Radio Link Lab: Exploring Signal Propagation and Coverage |…

What a Radio Link Is

A radio link is the path between two points in a communication system where data can be transmitted using electromagnetic waves. This simulation allows you to plan such links over complex terrains, ensuring reliable signal transmission.

The key components of a radio link include the transmitter and receiver, which must maintain line-of-sight or use techniques like diffraction and reflection to overcome obstacles.

Link Budget and Free-Space Loss

A link budget is an accounting of all gains and losses in a communication system. It helps determine the power required at the transmitter and the sensitivity needed at the receiver.

Free-space loss (FSL) accounts for the reduction in signal strength as it travels through space, which can be calculated using the formula FSL = 20log(d/λ), where d is the distance between the transmitter and receiver, and λ is the wavelength of the signal.

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Fresnel Zones and Knife-Edge Diffraction

Fresnel zones are regions around the line-of-sight path that affect radio wave propagation. Understanding these zones helps in designing links to avoid dead spots.

Knife-edge diffraction, a technique used here, involves calculating how signals bend around obstacles using an approximation of the Fresnel integral.

Terrain and Coverage Analysis

The simulation provides tools like viewsheds and RSSI (Received Signal Strength Indicator) maps to analyze signal coverage over complex terrains.

By optimizing the placement of masts and relays, you can ensure that all areas are within the desired signal strength range.

Frequently asked questions

What is a link budget used for?

A link budget helps in determining whether a radio communication system will work by accounting for all gains and losses between the transmitter and receiver.

How do Fresnel zones affect signal propagation?

Fresnel zones determine areas around the line-of-sight path where signals can experience significant loss or interference, impacting the reliability of the radio link.

Why is knife-edge diffraction important in this simulation?

Knife-edge diffraction helps in predicting how signals bend around obstacles, which is crucial for designing links that can effectively transmit over complex terrains without dead zones.

What does a viewshed and RSSI map show?

A viewshed shows the areas visible from a given point on the terrain, while an RSSI map indicates signal strength across different regions, helping to identify coverage gaps or strong signal areas.

Try it live

Everything above runs in your browser — open Radio Link Lab: Link Budget, Fresnel Zones, Knife-Edge Diffraction and Terrain Viewshed and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Radio Link Lab: Link Budget, Fresnel Zones, Knife-Edge Diffraction and Terrain Viewshed simulation