Application of access utilization

Abstract

A wireless device receives, from a mobility management node, of a first network, a first non-access stratum (NAS) message, wherein the first NAS message comprises a radio access technology (RAT) utilization control information, and the RAT utilization control information indicates an access technology associated with a second network being restricted. The wireless device sends, to a second mobility management node of the second network, a second NAS message, wherein the second NAS message is at least one of a message requesting registration of the wireless device for disaster roaming, or a message requesting transfer of a data session from the second network to the first network, comprising a request type field indicating an existing data session.

Description

Docket No.: 25-1021 PCTTITLEApplication of Access UtilizationCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 753,207, filed February 3, 2025, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

[0003] Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

[0004] FIG. 1A and FIG. 1B illustrate example communication networks including an access network and a core network.

[0005] FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D illustrate various examples of a framework for a servicebased architecture within a core network.

[0006] FIG. 3 illustrates an example communication network including core network functions.

[0007] FIG. 4A and FIG. 4B illustrate example of core network architecture with multiple user plane functions and untrusted access.

[0008] FIG. 5 illustrates an example of a core network architecture for a roaming scenario.

[0009] FIG. 6 illustrates an example of network slicing.

[0010] FIG. 7A, FIG. 7B, and FIG. 7C illustrate a user plane protocol stack, a control plane protocol stack, and services provided between protocol layers of the user plane protocol stack.

[0011] FIG. 8 illustrates an example of a quality of service model for data exchange.

[0012] FIG. 9A, FIG. 9B, FIG. 9C, and FIG. 9D illustrate example states and state transitions of a wireless device.

[0013] FIG. 10 illustrates an example of a registration procedure for a wireless device.

[0014] FIG. 11 illustrates an example of a service request procedure for a wireless device.

[0015] FIG. 12 illustrates an example of a protocol data unit session establishment procedure for a wireless device.

[0016] FIG. 13 illustrates examples of components of the elements in a communications network.

[0017] FIG. 14A, FIG. 14B, FIG. 14C, and FIG. 14D illustrate various examples of physical core network deployments, each having one or more network functions or portions thereof.

[0018] FIG. 15 illustrates an aspect of an example embodiment according to the present disclosure.

[0019] FIG. 16 illustrates an aspect of an example embodiment according to the present disclosure

[0020] FIG. 1 illustrates an aspect of an example embodiment according to the present disclosure.Docket No.: 25-1021 PCT

[0021] FIG. 18 illustrates an aspect of an example embodiment according to the present disclosure

[0022] FIG. 19 illustrates an aspect of an example embodiment according to the present disclosure.

[0023] FIG. 20 illustrates an aspect of an example embodiment according to the present disclosure..

[0024] FIG. 21 illustrates an aspect of an example embodiment according to the present disclosure.

[0025] FIG. 22 illustrates an aspect of an example embodiment according to the present disclosure.

[0026] FIG. 23 illustrates an aspect of an example embodiment according to the present disclosure.

[0027] FIG. 24 illustrates an aspect of an example embodiment according to the present disclosure.

[0028] FIG. 25 illustrates an aspect of an example embodiment according to the present disclosure.

[0029] FIG. 26 illustrates an aspect of an example embodiment according to the present disclosure.

[0030] FIG. 27 illustrates an aspect of an example embodiment according to the present disclosure

[0031] FIG. 28 illustrates an aspect of an example embodiment according to the present disclosure.

[0032] FIG. 29 illustrates an aspect of an example embodiment according to the present disclosure.

[0033] FIG. 30 illustrates an aspect of an example embodiment according to the present disclosure.

[0034] FIG. 31 illustrates an aspect of an example embodiment according to the present disclosure.

[0035] FIG. 32 illustrates an aspect of an example embodiment according to the present disclosure DETAILED DESCRIPTION

[0036] In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and / or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. In fact, after reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0037] Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and / or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and / or the like. When the one or moreDocket No.: 25-1021 PCTcriteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

[0038] A base station may communicate with a mix of wireless devices. Wireless devices and / or base stations may support multiple technologies, and / or multiple releases of the same technology. Wireless devices may have one or more specific capabilities. When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of a given LTE or 5G release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and / or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and / or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, those wireless devices or base stations may perform based on older releases of LTE or 5G technology.

[0039] In this disclosure, "a” and “an” and similar phrases refer to a single instance of a particular element, but should not be interpreted to exclude other instances of that element. For example, a bicycle with two wheels may be described as having “a wheel”. Any term that ends with the suffix “(s)” is to be interpreted as “at least one" and / or “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed 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 unenumerated components from being included in the element being described. By contrast, “consists of’ provides a complete enumeration of the one or more components of the element being described.

[0040] The phrases “based on", “in response to", “depending on”, “employing”, “using”, and similar phrases indicate the presence and / or influence of a particular factor and / or condition on an event and / or action, but do not exclude unenumerated factors and / or conditions from also being present and / or influencing the event and / or action. For example, if action X is performed “based on” condition Y, this is to be interpreted as the action being performed “based at least on” condition Y. For example, if the performance of action X is performed when conditions Y and Z are both satisfied, then the performing of action X may be described as being “based on Y”.

[0041] The term “configured” may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In otherDocket No.: 25-1021 PCTwords, the hardware, software, firmware, registers, memory values, and / or the like may be "configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0042] In this disclosure, a parameter may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter J comprises parameter K, and parameter K comprises parameter L, and parameter L comprises parameter M, then J comprises L, and J comprises M. A parameter may be referred to as a field or information element. In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages.

[0043] This disclosure may refer to possible combinations of enumerated elements. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from a set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, the seven possible combinations of enumerated elements A, B, C consist of: (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 the sake of brevity and legibility, these seven possible combinations may be described using any of the following interchangeable formulations: "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”; “A, B, and / or C”. It will be understood that impossible combinations are excluded. For example, “X and / or not-X” should be interpreted as “X or not-X”. It will be further understood that these formulations may describe alternative phrasings of overlapping and / or synonymous concepts, for example, "identifier, identification, and / or ID number”.

[0044] This disclosure may refer to sets and / or subsets. As an example, set X may be a set of elements comprising one or more elements. If every element of X is also an element of Y, then X may be referred to as a subset of Y. In this disclosure, only non-empty sets and subsets are considered. For example, if Y consists of the elements Y1, Y2, and Y3, then the possible subsets ofY are {Y1 , Y2, Y3}, {Y1, Y2}, {Y1, Y3}, {Y2, Y3}, {Y1 }, {Y2}, and {Y3}.

[0045] FIG. 1A illustrates an example of a communication network 100 in which embodiments of the present disclosure may be implemented. The communication network 100 may comprise, for example, a public land mobile network (PLMN) run by a network operator. As illustrated in FIG. 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 network (DNs) 108.Docket No.: 25-1021 PCT

[0046] The wireless device 101 may communicate with DNs 108 via AN 102 and CN 105. In the present disclosure, the term wireless device may refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (loT) device, vehicle road side unit (RSU), relay node, automobile, unmanned aerial vehicle, urban air mobility, and / or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0047] The AN 102 may connect wireless device 101 to CN 105 in any suitable manner. The communication direction from the AN 102 to the wireless device 101 is known as the downlink and the communication direction from the wireless device 101 to AN 102 is known as the uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), timedivision duplexing (TDD), and / or some combination of the two duplexing techniques. The AN 102 may connect to wireless device 101 through radio communications over an air interface. An access network that at least partially operates over the air interface may be referred to as a radio access network (RAN). The CN 105 may set up one or more end-to-end connection between wireless device 101 and the one or more DNs 108. The CN 105 may authenticate wireless device 101 and provide charging functionality.

[0048] In the present disclosure, the term base station may refer to and encompass any element of AN 102 that facilitates communication between wireless device 101 and AN 102. Access networks and base stations have many different names and implementations. The base station may be a terrestrial base station fixed to the earth. The base station may be a mobile base station with a moving coverage area. The base station may be in space, for example, on board a satellite. For example, WiFi and other standards may use the term access point. As another example, the Third-Generation Partnership Project (3GPP) has produced specifications for three generations of mobile networks, each of which uses different terminology. Third Generation (3G) and / or Universal Mobile Telecommunications System (UMTS) standards may use the term Node B. 4G, Long Term Evolution (LTE), and / or Evolved Universal Terrestrial Radio Access (E-UTRA) standards may use the term Evolved Node B (eNB). 5G and / or New Radio (NR) standards may describe AN 102 as a next-generation radio access network (NG-RAN) and may refer to base stations as Next Generation eNB (ng-eNB) and / or Generation Node B (gNB). Future standards (for example, 6G, 7G, 8G) may use new terminology to refer to the elements which implement the methods described in the present disclosure (e.g ., wireless devices, base stations, ANs, CNs, and / or components thereof). A base station may be implemented as a repeater or relay node used to extend the coverage area of a donor node. A repeater node may amplify and rebroadcast a radio signal received from a donor node. A relay node mayDocket No.: 25-1021 PCTperform the same / similar functions as a repeater node but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.

[0049] The AN 102 may include one or more base stations, each having one or more coverage areas. The geographical size and / or extent of a coverage area may be defined in terms of a range at which a receiver of AN 102 can successfully receive transmissions from a transmitter (e.g. , wireless device 101) operating within the coverage area (and / or vice-versa). The coverage areas may be referred to as 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 may be referred to as 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 referred to as hotspots). Examples of small cell base stations include, in order of decreasing coverage area, microcell base stations, picocell base stations, and femtocell base stations or home base stations. Together, the coverage areas of the base stations may provide radio coverage to wireless device 101 over a wide geographic area to support wireless device mobility.

[0050] A base station may include one or more sets of antennas for communicating with the wireless device 101 over the air interface. Each set of antennas may be separately controlled by the base station. Each set of antennas may have a corresponding coverage area. As an example, a base station may include three sets of antennas to respectively control three coverage areas on three different sides of the base station. The entirety of the base station (and its corresponding antennas) may be deployed at a single location. Alternatively, a controller at a central location may control one or more sets of antennas at one or more distributed locations. The controller may be, for example, a baseband processing unit that is part of a centralized or cloud RAN architecture. The baseband processing unit may be either centralized in a pool of baseband processing units or virtualized. A set of antennas at a distributed location may be referred to as a remote radio head (RRH).

[0051] FIG. 1B illustrates another example communication network 150 in which embodiments of the present disclosure may be implemented. The communication network 150 may comprise, for example, a PLMN run by a network operator. As illustrated in FIG. 1B, communication network 150 includes UEs 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, illustrated as generation node Bs (gNBs) 152A and next generation evolved Node Bs (ng eNBs) 152B. The 5G-CN 155 includes one or more network functions (NFs), including control plane functions 155A and user plane functions 155B. The one or more DNs 158 may comprise public DNs (e.g., the Internet), private DNs, and / or intra-operator DNs. Relative to corresponding components illustrated in FIG. 1A, these components may represent specific implementations and / or terminology.Docket No.: 25-1021 PCT

[0052] The base stations of the NG-RAN 152 may be connected to the UEs 151 via Uu interfaces. The base stations of the NG-RAN 152 may be connected to each other via Xn interfaces. The base stations of the NG-RAN 152 may be connected to 5G CN 155 via NG interfaces. The Uu interface may include an air interface. The NG and Xn interfaces may include an air interface, or may consist of direct physical connections and / or indirect connections over an underlying transport network (e.g., an internet protocol (IP) transport network).

[0053] Each of the Uu, Xn, and NG interfaces may be associated with a protocol stack. The protocol stacks may include a user plane (UP) and a control plane (CP). Generally, user plane data may include data pertaining to users of the UEs 151, for example, internet content downloaded via a web browser application, sensor data uploaded via a tracking application, or email data communicated to or from an email server. Control plane data, by contrast, may comprise signaling and messages that facilitate packaging and routing of user plane data so that it can be exchanged with the DN(s). The NG interface, for example, may be divided into an NG user plane interface (NG-U) and an NG control plane interface (NG-C). The NG-U interface may provide delivery of user plane data between the base stations and the one or more user plane network functions 155B. The NG-C interface may be used for control signaling between the base stations and the one or more control plane network functions 155A. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and / or warning message transmission. In some cases, the NG C interface may support transmission of user data (for example, a small data transmission for an loT device).

[0054] One or more of the base stations of the NG-RAN 152 may be split into a central unit (CU) and one or more distributed units (DUs). A CU may be coupled to one or more DUs via an F1 interface. The CU may handle one or more upper layers in the protocol stack and the DU may handle one or more lower layers in the protocol stack. For example, the CU may handle RRC, PDCP, and SDAP, and the DU may handle RLC, MAC, and PHY. The one or more DUs may be in geographically diverse locations relative to the CU and / or each other. Accordingly, the CU / DU split architecture may permit increased coverage and / or better coordination.

[0055] The gNBs 152A and ng-eNBs 152B may provide different user plane and control plane protocol termination towards the UEs 151. For example, the gNB 154A may provide new radio (NR) protocol terminations over a Uu interface associated with a first protocol stack. The ng eNBs 152B may provide Evolved UMTS Terrestrial Radio Access (E UTRA) protocol terminations over a Uu interface associated with a second protocol stack.

[0056] The 5G-CN 155 may authenticate UEs 151, set up end-to-end connections between UEs 151 and the one or more DNs 158, and provide charging functionality. The 5G-CN 155 may be based on a service-Docket No.: 25-1021 PCTbased architecture, in which the NFs making up the 5G-CN 155 offer services to each other and to other elements of the communication network 150 via interfaces. The 5G-CN 155 may include any number of other NFs and any number of instances of each NF.

[0057] FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D illustrate various examples of a framework for a servicebased architecture within a core network. In a service-based architecture, a service may be sought by a service consumer and provided by a service producer. Prior to obtaining a particular service, an NF may determine where such a service can be obtained. To discover a service, the NF may communicate with a network repository function (NRF). As an example, an NF that provides one or more services may register with a network repository function (NRF). The NRF may store data relating to the one or more services that the NF is prepared to provide to other NFs in the service-based architecture. A consumer NF may query the NRF to discover a producer NF (for example, by obtaining from the NRF a list of NF instances that provide a particular service).

[0058] In the example of FIG. 2A, an NF 211 (a consumer NF in this example) may send a request 221 to an NF 212 (a producer NF). The request 221 may be a request for a particular service and may be sent based on a discovery that NF 212 is a producer of that service. The request 221 may comprise data relating to NF 211 and / or the requested service. The NF 212 may receive request 221, perform one or more actions associated with the requested service (e.g., retrieving data), and provide a response 221 . The one or more actions performed by the NF 212 may be based on request data included in the request 221 , data stored by NF 212, and / or data retrieved by NF 212. The response 222 may notify NF 211 that the one or more actions have been completed. The response 222 may comprise response data relating to NF 212, the one or more actions, and / or the requested service.

[0059] In the example of FIG. 2B, an NF 231 sends a request 241 to an NF 232. In this example, part of the service produced by NF 232 is to send a request 242 to an NF 233. The NF 233 may perform one or more actions and provide a response 243 to NF 232. Based on response 243, NF 232 may send a response 244 to NF 231. It will be understood from FIG. 2B that a single NF may perform the role of producer of services, consumer of services, or both. A particular NF service may include any number of nested NF services produced by one or more other NFs.

[0060] FIG. 2C illustrates examples of subscribe-notify interactions between a consumer NF and a producer NF. In FIG. 2C, an NF 251 sends a subscription 261 to an NF 252. An NF 253 sends a subscription 262 to the NF 252. Two NFs are shown in FIG. 2C for illustrative purposes (to demonstrate that the NF 252 may provide multiple subscription services to different NFs), but it will be understood that a subscribe-notify interaction only requires one subscriber. The NFs 251, 253 may be independent from one another. For example, the NFs 251 , 253 may independently discover NF 252 and / or independently determine to subscribe to the service offered by NF 252. In response to receipt of a subscription, the NFDocket No.: 25-1021 PCT252 may provide a notification to the subscribing NF. For example, NF 252 may send a notification 263 to NF 251 based on subscription 261 and may send a notification 264 to NF 253 based on subscription 262.

[0061] As shown in the example illustration of FIG. 2C, the sending of the notifications 263, 264 may be based on a determination that a condition has occurred. For example, the notifications 263, 264 may be based on a determination that a particular event has occurred, a determination that a particular condition is outstanding, and / or a determination that a duration of time associated with the subscription has elapsed (for example, a period associated with a subscription for periodic notifications). As shown in the example illustration of FIG. 2C, NF 252 may send notifications 263, 264 to NFs 251 , 253 simultaneously and / or in response to the same condition. However, it will be understood that the NF 252 may provide notifications at different times and / or in response to different notification conditions. In an example, the NF 251 may request a notification when a certain parameter, as measured by the NF 252, exceeds a first threshold, and the NF 252 may request a notification when the parameter exceeds a second threshold different from the first threshold. In an example, a parameter of interest and / or a corresponding threshold may be indicated in the subscriptions 261 , 262.

[0062] FIG. 2D illustrates another example of a subscribe-notify interaction. In FIG. 2D, an NF 271 sends a subscription 281 to an NF 272. In response to receipt of subscription 281 and / or a determination that a notification condition has occurred, NF 272 may send a notification 284. The notification 284 may be sent to an NF 273. Unlike the example in FIG. 20 (in which a notification is sent to the subscribing NF), FIG. 2D demonstrates that a subscription and its corresponding notification may be associated with different NFs. For example, NF 271 may subscribe to the service provided by NF 272 on behalf of NF 273.

[0063] FIG. 3 illustrates another example communication network 300 in which embodiments of the present disclosure may be implemented. Communication network 300 includes a user equipment (UE) 301, an access network (AN) 302, and a data network (DN) 308. The remaining elements depicted in FIG. 3 may be included in and / or associated with a core network. Each element of the core network may be referred to as a network function (NF).

[0064] The NFs depicted in FIG. 3 include a user plane function (UPF) 305, an access and mobility management function (AMF) 312, a session management function (SMF) 314, a policy control function (PCF) 320, a network repository function (NRF) 330, a network exposure function (NEF) 340, a unified data management (UDM) 350, an authentication server function (AUSF) 360, a network slice selection function (NSSF) 370, a charging function (CHF) 380, a network data analytics function (NWDAF) 390, and an application function (AF) 399. The UPF 305 may be a user-plane core network function, whereas the NFs 312, 314, and 320-390 may be control-plane core network functions. Although not shown in the example of FIG 3, the core network may include additional instances of any of the NFs depicted and / or one or more different NF types that provide different services. Other examples of NF type include a gateway mobileDocket No.: 25-1021 PCTlocation center (GMLC), a location management function (LMF), an operations, administration, and maintenance function (OAM), a public warning system (PWS), a short message service function (SMSF), a unified data repository (UDR), and an unstructured data storage function (UDSF).

[0065] Each element depicted in FIG. 3 has an interface with at least one other element. The interface may be a logical connection rather than, for example, a direct physical connection. Any interface may be identified using a reference point representation and / or a service-based representation. In a reference point representation, the letter ‘N’ is followed by a numeral, indicating an interface between two specific elements. For example, as shown in FIG. 3, AN 302 and UPF 305 interface via 'N3', whereas UPF 305 and DN 308 interface via W . By contrast, in a service-based representation, the letter ‘N’ is followed by letters. The letters identify an NF that provides services to the core network. For example, PCF 320 may provide services via interface ‘Npcf . The PCF 320 may provide services to any NF in the core network via ‘Npcf . Accordingly, a service-based representation may correspond to a bundle of reference point representations. For example, the Npcf interface between PCF 320 and the core network generally may correspond to an N7 interface between PCF 320 and SMF 314, an N30 interface between PCF 320 and NEF 340, etc.

[0066] The UPF 305 may serve as a gateway for user plane traffic between AN 302 and DN 308. The UE 301 may connect to UPF 305 via a Uu interface and an N3 interface (also described as NG U interface). The UPF 305 may connect to DN 308 via an N6 interface. The UPF 305 may connect to one or more other UPFs (not shown) via an N9 interface. The UE 301 may be configured to receive services through a protocol data unit (PDU) session, which is a logical connection between UE 301 and DN 308. The UPF 305 (or a plurality of UPFs if desired) may be selected by SMF 314 to handle a particular PDU session between UE 301 and DN 308. The SMF 314 may control the functions of UPF 305 with respect to the PDU session. The SMF 314 may connect to UPF 305 via an N4 interface. The UPF 305 may handle any number of PDU sessions associated with any number of UEs (via any number of ANs). For purposes of handling the one or more PDU sessions, UPF 305 may be controlled by any number of SMFs via any number of corresponding N4 interfaces.

[0067] The AMF 312 depicted in FIG. 3 may control UE access to the core network. The UE 301 may register with the network via AMF 312. It may be necessary for UE 301 to register prior to establishing a PDU session. The AMF 312 may manage a registration area of UE 301, enabling the network to track the physical location of UE 301 within the network. For a UE in connected mode, AMF 312 may manage UE mobility, for example, handovers from one AN or portion thereof to another. For a UE in idle mode, AMF 312 may perform registration updates and / or page the UE to transition the UE to connected mode.

[0068] The AMF 312 may receive, from UE 301 , non-access stratum (NAS) messages transmitted in accordance with NAS protocol. NAS messages relate to communications between UE 301 and the coreDocket No.: 25-1021 PCTnetwork. Although NAS messages may be relayed to AMF 312 via AN 302, they may be described as communications via the N1 interface. NAS messages may facilitate UE registration and mobility management, for example, by authenticating, identifying, configuring, and / or managing a connection of UE 301. NAS messages may support session management procedures for maintaining user plane connectivity and quality of service (QoS) of a session between UE 301 and DN 309. If the NAS message involves session management, AMF 312 may send the NAS message to SMF 314. NAS messages may be used to transport messages between UE 301 and other components of the core network (e.g., core network components other than AMF 312 and SMF 314). The AMF 312 may act on a particular NAS message itself, or alternatively, forward the NAS message to an appropriate core network function (e.g., SMF 314, etc.)

[0069] The SMF 314 depicted in FIG. 3 may establish, modify, and / or release a PDU session based on messaging received UE 301. The SMF 314 may allocate, manage, and / or assign an IP address to UE 301, for example, upon establishment of a PDU session. There may be multiple SMFs in the network, each of which may be associated with a respective group of wireless devices, base stations, and / or UPFs. A UE with multiple PDU sessions may be associated with a different SMF for each PDU session. As noted above, SMF 314 may select one or more UPFs to handle a PDU session and may control the handling of the PDU session by the selected UPF by providing rules for packet handling (PDR, FAR, QER, etc.). Rules relating to QoS and / or charging for a particular PDU session may be obtained from PCF 320 and provided to UPF 305.

[0070] The PCF 320 may provide, to other NFs, services relating to policy rules. The PCF 320 may use subscription data and information about network conditions to determine policy rules and then provide the policy rules to a particular NF which may be responsible for enforcement of those rules. Policy rules may relate to policy control for access and mobility, and may be enforced by the AMF. Policy rules may relate to session management, and may be enforced by the SMF 314. Policy rules may be, for example, networkspecific, wireless device-specific, session-specific, or data flow-specific.

[0071] The NRF 330 may provide service discovery. The NRF 330 may belong to a particular PLMN. The NRF 330 may maintain NF profiles relating to other NFs in the communication network 300. The NF profile may include, for example, an address, PLMN, and / or type of the NF, a slice identifier, a list of the one or more services provided by the NF, and the authorization required to access the services.

[0072] The NEF 340 depicted in FIG. 3 may provide an interface to external domains, permitting external domains to selectively access the control plane of the communication network 300. The external domain may comprise, for example, third-party network functions, application functions, etc. The NEF 340 may act as a proxy between external elements and network functions such as AMF 312, SMF 314, PCF 320, UDM 350, etc As an example, NEF 340 may determine a location or reachability status of UE 301 based on reports from AMF 312, and provide status information to an external element. As an example, an externalDocket No.: 25-1021 PCTelement may provide, via NEF 340, information that facilitates the setting of parameters for establishment of a PDU session. The NEF 340 may determine which data and capabilities of the control plane are exposed to the external domain. The NEF 340 may provide secure exposure that authenticates and / or authorizes an external entity to which data or capabilities of the communication network 300 are exposed. The NEF 340 may selectively control the exposure such that the internal architecture of the core network is hidden from the external domain.

[0073] The UDM 350 may provide data storage for other NFs. The UDM 350 may permit a consolidated view of network information that may be used to ensure that the most relevant information can be made available to different NFs from a single resource. The UDM 350 may store and / or retrieve information from a unified data repository (UDR). For example, UDM 350 may obtain user subscription data relating to UE 301 from the UDR.

[0074] The AUSF 360 may support mutual authentication of UE 301 by the core network and authentication of the core network by UE 301. The AUSF 360 may perform key agreement procedures and provide keying material that can be used to improve security.

[0075] The NSSF 370 may select one or more network slices to be used by the UE 301. The NSSF 370 may select a slice based on slice selection information. For example, the NSSF 370 may receive Single Network Slice Selection Assistance Information (S NSSAI) and map the S NSSAI to a network slice instance identifier (NSI).

[0076] The CHF 380 may control billing-related tasks associated with UE 301. For example, UPF 305 may report traffic usage associated with UE 301 to SMF 314. The SMF 314 may collect usage data from UPF 305 and one or more other UPFs. The usage data may indicate how much data is exchanged, what DN the data is exchanged with, a network slice associated with the data, or any other information that may influence billing. The SMF 314 may share the collected usage data with the CHF. The CHF may use the collected usage data to perform billing-related tasks associated with UE 301. The CHF may, depending on the billing status of UE 301 , instruct SMF 314 to limit or influence access of UE 301 and / or to provide billing-related notifications to UE 301.

[0077] The NWDAF 390 may collect and analyze data from other network functions and offer data analysis services to other network functions. As an example, NWDAF 390 may collect data relating to a load level for a particular network slice instance from UPF 305, AMF 312, and / or SMF 314. Based on the collected data, NWDAF 390 may provide load level data to the PCF 320 and / or NSSF 370, and / or notify the PC220 and / or NSSF 370 if load level for a slice reaches and / or exceeds a load level threshold.

[0078] The AF 399 may be outside the core network, but may interact with the core network to provide information relating to the QoS requirements or traffic routing preferences associated with a particular application. The AF 399 may access the core network based on the exposure constraints imposed by theDocket No.: 25-1021 PCTNEF 340. However, an operator of the core network may consider the AF 399 to be a trusted domain that can access the network directly.

[0079] FIGS. 4A, 4B, and 5 illustrate other examples of core network architectures that are analogous in some respects to the core network architecture 300 depicted in FIG. 3. For conciseness, some of the core network elements depicted in FIG. 3 are omitted. Many of the elements depicted in FIGS.4A, 4B, and 5 are analogous in some respects to elements depicted in FIG. 3. For conciseness, some of the details relating to their functions or operation are omitted.

[0080] FIG. 4A illustrates an example of a core network architecture 400A comprising an arrangement of multiple UPFs. Core network architecture 400A includes a UE 401 , an AN 402, an AMF 412, and an SMF 414 Unlike previous examples of core network architectures described above, FIG. 4A depicts multiple UPFs, including a UPF 405, a UPF 406, and a UPF 407, and multiple DNs, including a DN 408 and a DN 409. Each of the multiple UPFs 405, 406, 407 may communicate with the SMF 414 via an N4 interface. The DNs 408, 409 communicate with the UPFs 405, 406, respectively, via N6 interfaces. As shown in FIG. 4A, the multiple UPFs 405, 406, 407 may communicate with one another via N9 interfaces.

[0081] The UPFs 405, 406, 407 may perform traffic detection, in which the UPFs identify and / or classify packets. Packet identification may be performed based on packet detection rules (PDR) provided by the SMF 414. A PDR may include packet detection information comprising one or more of: a source interface, a UE IP address, core network (CN) tunnel information (e.g . , a CN address of an N3 / N9 tunnel corresponding to a PDU session), a network instance identifier, a quality of service flow identifier (QFI), a filter set (for example, an IP packet filter set or an ethernet packet filter set), and / or an application identifier.

