[Starlink] An update on Tonga

[Ulrich Speidel]

On 2/09/2024 2:26 pm, Michael Richardson wrote:
> Ulrich Speidel via Starlink <starlink at lists.bufferbloat.net> wrote:
>      > There were quite a few folk on this list a couple of years back who were
>      > interested in what was happening to Internet in Tonga after the big volcanic
>      > eruption there. I'm not sure where I left off.
>
> Thank you for the update.
>
>      > Spare cable was ordered from France and was installed middle of 2023,
>      > restoring the TDCE to service.
>
> How long was the outage caused by lack of spare cable?
About 18 months. The eruption was in January 2022, the cable was 
repaired middle of last year.
> Is there an effort to keep more spare cable closer?
Yes. That was one of the lessons learned. After the eruption, the cable 
ship that went to Tonga to repair the damage called at the Subcom depot 
in Apia enroute to the cable grounds and pretty much loaded all 
available spare cable, including cable spares borrowed from other 
systems, many of which were used in the repair of the international 
cable and needed to be returned. It's worth knowing in this context that 
a "typical" cable fault is anchor damage in relatively shallow water, 
which doesn't need a lot of spare cable to fix. The worst case fault 
normally considered is a single-location break at ocean depth of around 
5000 m, and again that requires less than 10 km of cable to fix. So most 
cable systems will not keep more than a couple of patches of a dozen km 
or so as spares. But if a volcano or major landslide destroys dozens of 
km of cable, then obviously that takes a lot more spare cable to remedy.
>
>      > location. The operators were well aware of the risk, however re-routing the
>      > cable would have required it to be lengthened, with the need to insert
>      > repeaters, upgrade terminal equipment, and conduct a new marine survey, which
>      > would have meant further delays.
>
> Is this on the long-term plan?
Yes and no - they've certainly been looking at alternatives for a while, 
including the Hawaiki spur to Vava'u that I talked of in my other 
e-mail, and using different cable routes and / or microwave links to 
Ha'apai from both ends.
>
>      > On 26 August 2024, 11:29 am, a M6.9 quake struck in the area at a depth of
>      > about 106 km. Our Science building in Auckland has a "citizen science"
>      > seismograph with a big display in its foyer, and my student and I noticed the
>
> That's pretty neat.

If you ever find yourself in Auckland, it's in Building 303, a five 
minute stroll up from Queen Street, the building on the corner of 
Princes Street and Wellesley Street - the entrance about 50 m up Princes 
Street. Walk straight in through both sets of glass sliding doors and 
you can't miss. The seismometer is right there, too.

The current seismogram can be found here:

https://nzseis-stations.auckland.ac.nz/stations/AUCK/latest.png

The seismogram of the event is here:

https://nzseis-stations.auckland.ac.nz/stations/AUCK/p202408261316.png

>
>      > Meanwhile, Starlink has been licensed to operate commercially in Tonga. For
>      > many Pacific Island countries, this is a double-edged sword: On the one hand,
>      > this provides short-term relief, on the other hand, it deprives local ISPs of
>      > customers and therefore impacts on aspirations to achieve cable connectivity
>      > which could provide more bandwidth in the medium term.
>
> Yeah.  I see those edges.
>
-- 
****************************************************************
Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)

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