MLinkPlanner 1.2

Point-to-Point and Point-to-Multipoint Microwave Link Planning Software

Microwave link planning software user interface

User Manual

Part 1   Part 2   Part 3   Part 4
Path Profile

A path profile is a vertical sectional view of the terrain created by a plane passing through both ends of the hop. The path profile includes terrain elevation data, building and tree heights, and boundaries of water bodies.


MLinkPlanner creates path profiles using the following GIS data:


-    Global terrain elevation 1 arc sec (about 30 m) resolution SRTM (Shuttle Radar Topography Mission) data. Data sources: USGS EarthExplorer site https://earthexplorer.usgs.gov;
-    Global tree cover 1 arc sec (about 30 m) resolution data with information about tree heights. Data sources: High-Resolution Global Maps of 21st-Century Forest Cover Change Published by Hansen, Potapov, Moore, Hancher et al. Department of Geographical Sciences University of Maryland https://earthenginepartners.appspot.com and Jet Propulsion Laboratory California Institute of Technology https://landscape.jpl.nasa.gov/;
-    Global 3D buildings data from OpenStreetMap project database. Data sources: Our buildings database, which synchronizes every minute with the global OpenStreetMap (OSM) database.

 

All these types of geodata are downloaded for the desired area automatically as needed; there is no need to worry about preloading the geodata.

Creating the Path Profile with GIS

On the upper left panel, click on the Point-to-point tab, select a hop in the hop table, then on the lower-left panel, go to the Profile tab of that hop and click Generate profile. A warning dialog box will appear indicating that the path profile data will be changed. You should specify the average building floor height (typically 3 m) in this window. The OSM project database usually contains information about the number of floors of the buildings rather than its height in meters. Building height in the path profile will usually be based on the number of floors and floor height. You will also have to specify the height of the buildings for which OSM project database does not have information. Such buildings will be highlighted in red in the path profile.

 

If a building affects the qualitative characteristics of the hop as a critical obstruction, check the building’s height with third party sources to verify its exact height. The user can override the forest height information obtained from the Global Forest Change records and set a new value to be used in a path profile.

How to Create a Path Profile 

Figure 5. Path Profile Creating Settings

Click OK, and after a couple of seconds, the information about terrain elevation and clutter characteristics along the path profile will appear in the table cells. The view of the path profile will be displayed at the top right panel.

Figure 6. Path profile of a hop

Clutter:

green: trees;
orange: buildings whose height or number of floors can be found in the OpenStreetMap database;
red: buildings whose height and a number of floors are missing in the OpenStreetMap database.

Editing the Path Profile

Terrain elevations can be edited manually in the corresponding cells of the elevation table. To edit terrain elevations for multiple cells, select the desired cells and enter a new value. The new elevation will be saved to all selected cells, and the information about old elevations will be automatically removed. Only end values of this range will remain. To delete an entire row in the table, click on the triangle icon at the beginning of the row to select either a single row or multiple rows (by dragging the mouse or holding the Shift key and using the up or down arrow keys) and press Delete.

 
If you highlight a segment on the path profile by clicking and dragging the left mouse button, the segment will also be highlighted in the terrain elevation table, clutter table and on the basemap. Likewise, if you select rows in the elevation or clutter table, the corresponding section will be highlighted in the path profile view and on the basemap.

How to Edit a Path Profile

Figure 7. Highlighting the profile segment

The boundaries and elevation characteristics of clutter can be edited manually in the corresponding cells of the clutter table. To delete an entire row in the table, click on the triangle icon at the beginning of the row to select either a single row or multiple rows (by dragging the mouse or holding the Shift key and using the up or down arrow keys) and press Delete. 

Creating the Path Profile Manually

The application allows you to create a path profile by manually specifying all elevations on the path.
The information about forest, buildings and water bodies can be entered based on the basemaps, which you can open right in the application. Many online services allow you to view cartographic materials. They all differ in such parameters as map scale, coverage and displayed objects. Depending on the specific area where the hop is located, you may find useful one or several services. It is also important to select a proper scale of the map. More information about using custom basemaps can be found in the application.


After analyzing the basemap along the line of the path profile, you can enter boundaries of forests, buildings and water bodies. To do that, on the basemap, right-click on the point on the link path where you want to enter the start of a clutter object segment. A context menu will open where you can select corresponding types of the segment. When the ends of a segment are marked, a number field will appear that you must fill in to indicate forest or building height. On the path profile, the forest is highlighted in green, building in orange, water area in blue. Table entries for clutter and water information will be created automatically. You can delete any segment by right-clicking on it and selecting the corresponding action in the context menu that appears.

