Dedicated MBR configuration for network slicing in communication networks

Abstract

This disclosure generally relates to network slicing in a communication network. A method performed by a first NE includes: transmitting a first message to a second NE, the first message including a first network slice configuration of a first home network slice subscribed by a UE in its home network, such that the second NE is configured to configure a first network slice service corresponding to the first home network slice based on the first network slice configuration, wherein the first network slice configuration includes: a mapping between the first home network slice and a first visited network slice assigned to the UE to serve the first home network slice; and first MBR information applicable to the first home network slice but not to other home network slices of the UE.

Description

Technical Field

[0001] This disclosure relates to wireless communication, and more particularly to network slicing in communication networks. Background Technology

[0002] Network slicing is a key feature in communication networks, such as fifth-generation (5G) wireless networks. Using network slicing, multiple unique virtual networks can be created over a shared infrastructure. Each slice can have its own architecture and configuration to meet specific use cases. Each slice can also have specific Quality of Service (QoS) requirements, which in turn require different network resources such as bandwidth. Effective management of network slices across both the user equipment's (UE) home network and the UE's visited network is crucial. Summary of the Invention

[0003] This disclosure relates to network slicing in communication networks, and more particularly to providing a dedicated Maximum Bit Rate (MBR) configuration for network slicing when a user is in a visited network.

[0004] In one embodiment, this disclosure describes a method for wireless communication. The method is performed by a first network element (NE) in a wireless network, and includes: transmitting a first message to a second NE in the wireless network, the first message including a first network slice configuration of a first home network slice subscribed by a user equipment (UE) in its home network, wherein the first network slice configuration includes: a mapping between the first home network slice and a first visited network slice, wherein the first visited network slice is assigned to the UE to serve the first home network slice when the UE is in its visited network; and first maximum bit rate (MBR) information applicable to the first home network slice but not applicable to other home network slices of the UE.

[0005] In another embodiment, this disclosure describes a method for wireless communication. The method is performed by a first NE in a wireless network and includes: receiving a first message from a second NE in the wireless network, the first message including a first network slice configuration of a first home network slice subscribed to by a UE in its home network, wherein the first network slice configuration includes: a mapping between the first home network slice and a first visited network slice, the first visited network slice being assigned to the UE to serve the first home network slice when the UE is in its visited network; and first MBR information applicable to the first home network slice but not applicable to other home network slices of the UE.

[0006] In another embodiment, a network element or wireless device is disclosed, comprising a processor and a memory. The processor may be configured to read computer code from the memory to implement any of the methods described above.

[0007] In yet another embodiment, a computer program product is disclosed, comprising a non-transitory computer-readable program medium on which computer code is stored. When executed by a processor, the computer code can cause the processor to perform any of the methods described above.

[0008] The above embodiments and other aspects, and alternatives to their implementation, are explained in more detail in the accompanying drawings, description, and claims. Attached Figure Description

[0009] Figure 1 An exemplary communication network is shown, including various terminal devices, carrier networks, data networks, and service applications.

[0010] Figure 2 Exemplary network functions or network nodes in a communication network are shown.

[0011] Figure 3 An exemplary network function or network node in a wireless communication network is shown.

[0012] Figure 4 An example of an electronic device implementing a network element is shown.

[0013] Figures 5 to 8 Various exemplary methods and message flows for sending MBR configuration from AMF to RAN are shown.

[0014] Figure 9 An exemplary method and message flow for sending MBR configuration from a first RAN to a second RAN are shown.

[0015] Figure 10An exemplary method and message flow for sending MBR configuration from a source AMF to a target AMF and from a target AMF to the RAN are shown. Detailed Implementation

[0016] like Figure 1 The exemplary communication network shown in 100 may include terminal devices 110 and 112, carrier network 102, various service applications 140, and other data networks 150. Carrier network 102 may include, for example, access network 120 and core network 130. Carrier network 102 may be configured to transmit voice, data, and other information (collectively referred to as data traffic) between terminal devices 110 and 112, between terminal devices 110 and 112 and service applications 140, or between terminal devices 110 and 112 and other data networks 150. Communication sessions and corresponding data paths can be established and configured for such data transmission. Access network 120 may be configured to provide network access to core network 130 to terminal devices 110 and 112. Access network 120 may, for example, support wireless or wired access via radio resources. Core network 130 may include various network nodes or network functions configured to control communication sessions and perform network access management and data traffic routing. Service application 140 can be hosted by various application servers accessible to terminal devices 110 and 112 via the core network 130 of operator network 102. Service application 140 can be deployed as a data network outside of core network 130. Similarly, terminal devices 110 and 112 can access other data networks 150 via core network 130, and these other data networks 150 can appear as data destinations or data sources for specific communication sessions instantiated in operator network 102.

[0017] Figure 1 The core network 130 may include various geographically distributed and interconnected network nodes or functions to provide network coverage to the service area of ​​the carrier network 102. These network nodes or functions may be implemented as dedicated hardware network elements. Alternatively, these network nodes or functions may be virtualized and implemented as virtual machines or software entities. Each network node may be configured with one or more types of network functions. These network nodes or network functions may collectively provide configuration and routing capabilities for the core network 130. The terms "network node" and "network function" are used interchangeably in this disclosure.

[0018] Figure 2 An exemplary division of network functions in the core network 130 of the communication network 200 is further illustrated. Although Figure 2Only a single instance of a network node or function is shown, but those skilled in the art will readily understand that each of these network nodes can be instantiated as multiple instances of network nodes distributed throughout the core network 130. Figure 2 As shown, the core network 130 may include, but is not limited to, network nodes such as access management network node (AMNN) 230, authentication network node (AUNN) 260, network data management network node (NDMNN) 270, session management network node (SMNN) 240, data routing network node (DRNN) 250, policy control network node (PCNN) 220, and application data management network node (ADMNN) 210. Exemplary signaling and data exchange between various types of network nodes through various communication interfaces is provided by… Figure 2 Various solid lines are used to represent this. Such signaling and data exchange can be carried by signaling or data messages that follow a predetermined format or protocol.

