1. A method comprising steps of: upon detecting a start of an emergency call from a mobile station capable of supporting a plurality of wireless access technologies through a mobile communication network, determining one or more types of wireless access technologies available to the mobile station from the mobile communication network at the time of the emergency call, from among the plurality of wireless access technologies, wherein the wireless access technologies supported by the mobile station include two or more wireless access technologies selected from 1x Radio Transmission Technology (1xRTT), Long Term Evolution (LTE), and Evolution-Data Optimized (EvDO); comparing the determined one or more types of available wireless access technologies to a hierarchy regarding ability to determine location of the mobile station using each of the supported wireless access technologies to select a wireless access technology of the mobile communication network offering the ability to determine location of the mobile station during the emergency call, wherein the comparing step further includes: determining if the 1xRTT wireless access technology is available from among 1xRTT, LTE, and EvDO, upon determining 1xRTT is not available, determining if the LTE wireless access technology is available from among LTE and EvDO, and upon determining LTE is available, instructing the mobile station to operate in a LTE mode and select LTE measurements for position determination; initiating a determination of the location of the mobile station for purposes of the emergency call via the mobile communication network, using the selected wireless access technology for making air interface measurements for position determination; determining before the position determination is completed using LTE, that the mobile station is handed down to EvDO; upon determining that the mobile station is handed down to EvDO, determining if 1xRTT is available; and upon determining 1 xRTT is available, instructing the mobile station to change the EvDO wireless access technology to a 1xRTT mode and select 1xRTT measurements for position determination while using EvDO air interface to transport 1xRTT measurements to a location server.