WO2018167254A1

WO2018167254A1 - Unique qos marking ranges for smfs in a 5g communications network

Info

Publication number: WO2018167254A1
Application number: PCT/EP2018/056625
Authority: WO
Inventors: Paul Schliwa-Bertling; Stefan Rommer
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2017-03-16
Filing date: 2018-03-16
Publication date: 2018-09-20

Abstract

The embodiments herein relate generally to a Session Management Function (SMF) and a method performed by the SMF. More particularly the embodiments herein relate to handling marking of data traffic in a Fifth Generation (5G) communications network.

Description

UNIQUE QOS MARKING RANGES FOR SMFS IN A 5G COMMUNICATIONS

NETWORK

TECHNICAL FIELD

Embodiments herein relate generally to a Session Management Function (SMF) and a method performed by the SMF. More particularly the embodiments herein relate to handling marking of data traffic in a Fifth Generation (5G) communications network.

BACKGROUND

Overview

The standardization organization Third Generation Partnership Project (3GPP) is currently in the processes of specifying a new Radio Interface called New Radio (NR) or 5G or G- Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (G- UTRA) as well as a Next Generation Packet Core Network (NG-CN or NGC).

According to 3GPP TS 23.501 VO.3.1 (2017-03), "The 5G System architecture is defined to support data connectivity and services enabling deployments to use techniques such as e.g. Network Function Virtualization and Software Defined Networking. The 5G System architecture shall leverage service-based interactions between Control Plane (CP)

Network Functions where identified". Some key concept in 5G is that the User Plane (UP) functions are separated from the CP functions, that the function design is modularized etc.

The 5G system architecture consists of the Network Functions (NF). Below is a list of some of these NFs:

• Authentication Server Function (AUSF)

• Core Access and Mobility Management Function (AMF)

• Data network (DN), e.g. operator services, Internet access or 3rd party services

• Structured Data Storage network function (SDSF)

· Unstructured Data Storage network function (UDSF)

• Network Exposure Function (NEF)

• NF Repository Function (NRF)

• Policy Control function (PCF)

• Session Management Function (SMF)

· Unified Data Management (UDM)

• User plane Function (UPF) • Application Function (AF)

• User Equipment (UE)

• (Radio) Access Network ((R)AN)

In the 5G work in the 3GPP it has been agreed to do a further split between Mobility Management (MM) and Session Management (SM) compared to in the Evolved Packet Core (EPC) where the Mobility Management Entity (MME) supports both MM and some SM functionality. In 5G, the AMF supports the MM functionality and the SMF supports SM functionality. The SMF has an interface to the UPF and is in charge of controlling the UPF, e.g. instructing the UPF on tunnel endpoints, enforcements rules for maximum bitrate, charging control rules etc.

According to, 3GPP TS 23.501 VO.3.1 (2017-03), the SMF comprises at least one of the following functionality:

• Session Management e.g. Session establishment, modify and release, including tunnel maintain between UPF and AN node.

• UE IP address allocation & management (incl. optional Authorization). Selection and control of UP function.

• Configures traffic steering at UPF to route traffic to proper destination.

• Termination of interfaces towards Policy control functions.

• Control part of policy enforcement and Quality of Service (QoS).

• Lawful intercept (for SM events and interface to LI System).

• Termination of SM parts of Non-access stratum (NAS) messages.

• Downlink Data Notification.

• Initiator of AN specific SM information, sent via AMF over N2 to AN.

• Determine SSC mode of a session (for Internet Protocol (IP) type Protocol Data Unit (PDU) session).

• Roaming functionality.

• Handle local enforcement to apply QoS Service Level Agreements (SLAs)

(VPLMN).

• Charging data collection and charging interface (VPLMN).

• Lawful intercept (in VPLMN for SM events and interface to LI System).

• Support for interaction with external DN for transport of signaling for PDU session authorization/authentication by external DN. According to, 3GPP TS 23.501 VO.3.1 (2017-03), the UPF comprises at least one of the following functionality:

• Anchor point for lntra-/lnter-RAT mobility (when applicable).

· External PDU session point of interconnect to Data Network.

• Packet routing & forwarding.

• Packet inspection and User plane part of Policy rule enforcement.

• Lawful intercept (UP collection).

• Traffic usage reporting.

· Uplink classifier to support routing traffic flows to a data network.

• Branching point to support multi-homed PDU session.

• QoS handling for user plane, e.g. packet filtering, gating, Uplink/Downlink (UL/DL) rate enforcement.

• Uplink Traffic verification (SDF to QoS flow mapping).

· Transport level packet marking in the uplink and downlink.

• Downlink packet buffering and downlink data notification triggering.

When a UE is roaming in a visited network (e.g. Visited Public Land Mobile Network (VPLMN)), the roaming can be either home-routed roaming or visited access. Visited access can also be called Local Breakout (LBO). In home-routed roaming, the UE can access the visited network through a gateway in the home network (e.g. Home Public Land Mobile Network (HPLMN)) and obtain services provided by its home network. In visited access or LBO, the UE connects via a gateway in the visited network and the traffic is transmitted between the UE and the home network without going via a gateway in the home network.

A VPLMN may be described as that PLMN on which the mobile subscriber has roamed when leaving its HPLMN, the PLMN which is visited by the UE. A HPLMN is the home network of the UE, the network in which the UE subscribers profile is stored. For example, when the UE roams to a visited network, subscription information will be provide from the home network.