[0019] Above Figure 1 and Figure 2 The implementation methods described herein can be applied to both wireless and wired communication systems. Figure 3 It shows the basis Figure 2 An exemplary cellular wireless communication network 300 is a general implementation of the communication network 200 in the example. Figure 3 The wireless communication network 300 is shown to include a user equipment (UE) 310 (used as...) Figure 2 Terminal device 110), radio access network (RAN) 320 (used as...) Figure 2 The network comprises an access network 120, a data network (DN) 150, and a core network 130, the core network 130 including an access management function (AMF) 330 (used as...). Figure 2 AMNN 230), Session Management Function (SMF) 340 (used as AMNN 230), Session Management Function (SMF) 340 Figure 2 SMNN240 in the middle), Application Function (AF) 390 (used as Figure 2ADMNN 210), User Plane Function (UPF) 350 (used as Figure 2 DRNN 250), policy control function 322 (used as...) Figure 2 PCNN 220), Authentication Server Function (AUSF) 360 (used as Figure 2 AUNN 260) and Universal Data Management (UDM) function 370 (used as Figure 2 UDMNN 2). Similarly, although Figure 3 Only a single instance of some network functions or nodes for the wireless communication network 300 (particularly the core network 130) is shown, but those skilled in the art will readily understand that each of these network nodes or functions can have multiple instances distributed throughout the wireless communication network 300. While AF 390 is in Figure 3 They are depicted as part of the core network 130, but they can be considered to be associated with specific service applications 140 and can be considered to be outside the core network 140.

[0020] exist Figure 3 In this implementation, UE 310 can be implemented as various types of mobile devices configured to access core network 130 via RAN 320. UE 310 can include, but is not limited to, mobile phones, laptops, tablets, Internet of Things (IoT) devices, distributed sensing network nodes, wearable devices, and the like. The UE can also be a UE with multi-access edge computing (MEC) capabilities that supports edge computing. For example, RAN 320 can include multiple radio base stations distributed throughout the service area of ​​the operator network. Communication between UE 310 and RAN 320 can be performed via an over-the-air (OTA) radio interface, such as... Figure 3 As indicated by 311 in the document.

[0021] continue Figure 3 UDM 370 can form a persistent storage or database for user contract and subscription data. UDM can also include an authentication credential repository and processing function (ARPF, such as...). Figure 3As shown in section 370, it is used to store long-term security certificates used for user authentication and to perform calculations on encryption keys using such long-term security certificates as input, as described in more detail below. To prevent unauthorized exposure of UDM / ARPF data, UDM / ARPF 370 can be located in a secure network environment of a network operator or a third party.

[0022] The AMF / SEAF 330 can communicate with RAN 320, SMF 340, AUSF 360, UDM / ARPF 370, and Policy Control Function (PCF) 322 via communication interfaces indicated by various solid lines connecting these network nodes or functions. The AMF / SEAF 330 can handle signaling management from the UE to the non-access stratum (NAS), and is responsible for UE 310's configuration registration and access to the core network 130, as well as SMF 340 allocation, to support the communication needs of specific UEs. The AMF / SEAF 330 can also handle UE mobility management. The AMF may also include a security anchor function (SEAF, such as...) Figure 3 As shown in 330 (as described in more detail below), this security anchor function interacts with AUSF 360 and UE 310 for user authentication and management of encryption / decryption keys at various levels. AUSF 360 can terminate user registration / authentication / key generation requests from AMF / SEAF 330 and interact with UDM / ARPF 370 to complete such user registration / authentication / key generation.

[0023] The SMF 340 can be assigned by the AMF / SEAF 330 for specific communication sessions instantiated in the wireless communication network 300. The SMF 340 can be responsible for assigning the UPF 350 to support communication sessions and data flows within the user data plane, and for configuring / regulating the assigned UPF 350 (e.g., for developing packet detection and forwarding rules for the assigned UPF 350). As an alternative to assignment by the SMF 340, the UPF 350 can be assigned by the AMF / SEAF 330 for specific communication sessions and data flows. The UPF 350, assigned and configured by the SMF 340 and AMF / SEAF 330, can be responsible for data routing and forwarding, as well as reporting network usage for specific communication sessions. For example, the UPF 350 can be responsible for routing end-to-end data flows between UE 310 and DN150, and between UE 310 and service application 140. DN 150 and service application 140 may include, but are not limited to, data networks and services provided by the operator of wireless communication network 300 or by third-party data network and service providers.

[0024] PCF 322 can manage and provide AMF / SEAF 330 and SMF 340 with policies and rules at various levels applicable to communication sessions associated with UE 310. Thus, for example, AMF / SEAF 330 can assign SMF 340 to a communication session based on the policies and rules associated with UE 310 and obtained from PCF 322. Similarly, SMF 340 can assign UPF 350 based on the policies and rules obtained from PCF 322 to handle data routing and forwarding for the communication session.

[0025] Figure 3 Network identification and data security in the wireless communication network 300 can be managed via a user authentication process provided by AMF / SEAF 330, AUSF 360, and UDM / ARPF 370. Specifically, UE 310 can first communicate with AMF / SEAF 330 for network registration, and then be authenticated by AUSF 360 based on the user contract and subscription data in UDM / ARPF 370. After user authentication with the wireless communication network 300, the communication session established for UE 310 can then be protected by various levels of encryption / decryption keys. The generation and management of these keys can be coordinated by AUSF 360 and other network functions within the communication network 300.

[0026] Although Figures 1 to 3The various exemplary embodiments described below are based on cellular wireless communication networks, but the scope of this disclosure is not limited thereto, and the basic principles are applicable to other types of wireless and wired communication networks.

[0027] Figure 4 An example of an electronic device 400 implementing a network element (or network node, network device, network function) in a wireless communication network is shown. The network element may include core network elements, access network elements, etc. The electronic device 400 may include network interface circuitry 409 for communicating with other network elements. The network interface circuitry 409 may include optical or wired interconnection, Ethernet, and / or other data transmission media / protocols. The electronic device 400 may optionally include an input / output (I / O) interface 406 for communication with an operator or similar personnel.

[0028] The electronic device 400 may also include system circuitry 404. System circuitry 404 may include one or more processors 421 and / or memory 422. Memory 422 may include an operating system 424, instructions 426, and parameters 428. Instructions 426 may be configured to be used by one or more processors 421 to perform functions of the network element. Parameters 428 may include parameters supporting the execution of instructions 426. For example, these parameters may include network protocol settings, bandwidth parameters, radio frequency mapping allocation, and / or other parameters.

