Apparatus, method and computer program for wireless communication network

Abstract

A method, apparatus, and computer program are provided for: sending a first request to a first network function over a first access to establish a first access path for a multiple access protocol data unit session over the first access, the first request comprising a first access path identifier identifying the first access path; receiving, from the first network function via the first access, an indication of access permissible through multiple accesses of the same access type for a multiple access protocol data unit session, and a first access identifier; sending a second request to the first network function over a second access to establish a second access path for a multiple access protocol data unit session over the second access, the second request comprising: a second access path identifier identifying the second access, where the second access has the same access type as the first access; receiving a first set of rules from the first network function, the first set of rules defining how traffic of the data flow is to be distributed across the first access and the second access; and sending the service of the data flow across the first access path and the second access path according to the first rule set.

Description

[0001] Cross - Reference to Related Applications

[0002] This patent application claims priority to UK Patent Application No. 2219844.4, filed on December 30, 2022, which is hereby incorporated by reference in its entirety as if fully set forth herein. Technical Field

[0003] The examples described herein generally relate to apparatuses, methods, and computer programs, and more particularly (but not limited to) to apparatuses, methods, and computer programs for apparatuses for a wireless communication network. Background Art

[0004] A communication system can be regarded as a facility that enables communication between communication devices and one or more data networks to provide services for the communication devices. Non-limiting examples of services provided by a communication system can include enhanced mobile broadband, ultra-reliable low-latency communication, mission-critical communication, massive Internet of Things (IoT), and multimedia services.

[0005] Communication systems and their associated communication devices typically operate according to a given standard or specification that defines what the various entities of the communication system are allowed to do and how this should be achieved. Communication protocols and / or parameters to be used for communication between the various entities are also typically defined. An example of such a standard is the so-called 5G standard provided by the 3rd Generation Partnership Project (3GPP). 3GPP is a standards organization that has released multiple versions (Rel) of standards related to radio access technologies. The standard includes various technical specifications (TS) that define network configurations and protocols related to communication networks. Currently, Release 17 (Rel.17) of the 3GPP standard has been released.

[0006] A communication system can include various entities, including one or more access networks and a core network. Non-limiting examples of access networks include radio access networks, non-terrestrial networks (e.g., satellite networks), wireless local area networks, and fixed networks. A radio access network can typically be divided into cells and is thus often referred to as a cellular network. Summary of the Invention

[0007] According to a first aspect, there is provided an apparatus for a user equipment, the apparatus comprising components for: sending a first request to a first network function via a first access, the first request being for establishing a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is for transporting traffic of the multi-access protocol data unit session using a first access type; receiving, via the first access, access information related to the first request from the first network function, the access information including: an indication that access via the plurality of accesses for the multi-access protocol data unit session is permitted, and the first access identifier; receiving, via the first access or a second access, a first rule set from the first network function, the first rule set defining how the traffic will be transported across the first access and the second access, wherein the second access is for transporting traffic of the multi-access protocol data unit session using the first access type; and sending data of a data stream of the session across the first access and the second access according to the first rule set.

[0008] The multi-access request may include a mapping associating the second access with a second access identifier.

[0009] The component for sending data of the data stream of the session across the first access and the second access may include components for establishing the data stream by: receiving, via the second access, a message from the first network function and / or a second network function, the message including a second access identifier identifying the second access and session management information for the session; and using the session management information to establish the data stream for sending data.

[0010] The component for sending data of the data stream of the session across the first access and the second access may include components for: signaling, via the second access, a multi-access request to the first network function and / or the second network function, the multi-access request being for establishing a session via a plurality of accesses, the multi-access request including an identifier of the multi-access session and an identifier of the second access; receiving, via the second access, the second access identifier and a second rule set from the first network function and / or the second network function, the second rule set defining how the traffic will be transported across the first access and the second access; and transporting the traffic across the first access and the second access using the second rule set.

[0011] The second rule set may be used to replace the first rule set for transporting the traffic across the first access and the second access.

[0012] The apparatus may include components for: registering a user equipment via a first access; associating the registration via the first access with a first access identifier; registering the user equipment via a second access; and associating the registration via the second access with a second access identifier.

[0013] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0014] The first rule set and / or the second rule set may include rules for sending traffic across each access, which are used to control the splitting of uplink traffic of the user equipment between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0015] The first rule set and / or the second rule set may include rules for sending traffic across each access, which are used to allow the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified uplink traffic, and if the access is to act as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy pilot mode will apply, an indication of: which access paths will carry the identified uplink traffic and which access paths will carry at least a portion of a copy of the identified uplink traffic.

[0016] The first network function may be at least one of: a session management function and / or an access and mobility management function.

[0017] The first access type may be one of 3GPP access or non-3GPP access.

[0018] According to a second aspect, there is provided an apparatus for a first network function, the apparatus comprising components for: receiving, via a first access, a first request from a user equipment, the first request being for establishing a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is for transmitting traffic between the user equipment and the network via a first access type; signaling, via the first access, to the user equipment access information related to the first request, the access information including: an indication that access via a plurality of access paths is permitted for the multi-access protocol data unit session, and the first access identifier; signaling, via the first access or a second access, to the user equipment a first set of rules that define how the traffic will be transmitted across the first access and the second access, wherein the second access is for transmitting traffic of the multi-access protocol data unit session using the first access type; and enabling data flows of the session to be sent via the first access and the second access.

[0019] The first request may include a mapping associating the second access with a second access identifier.

[0020] The component for enabling the traffic of the session to be sent via the first access and the second access may include components for: transmitting, via the second access, signaling to the user equipment, the signaling including a second access identifier identifying the second access and session management information for establishing the session.

[0021] The component for enabling the traffic of the session to be sent via the first access and the second access may include components for: receiving, via the second access, from the user equipment a second multi-access request for establishing a multi-access protocol data unit session via a plurality of accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and signaling, via the second access, to the user equipment the second access identifier and a second set of rules for defining how the traffic will be transmitted across the first access and the second access.

[0022] The apparatus may include components for generating the first set of rules and / or the second set of rules based on policies and charging control rules obtained from a policy control function.

[0023] The apparatus may include components for providing a third rule to a user plane function, the third rule being for controlling the user plane function to split downlink traffic between at least one of: a plurality of 3GPP accesses; or a plurality of non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0024] The apparatus may include means for providing a fourth rule to the user plane function, the fourth rule being for allowing the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic and, if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or, when the conditional redundancy pilot mode is to be applied, an indication of which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0025] The first access identifier and / or the first rule set and / or the second rule set may be included in the protocol configuration option signaling operation.

[0026] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being for controlling the user equipment to split the uplink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0027] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being for allowing the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified uplink traffic and, if the access is to serve as the active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or, when the conditional redundancy pilot mode is to be applied, an indication of which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of a portion of the identified uplink traffic.

[0028] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic and, if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or, when the conditional redundancy pilot mode is to be applied, an indication of which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0029] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0030] The first access type may be one of 3GPP access or non-3GPP access.

[0031] According to a third aspect, there is provided an apparatus for a policy control function, the apparatus including components for: receiving, from a first network function, a request for a first rule set for transmitting services with a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and sending the first rule set to the first network function.

[0032] The first rule set may be configured to control the splitting of downlink traffic of a user plane function between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0033] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified downlink traffic, and if the access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry at least a portion of a copy of the identified downlink traffic.

[0034] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being used to control the splitting of uplink traffic of a user equipment between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0035] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow a user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified uplink traffic, and if the access is to serve as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication of which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of the identified uplink traffic.

[0036] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic, and if the access is to serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication of which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of the identified downlink traffic.

[0037] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0038] The first access type may be one of 3GPP access or non-3GPP access.

[0039] According to a fourth aspect, there is provided an apparatus for a user plane function, the apparatus including components for: receiving, from a first network function, a first rule set for transmitting traffic to a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and transmitting traffic to the user equipment using the first rule set described above.

[0040] The first rule set may be configured to control the user plane function to split downlink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0041] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic and, if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when the conditional redundancy leading mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0042] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0043] The first access type may be one of 3GPP access or non-3GPP access.

[0044] According to a fifth aspect, a method for a user equipment is provided, the method including: sending, via a first access, to a first network function: a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic of the multi-access protocol data unit session using a first access type; receiving, via the first access, from the first network function access information related to the first request, the access information including: an indication that access via the plurality of accesses is allowed for the multi-access protocol data unit session, and the first access identifier; receiving, via the first access or a second access, from the first network function a first rule set that defines how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and sending data of a data stream of the session via the first access and the second access according to the first rule set.

[0045] The multi-access request may include a mapping associating the second access with a second access identifier.

[0046] Sending data of the data stream of the session via the first access and the second access may include establishing the data stream by: receiving, via the second access, from the first network function and / or a second network function a message that includes a second access identifier identifying the second access and session management information for the session; and using the session management information to establish the data stream for sending data.

[0047] Data for transmitting the data stream of the above session via the first access and the second access may include: signaling a multi - access request for establishing a session via multiple accesses to the first network function and / or the second network function via the second access, the multi - access request including an identifier of the multi - access session and an identifier of the second access; receiving, via the second access, the second access identifier and a second rule set from the first network function and / or the second network function, the second rule set defining how the above service will be transmitted across the first access and the second access; and transmitting the above service across the first access and the second access using the above second rule set.

[0048] The above second rule set may be used to replace the above first rule set for transmitting the above service across the first access and the second access.

[0049] The method may include: registering a user equipment via the first access; associating the registration via the first access with a first access identifier; registering the user equipment via the second access; and associating the registration via the second access with a second access identifier.

[0050] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0051] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to control the splitting of uplink services by the user equipment between at least one of the following: multiple 3GPP accesses; or multiple non - 3GPP accesses; or at least one 3GPP access and at least one non - 3GPP access.

[0052] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to allow the user equipment to control the transmission of the identified uplink services based on at least one of the following policies: whether the access is allowed for the identified downlink service; or whether the access will act as an active access for the identified uplink service and, if the access is to act as an active access for the identified uplink service, the proportion of the identified uplink service that the access will carry; or an indication of the following when a conditional redundancy guiding mode will apply: which access paths will carry the identified uplink service and which access paths will carry at least a part of the copy of the identified uplink service.

[0053] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0054] The first access type may be one of 3GPP access or non - 3GPP access.

[0055] According to a sixth aspect, a method for a first network function is provided, the method comprising: receiving, via a first access, from a user equipment: a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic between the user equipment and the network via a first access type; signaling, via the first access, to the user equipment access information related to the first request, the access information including: an indication that access via a plurality of access paths is permitted for the multi-access protocol data unit session, and the first access identifier; signaling, via the first access or a second access, to the user equipment a first set of rules that define how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and enabling a data flow of the session to be sent via the first access and the second access.

[0056] The first request may include a mapping associating the second access with a second access identifier.

[0057] The enabling the traffic of the session to be sent via the first access and the second access may include: sending, via the second access, signaling to the user equipment, the signaling including a second access identifier identifying the second access and session management information for establishing the session.

[0058] The enabling the traffic of the session to be sent via the first access and the second access may include: receiving, via the second access, from the user equipment: a second multi-access request to establish a multi-access protocol data unit session via a plurality of accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and signaling, via the second access, to the user equipment the second access identifier and a second set of rules that define how the traffic will be transmitted across the first access and the second access.

[0059] The method may include generating the first set of rules and / or the second set of rules based on policy and charging control rules obtained from a policy control function.

[0060] The method may include providing a third rule to a user plane function, the third rule being used to control the user plane function to split downlink traffic between at least one of: a plurality of 3GPP accesses; or a plurality of non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0061] The method may include providing a fourth rule to a user plane function, the fourth rule being used to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access will serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0062] The first access identifier and / or the first rule set and / or the second rule set may be included in the protocol configuration option signaling operation.

[0063] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being used to control the user equipment to split the uplink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0064] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being used to allow the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified uplink traffic, and if the access will serve as the active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of a portion of the identified uplink traffic.

[0065] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access will serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0066] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0067] The first access type may be one of 3GPP access or non-3GPP access.

[0068] According to a seventh aspect, a method for a policy control function is provided, the method including: receiving, from a first network function, a request for a first rule set for transmitting traffic with a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and sending the first rule set to the first network function.

[0069] The first rule set may be configured to control the splitting of downlink traffic of a user plane function between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0070] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified downlink traffic and, if the access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry at least a portion of a copy of the identified downlink traffic.

[0071] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being used to control the splitting of uplink traffic of a user equipment between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0072] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow a user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified uplink traffic, and if the access is to serve as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which access paths will carry the identified uplink traffic and which access paths will carry a copy of at least a part of the identified uplink traffic.

[0073] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic, and if the access is to serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a part of the identified downlink traffic.

[0074] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0075] The first access type may be one of 3GPP access or non-3GPP access.

[0076] According to an eighth aspect, a method for a user plane function is provided, the method including: receiving, from a first network function, a first rule set for transmitting traffic to a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and transmitting traffic to the user equipment using the first rule set described above.

[0077] The first rule set may be configured to control the user plane function to split downlink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0078] The first rule set can be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic and, if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or, when the conditional redundancy guiding mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0079] The first network function can be at least one of the following: a session management function and / or an access and mobility management function.

[0080] The first access type can be one of 3GPP access or non-3GPP access.

[0081] According to a ninth aspect, there is provided an apparatus for a user equipment, the apparatus comprising: at least one processor; and at least one memory including code which, when executed by the at least one processor, causes the apparatus to perform: sending, via a first access, to a first network function: a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic of the multi-access protocol data unit session using the first access type; receiving, via the first access, from the first network function access information related to the first request, the access information including: an indication that access via the plurality of accesses is permissible for the multi-access protocol data unit session, and the first access identifier; receiving, via the first access or a second access, from the first network function a first rule set that defines how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and sending, according to the first rule set, data of a data stream of the session via the first access and the second access.

[0082] The multi-access request may include a mapping associating the second access with a second access identifier.

[0083] Sending, via the first access and the second access, data of a data stream of the session may include establishing the data stream by: receiving, via the second access, from the first network function and / or a second network function a message including a second access identifier identifying the second access and session management information for the session; and using the session management information to establish the data stream for sending data.

[0084] Data for sending the data stream of the above session via the first access and the second access may include: signaling, via the second access, a multi-access request for establishing a session through multiple accesses to a first network function and / or a second network function, the multi-access request including an identifier of the multi-access session and an identifier of the second access; receiving, via the second access, from the first network function and / or the second network function, the second access identifier and a second rule set that defines how the above service will be transmitted across the first access and the second access; and transmitting the above service across the first access and the second access using the above second rule set.

[0085] The above second rule set may be used to replace the above first rule set for transmitting the above service across the first access and the second access.

[0086] The apparatus may be caused to perform: registering a user equipment via a first access; associating the registration via the first access with a first access identifier; registering the user equipment via a second access; and associating the registration via the second access with a second access identifier.

[0087] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0088] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to control the splitting of uplink services by the user equipment between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0089] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to allow the user equipment to control the transmission of the identified uplink services based on at least one of the following policies: whether the access is allowed for the identified downlink service; or whether the access will act as an active access for the identified uplink service, and if the access is to act as an active access for the identified uplink service, the proportion of the identified uplink service that the access will carry; or an indication for the following when a conditional redundancy pilot mode will apply: which access paths will carry the identified uplink service and which access paths will carry at least a portion of a copy of the identified uplink service.

[0090] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0091] The first access type may be one of 3GPP access or non-3GPP access.

[0092] According to a tenth aspect, there is provided an apparatus for a first network function, the apparatus comprising: at least one processor; and at least one memory including code which, when executed by the at least one processor, causes the apparatus to perform: receiving, via a first access, from a user equipment: a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is for transmitting traffic between the user equipment and the network via a first access type; signaling, via the first access, to the user equipment access information related to the first request, the access information including: an indication that access via a plurality of access paths is permitted for the multi-access protocol data unit session, and the first access identifier; signaling, via the first access or a second access, to the user equipment a first set of rules that defines how the traffic will be transmitted across the first access and the second access, wherein the second access is for transmitting traffic of the multi-access protocol data unit session using the first access type; and enabling a data flow of the session to be sent via the first access and the second access.

[0093] The first request may include a mapping associating the second access with a second access identifier.

[0094] The enabling the traffic of the session to be sent via the first access and the second access may include: transmitting, via the second access, signaling to the user equipment, the signaling including a second access identifier identifying the second access and session management information for establishing the session.

[0095] The enabling the traffic of the session to be sent via the first access and the second access may include: receiving, via the second access, from the user equipment: a second multi-access request to establish a multi-access protocol data unit session via a plurality of accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and signaling, via the second access, to the user equipment the second access identifier and a second set of rules that defines how the traffic will be transmitted across the first access and the second access.

[0096] The apparatus may be caused to perform: generating the first set of rules and / or the second set of rules based on policies and charging control rules obtained from a policy control function.

[0097] The apparatus may be caused to perform: providing a third rule to a user plane function, the third rule being used to control the user plane function to split downlink traffic between at least one of: a plurality of 3GPP accesses; or a plurality of non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0098] The apparatus may be caused to perform: providing a fourth rule to a user plane function, the fourth rule being for allowing the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic and, if the access will serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when the conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0099] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0100] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being for controlling the user equipment to split uplink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0101] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being for allowing the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified uplink traffic and, if the access will serve as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or an indication for the following when the conditional redundancy pilot mode will be applied: which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of a portion of the identified uplink traffic.

[0102] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic and, if the access will serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when the conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0103] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0104] The first access type may be one of 3GPP access or non-3GPP access.

[0105] According to the eleventh aspect, there is provided an apparatus for a policy control function, the apparatus comprising: at least one processor; and at least one memory including code which, when executed by the at least one processor, causes the apparatus to perform: receiving, from a first network function, a request for a first rule set for transmitting traffic with a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and sending the first rule set to the first network function.

[0106] The first rule set may be configured to control the user plane function to split downlink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0107] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified downlink traffic and, if the access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will apply: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0108] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, the rules being used to control the user equipment to split uplink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0109] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow a user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified uplink traffic, and if the access is to serve as the active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication of which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of the identified uplink traffic.

[0110] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication of which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of the identified downlink traffic.

[0111] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0112] The first access type may be one of 3GPP access or non-3GPP access.

[0113] According to a twelfth aspect, there is provided an apparatus for a user plane function, the apparatus comprising: at least one processor; and at least one memory including code which, when executed by the at least one processor, causes the apparatus to perform: receiving, from a first network function, a first rule set for transmitting traffic to a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and transmitting traffic to the user equipment using the first rule set described above.

[0114] The first rule set may be configured to control the user plane function to split downlink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0115] The first rule set can be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic, and if the access is to serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of the identified downlink traffic.

[0116] The first network function can be at least one of the following: a session management function and / or an access and mobility management function.

[0117] The first access type can be one of 3GPP access or non-3GPP access.

[0118] According to a thirteenth aspect, there is provided an apparatus for a user equipment, the apparatus comprising: a transmitting circuitry for sending a first request to a first network function via a first access to establish a multi-access protocol data unit session through a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic of the multi-access protocol data unit session using a first access type; a receiving circuitry for receiving, via the first access, access information related to the first request from the first network function, the access information including: an indication that access through the plurality of accesses is permissible for the multi-access protocol data unit session, and the first access identifier; a receiving circuitry for receiving a first rule set from the first network function via the first access or a second access, the first rule set defining how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and a transmitting circuitry for transmitting data of a data stream of the session via the first access and the second access according to the first rule set.

[0119] The multi-access request may include a mapping associating a second access with a second access identifier.

[0120] The transmitting circuitry for transmitting data of the data stream of the session via the first access and the second access may include a establishing circuitry for establishing the data stream by: receiving, via the second access, a message from the first network function and / or a second network function, the message including a second access identifier identifying the second access and session management information for the session; and using the session management information to establish the data stream for transmitting data.

[0121] The transmission circuit system for transmitting data of the data stream of the above session via the first access and the second access may include: a signaling circuit system for signaling a multi-access request for establishing a session via multiple accesses to the first network function and / or the second network function via the second access, the multi-access request including an identifier of the multi-access session and an identifier of the second access; a receiving circuit system for receiving, via the second access, the second access identifier and the second rule set from the first network function and / or the second network function, the second rule set defining how the above service will be transmitted across the first access and the second access; and a usage circuit system for transmitting the above service across the first access and the second access using the above second rule set.

