Systems and methods for flow mobility control

Abstract

A wireless communication method for session management functionality is disclosed. The method comprises: receiving a policy and charging control (PCC) rule from a policy control function (PCF), the PCC rule comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of a plurality of accesses of the MA PDU session; and transmitting at least one rule to at least one wireless device, the at least one rule comprising at least one QoS flow of the MA PDU session and being determined based on the PCC rule.

Description

TECHNICAL FIELD

[0001] The present document relates generally to wireless communications, and more specifically to 5G (5th generation) communications. BACKGROUND

[0002] In the prior art, the term "ATSSS" refers to access traffic steering, switching and splitting. This feature is supported by the UE (user equipment) and the 5GC (5G Core) network, enabling a multi-access PDU (protocol data unit) connectivity service that enables the exchange of PDUs between the UE and a data network through the simultaneous use of one 3GPP (3rd generation partner project) access network and one non-3GPP access network and two independent N3 / N9 tunnels between the PSA (PDU session anchor) and the RAN / AN (radio access network / access network). The multi-access PDU connectivity service is implemented by establishing a multi-access PDU (MA PDU) session (i.e., a PDU session) that can have user plane resources on both access networks.

[0003] When the UE is registered through both 3GPP and non-3GPP accesses or when the UE is registered through only one access, the UE can request a MA PDU session.

[0004] After the MA PDU session is established, and when there are user plane resources on both access networks, the UE applies the network-provided policy (i.e., ATSSS rules) and considers local conditions (e.g., network interface availability, signal loss conditions, user preferences, etc.) to decide how to split the uplink traffic between the two access networks. Similarly, the UPF (user plane function) anchor point of the MA PDU session applies the network-provided policy (i.e., N4 rules) and feedback information received from the UE over the user plane (e.g., access network is not available or available) to decide how to split the downlink traffic between the two N3 / N9 tunnels and the two access networks. When there are user plane resources on only one access network, the UE applies the ATSSS rules and considers local conditions to trigger the establishment or activation of user plane resources on the other access. The type of MA PDU session can be one of the following types: IPv4, IPv6, IPv4v6, and Ethernet.

[0005] Figure 1 An architecture of ATSSS supported in existing 5GS (5G system) is shown. In Figure 1 - The UE supports one or more steering functions, e.g., MPTCP (Multi-Path Transmission Control Protocol) function and / or ATSSS-LL (Access Traffic Steering, Switching and Splitting - Lower Layer) function. Each steering function in the UE can implement traffic steering, switching and splitting between 3GPP access and non-3GPP access according to the network-provided ATSSS rules. For an Ethernet type of MA PDU session, the ATSSS-LL function is mandatory in the UE.

[0006] - The UPF can support MPTCP proxy function, which communicates with the MPTCP function in the UE by using MPTCP protocol (see IETF RFC 8684).

[0007] - The UPF can support ATSSS-LL function, which is similar to the ATSSS-LL function defined for the UE. No user plane protocol is defined between the ATSSS-LL function in the UE and the ATSSS-LL function in the UPF. Figure 1 The ATSSS-LL function in the UPF is not shown in.

[0008] ​- Furthermore, the UPF supports Performance Measurement Functionality (PMF) that can be used by the UE to obtain access performance measurements for the user plane over 3GPP access and / or non-3GPP access. SUMMARY

[0009] This document relates to methods, systems, and devices for flow mobility control, and in particular to methods, systems, and devices for flow mobility control over multiple access networks.

[0010] The present disclosure relates to a method of wireless communication for a session management function. The method comprises: receiving policy and charging control (PCC) rules from a policy control function (PCF), the PCC rules comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of multiple accesses of the MA PDU session, and transmitting at least one rule to at least one wireless device, the at least one rule comprising at least one QoS flow of the MA PDU session and being determined based on the PCC rules.

[0011] Various embodiments can preferably implement the following features.

[0012] Preferably, the at least one rule comprises at least one access traffic steering, switching, and splitting (ATSSS) rule.

[0013] Preferably, transmitting the at least one rule to the at least one wireless device, the at least one rule comprising at least one QoS flow of the MA PDU session and being determined based on the PCC rules, comprises transmitting the at least one ATSSS rule to a wireless terminal.

[0014] Preferably, the at least one rule comprises at least one N4 rule.

[0015] Preferably, transmitting the at least one rule to the at least one wireless device, the at least one rule comprising at least one QoS flow of the MA PDU session and being determined based on the PCC rules, comprises transmitting the at least one N4 rule to a user plane function (UPF).

[0016] Preferably, at least two of the multiple accesses have a same access type and / or a same radio access technology (RAT) type.

[0017] Preferably, the association between each QoS flow of the MA PDU session and one of the multiple accesses of the MA PDU session comprises an association between each QoS flow of the MA PDU session and an access node of one of the multiple accesses of the MA PDU session.

[0018] Preferably, the wireless communication method further comprises transmitting, to the PCF, a session management policy control creation message for a MA PDU session, wherein the session management policy control creation message indicates at least one access type and / or at least one RAT type of the multiple accesses.

[0019] Preferably, the wireless communication method further comprises receiving, from an access and mobility management function (AMF), a session management context creation message for the MA PDU session, wherein the session management context creation message comprises information associated with the multiple accesses.

[0020] Preferably, the information associated with the multiple accesses comprises at least one of: an indication about whether a wireless terminal of the MA PDU session is registered for at least two of the multiple accesses; an access type of each access that the UE is registered for, or a radio access technology (RAT) type of each access that the UE is registered for.

[0021] The present disclosure relates to a wireless communication method for a policy control function (PCF). The method comprises transmitting, to a session management function (SMF), a policy and charging control (PCC) rule, the PCC rule comprising an association between each quality of service (QoS) flow of a multiple access protocol data unit (MA PDU) session and one of multiple accesses of the MA PDU session.

