Techniques for supporting positioning for a terminal (sometimes referred to herein as a target device) in a wireless network are described. In an aspect, positioning for a target device includes transmitting a Request Assistance Data message to a location server, the Request Assistance Data message indicating at least one positioning method from a plurality of supported positioning methods. The Request Assistance Data message comprises common parameters that are applicable to all positioning methods indicated in the Request Assistance Data message. The common parameters comprise a serving cell identifier. Positioning for the target device further includes receiving assistance data sent in response to the Request Assistance Data message, and performing positioning based on the received assistance data.