Abstract: According to an aspect of the present invention, a mobile terminal apparatus and an intra-core network apparatus do not enable congestion control during connection of a mobile terminal apparatus to a non-public network (NPN) in 5GS. Alternatively, during connection of the mobile terminal apparatus to the NPN in 5GS, the mobile terminal apparatus and the intra-core network apparatus enable congestion control only in a public land mobile network (PLMN) specific to the congestion control to provide a congestion control method in an NAS level to the mobile terminal apparatus being connected to the non-public network (NPN) and the intra-core network apparatus in 5GS.

Abstract: Provided is communication control accompanied with establishment of a multi-access PDN connection or with rejection of establishment of a multi-access PDN connection, on the basis of a response to a PDN connectivity establishment request from a terminal device. This provides a method of communication control and the like accompanied with a multi-access PDN connectivity establishment request from the terminal device.

Abstract: A communication measure is provided that causes a PDU session established in a 5GS to return to the PDU session in an original state after the PDU session established in the 5GS is moved (handed over) to an EPS and then moved (handed over) to the 5GS again. In addition, according to the present invention, a communication measure is provided that causes a PDN connection established in the EPS to return to the PDN connection in an original state after the PDN connection established in the EPS is moved (handed over) to the 5GS and then again moved (handed over) to the EP. In addition, according to the present invention, a communication measure is provided that allows smooth mobility of the UE in an idle mode between the 5GS and the EPS. Further, a communication measure is provided that performs a handover between the 5GS and the EPS smoothly.

Abstract: A communication measure is provided that causes a PDU session established in a 5GS to return to an original state of the PDU session in a case that the PDU session is moved (handed over) to an EPS and then moved (handed over) to the 5GS again. In addition, according to the present invention, a communication measure is provided that causes a PDN connection established in the EPS to return to the PDN connection in an original state after the PDN connection established in the EPS is moved (handed over) to the 5GS and then again moved (handed over) to the EP. In addition, according to the present invention, a communication measure is provided that allows smooth mobility of the UE in an idle mode between the 5GS and the EPS. This allows a communication measure that performs a handover between the 5GS and the EPS smoothly to be provided.

Abstract: First identification information is a detach type for requesting disconnection from a system optimized for Internet of Things (IoT). A procedure includes a step of transmitting a detach request message that includes at least the first identification information to a core network, and a step of receiving a detach accept message from the core network as a response to the detach request message. Thus, a communication procedure such as an attach procedure suitable for a CIoT terminal is provided.

Abstract: According to an aspect of the present invention, provided are a communication unit for implementing a function for CIoT in a 5GS and a communication unit for implementing a network initiated procedure of changing a state of User Equipment (UE) (terminal apparatus). Even in the 5GS that supports a configuration update procedure initiated by the network and multiple types of session and service continuity, a communication unit for enabling use of the function for CIoT is provided. In addition, provided is a communication unit for a network initiated change of the state of the User Equipment (UE) (terminal apparatus) to a state in which user data communication via a control plane is restricted and a network initiated change of the state to a state in which user data communication via the control plane is not restricted.

Abstract: According to one aspect of the present invention, a communication control method is provided that determines whether congestion control is to be continued in a destination PLMN in a case that a PLMN is changed during the application of congestion control and the PLMN before the change is a home PLMN. In a case that the PLMN is changed while a back-off timer received along with a cause value for the congestion control is running and the PLMN before the change is a home PLMN, it is determined whether to allow UE to transmit an SM request message in the destination, based on the presence or absence of an information element notified from the network.

Abstract: According to one aspect of the present invention, a communication control method is provided that determines whether congestion control is to be continued in a destination PLMN in a case that a PLMN is changed during the application of congestion control and the PLMN before the change is a home PLMN. In a case that the PLMN is changed while a back-off timer received along with a cause value for the congestion control is running and the PLMN before the change is a home PLMN, it is determined whether to allow UE to transmit an SM request message in the destination, based on the presence or absence of an information element notified from the network.

Abstract: According to one aspect of the present invention, a communication control method is provided that determines whether congestion control is to be continued in a destination PLMN in a case that a PLMN is changed during the application of congestion control and the PLMN before the change is a home PLMN. In a case that the PLMN is changed while a back-off timer received along with a cause value for the congestion control is running and the PLMN before the change is a home PLMN, it is determined whether to allow UE to transmit an SM request message in the destination, based on the presence or absence of an information element notified from the network.

