Methods and devices for assisted positioning in wireless systems

A wireless transmit/receive unit (WTRU), comprising:

• memory storing processor-executable program instructions;
• and
• at least one processor configured to execute the program instructions to:
• receive a plurality of positioning reference signals from a plurality of terrestrial transmission points, the positioning reference signals including at least one positioning reference signal from a first terrestrial transmission point and at least one positioning reference signal from a second terrestrial transmission point;
• on condition that at least one measurement value of the plurality of positioning reference signals satisfies a condition, transmit a request to perform, at the WTRU, satellite-based positioning;
• receive, in response to the request, information regarding a set of satellites;
• select, based on the information, at least one satellite from the set of satellites;
• determine a second position estimate for the WTRU based on at least one positioning reference signal received from at least one selected satellite;
• and
• send to a network node a message comprising information indicating the second position estimate for the WTRU.