Patent ID: 11871287
Assignee: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. The first terminal according to claim 15, wherein the instructions further cause the first terminal to:
transmit, to the second cell, a downlink reception status message including information on a reception status of downlink data received from the first cell before the changing of the PCell of the first terminal;
when the lost data is lost downlink data, receive, from the second cell, the lost downlink data recovered by the second cell based on the downlink reception status message;
receive, from the second cell, an uplink reception status message including information on a reception status of uplink data transmitted to the first cell before the changing of the PCell of the first terminal;
identify whether there is lost uplink data based on the uplink reception status message; and
when there is the lost uplink data, recover the lost uplink data and transmit the lost uplink data which is recovered to the second cell.