In case of home-routed roaming in 5G, there are SMF functions in both the VPLMN (visited SMF (vSMF)) and in the HPLMN (home SMF (hSMF)). A roaming 5G System architecture for the home routed scenario is shown in Figure 1. In figure 1 , the VPLMN is illustrated on the left side of the dotted vertical center line and the HPLMN is illustrated on the right side of the dotted vertical center line. The UE is roaming in the VPLMN. As seen in figure 1 , there are one SMF and one UPF in each of the VPLMN and HPLMN. The v- SMF is comprised in the VPLMN and the h-SMF is comprised in the HPLMN. Figure 1 also illustrates that there is one PCF in each of the HPLMN and VPLMN, i.e. a vPCF in the VPLMN and a hPCF in the HPLMN.

Breakout of selected traffic

It has been further agreed in 5G that the Fifth Generation Core Network (5G CN, or 5GCN) architecture should support breakout of selective traffic of a single PDU Session. This can be done using different techniques (e.g. based on Internet Protocol (IP) filters or based on I Pv6 multihoming), but the common feature is that some traffic of a PDU Session can be broken out to a Data Network at one place (e.g. close to the access site), while other traffic of the PDU Session is forwarded to a Data Network at a different place (e.g. in a more central location). The architecture for the non-roaming case is shown in Figure 2. The example architecture applying non-roaming 5G System architecture in figure 2 is for concurrent access to two (e.g. local and central) data networks using a single PDU session. In figure 2, there is only one SMF but two UPFs. The breakout solution can also be combined with the home routed roaming scenario, in which case some traffic (of a single PDU Session) is broken out in VPLMN while other traffic is routed to the HPLMN. This is illustrated in Figure 3. Figure 3 illustrates an example roaming architecture with concurrent access to two (e.g. localA PLMN and central/HPLMN) data networks using a single PDU session. In figure 3, the VPLMN is illustrated on the left side of the dotted vertical center line and the HPLMN is illustrated on the right side of the dotted vertical center line. The UE is roaming in the VPLMN. As seen in figure 3, there is one SMF and one UPF in each of the VPLMN and HPLMN. The v- SMF is comprised in the VPLMN and the h-SMF is comprised in the HPLMN. Figure 3 also illustrates that there is one PCF in each of the HPLMN and VPLMN, i.e. a vPCF in the VPLMN and a hPCF in the HPLMN. One difference between the home-routed scenarios in figures 1 and 3 is that there is only one DN in figure 1 and two DNs in figure 3. Similarly, there may be scenarios also for the non-roaming case where it may be forced to use two SMFs in the serving network. This may e.g. apply in case a UPF is serving only limited areas and due to UE mobility there is a need to assign a new UPF between the anchor point UPF (i.e. the UPF with N6 interface) and the RAN. If such UPF that is inserted into the user plane path cannot be controlled by the same SMF as the anchor point UPF, there would be a need to use a separate SMF. This results in the non- roaming architecture shown in Figure 4. Figure 4 illustrates an example non-roaming architecture with two SMFs and concurrent access to two (e.g. local/VPLMN and central/HPLMN) data networks using a single PDU session. In figure 4 there are two UPFs and to SMFs (one intermediate SMF and one anchor SMF). There are also two PCFs (one (anchor) PCF and one intermediate PCF).

Packet marking for QoS

The 5G QoS model supports QoS flow based framework, and it supports both QoS flows that require guaranteed flow bit rate and QoS flows that do not require guaranteed flow bit rate. Each QoS flow (GBR and Non-GBR) may be associated with at least one of the following QoS parameters:

• 5G QoS Indicator (5QI),

• Allocation and Retention Priority (ARP).

Each GBR QoS flow is in addition associated with at least one of the following QoS parameters:

• Guaranteed Flow Bit Rate (GFBR) - UL and DL;

• Maximum Flow Bit Rate (MFBR) - UL and DL;

· Notification control.

The 5G QoS model is different from the EPC model. Instead of using separate General Packet Radio Services Tunneling Protocol-User Plane (GTP-U) tunnels per QoS class for the use plane, there will be a single tunnel for the PDU Session with packet markings per QoS class in the encapsulation header of each packet of that tunnel. The QoS profile for a certain traffic (e.g. IP flow) can be determined by the PCF but the actual value of the packet marking is determined by the SMF. In some cases, it may not be the SMF who decides on the packet marking values. Possibly another Network Function (e.g. PCF) could decide the marking and provide information about the decided marking to the SMF(s). A QoS class may also be referred to as a traffic class.

The SMF then instructs the UPF for how certain traffic (e.g. described by I P filters) should be marked. In case of down-link traffic this marking is used by the (radio) access network to determine what QoS treatment to apply to a packet.

In case there are more than one SMF (e.g. as shown above), each SMF is responsible for determining the packet marking value for a subset of the traffic. The v-SFM / intermediate- SMF is determining the packet marking value for traffic that is received from the local DN while the h-SMF / anchor-SMF is determining the packet marking value for traffic that is received from the more central DN. This may result in that the same packet marking value is used for traffic belonging to different QoS classes and it is not possible for (R)AN to distinguish between the two in down-link traffic.

SUMMARY

An objective of embodiments herein is therefore to obviate at least one of the above disadvantages and to provide improved handling of packet marking in 5G. According to a first aspect, the object is achieved by a method in performed by a first SMF for handling marking of data traffic in a 5G communications network. The first SMF obtains a first range of QoS marking values which is only available for use by the first SMF. The first range is different from a second range of QoS marking values which is only available for use by a second SMF.

