Abstract: A method of handling PDU session identity (PSI) mismatch for PDU session procedures is proposed. In case a user equipment (UE) receives a 5G session management (5GSM) message in which the PSI value indicates that the PDU session is in 5GSM state PDU SESSION INACTIVE, the UE stays in its current 5GSM state for the PDU session and responds with a 5GSM status message including a 5GSM cause #43 “Invalid PDU session identity” to reduce signaling and UE handling effort. In case the UE receives a 5GSM message in which the PSI value is a reserved or an assigned value, the UE stays in its current 5GSM state for the PDU session and ignores the 5GSM message to reduce signaling.

Abstract: Various examples and schemes pertaining to enhancement of Internet Protocol (IP) Multimedia Subsystem (IMS) signaling reliability in mobile communications are described. A processor of an apparatus receives, at a layer 2 of a New Radio (NR) protocol stack, a packet for a specific type of signaling from an application layer of the NR protocol stack. The processor identifies, at the layer 2, one data radio bear (DRB) to be used for delivery of the packet. The processor then activates a reliability enhancement mechanism for the identified DRB such that a retransmission of the packet via the identified DRB is coordinated at the layer 2 or a layer above the layer 2.

Abstract: A method to manage call continuity in a network environment including a circuit-switched network and an IP multimedia subsystem (IMS) network is provided. A UE monitors one or more ongoing sessions in an IMS network, and the ongoing sessions contain at least one conference call. The UE detects a network-switching event for the UE to switch from the IMS network to a circuit-switched CS network. The UE then determines the one or more ongoing sessions within the IMS network to be released or transferred to the CS network. Finally, the UE performs a session transfer procedure for transferring the determined sessions.

Abstract: A solution of supporting IP multimedia subsystem (IMS) call setup in a next generation system (5GS) is proposed. During a registration procedure, the network sends indications to a user equipment (UE) indicating whether IMS voice over PS session (VoPS) over 3GPP access and over non-3GPP access is supported or not. The indications comprise two independent indicators, one indicator for indicating whether IMS VoPS is supported over 3GPP access, and the other indicator for indicating whether IMS VoPS is supported over non-3GPP access. In one example, the two independent indicators are included in a 5GS network feature support information element (IE) carried by a registration accept message sent from the network during the registration procedure.

Abstract: A method of QoS rule management with enhanced handling on QoS flow description is proposed. UE checks QoS configuration received from the network for QoS operation errors. When UE receives a QoS rule associated with a specific QFI but has no QoS flow description for the QFI, UE further determines whether the QoS rule is of a GBR QoS flow. If so, UE detects a QoS operation error. If the QoS rule is the default QoS rule, then UE releases the PDU session. If the QoS rule is not the default QoS rule, then UE either rejects a PDU session modification command that carries the QoS rule or deletes the QoS rule carried by a PDU session establishment accept with a 5GSM cause value indicating the QoS operation error.

Abstract: Examples pertaining to flexible radio access technology (RAT) selection for 5th Generation (5G) mobile communications are described. A user equipment (UE) may receive, from a network node of a wireless network, information related to a RAT preference with respect to RAT selection by the UE. Based at least in part on the received information, the UE may perform a RAT or Public Land Mobile Network (PLMN) selection procedure. Alternatively, or additionally, the UE may receive, from the network node, information related to ability of one or more neighbor network nodes of one or more RATs in a region. Based at least in part on the received information, the UE may select one of the one or more RATs or one of the one or more neighbor network nodes.

Abstract: A method of 5G session management (5GSM) state mapping is proposed when interworking. For each PDU session in 5GSM state of PDU SESSION active, PDU SESSION MODIFICATION PENDING, or PDU SESSION INACTIVE PENDING, UE maps the PDU session to a PDN connection in 4G ESM state BEARER CONTEXT ACTIVE. For any other PDU session in 5GSM state of PDU SESSION inactive, or PDU SESSION ACTIVE PENDING, UE maps the PDU session to a PDN connection in 4G ESM state BEARER CONTEXT INACTIVE.

Abstract: A method for handling PDU session handover procedure collision in a next generation NG/5G system is proposed. Both network-triggered and UE-triggered PDU session handover procedures can occur at the same time. If Paging or Notification for PDU session handover comes before UE initiated MO PDU session establishment procedure for PDU session handover, then UE should avoid sending the PDU session establishment request for PDU session handover but only send the service request as a response to paging. On the other hand, if Paging or Notification for PDU session handover comes after UE initiated MO PDU session establishment procedure for PDU session handover, then UE should avoid sending the service request for PDU session handover but proceed with the PDU session establishment procedure as a response to paging.

Abstract: A method at 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 QoS rule should not be changed. When the QoS operation carried by the command message is “Modify existing QoS rule and delete packet filters”, then it is defined as a semantic error in the QoS operation if all the packet filters of a QoS rule are deleted, and the QoS rule is a QoS rule of a PDU session of IPv4, IPv6, IPv4v6, or Ethernet PDU session type.

Abstract: A method for UE route selection policy (URSP) rule matching is proposed. URSP is used by a UE to determine if a detected application can be associated to an established PDU session, can be offload to non-3GPP access outside a PDU session, or can trigger the establishment of a new PDU session. The UE first finds a non-default URSP rule with a matching traffic descriptor to the application. When the UE fails to find existing PDU session or setup new PDU session with any or the route selection descriptors of the non-default URSP rule, the UE moves to another non-default URSP rule, if any, and try the matching. If all non-default URSP rules cannot be matched with the application, then the UE tries the default URSP rule, which includes a match-all traffic descriptor.

