A technique is provided for receiving, by a user device from a serving base station, a list of base stations including base station identities and/or respective information about their physical channels used for broadcast signaling for which a timing advance measurement is being requested, receiving, by the user device, a positioning reference identifier associated with a timing advance measurement procedure with respect to the user device and one or more base stations identified in the list, and sending, by the user device to one or more of the base stations identified in the list, an uplink signal including a synchronization sequence and the positioning reference identifier.