[0082] In addition to indicating how a particular packet is to be detected, a PDR may further indicate rules for handling the packet upon detection thereof. The rules may include, for example, forwarding action rules (FARs), multi-access rules (MARs), usage reporting rules (URRs), QoS enforcement rules (QERs), etc. For example, the PDR may comprise one or more FAR identifiers, MAR identifiers, URR identifiers, and / or QER identifiers. These identifiers may indicate the rules that are prescribed for the handling of a particular detected packet.

[0083] The UPF 405 may perform traffic forwarding in accordance with a FAR. For example, the FAR may indicate that a packet associated with a particular PDR is to be forwarded, duplicated, dropped, and / or buffered. The FAR may indicate a destination interface, for example, "access” for downlink or “core” for uplink. If a packet is to be buffered, the FAR may indicate a buffering action rule (BAR). As an example, UPF 405 may perform data buffering of a certain number of downlink packets if a PDU session is deactivated.

[0084] The UPF 405 may perform QoS enforcement in accordance with a QER. For example, the QER may indicate a guaranteed bitrate that is authorized and / or a maximum bitrate to be enforced for a packetDocket No.: 25-1021 PCTassociated with a particular PDR. The QER may indicate that a particular guaranteed and / or maximum bitrate may be for uplink packets and / or downlink packets. The UPF 405 may mark packets belonging to a particular QoS flow with a corresponding QFI. The marking may enable a recipient of the packet to determine a QoS of the packet.

[0085] The UPF 405 may provide usage reports to the SMF 414 in accordance with a URR. The URR may indicate one or more triggering conditions for generation and reporting of the usage report, for example, immediate reporting, periodic reporting, a threshold for incoming uplink traffic, or any other suitable triggering condition. The URR may indicate a method for measuring usage of network resources, for example, data volume, duration, and / or event.

[0086] As noted above, the DNs 408, 409 may comprise public DNs (e.g., the Internet), private DNs (e.g., private, internal corporate-owned DNs), and / or intra-operator DNs. Each DN may provide an operator service and / or a third-party service. The service provided by a DN may be the Internet, an IP multimedia subsystem (IMS), an augmented or virtual reality network, an edge computing or mobile edge computing (MEG) network, etc. Each DN may be identified using a data network name (DNN). The UE 401 may be configured to establish a first logical connection with DN 408 (a first PDU session), a second logical connection with DN 409 (a second PDU session), or both simultaneously (first and second PDU sessions).

[0087] Each PDU session may be associated with at least one UPF configured to operate as a PDU session anchor (PSA, or “anchor”). The anchor may be a UPF that provides an N6 interface with a DN.

[0088] In the example of FIG. 4A, UPF 405 may be the anchor for the first PDU session between UE 401 and DN 408, whereas the UPF 406 may be the anchor for the second PDU session between UE 401 and DN 409. The core network may use the anchor to provide service continuity of a particular PDU session (for example, IP address continuity) as UE 401 moves from one access network to another. For example, suppose that UE 401 establishes a PDU session using a data path to the DN 408 using an access network other than AN 402. The data path may include UPF 405 acting as anchor. Suppose further that the UE 401 later moves into the coverage area of the AN 402. In such a scenario, SMF 414 may select a new UPF (UPF 407) to bridge the gap between the newly-entered access network (AN 402) and the anchor UPF (UPF 405). The continuity of the PDU session may be preserved as any number of UPFs are added or removed from the data path. When a UPF is added to a data path, as shown in FIG. 4A, it may be described as an intermediate UPF and / or a cascaded UPF.

[0089] As noted above, UPF 406 may be the anchor for the second PDU session between UE 401 and DN 409. Although the anchor for the first and second PDU sessions are associated with different UPFs in FIG. 4A, it will be understood that this is merely an example. It will also be understood that multiple PDU sessions with a single DN may correspond to any number of anchors. When there are multiple UPFs, aDocket No.: 25-1021 PCTUPF at the branching point (UPF 407 in FIG. 4A) may operate as an uplink classifier (UL-CL). The UL-CL may divert uplink user plane traffic to different UPFs.

[0090] The SMF 414 may allocate, manage, and / or assign an IP address to UE 401 , for example, upon establishment of a PDU session. The SMF 414 may maintain an internal pool of IP addresses to be assigned. The SMF 414 may, if necessary, assign an IP address provided by a dynamic host configuration protocol (DHCP) server or an authentication, authorization, and accounting (AAA) server. IP address management may be performed in accordance with a session and service continuity (SSC) mode. In SSC mode 1 , an IP address of UE 401 may be maintained (and the same anchor UPF may be used) as the wireless device moves within the network. In SSC mode 2, the IP address of UE 401 changes as UE 401 moves within the network (e.g., the old IP address and UPF may be abandoned and a new IP address and anchor UPF may be established). In SSC mode 3, it may be possible to maintain an old IP address (similar to SSC mode 1) temporarily while establishing a new IP address (similar to SSC mode 2), thus combining features of SSC modes 1 and 2. Applications that are sensitive to IP address changes may operate in accordance with SSC mode 1.

[0091] UPF selection may be controlled by SMF 414. For example, upon establishment and / or modification of a PDU session between UE 401 and DN 408, SMF 414 may select UPF 405 as the anchor for the PDU session and / or UPF 407 as an intermediate UPF. Criteria for UPF selection include path efficiency and / or speed between AN 402 and DN 408. The reliability, load status, location, slice support and / or other capabilities of candidate UPFs may also be considered.

[0092] FIG. 4B illustrates an example of a core network architecture 400B that accommodates untrusted access. Similar to FIG. 4A, UE 401 as depicted in FIG. 4B connects to DN 408 via AN 402 and UPF 405. The AN 402 and UPF 405 constitute trusted (e.g., 3GPP) access to the DN 408. By contrast, UE 401 may also access DN 408 using an untrusted access network, AN 403, and a non-3GPP interworking function (N3IWF) 404.

[0093] The AN 403 may be, for example, a wireless land area network (WLAN) operating in accordance with the IEEE 802.11 standard. The UE 401 may connect to AN 403, via an interface Y1, in whatever manner is prescribed for AN 403. The connection to AN 403 may or may not involve authentication. The UE 401 may obtain an IP address from AN 403. The UE 401 may determine to connect to core network 400B and select untrusted access for that purpose. The AN 403 may communicate with N3IWF 404 via a Y2 interface. After selecting untrusted access, the UE 401 may provide N3IWF 404 with sufficient information to select an AMF. The selected AMF may be, for example, the same AMF that is used by UE 401 for 3GPP access (AMF 412 in the present example). The N3IWF 404 may communicate with AMF 412 via an N2 interface. The UPF 405 may be selected and N3IWF 404 may communicate with UPF 405 via an N3Docket No.: 25-1021 PCTinterface. The UPF 405 may be a PDU session anchor (PSA) and may remain the anchor for the PDU session even as UE 401 shifts between trusted access and untrusted access.

[0094] FIG. 5 illustrates an example of a core network architecture 500 in which a UE 501 is in a roaming scenario. In a roaming scenario, UE 501 is a subscriber of a first PLMN (a home PLMN, or HPLMN) but attaches to a second PLMN (a visited PLMN, or VPLMN). Core network architecture 500 includes UE 501, an AN 502, a UPF 505, and a DN 508. The AN 502 and UPF 505 may be associated with a VPLMN. The VPLMN may manage the AN 502 and UPF 505 using core network elements associated with the VPLMN, including an AMF 512, an SMF 514, a PCF 520, an NRF 530, an NEF 540, and an NSSF 570. An AF 599 may be adjacent the core network of the VPLMN.

[0095] The UE 501 may not be a subscriber of the VPLMN. The AMF 512 may authorize UE 501 to access the network based on, for example, roaming restrictions that apply to UE 501. In order to obtain network services provided by the VPLMN, it may be necessary for the core network of the VPLMN to interact with core network elements of a HPLMN of UE 501 , in particular, a PCF 521 , an NRF 531 , an NEF 541, a UDM 551, and / or an AUSF 561. The VPLMN and HPLMN may communicate using an N32 interface connecting respective security edge protection proxies (SEPPs). In FIG. 5, the respective SEPPs are depicted as a VSEPP 590 and an HSEPP 591.

[0096] The VSEPP 590 and the HSEPP 591 communicate via an N32 interface for defined purposes while concealing information about each PLMN from the other. The SEPPs may apply roaming policies based on communications via the N32 interface. The PCF 520 and PCF 521 may communicate via the SEPPs to exchange policy-related signaling. The NRF 530 and NRF 531 may communicate via the SEPPs to enable service discovery of NFs in the respective PLMNs. The VPLMN and HPLMN may independently maintain NEF 540 and NEF 541. The NSSF 570 and NSSF 571 may communicate via the SEPPs to coordinate slice selection for UE 501. The HPLMN may handle all authentication and subscription related signaling. For example, when the UE 501 registers or requests service via the VPLMN, the VPLMN may authenticate UE 501 and / or obtain subscription data of UE 501 by accessing, via the SEPPs, the UDM 551 and AUSF 561 of the HPLMN.

[0097] The core network architecture 500 depicted in FIG. 5 may be referred to as a local breakout configuration, in which UE 501 accesses DN 508 using one or more UPFs of the VPLMN (i.e., UPF 505). However, other configurations are possible. For example, in a home-routed configuration (not shown in FIG. 5), UE 501 may access a DN using one or more UPFs of the HPLMN. In the home-routed configuration, an N9 interface may run parallel to the N32 interface, crossing the frontier between the VPLMN and the HPLMN to carry user plane data. One or more SMFs of the respective PLMNs may communicate via the N32 interface to coordinate session management for UE 501. The SMFs may control their respective UPFs on either side of the frontier.Docket No.: 25-1021 PCT

[0098] FIG. 6 illustrates an example of network slicing. Network slicing may refer to division of shared infrastructure (e.g., physical infrastructure) into distinct logical networks. These distinct logical networks may be independently controlled, isolated from one another, and / or associated with dedicated resources.

[0099] Network architecture 600A illustrates an un-sliced physical network corresponding to a single logical network. The network architecture 600A comprises a user plane wherein UEs 601 A, 601 B, 601 C (collectively, UEs 601) have a physical and logical connection to a DN 608 via an AN 602 and a UPF 605. The network architecture 600A comprises a control plane wherein an AMF 612 and a SMF 614 control various aspects of the user plane.

[0100] The network architecture 600A may have a specific set of characteristics (e.g., relating to maximum bit rate, reliability, latency, bandwidth usage, power consumption, etc.). This set of characteristics may be affected by the nature of the network elements themselves (e.g., processing power, availability of free memory, proximity to other network elements, etc.) or the management thereof (e.g., optimized to maximize bit rate or reliability, reduce latency or power bandwidth usage, etc.). The characteristics of network architecture 600A may change over time, for example, by upgrading equipment or by modifying procedures to target a particular characteristic. However, at any given time, network architecture 600A will have a single set of characteristics that may or may not be optimized for a particular use case. For example, UEs 601 A, 601 B, 601 C may have different requirements, but network architecture 600A can only be optimized for one of the three.

[0101] Network architecture 600B is an example of a sliced physical network divided into multiple logical networks. In FIG. 6, the physical network is divided into three logical networks, referred to as slice A, slice B, and slice C. For example, UE 601 A may be served by AN 602A, UPF 605A, AMF 612, and SMF 614A. UE 601B may be served by AN 602B, UPF 605B, AMF 612, and SMF 614B. UE 601C may be served by AN 602C, UPF 605C, AMF 612, and SMF 614C. Although the respective UEs 601 communicate with different network elements from a logical perspective, these network elements may be deployed by a network operator using the same physical network elements.

[0102] Each network slice may be tailored to network services having different sets of characteristics. For example, slice A may correspond to enhanced mobile broadband (eMBB) service. Mobile broadband may refer to internet access by mobile users, commonly associated with smartphones Slice B may correspond to ultra-reliable low-latency communication (URLLC), which focuses on reliability and speed. Relative to eMBB, URLLC may improve the feasibility of use cases such as autonomous driving and telesurgery. Slice C may correspond to massive machine type communication (mMTC), which focuses on low-power services delivered to a large number of users. For example, slice C may be optimized for a dense network of battery-powered sensors that provide small amounts of data at regular intervals. Many mMTC use cases would be prohibitively expensive if they operated using an eMBB or URLLC network.Docket No.: 25-1021 PCT

[0103] If the service requirements for one of the UEs 601 changes, then the network slice serving that UE can be updated to provide better service. Moreover, the set of network characteristics corresponding to eMBB, URLLC, and mMTC may be varied, such that differentiated species of eMBB, URLLC, and mMTC are provided. Alternatively, network operators may provide entirely new services in response to, for example, customer demand.

[0104] In FIG. 6, each of the UEs 601 has its own network slice. However, it will be understood that a single slice may serve any number of UEs and a single UE may operate using any number of slices. Moreover, in the example network architecture 600B, the AN 602, UPF 605 and SMF 614 are separated into three separate slices, whereas the AMF 612 is unsliced. However, it will be understood that a network operator may deploy any architecture that selectively utilizes any mix of sliced and unsliced network elements, with different network elements divided into different numbers of slices. Although FIG. 6 only depicts three core network functions, it will be understood that other core network functions may be sliced as well. A PLMN that supports multiple network slices may maintain a separate network repository function (NFR) for each slice, enabling other NFs to discover network services associated with that slice.

[0105] Network slice selection may be controlled by an AMF, or alternatively, by a separate network slice selection function (NSSF). For example, a network operator may define and implement distinct network slice instances (NSIs). Each NSI may be associated with single network slice selection assistance information (S NSSAI). The S NSSAI may include a particular slice / service type (SST) indicator (indicating eMBB, URLLC, mMTC, etc.). As an example, a particular tracking area may be associated with one or more configured S NSSAIs. UEs may identify one or more requested and / or subscribed S NSSAIs (e.g., during registration). The network may indicate to the UE one or more allowed and / or rejected S NSSAIs.

[0106] The S NSSAI may further include a slice differentiator (SD) to distinguish between different tenants of a particular slice and / or service type. For example, a tenant may be a customer (e.g., vehicle manufacture, service provider, etc.) of a network operator that obtains (for example, purchases) guaranteed network resources and / or specific policies for handling its subscribers. The network operator may configure different slices and / or slice types, and use the SD to determine which tenant is associated with a particular slice.

[0107] FIG. 7A, FIG. 7B, and FIG. 7C illustrate a user plane (UP) protocol stack, a control plane (CP) protocol stack, and services provided between protocol layers of the UP protocol stack.

[0108] The layers may be associated with an open system interconnection (OSI) model of computer networking functionality. In the OSI model, layer 1 may correspond to the bottom layer, with higher layers on top of the bottom layer. Layer 1 may correspond to a physical layer, which is concerned with the physical infrastructure used for transfer of signals (for example, cables, fiber optics, and / or radio frequency transceivers). In New Radio (NR), layer 1 may comprise a physical layer (PHY). Layer 2 may correspond toDocket No.: 25-1021 PCTa data link layer. Layer 2 may be concerned with packaging of data (into, e.g., data frames) for transfer, between nodes of the network, using the physical infrastructure of layer 1. In NR, layer 2 may comprise a media access control layer (MAC), a radio link control layer (RLC), a packet data convergence layer (PDCP), and a service data application protocol layer (SDAP).

[0109] Layer 3 may correspond to a network layer. Layer 3 may be concerned with routing of the data which has been packaged in layer 2. Layer 3 may handle prioritization of data and traffic avoidance. In NR, layer 3 may comprise a radio resource control layer (RRC) and a non-access stratum layer (NAS). Layers 4 through 7 may correspond to a transport layer, a session layer, a presentation layer, and an application layer. The application layer interacts with an end user to provide data associated with an application. In an example, an end user implementing the application may generate data associated with the application and initiate sending of that information to a targeted data network (e.g., the Internet, an application server, etc.). Starting at the application layer, each layer in the OSI model may manipulate and / or repackage the information and deliver it to a lower layer. At the lowest layer, the manipulated and / or repackaged information may be exchanged via physical infrastructure (for example, electrically, optically, and / or electromagnetically). As it approaches the targeted data network, the information will be unpackaged and provided to higher and higher layers, until it once again reaches the application layer in a form that is usable by the targeted data network (e.g., the same form in which it was provided by the end user). To respond to the end user, the data network may perform this procedure in reverse.

[0110] FIG. 7A illustrates a user plane protocol stack. The user plane protocol stack may be a new radio (NR) protocol stack for a Uu interface between a UE 701 and a gNB 702. In layer 1 of the UP protocol stack, the UE 701 may implement PHY 731 and the gNB 702 may implement PHY 732. In layer 2 of the UP protocol stack, the UE 701 may implement MAC 741, RLC 751, PDCP 761, and SDAP 771. The gNB 702 may implement MAC 742, RLC 752, PDCP 762, and SDAP 772.

[0111] FIG. 7B illustrates a control plane protocol stack. The control plane protocol stack may be an NR protocol stack for the Uu interface between the UE 701 and the gNB 702 and / or an N1 interface between the UE 701 and an AMF 712. In layer 1 of the CP protocol stack, the UE 701 may implement PHY 731 and the gNB 702 may implement PHY 732. In layer 2 of the CP protocol stack, the UE 701 may implement MAC 741 , RLC 751 , PDCP 761 , RRC 781 , and NAS 791. The gNB 702 may implement MAC 742, RLC 752, PDCP 762, and RRC 782. The AMF 712 may implement NAS 792.

[0112] The NAS may be concerned with the non-access stratum, in particular, communication between the UE 701 and the core network (e.g., the AMF 712). Lower layers may be concerned with the access stratum, for example, communication between the UE 701 and the gNB 702. Messages sent between the UE 701 and the core network may be referred to as NAS messages. In an example, a NAS message mayDocket No.: 25-1021 PCTbe relayed by the gNB 702, but the content of the NAS message (e.g., information elements of the NAS message) may not be visible to the gNB 702.

[0113] FIG. 7C illustrates an example of services provided between protocol layers of the NR user plane protocol stack illustrated in FIG. 7A. The UE 701 may receive services through a PDU session, which may be a logical connection between the UE 701 and a data network (DN). The UE 701 and the DN may exchange data packets associated with the PDU session. The PDU session may comprise one or more quality of service (QoS) flows. SDAP 771 and SDAP 772 may perform mapping and / or demapping between the one or more QoS flows of the PDU session and one or more radio bearers (e.g., data radio bearers). The mapping between the QoS flows and the data radio bearers may be determined in the SDAP 772 by the gNB 702, and the UE 701 may be notified of the mapping (e g., based on control signaling and / or reflective mapping). For reflective mapping, the SDAP 772 of the gNB 220 may mark downlink packets with a QoS flow indicator (QFI) and deliver the downlink packets to the UE 701. The UE 701 may determine the mapping based on the QFI of the downlink packets.

[0114] PDCP 761 and PDCP 762 may perform header compression and / or decompression. Header compression may reduce the amount of data transmitted over the physical layer. The PDCP 761 and PDCP 762 may perform ciphering and / or deciphering. Ciphering may reduce unauthorized decoding of data transmitted over the physical layer (e.g., intercepted on an air interface), and protect data integrity (e.g., to ensure control messages originate from intended sources). The PDCP 761 and PDCP 762 may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, duplication of packets, and / or identification and removal of duplicate packets. In a dual connectivity scenario, PDCP 761 and PDCP 762 may perform mapping between a split radio bearer and RLC channels.

[0115] RLC 751 and RLC 752 may perform segmentation, retransmission through Automatic Repeat Request (ARQ). The RLC 751 and RLC 752 may perform removal of duplicate data units received from MAC 741 and MAC 742, respectively. The RLCs 213 and 223 may provide RLC channels as a service to PDCPs 214 and 224, respectively.

[0116] MAC 741 and MAC 742 may perform multiplexing and / or demultiplexing of logical channels. MAC 741 and MAC 742 may map logical channels to transport channels. In an example, UE 701 may, in MAC 741 , multiplex data units of one or more logical channels into a transport block. The UE 701 may transmit the transport block to the gNB 702 using PHY 731. The gNB 702 may receive the transport block using PHY 732 and demultiplex data units of the transport blocks back into logical channels. MAC 741 and MAC 742 may perform error correction through Hybrid Automatic Repeat Request (HARQ), logical channel prioritization, and / or padding.

[0117] PHY 731 and PHY 732 may perform mapping of transport channels to physical channels. PHY 731 and PHY 732 may perform digital and analog signal processing functions (e.g., coding / decoding andDocket No.: 25-1021 PCTmodulation / demodulation) for sending and receiving information (e.g., transmission via an air interface). PHY 731 and PHY 732 may perform multi-antenna mapping.

[0118] FIG. 8 illustrates an example of a quality of service (QoS) model for differentiated data exchange. In the QoS model of FIG. 8, there are a UE 801 , a AN 802, and a UPF 805. The QoS model facilitates prioritization of certain packet or protocol data units (PDUs), also referred to as packets. For example, higher-priority packets may be exchanged faster and / or more reliably than lower-priority packets. The network may devote more resources to exchange of high-QoS packets.

[0119] In the example of FIG. 8, a PDU session 810 is established between UE 801 and UPF 805. The PDU session 810 may be a logical connection enabling the UE 801 to exchange data with a particular data network (for example, the Internet). The UE 801 may request establishment of the PDU session 810. At the time that the PDU session 810 is established, the UE 801 may, for example, identify the targeted data network based on its data network name (DNN). The PDU session 810 may be managed, for example, by a session management function (SMF, not shown). In order to facilitate exchange of data associated with the PDU session 810, between the UE 801 and the data network, the SMF may select the UPF 805 (and optionally, one or more other UPFs, not shown).

[0120] One or more applications associated with UE 801 may generate uplink packets 812A-812E associated with the PDU session 810. In order to work within the QoS model, UE 801 may apply QoS rules 814 to uplink packets 812A-812E. The QoS rules 814 may be associated with PDU session 810 and may be determined and / or provided to the UE 801 when PDU session 810 is established and / or modified. Based on QoS rules 814, UE 801 may classify uplink packets 812A-812E, map each of the uplink packets 812A-812E to a QoS flow, and / or mark uplink packets 812A-812E with a QoS flow indicator (QFI). As a packet travels through the network, and potentially mixes with other packets from other UEs having potentially different priorities, the QFI indicates how the packet should be handled in accordance with the QoS model. In the present illustration, uplink packets 812A, 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.

[0121] The QoS flows may be the finest granularity of QoS differentiation in a PDU session. In the figure, three QoS flows 816A-816C are illustrated. However, it will be understood that there may be any number of QoS flows Some QoS flows may be associated with a guaranteed bit rate (GBR QoS flows) and others may have bit rates that are not guaranteed (non-GBR QoS flows). QoS flows may also be subject to per-UE and per-session aggregate bit rates. One of the QoS flows may be a default QoS flow. The QoS flows may have different priorities. For example, QoS flow 816A may have a higher priority than QoS flow 816B, which may have a higher priority than QoS flow 816C. Different priorities may be reflected by different QoS flow characteristics. For example, QoS flows may be associated with flow bit rates. A particular QoS flow may be associated with a guaranteed flow bit rate (GFBR) and / or a maximum flow bit rate (MFBR). QoSDocket No.: 25-1021 PCTflows may be associated with specific packet delay budgets (PDBs), packet error rates (PERs), and / or maximum packet loss rates. QoS flows may also be subject to per-UE and per-session aggregate bit rates.

[0122] In order to work within the QoS model, UE 801 may apply resource mapping rules 818 to the QoS flows 816A-816C. The air interface between UE 801 and AN 802 may be associated with resources 820. In the present illustration, QoS flow 816A is mapped to resource 820A, whereas QoS flows 816B, 816C are mapped to resource 820B. The resource mapping rules 818 may be provided by the AN 802. In order to meet QoS requirements, the resource mapping rules 818 may designate more resources for relatively high-priority QoS flows. With more resources, a high-priority QoS flow such as QoS flow 816A may be more likely to obtain the high flow bit rate, low packet delay budget, or other characteristic associated with QoS rules 814. The resources 820 may comprise, for example, radio bearers. The radio bearers (e.g., data radio bearers) may be established between the UE 801 and the AN 802. The radio bearers in 5G, between the UE 801 and the AN 802, may be distinct from bearers in LTE, for example, Evolved Packet System (EPS) bearers between a UE and a packet data network gateway (PGW), S1 bearers between an eNB and a serving gateway (SGW), and / or an S5 / S8 bearer between an SGW and a PGW.

[0123] Once a packet associated with a particular QoS flow is received at AN 802 via resource 820A or resource 820B, AN 802 may separate packets into respective QoS flows 856A-856C based on QoS profiles 828. The QoS profiles 828 may be received from an SMF. Each QoS profile may correspond to a QFI, for example, the QFI marked on the uplink packets 812A-812E. Each QoS profile may include QoS parameters such as 5G QoS identifier (5QI) and an allocation and retention priority (ARP) The QoS profile for non-GBR QoS flows may further include additional QoS parameters such as a reflective QoS attribute (RQA).The QoS profile for GBR QoS flows may further include additional QoS parameters such as a guaranteed flow bit rate (GFBR), a maximum flow bit rate (MFBR), and / or a maximum packet loss rate. The 5QI may be a standardized 5QI which has one-to-one mapping to a standardized combination of 5G QoS characteristics per well-known services. The 5QI may be a dynamically assigned 5QI which the standardized 5QI values are not defined. The 5QI may represent 5G QoS characteristics. The 5QI may comprise a resource type, a default priority level, a packet delay budget (PDB), a packet error rate (PER), a maximum data burst volume, and / or an averaging window. The resource type may indicate a non-GBR QoS flow, a GBR QoS flow or a delay-critical GBR QoS flow. The averaging window may represent a duration over which the GFBR and / or MFBR is calculated. ARP may be a priority level comprising preemption capability and a pre-emption vulnerability. Based on the ARP, the AN 802 may apply admission control for the QoS flows in a case of resource limitations.

[0124] The AN 802 may select one or more N3 tunnels 850 for transmission of the QoS flows 856A-856C. After the packets are divided into QoS flows 856A-856C, the packet may be sent to UPF 805 (e.g., towards a DN) via the selected one or more N3 tunnels 850. The UPF 805 may verify that the QFIs of the uplinkDocket No.: 25-1021 PCTpackets 812A-812E are aligned with the QoS rules 814 provided to the UE 801. The UPF 805 may measure and / or count packets and / or provide packet metrics to, for example, a PCF.

[0125] The figure also illustrates a process for downlink. In particular, one or more applications may generate downlink packets 852A-852E. The UPF 805 may receive downlink packets 852A-852E from one or more DNs and / or one or more other UPFs. As per the QoS model, UPF 805 may apply packet detection rules (PDRs) 854 to downlink packets 852A-852E. Based on PDRs 854, UPF 805 may map packets 852A-852E into QoS flows. In the present illustration, downlink packets 852A, 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.

[0126] The QoS flows 856A-856C may be sent to AN 802. The AN 802 may apply resource mapping rules to the QoS flows 856A-856C. In the present illustration, QoS flow 856A is mapped to resource 820A, whereas QoS flows 856B, 856C are mapped to resource 820B. In order to meet QoS requirements, the resource mapping rules may designate more resources to high-priority QoS flows.

[0127] FIGS. 9A- 9D illustrate example states and state transitions of a wireless device (e.g . , a UE). At any given time, the wireless device may have a radio resource control (RRC) state, a registration management (RM) state, and a connection management (CM) state.

