SYSTEM AND METHODS FOR FLOW MOBILITY CONTROL
TECHNICAL FIELD
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This document is directed generally to wireless communications and in particular to 5G communications.
BACKGROUND
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In the existing art, the term “ATSSS” refers to access traffic steering, switching and splitting. This feature can be supported by a UE (user equipment) and a 5GC (5G Core) network enabling a multi-access PDU (protocol data unit) connectivity service, which can exchange PDUs between the UE and a data network by simultaneously using one 3GPP (3rd generation partner project) access network and one non-3GPP access network and two independent N3/N9 tunnels between a PSA (PDU session anchor) and a RAN/AN (radio access network/access network) . The multi-access PDU connectivity service is realized by establishing a multi-access PDU (MA PDU) session, i.e., a PDU session that may have user-plane resources on two access networks.
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The UE may request an MA PDU session when the UE is registered via both the 3GPP and non-3GPP accesses or when the UE is registered via one access only.
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After an establishment of the MA PDU session and when there are user-plane resources on both access networks, the UE applies network-provided policy (i.e., ATSSS rules) and considers local conditions (such as network interface availability, signal loss conditions, user preferences, etc. ) for deciding how to distribute uplink traffic across the two access networks. Similarly, the UPF (user plane function) anchor of the MA PDU session applies network-provided policy (i.e., N4 rules) and feedback information received from the UE via the user-plane (e.g., access network unavailability or availability) for deciding how to distribute downlink traffic across the two N3/N9 tunnels and two access networks. When there are user-plane resources on only one access network, the UE applies the ATSSS rules and considers local conditions for triggering the establishment or activation of the user plane resources over another access. The type of the MA PDU Session may be one of the following types: IPv4, IPv6, IPv4v6, and Ethernet.
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FIG. 1 shows an architecture with ATSSS support in the existing 5GS (5G system) . In FIG. 1:
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- The UE supports one or more of the steering functionalities, e.g., MPTCP functionality and/or ATSSS-LL functionality. Each steering functionality in the UE enables traffic steering, switching and splitting across 3GPP access and non-3GPP access, in accordance with the ATSSS rules provided by the network. The ATSSS-LL functionality is mandatory in the UE for MA PDU session of type Ethernet.
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- The UPF may support MPTCP Proxy functionality, which communicates with the MPTCP functionality in the UE by using the MPTCP protocol (see IETF RFC 8684) .
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- The UPF may support ATSSS-LL functionality, which is similar to the ATSSS-LL functionality defined for the UE. There is no user plane protocol defined between the ATSSS-LL functionality in the UE and the ATSSS-LL functionality in the UPF. The ATSSS-LL functionality in the UPF is not shown in FIG. 1.
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- In addition, the UPF supports Performance Measurement Functionality (PMF) , which may be used by the UE to obtain access performance measurements over the user-plane of 3GPP access and/or over the user-plane of non-3GPP access.
SUMMARY
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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 accesses networks.
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The present disclosure relates to a wireless communication method for use in a session management function. The method comprises:
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receiving, 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
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transmitting, to at least one wireless device, at least one rule which comprises at least one QoS flow of the MA PDU session and is determined based on the PCC rules.
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Various embodiments may preferably implement the following features:
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Preferably, the at least one rule comprises at least one access traffic steering, switching and splitting (ATSSS) rule.
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Preferably, transmitting, to the at least one wireless device, the at least one rule which comprises at least one QoS flow of the MA PDU session and is determined based on the PCC rules comprises: transmitting, to a wireless terminal, the at least one ATSSS rule.
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Preferably, the at least one rule comprises at least one N4 rule.
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Preferably, transmitting, to the at least one wireless device, the at least one rule which comprises at least one QoS flow of the MA PDU session and is determined based on the PCC rules comprises: transmitting, to a user plane function (UPF) , the at least one N4 rule.
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Preferably, at least two accesses in the plurality of accesses have the same access type and/or the same radio access technology (RAT) type.
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Preferably, 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.
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Preferably, the wireless communication method further comprises: transmitting, to the PCF, a session management policy control create message for the MA PDU session, wherein the session management policy control create message indicates at least one access type and/or at least one RAT type of the plurality of accesses.
