A mobile station performs Observed Time Difference of Arrival (OTDOA) positioning by measuring a time of arrival (TOA) of downlink signals transmitted from a reference cell and one or more neighbor cells. Reference Signal Time Differences (RSTDs) are generated using TOA measurements from the reference cell and each neighbor cell. The mobile station reports to a location server location information, including the RSTD measurements and the times of measurement for the TOA measurements. The mobile station may further generate and report additional RSTD and/or TOA measurements and associated times of measurement for the reference cell and/or neighbor cells. A location server may use the RSTD measurements, the times of measurement and any TOA measurements to determine a position of the mobile station taking into account user motion and base station clock drift and/or may adjust the uncertainty of the resulting position.