[0128] FIG. 9A is an example diagram showing RRC state transitions of a wireless device (e.g., a UE). The UE may be 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). The UE may implement different RAN-related control-plane procedures depending on its RRC state. Other elements of the network, for example, a base station, may track the RRC state of one or more UEs and implement RAN-related control-plane procedures appropriate to the RRC state of each.

[0129] In RRC connected 930, it may be possible for the UE to exchange data with the network (for example, the base station). The parameters necessary for exchange of data may be established and known to both the UE and the network. The parameters may be referred to and / or included in an RRC context of the UE (sometimes referred to as a UE context). These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g , relating to a 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 with which the UE is connected may store the RRC context of the UE.

[0130] While in RRC connected 930, mobility of the UE may be managed by the access network, whereas the UE itself may manage mobility while in RRC idle 910 and / or RRC inactive 920. While in RRC connected 930, the UE may manage mobility by measuring signal levels (e.g., reference signal levels) from a serving cell and neighboring cells and reporting these measurements to the base station currently servingDocket No.: 25-1021 PCTthe UE. The network may initiate handover based on the reported measurements. The RRC state may transition from RRC connected 930 to RRC idle 910 through a connection release procedure 930 or to RRC inactive 920 through a connection inactivation procedure 932.

[0131] In RRC idle 910, an RRC context may not be established for the UE. In RRC idle 910, the UE may not have an RRC connection with a base station. While in RRC idle 910, the UE may be in a sleep state for a majority of the time (e.g., to conserve battery power). The UE may wake up periodically (e.g., once in every discontinuous reception cycle) to monitor for paging messages from the access network. Mobility of the UE may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC idle 910 to RRC connected 930 through a connection establishment procedure 913, which may involve a random access procedure, as discussed in greater detail below.

[0132] In RRC inactive 920, the RRC context previously established is maintained in the UE and the base station. This may allow for a fast transition to RRC connected 930 with reduced signaling overhead as compared to the transition from RRC idle 910 to RRC connected 930. The RRC state may transition to RRC connected 930 through a connection resume procedure 923. The RRC state may transition to RRC idle 910 though a connection release procedure 921 that may be the same as or similar to connection release procedure 931.

[0133] An RRC state may be associated with a mobility management mechanism. In RRC idle 910 and RRC inactive 920, mobility may be managed by the UE through cell reselection. The purpose of mobility management in RRC idle 910 and / or RRC inactive 920 is to allow the network to be able to notify the UE of an event via a paging message without having to broadcast the paging message over the entire mobile communications network. The mobility management mechanism used in RRC idle 910 and / or RRC inactive 920 may allow the network to track the UE on a cell-group level so that the paging message may be broadcast over the cells of the cell group that the UE currently resides within instead of the entire communication network. Tracking may be based on different granularities of grouping. For example, there may be 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, referred to as a tracking area and identified by a tracking area identifier (TAI).

[0134] Tracking areas may be used to track the UE at the CN level. The CN may provide the UE with a list of TAIs associated with a UE registration area. If the UE moves, through cell reselection, to a cell associated with a TAI not included in the list of TAIs associated with the UE registration area, the UE may perform a registration update with the CN to allow the CN to update the UE’s location and provide the UE with a new the UE registration area.

[0135] RAN areas may be used to track the UE at the RAN level. For a UE in RRC inactive 920 state, the UE may be assigned a RAN notification area. A RAN notification area may comprise one or more cellDocket No.: 25-1021 PCTidentities, a list of RAIs, and / or a list of TAIs. In an example, a base station may belong to one or more RAN notification areas. In an example, a cell may belong to one or more RAN notification areas. If the UE moves, through cell reselection, to a cell not included in the RAN notification area assigned to the UE, the UE may perform a notification area update with the RAN to update the UE’s RAN notification area.

[0136] A base station storing an RRC context for a UE or a last serving base station of the UE may be referred to as an anchor base station. An anchor base station may maintain an RRC context for the UE at least during a period of time that the UE stays in a RAN notification area of the anchor base station and / or during a period of time that the UE stays in RRC inactive 920.

[0137] FIG. 9B is an example diagram showing registration management (RM) state transitions of a wireless device (e.g., a UE). The states are RM deregistered 940, (e.g , RM-DEREGISTERED) and RM registered 950 (e.g., RM-REGISTERED).

[0138] In RM deregistered 940, the UE is not registered with the network, and the UE is not reachable by the network. In order to be reachable by the network, the UE must perform an initial registration. As an example, the UE may register with an AMF of the network. If registration is rejected (registration reject 944), then the UE remains in RM deregistered 940. If registration is accepted (registration accept 945), then the UE transitions to RM registered 950. While the UE is RM registered 950, the network may store, keep, and / or maintain a UE context for the UE. The UE context may be referred to as wireless device context. The UE context corresponding to network registration (maintained by the core network) may be different from the RRC context corresponding to RRC state (maintained by an access network, .e.g., a base station). The UE context may comprise a UE identifier and a record of various information relating to the UE, for example, UE capability information, policy information for access and mobility management of the UE, lists of allowed or established slices or PDU sessions, and / or a registration area of the UE (i.e., a list of tracking areas covering the geographical area where the wireless device is likely to be found).

[0139] While the UE is RM registered 950, the network may store the UE context of the UE, and if necessary, use the UE context to reach the UE. Moreover, some services may not be provided by the network unless the UE is registered. The UE may update its UE context while remaining in RM registered 950 (registration update accept 955). For example, if the UE leaves one tracking area and enters another tracking area, the UE may provide a tracking area identifier to the network. The network may deregister the UE, or the UE may deregister itself (deregistration 954). For example, the network may automatically deregister the wireless device if the wireless device is inactive for a certain amount of time. Upon deregistration, the UE may transition to RM deregistered 940.

[0140] FIG. 9C is an example diagram showing connection management (CM) state transitions of a wireless device (e.g., a UE), shown from a perspective of the wireless device. The UE may be in CM idle 960 (e.g., CM-IDLE) or CM connected 970 (e.g., CM-CONNECTED).Docket No.: 25-1021 PCT

[0141] In CM idle 960, the UE does not have a non access stratum (NAS) signaling connection with the network. As a result, the UE cannot communicate with core network functions. The UE may transition to CM connected 970 by establishing an AN signaling connection (AN signaling connection establishment 967). This transition may be initiated by sending an initial NAS message. The initial NAS message may be a registration request (e.g., if the UE is RM deregistered 940) or a service request (e.g., if the UE is RM registered 950). If the UE is RM registered 950, then the UE may initiate the AN signaling connection establishment by sending a service request, or the network may send a page, thereby triggering the UE to send the service request.

[0142] In CM connected 970, the UE can communicate with core network functions using NAS signaling. As an example, the UE may exchange NAS signaling with an AMF for registration management purposes, service request procedures, and / or authentication procedures. As another example, the UE may exchange NAS signaling, with an SMF, to establish and / or modify a PDU session. The network may disconnect the UE, or the UE may disconnect itself (AN signaling connection release 976). For example, if the UE transitions to RM deregistered 940, then the UE may also transition to CM idle 960. When the UE transitions to CM idle 960, the network may deactivate a user plane connection of a PDU session of the UE.

[0143] FIG. 9D is an example diagram showing CM state transitions of the wireless device (e.g., a UE), shown from a network perspective (e.g., an AMF). The CM state of the UE, as tracked by the AMF, may be in 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 many establish an N2 context of the UE (N2 context establishment 989). When the UE transitions from CM connected 990 to CM idle 980, the AMF may release the N2 context of the UE (N2 context release 998).

[0144] FIGS. 10 - 12 illustrate example procedures for registering, service request, and PDU session establishment of a UE.

[0145] FIG. 10 illustrates an example of a registration procedure for a wireless device (e.g., a UE). Based on the registration procedure, the UE may transition from, for example, RM deregistered 940 to RM registered 950.

[0146] Registration may be initiated by a UE for the purposes of obtaining authorization to receive services, enabling mobility tracking, enabling reachability, or other purposes. The UE may perform an initial registration as a first step toward connection to the network (for example, if the UE is powered on, airplane mode is turned off, etc.). Registration may also be performed periodically to keep the network informed of the UE’s presence (for example, while in CM-IDLE state), or in response to a change in UE capability or registration area. Deregistration (not shown in FIG. 10) may be performed to stop network access.Docket No.: 25-1021 PCT

[0147] At 1010, the UE transmits a registration request to an AN. As an example, the UE may have moved from a coverage area of a previous AMF (illustrated as AMF#1) into a coverage area of a new AMF (illustrated as AMF#2). The registration request may be a NAS message. The registration request may include a UE identifier. The AN may select an AMF for registration of the UE. For example, the AN may select a default AMF. For example, the AN may select an AMF that is already mapped to the UE (e.g., a previous AMF). The NAS registration request may include a network slice identifier and the AN may select an AMF based on the requested slice. After the AMF is selected, the AN may send the registration request to the selected AMF.

[0148] At 1020, the AMF that receives the registration request (AMF#2) performs a context transfer. The context may be a UE context, for example, an RRC context for the UE. As an example, AMF#2 may send AMF#1 a message requesting a context of the UE. The message may include the UE identifier. The message may be a Namf_ Communication- UEContextTransfer message. AMF#1 may send to AMF#2 a message that includes the requested UE context. This message may be a Namf_ Communication-UEContextTransfer message. After the UE context is received, the AMF#2 may coordinate authentication of the UE. After authentication is complete, AMF#2 may send to AMF#1 a message indicating that the UE context transfer is complete. This message may be a Namf_ Communication- UEContextTransfer Response message.

[0149] Authentication may require participation of the UE, an AUSF, a UDM and / or a UDR (not shown). For example, the AMF may request that the AUSF authenticate the UE. For example, the AUSF may execute authentication of the UE. For example, the AUSF may get authentication data from UDM. For example, the AUSF may send a subscription permanent identifier (SUPI) to the AMF based on the authentication being successful. For example, the AUSF may provide an intermediate key to the AMF. The intermediate key may be used to derive an access-specific security key for the UE, enabling the AMF to perform security context management (SCM). The AUSF may obtain subscription data from the UDM. The subscription data may be based on information obtained from the UDM (and / or the UDR). The subscription data may include subscription identifiers, security credentials, access and mobility related subscription data and / or session related data.

[0150] At 1030, the new AMF, AMF#2, registers and / or subscribes with the UDM. AMF#2 may perform registration using a UE context management service of the UDM (Nudm_ UECM). AMF#2 may obtain subscription information of the UE using a subscriber data management service of the UDM (Nudm_ SDM). AMF#2 may further request that the UDM notify AMF#2 if the subscription information of the UE changes. As the new AMF registers and subscribes, the old AMF, AMF#1 , may deregister and unsubscribe. After deregistration, AMF#1 is free of responsibility for mobility management of the UE.Docket No.: 25-1021 PCT

[0151] At 1040, AMF#2 retrieves access and mobility (AM) policies from the PCF. As an example, the AMF#2 may provide subscription data of the UE to the PCF. The PCF may determine access and mobility policies for the UE based on the subscription data, network operator data, current network conditions, and / or other suitable information. For example, the owner of a first UE may purchase a higher level of service than the owner of a second UE. The PCF may provide the rules associated with the different levels of service. Based on the subscription data of the respective UEs, the network may apply different policies which facilitate different levels of service.

[0152] For example, access and mobility policies may relate to service area restrictions, RAT / frequency selection priority (RFSP, where RAT stands for radio access technology), authorization and prioritization of access type (e.g., LTE versus NR), and / or selection of non-3GPP access (e.g., Access Network Discovery and Selection Policy (ANDSP)). The service area restrictions may comprise a list of tracking areas where the UE is allowed to be served (or forbidden from being served). The access and mobility policies may include a UE route selection policy (URSP)) that influences routing to an established PDU session or a new PDU session. As noted above, different policies may be obtained and / or enforced based on subscription data of the UE, location of the UE (i.e., location of the AN and / or AMF), or other suitable factors.

[0153] At 1050, AMF#2 may update a context of a PDU session. For example, if the UE has an existing PDU session, the AMF#2 may coordinate with an SMF to activate a user plane connection associated with the existing PDU session. The SMF may update and / or release a session management context of the PDU session (Nsmf_PDUSession_UpdateSMContext, Nsmf_ PDUSession_ ReleaseSM Context)

[0154] At 1060, AMF#2 sends a registration accept message to the AN, which forwards the registration accept message to the UE. The registration accept message may include a new UE identifier and / or a new configured slice identifier. The UE may transmit a registration complete message to the AN, which forwards the registration complete message to the AMF#2. The registration complete message may acknowledge receipt of the new UE identifier and / or new configured slice identifier.

[0155] At 1070, AMF#2 may obtain UE policy control information from the PCF. The PCF may provide an access network discovery and selection policy (ANDSP) to facilitate non-3GPP access. The PCF may provide a UE route selection policy (URSP) to facilitate mapping of particular data traffic to particular PDU session connectivity parameters. As an example, the URSP may indicate that data traffic associated with a particular application should be mapped to a particular SSC mode, network slice, PDU session type, or preferred access type (3GPP or non-3GPP).

[0156] FIG. 11 illustrates an example of a service request procedure for a wireless device (e.g., a UE). The service request procedure depicted in FIG. 11 is a network-triggered service request procedure for a UE in a CM-IDLE state. However, other service request procedures (e.g., a UE-triggered service request procedure) may also be understood by reference to FIG. 11, as will be discussed in greater detail below.Docket No.: 25-1021 PCT

[0157] At 1110, a UPF receives data. The data may be downlink data for transmission to a UE. The data may be associated with an existing PDU session between the UE and a DN. The data may be received, for example, from a DN and / or another UPF. The UPF may buffer the received data. In response to the receiving of the data, the UPF may notify an SMF of the received data. The identity of the SMF to be notified may be determined based on the received data. The notification may be, for example, an N4 session report. The notification may indicate that the UPF has received data associated with the UE and / or a particular PDU session associated with the UE. In response to receiving the notification, the SMF may send PDU session information to an AMF. The PDU session information may be sent in an N1N2 message transfer for forwarding to an AN. The PDU session information may include, for example, UPF tunnel endpoint information and / or QoS information

[0158] At 1120, the AMF determines that the UE is in a CM-IDLE state. The determining at 1120 may be in response to the receiving of the PDU session information. Based on the determination that the UE is CM-IDLE, the service request procedure may proceed to 1130 and 1140, as depicted in FIG. 11. However, if the UE is not CM-IDLE (e.g. , the UE is CM-CONNECTED), then 1130 and 1140 may be skipped, and the service request procedure may proceed directly to 1150.

[0159] At 1130, the AMF pages the UE. The paging at 1130 may be performed based on the UE being CM-IDLE. To perform the paging, the AMF may send a page to the AN. The page may be referred to as a paging or a paging message. The page may be an N2 request message. The AN may be one of a plurality of ANs in a RAN notification area of the UE. The AN may send a page to the UE. The UE may be in a coverage area of the AN and may receive the page.

[0160] At 1140, the UE may request service. The UE may transmit a service request to the AMF via the AN. As depicted in FIG. 11, the UE may request service at 1140 in response to receiving the paging at 1130. However, as noted above, this is for the specific case of a network-triggered service request procedure In some scenarios (for example, if uplink data becomes available at the UE), then the UE may commence a UE-triggered service request procedure. The UE-triggered service request procedure may commence starting at 1140.

[0161] At 1150, the network may authenticate the UE. Authentication may require participation of the UE, an AUSF, and / or a UDM, for example, similar to authentication described elsewhere in the present disclosure. In some cases (for example, if the UE has recently been authenticated), the authentication at 1150 may be skipped.

[0162] At 1160, the AMF and SMF may perform a PDU session update. As part of the PDU session update, the SMF may provide the AMF with one or more UPF tunnel endpoint identifiers. In some cases (not shown in FIG. 11), it may be necessary for the SMF to coordinate with one or more other SMFs and / or one or more other UPFs to set up a user plane.Docket No.: 25-1021 PCT

[0163] At 1170, the AMF may send PDU session information to the AN. The PDU session information may be included in an N2 request message. Based on the PDU session information, the AN may configure a user plane resource for the UE. To configure the user plane resource, the AN may, for example, perform an RRC reconfiguration of the UE. The AN may acknowledge to the AMF that the PDU session information has been received. The AN may notify the AMF that the user plane resource has been configured, and / or provide information relating to the user plane resource configuration.

[0164] In the case of a UE-triggered service request procedure, the UE may receive, at 1170, a NAS service accept message from the AMF via the AN. After the user plane resource is configured, the UE may transmit uplink data (for example, the uplink data that caused the UE to trigger the service request procedure).

[0165] At 1180, the AMF may update a session management (SM) context of the PDU session. For example, the AMF may notify the SMF (and / or one or more other associated SMFs) that the user plane resource has been configured, and / or provide information relating to the user plane resource configuration. The AMF may provide the SMF (and / or one or more other associated SMFs) with one or more AN tunnel endpoint identifiers of the AN. After the SM context update is complete, the SMF may send an update SM context response message to the AMF.

[0166] Based on the update of the session management context, the SMF may update a PCF for purposes of policy control. For example, if a location of the UE has changed, the SMF may notify the PCF of the UE's a new location.

[0167] Based on the update of the session management context, the SMF and UPF may perform a session modification. The session modification may be performed using N4 session modification messages. After the session modification is complete, the UPF may transmit downlink data (for example, the downlink data that caused the UPF to trigger the network-triggered service request procedure) to the UE. The transmitting of the downlink data may be based on the one or more AN tunnel endpoint identifiers of the AN.

[0168] FIG. 12 illustrates an example of a protocol data unit (PDU) session establishment procedure for a wireless device (e.g., a UE). The UE may determine to transmit the PDU session establishment request to create a new PDU session, to hand over an existing PDU session to a 3GPP network, or for any other suitable reason.

[0169] At 1210, the UE initiates PDU session establishment. The UE may transmit a PDU session establishment request to an AMF via an AN. The PDU session establishment request may be a NAS message. The PDU session establishment request may indicate: a PDU session ID; a requested PDU session type (new or existing); a requested DN (DNN); a requested network slice (S NSSAI); a requested SSC mode; and / or any other suitable information. The PDU session ID may be generated by the UE. TheDocket No.: 25-1021 PCTPDU session type may be, for example, an Internet Protocol (IP)-based type (e.g., IPv4, IPv6, or dual stack IPv4 / IPv6), an Ethernet type, or an unstructured type.

[0170] The AMF may select an SMF based on the PDU session establishment request. In some scenarios, the requested PDU session may already be associated with a particular SMF. For example, the AMF may store a UE context of the UE, and the UE context may indicate that the PDU session ID of the requested PDU session is already associated with the particular SMF. In some scenarios, the AMF may select the SMF based on a determination that the SMF is prepared to handle the requested PDU session. For example, the requested PDU session may be associated with a particular DNN and / or S NSSAI, and the SMF may be selected based on a determination that the SMF can manage a PDU session associated with the particular DNN and / or S NSSAI.

[0171] At 1220, the network manages a 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 may include the PDU session establishment request received from the UE at 1210. The PDU session context request may be a Nsmf_ PDUSession_CreateSMContext Request and / or a Nsmf_PDUSession_UpdateSMContext Request. The PDU session context request may indicate identifiers of the UE; the requested DN; and / or the requested network slice. Based on the PDU session context request, the SMF may retrieve subscription data from a UDM. The subscription data may be session management subscription data of the UE. The SMF may subscribe for updates to the subscription data, so that the PCF will send new information if the subscription data of the UE changes. After the subscription data of the UE is obtained, the SMF may transmit a PDU session context response to the AMG. The PDU session context response may be a Nsmf_ PDUSession_ CreateSMContext Response and / or a Nsmf_PDUSession_UpdateSMContext Response. The PDU session context response may include a session management context ID.

[0172] At 1230, secondary authorization / authentication may be performed, if necessary. The secondary authorization / authentication may involve the UE, the AMF, the SMF, and the DN. The SMF may access the DN via a Data Network Authentication, Authorization and Accounting (DN AAA) server.

[0173] At 1240, the network sets up a data path for uplink data associated with the PDU session. The SMF may select a PCF and establish a session management policy association. Based on the association, the PCF may provide an initial set of policy control and charging rules (PCC rules) for the PDU session. When targeting a particular PDU session, the PCF may indicate, to the SMF, a method for allocating an IP address to the PDU Session, a default charging method for the PDU session, an address of the corresponding charging entity, triggers for requesting new policies, etc. The PCF may also target a service data flow (SDF) comprising one or more PDU sessions. When targeting an SDF, the PCF may indicate, to the SMF, policies for applying QoS requirements, monitoring traffic (e.g., for charging purposes), and / or steering traffic (e.g., by using one or more particular N6 interfaces).Docket No.: 25-1021 PCT

[0174] The SMF may determine and / or allocate an IP address for the PDU session. The SMF may select one or more UPFs (a single UPF in the example of FIG. 12) to handle the PDU session. The SMF may send an N4 session message to the selected UPF. The N4 session message may be an N4 Session Establishment Request and / or an N4 Session Modification Request. The N4 session message may include packet detection, enforcement, and reporting rules associated with the PDU session. In response, the UPF may acknowledge by sending an N4 session establishment response and / or an N4 session modification response.

[0175] The SMF may send PDU session management information to the AMF. The PDU session management information may be a session service request (e.g . , Namf_Communication_N1N2MessageTransfer) message. The PDU session management information may include the PDU session ID. The PDU session management information may be a NAS message. The PDU session management information may include N1 session management information and / or N2 session management information. The N1 session management information may include a PDU session establishment accept message. The PDU session establishment accept message may include tunneling endpoint information of the UPF and quality of service (QoS) information associated with the PDU session.

[0176] The AMF may send an N2 request to the AN. The N2 request may include the PDU session establishment accept message. Based on the N2 request, the AN may determine AN resources for the UE. The AN resources may be used by the UE to establish the PDU session, via the AN, with the DN. The AN may determine resources to be used for the PDU session and indicate the determined resources to the UE. The AN may send the PDU session establishment accept message to the UE. For example, the AN may perform an RRC reconfiguration of the UE. After the AN resources are set up, the AN may send an N2 request acknowledge to the AMF. The N2 request acknowledge may include N2 session management information, for example, the PDU session ID and tunneling endpoint information of the AN.

[0177] After the data path for uplink data is set up at 1240, the UE may optionally send uplink data associated with the PDU session. As shown in FIG. 12, the uplink data may be sent to a DN associated with the PDU session via the AN and the UPF.

[0178] At 1250, the network may update the PDU session context. The AMF may transmit a PDU session context update request to the SMF. The PDU session context update request may be a Nsmf_PDUSession_UpdateSMContext Request. The PDU session context update request may include the N2 session management information received from the AN. The SMF may acknowledge the PDU session context update. The acknowledgement may be a Nsmf_PDUSession_UpdateSMContext Response. The acknowledgement may include a subscription requesting that the SMF be notified of any UE mobility event. Based on the PDU session context update request, the SMF may send an N4 session message to the UPF. The N4 session message may be an N4 Session Modification Request. The N4 session messageDocket No.: 25-1021 PCTmay include tunneling endpoint information of the AN The N4 session message may include forwarding rules associated with the PDU session. In response, the UPF may acknowledge by sending an N4 session modification response.

[0179] After the UPF receives the tunneling endpoint information of the AN, the UPF may relay downlink data associated with the PDU session. As shown in FIG. 12, the downlink data may be received from a DN associated with the PDU session via the AN and the UPF.

[0180] FIG. 13 illustrates examples of components of the elements in a communications network. FIG. 13 includes a wireless device 1310, a base station 1320, and a physical deployment of one or more network functions 1330 (henceforth “deployment 1330”). Any wireless device described in the present disclosure may have similar components and may be implemented in a similar manner as the wireless device 1310. Any other base station described in the present disclosure (or any portion thereof, depending on the architecture of the base station) may have similar components and may be implemented in a similar manner as the base station 1320. Any physical core network deployment in the present disclosure (or any portion thereof, depending on the architecture of the base station) may have similar components and may be implemented in a similar manner as the deployment 1330.

[0181] The wireless device 1310 may communicate with base station 1320 over an air interface 1370. The communication direction from wireless device 1310 to base station 1320 over air interface 1370 is known as uplink, and the communication direction from base station 1320 to wireless device 1310 over air interface 1370 is known as downlink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and / or some combination of duplexing techniques. FIG. 13 shows a single wireless device 1310 and a single base station 1320, but it will be understood that wireless device 1310 may communicate with any number of base stations or other access network components over air interface 1370, and that base station 1320 may communicate with any number of wireless devices over air interface 1370.

[0182] The wireless device 1310 may comprise a processing system 1311 and a memory 1312. The memory 1312 may comprise one or more computer-readable media, for example, one or more non-transitory computer readable media. The memory 1312 may include instructions 1313. The processing system 1311 may process and / or execute instructions 1313. Processing and / or execution of instructions 1313 may cause wireless device 1310 and / or processing system 1311 to perform one or more functions or activities. The memory 1312 may include data (not shown). One of the functions or activities performed by processing system 1311 may be to store data in memory 1312 and / or retrieve previously-stored data from memory 1312. In an example, downlink data received from base station 1320 may be stored in memory 1312, and uplink data for transmission to base station 1320 may be retrieved from memory 1312. As illustrated in FIG. 13, the wireless device 1310 may communicate with base station 1320 using aDocket No.: 25-1021 PCTtransmission processing system 1314 and / or a reception processing system 1315. Alternatively, transmission processing system 1314 and reception processing system 1315 may be implemented as a single processing system, or both may be omitted and all processing in the wireless device 1310 may be performed by the processing system 1311. Although not shown in FIG. 13, transmission processing system 1314 and / or reception processing system 1315 may be coupled to a dedicated memory that is analogous to but separate from memory 1312, and comprises instructions that may be processed and / or executed to carry out one or more of their respective functionalities. The wireless device 1310 may comprise one or more antennas 1316 to access air interface 1370.

[0183] The wireless device 1310 may comprise one or more other elements 1319. The one or more other elements 1319 may comprise software and / or hardware that provide features and / or functionalities, for example, a speaker, a microphone, a keypad, a display, a touchpad, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g. , for a motor vehicle), and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, a global positioning sensor (GPS) and / or the like). The wireless device 1310 may receive user input data from and / or provide user output data to the one or more one or more other elements 1319. The one or more other elements 1319 may comprise a power source. The wireless device 1310 may receive power from the power source and may be configured to distribute the power to the other components in wireless device 1310. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof.

[0184] The wireless device 1310 may transmit uplink data to and / or receive downlink data from base station 1320 via air interface 1370. To perform the transmission and / or reception, one or more of the processing system 1311, transmission processing system 1314, and / or reception system 1315 may implement open systems interconnection (OSI) functionality. As an example, transmission processing system 1314 and / or reception system 1315 may perform layer 1 OSI functionality, and processing system 1311 may perform higher layer functionality. The wireless device 1310 may transmit and / or receive data over air interface 1370 using one or more antennas 1316. For scenarios where the one or more antennas 1316 include multiple antennas, the multiple antennas may be used to perform one or more multi-antenna techniques, such as spatial multiplexing (e.g., single-user multiple-input multiple output (MIMO) or multiuser M IMO), transmit / receive diversity, and / or beamforming.

[0185] The base station 1320 may comprise a processing system 1321 and a memory 1322. The memory 1322 may comprise one or more computer-readable media, for example, one or more non-transitory computer readable media. The memory 1322 may include instructions 1323. The processing system 1321 may process and / or execute instructions 1323. Processing and / or execution of instructions 1323 mayDocket No.: 25-1021 PCTcause base station 1320 and / or processing system 1321 to perform one or more functions or activities. The memory 1322 may include data (not shown). One of the functions or activities performed by processing system 1321 may be to store data in memory 1322 and / or retrieve previously-stored data from memory 1322. The base station 1320 may communicate with wireless device 1310 using a transmission processing system 1324 and a reception processing system 1325. Although not shown in FIG. 13, transmission processing system 1324 and / or reception processing system 1325 may be coupled to a dedicated memory that is analogous to but separate from memory 1322, and comprises instructions that may be processed and / or executed to carry out one or more of their respective functionalities. The wireless device 1320 may comprise one or more antennas 1326 to access air interface 1370.

