4 ms·

Is the total possible bandwidth available on these even comparable to optical fibers?

badgersnake 2y ago
Pretty obviously not, theoretically you could have tens of terrabits per fibre core. The limiting factor is the electronics at either end.
YetAnotherNick 2y ago
The bigger concern is the latency. Even if some technical progress increases the bandwidth, latency is bounded by speed of light and couldn't be as low as cable.
- larkost 2y ago
  The low-earth orbit generally means that this is not as big of an issue as in older satellite technologies. Currently if you are in an area where the satellite does not need to bounce your data through one or more other satellites before hitting a ground station they are in the tens of milliseconds of latency (20-60). Comcast is generally in the 20-30 neighborhood, unless you are using their gigabit service, then it is more like 10-15 milliseconds. So it is higher, but not debilitatingly so (unless your application is very sensitive to latency). I would imagine there is a lot more jitter in Starlink, but that is more a feel than real numbers. Mainly on a terrestrial system you wind up bouncing through more substations on the way to the general Internet, whereas with Starlink you are generally bouncing straight from your dish to the satellite to the base station. So less bounces, but farther to go. The physics favors the wire, but not as much as it used to.
0xcde4c3db 2y ago
SpaceX apparently doesn't like to give definitive numbers (perhaps there are too many configurable tradeoffs and/or dynamic adjustments to variable environmental conditions for that to make sense), but the downlink throughput of a Starlink V1 satellite is reportedly about 20 Gbps over an area of several square miles. Putting that on a single fiber wavelength is mature enough to be firmly in SOHO/homelab territory these days (e.g. QNAP and Mikrotik both have 25Gbps switches that are about $1000). It looks like commodity CWDM mux/demux boxes can cram 16 of those into a single fiber. It's safe to assume that the big guys like Comcast and CenturyLink/Lumen can get equipment capable of far more than that.

Pretty obviously not, theoretically you could have tens of terrabits per fibre core. The limiting factor is the electronics at either end.

YetAnotherNick 2y ago

The bigger concern is the latency. Even if some technical progress increases the bandwidth, latency is bounded by speed of light and couldn't be as low as cable.

larkost 2y ago
The low-earth orbit generally means that this is not as big of an issue as in older satellite technologies. Currently if you are in an area where the satellite does not need to bounce your data through one or more other satellites before hitting a ground station they are in the tens of milliseconds of latency (20-60). Comcast is generally in the 20-30 neighborhood, unless you are using their gigabit service, then it is more like 10-15 milliseconds. So it is higher, but not debilitatingly so (unless your application is very sensitive to latency). I would imagine there is a lot more jitter in Starlink, but that is more a feel than real numbers. Mainly on a terrestrial system you wind up bouncing through more substations on the way to the general Internet, whereas with Starlink you are generally bouncing straight from your dish to the satellite to the base station. So less bounces, but farther to go. The physics favors the wire, but not as much as it used to.

0xcde4c3db 2y ago

SpaceX apparently doesn't like to give definitive numbers (perhaps there are too many configurable tradeoffs and/or dynamic adjustments to variable environmental conditions for that to make sense), but the downlink throughput of a Starlink V1 satellite is reportedly about 20 Gbps over an area of several square miles. Putting that on a single fiber wavelength is mature enough to be firmly in SOHO/homelab territory these days (e.g. QNAP and Mikrotik both have 25Gbps switches that are about $1000). It looks like commodity CWDM mux/demux boxes can cram 16 of those into a single fiber. It's safe to assume that the big guys like Comcast and CenturyLink/Lumen can get equipment capable of far more than that.