Urban Gravity: A Model for Inter-City Telecommunication Flows

Abstract

We consider a network of mobile phone customers aggregated by geographical proximity. We analyze the anonymous communication patterns of 2.5 million customers of a Belgian mobile phone operator. Grouping customers by billing address, we build a social network of cities, that consists of communication between 571 cities in Belgium. We show that inter-city communication intensity is characterized by a gravity model: the communication intensity between two cities is proportional to the product of the size of the population of these cities divided by the square of their distance.