Mobile Base Station Relay Access

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D illustrate various examples of a framework for a service-based architecture within a core network.

FIG. 3 illustrates an example communication network including core network functions.

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

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

FIG. 6 illustrates an example of network slicing.

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.

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

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

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

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

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

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

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.

FIG. 15 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 16 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 17 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 18 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 19 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 20 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 21 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 22 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 23 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 24 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 25 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 26 is a diagram of an aspect of an example embodiment of the present disclosure.

FIG. 27 is a diagram of an aspect of an example embodiment of the present disclosure.

DETAILED DESCRIPTION

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.

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 more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

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.

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.

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”.

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 affect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, 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.

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.

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”.

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 of Y are {Y1, Y2, Y3}, {Y1, Y2}, {Y1, Y3}, {Y2, Y3}, {Y1}, {Y2}, and {Y3}. 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.

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 (IoT) device, vehicle roadside 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.

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), time-division 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.

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, Wi-Fi 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 (cNB). 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-cNB) 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 may perform 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.

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.

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).

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 cNBs) 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.

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).

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 IoT device).

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.

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-cNBs 152B may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) protocol terminations over a Uu interface associated with a second protocol stack.

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-based 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.

FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D illustrate various examples of a framework for a service-based 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).

In the example of FIG. 2A, an NF 211 (a consumer NF in this example) may send a request 231 to an NF 212 (a producer NF). The request 231 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 231 may comprise data relating to NF 211 and/or the requested service. The NF 212 may receive request 231, perform one or more actions associated with the requested service (e.g., retrieving data), and provide a response 231. The one or more actions performed by the NF 212 may be based on request data included in the request 231, data stored by NF 212, and/or data retrieved by NF 212. The response 232 may notify NF 211 that the one or more actions have been completed. The response 232 may comprise response data relating to NF 212, the one or more actions, and/or the requested service.

In the example of FIG. 2B, an NF 241 sends a request 221 to an NF 242. In this example, part of the service produced by NF 242 is to send a request 222 to an NF 243. The NF 243 may perform one or more actions and provide a response 223 to NF 242. Based on response 223, NF 242 may send a response 224 to NF 241. 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.

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 NF 252 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.

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.

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. 2C (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.

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).

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 mobile location 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).

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 ‘N6’. 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.

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.

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.

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 core network. 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.)

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.

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, network-specific, wireless device-specific, session-specific, or data flow-specific.

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.

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 external element 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.

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.

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.

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).

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.

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.

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 the NEF 340. However, an operator of the core network may consider the AF 399 to be a trusted domain that can access the network directly.

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.

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.

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.

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.

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.

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 packet associated 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.

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.

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 (MEC) 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).

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.

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.

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, a UPF 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.

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.

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.

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.

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 N3 interface. 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.

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.

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.

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.

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.

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.

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 601A, 601B, 601C (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.

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 601A, 601B, 601C may have different requirements, but network architecture 600A can only be optimized for one of the three.

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 601A 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.

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.

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.

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.

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.

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.

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.

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 to a 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).

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.

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.

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.

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 may be 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.

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 230 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.

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.

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 233 may provide RLC channels as a service to PDCPs 214 and 234, respectively.

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.

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 and modulation/demodulation) for sending and receiving information (e.g., transmission via an air interface). PHY 731 and PHY 732 may perform multi-antenna mapping.

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.

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).

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.

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). QoS flows 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.

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.

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 pre-emption 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.

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 uplink packets 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.

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.

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.

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.

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.

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.

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 serving the 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.

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.

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.

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).

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.

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 cell identities, 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.

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.

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).

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).

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.

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).

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.

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.

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 may 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).

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

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.

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.

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.

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.

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.

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.

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.

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.

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_ReleaseSMContext).

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.

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).

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.

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 NIN2 message transfer for forwarding to an AN. The PDU session information may include, for example, UPF tunnel endpoint information and/or QoS information.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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. The PDU 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.

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.

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.

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.

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).

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.

The SMF may send PDU session management information to the AMF. The PDU session management information may be a Namf_Communication_NIN2MessageTransfer 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.

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.

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.

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 message may 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.

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.

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.

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.

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 a transmission 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.

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.

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 multi-user MIMO), transmit/receive diversity, and/or beamforming.

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 may cause 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.

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 OSI 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.

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.

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 more functions 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.

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.

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 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++ 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.

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, increment 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.

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.

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 flexibly deployed 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).

