Interplay between Telecommunications and Face-to-Face Interactions: A Study Using Mobile Phone Data

TLDR

The study aims to investigate the relationship between call patterns and physical location using one year of anonymized telecom data from over one million European customers. It analyzes call records and cell tower data to assess how users’ telecommunication activity correlates with their spatial proximity. The analysis shows that more than 90% of callers share the same cell tower, about 70% of frequent callers co‑locate simultaneously, and the frequency of such co‑locations—predictable from call volume and home distance—serves as a proxy for coordination calls preceding face‑to‑face meetings.

Abstract

In this study we analyze one year of anonymized telecommunications data for over one million customers from a large European cellphone operator, and we investigate the relationship between people's calls and their physical location. We discover that more than 90% of users who have called each other have also shared the same space (cell tower), even if they live far apart. Moreover, we find that close to 70% of users who call each other frequently (at least once per month on average) have shared the same space at the same time - an instance that we call co-location. Co-locations appear indicative of coordination calls, which occur just before face-to-face meetings. Their number is highly predictable based on the amount of calls between two users and the distance between their home locations - suggesting a new way to quantify the interplay between telecommunications and face-to-face interactions.