On 25/09/2023 11:32 pm, Noel Butler via Starlink wrote:
On 25/09/2023 18:06, Alexandre Petrescu via Starlink wrote:
ah, sorry, probably we speak of the same thing.
I dont know whether or not the current in-car starlink devices
require an extra 12v-to-220V/110V adapter, or whether it's included,
or integrated.
Here, the "RV" is identical to a household service, the same stuff,
except your allowed to move around - not locked to the beam covering
your home location.
Depending on where on the globe you live, there is a difference in the
range of Dishy options available (or at least advertised), which is
where perhaps some of the confusion arises.
The "RV" option available in Australia and NZ at this time is indeed the
residential option without the cell lock. It's intended for stationary
use and assumes that you have a mains (AC) power source. We've tried it
here with the much taunted Yaosheng adapter, which however isn't 12V (it
needs 42V) and which gave us a lot more outages than the Starlink router
with Ethernet adapter.
There is also a "mobility" option available here (or at least they offer
sales consultations for it) that's shown mounted flat on the roof of a
speeding 4WD and seems to be quite different from a residential class
Dishy. Presumably that will run off 12V. Cost is significantly more than
for the RV option, and there's an "up to" caveat on the data rate, which
I take to mean "I you decide to hoon around with a Dishy that doesn't
really have the opportunity to track properly with its phased array,
then expect to have to track multiple sats in parallel to stay
connected, and expect to pay for the privilege of occupying a larger
number of slots, many of which you won't get to use properly".
These 12V-220V/110V adapters are relatively big, necessitate fans.
If you're getting the "RV/camping/portable" equipment you'd want to
use your 12volt system that nearly all campers and RV's I've seen with
factory electrics come with (A couple RV models are 24v) so the DC
supply woud need to accept 12 to 48 input, slightly less heat is
generated if you use 24v and even less again if 48v since it only
bucks it for the 12v parts of the circuitry in modem. You would not
want to use an AC supply, defeats the purpose of the design of that
service, the 12 to 48v boost converters for the dish to work have
decent heat sinks, a little better ventilation in the modems for that
little bit of extra heat would be beneficial.
If they are still needed for starlink in-car devices is probably
because of higher transmit power that is necessary to reach to 360km
altitude. They could reduce that in-car power need by bringing the
sats even lower, or other non-sat objects like HAPs. Or by
augmenting the starlink sat antennas sizes.
They are identical hardware, no extra power is needed, since there is
350 odd km's to the satellite, do you really think the 2 or so metres
AGL for campers, would really need more power compared to the standard
unit at 10 metres AGL, at say a house mounted dish :) In early days I
remember quite a few youtubers using the stand on the ground in their
back yard, and they probably still do.
Distance to the satellite is usually much more than 350 odd km. The vast
majority of Starlink sats orbit at around 550 km, and your Dishy does
not normally talk to satellites straight overhead (except in a few
select latitudes, such as close to the 53rd parallels, where it may do
so if there is one right overhead at the time). In moderate latitudes,
where much of humanity lives, Dishy will point itself in the direction
of the nearest 53rd parallel and track satellites it can see in roughly
that direction, meaning that most satellites Dishy talks to are more
like 800 - 1000 km away. Near the Equator, Dishy will remain in "coffee
table" position but avoid the geostationary arc, which also means that
the sats it talks to are quite a bit off to the side all of the time.
We've observed that our Dishy consumes more power during large downloads
than during uploads, which suggests that transmit power isn't the main
factor here. It appears that it's the signal processing that is needed
to receive and demodulate the incoming signal with the high bit rate
data stream that really eats the watts.
Incidentally, with more birds in the sky, Dishy seems to be willing to
put up with a bit more obstruction nowadays:
Think of this image as viewing our Dishy down its surface normal,
mirroring the sky. Anything in red is obstruction, anything in white (if
your background is white, save image and view against a dark background)
are successful communications with satellites. The obstruction you see
here is the corner of my roof at home, making up around a quarter of
Dishy's field of view. The obstruction resulted in a ping loss of 518
packets out of 635923, or 0.08%.
--
****************************************************************
Dr. Ulrich Speidel
School of Computer Science
Room 303S.594 (City Campus)
The University of Auckland
[email protected]
http://www.cs.auckland.ac.nz/~ulrich/
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