Protocol description handling of XR application in case of UE switch between 5GS and eps

Abstract

Described are approaches for interworking during inter-system change where a UE transitions from being connected to 5GS to being connected to an EPS and vice versa for handling PDU sessions for applications, such as XR applications UE and a SMF store a Protocol Description, if the SMF provided a Protocol Description associated with a PDU session to the UE. The UE and SMF maintain the stored Protocol Description associated with the PDU session after inter-system change from 5GS to EPS. If the UE transitions back to being connected to the 5GS, UE and SMF use the maintained Protocol Description associated with the PDU session. If the UE requested establishment of a PDN connection for the XR application when the UE was connected to the EPS and then UE transitions to being connected to the 5GS, then SMF may acquire a new Protocol Description of the PDU session and send the Protocol Description associated with the PDU session to the UE. UE and SMF store the new Protocol Description associated with the PDU session until associated PDU session is released by the 5GS. UE can use Protocol Description associated with a PDU session to identify PDUs belonging to PDU sets for an uplink direction.

Description

PROTOCOL DESCRIPTION HANDLING OF XR APPLICATION IN CASE OF UE SWITCH BETWEEN 5GS AND EPSRelated Applications

[0001] This patent application claims the benefit of priority of India Provisional Patent Application No. 202411028153 filed on April 5, 2024, which is hereby incorporated by reference as if reproduced in its entirety.Field

[0002] This disclosure generally relates to mobile communication systems such as a 5G system and evolved packet system, and more particularly to inter-system change procedures when a user equipment changes from operating in N1 mode to operating in S 1 mode and vice versa, and still more particularly to inter-system change procedures for transferring a service data flow from being sent via a protocol data unit session in a 5G system to a corresponding packet data network connection in a 4G system and vice versa.Background

[0003] A mobile communication network enables communications between user terminals (otherwise referred to as user equipment) and servers, such as edge servers (e.g., servers located at the edge of a data network connected to the mobile communication network). A communication network can include a communication system that includes access networks, including radio access networks, a core network and one or more communication devices. A communication network may establish data connections between the user equipment and a server over which data, for example, voice data carrying voice signals, electronic mail (email), data carrying short message service messages, application data such as multimedia data and / or content data. A communication network may provide services to user terminals. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network, such as the Internet. In a mobile communication network, communications between user terminals and base stations of an access node occur over a wireless link.

[0004] A communication device is often referred to as a user equipment (UE) or a user device. A communication device includes a transceiver for transmitting and receiving wireless signals, including radio signals. The communication device may access a carrier provided by a base station or access point of an access network of a communication network and transmit and / or receive communications on the carrier.

[0005] A communication network and user terminals typically operate in accordance with a given standards or standards specifications, such as those provided by 3 GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute).Summary

[0006] Methods, apparatuses, and computer program products are provided for facilitating interworking during inter-system change, e.g., of a service or a connection for a user equipment (UE), between fifth-generation system (5GS) and Evolved Packet System (EPS) for Protocol Data Unit (PDU) sessions or Packet Data Network (PDN) connections in extended Reality (XR) applications, or vice versa. During inter-system change from 5GS to EPS, a UE and / or a Session Management Function (SMF) can be configured to store a Protocol Description associated with a PDU session for the UE in XR for future use in the 5GS in case of inter-system change back to 5GS. If the PDN connection for the UE for an XR application was established in EPS and the UE moves and communicates with a 5GS, the SMF provides the UE a Protocol Description associated with the PDU session for the UE. The UE and / or SMF can store therein the Protocol Description associated with the PDU session for the UE for an XR application until the PDU session is released. The UE can use the Protocol Description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink (UL) traffic of a service-data flow for the XR application. SMF may including the Protocol Description associated with the PDU session for the UE in a PDU SESSION MODIFICATION COMMAND message and send the PDU SESSION MODIFICATION COMMAND message to the UE.

[0007] Further information about the information included in the protocol description can be found throughout the 3GPP standard, such as in 3GPP TS 23.501, the entire disclosure of which is hereby incorporated herein by reference in its entirety. For example, the protocol description can include Protocol Description information, such as an indication of a service protocol used by the flow, which is typically not provided for / used for PDR matching, but instead may be provided to assist in PDU Set identification when PDU Set Identification and marking applies to the PDR and / or to assist identification of the last packet of the Data burst in downlink when End of Data Burst identification and marking in downlink applies to the PDR.

[0008] The protocol description can further or alternatively include information to support PDU Set based QoS handling. For example, the PSA UPF can identify PDUs that belong to PDU Sets and determine PDU Set Information which it sends to the NG-RAN in the GTP-U header. The PDU Set information is used by the NG-RAN for PDU Set based QoS handling as described above.

[0009] The protocol description can include PDU Set Information that comprises one or more of: a PDU Set Sequence Number, an indication of End PDU of the PDU Set, a PDU Sequence Number within a PDU Set, the PDU Set Size in bytes, a PDU Set Importance (e.g., which can identify the relative importance of a PDU Set compared to other PDU Sets within a QoS Flow), and / or the like. The NG-RAN may use the Priority Level across QoS Flows and PDU Set Importance within a QoS Flow for PDU Set level packet discarding in presence of congestion. In addition to considering the PDU Set Importance within a QoS Flow, NG- RAN could also consider the relative PDU Set Importance across QoS Flows of the same Priority Level when determining which PDU Set needs to be discarded, which is up to implementation and configuration of operator.

[0010] The PDU Set Information can be different for different PDU Sets within a QoS Flow. If the NG-RAN has provided a PDU Set based handling support Indication indicating that PDU Set handling is supported and a Protocol Description together with 1) a PSIHI and / or 2) PSDB and PSER is included in the PCC rule, the SMF instructs PSA UPF to perform PDU Set marking and may provide the PSA UPF the DL Protocol Description used by the service data flow. The DL Protocol Description may be received in the PCC rule, based on information provided by the AF or by PCF local policies. PSA UPF can identify the PDU Set Information using the DL Protocol Description and the received transport protocol headers and payload or using implementation specific means. The details of the RTP / SRTP headers, header extensions and / or payloads used to identify PDU Set Information are described further in 3GPP TS 26.522, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes. For each DL PDU received on N6 for which PDU Set based QoS handling is indicated from the SMF, the PSA UPF applies the rules for PDU Set identification and provides the available PDU Set Information to the RAN in the GTP-U header. The PSA UPF is expected to assign a unique PDU Set Sequence Number in the GTP-U header to each PDU Set of the QoS Flow.

[0011] In some aspects, the SMF can provide the Protocol Description information to the UPF and request the UPF to mark PDU Set Information in each PDU belonging to the PDU Sets and to mark the End of Data burst in a last PDU in downlink based on the protocol header identified by the Protocol Description information, e.g., according to the local operator policies.

[0012] In some aspects, if the PDN connection for XR service was created / established in EPS itself, then there likely would not be any associated PD (protocol description) available. Hence, when the UE moves to 5G, it will not have any stored (and / or maintained) PD and a new PD should be created / sent by the SMF to the UE.

[0013] In some aspects, if the PDU session for XR was generated when the UE was in connected mode with the 5GS, then the UE would, should, or could have an associated PD which is stored (and / or maintained) therein. If / when the UE moves to 4G (EPS) and subsequently comes back from 4G (EPS) to 5G, the stored (and / or maintained) PD (mapped to the PDU session ID) can be used for communicating with the 5G system, such as when sending a session modification request or the like.

[0014] According to some aspects, a method for handling protocol descriptions associated with PDU sessions for a UE for XR application(s) when a UE switches from being connected to a 5GS to being connected to a EPS and vice versa can be carried out.

[0015] According to a first aspect, there is a method can be carried out or performed, e.g., by a UE that is configured to communicate with an evolved packet system (EPS) and a 5GS. The method comprising: in an instance in which the UE is in N1 mode, sending to a network function configured for management of protocol data unit (PDU) sessions and PDN connections, one or more session management parameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE and a packet data network gateway when the UE was in S 1 mode to a PDU session, providing, by the UE, to the network function, a first NAS message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session. In some aspects, the one or more session management capabilities refer to capabilities supported by the UE with respect to session management, which comprise one or more of: a quality of service (QoS) or ultrareliable low latency communications (URLLC).

[0016] According to a second aspect, there is provided a UE that is configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the UE is in N1 mode, sending to a network function configured for management of PDU sessions and PDN connections, one or more session managementparameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE and a packet data network gateway when the UE was in SI mode to a PDU session, providing, by the UE, to the network function, a first NAS message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session. In some aspects, the one or more session management capabilities refer to capabilities supported by the UE with respect to session management, which comprise one or more of: a quality of service (QoS) or ultra-reliable low latency communications (URLLC).

[0017] According to a third aspect, there is provided a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus (e.g., a UE) configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: in an instance in which the UE is in N1 mode, sending to a network function configured for management of PDU sessions and PDN connections, one or more session management parameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE and a packet data network gateway when the UE was in SI mode to a PDU session, providing, by the UE, to the network function, a first NAS message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session. In some aspects, the one or more session management capabilities refer to capabilities supported by the UE with respect to session management, which comprise one or more of: a quality of service (QoS) or ultra-reliable low latency communications (URLLC).

[0018] According to a fourth aspect, there is provided a UE that is configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the UE is in N1 mode, sending to a network function configured for management of PDU sessions and PDN connections, one or more session management parameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE and a packet data network gateway when the UE was in S 1 mode to a PDU session, providing, by the UE, to the network function, a first NAS messagecomprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session. In some aspects, the one or more session management capabilities refer to capabilities supported by the UE with respect to session management, which comprise one or more of: a quality of service (QoS) or ultrareliable low latency communications (URLLC).

[0019] According to a sixth aspect, there is provided a method can be carried out or performed by a network function configured for management of PDU sessions and PDN connections, the method comprising: receiving from a user equipment, a first NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with a PDN connection established for a UE when the UE was in SI mode; and providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session.

[0020] According to an aspect, an apparatus, e.g., a network function configured for management of PDU sessions and PDN connections, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: receiving from a user equipment, a first NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with / a PDN connection established for a UE when the UE was in SI mode; and providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session.

[0021] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a network function configured for management of PDU sessions and PDN connections, to perform a method, such as a method comprising: receiving from a user equipment, a first NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with a PDN connection established for a UE when the UE was in SI mode; and providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session.

[0022] According to an aspect, an apparatus, e.g., a network function configured for management of PDU sessions and PDN connections, can be provided that comprises means for performing a method, such as a method comprising: receiving from a user equipment, afirst NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with / a PDN connection established for a UE when the UE was in SI mode; and providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session.

[0023] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to support SI mode and N1 mode, the method comprising: determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE; maintaining the protocol description associated with the PDU session after changing from being in N1 mode to being in SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode.

[0024] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE; maintaining the protocol description associated with the PDU session after changing from being in N1 mode to being in SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode.

[0025] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to support SI mode and N1 mode, to perform a method, such as a method comprising: determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE; maintaining the protocol description associated with the PDU session after changing from being in N1 mode to being in SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode.

[0026] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises means for performing a method, such as a method comprising: determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE; maintaining the protocol description associated withthe PDU session after changing from being in N1 mode to being in SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode.

[0027] According to an aspect, a method can be carried out or performed, e.g., by a network function configured to perform management of protocol data unit sessions and packet data network connections, the method comprising: in an instance that a protocol description associated with a PDU session was provided for a UE, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE from being in N1 mode to being in S 1 mode.

[0028] According to an aspect, an apparatus, e.g., a network function configured to perform management of protocol data unit sessions and packet data network connections, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance that a protocol description associated with a PDU session was provided for a UE, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE from being in N1 mode to being in S 1 mode.

[0029] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a network function configured to perform management of protocol data unit sessions and packet data network connections, to perform a method, such as a method comprising: in an instance that a protocol description associated with a PDU session was provided for a UE, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE from being in N1 mode to being in SI mode.

[0030] According to another aspect, an apparatus, comprising a network function that is configured to perform management of protocol data unit sessions and packet data network connections, can be provided that comprises means for performing a method, such as a method comprising: in an instance that a protocol description associated with a PDU session was provided for a UE, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE from being in N1 mode to being in SI mode.

[0031] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to support S 1 mode and N 1 mode, the method comprising: in an instance in which the UE in N1 mode needs to indicate, to a network function, one or more session management parameters or one or more session management capabilities for a PDU session for the UE which is associated with a PDN connection established for the UE when the UE was in SI mode, providing, by the UE, to the network function, a first message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session.

[0032] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the UE in N1 mode needs to indicate, to a network function, one or more session management parameters or one or more session management capabilities for a PDU session for the UE which is associated with a PDN connection established for the UE when the UE was in SI mode, providing, by the UE, to the network function, a first message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session.

[0033] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to support SI mode and N1 mode, to perform a method, such as a method comprising: in an instance in which the UE in N1 mode needs to indicate, to a network function, one or more session management parameters or one or more session management capabilities for a PDU session which is associated with a PDN connection established for the UE when the UE was in SI mode, providing, by the UE, to the network function, a first message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session.

[0034] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises means for performing a method, such as a methodcomprising: in an instance in which the UE in N1 mode needs to indicate, to a network function, one or more session management parameters or one or more session management capabilities for a PDU session which is associated with a PDN connection established when in SI mode, providing, by the UE, to the network function, a first message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session.

[0035] According to an aspect, a method can be carried out or performed, e.g., by a network function configured to support inter-system change between SI mode and N1 mode, the method comprising: in an instance in which the network function receives from a user equipment, a first message comprising a request for modification of a PDU session and determines that the PDU session is associated with a PDN connection established for the UE when the UE was in SI mode, providing, to the UE, a second message comprising a protocol description associated with the PDU session.

[0036] According to an aspect, an apparatus, e.g., a network function configured to support inter-system change between SI mode and N1 mode, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the network function receives from a user equipment, a first message comprising a request for modification of a PDU session and determines that the PDU session is associated with a PDN connection for the UE established when the UE was in SI mode, providing, to the UE, a second message comprising a protocol description associated with the PDU session.

[0037] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) of a network function configured to support inter-system change between SI mode and N1 mode stored thereon that, when executed by at least one processor, cause an apparatus, e.g., , to perform a method, such as a method comprising: in an instance in which the network function receives from a user equipment, a first message comprising a request for modification of a PDU session and determines that the PDU session for the UE is associated with a PDN connection established for the UE when the UE was in SI mode, providing, to the UE, a second message comprising a protocol description associated with the PDU session.

[0038] According to an aspect, an apparatus, e.g., a network function configured to support inter-system change between SI mode and N1 mode, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the network function receives from a user equipment, a first message comprising a request for modification of a PDU session and determines that the PDU session for the is associated with / a PDN connection established for the UE when the UE was in SI mode, providing, to the UE, a second message comprising a protocol description associated with the PDU session.

[0039] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to support S 1 mode and N 1 mode, the method comprising: in an instance in which the UE determines that a protocol description associated with a PDU session is stored (and / or maintained) at the UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change from SI mode to N1 mode.

[0040] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the UE determines that a protocol description associated with a PDU session is stored (and / or maintained) at the UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change from SI mode to N1 mode.

[0041] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to support SI mode and N1 mode, to perform a method, such as a method comprising: in an instance in which the UE determines that a protocol description associated with a PDU session is stored (and / or maintained) at the UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after intersystem change from SI mode to N1 mode.

[0042] According to an aspect, an apparatus, e.g., a UE configured to support SI mode and N1 mode, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the UE determines that a protocol description associated with a PDU session is stored (and / or maintained) at the UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change from SI mode to N1 mode.

[0043] According to an aspect, a method can be carried out or performed by, e.g., a network function configured to support inter-system change between SI mode and N1 mode, the method comprising: in an instance in which the network function determines that the network function provided a protocol description associated with a PDU session for a UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode.

[0044] According to an aspect, an apparatus, e.g., a network function configured to support inter-system change between SI mode and N1 mode, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the network function determines that the network function provided a protocol description associated with a PDU session for a UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode.

[0045] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a network function configured to support inter-system change between SI mode and N1 mode, to perform a method, such as a method comprising: in an instance in which the network function determines that the network function provided a protocol description associated with a PDU session for a UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode.

[0046] According to an aspect, an apparatus, e.g., a network function configured to support inter-system change between SI mode and N1 mode, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the network function determines that the network function provided a protocol description associatedwith a PDU session for a UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode.

[0047] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to communicate with an EPS and a 5GS, the method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some aspects, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0048] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some aspects, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0049] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is not stored(and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some aspects, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0050] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some aspects, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0051] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to communicate with an EPS and a 5GS, the method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with the EPS to be the PDU session with the 5GS; and in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of the PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second NAS message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE does not have an existing protocoldescription stored (and / or maintained) at the UE. In some aspects, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0052] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with the EPS to be the PDU session with the 5GS; and in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of the PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some embodiments, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some embodiments, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0053] According to another embodiment, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with the EPS to be the PDU session with the 5GS; and in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of the PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, andstoring (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some embodiments, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some embodiments, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0054] According to another aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the 5GS is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with the EPS to be the PDU session with the 5GS; and in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a first message comprising a request for modification of the PDN connection with the EPS to be a PDU session with the 5GS, receiving, at the UE, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session. In some embodiments, the first message further comprises an indication that the UE does not have an existing protocol description stored (and / or maintained) at the UE. In some embodiments, the first message further comprises an indication that the UE is requesting a new protocol description associated with the PDU session.