[0122] The above second rule set may be used to replace the above first rule set for transmitting the above service across the first access and the second access.

[0123] The apparatus may include: a registration circuit system for registering a user equipment via the first access; an association circuit system for associating the registration via the first access with the first access identifier; a registration circuit system for registering the user equipment via the second access; and an association circuit system for associating the registration via the second access with the second access identifier.

[0124] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0125] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to control the splitting of uplink services of the user equipment between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0126] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to allow the user equipment to control the transmission of the identified uplink services based on at least one of the following policies: whether the access is allowed for the identified downlink service; or whether the access will act as an active access for the identified uplink service, and if the access is to act as an active access for the identified uplink service, the proportion of the identified uplink service that the access will carry; or an indication of the following when the conditional redundancy pilot mode will apply: which access paths will carry the identified uplink service and which access paths will carry at least a portion of a copy of the identified uplink service.

[0127] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0128] The first access type may be one of 3GPP access or non-3GPP access.

[0129] According to a fourteenth aspect, there is provided an apparatus for a first network function, the apparatus comprising: receiving circuitry for receiving, from a user equipment via a first access, a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to convey traffic between the user equipment and the network via a first access type; signaling circuitry for signaling, via the first access, access information related to the first request to the user equipment, the access information including: an indication that access via a plurality of access paths for the multi-access protocol data unit session is permissible, and the first access identifier; signaling circuitry for signaling, via the first access or a second access, a first rule set to the user equipment, the first rule set defining how the traffic will be conveyed across the first access and the second access, wherein the second access is used to convey traffic of the multi-access protocol data unit session using the first access type; and enabling circuitry for enabling data flows of the session to be sent via the first access and the second access.

[0130] The first request may include a mapping associating the second access with a second access identifier.

[0131] The enabling circuitry for enabling traffic of the session to be sent via the first access and the second access may include: transmitting circuitry for transmitting, via the second access, signaling to the user equipment, the signaling including a second access identifier identifying the second access and session management information for establishing the session.

[0132] The enabling circuitry for enabling traffic of the session to be sent via the first access and the second access may include: receiving circuitry for receiving, from the user equipment via the second access, a second multi-access request to establish a multi-access protocol data unit session via a plurality of accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and signaling circuitry for signaling, via the second access, the second access identifier and a second rule set to the user equipment, the second rule set for defining how the traffic will be sent across the first access and the second access.

[0133] The apparatus may include generating circuitry for generating the first rule set and / or the second rule set based on policy and charging control rules obtained from a policy control function.

[0134] The apparatus may include provisioning circuitry for providing a third rule to a user plane function, the third rule for controlling the user plane function to split downlink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0135] The apparatus may include provisioning circuitry for providing a fourth rule to a user plane function, the fourth rule for allowing the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified downlink traffic and, if the access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0136] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0137] The first rule set and / or the second rule set may include rules for sending traffic across each access, the rules for controlling the user equipment to split uplink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0138] The first rule set and / or the second rule set may include rules for sending traffic across each access, the rules for allowing the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified uplink traffic and, if the access is to act as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will be applied: which access paths will carry the identified uplink traffic and which access paths will carry a copy of at least a portion of the identified uplink traffic.

[0139] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access will serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0140] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0141] The first access type may be one of 3GPP access or non-3GPP access.

[0142] According to a fifteenth aspect, there is provided an apparatus for a policy control function, the apparatus comprising: receiving circuitry for receiving, from a first network function, a request for a first rule set for communicating traffic with a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and transmitting circuitry for transmitting the first rule set to the first network function.

[0143] The first rule set may be configured to control the user plane function to split downlink traffic among at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0144] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access will serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of a portion of the identified downlink traffic.

[0145] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to control the user equipment to split uplink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0146] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified uplink traffic, and if the access is to serve as the active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy leading mode will be applied, an indication for the following: which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of the identified uplink traffic.

[0147] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy leading mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of the identified downlink traffic.

[0148] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0149] The first access type may be one of 3GPP access or non-3GPP access.

[0150] According to a sixteenth aspect, there is provided an apparatus for a user plane function, the apparatus including: receiving circuitry for receiving a first rule set from a first network function, the first rule set being used to convey traffic to a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and transmitting circuitry for transmitting traffic to the user equipment using the first rule set described above.

[0151] The first rule set may be configured to control the splitting of downlink traffic of the user plane function among at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0152] The first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic and, if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when the conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0153] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0154] The first access type may be one of 3GPP access or non-3GPP access.

[0155] According to a seventeenth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program instructions for causing a device for a user equipment to perform: sending, via a first access, to a first network function: a first request to establish a multi-access protocol data unit session via multiple accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic of the multi-access protocol data unit session using a first access type; receiving, via the first access, from the first network function access information related to the first request, the access information including: an indication that access via multiple accesses is permissible for the multi-access protocol data unit session, and the first access identifier; receiving, via the first access or a second access, from the first network function a first rule set that defines how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and sending data of a data stream of the session via the first access and the second access according to the first rule set.

[0156] The multi-access request may include a mapping associating the second access with a second access identifier.

[0157] Data for transmitting the data stream of the session via the first access and the second access may include establishing the data stream by: receiving, via the second access, a message from a first network function and / or a second network function, the message including a second access identifier identifying the second access and session management information of the session; and using the session management information to establish the data stream for transmitting data.

[0158] Data for transmitting the data stream of the session via the first access and the second access may include: signaling, via the second access, a multi-address request for establishing a session via multiple accesses to the first network function and / or the second network function, the multi-address request including an identifier of the multi-address session and an identifier of the second access; receiving, via the second access, the second access identifier and a second rule set from the first network function and / or the second network function, the second rule set defining how the service will be transmitted across the first access and the second access; and transmitting the service across the first access and the second access using the second rule set.

[0159] The second rule set may be used to replace the first rule set for transmitting the service across the first access and the second access.

[0160] The apparatus may be caused to perform: registering the user equipment via the first access; associating the registration via the first access with a first access identifier; registering the user equipment via the second access; and associating the registration via the second access with a second access identifier.

[0161] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0162] The first rule set and / or the second rule set may include rules for transmitting services across each access, the rules being used to control the splitting of uplink services by the user equipment between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0163] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow a user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will act as an active access for the identified uplink traffic, and if the access is to act as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy pilot mode will be applied, an indication for: which access paths will carry the identified uplink traffic and which access paths will carry a copy of at least a part of the identified uplink traffic.

[0164] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0165] The first access type may be one of 3GPP access or non-3GPP access.

[0166] According to an eighteenth aspect, there is provided a non-transitory computer-readable medium including program instructions for causing an apparatus for a first network function to perform: receiving, from a user equipment via a first access: a first request to establish a multi-access protocol data unit session through a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access is used to transmit traffic between the user equipment and the network through the first access type; signaling, via the first access, to the user equipment access information related to the first request, the access information including: an indication that access through a plurality of access paths for the multi-access protocol data unit session is permissible, and the first access identifier; signaling, via the first access or a second access, to the user equipment a first rule set that defines how the traffic will be transmitted across the first access and the second access, wherein the second access is used to transmit traffic of the multi-access protocol data unit session using the first access type; and enabling a data stream of the session to be transmitted via the first access and the second access.

[0167] The first request may include a mapping associating the second access with a second access identifier.

[0168] The enabling the traffic of the session to be transmitted via the first access and the second access may include: transmitting, via the second access, signaling to the user equipment, the signaling including a second access identifier identifying the second access and session management information for establishing the session.

[0169] Enabling the service of the above session to be sent via the first access and the second access may include: receiving, via the second access, from a user equipment: a second multi-access request for establishing a multi-access protocol data unit session via multiple accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and signaling, via the second access, the second access identifier and a second rule set for defining how the above service will be sent across the first access and the second access.

[0170] The apparatus may be caused to perform: generating a first rule set and / or a second rule set based on policies and charging control rules obtained from a policy control function.

[0171] The apparatus may be caused to perform: providing a third rule to a user plane function, the third rule being used to control the user plane function to split downlink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0172] The apparatus may be caused to perform: providing a fourth rule to a user plane function, the fourth rule being used to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether an access is allowed for the identified downlink traffic; or whether an access will act as an active access for the identified downlink traffic, and if an access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or an indication for the following when a conditional redundancy pilot mode will be applied: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a part of the identified downlink traffic.

[0173] The first access identifier and / or the first rule set and / or the second rule set may be included in a protocol configuration option signaling operation.

[0174] The first rule set and / or the second rule set may include rules for sending traffic across each access, the rules being used to control the user equipment to split uplink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0175] The first rule set and / or the second rule set may include rules for transmitting traffic across each access, which are used to allow a user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified uplink traffic, and if the access is to serve as an active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy leading mode will be applied, an indication of which access paths will carry the identified uplink traffic and which access paths will carry at least a copy of the identified uplink traffic.

[0176] The first rule set may be configured to allow a user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the access is allowed for the identified downlink traffic; or whether the access will serve as an active access for the identified downlink traffic, and if the access is to serve as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy leading mode will be applied, an indication of which accesses will carry the identified downlink traffic and which accesses will carry at least a copy of the identified downlink traffic.

[0177] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0178] The first access type may be one of 3GPP access or non-3GPP access.

[0179] According to the nineteenth aspect, a non-transitory computer-readable medium is provided, which includes program instructions for causing a device for a policy control function to perform: receiving, from a first network function, a request for a first rule set for transmitting traffic with a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and sending the first rule set to the first network function.

[0180] The first rule set may be configured to control the user plane function to split downlink traffic among at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0181] The first rule set can be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a portion of the copy of the identified downlink traffic.

[0182] The first rule set and / or the second rule set can include rules for sending traffic across each access, which are used to control the user equipment to split the uplink traffic between at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0183] The first rule set and / or the second rule set can include rules for sending traffic across each access, which are used to allow the user equipment to control the transmission of the identified uplink traffic based on at least one of the following policies: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified uplink traffic, and if the access is to serve as the active access for the identified uplink traffic, the proportion of the identified uplink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which access paths will carry the identified uplink traffic and which access paths will carry at least a portion of the copy of the identified uplink traffic.

[0184] The first rule set can be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether access is allowed for the identified downlink traffic; or whether the access will serve as the active access for the identified downlink traffic, and if the access is to serve as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which accesses will carry the identified downlink traffic and which accesses will carry at least a portion of the copy of the identified downlink traffic.

[0185] The first network function can be at least one of the following: session management function and / or access and mobility management function.

[0186] The first access type can be one of 3GPP access or non-3GPP access.

[0187] According to a twentieth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program instructions for causing a device for user plane function to perform: receiving a first set of rules from a first network function, the first set of rules for transmitting traffic to a user equipment using each of a first access associated with a first access type and a second access associated with the first access type; and sending traffic to the user equipment using the first set of rules described above.

[0188] The first set of rules may be configured to control the user plane function to split downlink traffic between at least one of: multiple 3GPP accesses; or multiple non-3GPP accesses; or at least one 3GPP access and at least one non-3GPP access.

[0189] The first set of rules may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether an access is allowed for the identified downlink traffic; or whether an access will act as an active access for the identified downlink traffic, and if an access is to act as an active access for the identified downlink traffic, the proportion of the identified downlink traffic that the access will carry; or when a conditional redundancy pilot mode will apply, an indication for: which accesses will carry the identified downlink traffic and which accesses will carry a copy of at least a portion of the identified downlink traffic.

[0190] The first network function may be at least one of the following: a session management function and / or an access and mobility management function.

[0191] The first access type may be one of 3GPP access or non-3GPP access.

[0192] According to a twenty-first aspect, a computer program product stored on a medium is provided, the computer program product being capable of causing a device to perform any method described herein.

[0193] According to a twenty-second aspect, an electronic device is provided, the electronic device may include a device as described herein.

[0194] According to a twenty-third aspect, a chipset is provided, the chipset may include a device as described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0195] Some examples will now be described by way of illustration only with reference to the drawings, in which:

[0196] Figure 1 A schematic diagram of a 5G system is shown;

[0197] Figure 2 Shows a schematic diagram of a network device;

[0198] Figure 3 Shows a schematic diagram of a user equipment;

[0199] Figures 4 to 6B Illustrates operations that can be performed by the devices described herein;

[0200] Figures 7 to 13 Illustrates example signaling that can be exchanged in different network configurations; and

[0201] Figure 14 Illustrates example boot mode signaling. Detailed Description

[0202] Hereinafter, certain examples are explained with reference to a device that is capable of communicating with a communication system serving such a device. Before providing these specific examples, reference is made to Figure 1 、 Figure 2 and Figure 3 to briefly explain the general principles of a communication system that can include one or more access networks (ANs) and a core network, as well as devices (e.g., terminals served by the communication system). These are provided to assist in understanding the technology underlying the examples described later.

[0203] Figure 1 Shows a schematic diagram of a communication network including components of a 5G wireless communication system (5GS) and an evolved packet system (EPS). The 5GS can include an access network (AN), a 5G core network (5GC) including multiple network functions (NFs), one or more application functions (AFs), and one or more data networks (DNs). Also shown is a terminal configured to register with the 5GC. After briefly discussing the forms that the network functions and the terminal can take, reference will be made to Figure 2 and Figure 3 to discuss more fully Figure 1 the network configuration.

[0204] Figure 2 Illustrates what can be achieved Figure 1An example of an apparatus 200 of one or more NFs of the 5GC shown. The apparatus 200 may include at least one random access memory (RAM) 211a, at least one read-only memory (ROM) 211b, at least one processor 212, 213, and a network interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute software code 215. The software code 215 may include instructions for performing actions or operations of one or more NFs of the 5GC. The software code 215 may be stored in the ROM 211b. The apparatus 200 may implement one or more NFs of the 5GC and may be interconnected with another apparatus 200 that implements one or more other NFs in the 5GC. In such an example, the apparatus 200 may be part of a distributed computing system. In some examples, each NF of the 5GC may be implemented on a single apparatus 200. In such an example, the apparatus 200 may be a cloud computing system.

[0205] Figure 3 Illustrates an example of an apparatus 300 that can perform Figure 1 the functions of a terminal. The apparatus 300 may be any wireless communication device capable of transmitting and receiving radio signals. Non-limiting examples of the apparatus 300 include a terminal, a wireless communication device, a user equipment (UE), a mobile station (MS), or a mobile device (such as a mobile phone or a so-called "smartphone"), a computer provided with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA) or a tablet computer provided with wireless communication capabilities, a machine type communication (MTC) device, an Internet of Things (IoT) communication device, or any combination thereof, etc. In the following discussion, the examples generally relate to a user equipment, but it should be understood that the same principles may be applied to any example of the apparatus discussed above.

[0206] The apparatus 300 may be configured to communicate with an access node of at least one access network (e.g., an NG-eNB or a gNB) and communicate with the 5GC via the access node of at least one access network using non-access stratum (NAS) signaling. The communication between the apparatus 300 and the 5GC may include one or more of voice, email, text messages, multimedia, data, machine data, etc.

[0207] The apparatus 300 may receive wireless signals (e.g., radio or cellular signals) via an appropriate apparatus 306 for receiving wireless signals over the air or a radio interface 307 (generally referred to as the Uu interface), and may transmit wireless signals (e.g., radio or cellular signals) via an appropriate apparatus for transmitting wireless signals. In Figure 3In [the figure], device 306 includes one or more antennas (or an antenna array including multiple antennas) and a transceiver, and is schematically designated by block 306. Device 306 can be provided, for example, by means of radio components and an associated antenna arrangement including one or more antennas. The antenna arrangement can be disposed inside or outside the mobile device.

[0208] Device 300 can include at least one processor 301, at least one memory ROM 302a, at least one RAM 302b, and other possible components 303 for the software and hardware assisted execution of tasks (the device is designed to perform such tasks), including controlling access to the access network (such as a 5G-RAN access network or an NTN access network) and other devices 300, and communicating with the access network and other devices 300. At least one processor 301 is coupled to RAM 311a and ROM 311b. At least one processor 301 can be configured to execute appropriate software code 308. The software code 308 can include, for example, instructions that, when executed by at least one processor 301, perform one or more actions or operations of the presented aspects. For example, the software code can include instructions suitable for implementing access service steering, splitting (ATSSS) rules to perform one or more actions or operations in accordance with aspects of the present disclosure. The software code 308 can be stored in ROM 311b.

[0209] At least one processor 301, storage, and other related control devices can be provided on a suitable circuit board or chipset, or a combination of a circuit board and a chipset. This feature is denoted by reference numeral 304. Terminal 300 can optionally have a user interface, such as a keypad 305, a touch-sensitive display screen or touchpad, a combination thereof, etc. Depending on the type of device, one or more of a display, a speaker, and a microphone can be optionally provided.

[0210] At least a part of the route through which the terminal signals communication to the 5GC via the access network can be referred to as an access path. Since the terminal can be connected to the 5GC via multiple types of access networks, the access of the terminal to the 5GC can generally be provided via one or two access paths, each access path being associated with a corresponding access type (e.g., 3PPP or non-3GPP). Figure 1 Multiple different types of access networks are illustrated through which the terminal can be connected to the 5GC. These different types of access networks are all referred to herein as 5G ANs because they enable the UE to connect to the 5GC. In particular, Figure 1 A terminal is illustrated that can access the 5GC via any one of 5G-RAN, E-UTRAN, and / or non-3GPP access networks.

[0211] As a first example, the 5G AN may include a 5G Radio Access Network (5G-RAN) that supports 3GPP access types. The 5G-RAN is also referred to as the Next Generation Radio Access Network (NG-RAN). The 5G-RAN may be a terrestrial network (TN) or a non-terrestrial network (NTN). The 5G-RAN (also referred to as NG-RAN) may include one or more base stations (e.g., gNodeB (gNB)). The gNB of the 5G-RAN may include a gNB distributed unit connected to the gNB central unit, and a remote radio head connected to the gNB distributed unit. Additionally, the NTN 5G-RAN may include multiple satellites that may be located in various orbits, such as low Earth orbit (LEO), medium Earth orbit (MEO), and geostationary orbit (GEO). This type of access network may be referred to as a satellite access network.

[0212] As a second example, the 5G AN may include entities that support non-3GPP access networks, such as a non-3GPP Interworking Function (N3IWF) for untrusted non-3GPP access, a Trusted Non-3GPP Gateway Function (TNGF), and / or a Wired Access Gateway Function (W-AGF) for wired access.

[0213] As a third example, the 5G AN may include an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access network, such as an eNodeB 4G access network. The E-UTRAN AN is connected to a Mobility Management Entity (MME) that is only responsible for the control plane. The MME sends signaling to enable low-level connection management. The MME communicates with the eNodeB using the S1-MME interface. The MME is responsible for, for example, non-access stratum (NAS) signaling, user authentication and authorization, supporting the connection of the UE to the network, setting up and managing bearers, selecting the PGW and SGW for a given connection, selecting a different MME when handing over between eNodeBs, TA (tracking area) management, roaming support, and the SGW. Additionally, Figure 1 The Serving Gateway (SGW) that transfers data from the AN (E-UTRAN) to the UPF or SMF is shown. The SGW is responsible for routing, forwarding, packet marking and buffering, user mobility management, and supporting handover connections between two eNodeBs.

[0214] A communication system typically includes more than one (e / g)NodeB, where the (e / g)NodeB is also configured to communicate with each other via a wired or wireless link designed for this purpose. The (e / g)NodeB is a computing device configured to control the radio resources of the communication system coupled thereto. The NodeB may also be referred to as a base station, an access point, or any other type of interface device, including a relay station capable of operating in a wireless environment. The (e / g)NodeB includes a transceiver or is coupled to a transceiver. From the transceiver of the (e / g)NodeB, a connection is provided to an antenna unit that establishes a bi-directional radio link to the device. The antenna unit may include multiple antennas or antenna elements. The (e / g)NodeB is also connected to the core network (CN or Next Generation Core NGC). Depending on the technology deployed: the (e / g)NodeB is connected to a Serving and Packet Data Network Gateway (S-GW+P-GW) or a User Plane Function (UPF) for routing and forwarding user data packets and for providing connectivity of the device to one or more external packet data networks; and the (e / g)NodeB is connected to a Mobility Management Entity (MME) or an Access and Mobility Management Function (AMF) for controlling access and mobility of the device.

[0215] Figure 1 Some of the network functions that may be included in the 5GC are illustrated. It should be understood that the labels for the interfaces between different network functions are not restrictive and are only used hereinafter to denote the connections between network functions.

