System and method for determining a location area of a mobile user

A computer system (3) for determining a location area of a user using a mobile communication terminal (1) in a geographical area (4) covered by a mobile radio network (2), the system (3) comprising:

• a sub-area definition module (31) configured to divide the geographical area (4) into a plurality of sub-areas (41, 43);
• an antenna determination module (34) configured to determine the antenna used by the mobile communication terminal (1);
• means for determining for the sub-areas (41, 43) location probabilities, each location probability indicating the probability that the mobile communication terminal (1) is located in the respective sub-area (41, 43), based on field strengths expected in the sub-areas (41, 43) for antennas (A1, A2, A3, A4) located in the geographical area (4), and based on the antenna used by the mobile communication terminal (1);
• and
• a location area determination module (37) configured to determine at least one ellipse (5) defining the location area, based on the location probabilities of the sub-areas (41, 43).

A computer program product comprising computer program code means for controlling one or more processors of a computer system (3), such that the computer system (3)

• stores a plurality of sub-areas (41, 43) for the geographical area (4);
• determines the antenna used (S21) by the mobile communication terminal (1);
• determines location probabilities for the sub-areas (41, 43), each location probability indicating the probability that the mobile communication terminal (1) is located in the respective sub-area (41, 43), based on field strengths expected in the sub-areas (41, 43) for antennas (A1, A2, A3, A4) located in the geographical area (4), and based on the antenna used by the mobile communication terminal (1);
• and
• determines at least one ellipse (5) defining the location area, based on the location probabilities of the sub-areas (41, 43).