Re:Building a Private Lora Network
by superkuh on Wednesday November 16, 2022 @09:23AM
(#33623416)
No radio transmission that is above 30 MHz or so is really "high range". The modulation doesn't matter. The only thing that matters for range in non-ionospheric bouncing radio transmissions is the height above surrounding terrain of both ends of the link.
SMS works because the cell phone companies pay the big bucks to their base stations up very high above surrounding terrain.
There are transient exceptions like atmospheric gradients in water vapor density creating brief tropospheric ducts which VHF radio can bounce down but these are unreliable. And tropospheric scattering propagation requires very high powers and high gain antennas at both ends so it's not really feasible for people operating under FCC part 15 or even ham radio power restrictions (ie, <1500 watts).
SMS works because the cell phone companies pay the big bucks to their base stations up very high above surrounding terrain.
There are transient exceptions like atmospheric gradients in water vapor density creating brief tropospheric ducts which VHF radio can bounce down but these are unreliable. And tropospheric scattering propagation requires very high powers and high gain antennas at both ends so it's not really feasible for people operating under FCC part 15 or even ham radio power restrictions (ie, <1500 watts).