Radio communication system and position information providing apparatus

A position information providing apparatus that provides mobile station position information indicating a position of a mobile terminal, comprising:

• a receiver configured to acquire a delay time of a signal transmitted between the mobile terminal and a base station that performs radio communication with the mobile terminal;
• a position information acquiring unit configured to acquire a position of the base station;
• a calculating unit configured to calculate the position of the mobile terminal on the basis of the delay time acquired by the delay time acquiring unit, and the position of the base station acquired by the position information acquiring unit;
• and
• a providing unit configured to provide the mobile station position information, wherein
• when a predetermined exception condition is not satisfied, the providing unit provides, as the mobile station position information, the position of the mobile terminal calculated by the calculating unit, and
• when the predetermined exception condition is satisfied, the providing unit provides, as the mobile station position information, the position of the base station acquired by the position information acquiring unit, instead of using the position of the mobile terminal calculated by the calculating unit.