London Banter - View Single Post

Roland Perry · March 2nd 17, 01:04 PM posted to uk.transport.london

In message , at 07:46:46
on Thu, 2 Mar 2017, remarked:

You're confusing bandwidth with latency. They're not the same thing.

I don't think I am.

Well I'm not sure what you're saying about latency with 4G data speeds
compared to earlier generations then. Are you suggesting the extra data
speeds are down to the speed of light increasing and the signal getting
from the base station quicker? The time for a signal to reach a phone from
the base station is fixed and always will be. Ditto any signals going
down a fibre optic cable. The only difference in the latter is how quickly
a router can process and forward them but for this trivial amount of data
the transmission will be I/O bound, not CPU bound.

What I'm saying is that communications channels now being used are faster
than those in use since Oyster started. Full stop.

"Faster" is not a helpful word. Do you mean the end-to-end time (which
in any event is highly dependent on geography) or the delays in
processing packets at each node en route? I'm going to assume the "speed
of light" in the fibre doesn't change much.
--
Roland Perry