[0029] Example electronic device 400 may optionally include wireless transmission / receiving (Tx / Rx) circuitry 408 for transmitting / receiving communications with the UE and / or other network elements. Electronic device 400 with Tx / Rx circuitry 408 can be configured as a base station capable of providing wireless access functionality.

[0030] Network slicing

[0031] A key feature of wireless networks such as 5G is network slicing. Under network slicing, various resources within the network (such as computing, storage, and bandwidth resources) are divided to create a set of isolated virtual networks. Each virtual network can be considered a network slice (or multiple slices). Each slice can serve a specific user application and can be allocated customized resources to meet the specific needs of that application. A network slice can be created or instantiated in isolation from other network slices.

[0032] A UE can subscribe to multiple network slices within its home network (also known as the Home Public Land Mobile Network (HPLMN)). Each network slice can be referred to as a home network slice (or simply a home slice) when the UE is served within the home network. For example, a UE can subscribe to a first slice serving its Machine Type Communication (MTC) applications. A UE can also subscribe to a second slice serving its enhanced Mobile Broadband (eMBB) applications. In this case, the first and second slices can be configured with different network parameters, thus each slice has different characteristics. Network parameters can include the Maximum Bit Rate (MBR). The second slice can be configured with a larger MBR than the first slice because eMBB typically requires higher bandwidth. When the UE subscribes to these slices within the home network, the home network can allocate a specific MBR to each slice. The allocated MBR ensures that the slice meets its specific service requirements while protecting network resources by limiting the maximum bit rate used for the slice. As an example, the MBR allocated to the first slice could be 10 Mbps (10 megabits per second), while the MBR allocated to the second slice could be 20 Mbps.

[0033] In some example implementations, when a UE invokes (or requests) a network slicing service, it may be necessary to establish a Protocol Data Unit (PDU) session corresponding to that network slice. Accordingly, the PDU session can be configured based on the MBR allocated to that network slice. The maximum bit rate that can be allocated to a PDU session must not exceed the MBR allocated to the network slice. For example, if the MBR allocated to the network slice is 10 Mbps, then the maximum bit rate of the PDU session cannot exceed 10 Mbps.

[0034] In some other example implementations, multiple PDU sessions corresponding to the same network slice can be established. In this case, the sum of the maximum bit rates allocated to these PDU sessions may not exceed the MBR allocated to the network slice. For example, the network slice is configured with a 10 Mbps MBR. A first PDU session corresponding to this network slice is created with a maximum bit rate of 5 Mbps. Subsequently, a second PDU session needs to be created with a desired maximum bit rate equal to 8 Mbps. In this case, since the total maximum bit rate of the two PDU sessions is 13 Mbps, which exceeds the MBR of the network slice, the RAN can choose to refuse to create the second PDU session, or create a second PDU session with a reduced maximum bit rate (such as 5 Mbps) to ensure that the total maximum bit rate of the two PDU sessions does not exceed the MBR of the network slice. Therefore, it may be necessary to reference and check the MBR of the corresponding network slice before creating, establishing, or activating a PDU session. Furthermore, for established PDU sessions, their QoS characteristics or requirements can be dynamically updated, which can trigger an update of the maximum bit rate that needs to be allocated to the PDU session. In this case, it may also be necessary to check the MBR of the corresponding network slice to ensure that the network slice can support the updated maximum bit rate of the PDU session. Therefore, network elements such as RAN nodes may need to utilize MBR information to manage PDU sessions.

[0035] The UE can roam to a visited network (also known as a Visited Public Land Mobile Network (VPLMN)). Similarly, the visited network can also support network slicing. If the home network and the visited network share a uniform network slicing configuration, the UE can receive seamless network slicing services. However, the visited network may often have a different network slicing configuration compared to the home network. For example, the visited network may not support certain network slices; or the visited network may have fewer slices than the home network. Another example is that the granularity of the network slices is different. In this case, a visited network slice (or a guest slice) can serve multiple home slices. For example, guest slice 1 can serve both home slice 1 and home slice 2. That is, there is a mapping relationship between home slices and guest slices. Home slice 1 is mapped to guest slice 1 (forming a pair as home slice 1 + guest slice 1). Simultaneously, home slice 2 is also mapped to guest slice 1 (forming a different pair: home slice 1 + guest slice 2). In this disclosure, for ease of description, slice numbers can be used to identify network slices. However, network slice identifiers can use other formats, such as Single Network Slice Selection Assistance Information (S-NSSAI). For example, a UE can subscribe to a list of S-NSSAIs representing a list of network slices.

[0036] In a visited network, the UE can be served by an access network (AN). The access network can include a radio access network (RAN) or a wired access network. In this disclosure, the symbol (R)AN is used to refer to the access network in general, whether it is radio or wired. In this disclosure, RAN can be used for illustrative purposes, and the same basic principles apply to wired access networks.

[0037] When a UE invokes a network slice service in a visited network, the RAN participates in one or more network procedures to, for example, establish or create a PDU session corresponding to the network slice service. In doing so, the RAN needs the MBR information for the network slice. In current practice, the AMF (or another node or functional entity) of the visited network can notify the RAN of the MBR information. The notified MBR information is only applicable at the visitor slice level. For example, both Home Slice 1 (MBR = 10 Mbps in the home network) and Home Slice 2 (MBR = 20 Mbps in the home network) are served by Visitor Slice 1. The AMF can notify the RAN of the MBR information for Visitor Slice 1. The resolution of this MBR information is only down to the visitor slice level. In one implementation, the MBR of Visitor Slice 1 can be an aggregation of the MBRs of Home Slice 1 and Home Slice 2. Therefore, the MBR for Visitor Slice 1 is set to 30 Mbps. In another implementation, the MBR of Visitor Slice 1 can be selected as max(Home Slice 1 MBR, Home Slice 2 MBR), where "max" indicates the operation of selecting the maximum value. In this case, the MBR of Visitor Slice 1 can be 20 Mbps. Referring to Table 1 below, the MBR allocation in the visited network is shown.

