Computers, a user equipment, a computer system, computer program products, and a method for a computer system are disclosed. In some embodiments, the method comprises the steps of: receiving user IDs, cell IDs and time stamps associated with the cell IDs and the user IDs; requesting and receiving, from a cell ID database, geographical coordinates corresponding to the cell IDs; finding stations and times for each user ID based on, at least in part, the geographical coordinates and time stamps associated with each user ID; exchanging the stations with a place for each one of the stations; generating at least one OD sub-matrix associated with each user ID based on, at least in part, places and times of arrival and departure associated with these places; and merging the OD matrices into an OD matrix.