[0055] According to another aspect, a method can be carried out or performed, e.g., by a UE configured to communicate with an EPS and a 5GS, the method comprising: determining, at the UE, whether an existing protocol description associated with a PDU session between the UE and a 5GS is stored (and / or maintained) at the UE, the PDU session having been associated with a PDN connection for the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session to, e.g., identify a PDU Set associated with each PDU; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the newprotocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0056] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining, at the UE, whether an existing protocol description associated with a PDU session between the UE and a 5GS is stored (and / or maintained) at the UE, the PDU session having been associated with a PDN connection for the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0057] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: determining, at the UE, whether an existing protocol description associated with a PDU session between the UE and a 5GS is stored (and / or maintained) at the UE, the PDU session having been associated with a PDN connection for the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATIONCOMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0058] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: determining, at the UE, whether an existing protocol description associated with a PDU session between the UE and a 5GS is stored (and / or maintained) at the UE, the PDU session having been associated with a PDN connection for the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network function of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0059] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to communicate with an EPS and a 5GS, the method comprising: while the UE has a PDN connection active between the UE and an EPS, determining that the PDN connection is being associated with a PDU session for the UE; determining, at the UE, whether the PDN connection was originally established in N1 mode or in SI mode; in an instance in which the PDN connection was originally established in SI mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is stored (and / or maintained) at the UE; in an instance in which the PDN connection was originally established in N1 mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is not stored (and / or maintained) at the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network function of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocoldescription associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0060] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: while the UE has a PDN connection active between the UE and an EPS, determining that the PDN connection is being associated with / a PDU session for the UE; determining, at the UE, whether the PDN connection was originally established in N1 mode or in SI mode; in an instance in which the PDN connection was originally established in SI mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is stored (and / or maintained) at the UE; in an instance in which the PDN connection was originally established in N1 mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is not stored (and / or maintained) at the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network function of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0061] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: while the UE has a PDN connection active between the UE and an EPS, determining that the PDN connection is being associated with a PDU session for the UE ; determining, at the UE, whether the PDN connection was originallyestablished in N1 mode or in SI mode; in an instance in which the PDN connection was originally established in SI mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is stored (and / or maintained) at the UE; in an instance in which the PDN connection was originally established in N1 mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is not stored (and / or maintained) at the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0062] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: while the UE has a PDN connection active between the UE and an EPS, determining that the PDN connection is being associated with a PDU session for the UE; determining, at the UE, whether the PDN connection was originally established in N1 mode or in SI mode; in an instance in which the PDN connection was originally established in SI mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is stored (and / or maintained) at the UE; in an instance in which the PDN connection was originally established in N1 mode, determining that an existing protocol description associated with the PDU session between the UE and the 5GS is not stored (and / or maintained) at the UE; in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE, using the existing protocol description associated with the PDU session during the PDU session with the 5GS; and, in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE, providing, by the UE, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE is requesting a new protocol description associated with the PDU session, receiving, at the UE,a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE, the new protocol description associated with the PDU session.

[0063] According to an aspect, a method can be carried out or performed, e.g., by a UE configured to communicate with an EPS and a 5GS, the method comprising: before or during a transfer of a PDN connection with the EPS to a PDU session with the 5GS, determining whether a protocol description associated with the PDU session is stored (and / or maintained) at the UE; in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE, sending a PDU SESSION MODIFICATION REQUEST message towards the 5GS; receiving, at the UE, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session; and storing (and / or maintaining) the protocol description associated with the PDU session at the UE.

[0064] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: before or during a transfer of a PDN connection with the EPS to a PDU session with the 5GS, determining whether a protocol description associated with the PDU session is stored (and / or maintained) at the UE; in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE, sending a PDU SESSION MODIFICATION REQUEST message towards the 5GS; receiving, at the UE, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session; and storing (and / or maintaining) the protocol description associated with the PDU session at the UE.

[0065] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: before or during a transfer of a PDN connection with the EPS to a PDU session with the 5GS, determining whether a protocol description associated with the PDU session is stored (and / or maintained) at the UE; in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE, sending a PDU SESSION MODIFICATIONREQUEST message towards the 5GS; receiving, at the UE, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session; and storing (and / or maintaining) the protocol description associated with the PDU session at the UE.

[0066] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: before or during a transfer of a PDN connection with the EPS to a PDU session with the 5GS, determining whether a protocol description associated with the PDU session is stored (and / or maintained) at the UE; in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE, sending a PDU SESSION MODIFICATION REQUEST message towards the 5GS; receiving, at the UE, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session; and storing (and / or maintaining) the protocol description associated with the PDU session at the UE.

[0067] According to an aspect, a method can be carried out, such as by a UE or the like, that comprises: determining whether to transmit, from the UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session for the UE carrying XR traffic to be associated with a PDN connection for the UE; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session for the UE to be associated with the PDN connection for the UE, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0068] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining whether to transmit, from the UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session carrying XR traffic to be associated with a PDN connection for the UE; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session to be associated with / the PDN connection for the UE, providing the PDU session modification request message to the network entityof the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0069] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, to perform a method, such as a method comprising: determining whether to transmit, from the UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session carrying XR traffic to be associated with a PDN connection for the UE; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session for the UE to be associated with / the PDN connection for the UE, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0070] According to an aspect, an apparatus, e.g., a UE configured to communicate with an EPS and a 5GS, can be provided that comprises means for performing a method, such as a method comprising: determining whether to transmit, from the UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session for the UE carrying XR traffic to be associated with / a PDN connection for the UE; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session for the UE to be associated with the PDN connection for the UE, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0071] In some aspects, the method can further comprise: after the UE transfers back to being connected to the 5GS, using the protocol description stored (and / or maintained) at the UE for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the method can further comprise: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the network entity comprises a SMF of the 5GS.

[0072] According to an aspect, an apparatus can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining whether to transmit, from a UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session for the UE carrying XR traffic to be associated with a PDN connection for the UE; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session for the UE to be associated with / the PDN connection for the UE, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0073] In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: once the PDN connection is associated with an XR service / XRM / XR traffic flow transferred to / back to a PDU session with the 5GS, using the protocol description stored (and / or maintained) at the UE for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the network entity comprises a SMF of the 5GS.

[0074] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus to perform a method, such as a method comprising: determining whether to transmit, from a UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session carrying XR traffic to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to the PDN connection of the EPS, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0075] In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: once the PDN connection is associated with an XR service / XRM / XR traffic flow transferred back to the 5GS as the PDU session, using the protocol description stored (and / or maintained) at the UE for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the network entity comprises a SMF of the 5GS.

[0076] According to an aspect, an apparatus can be provided that comprises means for performing a method, such as a method comprising: determining whether to transmit, from a UE, towards a network entity of a 5GS, a PDU session modification request message for a PDU session carrying XR traffic to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to the PDNconnection of the EPS, providing the PDU session modification request message to the network entity of the 5GS; and upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE.

[0077] In some aspects, the apparatus can further comprise: means for once the PDN connection is associated with an XR service / XRM / XR traffic flow transferred back to the 5GS as the PDU session, using the protocol description stored (and / or maintained) at the UE for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the apparatus can further comprise: means for maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the network entity comprises a SMF of the 5GS.

[0078] According to an aspect, a method can be carried out, such as by a network entity configured for PDU session interworking in a 5GS upon an inter-system change from a PDN connection for a UE in an EPS, the method comprising: determining whether the PDN connection was established in the EPS or was associated with a PDU session for the UE; and, in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the method can further comprise: in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session. In some aspects, the method can further comprise: transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the method can further comprise: in an instance in which the PDN connection was associated with a PDU session for the UE, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the method can further comprise: in an instance in which the PDN connection was associated with a PDU session for the UE, determining that the UE already has stored (and / or maintained) therein the protocol description associatedwith the PDU session between the 5GS and the UE; and refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE.

[0079] According to an aspect, an apparatus, such as a network entity configured for PDU session interworking in a 5GS upon an inter-system change from a PDN connection for a UE in an EPS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining whether the PDN connection was established in the EPS or was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS; and, in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE.

[0080] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, such as a network entity configured for PDU session interworking in a 5GS uponan inter-system change from a PDN connection for a UE in an EPS, to perform a method, such as a method comprising: determining whether the PDN connection was established in the EPS or was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS; and, in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE.

[0081] According to an aspect, an apparatus, such as a network entity configured for PDU session interworking in a 5GS upon an inter-system change from a PDN connection for a UE in an EPS, can be provided that comprises means for carrying out a method, such as a method that comprises: determining whether the PDN connection was established in the EPS or was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS; and, in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the apparatus can further comprise: means for, in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session. In some aspects, the apparatus can further comprise: meansfor transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the apparatus can further comprise: means for, in an instance in which the PDN connection was associated with / a PDU session for the UE, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session for the UE; and means for refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE. In some aspects, the apparatus can further comprise: means for, in an instance in which the PDN connection for the UE was associated with an XR service / XRM / XR traffic flow transferred from a PDU session for the UE, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE; and means for refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE.

[0082] According to an aspect, a method can be carried out, such as by a network entity configured for PDU session interworking in a 5GS upon inter-system change from a PDN connection in an EPS, the method comprising: receiving, at a SMF in the 5GS, a message from an access and mobility management function (AMF) of the 5GS, the message comprising information regarding a registration request received from a UE, the registration request comprising a request to establish or re-establish a PDU session between the 5GS and the UE, wherein the PDU session was associated with an XR service / XRM / XR traffic flow transferred from the PDN connection with the EPS; determining whether the PDN connection was established when the UE was in SI mode or in N1 mode, and, in an instance in which it is determined that the PDN connection was established when the UE was in SI mode, receiving, at the SMF, a PDU SESSION MODIFICATION REQUEST message from the UE, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description.

[0083] In some aspects, the protocol description is configured to be used by the UE or network entities of the 5GS to identify the PDU session associated with PDUs transmitted or received in the PDU session. In some aspects, the PDU session comprises XR traffic. In some aspects, the XR traffic comprises PDUs that comprise one or more of: an I-frame or a P -frame. In some aspects, the XR traffic comprises one or more XR frames comprising a plurality of PDUs. In some aspects, the method further comprises: in an instance in which it is determined that the PDN connection was established when the UE was in N1 mode,determining that the UE has stored (and / or maintained) therein the protocol description associated with the PDU session; and refraining from generating a new protocol description associated with the PDU session.

[0084] According to an aspect, an apparatus, such as a network entity configured for PDU session interworking in a 5GS upon inter-system change from a PDN connection in an EPS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: receiving, at a SMF in the 5GS, a message from an access and mobility management function (AMF) of the 5GS, the message comprising information regarding a registration request received from a UE, the registration request comprising a request to establish or re-establish a PDU session between the 5GS and the UE, wherein the PDU session was associated with an XR service / XRM / XR traffic flow transferred from the PDN connection with the EPS; determining whether the PDN connection was established when the UE was in SI mode or in N1 mode, and, in an instance in which it is determined that the PDN connection was established when the UE was in SI mode, receiving, at the SMF, a PDU SESSION MODIFICATION REQUEST message from the UE, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description.

[0085] In some aspects, the protocol description is configured to be used by the UE or network entities of the 5GS to identify the PDU session associated with PDUs transmitted or received in the PDU session. In some aspects, the PDU session comprises XR traffic. In some aspects, the XR traffic comprises PDUs that comprise one or more of: an I-frame or a P -frame. In some aspects, the XR traffic comprises one or more XR frames comprising a plurality of PDUs. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which it is determined that the PDN connection was established when the UE was in N1 mode, determining that the UE has stored (and / or maintained) therein the protocol description associated with the PDU session; and refraining from generating a new protocol description associated with the PDU session.

[0086] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, such as a network entity configured for PDU session interworking in a 5GS uponinter-system change from a PDN connection in an EPS, to perform a method, such as a method comprising: receiving, at a SMF in the 5GS, a message from an access and mobility management function (AMF) of the 5GS, the message comprising information regarding a registration request received from a UE, the registration request comprising a request to establish or re-establish a PDU session between the 5GS and the UE, wherein the PDU session was associated with (e.g., a service data flow [an XR service / XRM / XR traffic flow] that was transferred from) the PDN connection with the EPS; determining whether the PDN connection was established when the UE was in SI mode or in N1 mode, and, in an instance in which it is determined that the PDN connection was established when the UE was in SI mode, receiving, at the SMF, a PDU SESSION MODIFICATION REQUEST message from the UE, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description.

[0087] In some aspects, the protocol description is configured to be used by the UE or network entities of the 5GS to identify the PDU session associated with PDUs transmitted or received in the PDU session. In some aspects, the PDU session comprises XR traffic. In some aspects, the XR traffic comprises PDUs that comprise one or more of: an I-frame or a P -frame. In some aspects, the XR traffic comprises one or more XR frames comprising a plurality of PDUs. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: in an instance in which it is determined that the PDN connection was established when the UE was in N1 mode, determining that the UE has stored (and / or maintained) therein the protocol description associated with the PDU session; and refraining from generating a new protocol description associated with the PDU session.

[0088] According to an aspect, an apparatus, such as a network entity configured for PDU session interworking in a 5GS upon inter-system change from a PDN connection in an EPS, can be provided that comprises means for performing a method, such as a method comprising: receiving, at a SMF in the 5GS, a message from an access and mobility management function (AMF) of the 5GS, the message comprising information regarding a registration request received from a UE, the registration request comprising a request to establish or re-establish a PDU session between the 5GS and the UE, wherein the PDU session was associated with an XR service / XRM / XR traffic flow transferred from the PDN connection with the EPS; determining whether the PDN connection was established when the UE was in SI mode or in N1 mode, and, in an instance in which it is determined that thePDN connection was established when the UE was in SI mode, receiving, at the SMF, a PDU SESSION MODIFICATION REQUEST message from the UE, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description.

[0089] In some aspects, the protocol description is configured to be used by the UE or network entities of the 5GS to identify the PDU session associated with PDUs transmitted or received in the PDU session. In some aspects, the PDU session comprises XR traffic. In some aspects, the XR traffic comprises PDUs that comprise one or more of: an I-frame or a P -frame. In some aspects, the XR traffic comprises one or more XR frames comprising a plurality of PDUs. In some aspects, the apparatus further comprises: means for, in an instance in which it is determined that the PDN connection was established when the UE was in N1 mode, determining that the UE has stored (and / or maintained) therein the protocol description associated with the PDU session; and means for refraining from generating a new protocol description associated with the PDU session.

[0090] According to an aspect, a method can be carried out, such as by a network entity of a 5GS, the method comprising: receiving, at a network entity of a 5GS, a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with an XR service / XRM / XR traffic flow transferred to a PDU session of the 5GS; in an instance in which the PDN connection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE; and determining that the protocol description for the PDU session is to be provided to the UE.

[0091] In some aspects, the method can further comprise: storing (and / or maintaining), at the network entity of the 5GS, the protocol description associated with the PDU session; and maintaining the protocol description until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the method can further comprise: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0092] According to an aspect, an apparatus, such as a network entity of a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: receiving, at a network entity of the 5GS, a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with / a PDU session for the UE; in an instance in which the PDN connection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE; and determining that the protocol description for the PDU session is to be provided to the UE.

[0093] In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: storing (and / or maintaining), at the network entity of the 5GS, the protocol description associated with the PDU session; and maintaining the protocol description until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0094] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, such as a network entity of a 5GS, to perform a method, such as a method comprising: receiving, at a network entity of the 5GS, a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with an XR service / XRM / XR traffic flow transferred to a PDU session of the 5GS; in an instance in which the PDN connection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE; and determining that the protocol description for the PDU session is to be provided to the UE.

[0095] In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform: storing (and / or maintaining), at the network entity ofthe 5GS, the protocol description associated with the PDU session; and maintaining the protocol description until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0096] According to an aspect, an apparatus can be provided that comprises means for performing a method, such as a method comprising: receiving, at a network entity of a 5GS, a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with a PDU session of the 5GS; in an instance in which the PDN connection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE; and determining that the protocol description for the PDU session is to be provided to the UE.

[0097] In some aspects, the apparatus can further comprise: means for storing (and / or maintaining), at the network entity of the 5GS, the protocol description associated with the PDU session; and means for maintaining the protocol description until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the apparatus can further comprise: means for, upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and means for, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0098] According to an aspect, a method can be carried out, such as by a network entity of a 5GS, such as a SMF of the 5GS, the method comprising: determining whether to initiate a PDU session modification procedure for a PDU session carrying XR traffic associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS; in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at a SMF in the 5GS,a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the 5GS and a UE; generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF in an uplink direction or provided towards the UE in a downlink direction. In some aspects, the protocol description is stored (and / or maintained), at the SMF, with one or both of: a PDU session identifier (ID) associated with the PDU session or a PDN ID associated with the PDN connection. In some aspects, the method can further comprise: maintaining the protocol description until release of the PDU session.

[0099] According to an aspect, an apparatus, such as a network entity of a 5GS, such as a SMF of the 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: determining whether to initiate a PDU session modification procedure for a PDU session carrying XR traffic associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS; in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at a SMF in the 5GS, a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the 5GS and a UE; generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF in an uplink direction or provided towards the UE in a downlink direction. In some aspects, the protocol description is stored (and / or maintained), at the SMF, with one or both of: a PDU session identifier (ID) associated with the PDU session or a PDN ID associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: maintaining the protocol description until release of the PDU session.

[0100] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, such as a network entity of a 5GS, such as a SMF of the 5GS, to perform a method, such as a method comprising: determining whether to initiate a PDU session modificationprocedure for a PDU session carrying XR traffic associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS; in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at a SMF in the 5GS, a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the 5GS and a UE; generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF in an uplink direction or provided towards the UE in a downlink direction. In some aspects, the protocol description is stored (and / or maintained), at the SMF, with one or both of: a PDU session identifier (ID) associated with the PDU session or a PDN ID associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: maintaining the protocol description until release of the PDU session.

[0101] According to an aspect, an apparatus, such as a network entity of a 5GS, such as a SMF of the 5GS, can be provided that comprises means for carrying out a method, such as a method comprising: determining whether to initiate a PDU session modification procedure for a PDU session carrying XR traffic associated with a PDN connection for a UE; in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at a SMF in the 5GS, a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the 5GS and a UE; generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF in an uplink direction or provided towards the UE in a downlink direction. In some aspects, the protocol description is stored (and / or maintained), at the SMF, with one or both of: a PDU session identifier (ID) associated with the PDU session or a PDN ID associated with the PDN connection. In some aspects, the apparatus can further comprise: means for maintaining the protocol description until release of the PDU session.

[0102] According to an aspect, a method can be performed, such as by a network element of a 5GS, the method comprising: generating, using a network element of the 5GS, a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for aPDU session between a UE and the 5GS, the PDU session carrying XR traffic between the 5GS and the UE; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and, upon an inter-system change for the PDU session carrying the XR traffic is carried out between the 5GS and an EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the 5GS as a PDU session carrying the XR traffic between the 5GS and the UE.

