This article is an introduction to embedded and mobile systems, i.e. the invisible computers that are integrated into a large number of objects used for communication (cell phones, PDAs, digital TV, etc.), in the transportation systems we use (cars, trains, planes), in large or small infrastructures (nuclear power plant control, industrial automation, etc.).
It presents the specific features of these systems in terms of cost, size, energy constraints and performance, with a particular focus on the real-time operating constraints that exist for a number of these systems.
It outlines the hardware characteristics of these systems: integration technologies used, types of processors used, from microcontrollers to on-chip multiprocessors. It introduces the main features of the software components and operating systems of these systems, as well as the essential design issues, in terms of modeling, simulation and verification.
Finally, we show that these systems concern not only individual components or localized infrastructures, but also distributed and communicating components and systems. Together with sensor networks, they are an integral part of the many applications of ubiquitous computing. Each of the major themes addressed in this introduction is or will be the subject of several articles in the "Embedded Systems" collection.