In a wireless network in which beams are transmitted by base stations, a beam relation database may be produced by crowdsourcing known positions of UEs and associated information related to beams received by the UEs at these positions. The beam information, for example, may include a beam identifier and cell identifier, and may further include measured signal parameters, such as Reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ). The beam relation database may be used by a network or the UE to determine a position of a UE based on beams that are detected by the UE. The position fix may be an initial position fix that may be used to generate assistance data for the UE. Additionally, the beam relation database may be used to identify relevant measurement objects in the assistance data based on beams that are detected by the UE.