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Preferably, the wireless communication method further comprises: receiving, from an access and mobility management function (AMF) , a session management context create message for the MA PDU session, wherein the session management context create message comprises information associated with the plurality of accesses.
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Preferably, 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 registers over at least two of the plurality of accesses, an access type of each access over which the UE registers, or a radio access technology (RAT) type of each access over which the UE registers.
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The present disclosure relates to a wireless communication method for use in a policy control function (PCF) . The method comprises transmitting, to a session management function (SMF) , policy and charging control (PCC) rules comprising an association between each QoS (quality of service) flow of a multi-access protocol data unit (MA PDU) session and one of a plurality of accesses of the MA PDU session.
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Various embodiments may preferably implement the following features:
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Preferably, at least two accesses in the plurality of accesses have the same access type and/or the same radio access technology (RAT) type.
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Preferably, the association between each QoS flow of the MA PDU session and one of the plurality of accesses of the MA PDU session comprises associations 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.
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Preferably, the wireless communication method further comprises: receiving, from the SMF, a session management policy control create message for the MA PDU session, wherein the session management policy control create message indicates at least one access type and/or at least one RAT type of the plurality of accesses.
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The present disclosure relates to a wireless communication method for use in an access and mobility management function (AMF) . The method comprises:
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transmitting, to a session management function, a session management context create message for a multi-access protocol data unit (MA PDU) session, wherein the session management context create message comprises information associated with a plurality of accesses of the MA PDU session.
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Various embodiments may preferably implement the following features:
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Preferably, 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 registers over at least two of the plurality of accesses, an access type of each access over which the UE registers, or a radio access technology (RAT) type of each access over which the UE registers.
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Preferably, the wireless communication method further comprises receiving, from a wireless terminal of the MA-PDU session, an establishment request for the MA PDU session, wherein the establishment request comprises an indication of supporting an MA PDU session via a plurality of accesses having the same access type and/or the same radio access technology (RAT) type.
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The present disclosure relates to a wireless communication method for use in a wireless terminal. The method comprises:
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receiving, from a session management function (SMF) , at least one access traffic steering, switching and splitting (ATSSS) rule which comprises at least one quality of service (QoS) flow of a multi access protocol data unit (MA PDU) session and is 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
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selecting at least one QoS flow for transmitting uplink traffic of the MA PDU session based on the at least one ATSSS rule.
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Various embodiments may preferably implement the following features:
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Preferably, at least two accesses in the plurality of accesses have the same access type and/or the same radio access technology (RAT) type.
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Preferably, 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.
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Preferably, the wireless communication method further comprises transmitting, to an access and mobility management function, an establishment request for the MA PDU session, wherein the establishment request comprises an indication of supporting an MA PDU session via a plurality of accesses having the same access type and/or the same radio access technology (RAT) type.
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The present disclosure relates to a wireless device. The wireless device comprises:
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a communication unit, configured to:
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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
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transmit, to at least one wireless device, at least one rule which comprises at least one QoS flow of the MA PDU session and is determined based on the PCC rules.
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Various embodiments may preferably implement the following features:
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Preferably, the wireless device comprises a session management function.
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Preferably, the wireless device further comprises a processor configured to perform the
wireless communication method of any of aforementioned wireless communication methods.
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The present disclosure relates to a wireless device. The wireless device comprises:
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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.
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Various embodiments may preferably implement the following features:
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Preferably, the wireless device comprises a policy control function.
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Preferably, the wireless device further comprises a processor configured to perform the wireless communication method of any of aforementioned wireless communication methods.
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The present disclosure relates to a wireless device. The wireless device comprises:
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a communication unit, configured to transmit, to a session management function, a session management context create message for a multi-access protocol data unit (MA PDU) session, wherein the session management context create message comprises information associated with a plurality of accesses of the MA PDU session.
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Various embodiments may preferably implement the following features:
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Preferably, the wireless device comprises an access and mobility management function.
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Preferably, the wireless device further comprises a processor configured to perform the wireless communication method of any of aforementioned wireless communication methods.
