Abstract: A method of performing MT services using an indication to avoid barring in access control is provided. UE sends an indication related to an MT service to the NAS layer when the MT service starts, or when a corresponding communication session of the MT service is handover to 3GPP access. Once the service has successfully been set up, then as long as the service is ongoing, the following access attempts are allowed to proceed without further access control checking in order to avoid barring: MMTEL voice, MMTEL video, and SMSoIP. In one novel aspect, based on the indication provided to the NAS layer when the MT service starts or when handover to 3GPP access occurs, UE skips access control after UE goes to idle mode and establishes an RRC connection to resume the MT service.

Abstract: A method for maintaining MBS session when UE performs intersystem change is provided. UE maintains a PDU session in 5G network. UE then joins an MBS session for receiving MBS service over the associated PDU session. Later on, UE performs intersystem change from 5G to 2/3/4G. The PDU session is then released or transferred to a PDN connection. From UE perspective, UE determines that the released or transferred PDU session is associated with the MBS session, and therefore locally leaves the MBS session. From NW perspective, NW determines that the released or transferred PDU session is associated with the MBS session, and therefore considers the UE is removed from the MBS session.

Abstract: A method for requesting to join an MBS session via a PDU session establishment procedure for existing PDU or MA PDU session is provided. A UE sends a PDU session establishment request message that includes a requested MBS container IE to request to join an MBS session. The request message initiates a PDU session establishment procedure, with a request type indicating that the PDU session establishment procedure is for an existing PDU session, or for an MA PDU session. A specific request type is used to indicate: 1)HANDOVER 5G PDU SESSION FROM NON-3GPP TO 3GPP; 2) TRANSFER 4G PDN CONNECTION (EPS) TO 5G; 3) TRANSFER 4G PDN CONNECTION (NON-3GPP) TO 5G; 4) ESTABLISH UP RESOURCE OVER 3GPP FOR 5G MA PDU; and 5) TRANSFER MA PDU (PDN LEG IN EPS) TO 5G MA PDU.

Abstract: A method of performing intersystem change without N26 interface supported or not supported when a UE is registered to the same or different networks over 3GPP and non-3GPP accesses is proposed. UE registers to one or more PLMN/SNPN over 3GPP access and non-3GPP access. UE receives a REGISTRATION ACCEPT message over 3GPP access, which carries a first 5GS network feature support IE, which indicates that interworking without N26 interface not supported. UE also receives a REGISTRATION ACCEPT message over non-3GPP access, which carries a second 5GS network feature support IE, which indicates that interworking without N26 interface supported. UE ignores the second indication received over non-3GPP access and considers that N26 interface is supported for interworking. As a result, after intersystem change from 5G to 4G, UE triggers a TAU procedure over LTE in 4G EPS.

Abstract: A method of determining UE access identity for a UE that is registered to the same or different PLMN networks over 3GPP and non-3GPP accesses is proposed. The UE registers to one or more Public Land Mobile Network (PLMN) or Standalone Non-Public Network (SNPN) over 3GPP access and non-3GPP access. If the UE registers to the same PLMN/SNPN over 3GPP and non-3GPP access, then the UE handles the UE access identity as one common parameters. On the other hand, if the UE registers to different PLMN/SNPN over 3GPP and non-3GPP, then the UE handles the UE access identity as two independent parameters. The access identity may comprise a priority indicator IE that is set to “Access Identity 1 valid” for MPS or “Access Identity 2 valid” for MCS.

Abstract: A method of determining UE registration status for a UE that is registered to different PLMN networks over 3GPP and non-3GPP accesses is proposed. The UE triggers registration to a second Public Land Mobile Network (PLMN) or Standalone Non-Public Network (SNPN) over a second access, and receives a REGISTRATION ACCEPT message from the second network over the second access. The REGISTRATION ACCEPT message carries a 5GS registration result IE having a 5GS registration result value. If the 5GS registration result value indicates that the UE is registered (or not registered) to a first network over a first access, then the UE may ignore the indication and considers the UE is not registered (or registered) to the first network over the first access.

