The Orange \Data for Development" challenge is an open data challenge on
anonymous call patterns of Orange's mobile phone users in Ivory Coast. The goal of the challenge is
to help address society development questions in novel ways by contributing to the socio-economic
development and well-being of the Ivory Coast population. Participants to the challenge are given
access to four mobile phone datasets and the purpose of this paper is to describe the four datasets.
The website http://www.d4d.orange.com contains more information about the participation rules.
The datasets are based on anonymized Call Detail Records (CDR) of phone calls and SMS
exchanges between ve million of Orange's customers in Ivory Coast between December 1, 2011 and
April 28, 2012. The datasets are: (a) antenna-to-antenna tra�c on an hourly basis, (b) individual
trajectories for 50,000 customers for two week time windows with antenna location information, (3)
individual trajectories for 50,000 customers over the entire observation period with sub-prefecture
location information, and (4) a sample of communication graphs for 5,000 customers.