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The present disclosure relates to a wireless terminal. The wireless terminal comprises:
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a communication unit, configured to receive, from a session management function (SMF) , at least one access traffic steering, switching and splitting (ATSSS) rule which comprises at least one quality of service (QoS) flow of a multi access protocol data unit (MA PDU) session and is 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
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a processor configured to select at least one QoS flow for transmitting uplink traffic of
the MA PDU session based on the at least one ATSSS rule.
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Various embodiments may preferably implement the following feature:
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Preferably, the processor is further configured to perform any of aforementioned wireless communication methods.
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The present disclosure relates to a computer program product comprising a computer-readable program medium code stored thereupon, the code, when executed by a processor, causing the processor to implement a wireless communication method recited in any one of foregoing methods.
BRIEF DESCRIPTION OF THE DRAWINGS
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The exemplary embodiments disclosed herein are directed to providing features that will become readily apparent by reference to the following description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the present disclosure.
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Thus, 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 acts in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented unless expressly stated otherwise.
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The invention is specified by the independent claims. Preferred embodiments are defined in the dependent claims. In the following description, although numerous features may be designated as optional, it is nevertheless acknowledged that all features comprised in the independent claims are not to be read as optional.
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The above and other aspects and their implementations are described in greater detail in
the drawings, the descriptions, and the claims.
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FIG. 1 shows a schematic diagram of a network (architecture) .
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FIG. 2 shows a schematic diagram of a network (architecture) according to an embodiment of the present disclosure.
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FIG. 3 shows a schematic diagram of a procedure according to an embodiment of the present disclosure.
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FIG. 4 shows an example of a schematic diagram of a wireless terminal according to an embodiment of the present disclosure.
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FIG. 5 shows an example of a schematic diagram of a wireless network node according to an embodiment of the present disclosure.
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FIG. 6 shows a flowchart of a method according to an embodiment of the present disclosure.
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FIG. 7 shows a flowchart of a method according to an embodiment of the present disclosure.
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FIG. 8 shows a flowchart of a method according to an embodiment of the present disclosure.
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FIG. 9 shows a flowchart of a method according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
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In an embodiment, the 5G QoS (quality of service) model for the Single-Access PDU Session is also applied to the MA PDU Session, i.e. the QoS Flow is the finest granularity of QoS differentiation in the MA PDU Session. One difference compared to the Single-Access PDU Session is that, in a MA PDU Session, there can be separate user-plane tunnels between the AN and the PSA, wherein each tunnel is associated with a different access. However, the QoS Flow is not associated with specific access (i.e., the QoS flow is access agnostic) , so the same QoS is supported when the traffic is distributed over 3GPP and non-3GPP accesses. The SMF provides the same QFI (QoS flow identifier) in the 3GPP and the non-3GPP accesses, so that the same QoS is supported in both accesses.
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In an embodiment, a QoS Flow of the MA PDU Session may be either Non-GBR or GBR depending on the corresponding QoS profile.
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In an embodiment, the ATSS rule is used by the UE to determine the path to transmit corresponding uplink traffic. For example, information "Access Selection Descriptor" is set with access type (i.e., "3GPP access" or "non-3GPP access" ) to indicate over which path the uplink traffic to be transmitted. However, in an embodiment of the MA-PDU session using two or more 3GPP accesses, the ATSSS rule (e.g., "Access Selection Descriptor" ) cannot show differences between the paths using the two or more 3GPP accesses because the ATSSS rules related to the paths using the 3GPP accesses only that the access type is the 3GPP access type.
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FIG. 2 shows a schematic diagram of a network (architecture) according to an embodiment of the present disclosure. In FIG. 2, a UE (user equipment) registers to the network (e.g., network functions shown in FIG. 2 comprising AMF (access and mobility management function) , SMF (session management function) , PCF (policy control function) and UPF (user plane function) ) via two access nodes RAN A and RAN B. In an embodiment, the RAN A and the 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) ) .
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FIG. 3 shows a schematic diagram of a procedure according to an embodiment of the present disclosure. The procedure shown in FIG. 3 is for a MA (multi-access) PDU (protocol data unit) session establishment. Specifically, the procedure comprises the following steps.
