Pathloss 4 Overview

The Pathloss program is a complete path design tool for radio links operating in the frequency range from 30 MHz to 100 GHz. The program is created by Contract Telecommunication Engineering at Canada and mostly used by telecom operator and vendor as a transmission planning tools.

Currently there are several versions of Pathloss 4.0:

• PL4B: basic design software for microwave transmission.

• PL4C: basic design software for microwave transmission and coverage calculation.

• PL4I: basic design software for microwave transmission + interference analysis.

• PL4CI: basic design software for microwave transmission + coverage calculation + interference analysis.

Pathloss program uses the Borland database engine (BDE Version 3.0) for interference calculations and the site database. Compatible with almost all windows operating system except for Windows 3.51.Need disk space for at least 25 mb and minimum of 64 mb RAM on windows 98/2000 and 128 mb RAM for windows NT/XP/Vista

This program is structured into eight path drawing modules, an area signal coverage module and a network module which integrates the radio paths and area coverage analysis. Switching between modules is accomplished by selecting the module from the menu bar. Transmission planning module contained in Pathloss are described below.


A. provides a central location for the entry of path data parameters. Path calculations are carried out down to the receive signal level. The Worksheet module completes the propagation reliability analysis. Some items such as the site names and call signs can only be entered in this module. Other entries, such as antenna heights, can be changed in any design module in the program.

B. provides the interface to the Pathloss site database for data entry and interference analysis.

C. sets the application type as either microwave (point to point or point to multipoint) or VHF-UHF.

Terrain Data Module

The design has been optimized for manual data entry and editing. Single structures (trees, buildings or water towers) or ranges of structures can be added to the profile. This consists of a table of distance and elevations between the two sites. Terrain profiles are created in this module using any of the following methods:

a) manual entry of distances and elevations from topographic maps

b) direct entry of distance – elevation data from topographic maps using a digitizing tablet

c) conversion of distance – elevation data in text files from other sources

d) distance-elevation data is read from a terrain database

Special features of this modules are grid coordinate systems, transformation between datums, terrain profile modifications and survey angles.

Antenna Heights

This module determines the antenna heights which satisfy a clearance criteria specified as an earth radius factor (K), a percentage of the first Fresnel zone radius and an optional fixed height. Two separate clearance criteria can be specified for both main and diversity antennas.


Display a complete transmission analysis including rain attenuation, diversity improvement calculations and propagation reliability.

Terrain Databases

A terrain database is required for area coverage analysis, OHLOSS calculations in interference analysis and the terrain view feature. Single path profiles can also be generated from a terrain data base

Site Database

All options of the program include an interface in the Summary and Network modules to a site database

Multipath Module

Ray tracing techniques are employed to analyze the reflective characteristics of a path and to simulate abnormal propagation environment.

Reflections Module

The Reflection module analyzes the deviation in receive signal level on paths whose geometry can support a specular reflection

Diffraction Module

Diffraction module consist a diffraction algorithm ( a diffraction loss calculation ), interactive diffraction loss calculation, tropospheric scatter loss combined with diffraction loss, time variability and variable parameters.

Coverage Module

Coverage modules display analysis of area coverage and line of sight. It’s require a terrain data base.

Antenna & Radio Data Files

Include microwave antenna data files, microwave radio data files,threshold-to-interference(T-I) ratio definition and VHF-UHF antenna data files.

Network Module ( Frequency Planning )

The Network module provides a geographic interface to the path design modules simply by clicking on the link between two sites. This feature significantly reduces the design effort on large projects. Intra system interference calculations are carried out in the Network module.

Intra System Interference

Interference calculations carry the analysis down to the combination threshold degradation of the victim receivers due to multiple interferences.

Terrain View

A 3D terrain view is available in the Terrain Data and Network modules. In the Network module, the user simply defines a rectangular area on the screen to display the terrain. New sites can be added in the terrain view.

I’ll post it on next chapter about profile terrain database with Pathloss.Please visit for more tutorial about telecom and computer at ngupi.

Source by Koe Rendra

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