[Ronja] is it possible to implement RONJA with a laser diode instead of a normal visible light ?

[Russell Valentine]

mohamad al-jamal,

You would have to re-encode the data instead of pass it through like the 
RONJA does, so you would have to redesign the whole thing pretty much. 
Since 10BASE-T uses hi lo (Manchester), and 100BASE-TX had hi, zero, lo 
(MLT-3). So you would need some electronics to take MLT-3 to NRZ then on 
the other side NRZ back to MLT-3.

Of course you would also need to redo the electronics that drive the 
LASER instead of the LED.

I wrote a paper of sorts that goes through some of the encoding and 
LASER vs LED. You can read it:
http://coldstonelabs.org/files/ronja.pdf

I don't promise everything is correct in the paper, if you find a 
problem let me know. I mainly put that together from looking up 
different things myself. Particularly see the section on signals.

I believe a billion other people asked about this same thing on the 
mailing list before. I'm sure someone wrote a better response that is 
located in the archives.


Russell Valentine

mohamad al-jamal wrote:
> Dears
> 
> I'm planing to install RONJA for internal networking between two apartments
> , but for my application i need a B.W more than 10 Mbps . from my readings ,
> i understand that this is possible if a laser diode is used instead of a
> normal visible light diode .. my question is here : is this true ? and what
> changes do i need to do to the circuitry ?
> 
> thanks in advance .
> 
>