BLE RSSI vs distance

The data set has been used in SmartCPS experiment within Fed4Fire+ continuous call for studying RSSI (of BLE devices sending advertisements) depending on the distance to the scanning nodes. The data set contains location information transferred over Bluetooth Low Energy from a single BLE tag and registered by 5 nodes from CityLab testbed: Node 9, Node 33, Node 34, Node 35, Node 36 The data is stored in CSV format (with the following columns):
node - id of the CityLab testbed node
(node_lat, node_lon) - GPS coordinates of the node
(tag_lat, tag_lon) - GPS coordinates of the tag
ts - timestamp (milliseconds since the UNIX epoch: 1 January 1970)
rssi - received signal strength indication