[0186] The base station 1320 may transmit downlink data to and / or receive uplink data from wireless device 1310 via air interface 1370. To perform the transmission and / or reception, one or more of the processing system 1321 , transmission processing system 1324, and / or reception system 1325 may implement OS I functionality. As an example, transmission processing system 1324 and / or reception system 1325 may perform layer 1 OSI functionality, and processing system 1321 may perform higher layer functionality. The base station 1320 may transmit and / or receive data over air interface 1370 using one or more antennas 1326. For scenarios where the one or more antennas 1326 include multiple antennas, the multiple antennas may be 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.

[0187] The base station 1320 may comprise an interface system 1327. The interface system 1327 may communicate with one or more base stations and / or one or more elements of the core network via an interface 1380. The interface 1380 may be wired and / or wireless and interface system 1327 may include one or more components suitable for communicating via interface 1380. In FIG. 13, interface 1380 connects base station 1320 to a single deployment 1330, but it will be understood that wireless device 1310 may communicate with any number of base stations and / or CN deployments over interface 1380, and that deployment 1330 may communicate with any number of base stations and / or other CN deployments over interface 1380. The base station 1320 may comprise one or more other elements 1329 analogous to one or more of the one or more other elements 1319.

[0188] The deployment 1330 may comprise any number of portions of any number of instances of one or more network functions (NFs). The deployment 1330 may comprise a processing system 1331 and a memory 1332. The memory 1332 may comprise one or more computer-readable media, for example, one or more non-transitory computer readable media. The memory 1332 may include instructions 1333. The processing system 1331 may process and / or execute instructions 1333. Processing and / or execution of instructions 1333 may cause the deployment 1330 and / or processing system 1331 to perform one or moreDocket No.: 25-1021 PCTfunctions or activities The memory 1332 may include data (not shown). One of the functions or activities performed by processing system 1331 may be to store data in memory 1332 and / or retrieve previously-stored data from memory 1332. The deployment 1330 may access the interface 1380 using an interface system 1337. The deployment 1330 may comprise one or more other elements 1339 analogous to one or more of the one or more other elements 1319.

[0189] One or more of the systems 1311, 1314, 1315, 1321, 1324, 1325, and / or 1331 may comprise one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, an on-board unit, or any combination thereof. One or more of the systems 1311, 1314, 1315, 1321 , 1324, 1325, and / or 1331 may perform signal coding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable wireless device 1310, base station 1320, and / or deployment 1330 to operate in a mobile communications system.

[0190] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g. hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab and / or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise computers, microcontrollers, microprocessors, DSPs, ASICs, FPGAs, and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors may be programmed using languages such as assembly, C, C++ and / or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0191] The wireless device 1310, base station 1320, and / or deployment 1330 may implement timers and / or counters. A timer / counter may start at an initial value. As used herein, starting may comprise restarting. Once started, the timer / counter may run. Running of the timer / counter may be associated with an occurrence. When the occurrence occurs, the value of the timer / counter may change (for example,Docket No.: 25-1021 PCTincrement or decrement). The occurrence may be, for example, an exogenous event (for example, a reception of a signal, a measurement of a condition, etc.), an endogenous event (for example, a transmission of a signal, a calculation, a comparison, a performance of an action or a decision to so perform, etc.), or any combination thereof. In the case of a timer, the occurrence may be the passage of a particular amount of time. However, it will be understood that a timer may be described and / or implemented as a counter that counts the passage of a particular unit of time. A timer / counter may run in a direction of a final value until it reaches the final value. The reaching of the final value may be referred to as expiration of the timer / counter. The final value may be referred to as a threshold. A timer / counter may be paused, wherein the present value of the timer / counter is held, maintained, and / or carried over, even upon the occurrence of one or more occurrences that would otherwise cause the value of the timer / counter to change. The timer / counter may be un-paused or continued, wherein the value that was held, maintained, and / or carried over begins changing again when the one or more occurrence occur. A timer / counter may be set and / or reset. As used herein, setting may comprise resetting. When the timer / counter sets and / or resets, the value of the timer / counter may be set to the initial value. A timer / counter may be started and / or restarted. As used herein, starting may comprise restarting. In some embodiments, when the timer / counter restarts, the value of the timer / counter may be set to the initial value and the timer / counter may begin to run.

[0192] FIGS. 14A, 14B, 14C, and 14D illustrate various example arrangements of physical core network deployments, each having one or more network functions or portions thereof. The core network deployments comprise a deployment 1410, a deployment 1420, a deployment 1430, a deployment 1440, and / or a deployment 1450. Each deployment may be analogous to, for example, the deployment 1330 depicted in FIG. 13. In particular, each deployment may comprise 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 (for example, other core network deployments). Each deployment may comprise one or more network functions (NFs). The term NF may refer to a particular set of functionalities and / or one or more physical elements configured to perform those functionalities (e.g., a processing system and memory comprising instructions that, when executed by the processing system, cause the processing system to perform the functionalities). For example, in the present disclosure, when a network function is described as performing X, Y, and Z, it will be understood that this refers to the one or more physical elements configured to perform X, Y, and Z, no matter how or where the one or more physical elements are deployed. The term NF may refer to a network node, network element, and / or network device.

[0193] As will be discussed in greater detail below, there are many different types of NF and each type of NF may be associated with a different set of functionalities. A plurality of different NFs may be flexibly1Docket No.: 25-1021 PCTdeployed at different locations (for example, in different physical core network deployments) or in a same location (for example, co-located in a same deployment). A single NF may be flexibly deployed at different locations (implemented using different physical core network deployments) or in a same location.Moreover, physical core network deployments may also implement one or more base stations, application functions (AFs), data networks (DNs), or any portions thereof. NFs may 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).

[0194] FIG. 14A illustrates an example arrangement of core network deployments in which each deployment comprises one network function. A deployment 1410 comprises an NF 1411, a deployment 1420 comprises an NF 1421, and a deployment 1430 comprises an NF 1431. The deployments 1410, 1420, 1430 communicate via an interface 1490. The deployments 1410, 1420, 1430 may have different physical locations with different signal propagation delays relative to other network elements. The diversity of physical locations of deployments 1410, 1420, 1430 may enable provision of services to a wide area with improved speed, coverage, security, and / or efficiency.

[0195] FIG. 14B illustrates an example arrangement wherein a single deployment comprises more than one NF. Unlike FIG. 14A, where each NF is deployed in a separate deployment, FIG. 14B illustrates multiple NFs in deployments 1410, 1420. In an example, deployments 1410, 1420 may implement a software-defined network (SDN) and / or a network function virtualization (NFV).

[0196] For example, deployment 1410 comprises an additional network function, NF 1411A. The NFs 1411, 1411 A may consist of multiple instances of the same NF type, co-located at a same physical location within the same deployment 1410. The NFs 1411 , 1411A may be implemented independently from one another (e.g., isolated and / or independently controlled). For example, the NFs 1411, 1411A may be associated with different network slices. A processing system and memory associated with the deployment 1410 may perform all of the functionalities associated with the NF 1411 in addition to all of the functionalities associated with the NF 1411A. In an example, NFs 1411, 1411A may be associated with different PLMNs, but deployment 1410, which implements NFs 1411, 1411A, may be owned and / or operated by a single entity.

[0197] Elsewhere in FIG. 14B, deployment 1420 comprises NF 1421 and an additional network function, NF 1422. The NFs 1421 , 1422 may be different NF types. Similar to NFs 1411 , 1411A, the NFs 1421 , 1422 may be co-located within the same deployment 1420, but separately implemented. As an example, a first PLMN may own and / or operate deployment 1420 having NFs 1421 , 1422. As another example, the first PLMN may implement NF 1421 and a second PLMN may obtain from the first PLMN (e.g., rent, lease, procure, etc.) at least a portion of the capabilities of deployment 1420 (e.g., processing power, dataDocket No.: 25-1021 PCTstorage, etc.) in order to implement NF 1422 As yet another example, the deployment may be owned and / or operated by one or more third parties, and the first PLMN and / or second PLMN may procure respective portions of the capabilities of the deployment 1420. When multiple NFs are provided at a single deployment, networks may operate with greater speed, coverage, security, and / or efficiency.

[0198] FIG. 14C illustrates an example arrangement of core network deployments in which a single instance of an NF is implemented using a plurality of different deployments. In particular, a single instance of NF 1422 is implemented at deployments 1420, 1440. As an example, the functionality provided by NF 1422 may be implemented as a bundle or sequence of subservices. Each subservice may be implemented independently, for example, at a different deployment. Each subservices may be implemented in a different physical location By distributing implementation of subservices of a single NF across different physical locations, the mobile communications network may operate with greater speed, coverage, security, and / or efficiency.

[0199] FIG. 14D illustrates an example arrangement of core network deployments in which one or more network functions are implemented using a data processing service. In FIG. 14D, NFs 1411, 1411 A, 1421, 1422 are included in a deployment 1450 that is implemented as a data processing service. The deployment 1450 may comprise, for example, a cloud network and / or data center. The deployment 1450 may be owned and / or operated by a PLMN or by a non-PLMN third party. The NFs 1411 , 1411 A, 1421 , 1422 that are implemented using the deployment 1450 may belong to the same PLMN or to different PLMNs. The PLMN(s) may obtain (e.g , rent, lease, procure, etc.) at least a portion of the capabilities of the deployment 1450 (e.g., processing power, data storage, etc.). By providing one or more NFs using a data processing service, the mobile communications network may operate with greater speed, coverage, security, and / or efficiency.

[0200] As shown in the figures, different network elements (e.g., NFs) may be located in different physical deployments, or co-located in a single physical deployment. It will be understood that in the present disclosure, the sending and receiving of messages among different network elements is not limited to interdeployment transmission or intra-deployment transmission, unless explicitly indicated.

[0201] In an example, a deployment may be a 'black box’ that is preconfigured with one or more NFs and preconfigured to communicate, in a prescribed manner, with other ‘black box' deployments (e.g., via the interface 1490). Additionally or alternatively, a deployment may be configured to operate in accordance with open-source instructions (e.g., software) designed to implement NFs and communicate with other deployments in a transparent manner. The deployment may operate in accordance with open RAN (O RAN) standards.

[0202] An example implementation depicted in FIG. 15 illustrates how a network can manage usage of one or more RATs and / or one or more access technologies allowable to a UE.Docket No.: 25-1021 PCT

[0203] In an example, a first core network node of a first system and / or a second core network node of a second system may receive one or more first policy information. The one or more first policy information may be one or more configuration information. The one or more first policy information may be associated with a first network to which the first core network node and / or the second core network node belong. For example, one of more third policy information of a second network may be different from the one or more first policy information of the first network. In the first network, the one or more first policy information may be applied to a first UE and / or the one or more first policy information may not be applied to a second UE. For example, a first home operator of the first UE may be different from a second home operator of the second UE.

[0204] For example, one or more policy information of a network may be an information indicating one or more (restricted) access technologies that are restricted in the network and / or an information indicating one or more (nonrestricted) access technologies that are not restricted in the network. For example, the one or more access technologies may comprise at least one of E-UTRAN, NG-RAN, 6G RAN (6G RAN), GSM, satellite-NG-RAN, and / or the like. For example, each of the one or more access technologies may be each of one or more RATs. In the network, one or more restricted access technologies for a first set of UEs may be different that for a second set of UEs For example, due to different service agreements and / or due to different categories of different UEs may lead to such different restriction.

[0205] For example, the one or more first policy information may indicate that E-UTRAN, E-UTRA, EPC, and / or EPS are allowed and / or may indicate that NG-RAN, NR, 5GC and / or 5GS are not allowed. In another example, the one or more second policy information may indicate that E-UTRAN, E-UTRA, EPC, and / or EPS are allowed and / or may indicate that NG-RAN, NR, 5GC and / or 5GS are not allowed. Being allowed may be not being restricted. Not being allowed may be being restricted. For example, based on roaming agreement, service policy, user grade, network congestion and / or the like, the one or more first policy information may be decided

[0206] In an example, the UE may send an Attach request message (MGS 1) to an MME (CN 1), via RAN 1 (E-UTRAN). The MME may receive the Attach request message. Because the one or more first policy information indicates that E-UTRAN, E-UTRA, EPC, and / or EPS are allowed, the MME may determine to allow first registration of the UE, for the CN 1 / RAN 1. Based on the determination, the MME may send an Attach accept message (MSG 2) to the UE. In response to receiving the Attach accept message, the UE may transit to (and / or stay in) EMM-registered state, for the EPS.

[0207] In an example, the UE may send a Registration request message (MGS 3) to an AMF (CN 2), via RAN 2 (NG-RAN). The AMF may receive the Registration request message. Because the one or more first policy information indicates that NG-RAN, E-UTRA, 5GC, and / or 5GS are not allowed, the AMF may determine to reject second registration of the UE, for the CN 2 / RAN 2. Based on the determination, the AMF may send a Registration reject message (MSG 4) to the UE In response to receiving the Registration reject message, the UE transits to (and / or stays in) 5GMM-deregistered state, for the 5GS.

[0208] The example of FIG.15 shows that the UE may perform unnecessary attemptfor the second registration, when the UE is not allowed for the RAN 2 / CN 2. For example, when the UE is not allowed to use one or more RATs, one or more RANs, one or more access technologies, and / or one or more (network) system, sending one or moreDocket No.: 25-1021 PCTmessages via / to the one or more RATs, the one or more RANs, the one or more access technologies, and / or one or more system may lead to waste of signalling resources, and / or to congestion in the signalling resources.

[0209] An example implementation depicted in FIG. 16 illustrates how unnecessary signalling can be reduced.

[0210] As shown in the example of FIG. 15, the MME and / or the AMF may be configured with and / or may receive the one or more first policy information. The UE may send the Attach request message to the MME. The MME may determine to allow the first registration of the UE. For example, the MME may send the Attach accept message to the UE.

[0211] Reverting back to FIG. 16, in an example, based on the one or more first policy information, the MME may determine to send to the UE, a RAT utilization control information (RATUCI). For example, the RATUCI may be based on the one or more first policy information. For example, the RATUCI may indicate one or more RATs (one or more access technologies) that are restricted. For example, the RATUCI may be an information indicating one or more access technologies that are restricted in the network. For example, the one or more access technologies may comprise at least one of E-UTRAN, NG-RAN, 6G RAN (6G RAN), GSM, satellite-NG-RAN, and / or the like. For example, the one or more access technologies may correspond to the one or more RATs. For example, the one or more RATs may be at least one of GSM, UTRA, E-UTRA, NR, 6GR, and / or the like. For example, the RATUCI may indicate that E-UTRAN, E-UTRA, EPC, and / or EPS are allowed and / or may indicate that NG-RAN, NR, 5GC and / or 5GS are not allowed

[0212] In an example, the Attach accept message may comprise the RATUCI. For example, the UE may receive the RATUCI from the MME via the Attach accept message.

[0213] In an example, the UE may determine whether to trigger a second registration procedure toward / via / using 5GS / 5GC / NG-RAN and / or NR. For example, when the UE determines to perform dual registration, the UE may determine whether to trigger the second registration procedure, after the UE successfully finishes the first registration

[0214] In an example, the UE may determine whether the RATUCI is stored in the UE and / or whether the UE received the RATUCI from the network for which the second registration applies. For example, determining whether the RATUCI is stored in the UE may be to determine whether the RATUCI is available for the network and / or whether the RATUCI is previously received from the network. For example, the network may be a network to which the UE may perform the second registration procedure.

[0215] Based on the RATUCI is available / stored, the UE may determine whether 5GS / 5GC / NG-RAN / NR associated with the second registration procedure is restricted or not and / or is allowed or not. For example, because the RATUCI indicates that 5GS / 5GC / NG-RAN / NR is restricted, in the network, the UE may determine not to trigger the second registration procedure and / or may abort any triggered registration procedure toward the 5GS / 5GC / NG-RAN / NR and / or the like.

[0216] As shown in the example of FIG. 16, the use of the RATUCI may help in preventing unnecessary attempt of the UE when one or more access technologies are restricted.

[0217] An example embodiment depicted in FIG. 17 may illustrate one example of multiple data sessions employed by a UE.Docket No.: 25-1021 PCT

[0218] In an example, a UE may perform one or more registration procedures for one or more systems of a network of a network operator For example, the network operator may operate the network. The network may comprise the one or more systems, to address various demands, based on different characteristics of the one or more systems. When the UE is registered to the network, a data session over the network may be supported using at least one of the one or more systems. Each registration procedure of the one or more registration procedures may comprise sending a request requesting registration and / or receiving a response, to / from / via a node of the one or more systems, to the one or more systems. The request may be a message.

[0219] In an example, each request message requesting registration may comprise one or more capability indicators. The one or more capability indicator may indicator indicating that the UE supports RAT utilization control. This may help a network to determine whether to send any RATUCI to the UE.

[0220] In an example, the system may be a network system, a communication system, a core network and / or the like. The system may comprise at least one of a UE, a RAN, a core network, and / or the like. A first network system may use different technology than the second network system.

[0221] For example, the response may be an accept of registration and / or a reject of registration. For example, the response may indicate accept (acceptance) of the registration and / or reject of the registration. For example, the request message may be at least one of an Attach request message, a Registration request message, a TA update request message, a message indicating request associated with mobility management, a message for requesting registration to 6G system (6GS), and / or the like. A response message may be at least one of an Attach accept message, an Attach reject message, a Registration accept message, a Registration reject message, a TA update accept message, a TA update reject message, a message indicating accept for mobility management, a message indicating reject for mobility management, a message for accepting registration to 6GS, a message for rejecting registration to 6GS and / or the like.

[0222] For example, the one or more registration procedures may comprise a first registration procedure to a first system, a second registration procedure to a second system, a third registration procedure to a third system, and / or the like. For example, the first registration procedure to the first system may be an Attach procedure to EPS, the second registration procedure to the second system may be a Registration procedure to 5GS, and / or the third registration procedure to the third system may be a 6G registration procedure to 6GS (e.g., 6G system). The first registration procedure may comprise: sending by the UE to a MME, the Attach request message (or TA update request message); receiving by the UE from the MME, at least one of the Attach Reject message (or TA update reject message) or the Attach Accept message (or TA update accept message). The second registration procedure may comprise: sending by the UE to an AMF, the registration request message; receiving by the UE from the AMF, at least one of the Registration Reject message or the Registration Accept message. The third registration procedure may comprise: sending by the UE to an 6GMF (e.g , a mobility management function of 6GS), the message for requesting registration to the 6GS; receiving by the UE from the 6GMF, at least one of the message for accepting registration to 6GS, or the message for rejecting registration to 6GS.

[0223] In an example, the UE may send a first NAS message to a first core network node of a first network system. The first NAS message may be at least one of a first attach request message or a first TA update request message.Docket No.: 25-1021 PCTThe first core network node of a first core network may be a first MME. The first network system may be a first EPS. A first core network associated with the first core network node may be an evolved packet core (EPC). The UE may send the first NAS message via a first radio access network (RAN) to the first core network node. The first radio access network may be a first E-UTRAN. The first E-UTRAN may use a first RAT toward the UE. The first RAT may be at least one of a E-UTRA, NR, and / or a 6GR (6G Radio). The first RAT may be a first access technology.

[0224] In an example, the UE may receive a second NAS message from the first core network node, via the first RAN. The second NAS message may be at least one of a second attach accept message, a second TA update accept message, and / or the like. The UE may receive the second NAS message via the first radio access network from the first core network node.

[0225] In an example, based on receiving the second NAS message and / or based on the second NAS message indicating accept, the UE may transit to a first registered state for the first system. The first registered state may be EMM-registered state for a first mobility management state for the first system. For example, because the second NAS message indicates accept of registration, the UE may consider that the UE is registered to the first network system.

[0226] In an example, the UE may send a third NAS message to a second core network node of a second network system. The UE may send the third NAS message while the UE stays in the EMM-registered state for the first network system. The third NAS message may be at least one of a third registration request message. The second core network node may be a second AMF. The second network system may be a second 5GS. A second core network associated with the second core network node may be a second 5GC (5G core) The UE may send the third NAS message via a second radio access network to the second core network node. The second radio access network may be a second NG-RAN. The second NG-RAN may use a second RAT. The second RAT may be at least one of an E-UTRA, NR, and / or a 6GR (6G Radio). The second RAT may be a second access technology.

[0227] In an example, the UE may receive a fourth NAS message from the second core network node. The fourth NAS message may be at least one of a fourth registration accept message, and / or the like. The UE may receive the fourth NAS message via the second radio access network from the second core network.

[0228] In an example, based on receiving the fourth NAS message, the UE may transit to a second registered state (e g., second mobility management state) for the second system. For example, the second registered state may be 5GMM-registered state. For example, because the fourth NAS message indicates accept of registration, the UE may consider that the UE is registered to the second network system.

[0229] In an example, the UE may manage one or more registration status for the one or more network systems. A registration status of the one or more registration status may be a registration state, a mobility management state, and / or the like. The registration status for a network system may indicate whether the UE is registered and / or deregistered for the network system.

[0230] A network of one or more networks may employ one or more systems. The one or more systems may use one or more RATs. The one or more system may have one or more cells. The one or more cells may be associated with one or more RATs. For example, the one or more RATs may be one or more access technologies .Docket No.: 25-1021 PCT

[0231] In an example, after registered via the one or more network systems, the UE may establish one or more data sessions for the one or more network system. For example, the one or more network systems may comprise a first network system and a second network system. The first network system may be an EPS and / or the second network system may be a 5GS. For example, the one or more data sessions may comprise a first data session and / or a second data session. For example, the first data session may be a PDN connection and / or the first data session may be established / anchored toward the EPS. For example, the second data session may be a PDU session and / or the second data session may be established / anchored toward the 5GS.

[0232] In an example, registration over a plurality of network systems may help the UE to minimize service interruption time. For example, if the UE is registered only via a first network system, when the UE loses a coverage of the first network system, the UE may need to perform a search of a cell, a network system which is available, and may perform registration toward to the network system which is available. This may cause longer interruption time. On the other hand, the UE is already registered to the network system which is available, while the UE is in coverage of the first network system. In this case, as soon as the UE loses the coverage of the first network system, the UE can switch to the network system which is available. This may help the UE to avoid the search of the cell and / the registration

[0233] When the UE is registered over the plurality of network systems, the UE may move a data session, of the one or more data sessions, from one network system to another network system. For example, when the UE loses coverage of the first network system, the UE may request transfer of the first data session from the first network system to the second network system. In another example, when a signal quality of the second network system gets worse and / or weaker, the UE may request transfer of the second data session from the second network system to the first network system. For example, as long as the UE is already registered to both the first network system and the second network system, the UE can send request of transfer of a data session. For example, if the UE is notyet registered to the first network system, the UE can send request of transfer of the data session from the second network system to the first network system, only after the UE finishes registration toward the first network system. A PDN connection of the EPS may corresponds to a PDU session of the 5GS. A PDU session of the 5GS may correspond to a PDN connection of the EPS. For example, when a PDN connection of the EPS is transferred to 5GS, the PDN connection becomes a PDU session.

[0234] An example embodiment depicted in FIG. 18 may illustrate one example of using RAT utilization control information

[0235] In an example, a UE may perform a plurality of registration procedure toward a plurality of network systems and / or via a plurality of access technologies (e.g., as shown in previous examples). For example, the UE may be registered for an EPS and / or the UE may be registered for a 5GS. In an example, the EPS and / or the 5GS may be of a network (e.g., the same network, first network, a first network operator)

[0236] In an example, the UE may establish one or more data sessions via the plurality of network systems. For example, the UE may establish a first data session (e.g., a first PDN connection) via the EPS and / or a second data session (e.g., a second PDU session) via the 5GS.Docket No.: 25-1021 PCT

[0237] In an example, the network may determine to restrict one or more access technologies. For example, the network may determine to restrict use of NG-RAN, NR, 5G core, and / or the 5G system. Based on the determination, the network may determine to send a RAT utilization control information to the UE. For example, an AMF of the 5GS of the network may send a NAS message to the UE. The NAS message may comprise the RAT utilization control information and / or the RAT utilization control information may comprise a parameter indicating that the NG-RAN, the NR, the 5G core, the 5G system is restricted and / or that E-UTRAN, E-UTRAN, EPC and / or EPS is not restricted.

[0238] In an example, in response to sending the NAS message, the AMF may determine to delete a context of the UE. For example, deleting the context of the UE may be to delete information of the UE in the AMF, and / or to request release of one or more PDU sessions of the UE. For example, based on that the UE established the second data session, and / or based on having information of the second data session of the UE, the AMF may send a release request to an SMF. For example, the release request may request release of the second data session.

[0239] In an example, in response to receiving the release request, the SMF may release resources of the second data session. Because the second data session is released, the UE may not be able to exchange data via the second data session For example, because the second data session is released, an IP address associated with the second data session may be released.

[0240] As shown in the example of FIG 18, in a potential existing implementation, in response to determining to restrict one or more access technologies, a core network node associated with the one or more access technologies may send a RAT utilization control information to the UE and / or may initiate a procedure to release one or more data sessions associated with the one or more access technologies This may unnecessarily reduce amount of time during which the UE may be able to exchange data. For example, if the UE is registered via a plurality of network systems and / or if at least one of the plurality of the network systems are not restricted, the UE may be able to continue data communication via a non-restricted access technology of the at least one of the plurality of the network systems. However, in the existing implementation, based on that the data session is active over the one or more restricted access technology, the core network node may just terminate the data communication of the one or more data sessions. This leads to lower quality of service. .

[0241] An example embodiment depicted in FIG. 19 may illustrate one example of using RAT utilization control information

[0242] In an example, a UE may perform a plurality of registration procedures toward a plurality of network systems and / or via a plurality of access technologies (e.g., as shown in previous examples). For example, the UE may be registered for an EPS and / or the UE may be registered for a 5GS. In an example, the EPS and / or the 5GS may be of a network (e.g., the same network, first network, a first network operator)

[0243] In an example, the UE may establish one or more data sessions via the plurality of network systems. For example, the UE may establish a first data session (e.g., a first PDN connection) via the EPS and / or a second data session (e.g., a second PDU session) via the 5GS.

[0244] In an example, the network may determine to restrict one or more access technologies. For example, the network may determine to restrict use of NG-RAN, NR, 5G core, and / or the 5G system. Based on the determination, the network may configure one or more network nodes. For example, the MME and / or the AMF may be configuredDocket No.: 25-1021 PCTwith and / or may receive one or more policy information. For example, the one or more policy information may be the one or more second policy information.

[0245] For example, the one or more second policy information may indicate that E-UTRAN, E-UTRA, EPC, and / or EPS are not allowed and / or may indicate that NG-RAN, NR, 5GC and / or 5GS are allowed. Being allowed may be not being restricted. Not being allowed may be being restricted. For example, based on roaming agreement, service policy, user grade, network congestion and / or the like, the one or more second policy information may be decided.

[0246] Based on the determination, the network may determine to send a RAT utilization control information to the UE. For example, based on receiving and / or being configured with the one or more second policy information, one or more network nodes of the network may send one or more NAS messages to the UE. For example, the one or more network node may comprise at least one of an AMF of the 5GS of the network and / or a MME of the EPS of the network.

[0247] In an example, based on receiving the one or more second policy information, the MME may determine to send a first RATUCI to the UE. For example, the first RATUCI may be based on the one or more second policy information In an example, the MME may determine whether the UE is in CM-connected state or not. For example, in CM-connected state, the UE is in RRC connected state. In CM-connected state, the UE can send and / or receive one or more NAS messages, without requesting an RRC layer to establish an RRC connection. If the UE is not in CM-connected state, before the UE can send and / or receive one or more NAS messages, the UE needs to request the RRC layer to establish an RRC connection, and after establishing the RRC connection, the UE transits to CM-connected state, and can send the one or more NAS messages.

