[Starlink] Re: Starlink and Iran

[David Lang <david@lang.hm>]

Ulrich Speidel wrote:

> Again, not that straightforward.
>
> These beams have to come from somewhere, and there has to be - from the 
> ground perspective - some angular separation between them, lest adjacent 
> beams both end up in the main lobe of the same receiver on the ground. So 
> there's only so much potential here - and 8 beams might already be pushing it 
> in a dynamic environment like LEO. Remember: You have to maintain that 
> angular separation until at least the next handover (and you don't want to 
> have these too often as they mean packets being sent pre-handover into queues 
> heading for the pre-handover satellite -> packet loss if these queues don't 
> clear before the handover).
>
> Phased arrays (unlike real dishes) also have non-insignificant side lobes, 
> and an unwanted beam getting into one of those raises the noise floor.

does anyone know what the various starlink dishe patterns look like?

everything you say is correct, but with ~10x the number of satellites needed for 
full coverage, and the satellites supporting multiple beams each (with newer 
satellites supporting more beams), it would seem reasonable to expect that there 
are enough in the right place at the right time.

personally, I would opt for more handovers if it means being able to support 
more users in an area. I normally do not notice handovers, so am not that 
worried about it.

> User density isn't just a matter of population density but also of fibre and 
> mobile penetration on the ground. In places like NZ, where fibre penetration 
> in cities and towns is high, user density is highest in their outer periphery 
> (where lifestyle block meets IT manager just outside fibre coverage). In 
> other places, where there hasn't ever been a concerted push to fibre up 
> cities, you find it's the townsfolk who buy Starlink's shelves bare. The US 
> are probably more in that category.

exactly my thoughts.

> Going over the limits in the US would be a nice experiment I think. If it 
> works there, I'm sure the likes of Brazil and the Philippines would be 
> watching closely.

exactly what I think is happening, and why I'm not as worried about 
international agreements as you are.

David Lang