[0216] The 5GC may include at least one of any of the following network functions: Network Slice Selection Function (NSSF); Network Exposure Function (NEF); Network Repository Function (NRF); Network Data Analytics Function (NWDAF), Policy Control Function (PCF); Unified Data Management (UDM); Authentication Server Function (AUSF); Access and Mobility Management Function (AMF); Session Management Function (SMF) and User Plane Function (UPF). The selection of these functions is illustrated with respect to Figure 1 The NFs of the 5GC may have a service-based architecture as described in TS 23.501 of the 3GPP standard. The NF services that may be provided by the NFs of the 5GC and the service-based interfaces for the NFs of the 5GC are described in the 3GPP standard, and in particular in TS 23.501 and TS 23.502 of the 3GPP standard. Additionally, it should be noted that although Figure 1 only one UPF is shown, the 5GS may include a range of UPFs, including a UPF anchor connected to the DN. Figure 1 The connections between the elements drawn are via the interfaces defined in TS 23.501 and TS 23.502 of the 3GPP standard.

[0217] In some examples, the AF is a customer of the 5GC and is connected to the user plane function (UPF) of the 5GC via a data network (DN) and to the network functions (NFs) of the 5GC via the network exposure function (NEF) of the 5GC. In some examples, the AF is a trusted application function, and thus the trusted AF is implemented in the 5GC and is directly connected to other NFs of the 5GC.

[0218] The 5GS supports certain functions for providing multi-access data connections at an upper layer (i.e., the layer above the access network). In other words, the 5GS provides the possibility of exchanging user plane traffic between a terminal (e.g., a UE) and a data network (DN) by simultaneously using two access networks in a communication network and two independent user plane tunnels between the access networks and an anchor user plane function (UPF) in the 5GC of the communication network. The current specification of the 3GPP standard limits the access network to one 3GPP access network and one non-3GPP access network. In particular, clause 5.6.1 of TS 23.501 stipulates that a PDU session can be (a) associated with a single access type (i.e., either 3GPP access or non-3GPP access) at a given time, or (b) associated with multiple access types (i.e., one 3GPP access and one non-3GPP access) simultaneously. A PDU session associated with multiple access types is called a multi-access PDU (MA-PDU) session, and it can be requested by a UE with ATSSS capabilities.

[0219] One of the items in the project considered to be part of a future 3GPP release of the 3GPP standard relates to how the ATSSS features described in TS24.501 of the 3GPP standard are affected when a UE and the 5GS support an MA PDU session over multiple accesses of the same access type.

[0220] The access service steering, handover, and splitting (ATSSS) features described in TS24.501 of the 3GPP standard are examples of features that can be used to determine how the traffic of a data stream will be sent from a UE to the UPF of the core network. To this end, ATSSS defines multiple different steering modes. The steering mode determines how the traffic of a data stream (e.g., a matching service data flow (SDF)) will be distributed across 3GPP access and non-3GPP access. Active-standby, continuous delay, load balancing, and priority-based are examples of steering modes of the ATSSS features, and these steering modes (and other steering modes) are more fully defined in clause 5.32.6 of TS 23.501. Some brief aspects of these example steering modes will be further described below.

[0221] · Active - standby is a steering mode that is used to steer the SDFs on an access network (i.e., the active access) to switch the traffic of the SDFs to another available access network (also known as the standby access) when the active access becomes unavailable. When the active access becomes available again, the SDFs will be switched back to the active access and cannot be transmitted on the other access. If the standby access is not defined, the SDFs can only be allowed on the active access and cannot be transmitted to the other access network.

[0222] · Minimum latency is a steering mode that is used to steer the SDFs to the access network determined to have the minimum round - trip time (RTT). The measurements can be obtained by the UE and the UPF to determine the RTT on 3GPP access and non - 3GPP access. Additionally, when an access becomes unavailable, all SDF traffic can be switched to another available access. Minimum latency can currently only be used for non - GBR SDFs.

[0223] · Load balancing is a steering mode that is used to split the SDFs across the two available accesses when both accesses are available. This steering mode includes the percentage of SDF traffic sent via at least one of 3GPP access and non - 3GPP access. Load balancing currently only applies to non - GBR SDFs. Additionally, when an access becomes unavailable, all SDF traffic can be switched to the other available access as if the percentage of SDF traffic transmitted via the available access is 100%.

[0224] · Priority - based is a steering mode that is used to steer all traffic of the SDFs to the high - priority access until the access is determined to be congested. When the high - priority access is determined to be congested, the traffic of the SDFs is also sent to the low - priority access, i.e., the SDF traffic is split across the two accesses. Additionally, when the high - priority access becomes unavailable, all SDF traffic can be switched to the low - priority access. How the UE and the UPF determine when congestion occurs on an access depends on the implementation. This steering mode can currently only be used for non - GBR SDFs.

[0225] Currently, according to the ATSSS rules provided by the Policy Control Function (PCF) of the core network, the ATSSS feature only enables the traffic of data flows to be sent across one 3GPP access and one non - 3GPP access.

[0226] The ATSSS features described in the 3GPP standard enable the multi-access (MA) protocol data unit (PDU) connection service, which can exchange PDUs between the UE and the data network by simultaneously using a 3GPP access and a non-3GPP access. The multi-access PDU connection service is achieved by establishing a multi-access PDU session (i.e., a PDU session that can have user plane resources on two access networks), which can exchange PDUs between the UE and the data network by simultaneously using a 3GPP access and a non-3GPP access. When the UE is dual-registered with the network via both the 3GPP access and the non-3GPP access, the UE can request the establishment of an MA PDU session as follows.

[0227] When the UE is dual-registered with a network (e.g., a PLMN) via both the 3GPP access and the non-3GPP access, or when the UE is dual-registered with an administrative domain (e.g., a public land mobile network (PLMN)) via the 3GPP access or the non-3GPP access of two different networks, the UE can initiate the establishment of an MA PDU session as follows. The UE can initiate the establishment of an MA PDU session by sending a request to establish a PDU session to the AMF, and the AMF selects an SMF for the requested PDU session. The request to establish a PDU session (referred to as a PDU session establishment request) can be sent using NAS signaling or a NAS message, and can include a "request type" that indicates whether the PDU session establishment request is for an existing PDU session or for a brand-new PDU session. The SMF selection can be at least partially based on obtaining information about the SMF from the UDM. The PDU session establishment request sent by the UE to the AMF can include the identifier of an existing PDU session ("PDU session ID") for which multiple accesses are being requested. When the PDU session establishment request is an initial request to establish an MA PDU session, the PDU session establishment request sent by the UE to the AMF may not include the identifier of an existing PDU session. The PDU session establishment request can include an indication of the access type of the access through which the UE sends the PDU session establishment request to the AMF.

[0228] When the 'Request Type' included in the PDU session establishment request received from the UE at the AMF indicates "Existing PDU session", the AMF selects the SMF based on the SMF identifier received from the UDM. When the 'Request Type' included in the PDU session establishment request received from the UE at the AMF indicates "Existing PDU session", and either the AMF fails to recognize the PDU session ID included in the PDU session establishment request received from the UE, or the subscription context received from the UDM by the AMF during the registration or subscription profile update notification procedure does not contain the SMF identifier corresponding to the PDU session ID, then an error situation is constituted, and the AMF updates the access type stored for the PDU session.

[0229] When the 'Request Type' indicates "Existing PDU session" and it is indicated that the existing PDU session will be moved between 3GPP access and non-3GPP access (e.g., from 3GPP access to non-3GPP access and vice versa), then if the serving PLMN session identifier of the PDU session (e.g., slice identifier such as single network slice selection assistance information (S-NSSAI)) exists in the allowed session identifiers of the target access type, the PDU session establishment procedure can be executed in the following cases:

[0230] · The SMF identifier corresponding to the PDU session ID and the AMF belong to the same PLMN;

[0231] · The SMF identifier corresponding to the PDU session ID belongs to the home PLMN.

[0232] Otherwise, the AMF rejects the PDU session establishment request sent by the UE with an appropriate rejection reason.

[0233] When the AMF has identified the SMF for the requested PDU session (e.g., by exchanging signaling with the UDM), the AMF sends a MA PDU session creation request to the identified SMF, and the identified SMF can establish the MA PDU session. As part of establishing the MA PDU session, the SMF can retrieve routing rules (such as ATSSS rules) from the PCF, which are used to distribute the traffic of service data flows across both 3GPP access and non-3GPP access. At least some of these routing rules can be provided to the UE (e.g., for routing uplink traffic) and to the UPF connected to the data network (e.g., for routing downlink traffic to the UE).

[0234] After the establishment of an MA PDU session and when user plane resources exist on both 3GPP access and non-3GPP access, the UE applies the policy provided by the PCF (where the policy may include ATSSS rules) considering local conditions (such as network interface availability, signal loss conditions, user preferences, etc.) for deciding how to distribute the uplink traffic of the data streams of the MA PDU session across 3GPP access and non-3GPP access. In other words, after the MA PDU session has been established by the network, the UE can utilize routing rules (e.g., ATSSS rules) to determine how the uplink traffic of the data streams of the MA PDU session will be distributed (e.g., split and / or steered) across 3GPP access and non-3GPP access. The UPF that sends the downlink traffic of the data stream to the UE can apply a similar network-provided policy for determining through which of 3GPP access and non-3GPP access to send the downlink traffic of the data stream to the UE.

[0235] In Figure 1 the example network of Figure 1 by providing each of the UE and UPF with its own respective Multipath Transmission Control Protocol (MPTCP) function and ATSSS lower layer (ATSSS-LL) function, it is possible to enable the establishment of an MA PDU session through 3GPP access and non-3GPP access. The MPTCP function enables the UE to send control protocol (TCP) packets between the UE and the UPF via the 3GPP access network and allows the transmission of Internet Protocol (IP) packets between the UE and the UPF via any access network.

[0236] One of the issues to be considered as part of this application is how the core network can indicate its support for establishing an MA PDU session through more than one 3GPP access and / or more than one non-3GPP access. Another issue to be considered as part of this application is: how the uplink traffic of the data streams of the MA PDU session can be switched, steered, and / or split by the UE through more than one 3GPP access and / or more than one non-3GPP access, and / or how the downlink traffic of the data streams of the MA PDU session can be switched, steered, and / or split by the UPF through more than one 3GPP access and / or more than one non-3GPP access.

[0237] This is because the routing rules for the MA PDU session currently only consider how traffic can be switched, steered, and / or split through one 3GPP access and one non-3GPP access, and because the AMF uses the network type identifier when selecting an SMF for session establishment.

[0238] To solve this problem, a mechanism is proposed below for providing a routing rule for an MA PDU session, which is used to distribute (e.g., handover, steering, and / or splitting) traffic across the access paths of an MA PDU session on one or more accesses of the same access type, where the MA PDU session includes (multiple) access paths (also referred to as (multiple) legs) on each access of the same access type. In other words, a mechanism is proposed below for providing a routing rule for an MA PDU session that includes access paths (legs) on multiple accesses of the same access type, such that a UE can distribute (e.g., handover, steering, and / or splitting) uplink traffic of service data flows for a single PDU session across multiple access paths between the UE and the user plane function of the core network. In this application, the access path (leg) on an access of an MA PDU session refers to the connection or path between the UE and the UPF of the core network, where the connection or path includes a radio connection (or the radio link between the UE and the access network of the access, and the tunnel between the access network and the UPF).

[0239] Enabling the core network to establish an MA PDU session that includes access paths on multiple accesses of the same access type and to provide a routing rule for such an MA PDU session will be useful in multiple different network configurations. For example, it will be useful to provide more efficient routing rules for distributing (e.g., handover, steering, and / or splitting traffic) service data flows across the access paths on multiple accesses of the same access type for at least one of the following network configurations: providing multiple accesses of the same access type within a single public land mobile network (PLMN), providing multiple accesses in a PLMN and a non-public network (NPN) (which can be a stand-alone network), providing multiple accesses of the same access type in at least two PLMNs, providing multiple accesses of the same access type (3GPP access) in the same or different networks, where each of the multiple accesses has a radio access technology (RAT) type that indicates that the access network of the access is a new radio (NR) access network, a non-terrestrial network (NTN), or a long term evolution (LTE). In this example, NTN refers to satellite access based on NR, including different orbits (e.g., geostationary orbit / medium earth orbit / low earth orbit (GEO / MEO / LEO)). For a network configuration that includes two PLMNs or a PLMN and an NPN, the two networks can be managed by the same operator or by different operators with a commercial agreement between them.

[0240] To further address this issue, the following presents that the UE provides an identifier of the access path of the MA PDU session that the UE wishes to establish, as part of the MA PDU session establishment request of the UE. For example, the UE may initiate the establishment of an MA PDU session and generate a PDU session establishment request for the access paths of establishing the MA PDU session through multiple accesses of the same access type, and send the PDU session establishment request to the session management function of the core network. The PDU session establishment request may include a first PDU session establishment request, which includes a first identifier of a first access path and a second identifier of a second access path. These first and second identifiers of the access paths may be regarded as identifying the corresponding access paths of the MA PDU session, which will be established through multiple accesses of the same access type, and the traffic of the service data flow may be routed through the corresponding access paths. The identifier of the access path indicates the unique path of the MA PDU session through which the UE can send the traffic of the service data flow. This identifier of the access path may be different from the PDU session identifier. In other words, this identifier of the access path may be independent of the identifier of the MA PDU session. This identifier of the access path (also referred to herein as "access path identifier") may be used to establish the path of the MA PDU session.

[0241] In response to receiving the access identifier and recognizing that the access paths on the first access and the second access will be used to route the traffic of the service data to and / or from the UE to the UPF of the core network for the same PDU session at the same time, the SMF may determine a routing rule for distributing (e.g., switching, steering, and / or splitting) the traffic of the service data flow across the access paths (i.e., branches) on the first access and the second access.

[0242] Figure 4 Figures 7 to 6 provide an overall overview of the operations performed by various devices of a wireless communication network during the establishment of a multi-access protocol data session, which includes paths on multiple accesses of the same access type that will be used to route the traffic of a data flow (e.g., service data flow), while Figures 7 to 13 illustrates examples of how these aspects are implemented in various different network configurations.

[0243] Figure 4Illustrated are operations that can be performed by a device. In some embodiments, the device can be a user equipment and can include a transceiver configured to send wireless signals to and receive wireless signals from a base station of an access network (such as 3GPP access network 101, 3GPP access network 103), or send signals to and receive signals from an access point of an access network (such as non-3GPP access network 105). The device can also include one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the device to perform Figure 4 the operations shown. In some embodiments, the device can be part of a user equipment and can include one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the device to perform Figure 4 the operations shown.

[0244] At operation 401, the device sends, via a first access, to a first network function of a core network: a first request to establish a multi-access protocol data unit session, the first request including a first access identifier that identifies a first access path of the MA PDU session to be established, wherein the first access path is for transporting traffic of the multi-access protocol data unit session between the device and a second network function (e.g., UPF) of the core network.

[0245] At operation 402, the device receives, via the first access, from the first network function access information related to the first request, the access information including: an indication that access via multiple accesses for the multi-access protocol data unit session is allowed, and the first access identifier. The first access identifier can identify the first access path to be established (e.g., the first path through which the device sends traffic of a data stream to and / or receives traffic of a data stream from a second network function of the core network, and the first path is on an access of a first access type). The access information can be included in a signaling (e.g., NAS message) that also includes session information for establishing the MA PDU session requested in the first request (in other words, the access information can accompany the session information). The access information can be sent separately from the session information for establishing the MA PDU session requested in the first request. The session information can include a session identifier that identifies the MA PDU session. If the first request includes a session identifier that identifies the MA PDU session, the session information can include the session identifier included in the first request.

[0246] At operation 403, the device receives, via the first access or a second access, from the first network function a first rule set that defines how traffic of service data flows will be transported (e.g., split, switched, or steered) across the first access and a second access path of the MA PDU session.

[0247] At operation 404, the apparatus sends traffic, a session (i.e., the requested MA PDU session) via a first access and a second access over a first access path. Thus, a multi-access data session (MA PDU session) over which traffic of a service data flow is conveyed can have multiple paths over an access of the same access type, where each access includes an access path from the apparatus (e.g., UE) to a second network function (e.g., UPF) connected to a data network.

[0248] The establishment of a multi-access data session can be performed in a number of different ways. Although described in more detail below with reference to a "first technique" and a "second technique" and Figures 7 to 13 are described in more detail below, some brief aspects of how to establish a multi-access data session are provided below.

[0249] The first request can include a mapping associating the second access with a second access path identifier.

[0250] When the mapping is included in the first request, the apparatus can receive a message from a first network function and / or a second network function via the second access, the message including a second access identifier and session management information for the above session, and the apparatus uses the session management information to establish the above data flow.

[0251] Regardless of whether the mapping is included in the multi-access request, the data flow for establishing the above session via the first access and the second access can include: the apparatus signaling via the second access to a first network function and / or a second network function a multi-access request for establishing a session over multiple accesses, the multi-access request including an identifier of the multi-access session and an identifier of the second access; the apparatus receiving from the first network function and / or the second network function via the second access the second access identifier and a second set of rules that define how the above traffic will be conveyed across the first access and the second access; and the apparatus using the above second set of rules to send the above traffic across the first access and the second access. When the first set of rules is initially received, the above second set of rules can be used to replace the above first set of rules for conveying the above traffic across the first access and the second access.

[0252] Before any establishment of a session is performed, the apparatus can: register the user equipment via the first access; associate the registration via the first access with a first access identifier; register the user equipment via the second access; and associate the registration via the second access with a second access identifier.

[0253] Figure 5 Illustrates operations that can be performed by an apparatus for a first network function. Depending on an example network configuration (as described below with reference to Figures 7 to 13As further illustrated, the first network function may be a session management function. The first network function may be the first network function described above with reference to Figure 4 The reference to the user equipment hereinafter may correspond to Figure 4 the user equipment in

[0254] During 501, the apparatus receives from the user equipment via a first access: a first request to establish a multi-access protocol data unit session via a plurality of accesses, the first request including a first access identifier identifying the first access, wherein the first access has a first access type.

[0255] During 502, the apparatus sends a PDU session establishment acceptance message to the user equipment via the first access, the PDU session establishment acceptance information indicating that the first network function has accepted the request to establish the MA PDU session. The PDU session establishment acceptance message includes access information related to the first request, the access information including the following items: an indication that access via a plurality of access paths for the above-mentioned multi-access protocol data unit session is allowed, and the first access identifier. As mentioned above with respect to Figure 4 The access information may be sent together with the session information for establishing the MA PDU session that is the subject of the first request, or may be sent separately from the session information for establishing the MA PDU session that is the subject of the first request. The session information may include a session identifier. If the first request includes a session identifier, the session information may include the session identifier of the first request.

[0256] During 503, the apparatus signals or sends a first rule set to the user equipment via the first access or a second access, the first rule set defining how the above-mentioned traffic will be transmitted (e.g., steered, split, and / or switched) across the first access and the second access, wherein the second access is used to transmit the traffic of the multi-access protocol data unit session using the first access type.

[0257] During 504, the apparatus enables the data stream of the above-mentioned session to be sent via the first access and the second access.

[0258] According to the network configuration, the above enabling may be performed in a variety of different ways. Although this will be discussed in more detail below with reference to Figures 7 to 13 it is first discussed some general aspects.

[0259] The first request may include a mapping associating the second access with a second access identifier.

[0260] When the first request includes a mapping, enabling the traffic of the above session to be sent via paths on the first access and the second access may include sending signaling (e.g., NAS message) to the device via the second access, the signaling including a second access identifier and session management information for establishing the session.

[0261] Whether or not the first request includes a mapping, enabling the traffic of the service data flow to be sent via access paths on the first access and the second access may include: the device receiving, via the second access, from the user equipment: a second multi-access request for establishing a multi-access protocol data unit session via multiple accesses, the second multi-access request including a session identifier associated with the first multi-access request and a second access identifier; and the device signaling, via the second access, the second access identifier and a second rule set for defining how the above traffic will be sent across the first access and the second access. The device may generate the first rule set and / or the second rule set based on policy and charging control rules obtained from the policy control function.

[0262] Reference Figure 4 to the example of Figure 5 and the example of

[0263] Figure 6A and Figure 6B illustrate operations that may be performed by the device of the corresponding network function.

[0264] Figure 6A illustrate operations that may be performed by the device of the policy control function.