[0248] In an example, if the MME determines that the UE is not in CM-connected state, the MME may initiate a first paging procedure. For example, to bring the UE from non-CM-connected state (e.g., CM-idle state) to the CM-connected state, the MME may start the first paging procedure. For example, the MME may send S1 paging request message to a first RAN. For example, the first RAN may be an E-UTRAN and / or may use EUTRA In response to receiving the S1 paging request message, the first RAN may send one or more paging messages over one or more cells that the E-UTRAN manages.

[0249] In an example, the UE may receive at least one of the one or more paging messages, and the UE may respond. For example, the UE may start a RRC connection establishment procedure. For the RRC connection establishment procedure, the UE may send to the first RAN, a RRC Setup request message, the UE may receive RRC Setup message from the first RAN, the UE may send RRC setup complete message, and / or the like. For example, to send the RRC setup request message, the UE may perform a random access procedure.

[0250] In an example, after establishing the RRC connection, in response to the paging message, the UE may send a service request message to the MME via the first RAN. By receiving the service request message, the MME may determine that the UE is in CM-connected state, and that the MME can send to the UE, the first RATUCI.

[0251] In an example, based on the one or more second policy information, that the first RAT is restricted, the MME may determine to deregister the UE. For example, the MME may send a deregistration request message to the UE, and the deregistration request message may comprise the first RATUCI.Docket No.: 25-1021 PCT

[0252] In an example, based on receiving the one or more second policy information, the AMF may determine to send a second RATUCI to the UE. The second RATUCI may be same as the first RATUCI. For example, the second RATUCI may be based on the one or more second policy information. In an example, the AMF may determine whether the UE is in CM-connected state or not.

[0253] In an example, if the AMF determines that the UE is in CM-connected state, the AMF may determine that the AMF can send to the UE, the second RATUCI.

[0254] In an example, based on the one or more second policy information, that the second RAT is not restricted, the AMF may determine not to deregister the UE and / or to keep the UE as being registered. For example, the AMF may send a message to the UE. The message may be at least one of a service accept message, a UE configuration update message, registration accept, a DL NAS transport message, and / or the like. For example, the message may comprise the second RATUCI

[0255] As shown in the example of FIG 19, in a potential existing implementation, when the UE is registered via a plurality of the network systems of the network, delivering the RATUCI to the UE may waste lots of signalling resource and battery power In one example, when the UE is registered via the plurality of the network system, the same RATUCI may be redundantly delivered, by a plurality of network nodes, to the UE. In another example, if the UE is in CM Idle state, to deliver the RATUCI, a network node may page the UE to bring the UE to CM connected state. If the network node is associated an access technology that soon would be restricted, as soon as the network node finishes delivery of the RATUCI, the network node may send deregistration request message to the UE, to release a CM connection. This means that, even though there is no active data transfer for the UE, the network node performs the paging procedure, just to deregister the UE over the access technology that is to be restricted, in the end. This unnecessary and not-urgent paging procedure results in reduced battery power for a plurality of UEs which share same paging occasion as the UE, because the plurality of the UE also wake up to receive the paging Also, if the paging of the UE comprises transmission in a plurality of cells, downlink radio resources in the plurality of cells are also wasted .

[0256] Example embodiments of the present disclosure may solve the above issues. In one embodiment, based on receiving a RAT utilization control information and / or based on whether being registered via a plurality of systems, the UE may determine to transfer a data session from a first system to a second system. In another embodiment, based on receiving the RAT utilization control information and / or based on a time information, the UE may determine when to apply the RAT utilization control information and / or until when the UE needs to perform transfer of the data session. In another example, a network node may determine whether a time period elapses and may send a request for data session release, based on the determination. This may help the UE to minimize service interruption. In one embodiment, based on receiving the RAT utilization control information, the UE may determine whether the UE needs to transition to de-registered state for at least one of the one or more network systems. This may help in reducing unnecessary signaling procedures. In one embodiment, when a UE receives a NAS message while storing a RAT utilization control information, the UE may determine, based on at least one of a type of the NAS message, a cause value in the NAS message, and / or based on whether the NAS message comprises a second RAT utilization control information, whether to keep or discard the RAT utilization control information. This may help the UE toDocket No.: 25-1021PCTreduce service interruption time. In another example, when a UE sends a NAS message to a network, the UE may indicate whether the UE has a stored RAT utilization control information or not. This may help the network to determine whether to send another RAT utilization control information and / or to effectively control one or more restricted RATs. In another embodiment, a UE may expose RAT utilization control information to a user. This may help a user to determine whether to try registration to a network or not. In another example, a UE may determine whether to keep or discard RATUCI, based on whether the UE is registered to a prioritized service (e.g., for emergency service and / or for disaster roaming). This may help not to discard the RATUCI.

[0257] In the specification, the term “network system” may be interpreted as, or may refer to, a system, a communication system, and / or a generation of the communication system. For example, one or more network systems may comprise an EPS, a 5GS, a 6th generation (6G) system, and / or the like. For example, a first network system may be the EPS. The EPS may comprise of one or more UEs, one or more eNB, one or more en-gNBs, and / or one or more EPCs. The one or more EPCs may comprise a MME, a SGW, a PGW (e.g., a PGW-C+SMF, a PGW-U+UPF), HSS, PCRF, and / or the like. For example, a second network system may be the 5GS. The 5GS may comprise of one or more UEs, one or more gNB, one or more ng-eNBs, one or more 5G core networks. The one or more 5G core networks may comprise one or more core network nodes. The one or more core network nodes may comprise an AMF, a SMF, a PCF, a UPF, a UDM, a NEF, and / or the like. In some embodiments, a core network node may be a combination of one or more core network nodes of one or more core networks. For example, a SMF+PGW-C (e.g., PGW-C+SMF) may act as both a SMF and a PGW (e.g., PGW-C). For example, a SMF may act as a 5G core network node and a 6G core network node. For example, a third network system may be a 6th generation (6G) system (6GS). The 6GS may comprise of one or more UEs, one or more 6G-RAN (e.g., a radio access network node of 6G system), one or more 6gNBs (e.g., an equivalent of gNB for 6GS), one or more 6G core networks. The one or more 6G core networks may comprise one or more 6G core network nodes (e.g., 6G core network functions) Each of the one or more core network nodes may support (implement) one or more functions (or services) provided by each of the one or more 5G core network nodes. For example, a node of the 6GS may perform a function of a radio access network and / or one or more roles performed by one or more 6G core network nodes (or by 5G core network nodes).

[0258] In the specification, the term “5G System” may be interpreted as, or may refer to, a 3GPP system consisting of at least one of 5G access network (or NG-RAN), 5G core network and / or a UE.

[0259] In the specification, the term “EPS” may be interpreted as, or may refer to, a 3GPP system consisting of at least one of EPC, E-UTRAN and / or a UE.

[0260] In the specification, the term “network node” may be interpreted as, or may refer to, at least one of a core network node, an access node, a base station, a UE, the like, and / or a combination thereof. A network may comprise one or more network nodes

[0261] In the specification, the term “core network node” may be interpreted as, or may refer to, a core network device, which may comprise at least one of an AMF, a SMF, a NSSF, a UPF, a NRF a UDM, a PCF, a SoR-AF, an AF, an DDNMF, an MB-SMF, an MB-UPF, a MME, a SGW, a PGW, a SMF+PGW-C, a SMF+PGW-U, a UDM+HSS and / or the like. The core network node may be a 5G core network node, a 6G core network node, a 4G core networkDocket No.: 25-1021PCTnode, the likes, and / or a combination thereof. One or more names may be used by a core network node. A function performed by a first core network node of 5GS may be performed by a second core network node of 6GS.

[0262] In the specification, the term “5G core network” may be interpreted as, or may refer to, a core network connecting to a 5G access network. This may be 5G core (5GC).

[0263] In the specification, the term “5G access network” may be interpreted as, or may refer to, an access network comprising at least one of a NG-RAN and / or non-3GPP RAN, and connecting to a 5G core network.

[0264] In the specification, the term “3GPP RAN” may be interpreted as, or may refer to, a radio access network using 3GPP RAT. For example, this may comprise at least one of a gNB, an eNB, a ng-eNB, an en-gNB, the like, and / or a combination thereof. For example, this may be at least one of an E-UTRAN, NG-RAN, 6G-RAN (6th generation RAN), the like, and / or a combination thereof. The 3GPP RAN may be 3GPP access node.

[0265] In the specification, the term “NG-RAN” may be interpreted as, or may refer to, a base station, which may comprise at least one of a gNB, a ng-eNB, a relay node, a base station central unit (e.g., gNB-CU), a base station distributed unit (e.g., gNB-DU), and / or the like. This may be a radio access network that connects to 5GC, supporting at least one of NR, E-UTRA, and / or a combination thereof

[0266] In the specification, the term “E-UTRAN” may be interpreted as, or may refer to, a base station, which may comprise at least one of an eNB, an en-gNB, and / or the like. This may be a radio access network that connects to evolved packet core (EPC), supporting at least one of NR, E-UTRA, and / or a combination thereof.

[0267] In the specification, the term “mobility management node” may be interpreted as, or may refer to, a function and / or a node performing mobility management for a UE. For example, mobility management may be at least one of management of registration status, management of context, management of authorization, management of registration area, management of paging, and / or the like. For example, the mobility management node may comprise at least one of a MME, AMF, and / or the like.

[0268] In the specification, a term “procedure” may be interpreted as, or may refer to, comprising sending by a first node to a second node a first message, receiving by the second node from the first node the first message, sending by the second node to the first node a second message, and / or receiving by the first node from the second node the second message. The first node may be one or more first network nodes, and the second node may be a one or more second network nodes. The procedure may comprise a registration procedure, a deregistration procedure, a service request procedure, a notification procedure, a PDU session establishment procedure, a PDU session modification procedure, a UE configuration update procedure, a cell selection procedure, a cell reselection procedure, a random access procedure, a capability update procedure, and / or the like

[0269] In the specification, a term “NAS message” may be interpreted as, or may refer to, a message exchanged between a UE and a core network node. The NAS message may be exchanged via a 3GPP access and / or via a N3GPP access. The NAS message may comprise a MM (mobility management) message, a SM (session management) message, and / or the like The MM message may comprise a registration request message, a registration accept message, a registration reject message, a UE configuration update message, a UL NAS transport message, a DL NAS transport message, a deregistration message, a service request message, a service accept message, a service reject message, a PDU session establishment request message, a PDU session establishmentDocket No.: 25-1021 PCTaccept message, a PDU session establishment reject message, a PDU session modification request message, a PDU session modification accept message, a PDU session modification reject message, a PDU session modification command message, a PDU session release request message, a PDU session release command message, an ATTACH request message, an ATTACH accept message, an ATTACH reject message, an TAU request message, an TAU response message, an TAU reject message, a detach request message, a detach accept message, a GUTI reallocation message, and / or the like

[0270] In an example, a timer may begin running once it is started and continue running until it is stopped or until it expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e g. the timer may be started or restarted from a value or may be started from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to change of the value). A timer may be used to measure a time period / window for a process. When the specification refers to an implementation and procedure related to one or more timers, it will be understood that there are multiple ways to implement the one or more timers. For example, it will be understood that one or more of the multiple ways to implement a timer may be used to measure a time period / window for the procedure. For example, a network slice inactivity window timer (e.g., a NS UE monitoring timer, a NS PDU monitoring timer) may be used for measuring a window of time for measuring the network slice inactivity. In an example, instead of starting and expiry of a network slice inactivity window timer, the time difference between two time stamps may be used. When a timer is restarted, a process for measurement of time window may be restarted. Other example implementations may be provided to restart a measurement of a time window.

[0271] In an example, indication (e.g., indicate, indicating) may be achieved in various ways. For example, a first indication may be done by including a first field in a first signalling (e.g., a message) Alternatively and / or additional, a second indication may be done by not including the first field in the first signalling. For example, if a first message comprises the first field (e.g., used / assigned for the first indication, e.g., field A), the first indication (e.g., a timer is used) may be done (e.g., achieved, delivered from a sender to a receiver). For example, if the first field in the first message is set to a value A, a third indication (e.g., timer value is value A) may be done. For example, if the first message does not comprise the first field, the second indication (e.g., timer is not used) may be done. In another example, a fourth indication (e.g , a UE is allowed for action C) may be done by sending a second signalling (e.g., a message whose name comprises ‘C’ and / or ‘accept’). Alternatively and / or additionally, a fifth indication (e.g , a UE is not allowed for action C) may be done by not sending the second signalling (e.g., a message, a field (e.g., allowed bit)). For example, the sender can indicate A, by sending a message A1 comprising an indicator (e.g., an information element) indicating A and / or by sending a message A2. For example, the message A2 may be used only to indicate A and / or the message A2 itself may indicate the A. For example, when a first entity indicates to a second entity about first something, the first entity may send to the second entity, an indicator (e.g., an information element) indicating the first something, and / or may send to the second entity, a message comprising the indicator and / or may send a first dedicated message for the first something. In other example, when a first entity does not indicate to a second entity about second something, the first entity may not send to the second entity, a first indicator (e.g., an information element) indicating the second something, may not send to the second entity, a message comprising theDocket No.: 25-1021 PCTfirst indicator, and / or may send to the second entity, a second indicator indicating that the second something does not apply, and / or may send a message not comprising the first indicator, and / or may send to the second entity, a second dedicated message for indicating the second something. In another example, ‘not sending any message’ may be interpreted as an indication. In an example, ‘indicate’ may mean 'comprise one or more parameter indicating’. In an example, an indication may be implemented using one or more parameters included in one or more messages.

[0272] In an example, an indicator and / or an indication may be a parameter. In an example, an indicator and / or an indication may comprise one or more parameters, and / or may be implemented using one or more parameters.

[0273] In an example, 'based on a message (one or more messages)’ may be interpreted, or may refer to, as, ‘based on one or more information (one or more parameters) included in the message (the one or more messages)’, ‘using (acting) on one or more information (one or more parameters) included in the message (the one or more messages)’, and / or the like.

[0274] In an example, that a message indicates A may be interpreted that a parameter of the message indicates A, that the parameter of the message is A, and / or the like.

[0275] In the specification, “protocol entity” may be interpreted, or may refer to, as an entity performing a set of specific functions related to a wireless access (e.g., LTE access, NR access) and / or a wireline access (e.g., Ethernet) and / or communication (e.g., TCP, IP). In an example, an entity (or a layer) may be interpreted as a protocol entity (or a protocol layer). In an example, the protocol entity of LTE and / or NR may be at least one of a SDAP entity, a PDCP entity, a RLC entity, a MAC entity, a RRC entity, a NAS entity, and / or a PHY entity. In an example, a layer (e g., a SDAP layer, a PDCP layer, a RLC layer, a MAC layer a PHY layer, a RRC layer, a NAS layer) may be interpreted as a protocol entity (e.g., SDAP entity, a PDCP entity, a RLC entity, a MAC entity, a PHY entity, a RRC entity, a NAS entity).

[0276] In the specification, “RAT utilization control information” may be interpreted, or may refer to, as an information that a network operator may use to restrict UE / subscriber’s access to certain access technologies A network (of the network operator) may send the RAT utilization control information for a current network. For example, the current network may be a current PLMN, equivalent PLMN(s), a NPN (non-public network), a SNPN (standalone NPN), and / or the like. A core network node of the network may send a NAS message comprising the RAT utilization control information (RATUCI) to a UE. For example, the NAS message may be at least one of an ATTACH ACCEPT, ATTACH REJECT, TAU ACCEPT, TAU REJECT, GUTI ALLOCATION, DETACH REQUEST, SERVICE ACCEPT, SERVICE REJECT, REGISTRATION ACCEPT, REGISTRATION REJECT, UE CONFIGURATION UPDATE COMMAND, DEREGISTRATION REQUEST, and / or the like. Each RATUCI of one or more RATUCIs may be associated with each network of one or more networks. Different networks may restrict different access technologies. A first network may apply restriction of different or same access technologies to different UEs. In one or more examples, access technology may be interpreted as a RAT, a RAN, a core network, a system. When the UE receives the RATUCI, the UE may store the RATUCI with an identity of the network from which the RATUCI is received. In an example, RATUCI may be a RAT utilization information. The RATUCI may be a RAT control utilization information, a RATCUI, and / or the like

[0277] For example, the RATUCI, associated with (linked to) the network, for the UE, may comprise at least one of:Docket No.: 25-1021 PCT

[0278] - whether a GERAN and / or GSM of the network is restricted or not to the UE;

[0279] - whether a UTRAN and / or WCDMA of the network is restricted or not to the UE;

[0280] - whether a E-UTRAN and / or EUTRA of the network is restricted or not to the UE;

[0281] - whether a NG-RAN and / or NR of the network is restricted or not to the UE;

[0282] - whether a 6G-RAN and / or 6GR of the network is restricted or not to the UE;

[0283] - whether a 7G-RAN (7th generation RAN) and / or 7GR (7th generation RAT / radio) of the network is restricted or not to the UE.

[0284] In an example, RATUCI may be different from other restriction information. For example, indication of rejecting a request via a WiFi may be not a RATUCI. For example, from 3GPP network point of view, one or more 3GPP access technologies (e.g., NG-RAN, E-UTRAN, etc ) are used solely for connecting to 3GPP network (network system). However, accessing 3GPP network via WiFi is one of reasons why a UE is connected to an access point providing WiFi. For example, when the UE is connected to a WiFi, the 3GPP network only can indicate not to use the WiFi for 3GPP network access, and / or cannot indicate not to use the WiFi for non-3GPP network access. In other example, RATUCI may be different of user’s decision to restrict use of certain access technology. For example, some access technologies may be restricted due to capability of a UE, and / or preference of a user of the UE. In this case, the network cannot control the restriction and / or the network may not be aware of the restriction, making the network to control steering of the UE.

[0285] In the specification, “RAT” may be interpreted, or may refer to a radio interface technology used for a UE. For example, one or more RATs may comprise a GSM, a WCDMA, a EUTRA, a NR, a 6GR, a 7GR, and / or the like. For example, the RAT may be interpreted as, or may refer to, as a transmission technology used in the access network for 3GPP accesses and / or for non-3GPP accesses. The RAT may refer to technology used over Uu interface, PC5 (sidelink) interface, and / or the like. In one or more example, the RAT may be interpreted as, may be interpreted as indicating, and / or may be interpreted as indicating association to, an access technology, a RAN, a core network, a system, and / or the like.

[0286] In the specification, “access technology” may be interpreted, or may refer to, a radio access used for search one or more networks / cells, select one or more networks / cells, access one or more networks / cells, communicate with one or more networks / cells and / or like. The radio access may be associated with a RAN, a RAT, a core network, a system, and / or the like. A type of access network and / or a type of radio access may indicate at least one of a type of RAN, a type of RAT, a type of core network, a type of system, and / or the like The access technology may be associated with a network. The network may be a PLMN, a NPN, a SNPN, and / or the like. A UE may use information of the access technology to determine what type(s) of radio carrier (e.g., frequency) to search for when attempting to select a network, and / or what type(s) or RAT to search / use, and / or the like. Examples of access technologies may be GSM, UTRAN, GSM COMPACT, EC-GSM-loT, cdma2000 1xRTT, cdma2000 HRPD, E-UTRAN (WB-S1 mode and NB-S1 mode), NG-RAN, satellite NG-RAN and satellite E-UTRAN (WB-S1 mode and NB-S1 mode), a 6G RAN, a 7G RAN, and / or the like. A network (e.g., a PLMN, a NPN) may support, deploy, and / or use more than one access technology. Access technology "E-UTRAN" maps to a core network type "EPC" and access technology "NG-RAN" may map to a core network type "5GCN". EPC may be Evolved Packet Core. A 5GCN may be a 5G core networkDocket No.: 25-1021 PCTand / or 5G core (5GC). An restricted access technology may be an access technology that is indicated as restricted by a RATUCI. A non- restricted access technology may be an access technology that is indicated as not being restricted by a RATUCI and / or an access technology that is not indicated by the RATUCI.

[0287] In the specification, “dual registration” may be interpreted, or may refer to, as a mode of registration, in which a UE handles independent registrations for 5GC (5GS), EPC (EPS), 6GC (6GS), and / or the like, using separate RRC connection. For example, in this mode, the UE maintains 5G-GUTI, EPS-GUTI, 6G-GUTi, and / or the like, independently. In this mode, the UE may be registered to 5GC only, EPC only, 6GC only, both 5GC and EPC, both 6GC and 5GC, both 6GC and EPC and / or both 6GC, 5GC and EPC.

[0288] In the specification, “data session” may be interpreted, or may refer to, as an association between a UE and a data network that provides a data session connectivity service. For example, the data session may be a PDU session, a PDN connection, and / or the like. For example, a first type of data session of a first system may correspond to a second type of data session of a second system. For example, a PDN connection of EPS may correspond to a PDU session of 5GS. For example, during handover between EPS and 5GS and / or during data session transfer, the PDN connection of EPS may be changed to the PDU session of 5GS, vice versa. For example, if a PDN connection used in the EPS is handed over to 5GS, the PDN connection may become a PDU session in the 5GS. Similarly, if a PDU session used in the 5GS is handed over to EPS, the PDU session may become a PDN connection in the 5GS. While the data session is not released in the first system, the UE can request handover / transfer of the data session to the second system. After the data session is released in the first system, the UE can not request handover / transfer of the data session to the second system, because there is no context for the second system to fetch from the first system, regarding the data session. Once the data session is established and / or until the data session is released, the UE may be able to receive data packet via the data session.

[0289] FIG. 20 illustrates an example as per an aspect of an embodiment of the present disclosure. In an example, a UE may receive a RATUCI from a network. The UE may determine whether a data session is established over an access technology that is restricted by the RATUCI Based on the determination, the UE may transfer the data session from the access technology that is restricted, to another access technology that is not restricted. This may help reduce service interruption time and / or support service continuity. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0290] In an example, a UE may perform one or more registration procedures for one or more systems. In an example, the one or more systems may be of a network of a network operator. For example, the network operator may operate the network. The network may comprise the one or more systems, to address various demands, based on different characteristics of the one or more systems. Each registration procedure, of the one or more registration procedures, may comprise sending a request message requesting registration and / or receiving a response message responding to the request message, to / from / via a node of the one or more systems, to the one or more systems.

[0291] In an example, each system of the one or more systems may be a network system, a communication system, and / or the like. The each system may comprise at least one of a UE, a RAN, a core network, and / or the like. The each system may be a network system. Each of the one or more systems may be at least one of a GSM system,Docket No.: 25-1021PCTa GERAN system, a UTRAN system, a UMTS, a EUTRAN system, an EPS, a NG RAN system, a 5GS, a 6G RAN system, a 6GS, and / or the like.

[0292] For example, the response message may be an accept message accepting registration, a reject message indicating registration, an accept message accepting a request, an reject message rejecting a request, a DL NAS transport message, and / or the like. For example, the response message may indicate accept (acceptance) of the registration and / or reject of the registration. For example, the request message may be at least one of an Attach request message, a Registration request message, a TA update request message, a service request message, a message indicating request associated with mobility management, a message for requesting registration to 6G system (6GS), and / or the like. A response message may be at least one of an Attach accept message, an Attach reject message, a Registration accept message, a Registration reject message, a TA update accept message, a TA update reject message, a service accept message, a service reject message, a message indicating accept for mobility management, a message indicating reject for mobility management, a message for accepting registration to 6GS, a message for rejecting registration to 6GS, a deregistration request message, a detach request message, a UE configuration update message, a DL NAS transport message, and / or the like.

[0293] For example, the one or more registration procedures may comprise a first registration procedure to a first system, a second registration procedure to a second system, a third registration procedure to a third system, and / or the like.

[0294] For example, the first registration procedure to the first system may be an Attach procedure to EPS, the second registration procedure to the second system may be a Registration procedure to 5GS, and / or the third registration procedure to the third system may be a 6G registration procedure to 6GS (e.g., 6G system).

[0295] The third registration procedure may comprise: sending by the UE to an 6GMF (e.g., a mobility management function of 6GS), the message for requesting registration to the 6GS; receiving by the UE from the 6GMF, at least one of the message for accepting registration to 6GS, or the message for rejecting registration to 6GS. For example, the third system may be a 5GS and / or 6GS.

[0296] In an example, the first registration procedure may comprise: sending by the UE to a MME, the Attach request message (or TA update request message, a service request message, a UL NAS transport message, a deregistration request message); receiving by the UE from the MME, at least one of the Attach Reject message (or TA update reject message, a service reject message, a DL NAS transport message, and / or the like) or the Attach Accept message (or TA update accept message, a service accept message, a DL NAS transport message, and / or the like). For example, the first system may be an EPS.

[0297] In an example, for the first registration procedure, the UE may send a first registration message to a first core network node of the first system The first system may be the first network system. The first registration request message may be at least one of a first attach request message or a first TA update request message, and / or the like. The first core network node of the first core network may be a first MME. The first network system may be a first EPS. The first core network associated with the first core network node may be an evolved packet core (EPC). The UE may send the first registration request message via a first radio access network (RAN) to the first core network node. The first radio access network may be a first E-UTRAN. The first E-UTRAN may use a first RAT toward theDocket No.: 25-1021 PCTUE. The first RAT may be at least one of a E-UTRA, NR, and / or a 6GR (6G Radio). The first RAT may be a first access technology.

[0298] In an example, the UE may receive a first registration response message, from the first core network node (e g., MME) of the first system (e.g., EPS), via the first RAN. The first registration response message may be at least one of a first attach accept message, a first TA update accept message, and / or the like. The UE may receive the first registration response message via the first radio access network from the first core network node.

[0299] In an example, based on receiving the first registration response message and / or based on the first registration response message indicating accept / acceptance of registration, the UE may transit to a first registered state for the first system. The first registered state may be EMM-registered state for a first mobility management state for the first system. For example, because the first registration response message indicates accept of registration, the UE may consider that the UE is registered to the first network system.

[0300] The second registration procedure may comprise: sending by the UE to an AMF, the registration request message (or a service request message, a UL NAS transport message, and / or the like); receiving by the UE from the AMF, at least one of the Registration Reject message (or a service reject message, a DL NAS transport message, and / or the like) or the Registration Accept message (or a service accept message, a DL NAS transport message, and / or the like). For example, the second system may be an 5GS and / or 6GS.

[0301] In an example, the UE may send a second registration request message to a second core network node of a second network system. The second system may be the second network system. The UE may send the second registration request message while the UE stays in first registered state for the first system. The second registration request message may be at least one of a second 5G registration request message The second core network node may be a second AMF. The second network system may be a second 5GS. A second core network associated with the second core network node may be a second 5GC (5G core). The UE may send the second registration message via a second radio access network to the second core network node. The second radio access network may be a second NG-RAN. The second NG-RAN may use a second RAT. The second RAT may be at least one of an E-UTRA, NR, and / or a 6GR (6G Radio). The second RAT may be a second access technology.

[0302] In an example, the UE may receive a second registration response message from the second core network node. The second registration response message may be at least one of a second 5GS registration accept message, and / or the like. The UE may receive the second registration response message via the second radio access network from the second core network.

[0303] In an example, based on receiving the second registration response message, and / or based on the second registration response message indicating acceptance of registration, the UE may transit to a second registered state (e g., second mobility management state) for the second system. For example, the second registered state may be 5GMM-registered state. For example, because the second registration response message indicates accept of registration, the UE may consider that the UE is registered to the second network system. The 5GMM-registered state may be 5G RM (registration management) registered state.

