• De-randomization
• OPTICS
• Privacy
• Probe Request
• Random and Changing MAC address (RCM)
• Scalability

The objective of this thesis is to develop a non-intrusive method for detecting the presence of people by tracking their WiFi-enabled personal devices. The method is based on the use of Probe Requests sent by these devices. However, privacy regulations have led to various randomization schemes in these messages to prevent easy discrimination of devices based on their addresses, message sequence numbers, data fields, and message data volume. In this scenario, an important challenge is to define novel de-randomization algorithms that identify individual devices by grouping Probe Request messages using different features. The key design parameter considered in this work is the scalability of the developed algorithm, which can be used in real systems that acquire a high number of messages to be analyzed.