Welcome to Pathloss Version 6

What’s New in Pathloss 6

Pathloss 6 has taken on a number of major changes to how the program operates while maintaining a consistent and familiar interface. New program organization is aimed to simplify or eliminate many of the complexities involved in getting started or re-started with Pathloss. New design ideas are intended to allow Pathloss 6 to evolve and adapt to industry needs in the long term.

Program Organization and Layout

Pathloss 6 is installed as a single application. There is no separate application for links as there was in Pathloss 5. Pathloss 6 will show the network window, the link window or both depending on how it is being used.

Opening Pathloss 6 normally or by double clicking on a Network File (gr5) will bring up the network window as in Pathloss 5. From here you can open an existing network or begin adding sites and links in the usual way. Clicking on a link with the Link Tool will bring up the Link Window and open the associated file for that link.

You can click Files – New Link Window or click the associated toolbar button to bring up a new blank Link Window.

Unlike version 5, the Link Window is not restricted in its file operations. You can open a new link file, or click Files – New to start a new link. You can click Files – Add to Network at any time to move the working link in to the network.

Double clicking a link file (pl5, plz) on the desktop or in explorer will start a new instance of Pathloss and open the file directly in the Link Window. Pathloss will exit when this Link Window is closed. When operating in this mode you can click Files – Add to Network to bring up the link in the Network Window.

Link files can now be dragged and dropped on to the network window to add the link to the network. You can also import link files by clicking Files – Import Link File from the main menu. (Not in the Site List as in Version 5)

Tiled Map Backdrop

Pathloss now produces backdrop imagery for networks anywhere in the world.

Map tiles are downloaded and displayed automatically. Click and drag on the map to pan the display with any cursor and use the mouse wheel to zoom in and out. Map tiles are stored locally for efficiency and performance. You can enable\disable the automatic download of files by toggling Configure – GIS System – Network Display – Map Utilities – Download Automatically.

You can enable\disable the tiled map system entirely with Configure – GIS System – Network Display – Use Tiled Map Backdrop. If this option is disabled, Pathloss operates exactly as version 5, using projections and backdrops defined in the GIS Setup Dialog.

Backdrop Options

There are 3 map styles available. These can be switched between by using the menu Configure – GIS System – Network Display – Map Style… The options are Topographic, Street Map or Satellite.

By default, Pathloss starts with backdrop tiles enabled. To change the start up option, click Configure – Options – Program Options and select the Startup and Defaults section. The option is called Use Tiled Map Backdrop.

There is a utility for deleting the cached map tiles.Click Configure – GIS System – Network Display – Map Utilities – Map Operations. Use the drop-down list to select whether to download files automatically or delete the locally cached tile.


Automatic Terrain Data Management

Pathloss 6 will download and manage terrain data. Pathloss currently offers 4 DEMs and 3 Clutter models.

Digital Elevation Models

  • SRTM 1" DSM (Global)
  • ASTER 1" DTM (Global)
  • NED 1" DTM (North America)
  • NED 1/3" DTM (USA)

Clutter Models

  • Copernicus Global Land Cover 100m (Global)
  • North American Land Cover 30m (North America)
  • National Land Cover Database 30m (USA)

Formats are added or updated as newer or more accurate sources become available.


Zoom the display to the area you wish to download and click Configure – GIS System – Download Terrain Data or click the associated toolbar button. The download dialog is pre-set with the coordinates of the screen and the formats corresponding to the terrain and clutter model in use. Click the Download button to begin the download.

Once the download is finished, the terrain data is ready to use for that area.

This process can be repeated for any area. The downloaded files are saved locally for performance and will be used automatically throughout Pathloss while using that model. You can switch between models at any time depending on the need or location of the network.

A list of available sources can be found at Terrain Data Sources

GDAL Integration

Pathloss 6 now includes the GDAL library for both raster and vector data. Including GDAL makes all common formats accessible. Pathloss 6 includes support for:

  • GeoTIFF formats including DEM and DSM for both elevation and clutter
  • ERDAS IMG formats
  • GeoJSON Vector Formats and Tiled Vector Building Data

New Methods for Adding Profile Structures

There are a couple of new ways to add structures and structure ranges to the profile.

Add Range in Design Links

There are some new options when using the Link Designer (Create PTP Links, Create PTMP Links, Design Links, and Edit Modify Links). These options are found in the Profile Generation section of the Link Design Rules dialog. If you selected the option to NOT use a clutter database, You can set what percentage of the profile should be covered, the height of the range, and the type (tree or building). The structure range will be added and saved in the designed links.

Add Structures to Links from Network Window

There is a new item in the right click popup menu for links: Add Structure at Location. This item will only be enabled when right clicking on a link that contains a filename and profile. To add a structure, you would first right click the link at the point on the link where the structure should be placed. Then select Add Structure at Location to open the link to the Terrain Data Design Section and display the add structure dialog. The Add Structure dialog will be pre-loaded with the distance to the structure corresponding to the location where the link was right clicked. The location will also be marked on the profile with an arrow. You can then fill in the height (and any other values) and place the structure at this location.

This can be helpful if there is a building visible on the map or satellite backdrop and you would like to add the structure to the link at the correct location.

Multiband Support

PLZ File Format

Pathloss 6 is utilizes an extensible file format for storing all information necessary for link design. This file has the extension plz. The plz format is currently used to facilitate multiband links.

Multiband operation allows you to add an additional set of equipment to an existing link. Each band will contain a complete set of equipment parameters, antenna heights, a channel table, design frequency and polarization. The site information, path profile and all calculation options are common to all bands in the link.

