The aim of the course is to provide the conceptual, methodological and computational tools necessary for setting up and solving simple Telecommunication problems. The course begins with a presentation of Telecommunication Networks highlighting the functions of the different types of systems that make up them: transmission, switching and terminal systems. The characteristics of certain and random signals are analyzed, in particular with regard to the representation of information and their treatment by linear and nonlinear systems. Then the different signal transmission methods, the effect of the various types of noise, and the methods to reduce its consequences, are introduced. Finally, some elements relating to telephone networks and data networks are presented together with analytical tools for a simple quantitative evaluation. The basic requirements for proper use of the course are the knowledge of electrical engineering, math analysis and probability calculation.