[0038] Table 1: Shared MBR Allocation

[0039]

[0040] As shown in Table 1, current practice uses a shared MBR allocation scheme, where MBR allocation only reaches the visitor slice level. The allocated MBR is shared by Home Slice 1 and Home Slice 2. This scheme may have potential problems. For example, when a UE first invokes a service based on Home Slice 1, the visited network will use Visitor Slice 1 to serve the request (because Home Slice 1 is mapped to Visitor Slice 1). Since the MBR allocation in Table 1 does not specify the MBR information for Home Slice 1 separately, the RAN can allocate a 20 Mbps MBR for this request (e.g., 20 Mbps is allocated to Home Slice 1). When the UE subsequently invokes a service based on Home Slice 2, the visited network will also use Visitor Slice 1 to serve the request (because Home Slice 2 is also mapped to Visitor Slice 1). However, the MBR for Home Slice 2 might be configured as 10 Mbps. It can be seen that Home Slice 1 receives more MBR than it is allocated in the home network, which may lead to a waste of network resources, while Home Slice 2 receives less MBR than it is allocated in the home network, which may lead to service degradation or service interruption. Therefore, this shared MBR allocation scheme has shortcomings.

[0041] This disclosure presents a dedicated MBR allocation scheme, as shown in Table 2 below.

[0042] Table 2: Dedicated MBR Allocation

[0043]

[0044] In this dedicated MBR allocation scheme, the MBR is allocated at the home slice level. Using Table 2 as an example, home slice 1 is mapped to visitor slice 1. This mapping forms a network slice pair consisting of the home slice and the mapped visitor slice (i.e., home slice 1, visitor slice 1). The dedicated MBR for this pair can be set to 10 Mbps, which is the same as the MBR set for home slice 1 when the UE is in the home network. Similarly, home slice 2 is mapped to visitor slice 1. This mapping forms a network slice pair (home slice 2, visitor slice 1). The dedicated MBR for this pair can be set to 20 Mbps, which is also the same as the MBR set for home slice 1 when the UE is in the home network. It can be seen that when the UE roams to the visited network, the MBR allocation goes to each specific home slice. Therefore, from the perspective of network slices, the visited network can gain more granular control over roaming UEs.

[0045] In one implementation, a triplet representing an MBR configuration (or MBR assignment) can be formed by: the home slice, the corresponding visitor slice, and the assigned MBR.

[0046] In one implementation, a PDU session ID can be added to a triple to identify a PDU session associated with the home slice / guest slice.

[0047] MBR configuration can be used by, for example, RAN nodes or other relevant nodes to create / establish / activate / update PDU sessions associated with the home slice and its corresponding guest slice pair.

[0048] MBR assignment can occur in various scenarios, such as:

[0049] • When a UE accesses a visited network and initiates a registration request;

[0050] • When a UE initiates a service request;

[0051] • When there is an update to the MBR assignment;

[0052] • When the UE's serving AMF changes from the source AMF to the target AMF;

[0053] • When the UE switches from the source RAN to the target RAN (e.g., handover scenario).

[0054] Meanwhile, MBR allocation may involve various network elements (such as AMF, RAN, and SMF). In handover scenarios, source RAN and target RAN may also be involved.

[0055] In this disclosure, various embodiments are described below to cover MBR allocation in a variety of use cases.

[0056] Example 1: MBR Configuration – From AMF to RAN

[0057] In this embodiment, the MBR configuration can be transmitted from the AMF to the RAN under various use cases. An example use case may include a UE in the visited network initiating a request to establish a PDU session. (See also...) Figure 5 The exemplary steps are described in detail below.

[0058] In this disclosure, when a message or signaling is transmitted to or from the RAN, it should be understood, unless explicitly specified, that the message or signaling is sent to a RAN node (e.g., gNodeB, ng-eNB, eNB, nodeB, etc.) within the RAN.

[0059] Step 1

[0060] The UE initiates a registration request to the RAN. The RAN selects an AMF for the UE and forwards the registration request to the AMF.

[0061] Steps 2a and 2b

[0062] If the AMF does not have subscription data for the UE, in step 2a, the AMF can retrieve the subscription data from the UDM by calling Nudm_SDM_Get. In step 2b, the UMD can return the UE subscription data to the AMF. This subscription data may contain a list of network slices subscribed to by the UE in its home network. For example, this list may be a list of S-NSSAIs. The subscription data may also include MBR information for each S-NSSAI.

[0063] Steps 3a and 3b

[0064] In step 3a, the AMF can subscribe to updates to UE subscriber data by calling Nudm_SDM_Subscribe to the UDM, and thus will be notified when the subscribed data is modified. For example, the AMF will be notified when the MBR used for the subscribed network slice is updated.

[0065] In step 3b, the UDM can send a response message to the AMF to indicate the execution status of step 3a.

[0066] Step 4

[0067] The Access and Mobility Control (AMC) selects a PCF for its Access and Mobility Control (AMF) policy and sends an Npcf_AMPolicyControl_Create request to that PCF. This request includes subscribed network slice information. Specifically, the subscribed network slice information may include the following list: (the subscribed home slice, its mapped visitor slice (also known as the visited network slice), and MBR information associated with the home slice and mapped visitor slice pair). For example, this list may be in the following format:

[0068] [(Home network slice 1, Visiting network slice 1, 10Mbps), (Home network slice 2, Visiting network slice 1, 20Mbps), (Home network slice 3, Visiting network slice 2, 10Mbps)...]

[0069] Similarly, as described above, the identifier of a slice can include the slice's S-NSSAI.

[0070] Step 5

[0071] Based on its policy, the PCF determines and returns the appropriate network slice information for authorized (or permitted) network slices by sending an Npcf_AMPolicyControl_Create response message to the AMF.

[0072] In some scenarios, not all home slices subscribed to by the UE may be supported or authorized in the visited network. The PCF returns authorized network slice information to the AMF. The authorized network slice information can have the same or similar format as the list described in step 4. For example, the list of authorized (or permitted) network slices can be in the following format:

[0073] [(Home network slice 1, Visiting network slice 1, 10Mbps), (Home network slice 2, Visiting network slice 1, 20Mbps)]. In this example, home network slice 3 is not authorized in the visited network, so it is not in the list.

