61–70 of 89 posts
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For other sat phones and sat internet, if a country makes it illegal, the sat carriers don't provide service when you're in that country.
What happens if you are in a border area and one country its legal and one country its illegal?
If this is going to work from my boat at some point, I'm never setting foot on land ever, again.
Earlier quoted context omitted.
For other sat phones and sat internet, if a country makes it illegal, the sat carriers don't provide service when you're in that country.
What happens if you are in a border area and one country its legal and one country its illegal?
This kind of technique has also been targeted at others in the Middle East.
If this is going to work from my boat at some point, I'm never setting foot on land ever, again.
Until you need to shop for groceries and boat repair supplies, of course.
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There are two approaches to mobile users. Either you have a beam from the satellite directly track a moving user, or you have many fixed beams from the satellite and the user has to jump from one to the next as they move. The first method was definitely used to begin with, but it doesn't scale - the satellite only has a certain number of beams available, so past a certain number of moving users it becomes necessary t…
Moving users do not make a difference as the relative speed between satellites and users are dominated by the speed of the satellites which is kilometers per second vs. kilometers per hour for a moving user. The Starlink dishes and satellites are using phased array antennas by the way which can steer the beam extraordinarily fast without having to physically move the antenna at all. https://en.wikipedia.org/wiki/Phas…
The beam steering takes about 10 milliseconds. That means effectively the beam can't be steered at all during use (imagine you steer the beam to one user, send a few packets to them, then steer the beam to another user, send a few packets to them, and repeat - thats a 20 millisecond jitter the users incur - completely unacceptable).
That forces the beams to remained trained on a single user or area (covering a group of users).
Does anyone have an image of what one of these ground stations looks like? Do they piggyback on some existing antenna shack? Or did they build their own from scratch? I also wonder whether they considered partnering with AWS Ground Station? https://aws.amazon.com/ground-station/ Or maybe the Starlink constellation's requirements are not amenable to that?
Source: my employer is that someone.
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That's how I understand it, yes. If double latency is okay, it may be possible to do M-shaped ones where an isolated ground station (with only power) relays solely between two different satellites to reach further, for example in the middle of oceans (with a ground station on an island or ship). I am not sure if they plan to implement this interim step or not, but it is technically possible. Their eventual goal is to…
The satellites in polar orbits (so far only 10, but they are planning to launch several hundred more this year) do have laser crosslinks. They said all satellites launched next year will have laser crosslinks Source: https://spacenews.com/spacex-adds-laser-crosslinks-to-polar-...
Yeah they've launched, but do they work? Teslas can be ordered with "autopilot" or "full self driving", too.
Nobody's ever done it before, and they've never said if it's working or not. I know they intend to do this, but it's important to draw a big fat line between what is planned to be accomplished and what is actually possible today. (To be clear, I am not casting doubt on their ability to accomplish it - the smartest people on Earth work for SpaceX. It's just not known publicly today if/when they will.)
Perhaps EM's best and most important skill is blurring the lines between today, tomorrow, next quarter, and next year as much as possible. Has someone named his Reality Distortion Field yet?
Earlier quoted context omitted.
The satellites in polar orbits (so far only 10, but they are planning to launch several hundred more this year) do have laser crosslinks. They said all satellites launched next year will have laser crosslinks Source: https://spacenews.com/spacex-adds-laser-crosslinks-to-polar-...
> The satellites in polar orbits (so far only 10, but they are planning to launch several hundred more this year) do have laser crosslinks. Yeah they've launched, but do they work? Teslas can be ordered with "autopilot" or "full self driving", too. Nobody's ever done it before, and they've never said if it's working or not. I know they intend to do this, but it's important to draw a big fat line between what is plann…
Earlier quoted context omitted.
The ground stations I saw on the map had 2.1GHz of uplink and 1.3GHz of downlink. If we assume 4b/hz (about as efficient as LTE/WiFi), thats 8.2Gbps up and 5.2Gbps down. I'm not too sure to what extent they can use MIMO techniques, but if they can, throughput could be multiplied by the number of MIMO channels.
I don't think you'd have much benefit of MIMO on a connection that's line of sight like this. MIMO is all about making the most of separate connection paths through reflections from walls, buildings etc. But in this case there'll be only one path.