This MOOC presents the services and the architecture of 5G networks, the main principles of the new radio interface (NR), data flow management, security and the new Service-Based Architecture (SBA). In recent years, operators have been deploying 5G technology on commercial mobile networks. The latter is announced as a major technological breakthrough with speeds beyond Gbit/s, very low latencies and above all a distribution in many sectors of activity (industry, transport, medicine, etc.). Beyond the announcement effects, this technology relies heavily on 4G. The waveform for radio transmission is identical, the management of data flows is similar. However, 5G significantly extends the possible options both in the choice of architectures and in the radio interface configurations as well as in the security mechanisms. All this is explained in the mooc. A certificate of successful completion is awarded by Coursera to learners who succeed in obtaining a mark greater than 50%. This MOOC has received financial support from the Patrick & Lina Drahi Foundation.