[0103] In some aspects, the method can further comprise: using the protocol description for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the method can further comprise: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the method can further comprise: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0104] According to an aspect, an apparatus, such as a network element of a 5GS, can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method, such as a method that comprises: generating, using a network element of a 5GS, a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for a PDU session between a UE and the 5GS, the PDU session carrying XR traffic between the 5GS and the UE; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and, upon an inter-system change for the PDU session carrying the XR traffic is carried out between the 5GS and an EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the 5GS as a PDU session carrying the XR traffic between the 5GS and the UE.

[0105] In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: using the protocol description for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In someaspects, the method can further comprise: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0106] According to an aspect, a computer program product can be provided that comprises a non-transitory computer-readable storage medium comprising instructions (e.g., computer program code) stored thereon that, when executed by at least one processor, cause an apparatus, such as a network element of a 5GS, to perform a method, such as a method comprising: generating, using a network element of the 5GS, a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for a PDU session between a UE and the 5GS, the PDU session carrying XR traffic between the 5GS and the UE; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and, upon an inter-system change for the PDU session carrying the XR traffic is carried out between the 5GS and an EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the 5GS as a PDU session carrying the XR traffic between the 5GS and the UE.

[0107] In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: using the protocol description for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the instructions, when executed by the at least one processor, can further cause the apparatus to perform at least: upon an inter-system change from SI mode to N1 mode, determining if thePDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0108] According to an aspect, an apparatus, such as a network element of a 5GS, can be provided that comprises means for carrying out a method, such as a method comprising: generating, using a network element of the 5GS, a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for a PDU session between a UE and the 5GS, the PDU session carrying XR traffic between the 5GS and the UE; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE; and, upon an inter-system change for the PDU session carrying the XR traffic is carried out between the 5GS and an EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the 5GS as a PDU session carrying the XR traffic between the 5GS and the UE.

[0109] In some aspects, the apparatus can further comprise: means for using the protocol description for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the apparatus can further comprise: means for maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or a EPS Bearer Identity associated with the PDN connection. In some aspects, the apparatus can further comprise: means for, upon an inter-system change from S 1 mode to N1 mode, determining if the PDN connection is a userplane resource of a multi-access (MA) PDU session; and means for, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction. In some aspects, the network entity comprises a SMF of the 5GS.

[0110] These and other aspects are described in further detail in the following sections of the present description.Brief Description of the Drawings

[0111] Having thus described aspects of the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0112] FIG. l is a block diagram of an example communications network that includes an evolved packet system and a fifth-generation system, according to an aspect;

[0113] FIG. 2 is a block diagram showing an example of inter-system change between evolved packet system and fifth-generation system, according to an aspect;

[0114] FIG. 3 is a block diagram of an example apparatus for an evolved packet system and / or a fifth-generation system, according to an aspect;

[0115] FIG. 4 is a block diagram of an example user equipment, according to an aspect;

[0116] FIG. 5 illustrates an example inter-system change procedure that involves a user equipment, an evolved packet system, and a fifth-generation system, according to an aspect;

[0117] FIG. 6 illustrates another example inter-system change procedure that involves a user equipment, an evolved packet system and a fifth-generation system, according to an aspect;

[0118] FIG. 7 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0119] FIG. 8 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0120] FIG. 9 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, , according to an aspect;

[0121] FIG. 10 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system , according to an aspect;

[0122] FIG. 11 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, , according to an aspect;

[0123] FIG. 12 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, , according to an aspect;

[0124] FIG. 13 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0125] FIG. 14 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0126] FIG. 15 illustrates an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0127] FIG. 16 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0128] FIG. 17 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation , according to an aspect;

[0129] FIG. 18 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, , according to an aspect;

[0130] FIG. 19 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0131] FIG. 20 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0132] FIG. 21 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0133] FIG. 22 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0134] FIG. 23 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0135] FIG. 24 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system network to a fifth-generation system, according to an aspect;

[0136] FIG. 25 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0137] FIG. 26 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0138] FIG. 27 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, , according to an aspect;

[0139] FIG. 28 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect;

[0140] FIG. 29 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect; and

[0141] FIG. 30 is an example flow chart illustrating operations performed for facilitating protocol description interworking for inter-system change from an evolved packet system to a fifth-generation system, according to an aspect.Symbols and Abbreviations

[0142] As used the present disclosure and in technical specifications incorporated herein by reference in their entireties, the following symbols and abbreviations are defined as follows:

[0143] 3GPP 3rd Generation Partnership Project

[0144] 5GC Fifth-Generation Core

[0145] 5GS 5G System

[0146] AF Application Function

[0147] AMF Access and Mobility Management Function

[0148] AN Application Network

[0149] API Application Programming Interface

[0150] AR Augmented Reality

[0151] AS Application Server

[0152] ATSSS Access Traffic Steering, Switching, and Splitting

[0153] AUSF Authentication Server Function

[0154] CN Core Network

[0155] CP Control Plane

[0156] DL Downlink

[0157] DN Data Network

[0158] E-UTRAN Evolved UMTS [Universal Mobile TelecommunicationsService] Terrestrial Radio Access

[0159] EAS Enterprise Application Server

[0160] EDGE Enhanced Data rates for GSM Evolution

[0161] EPS Evolved Packet System

[0162] GPU Graphics Processing Unit

[0163] GSM Global Systems for Mobile Communications

[0164] LTE Long Term Evolution

[0165] MME Mobility Management Entity

[0166] MR Mixed Reality

[0167] N3IWF Interworking Function Node

[0168] NEF Network Exposure Function

[0169] NRF Network Repository Function

[0170] NSSF Network Slice Selection Function

[0171] NWDAF Network Data Analytics Function

[0172] PCF Policy Control Function

[0173] PDN Packet Data Network

[0174] PCRF Policy and Charging Rules Function

[0175] PDU Protocol Data Unit

[0176] PSA PDU Session Anchor

[0177] QoS Quality of Service

[0178] RAN Radio Access Network

[0179] SCEF Service Capability Exposure Function

[0180] SMF Session Management Function

[0181] UE User Equipment

[0182] UL Uplink

[0183] UP User Plane

[0184] UPF User Plane Function

[0185] UTRAN Universal Terrestrial Radio Access Network

[0186] VR Virtual Reality

[0187] XR extended Reality

[0188] XRM XR and media servicesDetailed Description

[0189] Mobile telecommunication services rely on a continuous connection to a communication network to work properly and take advantage of the full service. To ensure the continuous connection, a communication device operating consuming a service of the communication network monitors a connection quality and regularly transmits, to a base station of the communication network, measurement reports comprising measurements related to the quality of the connection (e.g., the quality of a connection with a base station of a radio access network of the communication network). In the event of a drop in quality of the connection, e.g. due to movement of the communication device out of a coverage area of a base station, the communication network supports inter-system change for the communication device to another base station or network to maintain quality of the connection (e.g., the radio connection) with the communication network. As used herein “inter-system change” refers to mobility of a UE network connection between different systems and technologies, such as between LTE and 5G. Accordingly, an inter-system change for a UE may include the mobility or migration of a network connection (e.g., packet data network connection) with a first network or system (e.g., an EPS system ), to another network connection (e.g., protocol data unit session) with a second network or system (e.g., a 5G system). Corresponding mode changes at the UE can include, e.g., a change from N1 mode to SI mode, or the like.

[0190] For new generations of mobile communication networks such as 5G networks currently under standardization by the 3rd Generation Partnership Project (3GPP), virtual reality applications executed by the mobile stations are to be supported, as specified e.g. by 3GPP TR 26.928, version 16.1.0, version 17.0.0, and 18.0.0, the entire disclosures of each of which are hereby incorporated herein by reference in their entireties for all purposes. Among these applications, extended Reality (XR) and Cloud Gaming are some of the most important 5G media applications under consideration in the industry. XR is an umbrella term for different types of realities and refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. Different application domains of XR Applications include entertainment, healthcare, education, etc.

[0191] Third-Generation Partnership Project (3GPP) Technical Specification (TS) 23.558, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes, defines architectural solutions for enabling Edge applications. The term ‘Edge application’ refers to user applications which are supported and hosted by server elements of particular networks, which are a part of the overall communication network referred to as an Edge network. Edge networks, also known as Edge Data Networks (EDN), are typically logically located between a core network [CN] of the communication network, a Cloud Data Network, and UEs. In some aspects, an EDN may contain Edge Application Server(s) (EAS) and / or an Edge Enabler Server (EES). In some aspects, operation of the EES may be supported by an Edge Configuration Server (ECS). The EDN that includes EAS(s) and / or EES(s) may also include EDGE-X interfaces to communicate with the servers of the network. The UE may contain an application client, which has the task for the proper execution of an Mixed Reality (MR) application, Augmented Reality (AR) application, Virtual Reality (VR) application and / or XR application, and an Edge Enabler Client (EEC) as an interface to communicate with EDN network servers. More details about the EDN architecture and operation are disclosed in 3GPP TS 26.558, version 18.3.0, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.

[0192] The EAS is the application server resident in the Edge Data Network, performing the server functions and is connected to the 3GPP core via Radio Access Network (RAN). The EES facilitates context transfer between EES(s) and EAS(s) and interacts with the 3 GPP core either directly (e.g. via PCF) or indirectly (e.g. via SCEF, NEF, and / or SCEF+NEF). Additionally, the EES provides configuration information to Edge Enabler Client enabling exchange of application data traffic with the EAS. The ECS provides supporting functions needed for the Edge Enabler Client to connect with an EES. Additionally, the ECS supports the EES in identifying other EESs (and EASs) in case of application relocations. Furthermore, EDGE-9 symbolizes the connection to another EDN. In case of a relocation from one EAS to another, EDGE-9 is the connection from a source EES to a target EES.

[0193] Time-critical communications is a concept in communication networks and protocols, such as in 5G, 6G, and other technologies, for enabling services with reliable low latency requirements such as XR, which encompasses various immersive technologies, such as Virtual Reality (VR), Mixed Reality (MR), and Augmented Reality (AR). In VR, users are totally immersed in a simulated digital environment or a digital replica of reality. MR encompasses all forms of technology that blend virtual elements with real-worldsurroundings. AR overlays digital information onto real-life images observed through a device.

[0194] In XR, VR, AR, and MR viewing environments, visual media content is generated for display at the user device, which can include a heads-up display or head-mounted display (HMD), or the like. The user device and / or display device can be divided into sections or portions of 360 degrees of viewing perspective, which can be referred to as viewports, such that the visual media content can be generated for one or more viewports such that the rendered visual media content corresponds to a field of view (FOV) of the eyes of a user viewing the media content, inclusive of a stereoscopic offset to simulate natural parallax. As used herein, the term ‘viewport’ refers to a portion of the XR content to be rendered for a user based on pose information associated with the user and the user’s associated FOV within the full virtual scene, of which only the portion designated as the viewport during an associated time is being rendered.

[0195] The rendered viewport can then be adjusted in real-time based on changes in a user’s perceived location, viewing direction, head movements, rate of change of movement of these characteristics, and other user movements or behaviors. To do this, the user device can track its own pose and movement based on a variety of sensors, gyroscopes, magnetometers, accelerometers, and / or the like, and the user device can then receive a full complement of rendered raw visual media content for the entire virtual environment being viewed and experienced by the user, and then the user device can clip the user motion and pose adjusted viewport from the raw visual media content. However, such a solution requires the transmission of an unacceptably large amount of rendered visual media content, requires that the user device has exceedingly high computational capabilities, and incurs significant latency due to all rendering activities being carried out at the user device prior to display of the viewport during each associated period-of-time. The exceedingly high computational capabilities requirements, however, mean that the user device (e.g., virtual reality goggles, augmented reality glasses, heads-up display, head-mounted display, or the like) will be bulky and heavy due to increased battery capacity requirements, which will erode the immersiveness of the user experience, and will require processing chips and graphics cards having higher processing capacity, which increases the cost of the user device.

[0196] In an uplink and / or downlink direction between a network and a UE, protocol data units (PDUs) can be used to carry application layer payload, such as XR media content. As described in 3GPP TS 23.501, PDUs can be provided in a PDU Set, such as an I-frame or a P -frame. A PDU Set is comprised of one or more PDUs carrying an application layer payloadsuch as a video frame or video slice. In the downlink, the PDU Set based QoS handling by the NG-RAN is determined by PDU Set QoS Parameters in the QoS profile of the QoS Flow (e.g., specified in clause 5.7.7 of 3GPP TS 23.501) and PDU Set information provided by a PSA UPF via a N3 interface and / or N9 interface.

[0197] PDU Set Handling in 3GPP network for XR Traffic

[0198] Differentiated QoS handling of downlink PDUs that belong to different types of PDU Sets (e.g., I-Frames and P-Frames) can be done by mapping PDU Sets from the same application service flow to the same QoS Flow and providing differentiated QoS handling based on the PDU Set Importance marking provided by the UPF in the PDU Set Information of downlink packets.

[0199] An AF may provide PDU Set related assistance information for dynamic PCC control. One or more of the following PDU Set related assistance information may be provided to the NEF / PCF using the AF session with required QoS procedures.

[0200] Provided for measuring and reporting QoS are PDU Set QoS Parameters. One such PDU Set QoS Parameter is a ‘Protocol Description’, which may indicate the transport protocol used by the service data flow (e.g., RTP, SRTP) and information.

[0201] When an RTP Header Extension for PDU Set Marking (e.g., as defined in 3GPP TS 26.522 or other RTP header extensions as defined in, e.g., RFC 8285) is included, the differentiation between different RTP Header Extension Types is to be supported.

[0202] In the downlink direction, the PSA UPF can be configured to terminate the N6 interface of a PDU session within a 5G core network. The UPF may be configured to identify PDUs that belong to PDU Sets and marks them accordingly. If the PSA UPF receives a PDU that does not belong to a PDU Set based on Protocol Description for PDU Set identification, then the PSA UPF still maps it to a PDU Set and determines the PDU Set Information. Additional information about the structure and functionality of the PDU Session Anchor (PSA) UPF is described in 3GPP TS 23.501, version 18.5.0.

[0203] In the uplink direction, the UE may identify PDU Sets, and how this is done is left up to UE implementation. The SMF may send Protocol Description associated with the QoS rule to UE.

[0204] From time to time, a UE may experience an inter-system change when the UE moves between a 5GS and an EPS. When the UE moves from 5GS to EPS (e.g., LTE or 4G), an inter-system mode change happens as the UE switches from N1 mode to SI mode. If the UE later comes back from EPS to 5GS, then another inter-system mode change happens as the UE switches from SI mode to N1 mode.

[0205] According to an aspect, the 5GS or a network function (e.g., AMF, SMF, etc.) thereof, may want / need to support XR services in EPS, and may therefore want / need to allow interworking, despite a possible degradation of supported XR services upon inter-system change rather than completely disabling the services while a UE is in EPS. In some aspects, it may be preferred that inter-system change between EPS and 5GS be supported with respect to a PDU session for XR applications / XRM. Assuming that the uplink PDU session for XR was established for the UE in 5GS and a PDU session for XR application(s) (XR PDU session) is active, the UE may receive a Protocol Description from the SMF of the 5GS (e.g., in a 5G core).

[0206] As EPS does not support XR enhancements (e.g., Protocol Description), the Protocol Description could not be associated with an XR service / XRM / XR traffic flow transferred to the corresponding EPS PDN connection. In some aspects, QoS rules can be stored in the UE and / or SMF of the 5GS. In some aspects, XR enhancements can include continuity for an XR PDU session to continue in 4GZEPS. In some aspects, the XR traffic cannot get any priority treatments such as PDU Set based handling and will be treated as normal traffic. If the UE again moves back to the 5GS after some time, then it cannot have the Protocol Description that is required to efficiently handle the XR traffic (e.g., to avail the PDU Set handling). Alternatively, if a PDN connection for an XR application was first established in EPS and then the PDN connection is associated with an XR service / XRM / XR traffic flow transferred to the 5GS, the 3GPP standard currently does not define how the 5GS and the UE should operate (e.g., carry out PDU set based handling as defined in TS 23.501 vsl8.5.0 section 5.37.5).

[0207] As noted, inter-system change between EPS and 5GS is not currently supported with respect to a PDU session for XRM and XR applications. As such, the SMF operation in terms of mapped EPS bearer contexts inclusion needs to be defined.

[0208] In the approach(es) disclosed herein, inter-system change between EPS and 5GS is supported with respect to a PDU session for XR application. In some aspects, when the UE moves from 5GS to EPS, the SMF and UE are configured to store the Protocol Description with the mapped PDU session ID (and optionally mapped to the EPS Bearer Identity). In some aspects, if the PDN connection for XR application was established in EPS, and the UE moves back to 5GS, the UE and / or SMF need to use the stored (and / or maintained) Protocol Description. In some aspects, this can allow for the continuation of XR service / XR traffic / XRM delivery to UE and uplink packets / PDU sets without interruption and / or with minimized / reduced interruption.

[0209] In some aspects, after inter-system change from N1 mode to SI mode, the UE and the SMF shall maintain the PDU set specific protocol description, if applicable.

[0210] In some aspects, for a PDN connection established when in SI mode, upon an intersystem change from SI mode to N1 mode, if the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure and a UE-requested PDU session modification procedure has not been successfully performed yet, and the SMF determines, based on local policies or configurations in the SMF, to provide the protocol description for UL PDU set handling to the UE, the SMF may include the Protocol description IE in the PDU SESSION MODIFICATION COMMAND message.

[0211] In some aspects, the SMF may be configured to send the UL Protocol Description and associated QoS rule to the UE (e.g., in NAS message). In some aspects, if the PCF, based on the local configuration, provides the PCC rules with Protocol Descriptions for UL, the SMF may additionally provide the Protocol Description for UL with the associated QoS rule.

[0212] In some aspects, for the uplink direction, the UE may identify PDU Sets, and how this is done is left up to UE implementation. The SMF may send the UL Protocol Description associated with the QoS rule to UE.

[0213] In some aspects, the UE / SMF can store / maintain the Protocol Description along with the associated QoS rule.

[0214] In some aspects, inter-system change between EPS and 5GS is not supported with respect to a PDU session for XR application. In some aspects, the SMF determines whether include mapped EPS bearer contexts for a PDU session, wherein the SMF does not include mapped EPS bearer contexts for the PDU session if the SMF provided a protocol description to the UE for the PDU session.

