Network Slice Provisioning Management

Abstract

This disclosure describes a method comprising the steps of: a wireless device receiving a protocol data unit (PDU) session establishment denial message for an authorized network slice, the PDU session establishment denial message including a backoff timer value; the wireless device starting a session management timer using the backoff timer value; the wireless device receiving a configuration message indicating an alternative network slice for the authorized network slice; and the wireless device sending a request message requesting PDU session establishment based on the configuration message while the session management timer is running, the request message including an identifier for the alternative network slice and an identifier for the authorized network slice.

Description

Technical Field

[0001]

[0001] The present disclosure relates to the establishment of service sessions or data sessions in a cellular network. Specifically, the present disclosure relates, inter alia, to a method and corresponding apparatus for establishing a communication session with a network typically comprising a plurality of network slices.

Background Art

[0002]

[0002] For example, as shown in FIG. 6, a possible network architecture 600A has a specific set of characteristics (e.g., regarding maximum bit rate, reliability, latency, bandwidth usage, power consumption, etc.). This set of characteristics is affected by the nature of the network elements themselves (e.g., processing capacity, availability of free memory, proximity to other network elements, etc.) or their management (e.g., optimized to maximize bit rate or reliability, reduce latency or power bandwidth usage, etc.). The characteristics of network architecture 600A change over time, for example, by upgrading the equipment or by changing procedures to target specific characteristics. However, at any given time, network architecture 600A has a single set of characteristics that may or may not be optimized for a particular use case. For example, UEs 601A, 601B, 601C have different requirements, but network architecture 600A can only be optimized for one of the three.

[0003]

[0003] Network architecture 600B is an example of a sliced ​​physical network divided into multiple logical networks. In Figure 6, the physical network is divided into three logical networks called slice A, slice B, and slice C. For example, UE601A is serviced by AN602A, UPF605A, AMF612, and SMF614A. UE601B is serviced by AN602B, UPF605B, AMF612, and SMF614B. UE601C is serviced by AN602C, UPF605C, AMF612, and SMF614C. Each UE601 communicates with different network elements from a logical standpoint, but these network elements are deployed by the network operator using the same physical network elements.

[0004]

[0004] In these examples, each network slice is tailored to network services having a different set of characteristics. For example, slice A corresponds to enhanced mobile broadband (eMBB) services, which generally refers to internet access by mobile users associated with smartphones. Slice B corresponds to ultra-high reliability low-latency communications (URLLC), which emphasizes reliability and speed. Compared to eMBB, URLLC improves the feasibility of use cases such as autonomous driving and remote surgery. Slice C corresponds to massive machine-type communications (mMTC), which emphasizes low-power services delivered to a large number of users. For example, slice C is optimized for high-density networks of battery-powered sensors that provide small amounts of data at regular intervals. Many mMTC use cases would be prohibitively expensive if operated using eMBB or URLLC networks.

[0005]

[0005] When the UE attempts to connect to a network slice, the connection may fail, causing some processing delay. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006]

[0006] An object of the present invention is to alleviate some of the problems introduced in the background art of the present invention.

[0007]

[0007] Another object of the present invention is to reduce the time required to establish a connection with a network. [Means for solving the problem]

[0008]

[0008] Accordingly, the methods described in the appended claims of this specification are proposed.

[0009]

[0009] A wireless device claimed in the attached set of claims is also proposed.

[0010]

[0010] Some examples of the various embodiments of the present disclosure will be described herein with reference to the drawings. [Brief explanation of the drawing]

[0011] [Figure 1A-1B]

[0011] This figure shows an exemplary communication network including an access network and a core network. [Figure 2A-D]

[0012] This figure shows various examples of frameworks for service-based architectures within a core network. [Figure 3]

[0013] This diagram shows an exemplary communication network including core network functions. [Figure 4A]

[0014] This figure shows an example of a core network architecture with multiple user plane functions. [Figure 4B] This figure shows an example of a core network architecture with multiple user plane functions and untrusted access. [Figure 5]

[0015] It is a diagram showing an example of a core network architecture for a roaming scenario. [Figure 6]

[0016] It is a diagram showing an example of network slicing. [Figure 7A]

[0017] It is a diagram showing a user plane protocol stack. [Figure 7B] It is a diagram showing a control plane protocol stack. [Figure 7C] It is a diagram showing services provided between protocol layers of a user plane protocol stack. [Figure 8]

[0018] It is a diagram showing an example of a quality of service model for data exchange. [Figure 9A-D]

[0019] It is a diagram showing exemplary states and state transitions of a wireless device. [Figure 10]

[0020] It is a diagram showing an example of a registration procedure for a wireless device. [Figure 11]

[0021] It is a diagram showing an example of a service request procedure for a wireless device. [Figure 12]

[0022] It is a diagram showing an example of a protocol data unit session establishment procedure for a wireless device. [Figure 13]

[0023] It is a diagram showing examples of components of elements in a communication network. [Figure 14A-D]

[0024] It is a diagram showing various examples of physical core network deployments, each having one or more network functions or parts thereof. [Figure 15]

[0025] It is a diagram of an aspect of an exemplary embodiment of the present disclosure. [Figure 16]

[0026] It is a diagram of an aspect of an exemplary embodiment of the present disclosure. [Figure 17]

[0027] It is a diagram of an aspect of an exemplary embodiment of the present disclosure. [Figure 18]

[0028] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 19]

[0029] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 20]

[0030] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 21]

[0031] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 22]

[0032] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 23]

[0033] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 24]

[0034] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 25]

[0035] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 26]

[0036] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 27]

[0037] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 28]

[0038] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 29]

[0039] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 30]

[0040] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Figure 31]

[0041] This is a diagram of one embodiment of an exemplary embodiment of the present disclosure. [Modes for carrying out the invention]

[0012]

[0042] In this disclosure, various embodiments are presented as examples of how the disclosed techniques are implemented and / or how they are practiced in environments and scenarios. It will be apparent to those skilled in the art that various modifications in form and detail can be made therein without departing from the scope. In practice, it will be apparent to those skilled in the art how to implement alternative embodiments after reading this specification. These embodiments should not be limited by any of the illustrative embodiments described. Embodiments of this disclosure are described with reference to the accompanying drawings. Limitations, features, and / or elements from the exemplary embodiments disclosed are combined to create further embodiments within the scope of this disclosure. Any figures highlighting features and benefits are presented for illustrative purposes only. The disclosed architecture is sufficiently flexible and configurable to be used in ways other than those shown. For example, actions described in any flowchart may be rearranged or used only at will in some embodiments.

[0013]

[0043] The embodiments are configured to operate as needed. The disclosed mechanisms are implemented in, for example, wireless devices, base stations, radio environments, networks, or combinations thereof, when certain criteria are met. The exemplary criteria are at least partially based on, for example, wireless device or network node configuration, traffic load, initial system setup, packet size, traffic characteristics, or combinations thereof. When one or more criteria are met, various exemplary embodiments are applicable. Therefore, it is possible to implement exemplary embodiments that selectively implement the disclosed protocols.

[0014]

[0044] Base stations communicate with a mix of wireless devices. Wireless devices and / or base stations support multiple technologies and / or multiple releases of the same technology. Wireless devices have one or more specific capabilities. When this disclosure refers to a base station communicating with multiple wireless devices, this disclosure refers to a subset of all wireless devices in a coverage area. This disclosure refers, for example, to multiple wireless devices of a given LTE or 5G release having a given capability and located in a given sector of a base station. Multiple wireless devices in this disclosure refer to a selection of multiple wireless devices and / or a subset of all wireless devices in a coverage area operating in accordance with the disclosed method. There may be multiple base stations or multiple wireless devices in a coverage area that do not operate in accordance with the disclosed method, for example, those wireless devices or base stations operating on an older release of LTE or 5G technology.

[0015]

[0045] In this disclosure, “a” and “an” and similar phrases refer to a single instance of a particular element, but should not be construed as excluding other instances of that element. For example, a bicycle with two wheels is described as having “one wheel.” Any term ending in the suffix “(s)” should be construed as “at least one” and / or “one or more.” In this disclosure, the term “may” should be construed as “may, for example.” In other words, the term “may” indicates that the phrase following the term “may” is an example of one of several appropriate possibilities that may or may not be adopted by one or more of the various embodiments. The terms “comprises” and “consists of,” as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude components that are not enumerated from being included in the element being described. In contrast, “consists of” provides a complete enumeration of one or more components of the element being described.

[0016]

[0046] The phrases “based on,” “in response to,” “according to,” “adopt,” “use,” and similar phrases indicate the existence and / or influence of conditions relating to specific factors and / or events and / or actions, but do not exclude factors and / or conditions that are not listed from existing and / or influencing events and / or actions. For example, if action X is performed “based on” condition Y, this should be interpreted as action X being performed “at least on” condition Y. For example, if the performance of action X is performed when both conditions Y and Z are met, then performing action X is described as being “based on Y.”

[0017]

[0047] The term "configured" relates to the capabilities of a device, whether it is operational or non-operating. "Configured" refers to specific settings within a device that result in the device's operational characteristics, regardless of whether it is operational or non-operating. In other words, hardware, software, firmware, registers, memory values, etc., are "configured" within a device to provide it with specific characteristics, regardless of whether it is operational or non-operating. Terms such as "control messages to cause within a device" mean that control messages have parameters used to configure specific characteristics or to perform certain actions within a device, regardless of whether the device is operational or non-operating.

[0018]

[0048] In this disclosure, a parameter includes one or more information objects, and an information object includes one or more other objects. For example, if parameter J includes parameter K, parameter K includes parameter L, and parameter L includes parameter M, then J includes L and J includes M. Parameters are referred to as fields or information elements. In exemplary embodiments, when one or more messages include multiple parameters, it implies that the parameters among the multiple parameters are present in at least one of the one or more messages, but not each of the one or more messages.

[0019]

[0049] This disclosure refers to the possible combinations of the enumerated elements. For brevity and readability, this disclosure does not explicitly describe all substitutions that can be obtained by choosing from an optional set of features. This disclosure should be construed as explicitly disclosing all such substitutions. For example, the seven possible combinations of the enumerated elements A, B, and C are (1) "A", (2) "B", (3) "C", (4) "A and B", (5) "A and C", (6) "B and C", and (7) "A, B, and C". For brevity and readability, these seven possible combinations are described using any of the following interchangeable expressions: "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C". It is understood that impossible combinations are excluded. For example, "X and / or not X" should be interpreted as "X or not X." It is further understood that these expressions are alternative ways of saying redundant and / or synonymous concepts, such as "identifier, identifying information, and / or ID number."

[0020]

[0050] This disclosure refers to sets and / or subsets. For example, set X is a set of elements that contains one or more elements. If every element of X is also an element of Y, then X is called a subset of Y. This disclosure considers only non-empty sets and subsets. For example, if Y consists of elements Y1, Y2, and Y3, then possible subsets of Y are {Y1,Y2,Y3}, {Y1,Y2}, {Y1,Y3}, {Y2,Y3}, {Y1}, {Y2}, and {Y3}.

[0021]

[0051] Figure 1A shows an example of a communication network 100 in which embodiments of the present disclosure are implemented. The communication network 100 includes, for example, a public land mobile network (PLMN) operated by a network operator. As shown in Figure 1A, the communication network 100 includes a wireless device 101, an access network (AN) 102, a core network (CN) 105, and one or more data networks (DNs) 108.

[0022]

[0052] Wireless device 101 communicates with DN108 via AN102 and CN105. In this disclosure, the term wireless device means any mobile or fixed (non-mobile) device that requires or is capable of wireless communication, and includes them all. For example, wireless devices include telephones, smartphones, tablets, computers, laptops, sensors, meters, wearable devices, Internet of Things (IoT) devices, vehicle roadside units (RSUs), relay nodes, automobiles, unmanned aerial vehicles, urban air mobility, and / or any combination thereof. The term wireless device also includes other terms, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit / receive unit (WTRU), and / or wireless communication device.

[0023]

[0053] AN102 connects wireless device 101 to CN105 in any appropriate manner. The direction of communication from AN102 to wireless device 101 is known as the downlink, and the direction of communication from wireless device 101 to AN102 is known as the uplink. Downlink transmissions are isolated from uplink transmissions using frequency division duplexing (FDD), time division duplexing (TDD), and / or any combination of the two duplexing techniques. AN102 connects to wireless device 101 via radio communication over an air interface. An access network that operates at least partially over an air interface is called a radio access network (RAN). CN105 sets up one or more end-to-end connections between wireless device 101 and one or more DN108s. CN105 authenticates wireless device 101 and provides billing functionality.

[0024]

[0054] In this disclosure, the term "base station" refers to and encompasses any element of AN102 that facilitates communication between wireless device 101 and AN102. Access networks and base stations have many different names and implementation forms. A base station may be a ground base station fixed to the ground. A base station may be a mobile base station with a moving coverage area. A base station may be in space, for example, mounted on a satellite. For example, WiFi and other standards use the term access point. As another example, the Third Generation Partnership Project (3GPP®) has developed specifications for three generations of mobile networks, each of which uses different terminology. Third generation (3G) and / or Universal Mobile Telecommunications System (UMTS) standards use the term Node B. 4G, Long-Term Evolution (LTE), and / or Advanced Universal Terrestrial Radio Access (E-UTRA) standards use the term Advanced Node B (eNB). 5G and / or new radio (NR) standards describe AN102 as a next-generation radio access network (NG-RAN), and refer to base stations as next-generation eNBs (ng-eNBs) and / or generation node B (gNBs). Further standards (e.g., 6G, 7G, 8G) use new terminology to refer to elements (e.g., wireless devices, base stations, ANs, CNs, and / or their components) that implement the methods described in this disclosure. Base stations are implemented as repeater or relay nodes used to extend the coverage area of ​​a donor node. Repeater nodes amplify and rebroadcast radio signals received from donor nodes. Relay nodes perform the same / similar functions as repeater nodes, but decode radio signals received from donor nodes to remove noise before amplifying and rebroadcasting the radio signals.

[0025]

[0055] AN102 includes one or more base stations, each having one or more coverage areas. The geographical size and / or scale of a coverage area is defined in units of the range over which a receiver of AN102 can successfully receive transmissions from a transmitter (e.g., wireless device 101) operating within the coverage area (and / or vice versa). Coverage areas are also called sectors or cells (although in some contexts, the term cell refers to the carrier frequency used in a particular coverage area rather than the coverage area itself). Base stations with large coverage areas are called macrocell base stations. Other base stations cover smaller areas, for example, to provide coverage in areas with weak macrocell coverage or to provide additional coverage in areas with high traffic (sometimes called hotspots). Examples of small cell base stations include, in order of decreasing coverage area, macrocell base stations, picocell base stations, and femtocell base stations or home base stations. Overall, the base station's coverage area provides wireless coverage to the wireless device 101 over a wide geographical area to support wireless device mobility.

[0026]

[0056] A base station includes one or more sets of antennas for communicating with wireless devices 101 via an air interface. Each set of antennas is controlled separately by the base station. Each set of antennas has a corresponding coverage area. As an example, a base station includes three sets of antennas, each to control three coverage areas on three different sides of the base station. The entire base station (and its corresponding antennas) is deployed in a single location. Alternatively, a controller in a central location controls one or more sets of antennas in one or more distributed locations. The controller is, for example, a baseband processing unit, which is part of a centralized or cloud RAN architecture. The baseband processing unit is either centralized or virtualized within a pool of baseband processing units. The sets of antennas in distributed locations are called remote radio heads (RRHs).

[0027]

[0057] Figure 1B shows another exemplary communication network 150 in which embodiments of the present disclosure are implemented. The communication network 150 includes, for example, a PLMN operated by a network operator. As shown in Figure 1B, the communication network 150 includes a UE 151, a next-generation radio access network (NG-RAN) 152, a 5G core network (5G-CN) 155, and one or more DNs 158. The NG-RAN 152 includes one or more base stations, indicated as generation node B (gNB) 152A and next-generation advanced node B (ng-eNB) 152B. The 5G-CN 155 includes one or more network functions (NFs), including control plane functions 155A and user plane functions 155B. One or more DNs 158 include public DNs (e.g., the Internet), private DNs, and / or intra-operator DNs. Compared to the corresponding components shown in Figure 1A, these components represent specific implementation forms and / or terms.

[0028]

[0058] NG-RAN152 base stations are connected to UE151 via Uu interfaces. NG-RAN152 base stations are connected to each other via Xn interfaces. NG-RAN152 base stations are connected to 5G-CN155 via NG interfaces. The Uu interfaces include air interfaces. The NG and Xn interfaces include air interfaces or consist of direct physical and / or indirect connections via an underlying transport network (e.g., an Internet Protocol (IP) transport network).

[0029]

[0059] Each of the Uu interface, Xn interface, and NG interface is associated with a protocol stack. The protocol stack includes the user plane (UP) and the control plane (CP). Generally, user plane data includes data about the user of the UE151, such as internet content downloaded via a web browser application, sensor data uploaded via a tracking application, or email data communicated with an email server. In contrast, control plane data includes signaling and messages that facilitate the packaging and routing of user plane data so that it can be exchanged with DNs. The NG interface is divided into, for example, an NG user plane interface (NG-U) and an NG control plane interface (NG-C). The NG-U interface distributes user plane data between the base station and one or more user plane network functions 155B. The NG-C interface is used for control signaling between the base station and one or more control plane network functions 155A. The NG-C interface performs functions such as NG interface management, UE context management, UE mobility management, NAS message transport, paging, PDU session management, configuration transfer, and / or warning message transmission. In some cases, the NG-C interface supports the transmission of user data (e.g., small data transmission for IoT devices).

[0030]

[0060] One or more base stations in NG-RAN152 are split into a central unit (CU) and one or more distributed units (DUs). The CU is coupled to one or more DUs via an F1 interface. The CU handles one or more upper layers in the protocol stack, and the DUs handle one or more lower layers in the protocol stack. For example, the CU handles RRC, PDCP, and SDAP, while the DUs handle RLC, MAC, and PHY. One or more DUs are located in geographically dispersed locations relative to the CU and / or each other. Thus, the CU / DU split architecture enables expanded coverage and / or better coordination.

[0031]

[0061] The gNB152A and ng-eNB152B provide different user-plane protocol termination and control-plane protocol termination toward the UE151. For example, the gNB154A provides New Radio (NR) protocol termination via a Uu interface associated with a first protocol stack. The ng-eNB152B provides Advanced UMTS Terrestrial Radio Access (E-UTRA) protocol termination via a Uu interface associated with a second protocol stack.

[0032]

[0062] 5G-CN155 authenticates UE151, sets up end-to-end connectivity between UE151 and one or more DN158, and provides billing functionality. 5G-CN155 is based on a service-based architecture in which the NFs constituting 5G-CN155 provide services to each other and to other elements of the communication network 150 via interfaces. 5G-CN155 includes any number of other NFs and any number of instances of each NF.

[0033]

[0063] Figures 2A, 2B, 2C, and 2D illustrate various examples of frameworks for a service-based architecture within a core network. In a service-based architecture, services are requested by service consumers and provided by service producers. Before obtaining a particular service, the NF determines where such a service may be available. To discover services, the NF communicates with the Network Repository Function (NRF). As an example, an NF that provides one or more services registers with the Network Repository Function (NRF). The NRF stores data about one or more services that the NF is ready to provide to other NFs in a service-based architecture. Consumer NFs query the NRF to discover producer NFs (for example, by obtaining a list of NF instances that provide a particular service from the NRF).

[0034]

[0064] In the example in Figure 2A, NF211 (the consumer NF in this example) sends request 221 to NF212 (the producer NF). Request 221 is a request for a specific service and is sent based on the discovery that NF212 is the producer of that service. Request 221 contains data about NF211 and / or the requested service. NF212 receives request 221, performs one or more actions associated with the requested service (e.g., retrieving data), and provides response 221. The one or more actions performed by NF212 are based on the request data contained in request 221, the data stored by NF212, and / or the data retrieved by NF212. Response 222 notifies NF211 that one or more actions have been completed. Response 222 contains response data about NF212, one or more actions, and / or the requested service.

[0035]

[0065] In the example in Figure 2B, NF231 sends request 241 to NF232. In this example, part of the service produced by NF232 is sending request 242 to NF233. NF233 performs one or more actions and provides response 243 to NF232. Based on response 243, NF232 sends response 244 to NF231. From Figure 2B, it can be understood that a single NF performs the roles of service producer, service consumer, or both. A particular NF service includes any number of nested NF services produced by one or more other NFs.

[0036]

[0066] Figure 2C shows an example of a subscribe-notification interaction between a consumer NF and a producer NF. In Figure 2C, NF251 sends subscription 261 to NF252. NF253 sends subscription 262 to NF252. Although two NFs are shown in Figure 2C for illustrative purposes (to demonstrate that NF252 provides multiple subscription services to different NFs), it is understood that the subscribe-notification interaction requires only one subscriber. NF251 and 253 are independent of each other. For example, NF251 and 253 independently discover NF252 and / or independently decide to subscribe to the services provided by NF252. In response to receiving a subscription, NF252 provides notifications to the subscribing NFs. For example, NF252 sends notification 263 to NF251 based on subscription 261 and notification 264 to NF253 based on subscription 262.

[0037]

[0067] As illustrated in the exemplary example in Figure 2C, sending notifications 263 and 264 is based on the decision that a condition has occurred. For example, notifications 263 and 264 are based on the decision that a particular event has occurred, that a particular condition is prominent, and / or that the duration associated with the subscription (e.g., the period associated with the subscription for periodic notifications) has elapsed. As illustrated in the exemplary example in Figure 2C, NF252 sends notifications 263 and 264 to NF251 and 253 simultaneously and / or in response to the same condition. However, it is understood that NF252 may provide notifications at different times and / or in response to different notification conditions. In one example, NF251 requests a notification when a certain parameter measured by NF252 exceeds a first threshold, and NF252 requests a notification when the parameter exceeds a second threshold different from the first threshold. In one example, the parameter of interest and / or the corresponding thresholds are shown in subscriptions 261 and 262.

[0038]

[0068] Figure 2D shows another example of a subscribe-notification interaction. In Figure 2D, NF271 sends subscription 281 to NF272. In response to the decision that subscription 281 has been received and / or the notification conditions have been met, NF272 sends notification 284. Notification 284 is sent to NF273. Unlike the example in Figure 2C (where the notification is sent to the subscribed NF), Figure 2D explicitly shows that the subscription and its corresponding notification are associated with different NFs. For example, NF271 subscribes to a service provided by NF272 on behalf of NF273.

