Communication-enabled devices routinely carried by individuals have become pervasive, opening unprecedented opportunities for collecting digital metadata about the mobility of large populations. In this paper, we propose a novel methodology for the estimation of people density at metropolitan scales, using subscriber presence metadata collected by a mobile operator. Our approach suits the estimation of static population densities, i.e., of the distribution of dwelling units per urban area contained in traditional censuses. More importantly, it enables the estimation of dynamic population densities, i.e., the time-varying distributions of people in a conurbation. By leveraging substantial real-world mobile network metadata and ground-truth information, we demonstrate that the accuracy of our solution is superior to that granted by state-of-the-art methods in practical heterogeneous urban scenarios.
Subsequent works carried out more comprehensive evaluations. @cite_19 , the home location of each subscriber was localized as the most frequently visited cell with a home profile, , where the activity peaks at evening. The density of home locations was then found to match very well --with a 0.92 correlation-- census data on nationwide population distribution. Similarly, an excellent agreement between the overnight spatial density of mobile subscribers and that of nationwide static populations was found in @cite_8 @cite_1 . However, these results refer to populations at the scale of a whole country, with a spatial granularity at the level of counties or tracts, , large regions that comprise multiple cities each. Our focus is instead on urban population distribution estimation individual urban areas: down-scaling the investigation to a citywide level requires orders-of-magnitude higher accuracy, and is a harder challenge.
@cite_19 @cite_1 @cite_8
2004602565 2002644929
Mobile phone datasets allow for the analysis of human behavior on an unprecedented scale. The social network, temporal dynamics and mobile behavior of mobile phone users have often been analyzed independently from each other using mobile phone datasets. In this article, we explore the connections between various features of human behavior extracted from a large mobile phone dataset. Our observations are based on the analysis of communication data of 100,000 anonymized and randomly chosen individuals in a dataset of communications in Portugal. We show that clustering and principal component analysis allow for a significant dimension reduction with limited loss of information. The most important features are related to geographical location. In particular, we observe that most people spend most of their time at only a few locations. With the help of clustering methods, we then robustly identify home and office locations and compare the results with official census data. Finally, we analyze the geographic spread of users’ frequent locations and show that commuting distances can be reasonably well explained by a gravity model. This paper presents a strategy to evaluate long-distance travel patterns by tracking cellular phone positions. The authors first note that long-distance trips are generally under-reported in typical household surveys, because of relative low frequency of these trips. Yet transportation analysis and travel demand forecasting require data, including that for long-distance trips, in order to model the decisions that people make related to travel. They stress that their suggested approach allows passive data collection on many travelers over a long period of time at low costs. They present results of a study in Israel, conducted in 2007, that included an average sample of 10,200 cell phone numbers per week for 16 weeks. The tracking system was based on recording events that contain a change in the position of the cell phone with respect to a given antenna. The method was specifically designed to capture long distance trips, as part of the development of a national demand model conducted for the Economics and Planning Department of the Israel Ministry of Transport. Using this method, origin–destination tables can be constructed directly from the cellular phone positions. The authors conclude that this model offers the advantage of monitoring travel demand at the aggregate level and thus could be useful in several transportation and land use applications.