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Step 1: The UE transmits NAS Message (S-NSSAI (s) (Single Network Slice Selection Assistance Information) , UE Requested DNN (data network name) , PDU Session ID (identifier) , Request type, Old PDU Session ID, N1 SM container (PDU Session Establishment Request, [Port Management Information Container] ) ) to the AMF.
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In order to establish a new PDU Session, the UE generates a new PDU Session ID.
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The UE initiates the UE Requested PDU Session Establishment procedure shown in FIG. 3 by the transmission of a UL (uplink) NAS (non-access stratum) Transport message containing a PDU Session Establishment Request within the N1 SM (session management) container. The PDU Session Establishment Request includes a PDU session ID, Requested PDU Session Type, a Requested SSC (Session and Service Continuity) mode, 5GSM Capability, PCO, SM PDU DN Request Container, [Number Of Packet Filters] , [Header Compression Configuration] , UE Integrity
Protection Maximum Data Rate, [Always-on PDU Session Requested] , [RSN] and [PDU Session Pair ID] .
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In an embodiment, the UE provides the Request Type as "MA PDU Request" and "capability related to dual access" in the UL NAS Transport message. In an embodiment, the "capability related to dual access" is interpreted as or indicates that the UE supports MA PDU session via dual 3GPP access.
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Step 2: The AMF selects an SMF which supports MA PDU sessions via dual 3GPP access.
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Step 3: (From AMF to SMF) : In Nsmf_PDUSession_CreateSMContext Request message, the AMF informs the SMF that the request is for a MA PDU Session by including "MA PDU Request" indication. In addition, the AMF indicates SMF whether the UE is registered over both accesses and the RAT type of each access.
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Step 4: If Session Management Subscription data for 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) may get 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] ) and may subscribe to notifications from the UDR for the same data by using Nudr_DM_subscribe.
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Step 5 (From SMF to AMF) : Either Nsmf_PDUSession_CreateSMContext Response (Cause, SM Context ID or N1 SM container (PDU Session Reject (Cause) ) ) or an Nsmf_PDUSession_UpdateSMContext Response is transmitted from the SMF to the AMF based on the request received in step 3.
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Step 6 (Optional) : Secondary authentication/authorization.
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Step 7a: If dynamic PCC (policy control and charging) is to be used for the PDU Session, the SMF performs a PCF selection. Otherwise, the SMF may apply local policy.
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Step 7b: The SMF may perform an SM Policy Association Establishment procedure, to establish an SM Policy Association with the PCF and get the default PCC Rules for the PDU Session.
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In an embodiment, the SMF sends an "MA PDU Request" indication to the PCF in the SM Policy Control Create message and the ATSSS Capabilities (including capability related to dual access) of the MA PDU session. The SMF provides the currently used Access Type (s) and RAT Type (s) to the PCF. The PCF decides whether the MA PDU session is allowed or not based on operator policy and the subscription data. The PCF associates related QoS flows with current access node and related QoS flows with the other access node.
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In an embodiment, the PCF provides PCC rules that include MA PDU session control information. Based on the received PCC rules, the SMF derives:
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(a) ATSSS rule (s) , which will be sent to the UE for controlling the traffic steering, switching and splitting in the uplink direction, and
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(b) N4 rules, which will be sent to the UPF for controlling the traffic steering, switching and splitting in the downlink direction.
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In an embodiment, the SMF may also derive the Measurement Assistance Information. In the ATSSS rules, the identity of the QoS flow for specific access node is used to indicate the route/path on which the UL traffic flow is transmitted. In the N4 rules, the identity of the QoS flow for specific access node is used to indicate the route/path on which the DL traffic flow is transmitted.
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Step 8: The SMF selects an SSC mode for the PDU Session. The SMF also selects one or more UPFs as needed. In the case of the PDU Session Type IPv4 or IPv6 or IPv4v6, the SMF allocates an IP address/prefix for the PDU Session (unless configured otherwise) . In the case of the PDU Session Type IPv6 or IPv4v6, the SMF also allocates an interface identifier to the UE, for allowing the UE to build its link-local address. For Unstructured PDU Session Type, the SMF may allocate an IPv6 prefix for the PDU Session and N6 point-to-point tunnelling (based on UDP/IPv6) . For Ethernet PDU Session Type, neither a MAC nor an IP address is allocated by the SMF to the UE for this PDU Session.
