Summary page for equipment used in your system WorksheetObjective_info

Objective information and definitions. Worksheet

Temp Worksheet used for temporary data during system performancecalculations.

Worksheet

7DEOH��:RUNERRN�FRQWHQWV

The user should normally not make any changes in sheets described in the shaded cells in Table 11. Thesesheets are hidden in the standard set-up to prevent undesirable changes.

�� 1HUD�UDGLR�GDWDEDVH

The Nera radio database contains the main radio parameters for all available Nera radio-relay systems at thedate of issue. New radios may be added to the list, and changes can be made if required. An update of theradio database may be supplied more often than updates of the program itself.

The radio database contains radio types with capacities from 2 Mb/s to 155 Mb/s in frequency ranges from1.7 to 40 GHz with configurations up to 7+1 for 155 Mb/s equipment.

�� 1HUD�DQWHQQD�GDWD�EDVH

In order to make the selection of antennas more efficient, a data base sheet containing the key parameters forall Nera antennas are integrated in the program structure. The file can be located at another drive (local ornetwork) and the reference to the antenna database may be changed using the Project-Preferences command(see 4.1.8).

The program will open the antenna data base file correctly at program start-up if the antenna data base isfound at the specified location (see 4.1.8).

ANT-DATA.XLS is automatically closed without saving any changes to it when the WEDIG20 program isterminated. Changes in antenna data should be done by opening the ANT-DATA.XLS file manually,perform the changes and then save the file. Do not change the order of the columns in the data base as thiswill affect the selection of antenna parameters entered automatically by WEDIG20.



WEDIG 2.0c


�� )HHGHU�GDWDEDVHNera do not produce wave guides or coaxial cables. In order to have an effective organising of the antennafeeder parameters, specifications for Andrew and Radio Frequency Systems products have been included asa feeder database supplied with WEDIG20. New wave guide or coaxial types may be added by the user.

The feeder loss database is a separate workbook WG-DATA.XLS. Antenna feeder loss (in dB/100m).Feeder loss for other frequencies may be added.



WEDIG 2.0c


�� ,78�5�ZRUOG�PDSV

7.5.1 PL-contour maps (ITU-R rec. 453 [14])

Figure 33 Percentage of time gradient ≤ −100( )N / km : February



WEDIG 2.0c


Figure 34 Percentage of time gradient ≤ −100( )N / km : May



WEDIG 2.0c


Figure 35 Percentage of time gradient ≤ −100( )N / km : August



WEDIG 2.0c


Figure 36 Percentage of time gradient ≤ −100( )N / km : November



WEDIG 2.0c


7.5.2 Rainfall contour maps (ITU-R rec. PN. 837 [24])

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WEDIG 2.0c


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WEDIG 2.0c


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WEDIG 2.0c


7.5.3 Water vapour at ground level (ITU-R rec. P.836 [22])

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WEDIG 2.0c


�� ,QGH[

$

Absolute chart, 16access, 12Access, 67Add New path, 20Add Selected Path, 28Add system, 38antenna

back-to-back, 45data base, 72

Antenna database, 18Antenna gain, 24Antenna height, 24Antenna type, 24Antennas, 29Atmospheric gases, 40Auto-filter, 72

%

back-to-back antennas, 45budget, 41

&

&0, 47

ChartAbsolute, 16Pro-rata, 16

Clat, 47Clear all systems, 38Clon, 47Close program, 6Coastal links, 48Coastal links large water, 48Coastal links medium-sized water, 49co-channel

clear air effects, 58precipitation effects, 59

co-channel systems, 58combined diversity, 57Configuration, 33Costal, large size of water, 21Costal, medium-size of water, 21, 25Costal, uncertain size of water, 21, 25Cross Polar Discrimination, 58cross polar interference canceller, 59Cross-polar interference, 58Custom objectives, 12Customize Paths, 14Customize Single, 16Customize Systems, 14

'

DatabaseRadio, 72

Delete Path, 29Delete systems, 39diversity, 50

combined, 57frequency, 53hybrid, 56

Diversity, 34, 50Frequency, 34help, 24Space, 34

dry air, 40

(

Edit path, 28effective path length, 61Enable menus, 18Enter data, 6Equipment, 18Equipment sheet, 9Export to file, 10