[0265] During 601A, the device receives, from a first network function (e.g., Figure 5 the first network function of Figure 4 ), a request for a first rule set for a user equipment (e.g.,

[0266] the user equipment of

[0267] ), the first rule set being for communicating (handover, steering, and / or splitting traffic) via paths on a first access of a first access type and a second access of the first access type. The first rule set may relate only to the uplink traffic of the service data flow. The first rule set may relate only to the downlink traffic of the service data flow. The first rule set may relate to both the downlink traffic and the uplink traffic of the service data flow. Figures 4 to 6AFor any example, the first rule set may be configured to control the user plane function to send (e.g., handover, split, and / or steer) downlink traffic of service data flows destined for the device (e.g., UE) across at least one of the following: paths over multiple 3GPP accesses; or paths over multiple non-3GPP accesses.

[0268] For Figures 4 to 6A For any example, the first rule set may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic to the device (e.g., UE): whether the path over the access is allowed for the identified downlink traffic; or whether the path over the access will act as the active access for the identified downlink traffic and, if the path over the access will act as the active access for the identified downlink traffic, the proportion of the identified downlink traffic that the path over the access will carry; or an indication for the following when the conditional redundancy steering mode will apply: which paths over the accesses will carry the identified downlink traffic and which paths over the accesses will carry a copy of at least a portion of the identified downlink traffic. It should be understood that any other possible rules may be provided to configure how to send (e.g., handover, steer, split) downlink traffic across paths over multiple accesses of the same access type to the device (e.g., UE).

[0269] In Figure 4 and Figure 5 For both examples, the first rule set and / or the second rule set may include rules for sending (e.g., handover, steer, split) traffic across each access (e.g., each of the first access and the second access), and the rules are used to control the communication of the uplink traffic of the service data flows by the user equipment across at least one of the following: multiple 3GPP accesses; or multiple non-3GPP accesses.

[0270] In Figure 4 and Figure 5In examples of both, the first rule set and / or the second rule set may include rules for sending (e.g., splitting, steering, and / or switching) service data traffic for each access path across a MAPDU session, the rules being for allowing the device (e.g., UE) to control the transmission of the identified uplink traffic based on at least one of the following policies: whether the path on access is allowed for the identified uplink traffic; or whether the path on access will act as the active path for the identified uplink traffic and, if the path on access is to act as the active path for the identified uplink traffic, the proportion of the identified uplink traffic that the path on access will carry; or, when the conditional redundancy steering mode will apply, an indication of which access paths will carry the identified uplink traffic and which access paths will carry a copy of at least a portion of the identified uplink traffic. It should be understood that any other possible rules may be provided to configure how uplink traffic is conveyed through the network (e.g., steered, split).

[0271] Figure 6B Illustrates operations that may be performed by a device for user plane function.

[0272] During 601B, the device receives a first rule set from a first network function (e.g., Figure 5 the first network function of ) for sending traffic to a user equipment (e.g., Figure 4 the user equipment of ) using each of a first access path associated with a first access type and a second access path associated with the first access type.

[0273] During 602B, the device sends traffic to the user equipment according to the first rule set described above.

[0274] The first rule set may cause the user plane function to distribute (e.g., split, switch, and / or steer) the downlink traffic of service data across at least one of the following: multiple 3GPP access paths; or multiple non-3GPP access paths.

[0275] In Figures 5 to 6BIn any example, the first set of rules may be configured to allow the user plane function to apply at least one of the following policies to the transmission of the identified downlink traffic: whether the path on the access is allowed for the identified downlink traffic; or whether the path on the access will act as the active path for the identified downlink traffic, and if the path on the access is to act as the active path for the identified downlink traffic, the proportion of the identified downlink traffic that the path on the access will carry; or when the conditional redundancy guiding mode will be applied, an indication for the following: which paths on the access will carry the identified downlink traffic and which paths on the access will carry a copy of at least a part of the identified downlink traffic. It should be understood that any other possible rules may be provided to configure how the user plane function sends (e.g., guides, splits) the downlink traffic.

[0276] In Figures 5 to 6B all examples, the first access type may be one of 3GPP access and non-3GPP access.

[0277] The above aspects introduce new control plane signaling ("signaling") among entities such as UE, AMF, SMF, PCF, and UPF.

[0278] For a MA PDU session, the signaling may include multiple (i.e., more than one) paths (branches) on each of 3GPP access and / or non-3GPP access. Each path (branch) (also referred to herein as an access path, access route) has a corresponding identifier that is used to identify the corresponding path (branch) (hereinafter labeled as Leg_ID). The Leg_ID may be assigned by the UE and / or by a network entity (or network function) of the core network such as AMF.

[0279] For example, the UE, SMF, and / or AMF may use non-access stratum (NAS) signaling to determine the Leg_ID of each path (branch) of the MA PDU session as part of the UE's initial registration with the AMF or during part of the session establishment process. The Leg_ID may be included in the PDU session establishment request sent by the UE via the AMF to the SMF. The Leg_ID is known to the AMF because the Leg_ID may be provided in an uplink and / or downlink (UL / DL) NAS transport message that carries the MA PDU session establishment request, which will be forwarded to the SMF selected by the AMF for establishing the PDU session. This signaling does not affect any enhanced packet core (EPC) signaling. Additional examples of this signaling are provided below.

[0280] As a more specific example, and considering the case when the Leg_ID is set by the UE, the UE may send the Leg_ID inside the PDU session establishment message, which enables the SMF and / or the AMF to become aware of the Leg_ID set by the UE; or the UE may send the Leg_ID to the AMF inside the uplink NAS transport message to the AMF.

[0281] Since there are multiple (i.e., more than one) "paths", "branches", or "access paths" on each 3GPP access and / or non-3GPP access (and potentially more than two 3GPP and non-3GPP accesses), the service handover, splitting, and steering capabilities of the ATSSS feature and the steering mode of the ATSSS feature can be modified to accommodate this variation in the number of paths for each access of the same access type that can be used to transport service data flows between the UE and the network (e.g., between the UE and the user plane function, or between the UE and an entity configured to receive service data flows for a service in a non-5G network).

[0282] For example, a policy control (PCC) rule sent from the PCF to the SMF can be defined to accommodate the steering service (e.g., data) of service data flows associated with the same PDU session across two or more access paths on an access of the same access type (e.g., two or more 3GPP access paths or two or more non-3GPP access paths), the N4 rule (e.g., the updated multi-access rule (MAR)) sent from the SMF to the UPF can be updated to accommodate multiple paths on an access of the same access type, and the ATSSS rule sent from the SMF to the UE can be updated to accommodate multiple access paths on an access of the same access type.

[0283] The modification of the ATSSS steering mode of the ATSSS feature can be as follows.

[0284] First, for the active - standby mode, for each access path identifier (Leg_ID) associated with an access path, it can be indicated whether the access path associated with that access path identifier (Leg_ID) is active. For example, thus support can be provided to indicate that the access path with access path identifier Leg_ID1 is active, the access path with access path identifier Leg_ID2 is standby, and the access path with access path identifier Leg_ID3 will not be used (even as a standby access path); and / or indicate that, for example, the access path associated with Leg_ID1 is active, and other access paths are used as standby under certain conditions (load, latency, etc.) with a certain priority. In other words, a mechanism can be provided to indicate, for each access path identifier of each access path, whether the access path associated with that access path identifier will be used and / or whether at least one condition will be met to use the associated access.

[0285] Second, for the priority - based mode, the relative priority for each access path can be provided as part of the routing rules. For example, when the access path with the highest priority is congested, the UE can also consider using the access path with the second - highest priority to route traffic, and so on. As another example, the priority - based mode can be supported so that an access path can simply be defined as the highest - priority branch, and all other access paths can be used by treating all other access paths as having the same (lower) priority (i.e., when the high - priority access path is congested, any of the lower - priority access paths or all other access paths can be used).

[0286] Another possibility to support the priority - based mode is to provide priorities that can be used in both the active - standby and priority - based steering modes. For example, in the active - standby steering mode, when the active access path is unavailable, the entity (e.g., the UE for uplink data and the UPF for downlink data) that determines how the data for the session will be routed can use the corresponding priorities associated with each access path to select at least one standby branch to send the data for the session. When at least one access path is congested, the same priorities can be used when the entity is in the priority - based mode.

[0287] As another example, for the load - balancing mode, a split percentage value can be defined for each Leg_ID, where the sum of the percentage values on all branches is 100%.

[0288] As another example, for the redundancy mode (which will be introduced as a guiding mode in Rel-18), an indication can be provided for each branch, which indicates whether it is allowed to copy packets to other branches. In other words, the redundancy mode allows the definition of a primary branch, and the other branches are marked as secondary branches. In this case, when the primary branch is congested, the copied traffic can be signaled to one or any of the secondary branches. The branch to be used can be selected according to the associated priorities of the other branches and / or based on the configuration used to copy a certain percentage of the traffic to other branches. Therefore, the redundancy mode can be associated with the indication of the primary branch and the secondary branches provided in the routing rules.

[0289] In another example, when redundancy is unconditionally applied to a traffic flow (e.g., SDF) (i.e., when there is no definition of a primary branch and / or a requirement for the congested primary branch for redundancy), any pair of branches can be used for traffic copying. This can also be optionally linked to the corresponding priorities associated with each branch. For example, when branches 1 and 2 are available, SDF1 can be copied through each of branches 1 and 2 with a first priority; and when branches 1 and 2 are unavailable, SDF1 can be copied through branches 3 and 4 with a second priority, and so on.

[0290] In yet another example of unconditional redundancy, a percentage of the SDF may be copied to different pairs, and all of these add up to the entire traffic of the SDF. For example, the mode can be that 40% of the SDF traffic is unconditionally copied through branches 1 and 2, and 60% of the SDF traffic is unconditionally copied through branches 3 and 4.

[0291] In another example of conditional copying, when the primary branch is congested, the traffic is copied to the remaining branches according to a certain percentage. For example, when primary branch 1 is congested, the copied traffic can be signaled such that 30% of the traffic is copied to branch 2, and 70% of the copied traffic is signaled to branch 3.

[0292] For all the currently described routing mechanisms, at least one of the first technique and the second technique now described can be deployed.

[0293] In the first technique, the UE indicates only the Leg_ID of the access that the UE wants to establish to the network function (e.g., AMF and / or SMF) at a given time. Therefore, in the first technique, the network function does not know any potential future branches, and thus when requesting the ATSSS rules from the PCF, only the (multiple) currently indicated / established branches of the UE's PDU session are considered.

[0294] When the UE requests to establish a new branch for the same session and the same access type, the SMF considers this new branch (in addition to the previously established branches) and provides the UE with new / updated ATSSS rules. Thus, in the first established branch, the SMF may not indicate the ATSSS rules to the UE because only one access is established at that point in time. This is different from the current implementation of ATSSS, where the establishment of a MA PDU session on one access path triggers the provision of ATSSS rules from the SMF to the UE. In the current ATSSS definition, the number of possible access paths is known, which can be one (i.e., ATSSS is not active at all) or exactly two (i.e., one 3GPP path and one N3GPP path). However, in the future, many combinations of more than one 3GPP and / or more than one N3GPP path are possible.

[0295] An extension to this first technique will allow multiple possible or permitted combinations of 3GPP access paths and N3GPP access paths to be restricted by the standard either through implementation (e.g., up to two 3GPP paths and up to one N3GPP path) or through UE subscription data. In this extension, after the UE establishes a MA PDU session through one access path, a set of ATSSS rules can be provided to the UE to cover all possible path combinations.

[0296] According to the second technique, the UE actively indicates a list of access identifiers Leg_ID to the functional network (e.g., AMF / SMF) within the first MA PDU session request for the accesses through which the UE will establish access paths for the MA PDU session and the corresponding access paths (e.g., one NR, one LTE, one N3GPP).

[0297] In the second technique, when requesting the PCF to generate ATSSS rules and MAR rules, the network function can consider all these access paths (branches) as potentially available access paths (branches). The SMF can then actively indicate the ATSSS rules to the UE when confirming the first MAPDU session request from the UE. When the UE requests to establish a second access path (branch), the SMF can update the ATSSS rules and indicate them to the UE.

[0298] As an extension to this, the UE can forego actively indicating the list of access path identifiers (Leg_ID), and the PCF assigns new ATSSS rules based on all possible permitted access paths (branches). The permitted access paths (branches) can be determined by the operator policy or through UE subscription data, as described for the first technique.

[0299] These first and second techniques are described below with reference to Figures 7 to 13are described to illustrate how they may be implemented in different network configurations.

[0300] For simplicity and clarity, Figures 7 to 13 these additional examples consider the establishment of a MA PDU session initiated by a UE after the UE has registered with the core network of a mobile network via two 3GPP accesses. However, this is for illustrative purposes only, and it should be understood that the examples presented may apply to a UE requesting the establishment of a MA PDU session after the UE has registered with the core network of a mobile network (or different mobile networks) via more than two 3GPP accesses and / or more than two non-3GPP accesses.

[0301] It should also be understood that Figures 7 to 13 the examples of Figures 4 to 6B provide examples of how the devices described above interact with each other in different network configurations. Thus, the aspects described above with reference to the Figures 4 to 6B devices may be found to have counterparts in the operations performed by Figures 7 to 13 devices with equivalent names below.

[0302] Figure 7 illustrates a first technique for establishing a MA PDU session via multiple accesses of the same access type with respect to a first network configuration, and Figure 8 illustrates a second technique for establishing a MAPDU session via multiple accesses of the same access type with respect to a first network configuration.

[0303] In this first network configuration, there are a UE 701, a first 3GPP access network 702, a second 3GPP access network 703, a first AMF 704, a second AMF 705, an SMF 706, and a UPF 707. The first 3GPP access network 702, the first AMF (referred to as AMF1 704), the SMF 706, and the UPF 707 are located in or are part of a first public land mobile network (PLMN1). The second 3GPP access network 704 and the second AMF 705 (referred to as AMF2 705) are located in or are part of a second public land mobile network (PLMN2). The first 3GPP access network 702 is an NG-RAN (referred to as NG-RAN1). The second 3GPP access network 703 is also an NG-RAN (referred to as NG-RAN2). The first AMF (AMF1) 704, the SMF 706, and the UFP 707 are part of the core network of PLMN1, and the second AMF (AMF2) 705 is part of the core network of PLMN2. For ease of illustration, other network functions of the core network of PLMN1 and other network functions of the core network of PLMN2 are omitted. The UE 701 can send control plane signaling to and receive control plane signaling from the core network of PLMN1 via the first 3GPP access network 702. The UE 701 can also send control plane signaling to and receive control plane signaling from the core network of PLMN1 via the second 3GPP access network 703.

[0304] Figure 7 The figure illustrates control plane signaling (collectively referred to herein as signaling) that can be sent between the UE 701, the first 3GPP access network 702, the second 3GPP access network 703, AMF1 704, AMF2 705, SMF 706, and the UPF 707 according to a first technique with respect to the first network configuration to establish a MAP PDU session.

[0305] During 7001, the UE 701 registers with the AMF1 704 in the core network of PLMN1 via the first 3GPP access network 702 by sending a first registration request to the AMF1 704 via the first 3GPP access (hereinafter generally referred to as 3GPP1). The registration request sent by the UE 701 is a request to register the UE 701 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1), which indicates that the registration request is the first registration of the UE 701 with the network. During 7001, the UE 701 receives a registration acceptance message from the AMF1 704 via the first 3GPP access network 702. The registration acceptance message indicates to the UE 701 that the UE 701 is registered with PLMN1 via the first 3GPP access (3GPP1). In other words, the registration acceptance message indicates to the UE 701 that the AMF1 704 has accepted the request to register the UE 701 with PLMN1 and has a registration for the UE 701 via the first 3GPP access. During 7001, the UE 701 also obtains a first access path identifier Leg_ID1. Hereinafter, terms such as "Leg_ID" refer to identifiers of access paths. Therefore, Leg_ID1 refers to the identifier of the first access path, Leg_ID2 refers to the identifier of the second access path, and so on. Leg_ID1 identifies the first access path of the MA PDU session. The first access path of the MA PDU session includes the radio connection or radio link between the UE 701 and the first 3GPP access network 702, and the N3 tunnel from the NG-RAN1 to the UPF 707. The UPF 707 may perform the functions of the UPF 707 described above with respect to Figure 6B The functions of the UPF 707 described. The UE 701 may send traffic of service data flows to the UPF 707 via the first access path. Since the first access path includes a 3GPP access network (e.g., the first 3GPP access network 702), the first access path may be referred to as the first 3GPP access path.

[0306] During 7002, the UE 701 registers with the AMF2 705 in the core network of PLMN2 via a second 3GPP access network 703 by sending a registration request to the AMF2 705 via the second 3GPP access (hereinafter generally referred to as 3GPP2). The registration request sent by the UE 701 is a request to register the UE 701 with PLMN2. The registration request may include a registration identifier that indicates that the registration request is a second registration of the UE 701 with the network. During 7002, the UE 701 receives a registration acceptance message from the AMF2 705 via the first 3GPP access network 703. The registration acceptance message indicates to the UE 701 that the UE 701 is registered with PLMN2 via the second 3GPP access. In other words, the registration acceptance message indicates to the UE 701 that the AMF2 705 has accepted the request of the UE 701 to register with PLMN2 and has a registration for the UE 701 via the second 3GPP access. During 7002, the UE 701 also obtains an access path identifier, Leg_ID2. Leg_ID2 identifies a second access path of the MA PDU session. The second access path includes a radio connection or radio link between the UE 701 and the second 3GPP access network 702, and a tunnel between the 3GPP access network 703 and the UPF707 in the core network of PLMN1. The UPF 707 may perform the functions of the UPF described above with respect to Figure 6B The functions of the UPF described above. The UE 701 may send traffic of service data flows to the UPF 707 via the second access path. Since the second access path includes a 3GPP access network (e.g., the second 3GPP access network 703), the second access path may be referred to as the second 3GPP access path.

[0307] During 7003, the UE 701 determines that an MA PDU session will be established, and the MA PDU session includes a first access path and a second access path on two 3GPP accesses (i.e., a first access path on the first 3GPP access (3GPP1) and a second access path on the second 3GPP access (3GPP2)). For example, the UE 701 may determine that an MA PDU session (e.g., a PDU session with a PDU session identifier (ID)=5) will be established, and the MA PDU session has one access path on each of the two 3GPP accesses (i.e., a first access path on the first 3GPP access (3GPP1) and a second access path on the second 3GPP access (3GPP2), and thus has a total of two access paths).

[0308] At 7004, the UE 701 triggers a MAP PDU session establishment procedure for requesting to establish a first access path identified by a first access path identifier (Leg_ID1). For example, the UE 701 may trigger a PDU session establishment procedure and send session management signaling to the SMF 706. The session management (SM) signaling may be encapsulated in an uplink non-access stratum (NAS) signal, which is sent by the UE 701 to the AMF1 704 via the first 3GPP access network 702 through the first 3GPP access (3GPP1). The SM signaling may include the first access path identifier (Leg_ID1) and an identifier of the specific 3GPP access (3GPP1) through which the MAP PDU establishment request is being sent. The SM signaling may also include an indication that the establishment of the MAP PDU session is being requested, a PDU session identifier for the MAP PDU session (e.g., 5), and a PDU establishment request for the first access path for establishing the MAP PDU session through the first 3GPP access (3GPP1). In some embodiments, the uplink NAS signal includes the first access path identifier (Leg_ID1).

[0309] At 7005, the AMF1 704 signals the SM signaling received in the uplink NAS signal. In other words, the AMF1 704 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to the SMF 706. The SMF 706 may be the first network function described above with reference to Figures 4 to 6B that, but it should be understood that an AMF (such as the AMF1 704 or the AMF2 705) may perform the functions of the first network function. As described above, the SM signaling may thus include the first access path identifier (Leg_ID1), a PDU session identifier for the MAP PDU session (i.e., PDU session ID = 5), an indication that the establishment of the MAP PDU session is being requested, and a PDU establishment request for the first access path for establishing the MAP PDU session through the first 3GPP access (3GPP1). The AMF1 704 may signal the SM signaling to the SMF 706 by invoking the PDUSession_createSMcontextReq service operation.