[0022] Various embodiments can preferably implement the following features.

[0023] Preferably, at least two of the multiple accesses have a same access type and / or a same radio access technology (RAT) type.

[0024] Preferably, the association between each QoS flow of the MA PDU session and one of the multiple accesses of the MA PDU session comprises an association between each QoS flow of the MA PDU session and an access node of one of the multiple accesses of the MA PDU session.

[0025] Preferably, the wireless communication method further comprises receiving a session management policy control creation message for the MA PDU session from the SMF, wherein the session management policy control creation message indicates at least one access type and / or at least one RAT type of the multiple accesses.

[0026] The present disclosure relates to a wireless communication method for an Access and Mobility Management Function (AMF). The method comprises: transmitting a session management context creation message for a Multi-Access Protocol Data Unit (MA PDU) session to a Session Management Function, wherein the session management context creation message comprises information associated with multiple accesses of the MA PDU session.

[0027] Various embodiments can preferably implement the following features.

[0028] Preferably, the information associated with the multiple accesses comprises at least one of: an indication about whether a wireless terminal of the MA PDU session is registered for at least two accesses of the multiple accesses; an access type of each access the UE is registered for, or a Radio Access Technology (RAT) type of each access the UE is registered for.

[0029] Preferably, the wireless communication method further comprises receiving an establishment request for the MA PDU session from a wireless terminal of the MA PDU session, wherein the establishment request comprises an indication about supporting the MA PDU session over multiple accesses having a same access type and / or a same Radio Access Technology (RAT) type.

[0030] The present disclosure relates to a wireless communication method for a wireless terminal. The method comprises: receiving at least one Access Traffic Steering, Switching and Splitting (ATSSS) rule from a Session Management Function (SMF), the at least one ATSSS rule comprising at least one Quality of Service (QoS) flow of a Multi-Access Protocol Data Unit (MA PDU) session and being determined based on a Policy and Charging Control (PCC) rule comprising an association between each QoS flow of the MA PDU session and one access of multiple accesses of the MA PDU session, and selecting at least one QoS flow for transmitting uplink traffic of the MA PDU session based on the at least one ATSSS rule.

[0031] Various embodiments can preferably implement the following features.

[0032] Preferably, at least two accesses of the multiple accesses have a same access type and / or a same Radio Access Technology (RAT) type.

[0033] Preferably, the association between each QoS flow of the MA PDU session and one of the multiple accesses of the MA PDU session comprises an association between each QoS flow of the MA PDU session and an access node of one of the multiple accesses of the MA PDU session.

[0034] Preferably, the wireless communication method further comprises transmitting, to an access and mobility management function, a setup request for the MA PDU session, wherein the setup request comprises an indication about supporting MA PDU session over multiple accesses having a same access type and / or a same radio access technology (RAT) type.

[0035] The present disclosure relates to a wireless device. The wireless device comprises: a communication unit configured to: receive a policy and charging control (PCC) rule from a policy control function (PCF), the PCC rule comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of multiple accesses of the MA PDU session, and transmit, to at least one wireless device, at least one rule comprising at least one QoS flow of the MA PDU session and determined based on the PCC rule.

[0036] Various embodiments can preferably implement the following features.

[0037] Preferably, the wireless device comprises a session management function.

[0038] Preferably, the wireless device further comprises a processor configured to perform any of the above wireless communication methods.

[0039] The present disclosure relates to a wireless device. The wireless device comprises: a communication unit configured to transmit, to a session management function (SMF), a policy and charging control (PCC) rule comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of multiple accesses of the MA PDU session.

[0040] Various embodiments can preferably implement the following features.

[0041] Preferably, the wireless device comprises a policy control function.

[0042] Preferably, the wireless device further comprises a processor configured to perform any of the above wireless communication methods.

[0043] The present disclosure relates to a wireless device. The wireless device comprises: a communication unit configured to transmit, to a session management function, a session management context creation message for a multi-access protocol data unit (MAPDU) session, wherein the session management context creation message includes information associated with multiple accesses of the MAPDU session.

[0044] Various embodiments can preferably implement the following features.

[0045] Preferably, the wireless device comprises an access and mobility management function.

[0046] Preferably, the wireless device further comprises a processor configured to perform any of the above-described wireless communication methods.

[0047] The present disclosure relates to a wireless terminal. The wireless terminal comprises: a communication unit configured to receive, from a session management function (SMF), at least one access traffic steering, switching, and splitting (ATSSS) rule, the at least one ATSSS rule including at least one quality of service (QoS) flow of a multi-access protocol data unit (MAPDU) session and being determined based on a policy and charging control (PCC) rule, the PCC rule including an association between each QoS flow of the MAPDU session and one of multiple accesses of the MAPDU session; and a processor configured to select, based on the at least one ATSSS rule, at least one QoS flow for transmitting uplink traffic of the MAPDU session.

[0048] Various embodiments can preferably implement the following features.

[0049] Preferably, the processor is further configured to perform any of the above-described wireless communication methods.

[0050] The present disclosure relates to a computer program product comprising a computer readable program medium, code stored on the computer readable program medium, the code, when executed by a processor, causing the processor to implement the wireless communication method recited in any of the preceding methods. BRIEF DESCRIPTION OF DRAWINGS

[0051] The exemplary embodiments disclosed herein are intended to provide a number of features, which will become apparent to those of ordinary skill in the art upon the following description of the various embodiments in conjunction with the accompanying drawings. In accordance with various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that the embodiments are presented by way of example only, not limitation, and that various modifications could be made by those skilled in the art upon reading the present disclosure, while still falling within the scope of the present disclosure.

[0052] Accordingly, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present disclosure. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or operations in exemplary order and that the present disclosure is not limited to the specific order or hierarchy presented unless explicitly stated otherwise.