Abstract: According to an aspect of the present invention, provided are a communication unit for implementing a function for CIoT in a 5GS and a communication unit for implementing a network initiated procedure of changing a state of User Equipment (UE) (terminal apparatus). Even in the 5GS that supports a configuration update procedure initiated by the network and multiple types of session and service continuity, a communication unit for enabling use of the function for CIoT is provided. In addition, provided is a communication unit for a network initiated change of the state of the User Equipment (UE) (terminal apparatus) to a state in which user data communication via a control plane is restricted and a network initiated change of the state to a state in which user data communication via the control plane is not restricted.

Abstract: According to one aspect of the present invention, a communication control method is provided that determines whether congestion control is to be continued in a destination PLMN in a case that a PLMN is changed during the application of congestion control and the PLMN before the change is a home PLMN. In a case that the PLMN is changed while a back-off timer received along with a cause value for the congestion control is running and the PLMN before the change is a home PLMN, it is determined whether to allow UE to transmit an SM request message in the destination, based on the presence or absence of an information element notified from the network.

Abstract: To provide a communication control means for establishing a session between a terminal apparatus and a network in a network-initiated manner and/or a connection control means for supporting service continuity and/or a session establishment control means for supporting service continuity and/or a communication control means for service continuity, and the like. These provide a communication control method for establishing an optimal session for service continuity through which service is continued by switching between sessions for communication, an optimal communication control method for service continuity, and the like.

Abstract: To provide a communication control means for establishing a session suitable for a terminal apparatus connecting to multiple access networks of various kinds and a network apparatus, a user data communication control means suitable for a terminal apparatus that has established sessions via multiple access networks and a network apparatus, and the like. This provides a communication control means suitable for a terminal apparatus and a network apparatus that support connection to multiple access networks of various kinds.

Abstract: First identification information is information indicating a mobility type supported by a core network, and second identification information is information indicating a mobility type allowed by the core network. A communication control method for a terminal apparatus of the present invention includes a step of receiving an attach accept message from the core network via a base station apparatus, the attach accept message including at least the first identification information and/or the second identification information. Accordingly, there is provided a communication procedure that is suited to the determination of a mobility type of a terminal.

Abstract: A terminal apparatus or a device in a core network exchanges capability information for each function in a registration procedure or a PDU session establishment procedure, and in user data communication additional information is added into an uplink packet to implement terminal apparatus-initiated RQoS control, and additional information is added into a downlink packet to implement network device-initiated RQoS control. A dedicated control message and information for an authentication and/or authorization function by a DN are defined to implement the authentication and/or authorization function by the DN. Furthermore, the terminal apparatus and the device in the core network have a timer or a control process for each network slice to implement a management process such as congestion management for each network slice.

Abstract: Communication control for establishing a multi-access PDN connection is performed based on a response to a PDN connectivity establishment request from a terminal device. Communication control for transmitting and/or receiving user data using one or more default bearers for a multi-access PDN connection is performed. This provides a communication control method and the like along with a multi-access PDN connectivity establishment request from the terminal device.

Abstract: To provide a communication control means for establishing a session suitable for a terminal apparatus connecting to multiple access networks of various kinds and a network apparatus, a user data communication control means suitable for a terminal apparatus that has established sessions via multiple access networks and a network apparatus, and the like. This provides a communication control means suitable for a terminal apparatus and a network apparatus that support connection to multiple access networks of various kinds.

Abstract: Provided are: a terminal apparatus that can support establishment of sessions that connect to various DNs; a measure for communication control that is preferable for an apparatus on a network that can connect to the terminal apparatus; a measure for communication control for recognizing the types of DNs with which the sessions are connected; and a measure for communication control for achieving user data communication. With this configuration, the preferable measures for communication control and measures for achieving user data communication can be provided to a control apparatus and a terminal apparatus included in a communication system that supports the establishment of sessions that connect to various DNs.

Abstract: To provide a communication procedure for data transmission and/or reception suitable to a CIoT terminal. A communication control method of a terminal apparatus according to the present invention includes the steps of: transmitting an Attach Request message to a core network, receiving an Attach Accept message including at least identification information identifying Signalling Radio Bearer (SRB) and identification information identifying Data Radio Bearer (DRB) from the core network; and establishing the SRB and the DRB.

Abstract: A communication unit for implementing an operation for CIoT in 5GS and a communication unit for mapping a connection associated with the function for CIoT to an appropriate connection in a handover between the 5GS and EPS are provided. Even in the 5GS supporting a network slice, a communication unit for allowing the operation for CIoT to be used is provided. Furthermore, a communication unit for mapping a PDN connection associated with the operation for CIoT and established in the EPS to an appropriate PDU session in a handover of user equipment from the EPS to the 5GS is provided. Furthermore, a communication unit for mapping a PDU session established in the 5GS to an appropriate PDN connection in the handover of the user equipment from the 5GS to the EPS is provided.