[0039]

[0069] Figure 3 shows another exemplary communication network 300 in which embodiments of the present disclosure are implemented. The communication network 300 includes user equipment (UE) 301, an access network (AN) 302, and a data network (DN) 308. The remaining elements illustrated in Figure 3 are included in and / or associated with the core network. Each element of the core network is referred to as a network function (NF).

[0040]

[0070] The NF illustrated in Figure 3 includes User Plane Functions (UPF) 305, Access and Mobility Management Functions (AMF) 312, Session Management Functions (SMF) 314, Policy Control Functions (PCF) 320, Network Repository Functions (NRF) 330, Network Exposure Functions (NEF) 340, Unified Data Management (UDM) 350, Authentication Server Functions (AUSF) 360, Network Slice Selection Functions (NSSF) 370, Billing Functions (CHF) 380, Network Data Analysis Functions (NWDAF) 390, and Application Functions (AF) 399. UPF 305 is the user plane core network function, while NFs 312, 314, and 320-390 are control plane core network functions. Although not shown in the example in Figure 3, the core network includes the illustrated NFs and / or additional instances of one or more different NF types that provide different services. Other examples of NF types include Gateway Mobile Location Center (GMLC), Location Management Function (LMF), Operations, Management, and Maintenance Function (OAM), Public Warning System (PWS), Short Message Service Function (SMSF), Integrated Data Repository (UDR), and Unstructured Data Storage Function (UDSF).

[0041]

[0071] Each element illustrated in Figure 3 has an interface with at least one other element. The interface is a logical connection, not a direct physical connection, for example. Any interface is identified using a reference point representation and / or a service-based representation. In a reference point representation, the letter "N" is followed by a number indicating the interface between two specific elements. For example, as shown in Figure 3, AN302 and UPF305 interface via "N3", while UPF305 and DN308 interface via "N6". In contrast, in a service-based representation, the letter "N" is followed by a letter. The letter identifies the NF that provides services to the core network. For example, PCF320 provides services via the interface "Npcf". PCF320 provides services to any NF in the core network via "Npcf". Thus, a service-based representation corresponds to a bundle of reference point representations. For example, the NPCF interface between the PCF320 and the core network generally corresponds to the N7 interface between the PCF320 and the SMF314, and the N30 interface between the PCF320 and the NEF340, etc.

[0042]

[0072] UPF305 acts as a gateway for user plane traffic between AN302 and DN308. UE301 connects to UPF305 via the Uu interface and the N3 interface (also described as the NG-U interface). UPF305 connects to DN308 via the N6 interface. UPF305 connects to one or more other UPFs (not shown) via the N9 interface. UE301 is configured to receive services through protocol data unit (PDU) sessions, which are logical connections between UE301 and DN308. To handle a particular PDU session between UE301 and DN308, UPF305 (or multiple UPFs, if desired) is selected by SMF314. SMF314 controls the functionality of UPF305 with respect to PDU sessions. SMF314 connects to UPF305 via the N4 interface. UPF305 handles any number of PDU sessions associated with any number of UEs (via any number of ANs). For the purpose of handling one or more PDU sessions, the UPF305 is controlled by any number of SMFs via any number of corresponding N4 interfaces.

[0043]

[0073] The AMF312, illustrated in Figure 3, controls UE access to the core network. UE301 registers with the network via the AMF312. Registration of UE301 is required before establishing a PDU session. The AMF312 manages the registration area of ​​UE301 and allows the network to track the physical location of UE301 within the network. For UEs in connected mode, the AMF312 manages UE mobility, e.g., handover from one AN or part thereof to another. For UEs in idle mode, the AMF312 performs registration updates and / or paging the UE to transition it to connected mode.

[0044]

[0074] The AMF312 receives NAS messages sent from the UE301 according to the Non-Access Layer (NAS) protocol. NAS messages relate to communication between the UE301 and the core network. NAS messages are relayed to the AMF312 via the AN302, but are described as communication via the N1 interface. NAS messages facilitate UE registration and mobility management, for example, by authenticating, identifying, configuring, and / or managing the UE301's connection. NAS messages support session management procedures to maintain user plane connectivity and quality of service (QoS) for sessions between the UE301 and the DN309. If a NAS message involves session management, the AMF312 forwards the NAS message to the SMF314. NAS messages are used to transport messages between the UE301 and other components of the core network (e.g., core network components other than the AMF312 and SMF314). The AMF312 either acts according to the specific NAS message itself, or, alternatively, forwards the NAS message to the appropriate core network function (e.g., SMF314).

[0045]

[0075] The SMF314, illustrated in Figure 3, establishes, modifies, and / or releases PDU sessions based on messaging received by the UE301. For example, when establishing a PDU session, the SMF314 allocates, manages, and / or assigns an IP address to the UE301. There are multiple SMFs in the network, each associated with a group of wireless devices, base stations, and / or UPFs. A UE with multiple PDU sessions is associated with a different SMF for each PDU session. As described above, the SMF314 selects one or more UPFs to handle the PDU session and controls how the selected UPFs handle the PDU session by providing rules for packet handling (PDR, FAR, QER, etc.). Rules regarding QoS and / or billing for a particular PDU session are obtained from the PCF320 and provided to the UPF305.

[0046]

[0076] The PCF320 provides policy rule services to other Network Functions (NFs). The PCF320 uses subscription data and network conditions information to determine policy rules, then provides these rules to specific NFs, which are responsible for enforcing them. Policy rules related to access and mobility policy control are enforced by the AMF. Policy rules related to session management are enforced by the SMF314. Policy rules can be, for example, network-specific, wireless device-specific, session-specific, or data flow-specific.

[0047]

[0077] NRF330 provides service discovery. NRF330 belongs to a specific PLMN. NRF330 maintains NF profiles for other NFs within the communication network 300. The NF profile includes, for example, the address, PLMN, and / or the type of NF, a slice identifier, a list of one or more services provided by the NF, and the permissions required to access the services.

[0048]

[0078] The NEF340, illustrated in Figure 3, provides an interface to external domains, allowing them to selectively access the control plane of the communication network 300. External domains include, for example, third-party network functions and application functions. The NEF340 acts as a proxy between external elements and network functions such as AMF312, SMF314, PCF320, and UDM350. For example, the NEF340 determines the location or reachability status of UE301 based on reports from AMF312 and provides status information to external elements. For example, external elements provide information via the NEF340 to facilitate the setting of parameters for establishing a PDU session. The NEF340 determines which data and control plane capabilities are exposed to external domains. The NEF340 provides secure exposures that authenticate and / or authorize external entities to which data or communication network 300 capabilities are exposed. The NEF340 selectively controls exposures so that the internal architecture of the core network is hidden from external domains.

[0049]

[0079] The UDM350 provides data storage to other NFs. The UDM350 enables a unified view of network information used to ensure that different NFs can access the most relevant information from a single resource. The UDM350 stores and / or retrieves information from the Unified Data Repository (UDR). For example, the UDM350 retrieves user subscription data for UE301 from the UDR.

[0050]

[0080] AUSF360 supports mutual authentication of UE301 by the core network and authentication of the core network by UE301. AUSF360 implements key agreement procedures and provides key material that can be used to enhance security.

[0051]

[0081] The NSSF370 selects one or more network slices to be used by the UE301. The NSSF370 selects a slice based on slice selection information. For example, the NSSF370 receives Single Network Slice Selection Assistance Information (S-NSSAI) and maps the S-NSSAI to a Network Slice Instance Identifier (NSI).

[0052]

[0082] CHF380 controls billing-related tasks associated with UE301. For example, UPF305 reports traffic usage associated with UE301 to SMF314. SMF314 collects usage data from UPF305 and one or more other UPFs. The usage data shows how much data was exchanged, which DNs the data was exchanged with, the network slices associated with the data, or any other information that affects billing. SMF314 shares the collected usage data with CHF. CHF uses the collected usage data to perform billing-related tasks associated with UE301. Depending on the billing status of UE301, CHF instructs SMF314 to restrict or affect access to UE301 and / or provide billing-related notices to UE301.

[0053]

[0083] The NWDAF390 collects and analyzes data from other network functions and provides data analysis services to those functions. For example, the NWDAF390 collects data on the load level of a specific network slice instance from the UPF305, AMF312, and / or SMF314. Based on the collected data, the NWDAF390 provides load level data to the PCF320 and / or NSSF370, and / or notifies the PC220 and / or NSSF370 if the slice's load level reaches and / or exceeds the load level threshold.

[0054]

[0084] AF399 is external to the core network but interacts with it to provide information about QoS requirements or traffic routing preferences associated with specific applications. AF399 accesses the core network based on public restrictions imposed by NEF340. However, core network operators may consider AF399 to be a trusted domain with direct access to the network.

[0055]

[0085] Figures 4A, 4B, and 5 show other examples of core network architectures that are similar in several respects to the core network architecture 300 illustrated in Figure 3. For brevity, some of the core network elements illustrated in Figure 3 are omitted. Many of the elements illustrated in Figures 4A, 4B, and 5 are similar in several respects to the elements illustrated in Figure 3. For brevity, some of the details regarding their function or operation are omitted.

[0056]

[0086] Figure 4A shows an example of core network architecture 400A, which includes a configuration of multiple UPFs. Core network architecture 400A includes UE401, AN402, AMF412, and SMF414. Unlike the previous example of the core network architecture described above, Figure 4A illustrates multiple UPFs, including UPF405, UPF406, and UPF407, and multiple DNs, including DN408 and DN409. Each of the multiple UPF405, 406, and 407 communicates with SMF414 via the N4 interface. DN408 and 409 communicate with UPF405 and 406, respectively, via the N6 interface. As shown in Figure 4A, the multiple UPF405, 406, and 407 communicate with each other via the N9 interface.

[0057]

[0087] UPF405, 406, and 407 perform traffic detection in which the UPF identifies and / or classifies packets. Packet identification is performed based on packet detection rules (PDRs) provided by SMF414. PDRs include packet detection information, which includes one or more of the following: source interface, UE IP address, core network (CN) tunnel information (e.g., CN address of the N3 / N9 tunnel corresponding to the PDU session), network instance identifier, quality of service flow identifier (QFI), filter set (e.g., IP packet filter set or Ethernet packet filter set), and / or application identifier.

[0058]

[0088] In addition to indicating how a particular packet should be detected, a PDR further specifies the rules for handling packets upon detection. These rules include, for example, forwarding action rules (FARs), multiple access rules (MARs), usage reporting rules (URRs), and QoS enforcement rules (QERs). For instance, a PDR may include one or more FAR identifiers, MAR identifiers, URR identifiers, and / or QER identifiers. These identifiers indicate the rules prescribed for handling a particular detected packet.

[0059]

[0089] The UPF405 performs traffic forwarding according to FARs. For example, a FAR indicates that packets associated with a particular PDR should be forwarded, duplicated, dropped, and / or buffered. The FAR indicates the destination interface, e.g., "Access" for downlinks or "Core" for uplinks. If packets should be buffered, the FAR indicates a buffering action rule (BAR). As an example, when a PDU session is deactivated, the UPF405 performs data buffering of a certain number of downlink packets.

[0060]

[0090] UPF405 enforces QoS according to the QER. For example, the QER indicates the permitted guaranteed bitrate and / or the maximum bitrate that should be enforced for packets associated with a particular PDR. The QER indicates that the particular guaranteed bitrate and / or maximum bitrate are for uplink packets and / or downlink packets. UPF405 marks packets belonging to a particular QoS flow with the corresponding QFI. The marking allows the packet's recipient to determine the packet's QoS.

[0061]

[0091] UPF405 provides usage reports to SMF414 according to the URR. The URR specifies one or more triggering conditions for generating and reporting usage reports, e.g., immediate reporting, periodic reporting, threshold for incoming uplink traffic, or any other appropriate triggering conditions. The URR specifies a method for measuring network resource usage, e.g., data volume, duration, and / or events.

[0062]

[0092] As described above, DN408 and 409 include public DNs (e.g., the Internet), private DNs (e.g., private, internal, corporate-owned DNs), and / or intra-operator DNs. Each DN provides operator services and / or third-party services. Services provided by the DNs include the Internet, IP Multimedia Subsystems (IMS), augmented reality or virtual reality networks, edge computing or mobile edge computing (MEC) networks, etc. Each DN is identified using a Data Network Name (DNN). UE401 is configured to establish a first logical connection with DN408 (first PDU session), a second logical connection with DN409 (second PDU session), or both simultaneously (first and second PDU sessions).

[0063]

[0093] Each PDU session is associated with at least one UPF configured to act as a PDU session anchor (PSA, or "anchor"). The anchor is a UPF that provides the N6 interface to the DN.

[0064]

[0094] In the example in Figure 4A, UPF405 is the anchor for the first PDU session between UE401 and DN408, while UPF406 is the anchor for the second PDU session between UE401 and DN409. The core network uses anchors to provide continuity of service (e.g., IP address continuity) for a particular PDU session when UE401 moves from one access network to another. For example, suppose UE401 establishes a PDU session using a data path to DN408 using an access network other than AN402. The data path includes UPF405 acting as an anchor. Furthermore, suppose UE401 later enters the coverage area of ​​AN402. In such a scenario, SMF414 selects a new UPF (UPF407) to fill the gap between the newly entered access network (AN402) and the anchor UPF (UPF405). PDU session continuity is maintained when any number of UPFs are added to or removed from the data path. As shown in Figure 4A, when a UPF is added to the data path, the UPF is described as an intermediate UPF and / or a cascaded UPF.

[0065]

[0095] As mentioned above, UPF406 is the anchor for the second PDU session between UE401 and DN409. While the anchors for the first and second PDU sessions are associated with different UPFs in Figure 4A, this is just an example. Multiple PDU sessions with a single DN can correspond to any number of anchors. When there are multiple UPFs, the UPF at the branching point (UPF407 in Figure 4A) acts as an Uplink Classifier (UL-CL). The UL-CL reroutes uplink user plane traffic to a different UPF.

[0066]

[0096] The SMF414 allocates, manages, and / or assigns IP addresses to the UE401, for example, when establishing a PDU session. The SMF414 maintains an internal pool of IP addresses to be assigned. The SMF414 assigns IP addresses provided by a Dynamic Host Configuration Protocol (DHCP) server or an Authentication, Authorization, and Accounting (AAA) server, if necessary. IP address management is performed according to Session and Service Continuity (SSC) modes. In SSC mode 1, the UE401's IP address is maintained as the wireless device moves within the network (the same anchor UPF is used). In SSC mode 2, the UE401's IP address changes as it moves within the network (e.g., the old IP address and UPF are abandoned, and a new IP address and anchor UPF are established). In SSC mode 3, it is possible to temporarily maintain the old IP address (similar to SSC mode 1) while establishing a new IP address (similar to SSC mode 2), thus combining the features of SSC mode 1 and SSC mode 2. Applications sensitive to IP address changes should operate according to SSC mode 1.

[0067]

[0097] UPF selection is controlled by SMF414. For example, when establishing and / or modifying a PDU session between UE401 and DN408, SMF414 selects UPF405 as the anchor for the PDU session and / or UPF407 as the intermediate UPF. Criteria for UPF selection include path efficiency and / or speed between AN402 and DN408. Reliability, load status, location, slice support, and / or other capabilities of candidate UPFs are also considered.

[0068]

[0098] Figure 4B shows an example of core network architecture 400B that accepts untrusted access. Similar to Figure 4A, UE401 illustrated in Figure 4B connects to DN408 via AN402 and UPF405. AN402 and UPF405 constitute trusted (e.g., 3GPP®) access to DN408. In contrast, UE401 also accesses DN408 using an untrusted access network, AN403, and non-3GPP® interworking function (N3IWF) 404.

[0069]

[0099] AN403 is, for example, a wireless land area network (WLAN) operating according to the IEEE 802.11 standard. UE401 connects to AN403 via interface Y1, whatever the specified method for AN403 may or may not require authentication. UE401 obtains an IP address from AN403. UE401 decides to connect to core network 400B and selects untrusted access for that purpose. AN403 communicates with N3IWF404 via interface Y2. After selecting untrusted access, UE401 provides N3IWF404 with sufficient information to select an AMF. The selected AMF is, for example, the same AMF used by UE401 for 3GPP® access (AMF412 in this example). N3IWF404 communicates with AMF412 via interface N2. UPF405 is selected, and N3IWF404 communicates with UPF405 via the N3 interface. UPF405 is the PDU session anchor (PSA) and remains the anchor for the PDU session even if UE401 shifts between trusted and untrusted access.

[0070]

[0100] Figure 5 shows an example of the core network architecture 500 in a roaming scenario where UE501 is present. In the roaming scenario, UE501 is a subscriber to the first PLMN (home PLMN or HPLMN) but attaches to the second PLMN (destination PLMN or VPLMN). The core network architecture 500 includes UE501, AN502, UPF505, and DN508. AN502 and UPF505 are associated with the VPLMN. The VPLMN manages AN502 and UPF505 using core network elements associated with the VPLMN, including AMF512, SMF514, PCF520, NRF530, NEF540, and NSSF570. AF599 is adjacent to the core network of the VPLMN.

[0071]

[0101] UE501 may not be a subscriber to VPLMN. AMF512 allows UE501 to access the network, for example, based on roaming constraints applied to UE501. In order to obtain network services provided by VPLMN, the VPLMN's core network must interact with the HPLMN's core network elements on UE501, specifically PCF521, NRF531, NEF541, UDM551, and / or AUSF561. VPLMN and HPLMN communicate using N32 interfaces connected to their respective Security Edge Protected Proxy (SEPP). In Figure 5, the respective SEPPs are illustrated as VSEPP590 and HSEPP591.

[0072]

[0102] VSEPP590 and HSEPP591 communicate via the N32 interface for defined purposes, while concealing information about each PLMN from each other. SEPP applies roaming policies based on communication via the N32 interface. PCF520 and PCF521 communicate via SEPP to exchange policy-related signaling. NRF530 and NRF531 communicate via SEPP to enable NF service discovery in their respective PLMNs. VPLMN and HPLMN maintain NEF540 and NEF541 independently. NSSF570 and NSSF571 communicate via SEPP to coordinate slice selection for UE501. HPLMN handles all authentication and subscription-related signaling. For example, when UE501 registers or requests service via VPLMN, VPLMN authenticates UE501 and / or retrieves UE501's subscription data by accessing HPLMN's UDM551 and AUSF561 via SEPP.

[0073]

[0103] The core network architecture 500 illustrated in Figure 5 is called a local breakout configuration, in which UE501 accesses DN508 using one or more UPFs of the VPLMN (i.e., UPF505). However, other configurations are possible. For example, in a home routing configuration (not shown in Figure 5), UE501 accesses DN using one or more UPFs of the HPLMN. In the home routing configuration, the N9 interface operates in parallel with the N32 interface, crossing the boundary between the VPLMN and HPLMN to carry user plane data. One or more SMFs of each PLMN communicate via the N32 interface to coordinate session management for UE501. The SMFs control their respective UPFs on both sides of the boundary.

[0074]

[0104] Figure 6 shows an example of network slicing. Network slicing refers to dividing a shared infrastructure (e.g., physical infrastructure) into separate logical networks. These separate logical networks are controlled independently, isolated from each other, and / or associated with dedicated resources.

[0075]

[0105] Network architecture 600A represents an unsliced ​​physical network corresponding to a single logical network. Network architecture 600A includes a user plane in which UE601A, 601B, and 601C (collectively UE601) have physical and logical connections to DN608 via AN602 and UPF605. Network architecture 600A also includes a control plane in which AMF612 and SMF614 control various aspects of the user plane.

[0076]

[0106] Network Architecture 600A has a specific set of characteristics (e.g., regarding maximum bitrate, reliability, latency, bandwidth usage, power consumption, etc.). This set of characteristics is influenced by the nature of the network elements themselves (e.g., processing power, availability of free memory, proximity to other network elements, etc.) or their management (e.g., optimizing to maximize bitrate or reliability and reduce latency or power bandwidth usage, etc.). The characteristics of Network Architecture 600A change over time, for example, by upgrading equipment or by modifying procedures to target specific characteristics. However, at any given time, Network Architecture 600A has a single set of characteristics that may or may not be optimized for a particular use case. For example, UE601A, 601B, and 601C have different requirements, but Network Architecture 600A can only be optimized for one of the three.

[0077]

[0107] Network architecture 600B is an example of a sliced ​​physical network divided into multiple logical networks. In Figure 6, the physical network is divided into three logical networks called slice A, slice B, and slice C. For example, UE601A is serviced by AN602A, UPF605A, AMF612, and SMF614A. UE601B is serviced by AN602B, UPF605B, AMF612, and SMF614B. UE601C is serviced by AN602C, UPF605C, AMF612, and SMF614C. Each UE601 communicates with different network elements from a logical standpoint, but these network elements are deployed by the network operator using the same physical network elements.

[0078]

[0108] Each network slice is tailored to network services with different characteristics. For example, slice A supports enhanced mobile broadband (eMBB) services, which typically refer to internet access by mobile users associated with smartphones. Slice B supports ultra-high reliability low-latency communications (URLLC), which emphasizes reliability and speed. Compared to eMBB, URLLC improves the feasibility of use cases such as autonomous driving and remote surgery. Slice C supports massive machine-type communications (mMTC), which emphasizes low-power services delivered to a large number of users. For example, slice C is optimized for high-density networks of battery-powered sensors that provide small amounts of data at regular intervals. Many mMTC use cases would be prohibitively expensive if operated using eMBB or URLLC networks.

[0079]

[0109] If the service requirements for one of the UE601s change, the network slice will service so that the UE can be updated to provide better service. Furthermore, the set of network characteristics corresponding to eMBB, URLLC, and mMTC will change so that differentiated types of eMBB, URLLC, and mMTC are provided. Alternatively, the network operator may provide an entirely new service, for example, in response to customer demand.

[0080]

[0110] In Figure 6, each UE601 has its own network slice. However, it is understood that a single slice can serve any number of UEs, and a single UE can operate using any number of slices. Furthermore, in the exemplary network architecture 600B, AN602, UPF605, and SMF614 are divided into three separate slices, while AMF612 is not sliced. However, it is understood that network operators may deploy any architecture that selectively utilizes any mixture of sliced ​​and unsliced ​​network elements, where different network elements are divided into different numbers of slices. Although Figure 6 illustrates only three core network functions, it is understood that other core network functions can also be sliced. A PLMN supporting multiple network slices maintains a separate network repository function (NFR) for each slice, allowing other NFs to discover the network services associated with that slice.