[0053] The invention is defined by the independent claims. Preferred embodiments are defined in the dependent claims. In the following description, although many features can be designated as optional, it is to be understood that all features included in the independent claims are not to be considered optional.

[0054] The above and other aspects and implementations are described in more detail in the drawings and description below.

[0055] Figure 1 A schematic diagram of a network (architecture) is shown.

[0056] Figure 2 A schematic diagram of a network (architecture) is shown according to embodiments of the disclosure.

[0057] Figure 3 A schematic diagram of a process is shown according to embodiments of the disclosure.

[0058] Figure 4 An example of a schematic diagram of a wireless terminal is shown according to embodiments of the disclosure.

[0059] Figure 5 An example of a schematic diagram of a wireless network node is shown according to embodiments of the disclosure.

[0060] Figure 6 A flowchart of a method is shown according to embodiments of the disclosure.

[0061] Figure 7 A flowchart of a method is shown according to embodiments of the disclosure.

[0062] Figure 8 A flowchart of a method is shown according to embodiments of the disclosure.

[0063] Figure 9 A flowchart of a method is shown according to embodiments of the disclosure. DETAILED DESCRIPTION

[0064] In an embodiment, the 5G QoS (quality of service) model for single-access PDU session is also applicable to MA PDU session, i.e., QoS flow is the finest granularity of QoS differentiation in MA PDU session. One difference compared to single-access PDU session is that in MA PDU session, there can be separate user plane tunnels between AN and PSA, where each tunnel is associated with a different access. However, QoS flow is independent of the specific access (i.e., QoS flow is access-agnostic), so the same QoS is supported when traffic is distributed between 3GPP access and non-3GPP access. The SMF provides the same QFI (QoS flow identifier) in 3GPP access and non-3GPP access, so that the same QoS is supported in both accesses.

[0065] In an embodiment, the QoS flow of MA PDU session can be non-GBR or GBR (Guaranteed Bit Rate) according to the corresponding QoS profile.

[0066] In an embodiment, the UE uses ATSS rules to determine the path for transmitting the corresponding uplink traffic. For example, the information "Access Selection Descriptor" is set by access type (i.e., "3GPP access" or "non-3GPP access") to indicate which path the uplink traffic is transmitted through. However, in the embodiment of MA-PDU session using two or more 3GPP accesses, the ATSSS rules (e.g., "Access Selection Descriptor") cannot show the difference between the paths using two or more 3GPP accesses, because the ATSSS rules related to the path using 3GPP access only indicate the access type as 3GPP access type.

[0067] Figure 2 A schematic diagram of a network (architecture) according to an embodiment of the disclosure is shown. In Figure 2 A UE (user equipment) is registered to the network (e.g., 5G network) through two access nodes RAN A and RAN B. In Figure 2 The network functions shown in FIG. 1 include AMF (access and mobility management function), SMF (session management function), PCF (policy control function), and UPF (user plane function). In an embodiment, RAN A and RAN B have the same access type (e.g., 3GPP access or non-3GPP access) and / or the same RAT (radio access technology) type (e.g., NR (new radio)).

[0068] Figure 3A schematic diagram illustrating a procedure according to embodiments of the disclosure is shown. Figure 3 The procedure shown in FIG. 1 is for MA (Multi-Access) PDU (Protocol Data Unit) session establishment. Specifically, the procedure includes the following steps.

[0069] Step 1: The UE transmits a NAS message (S-NSSAI(s) (Single Network Slice Selection Assistance Information), DNN (data network name) requested by the UE, PDU session ID, request type, previous PDU session ID, N1 SM container (PDU session establishment request, [port management information container])) to the AMF.

[0070] To establish a new PDU session, the UE generates a new PDU session ID.

[0071] The UE initiates a UE-requested PDU session establishment procedure as shown in FIG. 2 by transmitting an UL (uplink) NAS (non-access stratum) transport message containing a PDU session establishment request within an N1 SM (session management) container. Figure 3 The PDU session establishment request includes a PDU session ID, a requested PDU session type, a requested SSC (Session and Service Continuity) mode, 5G SM (5G Session Management) capabilities, PCO (Protocol Configuration Option), a SM PDU DN (Session Management PDU Data Network) request container, [number of packet filters], [header compression configuration], UE integrity protection maximum data rate, [request always-on PDU session], [RSN (Redundancy Sequence Number)], and [PDU session pair ID].

[0072] In an embodiment, the UE provides a request type of “MA PDU request” and “dual access related capabilities” in the UL NAS transport message. In an embodiment, “dual access related capabilities” is interpreted as or indicates that the UE supports MA PDU sessions over dual 3GPP access.

[0073] Step 2: The AMF selects an SMF that supports MA PDU Session over dual 3GPP access.

[0074] Step 3: (From AMF to SMF): In the Nsmf_PDUSession_CreateSMContext request message, the AMF informs the SMF that the request is for a MA PDU Session by including the "MA PDU Request" indication. In addition, the AMF indicates to the SMF whether the UE is registered on both accesses and the RAT type of each access.

[0075] Step 4: If session management subscription data for the corresponding SUPI (Subscription Permanent Identifier), DNN and S-NSSAI of the HPLMN (home public land mobile network) is not available, the SMF retrieves the session management subscription data by using Nudm_SDM_Get and subscribes to be notified when this subscription data is modified by using Nudm_SDM_Subscribe. The UDM (Unified Data Management) can retrieve this information from the UDR (Unified Data Repository) by using Nudr_DM_Query (SUPI, subscription data, session management subscription data, selected DNN, S-NSSAI of the HPLMN, serving PLMN ID, [NID (Network Identifier)]) and can subscribe to be notified of the same data from the UDR by using Nudr_DM_subscribe.

[0076] Step 5: (From SMF to AMF): Based on the request received in step 3, the SMF transmits to the AMF either a Nsmf_PDUSession_CreateSMContext response (Cause, SM Context ID or N1 SM container (PDU Session Reject (Cause))) or a Nsmf_PDUSession_UpdateSMContext response.

