Please any one can Give help Hand

Thread Starter


Joined Sep 9, 2008
Dear Friends

i wanna to me make multiplex as project , to deliver trunk telephone lines
about 10 over a single wire pair. "pleas look to the attchment
any Advice.

thank you



Joined Apr 5, 2008

Keep in mind that the multiplexer and demultiplexer must be synchronized.
I think a clock and reset signal must be transfered too.
If you do not use that the signals may get mixed up.



Joined Jan 16, 2008
Without a specific question and with only a very general block diagram its hard to give any meaningful advice but here are a few general thoughts.

First off what you want to do is by no means a simple project. Its going to involve a great deal of work.

You don't say what format the phone data is in, is it analog or digital? If its analog your first task will be to digitise it.

You will need 2 pairs between the mux's otherwise you will have some rather one sided phone conversations.

Obviously the links between the mux's will need to be running a synchronous protocol and you will have to use some coding scheme such as NRZI to allow the clock to be recovered from the data stream. The easiest way to do all of this is to use a couple of short haul modems. In any case 100 meters is a bit too far to run raw baseband signal.

The data will have to assembled into frames with some sort of sync flag or start of frame marker to allow the mux's to synchronise.