Abstract: A communication method and apparatus are provided, to resolve a problem that a terminal device cannot perform normal communication on other accesses due to an operation performed on common parameters over some accesses of the terminal device. The method includes: When the terminal device on a first access is switched from a first PLMN to a second PLMN, if a state of the terminal device on a second access is that the terminal device is registering with the first PLMN or has registered with the first PLMN, the terminal device determines not to delete a first mobility management parameter on the first access. If a state of the terminal device on a second access is that the terminal device has not registered with the first PLMN, the terminal device determines to delete a first mobility management parameter on the first access.

Abstract: A security context update method and a communication apparatus are provided. The method is performed by a terminal, and includes: storing a security context of first access and a security context of second access when the first access of the terminal and the second access of the terminal enter a deregistered state. The first access is one of 3GPP access and non-3GPP access, the second access is the other of the 3GPP access and the non-3GPP access, and the first access and the second access are different. According to the method, when the terminal supports multiple records for multiple registration, storage occasions of NAS security contexts corresponding to the 3GPP access and the non-3GPP access are provided.

Abstract: In a communication method, a session management function network element initiates a procedure of a first operation for a first session; the session management function network element receives a request to establish user-plane resources for the first session from an access and mobility management function network element in a process of performing the first operation; and the session management function network element determines a subsequent procedure based on the first operation.

Abstract: This application discloses a method for configuring an EPS NAS security algorithm, and a related apparatus in the field of communication technologies. In the technical solution provided in this application, an access and mobility management function entity needs to determine whether a selected EPS NAS security algorithm has been successfully provided to a terminal device, and after determining that the selected EPS NAS security algorithm has not been successfully provided to the terminal device, the access and mobility management function entity provides the selected EPS NAS security algorithm to the terminal device again. According to the technical solution provided in this application, it is ensured that the access and mobility management function entity can successfully configure the EPS NAS security algorithm for the terminal device.

Abstract: This application discloses a communication method and apparatus. The method includes: A UE sends a registration request message to an AMF, where the registration request message includes indication information, and the indication information indicates whether a disaster scenario exists. The AMF receives the registration request message, and sends a registration response message to the UE based on the indication information and a load status. The UE receives the registration response message.

Abstract: A client device for efficient disaster handling based on a novel list of PLMNs for disaster conditions. The client device is provided with a list of PLMNs that is used by the client device in response to the serving PLMN of the client device going into a disaster condition. Upon determining that the serving PLMN is in a disaster condition, the client device registers at a visiting PLMN in the PLMN list. The novel list of PLMNs for disaster conditions enables the client device to roam into PLMNs which is forbidden during normal conditions.

Abstract: A network node for a communication system is associated with a serving public land mobile network (PLMN) for a first client device. The network node is configured to transmit a first control message to the first client device in response to determining that the serving PLMN for the first client device is in a disaster condition. The first control message indicates that the serving PLMN for the first client device is in the disaster condition.

Abstract: A method for processing a non-access stratum context is as follows: A terminal device sends a registration request message to a first public land mobile network PLMN. The terminal device receives a registration accept message from the first PLMN. When the terminal device deregisters from the first PLMN over a first access network, the terminal device stores, in a storage medium of the terminal device, a first PLMN identifier of the first PLMN and a first NAS security context established by the terminal device with the first PLMN. Embodiments of this application are used for a processing process of the non-access stratum context.

Abstract: A handover handling method and apparatus applied to a scenario in which user equipment (UE) is handed over from a first access and management function (AMF) to a second AMF, and where the method includes receiving, by the UE, a handover command message from a first access network device, wherein the handover command message carries a Non-Access Stratum container (NASC), performing, by the UE, integrity verification on the NASC, and continuing, by the UE, to use a first NAS security context when the integrity verification performed on the NASC fails, wherein the first NAS security context is a security context used between the UE and the first AMF.

Abstract: A communication method and a communications apparatus, where the method may include: selecting or re-selecting, by a terminal device, from a first cell to a second cell through cell selection or re-selection, where radio access technologies of the first cell and the second cell are different, and where the terminal device is in an inactive mode in the first cell; re-selecting, by the terminal device, to the second cell through cell re-selection; and initiating, by the terminal device, a registration procedure after completing the cell re-selection. When the terminal device in inactive mode performs cell re-selection based on different radio technologies, the terminal device initiates the registration procedure or a service request procedure, for NAS signaling connection recovery. When the terminal device changes a radio access technology, a network device can update information.

Abstract: A session processing method in wireless communications and a terminal device include sending, by the terminal device, a session establishment request to a core network device, where the session establishment request requests to establish a session, and the session is supported by a network slice corresponding to the session, determining, by the terminal device, that establishment of the session fails, determining, by the terminal device, a forbidden time period corresponding to the session, and forbidding, by the terminal device, the terminal device from sending the session establishment request within the forbidden time period.

Abstract: A handover handling method and apparatus applied to a scenario in which user equipment (UE) is handed over from a first access and management function (AMF) to a second AMF, and where the method includes receiving, by the UE, a handover command message from a first access network device, wherein the handover command message carries a Non-Access Stratum container (NASC), performing, by the UE, integrity verification on the NASC, and continuing, by the UE, to use a first NAS security context when the integrity verification performed on the NASC fails, wherein the first NAS security context is a security context used between the UE and the first AMF.

Abstract: A session processing method in wireless communications and a terminal device include sending, by the terminal device, a session establishment request to a core network device, where the session establishment request requests to establish a session, and the session is supported by a network slice corresponding to the session, determining, by the terminal device, that establishment of the session fails, determining, by the terminal device, a forbidden time period corresponding to the session, and forbidding, by the terminal device, the terminal device from sending the session establishment request within the forbidden time period.