[0310] At 7006, the SMF 706 responds to the AMF1 704. The SMF 706 can respond to the AMF1 704 by sending a response (i.e., sending a signaling or message) to the AMF1 704, and the response can include an indication that the request to establish a MA PDU session has been accepted by the SMF 706. The response can also include a first access path identifier (Leg_ID1) and an indication that the request for the first access path to establish a MA PDU session via the first 3GPP access (3GPP1) has been accepted. Optionally, the response can include a flag (or some other indication, labeled as "MultiLeg_support_IND" herein), which indicates whether the MA PDU session feature has been enabled / disabled and / or whether it is supported / unsupported by the SMF 706. The MA PDU session feature of the SMF 706 is the ability of the SMF 706 to establish a MA PDU session that includes access paths on multiple accesses of the same access type, and the "MultiLeg_support_IND" indicates whether the SMF 706 has the ability to establish a MA PDU session that includes access paths on multiple accesses of the same access type. In other words, the "MultiLeg_support_IND" indicates whether the SMF 706 can establish a MA PDU session that includes access paths on multiple accesses of the same access type. For example, when the SMF 706 does not support the MAPDU session feature, the SMF 706 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent by the SMF 706 to the UE 701. This can be regarded as an implicit indication that the SMF 706 does not support the MA PDU session feature (i.e., the SMF 706 cannot establish a MA PDU session via two 3GPP accesses). The support of the MA PDU session feature by the SMF 706 can also be indicated in other ways, such as during the registration process at 7001.

[0311] At 7007, the AMF1 704 forwards the response received from the SMF 706 to the UE 7k01. Forwarding the response received from the SMF 706 to the UE 701 by the AMF1 704 can be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 701. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MA PDU session feature is supported by the SMF 706, a new ATSSS rule, and an indication that the request for the establishment of the first access path for the MA PDU session has been accepted.

[0312] 7008 to 7009 relate to establishing a first access path for an MA PDU session, which includes establishing user plane resources for a radio connection or radio link between the UE 701 and the first 3GPP access network 702, and establishing a tunnel (e.g., N3 tunnel) between the first 3GPP access network 702 and the UPF 707.

[0313] At 7010, the UE 701 triggers an MA PDU session establishment request procedure for requesting the establishment of a second access path identified by a second access identifier (Leg_ID2). For example, the UE 701 may trigger a PDU session establishment request procedure and send session management signaling to the SMF 706. The SM signaling may include the second access path identifier (Leg_ID2) and an identifier of the specific 3GPP access (3GPP2) through which the MA PDU establishment request is being sent. The SM signaling may also include an indication that the establishment of the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., PDU session ID = 5), and a PDU establishment request for the second access path for establishing the MA PDU session through the second 3GPP access (3GPP2). In some embodiments, the uplink NAS signal includes the second access path identifier (Leg_ID2).

[0314] At 7011, the AMF2 705 signals the SM signaling received in the uplink NAS signal to the SMF 706. The SMF 706 may be identified by the AMF2 705 retrieving the subscription data of the UE 701. By retrieving the SM signaling from the uplink NAS signal and sending the SM signaling to the SMF 706, the AMF2 705 signals the received SM signaling to the SMF 706. The SM signaling includes an indication that the establishment of the MA PDU session is being requested, the second access path identifier (Leg_ID2), the PDU session identifier (PDU session ID) of the MAPDU session, and the MA PDU establishment request. The AMF2 705 may signal the received SM signaling to the SMF 706 by invoking the PDUSession_createSMcontextReq service operation.

[0315] During 7012, the SMF 706 notifies the PCF (not shown) that an MA PDU session will be established, which includes a first branch identified by Leg_ID1 and a second branch identified by the second access path identifier (Leg_ID2), and obtains new ATSSS rules and new MAR rules for the MA PDU session. The PCF (not shown) may include the above reference Figure 6AThe functions of the PCF. The SMF 706 also updates the UPF 707 with new MARs of the MAPDU session rules. The new MAR rules indicate how the traffic of the service data flow to be sent to the UE should be distributed (e.g., split, switched, and / or steered) across the first access path and the second access path of the MA PDU session.

[0316] At 7013, the SMF 706 responds to the AMF2 705. The SMF 706 can respond to the AMF2 705 by sending a response (i.e., sending a signaling or a message) to the AMF2 705, and the response can include an indication that the request to establish the MA PDU session has been accepted by the SMF 706. The response can also include the second access path identifier (Leg_ID2) and an indication that the request for the second access path to establish the MA PDU session via the second 3GPP access (3GPP2) has been accepted.

[0317] In addition, the response sent to the AMF2 705 at 7013 can include the new ATSSS rules for the MAPDU session obtained from the PCF at 7012.

[0318] At 7014, the AMF2 705 forwards the received information at 7012 to the UE 701. For example, this forwarding can be performed by sending downlink NAS signaling. In this example, the response sent to the AMF2 705 at 7013 includes Leg_ID2 and the new ATSSS rules.

[0319] 7015 to 7016 relate to establishing the second access path via the second 3GPP access (3GPP2), which includes establishing user plane resources between the UE 701 and the second access network 703, and establishing a tunnel (e.g., N3 tunnel) between the second 3GPP access network 703 and the UPF 707.

[0320] During 7017, the UE 701 uses the new ATSSS rules provided at 7014 to determine how to distribute (e.g., handover, split, and / or route) the uplink traffic of the service data flow to be sent to the UPF 707 across the first access path and the second access path of the MA PDU session. For example, after a MA PDU session including a first 3GPP access path and a second 3GPP access path is successfully established, the UE 701 uses the new ATSSS rules to distribute (e.g., handover, steer, split) the uplink traffic of the service data flow to be sent to the UPF 707 across the first access path (Leg_ID1) and the second access path (Leg_ID2). Similarly, the UPF 707 can use the new MAR rules to distribute (e.g., handover, steer, and / or split) the downlink traffic of the service data flow across the first access path (identified by the first access path identifier (Leg_ID1)) and the second access path (identified by the second access path identifier (Leg_ID2)).

[0321] How the first example network configuration implements the second technical reference for establishing a MAPDU session through multiple accesses of the same access type as described above Figure 8 will be described.

[0322] Figure 8 Illustrates the control plane signaling (collectively referred to as signaling) that can be sent between the UE 701, the first 3GPP access network 702, the second 3GPP access network 703, the AMF1 704, the AMF2 705, the SMF 706, and the UPF 707 in the first network configuration according to the second technique to establish a MA PDU session.

[0323] During 8001, the UE 701 registers with the AMF1 704 in the core network of PLMN1 via the first 3GPP access by sending a registration request to the AMF1 704 via the first 3GPP access network 702. The registration request sent by the UE 701 is a request to register the UE 701 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1), which identifies the registration request as the first registration to the network. During 8001, the UE 701 receives a registration acceptance message from the AMF1 704 via the first 3GPP access network 702. The registration acceptance message indicates to the UE 701 that the UE 701 is registered with the AMF1 704 of PLMN1 via the first 3GPP access. In other words, the registration acceptance message indicates to the UE 701 that the AMF1 704 has accepted the request of the UE 701 to register with PLMN1 and has a registration for the UE 701 via the first 3GPP access. During 8001, the UE 701 also obtains a first access path identifier Leg_ID1. As described above, terms such as "Leg_ID" refer to identifiers of access paths. Leg_ID1 identifies the first access path of the MA PDU session. The first access path includes a radio connection or radio link between the UE 701 and the first 3GPP access network 702, and a tunnel between the first 3GPP access network 702 and the UPF 707. The UPF 707 may perform the functions of the UPF described above with respect to Figure 6B The functions of the UPF described. The UE 701 may send traffic of service data flows to the UPF 807 via the first access path. Since the first access path includes a 3GPP access network (e.g., the first 3GPP access network 702), the first access path may be referred to as the first 3GPP access path.

[0324] During 8002, the UE 701 registers with the AMF2 705 in the core network of PLMN2 via the second 3GPP access network 703 by sending a registration request to the AMF2 705. The registration request sent by the UE 701 is a request to register the UE 701 with PLMN2. The registration request may include a registration identifier (e.g., Reg_ID2), which identifies the registration request as the second registration of the UE 701 with the network. During 8002, the UE 701 receives a registration acceptance message from the AMF2 705 via the second 3GPP access network 703. The registration acceptance message indicates to the UE 701 that it is registered with the AMF2 705 of PLMN2 via the second 3GPP access. In other words, the registration acceptance message indicates to the UE 701 that the AMF2 705 has accepted the request of the UE 701 to register with PLMN2 and has a registration for the UE 701 via the second 3GPP access. During 8002, the UE 701 also obtains a second access path identifier Leg_ID2. Leg_ID2 identifies the second access path of the MA PDU session. The second access path includes a radio connection or radio link between the UE 701 and the second 3GPP access network 703, and a tunnel between the second 3GPP access network 703 and the UPF 707 in the core network of PLMN1. The UPF 707 may perform the functions of the UPF described above regarding Figure 6B The functions of the UPF described above. The UE 701 may send traffic of service data flows to the UPF 707 via the second access path. Since the second access path includes a 3GPP access network (e.g., the second 3GPP access network 703), the second access path may be referred to as the second 3GPP access path.

[0325] During 8003, the UE 701 determines that an MA PDU session will be established, which includes a first access path and a second access path on two 3GPP accesses (i.e., the first access path on the first 3GPP access (3GPP1) and the second access path on the second 3GPP access (3GPP2)). For example, the UE 701 may determine that an MA PDU session (e.g., a PDU session with a PDU session identifier (ID)=5) will be established, which has one access path (branch) on each of the two 3GPP accesses (i.e., the first access path on the first 3GPP access (3GGP1) and the second access path on the second 3GPP access (3GPP2), and thus has a total of two access paths).

[0326] At 8004, the UE 701 triggers a MAP PDU session establishment procedure for requesting the establishment of a first access path identified by a first access path identifier (Leg_ID1). For example, the UE 701 may trigger a PDU session establishment procedure and send session management (SM) signaling to the SMF 706. The SM signaling may be encapsulated in an uplink non-access stratum (NAS) signal, which is sent by the UE 701 to the AMF1 704 via the first 3GPP access network 702 through the first 3GPP access (3GPP1). The SM signaling may include the first access path identifier (Leg_ID1) and an identifier of the specific 3GPP access (3GPP1). The SM signaling may also include an indication that the establishment of the MAP PDU session is being requested, a PDU session identifier for the MAP PDU session (e.g., = 5), and a PDU establishment request for the first access path for establishing the MAP PDU session through the first 3GPP access (3GPP1). In some embodiments, the uplink NAS signal includes the first access path identifier (Leg_ID1).

[0327] The SM signaling may also include a mapping of Registered_RAT / access / network ID to the access path identifier (Leg_ID). The mapping of Registered_RAT / access to the access path identifier (Leg_ID) may include the access path identifier (Leg_ID) of the access path of the MAP PDU session that the UE 701 will request to establish in the future, and the corresponding RAT / access type / PLMN or SNPN ID of the access path identifier. The mapping of Registered_RAT / access to the access path identifier (Leg_ID) may be used to enable the SMF 706 to provide new ATSSS rules and new MAR rules at this stage (or time), rather than waiting until other access paths of the MAP PDU session (i.e., the access paths identified by the LegIDs in the mapping) are established.

[0328] At 8005, the AMF1 804 signals the SM signaling received in the uplink NAS signal to the SMF 706. In other words, the AMF1 704 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to the SMF 706. The SMF 706 may be the one referred to above Figures 4 to 6BThe described first network function, it should be understood that an AMF (such as AMF1 or AMF2) may perform the functions of the first network function. As described above, the SM signaling may thus include a first access path identifier (Leg_ID1), a PDU session identifier (PDU session ID), and an indication that the establishment of the MA PDU is being requested, and a PDU establishment request for the first access path for establishing the MA PDU session via the first 3GPP access (3GPP1). AMF1 704 may signal the received SM signaling to the SMF 706 by invoking the PDUSession_createSMcontextReq service operation.

[0329] At 8006, the SMF 806 notifies the PCF (not shown) that an MA PDU session is to be established, the MA PDU session including a first access path identified by the first access path identifier (Leg_ID1) and other access paths identified by the access path identifier (Leg_ID) in the above mapping, including a second access path identified by the second access path identifier (Leg_ID2), and the SMF 806 obtains new ATSSS rules and new MAR rules for the MA PDU session. The new ATSSS rules and new MAR rules may be obtained from the PCF (not shown). The PCF (not shown) may include the functions of the PCF referred to above Figure 6A The SMF 706 also updates the UPF 707 with the new MAR rules for the MA PDU session. The UPF 807 may perform the functions of the UPF described above Figure 6B above.

[0330] At 8007, the SMF 706 responds to the AMF1 704. The SMF 706 can respond to the AMF1 704 by sending a response (i.e., a signaling or a message) to the AMF1 704, which can include an indication that the request to establish a MA PDU session has been accepted. The response can also include a first access path identifier (Leg_ID1) and an indication that the request for the first access path to establish a MA PDU session via a first 3GPP access (3GPP1) has been accepted. Optionally, the response can include a flag (or some other indication, labeled as "MultiLeg_support_IND" herein), which indicates whether the MA PDU session establishment feature has been enabled / disabled and / or is supported / unsupported by the SMF 706. As described above, the MAPDU establishment session feature of the SMF 706 is the ability of the SMF 706 to establish a MA PDU session that includes access paths on multiple accesses of the same access type, and the "MultiLeg_support_IND" indicates whether the SMF 706 has the ability to establish a MA PDU session that includes access paths on multiple accesses of the same access type. In other words, the "MultiLeg_support_IND" indicates whether the SMF706 is capable of establishing a MA PDU session that includes access paths on multiple accesses of the same access type. For example, when the SMF706 does not support the MA PDU session establishment feature, the SMF 706 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (LegID1) in the response sent by the SMF 706 to the UE 701. This can be regarded as an implicit indication that the SMF 706 does not support the MA PDU session establishment feature (i.e., the SMF 706 cannot establish a MA PDU session via two 3GPP accesses). The support of the SMF 706 for the MA PDU session establishment feature can also be indicated in other ways, such as during the registration process at 8001.

[0331] At 8008, the AMF1 704 forwards the response received from the SMF 706 to the UE 701. Forwarding the response received from the SMF706 to the UE 701 by the AMF1 704 can be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 701. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MA PDU session establishment feature is supported by the SMF 706, a new ATSSS rule, and an indication that the request for the establishment of the first access path for the MA PDU session has been accepted.

[0332] 8009 to 8010 relate to establishing a first access path for an MA PDU session, which includes establishing user plane resources for a radio connection or radio link between the UE 701 and the first access network 702, and establishing a tunnel (e.g., N3 tunnel) between the first access network 702 and the UPF 707.

[0333] At 8011, the UE 701 triggers an MA PDU session establishment request procedure for requesting the establishment of a second access path identified by a second access identifier (Leg_ID2). For example, the UE 701 may trigger a PDU session establishment request procedure and send session management signaling to the SMF 706. The SM signaling may include the second access path identifier (Leg_ID2) and an identifier of the specific 3GPP access (3GPP2) through which the MA PDU establishment request is being sent. The SM signaling may also include an indication that the establishment of the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., PDU session ID = 5), and a PDU establishment request for the second access path for establishing the MA PDU session through the second 3GPP access (3GPP2). In some embodiments, the uplink NAS signal includes the second access path identifier (Leg_ID2). The SM signaling may also include a mapping of Registered_RAT / access / network ID to access identifier (Leg_ID). This mapping of Registered_RAT / access to access identifier (Leg_ID) may include the access path identifier (Leg_ID) of the access path of the MA PDU session that the UE 701 will request to establish in the future, and the corresponding RAT / access type / PLMN or SNPNID of this access path identifier. This mapping can be used to enable the SMF 706 to provide new ATSSS rules and new MAR rules at this stage (or time), rather than waiting until other access paths of the MA PDU session (i.e., the access path identified by the LegID in the mapping) are established.

[0334] At 8012, the AMF2 705 signals the received SM signaling to the SMF 706. In other words, the AMF2 705 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to the SMF 706. The SMF 706 can be identified by the AMF2 705 retrieving the subscription data of the UE 701. As described above, the SM signaling can thus include a second access path identifier (Leg_ID2), a PDU session ID for the MA PDU session (e.g., 5), an indication that the establishment of the MA PDU session is being requested, and a PDU establishment request for the second access path for establishing the MA PDU session via a second 3GPP access (3GPP2). The AMF2 705 can send the SM signaling to the SMF 706 by invoking the PDUSession_createSMcontextReq service operation.

[0335] During 8013, the SMF 806 notifies a PCF (not shown) that an MA PDU session will be established, the MA PDU session including a first access path associated with Leg_ID1 and a second access path identified by a second access path identifier (Leg_ID2), and obtains new ATSSS rules and new MAR rules for the MA PDU session. The new ATSSS rules and new MAR rules can be obtained from the PCF (not shown). The PCF (not shown) can include the functions of the PCF described above with reference to Figure 6A The SMF706 also updates the UPF 707 with the new MAR rules for the MA PDU session. The new MAR rules indicate how the traffic of the service data flow to be sent to the UE should be distributed (e.g., split, switched, and / or steered) across the first access path and the second access path of the MA PDU session.

[0336] At 8014, the SMF 706 responds to the AMF2 705. The SMF 706 can respond to the AMF2 705 by sending a response (i.e., sending a signal or message) to the AMF2 705, the response can include an indication that the request to establish the MA PDU session has been accepted by the SMF706. The response can also include the second access path identifier (Leg_ID2) and an indication that the request for the second access path for establishing the MA PDU session via a second 3GPP access (3GPP2) has been accepted.

[0337] In addition, the response can include the new ATSSS rules obtained from the PCF during 8013.

[0338] At 8015, the AMF2 705 forwards the response received from the SMF 706 at 8014 to the UE 701. Forwarding the response received from the SMF 706 to the UE 701 by the AMF1 704 can be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 701. In this example, the response encapsulated in the downlink NAS signal includes a second access path identifier (Leg_ID2), a new ATSSS rule, and an indication that the request for the establishment of the second access path for the MA PDU session has been accepted.

[0339] 8016 to 8017 relate to the establishment of the second access path of the MA PDU session, which includes establishing user plane resources for a radio connection or radio link between the UE 701 and the second access network 702, and establishing a tunnel (e.g., N3 tunnel) between the second access network 702 and the UPF 707.

[0340] During 8018, the UE 701 uses the new ATSSS rule provided at 8015 to determine how to distribute (e.g., split / rout) the traffic of the service data flow destined for the UPF 707 across the first access path and the second access path. For example, after a PDU session including two accesses (two access paths) is successfully established, the UE 801 uses the new ATSSS rule to switch / steer / split the uplink traffic on Leg_ID1 and Leg_ID2. Similarly, the UPF 707 can use the new MAR rule to distribute (e.g., switch / steer / split) the downlink traffic across the first access path associated with Leg_ID1 and the second access path associated with Leg_ID2.

[0341] In Figure 8 the above example, the UE 701 provides a mapping of Registered_RAT / access / network ID to the access path identifier (Leg_ID), and the PCF (not shown) allocates a new ATSSS rule based on all possible access paths of the MA PDU session.

[0342] Figure 9 and Figure 10 illustrate how to implement the above first technique and second technique for establishing an MA PDU session through access by access type in a second network configuration.

[0343] In the second network configuration, there are a UE 901, a 3GPP access network 902, an AMF 903, an SMF 904, and a UPF 905. The 3GPP access network 902, the AMF 903, the SMF 904, and the UPF 905 are part of a public land mobile network (PLMN1). The 3GPP access network 902 is the NG-RAN1. The AMF 903, the SMF 904, and the UPF 905 are part of the core network of the PLMN1. The UE701 can send control plane signaling to the core network of the PLMN1 via the 3GPP access network 902 and receive control plane signaling from the core network of the PLMN1.

[0344] Figure 9 The figure illustrates the control plane signaling (collectively referred to as signaling) that can be sent between the UE 901, the 3GPP access network 902, the AMF 903, the SMF 904, and the UPF 905.

[0345] During 9001, the UE 901 registers with the AMF 903 in the core network via 3GPP access by sending a first registration request to the AMF 903 via the 3GPP access network 902. The first registration request sent by the UE 901 is the first request to register the UE 901 with the PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the first registration of the UE 901 with the PLMN1. During 9001, the UE 901 receives a registration acceptance message from the AMF 903 via the first 3GPP access network 902. The registration acceptance message indicates to the UE 901 that the AMF 903 has accepted the first request of the UE 901 to register with the PLMN1 and has a first registration for the UE 901 via 3GPP access. During 9001, the UE 901 also obtains a first access path identifier Leg_ID1. As described above, the first access path identifier (Leg_ID1) identifies the first access path of the MA PDU session. The first access path includes a first radio connection or first radio link between the UE 901 and the 3GPP access network 902, and a first tunnel between the 3GPP access network 902 and the UPF 905. The UPF 905 may perform the functions of the UPF described above Figure 6B After the first access path is established, as described in further detail below, the UE 901 can send traffic of service data flows to the UPF 905 via the first access path of the MA PDU session. Since the first access path includes the 3GPP access network 902, the first access path may be referred to as the first 3GPP access path.

