Conexiune wireless 2Km, fără vizibilitate directă

My goal was to send my internet connection to next point that is situated about 2Km from my location. I don’t have direct visibility ( the altitude difference is about 30m ), I tried in different modes to get an acceptable connection but permanently I had problems with connection lost. Accidentally I found a solution that works good, I told accidentally because I don’t have knowledge about radio communication, I just remember few things from physics lessons . ( For PDF version see the download link at the end of this article )