User data are collected by various methods. The spatial ­resolution of the data is determined by the cell structure of the mobile network.

From network side, it is possible to detailed monitor all events in an individual radio cells, or even “track” individual customers in order to identify and rectify specific problems. In this case, the network data which are continuously exchanged between the mobile and the network are recorded for one connection across all cell boundaries or for all of the connections in one cell.

The billing system for voice and data connections is collecting in a so-called “call detail record” information such as the type of service, the duration of the connection, the mobile device, the customer account number, or the number called. These data are customer-specific and can be spatially assigned to a billing address, but they also provide information about the cell in which a connection is established and the time when the connection is established.

Individual services can be analyzed in great detail by a “deep ­packet inspection” (DPI). During the DPI, the data packet header and the content of every data packet are examined in central network elements for typical distinctive features such as protocol violations or computer viruses. But it is also possible to recognize the content – video clips, music, pictures, etc. – which is being transported by means of the data packets. However the DPI does not provide any spatial information.

Direct access to the customers and their feedback regarding the experienced service quality is provided by customer relationship management systems. All customer inquiries regarding ­network disruptions, service disruptions, and problems with their end user devices are directed to these systems, recorded, and ­processed. The network operators obtain valuable comments from the customers’ viewpoint about problems during ­operation of end devices, network problems, and service quality.

Additional information about the quality of service as ­experienced by customers can be secured by conducting event-controlled surveys. One example: after completion of a phone call a text message is sent to the customer requesting answers to questions about the quality of the service. Such operations can also be performed automatically by applications on the mobile. For example, transmission of application data comprises a large proportion of the data volume from an iPhone.