[Starlink] 300ms Telecommunication Latency and FTL Communication

[David Lang]

Sebastian Moeller wrote:

>> video conferencing is more sensitive to latency than pure voice (in my personal opinion, no study I've read on this specifically), because we watch people's faces for reactions to what we say as we're speaking.
>
> [SM] I am happy to believe you on this, but ti turn this into something useful for my purpose I will need to find something published, preferably peer reviewed. But thanks to the pointer which should help in my search.

one factor to point out, almost all video conferencing is you to server to other 
user, not direct you to other user. If you have two people in the same house on 
a call together, they suffer double the latency.

>> If there is a noticeable lag there, it disrupts the conversation. On the other hand, the same lag in a pure voice discussion, which is inherently less synchronous, would not be noticeable.
>
> [SM] Not sure I fully agree here, assuming video and audio arrive both with 
> the same delay I would guess both suffer similarly from the delay... my gut 
> feeling is as long as natural speech sequence stays intact, that is no 
> unintended collisions due to both speaking at the same time, audio-only and 
> audio-video should both be sort of OK...

the longer the latency, the more likely people are to talk over each other, 
because they don't see/hear the other person talking when they start. If the 
latency is low, they can stop quickly, but as the latency increases, they are 
talking longer before they hear the other person.

1. this means it's harder to figure out who started first and should continue
2. this means that there is a longer time period of multiple people talking

I agree that this is the same video vs audio. That's why I was thinking back to 
the early AT&T research I've heard from Internet lore (back when AT&T had a huge 
R&D section). It may be useful to look not only for long distance info 
(including microwave relays vs direct cables vs satellite relays) but also if 
they have any research on early conference calling.

David Lang