According to a second aspect, the object is achieved by a first SMF for handling marking of data traffic in a 5G communications network. The first SMF is configured to obtain a first range of QoS marking values which is only available for use by the first SMF. The first range is different from a second range of QoS marking values which is only available for use by a second SMF.

Since a first range of QoS marking values is only available for use by the first SMF, and that the first range is different from a second range of QoS marking values which is only available for use by a second SMF, the handling of packet marking in 5G is improved in that there will be no colliding or overlapping ranges even when there are more than one SMF. This will result in that the different packet marking value are used for traffic belonging to different QoS classes and it is possible for the (R)AN to distinguish between the two in downlink traffic. Embodiments herein afford many advantages, of which a non-exhaustive list of examples follows:

One advantage of the embodiments herein is that QoS packet marking is possible when there are multiple NFs (e.g. SMFs) controlling the QoS marking for a single PDU Session.

The embodiments herein are not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will now be further described in more detail in the following detailed description by reference to the appended drawings illustrating the embodiments and in which:

Fig. 1 is a schematic block diagram illustrating embodiments of a roaming 5G

System architecture-Home routed scenario.

Fig. 2 is a schematic block diagram illustrating an example architecture applying non-roaming 5G System architecture for concurrent access to two (e.g. local and central) data networks using a single PDU session.

Fig. 3 is a schematic block diagram illustrating an example roaming architecture with concurrent access to two (e.g. localA PLMN and central/HPLMN) data networks using a single PDU session.

Fig. 4 is a schematic block diagram illustrating an example non-roaming

architecture with two SMFs and concurrent access to two (e.g. localA PLMN and central/HPLMN) data networks using a single PDU session. Fig. 5 is a schematic block diagram illustrating embodiments of a communications system.

Fig. 6 is a signaling diagram illustrating embodiments of a method.

Fig. 7 is a signaling diagram illustrating embodiments of a method.

Fig. 8 is a signaling diagram illustrating embodiments of a method. Fig. 9 is a signaling diagram illustrating embodiments of a UE-requested PDU

Session Establishment for home-routed roaming scenarios.

Fig. 10 is a flow chart illustrating embodiments of a method performed by a first

SMF.

Fig. 1 1 is a schematic block diagram illustrating embodiments of a first SMF.

The drawings are not necessarily to scale and the dimensions of certain features may have been exaggerated for the sake of clarity. Emphasis is instead placed upon illustrating the principle of the embodiments herein.

DETAILED DESCRIPTION

The embodiments herein relate to coordination of packet marking for QoS. QoS may be related to parameters such as throughput, errors, delay, bitrate, packet drop etc. in a communications system 100.

Figure 5 depicts a communications system 100 in which embodiments herein may be implemented. The entities illustrated in figure 5 may be nodes, units, modules, functions etc.

A UE 101 is served by the (R)AN 103, and is in this case capable of communicating with the (R)AN 103 over a communications link. The UE 101 may be referred to as a 5G UE, a 5G capable UE, a 5G compatible UE, a Next Generation (NextGen) UE etc. For example, a NextGen UE 101 can be described as a UE 101 connecting to a NextGen system. The UE 101 may be a device by which a subscriber may access services offered by an operator's network and services outside operator's network to which the operators radio access network and core network provide access, e.g. access to the Internet. The device may be any device, mobile or stationary, enabled to communicate in the communications network, for instance but not limited to e.g. user equipment, mobile phone, smart phone, sensors, meters, vehicles, household appliances, medical appliances, media players, cameras, Machine to Machine (M2M) device, Device to Device (D2D) device, Internet of Things (loT) device or any type of consumer electronic, for instance but not limited to television, radio, lighting arrangements, tablet computer, laptop or Personal Computer (PC). The UE 101 may be portable, pocket storable, hand held, computer comprised, or vehicle mounted devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another UE or a server.

The (R)AN 103, which is short for (Radio) Access Network may comprise one or more (R)AN nodes (not shown in figure 5). However, the reference number 103 is also used herein when referring to a (R)AN node as well as to the (R)AN. The (R)An may support one or more radio access, such as evolved Long Term Evolution (LTE) and/or New Radio (NR) radio access. A (R)AN node 103 may also be referred to as base station, GNodeB, NodeB, evolved NodeB (eNB), NextGen (R)AN, 5G (R)AN etc. The system 100 illustrated in figure 5 also shows several other nodes or functions, and at least one of them may be seen as being comprised in a Core Network (CN). These nodes or function may therefore be referred to as CN nodes or CN function. Such core network may be for example a NextGen Core Network (NGCN), and then the CN nodes or functions may be referred to as NGCN nodes, NGCN functions, 5GCN nodes, or 5GCN functions. Examples of such CN nodes or function illustrated in figure 5 are a first UPF 105a, a second UPF 105b, a first SMF 108a, a second SMF 108b. In addition, there may be other network functions 113 such as e.g. one or more PCFs.

Network Function is defined by the 3GPP as "A 3GPP adopted or 3GPP defined

processing function in a network, which has defined functional behaviour and 3GPP defined interfaces. A network function can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualised function instantiated on an appropriate platform, e.g. on a cloud

infrastructure."