[0304] In an example, the UE may manage one or more registration status for the one or more network systems. A registration status of the one or more registration status may be a registration state, a mobility management state,Docket No.: 25-1021 PCTand / or the like. The registration status for a network system may indicate whether the UE is registered and / or deregistered for the network system.

[0305] For example, when the UE supports dual registration, and / or when the UE determines to use dual registration, the UE may perform a plurality of registration procedures to a plurality of network systems. For example, the plurality of registration procedures may comprise two or more registration procedures, of the one or more registrations. For example, after the two or more registration procedures, the UE may remain registered for the plurality of network systems. For example, the plurality of network systems may comprise the first network system and / or the second network system. For example, the UE may be in 5GMM-registered and EMM-registered state. For example, the UE may be registered in both the first network system and / or the second network system In this case, the one or more network systems may be the plurality of network systems, the one or more registrations may be the plurality of registrations, the one or more registered state may be the plurality of registered states.

[0306] In an example, based on the UE being registered at least one of the one or more network systems, the UE may determine to establish one or more data sessions via the one or more network systems for which the UE is registered. For example, the UE may establish a second data session (e.g , a second data session e.g , second PDU connection) via the second network system and / or a first data session (e.g., a first data session, e g., first PDN session) via the first network system.

[0307] In an example, to establish the first data session, while the UE is in the first registered state, the UE may send a first data session establishment request message (e.g., PDN connection (connectivity) request message) to the first network system. For example, in response to sending the first data session establishment request message, the UE may receive from the first network node, a first data session establishment accept message. For example, the first data session establishment request message may comprise a first first system data session identifier of the first data session and / or a first second system data session identifier of the first data session. For example, the first first system data session identifier may identify the first data session when used in the first network system and / or the first second system data session identifier may identify the first data session when used in (transferred to) the second network system. For example, the first data session establishment accept message may comprise the first first system data session identifier of the first data session and / or the first second system data session identifier of the first data session.

[0308] In an example, to establish the second data session, while the UE is in the second registered state for the second network system, the UE may send a second data session establishment request message (e.g., PDU session establishment request message) to the second network system. For example, in response to sending the second data session establishment request message, the UE may receive from the second network node, a second data session establishment accept message. For example, the second data session establishment request message may comprise a second first system data session identifier of the second data session and / or a second second system data session identifier of the second data session. For example, the second second system data session identifier may identify the second data session when used in the second network system and / or the second first system data session identifier may identify the second data session when used in (transferred to) the first network system. For example, the second data session establishment accept message may comprise the second first systemDocket No.: 25-1021 PCTdata session identifier of the second data session and / or the second first system data session identifier of the second data session.

[0309] In an example, after establishing the one or more data sessions, the UE may exchange one or more data packets via the one or more data sessions. For each data session, of the one or more data sessions, the UE may send the one or more data packets via a current access technology where the each data session is associated currently (e g., at the time of the sending).

[0310] For example, the UE may send a data packet of the first data session via the first access technology: after the first data session is established via the first access technology until / before the first data session is released; after the first data session is established via the first access technology until / before the first data session is transferred to the second access technology; after the first data session is transferred from the second access technology to the first access technology until / before the first data session is released; after the first data session is transferred from the second access technology to the first access technology until / before the first data session is transferred to the second access technology; and / or the like.

[0311] For example, the UE may send the data packet of the first data session via the second access technology: after the first data session is established via the second access technology until / before the first data session is released; after the first data session is established via the second access technology until / before the first data session is transferred to the first access technology; after the first data session is transferred from the first access technology to the second access technology until / before the first data session is released; after the first data session is transferred from the first access technology to the second access technology until / before the first data session is transferred to the first access technology; and / or the like.

[0312] For example, the UE may send a data packet of the second data session via the second access technology: after the second data session is established via the second access technology until / before the second data session is released; after the second data session is established via the second access technology until / before the second data session is transferred to the first access technology; after the second data session is transferred from the first access technology to the second access technology until / before the second data session is released; after the second data session is transferred from the first access technology to the second access technology until / before the second data session is transferred to the first access technology; and / or the like.

[0313] While the UE is registered to the plurality of the network system, the UE may determine, for each data session that is established (and not released), whether to use the each data session via the first network system, whether to use the each data session via the second network system, whether to transfer the each data session from the first network system to the second network system, whether to transfer the each data session from the second network system to the first networks system.

[0314] In an example, the network may determine to restrict one or more access technologies, based on various configuration of the network. For example, the network may determine not to restrict use of the first access technology (e g., the first RAT, the first RAN, the first core network, the first network system) and / or may determine to restrict use of the second access technology (e.g., the second RAT, the second RAN, the second core network, theDocket No.: 25-1021 PCTsecond network system). For example, the second access technology may be an access technology that is restricted and / or the first access technology may be an access technology that is not restricted.

[0315] Based on the determination, the network may configure one or more network nodes (e g., the first core network node, the second core network node). A network node may be a core network node. For example, the one or more (core) network nodes may be configured with and / or may receive one or more policy information. For example, the one or more policy information may indicate, regarding the UE, one or more first access technologies that are not restricted and / or one or more second access technologies that are restricted. For example, the one or more first access technologies may comprise the first access technology and / or the one or more second access technologies may comprise the second access technology.

[0316] In an example, based on being configured with the one or more policy information and / or based on receiving the one or more policy information, the network may determine to send a RAT utilization control information (RATUCI) to the UE. For example, based on receiving and / or being configured with the one or more policy information, one or more first network nodes (e.g., the first core network node) of the network may determine to send one or more first NAS messages to the UE and / or one or more second network nodes (e.g., the second core network node) of the network may determine not to send the one or more first NAS messages to the UE For example, to save signalling, the one or more second network nodes may determine not to send the RATUCI. For example, the one or more network nodes may comprise one or more network nodes managing mobility of the UE. For example, the one or more network nodes comprises at least one of an AMF of the 5GS of the network and / or a MME of the EPS of the network.

[0317] In an example, based on receiving the one or more policy information, the first core network node of the first network system may determine to send a first NAS message, of the one or more first NAS messages, to the UE For example, the first NAS message may comprise one or more information identifiers indicating whether the first NAS message comprises the first RATUCI. If the one or more information identifiers indicate that the first NAS message comprises the first RATUCI, the first NAS message may further comprise the first RATUCI. For example, the first RATUCI may be based on the one or more policy information. The first RATUCI may comprise one or more first parameters and / or one or more second parameters.

[0318] The one or more first parameters may indicate that the one or more first access technologies are not restricted and / or that the one or more second access technologies are restricted. For example, for each access technology, of one or more access technologies, the one or more first parameter may indicate whether the each access technology is restricted or not restricted.

[0319] The one or more second parameters may indicate one or more conditions. For example, the one or more conditions may comprise one or more time criterion and / or one or more location criterion The one or more conditions may indicate when the one or more first parameters are valid and / or when the one or more first parameters are invalid. In an example, the one or more policy information may comprise the one or more second parameters.

[0320] For example, the one or more time criterion may indicate one or more time values and or one or more time periods.Docket No.: 25-1021 PCT

[0321] For example, each time value, of the one or more time values, may indicate at least one of: a (start) time from which the one or more first parameters are valid; an (end) time until when the UE needs to transfer a data session from the second access technology to the first access technology; a (start) time from which the UE cannot request to transfer the data session from the second access technology to the first access technology; a start time from when data transmission / reception via the second access technology is not allowed; a start time from when selection of the second access technology is not allowed; a start time from when selection of the first access technology is allowed; and / or the like

[0322] For example, each time period, of the one or more time periods, may indicate at least one of: a time duration during which the one or more first parameters are valid; a time duration during which the UE needs to transfer a data session from the second access technology to the first access technology; a time duration during which the UE cannot request to transfer the data session from the second access technology to the first access technology; a time duration during which data transmission / reception via the second access technology is not allowed; a time duration during which selection of the second access technology is not allowed; a time duration during which selection of the first access technology is allowed; and / or the like.

[0323] For example, the one or more location criterion may indicate one or more TAs, one or more Cells, and / or the like.

[0324] For example, the one or more location criterion may indicate at least one of: an area in which the one or more first parameters are valid; an area in which the UE needs to transfer a data session from the second access technology to the first access technology; an area in which the UE cannot request to transfer the data session from the second access technology to the first access technology; an area in which data transmission / reception via the second access technology is not allowed; an area in which selection of the second access technology is not allowed; an area which selection of the first access technology is allowed; and / or the like.

[0325] For example, the UE may receive the one or more first NAS messages from the network. For example, the UE may receive the one or more first NAS messages via the first access technology and / or from the first core network node (i.e., first network node). For example, the one or more first NAS messages may comprise the first NAS message.

[0326] In response to receiving the first NAS message, the UE may determine whether the first NAS message comprises the first RATUCI. In response to determining that the first NAS message comprises the first RATUCI, the UE may determine whether the first RATUCI comprises the one or more second parameters.

[0327] For example, if the first RATUCI does not comprise the one or more second parameters, the UE may immediately apply the one or more first parameters.

[0328] For example, applying the one or more first parameters may be at least one of: stop using one or more restricted access technologies; start / keep using one or more non-restricted access technologies; releasing one or more data sessions active over the one or more restricted access technology; sending release request messages for one or more data sessions active over the one or more restricted access technology; sending transfer request message for one or more data sessions active over the one or more restricted access technology, from the one or more restricted access technologies to the one or more non-restricted access technologies; sending de-registrationDocket No.: 25-1021 PCTrequest messages to the core network node via the one or more restricted access technology; not selecting a cell of the one or more restricted access technologies; disabling the one or more restricted access technologies; sending registration request to one or more non-restricted access technologies; selecting a cell of the one or more nonrestricted access technologies; and / or the like.

[0329] Alternatively and / or additionally, if the first RATUCI comprises the one or more second parameters, the UE may apply the one or more first parameters, based on the one or more second parameters. For example, based on the one or more second parameters, if the UE is in location area indicated by the one or more location criterion and / or a time is the time indicated by the one or more time criterion, the UE may apply the one or more parameters. For example, based on the one or more second parameters, if the UE is not in location area indicated by the one or more location criterion and / or a time is not the time indicated by the one or more time criterion, the UE may not apply the one or more first parameters For example, if the one or more second parameters indicate the start time from which the one or more first parameters are valid, and if the current time is before the start time, the UE may not apply the one or more first parameters For example, if the one or more second parameters indicate the start time from which the one or more first parameters are valid, and if the current time is after the start time, the UE may apply the one or more first parameters. For example, if the one or more second parameters indicate the time duration during which the one or more first parameters are valid, and if the current time is not in the time duration, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the time duration during which the one or more first parameters are valid, and if the current time is in the time duration, the UE may apply the one or more first parameters. For example, if the one or more second parameters indicate the end time during which the one or more first parameters are valid, and if the current time is after the end time, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the end time during which the one or more first parameters are valid, and if the current time is before the end time, the UE may apply the one or more first parameters.

[0330] In response to receiving the one or more first NAS messages comprising the first RATUCI, the UE may determine whether the UE needs to transfer one or more transfer data sessions to be transferred, among one or more established data sessions (e.g., the first data session, the second data session) that are established, from the second access technology to the first access technology. For example, for each established data session, among the one or more established data session, the UE may determine whether the each established data session is currently active / established / kept over the one or more restricted access technologies and / or over the one or more nonrestricted access technologies.

[0331] For example, if the first data session uses a resource of the non-restricted access technology, if the first data session is kept / active over the non-restricted access technology, if the first data session is not transferred to the restricted access technology since established over the non-restricted access technology, and / or the like, the UE may determine that first data session is currently active / established / kept over non-restricted access technology.

[0332] For example, if the UE determines that the each establish data session is currently active / established / kept over a non-restricted access technology, the UE may determine not to request transfer of the each established dataDocket No.: 25-1021 PCTsession. For example, the UE may not send a request message, to a network, requesting transfer of the first data session.

[0333] For example, if the second data session uses a resource of the restricted access technology, if the second data session is kept / active over the restricted access technology, if the second data session is not transferred to the non-restricted access technology since established over the restricted access technology, and / or the like, the UE may determine that the second data session is currently active / established / kept over a restricted access technology.

[0334] If the UE determines that the each establish data session is currently active / established / kept over the restricted access technology, the UE may determine whether to request transfer of the each established data session from one network system to another network system, or whether to release the each established data session. For example, if the UE determines that potential QoS quality available via the non-restricted access technology is not enough for the each established data session, the UE may determine to release (e.g., to send request message requesting release, not to send request message requesting transfer) the each data session. For example, if the UE determines that potential QoS quality available via the non-restricted access technology is enough for the each established data session, the UE may determine to request transfer of the each established data session.Additionally and / or alternatively, in above procedure, if the UE is registered for the plurality of network systems, the UE may determine to request transfer of the each established data session. Additionally and / or alternatively, in above procedure, if the UE is not registered for the plurality of network systems, the UE may determine not to request transfer of the each established data session.

[0335] In an example, in response to determining to release the each established data session, the UE may send a data session release request message for the each established data session, to the network and / or the UE may locally release the each established data session, to save signalling. For example, the UE may send the data session release request message, at least one of via the first access technology to the first core network node and / or via the second access technology to the second core network node.

[0336] In an example, if the one or more second parameters are received, based on the one or more second parameters, the UE may send the data session release request message, while the one or more conditions are met. For example, the UE may not send the data session release request message until a current time passes the start time value. For example, the UE may send the data session release request message after a current time passes the start time value. For example, the UE may send the data session release request message before a current time does not pass the end time value. For example, the UE may not send the data session release request message after a current time does not pass the end time value. For example, the UE may send the data session release request message during the time period. For example, the UE may send the data session release request message while not in the time period.

[0337] In an example, in response to determining to transfer the each established data session from one or more restricted access technologies to one or more non-restricted access technologies, the UE may send a data session transfer request message, for the each established data session, to the network. For example, the UE may send the data session transfer request message, via one or more non-restricted access technologies, to a core network nodeDocket No.: 25-1021PCTassociated with the one or more non-restricted access technology. For example, because the first access technology is not restricted by the RATUCI, because the second access technology is restricted by the RATUCI, and / or based on that the each established data session is currently established over the second access technology, the UE may send the data session transfer request message via the first access technology. The data session transfer request message may comprise one or more identifiers of the each established data session. For example, the one or more identifiers of the each established data session (e.g., the second data session) may comprise at least one of a first identifier (e g., the second first data session identifier) of the each established data session used in the first access technology and / or a second identifier (e.g , the second second data session identifier) of the each established data session associated with the second access technology. For example, the data session transfer request message may comprise a request type field. For example, the request type filed may indicate a value. The value may indicate at least one of that the each established data session is existing data session, handover, and / or the like.

[0338] In an example, if the UE determines to transfer the data session, the UE may send the data transfer request message, based on the one or more second parameters. The data transfer request message may be a data session transfer request message and / or a data session establishment request message for data transfer / handover. For example, if the one or more conditions are met, the UE may send the data transfer request message. For example, if the one or more time criterion are met and / or if the UE is in the one or more location areas, the UE may send the data transfer request message. In another example, if the one or more time criterion are not met and / or if the UE is not in the one or more location, the UE may send the data transfer request message. For example, the UE may not send the data transfer request message until a current time passes the start time value. For example, the UE may send the data transfer request message after a current time passes the start time value. For example, the UE may send the data transfer request message before a current time does not pass the end time value. For example, the UE may not send the data transfer request message after a current time does not pass the end time value. For example, the UE may send the data transfer request message during the time period. For example, the UE may send the data transfer request message while not in the time period.

[0339] For example, if the RATUCI indicates that E-UTRAN of EPS is restricted, the UE may send a data session transfer request to an AMF of 5GS For example, the data session transfer request may comprise a parameter indicating an identifier of the data session (e.g., PDN connectivity ID, PDU session ID) For example, the data session transfer request may comprise a parameter indicating that the data session is an existing session, that the request is due to handover, and / or the like. In an example, the RATUCI may comprise a time information Based on the time information and / or based on the RATUCI comprising the time information, the UE may determine whether to send the data transfer request message or not. For example, the data transfer request message may be a PDU session establishment request message. For example, the time information may indicate at least one of a start time when the restriction indicated by the RATUCI (e.g., restriction of EUTRAN) starts, an end time when a transfer of the data session is allowed, and / or the like. In this case, the UE may determine whether a current time (e.g., a time when the UE determines to request the transfer) is before / after the time indicated by the time information. If the current time is before / after the time, the UE may send the data transfer request message. If the current time is not before / after the time, the UE may not send the data transfer request message.Docket No.: 25-1021 PCT

[0340] In another example, if the RATUCI indicates that NG-RAN of 5GS is restricted, the UE may send a data session transfer request to an MME of EPS. For example, the data session transfer request may comprise a parameter indicating an identifier of the data session (e.g., PDU session ID, connectivity ID). For example, the data session transfer request may comprise a parameter indicating that the data session is an existing session, that the request is due to handover, and / or the like. In an example, the RATUCI may comprise a time information Based on the time information and / or based on the RATUCI comprising the time information, the UE may determine whether to send the data transfer request message or not. For example, the data transfer request message may be a PDN connectivity establishment request message. For example, the time information may indicate at least one of a start time when the restriction indicated by the RATUCI (e.g., restriction of NG-RAN) starts, an end time when a transfer of the data session is allowed, and / or the like. In this case, the UE may determine whether a current time (e.g., a time when the UE determines to request the transfer) is before / after the time indicated by the time information If the current time is before / after the time, the UE may send the data transfer request message. If the current time is not before / after the time, the UE may not send the data transfer request message.

[0341] In an example, the one or more network nodes may determine whether the one or more conditions of the one or more second parameters are met, or the one or more conditions are no longer met. For example, based on the one or more conditions, the one or more network nodes may release one or more second established data sessions, among the one or more established data sessions. For example, the one or more second established data sessions may be established over the one or more restricted access technologies, and / or may not yet transferred to the one or more non-restricted access technologies, and / or the like. For example, if the UE does not send a request to transfer a second established data sessions, among the one or more second established data sessions, from the one or more restricted access technologies to the one or more non-restricted access technologies, the second established data session may remain in the one or more restricted access technologies. In this case, if the one or more conditions are met and / or not met, the one or more network nodes may send a third network node, to release the second established data session. For example, the one or more network nodes may be one or more network nodes of the one or more restricted access technologies. The third network node may be a core network node managing the one or more second established data sessions. For example, that one or more conditions are met may be that the time until the UE needs to transfer the data session elapses, that a condition with which the one or more parameters are valid is met, that the time that the one or more restricted access technologies is not allowed starts, and / or the like.

[0342] Example embodiments of FIG. 20 may help to minimize a service interruption time during which the UE may not be able to use a data session. For example, based on the RATUCI and / or one or more parameters indicating time and / or location, the UE may be able to request transfer of one or more data session from one or more restricted RATs to one or more non-restricted RATs, the UE may be able to determine when the RATUCI is valid or not. This may help to manage one or more data session over one or more access technologies, while minimizing service interruption

[0343] FIG. 21 illustrates an example as per an aspect of an embodiment of the present disclosure. In an example, a UE may receive a RATUCI (RAT utilization control information) from a network. Based on the RATUCI, the UE mayDocket No.: 25-1021 PCTdetermine whether to request transfer of a data session. This may help in reducing service interruption For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0344] In an example, a UE may perform one or more registration procedures toward one or more (network) systems. In an example, the one or more systems may belong to a network of a (same) network operator. For example, the network operator may operate the network. The network may comprise a first system and a second system, to address various demands, based on different characteristics of the one or more systems. For example, the first system may be an 5GS and / or the second system may be an EPS.

[0345] For example, the one or more registration procedures may comprise a first registration procedure to the first system, a second registration procedure to the second system, a third registration procedure to a third system, and / or the like.

[0346] For example, the second registration procedure to the second system may be an Attach procedure to the EPS, the first registration procedure to the first system may be a registration procedure to the 5GS and / or a 6G registration procedure to the 6GS (e.g., 6G system).

[0347] In an example, the second registration procedure may comprise: sending by the UE to a MME, at least one of the Attach request message (or TA update request message, a service request message, a UL NAS transport message, a deregistration request message); receiving by the UE from the MME of the EPS, at least one of the Attach Reject message (or TA update reject message, a service reject message, a DL NAS transport message, and / or the like) or the Attach Accept message (or TA update accept message, a service accept message, a DL NAS transport message, and / or the like). For example, the second system may be the EPS

[0348] In an example, for the second registration procedure, the UE may send a second registration message to a second core network node of the second system The second system may be the second network system. The second registration request message may be at least one of a second attach request message or a second TA update request message, and / or the like. The second core network node of the second core network may be a second MME and / or a second AMF. The second network system may be a second EPS and / or a second 5GS. The second core network associated with the second core network node may be an evolved packet core (EPC) and / or a second 5GC. The UE may send the second registration request message via a second radio access network (RAN) to the second core network node. The second radio access network may be a second E-UTRAN and / or a second NG-RAN The second E-UTRAN may use a second RAT toward the UE. The second RAT may be at least one of a E-UTRA, NR, and / or a 6GR (6G Radio). The second RAT may be a first access technology.

[0349] In an example, the UE may receive a second registration response message from the second core network node, via the second RAN. The second registration response message may be at least one of a second attach accept message, a second TA update accept message, a second registration accept message, and / or the like. The UE may receive the second registration response message, via the second radio access network, from the second core network node.

[0350] In an example, based on receiving the second registration response message and / or based on the second registration response message indicating accept / acceptance of registration, the UE may transit to a second registered state for the second system. The second registered state may be EMM-registered state, for a secondDocket No.: 25-1021 PCTmobility management state, for the second system. For example, because the second registration response message indicates accept of registration, the UE may consider that the UE is registered to the second network system.

[0351] The first registration procedure may comprise: sending by the UE to an AMF of the 5GS, the registration request message (or a service request message, a UL NAS transport message, and / or the like); receiving by the UE from the AMF, at least one of the Registration Reject message (or a service reject message, a DL NAS transport message, UE configuration update message, and / or the like) or the Registration Accept message (or a service accept message, a DL NAS transport message, and / or the like). For example, the first system may be an 5GS and / or 6GS.

[0352] In an example, the UE may send a first registration request message to a first core network node of a first network system. The first system may be the first network system. The UE may send the first registration request message while the UE stays in the second registered state for the second system. The first registration request message may be at least one of a first 5G registration request message and / or a first 6G registration request. The first core network node may be a first AMF and / or a first 6G mobility function. The first network system may be a first 5GS and / or a first 6GS A first core network associated with the first core network node may be a first 5GC (5G core) a first 6GC (6G core). The UE may send the first registration message via a first radio access network to the first core network node The first radio access network may be a first NG-RAN and / or a first 6G-RAN. The first NG-RAN may use a first RAT. The first RAT may be at least one of an E-UTRA, NR, and / or a 6GR (6G Radio). The first RAT may be a first access technology.

[0353] In an example, the UE may receive a first registration response message from the first core network node. The first registration response message may be at least one of a first 5GS registration accept message, a first 6GS registration accept message and / or the like. The UE may receive the first registration response message via the first radio access network from the first core network.

[0354] In an example, based on receiving the first registration response message, and / or based on the first registration response message indicating acceptance of registration, the UE may transit to a first registered state (e g., first mobility management state) for the first system. For example, the first registered state may be 5GMM-registered state and / or 6G MM (6G mobility management-registered state. For example, because the first registration response message indicates accept of registration, the UE may consider that the UE is registered to the first network system. The 5GMM-registered state may be 5G RM (registration management) registered state. The 6GMM-registered state may be 6G RM (registration management) registered state.

[0355] In an example, the UE may manage one or more registration status (state) for the one or more network systems. A registration status of the one or more registration status may be a registration state, a mobility management state, and / or the like. The registration status for a network system may indicate whether the UE is registered and / or deregistered for the network system.

[0356] For example, when the UE supports dual registration, and / or when the UE determines to use dual registration, the UE may perform a plurality of registration procedures to a plurality of network systems. For example, the plurality of registration procedures may comprise two or more registration procedures, of the one or moreDocket No.: 25-1021PCTregistrations. For example, after the two or more registration procedures, the UE may remain registered for the plurality of network systems. For example, the plurality of network systems may comprise the first network system and / or the second network system. For example, the UE may be in 5GMM-registered (or6GMM-registered) and EMM-registered state. For example, the UE may be registered in both the first network system and / or the second network system.

[0357] For example, the first network system may be the 5GS and / or the second network system may be the EPS.

[0358] In an example, based on the UE being registered at least one of the first network system and / or the second network system, the UE may determine to establish one or more data sessions via the first network system and / or the second network system for which the UE is registered. For example, the UE may establish a first data session (e g., a first data session e.g., first PDU session) via the first network system and / or a second data session (e.g., a second data session, e.g., second PDN connection) from the second core network node (e.g., MME) via the second network system.

[0359] For example, the first data session may be the first PDU session and / or the second data session may be the second PDN connection. In an example, a PDN connection may be a PDN connectivity.

[0360] In an example, to establish the first data session (e.g., the first PDU session and / or a first PDN connection (mapped, associated with the first PDU session), while the UE is in the first registered state (e.g., in 5GMM registered state), the UE may send a first data session establishment request message to the first network system (and / or the first core network node). For example, the first data session establishment request message may be a PDU session establishment request message, a PDU session modification request message, and / or the like. For example, the first data session request message may comprise a request type field. For example, the request type field may be set to a value indicating 'initial request’. The first core network node may be the first network node.

[0361] For example, the first data session establishment request message may comprise a first first system data session identifier of the first data session and / or a first second system data session identifier of the first data session. For example, the first first system data session identifier may identify the first data session when used / active in the first network system. For example, the first first system data session identifier may be a first PDU session identifier (e g., PDU session ID 1, first PDU session ID). For example, the first second system data session identifier may identify the first data session when used in (active in, transferred to) the second network system. For example, the first second system data session identifier may be a first PDN connection identifier (e.g., PDN connection ID 1, PDN connectivity ID 1).

[0362] For example, in response to sending the first data session establishment request message, the UE may receive from the first network node, a first data session establishment accept message. For example, the first data session establishment accept message may be a PDU session establishment accept message, a PDU session modification accept message, and / or the like.

[0363] For example, the first data session establishment accept message may comprise the first first system data session identifier of the first data session and / or the first second system data session identifier of the first data session.Docket No.: 25-1021 PCT

[0364] In an example, to establish the second data session (e.g., the second PDU session and / or the second PDN connectivity), while the UE is in the second registered state for the second network system, the UE may send a second data session establishment request message to the second network node of the second network system. For example, the second network system may be an EPS, the second registered state may be an EMM registered state, and / or the second network node may be the second core network node.

[0365] For example, the second data session establishment request message may be a second PDN connectivity establishment request message, a second PDN connectivity modification request message, and / or the like. For example, the second data session request message may comprise a second request type field. For example, the second request type field may be set to a value indicating ‘initial request.

[0366] For example, the second data session establishment request message may comprise a second first system data session identifier (e.g., second PDU session ID, PDU session ID 2) of the second data session and / or a second second system data session identifier (e.g., second PDN connection ID, PDN connection ID 2) of the second data session. For example, the second first system data session identifier may identify the second data session when used / active in the first network system. For example, the second first system data session identifier may be a second PDU session identifier. For example, the second second system data session identifier may identify the second data session when used in (transferred to) the second network system. For example, the second second system data session identifier may be a second PDN connection identifier.

[0367] For example, in response to sending the second data session establishment request message, the UE may receive from the second network node (e.g., MME), a second data session establishment accept message. For example, the second data session establishment accept message may be a PDN Connectivity establishment accept message, a PDN connectivity modification accept message, and / or the like.

[0368] For example, the second data session establishment accept message may comprise the second first system data session identifier of the second data session and / or the second second system data session identifier of the second data session.

[0369] In an example, after establishing the one or more data sessions, the UE may exchange one or more data packets via the one or more (established) data sessions. For each data session, of the one or more data sessions, the UE may send the one or more data packets via a current access technology where the each data session is associated currently (e.g., at the time of the sending).