[0081]

[0111] Network slice selection is controlled by the AMF, or alternatively, by a separate Network Slice Selection Function (NSSF). For example, a network operator defines and enforces individual network slice instances (NSIs). Each NSI is associated with a single network slice selection assistance information (S-NSSAI). The S-NSSAI includes a specific slice / service type (SST) indicator (such as eMBB, URLLC, mMTC, etc.). As an example, a particular tracking area is associated with one or more configured S-NSSAIs. The UE identifies one or more requested and / or subscribed S-NSSAIs (e.g., during registration). The network shows the UE one or more permitted and / or denied S-NSSAIs.

[0082]

[0112] S-NSSAI further includes slice differentiaters (SDs) that distinguish different tenants for specific slices and / or service types. For example, a tenant is a customer of a network operator (e.g., a vehicle manufacturer, a service provider, etc.) who obtains (e.g., purchases) specific policies for handling guaranteed network resources and / or their subscribers. The network operator configures different slices and / or slice types and uses SDs to determine which tenants are associated with a particular slice.

[0083]

[0113] Figures 7A, 7B, and 7C illustrate the services provided between the user plane (UP) protocol stack, the control plane (CP) protocol stack, and the protocol layers of the UP protocol stack.

[0084]

[0114] The layers are associated with the Open System Interconnection (OSI) model of computer networking functionality. In the OSI model, Layer 1 corresponds to the bottom layer, and the upper layers are above the bottom layer. Layer 1 corresponds to the physical layer, which relates to the physical infrastructure used for signal transmission (e.g., cables, optical fibers, and / or radio frequency transceivers). In New Radio (NR), Layer 1 includes the Physical Layer (PHY). Layer 2 corresponds to the data link layer. Layer 2 relates to the packaging of data (e.g., into data frames) for transmission using the physical infrastructure of Layer 1 between nodes of the network. In NR, Layer 2 includes the Medium Access Control Layer (MAC), the Radio Link Control Layer (RLC), the Packet Data Convergence Layer (PDCP), and the Service Data Application Protocol Layer (SDAP).

[0085]

[0115] Layer 3 corresponds to the network layer. Layer 3 is involved in routing data packaged in Layer 2. Layer 3 handles data prioritization and traffic avoidance. In NR, Layer 3 includes the Radio Resource Control Layer (RRC) and the Non-Access Layer (NAS). Layers 4 through 7 correspond to the transport layer, session layer, presentation layer, and application layer. The application layer interacts with end users to provide data associated with the application. For example, an end user running an application generates data associated with the application and begins sending that information to the target data network (e.g., the internet, application server, etc.). Starting from the application layer, each layer in the OSI model manipulates and / or repackages the information and delivers it to the lower layers. At the lowest layer, the manipulated and / or repackaged information is exchanged via the physical infrastructure (e.g., electrically, optically, and / or electromagnetically). As the information approaches the target data network, it is unpackaged and delivered to the higher layers until it reaches the application layer again in a form usable by the target data network (e.g., the same form in which the information was provided by the end user). To respond to end users, the data network reverses this process.

[0086]

[0116] Figure 7A shows the user plane protocol stack. The user plane protocol stack is a new radio (NR) protocol stack for the Uu interface between UE701 and gNB702. In layer 1 of the UP protocol stack, UE701 implements PHY731 and gNB702 implements PHY732. In layer 2 of the UP protocol stack, UE701 implements MAC741, RLC751, PDCP761, and SDAP771. gNB702 implements MAC742, RLC752, PDCP762, and SDAP772.

[0087]

[0117] Figure 7B shows the control plane protocol stack. The control plane protocol stack is the NR protocol stack for the Uu interface between UE701 and gNB702 and / or the N1 interface between UE701 and AMF712. In layer 1 of the CP protocol stack, UE701 implements PHY731 and gNB702 implements PHY732. In layer 2 of the CP protocol stack, UE701 implements MAC741, RLC751, PDCP761, RRC781, and NAS791. gNB702 implements MAC742, RLC752, PDCP762, and RRC782. AMF712 implements NAS792.

[0088]

[0118] The NAS is involved in the non-access layer, specifically communication between the UE701 and the core network (e.g., AMF712). The lower layer is involved in the access layer, specifically communication between the UE701 and the gNB702. Messages sent between the UE701 and the core network are called NAS messages. In one example, NAS messages are relayed by the gNB702, but the content of the NAS messages (e.g., the information elements of the NAS message) is not visible to the gNB702.

[0089]

[0119] Figure 7C shows an example of services provided between the protocol layers of the NR user plane protocol stack shown in Figure 7A. UE701 receives services through a PDU session, which is a logical connection between UE701 and the data network (DN). UE701 and the DN exchange data packets associated with the PDU session. A PDU session contains one or more Quality of Service (QoS) flows. SDAP771 and SDAP772 perform mapping and / or demapping between one or more QoS flows of the PDU session and one or more radio bearers (e.g., data radio bearers). The mapping between QoS flows and data radio bearers is determined by gNB702 in SDAP772, and UE701 is notified of the mapping (e.g., based on control signaling and / or reflective mapping). In the case of reflective mapping, SDAP772 in gNB220 marks downlink packets with a QoS flow indicator (QFI) and delivers downlink packets to UE701. The UE701 determines the mapping based on the QFI of the downlink packet.

[0090]

[0120] PDCP761 and PDCP762 perform header compression and / or decompression. Header compression reduces the amount of data transmitted over the physical layer. PDCP761 and PDCP762 perform encryption and / or decryption. Encryption reduces unauthorized decryption of data transmitted over the physical layer (e.g., interception on the air interface) and protects data integrity (e.g., to ensure that control messages originate from the intended source). PDCP761 and PDCP762 perform retransmission of undelivered packets, sequential delivery and reordering of packets, packet duplication, and / or identification and removal of duplicate packets. In dual connectivity scenarios, PDCP761 and PDCP762 perform mapping between split radio bearers and RLC channels.

[0091]

[0121] RLC751 and RLC752 perform segmentation and retransmission via Automatic Retransmission Request (ARQ). RLC751 and RLC752 remove duplicate data units received from MAC741 and MAC742, respectively. RLC213 and 223 provide RLC channels as a service to PDCP214 and 224, respectively.

[0092]

[0122] MAC741 and MAC742 perform logical channel multiplexing and / or demultiplexing. MAC741 and MAC742 map logical channels to transport channels. In one example, UE701 multiplexes one or more data units of logical channels into a transport block at MAC741. UE701 uses PHY731 to send the transport block to gNB702. gNB702 uses PHY732 to receive the transport block and demultiplexes the data units of the transport block into logical channels. MAC741 and MAC742 perform error correction, logical channel prioritization, and / or padding using Hybrid Automatic Retransmission Request (HARQ).

[0093]

[0123] PHY731 and PHY732 perform the mapping of transport channels to physical channels. PHY731 and PHY732 perform digital and analog signal processing functions (e.g., coding / decoding and modulation / demodulation) for sending and receiving information (e.g., transmission via the air interface). PHY731 and PHY732 perform multi-antenna mapping.

[0094]

[0124] Figure 8 shows an example of a Quality of Service (QoS) model for differentiated data exchange. The QoS models in Figure 8 include UE801, AN802, and UPF805. QoS models facilitate the prioritization of certain packets, or protocol data units (PDUs), also called packets. For example, higher-priority packets are exchanged faster and / or more reliably than lower-priority packets. The network then dedicates more resources to exchanging high-QoS packets.

[0095]

[0125] In the example in Figure 8, a PDU session 810 is established between UE801 and UPF805. The PDU session 810 is a logical connection that enables UE801 to exchange data with a specific data network (e.g., the Internet). UE801 requests the establishment of the PDU session 810. When the PDU session 810 is established, UE801 identifies the target data network based on its data network name (DNN), for example. The PDU session 810 is managed by a session management function (SMF, not shown), for example. To facilitate the exchange of data associated with the PDU session 810 between UE801 and the data network, the SMF selects UPF805 (and optionally one or more other UPFs, not shown).

[0096]

[0126] One or more applications associated with UE801 generate uplink packets 812A-812E associated with PDU session 810. To operate within the QoS model, UE801 applies QoS rule 814 to uplink packets 812A-812E. QoS rule 814 is associated with PDU session 810 and is determined and / or provided to UE801 when PDU session 810 is established and / or modified. Based on QoS rule 814, UE801 classifies uplink packets 812A-812E, maps each of the uplink packets 812A-812E to a QoS flow, and / or marks uplink packets 812A-812E with a QoS flow indicator (QFI). As packets travel through the network and potentially mix with other packets from other UEs that have potentially different priorities, the QFI indicates how the packets should be handled according to the QoS model. In this example, uplink packets 812A and 812B are mapped to QoS flow 816A, uplink packet 812C is mapped to QoS flow 816B, and the remaining packets are mapped to QoS flow 816C.

[0097]

[0127] QoS flows represent the finest granularity of QoS differentiation within a PDU session. The diagram shows three QoS flows, 816A–816C. However, it is understood that any number of QoS flows are possible. Some QoS flows are associated with guaranteed bitrates (GBR QoS flows), while others have unguaranteed bitrates (non-GBR QoS flows). QoS flows are also subject to aggregate bitrates per UE and per session. One of the QoS flows is the default QoS flow. QoS flows have different priorities. For example, QoS flow 816A has a higher priority than QoS flow 816B, and QoS flow 816B has a higher priority than QoS flow 816C. These different priorities are reflected by different QoS flow characteristics. For example, QoS flows are associated with flow bitrates. Certain QoS flows are associated with guaranteed flow bitrates (GFBR) and / or maximum flow bitrates (MFBR). QoS flows are associated with a specific packet delay budget (PDB), packet error rate (PER), and / or maximum packet loss rate. QoS flows are also subject to aggregate bitrates per UE and per session.

[0098]

[0128] To operate within the QoS model, UE801 applies resource mapping rule 818 to QoS flows 816A-816C. The air interface between UE801 and AN802 is associated with resource 820. In this example, QoS flow 816A is mapped to resource 820A, while QoS flows 816B and 816C are mapped to resource 820B. Resource mapping rule 818 is provided by AN802. To satisfy QoS requirements, resource mapping rule 818 specifies more resources for relatively high-priority QoS flows. The more resources there are, the more likely high-priority QoS flows, such as QoS flow 816A, are to obtain a high flow bitrate, a low packet delay budget, or other characteristics associated with QoS rule 814. Resource 820 includes, for example, a radio bearer. The radio bearer (e.g., a data radio bearer) is established between UE801 and AN802. The wireless bearer in 5G between UE801 and AN802 is different from bearers in LTE, such as the Advanced Packet System (EPS) bearer between the UE and the Packet Data Network Gateway (PGW), the S1 bearer between the eNB and the Serving Gateway (SGW), and / or the S5 / S8 bearer between the SGW and the PGW.

[0099]

[0129] When a packet associated with a specific QoS flow is received by AN802 via resource 820A or resource 820B, AN802 divides the packet into its respective QoS flows 856A-856C based on QoS profile 828. QoS profile 828 is received from the SMF. Each QoS profile corresponds to a QFI, e.g., a QFI marked on uplink packets 812A-812E. Each QoS profile includes a 5G QoS identifier (5QI) and QoS parameters such as allocation and retention priority (ARP). QoS profiles for non-GBR QoS flows further include additional QoS parameters such as reflective QoS attributes (RQA). QoS profiles for GBR QoS flows further include additional QoS parameters such as guaranteed flow bitrate (GFBR), maximum flow bitrate (MFBR), and / or maximum packet loss rate. 5QI is a standardized 5QI with a one-to-one mapping to standardized combinations of well-known per-service 5G QoS characteristics. 5QI is a dynamically assigned 5QI for which no standardized 5QI values ​​are defined. 5QI represents 5G QoS characteristics. 5QI includes resource type, default priority level, packet delay budget (PDB), packet error rate (PER), maximum data burst volume, and / or averaging window. The resource type indicates a non-GBR QoS flow, a GBR QoS flow, or a delay-critical GBR QoS flow. The averaging window represents the duration for which GFBR and / or MFBR are calculated. ARP is a priority level that includes preemption capability and preemption vulnerability. Based on ARP, AN802 applies admission control to QoS flows in case of resource limitations.

[0100]

[0130] AN802 selects one or more N3 tunnels 850 for transmitting QoS flows 856A-856C. After the packets are divided into QoS flows 856A-856C, the packets are sent to UPF805 via the selected one or more N3 tunnels 850 (e.g., towards DN). UPF805 verifies that the QFI of uplink packets 812A-812E is consistent with the QoS rule 814 provided to UE801. UPF805 measures and / or counts the packets and / or provides the packet metrics to, for example, PCF.

[0101]

[0131] The diagram also illustrates the process for downlink. Specifically, one or more applications generate downlink packets 852A-852E. UPF805 receives downlink packets 852A-852E from one or more DNs and / or one or more other UPFs. According to the QoS model, UPF805 applies packet discovery rule (PDR) 854 to downlink packets 852A-852E. Based on PDR 854, UPF805 maps packets 852A-852E to QoS flows. In this example, downlink packets 852A and 852B are mapped to QoS flow 856A, downlink packet 852C is mapped to QoS flow 856B, and the remaining packets are mapped to QoS flow 856C.

[0102]

[0132] QoS flows 856A-856C are sent to AN802. AN802 applies resource mapping rules to QoS flows 856A-856C. In this example, QoS flow 856A is mapped to resource 820A, while QoS flows 856B and 856C are mapped to resource 820B. To meet QoS requirements, the resource mapping rules specify more resources for high-priority QoS flows.

[0103]

[0133] Figures 9A to 9D show exemplary states and state transitions of a wireless device (e.g., a UE). At any given time, the wireless device has a Radio Resource Control (RRC) state, a Registration Management (RM) state, and a Connection Management (CM) state.

[0104]

[0134] Figure 9A is an illustrative diagram showing the RRC state transitions of a wireless device (e.g., a UE). The UE is in one of three RRC states: RRC idle 910 (e.g., RRC_IDLE), RRC inactive 920 (e.g., RRC_INACTIVE), or RRC connected 930 (e.g., RRC_CONNECTED). Depending on its RRC state, the UE performs different RAN-related control plane procedures. Other elements of the network, such as a base station, track the RRC states of one or more UEs and perform RAN-related control plane procedures appropriate for each RRC state.

[0105]

[0135] In an RRC connection 930, the UE can exchange data with the network (e.g., a base station). The parameters necessary for data exchange are established and known to both the UE and the network. These parameters are called and / or contained within the UE's RRC context (sometimes called the UE context). These parameters include, for example, one or more AS contexts, one or more radio link configuration parameters, bearer configuration information (e.g., data radio bearer, signaling radio bearer, logical channel, QoS flow, and / or PDU session), security information, and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. The base station to which the UE is connected stores the UE's RRC context.

[0106]

[0136] While RRC connected 930, the UE's mobility is managed by the access network, but while RRC idle 910 and / or RRC inactive 920, the UE itself manages its mobility. While RRC connected 930, the UE manages its mobility by measuring signal levels (e.g., reference signal levels) from the serving cell and neighboring cells and reporting these measurements to the base station currently serving the UE. The network initiates a handover based on the reported measurements. The RRC state transitions from RRC connected 930 to RRC idle 910 via connection release procedure 930, or to RRC inactive 920 via connection deactivation procedure 932.

[0107]

[0137] In RRC idle 910, the RRC context is not established for the UE. In RRC idle 910, the UE does not have an RRC connection with the base station. While in RRC idle 910, the UE is in a sleep state for most of the time (e.g., to conserve battery power). The UE wakes up periodically (e.g., once per discontinuous receive cycle) to monitor paging messages from the access network. The mobility of the UE is managed by the UE through a procedure known as cell reselection. The RRC state transitions from RRC idle 910 to RRC connected 930 through connection establishment procedure 913, which involves a random access procedure, as will be discussed in more detail below.

[0108]

[0138] In RRC inactive state 920, the previously established RRC context is maintained at the UE and base station. This enables a faster transition to RRC connection 930 with reduced signaling overhead compared to the transition from RRC idle state 910 to RRC connection 930. The RRC state transitions to RRC connection 930 through connection restart procedure 923. The RRC state transitions to RRC idle state 910 through connection release procedure 921, which is the same as or similar to connection release procedure 931.

[0109]

[0139] The RRC state is associated with the mobility management mechanism. In RRC idle 910 and RRC inactive 920, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC idle 910 and / or RRC inactive 920 is to enable the network to notify the UE of events via paging messages without having to broadcast paging messages across the entire mobile communication network. The mobility management mechanism used in RRC idle 910 and / or RRC inactive 920 enables the network to track the UE at the cell group level so that paging messages are broadcast across cells in the cell group in which the UE currently resides, rather than across the entire communication network. Tracking is based on grouping at different granularities. For example, there are three levels of cell grouping granularity: individual cells, cells within a RAN area identified by a RAN Area Identifier (RAI), and cells within a group of RAN areas called a tracking area, identified by a Tracking Area Identifier (TAI).

[0110]

[0140] Tracking areas are used to track UEs at the CN level. The CN provides the UE with a list of TAIs associated with the UE registration area. If the UE moves to a cell associated with a TAI that is not included in the list of TAIs associated with the UE registration area, through cell re-selection, the UE performs a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0111]

[0141] RAN areas are used to track UEs at the RAN level. For UEs in an RRC inactive 920 state, the UE is assigned a RAN notification area. A RAN notification area contains one or more cell identities, a list of RAIs, and / or a list of TAIs. In one example, a base station belongs to one or more RAN notification areas. In another example, a cell belongs to one or more RAN notification areas. If a UE moves to a cell that is not included in the RAN notification area assigned to the UE through cell reselection, the UE performs a notification area update with the RAN to update the UE's RAN notification area.

[0112]

[0142] The base station that stores the RRC context for the UE, or the last serving base station of the UE, is called the anchor base station. The anchor base station maintains the RRC context for the UE for at least the duration that the UE remains in the anchor base station's RAN notification area and / or the duration that the UE remains in an RRC inactive 920.

[0113]

[0143] Figure 9B is an illustrative diagram showing the registration management (RM) state transitions of a wireless device (e.g., UE). The states are RM deregistration 940 (e.g., RM-DEREGISTERED) and RM registration 950 (e.g., RM-REGISTERED).

[0114]

[0144] In RM Deregistration 940, the UE is not registered with the network and is not reachable by the network. To be reachable by the network, the UE must perform initial registration. For example, the UE registers with the network's AMF. If registration is denied (registration denied 944), the UE remains in RM Deregistration 940. If registration is accepted (registration accepted 945), the UE transitions to RM Registration 950. While the UE is in RM Registration 950, the network stores, holds, and / or maintains a UE context for the UE. This UE context is called the Wireless Device Context. The UE context corresponding to network registration (maintained by the core network) is different from the RRC context corresponding to RRC status (maintained by the access network, e.g., base station). The UE context includes a UE identifier and a record of various information about the UE, e.g., UE capability information, policy information for UE access and mobility management, a list of permitted or established slice or PDU sessions, and / or the UE's registration area (i.e., a list of tracking areas covering the geographical area where the wireless device may be found).

[0115]

[0145] While the UE is in RM registration 950, the network remembers the UE's UE context and uses it to reach the UE if necessary. Furthermore, some services are not provided by the network unless the UE is registered. While the UE remains in RM registration 950, it updates its UE context (accept registration update 955). For example, if the UE leaves one tracking area and enters another, the UE provides the network with a tracking area identifier. The network deregisters the UE, or the UE deregisters itself (deregister 954). For example, if a wireless device is inactive for a certain period of time, the network automatically deregisters the wireless device. Upon deregistration, the UE transitions to RM deregister 940.

[0116]

[0146] Figure 9C is an exemplary diagram showing the connection management (CM) state transitions of a wireless device (e.g., UE), as seen from the perspective of the wireless device. The UE is either CM idle 960 (e.g., CM-IDLE) or CM connected 970 (e.g., CM-CONNECTED).

[0117]

[0147] In CM Idle 960, the UE does not have a Non-Access Layer (NAS) signaling connection with the network. As a result, the UE cannot communicate with the core network functions. The UE transitions to CM Connection 970 by establishing an AN signaling connection (AN Signaling Connection Establishment 967). This transition is initiated by sending an initial NAS message. The initial NAS message is either a registration request (e.g., if the UE is RM Unregistration 940) or a service request (e.g., if the UE is RM Register 950). If the UE is RM Register 950, the UE initiates AN signaling connection establishment by sending a service request, or the network sends a page, thereby triggering the UE to send a service request.

[0118]

[0148] In CM connection 970, the UE can communicate with core network functions using NAS signaling. For example, the UE exchanges NAS signaling with AMF for registration management purposes, service request procedures, and / or authentication procedures. As another example, the UE exchanges NAS signaling with SMF to establish and / or modify PDU sessions. The network disconnects the UE, or the UE disconnects itself (AN signaling connection release 976). For example, if the UE transitions to RM unregister 940, the UE also transitions to CM idle 960. When the UE transitions to CM idle 960, the network deactivates the user plane connection of the UE's PDU session.

[0119]

[0149] Figure 9D is an illustrative diagram showing the CM state transitions of a wireless device (e.g., UE) from the perspective of a network (e.g., AMF). The CM states of the UE tracked by the AMF are CM idle 980 (e.g., CM-IDLE) or CM connected 990 (e.g., CM-CONNECTED). When the UE transitions from CM idle 980 to CM connected 990, the AMF establishes the N2 context of the UE (N2 context established 989). When the UE transitions from CM connected 990 to CM idle 980, the AMF releases the N2 context of the UE (N2 context released 998).

[0120]

[0150] Figures 10-12 illustrate exemplary procedures for UE registration, service request, and PDU session establishment.

[0121]

[0151] Figure 10 shows an example of a registration procedure for a wireless device (e.g., UE). Based on the registration procedure, the UE transitions, for example, from RM unregistering 940 to RM registering 950.

[0122]

[0152] Registration is initiated by the UE for the purpose of obtaining permission to receive services, enabling mobility tracking, enabling reachability, or for other purposes. The UE performs initial registration as the first step toward connecting to the network (e.g., when the UE is powered on, when airplane mode is turned off, etc.). Registration is also performed periodically to keep the network informed of the UE's presence (e.g., while in the CM-IDLE state), or in response to changes in UE capabilities or registration area. Deregistration (not shown in Figure 10) is performed to terminate network access.