[0074] Step 6

[0075] AMF accepts UE registration and sends a registration acceptance message to the UE.

[0076] Step 7

[0077] The UE initiates a PDU session establishment request to the AMF via the RAN. From the authorized network slice list, the UE may include one or more of the following pairs in the request: the home network slice and the corresponding visited network slice.

[0078] Network slices can be identified by their S-NSSAI. Home network slices can be identified by their S-NSSAI in HPLMN, while visited network slices can be identified by their S-NSSAI in VPLMN.

[0079] Step 8

[0080] The AMF interacts with the SMF to establish one or more PDU sessions requested by the UE. For each PDU session to be established, the SMF performs the PDU session establishment procedure and then sends the created PDU session ID, the associated home network slice and its corresponding visited network slice (e.g., PDU session ID, S-NSSAI of HPLMN, and S-NSSAI of VPLMN) to the AMF.

[0081] Step 9

[0082] The AMF sends an N2 PDU session request message to the RAN. The N2 PDU session request message can carry the PDU session ID, the associated home network slice, and its corresponding visited network slice. Additionally, the AMF can provide MBR information associated with the home network slice and the corresponding visited network slice pair. The RAN can store the MBR information in the UE context.

[0083] In this step, MBR information is dedicated to home network slice and visited network slice pairs.

[0084] Step 10

[0085] The RAN can interact with the UE via Access Network (AN) specific signaling. Information from the SMF (in step 8 above) can be sent to the UE. AN-specific signaling can be used for resource establishment and can include a PDU session establishment acceptance message. For example, a Radio Resource Control (RRC) connection reconfiguration message can be sent to the UE to establish the necessary RAN resources in accordance with the QoS requirements for the PDU session. In this disclosure, MBR configuration can refer to MBR information, its associated home network slice, and its corresponding visited network slice. MBR configuration can also include the PDU session ID of the corresponding PDU session. For PDU session establishment, the RAN can refer to the MBR configuration.

[0086] The RAN can also allocate RAN tunnel resources for PDU sessions and pass RAN tunnel information to the UE.

[0087] Step 11

[0088] The RAN sends an N2 PDU session response to the AMF. If successful, this response can indicate that the PDU session has been successfully established and may include the PDU session ID, session management (SM) related information, AN tunnel information, etc.

[0089] Example 2: MBR Configuration – From AMF to RAN

[0090] In this embodiment, the MBR configuration can be transmitted from the AMF to the RAN. An example use case could be a UE in the visited network initiating a service request. See [reference] Figure 6 The exemplary steps are described in detail below.

[0091] Step 1

[0092] The UE initiates a service request to the AMF via the RAN. The service request may include a list of PDU sessions to be activated.

[0093] Step 2

[0094] For a PDU session indicated by the service request in step 1, the AMF can request the SMF to activate the PDU session by sending an Nsmf_PDUSession_UpdateSMContext request message to the SMF.

[0095] Step 3

[0096] SMF can activate a PDU session and send data to the RAN.

[0097] Nsmf_PDUSession_UpdateSMContext response message.

[0098] Step 4

[0099] The AMF can send an INITIAL CONTEXT SETUPREQUEST to the RAN, which includes information for all active PDU sessions. This information may include the PDU session ID, the associated home network slice and its corresponding visited network slice pair, and the MBR information associated with that home and visited network slice pair. The RAN can store the MBR-related configuration in the UE context. For example, the MBR-related configuration may include a list of entries, where each entry corresponds to a PDU session. Each entry in the list may include: the PDU session ID, the associated home network slice and its corresponding visited network slice, and the MBR information associated with that home and visited network slice pair.

[0100] Step 5

[0101] The RAN can send an INITIAL CONTEXT SETUP RESPONSE to the AMF. The RAN can also report the execution results of the requested resources for each PDU session.

[0102] Step 6

[0103] The RAN performs an RRC connection reconfiguration to the UE. Taking into account the corresponding MBR configuration, the PDU session requested by the UE in step 1 can be activated.

[0104] Example 3: MBR Configuration Update – From AMF to RAN

[0105] For established PDU sessions associated with network slices, the network slice configuration can be updated. The updated information may need to be allocated to the RAN and / or other relevant network elements so that the RAN can, for example, update the UE context accordingly. (See reference...) Figure 7 The exemplary steps are described in detail below.

[0106] Step 0

[0107] In this step, the RAN has an existing UE context regarding the MBR configuration.

[0108] Step 1

[0109] UDM notifies AMF via Nudm_SDM_Notify that the MBR information for the subscribed network slice (or list of subscribed network slices) has been changed.

[0110] Step 2

[0111] AMF sends the updated MBR configuration to PCF (for each network slice with the update) using the Npcf_AMPolicyControl_Update request. The updated MBR configuration may include MBR information, the associated home network slice, and its corresponding visited network slice pair.

[0112] Step 3

[0113] PCF provides AMF with the corresponding authorized MBR for each pair of home network slices and their corresponding visited network slices.

[0114] Step 4

[0115] AMF can send a UE CONTEXT MODIFICATION REQUEST message to RAN to update the MBR configuration for each pair of home network slices and their corresponding visited network slices that undergo MBR updates, so that RAN can update the corresponding UE context.

[0116] Step 5

[0117] The RAN can send a UE CONTEXT MODIFICATION RESPONSE message to the AMF.

[0118] Example 4: MBR Configuration – From Target AMF to Target RAN

[0119] In a visited network, a UE may need to be handed over from the source RAN (S-RAN) to the target RAN (T-RAN). For example, this could occur during a handover process. Alternatively, a fault condition may exist in the serving RAN, and the UE may need to be handed over to another RAN. The MBR configuration needs to be transmitted to the T-RAN to correctly create / establish a PDU session. (See reference...) Figure 8 The exemplary steps are described in detail below. Although this example uses a handover process as an illustration, the principle generally applies when a UE switches from one RAN to another.

[0120] Step 1

[0121] When a UE moves and the S-RAN decides to trigger relocation via N2, the S-RAN can send a Handover Required message to the source AMF (S-AMF). The Handover Required message can include a list of PDU sessions that need to be handed over. For example, all existing PDU sessions with active User Plane (UP) connections can be included in the Handover Required message.

