Mediatek Corporation

Chien-chun Huang-fu

Yuan-chieh Lin

Chi-Hsien Chen

Shang-Ru Mo

Po-Ying Chuang

Chia-Lin Lai

Po Kuang Lu

Bo-Hun Chen

Pan-Yen Chiang

A method for UE route selection policy (URSP) rule matching regarding S-NSSAI and PDU session type is proposed. When an application is executed, a UE finds an RSD of a matching URSP rule, and the association of the application with an existing PDU session should have some exceptions. In one example, regarding S-NSSAI, if there's only a single allowed S-NSSAI or the UE is aware of the default S-NSSAI, the UE can associate the PDU session with the application where the existing PDU session is established with an S-NSSAI provided by the UE, but the RSD doesn't include any S-NSSAI. In another example, regarding PDU session type, the PDU session type IPv4v6 in the RSD can match with PDU session type IPv4 or IPv6 of the PDU session, which was established when the UE requested IPv4v6 during the PDU session establishment.

Handling of URSP regarding S-NSSAI and PDU type

A method of handling NAS signaling connection release under mobility management congestion control for MUSIM UE is proposed. A MUSIM UE has established a NAS signaling connection on a first USIM in connected mode. Later on, the MUSIM UE has more important job to be started on the second USIM. The MUSIM UE wishes to initiate a service request procedure by transmitting a service request to the network, to release the NAS signaling connection on the first USIM. However, under the 5GMM/EMM signaling congestion condition with timer T3346 running, the AMF/MME rejects 5GMM/EMM signaling requests from UE. In one novel aspect, the MUSIM UE requests the network to release the NAS signaling connection while timer T3346 is still running. As a result, the MUSIM UE is able to start the more important job on the second USIM, or to improve user experience on the second USIM.

MUSIM SR procedure and MM congestion control

A method of determining paging restriction on downlink signals for MUSIM UEs is proposed. If a UE requests the network to support paging restriction over the first USIM, the UE can send a request message to the network, carrying a UE-preferred paging restriction information. Subsequently, the UE should then receive an accept message from the network that the paging is restricted over the first USIM based on the UE-preferred paging restriction information. As a result, when DL signaling is pending for the UE over the first USIM, the network can determine whether it should page the UE over the first USIM based on the paging restriction type indicated in the paging restriction information. Since the DL signaling is selectively restricted over USIM1, the UE can perform more important jobs over USIM2 with better performance and user experience.

MUSIM paging restriction in 5GS

A method for handling a collision of a UE-requested PDU session establishment procedure and a network-requested PDU session modification procedure is proposed. When a PDU SESSION ESTABLISHMENT REQUEST message indicates that the UE-requested PDU session establishment request procedure is to handover an existing PDU session between 5G 3GPP access and 5G non-3GPP access, UE and NW proceed with the UE-requested PDU session establishment procedure and abort the NW-requested PDU session modification procedure. When a PDU SESSION ESTABLISHMENT REQUEST message indicates that the UE-requested PDU session establishment request procedure is to establish user plane resources for an MA PDU session, UE and NW proceed with both the UE-requested PDU session establishment procedure and the NW-requested PDU session modification procedure.

Handling of collision between PDU session establishment and modification procedure

A method of handling parameters of a subscribed network upon accessing a selected Stand-alone Non-Public Network (SNPN) using credentials from a credential holder is proposed. The UE selects an SNPN using a configured list of subscriber data, e.g., based on SNPN selection parameters contained in a selected entry of the list of subscriber data, or selects the SNPN based on SNPN selection parameters associated with a PLMN subscription of a USIM card. The UE accesses the selected SNPN using credentials supplied by a subscribed network, which is identified by the selected entry or by the USIM card. Upon successful registration to the selected SNPN, the UE applies a list of 3GPP PS_Data_Off exempt services that is different from a configured list of 3GPP PS_Data_Off exempt services associated with the selected entry, and evaluates a URSP that is different from the pre-configured URSP of the subscribed network.

Parameters handling for SNPN-enabled UE

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.

Session continuity for 3GPP and non-3GPP interworking

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.

Stand-alone Non-Public Network as service provider

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.

Handling of 5GSM congestion timers

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.

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Hsin-Chu, Taiwan

Chien-chun Huang-fu