The system 100 also illustrates a data network 110. Example of a data network 100 is operator services, Internet access or 3rd party services.

The UE 101 is connected to the (R)AN 103. The (R)AN 103 is connected to the UE 101 and the second UPF 105b. The second UPF 105b is connected to the (R)AN 103, the first UPF 105a and to the second SMF 108b. The first UPF 105a is connected to the second UPF 105b, the first SMF 108a and the data network 1 10. The first SMF 108a is connected to the first UPF 105a and the other network function 1 13. The other network function 1 13 is connected to the first SMF 108a. The data network 1 10 is connected to the first UPF 105a. It should be noted that the communication links in the communications system 100 in figure 5 may be of any suitable kind including either a wired or wireless link. The link may use any suitable protocol depending on type and level of layer (e.g. as indicated by the

OSI model) as understood by the person skilled in the art. Even though figure 5 uses the term function for at least one of the illustrated units, the term node may be equally applied. In this case, the illustrated units may be referred to as first UP node, second UP node, first SM node, second SM node and other network node.

The system 100 illustrated in figure 5 may comprise additional nodes and functions which are not illustrated in figure 5. Examples of such nodes and functions are found in e.g. figures 1 -4.

There are at least the following two alternative methods for how to avoid conflict between packet marking values determined by different SMFs handling the same session: Alternative 1 : Separate ranges of the packet marking available for use by a specific SMF. • The ranges are pre-defined by standard in each SMF,

• The ranges are configured in each SMF, or

• The ranges are determined by other network node (e.g. PCF) and transmitted to each SMF.

Alternative 2: Dynamically signalling of range from one SMF to the other SMF:

• The first and second ranges are determined by the first SMF (pre-defined or configured).

The first SMF transmits the second range to the second SMF.

• The first range is determined by the first SMF. The first SMF transmits the first range to the second SMF.

• The second SMF determines the second range based on information about the first range.

• The first and second ranges are determined by the other network function. The other network function transmits the ranges to the first SMF. The first SMF transmits the second range to the second SMF.

• The first range is determined by the other network function. The other network function transmits the first range to the first SMF. The first SMF transmits the first range to the second SMF. The second SMF determines the second range based on information about the first range.

The method for handling marking of data traffic in a 5G communications network when there are two SMFs in the communications system 100, according to alternative 1 will now be described with reference to the signalling diagram in Figure 6. The dotted arrows and boxes represent optional steps and the continuous lines and boxes represent mandatory steps. The method comprises the following steps, which steps may as well be carried out in another suitable order than described below:

Step 201

This is an optional step. A QoS profile may be pre-defined, configured or determined by the other network function 1 13 and transmitted to the first SMF 108a. The first SMF 108a receives the QoS profile from the other network function 1 13. The QoS profile may also be transmitted from the other network function 1 13 to the second SMF 108a, and the second SMF 108b may receive the QoS profile from the other network function 1 13. Step 202 This is an optional step. The first range of QoS marking values may be pre-defined, configured or determined by the other network function 1 13 and transmitted to the first SMF 108a. The first SMF 108a receives the first range from the other network function 1 13. The first range may be for one or more QoS profile or QoS classes, or for any QoS profile or QoS class.

QoS packet marking may be used to assign packets to a QoS group, and the QoS group may be used to determine how to prioritize transmission of the packets.

Step 203

This is an optional step. The second range of QoS marking values may be pre-defined, configured or determined by the other network function 1 13 and transmitted to the second SMF 108b. The second SMF 108b receives the second range from the other network function 1 13.

The second range may be for one or more QoS profile or QoS classes, or for any QoS profile or QoS class.

Step 204

This is an optional step and a step that may be performed instead of steps 201 and 202. The QoS profile and/or the first range is pre-defined or configured in the first SMF 108a.

Step 205

This is an optional step and a step that may be performed instead of steps 201 and 203. The QoS profile and/or the second range is pre-defined or configured in the second SMF 108b.

Step 206

The first SMF 108a obtains the first range of QoS marking values which is only available for use by the first SMF 108a. The first range is different from a second range of QoS marking values which is only available for use by a second SMF 108b. The obtaining may be done by any of the optional step 201-205 described above. The first range is different from the second range in that none of the values in the first range is comprised in the second range, i.e. the first and second ranges are not overlapping. For example, the first range may be OOxxxxxx and the second range may be Ol xxxxxx, where xxxxxx indicates the bits available for use by a specific SMF. Or the first range may be 0-100 and the second range may be 101 -200, or any other suitable range. Step 207

This is an optional step. The first SMF 108a may determine at least a first QoS value for the first range. The first QoS value in the first range may be applied on a subset of data traffic received from a data network 1 10. Step 208

This is an optional step. The first SMF 108a may transmit instructions to the first UPF 105a that the subset of data traffic should be marked using the first QoS marking value of the first range The first UPF 105a may receive the instructions from the first SMF 108a. Step 209

The second SMF 108b obtains the second range of QoS marking values which is only available for use by the second SMF 108a. The second range is different from a first range of QoS marking values which is only available for use by a first SMF 108a. The obtaining may be done by any of the optional step 201 -205 described above.

For example, the first range may be OOxxxxxx and the second range may be Ol xxxxxx, where xxxxxx indicates the bits available for use by a specific SMF.

Step 210

This is an optional step. The second SMF 108b may determine at least a second QoS value for the second range. The second QoS value in the second range may be applied on a subset of data traffic received from a data network 1 10.

