Node close to a enforced concrete beam --> better to move 30-100 cm away?

Hi

If a node is attached to a reenforced concrete beam just above ground level (bridge), is it better to move it away a bit from the beam?

For example by adding a horizontal bar (like for parabolic antenna support) so that the node is placed 30-100 cm from the beam in free space. Any remarks about the exact distance?

The concrete will clearly absorb and screen the RF from the nodes antenna, depending on the direction of the Gateway, so the further away from the beam the better for sure.

I very much doubt there is a constistency in the various concrete types to provide an exact ‘tuned’ distance.

With the right LoRa test software it would not be too difficult to test the reality of the impact on node reception in such circumstances and my own LoRa library has the tools to carry out such real world tests, but discussion of point to point LoRa is outside the scope of this TTN forum …

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Discussions on how to get measurements to improve nodes or placement of nodes or how to measure antennas are welcome. Even if you have to use PtP Lora for the purpose. (Which understandably would be a lot easier to use for these measurements then LoRaWAN)

Thanks

I was more worried about a distance below the wavelength or something like that.

I know that measuring at where the gateway’s are is also important. I suppose that the absorbing of the concrete will make a rather good visible difference on the RSSI depending on the side of the beam’s.

I am not aware of any studies that have measured the impact on RF absorbtion, at various fractions of a wavelength from concrete versus the particular type of concrete. If you find such a study let us know.

I suppose that the absorbing of the concrete will make a rather good visible difference on the RSSI depending on the side of the beam’s.

It might, but you would need to run a large number of transmission and reception iterations, which is not really possible within TTN, your back in the realms of point to point LoRa link testing.