Start a building segment                Specify the beginning of the building segment on the path profile
Start a tree segment                       Specify the beginning of the tree segment on the path profile
Start a water segment                    Specify the beginning of the water segment on the path profile
End segment                                    Specify the end of any segment
Delete the nearest segment          Delete any nearest segment
Move site A                                       Move site A to the specified location
Move site B                                       Move site B to the specified location

The following must be observed when creating a path profile manually:
1.    The first elevation point must have a zero distance.
2.    The path profile must have at least two points.
3.    A clutter object must not extend beyond the last terrain point.


For more information about creating a path profile of microwave link hops, visit our YouTube channel.

Entering Main Parameters of Microwave Links

The equipment parameters for the selected hop must be entered for each site of the hop in the Site A and Site B tab.

Figure 8. Microwave radio parameters

Toolbar:
Copy from site B (A)—copy all the parameter data from Site A (B) to Site B (A).
Copy to Clipboard—copy to clipboard all the data of this site (for example, for use on another hop).
Paste from Clipboard—paste parameter data from the clipboard.
Import from RAF file—import radio equipment data file; Radio data files format matches the ASCII radio data file format *.raf used in Pathloss version 5 program.
Export to RAF file—export radio equipment data file in ASCII radio data file format *.raf.
Save current parameter values as a template for future use—save in template all the data of this site for use on new sites.

 

Below is the description of all input parameters that may be necessary to specify. The required input parameters are determined by the application automatically based on the equipment configuration and calculation requirements.


A number of common parameters (such as frequency) when entered for either Site A or Site B will be automatically copied to the remote site.

01. Main
Radio equipment                     Radio equipment code. Information only
Frequency, MHz                       Mean frequency of the microwave link. The value is automatically copied to the remote site
Diversity                                     Diversity configurations (None, Space Diversity, Frequency Diversity, Comb-4Rx)
Frequency spacing, MHz        Frequency spacing between TX channels for frequency diversity. Required if                                                                                                     frequency or combined diversity is selected
Polarization                                Polarization type (Vertical, Horizontal or Co-channel operation). The selected type is automatically                                                             copied to the remote site
02. Antennas and feeders
Primary antenna and feeder

Antenna model                          Antenna model code. Information only
Antenna height, m                     Antenna installation height relative to ground level, m. You can also change the                                                                                                antenna height in the profile window
Antenna gain, dBi                       Antenna gain, dBi

Vertical antenna beamwidth,

degrees                                        Antenna 3 dB beamwidth in a vertical plane, use only for reflection analysis. The default value is 3                                                              degrees
Feeder length, m                         Feeder length to the primary antenna, default value is 0 dB
Feeder specific loss, dB/m        Feeder specific loss, the default value is 0 dB/m
Branching loss, dB                      Branching loss at Tx and Rx (if any), the default value is 0 dB.
Diversity antenna and feeder
Antenna model                            Antenna model code. Information only
Antenna height, m                       Antenna installation height relative to ground level, m
Antenna gain, dBi                        Antenna gain, dBi

Vertical antenna beamwidth,

                                                    Degrees Antenna 3 dB beamwidth in a vertical plane, use only for refraction analysis. Default                                                                                          value is 3 degrees
Feeder length, m                          Feeder length to the antenna, default value is 0 dB
Feeder specific loss, dB/m         Feeder specific loss, the default value is 0 dB/m
Branching loss, dB                       Branching loss at Tx and Rx (if any), the default value is 0 dB
03. Cochannel    
Cross-polarization

improvement factor XPIF, dB      XPD improvement produced by the cross-polarized improvement device (XPIC                                                                                                  device), the default value is 18 dB
Carrier-to-interference

ratio Co/I, dB                                  Co-Channel Co/I at Rx input, the default value is 20 dB
Cross polarization

discrimination XPD, dB                 Antenna cross polarization discrimination, XPD. The default value is 30 dB
04. Radio specifications    
Use adaptive modulation    
         YES or NO.The selected type is automatically copied to the response site. In the                                                                                              case of adaptive modulation (YES), you need to enter the values of Tx power, Rx                                                                                               threshold, and Rx signature for each modulation type in the table that appears  below
Calculate selective outage

probability                                        YES or NO. The selected type is automatically copied to the remote site. The calculation of the                                                                  selective outage probability is usually valid for signals with a bandwidth of more than 10 MHz