[0215] In some aspects, inter-system change between EPS and 5GS is supported with respect to a PDU session for XR. An approach may comprise a first step in which a PDU session is established in 5GS. The SMF provides a protocol description, e.g., during the PDU session establishment. Then, an inter-system change from N 1 mode to S 1 mode occurs. After an inter-system change from N1 mode to SI mode, the UE and the SMF shall maintain the protocol description associated with a PDU session until a PDN connection corresponding to the PDU session is released. Then, an inter-system change from SI mode to N1 mode occurs. Upon inter-system change from SI mode to N1 mode, unless the PDN connection is a user-plane resource of an MA PDU session, the UE may use the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for the uplinkdirection. Alternately (if the UE has not stored (and / or maintained) the protocol description), the SMF may also send the Protocol Description to the UE (e.g., PDU SESSION MODIFICATION COMMAND message).

[0216] When the UE with an active XR PDN Session moves from EPS to 5GS, a PDN connection is established in EPS, an inter-system change from SI mode to N1 mode occurs, and, for a PDN connection established when in SI mode, upon an inter-system change from SI mode to N1 mode, if the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure, then the SMF includes the Protocol Description IE in the PDU SESSION MODIFICATION COMMAND message. In some aspects, if a UE-requested PDU session modification procedure has not been successfully performed yet, then the SMF includes the Protocol Description IE in the PDU SESSION MODIFICATION COMMAND message. In some aspects, the PDU session is a single access PDU session established over 3GPP access with IP PDU session type, then the SMF includes the Protocol Description IE in the PDU SESION MODIFICATION COMMAND message. In some aspects, if the SMF determines, based on operator policy, to provide the protocol description for UL PDU set handling to the UE, then the SMF includes the Protocol Description IE in the PDU SESSION MODIFICATION COMMAND message.

[0217] In some aspects, if the Protocol description IE is included in the PDU SESSION MODIFICATION COMMAND message and the PDU session is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established when in SI mode, the UE shall store the received Protocol description and may use it to identify PDUs belong to PDU sets for the uplink direction. Whether and how to use the protocol description to identify PDU sets is up to the UE implementation.

[0218] In some aspects, inter-system change between EPS and 5GS is not supported with respect to a PDU session for XR. In some aspects, the SMF shall not include any mapped EPS bearer contexts associated with a PDU session for which a protocol description needs to be provided. In such aspects, if the UE receives any mapped EPS bearer context for a PDU session associated with a protocol description, the UE may locally delete the mapped EPS bearer context.

[0219] Some aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, aspects of the disclosed concepts are shown. Indeed, various aspects of the disclosed approaches, systems, methods, apparatuses, devices, and computer program products may be embodied in many different forms and should not be construed as limited to the aspects set forth herein; rather,these aspects are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. As used herein, the terms “data,” “content,” “information,” and similar terms may be used interchangeably to refer to data capable of being transmitted, received and / or stored (and / or maintained) in accordance with aspects of the present disclosure. Thus, use of any such terms should not be taken to limit the spirit and scope of aspects of the present disclosure.

[0220] Additionally, as used herein, the term ‘circuitry’ refers to (a) hardware-only circuit implementations (e.g., implementations in analog circuitry and / or digital circuitry); (b) combinations of circuits and computer program product(s) comprising software and / or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions described herein; and (c) circuits, such as, for example, a microprocessor(s) or a portion of a microprocessor s), that require software or firmware for operation even if the software or firmware is not physically present. This definition of ‘circuitry’ applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term ‘circuitry’ also includes an implementation comprising one or more processors and / or portion(s) thereof and accompanying software and / or firmware. As another example, the term ‘circuitry’ as used herein also includes, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, other network device, and / or other computing device.

[0221] As defined herein, a “computer-readable storage medium,” which refers to a non- transitory physical storage medium (e.g., volatile or non-volatile memory device), can be differentiated from a “computer-readable transmission medium,” which refers to an electromagnetic signal. Such a medium may take many forms, including, but not limited to a non-transitory computer-readable storage medium (e.g., non-volatile media, volatile media), and transmission media. Transmission media include, for example, coaxial cables, copper wire, fiber optic cables, and carrier waves that travel through space without wires or cables, such as acoustic waves and electromagnetic waves, including radio, optical and infrared waves. Signals include man-made transient variations in amplitude, frequency, phase, polarization or other physical properties transmitted through the transmission media. Examples of non-transitory computer-readable media include a magnetic computer readable medium (e.g., a floppy disk, hard disk, magnetic tape, any other magnetic medium), an optical computer readable medium (e.g., a compact disc read only memory (CD-ROM), a digital versatile disc (DVD), a Blu-Ray disc, or the like), a random access memory (RAM),a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), a FLASH-EPROM, or any other non-transitory medium from which a computer can read. The term computer-readable storage medium is used herein to refer to any computer-readable medium except transmission media. However, it will be appreciated that where aspects are described to use a computer-readable storage medium, other types of computer-readable mediums may be substituted for or used in addition to the computer- readable storage medium in alternative aspects.

[0222] While various inventive aspects have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the inventive aspects described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be examples and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the inventive teachings is / are used. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive aspects described herein. It is, therefore, to be understood that the foregoing aspects are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive aspects may be practiced otherwise than as specifically described and claimed. Inventive aspects of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0223] In the following, certain aspects are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the exemplifying aspects, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to FIG. 1 to assist in understanding the technology underlying the described examples.

[0224] According to some aspects, a communication device or terminal can be provided for wireless access via cells, base stations, or similar wireless transmitter and / or receiver nodes, providing access points for a radio access system.

[0225] Access points and hence communications there through are typically controlled by at least one appropriate controller apparatus so as to enable operation thereof and management of mobile communication devices in communication therewith. In some embodiments, a control apparatus for a node may be integrated with, coupled to and / or otherwise provided for controlling the access points. In some embodiments, the control apparatus can be arranged to allow communications between a user equipment and a core network or a network entity of the core network. For this purpose, the control apparatus may comprise at least one memory, at least one data processing unit such as a processor or the like, and an input and / or output interface. Via the interface, the control apparatus can be coupled to relevant other components of the access point. The control apparatus can be configured to execute an appropriate software code to provide the control functions. It shall be appreciated that similar components can be provided in a control apparatus provided elsewhere in the network system, for example in a core network entity. The control apparatus can be interconnected with other control entities. The control apparatus and functions may be distributed between several control units. In some embodiments, each base station can comprise a control apparatus. In alternative embodiments, two or more base stations may share a control apparatus.

[0226] Access points and associated controllers may communicate with each other via a fixed line connection and / or via a radio interface. The logical connection between the base station nodes can be provided for example by an X2 or the like interface. This interface can be used for example for coordination of operation of the stations and performing reselection or handover operations.

[0227] The communication device or user equipment may comprise any suitable device capable of at least receiving wireless communication of data. For example, the device can be handheld data processing device equipped with radio receiver, data processing and user interface apparatus. Non-limiting examples include a mobile station (MS) such as a mobile phone or what is known as a ‘smart phone’, a portable computer such as a laptop or a tablet computer provided with a wireless interface card or other wireless interface facility, personal data assistant (PDA) provided with wireless communication capabilities, or any combinations of these or the like. Further examples include wearable wireless devices such as those integrated with watches or smart watches, eyewear, helmets, hats, clothing,earpieces with wireless connectivity, jewelry and so on, universal serial bus (USB) sticks with wireless capabilities, modem data cards, machine type devices or any combinations of these or the like.

[0228] In some aspects, a communication device, e.g., configured for communication with the wireless network or a core network entity, may be exemplified by a handheld or otherwise mobile communication device (or user equipment UE). A mobile communication device may be provided with wireless communication capabilities and appropriate electronic control apparatus for enabling operation thereof. Thus, the communication device may be provided with at least one data processing entity, for example a central processing unit and / or a core processor, at least one memory and other possible components such as additional processors and memories for use in software and hardware aided execution of tasks it is designed to perform. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and / or in chipsets. Data processing and memory functions provided by the control apparatus of the communication device are configured to cause control and signaling operations in accordance with certain embodiments as described later in this description. A user may control the operation of the communication device by means of a suitable user interface such as touch sensitive display screen or pad and / or a keypad, one of more actuator buttons, voice commands, combinations of these, or the like. A speaker and a microphone are also typically provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and / or for connecting external accessories, for example hands-free equipment, thereto.

[0229] In some embodiments, a communication device may communicate wirelessly via appropriate apparatus for receiving and transmitting signals. In some embodiments, a radio unit may be connected to the control apparatus of the device. The radio unit can comprise a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the communication device.

[0230] FIG. 1 illustrates an exemplary communications network 100 in which the embodiments described herein are implemented. As illustrated in FIG. 1, a UE 102 is in operable communication with the NG-RAN 104 of the communication network 100 (e.g., in operable communication with a transmission reception point (TRP), a base station, or a radio access network node, of the NG-RAN 104. In some embodiments, the NG-RAN 104 can communicate with various network functions or entities of a 5G core network (5GC).

[0231] In the context of a fifth-generation (5G) system, such as the 5GS illustrated in FIG. 1, the communications network 100 may comprise a series of connected network devices and specialized hardware that is distributed throughout a service region or country, and one or more network entities, which may be stored at and / or hosted by one or more of the connected network devices or specialized hardware. In some embodiments, the UE 102 may connect to a radio access node (not shown) of the NG-RAN 104 and send control plane messages to an AMF 108 of a 5GC via an N2 interface or data to a UPF+PGW-U 106 via a N3 interface. In some embodiments, the AMF 108 may be one or more network functions (NFs) of the 5GC and may communicate with via service-based interfaces, such as an Authentication Server Function (AUSF; not shown), a Network Slice Selection Function (NSSF; not shown), a Network Repository Function (NRF; not shown), a Policy Charging Function (PCF) 114, a Network Data Analytics Function (NWDAF; not shown), a Unified Data Management function 118 (UDM 118), a Session Management Function (SMF) 110.

[0232] In some embodiments, the SMF 110 may be configured to communicate with the User Plane Function (UPF) of the UPF+PWW-U 106. By way of example only, in some aspects, the UPF 106 may be in communication with the RAN 104 and the DN. In other aspects, the DN may be in communication with a first UPF 106 and the RAN 104 may be in communication with a second UPF 106, while the SMF 110 is in communication with both the first and second UPFs 106 and the first and second UPFs 106 are in communication each with the other.

[0233] In some aspects, the UE 102 can comprise a single-mode or a dual-mode device such that the UE 102 can be connected to one or more RANs 104. In some aspects, the RAN 104 may be configured to implement one or more radio access technologies (RATs), such as Bluetooth, Wi-Fi, and GSM, Universal Mobile Telecommunications System (UMTS), LTE or 5G NR, among others, that can be used to connect the UE 102 to the CN 101. In some aspects, the RAN 104 can comprise or be implemented using a chip, such as a silicon chip, in the UE 102 that can be paired with or otherwise recognized by a similar chip in the CN 101, such that the RAN 104 can establish a connection or line of communication between the UE 102 and the CN 101 by identifying and pairing the chip within the UE 102 with the chip within the CN 101. In some aspects, the RAN 104 can implement one or more base stations, towers or the like to communicate between the UE 102 and the AMF 108 of the CN 101.

[0234] In some aspects, the communications network 100 or components thereof (e.g., base stations, towers, etc.) can be configured to communicate with a communication device (e.g.,the UE 102) such as a cell phone or the like over multiple different frequency bands, e.g., FR1 (below 6 GHz), FR2 (mmWave), other suitable frequency bands, sub-bands thereof, and / or the like. In some aspects, the communications network 100 can comprise or employ massive multiple input and multiple output (massive MIMO) antennas. In some aspects, the communications network 100 can comprise multi-user MIMO (MU-MIMO) antennas. In some aspects, the communications network 100 can employ edge computing whereby the computing servers are communicatively, physically, computationally, and / or temporally closer to the communications device (e.g., UE 102) in order to reduce latency and data traffic congestion. In some aspects, the communications network 100 can employ other technologies, device, or techniques, such as small cell, low-powered RAN, beamforming of radio waves, WiFi-cellular convergence, non-orthogonal multiple access (NOMA), channel coding, and the like.

[0235] As illustrated in FIG. 1, the UE 102 may be configured to communicate with the RAN 104 in a Nl interface, e.g., according to a non-access stratum (NAS) protocol. In some aspects, RAN 104 can be configured to communicate with the CN 101 or a component thereof (e.g., the AMF 108) in a N2 interface, e.g., in a control plane between a base station of the RAN 104 and the AMF 108. In some embodiments, the RAN 104 can be configured to communicate with the UPF 106 in a N3 interface, e.g., in a user plane. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with other services or network entities within the CN 101 in various different interfaces and / or according to various different protocols. For instance, in some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the AUSF in a Nausf interface or an N12 interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the NSSF in a Nnssf interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the NRF in a Nnrf interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the PCF 114 in a Npcf interface or an N7 interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the NWDAF in a Nnwdaf interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the UDM 118 in a Nudm interface, an N8 interface, or an N10 interface. In some aspects, the AMF 108 and / or the SMF 110 can be configured to communicate with the AS / AF in a Naf interface. In some aspects, the SMF 110 can be configured to communicate with the UPF 106 in a N4 interface, which may act as a bridge between the control plane and the user plane, such as acting as a conduit for aProtocol Data Unit (PDU) session during which information is transmitted between, e.g., the UE 102 and the CN 101 or components and / or services thereof.

[0236] It will be appreciated that example aspects of the concepts disclosed and / or otherwise described herein arise in the context of a telecommunications network, including but not limited to a telecommunications network that conforms to and / or otherwise incorporates aspects of a fifth-generation (5G) architecture. While FIG. 1 illustrates various configurations and / or components of an exemplary architecture of the communications network 100, many other systems, system configurations, networks, network entities, and pathways and / or protocols for communication therein are contemplated and considered within the scope of this present disclosure.

[0237] While the methods, devices, and computer program products described herein are described within the context of a fifth-generation (5G) system, such as illustrated in FIG. 1 and described hereinabove, the described methods, devices, and computer program products can nevertheless be applied in a broader context within any suitable telecommunications system.

[0238] The communication network 100 shown in FIG. 1 can also include or be in communication with an evolved packet system (EPS). A brief description of the EPS follows, and additional information can be found in 3 GPP Release 13, such as in 3GPP TS 23.401, 3GPP TS 23.402, 3GPP TS 29.273, and 3GPP TS 29.274.

[0239] The EPS can be considered a legacy architecture that comprises legacy hardware and uses legacy radio access technologies, standards, and protocols, such as fourthgeneration (4G) or Long-Term Evolution (LTE). The EPS includes a mobility management entity (MME) 201 that is configured to communicate with user equipment (UE) 202 via a E- UTRAN 203. The MME 201 is configured to provide mobility session management, support subscriber authentication, manage roaming activities, and facilitate inter-network changes and session / registration handovers to other networks.

[0240] The EPS can also include a Serving Gateway (SGW) 204 that is configured to communicate with elements in the 5GS. The SGW 204 can reside in the user plane and be configured to forward and route data traffic (e.g., packets) received from base stations (e.g., eNodeB) of the E-UTRAN 203 via a Sl-U interface to a Packet Data Network (PDN) Gateway (PWG) of the UPF+PGW-U 106 via S5-U interface and to forward and route data traffic (e.g., packets) received from the PWG of the UPF+PGW-U 106 via the S5-U interface to base stations of the of the E-UTRAN 203 via the Sl-U interface.

[0241] The EPS can include a Home Subscriber Server (HSS; not shown) that is configured to store user / subscribe data and facilitate mobility management for the MME 201, user authentication, access authorization, etc. The PDN gateway can be configured to receive packets (e.g., PDUs, PDU sets, media content, data traffic, etc.) from the SGW 204. The EPS can further include a Policy and Charging Rules Function (PCRF; not shown) that is configured to determine / store access and subscriber policies, enforce policies, charge subscribers for access, confirm quality of service (QoS) compliance / levels, and other functions. The EPS can further include one or more operator IP services, which can include access to the Internet, one or more Intranets, IMS, PSS, etc.

[0242] The MME 201 can be configured to communicate with HSS in HHS+UDM 118 via a S6a interface. The MME 201 can be configured to receive Non-Access Stratum (NAS) signaling from the UE 102 to authenticate a user of the UE 202. The MME 201 is also responsible for generation and allocation of temporary identities to UEs. The MME 201 authorizes the UE to camp on a particular cell provided by the E-UTRAN 203 and enforces UE roaming restrictions.

[0243] The SGW 204 can be configured to communicate with a PDN Gateway (not shown) in the EPS . The SGW 204 can be configured to route and forward user data packets, act as a mobility anchor for user plane during base station handovers, and anchors mobility between EPS, LTE, 4G, and NR, 5G, or other networks or AN technologies.

[0244] In some aspects, the SMF 110 can comprise a processor (not shown) and a memory (not shown) storing instructions, such as computer program instructions therein. The computer program instruction can be provisioned via a computer-readable storage medium (not shown).

[0245] The SMF 110 in the communications system 100 can be configured to communicate with the EPS. The EPS can include the MME 201 and the SGW 204. The SMF 110 can communicate with the EPS via an eNB 212 or via the UE 102. The SMF 110 can be configured to interacting with a decoupled data plane, creating, updating, and removing PDU sessions, and managing session context with the UPF 106.

[0246] The SMF 110 can be configured to receive messages over the Ni l interface that represent a trigger to add, modify or delete a PDU session across the user plane. The SMF 110 can be configured to send messages to other elements of a 5GS, such as the UPF 106 over the N4 reference interface, e.g., using a PFCP (not shown).

[0247] During session establishment or modification, the SMF 110 may interact with the PCF 114 over the N7 interface, and the subscriber profile information stored within theUDM function 118 over the N10 interface. The PCF 114 can provide the foundation of a policy framework which, along with the more typical QoS and charging rules, includes network slice selection, which is regulated by a Network Slice Selection Function (NSSF; not shown).

