Have you ever wondered how information is transmitted using your mobile phone or a WiFi hotspot? Gain an understanding of the basic engineering tools used and tradeoffs encountered in the design of these communication systems. This course is divided into three parts. In Part 1, we examine the point-to-point link, which communicates information from a single transmitter to a single receiver. Part 2 examines how multiple transmitters can share the same physical channel. Part 3 discusses how information can be transmitted reliably from one station to another over a network that connects multiple stations. Online interactive exercises are included to help build your intuition. This course was inspired by and built upon the course 6.02 Digital Communication Systems developed at MIT, which Prof Bertram Shi worked on during his sabbatical in 2009.