Abstract: Under the existing SENSE solution, a PLMN with received signal quality >=the “Operator controlled signal threshold per access technology” has higher priority than a PLMN with received signal quality <the “Operator controlled signal threshold per access technology”. In one novel aspect, during network selection upon UE switch on or recovery from lack of coverage, the UE sets the priority of a PLMN broadcasting disaster related indication to be absolutely lower than other PLMNs (e.g., registered PLMN, HPLMN/EHPLMN, U-PLMN, O-PLMN, and LQ-PLMN), no matter the received signal strength or quality of the corresponding PLMN.

Abstract: Examples pertaining to improvement to signaling over satellite access in mobile communications are described. A user equipment (UE) initiates a procedure with a cell of a network over a satellite access. In response, the UE receives a message from the network indicating that the procedure cannot be completed due to an aspect of the satellite access. Then, the UE reattempts to complete the procedure responsive to a condition being met.

Abstract: Examples pertaining to user equipment (UE) handling of forbidden tracking area identifier (TAI) list information elements (IEs) in an Evolved Packet System (EPS) SERVICE ACCEPT message in mobile communications are described. A user equipment (UE) transmits a CONTROL PLANE SERVICE REQUEST message to an EPS network node of a wireless network. In response, the UE receives a SERVICE ACCEPT message from the EPS network node. The SERVICE ACCEPT message includes either or both of the following: (i) one or more forbidden tracking area identifiers (TAIs) for a list of “forbidden tracking areas for roaming” information element (IE); and (ii) one or more forbidden TAIs for a list of “forbidden tracking areas for regional provision of service” IE.

Abstract: Solutions pertaining to public land mobile network (PLMN) selection in international areas when a user equipment (UE) supports non-terrestrial network (NTN) communications are proposed. An apparatus implemented in a UE transmits a message indicating that the UE has a capability of NTN communication over a satellite access. The apparatus also receives an indication indicating whether the UE is allowed to utilize one or more NTNs over the satellite access. The apparatus then performs a PLMN selection in a country area or in an international area based on the capability.

Abstract: Examples pertaining to handling of reject causes and forbidden tracking area identifier (TAI) lists in reject messages in mobile communications are described. A user equipment (UE) receives a reject message from a satellite-accessing cell of a network. The UE then stores one or more TAIs that are included in at least one information element (IE) of the reject message in a list of forbidden tracking areas in the UE regardless of a reject cause indicated in the reject message.

Abstract: A method of NAS signaling connection handling when a UE initiates a de-registration or detach procedure to perform network selection is proposed. To allow the UE to perform PLMN selection, the UE needs to be in idle mode. Upon the completion of a UE-initiated de-registration or detach procedure, the UE starts a guard timer, e.g., T3540/T3440. In one example, the UE starts a guard timer upon receiving a de-registration accept message. In another example, the UE starts a guard timer upon receiving a detach accept message. The UE will locally release any NAS signaling connection upon the guard timer expiry so that the UE can enter idle mode and perform PLMN selection.

Abstract: In accordance with one novel aspect, a method of manual network selection at switch on for UE supporting CAG is proposed. A UE is in manual network selection mode, it supports CAG, and it is registered in an RPLMN. After switching on, the UE found that the registered RPLMN is no longer available. The UE also found that a most preferred home network is available. However, under certain circumstances, the UE determines not to auto change PLMN in manual mode, e.g., does not select or attempt registration on the most preferred home network. Instead, the UE initiates the Manual Network Selection Mode Procedure by presenting or displaying available PLMNs and CAGs (if any) for the user to select.

Abstract: A method of handling the maximum number of PDU sessions per SNPN per subscription is proposed. If the UE selects a first subscription to access a selected SNPN, then the UE should not send a PDU session establishment request message if the number of active PDU sessions has reached the maximum number of PDU sessions for the selected SNPN associated with the first subscription, e.g., a first number. Similarly, if the UE selects a second subscription to access the selected SNPN, then the UE should not send a PDU session establishment request message if the number of active PDU sessions has reached the maximum number of PDU sessions for the selected SNPN associated with the second subscription, e.g., a second number.

