Data Architecture

1. Introduction

The Internet of Things (IoT) is defined in [8] by the International Telecommunication Union (ITU) as a global infrastructure for the information society. In the RFID Journal [1], Kevin Ashton states that the phrase "Internet of Things" first appeared in a presentation he gave to Procter & Gamble in 1999. He explains that the phrase was part of the fact that at the time computers and thus the Internet were almost entirely dependent on humans for information. Indeed, according to him, almost all the data available on the Internet was first captured and created by humans, either by typing, pressing a record button, taking a digital photo or scanning a barcode. Considering that people have little time, attention and precision, an alternative had to be found to provide the Internet with very precise information (close to reality) while making it as autonomous as possible from humans. To overcome this problem, the proposed solution is to use connected objects. The objects may have their own network of connections/communication, we speak of the Internet of Things. It should be noted that today this field has undergone a great revolution seeing the birth of many start-ups and platforms working on the development of such tools for various applications. According to a team from the Polytechnic School of Zurich, due to smartphones and then the growing number of connected objects, in ten years $(2015-2025), 150$ billion objects should be connected to each other, to the Internet and to several billion people(source: Wikipedia).

IBat

As an example we can cite the IBat (Intelligent Building) platform of the ICube laboratory which is a deployment of connected objects in the context of intelligent buildings. The platform was initially built for the study and analysis of network traffic within the ICube laboratory located at the API cluster in Illkirch. For our application in aerothermics, we use the measurements provided by these connected objects to perform data assimilation for building thermics - a process that is also known as "data assimilation".

The application consists of providing a real-time simulation tool for the temperature within the building by combining an aerothermal model and experimental observations provided by the sensors. The main objective of this application is to provide a tool for regulating energy consumption in the building.

2. IoT

IoT

the acronym for Internet of Things, has undergone a great evolution since its first use by Kevin ASHTON. The term now refers to physical objects capable of emitting data through sensors, the network through which this data transits, and the platforms capable of collecting and analyzing it.

iot
Figure 1. Overview of IoT (ref: digora.com)

The IoT is based on three main branches of science: physics, computer science and mathematics. The link to physics stems from the use of sensors to measure physical fields such as temperature, air quality, noise, light, positioning, etc. A sensor is a device that transforms the state of an observed physical quantity into a signal that provides information about that quantity. It should be noted that sensors existed long before the IoT but were often passive. That is to say that they were limited to taking measurements. With the development of information technology, new types of so-called active sensors have been introduced which, in addition to generating data, are capable of enrichment processing and transmission via a network. This network part, is one of the most important and even indispensable bricks of the IoT. There are several network technologies used, a summary of which can be seen in the following table.