This is the first in a series of computer science lessons about wireless communication and digital signal processing. In these lessons you’ll learn about the nature of electromagnetic radiation, digital modulation and multiplexing techniques, and how to get the best out of mobile communication systems such as LTE, 5G and WiFi. This lesson describes the nature of electromagnetic waves in terms of oscillating electric and magnetic fields. It explains how electromagnetic waves can be generated by means of a half wave dipole antenna and defines fundamental terminology such as amplitude, wavelength, frequency and phase. The effects of linear superposition of electromagnetic waves, such as constructive and destructive interference are described, along with the implications of interference effects on the reception of radio signals. Chapters: 00:00 What are electromagnetic waves? 02:04 Dipole antenna 02:47 WiFi Access Point placement 03:05 Visualising electromagnetic waves 04:01 Amplitude 05:24 Wavelength 05:51 Frequency 06:15 Sine wave and the unit circle 07:11 Phase 08:41 Linear superposition 11:12 Radio signal interference