Creating a Multiband Link

You can add a new band to the link by clicking Operations – Multiband – Add Band – Copy Current Band. This will create a new band that is a duplicate of the first. The title bar of the link window shows the current band and total number of bands (Pathloss switches to the new band when it is added.)

You can now edit the band information manually or by other methods such as a link design rules file or by loading an existing link file as a template. Any changes to the equipment, antenna heights, frequency, channel table, or polarization will apply only to the current band. Any changes to the profile, or calculation options will apply to the link as a whole. This is true whether the changes are made manually or by using the auto designer or other methods. In the future, design of the band may be performed automatically as it is added.

To select a different band, use the menu Operations – Multiband – Switch Band… Or you can move to the next band by pressing Ctrl + B. To remove the current band, click Operations – Multiband – Remove Band.

Carrier Aggregation

The Carrier Aggregation report works with multiband links to determine the sum capacity of the link over the range of availabilities. This is a purely mathematical operation and by its nature assumes that the multipath fade probabilities in each band are independent from one another i.e., best case.

Carrier aggregation depends on the radio file having capacities defined for each modulation state. These should be in the file as a number in Mbps.

Multipath Aggregation Algorithm

Each band contributes a certain capacity for some percentage time of the year – Availability or “Time in Mode”. The algorithm determines all possible combinations of these states between bands. For each combination, the sum of the capacity and the probability of this combination occurring is computed.

Rain Consideration

For each state in a multiband system, a critical rain rate is determined. As the rain rate increases, any bands with a critical rain rate at or below that level will no longer contribute capacity. This rain calculation determines what combinations will be in effect at the critical rain rates and estimates the occurrence of those rates over the year.

The rain outage probabilities are also combined with the multipath values in the combinations above to produce a total availability for each combination.

Unlimited Number of Channels in Link Files and New Interface

A new interface was developed to manage the increased number of channels. The frequency plan is also integrated in to the dialog for easy access There are three grids for entering data: one TX Channel List for each end of the link, and a Frequency Plan. The grid interface works like other grid controls (SiteList), in Pathloss including all expected keyboard operations.

Data can be entered on any row but will be consolidated when closing the dialog. Only channels with a valid frequency are retained. There are an unlimited number of rows, press the down arrow key on the last row to add more rows.

The Frequency Plan is shown at the bottom of the dialog, along with controls to Open or Save frequency plan files (.tc5). Channel pairs can be added to the link by highlighting the row in the frequency plan and pressing one of the two Add Pair buttons (Site 1 Hi or Site 1 Low). There is also a section to generate a frequency plan by entering a channel spacing, a tx-rx spacing, and a starting frequency.

There is a provision to automatically assign the ID using a format string In this string, use "%d" to output the channel number or "%0Nd" to pad with zeros to make the output N characters wide. The ID is the appended with an 'H' or 'L'.  For example, if the format string was "Chan-%03d", the first id pair would be Chan-001H and Chan-001L.

This interface is used when clicking the Site 1 or Site 2 Channels button in the Transmission Analysis module. It is also used in the Assign Frequencies operation and the Site Interference operation.

Industry Standards

In addition to all of the standards in Pathloss 5, Pathloss 6 adds support for the following ITU standards

  • ITU-R P.530-18 - Propagation data and prediction methods required for the design of terrestrial line-of-sight systems
  • ITU-R P.530-17 - Propagation data and prediction methods required for the design of terrestrial line-of-sight systems
  • ITU-R P.837-7 - Characteristics of precipitation for propagation modelling
  • ITU-R P.676-12 - Attenuation by atmospheric gases and related effects
  • ITU-R P.835-6 - Reference standard atmospheres
  • ITU-R P.453-14 - The radio refractive index: its formula and refractivity data
  • ITU-R P.530 XPD calculation option. 

Pathloss 6 also adheres to the standards set out in the TIA (Telecommunications Industry Association) Standard TIA-10 Interference Criterion for Microwave Systems.

Also in Pathloss 6 is an experimental version of the Vigants-Barnett Multipath Fading algorithm that takes in to account path inclination.

FCC ULS Integration

Pathloss 6 includes support for the FCC ULS Database system. Users working in North America can download the FCC’s ULS data and use it in Pathloss to perform interference calculations against Pathloss designs. This feature is only available with the Interference option.

Licenses requiring coordination are displayed graphically in the new Browse Interference cases window. The NSMA defined coordination area is displayed along with the stations that met the interference objective. The user can toggle through the cases and the interfering paths are displayed. Users can also click on an interfering site, and the site details are displayed. This initial release displays the following information:

  • Site name
  • Callsign
  • Owner details and contact information
  • All coordinating stations for the license

The download process is fast and simple using the dedicated ULS Data Download (UDD) program. New License data is published every Sunday on the FCC website.

Google Earth Export

The network Google Earth export now uses .kmz format so that it can be used and transferred as a single unit. There is also the option to export the link Fresnel zones to google earth as well. There is a new toolbar button associated with the Google Earth export. In the future this button will open the network in google earth without needing to save a kmz file first.

Installation and Licensing

Pathloss 6 is now installed a single program with no standalone link program. This reduces complexity and enhances the relationship between the link and network window.

Pathloss 6 is compliant with modern Window application hierarchy which allows a wider range of installation environments and licensing options. Window 11 is fully supported.

Contact Us

Contract Telecommunication Engineering Ltd.
Delta, British Columbia, Canada
P: (604) 549-4404
E: cte@pathloss.com

About Us

For over 30 years we have been developing and refining the Pathloss program. Beginning with Version 1.4 in the late 1980s, Pathloss was quickly adopted by Equipment Manufactures, Telecommunications, Coordination and Engineering Service Providers worldwide.