# Sigfox and LoRaWAN Datasets for Fingerprint Localization in Large Urban and Rural Areas
## 3 Collection Methodology
### Sigfox Antwerp  
For the second dataset, 14,378 Sigfox messages were collected in the city center of Antwerp. The spatial and temporal spread of this dataset is depicted in Figures 4 and 5 respectively. In this area, [PERSON] et al created the City of Things testbed to conduct network and data experiments in a realistic urban setting [20]. One of these experiments aims to measure the air quality in the city of Antwerp. For this purpose, 20 cars of the Belgian postal services are provided with air quality sensors as well as communication hardware to forward the air quality measurements to a local server. Figure 6 shows the OCTA-Connect hardware modules that are used to broadcast the measurements via Sigfox or LoRaWAN [21]. One of the OCTA modules also includes a Firefly X1 GPS receiver which acquires new GPS coordinates every 0.1 s. Every twelve minutes, the latest GPS coordinates are sent over Sigfox via the TD1207R radio module. The collection methodology of this dataset has the same constraints as the rural Sigfox dataset. For fast moving transmitters, the GPS coordinates that were sent at transmission time might be different from the actual GPS coordinates at receiving time. Hence, the correlation between GPS coordinates and RSSI of a message could hold an additional GPS error. However, this error will be less severe compared to the rural Sigfox dataset, as traffic in the city center does not move as fast as in rural areas. Also, the transmitters were frequently halted because of the many stops the postal service cars have to make. The ground speed and HDOP of the transmitter were not added to the message due to the limited Sigfox payload size. From this point forward, the Sigfox messages are processed and stored with the same methodology that is used for the rural Sigfox dataset. The Sigfox backend forwards JSON strings for all duplicates of a message to a local data server. These strings, which contain GPS coordinates, base station ID, base station RSSI, receiving time and a message ID are then grouped to form a new database of unique Sigfox messages. By querying this database, a list of all messages within Antwerp is extracted. As shown in Table 3, the urban Sigfox dataset is structured in the same way as the rural Sigfox dataset. All rows represent one of the 14,378 messages in the urban dataset, the last three columns represent the receiving time, latitude and longitude of a message. The columns before indicate which  
Figure 4: The urban Sigfox dataset was collected in the city center of Antwerp. of the 84 base stations in the urban area have received the message. If a base station has not received the message, an RSSI of \(-200\) dB is inserted in the cell. As the urban and rural Sigfox datasets were recorded in adjacent areas, base stations that are located near the border of these areas can be found in both datasets. However, these stations do not necessarily share the same identifier: e.g., 'BS 1' in the urban Sigfox dataset could be the same station as 'BS 36' in the rural Sigfox dataset. If the user intends to combine both Sigfox datasets, the mapping of the base ID's of these base stations can be found in the Zenodo repository. Figure 5: The urban Sigfox dataset contains 14,378 messages which were obtained from 16 November 2017 to 5 February 2018. This figure illustrates the temporal spread of this dataset. Figure 6: OCTA-Connect hardware modules are used to send GPS data to the local data server [21]. **Bottom left**: Firefly X1 GPS receiver. **Top left**: TD1207R RF module for Sigfox communication. **Top right**: IM880B-L RF module for LoRaWAN communication. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**BS 1** & **BS 2** &... & **BS 84** & **RX Time** & **Latitude** & **Longitude** \\ \hline \(-122\) & \(-105\) &... & \(-200\) & 2018-01-24T09:20:09+00:00 & 51.2111778259 & 4.4175133705 \\ \(-114\) & \(-119\) &... & \(-200\) & 2018-01-09T13:11:01+00:00 & 51.2206916809 & 4.3969035149 \\... &... &... &... &... &... &... \\ \hline \hline \end{tabular}
\end{table}