[0122] Step 2

[0123] When the S-AMF can no longer serve the UE, the S-AMF can select a target AMF (T-AMF) and send a Namf_Communication_CreateUEContext request to the T-AMF to pass UE context information. The UE context information may include MBR configuration (e.g., MBR information, associated home network slices and their corresponding visited network slice pairs).

[0124] Step 3

[0125] For each PDU session indicated by S-RAN, T-AMF can invoke the Nsmf_PDUSession_UpdateSMContext request to the associated SMF.

[0126] Step 4

[0127] The SMF can first check whether an N2 handover for the indicated PDU session is acceptable. If the N2 handover for the PDU session is accepted, the SMF can send a message to the T-AMF.

[0128] The Nsmf_PDUSession_UpdateSMContext response may include N2 Session Management (SM) information, which may include: N3 UP address and User Plane Function (UPF) uplink (UL) core network (CN) tunnel ID, Quality of Service (QoS) parameters, etc.

[0129] Step 5

[0130] The T-AMF can determine the T-RAN for handover and send a handover request message to the T-RAN. The handover request may include a list of N2 SM information (e.g., PDU session ID, associated home network slice and its corresponding visited network slice pair). The handover request may also include MBR information associated with the pair of home network slices and their corresponding visited network slices.

[0131] As mentioned earlier, the home network slice can be represented by HPLMN S-NSSAI, and the visited network slice can be represented by VPLMN S-NSSAI.

[0132] Step 6

[0133] T-RAN sends a handover request confirmation to T-AMF. The handover request confirmation may include N2 SM information associated with each PDU session in the list of PDU sessions that need to be handed over. For each PDU session in the list, the N2 SM information may include T-RAN N3 addressing information (e.g., the T-RAN N3 UP address and tunnel ID used for the PDU session).

[0134] Step 7

[0135] For each PDU session in the list of PDU sessions that need to be switched, there exists a corresponding SMF that can be indicated by the PDU session ID. For each PDU session in this list, the T-AMF can send its N2 SM information to the corresponding SMF.

[0136] Step 8

[0137] SMF can send the Nsmf_PDUSession_UpdateSMContext response message for each PDU session to T-AMF.

[0138] Step 9

[0139] The T-AMF can monitor / supervise Nsmf_PDUSession_UpdateSMContext response messages from the involved SMFs. Upon the expiration of the maximum wait time or when all Nsmf_PDUSession_UpdateSMContext response messages have been received, the T-AMF can send a Namf_Communication_CreateUEContext response to the S-AMF.

[0140] Step 10

[0141] During the handover process, the UE is handed over to T-RAN. The PDU session can be established based on the corresponding MBR configuration (e.g., MBR information, associated home network slice pair and its corresponding visited network slice pair, and / or PDU session ID).

[0142] Example 5: MBR Configuration – From Source RAN to Target RAN

[0143] In this embodiment, MBR information can be directly transmitted from S-RAN to T-RAN. For example, if the handover is an inter-RAN handover based on Xn. (See also...) Figure 9 The exemplary steps are described in detail below. Although this example uses a handover process as an example, the principle generally applies when a UE switches from one RAN to another.

[0144] Step 1

[0145] An S-RAN node can initiate a handover process by sending a HANDOVER REQUEST message to a T-RAN node. This request can include MBR configuration (e.g., MBR information, associated home network slices, and their corresponding visited network slice pairs). The MBR configuration may also include the corresponding PDU session ID.

[0146] Step 2

[0147] T-RAN nodes can store the received MBR configuration in the UE context and use the received MBR configuration for the UE, for example, when establishing or creating a PDU session.

[0148] Example 6: MBR Configuration – From Old AMF to New AMF, and Then to RAN

[0149] When a UE initiates a registration request or registration update to the current AMF, the AMF may be different from the previous serving AMF the UE previously registered with. In this case, the current AMF (or the new AMF, the target AMF) can request the UE context from the previous AMF (or the old AMF, the source AMF). The UE context may include MBR configuration. Once the current AMF obtains the UE context, it can also assign the MBR configuration to the RAN serving the UE. Therefore, on the RAN side, for each PDU session in the UE context, the corresponding MBR configuration can be notified to the RAN. The MBR configuration may refer to the MBR information and its associated home network slice and its corresponding visited network slice. The MBR configuration may also include the PDU session ID of the corresponding PDU session.

[0150] Reference Figure 10 The exemplary steps are described in detail below.

[0151] Step 1

[0152] The UE initiates a registration request to the RAN. If the serving AMF has changed since the last registration process, the RAN selects a new AMF for the UE and forwards the registration request to the new AMF.

[0153] Step 2

[0154] If the registration request includes the UE's 5G Global Unique Temporary Identifier (5G-GUTI), the new AMF can send a Namf_Communication_UEContextTransfer request message to the old AMF to request the UE context.

[0155] Step 3

[0156] The old AMF can send a Namf_Communication_UEContextTransfer response message to the new AMF. This response message can include the MBR configuration for each slice pair (the home network slice and its corresponding visited network slice). For example, the response message can include a list of MBR configurations, where each entry corresponds to a slice pair.

[0157] Steps 4a and 4b

[0158] In step 4a, if the new AMF does not have subscription data for the UE, the new AMF can retrieve the subscription data from the UDM by calling Nudm_SDM_Get. In step 4b, the UMD can return the UE subscription data to the new AMF. The subscription data may contain a list of network slices subscribed to by the UE in its home network. For example, this list may be a list of S-NSSAIs. The subscription data may also include MBR information for each S-NSSAI.

[0159] Steps 5a and 5b

[0160] In step 5a, the new AMF can subscribe to updates to UE subscriber data by calling Nudm_SDM_Subscribe to the UDM, and thus be notified when the subscribed data is modified. For example, the new AMF will be notified when the MBR of the network slice used for the subscription is updated.

[0161] In step 5b, the UDM may send a response message to the new AMF indicating the execution status of step 5a.

