Often times when a book shows a bit pattern traveling down the wire it is cleaned up so you only see the logical representation of the data. What I mean is shown in Chapter 3: Transmission Basics and Networking Media and illustrated in Figure 3-3: An example of a digital signal.

But this is not how a signal really looks as it travels down the wire. A real digital signal would look more like the Analog and Digital Signals distorted by Noise illustrated in Figures 3.13 and 3.14. The receiving hardware has to sample this signal as it arrives at the destination. It samples the wire looking at the voltage peaks and valleys and makes a decision as to whether it is receiving a 0 or a 1.

Please answer the following questions:

Looking at the illustrations what do they tell you about the timing the hardware must use when sampling the wire looking for 1s and 0s?

If I tell you that clocks can drift over time what does that tell you?

What is the effect at higher transmission rates when the signal is

traveling faster down the wire?