Comment by wkat4242

4 days ago

Could you bring something like a starlink mini for backup i wonder? Id imagine this would be very worrying being stuck there as a foreigner in such a situation.

Starlink connects you to the internet via a ground station in the country where you are registered, and the antenna will also only operate in an approved zone (depending on your country and account type). You cannot use it in China.

  • > Starlink connects you to the internet via a ground station in the country where you are registered

    Not true anymore.

    > and the antenna will also only operate in an approved zone (depending on your country and account type). You cannot use it in China.

    This is still correct.

    • > Not true anymore.

      It’s still true because in order to be operating in a country Starlink has to get approval from the Gov and if the Gov requires Starlink to have to connect through a ground station then they’ll either comply or not operate in that country

    • They have a minor capability to do intra-constellation routing now but if they want to operate in China the authorities are going to demand all data be downlinked through Chinese downlink stations so they can do their monitoring.

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You can still bring a foreign SIM card. 100% effective (via data roaming) at bypassing the firewall, but expensive.

  • Oddly, many travel SIMs have started to route traffic through China. I used one in India that clearly routed through Hong Kong, and caused a lot of problems.

A friend of mine tried, no signal.

Depends a lot whether Starlink decides to let you.

  • No it does not. Against a huge state adversary like China it does not matter. They have satellites looking down so they can quickly locate any starlink users. And then ...

    The only thing that could bypass is GPS + laser links (meaning physically aiming a laser both on the ground AND on a satellite). You cannot detect that without being in the direct path of the laser (though of course you can still see the equipment aiming the laser, so it doesn't just need to work it needs to be properly disguised). That requires coherent beams (not easy, but well studied), aimed to within 2 wavelengths of distance at 160km (so your direction needs to be accurate to 2 billionths of a degree, obviously you'll need stabilization), at a moving target, using camouflaged equipment.

    This is not truly beyond current technology, but you can be pretty confident even the military doesn't have this yet.

    • The aim doesn't need to be that accurate. Laser beams diverge due to diffraction. You can't break the laws of physics - a non-divergent laser beam would need to be infinitely wide. A 1cm wide laser beam of 700nm light will have a divergence width of approximately asin(0.0000007/0.01) which is 0.004 degrees, which is 14 arcseconds, which is very easily aimable using off-the-shelf components. People get a tracking accuracy around 1 arcsecond using standard hobbyist telescope mounts.

      However, this solution is going to stop working when a cloud drifts past.

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    • What makes it so that this kind of precision is required? I have little knowledge of the physics behind it, but a few decades ago, a local university had an open day where they bounced lasers off of a retro reflector on the moon to measure the distance: https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment...

      The moon is 700 times farther away than the starlink satellites (or twice that, if you consider the bounce), so I find it hard to imagine that it would be impossible to communicate with much closer satellites over laser when both sides can have an active transmitter.

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