[0077] Step 6 (Optional): Secondary authentication / authorization.

[0078] Step 7a: If the PDU Session is to use dynamic PCC (Policy Control and Charging), the SMF performs PCF selection. Otherwise, the SMF can apply local policies.

[0079] Step 7b: The SMF can perform the SM Policy Association Establishment procedure to establish SM policy association with the PCF and obtain the default PCC rules for the PDU Session.

[0080] In an embodiment, the SMF sends an "MA PDU Request" indication to the PCF in the SM Policy Control Create message and ATSSS capabilities (including the capabilities related to dual access) for the MA PDU Session. The SMF provides the PCF the currently used access type(s) and RAT type(s). The PCF decides whether to allow the MA PDU Session based on operator policy and subscription data. The PCF associates the relevant QoS flows with the current access node and associates the relevant QoS flows with other access nodes.

[0081] In an embodiment, the PCF provides PCC rules including MA PDU Session control information. Based on the received PCC rules, the SMF derives: (a) ATSSS rule(s) to be sent to the UE for controlling traffic steering, switching, and splitting in the uplink direction, and (b) N4 rules to be sent to the UPF for controlling traffic steering, switching, and splitting in the downlink direction.

[0082] In an embodiment, the SMF can also derive measurement assistance information. In the ATSSS rules, the identification of the QoS flow for a specific access node is used to indicate the routing / path to transmit the UL traffic flow. In the N4 rules, the identification of the QoS flow for a specific access node is used to indicate the routing / path to transmit the DL traffic flow.

[0083] Step 8: The SMF selects the SSC mode for the PDU Session. The SMF also selects one or more UPFs as needed. In case of PDU Session Type IPv4 or IPv6 or IPv4v6, the SMF allocates an IP address / prefix for the PDU Session (unless configured otherwise). In case of PDU Session Type IPv6 or IPv4v6, the SMF also allocates an interface identifier for the UE to establish its link-local address. For unstructured PDU Session Type, the SMF can allocate an IPv6 prefix and N6 point-to-point tunnel for the PDU Session (based on UDP / IPv6). For Ethernet PDU Session Type, the SMF does not allocate a MAC address or IP address to the UE for this PDU Session.

[0084] Step 9: The SMF can perform the SMF-Initiated SM Policy Association Modification procedure to provide information about the fulfilled policy control request trigger condition(s).

[0085] Step 10: The SMF initiates the N4 session establishment procedure towards the selected UPF(s), or the SMF initiates the N4 session modification procedure towards the selected UPF(s).

[0086] Step 11: (SMF to AMF): Namf_Communication_N1N2MessageTransfer (PDU Session ID, N2 SM Information (PDU Session ID, QFI(s), QoS profile(s), CN (Core Network) tunnel information, S-NSSAI(s) in allowed NSSAI, Session-AMBR (Aggregate Maximum Bit Rate), PDU Session Type, User Plane Security Enforcement Information, UE Integrity Protection Maximum Data Rate, RSN, PDU Session Pair ID), N1 SM Container (PDU Session Establishment Accept ([ (one or more) QoS rules and QoS flow level QoS parameters required for (one or more) QoS flows associated with (one or more) QoS rules, if needed], Selected SSC mode, S-NSSAI(s), UE requested DNN, Allocated IPv4 address, Interface Identifier, Session-AMBR, Selected PDU Session Type, [Reflective QoS Timer] (if available), [(one or more) P-CSCF (Proxy-Call Session Control Function) address], [Control Plane Only Indicator], [Header Compression Configuration], [Always On PDU Session Authorization], [Small Data Rate Control Parameters], [Small Data Rate Control Status], [Service PLMN Rate Control], [(one or more) PVS FQDN (Provisioning Server Fully Qualified Domain Name) and / or (one or more) PVS IP address])). If multiple UPFs are used for the PDU session, the CN tunnel information contains the tunnel information related to the UPF(s) terminating N3.

[0087] Step 12: (AMF to (R)AN): N2 PDU Session Request (N2 SM Information, NAS message (PDU Session ID, N1 SM Container (PDU Session Establishment Accept)), [CN-Assisted RAN Parameter Adjustment]). If N2 SM Information is not included in Step 11, use N2 Downlink NAS Transport message instead.

[0088] In step 12, the AMF sends a NAS message to the (R)AN in the N2 PDU Session Request containing the PDU Session ID and PDU Session Establishment Accept for the UE received from the SMF and N2 SM information.

[0089] Step 13 ((R)AN to UE): The (R)AN can issue AN specific signaling exchange to the UE related to the information received from the SMF.

[0090] Step 14 ((R)AN to AMF): N2 PDU Session Response (PDU Session ID, Cause, N2 SM information (PDU Session ID, AN Tunnel Info, Accepted / Rejected QFI list, User Plane Enforcement Policy Notification)).

[0091] In an embodiment, the AN Tunnel Info corresponds to the access network address of the N3 tunnel the PDU Session is mapped to.

[0092] Step 15: (AMF to SMF): Nsmf_PDUSession_UpdateSMContext Request (SM Context ID, N2 SM information, Request Type).

[0093] In step 15, the AMF forwards the N2 SM information received from the (R)AN to the SMF.

[0094] Step 16a: The SMF initiates a N4 Session Modification procedure towards the UPF. The SMF provides the AN Tunnel Info and corresponding forwarding rules to the UPF.

[0095] Step 16b: The UPF provides a N4 Session Modification Response to the SMF.

[0096] Step 16c: If the Request Type indicated in step 3 is not "Emergency Request" or "Existing Emergency PDU Session" and if the SMF has not registered the PDU Session, the SMF registers for the given PDU Session towards the UDM by using Nudm_UECM_Registration (SUPI, DNN, S-NSSAI of HPLMN, PDU Session ID, SMF Identity, Serving Node PLMN ID, [NID]). Thus, the UDM stores the following information: SUPI, SMF Identity and associated DNN, S-NSSAI of HPLMN, PDU Session ID and serving network (PLMN ID, [NID]).

