US 11,895,488 B2
Method and apparatus for identifying security key in next generation mobile communication system
Donggun Kim, Suwon-si (KR); and Soenghun Kim, Suwon-si (KR)
Assigned to Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed on Jun. 7, 2021, as Appl. No. 17/341,176.
Application 17/341,176 is a continuation of application No. 16/946,446, filed on Jun. 22, 2020, granted, now 11,032,702.
Application 16/946,446 is a continuation of application No. 16/576,605, filed on Sep. 19, 2019, granted, now 10,694,377, issued on Jun. 23, 2020.
Claims priority of application No. 10-2018-0112498 (KR), filed on Sep. 19, 2018; and application No. 10-2018-0127036 (KR), filed on Oct. 23, 2018.
Prior Publication US 2021/0297854 A1, Sep. 23, 2021
Int. Cl. H04W 12/0433 (2021.01); H04W 76/11 (2018.01); H04W 12/45 (2021.01); H04W 76/27 (2018.01); H04W 12/106 (2021.01); H04W 12/037 (2021.01)
CPC H04W 12/0433 (2021.01) [H04W 12/037 (2021.01); H04W 12/106 (2021.01); H04W 12/45 (2021.01); H04W 76/11 (2018.02); H04W 76/27 (2018.02)] 16 Claims
OG exemplary drawing
 
1. A method performed by a terminal in a wireless communication system, the method comprising:
receiving, from a base station, a counter check message for at least one data radio bearer (DRB) including first information, the first information including an identity of a DRB and a first count value associated with the DRB; and
transmitting, to the base station as a response to the counter check message, a counter check response message including second information,
wherein, in case that a most significant bits of a second count value of the terminal associated with the DRB is different from a most significant bits of the first count value associated with the DRB, the second information includes the identity of the DRB and the second count value of the terminal associated with the DRB,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for uplink, the second count value of the terminal associated with the DRB is set to a value of TX_NEXT-1,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for downlink, the second count value of the terminal associated with the DRB is set to a value of RX_NEXT-1, and
wherein the TX_NEXT is a count value of a next packet data convergence protocol (PDCP) service data unit (SDU) to be transmitted and the RX_NEXT is a count value of a next PDCP SDU expected to be received.