## 3 Data and Methodology  
The primary dataset used in this project was initially compiled by the telecommunications company and was provided by the Lisbon City Council. The information in the dataset includes the number of mobile phones that entered, remained, and exited 3743 grid cells in Lisbon, each one measuring 200 by 200 m, from 15 September 2021 to 31 December 2022. The 24 variables of this dataset are shown in Table 2, along with their respective descriptions.  
As mentioned before, the available dataset was limited to the telecommunications company's customers only. Recognizing the need to understand the broader mobile phone usage in the area, the Lisbon City Council took the initiative to process this dataset further, in order to estimate the total number of mobile phones of all telecommunications companies in each grid, including the other two main telecommunications companies operating in the area.  
By understanding telecommunications company's market share, the Lisbon City Council was able to make estimates about the overall mobile phone usage in the area, encompassing all companies. For instance, if a telecommunications company's market share is known to be a certain percentage, say 30%, of the total telecom market in that area, and the telecommunications company reports a specific number of users, this information can be used to extrapolate or estimate the total number of users across all companies. This method allowed for a more comprehensive understanding of mobile phone usage across all telecommunications operators in the region, despite the lack of direct user data from some companies.  
\begin{table}
\begin{tabular}{c c} \hline
**Variable** & **Description** \\ \hline Grid\_ID & Identification of the grid cell number \\ \hline Datetime & Date and time \\ \hline extract\_year\_2 & Year \\ \hline extract\_month\_3 & Month \\ \hline extract\_day\_4 & Day \\ \hline C1 & Number of distinct terminals in the grid, during the 5 min \\ \hline C2 & Number of distinct terminals, roaming, in the grid, during the 5 min \\ \hline C3 & Number of distinct terminals remaining in the grid at the end of each 5 min \\ \hline C4 & Number of distinct terminals remaining in the grid, roaming, at the end of each 5 min \\ \hline C5 & Number of distinct terminal entries in the grid \\ \hline C6 & The number of distinct terminals exits in the grid \\ \hline C7 & Number of distinct terminal entries in the grid, roaming \\ \hline C8 & Number of distinct terminals exits in the grid, roaming \\ \hline C9 & Number of distinct terminals with an active data connection, in the grid cell, during the 5 min \\ \hline C10 & Number of distinct terminals with an active data connection, roaming, in the grid cell, during the 5 min \\ \hline C11 & Number of voice calls originating from the grid \\ \hline C12 & Number of entries into Lisbon along the 11 main roads \\ \hline C13 & Number of exits into Lisbon along the 11 main roads \\ \hline D1 & Top 10 home countries of terminal equipment roaming \\ \hline E1 & Number of voice calls terminated in the grid \\ \hline E2 & The average downstream rhythm of the grid \\ \hline E3 & The average upstream rhythm of the grid \\ \hline E4 & Peak downstream rhythm of the grid \\ \hline E5 & Peak upstream rhythm of the grid \\ \hline E6 & Top 10 apps (semicolon separated) \\ \hline E7 & Duration of the minimum stay within the grid \\ \hline E8 & Duration of the average stay within the grid \\ \hline E9 & Duration of the maximum stay within the grid \\ \hline E10 & Number of devices performing grid connection sharing during the 5 min \\ \hline \end{tabular}
\end{table}
Table 2: Description of each variable present in the main dataset files.