[0097] Step 17: (SMF to AMF): Nsmf_PDUSession_UpdateSMContext Response (Cause).

[0098] Step 18 [conditional] (SMF to AMF): Nsmf_PDUSession_SMContextStatusNotify (release).

[0099] If during this procedure, at any time after step 5, the PDU session establishment is not successful, the SMF informs the AMF by invoking Nsmf_PDUSession_SMContextStatusNotify (release). If allocated (e.g. IP address) and released the association with the PCF (if any), the SMF also releases any created N4 session(s) and releases any PDU session address(es). In this case, step 19 is skipped.

[0100] Step 19 (SMF to UE): In case of PDU session type IPv6 or IPv4v6, the SMF generates an IPv6 Router Advertisement and sends it to the UE. The SMF sends the IPv6 Router Advertisement through N4 and UPF.

[0101] Step 20: The SMF can initiate SM Policy Association Modification when the trigger for 5GS bridging information availability is met.

[0102] Step 21: If the PDU session establishment fails after step 4, the SMF performs the following operations: The SMF unsubscribes from the modification of the session management subscription data for the corresponding (SUPI, DNN, S-NSSAI of HPLMN) by using Nudm_SDM_Unsubscribe.

[0103] In an embodiment, the ATSSS rules provided to the UE can be expressed as: ATSSS rule no. xxx “Traffic descriptor: UDP traffic of Application 1”, “Steering mode: load balancing, QoS traffic 1 (over 3GPP NR) = 80%, QoS traffic 2 (over 3GPP NR) = 20%”, “Steering function: ATSSS-LL”.

[0104] wherein, xxx” refers to the number / index of the ATSSS rule. The ATSSS rule indicates / represents / means “use QoS flow 1 to transmit 20% of the UDP traffic of application 1, and use QoS flow 2 to transmit 80% of the UDP traffic of application 1 by using ATSSS-LL function”. In an embodiment, “QoS flow 1” and “QoS flow 2” in the ATSSS rule are the identities of QoS flow 1 and QoS flow 2. Since the QoS rules of QoS flow 1 and QoS flow 2 are associated with certain access nodes (e.g., RAN A or RAN B), the UE confirms which access node should be used to transmit the traffic.

[0105] In an embodiment, for MA PDU session establishment on two access nodes of the same access type: - When the network creates a QoS flow in the MA PDU session, the QoS flow is associated with the access node of the MA PDU session; and / or - The ATSSS rule includes the identity of the QoS flow associated with a specific access node to indicate the route / path to transmit UL traffic flows; and / or - The N4 rule includes the identity of the QoS flow associated with a specific access node to indicate the route / path to transmit DL traffic flows.

[0106] Figure 4 A schematic diagram related to a wireless terminal 40 according to embodiments of the present disclosure. The wireless terminal 40 can be a user equipment (UE), a mobile phone, a laptop computer, a tablet computer, an e-book, or a portable computer system, without limitation. The wireless terminal 40 can include a processor 400 (such as a microprocessor or an application specific integrated circuit (ASIC)), a storage unit 410, and a communication unit 420. The storage unit 410 can be any data storage device that stores program code 412, which is accessed and executed by the processor 400. Embodiments of the storage unit 410 include, but are not limited to, a subscriber identity module (SIM), a read-only memory (ROM), a flash memory, a random-access memory (RAM), a hard disk, and an optical data storage device. The communication unit 420 can be a transceiver and is configured to transmit and receive signals (e.g., messages or data packets) according to the processing result of the processor 400. In an embodiment, the communication unit 420 transmits and receives signals through at least one antenna 422 as shown. Figure 4

[0107] ​In an embodiment, the storage unit 410 and the program code 412 can be omitted, and the processor 400 can include a storage unit in which program code is stored.

[0108] The processor 400 can implement any of the steps in the exemplary embodiments on the wireless terminal 40, for example, by executing the program code 412.

[0109] The communication unit 420 can be a transceiver. Alternatively or in addition, the communication unit 420 can combine a transmission unit and a reception unit configured to transmit and receive signals to and from a wireless network node (e.g., a base station), respectively.

[0110] Figure 5A schematic diagram of a wireless network node 50 according to an embodiment of the disclosure is described. The wireless network node 50 can be a satellite, a base station (BS), a network entity, a Mobility Management Entity (MME), a Serving Gateway (S-GW), a Packet Data Network (PDN) Gateway (P-GW), a radio access network (RAN) node, a next generation RAN (NG-RAN) node, a gNB, an eNB, a gNB central unit (gNB-CU), a gNB distributed unit (gNB-DU), a data network, a core network, or a Radio Network Controller (RNC), without limitation. In addition, the wireless network node 50 can include (execute) at least one network function, such as an access and mobility management function (AMF), a session management function (SMF), a user place function (UPF), a policy control function (PCF), an application function (AF), and the like. The wireless network node 50 can include a processor 500 (e.g., a microprocessor or an ASIC), a storage unit 510, and a communication unit 520. The storage unit 510 can be any data storage device storing program code 512, which is accessed and executed by the processor 500. Examples of the storage unit 510 include, but are not limited to, a SIM, a ROM, a flash memory, a RAM, a hard disk, and an optical data storage device. The communication unit 520 can be a transceiver and is configured to transmit and receive a signal (e.g., a message or a packet) according to a processing result of the processor 500. For example, the communication unit 520 transmits and receives a signal through at least one antenna 522 as shown. Figure 5

[0111] In an embodiment, the storage unit 510 and the program code 512 can be omitted. The processor 500 can include a storage unit in which the program code is stored.