[0370] For example, the UE may send a data packet of the first data session (PDU session 1) via the first access technology (NG-RAN, 5GS): after the first data session is established via the first access technology until / before the first data session is released; after the first data session is established via the first access technology until / before the first data session is transferred to the second access technology (E-UTRAN, EPS); after the first data session (PDU session, PDN connectivity 1 (PDN connection 1)) is transferred from the second access technology to the first access technology until / before the first data session is released; after the first data session is transferred from the second access technology to the first access technology until / before the first data session is transferred to the second access technology; and / or the like.Docket No.: 25-1021 PCT

[0371] For example, if the first PDU session is currently active over the first access technology (e.g., NG-RAN) and / or is established over the 5GS, the UE may send and / or receive a data packet of the first PDU session in the 5GS / NG-RAN. For example, if the first PDU session (PDU session 1) is handed over (transferred) to the EPS, the UE may send and / or receive of the first PDN connection (PDN connectivity 1 (PDN connection 1) e.g., corresponds to the first PDU session) via EPS / EUTRAN.

[0372] For example, the UE may send the data packet of the first data session (PDN connection 1 , corresponding to the PDU session 1) via the second access technology (EUTRAN / EPS): after the first data session is established via the second access technology until / before the first data session is released; after the first data session (PDN connectivity 1) is established via the second access technology until / before the first data session (PDU connection 1) is transferred to the first access technology; after the first data session is transferred from the first access technology to the second access technology until / before the first data session is released; after the first data session is transferred from the first access technology to the second access technology until / before the first data session is transferred to the first access technology; and / or the like.

[0373] For example, the UE may send a data packet of the second data session (PDN connectivity 2, PDN connection 2, corresponds to PDU session 2) via the second access technology (EUTRAN / EPS): after the second data session is established via the second access technology until / before the second data session is released; after the second data session is established via the second access technology until / before the second data session is transferred to the first access technology (NR / NG-RAN / 5GS); after the second data session is transferred from the first access technology to the second access technology until / before the second data session is released; after the second data session is transferred from the first access technology to the second access technology until / before the second data session is transferred to the first access technology; and / or the like.

[0374] While the UE is registered to the plurality of the network system, the UE may determine, for each (established) data session that is established (and not released), whether to use the each data session via the first network system, whether to use the each data session via the second network system, whether to transfer the each data session from the first network system to the second network system, whether to transfer the each data session from the second network system to the first networks system.

[0375] In an example, the network may determine to restrict at least one of one or more access technologies, based on various configuration / decision of the network. For example, the network may determine not to restrict use of the first access technology (e.g., the first RAT, the first RAN, the first core network, the first network system, NR, NG-RAN, 5GS) and / or may determine to restrict use of the second access technology (e.g., the second RAT, the second RAN, the second core network, the second network system, EUTRA, EUTRAN, EPS). For example, the second access technology may be an access technology that is restricted and / or the first access technology may be an access technology that is not restricted.

[0376] Based on the determination, the network may configure one or more network nodes (e g., the first core network node, the second core network node). A network node may be a core network node (e.g., AMF, MME). For example, the one or more (core) network nodes may be configured with and / or may receive one or more policy information For example, the one or more policy information may indicate, regarding the UE, one or more firstDocket No.: 25-1021 PCTaccess technologies (e g., NG-RAN, NR, 5GS) that are not restricted and / or one or more second access technologies (e.g., EUTRAN, EUTRA, EPS) that are restricted. For example, the one or more first access technologies may comprise the first access technology and / or the one or more second access technologies may comprise the second access technology.

[0377] In an example, based on being configured with the one or more policy information and / or based on receiving the one or more policy information, the network may determine to send a RAT utilization control information (RATUCI) to the UE. For example, based on receiving and / or being configured with the one or more policy information, one or more first network nodes (e.g., the first core network node (AMF)) of the network may determine to send one or more first NAS messages (e.g., UE configuration update, registration accept, registration reject, service accept, service reject, deregistration request, DL NAS transport) to the UE and / or one or more second network nodes (e.g., the second core network node (MME)) of the network may determine not to send one or more first NAS messages (e.g., Attach reject, Attach accept, TAU accept, TAU reject, GUTI reallocation, service reject, service accept, DL NAS transport) to the UE. For example, to save signalling, the one or more second network nodes (e g., MME) may determine not to send the RATUCI, e.g., based on that the UE is not in CM (connection management) connected state, for the second network system For example, the one or more network nodes may comprise one or more network nodes managing mobility of the UE. For example, the one or more network nodes comprises at least one of an AMF of the 5GS of the network and / or an MME of the EPS of the network. The one or more first NAS messages may comprise the RATUCI

[0378] In an example, based on receiving the one or more policy information, the first core network node (AMF) of the first network system (5GS) may determine to send a first NAS message, of the one or more first NAS messages, to the UE. The first NAS message may be at least one of UE configuration update, registration accept, registration reject, service accept, service reject, deregistration request, DL NAS transport.

[0379] For example, the first NAS message may comprise one or more information identifiers indicating whether the first NAS message comprises the first RATUCI. For example, the one or more information identifiers may be a value set to indicate the existence of the first RATUCI. If the one or more information identifiers indicate that the first NAS message comprises the first RATUCI and / or if the one or more information identifiers exist in the first NAS message, the first NAS message may further comprise the first RATUCI For example, the first RATUCI may be based on the one or more policy information. The first RATUCI may comprise one or more first parameters and / or one or more second parameters

[0380] The one or more first parameters may indicate that the one or more first access technologies are not restricted and / or that the one or more second access technologies are restricted. For example, for each access technology, of one or more access technologies, the one or more first parameter may indicate whether the each access technology is restricted or not restricted. For example, the one or more first parameters may indicate whether the NG-RAN is restricted or not, whether the EUTRAN is restricted or not. In one embodiment, the one or more first parameters may indicate that the NG-RAN is restricted and / or that the E-UTRAN is not restricted. In another embodiment, the one or more first parameters may indicate that the NG-RAN is not restricted and / or that the E-UTRAN is restricted. In another embodiment, the one or more first parameters may indicate that the NG-RAN isDocket No.: 25-1021 PCTrestricted and / or that the E-UTRAN is restricted. In another embodiment, the one or more first parameters may indicate that the NG-RAN is not restricted and / or that the E-UTRAN is not restricted.

[0381] The one or more second parameters may indicate one or more conditions. For example, the one or more conditions may comprise one or more time criterion and / or one or more location criterion The one or more conditions may indicate when the one or more first parameters are valid and / or when the one or more first parameters are invalid. The one or more conditions may indicate when the RATUCI applies and / or when the RATUCI does not apply. In an example, the one or more policy information may comprise the one or more second parameters.

[0382] For example, the one or more time criterion may indicate one or more time values and or one or more time periods.

[0383] In an embodiment, each time value, of the one or more time values, may indicate at least one of: a (start) time from which the second access technology is restricted; a (start) time from which the UE can transfer a data session; an end time until when the UE needs to transfer a data session (e.g.., the second PDN connectivity, the second data session) from the second access technology (e.g., one or more restricted access technologies) to the first access technology (e.g., one or more non-restricted access technologies); a start time from which the UE cannot request to transfer the second data session from the second access technology to the first access technology; a start time from when data transmission / reception via the second access technology is not allowed; a start time from when selection of the second access technology is not allowed; a start time from when selection of the first access technology is allowed; and / or the like

[0384] In another embodiment, each time value, of the one or more time values, may indicate at least one of: a (start) time from which the first access technology is restricted; a (start) time from which the second access technology is restricted; a (end) time from which the first access technology is restricted; a (end) time from which the second access technology is restricted; a (start) time from which the first access technology is not restricted; a (start) time from which the second access technology is not restricted; a (end) time from which the first access technology is not restricted; a (end) time from which the second access technology is not restricted; an end time until when the UE needs to transfer a data session from the first access technology to the second access technology; a start time from which the UE cannot request to transfer the data session from the first access technology to the second access technology; an end time from when the UE can transfer a data session from the first access technology to the second access technology; a start time from when the UE can request to transfer the data session from the first access technology to the second access technology; a start time from when data transmission / reception via the first access technology is not allowed; a start time from when selection of the first access technology is not allowed; a start time from when selection of the second access technology is allowed; a start time from when the UE can request to transfer the data session from the first access technology to the second access technology; a start time from when data transmission / reception via the first access technology is allowed; a start time from when selection of the first access technology is allowed; a start time from when selection of the second access technology is allowed; and / or the like.

[0385] For example, each time period, of the one or more time periods, may indicate at least one of: a time duration during which the UE is not allowed to use the one or more second access technologies; a time duration during whichDocket No.: 25-1021 PCTthe UE is not allowed to use the one or more restricted access technologies; a time duration during which the UE is allowed to use the one or more non-restricted access technologies; a time duration during which the UE is not allowed to use the one or more first access technologies; a time duration during which the UE is allowed to use the one or more second access technologies; a time duration during which the UE is allowed to use the one or more first access technologies; a time duration during which the UE needs to transfer a data session from the second access technology to the first access technology; a time duration during which the UE cannot request to transfer the data session from the second access technology to the first access technology; a time duration during which data transmission / reception via the second access technology is not allowed; a time duration during which selection of the second access technology is not allowed; a time duration during which selection of the first access technology is allowed; and / or the like.

[0386] For example, the one or more location criterion may indicate one or more location areas. The one or more location areas may be indicated by one or more TAs (tracking areas), one or more Cells, one or more geographical coordinates and / or the like.

[0387] For example, each of the one or more location criterion may indicate at least one of: an area in which the one or more first access technologies are restricted; an area in which the one or more second access technologies are restricted; an area in which the one or more first access technologies are not restricted; an area in which the one or more second access technologies are not restricted; an area in which the UE needs to transfer a data session from the second access technology to the first access technology; an area in which the UE cannot request to transfer the data session from the second access technology to the first access technology; an area in which data transmission / reception via the second access technology is not allowed; an area in which selection of the second access technology is not allowed; an area which selection of the second access technology is not allowed; an area which selection of the first access technology is allowed; and / or the like. For example, the first access technology may be a non-restricted access technology and / or the second access technology may be a restricted access technology.

[0388] For example, the UE may receive the one or more first NAS messages from the network. For example, the UE may receive the one or more first NAS messages via the first access technology and / or from the first core network node (i.e., first network node). For example, the first network node may be an AMF. For example, the first access technology may be a NG-RAN and / or NR. For example, the one or more first NAS messages may comprise the first NAS message.

[0389] In response to receiving the first NAS message, the UE may determine whether the first NAS message comprises the RATUCI. The RATUCI may be the first RATUCI. In response to determining that the first NAS message comprises the first RATUCI, the UE may determine whether the first RATUCI comprises the one or more second parameters.

[0390] For example, if the first RATUCI does not comprise the one or more second parameters, the UE may immediately apply the one or more first parameters. Applying the one or more first parameters may be applying the RATUCI (e.g., the first RATUCI).Docket No.: 25-1021 PCT

[0391] For example, applying the one or more first parameters may be at least one of: stop using one or more restricted access technologies (e.g., the second access technology, e g., EUTRAN); start / keep using one or more non-restricted access technologies (e.g , the first access technology, e.g., NGRAN); releasing one or more data sessions (e.g., a PDN connection established / active over the EUTRAN) active over the one or more restricted access technology; sending release request messages for one or more data sessions active over the one or more restricted access technology; sending transfer request message for one or more data sessions active over the one or more restricted access technology, from the one or more restricted access technologies to the one or more nonrestricted access technologies; sending de-registration request messages (requesting de-registration for a network system of restricted access technology) to the core network node via the one or more restricted access technology; not selecting a cell of the one or more restricted access technologies; disabling the one or more restricted access technologies; sending registration request to one or more non-restricted access technologies; selecting a cell of the one or more non-restricted access technologies; and / or the like.

[0392] For example, the release request message may be at least one of a PDN disconnect request message, PDN connectivity disconnect request message, Deactivate EPS bearer Context request, a PDU session release request message, a PDU session modification request message, a UL NAS transport message and / or the like.

[0393] For example, the transfer request message may be at least one of a PDN connectivity modification request message, a PDN connectivity establishment request message, a PDU session establishment request message, a PDU session modification request message, a UL NAS transport message and / or the like. For example, the transfer request message may comprise a request type field. A value of the request type field may be at least one of ‘handover’, ‘existing PDU session’, ‘existing PDN connectivity’, and / or the like. For example, the transfer request message comprise one or more identifiers of the data sessions requested to be transferred. For example, if the UE requests transfer of the first data session, the transfer request message may comprise the first first data session identifier and / or the first second data session identifier. For example, if the UE requests transfer of the second data session, the transfer request message may comprise the second first data session identifier and / or the second second data session identifier.

[0394] For example, the transfer request message may be sent over the one or more non-restricted access technology. For example, if the second access technology is restricted and / or if the first access technology is not restricted, the transfer request message may be sent over the first access technology.

[0395] Alternatively and / or additionally, if the first RATUCI comprises the one or more second parameters, the UE may apply the one or more first parameters, based on the one or more second parameters. For example, based on the one or more second parameters, if the UE is in location area indicated by the one or more location criterion and / or a time is the time indicated by the one or more time criterion, the UE may apply the one or more first parameters. For example, based on the one or more second parameters, if the UE is not in location area indicated by the one or more location criterion and / or a time is not the time indicated by the one or more time criterion, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the start time from which the one or more first parameters are valid, and if the current time is before the start time, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the start timeDocket No.: 25-1021 PCTfrom which the one or more first parameters are valid, and if the current time is after the start time, the UE may apply the one or more first parameters For example, if the one or more second parameters indicate the time duration during which the one or more first parameters are valid, and if the current time is not in the time duration, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the time duration during which the one or more first parameters are valid, and if the current time is in the time duration, the UE may apply the one or more first parameters. For example, if the one or more second parameters indicate the end time during which the one or more first parameters are valid, and if the current time is after the end time, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the end time during which the one or more first parameters are valid, and if the current time is before the end time, the UE may apply the one or more first parameters.

[0396] For example, if the one or more second parameters indicate the start time from which the second access technology is restricted and / or the end time from which the second access technology is not restricted, and if the current time is after the start time and / or if the current time is before the end time, the UE may apply the one or more first parameters and / or the UE may regard the second access technology is restricted.

[0397] For example, if the one or more second parameters indicate the start time from which the second access technology is restricted and / or the end time from which the second access technology is not restricted, and if the current time is before the start time and / or if the current time is after the end time, the UE may not apply the one or more first parameters and / or the UE may regard the second access technology is not restricted.

[0398] For example, if the one or more second parameters indicate the time duration during which the second access technology is restricted, and if the current time is not within the time duration, the UE may not apply the one or more first parameters and / or the UE may consider (act as if) that the second access technology is not restricted. For example, if the one or more second parameters indicate the time duration during which the second access technology is restricted, and if the current time is within the time duration, the UE may not apply the one or more first parameters and / or the UE may consider (act as if) that the second access technology is restricted

[0399] For example, if the one or more second parameters indicate the time duration during which the one or more first parameters are valid, and if the current time is in the time duration, the UE may apply the one or more first parameters and / or the UE may consider that the one or more first parameters is valid (e.g., restriction applies). For example, if the one or more second parameters indicate the end time after which the one or more first parameters are not valid, and if the current time is after the end time, the UE may not apply the one or more first parameters. For example, if the one or more second parameters indicate the end time after which the one or more first parameters are not valid, and if the current time is before the end time, the UE may apply the one or more first parameters.

[0400] In response to receiving the one or more first NAS messages comprising the first RATUCI, and / or based on the one or more second parameters, the UE may determine whether the UE needs to transfer one or more transfer data sessions to be transferred, among one or more established data sessions (e g., the first data session, the second data session) that are established, from the second access technology (e.g., restricted access technology) to the first access technology (e.g., non-restricted access technology). For example, for each established data session, among the one or more established data session, the UE may determine whether the each established data sessionDocket No.: 25-1021 PCTis currently active / established / kept over the one or more restricted access technologies and / or over the one or more non-restricted access technologies.

[0401] For example, if the second data session uses a resource of the second access technology, if the second data session is kept / active over the restricted access technology (the second access technology), if the second data session is not transferred to the non-restricted access technology (the first access technology) since established over the restricted access technology, and / or the like, the UE may determine that second data session is currently active / established / kept over the restricted access technology.

[0402] For example, if the UE determines that the second data session is currently active / established / kept over the restricted access technology, the UE may determine to request transfer of the second data session. Based on determining, for example, the UE may send a request message, to a network, requesting transfer of the first data session. For example, the request message may be the transfer request message.

[0403] For example, if the second data session does not use a resource of the restricted access technology, if the second data session is kept / active over the non-restricted access technology, if the second data session is not transferred to the restricted access technology since established over the non-restricted access technology, and / or the like, the UE may determine that the second data session is currently active / established / kept over a nonrestricted access technology.

[0404] For example, if the UE determines that the second data session is currently active / established / kept over the non-restricted access technology, the UE may determine to keep the second data session over the non-restricted access technology and / or not to request transfer of the second data session.

[0405] In another example, if the UE determines that the second data session is currently active / established / kept over the restricted access technology, the UE may determine whether to request transfer of the second data session from EPS (associated with the restricted access technology) to 5GS (associated with the non-restricted access technology), or whether to release the second data session.

[0406] In an example, in response to determining to release the second data session, the UE may send a data session release request message for the second data session, to the network and / or the UE may locally release the second data session, to save signalling For example, the UE may send the data session release request message, at least one of via the first access technology to the first core network node and / or via the second access technology to the second core network node. The data session release request message may be the rerelease request message.

[0407] In an example, if the one or more second parameters are received, based on the one or more second parameters, the UE may send the data session release request message, while the one or more conditions are met. For example, the UE may not send the data session release request message until a current time is after the start time value when the restricted access technology is restricted. For example, the UE may send the data session release request message after a current time passes the start time value when the restricted access technology is restricted. For example, the UE may send the data session release request message before a current time does not pass the start time value when the restricted access technology is restricted. For example, the UE may not send the data session release request message after start time. For example, the UE may send the data session releaseDocket No.: 25-1021 PCTrequest message outside the time period during which the restricted access technology is restricted. For example, the UE may send the data session release request message while not in the time period during which the restricted access technology is restricted.

[0408] Alternatively and / or additionally, based on receiving the RATUCI, the one or more first parameters, and / or the first NAS message, the UE may determine whether at least one of one or more access technologies over which the UE is registered is restricted by the RATUCI. For example, the UE may be dual registered. For example, the UE may be registered for the plurality of network system. For example, the UE may be registered by the first network system (e.g., 5GS) and / or by the second network system (e.g., EPS). For example, for each access technology, among the plurality of network systems for which the UE is registered, the UE may determine whether the each access technology is restricted. If the each access technology is restricted by the RATUCI and / or if the UE is registered by the each access technology, the UE may locally transit from the registered state to the de-registered state, for the each access technology. If the each access technology is not restricted by the RATUCI and / or if the UE is registered by the each access technology, the UE may stay in the registered state for the each access technology.

[0409] For example, based on that the UE is registered for both EPS and 5GS, and if the RATUCI indicates that the EUTRAN associated with the EPS is restricted, the UE may transit from the EMM-registered state to EMM-deregistered state. For example, based on that the UE is registered for both EPS and 5GS, and if the RATUCI indicates that the EUTRAN associated with the EPS is not restricted, the UE may stay in the EMM-registered state. In this case, if the RATUCI comprises one or more second parameters, the UE may transit to the EMM deregistered state, after the start time and / or if the one or more conditions are met.

[0410] For example, based on that the UE is registered for both EPS and 5GS, and if the RATUCI indicates that the NGRAN associated with the 5GS is restricted, the UE may transit from the 5GMM-registered state to 5GMM-deregistered state. For example, based on that the UE is registered for both EPS and 5GS, and if the RATUCI indicates that the NGRAN associated with the 5GS is not restricted, the UE may stay in the 5GMM-registered state. In this case, if the RATUCI comprises one or more second parameters, the UE may transit to the 5GMM deregistered state, after the start time (and / or when the one or more condition are met).

[0411] In an example, based on transiting to de-registered state for the each access technology, the UE may locally release one or more remaining data sessions over the each access technology, if the each access technology is restricted by the RATUCI.

[0412] In an example, after the UE transits to deregistered state for the each access technology, the UE may perform a PLMN selection. For example, based on the PLMN selection, the UE may find a candidate cell, using the each access technology (which is not restricted), of a second operator. If the each access technology is not restricted for the second operator, the UE may send a registration request (e.g., attach request) message to the second operator, and / or via the each access technology. The second operator may different from the first operator (or operator of the first network).

[0413] In an example, in response to determining to transfer the second data session from one or more restricted access technologies (e g., the second access technology, e.g., EUTRAN) to one or more non-restricted access technologies (e.g., the first access technology, e.g., NG-RAN), the UE may send a data session transfer requestDocket No.: 25-1021 PCTmessage, for the second data session, to the network and / or to a network node (e.g. , AMF). The data session transfer request message may be the transfer request message. For example, the UE may send the data session transfer request message, via the first access technologies (e.g., non-restricted access technology), to a core network node (e.g., AMF) associated with the non-restricted access technology. For example, because the first access technology is not restricted by the RATUCI, because the second access technology is restricted by the RATUCI, and / or based on that the second data session is currently established over the second access technology, the UE may send the data session transfer request message via the first access technology and / or to the first network system. The data session transfer request message may comprise one or more identifiers of the second data session. For example, the one or more identifiers of the second data session may comprise at least one of a first identifier (e.g., the second first data session identifier) of the second data session used in the first access technology and / or a second identifier (e.g , the second second data session identifier) of the second data session associated with the second access technology. For example, the first identifier may be the second PDU session ID and / or the second identifier may be the second PDN connectivity ID. For example, the data session transfer request message may comprise a request type field. For example, the request type filed may indicate a value. The value may indicate at least one of that the each established data session is existing data session, handover, and / or the like.

[0414] In one or more example, a PDN connectivity ID may be replaced by a network slice identifier and / or information of SMF+PGW-C (e.g., SMF+PGW-C FQDN).

[0415] In an example, if the UE determines to transfer the data session, the UE may send the data transfer request message, based on the one or more second parameters. The data transfer request message may be a data session transfer request message and / or a data session establishment request message for data transfer / handover. For example, if the one or more conditions are met, the UE may send the data transfer request message. For example, if the one or more time criterion are met and / or if the UE is in the one or more location areas, the UE may send the data transfer request message. In another example, if the one or more conditions are met, the UE may not send the data transfer request message. In another example, if the one or more time criterion are not met and / or if the UE is not in the one or more location, the UE may send the data transfer request message. For example, the UE may not send the data transfer request message until a current time passes a time indicated by the start time value. For example, the UE may send the data transfer request message after a current time passes the start time value. For example, the UE may send the data transfer request message before a current time passes the time indicated by the start time value. For example, the UE may not send the data transfer request message after a current time passes the start time value. For example, the UE may not send the data transfer request message before a current time passes the end time value. For example, the UE may not send the data transfer request message until a current time passes the end time value. For example, the UE may send the data transfer request message during the time period In another example, the UE may send the data transfer request message while not in the time period.

[0416] In an example, if the UE determines to transfer the data session, the UE may send the data transfer request message, based on the one or more second parameters. For example, based on the one or more second parameters, the UE may determine when the RATUCI applies and / or when the one or more restricted access technologies start to be restricted. For example, the UE may send the data transfer request message, before the timeDocket No.: 25-1021 PCTwhen the RATUCI applies, and / or before the time when the one or more restricted access technologies are restricted. Alternatively, for example, the UE may send the data transfer request message, after the time when the RATUCI applies, and / or after the time when the one or more restricted access technologies starts to be restricted. Alternatively, for example, the UE may send the data transfer request message, before the end time until when the UE needs to transfer a data session from the second access technology to the first access technology. Alternatively, for example, the UE may send the data transfer request message, before the start time from which the one or more first parameters are valid. Alternatively, for example, the UE may send the data transfer request message, before the start time from which the UE cannot request to transfer the data session from the second access technology to the first access technology

[0417] In an example, the one or more network nodes may determine whether the one or more conditions of the one or more second parameters are met, or the one or more conditions are no longer met. For example, based on the one or more conditions, the one or more network nodes may release one or more second established data sessions, among the one or more established data sessions, established / active over the one or more restricted access technologies. For example, the one or more second established data sessions may be established over the one or more restricted access technologies, and / or may not yet transferred to the one or more non-restricted access technologies, and / or the like. For example, if the UE does not send a request to transfer a second established data sessions, among the one or more second established data sessions, from the one or more restricted access technologies to the one or more non-restricted access technologies, the second established data session may remain in the one or more restricted access technologies. In this case, if the one or more conditions are met and / or not met, and / or based on sending the first RATUCI, the one or more network nodes may send a third network node, a request to release the second established data session. For example, the one or more network nodes may be one or more network nodes of the one or more restricted access technologies. The third network node may be a core network node managing the one or more second established data sessions. For example, that one or more conditions are met may be that the time until the UE needs to transfer the data session elapses, that a condition with which the one or more parameters are valid is met, that the time that the one or more restricted access technologies is not allowed starts, and / or the like.

[0418] Example embodiments of FIG. 21 may help to minimize a service interruption time during which the UE may not be able to use a data session. For example, based on the RATUCI and / or one or more parameters indicating time and / or location, the UE may be able to request transfer of one or more data session from one or more restricted RATs to one or more non-restricted RATs, the UE may be able to determine when the RATUCI is valid or not. This may help to manage one or more data session over one or more access technologies, while minimizing service interruption

[0419] FIG. 22 illustrates an example as per an aspect of an embodiment of the present disclosure. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0420] While the first access technology is not restricted and / or the second access technology is restricted in example of the FIG. 21 , the second access technology is not restricted and / or the first access technology is restrictedDocket No.: 25-1021 PCTin FIG. 22. The mechanism and / or principles described in the example of FIG.21 can be applied to the example of FIG. 22.

[0421] FIG. 23 illustrates an example as per an aspect of an embodiment of the present disclosure. In an example, a UE may receive a RATUCI via an access technology which will be restricted. In this case, after performing transfer of a data session, the UE may indicate via the access technology, the end of transfer. This may help a network system to detect when the network system can remove the UE For example, this may help the UE to determine whether to perform dual-registration and / or over which access technologies the UE performs dual registration. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0422] In an example, as shown in previous examples, the UE may be dual registered to the 5GS and / or to the EPS. As shown in previous examples, the UE may establish the one or more data sessions via the 5GS and / or the EPS. For example, the UE may establish a third data session (e.g., a third PDU session) via the first access technology (e g., via the NG-RAN, NR, 5GS) and / or a fourth data session (e.g., a fourth PDN session connection) via the EPS.

[0423] In an example, the network may send a second NAS message to the UE via the first access technology. The second NAS message may comprise the RATUCI. For example, the RATUCI may be a second RATUCI. For example, the second NAS message may be a deregistration request message. For example, the second NAS message may comprise the second RATUCI. For example, the AMF of the network and / or of the first network system may send the second NAS message.

[0424] In an example, the second RATUCI may indicate that the second access technology is not restricted and / or that the first access technology is restricted and / or a time value. For example, the time value may indicate at least one of: a time when the UE needs to finish transfer of data session to other system and / or to other non-restricted access technology; a time when the UE needs to send a response message (e.g., deregistration accept message, deregistration request message, a UL NAS transport message) which is response to the second NAS message; a start time from when the restriction of the first access technology applies; a end time from when the restriction of the first access technology no more applies; and / or the like.

[0425] The second RATUCI may comprise one or more third parameters and / or one or more fourth parameters and / or one or more fifth parameters.

