Awakening City: Traces of the Circadian Rhythm within the Mobile Phone Network Data

TL;DR

This study analyzes mobile phone data to uncover circadian rhythms in Budapest, introducing a wake-up time indicator that correlates with mobility, socioeconomic status, and daily activity patterns, demonstrating practical applications like workplace detection.

Contribution

It introduces a novel wake-up time indicator derived from CDR data and applies it to analyze urban circadian behaviors and socioeconomic differences.

Findings

Negative correlation between wake-up time and mobility indicators

Lower socioeconomic groups tend to wake up earlier

The approach aligns with real-life activity patterns like mall hours and nightlife

Abstract

In this study, Call Detail Records (CDR), covering Budapest, Hungary has been processed to analyze the circadian rhythm of the subscribers. An indicator, called wake-up time, is introduced to describe a behavior of a group of subscribers. It is defined as the time, when the mobile phone activity of a group rises in the morning. Its counterpart is the time, when the activity falls in the evening. Inhabitant and area-based aggregation are also presented. The former is to consider the people who live in an area, the latter uses the transit activity in an area to describe the behavior of a part of the city. The opening hours of the malls and the nightlife of the party district was used to demonstrate this application, as real-life examples. The proposed approach was also used to estimate the working hours of the workplaces. The findings are in a good agreement with practice in Hungary, and also support the workplace detection method. Negative correlation was found between wake-up time and mobility indicators (Entropy, Radius of Gyration): On workdays, people wake up earlier and travel more, on holidays it is quite the contrary. The wake-up time was evaluated in different socioeconomic classes, using housing prices and mobile phones prices, as well. It was found that lower socioeconomic groups tend to wake up earlier.