[0112] The processor 500 can implement any steps described in the exemplary embodiments on the wireless network node 50, for example, by executing the program code 512.

[0113] ​The communication unit 520 can be a transceiver. Alternatively or in addition, the communication unit 520 can combine a transmission unit and a reception unit configured to respectively transmit and receive signals to and from a wireless terminal (e.g. a user equipment or another wireless network node).

[0114] In this disclosure, a wireless device that contains network function(s) (e.g. SMF, AMF and / or PCF and / or SMF) refers to a (wireless) device that performs at least part of the functions of the network function.

[0115] Figure 6 A flowchart of a method according to embodiments of the disclosure is shown. Figure 6 The method shown in Fig. 6 can be used for a SMF (e.g. a wireless device or a wireless device comprising a SMF) and comprises the following steps.

[0116] Step 601 : Receiving PCC rule(s) from a PCF, the PCC rule(s) comprising an association between each QoS flow of a Multiple Access Protocol Data Unit (MA PDU) session and one of a plurality of accesses of the MA PDU session.

[0117] Step 602: Transmitting at least one rule to at least one wireless device, the at least one rule comprising at least one QoS flow of a MA PDU session and being determined based on the PCC rule(s).

[0118] In Figure 6 In Fig. 6, the SMF receives PCC rule(s) from a PCF, wherein the received PCC rule(s) comprise an association between each QoS flow of a Multiple Access Protocol Data Unit (MA PDU) session and one of a plurality of accesses of the MA PDU session. That is, a QoS flow is associated with an access of the MA PDU session. In an embodiment, an access can refer to a corresponding access node or access network. Based on the association in the PCC rule(s), the SMF generates / determines at least one rule, the at least one rule comprising or referring to the QoS flow(s) of the MA PDU session. The generated / determined rule(s) are transmitted from the SMF to a corresponding wireless device.

[0119] In an embodiment, the generated / determined rule(s) are / comprise ATSSS rule(s). In this embodiment, the ATSSS rule(s) are transmitted to a wireless terminal (e.g. a UE).

[0120] In an embodiment, the generated / determined rule(s) are / include N4 rule(s). In this embodiment, the N4 rule(s) are transmitted to a UPF (e.g., a wireless device comprising the UPF).

[0121] In an embodiment, at least two accesses of the plurality of accesses have a same access type and / or a same RAT type. For example, at least two accesses of the plurality of accesses are of a 3GPP access type and / or have a RAT type of “NR”. Note that, Figure 3 The embodiment shown in FIG. 6 illustrates an example of a MA PDU session with / supporting dual (3GPP) accesses. This MA PDU session can support two or more (3GPP) accesses.

[0122] In an embodiment, the SMF transmits, to a PCF, a session management policy control creation message for a MA PDU session, wherein the session management policy control creation message indicates at least one access type and / or at least one RAT type of a plurality of accesses. Based on the indication, the PCF is able to determine an association between a QoS flow of the MA PDU and an access (e.g., an access node or an access network).

[0123] In an embodiment, the SMF receives, from an AMF, a session management context creation message for a MA PDU session, wherein the session management context creation message comprises information associated with a plurality of accesses. For example, the information associated with the plurality of accesses comprises at least one of: - an indication of whether a wireless terminal of the MA PDU session is registered for at least two accesses of the plurality of accesses; - an access type of each access for which the UE is registered, or - a RAT type of each access for which the UE is registered.

[0124] Figure 7 A flowchart of a method according to embodiments of the disclosure is shown. Figure 7 The method shown in FIG. 6 can be used by a PCF (e.g., a wireless device or a wireless device comprising the PCF), and comprises: Step 701: transmitting, to a SMF, PCC rule(s) comprising an association between each QoS flow of a MA PDU session and one access of a plurality of accesses of the MA PDU session.

[0125] In Figure 7In an embodiment, the PCF transmits the PCC rule(s) to the SMF. The transmitted PCC rule(s) include an association between each QoS flow of the MA PDU session and one of the multiple accesses of the MA PDU session. Based on the transmitted PCC rule(s) (association), the SMF is able to generate / determine a rule that indicates a route / path to transmit traffic of the MA PDU session.

[0126] In an embodiment, at least two of the multiple accesses have a same access type and / or a same RAT type. For example, at least two of the multiple accesses are of a 3GPP access type and / or have a RAT type "NR". Note that, Figure 3 The embodiment shown in the figure illustrates an example of a MA PDU session with / supporting dual (3GPP) accesses. The MA PDU session can support two or more (3GPP) accesses.

[0127] In an embodiment, the PCF receives a session management policy control creation message for a MA PDU session. The session management policy control creation message includes an indication of at least one access type and / or at least one RAT type of the multiple accesses.

[0128] Figure 8 A flowchart of a method according to an embodiment of the disclosure is shown. Figure 8 The method shown in the figure can be used by an AMF (e.g., a wireless device or a wireless device comprising the AMF), and comprises: Step 801 : transmitting, to a SMF, a session management context creation message for a MA PDU session, wherein the session management context creation message includes information associated with multiple accesses of the MA PDU session.

[0129] In Figure 8 In an embodiment, the AMF transmits, to a SMF, a session management context creation message for a MA PDU session. The session management context creation message includes information associated with multiple accesses of the MA PDU session.

[0130] In an embodiment, the information associated with the multiple accesses includes at least one of: - an indication whether a wireless terminal (e.g., a UE) of the MA PDU session is registered for at least two of the multiple accesses; - an access type of each access the UE is registered for, or - a radio access technology (RAT) type of each access the UE is registered for.

