Telephone switchboards

[the tree]

How do telephone switchboards (not the TCP/IP variety) that control the phone system inside a building manage having many different signals going across one phsical line?

[RyanJ]

How do telephone switchboards (not the TCP/IP variety) that control the phone system inside a building manage having many different signals going across one phsical line?

 

It depends, on work experience I asked this exact question and the technician said that the company used an optical system to handel it because it can carry a huge data load and multiple loads at once.

 

Other then that I have no idea unless its something simmilar to how one cna use broadband and the phone at the same time?

 

Edit: Maybe this an help: http://en.wikipedia.org/wiki/Telephone_switchboard

 

Cheers,

 

Ryan Jones

[Externet]

Hi.

You may be under the wrong impression seeing one single cable that actually has many wire pairs in it, each pair handling only one communication path.

 

If it is truly a single metal pair, can be digital communication, where the voices of multiple simoultaneous users are sliced in tiny portions, fed into the single wire pair (multiplexed) and at the other end, the slices sorted and put back together and properly re-routed (demultiplexing)

 

Links between telephone central stations use the same multiplexing method on a single fiber optic, with thousands of rapidly sliced signals.

 

Miguel

[Twerpy]

Lets say that all telephone signals are made of bits. If the telephone uses a sampling rate of 40Hz lets say then it means, per conversation, it has to send 40 packages of information. Lets say each of these is 8 bits (1 byte). For one conversation the phone has to send 40 bytes of info per second. A standard optical fibre will be able to transmit thousands of bytes per second. What happens is the signal in the fibre is divided into blocks of 8, thousands of these per seconds. The system will send 1 byte of information from your conversation at a set interval, every 100 bytes per example. So for every 100 bytes going through a cable only 1 of these is yours. The switchboard or whatever at the other end then reads every hundredth byte and sends it to the right place. This way you can have lots of information at once from different conversations, each being send a byte at a time.

 

I hope this makes at least some sense. If not let me know and I'll try and clarify.

[the tree]

Thanks Ryan and Anthony.

 

Miguel, I was talking about twisted pair.