Abstract: A method to establish and activate an MA PDU session for data transmission over a selected access is proposed. UE initiates a UE-requested PDU session establishment procedure. Once the UE receives a PDU SESSION ESTABLISHMENT ACCEPT message with ATSSS container IE, the UE can consider the MA PDU session has been activated and user plane resources are successfully established on the selected access. A method to convert an SA PDU session to an MA PDU session for data transmission over a selected access is proposed. UE initiates a UE-requested PDU session modification procedure. Once the UE receives a PDU SESSION MODIFICATION COMMAND message with ATSSS container IE, the UE can consider the MA PDU session has been converted from the SA PDU session and user plane resources are successfully established on the selected access.

Abstract: A User Equipment (UE) including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception to and from a first service network utilizing a first RAT or a second service network utilizing a second RAT. The controller sends an indicator of a connection release request to the first service network via the wireless transceiver in response to terminating a first communication service with the first service network or in response to leaving the first service network for the second service network. Also, the controller releases a Radio Resource Control (RRC) connection with the first service network after sending the indicator of the connection release request.

Abstract: Solutions pertaining to user equipment (UE) and network behavior at and after a network disaster in mobile communications are proposed. An apparatus, implemented in or as a UE, determines whether a disaster condition is met with respect to a first public land mobile network (PLMN). The apparatus then selects a second PLMN according to information listing one or more PLMNs which are allowed to be selected by the UE when the disaster condition is met. The apparatus also attempts a registration in the second PLMN.

Abstract: A method for S-NSSAI handling of a 5GS capable UE supporting session continuity between 3GPP and non-3GPP interworking is proposed. The UE maintains a PDN connection/PDU session. The UE performs interworking among S1 mode, N1 mode (including 3GPP and non-3GPP access), and ePDG. The UE associates the existing S-NSSAI with the new PDN connection/PDU session after interworking, no matter whether the S-NSSAI is provided by the network or not. The UE can update the S-NSSAI upon receipt of new value from the network. When interwork to N1 mode, the UE applies the S-NSSAI.

Abstract: A method for S-NSSAI handling of a 5GS capable UE supporting session continuity between 3GPP and non-3GPP interworking is proposed. The UE maintains a PDN connection/PDU session. The UE performs interworking among S1 mode, N1 mode (including 3GPP and non-3GPP access), and ePDG. The UE associates the existing S-NSSAI with the new PDN connection/PDU session after interworking, no matter whether the S-NSSAI is provided by the network or not. The UE can update the S-NSSAI upon receipt of new value from the network. When interwork to N1 mode, the UE applies the S-NSSAI.

Abstract: A method of enhanced handling of a Forbidden SNPN list by a UE is proposed. When the UE registers to a first SNPN using credentials supplied by a second SNPN and receives a rejection from the network, the UE adds an entry of the first SNPN into one of the forbidden SNPN lists, and also creates an association between the first SNPN and the second SNPN. As a result, the UE is refrained from registering to the first SNPN using the credentials supplied by the second SNPN as long as the first SNPN entry remains in the forbidden SNPN list. However, the UE is allowed to register to the first SNPN using credentials supplied by other SNPNs.

Abstract: Aspects of the disclosure provide methods and apparatuses. The method can include receiving, at a user equipment (UE), system information broadcast from one or more base stations which may be shared by one or more PLMNs and/or one or more SNPNs, the system information including an indication of whether accessing an SNPN using home service provider (HSP) subscription of a HSP network is supported. The UE can be configured with subscription information of the HSP network. The subscription information can include the HSP subscription and a selection list that includes one or more candidate networks each represented by an SNPN identifier. The method can further include responsive to the system information, selecting a network from the selection list according to a priority order of the candidate networks, and accessing the network selected from the selection list using the HSP subscription.

Abstract: A method for 5G Session Management (5GSM) handling of network rejection not due to congestion control is provided. A User Equipment (UE) receives a 5GSM reject message from a mobile communication network. The 5GSM reject message indicates a network rejection not due to congestion control. The UE associates a back-off timer with a Home Public Land Mobile Network (HPLMN) Single-Network Slice Selection Assistance Information (S-NSSAI). The UE prevents itself from sending a 5GSM request message for the same HPLMN S-NSSAI that is associated with the back-off timer.

Abstract: In 5GS, Single-Network Slice Selection Assistance Information (S-NSSAI) based backoff (BO) timers (T3584/T3585) can be applied to either the registered PLMN or all the PLMNs based on a 5GSM congestion re-attempt indicator. For a specific PDU session, the corresponding BO timer applied to the registered PLMN and the BO timer applied to all PLMN can be both running concurrently. It is proposed for a UE to stop both the BO timer applied to all the PLMNs and the BO timer applied to the registered PLMN, if running, in all the following scenarios: 1) Receiving a PDU session release command without a BO timer, 2) Receiving a PDU session release command with 5GSM cause #39, 3) Receiving a PDU session modification command, 4) Receiving a 5GSM message with a 5GSM congestion control BO timer value, and 5) Receiving a PDU session authentication command.

Abstract: Various solutions for extended reality (XR) enhancement in mobile communications are described. An apparatus establishes a communication with a network node of a wireless network. The apparatus performs an operation with respect to XR-related computation offloading from a user end to result in XR enhancement at the user end.

