## 4 The Proposed Use Case: Data Model and Scalability Analysis
### The Smart Campus Use Case  
In this subsection, the smart campus use case is detailed according to distributed control architecture described in Section 2.1. From the point of view of the communication process, three different scenarios can be identified, for both the monitoring and the supervisory control functions: (i) the supervision of independent sensors, generators, and equipment, (ii) the coordination of local energy controllers, and (iii) the coordination of BEMS. In the proposed use case, only the scenario concerning independent sensors, generators, and equipment (including the related distributed controllers) will be considered, such as it represents the typical implementation of a LPWAN infrastructure integrating dispersed resources under the supervisory control of BEMSs or EMSs. Different types of measuring instruments can be implemented in smart campus environments: from water and electrical power meters, to environmental sensors (e.g., for the measurement of room and ambient temperatures, volatile compound concentrations, solar irradiance, etc. ), presence  
Figure 4: The IoT architecture with LoRaWAN integration. sensing devices, people counters, and many others. Concerning the amount of transferred information, electrical power meters are by far the most complex devices, by involving the measurement of several quantities, from energy flows, to power quality measurements. The reference set of information provided by such devices is reported in Table 1, by considering the typical set of measurements provided by a smart meter with a measuring full scale of 200 kVA. As detailed in Table 1, the maximum size of each set of information transferred by electrical power meters to the supervisory EMS or BEMS is equal to 37 B, and the related application level data throughput is on the order of 0.041 B/s, by assuming a monitoring time interval of 15 min. On the opposite, when simple sensors are considered (e.g., sensors involving the measurement of a single quantity), the monitored set of information can be noticeably reduced. In this case, such as reported in Table 2, if we assume that a 16 bit value is adequate to represent any single measurement, the maximum size of each set of information is equal to 9 B, and the related data throughput is on the order of 0.01 B/s. Concerning the transmission of information from the supervisory entity to independent sensors, the time information (synchronization) can be optionally requested by each sensor every 3 h (i.e., every \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Information** & **Range** & **Resolution** & **Size (B)** \\ \hline Identification code of the sensor & - & - & 2 \\ Timestamp of the set of information & - & 1 s & 5 \\ Three-phase voltage (RMS value) & 0 \(\div\) 500 V & \(<\) 0.01 V & 2 \\ Three-phase current (RMS value) & 0 \(\div\) 300 A & \(<\) 0.01 A & 2 \\ Three-phase active power & 0 \(\div\) 200 kW & 0.01 W & 3 \\ Three-phase reactive power & \(-\)200 \(\div\) 200 kvar & 0.02 var & 3 \\ Phase 1 voltage (RMS value) & 0 \(\div\) 250 V & 1 V & 1 \\ Phase 1 current (RMS value) & 0 \(\div\) 150 A & \(<\) 0.01 A & 2 \\ Phase 1 voltage THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 1 current THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 1 Power Factor (PF) & 0 \(\div\) 1 & \(<\) 0.01 & 1 \\ Phase 2 voltage (RMS value) & 0 \(\div\) 250 V & 1 V & 1 \\ Phase 2 current (RMS value) & 0 \(\div\) 150 A & \(<\) 0.01 A & 2 \\ Phase 2 voltage THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 2 current THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 2 power Factor (PF) & 0 \(\div\) 1 & \(<\) 0.01 & 1 \\ Phase 3 voltage (RMS value) & 0 \(\div\) 250 V & 1 V & 1 \\ Phase 3 current (RMS value) & 0 \(\div\) 150 A & \(<\) 0.01 A & 2 \\ Phase 3 voltage THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 3 current THD & 0 \(\div\) 100\% & \(<\) 1\% & 1 \\ Phase 3 Power Factor (PF) & 0 \(\div\) 1 & \(<\) 0.01 & 1 \\ Grid Frequency & 0 \(\div\) 100 Hz & \(<\) 0.01 Hz & 2 \\ \hline \hline \end{tabular}
\end{table}