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Step 9: The SMF may perform an SMF initiated SM Policy Association Modification procedure, to provide information on the Policy Control Request Trigger condition (s) that have been met.
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Step 10: The SMF initiates an N4 Session Establishment procedure with the selected UPF (s) , otherwise the SMF initiates an N4 Session Modification procedure with the selected UPF (s) .
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Step 11: (SMF to AMF) : Namf_Communication_N1N2MessageTransfer (PDU Session ID, N2 SM information (PDU Session ID, QFI (s) , QoS Profile (s) , CN Tunnel Info, S-NSSAI from the Allowed NSSAI, Session-AMBR, 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 ( [QoS Rule (s) and QoS Flow level QoS parameters if needed for the QoS Flow (s) associated with the QoS rule (s) , and the RAT type with which the QoS flow (s) associated] , 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) , [P-CSCF address (es) ] , [Control Plane Only indicator] , [Header Compression Configuration] , [Always-on PDU Session Granted] , [Small Data Rate Control parameters] , [Small Data Rate Control Status] , [Serving PLMN Rate Control] , [PVS FQDN (s) and/or PVS IP address (es) ] ) ) ) . If multiple UPFs are used for the PDU Session, the CN Tunnel Info contains tunnel information related with the UPFs that terminate N3.
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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 parameters tuning] ) . If the N2 SM information is not included in step 11, an N2 Downlink NAS Transport message is used instead.
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In step 12, the AMF sends, to the (R) AN, the NAS message containing PDU Session ID and PDU Session Establishment Accept targeted to the UE and the N2 SM information received from the SMF within the N2 PDU Session Request.
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Step 13 ( (R) AN to UE) : The (R) AN may issue AN specific signaling exchange with the UE that is related with the information received from the SMF.
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Step 14 ( (R) AN to AMF) : N2 PDU Session Response (PDU Session ID, Cause, N2 SM information (PDU Session ID, AN Tunnel Info, List of accepted/rejected QFI (s) , User Plane Enforcement Policy Notification) ) .
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In an embodiment, the AN Tunnel Info corresponds to the Access Network address of the N3 tunnel corresponding to the PDU Session.
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Step 15: (AMF to SMF) : Nsmf_PDUSession_UpdateSMContext Request (SM Context ID, N2 SM information, Request Type) .
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In step 15, the AMF forwards the N2 SM information received from (R) AN to the SMF.
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Step 16a: The SMF initiates an N4 Session Modification procedure with the UPF. The SMF provides AN Tunnel Info to the UPF as well as the corresponding forwarding rules.
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Step 16b: The UPF provides an N4 Session Modification Response to the SMF.
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Step 16c: If the Request Type in step 3 indicates neither "Emergency Request" nor "Existing Emergency PDU Session" and if the SMF has not yet registered for this PDU Session, the SMF registers with the UDM by using Nudm_UECM_Registration (SUPI, DNN, S-NSSAI of HPLMN, PDU Session ID, SMF Identity, Serving Node PLMN ID, [NID] ) for a given PDU Session. As a result, the UDM stores the following information: SUPI, SMF identity and the associated DNN, S-NSSAI of HPLMN, PDU Session ID and Serving Network (PLMN ID, [NID] ) .
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Step 17: (SMF to AMF) : Nsmf_PDUSession_UpdateSMContext Response (Cause) .
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Step 18 [Conditional] (SMF to AMF) : Nsmf_PDUSession_SMContextStatusNotify (Release) .
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If during the procedure, any time after step 5, the PDU Session establishment is not successful, the SMF informs the AMF by invoking Nsmf_PDUSession_SMContextStatusNotify (Release) . The SMF also releases any N4 session (s) created and any PDU Session address if allocated (e.g., IP address) and releases the association with the PCF, if any. In this case, step 19 is skipped.
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Step 19 (SMF to UE) : In the 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 via N4 and the UPF.