[0123]

[0153] In 1010, the UE sends a registration request to the AN. For example, the UE is moving from the coverage area of ​​the previous AMF (indicated as AMF#1) to the coverage area of ​​the new AMF (indicated as AMF#2). The registration request is a NAS message. The registration request includes the UE identifier. The AN selects an AMF for the UE's registration. For example, the AN selects the default AMF. For example, the AN selects an AMF that is already mapped to the UE (e.g., the previous AMF). The NAS registration request includes a network slice identifier, and the AN selects an AMF based on the requested slice. After the AMF is selected, the AN sends the registration request to the selected AMF.

[0124]

[0154] In 1020, the AMF (AMF#2) that receives the registration request performs a context transfer. The context is a UE context, for example, an RRC context for the UE. As an example, AMF#2 sends a message to AMF#1 requesting the UE context. The message contains the UE identifier. This message is a Namf_Communication_UEContextTransfer message. AMF#1 sends a message to AMF#2 containing the requested UE context. This message is a Namf_Communication_UEContextTransfer message. After the UE context is received, AMF#2 coordinates the authentication of the UE. After authentication is complete, AMF#2 sends a message to AMF#1 indicating that the UE context transfer is complete. This message is a Namf_Communication_UEContextTransfer Response message.

[0125]

[0155] Authentication requires the participation of the UE, AUSF, UDM, and / or UDR (not shown). For example, AMF requests that AUSF authenticate the UE. For example, AUSF performs authentication on the UE. For example, AUSF obtains authentication data from the UDM. For example, AUSF sends a Subscription Permanent Identifier (SUPI) to AMF based on successful authentication. For example, AUSF provides AMF with an intermediate key. The intermediate key is used to derive an access-specific security key for the UE, enabling AMF to perform Security Context Management (SCM). AUSF obtains subscription data from the UDM. The subscription data is based on information obtained from the UDM (and / or UDR). The subscription data includes the subscription identifier, security credentials, access and mobility-related subscription data, and / or session-related data.

[0126]

[0156] In 1030, the new AMF, AMF#2, registers and / or subscribes to the UDM. AMF#2 uses the UDM's UE Context Management Service (Nudm_UECM) to perform the registration. AMF#2 uses the UDM's Subscriber Data Management Service (Nudm_SDM) to retrieve the UE's subscription information. AMF#2 further requests that the UDM notify AMF#2 if the UE's subscription information changes. Once the new AMF registers and subscribes, the old AMF, AMF#1, deregisters and unsubscribes. After deregistration, AMF#1 is released from its responsibility for UE mobility management.

[0127]

[0157] In 1040, AMF#2 extracts Access and Mobility (AM) policies from PCF. For example, AMF#2 provides UE subscription data to PCF. PCF determines Access and Mobility policies for UEs based on subscription data, network operator data, current network conditions, and / or other relevant information. For example, the owner of one UE subscribes to a higher level of service than the owner of a second UE. PCF provides rules associated with different levels of service. Based on each UE's subscription data, the network applies different policies to facilitate different levels of service.

[0128]

[0158] For example, access and mobility policies relate to service area constraints, RAT / frequency selection priority (RFSP, where RAT stands for Radio Access Technology), access type authorization and prioritization (e.g., LTE vs. NR), and / or non-3GPP® access (e.g., Access Network Discovery and Selection Policy (ANDSP)). Service area constraints include a list of tracking areas from which a UE is permitted to be served (or prohibited from being served). Access and mobility policies include UE route selection policies (URSP) that affect routing to established or new PDU sessions. As described above, different policies are acquired and / or enforced based on the UE's subscription data, the UE's location (i.e., the AN and / or AMF location), or other appropriate factors.

[0129]

[0159] In 1050, AMF#2 updates the PDU session context. For example, if the UE has an existing PDU session, AMF#2 works with SMF to activate the user plane connection associated with the existing PDU session. SMF updates and / or releases the session management context of the PDU session (Nsmf_PDUSession_UpdateSMContext, Nsmf_PDUSession_ReleaseSMContext).

[0130]

[0160] In 1060, AMF#2 sends a registration acceptance message to AN, and AN forwards the registration acceptance message to UE. The registration acceptance message includes the new UE identifier and / or the newly configured slice identifier. UE sends a registration complete message to AN, and AN forwards the registration complete message to AMF#2. The registration complete message acknowledges receipt of the new UE identifier and / or the newly configured slice identifier.

[0131]

[0161] In 1070, AMF#2 obtains UE policy control information from the PCF. The PCF provides Access Network Discovery and Selection Policies (ANDSP) to facilitate non-3GPP® access. The PCF also provides UE Route Selection Policies (URSP) to facilitate the mapping of specific data traffic to specific PDU session connectivity parameters. For example, a URSP indicates that data traffic associated with a particular application should be mapped to a specific SSC mode, network slice, PDU session type, or preferred access type (3GPP® or non-3GPP®).

[0132]

[0162] Figure 11 shows an example of a service request procedure for a wireless device (e.g., a UE). The service request procedure illustrated in Figure 11 is a network-triggered service request procedure for a UE in the CM-IDLE state. However, other service request procedures (e.g., UE-triggered service request procedures) can also be understood by referring to Figure 11, as will be discussed in more detail below.

[0133]

[0163] In 1110, the UPF receives data. The data is downlink data to be sent to the UE. The data is associated with an existing PDU session between the UE and the DN. The data is received, for example, from the DN and / or another UPF. The UPF buffers the received data. In response to receiving the data, the UPF notifies the SMF of the received data. The identity of the SMF to be notified is determined based on the received data. The notification is, for example, an N4 session report. The notification indicates that the UPF has received data associated with the UE and / or a specific PDU session associated with the UE. In response to receiving the notification, the SMF sends the PDU session information to the AMF. The PDU session information is sent in an N1N2 message forwarding to the AN. The PDU session information includes, for example, UPF tunnel endpoint information and / or QoS information.

[0134]

[0164] At step 1120, the AMF determines that the UE is in the CM-IDLE state. This determination at step 1120 is in response to the receipt of PDU session information. Based on the determination that the UE is CM-IDLE, the service request procedure proceeds to steps 1130 and 1140, as illustrated in Figure 11. However, if the UE is not CM-IDLE (for example, the UE is CM-CONNECTED), steps 1130 and 1140 are skipped, and the service request procedure proceeds directly to step 1150.

[0135]

[0165] In 1130, the AMF pages the UE. Paging in 1130 is performed based on the UE being CM-IDLE. To perform paging, the AMF sends a page to an AN. A page is called a paging message. A page is an N2 request message. An AN is one of several ANs within the UE's RAN notification area. The AN sends a page to the UE. The UE is within the AN's coverage area and receives the page.

[0136]

[0166] At 1140, the UE requests service. The UE sends the service request to the AMF via the AN. As illustrated in Figure 11, the UE requests service at 1140 in response to receiving paging at 1130. However, as mentioned above, this is a specific case of a network-triggered service request procedure. In some scenarios (for example, when uplink data becomes available at the UE), the UE initiates a UE-triggered service request procedure. A UE-triggered service request procedure starts at 1140.

[0137]

[0167] In step 1150, the network authenticates the UE. Authentication requires the participation of the UE, AUSF, and / or UDM, similar to authentication described elsewhere in this disclosure. In some cases (for example, if the UE has just been authenticated), authentication in step 1150 is skipped.

[0138]

[0168] In 1160, the AMF and SMF perform PDU session renewal. As part of the PDU session renewal, the SMF provides the AMF with one or more UPF tunnel endpoint identifiers. In some cases (not shown in Figure 11), the SMF needs to coordinate with one or more other SMFs and / or one or more other UPFs to set up the user plane.

[0139]

[0169] In 1170, the AMF sends PDU session information to the AN. The PDU session information is included in the N2 request message. Based on the PDU session information, the AN configures the user plane resources for the UE. To configure the user plane resources, the AN performs, for example, RRC reconfiguration of the UE. The AN acknowledges to the AMF that the PDU session information has been received. The AN notifies the AMF that the user plane resources have been configured and / or provides information regarding the user plane resource configuration.

[0140]

[0170] In the case of a UE-triggered service request procedure, the UE receives a NAS service acceptance message from the AMF via the AN at 1170. After the user plane resources are configured, the UE sends uplink data (e.g., the uplink data that triggered the service request procedure to the UE).

[0141]

[0171] In 1180, the AMF updates the session management (SM) context of the PDU session. For example, the AMF notifies the SMF (and / or one or more other related SMFs) that a user plane resource has been configured and / or provides information about the user plane resource configuration. The AMF provides the SMF (and / or one or more other related SMFs) with one or more AN tunnel endpoint identifiers for the AN. After the SM context update is complete, the SMF sends an updated SM context response message to the AMF.

[0142]

[0172] Based on updates to the session management context, the SMF updates the PCF for policy control purposes. For example, if the UE's location changes, the SMF notifies the PCF of the UE's new location.

[0143]

[0173] Based on the update of the session management context, SMF and UPF perform session changes. Session changes are performed using N4 session change messages. After the session change is complete, UPF sends downlink data (e.g., downlink data that triggered a network-triggered service request procedure to UPF) to the UE. The transmission of downlink data is based on one or more AN tunnel endpoint identifiers of the AN.

[0144]

[0174] Figure 12 shows an example of a protocol data unit (PDU) session establishment procedure for a wireless device (e.g., a UE). The UE decides to send a PDU session establishment request to create a new PDU session, either to hand over an existing PDU session to a 3GPP® network or for any other appropriate reason.

[0145]

[0175] In 1210, the UE initiates PDU session establishment. The UE sends a PDU session establishment request to the AMF via AN. The PDU session establishment request is a NAS message. The PDU session establishment request indicates the PDU session ID, the requested PDU session type (new or existing), the requested DN (DNN), the requested network slice (S-NSSAI), the requested SSC mode, and / or any other appropriate information. The PDU session ID is generated by the UE. The PDU session type is, for example, an Internet Protocol (IP) based type (e.g., IPv4, IPv6, or dual-stack IPv4 / IPv6), an Ethernet type, or an unstructured type.

[0146]

[0176] The AMF selects an SMF based on the PDU session establishment request. In some scenarios, the requested PDU session is already associated with a specific SMF. For example, the AMF remembers the UE context of a UE, and the UE context indicates that the PDU session ID of the requested PDU session is already associated with a specific SMF. In some scenarios, the AMF selects an SMF based on the decision that the SMF is ready to handle the requested PDU session. For example, the requested PDU session is associated with a specific DNN and / or S-NSSAI, and the SMF is selected based on the decision that the SMF is capable of managing PDU sessions associated with that specific DNN and / or S-NSSAI.

[0147]

[0177] At 1220, the network manages the context of the PDU session. After selecting the SMF at 1210, the AMF sends a PDU session context request to the SMF. The PDU session context request includes the PDU session establishment request received from the UE at 1210. The PDU session context request is an Nsmf_PDUSession_CreateSMContext request and / or an Nsmf_PDUSession_UpdateSMContext request. The PDU session context request indicates the UE identifier, the requested DN, and / or the requested network slice. Based on the PDU session context request, the SMF retrieves subscription data from the UDM. The subscription data is the UE's session management subscription data. The SMF subscribes to updates to the subscription data so that the PCF sends new information when the UE's subscription data changes. After the UE's subscription data is retrieved, the SMF sends a PDU session context response to the AMF. The PDU session context response is an Nsmf_PDUSession_CreateSMContext response and / or an Nsmf_PDUSession_UpdateSMContext response. The PDU session context response includes the session management context ID.

[0148]

[0178] In 1230, secondary authorization / authentication is performed if necessary. Secondary authorization / authentication requires UE, AMF, SMF, and DN. SMF accesses DN via the Data Network Authentication, Authorization and Accounting (DN AAA) server.

[0149]

[0179] In 1240, the network sets up a data path for uplink data associated with the PDU session. The SMF selects the PCF and establishes a session management policy association. Based on that association, the PCF provides an initial set of policy control and billing rules (PCC rules) for the PDU session. When targeting a specific PDU session, the PCF tells the SMF how to assign an IP address to the PDU session, the default billing method for the PDU session, the address of the corresponding billing entity, triggers for requesting a new policy, etc. The PCF also targets a Service Data Flow (SDF) containing one or more PDU sessions. When targeting an SDF, the PCF tells the SMF policies to enforce QoS requirements, monitor traffic (e.g., for billing purposes), and / or steer traffic (e.g., by using one or more specific N6 interfaces).

[0150]

[0180] The SMF determines and / or allocates an IP address for the PDU session. The SMF selects one or more UPFs (a single UPF in the example in Figure 12) to handle the PDU session. The SMF sends an N4 session message to the selected UPF. The N4 session message is an N4 session establishment request and / or an N4 session modification request. The N4 session message includes packet discovery, enforcement, and reporting rules associated with the PDU session. In response, the UPF acknowledges by sending an N4 session establishment response and / or an N4 session modification response.

[0151]

[0181] The SMF sends PDU session management information to the AMF. This PDU session management information is a session service request message (e.g., Namf_Communication_N1N2MessageTransfer). The PDU session management information includes the PDU session ID. The PDU session management information is a NAS message. The PDU session management information includes N1 session management information and / or N2 session management information. The N1 session management information includes a PDU session establishment acceptance message. The PDU session establishment acceptance message includes UPF tunneling endpoint information and quality of service (QoS) information associated with the PDU session.

[0152]

[0182] The AMF sends an N2 request to the AN. The N2 request includes a PDU session establishment acceptance message. Based on the N2 request, the AN determines the AN resources for the UE. The AN resources are used by the UE to establish a PDU session with the DN via the AN. The AN determines the resources to be used for the PDU session and informs the UE of the determined resources. The AN sends a PDU session establishment acceptance message to the UE. For example, the AN performs RRC reconfiguration on the UE. After the AN resources are set up, the AN sends an N2 request acknowledgment to the AMF. The N2 request acknowledgment includes N2 session management information, such as the PDU session ID and the AN's tunneling endpoint information.

[0153]

[0183] After the data path for uplink data is set up at 1240, the UE optionally sends uplink data associated with the PDU session. As shown in Figure 12, the uplink data is sent to the DN associated with the PDU session via the AN and UPF.

[0154]

[0184] At 1250, the network updates the PDU session context. The AMF sends a PDU session context update request to the SMF. The PDU session context update request is an Nsmf_PDUSession_UpdateSMContext request. The PDU session context update request includes N2 session management information received from the AN. The SMF acknowledges the PDU session context update. The acknowledgment is an Nsmf_PDUSession_UpdateSMContext response. The acknowledgment includes a subscription requesting that the SMF be notified of any UE mobility events. Based on the PDU session context update request, the SMF sends an N4 session message to the UPF. The N4 session message is an N4 session change request. The N4 session message includes the AN's tunneling endpoint information. The N4 session message includes the forwarding rules associated with the PDU session. In response, the UPF acknowledges by sending an N4 session change response.

[0155]

[0185] After the UPF receives the tunneling endpoint information from the AN, the UPF relays the downlink data associated with the PDU session. As shown in Figure 12, the downlink data is received from the DN associated with the PDU session via the AN and the UPF.

[0156]

[0186] Figure 13 shows an example of the components of an element in a communication network. Figure 13 includes a wireless device 1310, a base station 1320, and a physical deployment 1330 (hereinafter "Deployment 1330") of one or more network functions. Any wireless device described in this disclosure has similar components and is implemented in a similar manner to wireless device 1310. Any other base station (or any part thereof, depending on the architecture of the base station) described in this disclosure has similar components and is implemented in a similar manner to base station 1320. Any physical core network deployment (or any part thereof, depending on the architecture of the base station) described in this disclosure has similar components and is implemented in a similar manner to deployment 1330.

[0157]

[0187] Wireless device 1310 communicates with base station 1320 via air interface 1370. The communication direction from wireless device 1310 to base station 1320 via air interface 1370 is known as the uplink, and the communication direction from base station 1320 to wireless device 1310 via air interface 1370 is known as the downlink. Downlink transmissions are isolated from uplink transmissions using some combination of FDD, TDD, and / or duplex techniques. Figure 13 shows a single wireless device 1310 and a single base station 1320, but it is understood that wireless device 1310 communicates with any number of base stations or other access network components via air interface 1370, and base station 1320 communicates with any number of wireless devices via air interface 1370.

[0158]

[0188] The wireless device 1310 comprises a processing system 1311 and a memory 1312. The memory 1312 includes one or more computer-readable media, for example, one or more non-temporary computer-readable media. The memory 1312 includes an instruction 1313. The processing system 1311 processes and / or executes the instruction 1313. Processing and / or executing the instruction 1313 causes the wireless device 1310 and / or the processing system 1311 to perform one or more functions or activities. The memory 1312 includes data (not shown). One of the functions or activities performed by the processing system 1311 is to store data in the memory 1312 and / or to retrieve previously stored data from the memory 1312. In one example, downlink data received from the base station 1320 is stored in the memory 1312, and uplink data to be transmitted to the base station 1320 is retrieved from the memory 1312. As shown in Figure 13, the wireless device 1310 communicates with the base station 1320 using a transmit processing system 1314 and / or a receive processing system 1315. Alternatively, the transmit processing system 1314 and the receive processing system 1315 may be implemented as a single processing system, or both may be omitted, with all processing in the wireless device 1310 performed by processing system 1311. Although not shown in Figure 13, the transmit processing system 1314 and / or the receive processing system 1315 are similar to, but separate from, memory 1312, and are coupled to a dedicated memory containing instructions to process and / or execute to perform one or more of their respective functions. The wireless device 1310 includes one or more antennas 1316 for accessing the air interface 1370.

[0159]

[0189] The wireless device 1310 comprises one or more other elements 1319. One or more other elements 1319 comprises software and / or hardware that provides features and / or functions, such as a speaker, microphone, keypad, display, touchpad, satellite transceiver, Universal Serial Bus (USB) port, hands-free headset, frequency modulation (FM) radio unit, media player, internet browser, electronic control unit (e.g., for automobiles), and / or one or more sensors (e.g., accelerometer, gyroscope, temperature sensor, radar sensor, lidar sensor, ultrasonic sensor, light sensor, camera, global positioning sensor (GPS), etc.). The wireless device 1310 receives user input data from one or more other elements 1319 and / or provides user output data to one or more other elements 1319. One or more other elements 1319 includes a power supply. The wireless device 1310 is configured to receive power from the power supply and distribute the power to other components within the wireless device 1310. The power source includes one or more power sources, such as batteries, solar cells, fuel cells, or any combination thereof.

[0160]

[0190] The wireless device 1310 transmits uplink data to and / or receives downlink data from the base station 1320 via the air interface 1370. To perform transmission and / or reception, one or more of the processing systems 1311, transmit processing system 1314, and / or receive processing system 1315 perform open system interconnect (OSI) functions. For example, the transmit processing system 1314 and / or receive processing system 1315 perform Layer 1 OSI functions, and processing system 1311 performs higher layer functions. The wireless device 1310 transmits and / or receives data via the air interface 1370 using one or more antennas 1316. In scenarios where one or more antennas 1316 include multiple antennas, the multiple antennas are used to perform one or more multi-antenna techniques such as spatial multiplexing (e.g., single-user multiple-input multiple-output (MIMO) or multi-user MIMO), transmit / receive diversity, and / or beamforming.

[0161]

[0191] The base station 1320 comprises a processing system 1321 and a memory 1322. The memory 1322 includes one or more computer-readable media, for example, one or more non-temporary computer-readable media. The memory 1322 includes an instruction 1323. The processing system 1321 processes and / or executes the instruction 1323. Processing and / or executing the instruction 1323 causes the base station 1320 and / or the processing system 1321 to perform one or more functions or activities. The memory 1322 includes data (not shown). One of the functions or activities performed by the processing system 1321 is to store data in the memory 1322 and / or to retrieve previously stored data from the memory 1322. The base station 1320 communicates with the wireless device 1310 using a transmit processing system 1324 and a receive processing system 1325. Although not shown in Figure 13, the transmit processing system 1324 and / or receive processing system 1325 are similar to, but separate from, memory 1322, and are coupled to a dedicated memory containing instructions to process and / or execute in order to perform one or more of their respective functions. The wireless device 1320 includes one or more antennas 1326 for accessing the air interface 1370.

[0162]

[0192] Base station 1320 transmits downlink data to and / or receives uplink data from wireless device 1310 via air interface 1370. To perform transmission and / or reception, one or more of processing systems 1321, transmit processing system 1324, and / or receive processing system 1325 perform OSI functions. For example, transmit processing system 1324 and / or receive processing system 1325 perform Layer 1 OSI functions, and processing system 1321 performs higher layer functions. Base station 1320 transmits and / or receives data via air interface 1370 using one or more antennas 1326. In scenarios where one or more antennas 1326 include multiple antennas, the multiple antennas are used to perform one or more multi-antenna techniques such as spatial multiplexing (e.g., single-user multiple-input multiple-output (MIMO) or multi-user MIMO), transmit / receive diversity, and / or beamforming.

[0163]

[0193] Base station 1320 comprises an interface system 1327. Interface system 1327 communicates with one or more base stations and / or one or more elements of the core network via interface 1380. Interface 1380 is wired and / or wireless, and interface system 1327 includes one or more components suitable for communicating via interface 1380. In Figure 13, it is understood that interface 1380 connects base station 1320 to a single deployment 1330, but wireless device 1310 communicates with any number of base stations and / or CN deployments via interface 1380, and deployment 1330 communicates with any number of base stations and / or other CN deployments via interface 1380. Base station 1320 comprises one or more other elements 1329 similar to one or more of the one or more other elements 1319.

[0164]

[0194] Deployment 1330 includes any number of instances of any number of network functions (NFs). Deployment 1330 comprises a processing system 1331 and memory 1332. Memory 1332 includes one or more computer-readable media, for example, one or more non-temporary computer-readable media. Memory 1332 includes an instruction 1333. Processing system 1331 processes and / or executes instruction 1333. Processing and / or executing instruction 1333 causes deployment 1330 and / or processing system 1331 to perform one or more functions or activities. Memory 1332 includes data (not shown). One of the functions or activities performed by processing system 1331 is to store data in memory 1332 and / or to retrieve previously stored data from memory 1332. Deployment 1330 accesses interface 1380 using interface system 1337. The expansion 1330 comprises one or more other elements 1339 that are similar to one or more of the other elements 1319.

