Patent ID: 11937079
Assignee: NEC CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 2:
3. A method for a communication terminal, the method comprising:
initiating registration in a network node over 3GPP access and Non-3GPP access; and
establishing a first Non-Access Stratum (NAS) connection for the 3GPP access and a second NAS connection for the Non-3GPP access with the network node in a network,
wherein the first NAS connection is specified by a first parameter,
wherein the second NAS connection is specified by a second parameter,
wherein the first parameter and the second parameter are for NAS security,
wherein the first parameter is a first fixed value corresponding to the 3GPP access,
wherein the second parameter is a second fixed value corresponding to the Non-3GPP access, and
wherein the method further comprises:
deriving a first security key using at least the first fixed value;
deriving a second security key using the first security key; and
protecting a Radio Resource Control (RRC) message using the second security key.