Method for reporting mobility history of UE and device supporting the same

A method performed by a base station (BS) in a wireless communication system, the method comprising:

• performing a procedure for transitioning a state of an aerial user equipment (UE) from a radio resource control (RRC) inactive state or an RRC idle state to a RRC connected state;
• receiving, from the aerial UE, a first message indicating that reporting the mobility history information is available;
• transmitting, to the aerial UE, a second message requesting the mobility history information in response to the first message;
• receiving, from the aerial UE, mobility history information;
• and
• estimating a mobility state of the aerial UE based on the mobility history information,
• wherein the mobility history information includes a cell identity, a time spent in a previous cell, and altitude information of the aerial UE,
• wherein the cell identity and the altitude information are stored at the aerial UE based on a cell change or entering an out of service state of the aerial UE while the aerial UE is in the RRC inactive state or the RRC idle state,
• wherein, in the case of the aerial UE height being less than one or more thresholds, the altitude information indicates a low location,
• wherein, in the case of the aerial UE height being greater than the one or more thresholds, the altitude information indicates a high location,
• wherein, in the case of the one or more thresholds being more than one threshold, and the aerial UE height being greater than one threshold and less than another threshold of the more than one threshold, the altitude information indicates a medium location, and
• wherein the aerial UE is capable of flight.

An aerial user equipment (UE) in a wireless communication system, the aerial UE comprising:

• a transceiver;
• and
• a processor operatively coupled to the transceiver and configured to:
• receive, from a first base station, information related to one or more thresholds;
• enter a radio resource control (RRC) inactive state or an RRC idle state in a cell of the first base station;
• identify a cell change or entering an out of service state during the RRC inactive state or the RRC idle state;
• store mobility history information including a cell identity of a previous cell, a time spent in the previous cell, and altitude information of the aerial UE, based on the cell change or the entering of the out of service state;
• enter an RRC connected state in a cell of a second base station;
• transmit, to the second base station, a first message indicating that reporting the mobility history information is available, based on entering the RRC connected state;
• receive, from the second base station, a second message requesting the mobility history information;
• and
• transmit, to the second base station, a third message including the mobility history information, after the aerial UE enters the RRC connected state,
• wherein, in the case of the aerial UE height being less than the one or more thresholds, the altitude information indicates a low location,
• wherein, in the case of the aerial UE height being greater than the one or more thresholds, the altitude information indicates a high location,
• wherein, in the case of the one or more thresholds being more than one threshold, and the aerial UE height being greater than one threshold and less than another threshold of the more than one threshold, the altitude information indicates a medium location, and
• wherein the aerial UE is capable of flight.