[0165]

[0195] One or more of systems 1311, 1314, 1315, 1321, 1324, 1325, and / or 1331 comprises one or more controllers and / or one or more processors. One or more controllers and / or one or more processors include, for example, general-purpose processors, digital signal processors (DSPs), microcontrollers, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) and / or other programmable logic devices, discrete gates and / or transistor logic, discrete hardware components, onboard units, or any combination thereof. One or more of systems 1311, 1314, 1315, 1321, 1324, 1325, and / or 1331 perform signal coding / processing, data processing, power management, input / output processing, and / or any other functions that enable the wireless device 1310, base station 1320, and / or deployment 1330 to operate in a mobile communication system.

[0166]

[0196] Many of the elements described in the disclosed embodiments are implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. Modules described in this disclosure are implemented in hardware, software combined with hardware, firmware, wetware (e.g., hardware with biological elements), or combinations thereof, which are behaviorally equivalent. For example, a module is implemented as a software routine written in a computer language (such as C, C++, Fortran, Java, Basic, Matlab) configured to run on a hardware machine, or as a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript. Modules can be implemented using physical hardware that incorporates individual or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include computers, microcontrollers, microprocessors, DSPs, ASICs, FPGAs, and composite programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, and C++. FPGAs, ASICs, and CPLDs are often programmed using hardware description languages ​​(HDLs) such as VHSIC (VHDL) or Verilog, which establish connections between internal hardware modules with fewer functionalities on a programmable device. The techniques mentioned are often used in combination to achieve the results of functional modules.

[0167]

[0197] The wireless device 1310, base station 1320, and / or deployment 1330 implement timers and / or counters. The timer / counter starts from an initial value. As used herein, starting includes restarting. Once started, the timer / counter operates. The operation of the timer / counter is associated with events. When an event occurs, the value of the timer / counter changes (e.g., increments or decrements). Events are, for example, extrinsic events (e.g., receiving a signal, measuring a condition), intrinsic events (e.g., transmitting a signal, calculation, comparison, performing an action, or deciding to perform such an action), or any combination thereof. In the case of a timer, the event is the passage of a specific period of time. However, it is understood that a timer is described and / or implemented as a counter that counts the passage of a specific unit of time. The timer / counter operates toward a final value until it reaches that final value. Reaching the final value is called the expiration of the timer / counter. The final value is called the threshold. A timer / counter may be paused, and even if one or more events occur that would normally change the timer / counter's value, the timer / counter's current value is held, maintained, and / or carried over. A timer / counter may be unpaused or resumed, and when one or more events occur, the held, maintained, and / or carried-over value begins to change again. A timer / counter may be set and / or reset. As used herein, setting includes resetting. When a timer / counter is set and / or reset, its value is set to its initial value. A timer / counter may be started and / or restarted. As used herein, starting includes restarting. In some embodiments, when a timer / counter is restarted, its value is set to its initial value and the timer / counter begins operating.

[0168]

[0198] Figures 14A, 14B, 14C, and 14D illustrate various exemplary configurations of a physical core network deployment, each having one or more network functions or parts thereof. The core network deployments include deployments 1410, 1420, 1430, 1440, and / or 1450. Each deployment is similar, for example, to deployment 1330 illustrated in Figure 13. Specifically, each deployment comprises a processing system for performing one or more functions or activities, memory for storing data and / or instructions, and an interface system for communicating with other network elements (e.g., other core network deployments). Each deployment comprises one or more network functions (NFs). The term NF refers to a particular set of functions and / or one or more physical elements configured to perform those functions (e.g., a processing system and memory containing instructions that, when executed by the processing system, cause the processing system to perform the functions). For example, when a network function is described in this disclosure as performing X, Y, and Z, it is understood that this refers to one or more physical elements configured to perform X, Y, and Z, regardless of how or where one or more physical elements are deployed. The term NF refers to network nodes, network elements, and / or network devices.

[0169]

[0199] As will be discussed in more detail below, there are many different types of Network Functions (NFs), each type of NF associated with a different set of functions. Multiple different NFs can be deployed flexibly in different locations (e.g., within different physical core network deployments) or in the same location (e.g., co-located within the same deployment). A single NF can be deployed flexibly in different locations (implemented using different physical core network deployments) or in the same location. Furthermore, a physical core network deployment also implements one or more base stations, application functions (AFs), data networks (DNs), or any part thereof. NFs can be implemented in many ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0170]

[0200] Figure 14A shows an exemplary configuration of a core network deployment, where each deployment includes one network function. Deployment 1410 includes NF1411, deployment 1420 includes NF1421, and deployment 1430 includes NF1431. Deployments 1410, 1420, and 1430 communicate via interface 1490. Deployments 1410, 1420, and 1430 have different physical locations with different signal propagation delays relative to other network elements. The diversity of physical locations of deployments 1410, 1420, and 1430 enables the provision of services to a wide area with improved speed, coverage, security, and / or efficiency.

[0171]

[0201] Figure 14B shows an exemplary configuration in which a single deployment includes two or more Network Functions (NFs). Unlike Figure 14A, where each NF is deployed in a separate deployment, Figure 14B shows multiple NFs in deployments 1410 and 1420. In one example, deployments 1410 and 1420 implement software-defined networking (SDN) and / or network function virtualization (NFV).

[0172]

[0202] For example, deployment 1410 includes additional network functionality, NF1411A. NF1411, 1411A consists of multiple instances of the same NF type, co-located at the same physical location within the same deployment 1410. NF1411, 1411A operate independently of each other (e.g., isolated and / or independently controlled). For example, NF1411, 1411A are associated with different network slices. The processing system and memory associated with deployment 1410 perform all the functions associated with NF1411, in addition to all the functions associated with NF1411A. In one example, NF1411, 1411A are associated with different PLMNs, but deployment 1410, which implements NF1411, 1411A, is owned and / or operated by a single entity.

[0173]

[0203] Elsewhere in Figure 14B, Deployment 1420 includes NF1421 and additional networking capabilities, NF1422. NF1421 and NF1422 are different NF types. Similar to NF1411 and NF1411A, NF1421 and NF1422 are colocate within the same Deployment 1420 but are implemented separately. As an example, a first PLMN owns and / or operates Deployment 1420 having NF1421 and NF1422. As another example, a first PLMN implements NF1421, and a second PLMN acquires (e.g., rent, lease, procure, etc.) at least a portion of Deployment 1420's capabilities (e.g., processing capacity, data storage, etc.) from the first PLMN to implement NF1422. As yet another example, the Deployment is owned and / or operated by one or more third parties, and the first PLMN and / or the second PLMN procure the respective portions of Deployment 1420's capabilities. When multiple network infrastructures (NFs) are provided in a single deployment, the network operates with better speed, coverage, security, and / or efficiency.

[0174]

[0204] Figure 14C shows an exemplary configuration of a core network deployment where a single instance of NF is implemented using multiple different deployments. Specifically, a single instance of NF1422 is implemented in deployments 1420 and 1440. For example, the functionality provided by NF1422 is implemented as a bundle or sequence of subservices. Each subservice is implemented independently, for example, in a different deployment. Each subservice is implemented in a different physical location. By distributing the implementation of subservices of a single NF across different physical locations, the mobile communication network operates with better speed, coverage, security, and / or efficiency.

[0175]

[0205] Figure 14D shows an exemplary configuration of a core network deployment in which one or more network functions are performed using data processing services. In Figure 14D, NFs 1411, 1411A, 1421, and 1422 are included in deployment 1450, which is performed as data processing services. Deployment 1450 includes, for example, a cloud network and / or data center. Deployment 1450 is owned and / or operated by a PLMN or a non-PLMN third party. NFs 1411, 1411A, 1421, and 1422, which are performed using deployment 1450, belong to the same PLMN or different PLMNs. The PLMN acquires (e.g., rents, leases, procures, etc.) at least a portion of the capabilities of deployment 1450 (e.g., processing capacity, data storage, etc.). By providing one or more NFs using data processing services, the mobile communications network operates with better speed, coverage, security, and / or efficiency.

[0176]

[0206] As shown in the diagram, different network elements (e.g., NFs) are located in different physical deployments or are collocated into a single physical deployment. It is understood that, unless expressly indicated otherwise, sending and receiving messages between different network elements is not limited to transmissions between deployments or transmissions within a deployment.

[0177]

[0207] In one example, a deployment is a "black box" pre-configured with one or more NFs and pre-configured to communicate with other "black box" deployments in a defined manner (e.g., via interface 1490). Additionally or alternatively, a deployment may be configured to operate according to open-source instructions (e.g., software) designed to implement NFs and communicate transparently with other deployments. The deployment operates according to the Open RAN (O RAN) standard.

[0178]

[0208] In the exemplary embodiment illustrated in Figure 15, a network slice experiences congestion or resource depletion. For example, a network slice experiences resource depletion if there is a huge demand for it from many UEs, or if network resources are allocated to high-priority network slices. To prevent a decrease in QoS for that network slice and / or for other network slices in the network, the core network node uses a backoff timer. This helps the network cope with network congestion.

[0179]

[0209] For example, a network may include one or more network nodes. For instance, one or more network nodes may include at least one of the following: AMF, SMF, NG-RAN, PCF, UPF, etc. For example, a network may employ one or more network slices to deliver differentiated services to differentiated UE / applications. One or more network slices may include at least a first network slice (e.g., slice A, slice 1), a second network slice (e.g., slice B), and so on.

[0180]

[0210] In one example, UE1 (the first UE) sends a slice service request message to one or more network nodes. For example, a slice service request is at least one of the following: a registration request message, a service request message, a PDU session establishment request message, a PDU session modification request message, etc. For example, a slice service request for a network slice requests at least one of the following: permission to access the network, registration of the network slice, establishment of a PDU session for the network slice, etc. For example, a slice service request indicates and / or is associated with a network slice. For example, a slice service request indicates slice A. For example, slice A is at least one of the permitted network slices and / or requested network slices.

[0181]

[0211] For example, a UE consists of information for one or more configured network slices. For instance, the UE receives information from the network and / or from local storage (e.g., volatile memory, local memory, USIM, etc.). The information for one or more configured network slices points to one or more first network slice identifiers for one or more second network slice identifiers. For example, the UE subscribes to one or more network services (e.g., network slices) from a home operator and / or establishes a service contract with the home operator. For example, the home operator points to one or more second network slice identifiers for the UE. One or more second network slice identifiers are one or more subscribed network slice identifiers and / or point to one or more subscribed network slices. One or more subscribed network slice identifiers point to one or more network slices that the UE subscribes to in the home network. For example, when the UE communicates with one or more network nodes in the home network, the UE uses one or more subscribed network slice identifiers. A UE roams to other networks (e.g., visiting networks). For example, when a UE leaves its home country, it connects to a visiting network in a foreign region (e.g., country, state). Other networks establish roaming agreements with the home network. For example, other networks assign one or more first network slice identifiers to one or more second network slice identifiers. For example, a home network may want to hide sensitive information (e.g., network topology, network identity, etc.) from the home network. For example, for security, privacy, and / or data protection, a home network may want to use different identifiers for different visiting networks.For example, in the case of subscribed network slice identifier 1, the home network assigns configured network slice identifier 1 to visited network 1, and / or the home network assigns configured network slice identifier 2 to visited network 2. One or more configured network slice identifiers include configured network slice identifier 2 and / or configured network slice identifier 1. This helps protect security and privacy. In the case of subscribed network slice 1, when the UE is communicating with visited network 1, the UE uses configured network slice identifier 1. In the case of subscribed network slice 1, when the UE is communicating with visited network 2, the UE uses configured network slice identifier 2.

[0182]

[0212] In one example, a network node receives a slice service request message sent by the UE. The network node checks whether the network can provide the service requested by the UE. For example, if the UE is requesting a service associated with slice A (e.g., PDU sessions, registration), the network node checks whether there are available resources for the UE and / or for slice A. If there are insufficient resources for slice A and / or slice A is congested (e.g., unable to meet the QoS requirements for slice services), the network node rejects the UE's (slice service) request. For example, the network node sends a slice service denial message to reject the UE's request. To prevent the UE from sending further requests associated with slice A or repeated requests for slice A, the network node sends the UE a slice service denial message that includes a backoff timer value. This value indicates the period of time during which the UE is not permitted to request slice services for slice A again. For example, while the backoff timer for slice A is active, the UE will not send requests associated with slice A. For example, if the backoff timer for slice A is not active, the UE will send requests associated with slice A. For example, backoff timers include T3585, T3396, T3584, MM (Mobility Management) timers, and SM (Session Management) timers. For example, when a UE receives a slice denial-of-service message containing a value, the UE starts a (backoff) timer and / or a time period associated with slice A (e.g., a backoff time period managed by the UE). The timer operates for the time indicated by the value if it is not stopped or deactivated after it has started.

[0183]

[0213] For example, when a network node sends a slice denial-of-service message and / or indicates a value, the network node initiates a time period (controlled by the network node). This time period, controlled by the network node, is used to enforce the suppression of requests from the UE. For instance, if the UE's clock runs fast, the timer controlled by the UE will expire sooner than expected. In this case, the UE sends another slice service request sooner than the network node intended. If the network node receives another slice service request from the UE while the timer controlled by the network node is running, the network node will deny the other slice service request from the UE.

[0184]

[0214] For example, the value of the backoff timer (timer, duration, backoff timer period, etc.) is determined by the network node based on estimations. For instance, if network slice congestion is estimated to end in 20 minutes, the network node will determine the backoff timer value to be at least 20 minutes. This prevents UEs from requesting slices and / or services for the 20 minutes that congestion is expected to last.

[0185]

[0215] For example, the UE determines whether it needs to send another request for a network slice (e.g., slice A) (e.g., registering the network slice and / or establishing a PDU session for the network slice). For example, the UE determines whether it needs to send another request for a network slice (e.g., slice A) if it has received data from an application associated with the network slice, if it still has the data that triggered the previous slice service request, and / or if it has received a request from the application to establish a PDU session for the network slice.

[0186]

[0216] In one example, when a UE decides it needs to send another request for a network slice (for example, to register or to establish a PDU session), the UE further decides whether it is permitted to send another request for the network slice. For example, the UE checks whether the backoff timer associated with the network slice is running (or not stopped). If the backoff timer associated with the network slice is running, the UE does not send another request for the network slice to the network, and / or the UE refrains from sending another request for the network slice. In another example, if the backoff timer associated with the network slice is not running, the UE sends another request for the network slice to the network. In response to receiving another service request, if resources for the network slice are available, the network sends a slice service acceptance message to the UE.

[0187]

[0217] For example, the backoff timer is at least one of the following: T3585, T3396, T3586, T3583, MM timer, SM timer, etc.

[0188]

[0218] For example, T3585 is used to control when a UE can send a signaling message for a PDU session or when a UE can initiate / trigger a procedure associated with a PDU session. For example, a signaling message is at least one of the following: a PDU session establishment request, a PDU session modification request, etc. For example, when a UE receives a PDU session rejection message (e.g., PDU session establishment rejection, PDU session modification rejection, PDU session command, etc.) containing a timer value and / or cause value #67, the UE uses that value to start a timer (e.g., T3585 associated with a network slice, timer T3585) and / or uses that value to start the timer period (e.g., T3585). For example, when a UE receives a NAS message and timer value (associated with a PDU session rejection message (e.g., PDU session establishment rejection, PDU session modification rejection, PDU session command, etc.)), the UE uses that value to start a timer (e.g., T3585, timer T3585) and / or uses that value to start the timer period (e.g., T3585). For example, when the UE receives a PDU session command (e.g., a PDU session release command, a PDU session modification command, or a PDU session authentication command), the UE stops the timer. For example, while the timer is running, the UE does not send any requests to the network that are associated with the PDU session and / or network slice.

[0189]

[0219] For example, T3396 is used to control when a UE can send a signaling message for a PDP context or when a UE can initiate / trigger a procedure associated with a PDP context (e.g., for a relevant PDU session). For example, the signaling message could be at least one of the following: ACTIVATE PDP CONTEXT REQUEST, ACTIVATE SECONDARY PDP CONTEXT REQUEST, DEACTIVATE PDP CONTEXT REQUEST, or MODIFY PDP CONTEXT REQUEST. In one example, when a UE receives a PDP context rejection message containing a timer value and / or cause value #26 (e.g., ACTIVATE PDP CONTEXT REJECT, ACTIVATE MBMS CONTEXT REJECT, ACTIVATE SECONDARY PDP CONTEXT REJECT, DEACTIVATE PDP CONTEXT REJECT, or MODIFY PDP CONTEXT REJECT), the UE uses that value to start a timer (e.g., T3396, Timer T3396) and / or uses that value to start the timer period (e.g., T3396). In another example, when a UE receives a NAS message containing a PDP context rejection message and a timer value, the UE uses that value to start a timer (e.g., T3396, Timer T3396) and / or uses that value to start the timer period (e.g., T3396).For example, when the UE receives a PDU session command (such as REQUEST PDP CONTEXT ACTIVATION, REQUEST SECONDARY PDP CONTEXT ACTIVATION, MODIFY PDP CONTEXT REQUEST, REQUEST MBMS CONTEXT ACTIVATION, ACTIVE DEFAULT EPS BEARER CONTEXT REQUEST, ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST, MODIFY EPS BEARER CONTEXT REQUEST, or DETACH REQUEST), the UE stops the timer.

[0190]

[0220] For example, T3584 is used to control when a UE can send a signaling message for a PDU session or when a UE can initiate / trigger a procedure associated with a PDU session. For example, a signaling message is at least one of the following: a PDU session establishment request, a PDU session modification request, or an MM procedure (e.g., a registration procedure, a service request procedure, or a NAS transport procedure). For example, a signaling message is associated with a network slice. For example, when a UE receives a PDU session rejection message associated with a network slice (e.g., a PDU session establishment rejection, a PDU session modification rejection, or a PDU session command) that includes a timer value and / or cause value #69, the UE uses that value to start a timer (e.g., T3584, Timer T3584) and / or uses that value to start the timer period (e.g., T3584). In one example, when the UE receives a NAS message containing at least one of a PDU session denial message and a timer value, the UE uses that value to start a timer (e.g., T3584, timer T3584) and / or uses that value to start the timer period (e.g., T3584). In another example, when the UE receives a PDU session command associated with a network slice (e.g., a PDU session release command, a PDU session change command, a PDU session authentication command, etc.), the UE stops the timer. In another example, while the timer is running, the UE sends requests associated with the network slice.

[0191]

[0221] For example, an MM (Mobility Management) timer is used to control when a UE can send an MM message for a network slice or when a UE can initiate / trigger a procedure associated with registering a network slice. For example, an MM message is at least one of the following: a registration request message, a service request message, a NAS transport message, etc. For example, when a UE receives a registration (or NAS transport) denial message associated with a network slice along with a timer value, the UE uses that timer value to start the timer (e.g., T3584). For example, when a UE receives a NAS message containing at least one of a PDU session denial (request) message and a timer value, the UE uses that value to start the timer (e.g., T3584, Timer T3584) and / or uses that value to start the timer period (e.g., T3584). For example, when a UE receives a PDU session command (e.g., a PDU session release command, a PDU session change command, a PDU session authentication command, etc.), the UE stops the timer. For example, while the timer is running, the UE sends requests associated with the network slice.

[0192]

[0222] In the exemplary embodiment illustrated in Figure 16, a network slice (e.g., slice A) is provided in one or more areas. In one example, the one or more areas include a first area (area 1) and / or a second area (area 2). For example, the first area may include a sports complex, a stadium, etc. The demand for the network slice in one or more areas changes over time. If there is an ongoing event in the first area, a large number of UEs will be present in the first area, resulting in a greater demand for network services. On the other hand, when there are no scheduled events in the first area, the number of UEs in the first area will be smaller, resulting in a smaller demand for network services. For example, the second area may include a residential area, one or more houses, etc. The average number of UEs present in the second area remains constant throughout the day, resulting in a stable demand for the network slice. Based on these different characteristics of different areas, the network operator allocates different amounts of resources to different areas. For example, based on the fact that the number of UEs in the first area is, on average, small, the network operator will allocate a small amount of network resources to network slices within the first area. For example, based on the fact that the number of UEs in the second area is, on average, large, the network operator will allocate a larger amount of network resources to network slices within the second area.

[0193]

[0223] In one example, at T=t1, a UE (e.g., a wireless device) moves from area 2 to area 1. For example, the UE leaves area 2 to participate in an event scheduled in area 1. The event takes place from T=t2 to T=t3. The UE is configured to use a network slice (e.g., slice A) for area 1 and / or area 2. As the event start time approaches, the number of UEs in area 1 increases. If UEs are subscribed to the network slice, the demand for the network slice increases dramatically compared to other times (e.g., when there are no events). As the demand for the network slice increases, the load on the network slice increases. If the amount of resources reserved for the network slice is insufficient to handle the load on the network slice, the QoS provided to subscribers of the network slice in area 1 deteriorates. For example, the amount of resources required for the number of UEs (e.g., radio frequency resources, computing resources) is greater than the amount of resources reserved for the network slice. In this case, even if network slices are set up for the number of UEs, the actual QoS achieved at each UE is not sufficient to meet the requirements of the applications running at each UE. This is called network slice congestion.

[0194]

[0224] Figure 17 illustrates an exemplary embodiment of using an alternate slice. For example, an alternate slice is a slice that can be used as an alternative for a network slice. For example, an alternate slice (e.g., slice B) for a network slice (e.g., slice A) is assigned and / or provided to the UE with the instruction that the alternate slice (e.g., slice B) will be used as an alternative for the network slice (e.g., slice A). For example, at T=t1, the UE leaves a second area and moves to a first area. The network indicates to the UE that slice B is an alternate slice for slice A. When the UE arrives in the first area, the UE decides to establish a PDU session for slice A. Based on the availability of an alternate slice (e.g., slice B) for slice A and / or by using the information that slice B is an alternate slice for slice A, the UE sends a request to establish a PDU session via slice B. The request indicates slice A and its alternate slice (slice B). Based on the request, the network determines whether the request is associated with slice A, whether the request is associated with slice B, and / or whether slice B is an alternative slice for slice A. Based on this determination, the network adjusts network resource usage. For example, based on the fact that slice B is an alternative to slice A, the network considers the status of network resources for slice A and / or slice B to meet the UE's QoS requirements. For example, if resources for slice A are available, the network fulfills the UE's request by using slice A. For example, if resources for slice A are not available, the network fulfills the UE's request by using an alternative slice (e.g., slice B). Using alternative slice information in addition to network slice information helps the network optimize the allocation of network resources to serve the UE. As shown in Figure 17, alternative slices help the operator provide network slice services to the UE even when there is congestion on a network slice.However, resource availability due to the use of alternative network slices can result in prolonged service interruptions for the UE, as shown in Figure 18.

