A method for enhancing the accuracy of Advanced Forward Link Trilateration (AFLT)
position location calculations is disclosed. A position determination entity (PDE)
constructs a statistical database of pilot phase measurements reported by mobile
stations (MSs) located in a geographic region about a reference base station (BS).
When a MS's location is to be calculated, the MS reports a set of PN phase offsets
to the PDE. Using only that set of PN phase offsets, the PDE determines a rough
estimate of the MS's location using conventional AFLT and also determines the region
within which the MS is located. If the PDE determines that the MS did not report
one or more earlier arriving PN phase offsets but reported a delayed multipath
component, the PDE sends a message to the MS to look for an earlier arriving PN
phase offset at a certain time prior to the reported PN phase offset.