rejectMAC-I是什么

qy08211071

When the UE decidesto resume the RRC connection to transit from RRC_INACTIVE to RRC_CONNECTED or to notify the network, if it moves out of theconfigured RNA, the UE sends RRC Resume Request message. Onreceiving the RRC Resume Request message, if the gNB is not able to handle theprocedure, due to congestion, then the gNB decidesto send the RRCReject message. When the gNB decides to reject the RRC ResumeRequest message from the UE, the RRC Reject message shall include the resumecause and a rejectMAC-I. The rejectMAC-I is the message authentication code,the gNB calculates it using the integrity algorithm (NIA) in the stored ASsecurity context, which was negotiated between the UE and the source gNB andthe current KRRCint with the following inputs:

请问这个rejectMAC-I具体是什么