Step 21 1

This is an optional step. The second SMF 108b may transmit instructions to the second UPF 105b that the subset of data traffic should be marked using the second QoS marking value of the second range. The second UPF 105b may receive the instructions from the second SMF 108b. The method for handling marking of data traffic in a 5G communications network when there are two SMFs in the communications system 100, according to alternative 2 will now be described with reference to the signalling diagram in Figure 7. The dotted arrows and boxes represent optional steps and the continuous lines and boxes represent mandatory steps. The method comprises the following steps, which steps may as well be carried out in another suitable order than described below:

Step 301

This is an optional step. A QoS profile may be pre-defined, configured or determined by the other network function 1 13 and transmitted to the first SMF 108a. The first SMF 108a receives the QoS profile from the other network function 1 13. The QoS profile may also be transmitted from the other network function 1 13 to the second SMF 108a, and the second SMF 108b may receive the QoS profile from the other network function 1 13. Step 302

This is an optional step. A QoS profile may be pre-defined, configured or determined by each of the first and second SMFs 108a, 108b.

Step 303

The first SMF 108a obtains the first range of QoS marking values which is only available for use by the first SMF 108a. The first range is different from a second range of QoS marking values which is only available for use by a second SMF 108b.

The first range may be for a QoS profile, and the QoS profile may be obtained as described in any of steps 301-302. Step 304

This is an optional step. The first SMF 108a may determine at least a first QoS value for the first range. The first QoS value in the first range may be applied on a subset of data traffic received from a data network 1 10. Step 305

This is an optional step. The first SMF 108a may transmit the first range to the second SMF 108b. The second SMF 108b may receive the first range from the first SMF 108a. Step 306

This is an optional step. The first SMF 108a may transmit instructions to the first UPF 105a that the subset of data traffic should be marked using the first QoS marking value of the first range The first UPF 105a may receive the instructions from the first SMF 108a. Step 307

This is an optional step. The second SMF 108b may obtain the second range based on the information about the first range received in step 305. The second range is different from a first range which is only available for use by a first SMF 108a. Step 308

This is an optional step. The second SMF 108b may determine at least a second QoS value for the second range. The second QoS value in the second range may be applied on a subset of data traffic received from a data network 1 10. Step 309

This is an optional step. The second SMF 108b may transmit instructions to the second UPF 105b that the subset of data traffic should be marked using the second QoS marking value of the second range. The second UPF 105b may receive the instructions from the second SMF 108b.

The method for handling marking of data traffic in a 5G communications network when there are two SMFs in the communications system 100, according to alternative 2 will now be described with reference to the signalling diagram in Figure 8. The dotted arrows and boxes represent optional steps and the continuous lines and boxes represent mandatory steps. One difference between the methods in figures 7 and 8 is that the first range is obtained by the first SMF 108a and the second range is obtained by the second SMF 108b in figure 7, and the first and second ranges are both obtained by the first SMF 108a in figure 8.

The method comprises the following steps, which steps may as well be carried out in another suitable order than described below: Step 401

This is an optional step. A QoS profile may be pre-defined, configured or determined by the other network function 1 13 and transmitted to the first SMF 108a. The first SMF 108a receives the QoS profile from the other network function 1 13. The QoS profile may also be transmitted from the other network function 1 13 to the second SMF 108a, and the second SMF 108b may receive the QoS profile from the other network function 1 13.

Step 402

Step 403

The first SMF 108a obtains the first range of QoS marking values which is only available for use by the first SMF 108a and the second range of QoS marking values which is only available for use by the second SMF 108b. The first range is different from a second range of QoS marking values which is only available for use by a second SMF 108b.

The first range and the second range may be for a QoS profile, and the QoS profile may be obtained as described in any of steps 401 -402. Step 404

This is an optional step. The first SMF 108a may determine at least a first QoS value for the first range. The first QoS value in the first range may be applied on a subset of data traffic received from a data network 1 10. Step 405

The first SMF 108a may transmit the second range to the second SMF 108b. The second SMF 108b may receive the second range from the first SMF 108a. Step 406

This is an optional step. The first SMF 108a may transmit the first QoS value for the first range to the first UPF 105a. The first UPF 105a may receive the first QoS value from the first SMF 108a.

Step 407

This is an optional step. The second SMF 108a may determine at least a second QoS value for the second range. The second QoS value in the second range may be applied on a subset of data traffic received from a data network 1 10.

Step 408

This is an optional step. The second SMF 108b may transmit the second QoS value for the second range to the second UPF 105b. The second UPF 105b may receive the second QoS value from the second SMF 108b.

Another example for Alternative 2 is illustrated in Figure 9. In figure 9, the first SMF 108a is represented by a hSMF and the second SMF 108b is represented by a vSMF.

Steps 1-12: Same as in TS 23.502, vO.2.01.1

Step 913: The hSMF 108a indicates a certain range of QoS markings to the v-SMF 108b. This range can then be used by vSMF 108b in future procedures where QoS marking is needed.

Steps 14-12: Same as in TS 23.502, vO.2.01 .1

It should be noted that the above call flow in figure 9 is only an example. QoS marking values could also be provided in other procedures (e.g. PDU Session Modification procedure). As an alternative it is also possible for v-SMF 108b to provide a range of QoS marking values to h- SMF 108a in step 3 in figure 9.