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Step 20: When the trigger for 5GS Bridge information available is armed, the SMF may initiate the SM Policy Association Modification.
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Step 21: If the PDU Session establishment failed after step 4, the SMF performs the following operations:
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The SMF unsubscribes to the modifications of Session Management Subscription data for the corresponding (SUPI, DNN, S-NSSAI of the HPLMN) by using Nudm_SDM_Unsubscribe.
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In an embodiment, the ATSSS rule provided to UE may be expressed as:
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ATSSS rule no. xxx: "Traffic Descriptor: UDP traffic of Application-1" , "Steering
Mode: Load-Balancing, QoS flow 1 (over 3GPP NR) =80%, QoS flow 2 (over 3GPP NR) =20%" , "Steering Functionality: ATSSS-LL" .
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Wherein “xxx” refers to a number/index of the ATSSS rule. This ATSSS rule means/represents/indicates that "send 20%of the UDP traffic of Application-1 using QoS flow 1 and 80%using QoS flow 2 by using the ATSSS-LL functionality" . In an embodiment, the “QoS flow 1” and “QoS flow 2” in the ATSSS rule are identities of the QoS flow 1 and the QoS flow 2. Because QoS rules of the QoS flow 1 and the QoS flow 2 are associated with certain access nodes (e.g., either RAN A or RAN B) , the UE acknowledges that which access node should be used for transmitting the traffic.
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In an embodiment, for an MA PDU session establishment over two access nodes of the same access type:
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- When the network creates the QoS flow in the MA PDU session, the QoS flow is associated with an access node of the MA PDU session; and/or
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- ATSSS rules include the identity of the QoS flow associated with specific access node, to indicate the route/path on which UL traffic flow is transmitted; and/or
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- N4 rules include the identity of the QoS flow associated with specific access node, to indicate the route/path on which DL traffic flow is transmitted.
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FIG. 4 relates to a schematic diagram of a wireless terminal 40 according to an embodiment of the present disclosure. The wireless terminal 40 may be a user equipment (UE) , a mobile phone, a laptop, a tablet computer, an electronic book or a portable computer system and is not limited herein. The wireless terminal 40 may include a processor 400 such as a microprocessor or Application Specific Integrated Circuit (ASIC) , a storage unit 410 and a communication unit 420. The storage unit 410 may be any data storage device that stores a 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) , read-only memory (ROM) , flash memory, random-access memory (RAM) , hard-disk, and optical data storage device. The communication unit 420 may a transceiver and is used to transmit and receive signals (e.g., messages or packets) according to processing results of the processor 400. In an embodiment, the communication unit 420 transmits and receives the signals via at least one antenna 422 shown in FIG. 4.
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In an embodiment, the storage unit 410 and the program code 412 may be omitted and the processor 400 may include a storage unit with stored program code.
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The processor 400 may implement any one of the steps in exemplified embodiments on the wireless terminal 40, e.g., by executing the program code 412.
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The communication unit 420 may be a transceiver. The communication unit 420 may as an alternative or in addition be combining a transmitting unit and a receiving unit configured to transmit and to receive, respectively, signals to and from a wireless network node (e.g., a base station) .
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FIG. 5 relates to a schematic diagram of a wireless network node 50 according to an embodiment of the present disclosure. The wireless network node 50 may be a satellite, a base station (BS) , a network entity, a Mobility Management Entity (MME) , Serving Gateway (S-GW) , 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) , and is not limited herein. In addition, the wireless network node 50 may comprise (perform) 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) , etc. The wireless network node 50 may include a processor 500 such as a microprocessor or ASIC, a storage unit 510 and a communication unit 520. The storage unit 510 may be any data storage device that stores a 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, ROM, flash memory, RAM, hard-disk, and optical data storage device. The communication unit 520 may be a transceiver and is used to transmit and receive signals (e.g., messages or packets) according to processing results of the processor 500. In an example, the communication unit 520 transmits and receives the signals via at least one antenna 522 shown in FIG. 5.
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In an embodiment, the storage unit 510 and the program code 512 may be omitted. The processor 500 may include a storage unit with stored program code.
