Patent ID: 8135416

Claim:
A method of determining positions of mobile terminals in a cell of a mobile communication network where time alignment (TA) is employed for terminal transmissions in timeslots to a serving base station providing radio coverage in said cell, the method comprising: determining a TA independent distance (D) to the base station for at least one mobile terminal in the cell using a TA independent positioning method; obtaining a current TA value used by the at least one mobile terminal for time alignment of uplink signal transmissions in an allocated timeslot; estimating a relation between the determined TA independent distance and the obtained current TA value for each of the at least one mobile terminals; determining a TA bias of the cell based on the estimated relation as a calibration parameter for position determination of any mobile terminals in said cell using a TA based positioning method; determining a position of a subsequent mobile terminal using the TA based positioning method and said TA bias such that a current TA value used by the subsequent terminal is adjusted by the TA bias and the position of said subsequent mobile terminal is determined based on the adjusted TA value.