The notification about QoS marking range can also be provided separately from the PDU Session Establishment procedure, e.g. in case the h-SMF provides information to the v-SMF 108b that breakout of traffic locally is allowed. A PDU Session is defined by the 3GPP as "Association between the UE and a Data Network that provides a PDU connectivity service. The type of association can be IP, Ethernet or unstructured." The method described above will now be described seen from the perspective of the first SMF 108a. The method comprises at least one of the following steps to be performed by the first SMF 108a:

Step 1001

This step corresponds to steps 202, 204, 206, 302 in figure 6, steps 303, 304 in figure 7 and steps 402, 403, 404 in figure 8. The first SMF 108a obtains a first range of QoS marking values which is only available for use by the first SMF 108a. The first range is different from a second range of QoS marking values which is only available for use by a second SMF 108b.

The first range may be obtained (steps 202, 302) from another network function 1 13, or the first range may be pre-defined (steps 204, 303) in the first SMF 108a, or the first range may be obtained (steps 204, 303) via configuration of the first SMF 108a.

The obtaining of the first range may be triggered by detecting the presence of the second SMF 108b, or by detecting that the second SMF 108b supports breakout of selective traffic of a single PDU session.

The first range may be determined (steps 201 , 202, 301 , 302, 401 , 402) by another network function 1 13 and then sent (steps 201 , 202) to the first SMF 108a. The first SMF 108a then obtains the first range by receiving it from the other network function 1 13. The first range may be determined (steps 206, 304, 404) by the first SMF 108a. The first SMF 108a then obtains the first range by determining itself.

Step 1002

This step corresponds to step 207 in figure 6, step 305 in figure 7 and step 405 in figure 8. The first SMF 108a may determine at least one first QoS marking value in the first range to be applied on a subset of data traffic received from a data network 1 10. Step 1003

This step corresponds to step 208 in figure 6, step 307 in figure 7 and step 407 in figure 8. The first SMF 107a may send instructions to the first UPF 105a that the subset of data traffic should be marked using the first QoS marking value

Step 1004

This step corresponds to step 306 in figure 7. The first SMF 108a may provide the second SMF 108b with information about the first range which is only available for use by the first SMF 108a and not by the second SMF 108b.

The second SMF 108b may be provided with information about the first range in a Create PDU Session Response message or in a PDU Session modification message transmitted from the first SMF 108a to the second SMF 108b. The information may be provided to the second SMF for example by transmitting the information from the first SMF to the second SMF, or by that the first SMF 108a stores the information in a memory from which the second SMF 108b can retrieve the information.

Step 1005

This step corresponds to steps 402, 403, 404 in figure 8. The first SMF 108a may obtain the second range which is only available for use by the second SMF 108b.

The second range may be obtained (step 402) from another network function 1 13, or the second range may be pre-defined (step 403) in the first SMF 108a, or the second range may be obtained via configuration (step 403) of the first SMF 108a.

Step 1006

This step corresponds to step 406 in figure 8. The first SMF 108a may provide the second SMF 108b with information about the second range.

The second SMF 108b may be provided with information about the second range in a

Create PDU Session Response message or in a PDU Session modification message transmitted from the first SMF 108a to the second SMF 108b. The information may be provided to the second SMF for example by transmitting the information from the first SMF to the second SMF, or by that the first SMF 108a stores the information in a memory from which the second SMF 108b can retrieve the information. Below is an overview of different example of the SMFs and UPFs.

The first SMF 108a may be a home SMF located in the hPLMN of the UE 101 and the second SMF 108b is a visited SMF located in the vPLMN which is visited by the UE 101 when the UE 101 is roaming. The first UPF 105a may be a home UPF is located in the home PLMN and the second UPF 105b may be a visited UPF is located in the visited

UPF. The first SMF 108a may be an anchor SMF, the second SMF 108b may be an

intermediate SMF, the first UPF 105a may be an anchor UPF and the second UPF 105b may be an intermediate UPF. All functions may be are located in the serving network which serves the UE 101. The first SMF 108a may be a central SMF, the second SMF 108b may be a local SMF, the first UPF 105a may be a central UPF and the second UPF 105b may be a local UPF.

All functions may be located in the serving network which serves the UE 101 .

The data traffic may be downlink data traffic.

The other network function may be for example a PCF, NEF or UDM.

To perform the method steps shown in figures 5, 6, 7, 8, 9, and 10 for handling marking of data traffic in a 5G communications network, the first SMF may comprises an

arrangement as shown in Figure 11. The first SMF 108a is configured to, e.g. by means of an obtaining module 1101 , obtain a first range of QoS marking values which is only available for use by the first SMF 108a. The first range is different from a second range of QoS marking values which is only available for use by a second SMF 108b. The obtaining module 1 101 may also be referred to as an obtaining unit, an obtaining means, an obtaining circuit, means for obtaining etc. The obtaining module 1 101 may be a processor 1103 of the first SMF 108a.

The first SMF 108a may be configured to, e.g. by means of a determining module 1105, determine at least one first QoS marking value in the first range to be applied on a subset of data traffic received from a data network 1 10. The determining module 1 105 may also be referred to as a determining unit, a determining means, a determining circuit, means for determining etc. The determining module 1 105 may be the processor 1 103 of the first SMF 108a.

