meshtastic/docs/hardware/antenna/non-aerial.md

id	title	sidebar_label	slug
non-aerial	Non-aerial factors affecting transmission	Non-aerial factors	/hardware/non-aerial

Unless you're using your devices in a vacuum with clear line of sight between aerials the following will have an affect:

• Weather (temperature, humidity & air pressure),
• Transmission power, spreading and other associated channel factors,
• Number of nodes within reach in the mesh (affects retries consequent duty cycle hit),
• Absorption by materials (with varying degrees attenuation, by material and depth),
• Reflection off surfaces (and channeled through material tunnels, including warm / cold air tunnels commonly present in the atmosphere),
• Diffraction around obstacles (over forests and around corners).

Environmental factors

For a bit of light reading on environmental research:

• RF attenuation in vegetation (yes really); if you wander through the woods wondering how your RF is bouncing off leaves dependent on their variety, and wind speed … well you do, now.
• RF attenuation with various building materials.
• This one by ITU again is very detailed in its analysis of the drivers of attenuation (I wasn’t aware that all EMF radiation exhibits reflection / transmission characteristics akin to light hitting a material boundary. So, depending on the angle of incidence, material and the EMF wavelength, it will be reflected and / or transmitted through).
• These RF bands are also made more noisy by adjacent LTE

In summary - wavelengths in Europe fair well in plain sight, curve over not-so-tall obstacles (including trees), reflect of surfaces at low angles of incidence. They go through humans without much attenuation; but not brick or stone or anything much above glass / Kevlar. Oh, and don’t sit under an LTE tower and expect it to be plain sailing.