[0248] In other aspects, the SMF 110 can perform the role of DHCP server and IP Address Management (IP AM) system. In some aspects, together with the UPF 106, the SMF 110 maintains a record of PDU session state by means of a 24bit PDU Session ID. The SMF 110 sets configuration parameters in the UPF 106 that define traffic steering parameters and ensure the appropriate routing of packets. The SMF 110 may also guarantee the delivery of incoming packets though a Downlink (DL) data notification. In 4G EPC architectures, this is a SGW 204 to MME message. The SMF 110 is responsible for checking whether the UE 102 requests are compliant with the user subscription and for connectivity charging, which is achieved by interacting with a CHF, such as described further in 3GPP TS 32.255, the entire disclosure of which is hereby incorporated herein by reference in its entirety.

[0249] In some aspects, after the UE 102 changes from operating in N1 mode to operating in SI mode (e.g., the UE connects to a 5GS), the SMF 110 shall store the PDU set specific protocol description.

[0250] In some aspects, for a PDN connection established when in SI mode, upon an intersystem change by the UE 102 from SI mode to N1 mode, if the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure and a UE-requested PDU session modification procedure has not been successfully performed yet, and the SMF 110 determines, based on local policies or configurations in the SMF 110, to provide the protocol description for UL PDU set handling to the UE 102, the SMF 110 may include the Protocol description IE in the PDU SESSION MODIFICATION COMMAND message.

[0251] In some aspects, the SMF 110 may be configured to send the UL Protocol Description and associated QoS rule to the UE 102 (e.g., in NAS message). In some aspects, if the PCF 114, based on the local configuration, provides the PCC rules with Protocol Descriptions for UL, the SMF 110 may additionally provide the Protocol Description to the UE 102 for UL with the associated QoS rule.

[0252] In some aspects, for the uplink direction, the UE 102 may identify PDU Sets, and how this is done is left up to UE implementation. The SMF 110 may send the UL Protocol Description associated with the QoS rule to UE 102.

[0253] In some aspects, the SMF 110 can store / maintain the Protocol Description along with the associated QoS rule.

[0254] In some aspects, the SMF 110 can be configured to handle protocol descriptions of XR application(s) during UE 102 switching or inter-system change from new radio (NR) and / or fifth-generation (5GS) to legacy networks or technologies, such as the EPS. In some aspects, the SMF 110 can be configured to perform receiving, from a UE 102, a first NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established a UE 102 and a packet data network gateway (e.g., via 106 and / or 110) when the UE 102 was in SI mode; and providing, to the UE 102, a second NAS message comprising a protocol description associated with the PDU session.

[0255] In some aspects, the SMF 110 can be configured to perform, in an instance that a protocol description associated with a PDU session was provided for a UE 102, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE 102 from being in N1 mode to being in SI mode. In some aspects, the SMF 110 can be configured to perform, in an instance in which the network function receives from a UE 102, a first message comprising a request for modification of a PDU session and determines that the PDU session is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established when in SI mode, providing, to the UE 102, a second message comprising a protocol description associated with the PDU session. In some aspects, the SMF 110 can be configured to perform, in an instance in which the network function determines that the network function provided a protocol description associated with a PDU session for a UE 102, maintaining the protocol description associated with the PDU session after inter-system change by the UE 102 from N1 mode to SI mode.

[0256] In some aspects, the SMF 110 can be configured to perform: determining whether the PDN connection was established in the EPS or was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS; and, in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE 102. In some aspects, the SMF 110 can be configured to perform: in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session. In some aspects, the SMF 110 can be configured to perform: transmitting, towards the UE 102, a message comprising the protocol description associated with the PDU session between the 5GS and the UE 102. In some aspects, the SMF 110 can be configured toperform: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE 102 already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE 102; and refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE 102. In some aspects, the SMF 110 can be configured to perform: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE 102 already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE 102; and refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE 102.

[0257] In some aspects, the SMF 110 can be configured to perform: receiving a message from the AMF 108 of the communications network 100, the message comprising information regarding a registration request received from a UE 102, the registration request comprising a request to establish or re-establish a PDU session between the communications network 100 and the UE 102, wherein the PDU session was associated with an XR service / XRM / XR traffic flow transferred from the PDN connection with the EPS; determining whether the PDN connection was established when the UE 102 was in SI mode or in N1 mode, and, in an instance in which it is determined that the PDN connection was established when the UE 102 was in SI mode, receiving, at the SMF 110, a PDU SESSION MODIFICATION REQUEST message from the UE 102, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description.

[0258] In some aspects, the SMF 110 can be configured to store and use the protocol description to identify the PDU session associated with PDUs transmitted or received in the PDU session. In some aspects, the PDU session comprises XR traffic. In some aspects, the XR traffic comprises PDUs that comprise one or more of: an I-frame or a P-frame. In some aspects, the XR traffic comprises one or more XR frames comprising a plurality of PDUs. In some aspects, the SMF 110 can be configured to perform: in an instance in which it is determined that the PDN connection was established when the UE 102 was in N1 mode, determining that the UE 102 has stored (and / or maintained) therein the protocol description associated with the PDU session; and refraining from generating a new protocol description associated with the PDU session.

[0259] In some aspects, the SMF 110 can be configured to perform: receiving a PDN modification request for a PDN connection carrying XR traffic of the EPS associated with a PDU session of the communications network 100; in an instance in which the PDN connection was initially established between a UE 102 and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE 102; and determining that the protocol description for the PDU session is to be provided to the UE 102.

[0260] In some aspects, the SMF 110 can be configured to perform: storing (and / or maintaining), at the network entity of the communications network 100, the protocol description associated with the PDU session; and maintaining the protocol description until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the SMF 110 can be configured to perform: upon an inter-system change from SI mode to N1 mode, determining if the PDN connection is a user-plane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction.

[0261] In some aspects, the SMF 110 can be configured to perform: determining whether to initiate a PDU session modification procedure for a PDU session carrying XR traffic associated with the communications network 100 to a PDN connection of the EPS; in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at the SMF 110, a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the communications network 100 and aUE 102; generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE 102; and using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF 110 in an uplink direction or provided towards the UE 102 in a downlink direction. In some aspects, the protocol description is stored (and / or maintained), at the SMF 110, with one or both of: a PDU session identifier (ID) associated with the PDU session or a PDN ID associated with the PDN connection. In some aspects, the SMF 110 can be configured to perform: maintaining the protocol description until release of the PDU session.

[0262] In some aspects, the SMF 110 can be configured to perform: generating a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for a PDU session between a UE 102 and the communications network 100, the PDU session carrying XR traffic between the 5GS and the UE 102; transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE 102; and, upon an inter-system change for the PDU session carrying the XR traffic is carried out between the communications network 100 and the EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE 102 and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the communications network 100 as a PDU session carrying the XR traffic between the communications network 100 and the UE 102.

[0263] In some aspects, the SMF 110 can be configured to perform: using the protocol description for identifying PDUs belonging to one or more PDU sets for XR traffic in an uplink direction. In some aspects, the SMF 110 can be configured to perform: maintaining the protocol description associated with the PDU session until release of the PDU session. In some aspects, the protocol description is associated with one or both of: a PDU session identifier (ID) associated with the PDU session or an EPS Bearer Identity associated with the PDN connection. In some aspects, the SMF 110 can be configured to perform: upon an inter-system change from S 1 mode to N1 mode, determining if the PDN connection is a userplane resource of a multi-access (MA) PDU session; and, if the PDN connection is not a user-plane resource of an MA PDU session, using the protocol description associated with the PDU session to identify PDUs belonging to PDU sets for an uplink direction.

[0264] In some aspects, the UE 102 can be configured to communicate with the EPS and the communications network 100, the method comprising: in an instance in which the UE 102 is in N1 mode, sending to a network function configured for management of PDU sessions and PDN connections, one or more session management parameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE 102 and a packet data network gateway when the UE was in SI mode to a PDU session, providing, by the UE 102, to the network function, a first NAS message comprising a request for modification of the PDU session, receiving, at the UE 102, a second message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE 102, the protocol description associated with the PDU session. In some aspects, the one or more session management capabilities refer to capabilities supported by the UE 102with respect to session management, which comprise one or more of: a quality of service (QoS) or ultra-reliable low latency communications (URLLC).

[0265] In some aspects, after the UE 102 undergoes a inter-system change from N1 mode to SI mode, the UE 102 shall store and maintain therein the PDU set specific protocol description, if applicable.

[0266] In some aspects, for a PDN connection established when in SI mode, upon an intersystem change by the UE 102 from SI mode to N1 mode, if the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure and a UE-requested PDU session modification procedure has not been successfully performed yet, and, e.g., if the SMF 110 determines, based on local policies or configurations in the SMF 110, to provide the protocol description for UL PDU set handling to the UE 102, the UE 102 can receive, from the SMF 110, the Protocol description IE in the PDU SESSION MODIFICATION COMMAND message.

[0267] In some aspects, the UE 102 may be configured to receive, from the SMF 110, the UL Protocol Description and associated QoS rule (e.g., in NAS message). In some aspects, if the PCF, based on the local configuration, provides the PCC rules with Protocol Descriptions for UL, the UE 102 may receive, from the SMF 110, the Protocol Description for UL with the associated QoS rule.

[0268] In some aspects, for the uplink direction, the UE 102 may identify PDU Sets, and how this is done is left up to UE implementation. The UE 102 can receive, from the SMF 110, the UL Protocol Description associated with the QoS rule.

[0269] In some aspects, the UE 102 can store / maintain the Protocol Description along with the associated QoS rule.

[0270] In some aspects, the UE 102 can be configured to perform: determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE 102; maintaining the protocol description associated with the PDU session after changing from being in N1 mode to being in SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode.

[0271] In some aspects, the UE 102 can be configured to perform: in an instance in which the UE 102 in N1 mode needs to indicate, to a network function, one or more session management parameters or one or more session management capabilities for a PDU session which is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established when in SI mode, providing, by the UE, to the network function, afirst message comprising a request for modification of the PDU session, receiving, at the UE 102, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE 102, the protocol description associated with the PDU session.

[0272] In some aspects, the UE 102 can be configured to perform: in an instance in which the UE determines that a protocol description associated with a PDU session is stored (and / or maintained) at the UE 102, maintaining the protocol description associated with the PDU session after inter-system change by the UE 102 from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change by the UE 102 from SI mode to N1 mode.

[0273] In some aspects, the UE 102 can be configured to perform: in an instance in which the UE 102 determines that an existing protocol description associated with a PDU session with the communications network 100 is not stored (and / or maintained) at the UE 102, providing, by the UE 102, to a network element (e.g., AMF, SMF, N3IWF, etc.) of the communications network 100, a first message comprising a request for modification of a PDN connection with the EPS to be a PDU session with the communications network 100, receiving, at the UE 102, a second message comprising a new protocol description, and storing (and / or maintaining), at the UE 102, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE 102 does not have an existing protocol description stored (and / or maintained) at the UE 102. In some aspects, the first message further comprises an indication that the UE 102 is requesting a new protocol description associated with the PDU session.

[0274] In some aspects, the UE 102 can be configured to perform: in an instance in which the UE determines that an existing protocol description associated with a PDU session with the communications network lOOis stored (and / or maintained) at the UE 102, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with the EPS to be the PDU session with the communications network 100; and in an instance in which the UE determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE 102, providing, by the UE 102, to a network element of the communications network 100, a first message comprising a request for modification of the PDN connection with the EPS to be a PDU session with the communications network 100, receiving, at the UE 102, a second message comprising a new protocol description, and storing (and / or maintaining),at the UE 102, the new protocol description associated with the PDU session. In some aspects, the first message further comprises an indication that the UE 102 does not have an existing protocol description stored (and / or maintained) at the UE 102. In some aspects, the first message further comprises an indication that the UE 102 is requesting a new protocol description associated with the PDU session.

[0275] In some aspects, the UE 102 can be configured to perform: determining, at the UE 102, whether an existing protocol description associated with a PDU session between the UE 102 and a communications network lOOis stored (and / or maintained) at the UE 102, the PDU session having been associated with an XR service / XRM / XR traffic flow transferred from a PDN connection with an EPS; in an instance in which the UE 102 determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE 102, using the existing protocol description associated with the PDU session during the PDU session with the communications network 100; and, in an instance in which the UE 102 determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE 102, providing, by the UE 102, to a network element of the communications network 100, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE 102 is requesting a new protocol description associated with the PDU session, receiving, at the UE 102, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE 102, the new protocol description associated with the PDU session.

[0276] In some aspects, the UE 102 can be configured to perform: while the UE 102 has a PDN connection active between the UE 102 and an EPS, determining that the PDN connection is being associated with an XR service / XRM / XR traffic flow transferred to a PDU session between the UE 102 and the communications network 100; determining, at the UE 102, whether the PDN connection was originally established in N1 mode or in SI mode; in an instance in which the PDN connection was originally established in SI mode, determining that an existing protocol description associated with the PDU session between the UE 102 and the communications network 100 is stored (and / or maintained) at the UE 102; in an instance in which the PDN connection was originally established in N1 mode, determining that an existing protocol description associated with the PDU session between the UE 102 and the communications network 100 is not stored (and / or maintained) at the UE 102; in an instance in which the UE 102 determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the UE 102, using theexisting protocol description associated with the PDU session during the PDU session with the communications network 100; and, in an instance in which the UE 102 determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the UE 102, providing, by the UE 102, to a network element of the communications network 100, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the UE 102 is requesting a new protocol description associated with the PDU session, receiving, at the UE 102, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the UE 102, the new protocol description associated with the PDU session.

[0277] In some aspects, the UE 102 can be configured to perform: before or during a transfer of a PDN connection with an EPS to a PDU session with the communications network 100, determining whether a protocol description associated with the PDU session is stored (and / or maintained) at the UE 102; in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE 102, sending a PDU SESSION MODIFICATION REQUEST message towards the communications network 100; receiving, at the UE 102, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session; and storing (and / or maintaining) the protocol description associated with the PDU session at the UE 102.

[0278] In some embodiments, the UE 102 can be configured to perform: determining whether to transmit towards a network entity of the communications network 100 (e.g., 5GS), a PDU session modification request message for a PDU session carrying XR traffic to be associated with the communications network 100 to a PDN connection of an EPS; in the instance in which it is determined to transmit a PDU session modification request message for the PDU session to be associated with an XR service / XRM / XR traffic flow transferred from the communications network 100 to the PDN connection of the EPS, providing the PDU session modification request message to the network entity of the communications network 100; and upon receiving from the network entity of the communications network 100 a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the communications network 100 and the UE 102, storing (and / or maintaining), at the UE 102, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the communications network 100 and the UE 102.

[0279] Aspects of the present disclosure introduce procedures for transfer of a service data flow of XR application from an EPS to the communications network 100 (e.g., a 5GS) when a UE transitions from being in SI mode (e.g., connected to an EPS) to being in N1 mode (e.g. being connected to a 5GS), and vice versa. 3GPP TR 26.928 defines, generally, the terms Virtual Reality (VR), Augmented Reality (AR), Mixed Reality (MR), and XR as follows.

[0280] Virtual reality (VR) is a rendered version of a delivered visual and audio scene. The rendering is designed to mimic the visual and audio sensory stimuli of the real world as naturally as possible to an observer or user as they move within the limits defined by the application. Virtual reality usually, but not necessarily, requires a user to wear a head mounted display (HMD), to completely replace the user’s field of view with a simulated visual component, and to wear headphones, to provide the user with the accompanying audio. Some form of head and motion tracking of the user in VR is usually employed to allow the simulated visual and audio components to be updated in order to ensure that, from the user’s perspective, items and sound sources remain consistent with the user’s movements. Additional means to interact with the virtual reality simulation may be provided.

[0281] Augmented reality (AR) is when a user is provided with additional information, artificially generated items, or content overlaid upon their current environment. Such additional information or content will usually be visual and / or audible and their observation of their current environment may be direct, with no intermediate sensing, processing, and rendering, or indirect, where their perception of their environment is relayed via sensors and may be enhanced or processed.

[0282] Mixed reality (MR) is an advanced form of AR where some virtual elements are inserted into the physical scene with the intent to provide the illusion that these elements are part of the real scene.

[0283] Extended reality (XR) refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. XR includes representative forms such as AR, MR and VR and the areas interpolated among them. The levels of virtuality range from partially sensory inputs to fully immersive VR. A key aspect of XR is the extension of human experiences especially relating to the senses of existence (represented by VR) and the acquisition of cognition (represented by AR).

[0284] Likewise, the term XR is used herein as a superordinate category covering AR, MR and VR including purely virtual applications.

[0285] According to the descriptions of use cases of virtual reality applications such as XR applications given by 3GPP TR 22.842, version 17.2.0, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes, many of the XR applications are expected to be stateful, meaning that the applications have a state describing the UE application status at a certain point of time. Additionally, the fact that the UEs are expected to interact (e.g., in gaming applications) implies that the various UEs' states should be shared among the UEs. This introduces several challenges during a handover (HO) procedure: a. The target gNB should be prepared and have adequate radio resources to accommodate the UE executing the XR application. b. In case of a handover failure, the UE will experience service interruption, thus the network should try to ensure seamless handover (considering also application relocation) to avoid an interruption of the XR application. c. In case of a User Plane Function (UPF) relocation, the new UPF may not be able to offer the XR service. d. During the handover, the target EAS may not be properly prepared to take over the EAS functionalities from the previous EAS to avoid long delays. e. Upon transition from EPS to 5GS, the UE and SLF at the 5GS need to identify PDUs and PDU Sets (e.g., I-frames, P-frames) from among XR traffic in the uplink and / or downlink direction.

[0286] The present disclosure addresses these challenges and generally relates to a handover in a communication network such as a mobile communication network, e.g. a 5G network, and between communication networks, e.g., from an EPS to a 5GS.

[0287] Note that the present disclosure relates to various types and generations of communication networks configured to communicate over the transmission medium using any of various radio access technologies (RATs), also referred to as wireless communication technologies, or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), 5G new radio (5G NR), HSPA, 3GPP2 CDMA2000 (e.g, IxRTT, IxEV-DO, HRPD, eHRPD), etc.

[0288] The communication network is equipped with a plurality of base stations including a source base station and a target base station. The handing concerns a UE executing an XR application over a connection with the source base station. As used herein, the term "user equipment" may refer to any of various types of computer systems devices which are mobile or portable and which perform wireless communications. Examples of UEs include mobiletelephones or smart phones, portable gaming devices, laptops, wearable devices (e.g., smart watch, smart glasses), Personal Digital Assistants (PDAs), portable Internet devices, music players, data storage devices, or other handheld devices, etc. In general, the term "UE" can be broadly defined to encompass any electronic, computing, and / or telecommunications device (or combination of devices) which is easily transported by a user and capable of wireless communication.