The first SMF 108a may be configured to, e.g. by means of a sending module 1108, send instructions to the first UPF that the subset of data traffic should be marked using the first QoS marking value. The sending module 1 108 may also be referred to as a sending unit, a sending means, a sending circuit, means for sending, output unit etc. The sending module 1 108 may be a transmitter, a transceiver etc. The sending module 1 108 may be a wireless transmitter of the first SMF 108a of a wireless or fixed communications system.

The first SMF 108a may be configured to, e.g. by means of a providing module 1109, provide the second SMF 108b with information about the first range which is only available for use by the first SMF 108a and not by the second SMF 108b. The providing module 1 109 may also be referred to as a providing unit, a providing means, a providing circuit, means for providing etc. The providing module 1 109 may be the processor 1 103 of the first SMF 108a.

The second SMF 108b may be provided with information about the first range in a Create PDU Session Response message or in a PDU Session modification message transmitted from the first SMF 108a to the second SMF 108b. The information may be provided to the second SMF for example by transmitting the information from the first SMF to the second SMF, or by that the first SMF 108a stores the information in a memory from which the second SMF 108b can retrieve the information. The first SMF 108a may be further configured to, e.g. by means of the obtaining module 1 101 , obtain the second range which is only available for use by the second SMF 108b.

The first SMF 108a may be further configured to, e.g. by means of the providing module 1 109, provide the second SMF 108b with information about the second range.

Create PDU Session Response message or in a PDU Session modification message transmitted from the first SMF 108a to the second SMF 108b. The information may be provided to the second SMF for example by transmitting the information about the second range from the first SMF to the second SMF, or by that the first SMF 108a stores the information in a memory from which the second SMF 108b can retrieve the information. The second range may be obtained from another network function 1 13, or the second range may be pre-defined in the first SMF, or the second range may be obtained via

configuration of the first SMF 108a.

The first range may be obtained from another network function 1 13, or the first range may be pre-defined in the first SMF, or the first range may be obtained via configuration of the first SMF 108a.

The obtaining of the first range may be triggered by: detecting, e.g. by means of a

detecting module 1110 comprised in the first SMF 108a, the presence of the second

SMF 108b, or by detecting, by means of the detecting module 1 1 10 that the second SMF 108b supports breakout of selective traffic of a single PDU session. The detecting module 1 1 10 may also be referred to as a detecting unit, a detecting means, a detecting circuit, means for detecting etc. The detecting module 1 1 10 may be the processor 1 103 of the first SMF 108a. The first range may be determined by another network function 1 13 and then sent to the first SMF 108a. The first SMF 108a may then be configured to, e.g. by means of a receiving module 1113, receive the first range from the other network function 1 13. The receiving module 1 1 13 may also be referred to as a receiving unit, a receiving means, a receiving circuit, means for receiving, input unit etc. The receiving module 1 1 13 may be a receiver, a transceiver etc. The receiving module 1 1 13 may be a wireless receiver of the first SMF 108a of a wireless or fixed communications system.

The first range may be determined by the first SMF 108a, e.g. by means of the determining module 1 105.

The first SMF 108a may be a home SMF located in the hPLMN of the UE 101 and the second SMF 108b may be a visited SMF located in the vPLMN which is visited by the UE 101 when the UE 101 is roaming, and the first UPF 105a may be located in the home PLMN and the second UPF 105b may be located in the visited UPF.

The first SMF 108a may be an anchor SMF, the second SMF 108b may be an intermediate SMF, the first UPF 105a may be an anchor UPF and the second UPF 105b may be an intermediate UPF, and all functions may be located in the serving network which serves the UE 101 .

The first SMF 108a may be a central SMF, the second SMF 108b may be a local SMF, the first UPF 105a may be a central UPF and the second UPF 105b may be a local UPF, and all functions may be located in the serving network which serves the UE 101 .

The data traffic may be downlink data traffic.

The other network function may be a PCF, NEF or UDM. The first SMF 108a may comprises a memory 1115, and the memory 1 1 15 comprises instructions executable by the processor 1 103. The memory 1 15 comprises one or more memory units. The memory 1 1 15 is arranged to be used to store data, received data streams, power level measurements, first range, second range, values, QoS profile, threshold values, time periods, configurations, scheduling, data traffic, and applications to perform the methods herein when being executed in the first SMF 108a. Those skilled in the art will also appreciate that the obtaining module 1 101 , the determining module 1 105, the sending module 1 108, the providing module 1 109, the detecting module 1 1 10 and the receiving module 1 1 13 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the processor 1 103 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single application-specific integrated circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC).

The present mechanism for handling marking of data traffic in a 5G communications network may be implemented through one or more processors, such as a processor 1 103 in the first SMF arrangement depicted in Figure 1 1 , together with computer program code for performing the functions of the embodiments herein. The processor may be for

example a Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC) processor, Field-programmable gate array (FPGA) processor or microprocessor. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the first SMF 108a. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code can furthermore be provided as pure program code on a server and downloaded to the first SMF 108a.

In some embodiments, a computer program may comprise instructions which, when

executed on at least one processor, cause the at least one processor to carry out at least one of the method steps in figures 6, 7, 8, 9 and 10. A carrier may comprise the computer program, and the carrier is one of an electronic signal, optical signal, radio signal or

computer readable storage medium.

There are different options for how to avoid conflict between packet marking values determined by different SMFs handling the same session:

• Alternative 1 : Separate ranges of the packet marking, e.g. a certain number of bits in the marking IE is indicating which SMF is deciding the marking 00xxxxxx=hSMF, 01 xxxxxx=vSMF etc. where xxxxxx indicates the bits available for use by a specific SMF. The ranges could either be pre-defined by the standard, or configured in each SMF based on O&M and roaming agreements.