[0195]

[0225] In the example in Figure 18, the UE receives a slice denial-of-service message, similar to the example shown in Figure 15. Subsequently, the UE receives information about an alternative network slice (e.g., an alternative slice), similar to the example shown in Figure 17.

[0196]

[0226] Returning to Figure 18, at time t=t0, the UE sends a slice service request for slice A to the network node. In response to sending the slice service request, the UE receives a slice service denial message from the network. The slice service denial message indicates that service for slice A is denied and / or that the backoff timer value is associated with slice A. At t=t1, the UE starts a time period using the value for slice A. If not stopped, the time period expires at t=t4.

[0197]

[0227] In one example, to alleviate network congestion, at time t=t2, the network node decides to use an alternative slice of slice A. Time t=t2 is earlier than time t=t4.

[0198]

[0228] In one example, at t=t3 (not shown in the figure), an application associated with slice A and / or data arrivals associated with slice A trigger the UE to request slice service. For example, t=t3 is later than t=t1 and / or earlier than t=t4. Because the time period (e.g., timer) has not expired and / or because the time period has progressed at t=t3, the UE stops requesting slice service and / or does not send a slice service request for network slice A.

[0199]

[0229] In one example, at t=t4, the time period for network slice A expires. Because the time period has expired, no further time has passed, and / or a slice service request is triggered, the UE sends a slice service request for slice A to the network. In response to receiving the slice service request for slice A, and / or because slice B is allocated as an alternative slice for slice A, the network node rejects the slice service request (for slice A) and / or sends a slice service update message to the UE. The slice service update message indicates that slice B is an alternative slice for slice A. The UE receives the slice service update message and sends another slice service request message indicating the alternative slice.

[0200]

[0230] As illustrated in the example in Figure 18, existing techniques delay service provisioning to the UE. Even if a network node decides to use an alternative network slice (e.g., slice B) for a network slice (e.g., slice A) at t=t2, the UE can only use the service associated with the network slice after t=t5. This results in an unnecessary delay in service provisioning to the UE (e.g., a time interval of t5-t2). While the use of backoff periods helps the network alleviate congestion, backoff periods are inefficient in providing as much service as possible to the UE, and / or increase the amount of time the UE cannot use services through a network slice.

[0201]

[0231] Exceptional embodiments of this disclosure improve the service experience of a UE by reducing the amount of service interruption time. In one example, a core network node provides information about an alternative network slice for a network slice to a wireless device having an operating timer. This helps the UE to be aware of the availability of an alternative network slice. In one example, when the UE receives information about an alternative network slice for a network slice, the UE stops the timer associated with the network slice. This helps reduce the latency for the UE to resend a service request associated with the network slice. In one example, the UE manages a backoff timer for an alternative network slice. This prevents the UE from sending a service request for the alternative network slice if the alternative network is experiencing further resource congestion. In one example, when the UE receives service acceptance for an alternative slice, the UE pauses for a time period. This helps avoid further congestion of network resources. In one example, the UE decides whether to send a slice service request for a network slice based on the availability of an alternative slice and / or a time period. This helps the UE avoid unnecessarily long service downtimes.

[0202]

[0232] In this specification, the term "NG-RAN" is interpreted as a base station comprising at least one of the following: gNB, eNB, ng-eNB, node B, access node, access point, N3IWF, relay node, base station central unit (e.g., gNB-CU), base station distributed unit (e.g., gNB-DU). In this specification, gNB is interpreted as a base station. In this specification, gNB-CU is interpreted as a base station central unit. In this specification, gNB-DU is interpreted as a base station distributed unit.

[0203]

[0233] In this specification, the term “core network” node is interpreted as a core network device including at least one of the following: AMF, SMF, NSSF, UPF, NRF, UDM, PCF, SoR-AF, AF, DDNMF, MB-SMF, MB-UPF, etc. The term “core network” is interpreted as one or more core network nodes. In this specification, the term “access node” is interpreted as a base station including NG-RAN, etc.

[0204]

[0234] In this specification, the term "network node" is interpreted as one of the following: a core network node, an access node, an NG-RAN, an UE, etc. A network includes one or more network nodes.

[0205]

[0235] In this specification, the term “alternative network slice” refers to a network slice (e.g., slice B, replacement network slice, S-NSSAI B) that is compatible with a network slice (e.g., slice A, replacement network slice, S-NSSAI A), and / or a network slice (e.g., slice B) that is used as a replacement for a network slice (e.g., slice A). For example, this refers to an S-NSSAI (e.g., slice B, replacement network slice, S-NSSAI B) that is compatible with an S-NSSAI (e.g., slice A, replacement network slice, S-NSSAI A) in an authorized NSSAI (e.g., list of authorized network slices, authorized slices, authorized network slices, one or more authorized S-NSSAIs) that AMF uses to replace an S-NSSAI when the S-NSSAI is unavailable or congested. For example, if a network slice is unavailable or congested, an alternative network slice is used to replace the network slice. For example, a UE requests service for network slice A from the network. If network slice A is unavailable or congested, the network indicates to the UE that another network slice (e.g., network slice B) is an alternative network slice for network slice A. The identifier of the alternative network slice is at least one of the following: NSSAI, S-NSSAI, etc. The identifier of the alternative network slice indicates that the UE is requesting an alternative network slice. The identifier of the alternative network slice indicates the network resources (e.g., resources in slice B) to serve the network slice (e.g., slice A). The alternative network slice is an alternative slice.

[0206]

[0236] In this specification, the term “backoff timer” is interpreted as a timer that controls the period during which the UE is not permitted to perform the procedures associated with the backoff timer (e.g., sending signaling messages). The UE has one or more backoff timers for one or more PDU sessions, one or more networks, one or more locations, and / or one or more network slices. The backoff timer is at least one of the following: T3584, T3585, T3396, MM timer, SM timer, etc. The backoff timer is a backoff time window and / or backoff time period.

[0207]

[0237] A timer begins operating once started and continues operating until stopped or expires. A timer is started if it is not operating, or restarted if it is operating. A timer is associated with a value (for example, a timer starts or restarts from a value or starts from zero and expires when that value is reached). The duration of a timer is not updated until it is stopped or expires. Timers are used to measure the time duration / window of a process. When this specification refers to implementations and procedures relating to one or more timers, it is understood that there are multiple ways of implementing one or more timers. For example, it is understood that one or more of the multiple ways of implementing a timer are used to measure the time duration / window of a procedure. For example, a backoff timer is used to measure a time window for receiving a random access response. In one example, instead of the start and expiration of a backoff timer, a time difference between two timestamps is used. When a timer is restarted, the process for measuring the time window is restarted. Other exemplary implementations are provided for restarting the measurement of a time window. Hereinafter, the term “time duration” is interpreted as “timer”. When the timer is stopped, the timer is not running. When the timer expires, the timer is not running. When the timer is started and / or after it has started, and before it is stopped and / or expires, the timer is running.

[0208]

[0238] Figure 19 illustrates one exemplary embodiment of the present disclosure. In this example, the UE is provided with information on alternative network slices (e.g., alternative slice, replacement slice) for network slices (e.g., original slice, original network slice, requested network slice, requested slice, authorized network slice, authorized slice, replacement slice, etc.). In response to receiving the information, the UE stops the backoff timer associated with the network slice. This helps reduce the time the UE is out of service.

[0209]

[0239] In one example, the UE sends one or more first slice service request messages to one or more network nodes. In another example, the UE receives one or more first slice service response messages from one or more network nodes. Each of the one or more first slice service request messages is at least one of the following: registration request message, service request message, PDU session establishment request message, PDU session change request message, UL NAS transport, etc. Each of the one or more first slice service response messages is at least one of the following: registration response (e.g., accept, reject) message, service response (e.g., accept, reject) message, PDU session establishment response (e.g., accept, reject) message, PDU session change response (e.g., accept, reject) message, UE configuration update message, DL NAS transport, etc.

[0210]

[0240] In one example, a UE sends a first slice service request message to the AMF, one of one or more first slice service request messages. For example, the first slice service request message includes at least one of the following: the UE identifier, a list of requested network slices (e.g., requested slices), and / or a network slice substitution capability indicator. The UE identifier indicates the identity of the UE. For example, the UE identifier is at least one of SUPI, SUCI, IMEI, IMSI, GUTI, etc. The list of requested network slices indicates one or more network slices that the UE requests from the network. For example, the list of requested network slices indicates at least network slice A (e.g., slice A). For example, the list of requested network slices includes one or more identifiers of one or more network slices that the UE requests from the network. The network slice substitution capability indicator indicates whether the UE supports the functionality of network slice substitution. For example, the functionality of network slice substitution is to use, process, handle, and / or interpret information associated with alternative network slices. For example, the network slice replacement capability indicator for the first slice service request indicates that the UE supports the network slice replacement functionality.

[0211]

[0241] In one example, the AMF receives a first slice service request message from the UE. In one example, in response to receiving the first slice service request message from the UE, the AMF sends the UE one of one or more first slice service response messages, specifically a first slice service response message. For example, the first slice service response message includes at least one of the following: a list of authorized network slices (e.g., authorized network slices, authorized slices), a list of denied network slices (e.g., denied network slices, denied slices), and / or a list of configured network slices (e.g., configured network slices, configured slices). The list of authorized network slices indicates one or more network slices that the UE is permitted to use. For example, the list of authorized network slices includes one or more identifiers of network slices that the UE is permitted to use from one or more requested network slices. The list of denied network slices indicates one or more network slices that the UE is denied (not permitted) to use. For example, the list of denied network slices includes one or more identifiers of network slices that the UE is denied to use from one or more requested network slices. The list of denied network slices is associated with one or more reasons for the denial, and / or the first slice service response message contains one or more reasons for the denial. For example, the first slice service response message indicates that slice A is permitted to the UE.

[0212]

[0242] In one example, the UE receives a first slice service response message. The UE stores the information contained in the first slice service response message in storage. For example, the storage is the UE's memory.

[0213]

[0243] In one example, after receiving a first slice service response message, the UE sends a second slice service request message to the AMF, which is one or more of the first slice service request messages. When the UE receives a second slice service request message from the application, it decides whether to send a second slice service request message. For example, if the network slice associated with the application (e.g., slice A) is permitted, the UE decides to send a second slice service request for slice A. For example, the second slice service request message includes at least one of the following: the identifier of the PDU session, information about the network slice associated with the PDU session, and information about the QoS requirements for the PDU session. For example, the network slice information associated with the PDU session indicates the network slice (e.g., slice A) on which the UE requests the PDU session. For example, the network slice (e.g., slice A) associated with the PDU session is one of the permitted network slices.

[0214]

[0244] In one example, the network receives a second slice service request message from the UE. For example, the AMF receives the second slice service request message and / or forwards the second slice request message to the SMF.

[0215]

[0245] For example, in response to a second slice service request message, the SMF determines whether a service (e.g., a PDU session) for the UE can be established / modified on a network slice (e.g., slice A) and / or whether the QoS requirements for the service can be met on the network slice. For example, if the UE requests a PDU session on slice A, the SMF determines whether resources can be allocated on slice A for the PDU session. If there are not enough resources on slice A and / or the QoS requirements for slice A cannot be met, the SMF decides to reject the request from the UE. For example, if the SMF decides to reject the request from the UE, it determines the time value for the backoff timer. For example, the backoff timer is associated with the UE, the PDU session, and / or the network slice (e.g., slice A). For example, the SMF determines the time value based on a forecast. For example, if a forecast indicates that resources for the network slice will be available in one hour, the SMF decides the time value to be one hour. The SMF uses the time value to prevent further access from the UE within that time. This helps the SMF reduce further congestion in the network caused by the UE.

[0216]

[0246] For example, the SMF sends a second slice service response message to the UE, which is one or more first slice service response messages. For example, the second slice service response message indicates that the request (e.g., the second slice service request) has been rejected. For example, the second slice service response message is at least one of a PDU session establishment rejection message, a DL NAS transport message, etc. For example, the second slice service response message includes at least one of the PDU session identifier, the reason for rejection, a time value, etc. Alternatively and / or additionally, when the AMF receives a second slice service request message, the AMF identifies the network slice associated with the second slice service request message. If the AMF knows the SMF associated with the second slice service request message and / or the AMF knows the network slice (e.g., slice A) associated with the second slice service request message, the AMF sends a second slice service response message.

[0217]

[0247] In one example, the UE receives a second slice service response message. If the second slice service response message indicates that the UE's request has been rejected, the UE determines whether the second slice service response message contains a time value. If the second slice service response message contains a time value, the UE uses that time value to start a backoff timer (e.g., a time period) associated with the network slice (e.g., the network slice indicated in the second slice service request, slice A). For example, the time value could be 1 second, 2 minutes, etc.

[0218]

[0248] In one example, an application within the UE generates data to send and / or requests the UE to establish a PDU session. For example, the data and / or PDU session are associated with a network slice (e.g., slice A). Based on the status of timers (associated with the PDU session and / or the network slice (slice A)), the UE decides whether to send the request to the network. For example, if the status of the timer (e.g., a backoff timer associated with the network slice) is running (e.g., not stopped, not expired), the UE decides not to send another slice service request (for the PDU session and / or slice A) to the network. In this case, the UE buffers the data and / or request until it can send another slice service request to the network. In another example, if the status of the timer is stopped (e.g., not running, expired), the UE decides to send another slice service request (for the PDU session and / or slice A) to the network.

[0219]

[0249] For example, a network decides whether to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). For example, a network node (e.g., AMF, SMF, PCF, NSSF, OAM, etc.) monitors the resources available for a network slice, checks for congestion on the network slice, and / or checks whether the QoS requirements for the network slice are met. For example, if there is a shortage of network resources for slice A, if there is congestion on slice A, if the QoS requirements for slice A are not met, if there are remaining / available resources for slice B, and / or if slice B can be used as an alternative to slice A, the network node decides to use an alternative slice for slice A (e.g., slice B, slice B1, slice B2, etc.).

[0220]

[0250] For example, based on the decision to use an alternative slice (e.g., slice B) for slice A, a network node (e.g., AMF) sends a slice service update message to the UE. For example, a slice service update message is at least one of the following: a registration acceptance message, a registration rejection message, a PDU session establishment acceptance message, a PDU session establishment rejection message, a service acceptance message, a service rejection message, a UE configuration update message, a PDU session change command / request message, a DL NAS transport message, etc. For example, a slice service update message includes at least one of the following: a list of (updated) allowed network slices (e.g., allowed network slices, allowed slices), a list of (updated) rejected network slices (e.g., rejected network slices, rejected slices), a list of (updated) alternative network slices (e.g., alternative network slices, alternative slices), a list of configured network slices (e.g., configured network slices, configured slices), etc. For example, a slice service update message indicates that slice B is an alternative slice for slice A.

[0221]

[0251] In one example, the UE receives a slice service update message from a network node. The UE stores the information in the slice service update message. Since the slice service update message indicates that there is an alternative slice for slice A (e.g., slice B), the UE determines whether there are any associated active timers for slice A. For example, the UE identifies that a backoff timer for slice A is running. Because the backoff timer associated with slice A is running and / or the UE has received an instruction that an alternative slice (e.g., slice B) will be allocated to network slice A, the UE stops the backoff timer associated with slice A.

[0222]

[0252] In one example, the UE receives new data from a new application associated with slice A. Since an alternative slice B is available for slice A, the backoff timer associated with slice A stops (is not running), and the UE decides to send a third slice service request to the network. For example, the third slice service request is at least one of the following: a second PDU session establishment request, a second PDU session modification request, etc. For example, the third slice service request indicates at least one of the following: a PDU session identifier, a network slice identifier (e.g., slice A), an alternative slice identifier (e.g., slice B), etc. In another example, the UE has buffered data received from an application (associated with slice A). For example, if the UE receives data while the backoff timer is running, the data is buffered. Since an alternative slice B is available for slice A, the data for network slice A is buffered (available), and the UE decides to send a third slice service request to the network.

[0223]

[0253] In one example, the AMF and / or SMF receive a third slice service request message from the UE and / or establish a PDU session on the (alternative) network slice. After the PDU session is established, the UE exchanges data with the network.

[0224]

[0254] In the example shown in Figure 19, the embodiment helps the UE reduce the amount of out-of-service time.

[0225]

[0255] Figure 20 illustrates one exemplary embodiment of the present disclosure. In this example, similar to the example in Figure 19, the UE receives slice service update messages while the backoff timer is running. In the example in Figure 20, when the UE receives data from the application associated with the network slice, the UE decides whether to send a slice service request based on the availability of an alternative slice. This helps the network to prevent the UE from using the network slice while suppressing requests for the network slice. For brevity, redundant details are omitted.

[0226]

[0256] In one example, the UE sends one or more first slice service request messages to the network and / or receives one or more first slice service response messages. For example, a second slice service response message among the one or more first slice service response messages indicates a refusal to establish a PDU session for a network slice (e.g., slice A) and / or indicates a time value for a backoff timer. Using the time value in the second slice service response message, the UE starts the backoff timer.

[0227]

[0257] In one example, the network decides to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice to slice A. In another example, the UE receives the slice service update message and / or stores the information contained within it.

[0228]

[0258] In one example, the UE receives new data from a new application associated with slice A and / or the UE has buffered data (requested) associated with a previous slice service request. In another example, the UE determines whether an alternative slice is available for slice A. For example, the UE determines whether an alternative slice is available for slice A before checking whether the backoff timer is running for slice A. If an alternative slice (e.g., slice B) is available for slice A, the UE decides to send a third slice service request. If an alternative slice (e.g., slice B) is available for slice A, the UE skips checking the timer status. In another example, when an alternative slice (e.g., slice B) is available for slice A, the UE skips checking whether the backoff timer is running for slice A, ignores the backoff timer associated with network slice A, and / or the UE decides to send a third slice service request message. For example, the UE sends a third slice service request message (indicating the network slice and / or an alternative network slice) while the backoff timer for network slice A is running.

[0229]

[0259] In one example, in response to sending a third slice service request message, the UE receives a third slice service response message. For example, the third slice service response message indicates the establishment of a PDU session for the network slice, acceptance of the network slice request, and / or activation of the PDU session. In one example, while the backoff timer associated with network slice A is running, the UE sends and / or receives data on the PDU session associated with the alternative network slice B (and / or slice A).

[0230]

[0260] In one example, the alternate slice becomes congested. For instance, if many UEs request the alternate slice, alternate slice B becomes congested. Based on the congestion of the alternate slice, the network decides to stop using slice B as an alternate for network slice A. The network instructs the UEs that there are no alternate slices for slice A and / or to stop using slice B as an alternate for slice A. In this case, the operating backoff timer associated with slice A prevents the UEs from sending additional slice service requests for slice A. This helps the network control the stability of network slices and / or alternate network slices.

[0231]

[0261] Figure 21 illustrates one exemplary embodiment of the present disclosure. In this example, similar to the example in Figure 20, the UE receives slice service update messages while the backoff timer is running. In the example in Figure 21, when the UE receives a third slice service response message, the UE stops the backoff timer. This helps prevent further congestion on the network for the alternative slice. For brevity, redundant details are omitted.

[0232]

[0262] In one example, the UE sends one or more first slice service request messages to the network and / or receives one or more first slice service response messages. For example, a second slice service response message indicates a refusal to establish a PDU session for a network slice (e.g., slice A) and / or indicates a time value for the backoff timer (for slice A). Using the time value in the second slice service response message, the UE starts the backoff timer for slice A.

[0233]

[0263] In one example, the network decides to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice to slice A. In another example, the UE receives the slice service update message and / or stores the information contained within it.

[0234]

[0264] In one example, the UE receives new data from a new application associated with slice A. In another example, before checking whether the backoff timer is running for slice A, the UE determines whether an alternative slice is available for slice A. If an alternative slice (e.g., slice B) is available for slice A, the UE decides to send a third slice service request. In yet another example, when an alternative slice (e.g., slice B) is available for slice A, the UE skips checking whether the backoff timer is running for slice A, ignores the backoff timer associated with network slice A, and / or the UE decides to send a third slice service request message. For example, the UE sends a third slice service request message (indicating network slice A and / or alternative network slice B) while the backoff timer for network slice A is running.

[0235]

[0265] In one example, in response to sending a third slice service request message, the UE receives a third slice service response (e.g., an accept) message. For example, the third slice service response message indicates the establishment of a PDU session for the network slice (and / or for the associated alternate network slice) and / or activation of the PDU session. In response to receiving the third slice service response message, the UE stops the backoff timer associated with the network slice. Since the backoff timer has been stopped, the UE establishes an additional PDU session for the network slice (and / or for the alternate slice). In another example, if the alternate slice is also congested, the network wants to reject the third slice service request and / or suppress further requests for the network slice (and / or the alternate network slice). In this case, since the UE fails to establish a PDU session via the third slice service request, the UE does not stop the backoff timer for the network slice (and / or for the alternate network slice) and / or keeps the backoff timer for the network slice running. The embodiment in Figure 21 helps the network control whether the UE needs to keep the backoff timer running or not.

[0236]

[0266] Figure 22 illustrates one exemplary embodiment of the present disclosure. In this example, as in the example in Figure 21, the UE receives slice service update messages while the backoff timer is running. In the example in Figure 22, when the UE receives a fourth slice service response message denying service for the network slice, the UE activates the backoff timer for the alternate slice. This helps the network control access to the network slice separately from access to the alternate network slice. For brevity, redundant details are omitted.

[0237]

[0267] In one example, the UE sends one or more first slice service request messages to the network and / or receives one or more first slice service response messages. For example, a second slice service response message among the one or more first slice service response messages indicates a refusal to establish (or modify) a PDU session for a network slice (e.g., slice A) and / or indicates a time value for the backoff timer for the network slice. Using the time value in the second slice service response message, the UE starts the backoff timer.

[0238]

[0268] In one example, the network decides to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice to slice A. In another example, the UE receives the slice service update message and / or stores the information contained within it.

[0239]

[0269] In one example, the UE receives new data from a new application associated with slice A. In another example, before checking whether the backoff timer is running for slice A, the UE determines whether an alternative slice is available for slice A. If an alternative slice (e.g., slice B) is available for slice A, the UE decides to send a third slice service request. In yet another example, when an alternative slice (e.g., slice B) is available for slice A, the UE skips checking whether the backoff timer is running for slice A, ignores the backoff timer associated with network slice A, and / or the UE decides to send a third slice service request message. For example, the UE sends a third slice service request message (indicating the network slice and / or an alternative network slice) while the backoff timer for network slice A is running. Alternatively, the UE checks whether the backoff timer is running. If the backoff timer for the network slice is running, the UE further checks whether an alternative slice is available for the network slice. If an alternative network slice is available for the network slice, the UE determines whether the timer associated with the alternative network slice (e.g., the backoff timer) is running. If the alternative network slice is not working, the UE sends a third slice service request.

