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There is a lot less distance between Low Earth Orbit and New York City than there is between New York City and Los Angeles.
SpaceX plans worldwide satellite Internet with low latency, gigabit speed
111–120 of 540 posts
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#112Earlier quoted context omitted.
Laying fiber isn't going to get your Tesla connected.
Interesting idea but wouldn't a satellite to car connection be pretty unreliable? Since the line of sight would often have things in the way. I'm assuming trees, bridges, and being in a garage would interfere with it.
Yet GPS works.
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#113Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#114Earlier 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...
Can't lay fiber to the entire planet for $300mil
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#115[deleted]
Specs for minimum ping of some internet technologies:
2G (100–400 Kbit/s) 300–1000 ms
3G (0.5–5 Mbit/s) 100–500 ms
4G (1–50 Mbit/s) ADSL+PPP (0.1-200 Mbit/s) 40 ms
Cable (2 Mbit/s - 1 Gbit/s) 80 ms
Fibre (1 Gbit/s - 100 Gbit/s) 5 ms
Note that this latency is just the transmission delay, it does not send your data more than a few hundred meters (technically up to 200km for fibre, but usually the actual distance sent is still hundreds of meters).
After that, you should consider that your data is probably being sent at least to the capital of your state, or some other large city, before there is any routing (meaning a packet to your neighbor gets sent to this large city and back). This distance tends to be more than the distance to LEO and back (but of course, your wouldn't be sending it straight up to LEO but at an angle, so the number of satellites makes a large difference. At 4000, it won't be a huge angle).
So this can still beat every technology except perhaps FTTH, which is hugely expensive and not widely spread at all. Furthermore, it can beat every mobile last mile technology.
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#116[deleted]
These satellites are orbiting at around ~900 miles up, which is about a 10ms round trip ping. I average around 75ms ping on my T Mobile LTE connection, which I think will be in line with SpaceX's offering.
The altitude of the ISS is only ~250 miles above sea level, while the distance from SF to LA is ~400.
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#117Didn't SpaceX blow up the rocket carrying Facebook's Internet.org satellites (which more or less were doing exactly this)? https://techcrunch.com/2016/09/01/a-spacex-falcon-9-rocket-j...
"Doing exactly this" is kind of a misrepresentation.
SpaceX is launching a fleet of low-earth-orbit satellites. The rocket that blew up was carrying a single satellite, owned/built by an Israeli company and destined for geostationary orbit; Facebook had signed an agreement to lease part of that satellite's capacity for several years.
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#118I 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…
They could sell bandwidth to LTE providers too who will upsell to cell consumers.
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#119[deleted]
In the article it says that it's because of the current deployment of satellites being at 22k miles high. Tesla plans to launch the satellites at a range of 715-823 miles which will reduce the latency to 25-35ms.
tiny lol at "Tesla plans to launch the satellites..." Guess I'm not the only one who makes this mistake from time to time :)
Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed
#120Earlier quoted context omitted.
Interesting idea but wouldn't a satellite to car connection be pretty unreliable? Since the line of sight would often have things in the way. I'm assuming trees, bridges, and being in a garage would interfere with it.
Yet GPS works.
AIUI, GPS isn't a connection. It's broadcast, one-way communication. Also, I assume the information transferred is much lower, not much more than time and position, plus redundancy to handle things like interruptions due to landscape.