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.

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).

For example, deployment 1410 comprises an additional network function, NF 1411A. The NFs 1411, 1411A 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.

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, data storage, 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.

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.

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, 1411A, 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, 1411A, 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.

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 inter-deployment transmission or intra-deployment transmission, unless explicitly indicated.

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.

FIG. 15 illustrates an example scenario in which one or more cells (base stations) are deployed to provide connectivity services to one or more UEs. For example, a network may comprise one or more base stations. Each of the one or more base stations may comprise one or more cells. Each of the one or more cells may cover an area where the network provides the connectivity services to the one or more UEs. A union of one or more areas of the one or more cells of the network may be a coverage of the network. If a UE is in the coverage of the network, the UE may be able to send/receive a data. If the UE is outside of the coverage of the network, the UE may not be able to send/receive a data. The coverage may be dependent on various factors. For example, the various factors may comprise whether a network equipment can be installed in one or more areas, whether enough users are available in one or more areas, and/or the like. For example, in a first area along a street in the middle of office buildings, demand for a connectivity service may exist almost always. This may make the network to provide connectivity service in the first area. On the other hand, a second area along a road in the middle of mountain areas, there may be no demand for connectivity service most of the time. The second area may not in the coverage of the network. If a UE (e.g., UE2) moves along the second area, the UE 2 may not be able to send/receive a data.

FIG. 16 illustrates an example scenario in which a connectivity service can be provided on the spot and/or based on demand. For example, instead of providing a coverage using a stationary cell, a vehicle equipped with capability of a base station may be used to provide a cell. Using wireline connection between a core network and a base station for backhaul (e.g., data transport channel between the core network and the base station) may be one of factors that a cell (or a base station) is fixed in location, and/or may limit a size of the coverage. However, if a wireless connectivity between the core network and the cell is usable, one or more cells may be nomadic, and/or may allow flexible adjustment of the coverage. A reliable and boosted capacity of 5G system may allow transition from wireline backhaul to wireless backhaul.

In an example, a vehicle (e.g., a taxi, a bus, a train, and/or the like) may be equipped with capability of a base station. For example, the vehicle may be equipped with a larger antenna compared to an antenna of smartphone, and/or with high-power amplifiers. These may allow a signal of the vehicle to reach farther than a signal of the smartphone. For example, the vehicle in the FIG. 16 may connect to a fixed cell (or other cell) while a UE (e.g., a smartphone) inside the vehicle may not be able to connect to the fixed cell. In this case, the vehicle may be able to act as a relay. For example, the vehicle may receive a downlink data from the fixed cell and/or may deliver the data to the UE. For example, the vehicle may receive an uplink data from the UE and/or may deliver the data to the fixed cell. This relaying by the vehicle may expand a coverage and may reduce a time when the UE is not able to use connectivity service. This mechanism is called integrated access and backhaul (IAB), which will be further explained below.

FIG. 17 illustrates an example of integrated access and backhaul (IAB). IAB functionality enables a UE act as a base station (e.g., gNB, eNB, MeNB, SgNB, gNB-DU, gNB-CU, or part of a base station, etc.) and/or a relay node (e.g., wireless relay node, a relay UE). IAB functionalities enable one part (e.g., gNB-CU) of a base station to connect wirelessly to other part (e.g., gNB-DU) of a base station. IAB functionalities may allow a node to act as a UE (e.g., IAB-MT) and/or a base station (or part of base station, e.g., IAB-DU).

In the example figure, several user equipment (UE 1791, UE 1792, UE 1793) access a network via wireless access links of several base stations (BS 1701, BS 1702, BS 1703). Each wireless access link between a UE and a BS may operate as a Uu interface. In particular, the UE 1791 accesses BS 1701 via Uu 1711, UE 1792 accesses the BS 1702 via Uu 1712, and UE 1793 accesses BS 1703 via Uu 1713.

As noted above, IAB functionality enables the BSs 1701-1703 to connect wirelessly. The BSs 1701-1703 may communicate via wireless backhaul links. The wireless backhaul link between BSs may operate as a Uu interface. In particular, BS 1701 has Uu 1714 with BS 1702 and BS 1702 has Uu 1715 with BS 1703.

The BS 1703 has an interface with a core of the network. The interface may be an NG interface (as shown in the figure), an S1-U interface, etc.

