On the Definition of Real-Time: Applications and Systems

Real-time personalization is being increasingly referred to as the next major technological milestone of the Internet age. Digital assistants such as Siri, Cortana, Google Now are the first steps towards the same. Internet of Things (IoT) is expected to drive hyper-personalization going forward, i.e., enable personalization across the board, for example but not limited to, home, health care, marketing, transportation, energy, infrastructure. There exists a large body of prior research in real-time systems. For instance, research and development of real-time systems has been done in domains such as control systems, avionics, operations research et cetera for over 50 years. With BigData analytics becoming mainstream since the turn of the century and the growing need to leverage real-time data to grow business, several real-time systems are being researched and deployed in the consumer space. Although a lot of emphasis is being laid on real-time processing, the notion of real-time is not well defined. This, in part, stems from the fact that the notion of real-time is a function of the target application. In this paper, we walk the reader through a brief history of prior work in real-time systems, give an in-depth view of the classification of real-time systems. Further, we overview the various systems in use today for real-time processing.