CS 536 Fundamentals of data transmission. (lec1)

Sending Bits using physical signals

    Choices for physical signals:

        Sound waves

        sonar

        light (electromagnetic) is the most dominant system, used for speed

            What is an electromagnetic wave?

            Too complicated for this class.

            In simplest form, a measurable quantity varies in a regular fashion.

            Key feature is its magnitude, where if its loud its 1 if quiet its 0.

                Called amplitude modulation

                1 bud/sec (bits/bud) communication system

                Can do 2 bud/sec (bits/bud) with 4 levels instead of 2

                2^n levels for n bud/sec

    Same concept as AM radio, but the difference is that in data transmission, we utilize multiple discrete signal levels to increase the data rate, allowing for more bits to be transmitted simultaneously.