Abstract: A method of UE autonomously updating a CAG related configuration upon receiving a downlink NAS message is provided. If a CAG-ID is included in an allowed CAG-IDs list of the CAG related configuration and is supported by a CAG cell in a PLMN, then UE may attempt to access the CAG cell in the PLMN. If the access is denied, e.g., UE receives a DL NAS message with a cause value, then UE needs to update the CAG related configuration. If the CAG-ID is not associated with any validity or restriction information, then the CAG-ID should be deleted from the CAG related configuration. If the CAG-ID is associated with validity or restriction information and corresponding validity or restriction criteria are not met, then the CAG-ID should not be deleted from the CAG related configuration.

Abstract: A method of subscription selection for manual SNPN hosting network selection is proposed. When a UE supports accessing NPN, the UE has a 1st SNPN/PLMN subscription for accessing a selected SNPN as hosting network for localized services. If the selected SNPN is associated with validity information and validity criteria are met, the UE can register to the selected SNPN using the 1st subscription. If the UE has multiple subscriptions that can be used to access to the selected SNPN, then the UE can register to the selected SNPN using any of the subscriptions. The UE may determine which subscription to use based on whether the validity information associated with the selected SNPN that is included in the corresponding subscription, e.g., whether the selected SNPN is associated with validity information, and how long is the remaining (time) duration of the validity information.

Abstract: A method of enhanced manual network selection procedure for access localized services in PNI-NPN is proposed. For manual CAG/PNI-NPN selection as hosting network, if a CAG cell in a PLMN broadcasting a CAG-ID is available and included in the (Allowed) CAG-ID list of the UE-stored CAG related configuration of the PLMN, the user may manually select the CAG cell as a suitable cell. However, the CAG-ID that is associated with validity information, and the corresponding validity criteria may or may not be satisfied, e.g., due to the UE-stored CAG related configuration is different from the NW-maintained CAG related configuration. Therefore, the UE does not know whether the CAG cell is suitable. In response, the UE triggers a registration procedure for mobility and periodic registration update, and obtains the updated CAG related configuration.

Abstract: A method of enhanced manual network selection mode for access localized services in NPN is proposed. If an SNPN is available and included in the UE-stored configuration for SNPN selection, the UE presents to the user whether the SNPN is associated with validity information and whether the corresponding validity criteria are met. If a CAG cell in a PLMN broadcasting a CAG-ID is available and included in the (Allowed) CAG list of the UE-stored CAG related configuration of the PLMN, the UE presents to the user whether the CAG-ID is associated with validity information and whether the corresponding validity criteria are met, e.g., whether the CAG-ID is authorized based on the (Allowed) CAG list.

Abstract: A method of a UE determining whether a current camped CAG cell is suitable and thereby entering limited service state for PNI-NPN as a hosting network is provided. When the PNI-NPN is a hosting network providing localized services, one or more allowed CAG IDs are associated with validity information per UE stored configuration, e.g., time and/or location validity criteria. Once a CAG cell is selected and camped by the UE in a PLMN, the UE needs to consider whether the current CAG cell is suitable for obtaining normal service from the PLMN. If the hosting network functionality is not enabled (by user), or if the time and/or location validity criteria associated with CAG-IDs broadcasted by the current CAG cell are not met, then the current CAG cell is not suitable. As a result, the UE enters limited service state, and triggers cell reselection or PLMN selection procedure.

Abstract: A method of handling updated CAG related configuration is proposed. UE receives an updated CAG related configuration in a DL NAS message via a CAG cell, which broadcasts a list of supported CAG-IDs of the current network. UE may also receive an updated CAG related configuration in a DL NAS message via a non-CAG cell of the current network. The UE examines the list of allowed CAG-IDs in the updated CAG related configuration, determines whether they are supported by the CAG cell, whether they are associated with validity information, whether the validity criteria are met, whether the UE is ONLY allowed to access 5GS via CAG cells, and whether the UE has any emergency PDU session. Depending on the determination, the UE then either enters LIMITED-SERVICE and search for suitable cell in the current network, or enters PLMN-SEARCH state and applies PLMN selection process.