[0162] Step 6

[0163] The new AMF selects a PCF for the Access and Mobility Control policy and sends an Npcf_AMPolicyControl_Create request to that PCF. This request includes subscribed network slice information. Specifically, the subscribed network slice information can include the following list: (the subscribed home slice, its mapped visitor slice (also known as the visited network slice), and MBR information associated with the home slice and mapped visitor slice pair). For example, this list could be in the following format:

[0164] [(Home network slice 1, Visiting network slice 1, 10Mbps), (Home network slice 2, Visiting network slice 1, 20Mbps), (Home network slice 3, Visiting network slice 2, 10Mbps)...]

[0165] Similarly, as described above, the identifier of a slice can include the slice's S-NSSAI.

[0166] Step 7

[0167] Based on its policy, the PCF determines and returns the appropriate network slice information for authorized (or permitted) network slices by sending an Npcf_AMPolicyControl_Create response message to the AMF.

[0168] In some scenarios, not all home slices subscribed to by the UE may be supported or authorized in the visited network. The PCF returns authorized network slice information to the AMF. The authorized network slice information can have the same or similar format as the list described in step 4. For example, the list of authorized (or permitted) network slices can be in the following format:

[0169] [(Home network slice 1, Visiting network slice 1, 10Mbps), (Home network slice 2, Visiting network slice 1, 20Mbps)]. In this example, home network slice 3 is not authorized in the visited network, so it is not in the list.

[0170] Step 8

[0171] AMF accepts UE registration and sends a registration acceptance message to the UE.

[0172] Step 9

[0173] The AMF sends an N2 message to the RAN to forward the MBR configuration list for each slice pair. The RAN can then store this list in the UE context.

[0174] Step 10

[0175] The UE initiates a PDU session establishment request to the new AMF via the RAN. From the authorized network slice list, the UE can include the following pair in the request: home network slice and corresponding visited network slice. The request can also include multiple pairs of home network slices and corresponding visited network slices.

[0176] Network slices can be identified by their S-NSSAI. Home network slices can be identified by their S-NSSAI in HPLMN, while visited network slices can be identified by their S-NSSAI in VPLMN.

[0177] Step 11

[0178] The new AMF interacts with other network elements (such as the PCF and / or SMF, not shown in the figure) to establish one or more PDU sessions requested by the UE. For each PDU session to be established, the SMF performs the PDU session establishment procedure and then sends the created PDU session ID, the associated home network slice, and its corresponding visited network slice (e.g., PDU session ID, S-NSSAI of HPLMN, and S-NSSAI of VPLMN) to the new AMF.

[0179] Step 12

[0180] The new AMF sends an N2 PDU session request message to the RAN. The N2 PDU session request message can carry the PDU session ID, the associated home network slice, and its corresponding visited network slice. It should be noted that the MBR information associated with the home network slice and its corresponding visited network slice has already been forwarded to the RAN in step 9 above. Therefore, the RAN can look up the MBR configuration corresponding to the PDU session identified by the PDU session ID.

[0181] Optionally, in the N2 PDU session request message, the new AMF may choose to provide MBR information associated with the home network slice and the corresponding visited network slice pair.

[0182] In this step, MBR information is dedicated to home network slice and visited network slice pairs.

[0183] Step 13

[0184] The RAN can interact with the UE via Access Network (AN) specific signaling. Information from the SMF (in step 8 above) can be sent to the UE. AN-specific signaling can be used for resource establishment and may include a PDU session establishment acceptance message. For example, a Radio Resource Control (RRC) connection reconfiguration message can be sent to the UE to establish the necessary RAN resources in accordance with the QoS requirements for the PDU session. In this disclosure, MBR configuration may refer to MBR information, its associated home network slice, and its corresponding visited network slice. The MBR configuration may also include the PDU session ID of the corresponding PDU session. The RAN can refer to this MBR configuration for PDU session establishment.

[0185] The RAN can also allocate RAN tunnel resources for PDU sessions and transmit RAN tunnel information to the UE.

[0186] Step 14

[0187] The RAN sends an N2 PDU session response to the new AMF. If successful, the response can indicate that the PDU session has been successfully established and may include the PDU session ID, session management (SM) related information, AN tunnel information, etc.

[0188] In this disclosure, information lists such as MBR configuration lists (one configuration per slice pair) can be sent together in a single message (aggregation method). Information lists can also be sent in multiple messages, each carrying one or more elements from the list.

[0189] This disclosure discloses various embodiments of MBR configuration for providing network slices when a UE is in a visited network. The MBR configuration is at the home slice level and applies to the home slice and its corresponding visited network slice pair. The MBR configuration can be transmitted from the AMF to the RAN, or from a first RAN to a second RAN. On the RAN side, for each PDU session in the UE context, the corresponding initial MBR configuration and any updates thereof can be notified to the RAN.

[0190] In this disclosure, the steps in each embodiment are for illustrative purposes only, and other alternatives can be derived based on the disclosed embodiments as needed. For example, only some steps may need to be performed. For another example, the order of the steps may be adjusted. For yet another example, several steps may be combined (e.g., several messages may be combined into one message). Furthermore, a single step may be split (e.g., one message may be sent via two sub-messages).

[0191] In this disclosure, the message names are for illustrative purposes. Messages with other names may be used to achieve the same functionality (e.g., to perform MBR configuration).

[0192] The accompanying drawings and description above provide specific example embodiments and implementations. However, the described subject matter can be embodied in a variety of different forms, and therefore, the covered or claimed subject matter is intended to be construed as not being limited to any of the example embodiments set forth herein. A reasonably broad scope is intended for the claimed or covered subject matter. Among other things, the subject matter can be embodied as a method, apparatus, component, system, or non-transitory computer-readable medium for storing computer code. Therefore, embodiments can take the form, for example, hardware, software, firmware, storage medium, or any combination thereof. For example, the method embodiments described above can be implemented by a component, apparatus, or system including memory and a processor by executing computer code stored in memory.

[0193] Throughout this specification and claims, terms may have subtle meanings implied or suggested by the context, in addition to their expressly stated meanings. Similarly, the phrase "in one embodiment / implementation" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" as used herein does not necessarily refer to a different embodiment. For example, the subject matter intended to be claimed includes combinations of all or some of the exemplary embodiments.