[0346] During 9002, the UE 901 registers with the AMF 904 in the core network of PLMN1 via the 3GPP access network 902 by sending a second registration request to the AMF 904. The second registration request sent by the UE 901 is the second request to register the UE 901 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID2) that identifies the registration request as the second registration of the UE 901 with PLMN1. During 9002, the UE 901 receives a registration acceptance message from the AMF 904 via the 3GPP access network 902. The registration acceptance message indicates to the UE 901 that the AMF1 903 has accepted the second request for the UE 901 to register with PLMN1 and has a first registration for the UE 901 via the 3GPP access. During 9002, the UE 901 also obtains a second access path identifier Leg_ID2. The second access path includes a second radio connection or second radio link from the UE 901 to the 3GPP access network 902 and a tunnel from the 3GPP access network 902 to the UPF 907. The UPF 907 may perform the functions of the UPF as described above regarding Figure 6B the UPF. As described in further detail below, after the second access path is established, the UE 901 may send traffic of service data flows to the UPF 907 via the second access path. Since the second access path includes a 3GPP access network, the second access path may be referred to as a second 3GPP access path.

[0347] During 9003, the UE 901 determines that an MA PDU will be established that includes a first access path and a second access path over the 3GPP access. For example, the UE 901 may determine that an MA PDU session (e.g., a PDU session with a PDU session identifier (ID) = 5) will be established that has two access paths over the 3GPP access (i.e., a total of two access paths in this example).

[0348] At 9004, UE 901 triggers a MAP PDU session establishment procedure for requesting to establish a first access path identified by a first access path identifier (Leg_ID1). For example, UE 901 may trigger a PDU session establishment procedure to send session management (SM) signaling to SMF 904. The SM signaling may be encapsulated inside an uplink non-access stratum (NAS) signal, which is sent by UE 701 to AMF 903 via a 3GPP access network 902 over 3GPP access 3GPP1. The SM signaling may include the first access path identifier (Leg_ID1) and an identifier of a specific 3GPP access (3GPP1). The SM signaling may further include an indication that the establishment of the MAP PDU session is being requested, a PDU session identifier for the MAP PDU session (e.g., 5), and a PDU establishment request for the first access path for establishing the MAP PDU session.

[0349] At 9005, AMF 903 signals the SM signaling received in the uplink NAS signal to SMF 904. In other words, AMF 903 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to SMF 904. SMF 904 may be the first network function described above with reference to Figures 4 to 6B but it should be understood that an AMF (such as AMF 903) may perform the functions of the first network function. AMF 903 may signal the SM signaling to SMF 904 by invoking the PDUSession_createSMcontextReq service operation.

[0350] At 9006, the SMF 904 responds to the AMF 903. The SMF 904 can respond to the AMF 903 by sending a response (i.e., by sending a signaling or a message), and the response can include an indication that the MAPDU session establishment request has been accepted by the SMF 904. The response can also include a first access path identifier (Leg_ID1) and an indication that the PDU establishment request (i.e., the request for the first access path for establishing the MAPDU session) has been accepted by the SMF 904. Optionally, the response can include a flag (or some other indication, labeled as "MultiLeg_support_IND" herein), which indicates whether the MAPDU session feature has been enabled / disabled and / or whether it is supported / not supported by the SMF 904. The MAPDU session feature of the SMF 904 is the ability of the SMF 904 to establish a MAPDU session with multiple access paths on an access including an access type (e.g., a MAPDU session with multiple access paths on 3GPP access), and "MultiLeg_support_IND" indicates whether the SMF 904 has the ability to establish a MAPDU session with multiple access paths on an access including an access type. For example, when the SMF 904 does not support the MAPDU session feature, the AMF 903 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent to the UE 901. This can be regarded as an implicit indication that the SMF904 does not support the MAPDU session feature (i.e., the SMF 904 cannot establish a MAPDU session with two access paths on 3GPP access). The support of the SMF 906 for the MAPDU session feature can also be indicated in other ways, such as during the registration process at 9001.

[0351] At 9007, the AMF 903 forwards the received response to the UE 901. The AMF 903 forwarding the response received from the SMF 904 to the UE 901 can be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 901. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MAPDU session establishment feature is supported by the SMF 904, and an indication that the request for the establishment of the first access path for the MAPDU session has been accepted.

[0352] 9008 to 9009 relate to establishing a first access path for a MA PDU session, which includes establishing user plane resources of a radio connection or radio link between the UE 901 and the 3GPP access network 902, and establishing a tunnel (e.g., N3 tunnel) between the 3GPP access network 902 and the UPF 905. The UPF 905 may perform the functions of the UPF as described above with respect to Figure 6B the UPF described.

[0353] At 9010, the UE 901 triggers a PDU session establishment procedure for requesting the establishment of a second access path identified by a second access path identifier (Leg_ID2). For example, the UE 901 may trigger a PDU session establishment procedure to send session management (SM) signaling to the SMF 904. The SM signaling may be encapsulated inside an uplink non-access stratum (NAS) signal, which is sent by the UE 701 via the 3GPP access network 902 to the AMF 903 through the 3GPP access 3GPP1. The SM signaling may include a first access path identifier (Leg_ID1) and an identifier of a specific 3GPP access (3GPP1). The SM signaling may further include an indication that the establishment of the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., PDU session ID = 5), and a PDU establishment request for establishing the first access path of the MA PDU session.

[0354] At 9011, the AMF 903 signals the SM signaling received in the uplink NAS signal to the SMF 904. The SMF 904 may be identified by the AMF 903 retrieving the subscription data of the UE 901. By retrieving the SM signaling from the uplink NAS signal and sending the SMF signaling to the SMF 904, the AMF 903 signals the SM signaling received in the uplink NAS signal to the SMF 904. The SM signaling may further include an indication that the establishment of the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., PDU session ID = 5), and a PDU establishment request for establishing the second access path of the MA PDU session. The AMF 903 may signal the SM signaling to the SMF 904 by invoking the PDUSession_createSMcontextReq service operation.

[0355] During 9012, the SMF 904 notifies the PCF (not shown) that the MA PDU session will be established, and obtains new ATSSS rules and new MAR rules for the MAPDU session. The ATSSS rules and MAR rules may be obtained from the PCF (not shown). The PCF (not shown) may include the above reference Figure 6AThe functions of the described PCF. The SMF 904 also updates the UPF 905 with new MAR rules received from the PCF (not shown).

[0356] At 9013, the SMF 904 responds to the AMF 903. This response may include an indication that the requested PDU session has been established. This response may include a second access path identifier (Leg_ID2).

[0357] In addition, the response sent at 9013 may include new ATSSS rules obtained from the PCF (not shown) during 9012.

[0358] At 9014, the AMF 903 forwards the response received from the SMF 904 to the UE 901. Forwarding the response received from the SMF 904 to the UE 901 by the AMF 903 may be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 901. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MAPDU session establishment feature is supported by the SMF 904, and an indication of the request and acceptance of the establishment of the first access path for the MAPDU session, as well as the new ATSSS rules. 9015 to 9016 relate to establishing the second access path of the MAPDU session, which includes establishing user plane resources of a radio connection or radio link between the UE 901 and the 3GPP access network 902, and establishing a tunnel (e.g., N3 tunnel) between the 3GPP access network 902 and the UPF 905.

[0359] At 9017, the UE 901 uses the new ATSSS rules provided at 9014 to determine how to distribute (e.g., handover, steer, and / or split) the traffic of the service data flow destined for the UPF 905 across the first access path and the second access path. For example, after a PDU session including two access paths on the 3GPP access (i.e., the first access path and the second access path) is successfully established (i.e., via the 3GPP access network 902), the UE 901 uses the new ATSSS rules to distribute (e.g., handover / steer / split) the uplink traffic across the first access path and the second access path. Similarly, the UPF 905 may use the new MAR rules to distribute (e.g., handover, steer, and / or split) the downlink traffic of the service data flow destined for the UE 901 across the first access path and the second access path on the 3GPP access.

[0360] Figure 10 Illustrates how to implement a second technique for establishing a MAPDU session through multiple accesses of the same access type in a second network configuration.

[0361] Figure 10 Illustrated is control plane signaling (collectively referred to as signaling) that can be sent between a UE 901, a 3GPP access network 902, an AMF 903, an SMF 904, and a UPF 905 in a second network configuration according to a second technique for establishing a MA PDU session through multiple accesses of the same access type.

[0362] At 10001, the UE 1001 registers with the AMF 903 of the core network of PLMN1 via 3GPP access by sending a first registration request to the AMF 903 via the 3GPP access network 902. The first registration request sent by the UE 901 is the first request to register the UE 901 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the first registration of the UE 901 with PLMN1. During 10001, the UE 901 receives a registration acceptance message from the AMF 903 via the first 3GPP access network 902. The registration acceptance message indicates to the UE 901 that the AMF 903 has accepted the first request for the UE 901 to register with PLMN1 and has a first registration for the UE 901 via 3GPP access. During 10001, the UE 1001 also obtains a first access path identifier Leg_ID1. As described above, the first access path identifier (Leg_ID1) identifies the first access path of the MA PDU session. The first access path includes a first radio connection or first radio link between 901 and the 3GPP access network 902 and a first tunnel between the 3GPP access network 902 and the UPF 905. The UPF 905 may perform the functions of the UPF as described above with respect to Figure 6B After the first access path is established, as described in further detail below, the UE 901 may send traffic of service data flows to the UPF 905 via the first access path. Since the first access path includes a 3GPP access network, the first access path may be referred to as the first 3GPP access path.

[0363] During 10002, the UE 1001 re-registers with the AMF 903 in the core network via the 3GPP access network 902 by sending a registration request to the AMF 903. The registration request sent by the UE 901 is the second request to register the UE 901 with the PLMN1. Therefore, the UE 901 is requesting a dual registration with the PLMN1. The registration request may include a registration identifier (e.g., Reg_ID2) that identifies the registration request as the second registration of the UE 901 with the PLMN1. During 10002, the UE 901 receives a registration acceptance message from the AMF via the 3GPP access network 902. The registration acceptance message indicates to the UE 901 that the AMF 903 has accepted the first request for the UE 901 to register with the PLMN1 and has a second registration for the UE 901 via the 3GPP access. During 10002, the UE 1001 also obtains a second access path identifier Leg_ID2. As described above, Leg_ID2 identifies the second access path of the MA PDU session. The second access path includes a second radio connection or second radio link between the UE 901 and the 3GPP access network 902, and a second tunnel between the 3GPP access network 902 and the UPF 905. As described in further detail below, after the second access path is established, the UE 901 may send traffic of service data flows to the UPF 905 via the second access path. Since the second access path includes a 3GPP access network, the second access path may be referred to as a second 3GPP access path.

[0364] During 10003, the UE 901 determines that a MA PDU session will be established that includes a first access path and a second access path over the 3GPP access. For example, the UE 901 may determine that a MA PDU session (e.g., a PDU session with a PDU session identifier (PDU session ID) = 5) will be established that has two access paths (i.e., a first access path and a second access path) over the 3GPP access (i.e., a total of two access paths in this example). [[ID=[4]]

[0365] At 10004, the UE 901 triggers a MAP PDU session establishment procedure for requesting the establishment of a first access path identified by a first access path identifier (Leg_ID1). For example, the UE 901 may trigger a PDU session establishment procedure to send session management (SM) signaling to the SMF 904. The SM signaling may be encapsulated inside an uplink non-access stratum (NAS) signal, which is sent by the UE 701 to the AMF 903 via the 3GPP access network 902 over 3GPP access 3GPP1. The SM signaling may include the first access path identifier (Leg_ID1) and an identifier of the specific 3GPP access (3GPP1) through which the MAP PDU establishment request is being sent. The SM signaling may also include an indication that the establishment of the MAP PDU session is being requested, a PDU session identifier for the MAP PDU session (e.g., ID = 5), and a PDU establishment request for the first access path for establishing the MAP PDU session.

[0366] The SM signaling may also include a mapping of Registered_RAT / Access / Network ID to access path identifier (Leg_ID). Such a mapping of Registered_RAT / Access to access path identifier (Leg_ID) may include the next access paths (Leg_ID) that the UE 901 will establish in the future, and the corresponding RAT / Access type / PLMN or SNPNID of that access path. This mapping may be used to enable the SMF 904 to have provided new ATSSS rules to the UE 901 and new MAR rules to the UPF 905 at this stage (or time), rather than waiting until other access paths of the MAP PDU session (i.e., the access paths identified by the LegID in the mapping) are established.

[0367] At 10005, the AMF 903 signals the SM signaling received in the uplink NAS signal to the SMF 904. The SMF 904 may be the one referred to above Figures 4 to 6BThe first network function described above. However, it should be understood that an AMF (such as AMF 903) can perform the functions of the first network function. By retrieving the SM signaling from the uplink NAS signal and sending the SM signaling to the SMF 904, the AMF 903 signals the SMF 904 about the SM signaling received in the uplink NAS signal. Thus, the SM signaling can include a first access path identifier (Leg_ID1), a PDU session identifier (PDU session ID) for the MA PDU session, an indication that the MA PDU session is being requested, and a PDU establishment request for the first access path for establishing the MA PDU session. The AMF 903 can signal the received SM signaling to the SMF 904 by invoking the PDUSession_createSMcontextReq service operation.

[0368] During 10006, the SMF 904 notifies a PCF (not shown) that an MA PDU session will be established, the MA PDU session including a first access path identified by a first access path identifier (Leg_ID1) and a second access path identified by a second access path identifier (Leg_ID2), and obtains new ATSSS rules and new MAR rules for the MA PDU session. The ATSSS rules and MAR rules can be obtained from the PCF (not shown). The PCF (not shown) can include the functions of the PCF described above Figure 6A The SMF 904 also updates the UPF 905 with the new MAR obtained from the PCF (not shown). The UPF 905 can perform the functions of the UPF described above Figure 6B above.

[0369] At 10007, the SMF 1004 responds to the AMF 1003. The SMF 904 can respond to the AMF 903 by sending a response (i.e., by sending a signaling or message), which can include an indication that the MA PDU session establishment request has been accepted by the SMF 904. The response can also include a first access path identifier (Leg_ID1) and an indication that the PDU establishment request (i.e., the request for the first access path to establish the MAPDU session) has been accepted by the SMF 904. Optionally, the response can include a flag (or some other indication, labeled as "MultiLeg_support_IND" herein), which indicates whether the MA PDU session feature has been enabled / disabled and / or whether it is supported / unsupported by the SMF 904. The MA PDU session feature of the SMF 904 is the ability of the SMF 904 to establish a MA PDU session that includes multiple access paths on an access of an access type (e.g., a MA PDU session that includes multiple access paths on 3GPP access), and the "MultiLeg_support_IND" indicates whether the SMF 904 has the ability to establish a MA PDU session that includes multiple access paths on an access of an access type. For example, when the SMF904 does not support the MA PDU session feature, the AMF 903 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent to the UE 901. This can be regarded as an implicit indication that the SMF904 does not support the MA PDU session feature (i.e., the SMF 904 cannot establish a MAPDU session that includes two access paths on 3GPP access). The support of the MA PDU session feature by the SMF 906 can also be indicated in other ways, such as during the registration process at 10001.

[0370] At 10008, the AMF 903 forwards the response received from the SMF 904 to the UE 901. Forwarding the response received from the SMF904 to the UE 901 by the AMF 903 can be performed, for example, by encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 901. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MA PDU session establishment feature is supported by the SMF 904, and an indication that the request for the establishment of the first access path for the MAPDU session has been accepted.

[0371] 10009 to 10010 relate to establishing a first access path for an MA PDU session, which includes establishing user plane resources for a first radio connection or a first radio link between the UE 901 and the 3GPP access network 902, and establishing a first tunnel (e.g., N3 tunnel) between the 3GPP access network 902 and the UPF 905.

[0372] At 10011, the SMF 904 signals the SM information for establishing a second access path for the MA PDU session to the AMF 903. The SMF 904 can signal the AMF 903 by sending an N1N2 messageTransfer signal including the SM information for establishing a second access path for the MA PDU session. The SM information for establishing a second access path for the MA PDU session may include a second access path identifier (Leg_ID2) and information for the AMF, as well as information for establishing a second access path for the MA PDU session in the 3GPP access network.

[0373] At 10012, the AMF 1003 forwards the SM information for establishing a second access path for the MA PDU session received from the SMF 904 to the 3GPP access network 902.

[0374] 10013 to 10014 relate to establishing a second access path for an MA PDU session, which includes establishing additional user plane resources for a second radio connection or a second radio link between the UE 901 and the 3GPP access network 902, and establishing a second tunnel (e.g., a second N3 tunnel) between the 3GPP access network 902 and the UPF 905.

[0375] During 10015, the UE 901 uses the new ATSSS rules provided in the downlink NAS signaling to determine how to distribute (handover, steer, and / or split) the traffic of service data flows across the first access path and the second access path on the 3GPP access. For example, after the MA PDU session including the first access path and the second access path on the 3GPP access is successful, the UE 901 uses the new ATSSS rules to distribute (handover, steer, and / or split) the uplink traffic of service data flows destined for the UPF 905 across the first access path and the second access path on the 3GPP access. Similarly, the UPF 905 can use the new MAR rules to distribute (handover, steer, and / or split) the downlink traffic of service data flows destined for the UE 902 across the first access path and the second access path on the 3GPP access.

[0376] At Figure 10In the above example, UE 1001 establishes a PDU session (PDU session ID = 5) including a first access path (identified by a first access identifier (Leg_ID1)), and UE 901 obtains a new ATSSS rule in advance from the PCF (not shown) via SMF 904, i.e., before establishing the second access path during 10013 and 10014. In addition, since the second access path (identified by a second access path identifier (Leg_ID2)) is on the same 3GPP access as the first access path and points to the same AMF (same PLMN), SMF 904 can actively use N1N2 messageTransfer(10011) to establish the second access path, which includes establishing user plane resources for the second radio link of the second access path and establishing a tunnel for the second access path, without waiting for a new trigger from UE 901 (although it can be understood that establishing user plane resources for the second radio link of the second access path and the tunnel for the second access path can be performed in response to a trigger received from UE 901). UE 901 then receives an indication that the user plane resources for the second radio link of the second access path have been established.

[0377] Figures 11 to 13 Illustrates signaling for establishing a MA PDU session via multiple accesses of the same access type in a third network configuration.

[0378] In this third network configuration, there are UE 1101, a first 3GPP access network 1102, a second 3GPP access network 1103, AMF 1104, MME 1105, PGW-C and SMF 1106, and UPF 1107. The first 3GPP access network 302 is NG-RAN, and the second 3GPP access network 1103 is E-UTRAN. The first 3GPP access network 1102, the second 3GPP access network 1103, AMF 1104, MME 1105, PGW-C and SMF 1106, and UPF 1107 are part of a public land mobile network (PLMN1). AMF 1104, MME 1105, PGW-C and SMF 1106, and UPF 1107 are part of the core network of PLMN1.

[0379] Figure 11 Illustrates a first technique for implementing the establishment of a MAPDU session via multiple accesses of the same access type in a third network configuration.

[0380] Figure 11Illustrated is the control plane signaling (collectively referred to as signaling) that can be sent between the UE 1101, the first access network 1102, the second 3GPP access network 1103, the AMF 1104, the MME 1105, the PGW-C and SMF 1106, and the UPF 1107.

[0381] During 11001, by sending a registration request to the AMF 1104 via the first 3GPP access network 1102, the UE 1101 registers with the AMF 1104 of the core network of PLMN1 through the first 3GPP access (hereinafter referred to as 3GPP1). The registration request sent by the UE 1101 is a request to register the UE 1101 with the AMF 1104 of PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the first registration of the UE 1101 with the AMF1 of PLMN1. During 11001, the UE 1101 receives a registration acceptance message from the AMF 1104 via the first 3GPP access network. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the AMF 1104 of PLMN1 through the first 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the AMF1104 has accepted the request of the UE 1101 to register with PLMN1 and has a registration for the UE 1101 through the first 3GPP access. During 11001, the UE 1101 also obtains the first access path identifier Leg_ID1. Leg_ID1 identifies the first access path of the MA PDU session. The first access path includes a radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and a tunnel between the 3GPP access network 1102 and the UPF 1107. The UPF 1107 may perform the functions of the UPF described above with respect to Figure 6B As described in further detail below, after the first access path is established, the UE 1101 may send traffic of service data flows to the UPF 1107 via the first access path. Since the first access path includes a 3GPP access network, the first access path may be referred to as the first 3GPP access path.