[0289] FIG. 2 illustrates an example of inter-system change where a UE 202 transitions from being connected to a 5GS 205 to being connect to an EPS 200, and vice versa. FIG. 2 shows a PDN between the UE 202 and the EPS 200 and a PDU session between the UE 202 and the 5GS 205. The UE 202 can be configured to send / receive packets via the PDN Connection to / from an EPS 200) and send / receive PDUs to / from a 5GS 205 via the PDU Session. The PDN Connection can be established initially between the UE 202 and the EPS 200, or the PDU Session can be established initially between the UE 202 and the 5GS 205. Subsequently, the UE 202 can undergo an inter-system change where the UE 202 transitions from being connected to the 5GS 205 (e.g., transitions from being in N1 mode) to being connected to the EPS 200 (e.g., to being in SI mode) or the UE transitions from being connected to EPS 200 (e.g., transitions from being in SI mode) to being connected to the 5GS 205 (e.g., to being in N1 mode). When the UE 202 is initially registered with the 5GS 205 and then transitions to the EPS and later transitions back to the 5GS 205, the same information that was used for identifying PDUs from / to the 5GS 205 initially can be used again for identifying PDUs from / to the 5GS 205 upon the UE 202 transferring back to being connected to the 5GS 205.

[0290] Turning now to FIG. 3, an example a core network apparatus 300 (CNA 300) in accordance with an example aspect of the present disclosure is shown. As described below in conjunction with the flowcharts of FIGs. 7-30, the CNA 300 is an example of a computing device, such as UE 102, UE 202, the SMF 110, and / or the like. The CNA 300 can be configured to store, host, or comprise one or more network functions of a core network that are configured to perform the operations of the core network functions described herein. In any instance, the CNA 300 may more generally be a computing device or computing, such as a server, a standalone computer, a distributed computing system, or a cloud computing system. Regardless of the manner in which the CNA 300 is embodied, the apparatus of an example aspect may be configured as shown in FIG. 3 so as to include, be associated with or otherwise be in communication with processing circuitry including, for example, aprocessor 302 and a memory device 304 and, in some aspects, and / or a communication interface 306.

[0291] As illustrated in FIG. 3, the processor 302 (and / or co-processors or any other circuitry assisting or otherwise associated with the processor 302) of the CNA 300 may be in communication with the memory device 304 via a bus for passing information among components of the CNA 300. The memory device 304 may include, for example, one or more volatile and / or non-volatile memories. In other words, for example, the memory device 304 may be an electronic storage device (e.g., a computer readable storage medium) comprising gates configured to store data (e.g., bits) that may be retrievable by a machine (e.g., a computing device like the processor 302). The memory device 304 may be configured to store information, data, content, applications, instructions, or the like for enabling the CNA 300 to carry out various operations of one or more core network functions in accordance with an example aspect of the present disclosure. For example, the memory device 304 could be configured to buffer input data for processing by the processor 302. Additionally or alternatively, the memory device 304 could be configured to store instructions of core network functions for execution by the processor 302.

[0292] The processor 302 may be embodied in a number of different ways. For example, the processor 302 may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some aspects, the processor 302 may include one or more processing cores configured to perform independently. A multi-core processor may enable multiprocessing within a single physical package. Additionally or alternatively, the processor 302 may include one or more other processors configured in tandem via the bus to enable independent execution of instructions, pipelining and / or multithreading.

[0293] In an example aspect, the processor 302 may be configured to execute instructions stored in the memory device 304 or otherwise accessible to the processor 302. Alternatively or additionally, the processor 302 may be configured to execute hard coded functionality. As such, whether configured by hardware or software methods, or by a combination thereof, the processor 302 may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an aspect of the present disclosure while configuredaccordingly. Thus, for example, when the processor 302 is embodied as an ASIC, FPGA or the like, the processor 302 may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor 302 is embodied as an executor of instructions, the instructions may specifically configure the processor 302 to perform the algorithms and / or operations described herein when the instructions are executed. However, in some cases, the processor 302 may be a processor of a specific device (e.g., an encoder and / or a decoder) configured to employ an aspect of the present disclosure by further configuration of the processor 302 by instructions for performing the algorithms and / or operations described herein. The processor 302 may include, among other things, a clock, an arithmetic logic unit (ALU) and logic gates configured to support operation of the processor 302.

[0294] In aspects that include a communication interface 306, the communication interface 306 may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and / or transmit data from and / or to a network and / or any other device or module in communication with the CNA 300, such as an NF, an NRF, a UE (e.g., 102), a RAN (e.g., 104) core network services, an application server and / or function, a database or other storage device, etc. In this regard, the communication interface 306 may include, for example, an antenna (or multiple antennas) and supporting hardware and / or software for enabling communications with a wireless communication network. Additionally or alternatively, the communication interface 306 may include the circuitry for interacting with the antenna(s) to cause transmission of signals via the antenna(s) or to handle receipt of signals received via the antenna(s). In some environments, the communication interface 306 may alternatively or also support wired communication. As such, for example, the communication interface 306 may include a communication modem and / or other hardware and / or software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB) or other mechanisms. In some aspects, a session management function (e.g., 110) can comprise a 5GC session management function for any suitable CUPS architecture, such as for the gateway GPRS support node (GGSN-C), TWAG-C, BNG-CUPS, N4, Sxa, Sxb, Sxc, evolved packet core (EPC) SWG-C, EPC PGW-C, EPC TDF-C, and / or the like.

[0295] In some aspects, the CNA 300 may represent a user equipment (e.g., 102) that is configured to be connected to other core network entities or network equipment. In some aspects, user equipment can comprise a mobile telephone (cell phone) or the like.

[0296] As illustrated, the CNA 300 can include the processor 302 in communication with the memory 304 and configured to provide signals to and receive signals from the communication interface 306. In some aspects, the communication interface 306 can include a transmitter and a receiver. In some aspects, the processor 302 can be configured to control the functioning of the CNA 300, at least in part. In some aspects, the processor 302 may be configured to control the functioning of the transmitter and receiver by effecting control signaling via electrical leads to the transmitter and receiver. Likewise, the processor 302 may be configured to control other elements of CNA 300 by effecting control signaling via electrical leads connecting the processor 302 to the other elements, such as a display or the memory 304. The processor 302 may, for example, be embodied in a variety of ways including circuitry, at least one processing core, one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits (for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and / or the like), or some combination thereof. Accordingly, although illustrated in FIG. 3 as a single processor, in some example aspects the processor 302 may comprise a plurality of processors or processing cores.

[0297] The CNA 300 may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, and / or the like. Signals sent and received by the processor 302 may include signaling information in accordance with an air interface standard of an applicable cellular system, and / or any number of different wireline or wireless networking techniques, comprising but not limited to Wi-Fi, wireless local access network (WLAN) techniques, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, 802.3, ADSL, DOCSIS, and / or the like. In addition, these signals may include speech data, user generated data, user requested data, and / or the like.

[0298] For example, the CNA 300 and / or a cellular modem therein may be capable of operating in accordance with various first generation (1G) communication protocols, second generation (2G or 2.5G) communication protocols, third-generation (3G) communication protocols, fourth-generation (4G) communication protocols, fifth-generation (5G) communication protocols, Internet Protocol Multimedia Subsystem (IMS) communication protocols (for example, session initiation protocol (SIP) and / or the like. For example, the CNA 300 may be capable of operating in accordance with 2G wireless communicationprotocols IS-136, Time Division Multiple Access TDMA, Global System for Mobile communications, GSM, IS-95, Code Division Multiple Access, CDMA, and / or the like. In addition, for example, the CNA 300 may be capable of operating in accordance with 2.5G wireless communication protocols General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), and / or the like. Further, for example, the CNA 300 may be capable of operating in accordance with 3G wireless communication protocols, such as Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), Wideband Code Division Multiple Access (WCDMA), Time Division-Synchronous Code Division Multiple Access (TD-SCDMA), and / or the like. The CNA 300 may be additionally capable of operating in accordance with 3.9G wireless communication protocols, such as Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or the like. Additionally, for example, the CNA 300 may be capable of operating in accordance with 4G wireless communication protocols, such as LTE Advanced, 5G, and / or the like as well as similar wireless communication protocols that may be subsequently developed. In some aspects, the CNA 300 may be capable of operating according to or within the framework of any suitable control and user plane separation (CUPS) architecture, such as for the gateway GPRS support node (GGSN-C), trusted wireless access gateway (TWAG-C), broadband network gateways (BNGs), N4, Sxa, Sxb, Sxc, evolved packet core (EPC) SWG-C, EPC PGW-C, EPC TDF- C, and / or the like.

[0299] It is understood that the processor 302 may include circuitry for implementing audio and / or video and logic functions of the CNA 300. For example, the processor 302 may comprise a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, and / or the like. Control and signal processing functions of the CNA 300 may be allocated between these devices according to their respective capabilities. The processor 302 may additionally comprise an internal voice coder (VC), an internal data modem (DM), and / or the like. Further, the processor 302 may include functionality to operate one or more software programs, which may be stored in memory 304. In general, the processor 302 and software instructions stored in memory 306 may be configured to cause the CNA 300 to perform actions. For example, the processor 302 may be capable of operating a connectivity program, such as a web browser. The connectivity program may allow the CNA 300 to transmit and receive web content, such as locationbased content, according to a protocol, such as wireless application protocol, WAP, hypertext transfer protocol, HTTP, and / or the like.

[0300] As shown in FIG. 3, CNA 300 may also include one or more mechanisms for sharing and / or obtaining data, illustrated as the communication interface 306. For example, the communication interface 306 of the CNA 300 may include a short-range radio frequency (RF) transceiver and / or interrogator, so data may be shared with and / or obtained from electronic devices in accordance with RF techniques. The CNA 300 may include other short- range transceivers, such as an infrared (IR) transceiver, a Bluetooth™ (BT) transceiver operating using Bluetooth™ wireless technology, a wireless universal serial bus (USB) transceiver, a Bluetooth™ Low Energy transceiver, a ZigBee transceiver, an ANT transceiver, a cellular device-to-device transceiver, a wireless local area link transceiver, and / or any other short-range radio technology. In some aspects, the CNA 300 and, in particular, the short-range transceiver may be capable of transmitting data to and / or receiving data from electronic devices within the proximity of the apparatus, such as within about 10 meters, for example. The CNA 300 including the Wi-Fi or wireless local area networking modem may also be capable of transmitting and / or receiving data from electronic devices according to various wireless networking techniques, including 6LoWpan, Wi-Fi, Wi-Fi low power, WLAN techniques such as IEEE 802.11 techniques, IEEE 802.15 techniques, IEEE 802.16 techniques, and / or the like.

[0301] The CNA 300 can be or comprise any suitable computing device or computer, such as a computing device that hosts virtualized network functions (VNFs) of a core network of a communications network (e.g., 100, 205). The CNA 300 may be connected to a radio access network (RAN) to send and receive control plane messages and data thereto. In some embodiments, the CNA 300 can be configured to host UPF, e.g., to a DN. The CNA 300 may be or comprise a server, a distributed computing system, hardware infrastructure of a cloud core network, and / or the like.

[0302] The CNA 300 may include volatile memory and / or non-volatile memory, which can comprise some or all of the memory 304 or can alternatively be a separate memory within or connected to the CNA 300. For example, volatile memory may include Random Access Memory (RAM) including dynamic and / or static RAM, on-chip or off-chip cache memory, and / or the like. Non-volatile memory, which may be embedded and / or removable, may include, for example, read-only memory, flash memory, magnetic storage devices, for example, hard disks, floppy disk drives, magnetic tape, optical disc drives and / or media, non-volatile random access memory (NVRAM), and / or the like. Like volatile memory, nonvolatile memory may include a cache area for temporary storage of data. At least part of the volatile and / or non-volatile memory may be embedded in processor 302. The memories maystore one or more software programs, instructions, pieces of information, data, and / or the like. For example, the memory 304 may store software or instructions of one or more network functions of the core network which may be used by the apparatus for performing operations disclosed herein.

[0303] Some of the aspects disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware may reside on the memory 304, the processor 302, or electronic components, for example. In some example aspect, the application logic, software or an instruction set is maintained on any one of various conventional computer- readable media. In the context of this document, a “computer-readable medium” may be any non-transitory media that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer or data processor circuitry, with examples depicted at FIG. 3, computer-readable medium may comprise a non-transitory computer-readable storage medium that may be any media that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[0304] FIG. 4 illustrates an example of a communication device 400, which may be configured in accordance with example aspects of the present disclosure. As described below in conjunction with FIGs. 7-30, the communication device 400 is an example of a computing device, such as UE 102, UE 202, the SMF 110, and / or the like. The communication device 400 may be configured to perform the functions, processes, and methods described herein, combinations thereof, variations thereof, or parts thereof. As described herein, the terms “UE”, “user device”, “terminal device”, and “XR device” are often used interchangeably to refer to any communication device configured to receive rendered XR media content, whether or not the communication device is configured to display the XR media content, whether or not the communication device is configured to measure, detect, calculate, sense, or otherwise determine a user’s pose information, and whether or not the communication device is rendering another portion of the XR media content. Also, as described herein, the terms “function,” “element,” “node,” “engine,” “apparatus,” “device,” “server,” “component,” “system,” or “sub-system” may refer to any component of the network 100, hardware, or virtualized entity.

[0305] In some aspects, the communication device 400 is or comprises exemplary specialized hardware particularly dimensioned and configured to carry out any of the methods, processes, and approaches described herein. In some aspects, the communicationdevice 400 can be a part of the communications system 100, the EPS 200, or in communication with a component thereof. It will be appreciated that the communication device 400 is provided as an example of one aspect and should not be construed to narrow the scope or spirit of the disclosure in any way. In this regard, the scope of the disclosure encompasses many potential aspects in addition to those illustrated and described herein. As such, while FIG. 4 illustrates one example of a configuration of an apparatus for carrying out or facilitating various of the disclosed approaches and methods, other wireless communication system, such as a 5G system, a 6G system, or other configurations may also be used to implement certain aspects of the present disclosure.

[0306] The communication device 400 may be embodied as a desktop computer, laptop computer, mobile terminal, mobile computer, mobile phone, mobile communication device, game device, digital camera and / or camcorder, audio and / or video player, television device, radio receiver, digital video recorder, positioning device, a chipset, a computing device comprising a chipset, any combination thereof, and / or the like. In some example aspects, the communication device 400 is embodied as a mobile computing device, such as mobile telephones, mobile computers, personal digital assistants (PDAs), pagers, laptop computers, desktop computers, gaming devices, televisions, e-papers, and other types of electronic systems, which may employ various aspects of the disclosure.

[0307] The communication device 400 can include a computing device 402 including a processor 404, and storage, such as a non-volatile memory 406 and / or volatile memory 408 (interchangeably and / or collectively referred to herein as “memory 406 and / or 408”). In some aspects, the processor 404 may, for example, be embodied as various means including circuitry, one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or FPGA (field programmable gate array), or some combination thereof. Accordingly, although illustrated in FIG. 4 as a single processor, in some aspects the processor 404 comprises a plurality of processors. These signals sent and received by the processor 404 may include signaling information in accordance with an air interface standard of an applicable cellular system, and / or any number of different wireline or wireless networking techniques, comprising but not limited to Wi-Fi, wireless local access network (WLAN) techniques such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, and / or the like.In addition, these signals may include speech data, user generated data, user requested data, and / or the like. In this regard, the mobile terminal may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, and / or the like. More particularly, the mobile terminal may be capable of operating in accordance with various first generation (1G), second generation (2G), 2.5G, third- generation (3G) communication protocols, fourth-generation (4G) communication protocols, fifth-generation (5G), sixth-generation (6G), any band, frequency or protocol thereof, Internet Protocol Multimedia Subsystem (IMS) communication protocols (e.g., session initiation protocol (SIP)), and / or the like. For example, the mobile terminal may be capable of operating in accordance with 2G wireless communication protocols IS- 136 (Time Division Multiple Access (TDMA)), Global System for Mobile communications (GSM), IS- 95 (Code Division Multiple Access (CDMA)), and / or the like. Also, for example, the mobile terminal may be capable of operating in accordance with 2.5G wireless communication protocols General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), and / or the like. Further, for example, the mobile terminal may be capable of operating in accordance with 3G wireless communication protocols such as Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), Wideband Code Division Multiple Access (WCDMA), Time Division- Synchronous Code Division Multiple Access (TD-SCDMA), and / or the like. The mobile terminal may be additionally capable of operating in accordance with 3.9G wireless communication protocols such as Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and / or the like. Additionally, for example, the mobile terminal may be capable of operating in accordance with fourth-generation (4G) wireless communication protocols and / or the like as well as similar wireless communication protocols that may be developed in the future.

[0308] In addition to broad-band systems, some Narrow-band Advanced Mobile Phone System (NAMPS), as well as Total Access Communication System (TACS), mobile terminals may also benefit from embodiments of this disclosure, as should dual or higher mode phones (e.g., digital / analog or TDMA, CDMA, and / or analog phones). Additionally, the communication device 400 or a component thereof may be capable of operating according to Wi-Fi or Worldwide Interoperability for Microwave Access (WiMAX) protocols.

[0309] It is understood that the processor 404 may comprise circuitry for implementing audio and / or video and logic functions of the communication device 400. For example, theprocessor 404 may comprise a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, and / or the like. Control and signal processing functions of the mobile terminal may be allocated between these devices according to their respective capabilities. The processor may additionally comprise an internal voice coder (VC), an internal data modem (DM), and / or the like. Further, the processor 404 may comprise functionality to operate one or more software programs, which may be stored in memory. For example, the processor 404 may be capable of operating a connectivity program, such as a web browser. The connectivity program may allow the communication device 400 to transmit and receive web content, such as location-based content, according to a protocol, such as Wireless Application Protocol (WAP), hypertext transfer protocol (HTTP), and / or the like. The communication device 400 may be capable of using a Transmission Control Protocol and / or Internet Protocol (TCP / IP) to transmit and receive web content across the internet or other networks.

