"no clouds" is overstating the effect somewhat. I've operated a number of mission critical Ku band based systems that met four nines of overall link uptime. The operational effect of a cloud that isn't an active downpour of rain is negligible. Continual overcast of clouds is not much of a problem at all, it's active rain rate in mm/hour and its statistical likelihood, climate parameters of the location.
Yes, during rain fade events, current generation VSAT modems will drop all the way down to BPSK 1/2 code rate to maintain a link, with corresponding effect on real world throughput in kbps each direction, but entirely dropping a link is rare. On Mon, Jul 6, 2020 at 9:40 PM Denys Fedoryshchenko < nuclear...@nuclearcat.com> wrote: > On 2020-07-07 06:48, Eric Kuhnke wrote: > > This is why adaptive coding and modulation systems exist. Also dynamic > > channel size changes and advanced computationally intensive FECs. > > > > You don't think people working on microwave band projects above 10GHz > > with dollar figures in the hundreds of millions are unaware of basic > > rain fade and link budget methodology, do you? > > > > On Mon, Jul 6, 2020, 8:44 PM Denys Fedoryshchenko > > <nuclear...@nuclearcat.com> wrote: > > > >> On 2020-07-07 05:04, joe mcguckin wrote: > >>> Theoretically, Starlink should be faster cross country than > >> terrestrial > >>> fiber. > >>> > >>> > >>> Joe McGuckin > >>> ViaNet Communications > >>> > >>> j...@via.net > >>> 650-207-0372 cell > >>> 650-213-1302 office > >>> 650-969-2124 fax > >> > >> When there is no clouds. > > In my experience, all that ACM has achieved is that when link becomes > "slow" and if it rains outside, it means that it will be down completely > after few seconds. > Previously with CCM or DVB-S without 2, it simply disappear without > warning. > And yes, I have and cheap and expensive Microwaves >10Ghz too. > ACM/VCM really helps if you want to live on the edge, milking each db, > (edge of link budget, e.g. small antenna size, interference), and this > is actually very important to increase profitability, especially in case > of multipoint VSAT, but it is near useless against rain fade. >
