Papers by Zbigniew Smoreda
PLOS ONE, Jul 13, 2011
In this study we analyze one year of anonymized telecommunications data for over one million cust... more 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.
IEEE Access, 2019
Estimating migration flows and forecasting future trends is important, both to understand the cau... more Estimating migration flows and forecasting future trends is important, both to understand the causes and effects of migration and to implement policies directed at supplying particular services. Over the years, less research has been done on modeling migration flows than the efforts allocated to modeling other flow types, for instance, commute. Limited data availability has been one of the major impediments for empirical analyses and for theoretical advances in the modeling of migration flows. As a migration trip takes place much less frequent compared to the commute, it requires a longitudinal set of data for the analysis. This study makes use a massive mobile phone network data to infer migration trips and their distribution. Insightful characteristics of the inferred migration trips are revealed, such as intra/inter-district migration flows, migration distance distribution, and origin-destination (O-D) movements. For migration trip distribution modelling, log-linear model, traditional gravity model, and recently introduced radiation model were examined with different approaches taken in defining parameters for each model. As the result, the gravity and log-linear models with a direct distance (displacement) used as its travel cost and district centroids used as the reference points perform best among the other alternative models. A radiation model that considers district population performs best among the radiation models, but worse than that of the gravity and log-linear models.
Réseaux et communication interpersonnelle. Du téléphone à Facebook
HAL (Le Centre pour la Communication Scientifique Directe), Jan 9, 2014
Lieu : Institut National d’Histoire de l’Art (INHA)International audienc
Potential of cellular signaling data for time-of-day estimation and spatial classification of travel demand: a large-scale comparative study with travel survey and land use data
Transportation Letters: The International Journal of Transportation Research, Jun 26, 2021
Transportation, Apr 20, 2020
Spatiotemporal data, and more specifically origin-destination matrices, are critical inputs to mo... more Spatiotemporal data, and more specifically origin-destination matrices, are critical inputs to mobility studies for transportation planning and urban management purposes. Traditionally, high-cost and hard-to-update household travel surveys are used to produce large-scale origin-destination flow information of individuals' whereabouts. In this paper, we propose a methodology to estimate Origin-Destination (O-D) matrices based on passively-collected cellular network signalling data of millions of anonymous mobile phone users in the Rhône-Alpes region, France. Unlike Call Detail Record (CDR) data which rely only on phone usage, signalling data include all network-based records providing higher spatiotemporal granularity. The explored dataset, which consists of time-stamped traces from 2G and 3G cellular networks with users' unique identifier and cell tower locations, is used to first analyse the cell phone activity degree indicators of each user in order to qualify the mobility information involved in these records. These indicators serve as filtering criteria to identify users whose device transactions are sufficiently distributed over the analysed period to allow studying their mobility. Trips are then extracted from the spatiotemporal traces of users for whom the home location could be detected. Trips have been derived based on a minimum stationary time assumption that enables to determine activity (stop) zones for each user. As a large, but still partial, fraction of the population is observed, scaling is required to obtain an O-D matrix for the full population. We propose a method to perform this scaling and we show that signalling data-based O-D matrix carries similar estimations as those that can be obtained via travel surveys.
HAL (Le Centre pour la Communication Scientifique Directe), Jan 13, 2019
Spatiotemporal data, and more specifically origin-destination matrices, are critical inputs to mo... more Spatiotemporal data, and more specifically origin-destination matrices, are critical inputs to mobility studies for transportation planning and urban management purposes. In this paper, we propose a methodology to infer origin-destination (O-D) matrices based on passively-collected cellular signaling data of millions of anonymized mobile phone users in the Rhône-Alpes region, France. This dataset, which consists of records time-stamped with users' unique identifier and tower locations, is used to first analyze the cell phone activity degree indicators of each user in order to qualify the mobility information involved in these records. These indicators serve as filtering criteria to identify users whose device transactions are sufficiently distributed over the analyzed period to allow studying their mobility. Trips are then extracted from the spatiotemporal traces of users for whom the home location could be detected. Trips have been derived based on a minimum stationary time assumption that enables to determine activity (stop) zones for each user. As a large, but still partial, fraction of the population is observed, scaling is required to obtain an O-D matrix for the full population. We propose a method to perform this scaling and we show that signaling data-based O-D matrix carries similar estimations as those that can be obtained via travel surveys.
Le mondial mobile
Réseaux, Dec 30, 2007
Résumé Le sport, qui fait maintenant partie des sujets d'actualité récur... more Résumé Le sport, qui fait maintenant partie des sujets d'actualité récurrents et incontournables, est au cœur des pratiques de la sociabilité ordinaire. Avec comme point d'entrée la Coupe du monde football 2006, nous proposons dans cet article de discuter une des composantes de cette sociabilité, à travers les communications mobiles effectuées lors des matchs de l'équipe de France dans son parcours lors de ce Mondial. Nous analyserons la structure des échanges mobiles au regard du développement des matchs. Nous ...