[0131] In an embodiment, the AMF receives a setup request for a MA PDU session from a wireless terminal for a MA PDU session. The setup request includes an indication that the MA PDU session is supported over multiple accesses that have a same access type and / or a same RAT type. For example, the setup request can indicate or include an indication of "dual access" (see Figure 3

[0132] Figure 9 A flowchart of a method according to embodiments of the disclosure is shown. Figure 9 The method shown in Step 901 : receiving at least one ATSSS rule from the SMF, the at least one ATSSS rule including at least one QoS flow of the MA PDU session and being determined based on PCC rules including an association between each QoS flow of the MA PDU session and one of the multiple accesses for the MA PDU session.

[0133] Step 902: selecting at least one QoS flow for transmission of uplink traffic for the MA PDU session based on the at least one ATSSS rule.

[0134] In Figure 9 , the wireless terminal receives at least one ATSSS rule from the SMF, the at least one ATSSS rule including at least one QoS flow of the MA PDU session. The ATSSS rule(s) are determined based on an association between each QoS flow of the MA PDU session and one of the multiple accesses for the MA PDU session (included in the PCC rules). For example, the ATSSS rule(s) include an identification of a QoS flow associated with a particular access node (such as an access or an access network) to indicate a route / path for transmission of UL traffic for the MA PDU session. Based on the received ATSSS rule(s), the UE selects at least one QoS flow for transmission of UL traffic for the MA PDU session.

[0135] In an embodiment, at least two of the multiple accesses have a same access type and / or a same RAT type. For example, at least two of the multiple accesses are of a 3GPP access type and / or have a RAT type "NR". Note that Figure 3 The embodiment shown in

[0136] In an embodiment, the access(es) refer to access node(s) or access network(s).​

[0137] In an embodiment, the wireless terminal transmits to the AMF a request for establishment of a MAPDU session. The request for establishment includes an indication that the MAPDU session is supported over multiple accesses having the same access type and / or the same RAT type. For example, the request for establishment includes an indication of "dual (3GPP) access."

[0138] While various embodiments of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not limitation. Likewise, the various figures can depict example architectures or configurations, which can be employed, as appropriate, to embody an example feature of the present disclosure. It will be appreciated that a person of ordinary skill in the art will be able to devise other ways to implement the present disclosure from this description, and thus the breadth and scope of the present disclosure should not be limited by any of the above described example embodiments.

[0139] It also should be understood that any reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." In other words, unless specified otherwise, the recitation "at least one" of a particular element means "one or more" of the element. In addition, it should be understood that references to

[0140] Furthermore, those of ordinary skill in the art will appreciate that the functions of the various elements that have been described can be carried out by either analog or digital circuits, by a processor (whether programmed or microengine), or by any combination of these. It is therefore, contemplated to be within the scope of the claims to carry out the present disclosure in a process or a machine comprising a processor, as either

[0141] Those of skill would further appreciate that any of the various illustrative logical blocks, units, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a number of logic elements, such as a digital implementation, an analog implementation, or a combination of the two), firmware, various forms of program or design code incorporating routines (e.g., those listed in the flow charts above), or any combination thereof. Those of skill would further recognize that when the various elements are implemented in software, the software can be implemented to include but is not limited to: a plurality of code sections being organized into routines, programs, functions, methods, procedures, modules, software packages, or the like.

[0142] To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, units, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination thereof, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, unit, etc. can be configured to perform one or more of the functions described herein. As used herein, the terminology “configured to”, “configured for” or “adapted to” with reference to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. physically constructed, programmed or arranged such that it can perform the specified operation or function.

[0143] Further, those skilled in the art will appreciate that the various illustrative logical blocks, units, devices, components, and circuits described herein can be implemented within or performed by an integrated circuit (IC), which can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or a combination of these or any other suitable components. The logical blocks, units, and circuits can also include antennas and / or transceivers to communicate with various components within a network or within a device. The general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. The processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The functionality of these components, if implemented in software, can be stored on one or more computer readable mediums. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer readable medium. Such software can include, but is not limited to, firmware, resident software, microcode, etc.

[0144] Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program or code from one place to another. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM (Electrically Erasable Programmable Read-Only Memory), compact disk (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Computer program or programs can be implemented in a high-level procedural or object-oriented programming language to operate in conjunction with a computer's operating system.

[0145] In this document, the term "unit" as used herein, refers to a software, firmware, hardware, and any combination of these elements for performing the related function descnbed herein. Furthermore, each unit can be implemented as software, firmware, hardware or any combination thereof. In addition, for the purposes of this document, a "computer" is meant to include any processor-based or digital processing device.

[0146] In addition, memory or other storage devices, and communication components can be used in embodiments of the present disclosure. It will be appreciated that, for clarity, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains can be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic elements or controllers can be performed by the same processing logic element or controller. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0147] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the scope of the claims. Thus, the present disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication for a session management function, the method comprising: receiving policy and charging control (PCC) rules from a policy control function (PCF), the PCC rules comprising an association between each QoS flow of a multi-access protocol data unit (MAPDU) session and one of multiple accesses of the MAPDU session, and transmitting at least one rule to at least one wireless device, the at least one rule comprising at least one QoS flow of the MAPDU session and being determined based on the PCC rules.

2. The wireless communication method according to claim 1, wherein, the at least one rule comprises at least one access traffic steering, switching, and splitting (ATSSS) rule, and wherein transmitting the at least one rule to the at least one wireless device, the at least one rule comprising at least one QoS flow of the MAPDU session and being determined based on the PCC rules, comprises: transmitting the at least one ATSSS rule to a wireless terminal.

3. The wireless communication method according to claim 1 or 2, wherein, the at least one rule comprises at least one N4 rule, and wherein transmitting the at least one rule to the at least one wireless device, the at least one rule comprising at least one QoS flow of the MAPDU session and being determined based on the PCC rules, comprises: transmitting the at least one N4 rule to a user plane function (UPF).

4. The wireless communication method according to any one of claims 1 to 3, wherein, at least two of the multiple accesses have a same access type and / or a same radio access technology (RAT) type.

