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Name: sroberts
Status: N/a
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993


Question:
Could you explain how information -- like my "hello" when I answer the phone -- is carried over a phone line?



Replies:
There are two distinct ways at present. Both of them rely on the ability of an electrical signal to be generated at your phoneand be sent over the wires to the receiving set. The actual signal is a series of time varying pulses or oscillations of voltage over the wires. The two ways your signal is coded represent the two ways that signals are sent over the lines. The old and still used way if for the strength of the signal in response to your words to be directly sent over the line. This is called analog and is essentially the same thing that happens with AM radio. The second method is for a computer to convert your message into digital signals, essentially short pulses at different frequencies , to code your message so that it is converted at the other end by another computer. Some of this is done for long distance calls.

Sam Bowen



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