The centre refractive index for fibre is about 1.48. giving a velocity
factor of 0.672 which is very similar to coaxial cable with solid
dielectric.
Twisted pair cable is likely to have a slightly higher velocity factor
as the effective dielectric constant will be lower - therefore the
fibre will probably work out slightly "slower" than the cable.

RP

On 23/10/05, Rob Hamerling <r.hamerling@hccnet.nl> wrote:
>
>
> Wouter van Ooijen wrote:
> >>>>You cannot send ethernet over 1km
> >>>>not electrically, but surely fiber should do the trick?
> >>>
> >>
> >>The main reason for not allowing more than 1km of ethernet has to
> >>do with retaining the ability to detect collisions in a timely
> >>manner.
> >
> >
> > Indeed. That's why I suggested fiber, in which light travels with the
> > speed of light :) Just don't try this on the disk.
>
> And how does that compare to the speed of an electric signal in a copper
> wire?  As far as I know only about 50% faster.
>
> Rob.
>
> --
> Rob Hamerling, Vianen, NL phone +31-347-322822
> homepage: http://www.robh.nl/
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist