Methods and apparatus for processing positioning assistance data are provided. An exemplary method includes receiving, from a positioning server, virtual access point (VAP) data including a list of unique identifiers, and determining a location of a mobile device by using the VAP. The VAP data indicates that the unique identifiers included on the list identify signals originating from the same physical access point. The unique identifiers can be MAC addresses. In an example, the location determining the can include actively scanning a signal identified by a unique identifier on the list and not actively scanning a different signal identified by a different unique identifier also on the list. Not scanning the other MAC addresses that are on the access point's list and assigned to the mobile device keeps the mobile device from performing duplicative scanning that wastes time, processor cycles, and energy.