81–90 of 540 posts
I don't know how they're going to get 25/35ms hops. If they're using low orbits to reduce latency, the surface coverage is going to be lower so they're going to have to mesh them in some way to span large areas. That means routers and intelligence which means uplink, interlink, downlink hops in both directions. 600ms here we come again.
I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?
It will be expensive bandwidth no matter what. The way they can make this work is if they 1) are targeting traditional satellite internet customers (ships on the sea, commercial aviation, etc) and 2) integration with 5th generation mobile networks trough wireless network virtualization. Mobile network provider can sell a service where traveling customer pays extra for connection that works in the middle of nowhere. W…
Earlier quoted context omitted.
Doubt it. Elon's made his fortune by replacing existing products with superior alternatives. He's said in every case that driving cost down is one of the most important parts of creating something people want. Why do you think he wouldn't do the same here? He knows everyone hates existing telecoms. He's trying to create a better alternative.
> He knows everyone hates existing telecoms. Not true everywhere. I'm paying < $40/month for a 100 MBit connection and I don't hate my telecom.
I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?
People aren't generally using a 1 gbps connection at 100% capacity 100% of the time. If we assume customers use an average of 1 TB of data per month and the time they use it is pretty spread out (seems reasonable since they are going to be spread out accross timezones eventually), you can serve about 6 million customers with 800 satelites @ 23 GBPS, and with 4400 @ 23 GBPS you could do ~33 million. Admittedly these n…
Earlier quoted context omitted.
Still. What's the cost of deploying 800 sattelites vs cost of fiber infrastructure for 6 million people?
So long as it breaks even, SpaceX comes out ahead, since they're deploying the sats, and learning how to build the sats in a mass produced way.
Earlier quoted context omitted.
People aren't generally using a 1 gbps connection at 100% capacity 100% of the time. If we assume customers use an average of 1 TB of data per month and the time they use it is pretty spread out (seems reasonable since they are going to be spread out accross timezones eventually), you can serve about 6 million customers with 800 satelites @ 23 GBPS, and with 4400 @ 23 GBPS you could do ~33 million. Admittedly these n…
Still. What's the cost of deploying 800 sattelites vs cost of fiber infrastructure for 6 million people?
It's really hard to estimate since we don't know their satellite costs, but $100 million per satellite (launched) is probably a good starting point. That ends up being $13k capital cost per customer. If they can borrow capital at 5% or less, that works out to ~$55/month.
But if they succeed with reusable rockets (and it sure looks like they will), they can probably drop the launch cost from $60m to $10m in the near term. If we assume the satellite still costs $40m, that still cuts the total cost in half to ~$27/month @ 5%. Maybe they can mass produce these satellites and get them to $10-20m each, which would reduce it to more like $15/month.
Again all these numbers are pretty rough/best case scenarios, but even if we multiply them by 10 we could be looking at 1 gbps connections for $150-500/month. That could be cheaper than fiber infrastructure in a lot of places and still immensely useful in applications where fiber isn't possible (in a car, plane, or boat). That's also assuming 1 TB/customer. In many cases you may just buy the bandwidth in smaller increments at $1-10/gigabyte which is a few orders of magnitude cheaper than current satellite internet and comparable with LTE cell coverage.
I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?
People aren't generally using a 1 gbps connection at 100% capacity 100% of the time. If we assume customers use an average of 1 TB of data per month and the time they use it is pretty spread out (seems reasonable since they are going to be spread out accross timezones eventually), you can serve about 6 million customers with 800 satelites @ 23 GBPS, and with 4400 @ 23 GBPS you could do ~33 million. Admittedly these n…
For example, 23*4400 = 101Tbps, but I guess many of the satellites will end up above water, so maybe around 60Tbps. One cable by google did that for 300mil$ [1]
Maybe it is good for last mile connectivity, which is probably a good target, but only for less populated areas where LTE isn't available.
[1] https://www.extremetech.com/internet/231074-googles-faster-u...
I worked for a company called Lightsquared that tried to do this. Big problems were faced from lobbyists, maybe SpaceX has more money to protect themselves though: https://en.wikipedia.org/wiki/Ligado_Networks
Lobbyists were not the issue, a bonehead technical decision was.
Presumably SpaceX will be able to avoid any errors that obvious in their use of spectrum for their system.
> “Optical inter-satellite links permit flexible routing of traffic on-orbit. Further, the constellation ensures that frequencies can be reused effectively across different satellites to enhance the flexibility and capacity and robustness of the overall system.” Is optical communication between satellites an existing technology that's already known to work, or is this new? Also, is this sort of thing done (or expecte…
This[1] article does a nice job of covering the subject, but in essence, laser-based communication between satellites has been done and it works pretty well. [1] http://www.osa-opn.org/home/articles/volume_27/may_2016/feat...
Earlier quoted context omitted.
People aren't generally using a 1 gbps connection at 100% capacity 100% of the time. If we assume customers use an average of 1 TB of data per month and the time they use it is pretty spread out (seems reasonable since they are going to be spread out accross timezones eventually), you can serve about 6 million customers with 800 satelites @ 23 GBPS, and with 4400 @ 23 GBPS you could do ~33 million. Admittedly these n…
But isn't it still cheaper to lay fiber cables? For example, 23*4400 = 101Tbps, but I guess many of the satellites will end up above water, so maybe around 60Tbps. One cable by google did that for 300mil$ [1] Maybe it is good for last mile connectivity, which is probably a good target, but only for less populated areas where LTE isn't available. [1] https://www.extremetech.com/internet/231074-googles-faster-u...