Electronic – How well does telephone delay correlate to geographic distance


I have a friend who lives on the other side of the world, and every time we speak over the phone, there's roughly a second of delay between one of us saying something and the other hearing it. I've tested this by having her put her phone on speaker so my own voice is detected and returned back to me over her phone as feedback, and the delay over that particular distance is quite consistent.

While surely there are a number of other factors contributing to phone delay beyond propagation time, many of these factors are constant regardless of distance. So if the distance between us were halved, would the delay be as well?

Best Answer

It used to be that the telephone delay was due to the signal being sent through a geosynchronous satellite. These are a long way up and the signal took that long to get there and back.

Today delays through routing devices are more likely to be the cause of the pause.

Half way round the earth is about 20 million meters with light or signal travelling at 300 million m/s direct transmission delay would only be about .066 seconds. Of course your wiring distance may be a little different,