In the example figure, BSs 1701-1703 have IAB functionality. At the bottom of the example figure, BS 1701 and BS 1702 are depicted in terms of IAB architecture. In particular, BS 1701 and BS 1702 are depicted as IAB-node (or IAB node) 1721 and IAB-node 1722, respectively, and BS 1703 is depicted as IAB-donor 1723.

The IAB-nodes 1721-1722 have distributed unit (DU) functionality. The DU functionality of each IAB-node may be directed downstream (toward the left in the example figure). The DU functionality is illustrated as IAB-DU 1761 and IAB-DU 1762, respectively. The IAB-DUs 1761-1762 use the DU functionality to communicate downstream via a wireless access link (e.g., Uu interface). For example, IAB-node 1721 uses IAB-DU 1761 to communicate downstream to UE 1791 via Uu 1711. IAB-node 1722 uses IAB-DU 1762 to communicate downstream to UE 1792 via Uu 1712. As will be discussed in greater detail below, IAB-node 1722 also uses IAB-DU 1762 to communicate downstream to IAB-node 1721 via Uu 1714.

In addition to DU functionality (for communicating downstream in an IAB context, e.g., with one or more child nodes), each IAB-node may have mobile terminal (MT) functionality (for communicating upstream, e.g., with one or more parent nodes, or IAB-donor). The MT functionalities are illustrated as IAB-MT 1771 and IAB-MT 1772, respectively. The IAB-MTs 1771-1772 use the MT functionality to communicate upstream via a Uu interface. For example, IAB-node 1721 uses IAB-MT 1771 to communicate upstream to IAB-node 1722 via Uu 1714. IAB-node 1722 uses IAB-MT 1772 to communicate upstream to IAB-donor 1723 via Uu 1715. Alternatively and/or additionally, the MT functionalities may be implemented as a UE (or a wireless device). For example, an IAB-node (e.g., IAB-node 1722, IAB-node 1721) may be considered both a UE (e.g., considering IAB-MT 1772, IAB-MT 1771) and a BS (or part of BS, e.g., considering IAB-DU 1762, IAB-DU 1771).

The IAB-donor 1723 has central unit (CU) functionality. The CU functionality is illustrated as IAB-CU 1783. The IAB-donor 1723 uses the CU functionality to communicate upstream with the core of the network (e.g., via an NG interface, S1-U interface, etc.). Similar to the IAB-nodes 1721-1722, the IAB-donor 1723 may have DU functionality (e.g., IAB-Doner DU), illustrated as IAB-DU 1763. Similar to the IAB-nodes 1721-1722, the IAB-donor 1723 uses the DU functionality to communicate downstream via a Uu interface. For example, IAB-donor 1723 uses IAB-DU 1763 to communicate downstream to UE 1793 via Uu 1713. IAB-donor 1723 also uses IAB-DU 1763 to communicate downstream to IAB-node 1722 via Uu 1715.

From the perspective of the IAB-CU 1783 of the IAB-donor 1723, the IAB-node 1721 and IAB-node 1722 may be regarded as distributed units, similar to IAB-DU 1763. For example, BS 1703 may operate as a base station central unit with F1 interfaces to several base station distributed units. An F1 interface 1717 may be implemented within BS 1703 between IAB-CU 1783 and IAB-DU 1763. Another base station distributed unit may be implemented as DU functionality within BS 1702. An F1 interface 1717 may be implemented between IAB-CU 1783 and IAB-DU 1762, employing the wireless backhaul link Uu 1715. Yet another base station distributed unit may be implemented as DU functionality within BS 1701. An F1 interface 1718 may be implemented between IAB-CU 1783 and IAB-DU 1761, employing the series of wireless backhaul links Uu 1714-1715. It will be understood that a ‘multi-hop’ F1 interface may be implemented across any number of wireless backhaul links. In this manner, base stations configured with IAB functionality may act as IAB-nodes, enabling the base stations (and/or the UEs) to act as communication relays.

In light of the foregoing example, it will be understood that IAB enables wireless relaying in NG-RAN. The relaying node, referred to as IAB-node, supports access and backhauling via 3GPP new radio (NR). The terminating node of NR backhauling may be referred to as the IAB-donor, which represents a base station (e.g., gNB) with additional functionality to support IAB. Backhauling can occur via a single hop (e.g., between IAB-node 1722 and IAB-doner 1723) or via multiple hops (e.g., between IAB-node 1721 and IAB-doner 1723). For IAB, backhauling (or backhaul interface, F1, and/or the like) may refer to data/signaling exchange between a DU and a CU, and/or access (or access interface, Uu, and/or the like) may refer data/signaling exchange between a UE (or a MT) and a DU.