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The processor 500 may implement any steps described in exemplified embodiments on the wireless network node 50, e.g., via executing the program code 512.
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The communication unit 520 may be a transceiver. The communication unit 520 may as an alternative or in addition be combining a transmitting unit and a receiving unit configured to
transmit and to receive, respectively, signals to and from a wireless terminal (e.g., a user equipment or another wireless network node) .
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In the present disclosure, a wireless device comprising network function (s) (e.g., SMF, AMF and/or PCF and/or SMF) refers to a (wireless) device performing at least part of functionalities of the network function.
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FIG. 6 shows a flowchart of a method according to an embodiment of the present disclosure. The method shown in FIG. 6 may be used in an SMF (e.g., a wireless device or a wireless device comprising SMF) and comprises the following steps:
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Step 601: Receive, from a PCF, PCC rule (s) comprising an association between each QoS flow of a MA PDU session and one of a plurality of accesses of the MA PDU session.
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Step 602: Transmit, to at least one wireless device, at least one rule which comprises at least one QoS flow of the MA PDU session and is determined based on the PCC rule (s) .
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In FIG. 6, the SMF receives PCC rule (s) from the PCF, wherein the received PCC rule (s) comprises 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. That is the QoS flow is associated with the access (es) of the MA PDU session. In an embodiment, the access may refer to corresponding access node or access network. Based on (the association in) the PCC rules, the SMF generates/determines at least one rule which comprises or relates to the QoS flow (s) of the MA PDU session. The generated/determined rule (s) is transmitted from the SMF to corresponding wireless device.
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In an embodiment, the generated/determined rule (s) is/comprises ATSSS rule (s) . In this embodiment, the ATSSS rule (s) is transmitted to a wireless terminal (e.g., UE) .
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In an embodiment, the generated/determined rule (s) is/comprises N4 rule (s) . In this embodiment, the N4 rule (s) is transmitted to a UPF (e.g., a wireless device comprising the UPF) .
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In an embodiment, at least two accesses in the plurality of accesses have the same access type and/or the same RAT type. For example, the at least two accesses in the plurality of accesses are 3GPP access type and/or have the RAT type “NR” . Note that the embodiment shown in FIG. 3 shows an example of the MA PDU session with/supporting dual (3GPP) access. The MA PDU session may support two or more (3GPP) accesses.
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In an embodiment, the SMF transmits a session management policy control create message for the MA PDU session to the PCF, wherein the session management policy control create message indicates at least one access type and/or at least one RAT type of the plurality of accesses. Based on the indication, the PCF is able to determine the association between the QoS flows of the MA PDU and the accesses (e.g., access nodes or access networks) .
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In an embodiment, the SMF receives a session management context create message for the MA PDU session from an AMF, wherein the session management context create message comprises information associated with the plurality of accesses. For example, the information associated with the plurality of accesses comprises at least one of:
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- an indication of whether a wireless terminal of the MA PDU session registers over at least two of the plurality of accesses,
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- an access type of each access over which the UE registers, or
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- a RAT type of each access over which the UE registers.
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FIG. 7 shows a flowchart of a method according to an embodiment of the present disclosure. The method shown in FIG. 7 may be used in a PCF (e.g., a wireless device or a wireless device comprising the PCF) and comprises:
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Step 701: Transmit, to an SMF, PCC rule (s) comprising an association between each QoS flow of an MA PDU session and one of a plurality of accesses of the MA PDU session.
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In FIG. 7, the PCF transmits PCC rule (s) to the SMF. The transmitted PCC rule (s) comprises an association between each QoS flow of an MA PDU session and one of a plurality of accesses of the MA PDU session. Based on (the association) the transmitted PCC rule (s) , the SMF is able to generate/determine rule indicating the route/path of transmitting traffic of the MA PDU session.
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In an embodiment, at least two accesses in the plurality of accesses have the same access type and/or the same RAT type. For example, the at least two accesses in the plurality of accesses are 3GPP access type and/or have the RAT type “NR” . Note that the embodiment shown in FIG. 3 shows an example of the MA PDU session with/supporting dual (3GPP) access. The MA PDU session may support two or more (3GPP) accesses.
