Previously
we talked about digitizing voice and by doing that we solved the distance
problem as analog signals need to be regenerated after certain amount of
distance, but this introduces more white noise in the signal which causes major
quality problem over long distances.
The second
difficulty encountered with analog connections was the large number of wires
the phone company needs to support a large geographical area or a business with
a large number of phones. Because each phone required two wires, the bundles of
wire became massive and difficult to maintain. So a solution to send multiple
calls over a single wire was needed and digital connection is that solution.
It means
that when the samples of 24 different voice signals have been transmitted
through 24 DS0 channels of T-1 line in 24 different time slots, then these 193
bits (8 x 24 + 1 framing bit = 193) are called a frame.