[0426] The one or more third parameters may indicate that the one or more first access technologies are restricted and / or that the one or more second access technologies are not restricted. For example, for each access technology, of one or more access technologies, the one or more third parameter may indicate whether the each access technology is restricted or not restricted. For example, the one or more third parameters may indicate that the first access technology (e.g., NG-RAN, EUTRAN) is restricted and / or that the second access technology (e.g, EUTRAN, NG-RAN) is not restricted.

[0427] The one or more fourth parameters may indicate one or more second conditions. For example, the one or more second conditions may comprise one or more second time criterion and / or one or more second location criterion. The one or more second conditions may indicate when the one or more third parameters are valid, whenDocket No.: 25-1021 PCTthe one or more third parameters apply, when the one or more third parameters do not apply, and / or when the one or more third parameters are invalid. For example, examples of previous figures can be used.

[0428] The one or more fifth parameters may indicate one or more fifth time values. For example, each of the one or more fifth time values may indicate a time and / or a timer value For example, the one or more fifth time value may be used to determine a time until when the UE can / need to perform transfer of the one or more data session from a restricted access technology to a non-restricted access technology. For example, the one or more fifth time value may indicate a time until when the UE needs to send a response to the second NAS message, indicating confirmation of reception of the second RATUCI, and / or completion of the transfer. In an example, the one or more fifth parameters may be the one or more fourth parameters. For example, to determine the time, the UE may start a timer with the time value. For example, the time value may indicate the time.

[0429] In an example, based on receiving the second RATUCI, based on the third data session being established / active over the first access technology (e.g., the restricted access technology), the UE may determine to transfer the third data session from the first access technology to the second access technology (e.g., the nonrestricted access technology). For example, because the RATUCI being received via the first access technology, the first access technology being indicated as restricted, the second access technology being non-restricted, and / or the third data session being established over the first access technology, the UE may send a message requesting transfer of the third data session, via the second access technology and / or to a node associated with the second access technology.

[0430] For example, the message requesting transfer of the third data session may be at least one of the data session transfer request message, the data transfer request message, the data session transfer request message and / or the like. For example, the message requesting transfer of the third data session may be at least one of a PDU session establishment message, a PDN connectivity establishment request message, an ATTACH request message, a TAU request message, a UL NAS data transfer message, and / or the like The message requesting transfer of the third data session may comprise a request type field. For example, the request type filed may indicate a value. The value may indicate at least one of that the third data session is existing data session, handover, and / or the like. For example, the message requesting transfer of the third data session may comprise one or more identifiers of the third data session. For example, the one or more identifiers of the third data session may comprise an identifier of PDU session of the third data session, an identifier of the PDN connection associated with the third data session, and / or the like.

[0431] In an example, the UE may successfully transfer the third data session from the restricted access technology (e g., the NG-RAN, the first access technology) to the non-restricted access technology (e.g., the EUTRAN, the second access technology)

[0432] In an example, the UE may determine whether to send a response to the first core network via the first access technology. For example, the UE may receive the second RATUCI via the first access technology. For example, the UE may determine whether to send the response, based on a type of the second NAS message, the one or more fifth parameters, the one or more fourth parameters, and / or the second RATUCI.Docket No.: 25-1021 PCT

[0433] For example, the UE may determine to send the response (message) to the second NAS message, if the one or more following conditions are met:

[0434] - that the UE receives a deregistration request message comprising the second RATUCI;

[0435] - that the time indicated by the one or more fifth parameters and / or the one or more fourth parameters has not yet elapsed;

[0436] - that the second RATUCI is received by the first access technology which is restricted by the second RATUCI;

[0437] - that the second NAS message indicates the one or more fifth parameters;

[0438] - that the second NAS message requests the response;

[0439] - that the UE finishes / completes transfer of the third data session to the second access technology;

[0440] - that the UE does not have any data session to transfer to the non-restricted access technology.

[0441] In an example, if the one or more conditions are met, the UE may send the response to a network node (e g., AMF) the first network system from which the second NAS message is received.

[0442] In an example, the network node may receive the response message to the second NAS message. In response to receiving the response message, the network node may determine that the UE is ready, that the UE transferred the third data session, that there is no more data session to transfer to the non-restricted access technology, and / or the like.

[0443] In an example, the network node may determine whether there is one or more second core network nodes for which one or more data sessions of the UE are associated. For example, based on receiving the response message, based on the expiry of timer to determine the time, and / or after the time, the network node may send, to the one or more second core network nodes, one or more request message requesting release of the one or more data sessions. This may help the second core network nodes to clean up and / or release for which the UE may not need to transfer from the first access technology to the second access technology.

[0444] Example embodiments of FIG. 23 may help a network to control until when it can delay performing release of one or more data sessions, when an access technology over which the one or more data sessions are established needs to be restricted.

[0445] FIG. 24 illustrates an example as per an aspect of an embodiment of the present disclosure. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0446] While the first access technology is restricted and / or the second access technology is not restricted in example of the FIG. 23, the second access technology is restricted and / or the first access technology is not restricted in FIG. 24. The mechanism and / or principles described in the example of FIG.23 can be applied to the example of FIG. 24.

[0447] FIG. 25 illustrates an example as per an aspect of an embodiment of the present disclosure. When one or more network nodes are not coordinated, the one or more network nodes may determine to send one or more RATUCIs to the UE at different times In one implementation, a network node may determine may use a reject message to restrict a use of an access technology. This may cause some difficulty for the UE to determine whether there is no more restricted access technology. In an example, one or more messages rejecting one or more requestDocket No.: 25-1021 PCTfrom the UE may comprise the RATUCI. This may help consistent application of the RATUCI. For example, this may help the UE to determine whether to perform dual-registration and / or over which access technologies the UE performs dual registration. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0448] In an example, as shown in previous examples, the UE may be dual registered to the 5GS and / or to the EPS. As shown in previous examples, the UE may establish the one or more data sessions via the 5GS and / or the EPS.

[0449] In an example, the first network node (e.g., first AMF, first MME) of the first network system (e.g , 5GS, EPS) may send the first NAS message to the UE. For example, the first NAS message may comprise the RATUCI. For example, the RATUCI may indicate that the first access technology associated with the first network system is not restricted and / or that the second access technology associated with the second network system is restricted. For example, because the UE is in CM connected state and / or RRC connected state for the first network system, the first network node may send the first NAS message.

[0450] In an example, the second network node (e.g., second M E, second A F) of the second network system (e g., EPS, 5GS) may receive one or more policy information. For example, the one or more policy information may indicate that the second network system and / or the second access technology associated with the second network system is restricted and / or that the first network system and / or the first access technology associated with the first network system is not restricted.

[0451] In an example, the second network node may determine whether the UE is in CM connected state and / or in CM idle state and / or in RRC connected state and / or in RRC idle state, for the second network system. For example, the second network node may determine that the UE is not in CM connected state and / or that the UE is in CM idle state. For example, in response to determining that the UE is not in CM connected state and / or that the UE is in CM idle state, for the second network system, and based on that the second network system and / or the second access technology is restricted, the second network node may determine to page the UE to bring the UE from CM idle state to the CM connected state.

[0452] In response to determining to page the UE, the second network node may send to a second RAN (e.g., E-UTRAN) of the second network system, a request requesting paging of the UE. Based on receiving the request, the second RAN may send one or more paging messages via Uu interface, in one or more cells managed by the second RAN, to the UE.

[0453] In an example, the UE may receive a paging message of the one or more paging messages. For example, in response to receiving the paging message, the UE may trigger a (network-triggered) service request procedure. For the service request procedure, the UE may send a request message (e.g., a service request message) to the second network node. For example, the request message may be at least one of a service request message, a registration request message, an attach request message, a deregistration request message, a detach request message, an UL NAS transport message, a TAU request message and / or the like.

[0454] Alternatively and / or additionally, when the UE has a data to send, the UE may trigger the service request procedure.Docket No.: 25-1021 PCT

[0455] In an example, the second network node may receive the request message, via the second access technology. In response to receiving the request message, the second network node may determine whether to allow (accept) the request message To determine whether to allow the request message or not, the second network node may determine whether the second access technology is restricted or not, based on the one or more policy information

[0456] In an example, because the one or more policy information indicates that the second access technology is restricted and / or that the second network system is restricted to the UE, the second network node may determine to reject the request message. Based on determining to reject the request message, the second network node may determine to send a request reject message to the UE. For example, based on the one or more policy information, the request reject message may comprise the RATUCI. For example, the RATUCI may indicate that the first access technology is not restricted and / or that the second access technology is restricted. For example, the request reject message may comprise a cause value. Because one or more access technologies are restricted, the cause value may indicate no suitable cells in a tracking area. For example, the request reject message may be at least one of a service reject message, a TAU reject message, an registration reject message, an attach reject message, a DL NAS transport message, an deregistration request message, a detach request message, and / or the like.

[0457] In an example, the UE may receive the request reject message from the second network node (e.g., AMF, MME). Because the request reject message comprises the RATUCI and / or based on the cause value in the request reject message, the UE may determine whether to store the RATUCI and / or whether to apply the RATUCI. For example, because the request reject message comprise the RATUCI and / or because the cause value indicates no suitable cells in a tracking area, the UE may determine to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine to apply the RATUCI. In another example, because the request reject message comprise the RATUCI and / or because the cause value does not indicate no suitable cells in a tracking area, the UE may determine not to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine not to apply the RATUCI.

[0458] In an example, alternatively and / or additionally, the UE may receive the request reject message from the second network node (e.g., AMF, MME). Because the request reject message comprises the RATUCI and / or based on the cause value in the request reject message and / or based on whether the request reject message is integrity protected or not, the UE may determine whether to store the RATUCI and / or whether to apply the RATUCI. For example, because the request reject message comprise the RATUCI and / or because the cause value indicates no suitable cells in a tracking area and / or because the request reject message is integrity-protected, the UE may determine to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine to apply the RATUCI. In other example, because the request reject message comprise the RATUCI and / or because the cause value indicates no suitable cells in a tracking area and / or because the request reject message is not integrity-protected, the UE may determine not to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine not to apply the RATUCI. In other example, because the request reject message comprise the RATUCI and / or because the cause value does not indicate no suitable cells in a tracking area and / or because the request reject message is not integrity-protected, the UE may determine not to store the RATUCIDocket No.: 25-1021 PCTwith an identifier of the network (e.g., of the second network node), and / or may determine not to apply the RATUCI. In other example, because the request reject message comprise the RATUCI and / or because the cause value does not indicate no suitable cells in a tracking area and / or because the request reject message is integrity-protected, the UE may determine not to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine not to apply the RATUCI. In other example, because the request reject message comprise the RATUCI and / or because the cause value does not indicate no suitable cells in a tracking area and / or because the request reject message is integrity-protected, the UE may determine to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine to apply the RATUCI. For example, that the cause value does not indicate no suitable cells in a tracking area may be that the cause value indicates at least one of congestion, severe network failure, EPS service is not allowed, 5GS service is not allowed, tracking area not allowed, implicitly detached, PLMN notallowed, and / or the like

[0459] In another example, after the UE receives the RATUCI via the first access technology and / or from the first network node, the UE may store the RATUCI. Later, if the UE may be out of coverage of the first access technology and / or if the second access technology is not congested and / or if the UE comes back into the coverage of the second access technology, the UE may not have up-to-date information of restricted access technology. This may cause limited access to a network, if the UE keep applying old out-of-data RATUCI.

[0460] In an example, in response to sending the request message, alternatively and / or additionally, the UE may receive the request reject message from the second network node (e.g., AMF, MME). For example, the request reject message may not comprise the RATUCI, e.g., due to updated policy in the network.

[0461] Because the UE has a stored RATUCI (e.g., received from the first network node), because the request reject message does not comprise the RATUCI, based on the cause value in the service reject message and / or based on whether the service reject message is integrity protected or not, the UE may determine whether to discard / delete the stored RATUCI and / or whether to stop applying the (stored, received) RATUCI.

[0462] For example, because the UE has a stored RATUCI (e.g., RATUCI received via the first NAS message and not yet deleted), because the request reject message does not comprise the RATUCI, based on that the cause value in the service reject message does not indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may discard the stored RATUCI for the network associated with the second network system and / or may stop applying the RATUCI.

[0463] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message does not indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may not discard the stored RATUCI for the network of the second network system and / or may applying the RATUCI.

[0464] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message does not indicate no suitable cells in the tracking area and / or based on that the request reject message isDocket No.: 25-1021 PCTnot integrity protected, the UE may not discard the stored RATUCI for the network of the second network system and / or may applying the RATUCI.

[0465] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may discard the stored RATUCI for the network of the second network system and / or may not applying the RATUCI.

[0466] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message indicate no suitable cells in the tracking area and / or based on that the request reject message is not integrity protected, the UE may not discard the stored RATUCI for the network of the second network system and / or may apply the RATUCI.

[0467] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message does not indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may discard the stored RATUCI for the network of the second network system and / or may applying the RATUCI.

[0468] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message does not indicate no suitable cells in the tracking area and / or based on that the request reject message is not integrity protected, the UE may discard the stored RATUCI for the network of the second network system and / or may applying the RATUCI.

[0469] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may not discard the stored RATUCI for the network of the second network system and / or may not applying the RATUCI.

[0470] Alternatively and / or additionally, in another example, because the UE has the stored RATUCI, because the request reject message does not comprise the RATUCI and / or based on that the cause value in the service reject message indicate no suitable cells in the tracking area and / or based on that the request reject message is integrity protected, the UE may discard the stored RATUCI for the network of the second network system and / or may not applying the RATUCI.

[0471] For example, applying the RATUCI may be at least one of: that the UE does not send a data / message to one or more restricted access technology; that the UE does not select a cell of the one or more restricted access technology; that the UE stored the RATUCI. For example, not applying the RATUCI may be at least one of: that the UE may send a data / message to one or more restricted access technology indicated by the RATUCI; that the UEDocket No.: 25-1021 PCTmay select a cell of the one or more restricted access technology that is indicated by the RATUCI; that the UE discard the stored RATUCI and / or the received RATUCI.

[0472] In another example, because the service reject message comprise the RATUCI and / or because the cause value does not indicate no suitable cells in a tracking area, the UE may determine not to store the RATUCI with an identifier of the network (e.g., of the second network node), and / or may determine not to apply the RATUCI.

[0473] Example embodiments of FIG. 25 may help consistent management of RATUCI, e.g., delivering, storing, discarding the RATUCI.

[0474] FIG. 26 illustrates an example as per an aspect of an embodiment of the present disclosure. In an example, based on whether a message is a reject message or not, a cause value, a UE may determine whether to keep / discard a RATUCI. This may help to reduce unnecessary restriction of an access technology. For example, this may help the UE to determine whether to perform dual-registration and / or over which access technologies the UE performs dual registration. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0475] In an example, a UE may may receive from a first network system, of a first network, and / or via a first access network, a RATUCI. The first network system may be associated with a first RAT, a first access network and / or the like. For example, a first network node (e.g., AMF, MME) of the first network system (e.g., 5GS, EPS) may send a first NAS message comprising the RATUCI. For example, the first NAS message may be at least one of registration accept message, a TAU accept message, a DL NAS transport message, a service accept message, an attach accept message, and / or the like. The RATUCI may indicate one or more restricted access technologies and / or one or more non-restricted access technologies.

[0476] In an example, the UE may receive the first NAS message, and / or may store the RATUCI with an identifier of the first network, from a core network node of the first network system.

[0477] In an example, the UE may send a second NAS message, to the first network. For example, the UE may send the second NAS message, via using at least one non-restricted access technology, of the one or more nonrestricted access technologies. Alternatively, the UE may send the second NAS message via at least one restricted access technology, of the one or more restricted access technology, based on that a user of the UE manually select the at least one restricted access technology and / or based on that an emergency session is requested For example, the second NAS message may be at least one of a registration request message, a TAU request message, a UL NAS transport message, an attach request message, a deregistration request message, a detach request message, a service request message, and / or the like. For example, the second NAS message may be a request.

[0478] In response to receiving the second NAS message, the first network may determine whether to accept the request and / or to reject the request. For example, the first network may determine to reject, based on: the first network is congested; the first network does not have resource; the first network decides not to allow the access technology (from which the second NAS message is received; and / or the like.

[0479] In an example, if the first network determines to continue restriction of one or more access technologies, the first network may construct a third NAS message comprising the RATUCI. In this case, the third NAS message mayDocket No.: 25-1021 PCTcomprise a cause value indicating no suitable cell in a TA. For example, a core network node of the first network may construct and / or send the third NAS message to the UE.

[0480] Alternatively, and / or additionally, if the first network determines not to continue restriction of one or more access technologies, the first network may construct a third NAS message not comprising the RATUCI. In this case, the third NAS message may comprise a cause value indicating no suitable cell in a TA and / or a cause value not indicating no suitable cell in the TA, and / or a cause value indicating congestion

[0481] In an example, the UE may receive the third NAS message from the first network. For example, the third NAS message may indicate a response. The response may be a reject to the second NAS message and / or the request. For example, the third NAS message may be at least one of a registration reject message, a TAU reject message, a DL NAS transport message, an attach reject message, a deregistration reject message, a detach reject message, and / or the like.

[0482] In an example, the third NAS message may comprise a cause value indicating reasons of the reject and / or the third NAS message may not comprise the RATUCI.[...

Claims

Docket No.: 25-1021PCTCLAIMSWhat is claimed is:

1. A method comprising:receiving, by a wireless device, at least one of:a registration accept message from an access and mobility management function (AMF) of a 5G system (5GS); andan attach accept message from a mobility management entity (MME) of evolved packet system (EPS);establishing, by the wireless device, a data session;receiving, by the wireless device from the AMF, a configuration update message comprising a radio access technology (RAT) utilization control information, wherein the RAT utilization control information indicates an evolved terrestrial radio access network (E-UTRAN), of the EPS, being restricted;determining, by the wireless device, whether to discard the RAT utilization control information, based on at least one of:disaster roaming;a cause value; ora time information associated with the RAT utilization control information; and sending, by the wireless device to a second mobility management node of the EPS, a second message, wherein the second message is at least one of:a message requesting registration of the wireless device for the disaster roaming; or a message, requesting transfer of the data session from the EPS to the 5GS, and comprising a request type field indicating an existing data session.

2. A method comprising:receiving, by a wireless device from a mobility management node, of a first network, a first non-access stratum (NAS) message, wherein:the first NAS message comprises a radio access technology (RAT) utilization control information; andthe RAT utilization control information indicates an access technology associated with a second network being restricted; andsending, by the wireless device to a second mobility management node of the second network, a second NAS message, wherein the second NAS message is at least one of:a message requesting registration of the wireless device for disaster roaming; orDocket No.: 25-1021 PCTa message requesting transfer of a data session from the second network to the first network, comprising a request type field indicating an existing data session.

3. The method of claim 2, further comprising receiving, by the wireless device, at least one of:a registration accept message from the mobility management node, of the first network; andan attach accept message from the second mobility management node, of the second network.

4. The method of any one of claims 2 to 3, wherein the mobility management node comprises an access and mobility management function (AMF).

5. The method of any one of claims 2 to 4, further comprising sending by the wireless device, a third NAS message requesting the data session.

6. The method of claim 5, wherein the third NAS message requesting the data session is a PDN connection establishment request message, and the data session is a PDN connection.

7. The method of any one of claims 5 to 6, further comprising receiving by the wireless device, a fourth NAS message accepting the data session.

8. The method of any one of claims 2 to 7, wherein the RAT utilization control information further comprise a time information, wherein the RAT utilization control information applies after a time indicated by the time information.

9. The method of claim 8, wherein the time is a start time when the RAT utilization control information starts to be applied.

10. The method of any one of claims 8 to 9, wherein the RAT utilization control information further comprises an end time information, wherein the end time information indicates until when the wireless device is allowed to use the access technology.

11. The method of any one of claims 2 to 10, wherein the RAT utilization control information indicates that the access technology is restricted and that a second access technology is not restricted.

12. The method of any one of claims 2 to 11 , wherein the second access technology is associated with the first network.

13. The method of any one of claims 2 to 12, further comprising determining by the wireless device, whether to discard the RAT utilization control information, based on at least one of:disaster roaming;a type of a received message;a cause value;integrity protection; ora time information associated with the RAT utilization control information.Docket No.: 25-1021 PCT14. The method of claim 13, wherein the wireless device sends the second NAS message requesting transfer of the data session, based on the time information.

15. The method of claim 14, wherein the wireless device discards the RAT utilization control information based on at least one of triggering the disaster roaming or registering for the disaster roaming.

16. The method of claim 15, wherein the wireless device sends the second NAS message, after discarding the RAT utilization control information.

17. The method of any one of claims 2 to 16, wherein, based on the RAT utilization control information indicating that the access technology is restricted and based on registration for the disaster roaming being triggered, sending by the wireless device and via the access technology, the second NAS message.

18. The method of any one of claims 2 to 17, further comprising, receiving by the wireless device, a fifth NAS message comprising a cause value and not comprising a third RAT utilization control information.

19. The method of claim 18, wherein the cause value indicates a congestion of a network.

20. The method of any one of claims 18 to 19, wherein the wireless device discards the RAT utilization control information, based on that the fifth NAS message not comprising the third RAT utilization control information and that the cause value indicates congestion.

21. The method of any one of claims 18 to 20, wherein the wireless device stores a third RAT utilization control information, based on the fifth NAS message comprising the third RAT utilization control information and that the cause value indicates congestion.

22. The method of any one of claims 18 to 21 , wherein the wireless device keeps the RAT utilization control information, based on that the fifth NAS message not comprising the third RAT utilization control information and that the cause value indicates no suitable cells in tracking area.

23. The method of any one of claims 18 to 22, wherein the wireless device transitions to a second MM registered state, based on receiving the fifth NAS message.

24. The method of any one of claims 18 to 23, wherein the wireless device receives the fifth NAS message in response to sending the second NAS message.

25. The method of any one of claims 18 to 24, wherein the fifth NAS message is a second attach accept message not comprising a second RAT utilization control information.

26. The method of any one of claims 18 to 25, wherein the third RAT utilization control information further comprises a third version information.

27. The method of any one of claims 18 to 26, wherein the RAT utilization control information further comprises a version information.

28. The method of claim 27, wherein the wireless device determines whether to store or discard the third RAT utilization control information, based on the version information and the third version information.Docket No.: 25-1021 PCT29. The method of any one of claims 2 to 28, wherein the wireless device transitions to a second MM deregistered state, for the second network, based on receiving the RAT utilization control information indicating that the access technology is restricted, while remaining in a first MM registered state for the second access technology.

30. The method of any one of claims 2 to 29, wherein the wireless device releases the data session anchored in the access technology, based on receiving the RAT utilization control information indicating that the access technology is restricted.

31. The method of any one of claims 2 to 30, wherein the wireless device sends to the second network, a deregistration request message requesting deregistration of the second network, based on receiving the RAT utilization control information indicating that the access technology is restricted.

32. The method of any one of claims 2 to 31 , the disaster roaming is an emergency service.

33. The method of any one of claims 2 to 32, wherein the wireless device is dual-registered to the first network and the second network, of a same network operator.

34. The method of any one of claims 2 to 33, wherein the wireless device selects at least one of the second network and the access technology, based on the second network being selected manually for network selection.

35. The method of any one of claims 2 to 34, wherein the wireless device selects the second network, based on that the disaster roaming is triggered.

36. The method of any one of claims 2 to 35, wherein the wireless device selects at least one of the access technology and the second network, based on that the disaster roaming is triggered.

37. The method of any one of claims 2 to 36, wherein the wireless device determines whether to store or discard the RAT utilization control information, based on at least one of:- whether the first NAS message is integrity protected or not;- a cause value in the first NAS message; or- whether the first NAS message indicates a reject.

38. The method of claim 37, wherein the cause value indicates at least one of.- no suitable cell in a tracking area; or- congestion.

39. The method of any one of claims 2 to 38, wherein the wireless device selects the access technology after discarding the RAT utilization control information restricting the access technology.

40. The method of any one of claims 2 to 39, wherein the access technology and the second access technology comprises at least one of a E-UTRA, new radio (NR), 6G radio (6GR), NG-RAN, 6G-RAN, E-UTRAN.Docket No.: 25-1021 PCT41. The method of any one of claims 2 to 40, further comprising sending, by the wireless device to the mobility management node, a third NAS message comprising an indication42. A method comprising:receiving, by a wireless device, one or more non-access stratum (NAS) messages accepting registration for a plurality of systems;transitioning, by the wireless device and based on the one or more NAS messages, to a registered state for a first system, of the plurality of the systems;receiving, by the wireless device via a first access technologies of the first system, a message indicating that a second access technology is restricted; andbased on the message, by the wireless device:transitioning to a deregistered state for the second system; andreleasing one or more data sessions over the second system.

43. A method comprising:receiving, by a wireless device via a first access technologies, a message indicating that a second access technology is restricted for a network; andtransitioning, by the wireless device and based on the message, to a deregistered state for a second system associated with the second access technology.

44. A method comprising:receiving, by a wireless device from a network, a first message comprising a radio access technology (RAT) utilization control information indicating one or more restricted access technologies; andreceiving, by the wireless device from the network, a second message, accepting an emergency registration, not comprising the RAT utilization control information; and sending, by the wireless device to the network, a third request message requesting registration for non-emergency service, via an access technology, wherein the one or more restricted access technologies does not comprise the access technology.

45. A method comprising:receiving, by a wireless device and from a first network, a first non-access stratum (NAS) message comprising a radio access technology (RAT) utilization control information, wherein the RAT utilization control information indicates an access technologies restricted for the wireless device to select for the first network; andreceiving, by the wireless device and from the network, a deregistration request message comprising a cause value;Docket No.: 25-1021 PCTdetermining, by the wireless device, whether to discard the RAT utilization control information, based on:the cause value; andwhether the deregistration request message comprises the RAT utilization control information; anddiscarding, by the wireless device and based on the determining, the RAT utilization control information; andsending, by the wireless device, a message requesting registration via the access technology.

46. A method comprising:receiving, by a wireless device from a network, a first message comprising a first radio access technology (RAT) utilization control information indicating at least one of:one or more restricted access technologies; andone or more non-restricted access technologies;sending, by the wireless device to the network, a registration message comprising a registration type indicator, wherein the registration type indicates at least one of an emergency registration and non-emergency registration;receiving, by the wireless device from the network, a registration accept message not comprising a RAT utilization control information;determining, by the wireless device and based on the registration type, at least one of:to discard the first RAT utilization control information, in response to the registration type being the non-emergency registration; andto keep the first RAT utilization control information, in response to the registration type being the emergency registration; andsending, by the wireless device to the network, a third request message requesting registration, via an access technology, among the one or more restricted access technologies and the one or more non-restricted access technologies.

47. A method comprising:receiving, by a wireless device from a first network, a first non-access stratum (NAS) message comprising a radio access technology (RAT) utilization control information;storing, by the wireless device, the RAT utilization control information;sending, by the wireless device to the first network, a second NAS message comprising an indication that the wireless device has the RAT utilization control information stored; andDocket No.: 25-1021 PCTreceiving, by the wireless device from the first network, a third NAS message, wherein whether the third NAS message comprises a second RAT utilization control information is based on the indication.

48. A method comprising:receiving, by a wireless device from a first network, a first non-access stratum (NAS) message comprising a radio access technology (RAT) utilization control information and a cause value; adding, by the wireless device, an entry to a list of forbidden tracking areas, based on the cause value;starting, by the wireless device, a timer associated with the entry;upon expiry of the timer, determining, by the wireless device, whether the RAT utilization control information is stored; andbased on that the RAT utilization control information is stored, keeping, by the wireless device, the entry in the list of forbidden tracking areas.

49. A wireless device comprising one or more processors and memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method of any of claims 1 to 48.

50. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause a wireless device to perform the method of any of claims 1 to 48.

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