The IAB-node supports the gNB-DU functionality to terminate the NR access interface to UEs and next-hop IAB-nodes, and to terminate the F1 protocol to the gNB-CU functionality, on the IAB-donor. The gNB-DU functionality on the IAB-node may be referred to as IAB-DU.

In addition to the gNB-DU functionality, the IAB-node also supports a subset of the UE functionality referred to as IAB-MT, which includes, e.g., physical layer, layer-2, radio resource control (RRC) and non-access stratum (NAS) functionality to connect to the DU functionality of another IAB-node or the IAB-donor; to connect to the gNB-CU on the IAB-donor; and to connect to the core network.

One or more IAB nodes may comprise a first-type IAB nodes and/or a second-type IAB nodes. For example, the first-type IAB nodes may be one or more IAB nodes which may change locations and/or may move. For example, the second-type IAB nodes may be one or more IAB nodes which may not change locations and/or may not move. For example, a first-type IAB node may indicate that the first-type IAB node is an IAB node, and/or that the first-type IAB node is mobile. For example, a second-type IAB node may not indicate that the second-type IAB node is an IAB node and/or that the second-type IAB node is mobile.

The IAB-node may access the network using standalone architecture (SA mode) or E-UTRA-NR dual connectivity (EN-DC). In EN-DC, the IAB-node connects via E-UTRA to a master cNB (MeNB), and the IAB-donor terminates an X2-C interface as a secondary gNB (SgNB).

FIG. 18 illustrates an example of a mobile base station relay (MBSR). The figure illustrates an MBSR 1801. The MBSR 1801 may be an IAB node. The MBSR 1801 may comprise IAB functionality, for example, similar to the BS 1801 and/or IAB-node 1821 illustrated in FIG. 18. As noted above, IAB functionality enables base stations (e.g., gNB, cNB, MeNB, SgNB, etc.) to act as relay nodes (e.g., wireless relay nodes) and/or enables a UE to act as part (e.g., gNB-DU) of the base stations.

In the example of FIG. 18, several user equipment (UE 1891, UE 1892, UE 1893) access a network via wireless access links of several base stations (MBSR 1801, BS 1802, BS 1803, BS 1804). The MBSR 1801 is a mobile base station (or MBSR), for example, a base station that is configured and/or intended to move within the network. The MBSR 1801 is illustrated as a bus with an integrated base station, but it will be understood that base station mobility may be implemented in any suitable manner (train, boat, aerial drone, etc.). The UE 1891a is illustrated as being outside of the bus, whereas the UE 1891b is illustrated as being inside the bus (e.g., moving with and/or transported by the MBSR 1801).

As one use-case scenario for MBSRs, consider that the MBSR 1801 may be located (e.g., parked) at the edge of a coverage area of a non-mobile base station (e.g., BS 1802) to extend a coverage area of the network. Even if UE 1891a is at or beyond an edge of a coverage area of the BS 1802, the UE 1891a may access BS 1802 (and the upstream network) via MBSR 1801 (and/or a multi-hop chain of additional MBSRs, not illustrated). Accordingly, MBSRs may be advantageously or spontaneously deployed if coverage is needed in a remote area (an off-the-grid music festival, a rescue operation, etc.).

As another use-case scenario for MBSRs, consider that the MBSR 1801 may transport a plurality of users (e.g., UE 1891b plus several other passenger UEs) through various coverage areas (of BS 1802, BS 1803, BS 1804, etc.). If the MBSR 1801 lacked MBSR capabilities (i.e., if the MBSR 1801 was a normal bus), then each of the passenger UEs would re-register in each TA (TA2, TA3, TA4, etc.). This would predictably result in a sudden spike of control signaling in each base station's coverage area as the bus entered. A benefit of MBSR is that the need for control signaling can be reduced. For example, because MBSR 1801 has the DU functionality of an IAB-node, each of the users (UE 1891b, etc.) can remain in a coverage area of the MBSR 1801. From the perspective of the passenger UEs, MBSR 1801 remains “stationary”. In an example, only the MBSR 1801 itself re-registers in each tracking area (e.g., using its MT functionality), thereby reducing the amount of control signaling. MBSRs of this kind may be advantageously deployed along high-traffic corridors (e.g., on a bus or in a train car) to limit waves of registration requests.

