[Starlink] Starlink for Tonga?

Ulrich Speidel ulrich at cs.auckland.ac.nz
Mon Feb 7 17:22:59 EST 2022


Nice tracker, Mike!

That said: It's not just a matter of geometry though. Presuming that a 
dishy aims itself at whichever portion of the sky it seems most 
satellites (with gateway service), there's another aspect to the 
elevation angle. The lower your elevation, the longer the path that the 
signal has to take through the atmosphere, and the higher the degree of 
service disruption as a result of rain fade, or in Tonga's case, 
potential ash cloud fading. In Fiji's case, Starlink also has to find a 
site with low elevation take-off to Tonga AND fibre connectivity. Plus 
they have to get past the regulator in a country that's know to regulate 
heavily and that currently experiences a lot of Covid-related disruption 
with people in badly connected home office.

Note that Tonga has had emergency service for a while now: Intelsat, SES 
and Kacific are all at present providing service (Kacific at 1 Gbps 
even). That's plenty for emergency use.

The big sticky point is that mobile Internet isn't working, people have 
to go to Tonga Telecom offices for access or wifi. That's an issue 
because 4 out of 5 households in Tonga rely on remittances from family 
overseas, which are usually sent via Western Union. Moneygram etc., 
whose apps are out of action right now.

And yes, the date line is fun. Pacific countries are known for having 
shifted it back and forth for spurious reasons, which is why it's badly 
bent, and these days I'm still  grateful if people have maps online that 
don't end at the date line ;-)

On 8/02/2022 10:36 am, Mike Puchol wrote:
> Placing a gateway at the Fiji teleport results in satellites that 
> cover Tonga being serviced. However, satellite density, but most 
> importantly, GSO protection, take out a significant portion of the 
> coverage from the satellites.
>
> They would need to lower minimum elevation (now 25° everywhere) to 
> improve the situation. With things as-is, Tonga would be covered by 
> 1-2 satellites which should be enough for emergency service restoration.
>
> You can play around with this on my tracker at https://starink.sx 
> <https://starink.sx>, 
> I will be adding the temporary gateway in a few minutes.
>
> Please not that the date line causes some weird issues with the map 
> and the algorithms, which I’m still trying to fix. You can thank 
> whoever thought moving from -180° to +180° across a line was a good idea.
>
> Best,
>
> Mike
> On Feb 7, 2022, 22:24 +0100, David Lang <david at lang.hm>, wrote:
>> the dish aimes at where it sees the most satellites, not necessarily 
>> 53. I took
>> my dish to a campground where there were trees to the north and it 
>> ended up
>> pointing straight up (Los Angeles area) performance was fine.
>>
>> when you power it on, the dish tilts and swivels to point straight up 
>> (no idea
>> what the angle logic is), and after a few min of watching the sky 
>> will re-aim
>> itself if/as needed.
>>
>> David Lang
>>
>> On Mon, 7 Feb 2022, Ben Greear wrote:
>>
>>> Date: Mon, 7 Feb 2022 13:18:49 -0800
>>> From: Ben Greear <greearb at candelatech.com>
>>> To: starlink at lists.bufferbloat.net
>>> Subject: Re: [Starlink] Starlink for Tonga?
>>>
>>> 90 or even much smaller percentage is a lot better than zero.
>>>
>>> I wonder if they can point the dish towards the horizon to pick up 
>>> the sat
>>> where
>>> it can best see the functional downlink. I realize the dish auto-points
>>> itself
>>> now, but surely engineers that can design that can also design an 'off'
>>> switch
>>> for that and let their on-the-ground folks do some hacking....
>>>
>>> Thanks,
>>> Ben
>>>
>>> On 2/7/22 11:05 AM, Christian von der Ropp wrote:
>>>> But in practice the satellites won't be sitting and waiting at the 
>>>> edge of
>>> this 940km radius. They are moving in and out the radius and the 
>>> question is
>>> if
>>>> satellite density is high enough so that once the serving satellite 
>>>> loses
>>> its gateway link there's another satellite in the 940km radius which 
>>> also
>>> covers
>>>> Tonga. And then this new satellite cannot be within certain elevation
>>> angles (~60-80° at 0° azimuth) where the geostationary arc crosses 
>>> Fijian
>>> skies and the
>>>> gateway antennas have to seize emission. My gut feeling is that
>>> availability in Tonga would be <90% simply because it's too far out 
>>> at the
>>> edge of a Fijian
>>>> gateway's range where there will be frequent service interruptions.
>>>>
>>>>
>>>> Am 07.02.2022 um 19:51 schrieb Nathan Owens:
>>>>> The current coverage radius of a gateway/ground station with a 25 
>>>>> degree
>>> minimum elevation is ~940km, so nothing in theory.
>>>>>
>>>>> On Mon, Feb 7, 2022 at 10:50 AM Daniel AJ Sokolov 
>>>>> <daniel at sokolov.eu.org>
>>> wrote:
>>>>>
>>>>> Hello,
>>>>>
>>>>> I hope this is not offtopic: Starlink wants to build a ground station
>>> on
>>>>> Fiji to supply Tonga with internet.
>>>>>
>>>>> The distance between Tonga and Fiji is about 750 km minimum. That's
>>>>> quite the distance.
>>>>>
>>>>> What does Starlink have to do to make this work?
>>>>>
>>>>> Cheers
>>>>> Daniel
>>>>> _______________________________________________
>>>>> Starlink mailing list
>>>>> Starlink at lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/starlink 
>>>>> <https://lists.bufferbloat.net/listinfo/starlink>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Starlink mailing list
>>>>> Starlink at lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/starlink 
>>>>> <https://lists.bufferbloat.net/listinfo/starlink>
>>>>
>>>>
>>>> _______________________________________________
>>>> Starlink mailing list
>>>> Starlink at lists.bufferbloat.net
>>>> https://lists.bufferbloat.net/listinfo/starlink 
>>>> <https://lists.bufferbloat.net/listinfo/starlink>
>>>>
>>>
>>>
>>>
>> _______________________________________________
>> Starlink mailing list
>> Starlink at lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starlink 
>> <https://lists.bufferbloat.net/listinfo/starlink>
>
> _______________________________________________
> Starlink mailing list
> Starlink at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink
>
-- 
****************************************************************
Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)
Ph: (+64-9)-373-7599 ext. 85282

The University of Auckland
ulrich at cs.auckland.ac.nz  
http://www.cs.auckland.ac.nz/~ulrich/
****************************************************************


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/starlink/attachments/20220208/3f35426a/attachment-0001.html>


More information about the Starlink mailing list