20-01-2012, 03:29 PM
MOBILE FRAUDETECTION
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Introduction
It is estimated that the mobile communications industry loses several million customers per year due to fraud. Therefore, prevention and early detection of fraudulent activity is an important goal for network operators. It is clear that the additional security measures taken in GSM and in the future UMTS (Universal Mobile Telecommunications System) make these networks less vulnerable to fraud than the analogue networks. Nevertheless, certain types of commercial fraud are very hard to preclude by technical means
Indicators
Subsequently, typical indicators have been identified which may be used for the purposes of detecting fraud committed using mobile telephones. In order to provide an indication of the likely ability of particular indicators to identify a specific fraud, these indicators have been classified both by their type and by their use.
Toll Ticket
The potential fraud indicators have been mapped to network data required to measure them. The information required to monitor the use of the communications network is contained in the toll tickets.
Absolute analysis
Existing fraud detection systems tend to interrogate sequences of Toll Tickets comparing a function of the various fields with fixed criteria known as triggers. A trigger, if activated, raises an alert status, which cumulatively would lead to an investigation by the network operator. Such fixed trigger systems perform what is known as an absolute analysis of the Toll Tickets and are good at detecting the extremes of fraudulent activity.
Differential analysis
Another approach to the problem is to perform a differential analysis. Here we monitor behavioural patterns of the mobile phone comparing its most recent activities with a history of its usage. Criteria can then be derived to use as triggers that are activated when usage patterns of the mobile phone change significantly over a short period of time. A change in the behaviour pattern of a mobile phone is a common characteristic in nearly all fraud scenarios excluding those committed on subscription where there is no behavioural pattern established