Without adaptive modulation
Modulation                                       Modulation type. The value is automatically copied to the remote site. Information only
Capacity, Mbit/s                              Channel capacity, Mbit/s. The value is automatically copied to the remote site. Information only
Tx power, dBm                                 Transmitter power, dBm
Rx threshold, dBm                           Receiver threshold level, dB. The receive threshold level must correspond to bit                                                                                                 error rate of 10-3, 10-6 or to the special SDH bit error rate referred to as the SES BER.                                                                                    Numerically this is between 10-3 and 10-6. The fade margin is based on this entry
Signature delay, ns                          Signature delay, ns. Radio equipment parameter, used for selective outage                                                                                                        calculation. Default value is 6.3 ns. The value is automatically copied to the response site
Signature width, MHz                     Signature width, MHz. Radio equipment parameter, used for selective outage                                                                                                    calculation. The value is automatically copied to the remote site
Signature depth min phase, dB     Signature depth min phase, dB. Radio equipment parameter, used for selective                                                                                                outage calculation. The value is automatically copied to the remote site
Signature depth nonmin

phase, dB                                           Signature depth nonmin phase, dB. Radio equipment parameter, used for                                                                                                         selective outage calculation. The value is automatically copied to the remote site

With adaptive modulation
                           

Figure 9. Microwave radio parameters with ADM

The meaning of the parameters for each type of modulation is the same as in the previous table.

Objectives

On this tab, you need to specify your approach to determining the reliability of the microwave link, and, if necessary, enter additional parameters of the hop to calculate the performance and availability objectives.

Total annual time below level

Outage times are reported for the worst month and annually without considering the fade duration. The annual rain outage is simply added to the annual multipath outage for the total annual outage. This assumes that the conditions for high-intensity rain and severe multipath fading are different and the two fading mechanisms do not occur at the same time. Outage probabilities can be expressed as availability (99.9999%) or unavailability (sec).

Use of Error Performance Objectives (ITU-R F.1668) and Availability Objectives (ITU-R F.1703)

In this case, Severely Errored Seconds is calculated for the worst month as a ratio (SESR) and in seconds (SES). Availability is reported as a ratio per year; unavailability is reported in seconds per year. It is assumed that a rain fade will always last longer than 10 consecutive seconds; and therefore, the rain outage is always classed as unavailability.
For the objectives calculation you have to specify if the hор is part of an International or National Link and select among the relevant subcategories—Long Haul, Short Haul, Access.

Microwave link error performance and availability calculation

MLinkPlanner calculates path reliability and outage under the model recommended in the ITU-R P.530-17.
To start the calculation, click Report and a calculation report will come up. You can switch between the short report view and the full report view.


The short report displays only calculation results;
The full report displays input parameters, calculation results, path profile drawing and path profile diagram on the map.


You can print the report or save it as PDF, Microsoft Word or Excel.

How to do Microwave Link Availability Calculation

Figure 10. Report for microwave link with ADM

You can also save summary information for all Point-to-Point links in Excel spreadsheet. Click the "Summary Report" button on the PtP tab and Excel spreadsheet will open. 

Figure 11. Summary Report for Point-to-Point links

Optimizing Antenna Heights According to with Rec. ITU-R P.530-17

MLinkPlanner can calculate the height of main and diversity antennas using the clearance criteria described in the Rec. ITU-R P.530-16.
To calculate minimum antenna height, click an icon           next to the desired antenna. In the window that opens, specify the optimization parameters. The height of the remote antenna will be fixed at the current value.

How to Calculate the Antenna Height

Figure 12. Antenna height calculation

Climate                                       Temperate climate
                                                     Tropical climate
Type of obstruction                  Obstruction is extended along a portion of the path
                                                     Single isolated path obstruction
Criteria                                        Standard
                                                     Less conservative criteria. May be necessary for frequencies less than                                                                           about 2 GHz to avoid unacceptably large antenna heights
Standard k-factor                      The median value of the k-factor (equivalent earth radius factor) for standard                                                               atmosphere. Can be modified by the designer
Extreme k-factor                        The lowest expected (minimum) value of the k-factor, computed from ITU-R Rec.                                                         P.530-17, as a function of path length. Can be modified by the designer
Part of Fresnel Radius              Part of the First Fresnel ellipsoid that is required to be free of any obstruction for                                                        the appropriate value of the k-factor. Is automatically determined depending on the                                                        Type of Climate, Type of the Obstruction and Criteria from above, but can be                                                                  modified by the designer

In a space diversity configuration, the minimum height of secondary antennas is calculated without taking into account climate and extreme k-factor as per Rec. ITU-R P.530-17.


Minimum antenna height is calculated with consideration for clutters (forest and buildings) located on the hop.


Once the required preferences are selected, click Calculate antenna height and the minimum antenna height will appear on the right. The path profile image will display the criterion used to calculate the antenna height. Click OK to change the antenna height according to the calculated value. To discard the calculated value, click Cancel.

Figure 13. Path profile showing a triggered criterion