OTDOA
Observed Time Difference On Arrival
OTDOA is a subscriber location technique which was introduced in Release 9 of the 3GPP specifications. OTDOA is based on the mobile taking TDOA measurements from the PRS (Positioning Reference Signal) associated with the neighbouring eNBs that the mobile is able to receive. These measurements are then supplied to the ESMLC (Enhanced Serving Mobile Location Centre) by the mobile, which the ESMLC is able to utilize in order to calculate the location of the mobile.