Réseaux and changing sociability
Reseaux, 2014
Reseaux was created under the auspices of the Centre National d’Etudes des Telecommunications (CN... more Reseaux was created under the auspices of the Centre National d’Etudes des Telecommunications (CNET) to bring closer together media communication research and the interpersonal exchanges that take place with telecommunication tools. This synthesis explores the journal’s production both on the question of telephone communication and on the digital sociabilities that appeared with the use of Internet as a platform for generalized interaction. The article examines four orientations in the articles published in Reseaux. The first two, the “continuist” hypothesis and the question of intertwined media, attest to the journal’s endeavour to introduce communication issues – until then considered mainly through the prism of mass media – into the sociology of everyday life. The other two, the strength of weak ties and the construction of collectives based on interactions, show how the question of digital sociabilities was introduced as one of the journal’s focuses and gave rise to the new research field of digital studies.
The rapid growth of mobile traffic and the emergence of advanced mobile services and infrastructu... more The rapid growth of mobile traffic and the emergence of advanced mobile services and infrastructures are shifting significant attention toward the cellular network back-hauling infrastructure. At this network segment, there is a growing interest in understanding spatio-temporal mobile traffic distributions at different network levels, in order to better define flexible networking solutions for forthcoming smart 5G infrastructures including, for instance, mobile edge computing features. In this work we study these aspects and characterize the load on cellular access networks using real-world anonymized subscriber data, from the Lyon metropolitan area in France, providing statistical distribution to the research community. We find that the traffic distribution at Node-B level is best fit by a Weibull distribution, and that at the radio network aggregation it is best fit by a hybrid Weibull-Pareto distribution.
The Birth of a First Child
Réseaux, 2002
BIRTH OF A FIRST CHILD Ranking social relations and modes of communication The birth of a first c... more BIRTH OF A FIRST CHILD Ranking social relations and modes of communication The birth of a first child is a crucial, founding event in the creation of a family and in the daily and social lives of couples. The study presented here assesses the effects of this event on social networks and communication practices. It also examines how the actors themselves use communication tools to manage, maintain or even select their networks of relations. The analysis reveals two hierarchies - one of interpersonal relations and the other of modes of communication - organized around the baby's birth. These can be seen as a norm or language through which closeness or distance are expressed. The young parents' interlocutors identify their position in the couple's network by the tools and modalities chosen to interact with them.
The Mobile World Cup
Réseaux, 2007
Sport, which is now a recurrent and unavoidable news item, is at the heart of practices of ordina... more Sport, which is now a recurrent and unavoidable news item, is at the heart of practices of ordinary sociability. With the World Cup Football 2006 as a starting point, the authors of this article discuss one of the components of that sociability, through mobile communication during the French team's matches. They analyse the structure of mobile interactions in relation to the course of matches. We see that there is a generic form of these communication practices, which can be affected by specific events relating to the singularity of matches.
The Spread of Information and Communications Technology (ICT)
Réseaux, 2007
DIFFUSION OF INFORMATION AND COMMUNICATION TECHNOLOGIES A longitudinal survey in Poland Dominik B... more DIFFUSION OF INFORMATION AND COMMUNICATION TECHNOLOGIES A longitudinal survey in Poland Dominik Batorski, Zbigniew Smoreda Drawing on the results of the , 34 , $54 0.3, survey on the living conditions of individuals and households in Poland, the authors analyse data for 2003 and 2005 on the diffusion and use of ICT. These longitudinal data allow for detailed analysis of the Internet drop-out phenomenon. Even though differences are revealed in comparison with Western countries - e.g. absence of sexagenarians among computer users -, the diffusion of ICT in Poland seems to be following the same pattern as that of more technologically-advanced countries. The data also show that the diffusion of various technologies worsens inequalities within the Polish population. The Internet and cell phone tend to be adopted by the same people and the democratization of access is no longer guaranteed.
Challenges and Opportunities for Cloud-based Computation Offloading for Mobile Devices
HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2013
Mobile cloud computing is a new rapidly growing field. In addition to the conventional fashion th... more Mobile cloud computing is a new rapidly growing field. In addition to the conventional fashion that mobile clients access cloud services as in the well-known client/server model, existing work has proposed to explore cloud functionalities in another perspective - offloading part of the mobile codes to the cloud for remote execution in order to optimize the application performance and energy efficiency of the mobile device. In this position paper, we investigate the state of the art of code offloading for mobile devices, highlight the significant challenges towards a more efficient cloud-based offloading framework, and also point out how existing technologies can provide us opportunities to facilitate the framework implementation.
