However it would be too expensive to directly wire every telephone in North

However it would be too expensive to directly wire

This preview shows page 2 - 3 out of 3 pages.

you and your friend. However, it would be too expensive to directly wire every telephone in North America to every telephone in Asia. Laying one wired connection across the Pacific Ocean is expensive enough. Have a look at the animation at system.gif. Here we see a solution for wiring telephones in North America to telephones in Asia: have one wire between the continents, and connect telephones from the two continents to either end of this one wire, as needed for conversations. (This technique is known as time-division multiplexing. ) TODO (pre-lab): In the animation, five conversations are being connected. Draw what it would look like if six conversations were being connected. The connection scheme in the animation uses a circuit called a demultiplexer to undo the e ff ect of the multiplexer. The multiplexer selects the caller’s signal and passes it to the demultiplexer, which then selects the appropriate receiver to send the signal to, thus connecting the two friends. A 1-to-2 demultiplexer has two inputs: s , analogous to s (select) in our multiplexer, and y , an input wire. It produces two outputs: x0 and x1 , the demultiplexed signals. It works like this: When s = 0, x0 outputs the value of y , and x1 outputs LOW.
Image of page 2
Image of page 3

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture