6 ms·

I see comments on latency every so often when Starlink come ups. I would love some clarity on how satellite connectivity is expected to perform. Example: Stream

by psaux 6y ago

I see comments on latency every so often when Starlink come ups. I would love some clarity on how satellite connectivity is expected to perform. Example: Streaming services will be great, but syn ack dependent SAAS apps have to be optimized for local cache and data retrieval? What ways are they looking to overcome latency? I could soap box, but this community is much smarter than me.

andy_ppp 6y ago
LEO leads to very little latency about 20-40 ms.
db48x 6y ago
This video has a good simulation of the latency: https://www.youtube.com/watch?v=m05abdGSOxY https://www.youtube.com/watch?v=m05abdGSOxY
- psaux 6y ago
  This video is great, thank you for sharing.
TaylorAlexander 6y ago
The satellites are very low altitude. They are not geosynchronous which would require them to be very far from the earth's surface. Instead they orbit at low altitude and the antenna base station uses a complex antenna arrangement (a phased array) to follow the satellites as they move rapidly overhead. Once the inter-satellite laser links are fully deployed, starlink will be the fastest way to ping a signal to the other side of the planet.
- deleted 6y ago
  [deleted]
evil-olive 6y ago
the "original" satellite internet [0] used geosynchronous satellites. geosynchronous satellites (~35,000km) have an inherent speed-of-light latency of ~250ms. that means even if every other link along the route imposes <1ms latency, you've still got that absolute minimum quarter of a second on every single packet. Starlink is in LEO (~500km) with a corresponding reduction in the minimum possible latency. that lower altitude also requires much more complex antennas and other ground hardware, compared to just pointing your antenna at a (relatively) stationary point in the sky. 0: https://en.wikipedia.org/wiki/Satellite_Internet_access#History_of_satellite_Internet https://en.wikipedia.org/wiki/Satellite_Internet_access#Hist...

by psaux 6y ago

andy_ppp 6y ago

LEO leads to very little latency about 20-40 ms.

db48x 6y ago

This video has a good simulation of the latency: https://www.youtube.com/watch?v=m05abdGSOxY https://www.youtube.com/watch?v=m05abdGSOxY

psaux 6y ago
This video is great, thank you for sharing.

TaylorAlexander 6y ago

The satellites are very low altitude. They are not geosynchronous which would require them to be very far from the earth's surface. Instead they orbit at low altitude and the antenna base station uses a complex antenna arrangement (a phased array) to follow the satellites as they move rapidly overhead. Once the inter-satellite laser links are fully deployed, starlink will be the fastest way to ping a signal to the other side of the planet.

deleted 6y ago
[deleted]

evil-olive 6y ago

the "original" satellite internet [0] used geosynchronous satellites. geosynchronous satellites (~35,000km) have an inherent speed-of-light latency of ~250ms. that means even if every other link along the route imposes <1ms latency, you've still got that absolute minimum quarter of a second on every single packet. Starlink is in LEO (~500km) with a corresponding reduction in the minimum possible latency. that lower altitude also requires much more complex antennas and other ground hardware, compared to just pointing your antenna at a (relatively) stationary point in the sky. 0: https://en.wikipedia.org/wiki/Satellite_Internet_access#History_of_satellite_Internet https://en.wikipedia.org/wiki/Satellite_Internet_access#Hist...