[0240]

[0270] In one example, in response to sending a third slice service request message, the UE receives a fourth slice service response (e.g., rejection) message. For example, the fourth slice service response message rejects the establishment (activation, and / or modification) of a PDU session for the network slice (and / or for an alternate network slice) and / or indicates a second time value for a second backoff timer. In response to receiving the fourth slice service response message, if the fourth slice service response message rejects the third slice service request, if the third slice service request is associated with an alternate slice, and / or if the fourth slice service response message contains a second time value, the UE starts a second backoff timer using the second time value. For example, the second backoff timer is associated with an alternate network slice. For example, the second backoff timer is associated with an alternate network slice and / or a combination of network slices.

[0241]

[0271] In one example, when the second backoff timer is active, the UE does not send a slice service request associated with alternate slice B. For example, if network slice B is an alternate slice of network slice C, and the second backoff timer associated with alternate slice B is active, the UE does not send a slice service request for alternate slice B and / or does not send a slice service request for network slice C (along with the instruction for alternate slice B). In another example, the third slice service request is associated with slice A and alternate slice B, so the second backoff timer is associated with the combination of network slice A and alternate slice B. In this case, when the second backoff timer is active, the UE sends a slice service request for slice B, the UE sends a slice service request for slice C, the UE sends a slice service request for slice C (along with the instruction for alternate slice B), the UE does not send a slice service request for slice A and / or the UE does not send a slice service request for slice A (along with the instruction for alternate slice B). In this case, when the second backoff timer is not running, the UE sends a slice service request for slice A and / or the UE does not send a slice service request for slice A (along with an instruction for alternative slice B).

[0242]

[0272] The example in Figure 22 shows how the network helps prevent further congestion caused by the use of alternative network slices.

[0243]

[0273] Figure 23 illustrates one exemplary embodiment of the present disclosure. In this example, similar to the example in Figure 22, the UE receives slice service update messages while the backoff timer is running. In the example in Figure 23, when the UE receives a fourth slice service response message denying service for the network slice, the UE restarts the backoff timer for the network slice. This helps the network control access to the network slice when congestion does not improve. For brevity, redundant details are omitted.

[0244]

[0274] In one example, the UE sends one or more first slice service request messages to the network and / or receives one or more first slice service response messages. For example, a second slice service response message indicates a refusal to establish a PDU session for a network slice (e.g., slice A) and / or indicates a time value for a backoff timer. Using the time value in the second slice service response message, the UE starts the backoff timer.

[0245]

[0275] In one example, the network decides to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice to slice A. In another example, the UE receives the slice service update message and / or stores the information contained within it.

[0246]

[0276] In one example, upon receiving information about an alternative slice for a network slice, the UE stops the backoff timer associated with the network slice (e.g., slice A).

[0247]

[0277] In one example, the UE receives new data from a new application associated with slice A. In response to receiving the data, if the backoff timer for network slice A is not running, the UE sends a third slice service request message (indicating the network slice and / or an alternative network slice).

[0248]

[0278] In one example, in response to sending a third slice service request message, the UE receives a fourth slice service response (e.g., a rejection) message. For example, the fourth slice service response message indicates a rejection of establishing (activating and / or modifying) a PDU session for the network slice (and / or for an alternate network slice). Since the third slice service request message is associated with a network slice (e.g., slice A), if the UE receives a fourth slice service rejection message associated with a network slice (e.g., slice A), the UE starts (or restarts) the backoff timer associated with slice A. Since the third slice service request message indicates both a network slice (slice A) and / or an alternate network slice (slice B), the AMF uses the rejection of the third slice service request as a rejection for both the network slice and the alternate network slice. For example, by sending a fourth slice service response message, the AMF instructs the UE to start (restart) the backoff timer for network slice A. In this case, the UE starts a backoff timer for network slice A and / or does not send any slice service requests for the network slice (and / or alternate network slices) while the backoff timer is running. For example, in response to receiving a fourth slice service response message (e.g., indicating a denial of an alternate network slice), the UE starts a second backoff timer for the alternate network slice. In this case, even if an alternate network slice is available for network slice A, the UE does not send another request for slice A while the timer is running. In this case, even if an alternate network slice is available for network slice A, the UE sends another request for slice A after the timer has stopped (expired).

[0249]

[0279] The example in Figure 23 shows how the network helps prevent further congestion when the original slice (e.g., slice A) and the alternative slice (e.g., slice B) become congested.

[0250]

[0280] Figure 24 illustrates one exemplary embodiment of the present disclosure. In this example, as in the previous example, the UE receives a slice service update message. In the example of Figure 24, when the UE receives a fourth slice service response message denying service for the network slice, the UE starts a backoff timer for an alternative network slice for the network slice. This helps the network control access to the network slice when congestion occurs on the alternative network slice as well. For brevity, redundant details are omitted.

[0251]

[0281] In one example, the network decides to use an alternative slice (e.g., slice B) for network slices (e.g., slice A, slice C). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice for slice A and / or slice B is an alternative slice for slice C. In another example, the UE receives the slice service update message and / or stores the information contained within it.

[0252]

[0282] In one example, the UE receives new data from a new application associated with slice A. In response to receiving the data, since slice B is an alternate slice for slice A, the UE sends a third slice service request message (indicating the network slice and / or alternate network slice).

[0253]

[0283] In one example, a network node (e.g., AMF, SMF) receives a third slice service request from the UE. Since slice B is an alternative slice to network slice A, the network node determines whether the resources are available through the alternative network slice. If there are not enough resources for the alternative network slice, the network decides to reject the third slice service request from the UE. For example, the network node sends a fourth slice service response message to the UE.

[0254]

[0284] For example, in response to sending a third slice service request message, the UE receives a fourth slice service response (e.g., a rejection) message. For example, the fourth slice service response message indicates a rejection of establishing (activating and / or modifying) a PDU session for network slice A (and / or for alternate network slice B). Since the third slice service request message is associated with a network slice (e.g., slice A), if the UE receives a fourth slice service response message associated with a network slice (e.g., slice A), the UE starts one or more backoff timers associated with slice A and / or alternate slices (e.g., slice B). For example, since the third slice service request message indicates a network slice (slice A) and / or alternate network slice (slice B), the UE starts a fourth backoff timer (e.g., associated with slice A) and / or a fifth backoff timer (e.g., associated with slice B). For example, the fourth backoff timer controls whether the UE is allowed to send a slice service request for network slice (e.g., slice A). For example, a fifth backoff timer controls whether the UE is allowed to send a slice service request to use an alternative network slice (e.g., slice B).

[0255]

[0285] For example, when an application generates data associated with slice A, the UE does not send requests (e.g., registrations for PDU sessions) associated with slice A to the network while the fourth backoff timer is running and / or the fifth backoff timer is running. For example, when an application generates data associated with slice A, if the fourth backoff timer (e.g., for network slice A) is not running and / or the fifth backoff timer (e.g., for alternative slice B of slice A) is not running, the UE sends requests associated with network slice A to the network.

[0256]

[0286] For example, if another application generates data associated with slice C, the UE will not send requests (e.g., registrations for PDU sessions) associated with slice C to the network while the sixth backoff timer (associated with slice C) is not running and / or the fifth backoff timer is running. For example, if an application generates data associated with slice C, and the sixth backoff timer (e.g., for network slice C) is not running and / or the fifth backoff timer (e.g., for alternative slice B of slice C) is not running, the UE will send requests associated with network slice C to the network.

[0257]

[0287] In the example in Figure 24, the embodiment helps the network manage access from the UE when a network slice is assigned as an alternative slice to multiple network slices.

[0258]

[0288] Figure 25 illustrates one exemplary embodiment of the present disclosure. In this example, as in the previous example in Figure 24, the UE receives a slice service update message. In the example in Figure 25, the UE manages multiple backoff timers for different network slices and / or alternate slices. This helps the network control access to the network when congestion occurs on the alternate network slice as well. For brevity, redundant details are omitted.

[0259]

[0289] In one example, in response to sending a third slice service request message, the UE receives a fourth slice service response (e.g., a rejection) message. For example, the fourth slice service response message indicates a rejection of establishing (activating and / or modifying) a PDU session for network slice A (and / or for alternate network slice B). Since the third slice service request message is associated with a network slice (e.g., slice A), if the UE receives a fourth slice service response message associated with a network slice (e.g., slice A), the UE starts the backoff timers associated with slice A and / or the alternate slice (e.g., slice B). Since the third slice service request message indicates a network slice (slice A) and / or an alternate network slice (slice B), the UE starts a fourth backoff timer (e.g., associated with slice A), a fifth backoff timer (e.g., associated with slice B), and / or a sixth backoff timer (e.g., associated with both slice A and slice B). For example, UE does not start a seventh backoff timer (e.g., associated with slice C) and / or an eighth backoff timer (e.g., associated with slice C and / or alternative slice B of slice C).

[0260]

[0290] For example, when an application generates data associated with slice A, while the fourth backoff timer is operating and / or the fifth backoff timer is operating, the UE does not send a request (e.g., for registration of a PDU session) associated with slice A to the network. For example, when an application generates data associated with slice A, if the fourth backoff timer (e.g., for network slice A) is not operating and / or the fifth backoff timer (e.g., for alternative slice B of slice A) is not operating, the UE sends a request associated with network slice A to the network.

[0261]

[0291] For example, when another application generates data associated with slice C, while the sixth backoff timer (associated with slice C) is operating and / or the seventh backoff timer is operating, the UE does not send a request (e.g., for registration of a PDU session) associated with slice C to the network. For example, when an application generates data associated with slice C, if the sixth backoff timer (e.g., for network slice C) is not operating and / or the seventh backoff timer (e.g., for alternative slice B of slice C) is not operating, the UE sends a request associated with network slice C to the network.

[0262]

[0292] In the example of FIG. 25, the embodiment helps the network to distinguish access to different network slices when an alternative network slice is assigned as an alternative slice of a plurality of network slices.

[0263]

[0293] Figure 26 illustrates one exemplary embodiment of the present disclosure. In one example, as in the previous example, the UE receives a slice service update message. In the example of Figure 26, the UE distinguishes a first access to a network slice (used for an application associated with the network slice) from another access to a network slice (used as an alternative network slice to another network slice). This helps the network control how much the network slice is used as an alternative slice. For the sake of brevity, redundant details are omitted.

[0264]

[0294] In one example, the UE sends a registration request message to the AMF. The registration request message indicates a request for slice A and / or slice B. In response to receiving the registration request message, the AMF sends a registration acceptance message to the UE. The registration acceptance message indicates that slice A is permitted and / or slice B is not permitted. For example, the UE does not have a subscription for slice B and / or the UE is in a location where slice B is not permitted. For example, the registration acceptance message indicates a backoff time value for slice B. In response to receiving the registration acceptance message, the UE starts a backoff timer for slice B using the backoff time value.

[0265]

[0295] In one example, the UE receives a slice service update message (e.g., a UE configuration update message) from the AMF. The slice service update message indicates that slice B is an alternative slice to slice A.

[0266]

[0296] In one example, an application associated with slice A generates data. The UE checks whether the backoff timer associated with slice A is running. Since the backoff timer associated with slice A is not running, the UE skips checking the status (e.g., running, stopped, expired) of the backoff timer associated with the alternative slice for slice A (e.g., slice B). Based on the fact that the backoff timer associated with slice A is not running, the UE sends another slice service request message (e.g., PDU session establishment / modification request) to the AMF. For example, the other slice service request message indicates slice A and / or slice B (as an alternative slice for slice A).

[0267]

[0297] In one example, an application associated with slice B generates data. The UE checks whether the backoff timer associated with slice B is running. Because the backoff timer associated with slice B is running, the UE does not send another slice service request message for slice B (e.g., a PDU session establishment request) to the AMF.

[0268]

[0298] For example, as an addition and alternative, when the UE receives a slice service update message, the UE stops the backoff timer for slice B. For instance, based on the fact that slice B is set as an alternative slice for slice A, the UE stops the backoff timer associated with slice B. This allows the UE to use slice B as an alternative slice for slice A.

[0269]

[0299] Figure 27 illustrates one exemplary embodiment of the present disclosure. In this example, similar to the example in Figure 19, the UE receives a slice service update message while the backoff timer is running. In the example in Figure 27, the slice service update message indicates whether the UE is able to send a network slice request. This helps prevent the network from being overwhelmed by requests for alternative network slices from one or more UEs. For brevity, redundant details are omitted.

[0270]

[0300] In one example, the UE sends one or more first slice service request messages to the network and / or receives one or more first slice service response messages. For example, a second slice service response message indicates a refusal to establish a PDU session for a network slice (e.g., slice A) and / or indicates a time value for a backoff timer. Using the time value in the second slice service response message, the UE starts the backoff timer.

[0271]

[0301] In one example, the network decides to use an alternative slice (e.g., slice B) for a network slice (e.g., slice A). This decision prompts the network (e.g., AMF) to send a slice service update message indicating that slice B is an alternative slice for slice A. The slice service update message includes override instructions. These instructions indicate whether the UE can stop the backoff timer for the network slice, whether the UE is allowed to retry the network slice, and / or whether the UE can request a slice service request while the backoff timer for the network slice is running, for a period of time after the UE can use the alternative slice for the network slice. In one example, the UE receives the slice service update message and / or stores the information within it.

[0272]

[0302] In one example, based on an override instruction, the UE stops the backoff timer for a network slice (e.g., slice A). For example, if the override instruction indicates that the UE is permitted to stop the backoff timer for a network slice, the UE stops the backoff timer for the network slice. For example, if the override instruction indicates that the UE is permitted to stop the backoff timer, and / or if an alternative slice for the network slice is available, the UE stops the backoff timer for the network slice. In another example, based on an override instruction, the UE starts a time period. For example, the time period expires at a first time. For example, the UE starts a time period that ends at a first time. When the time period expires (is reached) and / or when the time is the first time, the UE stops the backoff timer for the network slice. For example, when the first time has passed and / or the backoff timer for the network slice has stopped, the UE sends a third slice service request to the AMF. For example, the third slice service request indicates the network slice and / or an alternative slice for the network slice.

[0273]

[0303] In one example, the UE receives new data from a new application associated with slice A. For example, if an override instruction indicates that the UE can request slice services while the backoff timer is running, the UE decides to send a third slice service request message. For example, if the time is the first time and / or the backoff timer associated with the network slice has stopped, the UE decides to send a third slice service request message. In other examples, if an override instruction indicates that the UE cannot request slice services while the backoff timer is running, if an override instruction indicates that the UE will not stop the backoff timer and / or the backoff timer is running, the UE decides not to send a third slice service request message. For example, if the time has not reached the first time and / or the backoff timer associated with the network slice is running, the UE decides not to send a third slice service request message.

[0274]

[0304] The example in Figure 27 helps prevent overloading of alternate slices by controlling when the UE can access them.

[0275]

[0305] Figure 28 illustrates one exemplary embodiment of the present disclosure. In this example, similar to the example in Figure 19, the UE receives slice service update messages while the backoff timer is running. In the example in Figure 28, the NSACF (Network Slice Access Control Function) receives quota information associated with the alternate slice. For brevity, redundant details are omitted.

[0276]

[0306] In one example, the UE sends a registration request message for the registration of one or more network slices. For example, the registration request message includes a list of requested network slices. The list of requested network slices includes one or more identifiers of the one or more requested network slices. For example, one or more requested network slices include slice A.

[0277]

[0307] In one example, the UE receives a registration acceptance message from the AMF. The registration acceptance message contains identifiers for one or more authorized network slices. For example, the AMF determines one or more authorized network slices from one or more requested network slices. For example, one or more authorized network slices include slice A. In one example, the AMF indicates the network slice and / or UE to the NSCAF (associated with the network slice).

[0278]

[0308] In one example, the UE sends a NAS message to the AMF. The NAS message includes at least one of the following: a PDU session establishment (or modification) request message, a PDU session identifier, and an identifier for the network slice associated with the PDU session. For example, a PDU session establishment request requests a PDU session on slice A. For example, a PDU session establishment request message includes a network slice identifier.

[0279]

[0309] In one example, the AMF receives a NAS message. Since the NAS message contains an identifier for slice A, the AMF determines that the NAS message is associated with slice A and / or the PDU session establishment request message is associated with slice A.

[0280]

[0310] For example, the AMF determines that slice A is congested. Because slice A is congested and / or a NAS message is associated with slice A, the AMF decides to reject the UE's request. For example, the AMF sends a NAS rejection message to the UE and / or does not forward the PDU session establishment request to the SMF. For example, the NAS rejection message is a DL NAS transport message. For example, the NAS rejection message includes the timer value of the backoff timer associated with slice A.

[0281]

[0311] In another example, the AMF forwards a PDU session establishment request message to the SMF. If slice A associated with the PDU session establishment request is congested, the SMF decides to send a PDU session establishment rejection message to the UE. For example, the PDU session establishment rejection message includes the time value of the backoff timer associated with slice A. The AMF delivers the PDU session establishment rejection (received from the SMF) to the UE.

[0282]

[0312] In one example, the UE receives a NAS rejection message and / or a PDU session establishment rejection message. The UE receives a time value via the NAS rejection message and / or PDU session establishment rejection message, and uses that time value to start the backoff timer associated with network slice A.

[0283]

[0313] In one example, the AMF receives instructions from the OAM / NSSF that slice A is congested and / or that slice B is an alternative slice for slice A. The AMF sends a UE configuration update message to the UE. The UE configuration update message indicates that slice B is an alternative slice for slice A.

[0284]

[0314] In one example, the UE receives a UE configuration update message. The UE configuration update message indicates that slice B is an alternative slice to slice A, so the UE stops the backoff timer associated with slice A.

[0285]

[0315] In one example, the UE sends a second PDU session establishment request. The second PDU session establishment request indicates slice A and / or slice B (as an alternative slice to slice A). The SMF receives the second PDU session establishment request. The SMF decides to notify / update the NSACF (Network Slice Access Control Function) for quota control. For example, since the second PDU session establishment is associated with slice A, the SMF sends a first slice quota update request to the NSCAF associated with slice A and / or indicates the slice quota for slice A. For example, since the second PDU session establishment is associated with the alternative slice B, the SMF sends a second slice quota update request to the NSCAF associated with slice B and / or indicates the request / increase of the slice quota for slice B. For example, since the second PDU session establishment is associated with the alternative slice B and slice A, the SMF sends a third slice quota update request to the NSCAF associated with slice A and slice B and / or indicates the request / increase of the slice quota for slice B and slice A. The first slice quota request, the second slice quota request, and / or the third slice quota request indicate the identifier of slice A and / or the identifier of slice B.

[0286]

[0316] FIG. 29 illustrates one exemplary embodiment of the present disclosure. In one example, similar to the example of FIG. 28, the UE receives a slice service update message while the backoff timer is running. In the example of FIG. 29, the UE performs cell reselection for an alternative slice. For the sake of brevity, redundant details are omitted.

[0287]

[0317] In one example, the UE sends a registration request message via the first NG-RAN (e.g., NG-RAN1). In another example, the UE receives a registration acceptance message from the AMF via the first NG-RAN. In yet another example, the UE receives a NAS message and / or a PDU session establishment rejection message via the first NG-RAN. In yet another example, the UE receives a UE configuration update message via the first NG-RAN.

[0288]

[0318] For example, the UE decides to send a second PDU session establishment request. For example, the second PDU session establishment request specifies a network slice (e.g., slice A) and / or an alternate slice associated with the network slice. For example, the UE decides whether the alternate slice is supported in the first NG-RAN. If the first NG-RAN does not support the alternate slice, the UE performs cell reselection to a cell that does support the alternate slice (e.g., a cell in the second NG-RAN). For example, if the cell to which the UE camps on supports the alternate slice of the network slice, the UE stops the backoff timer associated with network slice A. For example, if the UE performs cell reselection to a cell that supports the alternate slice of the network slice, the UE stops the backoff timer associated with network slice A.

[0289]

[0319] For example, after cell reselection, the UE decides to send a second PDU session establishment request via a second NG-RAN. For instance, the UE sends a second RRC request message to the second NG-RAN. For example, the second RRC request message includes at least one of the following: the UE identifier, the network slice identifier, the alternate network slice identifier, and / or the second PDU session establishment request. For example, the alternate network slice identifier helps the second NG-RAN determine which AMF (e.g., AMF2) supports the alternate network slice.

[0290]

[0320] Figure 30 illustrates one exemplary embodiment of the present disclosure.

[0291]

[0321] In one example, the UE sends a registration request message to a network node (e.g., AMF, SMF). The registration request message requests a first network slice (e.g., the first slice).

[0292]

[0322] In one example, the UE receives a registration acceptance message from a network node. The registration acceptance message indicates permission for the first network slice.

[0293]

[0323] In one example, the UE sends a PDU session establishment request message to the network node. For instance, the PDU session establishment request message requests the establishment of a PDU session on the first network slice.

[0294]

[0324] In one example, the UE receives a PDU session establishment denial message from a network node. For example, the PDU session establishment denial message indicates the backoff time value of the backoff timer associated with the first network slice. In one example, the UE uses the backoff time value to start the backoff timer.

[0295]

[0325] For example, while a backoff timer (e.g., a time period) is running (e.g., not expired), the UE decides whether to receive configuration update messages from network nodes. For example, the UE receives UE configuration update messages from the AMF.

[0296]

[0326] For example, if the UE receives a UE configuration update message while the backoff timer is running, the UE checks whether the UE configuration update message contains information about an alternative network slice (e.g., a second network slice) for the first network slice.

[0297]

[0327] For example, if the UE receives information about an alternative network slice for the first network slice, the UE stops the backoff timer for the first network slice.

[0298]

[0328] In one example, the UE determines whether a timer (e.g., a time period) has expired (stopped).

[0299]

[0329] In one example, the UE receives data from an application associated with a first network slice. For example, the UE constructs a PDU session message associated with the first network slice (e.g., a PDU session establishment request). For example, the PDU session message includes an identifier for an alternate network slice.