Abstract: A method to establish and activate an MA PDU session for data transmission over a selected access is proposed. UE initiates a UE-requested PDU session establishment procedure. Once the UE receives a PDU SESSION ESTABLISHMENT ACCEPT message with ATSSS container IE, the UE can consider the MA PDU session has been activated and user plane resources are successfully established on the selected access. A method to convert an SA PDU session to an MA PDU session for data transmission over a selected access is proposed. UE initiates a UE-requested PDU session modification procedure. Once the UE receives a PDU SESSION MODIFICATION COMMAND message with ATSSS container IE, the UE can consider the MA PDU session has been converted from the SA PDU session and user plane resources are successfully established on the selected access.

Abstract: A method of enhancing IP packet forwarding feature support after interworking is proposed. When a PDU session in 5GS is transferred to a PDN connection in EPS, the UE shall assume the feature is supported after inter-system change from 5GS to EPS. When a PDN connection is established in EPS, the network indicated that the feature is not supported, and the network provided 5GSM parameters for ESM/5GSM interworking for this PDN connection, then UE shall assume the feature is supported after inter-system change from EPS to 5GS, the UE shall also assume the feature is supported after inter-system change from 5GS back to EPS. The IP packet forwarding features include PS data off and local IP address in TFT.

Abstract: A User Equipment (UE) including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception to and from a first service network utilizing a first RAT or a second service network utilizing a second RAT. The controller sends an indicator of a connection release request to the first service network via the wireless transceiver in response to terminating a first communication service with the first service network or in response to leaving the first service network for the second service network. Also, the controller releases a Radio Resource Control (RRC) connection with the first service network after sending the indicator of the connection release request.

Abstract: A method of for performing carbon neutralization in a communication network is provided. The method includes receiving a service task from a user equipment. The method also includes obtaining a carbon neutralization calculation parameter related to performing the received service task. The method further includes selecting, based on the obtained carbon neutralization calculation parameter, a target entity from a plurality of candidate targets at which the received service task can be performed. The method further includes sending the received service task to the selected target entity.

Abstract: Various solutions for single network slice selection assistance information (S-NSSAI) based congestion control with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a message with a back-off timer from the network node. The apparatus may determine whether an S-NSSAI of a protocol data unit (PDU) session is provided by the network node. The apparatus may start the back-off timer and associate the back-off timer with the S-NSSAI of the PDU session in an event that the S-NSSAI is provided by the network node.

Abstract: A User Equipment (UE) including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception to and from a first service network utilizing a first RAT or a second service network utilizing a second RAT. The controller sends an indicator of a connection release request to the first service network via the wireless transceiver in response to terminating a first communication service with the first service network or in response to leaving the first service network for the second service network. Also, the controller releases a Radio Resource Control (RRC) connection with the first service network after sending the indicator of the connection release request.

Abstract: Aspects of the disclosure provide methods and apparatuses. The method can include receiving, at a user equipment (UE), system information broadcast from one or more base stations which may be shared by one or more PLMNs and/or one or more SNPNs, the system information including an indication of whether accessing an SNPN using home service provider (HSP) subscription of a HSP network is supported. The UE can be configured with subscription information of the HSP network. The subscription information can include the HSP subscription and a selection list that includes one or more candidate networks each represented by an SNPN identifier. The method can further include responsive to the system information, selecting a network from the selection list according to a priority order of the candidate networks, and accessing the network selected from the selection list using the HSP subscription.

Abstract: A method of enhancing session continuity for system interworking is proposed. Upon a UE performs inter-system change from A/Gb mode or Iu mode to S1 mode, the UE identifies that some PDN connection(s) are not associated with a PDU session ID (PSI). In one novel aspect, the UE deactivates all EPS bearer contexts for such PDN connection(s) locally, includes the EPS bearer context status IE in a TRACKING AREA UPDATE REQUEST message of a tracking area updating (TAU) procedure upon inter-system change from A/Gb mode or Iu mode to S1 mode, and then initiates UE requested PDN connectivity procedure(s) for such PDN connection(s). Furthermore, if no EPS bearer exists after local deactivation and EMM-REGISTERED without PDN connection is not supported by the UE, then the UE initiates a re-attach procedure followed by the UE requested PDN connectivity procedure(s) for such PDN connection (s) .

Abstract: A method of enhancing session continuity for system interworking is proposed. Upon intersystem change from S1 mode to N1 mode, a UE may perform deregistration when re-registration is required. The UE stops all 5GSM non-congestion back-off timers. In addition to the 5GSM non-congestion back-off timers, there may be ESM non-congestion back-off timers running. The UE may take the RATC and the EPLMNC indicators in the Re-attempt indicator IE into consideration, and stops all ESM non-congestion timers. Upon intersystem change from N1 mode to S1 mode, the UE may perform detach procedure when re-attach is required. The UE stops all ESM non-congestion back-off timers. In addition to the ESM non-congestion back-off timers, there may be 5GSM non-congestion back-off timers running. The UE may take the RATC and the EPLMNC indicators in the Re-attempt indicator IE into consideration, and stops all 5GSM non-congestion timers.

Abstract: A method of enhanced error handling for 5G QoS operations is proposed. A PDU session defines the association between the UE and the data network that provides a PDU connectivity service. Each PDU session is identified by a PDU session ID, and may include multiple QoS flows and QoS rules. Within a PDU session, there should be one and only one default QoS rule. The default QoS rule indication (DQR) and the QoS flow identifier (QFI) of a signaled QoS rule should not be changed. Two new 5G session management (5GSM) causes are defined: a semantic error in the QoS operation (cause value #83) and a syntactic error (cause value #84) in the QoS operation. The UE should check the QoS rule provided in a PDU session modification command message for different types of QoS rule errors.