)

fading margin, 40, 42fading occurrence factor, 46far-field, 45Feeder database, 18Feeder help, 24Feeder length, 24, 35

horizontal, 35Feeder loss, 18Feeder type, 36file locations, 13file reference, 10Flat Fading, 46free space

formula, 40loss, 40

frequencydiversity, 53

improvement factor, 55Frequency

Center, 33Lower, 33Upper, 33

Frequency diversity, 34Frequency Selective Fading, 49Functions sheet, 8



WEDIG 2.0c


*

G.821, 12, 63G.826, 12, 65gain of plane reflector, 44Geoclimatic factor, 47

+

High grade objectives, 12, 63High power, 33Hills, 21, 48hot standby, 55

,

Improvement, 50combined, 57frequency, 53redundant N+1, 55space, 51

Info, 18Info sheet, 8, 10Info Window, 8Inland, 25Inland, 21Inland links, 47Inland, many lakes, 21, 25input, 9Insert Path, 28Insert system, 39Installation, 5intermediate, 12Intermediate country, 66International portion, 12, 65

/

Link budget, 41Local grade objectives, 12, 65long haul, 12Long haul, 67

0

macros, 7maps, 74maximum path length, 36Medium grade objectives, 12, 63menus, 9Modulation, 33Mountains, 21, 25, 48Move path, 29Multipath fading, 45

1

Name, 24National portion, 12, 67Nera antennas, 72net path loss, 41New, 1013/, 41

2

objectives, 8Objectives, 12, 63Open, 10Open File, 10Other loss, 26output, 9

3

passive repeater, 43Passive repeater, 26

gain, 26password, 9Path

latitude, 26position, 26

Path echo delay, 50path length, 36Path length, 25, 36Path parameters, 25Paths, 17, 20

menus, 20Paths sheet, 7Performance objectives, 63Plains, 21, 25, 48Plane passive repeater, 26plane reflector, 43Plane reflector

Area, 26gain, 44Reflection angle, 26

Planning method, 25PL-factor, 25PL-maps, 74Position, 24Power budget, 40precipitation effects for co-channel systems, 62Prediction model, 40preferences, 13pressure, 41Print, 18

All paths separately, 19Equipment, 20Info, 19Paths, 19Project, 19Selected Path, 19



WEDIG 2.0c


Systems, 19project

information, 11Project, 9Project information, 10Project menus, 9Project objectives, 12Pro-rata chart, 16

5

Radio, 32Radio database, 18, 72Radio family, 33Radio type, 25, 28, 33rain

cell, 61coefficients, 25

Rainintensity, 25rate, 25

rain rate, 61Rain sheet, 8Rainfall maps, 78UF, 49

References, 69regions with many lakes, 49regression coefficients, 61Reset page set-ups, 20

6

Save, 10Save As, 10Selected path, 17selective correlation coefficient, 52setup, 5set-up, 6short haul, 126KRUW�KDXO, 67signature factor, 50Single sheet, 9Site level, 24Site parameters, 24space diversity

improvement factor, 51Space Diversity, 34specific attenuation, 61Start program, 5Systems, 17, 38

Add, 38Clear all, 38Delete, 39Insert, 39

Systems sheet, 8

7

terminating, 12Termination country, 66Threshold level, 33Today, 10total outage due to multipath, 46Tune, 29

Antennas, 29Diversity, 34Feeder length, 35Frequency diversity, 34Path length, 36Radio, 32Space diversity, 34Threshold degradation, 34

Tune Threshold degradation, 34type of link terrain, 48

8

unavailabilityobjectives, 65, 66, 68

Unavailability due to rain, 60Unavailability due to rain attenuation, 62Unavailability objectives, 63uncertain size of body of water, 49Update, 37

All parameters, 38Feeder only, 38Radio only, 38This path only, 37

User preferences, 13User set-up, 6

9

Variation Charts, 17View, 14

Absolute chart, 16Absolute Chart, 16Antenna database, 18Customize Paths, 14Customize Single, 16Equipment, 18Info, 18Paths, 17Pro-rata chart, 16Pro-rata Chart, 16Radio database, 18Selected path, 17Systems, 17Variation charts, 17

Visual Basic, 7



WEDIG 2.0c


:

water vapour, 40WEDIG, 5What’s new, 6workbook, 7Workbook

contents, 7, 72sheets, 7

structure, 71workspace, 7

;

XPD, 58XPIC, 33, 59XPIF, 59