[0310] The communication device 400 may also comprise a user interface 412 including, for example, an earphone or speaker, a ringer, a microphone, a user display, a user input interface, and / or the like, which may be operationally coupled to the processor 404. In this regard, the processor 404 may comprise user interface circuitry configured to control at least some functions of one or more elements of the user interface, such as, for example, the speaker, the ringer, the microphone, the display, and / or the like. The processor 404 and / or user interface circuitry comprising the processor 404 may be configured to control one or more functions of one or more elements of the user interface through computer program instructions (e.g., software and / or firmware) stored on a memory accessible to the processor 404 (e.g., non-volatile memory 406, volatile memory 408, and / or the like). Although not shown, the communication device 400 may comprise a battery for powering various circuits related to the communication device 400, for example, a circuit to provide mechanical vibration as a detectable output. The communication device 400 can further comprise a display 414. In some aspects, the display 414 may be of any type appropriate for the electronic device in question with some examples including a plasma display panel (PDP), a liquid crystal display (LCD), a light-emitting diode (LED), an organic light-emitting diode display (OLED), a projector, a holographic display, or the like. The user interface 412 may comprise devices allowing the communication device 400 to receive data, such as a keypad, a touch display (e.g., some example aspects wherein the display 414 is configured as a touch display), a joystick (not shown), and / or other input device. In aspects including a keypad,the keypad may comprise numeric (0-9) and related keys (#, *), and / or other keys for operating the communication device 400.

[0311] The communication device 400 may comprise memory, such as the non-volatile memory 406 and / or the volatile memory 408, such as RAM, read only memory (ROM), nonvolatile RAM (NVRAM), a subscriber identity module (SIM), a removable user identity module (R-UIM), and / or the like. In addition to the memory, the communication device 400 may comprise other removable and / or fixed memory. In some aspects, the volatile memory 408 may include Random Access Memory (RAM) including dynamic and / or static RAM, on-chip or off-chip cache memory, and / or the like. In some aspects, the non-volatile memory 406, which may be embedded and / or removable, may include, for example, readonly memory, flash memory, magnetic storage devices (e.g., hard disks, floppy disk drives, magnetic tape, etc.), optical disc drives and / or media, non-volatile random access memory (NVRAM), and / or the like. Like the volatile memory 408, the non-volatile memory 406 may include a cache area for temporary storage of data. The memories may store one or more software programs, instructions, pieces of information, data, and / or the like which may be used by the mobile terminal for performing functions of the mobile terminal. For example, the memories may comprise an identifier, such as an international mobile equipment identification (IMEI) code, capable of uniquely identifying the communication device 400.

[0312] In some example aspects, the communication device 400 includes various means for performing the various functions herein described. These means may comprise one or more of the processor 404, the non-volatile memory 406, the volatile memory 408, the user interface 412, or the display 414. The means of the communication device 400 as described herein may be embodied as, for example, circuitry, hardware elements (e.g., a suitably programmed processor, combinational logic circuit, and / or the like), a computer program product comprising computer-readable program instructions (e.g., software or firmware) stored on a computer-readable storage medium (e.g., memory 406 or 408) that is executable by a suitably configured processing device (e.g., the processor 404), or some combination thereof.

[0313] In some example aspects, one or more of the means illustrated in FIG. 4 may be embodied as a chip or chip set. In other words, the communication device 400 may comprise one or more physical packages (e.g., chips) including materials, components and / or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and / or limitation of electrical interaction for component circuitry included thereon. In this regard, the processor 404, the memory 406 and / or 408, theuser interface 412, and / or the display 414 may be embodied as a chip or chip set. The communication device 400 may therefore, in some cases, be configured to or may comprise component(s) configured to implement aspects of the present disclosure on a single chip or as a single “system on a chip.” As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0314] The processor 404 may, for example, be embodied as various means including one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or FPGA (field programmable gate array), one or more other types of hardware processors, or some combination thereof. Accordingly, although illustrated in FIG. 4 as a single processor, in some aspects the processor 404 comprises a plurality of processors. The plurality of processors may be in operative communication with each other and may be collectively configured to perform one or more functionalities of the communication device 400, e.g., as described herein. The plurality of processors may be embodied on a single computing device or distributed across a plurality of computing devices collectively configured to function as the communication device 400. In some aspects, e.g., wherein the apparatus is embodied as an communication device 400, the processor 404 may be embodied as or comprise the processor 404 (shown in FIG. 4). In some example aspects, the processor 404 is configured to execute instructions stored in the memory 406 and / or 408 or otherwise accessible to the processor 404. These instructions, when executed by the processor 404, may cause the apparatus 400 to perform one or more of the functionalities of the communication device 400 as described herein. As such, whether configured by hardware or software methods, or by a combination thereof, the processor 404 may comprise an entity capable of performing operations according to aspects of the present disclosure while configured accordingly. Thus, for example, when the processor 404 is embodied as an ASIC, FPGA or the like, the processor 404 may comprise specifically configured hardware for conducting one or more operations described herein. Alternatively, as another example, when the processor 404 is embodied as an executor of instructions, such as may be stored in the memory 406 and / or 408, the instructions may specifically configure the processor 404 to perform one or more algorithms and operations described herein.

[0315] The memory 406 and / or 408 may comprise, for example, volatile memory, nonvolatile memory, or some combination thereof. In this regard, the memory 406 and / or 408 may comprise a non-transitory computer-readable storage medium. Although illustrated in FIG. 4 as a single memory, the memory 406 and / or 408 may comprise a plurality of memories. The plurality of memories may be embodied on a single computing device or may be distributed across a plurality of computing devices collectively configured to function as the communication device 400. In various example aspects, the memory 406 and / or 408 may comprise a hard disk, random access memory, cache memory, flash memory, a compact disc read only memory (CD-ROM), digital versatile disc read only memory (DVD-ROM), an optical disc, circuitry configured to store information, or some combination thereof. In some aspects, the memory 406 and / or 408 may comprise the volatile memory 408 and / or the nonvolatile memory 406 (shown in FIG. 4). The memory 406 and / or 408 may be configured to store information, data, applications, instructions, or the like for enabling the communication device 400 to carry out various functions in accordance with various example embodiments. For example, in some example embodiments, the memory 406 and / or 408 is configured to buffer input data for processing by the processor 404. Additionally or alternatively, the memory 406 and / or 408 may be configured to store program instructions for execution by the processor 404. The memory 406 and / or 408 may store information in the form of static and / or dynamic information. The stored information may include, for example, images, content, media content, user data, application data, and / or the like. This stored information may be stored and / or used by the processor 404 during the course of performing its functionalities.

[0316] In some aspects, the communication device 400 can further comprise a communication interface 416 that may be embodied as any device or means embodied in circuitry, hardware, a computer program product comprising computer readable program instructions stored on a computer readable medium (e.g., the memory 406 and / or 408) and executed by a processing device (e.g., the processor 404), or a combination thereof that is configured to receive and / or transmit data from and / or to another computing device. In some aspects, the communication interface 416 can be or comprise a transceiver, an antenna, an antenna array, a modem, and / or the like.

[0317] In some aspects, the communication interface 416 is at least partially embodied as or otherwise controlled by the processor 404. In this regard, the communication interface 416 may be in communication with the processor 404, such as via a bus. The communication interface 416 may include, for example, an antenna, a transmitter, a receiver,a transceiver and / or supporting hardware or software for enabling communications with one or more remote computing devices. In some aspects, e.g., wherein the apparatus is embodied as the communication device 400, the communication interface 416 may be embodied as or comprise a transmitter and a receiver. The communication interface 416 may be configured to receive and / or transmit data using any protocol that may be used for communications between computing devices. In this regard, the communication interface 416 may be configured to receive and / or transmit data using any protocol that may be used for transmission of data over a wireless network, wireline network, some combination thereof, or the like by which the communication device 400 and one or more computing devices may be in communication. As an example, the communication interface 416 may be configured to receive and / or otherwise access content (e.g., web page content, streaming media content, and / or the like) over a network from a server or other content source. The communication interface 416 may additionally be in communication with the memory 406 and / or 408, user interface 412 and / or the processor 404, such as via a bus.

[0318] The user interface 412 may be in communication with the processor 404 and configured to receive an indication of a user input and / or to provide an audible, visual, mechanical, or other output to a user. As such, the user interface 412 may include, for example, a keyboard, a mouse, a joystick, a display, a touch screen display, a microphone, a speaker, and / or other input and / or output mechanisms. In some aspects, the user interface 412 of the communication device 400 may be embodied as or comprise the user input interface, such as the display 414 (shown in FIG. 4), and other components such as a keypad, mouse, etc. The user interface 412 may be in communication with the memory 406 and / or 408, communication interface 416, a sensor, a speaker, and / or the processor 404, such as via a bus. In some example embodiments, the user interface 412 may comprise a single input and / or output mechanism. In other embodiments, the user interface 412 may comprise a content display and touch display, such as the display 414. In some aspects, the user interface 412 may comprise a touch display user interface with a content display portion and a dedicated user input portion, such as a virtual keyboard, virtual piano, or an application with a designated key for user input.

[0319] The processor 404 may be embodied as various means, such as circuitry, hardware, a computer program product comprising computer readable program instructions stored on a computer readable medium (e.g., the memory 406 and / or 408) and executed by a processing device (e.g., the processor 404), or some combination thereof and, in some aspects, is embodied as or otherwise controlled by the processor 404. The processor 404 mayfurther be in communication with one or more of the memory 406 and / or 408, or user interface 412, such as via a bus.

[0320] The processor 404 may be configured to receive a user input from a user interface 412, such as a touch display. The user input or signal may carry positional information indicative of the user input. In this regard, the position may comprise a position of the user input in a two-dimensional space, which may be relative to the surface of the touch display user interface. For example, the position may comprise a coordinate position relative to a two-dimensional coordinate system (e.g., an X and Y axis), such that the position may be determined. Accordingly, the processor 404 may determine an element, instruction, and / or command that corresponds with a key, or image, displayed on the touch display user interface at the determined position or within a predefined proximity (e.g., within a predefined tolerance range) of the determined position. The processor 404 may be further configured to perform a function or action related to the key corresponding to the element, instruction, and / or command determined by the processor 404 based on the position of the touch or other user input.

[0321] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example aspects disclosed herein may be improved user equipment or network equipment configuration. As such, any aspect of a method, system, approach, device, apparatus, or computer program described or illustrated herein is understood to comprise any or all of the components, functionalities, elements, or steps of any other aspect such that any method can be carried out by the CNA 300, the communication device 400, or by any other suitable system or device, and likewise can be carried out according to a computer program code envisioned within the scope of this disclosure.

[0322] Referring now to FIG. 5, an example inter-system change procedure 500 that involves the UE 202, the EPS 200, and the 5GS 205 is illustrated. As illustrated, step 1 of the inter-system change procedure 500 represents establishment of a PDU session between the UE 202 and the 5GS 205. During step 1, the UE 202 is in N1 mode (e.g., is connected to the 5GS) and the UE 202 sends a PDU session establishment request message to the 5GS 205 (e.g., a SMF 110 of the 5GS 205). Also, during step 1, the UE 202 receives from the 5GS 205 (e.g., the SMF 110 of the 5GS 205) a PDU session establishment accept message when the 5GS 205 has established a PDU session between the UE 202. Step 2 of the intersystem change procedure 500 represents one or more control plane message that are sent between the UE 202, the EPS 200 and / or the 5GS 205 during an inter-system change (e.g.,when the UE 202 transitions from being connected to the 5GS 205 to being connected to the EPS 200 so that the UE 202 transitions from being in N1 mode to being in SI mode). Step3 represents an operation performed by the UE 202. At step 3, the Protocol Description associated with the PDU session by storing (and / or maintaining) the Protocol Description at the UE 202. Step 4 represents a determination by the 5GS 205 to maintain a Protocol Description associated with the PDU session by storing (and / or maintaining) the Protocol Description at the 5GS 205.

[0323] Step 5 represents one or more control plane messages that are sent between the UE 202 and the EPS 200 and / or the 5GS 205 during an inter-system change (e.g., when the UE 202 transitions from being connected to the EPS 200 to being connected to the 5GS 205 so that the UE 202 transitions from being in SI mode to being in N1 mode). At step 6, the UE 202 uses the Protocol Description stored (and / or maintained) therein to associate PDUs sent and / or received with a PDU Set, such as an I-frame or a P-frame.

[0324] Referring now to FIG. 6, an example inter-system change procedure 600 that involves the UE 202, the EPS 200, and the 5GS 205, is illustrated. As illustrated, the intersystem change procedure 600 represents at least portions of a process for establish of a PDN connection between the UE 202 and the EPS 200, followed by modifying a PDU session between the UE 202 and the 5GS 205 following transfer of XR traffic / flow / services from the PDN connection with the EPS 200 to the PDU session with the 5GS 205. During step 1 of the inter-system change procedure 600, a PDN connection is established between the UE 202 and the EPS 200 such that the UE 202 is in SI mode (e.g., is connected to the EPS 200). Step 2 of the inter-system change procedure 600 represents one or more control plane messages that are sent between the UE 202, and the EPS 200 and / or the 5GS 205 to initiate or facilitate an inter-system change (e.g., when the UE 202 transitions from being connected to the EPS 200 to being connected to the 5GS 205 so that the UE 202 transitions from being in SI mode to being in N1 mode).

[0325] Step 3 of the inter-system change procedure 600 represents an operation performed by an SMF (e.g., 110) of the 5GS 205. During step 3, the SMF of the 5GS 205 determines whether to generate and send a Protocol Description to the UE 202, the Protocol Description being associated with a PDU session established between the UE 202 and the 5GS 205. Step4 represents an action performed by a network element / network function (e.g., SMF) of the 5GS 205. During Step 4, the SMF or the like of the 5GS 205 generates and provides / transmits towards the UE 202 a PDU SESSION MODIFICATION COMMAND message comprising a Protocol Description associated with the PDU session establishedbetween the UE 202 and the 5GS 205. Step 5 represents an action carried out by the UE 202 in which the UE 202 stores (and / or maintains) the Protocol Description received from the 5GS 205 in the PDU SESSION MODIFICATION COMMAND message. The UE 202 can use the Protocol Description stored (and / or maintained) therein to associate PDUs sent / received with a PDU Set, such as an I-frame or a P-frame.

[0326] Referring now to FIGs 7-30, various methods are described and illustrated for managing PDU sessions and PDN connections. In some aspects, the CNA 300 can be configured to carry out some or all portions of any of the methods described herein.

[0327] Referring now to FIG. 7, a method 700 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), , which can cause the user equipment to perform at least in an instance in which the UE is in N1 mode, sending to a network function configured for management of PDU sessions and PDN connections (e.g., the SMF+PGW-C 114), one or more session management parameters or one or more session management capabilities for a PDU session which is being changed from a PDN connection established between the UE and a packet data network gateway when the UE was in S 1 mode to a PDU session, providing to the network function, a first NAS message comprising a request for modification of the PDU session, receiving, at the UE, a second NAS message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing (and / or maintaining), at the UE, the protocol description associated with the PDU session, at 701.

[0328] Referring now to FIG. 8, a method 800 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least receiving from a user equipment, a first NAS message comprising a request for modification of a PDU session, at 801. The method 800 can further comprise determining that the PDU session is associated with a PDN connection established a UE and a packet data network gateway when the UE was in SI mode, at 802. The method 800 can further comprise providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session, at 803.

[0329] Referring now to FIG. 9, a method 900 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memorydevice (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least determining whether a protocol description associated with a PDU session is stored (and / or maintained) at the UE, at 901. The method 900 can further include maintaining the protocol description associated with the PDU session after changing from being in N1 mode to being in SI mode, at 902. The method 900 can further include using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after changing from being in SI mode to being in N1 mode, at 903.

[0330] Referring now to FIG. 10, a method 1000 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least, in an instance that a protocol description associated with a PDU session was provided for a UE, maintaining the protocol description associated with the PDU session after receiving an indication of change of the UE from being in N1 mode to being in SI mode, at 1001.

[0331] Referring now to FIG. 11, a method 1100 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least, in an instance in which the UE in N1 mode needs to indicate, to a network function of a 5GS (e.g., 205), one or more session management parameters or one or more session management capabilities for a PDU session which is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established when in SI mode, providing, to the network function, a first message comprising a request for modification of the PDU session, receiving, at the UE, a second message comprising a protocol description associated with the PDU session, and storing (and / or maintaining) the protocol description associated with the PDU session, at 1101.

[0332] Referring now to FIG. 12, a method 1200 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least, in an instance in which the network function receivesfrom a user equipment, a first message comprising a request for modification of a PDU session and determines that the PDU session is associated with an XR service / XRM / XR traffic flow transferred from a PDN connection established when in SI mode, providing, to the UE, a second message comprising a protocol description associated with the PDU session, at 1201.

[0333] Referring now to FIG. 13, a method 1300 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least, in an instance in which the user equipment determines that a protocol description associated with a PDU session is stored (and / or maintained) at the user equipment, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode; and using the protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change from SI mode to N1 mode, at 1301.

[0334] Referring now to FIG. 14, a method 1400 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least, in an instance in which the network function determines that the network function provided a protocol description associated with a PDU session for a UE, maintaining the protocol description associated with the PDU session after inter-system change from N1 mode to SI mode, at 1401.

[0335] Referring now to FIG. 15, a method 1500 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least, in an instance in which a UE determines, at 1501, that an existing protocol description associated with a PDU session with a fifth-generation system (5GS 205) network is not stored (and / or maintained) at the user equipment: providing, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with an EPS to be a PDU session with the 5GS, at 1502, receiving, at the user equipment, a second message comprising a new protocol description,at 1503, and storing (and / or maintaining), at the user equipment, the new protocol description associated with the PDU session, at 1504.

[0336] Referring now to FIG. 16, a method 1600 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least, in an instance in which the user equipment determines that an existing protocol description associated with a PDU session with a fifth-generation system (5GS 205) network is stored (and / or maintained) at the user equipment, using the existing protocol description associated with the PDU session during and after requesting modification of a PDN connection with an EPS to be the PDU session with the 5GS, at 1601. In some aspects, the method 1600 can further include, in an instance in which the user equipment determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the user equipment, at 1602. In some aspects, the method 1600 can further include providing, to a network element of the 5GS, a first message comprising a request for modification of a PDN connection with an EPS to be a PDU session with the 5GS, at 1603. In some aspects, the method 1600 can further include receiving, at the user equipment, a second message comprising a new protocol description, at 1604. In some aspects, the method 1600 can further include storing (and / or maintaining), at the user equipment, the new protocol description associated with the PDU session, at 1605.

