Techniques for observing the flow of people are creating new means for observing the dynamics between people and the environments they pass through. This ubiquitous connectivity can be observed and interpreted in real-time, through mobile device activity patterns. Recent research into urban analysis through the use of mobile device usage statistics has presented a need for the collection of this data independently from mobile network operators. In this paper we demonstrate that by extracting cumulative received signal strength indication (RSSI) for overall mobile device transmissions, such information can be obtained independently from network operators. We present preliminary results and suggest future applications for which this collection method may be used.