A Local Structure-Based Method for Nodes Clustering: Application to a Large Mobile Phone Social Network
Lecture notes in social networks, Dec 21, 2012
Abstract In this paper we present a method for describing how a node of a given graph is connecte... more Abstract In this paper we present a method for describing how a node of a given graph is connected to the network. We also propose a method for grouping nodes into clusters based on the structure of the network in which they are embedded, so on the description provided by the first method. We apply these methods to a mobile phone communications network. When confronting the obtained clusters of individuals to their age and to their intensity of communication, the results are quite promising: the two measures are correlated to the ...
Bulletin de méthodologie sociologique, 2009
Extracting Ego-Centered Networks From Very Large Social Networks: This article presents a method ... more Extracting Ego-Centered Networks From Very Large Social Networks: This article presents a method at the intersection of macro and micro approaches in social networks. In examining ego-centered network, it proposes an approach to this type of study for very large networks. The calculation of several local indicators makes it possible to create aggregate statistics for each of the nodes of the network, which can then be seen as a corpus of ego-centered networks. An application is made on a network of telephone conversations between two million people, and a comparison is made with a classic ego-centered network study, based on an ethnographic research project.
Les Annales de la Recherche Urbaine, 2001
Réseaux and changes in sociability
Reseaux, 2014
Reseaux was created under the auspices of the Centre National d’Etudes des Telecommunications (CN... more Reseaux was created under the auspices of the Centre National d’Etudes des Telecommunications (CNET) to bring closer together media communication research and the interpersonal exchanges that take place with telecommunication tools. This synthesis explores the journal’s production both on the question of telephone communication and on the digital sociabilities that appeared with the use of Internet as a platform for generalized interaction. The article examines four orientations in the articles published in Reseaux. The first two, the “continuist” hypothesis and the question of intertwined media, attest to the journal’s endeavour to introduce communication issues – until then considered mainly through the prism of mass media – into the sociology of everyday life. The other two, the strength of weak ties and the construction of collectives based on interactions, show how the question of digital sociabilities was introduced as one of the journal’s focuses and gave rise to the new research field of digital studies.
This paper presents a visualization tool for mobile phone usage analysis. Data of mobile phone us... more This paper presents a visualization tool for mobile phone usage analysis. Data of mobile phone usage from Portugal is used for demonstration. The visualization runs on two modes: Flow and Intensity. Flow mode displays a 3D animation of mobile phone usage, showing the communication flows between municipalities. Intensity mode displays a 3D animation of the intensity level (amount of mobile phone usage) per cellular tower aggregated every 30 minutes. The tool also allows the user to interact with it by not only selecting different modes of display, but also visualizing data of any selected municipality. The visualization gives an overview of the dynamic communication flows, which helps describe mobile phone usage characteristics and social behavior. It can also be useful for telecom operators for better informed planning and management, as well as for urban planners and researchers for exploratory behavioral analysis.
Analysis of long-distance travel demand has become more relevant in recent times. The reason is t... more Analysis of long-distance travel demand has become more relevant in recent times. The reason is the growing share of traffic induced by journeys related to remote activities, which are not part of daily life. In today's mobile world, these journeys are responsible for almost 50 percent of the overall traffic. Traditionally, surveys have been used to gather data needed for the analysis of travel demand. Due to the high response burden and memory issues, respondents are known to underreport the number of journeys. The question of the real number of long-distance journeys remains unanswered without additional data sources. This paper shows how an alternative data source, mobile phone billing data, can be used to estimate long-distance travel demand. We take a sample of mobile phone billing data covering 5 months, reconstructed long-distance tours and imputed purposes. The latter was done based on a national travel survey Keywords long-distance travel demand; mobile phone data
ISPRS international journal of geo-information, May 7, 2020
For billing purposes, telecom operators collect communication logs of our mobile phone usage acti... more For billing purposes, telecom operators collect communication logs of our mobile phone usage activities. These communication logs or so called CDR has emerged as a valuable data source for human behavioral studies. This work builds on the transportation modeling literature by introducing a new approach of crowdsource-based route choice behavior data collection. We make use of CDR data to infer individual route choice for commuting trips. Based on one calendar year of CDR data collected from mobile users in Portugal, we proposed and examined methods for inferring the route choice. Our main methods are based on interpolation of route waypoints, shortest distance between a route choice and mobile usage locations, and Voronoi cells that assign a route choice into coverage zones. In addition, we further examined these methods coupled with a noise filtering using Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and commuting radius. We believe that our proposed methods and their results are useful for transportation modeling as it provides a new, feasible, and inexpensive way for gathering route choice data, compared to costly and time-consuming traditional travel surveys. It also adds to the literature where a route choice inference based on CDR data at this detailed level-i.e., street level-has rarely been explored.
Uploads
Papers by Zbigniew Smoreda