[0337] Referring now to FIG. 17, a method 1700 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least determining whether an existing protocol description associated with a PDU session between the user equipment and a fifth-generation system (5GS 205) network is stored (and / or maintained) at the user equipment, the PDU session having been associated with an XR service / XRM / XR traffic flow transferred from a PDN connection with an EPS, at 1701. In some aspects, the method 1700 can further include, in an instance in which the user equipment determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the user equipment, using the existing protocol description associated with the PDU session during the PDU session with the 5GS, at 1702.

[0338] Referring now to FIG. 18, a method 1800 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least determining, at the user equipment, whether an existing protocol description associated with a PDU session between the user equipment and a fifth-generation system (5GS 205) network is stored (and / or maintained) at the user equipment, the PDU session having been associated with an XR service / XRM / XR traffic flow transferred from a PDN connection with an EPS, at 1801. In some aspects, the method 1800 can further include, in an instance in which the UE determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the user equipment, using the existing protocol description associated with the PDU session during the PDU session with the 5GS, at 1802. In some aspects, the method 1800 can further include, in an instance in which the user equipment determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the user equipment, providing, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the user equipment is requesting a new protocol description associated with the PDU session, receiving, at the user equipment, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the user equipment, the new protocol description associated with the PDU session, at 1803.

[0339] Referring now to FIG. 19, a method 1900 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least, while the user equipment has a PDN connection active between the user equipment and an EPS, determining that the PDN connection is being associated with an XR service / XRM / XR traffic flow transferred to a PDU session between the user equipment and a fifth-generation system (5GS 205) network, at 1901. In some aspects, the method 1900 can further include determining whether the XR service / XRM / XR traffic flow / XR application session was originally established while the user equipment was in N1 mode or in SI mode, at 1902. In some aspects, the method 1900 can further include, in an instance in which the XR service / XRM / XR traffic flow / XR application session was originally established while the user equipment was in SI mode,determining that an existing protocol description associated with the PDU session between the user equipment and the 5GS is stored (and / or maintained) at the user equipment, at 1903. In some aspects, the method 1900 can further include, in an instance in which the XR service / XRM / XR traffic flow / XR application session was originally established while the user equipment was in N1 mode, determining that an existing protocol description associated with the PDU session between the user equipment and the 5GS is not stored (and / or maintained) at the user equipment, at 1904. In some aspects, the method 1900 can, optionally, further include in an instance in which the user equipment determines that an existing protocol description associated with the PDU session is stored (and / or maintained) at the user equipment, using the existing protocol description to associate PDUs with PDU Sets in uplink or downlink traffic over the PDU session with the 5GS, at 1905. In some aspects, the method 1900 can, optionally, further include, in an instance in which the user equipment determines that an existing protocol description associated with the PDU session is not stored (and / or maintained) at the user equipment, providing, to a network element of the 5GS, a PDU SESSION MODIFICATION REQUEST message comprising an indication that the user equipment is requesting a new protocol description associated with the PDU session, receiving, at the user equipment, a PDU SESSION MODIFICATION COMMAND message comprising the new protocol description, and storing (and / or maintaining), at the user equipment, the new protocol description associated with the PDU session, at 1906.

[0340] Referring now to FIG. 20, a method 2000 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least, before or during a transfer of a PDN connection with an EPS to a PDU session with a fifth-generation system (5GS 205), determining whether a protocol description associated with the PDU session is stored (and / or maintained) in the memory of the UE, at 2001. In some aspects, the method 2000 can further comprise: in the instance in which it is determined that the protocol description associated with the PDU session is not stored (and / or maintained) at the UE, sending a PDU SESSION MODIFICATION REQUEST message towards the 5GS, at 2002. In some aspects, the method 2000 can further comprise: receiving, at the UE, a PDU SESSION COMMAND message comprising the protocol description associated with the PDU session, at 2003. In some aspects, the method 2000 can further comprise: storing (and / or maintaining) the protocol description associated with the PDU session in the memory, at 2004.

[0341] Referring now to FIG. 21, a method 2100 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least determining whether to transmit, from a UE towards a network entity of a fifth-generation system (5GS 205) network, a PDU session modification request message for a PDU session carrying XR traffic to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to a PDN connection of an EPS, at 2101. In some aspects, the method 2100 can further include: in the instance in which it is determined to transmit a PDU session modification request message for the PDU session to be associated with an XR service / XRM / XR traffic flow transferred from the 5GS to the PDN connection of the EPS, providing the PDU session modification request message to the network entity of the 5GS, at 2102. In some aspects, the method 2100 can further include: upon receiving from the network entity of the 5GS a PDU session modification command message comprising a protocol description associated with the PDU session carrying the XR traffic over the PDU session between the 5GS and the UE, storing (and / or maintaining), at the UE, the protocol description associated with the PDU session carrying the XR traffic within the PDU session between the 5GS and the UE, at 2103.

[0342] Referring now to FIG. 22, a method 2200 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least determining whether a PDN connection was originally established between a UE and an EPS or was changed from a PDU session between the UE and a fifth-generation system (5GS 205) network to the PDN connection between the UE and the EPS, at 2201. In some aspects, the method 2200 can further include: in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE, at 2202. In some aspects, the method 2200 can further include: in an instance in which the PDN connection was established in the EPS, receiving a message from the UE requesting modification of the PDU session, at 2203.

[0343] Referring now to FIG. 23, a method 2300 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g.,110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least determining whether a PDN connection was originally established between a UE and an EPS or was changed from a PDU session between the UE and a fifth-generation system (5GS 205) network to the PDN connection between the UE and the EPS, at 2301. In some aspects, the method 2300 can further include: in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE, at 2302. In some aspects, the method 2300 can further include: transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE, at 2303.

[0344] Referring now to FIG. 24, a method 2400 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least determining whether a PDN connection was originally established between a UE and an EPS or was changed from a PDU session between the UE and a fifth-generation system (5GS 205) network to the PDN connection between the UE and the EPS, at 2401. In some aspects, the method 2400 can further include: in an instance in which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE, at 2402. In some aspects, the method 2400 can further include: in an instance in which the PDN connection was associated with an XR service / XRM / XR traffic flow transferred from a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE, at 2403. In some aspects, the method 2400 can further include: refraining from transmitting, towards the UE, a message comprising the protocol description associated with the PDU session between the 5GS and the UE, at 2404.

[0345] Referring now to FIG. 25, a method 2500 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least determining whether a PDN connection was originally established between a UE and an EPS or was changed from a PDU session between the UE and a fifth-generation system (5GS 205) network to the PDN connection between the UE and the EPS, at 2501. In some aspects, the method 2500 can further include in an instancein which the PDN connection was established in the EPS, generating a protocol description associated with the PDU session between the 5GS and the UE, at 2502. In some aspects, the method 2500 can further include in an instance in which the PDN connection was associated with a PDU session in the 5GS, determining that the UE already has stored (and / or maintained) therein the protocol description associated with the PDU session between the 5GS and the UE, at 2503. In some aspects, the method 2500 can further include refraining from generating a new protocol description associated with the PDU session between the 5GS and the UE, at 2504.

[0346] Referring now to FIG. 26, a method 2600 can be carried out by a user equipment, e.g., the communication device 400, which may comprise means, such as a processor (e.g., processor 404), a memory device (memory device 406, 408) storing computer program instructions (e.g., computer program instructions 410), which can cause the user equipment to perform at least determining whether to initiate a PDU session modification procedure for a PDU session carrying XR traffic associated with an XR service / XRM / XR traffic flow transferred from a fifth-generation system (5GS 205) network to a PDN connection of an EPS, at 2601. In some aspects, the method 2600 can further include in the instance in which it is determined to initiate a PDU session modification procedure for the PDU session transfer, storing (and / or maintaining), at a SMF in the 5GS network, a protocol description associated with a PDU session carrying XR traffic over a PDN connection between the 5GS and a UE, at 2602. In some aspects, the method 2600 can further include generating a PDU SESSION MODIFICATION COMMAND message comprising the protocol description associated with the PDU session, at 2603. In some aspects, the method 2600 can further include transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE, at 2604. In some aspects, the method 2600 can further include using the protocol description for indicating PDUs that belong to one or more PDU sets in the XR traffic received at the SMF in an uplink direction or provided towards the UE in a downlink direction, at 2604.

[0347] Referring now to FIG. 27, a method 2700 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least receiving a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with a PDU session in the 5GS, at 2701. In some aspects, the method 2700 can further include in an instance in which the PDNconnection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE, at 2702. In some aspects, the method 2700 can further include determining that the protocol description for the PDU session is to be provided to the UE, at 2703.

[0348] Referring now to FIG. 28, a method 2800 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least receiving a PDN modification request for a PDN connection carrying XR traffic of an EPS associated with an XR service / XRM / XR traffic flow transferred to a PDU session of a 5GS, at 2801. In some aspects, the method 2800 can further include, in an instance in which the PDN connection was initially established between a UE and the EPS, determining that a protocol description for the PDU session corresponding to the PDN connection is not saved at the UE, at 2802. In some aspects, the method 2800 can further include determining that the protocol description for the PDU session is to be provided to the UE, at 2803. In some aspects, the method 2800 can, optionally, further include determining that the protocol description for the PDU session is to be provided to the UE, at 2804. In some aspects, the method 2800 can, optionally, further include determining that the protocol description for the PDU session is to be provided to the UE, at 2805.

[0349] Referring now to FIG. 29, a method 2900 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least receiving a message from an access and mobility management function (AMF) of the 5GS, the message comprising information regarding a registration request received from a UE, the registration request comprising a request to establish or re-establish a PDU session between the 5GS and the UE, wherein the PDU session was associated with an XR service / XRM / XR traffic flow transferred from a PDN connection with an EPS, at 2901. In some aspects, the method 2900 can further include determining whether the PDN connection was established when the UE was in SI mode or in N1 mode, at 2902. In some aspects, the method 2900 can further include in an instance in which it is determined that the PDN connection was established when the UE was in SI mode, receiving, at the SMF, a PDU SESSION MODIFICATION REQUEST message fromthe UE, generating a protocol description associated with the PDU session, and providing a PDU SESSION MODIFICATION COMMAND message comprising the protocol description, at 2903.

[0350] Referring now to FIG. 30, a method 3000 can be carried out by an apparatus, e.g., the CNA 300, which may comprise means, such as a processor (e.g., processor 302), a memory device (e.g., memory device 304) storing computer program code of a SMF (e.g., 110), and a communications interface (e.g., communication interface 306, 416), which can cause the apparatus to perform at least generating a PDU SESSION MODIFICATION COMMAND message comprising a protocol description for a PDU session between a UE and a 5GS, the PDU session carrying XR traffic between the 5GS and the UE, at 3001. In some aspects, the method 3000 can further include transmitting the PDU SESSION MODIFICATION COMMAND message towards the UE, at 3002. In some aspects, the method 3000 can further include upon an inter-system change for the PDU session carrying the XR traffic is carried out between the 5GS and an EPS, and in an instance in which the PDU session corresponds to a PDN connection that was initially established between the UE and the EPS, receiving an indication that the PDN connection is transferring back from the EPS to the 5GS as a PDU session carrying the XR traffic between the 5GS and the UE, at 3003.

[0351] As described above, FIGs. 7-30 are flowcharts of methods that can be carried out by a user equipment (e.g., 102, 202) and / or an apparatus (110, 300, 400) according to related computer program products comprising computer program code. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware, firmware, processor (e.g., processor 302, 404), circuitry, and / or other devices associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory device (e.g., memory device 304, 406, 408), of an apparatus, e.g., apparatus 300, communication device 400, employing an aspect of the present disclosure and executed by processing circuitry, e.g., 302, 404, of the apparatus. As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus implements the functions specified in the flowchart blocks. These computer program instructions may also be stored in a computer-readable memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture, the execution of which implements the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks.

[0352] A computer program product is therefore defined in those instances in which the computer program instructions, such as computer-readable program code portions, are stored by at least one non-transitory computer-readable storage medium with the computer program instructions, such as the computer-readable program code portions, being configured, upon execution, to perform the functions described above, such as in conjunction with the flowcharts of at least FIGs. 7-30. In other aspects, the computer program instructions, such as the computer-readable program code portions, need not be stored or otherwise embodied by a non-transitory computer-readable storage medium, but may, instead, be embodied by a transitory medium with the computer program instructions, such as the computer-readable program code portions, still being configured, upon execution, to perform the functions described above.

[0353] Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions and combinations of operations for performing the specified functions for performing the specified functions. It will also be understood that one or more blocks of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

[0354] In some aspects, certain ones of the operations above may be modified or further amplified. Furthermore, in some aspects, additional optional operations may be included. Modifications, additions, or amplifications to the operations above may be performed in any order and in any combination.

[0355] Many modifications and other aspects of the concepts, approaches, methods, systems, apparatuses, devices, and computer program products set forth herein will come to mind to one skilled in the relevant field(s) of to which these concepts pertain, having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.Therefore, it is to be understood that the present disclosure is not to be limited to the specific aspects disclosed and that modifications and other aspects are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example aspects in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative aspects without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Any application, publication, technical document, or the like that is cited in this disclosure is hereby incorporated herein by reference in its entirety for all purposes.

[0356] In general, the routines executed to implement the aspects, whether implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions, or even a subset thereof, may be referred to herein as "computer program code" or simply "program code". Program code typically comprises computer- readable instructions that are resident at various times in various memory devices (e.g., 304, 406, 408) and storage devices in a computer and that, when read and executed by one or more processors (e.g., 302, 402) in the computer, cause the computer to perform the operations necessary to execute operations and / or elements embodying the various aspects of the aspects of the present disclosure. Computer readable program instructions for carrying out operations of the aspects of the disclosure may be, for example, assembly language or either source code or object code written in any combination of one or more programming languages.

[0357] In certain alternative aspects, the functions and / or acts specified in the flowcharts, sequence diagrams, and / or block diagrams may be re-ordered, processed serially, and / or processed concurrently without departing from the scope of the disclosure. Moreover, any of the flowcharts, sequence diagrams, and / or block diagrams may include more or fewer blocks than those illustrated consistent with aspects of the disclosure.

[0358] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the aspects of the disclosure. It will be further understood that the terms "comprise" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but donot preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, to the extent that the terms "includes", "having", "has", "with", "comprised of, or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0359] While various aspects disclosed herein have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The written description describes the disclosed approaches, methods, systems, devices, apparatuses, and computer program products in their broader aspects and is therefore not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the concepts disclosed herein.

Claims

Claims1. A method performed by a user equipment (UE) the method comprising: in an instance in which the UE is in N1 mode, determines to indicate, to a network function configured for management of protocol data unit (PDU) sessions and packet data network (PDN) connections, one or more session management parameters or one or more session management capabilities for a PDU session for the UE which is associated with a PDN connection established for the UE when the UE was in SI mode, providing to the network function, a first NAS message comprising a request for modification of the PDU session, receiving a second NAS message comprising a response to the request, the response comprising a protocol description associated with the PDU session, and storing, at the UE, the protocol description associated with the PDU session.

2. The method of claim 1, wherein the session management parameters or session management capabilities comprise one or more of: UE session management capabilities, whether the UE supports more than 16 packet filters, maximum data rate per UE for userplane integrity protection supported by the UE for uplink, maximum data rate per UE for user-plane integrity protection supported by the UE for downlink, and whether the UE requests the PDU session to be an always-on PDU session.

3. The method of claim 1, further comprising: in an instance in which the PDU session is released, removing the protocol description associated with the PDU session.

4. A method performed by a network function configured for management of protocol data unit (PDU) sessions and packet data network (PDN) connections, the method comprising: receiving from a user equipment, a first NAS message comprising a request for modification of a PDU session; determining that the PDU session is associated with a PDN connection established when the UE was in SI mode; and providing, to the UE, a second NAS message comprising a protocol description associated with the PDU session.

5. The method of claim 4, further comprising: maintaining, at the network function, the protocol description associated with the PDU session.

6. The method of claim 5, further comprising: in an instance in which the PDU session is released, removing the protocol description associated with the PDU session.

7. A method performed by a user equipment (UE), the method comprising: determining whether a protocol description associated with a protocol data unit(PDU) session is received at the UE; maintaining the protocol description associated with the PDU session for the user equipment after inter-system change where the UE transitions from being in N1 mode to being in SI mode; and using the maintained protocol description associated with the PDU session to identify one or more PDUs belonging to one or more PDU sets after inter-system change from SI mode to Nl mode.

8. The method of claim 7, further comprising: in an instance in which the PDU session is released, removing the protocol description associated with the PDU session.

9. A method performed by a network function configured to perform management of protocol data unit sessions and packet data network connections, the method comprising: in an instance that a protocol description associated with a protocol data unit (PDU) session for a user equipment was provided to the user equipment, maintaining the protocol description associated with the PDU session after detecting inter-system change from N1 mode to SI mode.

10. The method of claim 9, further comprising: in an instance in which the PDU session is released, removing the protocol description associated with the PDU session.

11. A user equipment comprising: at least one processor; and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the user equipment to perform a method according to any of claims 1- 3 or 7-8.

12. An apparatus comprising: at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the apparatus to perform a method according to any of claims 4-6 and 9-10.

13. A user equipment comprising means for carrying out a method according to any of claims 1-3 or 7-8.

14. An apparatus comprising means for carrying out a method according to any of claims 4-6 or 9-10.

15. An apparatus comprising: a network function for management of protocol data unit (PDU) sessions and packet data network (PDN) connections, the network function configured to carry out a method according to any of claims 4-6 or 9-10.

16. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor of user equipment, cause the user equipment to perform a method according to any of claims 1-3 or 7-8.

17. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor of an apparatus, cause the apparatus to perform a method according to any of claims 4-6 or 9-10.

18. A computer program comprising instructions, wherein when the computer program is run on a user equipment, the user equipment is caused to carry out the method of any of claims 1-3 or 7-8.

19. A computer program comprising instructions, wherein when the computer program is run on an apparatus, the apparatus is caused to carry out the method of any of claims 4-6 or 9-10.

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