Abstract: Aspects of the disclosure provide a method for reflective quality of service (QoS) control and management at a user equipment (UE). The method can include creating a derived QoS rule belonging to a session and having a QoS flow identifier (QFI). The derived QoS rule includes a precedence value that is set to one of a precedence value associated with a session identifier (ID) of the session received from a core network (CN) of a wireless communication system during a session establishment procedure for establishing the session, a precedence value associated with the QFI received from the CN during the session establishment procedure for establishing the session or when a downlink QoS flow having the QFI is added to the session, or a precedence value that is defined by an operator of the wireless communication system.

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.

Abstract: A method for Procedure Transaction Identity (PTI) exception handling on protocol data unit (PDU) session modification and establishment procedure is proposed. If a UE receives a PDU SESSION MODIFICATION COMMAND message in which the PTI value is an assigned value that does not match any PTI in use, the UE stays in the current 5GSM state and sends a 5GSM STATUS message including 5GSM cause #47 “PTI mismatch”, and the network will send another COMMAND message with the correct PTI value. If the UE receives a PDU SESSION ESTABLISHMENT ACCEPT or REJECT message in which the PTI value is an assigned value that does not match any PTI in use, the UE responds with a 5GSM STATUS message including 5GSM cause #47 “PTI mismatch”, and the network will send another ACCEPT or REJECT message with the correct PTI value.

Abstract: Examples pertaining to indication of user equipment (UE) voice capabilities using non-access stratum (NAS) signaling in 5th Generation (5G) mobile communications are described. A processor of an apparatus (e.g., a user equipment (UE)) transmits an indication of a voice domain preference in a 5th Generation System (5GS) to a communication entity of a 5G mobile network. The processor then receives a voice service from the 5G mobile network responsive to the transmission of the indication.

Abstract: Aspects of the disclosure can provide an apparatus and method for performing protocol data unit (PDU) session establishment restriction in emergency registration in a fifth generation system (5GS). The apparatus comprises processing circuitry which is configured to detect whether user equipment (UE) is registered for emergency services via a first access type in the 5GS. When the UE is registered but without an established emergency PDU session, the processing circuitry is configured to establish a new emergency PDU session in the first access type. When the UE is registered and has the established emergency PDU session, the processing circuitry is configured to transfer the established emergency PDU session in the first access type to a second emergency PDU session in a second access type by performing a PDU session establishment procedure or a service request procedure to transfer the established emergency PDU session.

Abstract: A method of enhanced handling of a Forbidden Public Land Mobile Network (PLMN) list is proposed. When a UE tries to attach to a PLMN and receives an ATTACH Reject message having no integrity protection, it could be transmitted from a network entity trying to block the PLMN for providing service. Therefore, by introducing a temporary forbidden PLMN list and a timer T3247, UE can avoid adding the PLMN ID to the Forbidden PLMN list and avoid being blocked for network access. Instead, UE is only temporary refrained from selecting the PLMN ID and is able to retry for the network access after T3247 expiry. The temporary list together with T3247 mechanism thus gives UE more opportunity to try with the same PLMN ID at a different time and/or a different UE location, where the malicious blocking is no longer available.

Abstract: A method of modifying PS_Data_Off status via a PDN connection modification procedure and interpreting network PS_Data_Off support feature is proposed. A UE modifies the PS data off status by using a bearer resource modification procedure. The UE receives a response to the modification request and monitors whether the response includes the 3GPP PS_Data_Off Support indication. In one embodiment, if the network does not provide the 3GPP PS_Data_Off Support Indication, the UE thinks that the network does not support PS data off feature regardless whether the network accept or reject the modification request. In another embodiment, if the network does not provide the 3GPP PS_Data_Off Support Indication, then UE thinks that the network supports PS data off feature if it accepts the modification request, and does not support PS data off feature if it rejects the modification request.

Abstract: Various examples pertaining to handling of Public Land Mobile Network (PLMN)-specific attempt counter in mobile communications are described. An apparatus (e.g., user equipment) detects an occurrence of a predefined condition. In response to the detecting, the apparatus performs certain operations, including: (i) adding a visited Public Land Mobile Network (VPLMN) identification (ID) to a list of one or more forbidden PLMNs stored in a storage device, (ii) removing the VPLMN ID from a list of extension of forbidden PLMNs stored in the storage device; and (iii) resetting a PLMN-specific attempt counter specific to the PLMN ID to zero.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE sends, in a first transaction, a request to a network for releasing a protocol data unit (PDU) session established between the UE and the network. The UE receives, while waiting for a first command sent from the network for releasing the PDU session in the first transaction, a second command from the network for releasing the PDU session in a second transaction. The UE aborts the first transaction.

Abstract: A method for handling network feature capabilities is provided. The method includes a UE determining whether a first access network with a first access type and a second access network with a second access type are registered on the same PLMN; if the first access network and the second access network register on the same PLMN, the UE determines whether a first registration procedure over the first access network occurred earlier than the second registration procedure over the second access network. The first registration procedure corresponds to first setting values for a plurality of network feature capabilities and the second registration procedure corresponds to second setting values for the network feature capabilities. If the first registration procedure over the first access network occurred earlier than the second registration procedure over the second access network, the UE adopts the second setting values for the network feature capabilities.