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In an embodiment the PCF receives a session management policy control create message
for the MA PDU session. The session management policy control create message comprises indication of at least one access type and/or at least one RAT type of the plurality of accesses.
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FIG. 8 shows a flowchart of a method according to an embodiment of the present disclosure. The method shown in FIG. 8 may be used in an AMF (e.g., a wireless device or a wireless device comprising the AMF) and comprises:
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Step 801: Transmit, to an SMF, a session management context create message for an MA PDU session, wherein the session management context create message comprises information associated with a plurality of accesses of the MA PDU session.
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In FIG. 8, the AMF transmits a session management context create message for an MA PDU session to an SMF. The session management context create message comprises information associated with a plurality of accesses of the MA PDU session.
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In an embodiment, the information associated with the plurality of accesses comprises at least one of:
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- an indication of whether a wireless terminal (e.g., UE) of the MA PDU session registers over at least two of the plurality of accesses,
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- an access type of each access over which the UE registers, or
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- a radio access technology (RAT) type of each access over which the UE registers.
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In an embodiment, the AMF receives an establishment request for the MA PDU session from the wireless terminal of the MA PDU session. The establishment request comprises an indication of supporting an MA PDU session via a plurality of accesses having the same access type and/or the same RAT type. For example, the establishment request may indicate or comprise an indication of “dual access” (see the embodiment of FIG. 3) .
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FIG. 9 shows a flowchart of a method according to an embodiment of the present disclosure. The method shown in FIG. 9 may be used in a wireless terminal (e.g., UE) and comprises:
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Step 901: Receive, from an SMF, at least one ATSSS rule which comprises at least one QoS flow of an MA PDU session and is determined based on 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.
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Step 902: Select at least one QoS flow for transmitting uplink traffic of the MA PDU session based on the at least one ATSSS rule.
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In FIG. 9, the wireless terminal receives at least one ATSSS rule comprising at least one QoS flow of an MA PDU session from an SMF. The ATSSS rule (s) is determined based on (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. For example, the ATSSS rule (s) comprises (the identity of) the QoS flow associated with specific access node (e.g. access or access network) , to indicate the route/path on which UL traffic of the MA PDU session is transmitted. Based on the received ATSSS rule (s) , the UE selects at least one QoS flow for transmitting UL traffic of the MA PDU session.
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In an embodiment, at least two accesses in the plurality of accesses have the same access type and/or the same RAT type. For example, the at least two accesses in the plurality of accesses are 3GPP access type and/or have the RAT type “NR” . Note that the embodiment shown in FIG. 3 shows an example of the MA PDU session with/supporting dual (3GPP) access. The MA PDU session may support two or more (3GPP) accesses.
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In an embodiment, the access (es) refers to access node (s) or access network (s) .
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In an embodiment, the wireless terminal transmits an establishment request for the MA PDU session to an AMF. The establishment request comprises an indication of supporting an MA PDU session via a plurality of accesses having the same access type and/or the same RAT type. For example, the establishment request comprises an indication of “dual (3GPP) access” .
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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 by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand exemplary features and functions of the present disclosure. Such persons would understand, however, that the present disclosure is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any one of the above-described exemplary embodiments.
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It is also understood that any reference to an element herein using a designation such as
"first, " "second, " and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.
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Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any one of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
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A skilled person would further appreciate that any one 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 digital implementation, an analog implementation, or a combination of the two) , firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software unit” ) , or any combination of these techniques.
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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 of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause 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. The term “configured to” or “configured for” as used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed and/or arranged to perform the specified operation or function.
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Furthermore, a skilled person would understand that various illustrative logical blocks, units, devices, components and circuits described herein can be implemented within or performed by
an integrated circuit (IC) that 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 any combination thereof. The logical blocks, units, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A 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 suitable configuration to perform the functions described herein. If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium.
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Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A 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 include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.
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In this document, the term "unit" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various units are described as discrete units; however, as would be apparent to one of ordinary skill in the art, two or more units may be combined to form a single unit that performs the associated functions according to embodiments of the present disclosure.
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Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present disclosure. It will be appreciated that, for clarity purposes, 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 may be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic
element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.
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Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of the claims. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.