5. The wireless communication method according to any one of claims 1 to 4, wherein, the association between each QoS flow of the MAPDU session and one of the multiple accesses of the MAPDU session comprises an association between each QoS flow of the MAPDU session and an access node of one of the multiple accesses of the MAPDU session.

6. The method of wireless communication of any one of claims 1-5, further comprising: transmitting, to the PCF, a session management policy control creation message for a MAPDU session, wherein the session management policy control creation message indicates at least one access type and / or at least one RAT type of the multiple accesses.

7. The method of wireless communication of claim 6, further comprising: receiving, from an access and mobility management function (AMF), a session management context creation message for the MAPDU session, wherein the session management context creation message comprises information associated with the multiple accesses.

8. The wireless communication method according to claim 7, wherein the information associated with the multiple accesses comprises at least one of: an indication of whether a wireless terminal of the MAPDU session is registered with at least two of the multiple accesses; an access type of each access with which the UE is registered, or a radio access technology (RAT) type of each access with which the UE is registered.

9. A method of wireless communication for a policy control function (PCF), the method comprising: transmitting policy and charging control (PCC) rules to a session management function (SMF), the PCC rules comprising an association between each quality of service (QoS) flow of a multi-access protocol data unit (MA PDU) session and one of multiple accesses of the MA PDU session.

10. The wireless communication method according to claim 9, wherein, At least two of the multiple accesses have a same access type and / or a same radio access technology (RAT) type.

11. The wireless communication method according to claim 9 or 10, wherein, The association between each QoS flow of the MA PDU session and one of the multiple accesses of the MA PDU session comprises an association between each QoS flow of the MA PDU session and an access node of one of the multiple accesses of the MA PDU session.

12. The wireless communication method of any one of claims 9-11, further comprising: receiving a session management policy control creation message for a MA PDU session from an SMF, wherein the session management policy control creation message indicates at least one access type and / or at least one RAT type of the multiple accesses.

13. A wireless communication method for an access and mobility management function (AMF), the method comprising: transmitting a session management context creation message for a multi-access protocol data unit (MA PDU) session to a session management function, wherein the session management context creation message comprises information associated with multiple accesses of the MA PDU session.

14. The wireless communication method of claim 13, wherein, The information associated with the multiple accesses comprises at least one of: an indication of whether a wireless terminal of the MA PDU session is registered for at least two of the multiple accesses; an access type of each access for which the UE is registered, or a radio access technology (RAT) type of each access for which the UE is registered.

15. The wireless communication method of claim 13 or 14, further comprising: receiving a setup request for the MA PDU session from a wireless terminal of the MA-PDU session, wherein the setup request comprises an indication that the MA PDU session is supported over multiple accesses having a same access type and / or a same radio access technology (RAT) type.

16. A wireless communication method for a wireless terminal, the method comprising: receiving at least one access traffic steering, switching, and splitting (ATSSS) rule from a session management function (SMF), the at least one ATSSS rule comprising at least one quality of service (QoS) flow of a multi-access protocol data unit (MA PDU) session and being determined based on policy and charging control (PCC) rules comprising an association between each QoS flow of the MA PDU session and one of multiple accesses of the MA PDU session, and selecting at least one QoS flow for transmitting uplink traffic of the MA PDU session based on the at least one ATSSS rule.

17. The wireless communication method of claim 16, wherein, At least two of the plurality of accesses have a same access type and / or a same radio access technology (RAT) type.

18. The wireless communication method according to claim 16 or 17, wherein, The association between each QoS flow of the MA PDU session and one of the plurality of accesses of the MA PDU session comprises an association between each QoS flow of the MA PDU session and an access node of one of the plurality of accesses of the MA PDU session.

19. The wireless communication method according to any one of claims 16 to 18, further comprising: transmitting, to an access and mobility management function, a setup request for the MA PDU session, wherein the setup request comprises an indication about supporting the MA PDU session through a plurality of accesses having a same access type and / or a same radio access technology (RAT) type.

20. A wireless device comprising: a communication unit configured to: receive, from a policy control function (PCF), policy and charging control (PCC) rules comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of a plurality of accesses of the MA PDU session, and transmit, to at least one wireless device, at least one rule comprising at least one QoS flow of the MA PDU session and determined based on the PCC rules.

21. The wireless device of claim 20, further comprising: a processor configured to perform the wireless communication method according to any one of claims 2 to 8.

22. A wireless device comprising: a communication unit configured to transmit, to a session management function (SMF), policy and charging control (PCC) rules comprising an association between each QoS flow of a multi-access protocol data unit (MA PDU) session and one of a plurality of accesses of the MA PDU session.

23. The wireless communication method of claim 22, further comprising: a processor configured to perform the wireless communication method according to any one of claims 10 to 12.

24. A wireless device comprising: a communication unit configured to transmit, to a session management function, a session management context creation message for a multi-access protocol data unit (MA PDU) session, wherein the session management context creation message comprises information associated with a plurality of accesses of the MA PDU session.

25. The wireless communication method of claim 24, further comprising: a processor configured to perform the wireless communication method according to claim 14 or 15.

26. A wireless terminal comprising: a communication unit configured to receive, from a session management function (SMF), at least one access traffic steering, switching, and splitting (ATSSS) rule comprising at least one quality of service (QoS) flow of a multi-access protocol data unit (MA PDU) session and determined based on policy and charging control (PCC) rules comprising an association between each QoS flow of the MA PDU session and one of a plurality of accesses of the MA PDU session; and a processor configured to select, based on the at least one ATSSS rule, at least one QoS flow for transmission of uplink traffic for the MAP PDU session.

27. The wireless terminal of claim 26, wherein, The processor is further configured to perform the wireless communication method according to any one of claims 17-19.

28. A computer program product comprising a computer readable program medium, code stored on the computer readable program medium, the code, when executed by a processor, causing the processor to implement the wireless communication method according to any one of claims 1-19.

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