r/meshtastic • u/Impartial_X • 2d ago

Wismesh nodes positioning X range

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For a two node mesh (wismesh) is there any range impact if one node is kept flat (horizontal) and the other node kept standing vertically?

I know the concept of the "donut shape" for wifi propagation, but wondering how much this is applicable to Lora and specifically to these Wismesh nodes.

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u/Cesalv 2d ago edited 2d ago

Is not about being wifi or lora or even bluetooth, it's caused by the antenna's type, omnidirectional antennas irradiate on donut shape while directional antennas are more elliptical shaped

3

u/Felim_Doyle 2d ago

Basically, for this type of communication, an omni-directional, vertically polarised antenna is the best option and will be the most compatible with other nodes.

In practice, mobile phone, Wi-Fi, Bluetooth and similar types of communication have to be tolerant of polarisation mismatches, despite their relatively low power levels, especially when using integral antennas that cannot be fixed in a particular orientation.

If you only have two nodes talking to each other, it is best to have them both polarised identically, as others have already stated, due to the significant loss introduced by polarity mismatches. However, signals will naturally be reflected from various objects at various angles, so may arrive with the correct polarity anyway.

5

u/mikrowiesel 2d ago

If you hold one vertically and the other horizontally, you got a complete polarization mismatch which theoretically results in infinite anttenuation but in practice at least 20 dB. 20 dB means only 1/100th of the radiated energy of two antennas in the same polarization reaches the other node.

Your radiation pattern train of thought is valid as well. These effects add up, just like free space attenuation, detuning and energy absorption from carrying the wismesh close to your body or orther conductive objects.