[0300]

[0330] For example, based on the fact that a PDU session message is associated with a first network slice, the UE determines whether the backoff timer for the first network slice has stopped (or expired, or is not operating). If the backoff timer for the first network slice is not operating for the PDU session message, the UE sends an RRC request message to the base station. For example, the RRC request message is at least one of the following: a UL RRC message, an RRC setup complete message, an RRC restart complete message, an RRC restart message, or an RRC setup request message. The RRC request message includes a NAS message. The RRC request message includes the identifier of the first network slice, the identifier of the UE, and / or the identifier of an alternative network slice for the first network slice (e.g., a second network slice). The NAS message is at least one of the following: a registration request message, a service request message, or a UL NAS transport message. The NAS message includes the identifier of the first network slice, the identifier of the UE, and at least one of the PDU session message. A PDU session message is at least one of the following: a PDU session establishment request message, a PDU session modification request message, etc. A PDU session message includes at least one of the following: the QoS requirements for the PDU session, the identifier of the PDU session, the identifier of the first network slice, and / or the identifier of an alternative network slice for the first network slice (e.g., a second network slice).

[0301]

[0331] In one example, a base station receives an RRC request message. The base station forwards the NAS message of the RRC request message to the core network node. The base station selects the core network node if it supports the first network slice and / or an alternate network slice. For example, if the RRC request message indicates an alternate network slice, the base station selects the core network node that supports the alternate network slice.

[0302]

[0332] Figure 31 illustrates one exemplary embodiment of the present disclosure.

[0303]

[0333] In one example, the UE sends a registration request message to a network node (e.g., AMF, SMF). The registration request message requests a first network slice (e.g., the first slice).

[0304]

[0334] In one example, the UE receives information about an alternative network slice (e.g., a second network slice) for the first network slice.

[0305]

[0335] In one example, the UE receives data from the application associated with the first network slice. For instance, the UE decides whether to send a PDU session establishment request for the first network slice.

[0306]

[0336] For example, the UE determines whether the first backoff timer for the first network slice is running. If, for instance, the first backoff timer for the first network slice is running, the UE decides not to send a PDU session establishment request and / or to delay sending the request until the first backoff timer expires.

[0307]

[0337] For example, if the first backoff timer for the first network slice is not running and / or an alternative network slice is associated with the first network slice, the UE determines whether the second backoff timer for the alternative network slice (e.g., the second network slice) is running. For example, if the second backoff timer for the alternative network slice is not running, the UE sends a PDU session establishment request message to the AMF. For example, the PDU session establishment request message indicates the first network slice and / or the alternative network slice. For example, if the second backoff timer for the alternative network slice is running, the UE does not send a PDU session establishment request message to the AMF and / or delays sending the PDU session establishment request message until the second (and / or first) backoff timer expires.

[0308]

[0338] In one example, the UE sends an RRC request message to the base station. For instance, the RRC request message includes a PDU session establishment request message.

[0309]

[0339] In one example, if the backoff timer for the second network slice (e.g., an alternative slice to the first network slice) is active, the UE will not initiate the PDU session establishment (modification) procedure and / or the NAS transport procedure for the PDU session associated with the first network slice. In another example, if the backoff timer for the second network slice is not active, the UE will initiate the PDU session establishment (modification) procedure and / or the NAS transport procedure for the PDU session associated with the first network slice.

[0310]

[0340] In one example, one or more network slices (e.g., the first network slice, the third network slice) are associated with an alternate network slice (e.g., the second network slice). In this case, requests for one or more network slices are mapped to the alternate network slice, which causes further congestion on the alternate network slice. In one example, the UE receives information from the AMF about the number of allowed PDU sessions established on the alternate network slice. For example, the AMF sends a configuration to the UE. The configuration indicates that the second network slice is an alternate network slice for the first network slice and / or the third network slice, and that the maximum number of allowed PDU sessions for the first network slice and / or the third network slice on the alternate network slice is a first number. In this case, if the UE establishes a first number of PDU sessions for the first network slice and / or the second network slice on the alternate network slice, the UE does not request any further PDU sessions for the first network slice and / or the third network slice using the alternate network slice. If the UE establishes fewer than a first number of PDU sessions for the first network slice and / or the second network slice on an alternate network slice, the UE requests additional PDU sessions for the first network slice and / or the third network slice using the alternate network slice.

[0311]

[0341] In one example, the UE sends a first request to the Access and Mobility Management Function (AMF). For example, to send the first request, the UE sends a first message to the AMF. The first request is a request to establish a PDU session. The first message is at least one of the following: a PDU session establishment request message, a PDU session modification request message, etc. The first request and / or the first request message requests the establishment of a protocol data unit session for an authorized network slice. For example, the UE requests the establishment of a PDU session on and / or using an authorized network slice. The AMF receives the first request and / or the AMF delivers the first request to the SMF.

[0312]

[0342] In one example, the UE receives a second message from the AMF. For example, the UE receives a second message from the AMF in response to having sent a first request. For example, the AMF sends a second message to the UE in response to having received the first request. The second message indicates a rejection of the first request. For example, if the AMF rejects the first request, the AMF sends a second message. For example, the second message indicates that the permitted network slice has been denied and / or that the establishment of a PDU session on the permitted network slice has been denied. The second message includes a time value. For example, the time value indicates the time during which the UE is not permitted to send another request to establish a PDU session on the permitted network slice.

[0313]

[0343] For example, the UE starts a timer. For instance, the timer is associated with an authorized network slice. For example, the UE starts a timer because it has received a second message, because the second message contains a time value, and / or because the establishment of a PDU session for the authorized network slice was denied. For example, the UE starts a timer using a time value.

[0314]

[0344] In one example, while the timer is running, the UE receives information from the AMF indicating an alternative network slice for the permitted network slice. For example, the information indicates the identifier of the alternative network slice. For example, the information indicates that the alternative network slice will be used as a substitute for the permitted network slice.

[0315]

[0345] In one example, the UE stops the timer when it receives information indicating an alternative network slice for an authorized network slice.

[0316]

[0346] In one example, the UE sends a second request to the AMF for establishing a PDU session. The UE sends a second request, for example, based on the fact that the timer for the authorized network slice is stopped (e.g., not running), based on the fact that the establishment of a PDU session for the authorized network slice was denied, based on the fact that the timer is not running, and / or based on the fact that an alternative network slice is available for the authorized network slice. For example, the second request includes at least one of the identifiers of the authorized network slice or the alternative network slice.

[0317]

[0347] In one example, the UE sends a registration request message to the AMF. For example, the registration request message includes one or more identifiers of one or more requested network slices. For example, one or more requested network slices indicate one or more network slices that the UE is requesting to register.

[0318]

[0348] In one example, a UE receives a registration acceptance message from the AMF. For instance, the AMF sends a registration acceptance message in response to a registration request message received from the UE. The registration acceptance message contains one or more identifiers of one or more accepted (authorized) network slices. For example, one or more accepted network slices represent one or more network slices from one or more requested network slices.

[0319]

[0349] In one example, the UE sends a request for a PDU session on an authorized network slice. The authorized network slice is one of one or more authorized network slices. For example, the request is a PDU session establishment request message for the PDU session and / or a PDU session modification request message for the PDU session. The PDU session is established on and / or associated with the authorized network slice.

[0320]

[0350] For example, the UE receives a rejection message. For example, a rejection message rejects a request for a PDU session. For example, a rejection message indicates a rejection of establishing (and / or modifying) a PDU session on an authorized network slice. For example, a rejection message indicates a rejection of a request for an authorized network slice, indicates congestion (resource shortage, unavailability) on the authorized network slice, or indicates a failure of the session management procedure for the authorized network slice. For example, a rejection message includes a timer time value. For example, a rejection message is at least one of the following: PDU session establishment rejection, PDU session modification rejection, UL NAS transport rejection, DL NAS transport rejection, NAS message, etc.

[0321]

[0351] For example, a UE uses a time value to start a timer for an authorized network slice. Examples of timers include backoff timers, T3585, T3584, MM timers, and SM timers. For instance, a timer is used to control when a UE can send a request associated with that timer. For example, a timer is used to control when a UE can send a request associated with an authorized network slice (e.g., PDU session establishment, service request, registration request). For example, a UE will not send a request from the time the timer was started until the time value has passed the time the timer was started. For example, a UE will send a request after the timer has stopped and / or expired.

[0322]

[0352] For example, while the timer is running, the UE receives information from the AMF indicating an alternative network slice for the permitted network slice. For example, the UE stores this information in memory. For example, because the information indicates an alternative network slice for the permitted network slice, and / or because an alternative network slice is available for the permitted network slice, the UE decides to stop the timer associated with the network slice.

[0323]

[0353] For example, a timer operates from the time it is started until it is stopped or expires. For instance, a timer does not operate from the time it is stopped and / or expires until it is started and / or restarted.

[0324]

[0354] For example, the UE sends a second request to the AMF. For example, the second request requests the establishment of a PDU session. For example, a PDU session is associated with an authorized network slice, associated with data configured to use the authorized network slice, and triggered for the authorized network slice. For example, the second request further includes the identifier of an alternate network slice and / or the identifier of a network slice. For example, the UE sends a second request after the timer has stopped due to the receipt of information. For example, the UE sends a second request based on the receipt of information about an alternate network slice. For example, the UE sends a second request if the timer is not running. For example, the UE stops the timer when it receives information about an alternate network slice.

[0325]

[0355]

[0356] In one example, the UE sends a registration request message to the AMF. For example, the registration request message includes one or more identifiers of one or more requested network slices. For example, one or more requested network slices indicate one or more network slices that the UE is requesting to register.

[0326]

[0357] In one example, a UE receives a registration acceptance message from the AMF. For example, the AMF sends a registration acceptance message in response to a registration request message received from the UE. The registration acceptance message includes one or more identifiers of accepted network slices and / or one or more identifiers of rejected network slices. For example, one or more accepted network slices indicate one or more network slices from one or more requested network slices. For example, one or more rejected network slices indicate one or more network slices from one or more requested network slices. In one example, the registration acceptance message indicates the time value of a rejected network slice from one or more rejected network slices. For example, a rejected network slice is a requested network slice from one or more requested network slices.

[0327]

[0358] For example, a UE might start a timer for a rejected network slice using a time value. For instance, a timer might be associated with a rejected network slice (e.g., a configured network slice, a subscribed network slice, a requested network slice) using a time value. Examples of timers include backoff timers and mobility management timers. For example, a timer might be used to control when a UE can resend (e.g., retry) a request associated with the timer. For example, a timer might be used to control when a UE can send another request associated with a rejected network slice. For example, a timer might be used to control when a UE can send another registration request requesting registration for a network slice associated with a rejected network slice. For example, a UE might not send a request from the time the timer was started until the time value has passed the time the timer started. For example, a UE might send a request after the timer has stopped (e.g., is not running) and / or after the timer has expired.

[0328]

[0359] For example, while the timer is running, the UE receives information from the AMF indicating an alternative network slice for the requested network slice (e.g., a rejected network slice, a subscribed network slice, a configured network slice). For example, the requested network slice is a configured network slice and / or it indicates an alternative network slice for the configured network slice. For example, the UE stores the information in memory. For example, since the information indicates an alternative network slice for the requested network slice and / or an alternative network slice is available for the requested network slice, the UE stops the timer associated with the requested network slice (e.g., a rejected network slice).

[0329]

[0360] For example, a timer operates from the time it is started until it is stopped or expires. For instance, a timer does not operate from the time it is stopped and / or expires until it is started and / or restarted.

[0330]

[0361] For example, the UE sends a second request to the AMF. For example, the second request requests registration of the requested network slice. For example, the second request further includes the identifier of the alternative network slice and / or the identifier of the requested network slice. For example, the UE sends a second request after the timer has stopped due to the receipt of information. For example, the UE sends a second request based on the receipt of information about the alternative network slice. For example, the UE sends a second request if the timer is not running.

[0331]

[0362] In one example, the UE receives a rejection message that rejects a PDU session for an authorized network slice. The rejection message includes a time value. The UE uses the time value to start a timer for the authorized network slice. While the timer is running, the UE receives information indicating an alternative network slice for the authorized network slice. While the timer is running and / or before the timer expires, and / or based on the information (for example, if information on an alternative slice for the authorized network slice is available), the UE sends a request message containing the alternative network slice and the authorized network slice. For example, the request message requests the establishment of a PDU session associated with the authorized network slice and / or the authorized network slice.

[0332]

[0363] In one example, the UE receives a message rejecting the registration of a network slice. The message includes a time value for the network slice. The UE uses the time value to start a timer for the network slice. While the timer is running, the UE receives information indicating alternative network slices for the configured network slice. For example, the configured network slice is a network slice. While the timer is running and / or before the timer expires, and / or based on the information (for example, if information on alternative slices for the configured (or requested, rejected) network slice is available), the UE sends a second registration request message. The second registration request message requests registration of at least one of the alternative network slices and / or network slices associated with the network slice.

[0333]

[0364] In one example, the UE starts a backoff timer for an authorized network slice using a time value. For example, the UE starts the backoff timer when it receives a rejection to establish a PDU session using an authorized network slice and / or when it receives a rejection to register for an authorized network slice. The UE sends a request message requesting a PDU session. For example, the request message indicates an alternative network slice for the authorized network slice. The UE receives a message indicating acceptance of establishing a PDU session for the alternative network slice. In response to receiving a message indicating establishment of a PDU session on the alternative network slice, the UE stops the backoff timer for the authorized network slice.

[0334]

[0365] In one example, the UE receives a first denial message refusing to establish a protocol data unit (PDU) session for an authorized network slice. In another example, the UE starts a first backoff timer associated with the authorized network slice. In yet another example, the UE sends a request message to establish a PDU session. For example, the request message indicates an alternative network slice for the authorized network slice. The UE receives a second denial message rejecting the request. For example, the second denial message indicates that the establishment of a PDU session associated with the alternative network slice has been denied, and / or the establishment of a PDU session associated with the alternative network slice and / or the authorized network slice has been denied. In yet another example, the UE starts a second backoff timer. For example, the second backoff timer is associated with the alternative network slice and / or the authorized network slice. For example, while the second backoff timer is running, the UE does not send PDU session establishment requests associated with the alternative network slice, nor does it send PDU session establishment requests associated with the alternative network slice and / or the authorized network slice. For example, while the first backoff timer is running, the UE does not send PDU session establishment requests associated with the authorized network slice. For example, while the first backoff timer is running and / or the second backoff timer is running, the UE does not send requests to establish PDU sessions associated with the permitted network slice and / or alternative network slice.

Claims

1. A wireless device receives a protocol data unit (PDU) session establishment denial message for an authorized network slice, wherein the PDU session establishment denial message includes a backoff timer value. The steps include: starting a session management timer using the backoff timer value via the wireless device; The steps include: receiving a configuration message from the wireless device indicating an alternative network slice for the permitted network slice; The steps include: sending a request message to the wireless device, while the session management timer is running, requesting the establishment of a PDU session based on the configuration message, wherein the request message includes the identifier of the alternate network slice and the identifier of the authorized network slice; A method having

2. The method according to claim 1, wherein the session management timer controls congestion of the permitted network slice.

3. The method according to claim 1 or 2, wherein the alternative network slice indicates a network slice compatible with the permitted network slice.

4. The method according to any one of claims 1 to 3, further comprising the step of sending a registration request by the wireless device.

5. The method according to claim 4, wherein the registration request indicates at least the requested network slice.

6. The method according to any one of claims 1 to 5, further comprising the step of receiving registration acceptance by the wireless device.

7. The method according to claim 6, wherein the registration acceptance indicates at least the permitted network slice.

8. The method according to claim 6 or 7, dependent on claim 4 or 5, wherein the wireless device receives the registration acceptance in response to sending the registration request.

9. The method according to any one of claims 1 to 8, wherein the wireless device receives the PDU session establishment rejection message in response to the wireless device sending a PDU session establishment request message.

10. The method according to any one of claims 1 to 9, wherein the wireless device receives the rejection message from at least one of the access and mobility management functions or the session management function.

11. The wireless device further includes the step of sending a radio resource control (RRC) message, The RRC message indicates at least one of the alternative slice and the permitted network slice, and / or The RRC message further includes the request message, The method according to any one of claims 1 to 10.

12. The method according to any one of claims 1 to 11, further comprising the step of receiving a UE configuration update message by the wireless device, wherein the UE configuration update message includes a configuration message indicating a mapping of the alternate network slice and the permitted network slice.

13. The method according to any one of claims 1 to 12, further comprising the step of reselecting a cell that supports at least the alternative network slice using the wireless device.

14. The method according to claim 12, wherein the UE configuration update message further includes at least an action instruction or a second time.

15. The method according to claim 14, wherein the action instruction indicates whether the wireless device needs to stop the timer.

16. The method according to claim 15, wherein the wireless device stops the timer based on the action instruction instructing the wireless device to stop the timer.

17. The method according to claim 14, wherein the second time indicates the time until the wireless device is permitted to use the alternative network slice.

18. The method according to any one of claims 1 to 17, wherein after the timer has been stopped, the timer does not operate and the timer is not started or restarted.

19. The method according to any one of claims 1 to 18, wherein after the timer expires, the timer does not operate and the timer is not started or restarted.

20. The method according to any one of claims 1 to 19, further comprising the step of not sending the request message by the wireless device on the basis that the alternative network slice is unavailable while the timer is operating.

21. The method according to claim 20, further comprising the step of determining that the wireless device will send a second request message including the permitted network slice after the timer has expired.

22. The steps include: a wireless device starting a timer for an authorized network slice using the timer value of a Protocol Data Unit (PDU) session establishment denial message; While the timer is running, the wireless device sends a request message requesting the establishment of a PDU session for the permitted network slice based on an alternative network slice for the permitted network slice. A method having

23. A receiving processing system that receives a protocol data unit (PDU) session establishment denial message for an authorized network slice and a configuration message indicating an alternative network slice for the authorized network slice, wherein the PDU session establishment denial message includes a backoff timer value. A processing system that starts a session management timer using the aforementioned backoff timer value, A transmission processing system that, while the session management timer is operating, sends a request message requesting the establishment of a PDU session based on the configuration message, wherein the request message includes the identifier of the alternate network slice and the identifier of the authorized network slice. A wireless device equipped with the following features.

24. A wireless device receives a rejection message that rejects the establishment of a protocol data unit session for an authorized network slice, wherein the rejection message includes a time value. The steps include: using the wireless device to start a timer for the permitted network slice using the time value; The steps include receiving information from the wireless device indicating an alternative network slice for the permitted network slice, The steps include: stopping the timer in response to receiving the information via the wireless device; A method having

25. The method according to claim 24, wherein the alternative slice indicates a network slice compatible with the permitted network slice.

26. The method according to claim 24 or 25, further comprising the step of sending a third message requesting the PDU session via the wireless device.

27. The method according to claim 26, wherein the third message includes at least one of the identifiers of the permitted network slice or the identifier of the alternate slice.

28. The method according to claim 27, wherein the wireless device sends the third message based on the stopping of the timer.

29. The method according to any one of claims 24 to 28, wherein stopping the timer means that the timer is not operating.

30. The method according to any one of claims 24 to 29, further comprising the step of sending a registration request by the wireless device.

31. The method according to claim 30, wherein the registration request indicates at least the requested network slice.

32. The method according to any one of claims 24 to 31, further comprising the step of receiving registration acceptance by the wireless device.

33. The method according to claim 32, wherein the registration acceptance indicates at least the accepted network slice.

34. The method according to claim 32 or 33, wherein the registration acceptance indicates the accepted network slice in response to the sending of the registration request.

35. The method according to any one of claims 24 to 34, wherein the rejection message is at least one of a NAS message, a PDU session establishment rejection, or a denial of service.

36. The method according to any one of claims 24 to 35, wherein the wireless device receives the rejection message from at least one of the access and mobility management function and the session management function.

37. The method according to any one of claims 24 to 36, further comprising the step of sending a radio resource control (RRC) message by the wireless device, wherein the RRC message indicates at least one of the alternate slice and the authorized network slice.

38. The method according to claim 37, which is dependent on claim 26, wherein the RRC message further includes the third message.

39. The method according to claim 26, wherein the third message is at least one of a PDU session establishment request, a service request, and a PDU session modification request.

40. The method according to any one of claims 24 to 39, further comprising the step of receiving a second message by the wireless device.

41. The method according to claim 40, wherein the second message is a UE configuration update message.

42. The method according to claim 41, wherein the second message includes the information indicating an alternative network slice for the permitted network slice.

43. The method according to claim 39, wherein the third message further includes network slice access group information associated with the alternative network slice.

44. The method according to any one of claims 24 to 43, further comprising the step of reselecting a cell that supports at least the alternative network slice or network slice access group using the wireless device.

45. The method according to claim 39, wherein the third message further includes at least an action instruction or a second time.

46. The method according to claim 45, wherein the action instruction indicates whether the wireless device needs to stop the timer.

47. The method of claim 45, wherein the wireless device stops the timer based on the action instruction instructing the wireless device to stop the timer.

48. The method according to claim 45, wherein the second time indicates the time until the wireless device is permitted to use the alternative network slice.

49. The method according to claim 24, wherein after the timer is stopped or expires, the timer does not operate and is not started or restarted.

50. A receiving processing system that receives a rejection message refusing to establish a protocol data unit session for an authorized network slice and information indicating an alternative network slice for the authorized network slice, wherein the rejection message includes a time value. A processing system that starts a timer for the permitted network slice using the aforementioned time value and stops the timer in response to receiving the aforementioned information. A wireless device equipped with the following features.

51. A wireless device receives a rejection message that rejects a protocol data unit session for an authorized network slice, wherein the rejection message includes a time value. The steps include: using the wireless device to start a timer for the permitted network slice using the time value; The steps include receiving information from the wireless device indicating an alternative network slice for the permitted network slice, Before the timer expires, the wireless device sends a request message including the alternative network slice and the permitted network slice in response to receiving the information. A method having

52. The wireless device initiates a backoff timer for an authorized network slice using a time value, The steps include: sending a request message via the wireless device that includes an alternative network slice for the permitted network slice and the permitted network slice; The steps include: receiving a message from the wireless device indicating acceptance of the service for the alternative network slice; The steps include: stopping the backoff timer in response to receiving the message by the wireless device; A method having

53. The steps include: receiving a first rejection message from a wireless device that rejects a protocol data unit (PDU) session for an authorized network slice; The steps include: starting a first backoff timer associated with the permitted network slice using the wireless device; The steps include: sending a request message for the PDU session by the wireless device, wherein the request message indicates an alternative network slice for the authorized network slice; The steps include: receiving a second rejection message rejecting the request via the wireless device; The steps include: starting a second backoff timer associated with the alternative network slice and the permitted network slice using the wireless device; A method having

Images