[0382] During 11002, the UE 1101 registers with the MME 1105 in the core network of PLMN1 via the second 3GPP access network 1103 by sending a registration request to the MME 1105. The registration request sent by the UE 1101 is a request to register the UE 1101 with the MME 1105 of PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the second registration of the UE 1101 with PLMN1. During 11002, the UE 1101 receives a registration acceptance message from the MME 1105 via the second 3GPP access network 1103. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the MME 1105 of PLMN1 via the second 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the MME 1105 has accepted the request of the UE 1101 to register with the MME 1105 of PLMN1, and the MME 1105 has a registration for the UE 1101 via the second 3GPP access. During 11002, the UE 1101 also obtains a second access path identifier Leg_ID2. Leg_ID2 identifies the second access path of the MA PDU session. The second access path includes a radio connection or radio link between the UE 1101 and the second 3GPP access network 1103, and a tunnel between the 3GPP access network 1103 and the UPF 1107. The UPF 1107 may perform the functions of the UPF described above with respect to Figure 6B The UPF described. The UE 1101 may send traffic of service data flows to the UPF 1107 via the second access path. Since the second access path includes a 3GPP access network (e.g., the second 3GPP access network 1103), the first access path may be referred to as the second 3GPP access path.

[0383] During 11003, the UE 1101 determines that an MA PDU session will be established, and the MA PDU session includes a first access path and a second access path on two 3GPP accesses (3GPP1, 3GPP2) (i.e., the first access path on the first 3GPP access (3GPP1) and the second access path on the second 3GPP access (3GPP2)). For example, the UE 1101 may determine that a PDU session (e.g., a PDU session with a PDU session identifier (ID) = 5) will be established, and the PDU session has one access path on each of the two 3GPP accesses (i.e., a total of two 3GPP access paths).

[0384] At 11004, the UE 1101 triggers a PDU session establishment procedure for requesting to establish a first access path identified by a first access path identifier (Leg_ID). For example, the UE 1101 may trigger a PDU session establishment request procedure and send session management (SM) signaling to the PGW-C and the SMF 1106. The SM signaling may be encapsulated in an uplink non-access stratum (NAS) signal, which is sent by the UE 1101 to the AMF 1104 via the first 3GPP access network 1102 through the first 3GPP access (3GPP1). The SM signaling may include the first access path identifier (Leg_ID1) and an identifier of the specific 3GPP access (3GPP1). The SM signaling may also include an indication that the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., ID = 5), and a PDU establishment request for the first access path for establishing the MA PDU session. In some embodiments, the uplink NAS signal includes the first access path identifier (Leg_ID1).

[0385] At 11005, the AMF 1104 signals the SM signaling received in the uplink NAS signal to the PGW-C and the SMF 1106. In other words, the AMF 1103 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to the PGW-C and the SMF 1106. The PGW-C and the SMF 1106 may be the first network functions described above Figures 4 to 6B but it should be understood that the AMF (such as the AMF 1104) may perform the functions of the first network function. The AMF 1104 may signal the SM signaling received in the uplink NAS signal to the PGW-C and the SMF 1106 by invoking the PDUSession_createSMcontextReq service operation.

[0386] At 11006, the PGW-C and the SMF 1106 respond to the AMF 1104. The PGW-C and the SMF 1106 can respond to the AMF 1104 by sending a response (e.g., by sending a signaling or a message), which can include an indication that the request to establish the MA PDU session has been accepted by the PGW-C and the SMF 1106. The response can include a first access path identifier (Leg_ID1). Optionally, the response can include a flag (or some other indication, labeled herein as "MultiLeg_support_IND"), which indicates whether the MA PDU session feature has been enabled / not enabled and / or supported / not supported by the PGW-C and the SMF 1106. The MA PDU session feature of the PGW-C and the SMF 1106 is the ability of the PGW-C and the SMF 1106 to establish an MA PDU session with access paths on multiple accesses of the same access type, and the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 have the ability to establish an MA PDU session with access paths on multiple accesses of the same access type. In other words, the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 are able to establish an MA PDU session with access paths on multiple accesses of the same access type. For example, when the PGW-C and the SMF 1106 do not support the MA PDU session feature, the PGW-C and the SMF 1106 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent to the UE 1104. This can be regarded as an implicit indication of not supporting the MA PDU session feature (i.e., the PGW-C and the SMF 1106 cannot establish an MA PDU session with access paths on two 3GPP accesses). The support of the PGW-C and the SMF 1106 for the MA PDU session feature can also be indicated in other ways, e.g., during the registration process at 11001.

[0387] At 11007, the AMF 1104 forwards the received response to the UE 1101. Forwarding the response received from the PGW-C and the SMF 1106 to the UE 1101 can be performed, for example, by the AMF 1104 encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 1101. In this example, the response encapsulated in the downlink NAS signal includes a first access path identifier (Leg_ID1), an indication that the MA PDU session characteristics are supported by the PGW-C and the SMF 1106, and an indication that the request for the establishment of the first access path for the MA PDU session has been accepted by the PGW-C and the SMF 1106. 11008 to 11009 relate to the establishment of the first access path for the MA PDU session, which includes establishing user plane resources for a radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and establishing a tunnel (e.g., N3 tunnel) between the first 3GPP access network 102 and the UPF 1107. The UPF 1107 can perform the functions of the UPF described above with respect to Figure 6B as described.

[0388] At 11010, the UE 1101 signals the PGW-C and the SMF 1106 via the second 3GPP access network 1103 by means of a second 3GPP access (3GPP2). This signaling can be performed via the MME 1105. In other words, the UE 1101 can signal the MME 1105 during 11010, and the MME 1105 can forward this signaling to the PGW-C and the SMF 1106. This signaling can be a request for handover of a packet data network (PDN) connection for a second access path identified by a second access path identifier (Leg_ID). The protocol configuration options (PCO) included in this signaling can include a PDU session identifier (e.g., 5), a second access path identifier (Leg_ID2), and a MA PDU establishment request. Including a PDU session identifier (e.g., 5), a second access path identifier (Leg_ID2), and a MA PDU establishment request in the PCO can allow avoiding affecting the currently defined ESM (EPS session management) signaling. The purpose of the PCO is to provide additional optional information about the destination network to which the UE is connecting. For example, when the UE connects to the Internet, the UE will be given an Internet Protocol (IP) address, and will be given a PCO that includes a default gateway IP address, a Domain Name System (DNS) server address, etc. All these additional types of information are given in the PCO.

[0389] At 11011, the PGW-C and the SMF 1106 notify the PCF that an MA PDU session will be established and obtain new ATSSS rules and new MAR rules for the MAPDU session. The ATSSS rules and the MAR rules can be obtained from the PCF (not shown). The PCF (not shown) may include the functions of the PCF described above with reference to Figure 6A the PCF described. The PGW-C and the SMF 1106 also update the UPF 1107 with the new MAR rules of the MA PDU session.

[0390] At 11012, the PGW-C and the SMF 1106 signal the UE 1101. This signaling may include a request for an active default bearer (e.g., a default EPS bearer). In the PCO, this signaling may include a second access path identifier (Leg_ID2) and the new ATSSS rules obtained at 11011.

[0391] At 11013, the UE 1101 signals the PGW-C and the SMF 1106. This signaling may indicate that the UE 1101 has accepted the default bearer request of 11012. This signaling may include a second access path identifier (Leg_ID2) for identifying the access path on which the bearer will be operated.

[0392] 11014 to 11015 relate to establishing a second access path for the MA PDU session, which includes establishing radio user plane resources for the radio link between the UE 1101 and the second 3GPP access network 1103, and establishing a tunnel (e.g., an N3 tunnel) between the second 3GPP access network 1103 and the UPF 1107.

[0393] At 11016, the UE 1101 uses the new ATSSS rules provided at 11012 to determine how to distribute (switch, steer, and / or split) the traffic of the service data flow destined for the UPF 1106 across the first access path and the second access path. For example, after an MA PDU session including a first access path on a first 3GPP access (3GPP1) and a second access path on a second 3GPP access (3GPP2) is successfully established, the UE 1101 uses the new ATSSS rules to distribute (switch, steer, and / or split) the uplink traffic of the service data flow across the first access path and the second access path. Similarly, the UPF 1107 may use the new MAR rules received from the SMF 1106 to distribute (switch, steer, and / or split) the downlink traffic of the service data flow across the first access path and the second access path.

[0394] Figure 12 is illustrated Figure 11A variant of the signaling. In this variant, instead of indicating the new ATSSS rule within the PCO during 11012, the PDU session modification procedure carrying the new ATSSS rule can be used on the first 3GPP access (3GPP1). This will avoid potentially affecting the current definition of the PCO structure.

[0395] Figure 12 Illustrates the control plane signaling (collectively referred to as signaling herein) between the UE 1101, the first 3GPP access network 1102, the second access network 1103, the AMF 1104, the MME1105, the PGW-C and SMF 1106, and the UPF 1107.

[0396] During 12001, the UE 1101 registers with the AMF 1104 of the core network of the PLMN1 through the first 3GPP access (3GPP1) by sending a registration request to the AMF 1104 via the first 3GPP access network 1102. The registration request sent by the UE 1101 is a request to register the UE 1101 with the PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the first registration of the UE 1101 with the PLMN1. During 12001, the UE 1101 receives a registration acceptance message from the AMF 1104 via the first 3GPP access network 1102. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the AMF 1104 of the PLMN1 through the first 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the AMF 1104 has accepted the request of the UE 1101 to register with the PLMN1 and has a registration for the UE 1101 through the first 3GPP access. During 12001, the UE 1101 also obtains the first access path identifier Leg_ID1. Leg_ID1 identifies the first access path of the MA PDU session. The first access path includes the radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and the tunnel between the first 3GPP access network 1102 and the UPF 1107. The UPF 1107 may perform the functions of the UPF described above regarding Figure 6B The functions of the UPF described above. The UE may send traffic of the service data flow to the UPF 1107 via the first access path. Since the first access path includes a 3GPP access network (e.g., the first 3GPP access network 1102), the first access path may be referred to as the first 3GPP access path.

[0397] During 12002, the UE 1101 registers with the MME 1105 of the core network of PLMN1 via a second 3GPP access network 1103 by sending a registration request to the MME 1105 via the second 3GPP access (collectively referred to as 3GPP2). The registration request sent by the UE 1101 is a request to register the UE 1101 with the MME 1105 of PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as a second registration of the UE 1101 with PLMN1. During 12002, the UE 1101 receives a registration acceptance message from the MME 1105 via the second 3GPP access network 1103. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the MME 1105 of PLMN1 via the second 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the MME1105 has accepted the request of the UE 1101 to register with PLMN1 and has a registration for the UE 1101 via the second 3GPP access. During 12002, the UE 1101 also obtains a second access identifier, Leg_ID2. Leg_ID2 identifies the second access path of the MA PDU session. The second access path includes a radio connection or radio link between the UE 1101 and the second 3GPP access network 1103, and a tunnel between the second 3GPP access network 1103 and the UPF 1107. The UPF 1107 may perform the functions of the UPF described above with respect to Figure 6B The UPF described. The UE 1101 may send traffic of service data flows to the UPF 1107 via the second access path. Since the second access path includes a 3GPP access network (e.g., the second 3GPP access network 1103), the first access path may be referred to as the second 3GPP access path.

[0398] During 12003, the UE 1101 determines that a MA PDU session will be established, which includes a first access path and a second access path on two 3GPP accesses (3GPP1, 3GPP2) (i.e., the first access path on the first 3GPP access and the second access path on the second 3GPP access). For example, the UE 1101 may determine that a PDU session (e.g., a PDU session with a PDU session identifier (ID)=5) will be established, which has one access path on each of the two 3GPP accesses (i.e., a total of two access paths).

[0399] During 12004, the UE 1201 triggers a PDU session establishment request for the first Leg_ID. For example, the UE 1201 may trigger a PDU session establishment request procedure that causes the UE to generate a PDU establishment request (session management signaling), encapsulate the PDU establishment request in an uplink non-access stratum (NAS) signal (or NAS message), and send the NAS signal (or NAS message) to the AMF 1104 via a 3GPP access. In other words, the UE sends a NAS signal (or NAS message) to the AMF1 1204 via the 3GPP access network 3GPP1 network. The SM signaling may include Leg_ID1 and an identifier for a specific 3GPP access (3GPP1). The SM signaling may also include an indication that the MA PDU session is being requested, a PDU session identifier for the MA PDU session (e.g., ID = 5), and a PDU establishment request for the first access path for establishing the MA PDU session. In some embodiments, the uplink NAS signal includes a first access path identifier (Leg_ID1).

[0400] At 12005, the AMF 1104 signals the SM signaling received in the uplink NAS signal to the PGW-C and the SMF 1106. The AMF 1104 may signal the SM signaling to the PGW-C and the SMF 1106 by retrieving the SM signaling from the uplink NAS message and sending the SM signaling to the PGW-C and the SMF 1106. The PGW-C and the SMF 1106 may be the first network functions described above Figures 4 to 6B but it should be understood that an AMF (such as the AMF 1104) may perform the functions of the first network function. The AMF 1104 may signal the SM signaling to the PGW-C and the SMF 1106 by invoking the PDUSession_createSMcontextReq service operation.

[0401] At 12006, the PGW-C and the SMF 1106 respond to the AMF 1104. The PGW-C and the SMF 1106 respond to the AMF 1104 by sending a response (i.e., by sending a signaling or a message), which may include an indication that the requested MA PDU session has been accepted. The response may include a first access path identifier (Leg_ID1). Optionally, the response may include a flag (or some other indication, herein labeled as "MultiLeg_support_IND"), which indicates whether the MA PDU session feature has been enabled / disabled and / or whether it is supported / unsupported by the PGW-C and the SMF 1106. The MA PDU session feature of the PGW-C and the SMF 1106 is the ability of the PGW-C and the SMF 1106 to establish an MA PDU session with access paths on multiple accesses of the same access type, and the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 have the ability to establish an MA PDU session with access paths on multiple accesses of the same access type. In other words, the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 are capable of establishing an MA PDU session with access paths on multiple accesses of the same access type. For example, when the PGW-C and the SMF 1216 do not support the MA PDU session feature, the PGW-C and the SMF 1216 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent to the UE1101. This can be regarded as an implicit indication that the PGW-C and the SMF 1106 do not support the MA PDU session feature (i.e., the PGW-C and the SMF 1106 cannot establish an MA PDU session via two 3GPP accesses). The support of the PGW-C and the SMF 1106 for the MA PDU session feature can also be indicated in other ways, for example, during the registration process at 12001.

[0402] At 12007, the AMF 1104 forwards the received response to the UE 1101. Forwarding the response received from the PGW-C and the SMF 1106 to the UE 1101 can be performed, for example, by the AMF 1104 encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 1101. In this example, the response encapsulated in the downlink NAS signal includes the first access path identifier (Leg_ID1), an indication that the MA PDU session feature is supported by the PGW-C and the SMF 1106, and an indication that the request for the establishment of the first access path of the MA PDU session has been accepted by the PGW-C and the SMF 1106.

[0403] In 12008 - 12009, establishing a first access path via a first 3GPP access (3GPP1) is involved, which includes establishing user plane resources for a radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and establishing a tunnel (e.g., N3 tunnel) between the first 3GPP access network 1101 and the UPF 1107. The UPF 1107 may perform the functions of the UPF as described above with respect to Figure 6B the described UPF.

[0404] At 12010, the UE 1101 signals the PGW - C and the SMF 1106 via a second 3GPP access (3GPP2). This signaling may be performed via the MME 1105. In other words, the UE 1101 may signal the MME 1105 at 12010, and the MME 1105 may forward this signaling to the PGW - C and the SMF 1106. This signaling may be a packet data network (PDN) connection handover request for a second access path identified by a second access path identifier (Leg_ID). The PCO included in this signaling may include an indication of the PDU session (e.g., PDU session ID 5), the second access path identifier (Leg_ID2), and a request for the MA PDU to be performed. Including this information in the PCO may allow avoiding affecting the currently defined ESM (EPS) signaling.

[0405] During 12011, the PGW - C and the SMF 1106 notify the PCF (not shown) that an MA PDU session will be established, and obtain new ATSSS rules and new MAR rules for the MA PDU session. The ATSS rules and MAR rules may be obtained from the PCF (not shown). The PCF (not shown) may include the functions of the PCF as described above with reference to Figure 6A the described PCF. The PGW - C and the SMF 1106 also update the UPF 1107 with the new MAR rules.

[0406] At 12012, the PGW - C and the SMF 1106 signal the UE 1101. This signaling may include a request for an active default bearer (e.g., default EPS bearer). In the PCO, this signaling may include the second access path identifier (Leg_ID2). This signaling does not include the new ATSSS rules obtained during 12011.

[0407] At 12013, UE 1101 signals the PGW-C and SMF 1206. This signaling can indicate that UE 1101 has accepted the default bearer request of 12012. This signaling can include a second access path identifier (Leg_ID2) for identifying the access path on which the bearer will be operated.

[0408] 12014 to 12015 relate to establishing a second access path for the MA PDU session, which includes establishing user plane resources for a radio connection or radio link between UE 1101 and the second 3GPP access network 1103, and establishing a tunnel (e.g., N3 tunnel) between the second 3GPP access network 1103 and the UPF 1107.

[0409] At 12016, the PGW-C and SMF 1106 signal UE 1101. This signaling can include a PDU session modification command. This signaling can include an identifier of the PDU session to be modified (e.g., PDU session ID = 5). This signaling can include the ATSSS rules determined during 12011.

[0410] At 12017, UE 1101 signals the PGW-C and SMF 1206. This signaling can indicate that the requested PDU session modification of 12016 has been completed.

[0411] During 12018, UE 1101 uses the new ATSSS rules provided during 12016 to determine how to distribute (switch, steer, and / or split) traffic destined for the UPF 1107 across the first access path and the second access path. For example, after a MA PDU session including a first access path on the first 3GPP access (3GPP1) and a second access path on the second 3GPP access (3GPP2) is successfully established, UE 1101 uses the new ATSSS rules to distribute (switch, steer) the uplink traffic of the service data flow across the first access path and the second access path. Similarly, the UPF 1107 can use the new MAR rules to distribute (switch, steer, and / or split) the downlink traffic of the service data flow across the first access path and the second access path.

[0412] Figure 13 Illustrates a second technique for implementing the establishment of a MAPDU session through multiple accesses of the same access type in a third network configuration.

[0413] Figure 13 Illustrates the signaling between UE 1101, 3GPP1 1302, 3GPP2 1303, AMF1 1304, MME 1305, PGW-C and SMF1306, and UPF 1307.

[0414] During 13001, the UE 1101 registers with the AMF 1104 in the core network of PLMN1 through the first 3GPP access by sending a registration request to the AMF 1104 via the first 3GPP access network 1102. The registration request sent by the UE 1101 is a request to register the UE 1101 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the first registration of the UE1101 with PLMN1. During 12001, the UE 1101 receives a registration acceptance message from the AMF 1104 via the first 3GPP access network 1102. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the AMF 1104 of PLMN1 through the first 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the AMF 1104 has accepted the request of the UE 1101 to register with PLMN1 and has a registration for the UE 1101 through the first 3GPP access. During 13001, the UE 1101 also obtains a first access path identifier, Leg_ID1. Leg_ID1 identifies the first access path of the MA PDU session. The first access path includes a radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and a tunnel between the first 3GPP access network 1102 and the UPF 1107. The UPF 1107 may perform the functions of the UPF described above with respect to Figure 6B The UE 1101 may send traffic of service data flows to the UPF 1107 via the first access path. Since the first access path includes a 3GPP access network (e.g., the first 3GPP access network 1102), the first access path may be referred to as the first 3GPP access path.