[0194] Generally, terms can be understood, at least in part, based on their usage in the context. For example, terms such as “and,” “or,” or “and / or” as used herein may include a variety of meanings, which can depend, at least in part, on the context in which such terms are used. Typically, if “or” is used with an associative list such as A, B, or C, it is intended to mean that A, B, and C are used here in an inclusive sense, and that A, B, or C are used here in an exclusive sense. Furthermore, the term “one or more,” as used herein, depends at least in part on the context and can be used to describe any feature, structure, or characteristic in a singular sense, or can be used to describe a combination of features, structures, and characteristics in a plural sense. Similarly, terms such as “a,” “an,” or “the” can be understood to express a singular usage or a plural usage, depending at least in part on the context. Moreover, the term “based on” can be understood not necessarily to express a set of exclusive factors, but can allow for the existence of additional factors that are not necessarily explicitly described, again depending at least in part on the context.

[0195] References to features, advantages, or similar language throughout this specification do not imply that all features and advantages achievable using this solution should be or are included in any single implementation thereof. Rather, language relating to features and advantages is to be understood as indicating that a specific feature, advantage, or characteristic described in conjunction with an embodiment is included in at least one embodiment of this solution. Therefore, throughout this specification, the discussion of features and advantages and similar language may, but do not necessarily, refer to the same embodiments.

[0196] Furthermore, the features, advantages, and characteristics described in this solution can be combined in one or more embodiments in any suitable manner. Those skilled in the art will recognize that, based on the description herein, this solution can be implemented without one or more specific features or advantages of a particular embodiment. In other instances, additional features and advantages that may not be present in all embodiments of this solution may be recognized in certain embodiments.

Claims

1. A method for wireless communication, the method being performed by a first network element NE in a wireless network, the method comprising: A first message is transmitted to the second NE in the wireless network, the first message including a first network slice configuration of a first home network slice subscribed by the user equipment UE in the UE's home network, wherein the first network slice configuration includes: The mapping between the first home network slice and the first visited network slice, wherein when the UE is in the visited network of the UE, the first visited network slice is assigned to the UE to serve the first home network slice; and The first maximum bit rate (MBR) information applies to the first home network slice corresponding to the first visited network slice, but not to other home network slices corresponding to the first visited network slice of the UE. The first NE includes the Access and Mobility Management Function (AMF) of the visited network, and the second NE includes the Radio Access Network (RAN) node of the visited network.

2. The method according to claim 1, wherein, The first network slice configuration also includes the identifier of the Protocol Data Unit (PDU) session corresponding to the first home network slice and the first visited network slice.

3. The method according to claim 1, wherein, The first message further includes a second network slice configuration of the second home network slice subscribed by the UE in the UE's home network, such that the second NE is configured to configure a second network slice service corresponding to the second home network slice based on the second network slice configuration, wherein the second network slice configuration includes: The mapping between the second home network slice and the first visited network slice, wherein when the UE is in the visited network, the first visited network slice is further assigned to the UE to serve the second home network slice; and The second MBR information applies to the second home network slice but not to other home network slices of the UE.

4. The method according to claim 1, wherein, The UE is receiving services in the visited network.

5. The method according to claim 4, wherein, Before transmitting the first message to the second NE, the method further includes: In response to receiving a second message from the UE requesting the establishment of a PDU session corresponding to the first home network slice, the system interacts with the Session Management Function (SMF) to establish the PDU session; and Receive a third message from the SMF, the third message including: Network slice pairs, the network slice pairs including the first home network slice and the first visited network slice; and The identifier of the PDU session.

6. The method according to claim 5, wherein: The first message includes an N2 PDU session request message; and The second message includes a PDU session establishment request message.

7. The method according to claim 4, wherein, Before transmitting the first message to the second NE, the method further includes: The UE receives a service request message requesting the activation or creation of a PDU session corresponding to the first home network slice.

8. The method according to claim 7, wherein: The first message includes an initial context establishment request message.

9. The method according to claim 4, further comprising: Receive a second message from the Policy Control Function (PCF), the second message including updated first MBR information; as well as A third message is transmitted to the second NE, the third message including an updated first network slice configuration, wherein the updated first network slice configuration includes: The mapping between the first home network slice and the first visited network slice; and The updated first MBR information applicable to the first home network slice.

10. The method according to claim 9, wherein: The second message includes an access and mobility policy control service update response message; and The third message includes a UE context modification request message.

11. A method for wireless communication, the method being performed by a second network element NE in a wireless network, the method comprising: A first message is received from a first NE in the wireless network, the first message including a first network slice configuration of a first home network slice subscribed by the UE in the UE's home network, wherein the first network slice configuration includes: The mapping between the first home network slice and the first visited network slice, wherein when the UE is in the visited network of the UE, the first visited network slice is assigned to the UE to serve the first home network slice; and The first maximum bit rate (MBR) information applies to the first home network slice corresponding to the first visited network slice, but not to other home network slices corresponding to the first visited network slice of the UE. The first NE includes the Access and Mobility Management Function (AMF) of the visited network, and the second NE includes the Radio Access Network (RAN) node of the visited network.

12. The method according to claim 11, wherein, The first network slice configuration also includes an identifier for a Protocol Data Unit (PDU) session corresponding to the first home network slice.

13. The method according to claim 11, wherein, The first message also includes a second network slice configuration for a second home network slice subscribed by the UE in the UE's home network, wherein the second network slice configuration includes: The mapping between the second home network slice and the first visited network slice, wherein when the UE is in the visited network, the first visited network slice is further assigned to the UE to serve the second home network slice; and The second MBR information applies to the second home network slice but not to other home network slices of the UE.

14. The method according to claim 11 or claim 12, wherein, The second NE determines the execution of the MBR based on both the information of the visited network slice to which each session belongs and the information of the home network slice.

15. A node for wireless communication, the node comprising one or more processors, which, when executed, cause the device to perform the method of any one of claims 1 to 10.

16. A device for wireless communication, the device comprising a processor, which, when executed, causes the device to perform the method of any one of claims 11 to 14.

17. A computer program product comprising a non-transient computer-readable program medium having computer code stored thereon, wherein, when run by one or more processors, the computer code causes the one or more processors to perform the method according to any one of claims 1 to 10.

18. A computer program product comprising a non-transient computer-readable program medium having computer code stored thereon, wherein, when executed by a processor, the computer code causes the processor to perform the method according to any one of claims 11 to 14.

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