Bit framing

[Average Joe]

"To achieve succesful exchange of data, the transmitter and receiver must agree on a common bit-time. Apart from this, the two ends of the link must be synchronised as well. That is, the receiver should start reading its input line at the same instant the transmitter starts transmitting a bit. This synchronisation can be achieved in two ways, which leads to two modes of transmission: synchronous and asynchronous..."

The above paragraph is from a book I'm reading at the moment called 'Multimedia Information Networking'. What has puzzled me in the above paragraph is the idea of two ends of a line transmitting and receiving at the same time. I must be confusing this synchronisation of data with something else because surely there will be a delay in the line, making synchronised transmission and receipt impossible. I understand that bit-timing can be possible because the transmitter and receiver just space bits at X milliseconds/nanoseconds.

Anyone have an idea of where my thinking is going wrong here?

Cheers!

[bla!!]

This is a random guess, but I'm thinking frame of reference on the section you're reading.

I think this on the physical transmission media, so it could be possible to synchronize the data transmission on a single hop in the media (ie from computer to switch, or switch to switch) which has a maximum length of 100 meters (in a cat5/5e/6 network). At the speed of light this would be a very negligible delay.

Once again, this is me just reasoning through it.

[Average Joe]

Yeah I guess I would need to know the delays in lines to know whether or not it's possible. I'm assuming that there is too much of a delay.

'Never assume, it makes an *** out of u and me!' - I need to remember that!

Cool, well hopefully this is right, seems so.

EDIT: Boo! They don't let you say the a word haha.