[0415] During 13002, the UE 1101 registers with the MME 1105 of the core network of PLMN1 via a second 3GPP access network 1103 by sending a registration request to the MME 1105. The registration request sent by the UE 1101 is a request to register the UE 1101 with PLMN1. The registration request may include a registration identifier (e.g., Reg_ID1) that identifies the registration request as the second registration of the UE 1101 with PLMN1. During 12002, the UE 1101 receives a registration acceptance message from the MME 1105 via the second 3GPP access network 1103. The registration acceptance message indicates to the UE 1101 that the UE 1101 is registered with the MME 1105 of PLMN1 via the second 3GPP access. In other words, the registration acceptance message indicates to the UE 101 that the MME 1105 has accepted the request of the UE 1101 to register with PLMN1 and has a registration for the UE 1101 via the second 3GPP access. During 13002, the UE 1301 also obtains a second access path identifier Leg_ID2. Leg_ID2 identifies the second access path of the MA PDU session. The second access path includes a link from the UE 1301 to the second 3GPP access network and a tunnel from the 3GPP access to the UPF 1307. The UPF 1307 may perform the functions of the UPF described above with respect to Figure 6B The functions of the UPF described above. The UE may send traffic of the data stream of the MA PDU session to the UPF 1307 via the second access path. Since the second access path includes a 3GPP access network, the first access path may be referred to as the second 3GPP access path.

[0416] During 13003, the UE 1101 determines that an MA PDU session will be established, which includes a first access path and a second access path (i.e., the first access path on the first 3GPP access and the second access path on the second 3GPP access) on two 3GPP accesses (3GPP1, 3GPP2). For example, the UE 1101 may determine that a PDU session (e.g., a PDU session with a PDU session identifier (ID) = 5) will be established, which has one access path on each of the two 3GPP accesses (i.e., a total of two access paths).

[0417] During 13004, the UE 1101 triggers a PDU session establishment procedure for requesting the establishment of a first access path identified by a first access path identifier (Leg_ID1). For example, the UE 1101 may trigger the PDU session establishment procedure and send session management (SM) signaling to the PGW-C and the SMF 1106. The SM signaling may be encapsulated in an uplink non-access stratum (NAS) signal, which is sent by the UE 1101 to the AMF 1104 via the first 3GPP access network 1102 through the first 3GPP access (3GPP1). The SM signaling of 13004 may include the first access path identifier (Leg_ID1) and an identifier of a specific 3GPP access (e.g., the identifier of 3GPP1). The SM signaling may also include an indication that the establishment of the MA PDU session is being requested, the PDU session identifier of the MA PDU session being requested (e.g., 5), the PDU session identifier for the MA PDU session (e.g., ID = 5), and a PDU establishment request for the first access path for establishing the MA PDU session. In some embodiments, the uplink NAS signal includes the first access path identifier (Leg_ID1).

[0418] The SM signaling may also include a mapping of at least one of the following: Registered_RAT to Leg_ID, access to access path identifier (Leg_ID), or network ID to access path identifier (Leg_ID). The mapping of Registered_RAT, access, or network ID to access path identifier (Leg_ID) may include: the access path identifier (Leg_ID) of the access path of the MA PDU session that the UE will establish in the future, and the corresponding RAT / access type / PLMN or SNPNID of the access path identifier. This mapping may be used to enable the PGW-C and the SMF 1106 to provide new ATSSS rules and new MAR rules at this stage (or time), rather than waiting until other access paths of the MA PDU session are established.

[0419] At 13005, the AMF 1104 signals the SM signaling received in the uplink NAS signal to the PGW-C and the SMF 1106. In other words, the AMF 1104 retrieves the SM signaling from the uplink NAS signal and sends the SM signaling to the PGW-C and the SMF 1106. The PGW-C and the SMF 1106 may be as referred to above Figures 4 to 6BThe described first network function, it should be understood that an AMF (such as AMF 1104) may perform the functions of the first network function. AMF 1104 may signal SM signaling to PGW-C and SMF 1106 by invoking the PDUSession_createSMcontextReq service operation.

[0420] During 13006, PGW-C and SMF 1106 notify a PCF (not shown) that an MA PDU session will be established and obtain new ATSSS rules and new MAR rules for the MA PDU session. The ATSSS rules and MAR rules may be obtained from a PCF (not shown). The PCF (not shown) may include the functions of the PCF described above with reference to Figure 6A The described functions of the PCF are provided. PGW-C and SMF 1106 also use the new MAR rules to update UPF 1107. UPF 1307 may perform the functions of the UPF described above with respect to Figure 6B The described functions of the UPF.

[0421] At 13007, the PGW-C and the SMF 1106 respond to the AMF 1104. The PGW-C and the SMF 1106 respond to the AMF 1104 by sending a response (i.e., by sending a signaling or a message), which may include an indication that the request to establish a MA PDU session has been accepted by the PGW-C and the SMF 1106. The response may include a first access path identifier (Leg_ID1). Optionally, the signaling may include a flag (or some other indication, labeled as "MultiLeg_support_IND" herein), which indicates whether the MA PDU session feature has been enabled / disabled and / or whether it is supported / unsupported by the PGW-C and the SMF 1106. The MA PDU session feature of the PGW-C and the SMF 1106 is the ability of the PGW-C and the SMF 1106 to establish a MA PDU session with access paths on multiple accesses of the same access type, and the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 have the ability to establish a MA PDU session with access paths on multiple accesses of the same access type. In other words, the "MultiLeg_support_IND" indicates whether the PGW-C and the SMF 1106 are capable of establishing a MA PDU session with access paths on multiple accesses of the same access type. For example, when the PGW-C and the SMF 1106 do not support the MA PDU session feature, the PGW-C and the SMF 1106 will ignore the provided first access path identifier (Leg_ID1) and will not include the first access path identifier (Leg_ID1) in the response sent to the UE 1101. This can be regarded as an implicit indication of not supporting the MA PDU session feature (i.e., the PGW-C and the SMF 1106 cannot establish a MA PDU session through two 3GPP accesses). The support of the PGW-C and the SMF 1106 for the MA PDU session feature can also be indicated in other ways, such as during the registration process at 13001.

[0422] At 13008, the AMF 1104 forwards the received response to the UE 1101. This forwarding of the response received from the PGW-C and the SMF 1106 may be performed, for example, by the AMF 1104 encapsulating the response in a downlink NAS signal and sending the downlink NAS signal to the UE 1101. In this example, the response encapsulated in the downlink NAS signal includes the first access path identifier (Leg_ID1), an indication that the MA PDU session feature is supported by the PGW-C and the SMF 1106, and an indication that the request for the establishment of the first access path of the MA PDU session has been accepted by the PGW-C and the SMF 1106.

[0423] 13009 to 13010 relate to establishing a first access path for an MA PDU session via a first 3GPP access (3GPP1), which includes establishing user plane resources for a radio connection or radio link between the UE 1101 and the first 3GPP access network 1102, and establishing a tunnel (e.g., N3 tunnel) between the first 3GPP access network 1102 and the UPF 1107.

[0424] During 13010, the UE 1101 signals the PGW-C and the SMF 1106 via a second 3GPP access (3GPP2). This signaling can be a packet data network (PDN) connection handover request for a second access path identified by a second access path identifier (Leg_ID). The PCO included in this signaling can include a PDU session identifier (e.g., 5), a second access path identifier (Leg_ID2), and an indication that an MA PDU will be established. Including this information in the PCO can allow avoiding affecting the currently defined ESM (EPS) signaling.

[0425] During 13011, the PGW-C and the SMF 1106 notify the PCF (not shown) that an MA PDU session will be established, and obtain new ATSSS rules and new MAR rules for this MA PDU session. The ATSSS rules and MAR rules can be obtained from the PCF (not shown). This PCF (not shown) can include the functions of the PCF described above with reference to Figure 6A The functions of the PCF described. The PGW-C and the SMF 1106 also use the new MAR rules to update the UPF 1107.

[0426] During 13012, the PGW-C and the SMF 1106 signal the UE 1101. This signaling can include a request for an active default bearer (e.g., default EPS bearer). In the PCO, this signaling can include an indication of the second access path identifier (Leg_ID2) and the new ATSSS rules obtained during 13011.

[0427] At 13013, the UE 1101 signals the PGW-C and the SMF 1106. This signaling can indicate that the UE 1101 has accepted the default bearer request of 13012. This signaling can include the second access path identifier (Leg_ID2) for identifying the access path on which the bearer will be operated.

[0428] 13014 to 13015 relate to a second access path for establishing an MA PDU session via a second 3GPP access (3GPP2), which includes establishing user plane resources for a radio connection or radio link between the UE 1101 and the second 3GPP access network 1103, and establishing a tunnel (e.g., N3 tunnel) between the second 3GPP access network 1103 and the UPF 1107.

[0429] During 13016, the UE 1101 uses the new ATSSS rules provided during 13012 to determine how to distribute (e.g., switch, split, and / or steer) the traffic of service data flows destined for the UPF 1107 across the first access path and the second access path. For example, after an MA PDU session including a first access path on the first 3GPP access (3GPP1) and a second access path on the second 3GPP access (3GPP2) is successfully established, the UE 1101 uses the new ATSSS rules to distribute (e.g., switch, steer, and / or split) the uplink traffic of service data flows across the first access path and the second access path. Similarly, the UPF 1107 can use the new MAR rules to distribute (e.g., switch, steer, and / or split) the downlink traffic of service data flows across the first access path and the second access path.

[0430] Although not shown, it can be understood that Figure 13 variants of the signaling can include: instead of indicating the new ATSSS rules within the PCO during 13012, a PDU session modification procedure carrying the new ATSSS rules can be used on 3GPP1. This will avoid potentially affecting the current definition of the PCO structure. This is similar to Figure 12 the signaling depicted in

[0431] In all the above examples, to support the possibility of distributing (e.g., switching, splitting, and steering) the traffic of service data flows across multiple access paths (access paths) of an MA PDU session that pass through different access networks or the same access network with the same or different RATs and terminate at different mobile networks or the same mobile network (e.g., PLMN or SNPN), new rules, policies, and capabilities can be introduced for the ATSSS feature described in the 3GPP standard to help deliver the new ATSSS rules to the UE and the MAR rules to the UPF.

[0432] The new rules, policies, and capabilities for the ATSSS feature include updates to the definition of PCC rules (PCF to SMF), updates to N4 rules (MAR rules) (SMF to UPF), and updates to ATSSS rules (SMF to UE). The following sections will explain examples of such rules.

[0433] Table 1 shows an example of how to define the attribute "SteeringMode" to accommodate the above changes.

[0434]

[0435]

[0436]

[0437] Table 1: Steering Mode Attribute Definition

[0438] According to this definition, when the steering mode is defined as active standby, for each corresponding access path identifier (Leg_ID), an attribute can be indicated that indicates whether the access path (branch) identified by the corresponding access path identifier (Leg_ID) is active.

[0439] In addition, when the steering mode is defined as load balancing, for each Leg_ID, the expected traffic percentage on the access path can be indicated.

[0440] In addition, when the steering mode is defined as priority-based or active-standby, for each Leg_ID, the relative priority of each access path can be indicated.

[0441] In addition, as a redundant steering mode can be associated with an indication of the following: the primary access path (the first Leg_ID in prioAcc) and the secondary access paths (the other access paths listed in prioAcc).

[0442] As another example, the redundancy can be unconditional. In this case, there is no need to define the primary_leg, and only the access pairs for traffic replication need to be defined.

[0443] Table 2 shows how to define MAR rules to support more than one access path per access type (in addition to the current MAR rules).

[0444]

[0445] Table 2: MAR Rule Definition

[0446] Under this update, there can be more than two forwarding action information elements. The forwarding action information can include at least one of the following:

[0447] - Forwarding Action Rule (FAR) ID, which controls the packet forwarding of the access path to the MA PDU session;

[0448] - Weight, which indicates the proportion of traffic to be forwarded by a given FAR when the steering mode is set to "load sharing";

[0449] - Priority, which indicates under what conditions traffic will be forwarded by a given FAR when the steering mode is set to "active - standby" or "priority - based".

[0450] - URR ID list, which enables the SMF to use reports separately for different access requests.

[0451] - In the case of the redundancy mode, the first access path access forwarding action indicates the access path carrying all traffic, while the other access path access forwarding action corresponds to the access path in which traffic will be replicated, and the weight indicates the proportion of traffic to be replicated.

[0452] The ATSSS rules can be further changed to allow a bit to indicate which access path is active. This is Figure 14 illustrated therein, where when the steering mode is defined as load balancing, there is one octet for each access path, and this octet is used to show the percentage of SDF traffic sent through the access path.

[0453] It should be understood that the above examples only illustrate the aspects currently described, and the claimed invention is not limited to these examples.

Claims

1. A user equipment, comprising components for: Send a first request to a first network function via a first access, the first request being for establishing a first access path of a multi-access protocol data unit session via the first access, the first request including: An identifier of a first access path for identifying the first access path; Receiving, via the first access, from the first network function: an indication that access through multiple accesses of the same access type is allowed for the multi-access protocol data unit session, and the first access identifier; Sending a second request to the first network function via a second access, the second request for establishing a second access path of the multi-access protocol data unit session via the second access, the second request including: an identifier of the second access path for identifying the second access, wherein the second access has the same access type as the first access; Receiving a first set of rules from the first network function, the first set of rules defining how traffic of a data stream is to be distributed across the first access and the second access; and Transmitting the traffic of the data stream across the first access path and the second access path according to the first set of rules.

2. The user equipment according to claim 1, wherein the first request further comprises: A mapping associating the second access with the second access path identifier.

3. The user equipment according to claim 2, wherein the first set of rules is received before sending the second request.

4. The user equipment according to any one of claims 1 to 3, the components further for: Receiving, via the second access, from the first network function the second access path identifier and a second set of rules, the second set of rules defining how the traffic is to be distributed across the first access and the second access; and Transmitting the traffic of the data stream across the first access path and the second access path according to the second set of rules.

5. The user equipment according to claim 4, wherein the second set of rules replaces the first set of rules for distributing the traffic of the data stream across the first access and the second access.

6. The user equipment according to any one of claims 1 to 5, wherein the user equipment is registered with the first network function via the first access and the second access before sending the first request and the second request.

7. An apparatus, comprising: A first network function configured to: Receiving, via a first access, from a user equipment a first request for establishing a multi-access protocol data unit session through multiple accesses, the first request including: an identifier of a first access path of the multi-access protocol data unit session, wherein the first access path is for transmitting traffic between the user equipment and the network via the first access; Signaling to the user equipment via the first access: an indication that access through multiple access paths is allowed for the multi-access protocol data unit session, and the first access path identifier; Receive a second request from the user equipment via a second access, the second request being for establishing the multi-access protocol data unit session via a plurality of accesses, the second request including: a second access path identifier identifying a second access path of the multi-access protocol data unit session, wherein the second access path is used to transmit traffic between the user equipment and the network via the second access, wherein the second access has the same access type as the first access; and Signal to the user equipment via the first access a first set of rules that defines how traffic of a data stream will be distributed across the first access path and the second access.

8. The apparatus according to claim 7, wherein the first request comprises: A mapping associating the second access with the second access path identifier.

9. The apparatus according to any one of claims 7 to 8, wherein the first network function further performs the following: Send a signaling message to the user equipment via the second access, where the signaling message includes: The second access path identifier identifying the second access path, and session management information for establishing the multi-access protocol data unit session.

10. The apparatus according to any one of claims 7 to 8, wherein the first network function is further configured to: After receiving the second request, signal to the user equipment via the second access the second access identifier and a second set of rules that defines how the traffic of the data stream will be sent across the first access path and the second access path of the multi-access protocol data unit session.

11. The apparatus according to claim 10, wherein the first network function is further configured to generate the first set of rules and / or the second set of rules based on policies and charging control rules obtained from a policy control function.

12. The apparatus according to any one of claims 7 to 11, wherein the first network function is further configured to provide a third rule to a user plane function, the third rule being for controlling the user plane function to distribute the downlink traffic of the data stream between at least one of the first access path and the second access path of the multi-access protocol data unit session.

13. The apparatus according to any one of claims 7 to 12, the first network function is further configured to provide a fourth rule to the user plane function, the fourth rule being for allowing the user plane function to apply the following to the transmission of the downlink traffic of the data stream: Whether the first access path or the second access path is allowed to be used for the transmission of the downlink traffic of the data stream; or Whether the first access path or the second access path will act as an active access path for the downlink traffic of the data stream, and if the first access path or the second access path will act as an active access path for the downlink traffic of the data stream, the proportion of the downlink traffic that the active access path will carry; or When the conditional redundancy steering mode is to be applied, an indication for: which one of the first access path and the second access path will carry the downlink traffic of the data stream, and which one of the first access path and the second access path will carry at least a copy of the identified downlink traffic of the data stream.

14. The apparatus according to any one of the preceding claims, wherein the first access identifier and / or the first rule set and / or the second rule set are included in a protocol configuration option signaling operation.

15. An apparatus, comprising: A policy control function, the policy control function being configured to: Receive, from a first network function, a request for a first rule set for transmitting traffic with a user equipment using a multi-access protocol data unit session, the multi-access protocol data unit session including: a first access path on a first access of a first access type, and a second access path on a second access of the first access type; and Send the first rule set to the first network function.

16. The apparatus according to claim 15, wherein the first rule set is configured to: control a user plane function to distribute downlink traffic across the first access path and the second access path of the multi-access protocol data unit session, wherein the first access type is 3GPP access or non-3GPP access.

17. The apparatus according to any one of claims 15 to 16, wherein the first rule set is configured to: allow the user plane function to apply at least one of the following policies to the transmission of the downlink traffic: Whether the first access path or the second access path is allowed for the transmission of the downlink traffic; or Whether the first access path or the second access path will act as an active access path for the downlink traffic, and if the first access path or the second access path will act as an active access path for the downlink traffic, the proportion of the downlink traffic that the active access path will carry; or When the conditional redundancy steering mode is to be applied, an indication for: which one of the first access path or the second access path will carry the downlink traffic, and which one of the first access path or the second access path will carry at least a copy of the downlink traffic.

18. The apparatus according to any one of the preceding claims, wherein the first set of rules and / or the second set of rules includes: Rules for distributing traffic across the first access path and the second access path, the rules being used to control the user equipment to distribute uplink traffic between the first access path and the second access path, wherein the first access type is 3GPP access or non-3GPP access.

19. The apparatus according to any one of the preceding claims, wherein the first set of rules and / or the second set of rules comprises: Rules for transmitting traffic across at least the first access path and the second access path, the rules being used to allow the user equipment to control the transmission of the uplink traffic of the data stream based on at least one of the following policies: whether the first access path or the second access path is permitted for the uplink service; or whether the first access path or the second access path will serve as the active access for the identified uplink service, and if the first access path or the second access path will serve as the active access for the identified uplink service, the proportion of the uplink service that the active access path will carry; or when the conditional redundancy guiding mode will be applied, an indication for: which one of the first access path and the second access path will carry the uplink service, and which one of the first access path and the second access path will carry at least a copy of the uplink service.

20. A method performed by a user equipment, the method comprising: sending, via a first access, a first request to a first network function, the first request for establishing a first access path of a multi-access protocol data unit session via the first access, the first request including: a first access path identifier identifying the first access path; receiving, via the first access, from the first network function: an indication that access via multiple accesses of the same access type is permitted for the multi-access protocol data unit session, and the first access identifier; sending, via a second access, a second request to the first network function, the second request for establishing a second access path of the multi-access protocol data unit session via the second access, the second request including: a second access path identifier identifying the second access, wherein the second access has the same access type as the first access; receiving a first rule set from the first network function, the first rule set defining how traffic of a data stream will be distributed across the first access and the second access; and sending the traffic of the data stream across the first access path and the second access path according to the first rule set.

21. The method according to claim 20, wherein the first request further comprises: A mapping associating the second access with the second access path identifier.

22. The method according to claim 21, wherein the first rule set is received before sending the second request.

23. The method according to any one of claims 20 to 22, the component is further configured to: receive, via the second access, from the first network function the second access path identifier and a second rule set, the second rule set defining how the traffic will be distributed across the first access and the second access; and send the traffic of the data stream across the first access path and the second access path according to the second rule set.

24. The method according to claim 23, wherein the second rule set replaces the first rule set for distributing the traffic of the data stream across the first access and the second access.

25. The method according to any one of claims 20 to 24, wherein the user equipment is registered with the first network function via the first access and the second access before sending the first request and the second request.

26. A computer-readable medium comprising instructions that, when executed by at least one processor of a user equipment, cause the user equipment to perform the method according to any one of claims 20 to 25.

27. A computer program comprising instructions, wherein the instructions of the computer program, when executed by at least one processor of a user equipment, cause the user equipment to perform the method according to any one of claims 20 to 24.

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