Techniques for supporting positioning for terminals in a wireless network are described. In an aspect, positioning for a target device includes exchanging positioning messages that support a plurality of positioning methods between the target device and a location server. The positioning message may include common parameters applicable for all positioning methods. One of the positioning messages may be a Request Assistance Data message to request assistance data for a first positioning method, wherein the common parameters for the Request Assistance Data message includes an approximate location of the target device determined using a different positioning method. Another positioning message may be a Provide Assistance Data message to provide assistance data that is not in response to a request for assistance data, wherein the common parameters for the Provide Assistance Data message may include an approximate location of the target device or a current time.