• Alternative 2: Dynamic signaling of used marking. E.g. hSMF provides the vSMF with information of what value range vSMF may use, or provides the vSMF with information of what value range hSMF intends to use

The 5G CN architecture herein supports breakout of selective traffic of a single PDU session. The embodiments herein are not limited to the above described embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above

embodiments should not be taken as limiting the scope of the embodiments.

It should be emphasized that the term "comprises/comprising" when used in this

specification is taken to specify the presence of stated features, integers, steps or

components, but does not preclude the presence or addition of one or more other

features, integers, steps, components or groups thereof. It should also be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. The terms "consisting of" or "consisting essentially of" may be used instead of the term comprising.

The term "configured to" used herein may also be referred to as "arranged to", "adapted to", "capable of or "operative to". It should also be emphasised that the steps of the methods may, without departing from the embodiments herein, be performed in another order than the order in which they

appear.

Claims

1. A method performed by a first Session Management Function, SMF, (108a) for handling marking of data traffic in a 5G communications network, the method comprising:

obtaining (202, 204, 206, 302, 303, 304, 402, 403, 404) a first range of

Quality of Service, QoS, marking values which is only available for use by the first SMF (108a), and wherein the first range is different from a second range of QoS marking values which is only available for use by a second SMF (108b).

2. The method according to claim 1 , further comprising:

determining (207, 305, 405) at least one first QoS marking value in the first range to be applied on a subset of data traffic received from a data network (1 10).

3. The method according to any one of claims 1 -2, further comprising:

sending (208, 307, 407) instructions to the first User plane Function, UPF, that the subset of data traffic should be marked using the first QoS marking value.

4. The method according to any one of claims 1 -3, further comprising:

providing (306) the second SMF (108b) with information about the first range which is only available for use by the first SMF (108a) and not by the second SMF (108b).

5. The method according to claim 4, wherein the second SMF (108b) is provided (306) with information about the first range in a Create Protocol Data Unit, PDU, Session Response message (913) or in a PDU Session modification message transmitted from the first SMF (108a) to the second SMF (108b).

6. The method according to any one of claims 1 -5, further comprising:

obtaining (402, 403, 404) the second range which is only available for use by the second SMF (108b); and

providing (406) the second SMF (108b) with information about the second range.

7. The method according to claim 6, wherein the second SMF (108b) is provided (406) with information about the second range in a Create PDU Session Response message (913) or in a PDU Session modification message transmitted from the first SMF (108a) to the second SMF (108b).

8. The method according to any one of claims 1 -7,

5 wherein the second range is obtained (402) from another network function (1 13); or wherein the second range is pre-defined (403) in the first SMF; or

wherein the second range is obtained via configuration (403) of the first SMF (108a).

9. The method according to any one of claims 1 -8,

10 wherein the first range is obtained (202, 302) from another network function (1 13); or wherein the first range is pre-defined (204, 303) in the first SMF; or

wherein the first range is obtained (204, 303) via configuration of the first SMF (108a).

10. The method according to any one of claims 1-9, wherein the obtaining (202, 206, 302, 15 304, 402, 403, 404) of the first range is triggered by:

detecting the presence of the second SMF (108b), or by

detecting that the second SMF (108b) supports breakout of selective traffic of a single PDU session.

20 1 1 . The method according to any one of claims 1-10, wherein the first range is

determined (201 , 202, 301 , 302, 401 , 402) by another network function (1 13) and then sent (201 , 202) to the first SMF (108a).

12. The method according to any one of claims 1-1 1 , wherein the first range is

25 determined (206, 304, 404) by the first SMF (108a).

13. The method according to any one of claims 1-12, wherein the first SMF (108a) is a home SMF located in the Home Public Land Mobile Network, hPLMN, of the UE (101 ) and the second SMF (108b) is a visited SMF located in the Visited Public Land Mobile

30 Network, vPLMN, which is visited by the UE (101 ) when the UE (101 ) is roaming, and wherein the first UPF (105a) is located in the hPLMN, and the second UPF (105b) is located in the visited UPF.

14. The method according to any one of claims 1-13, wherein the first SMF (108a) is an anchor SMF, the second SMF (108b) is an

intermediate SMF, the first UPF (105a) is an anchor UPF and the second UPF (105b) is an intermediate UPF, and wherein all functions are located in the serving network which serves the UE (101 ).

15. The method according to any one of claims 1-14,

wherein the first SMF (108a) is a central SMF, the second SMF (108b) is a local SMF, the first UPF (105a) is a central UPF and the second UPF (105b) is a local UPF, and wherein all functions are located in the serving network which serves the UE (101 ).

16. The method according to any one of claims 1-15, wherein the data traffic is downlink data traffic.

17. The method according to any one of claims 1-16, wherein the other network function is a Policy Control function, PCF, Network Exposure Function, NEF, or Unified Data

Management, UDM.

18. A first SMF (108a) for handling marking of data traffic in a 5G communications network, the first SMF (108a) being configured to:

obtain a first range of QoS marking values which is only available for use by the first SMF (108a), and wherein the first range is different from a second range of QoS marking values which is only available for use by a second SMF (108b).

19. A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1-17.

20. A carrier comprising the computer program of claim 19, wherein the carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium.