Indoor environment in a digital future - Master thesis - s154397 - s153767 (1)

In order to fully comprehend the possibilities and limitations of IoT, it is crucial to understand the different
elements in IoT systems. The term ’Internet of Things’ was first introduced in 1999, and described
as a system where sensors acted like the eyes and ears of a computer: an entirely new way for computers
to see, hear and interpret their surroundings [53]. Figure 2.6 presents the architectural layers
of IoT systems. The context of the IoT system can be buildings, infrastructure and factories etc.
Figure 2.6: Architectural layers in IoT systems
The ’T’ in IoT are devices with one or more sensors, including thermometers measuring the temperature,
gas detectors measuring pollution, passive infrared sensors registering occupancy etc. The IoT
devices are in the”edge” of the network. There are more than 50 billion IoT devices worldwide [54].
The data from sensors, are called payloads and to make sense of the payload it must be stored and
analysed. An example of such is presented in Figure 2.7.
Figure 2.7: Example of payload from IoT device
The transportation and storage of payloads is the ’I’ in IoT. The data is transported through network
connections like the well-known Wi-Fi or Bluetooth or other protocols such as LoRa, NB-IoT or Sigfox
[54]. The payload of the device is most commonly sent to local servers called nodes. There are
millions of nodes categorised as ”Fog”. The nodes are transient storage for immediate data and
performs real-time analytics or analytics performed on data while it is being collected. The goal
of the ”Fog” is to improve the efficiency of local and cloud data storage, sorting and minimising
the amount of data required to be sent to the cloud to advance data analysis efficiency and the
security of IoT [54]. The ”Cloud” is a term used to describe data centres. It stores data summaries
from multiple fog nodes and performs deeper analysis on large data sets [54].
20 INDOOR ENVIRONMENT IN A DIGITAL FUTURE