Analog vs. Digital Signals The electromagnetic spectrum can carry communication signals using wave frequencies. An enormous amount of information can be sent this way. For instance, the internet you use for this course utilizes electromagnetic waves to get information from the web to your computer. In general, high-frequency electromagnetic signals travel shorter distances but have a higher data capacity. This physical characteristic of electromagnetic waves limits how far away a receiver can be from the source of data and information being sent. Since electromagnetic waves move outward in all directions, wave transmitters need to be focused to transmit their signals to the right location. Likewise, wave receivers need to maximize their signal reception in order to receive the data from a specific location. Even with maximum reception, wave receivers can still detect unwanted signals that can interfere with their reception. Signal interference is the reason people are asked not to use their mobile devices on planes. Mobile devices can interrupt important communication between air traffic controllers and the pilots of the plane. To avoid signal interference problems, multiple users cannot transmit data signals at the same frequencies, at the same time, and in the same direction. Only one wave transmitter