A troposcatter link is a PERMANENT available conntection over the horizon between two radiostations in the VHF / UHF / SHF frequency range.
To establish such a link usually ERP over 1 kW is needed to compensate for the free space and scattering losses.
Newly amateur-radio operators have programmed Software (e.g. WSQ2) that runs on common PC and uses the incorporated soundcard as a slow data-rate modem to create a very penetrating modulation which is decodable more than 15 dB under (!) the noise level.
The radio operator can´t hear anything, but the program is able to decode the text message!
With the big benefit of a program like WSQ2 everyone can establish a permanent radio-link over hundreds of km with a couple of watts and a simple antenna with some dB gain.
Certainly, all rules of a common troposcatter connection must be respected e.g. free sight to the horizon, low radiation angle, horizontal polarization, no obstacles before the antenna …