As noted above, IAB functionality enables MBSR 1801/BSs 1802-1804 to act as wireless relay nodes. MBSR 1801 and BS 1802 may communicate upstream via wireless backhaul links (Uu 1814, Uu 1815). In the example figure, BS 1803 and BS 1804 have interfaces with a core of the network. In the example figure, MBSR 1801 and BSs 1802-1804 have IAB functionality.

MBSR 1801 and BS 1802 may operate as IAB-nodes. Accordingly, MBSR 1801 and BS 1702 may have DU functionality and MT functionality. For example, the BS 1802 may be wirelessly connected to BS 1803. For example, the BS 1802 may be an IAB-node which is fixed in location and/or mostly does not move.

BS 1803 and BS 1804 may operate as IAB-donors. BSs 1803-1804 may have CU functionality and DU functionality.

Unlike the BS 1801 illustrated in FIG. 18, MBSR 1801 is mobile. Accordingly, MBSR 1801 may move through the coverage areas of BS 1802 and BS 1803, and may sometimes be regarded (due to its MT functionality), from an upstream perspective, as any other wireless device (e.g., UE).

MBSR 1801 and BSs 1802-1804 may belong to different tracking areas, respectively (TA1, TA2, TA3, TA4 in the illustration). Each may transmit (e.g., broadcast) a SIB indicating its tracking area. In an example, the respective TAs may be associated with different registration areas (e.g., a UE may re-register upon exiting and/or entering a TA). In other example, some (e.g., MBSR 1801, BS 1802, BS 1803) of the MBSR 1801 and the BSs 1802-1804 may be associated with a same TA (e.g., TA X).

Moreover, MBSR 1801 and BSs 1802-1804 may have different supports and/or restrictions. In the illustrated example, TA2 (e.g., served by fixed IAB-node) may support a legacy UE (e.g., not supporting a cell of mobile IAB-node), and/or TA1 (e.g., served by mobile IAB-node) may not support the legacy UE. In other example, a first-tier (e.g., general user category) UE may be allowed to access a legacy cell (e.g., a cell which is not provided by an IAB-node) and/or a second-tier UE (e.g., priority user category) may be allowed to access a cell of an IAB node.

In the specification, the term “NG-RAN” may be interpreted as a base station, which may comprise at least one of a gNB, an eNB, a ng-cNB, a NodeB, an access node, an access point, an N3IWF, 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. In the specification, a gNB may be interpreted as a base station. In the specification, a gNB-CU may be interpreted as a base station central unit. In the specification, a gNB-DU may be interpreted as a base station distributed unit.

In the specification, the term “IAB-donor” may be a gNB (or base station) that provides network access to UEs via a network of backhaul and access links. In the specification, the term “IAB-DU” may be a gNB-DU functionality supported by the IAB-node to terminate the NR access interface to UEs and next-hop IAB-nodes, and to terminate the F1 protocol to the gNB-CU functionality on the IAB-donor. In the specification, the term “IAB-MT” may be an IAB-node function that terminates the Uu interface to the parent node using the procedures and behaviors specified for UEs. In the specification, the term “IAB-node” may be a RAN node (or a network node) that supports NR access links to UEs and/or NR backhaul links to parent nodes and child nodes. For example, a MBSR may be the IAB-node. For example, the MBSR may be a mobile IAB-node.

In the specification, the term “core network” node may be interpreted as 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 and/or the like. A term of core network may be interpreted as a core network node. In the specification, a term of an access node may be interpreted as a base station, which may comprise a NG-RAN, and/or the like.

In the specification, the term “network node” may be interpreted as a core network node, an access node, a NG-RAN, a UE, and/or the like. A network may comprise one or more network nodes.

In the specification, the term “a cell of a MBSR” and/or “a cell of a mIAB” may be interpreted as one or more cells of one or more MBSRs and/or one or more cells of one or more mIAB nodes.

In the specification, to access a cell of a MBSR may mean to access one or more cells of one or more MBSRs. For example, when a UE is allowed to access a cell of a MBSR, the UE may be allowed to access one or more cells of one or more MBSR. For example, when a UE is allowed to access a cell of a MBSR, the UE may be allowed to access one or more cells operated (or, served, provided, implemented, managed) by one or more MBSRs. For example, when a UE is not allowed to access a cell of a MBSR, the UE may not be allowed to access one or more cells operated (or, served, provided, implemented, managed) by one or more MBSRs. For example, a network may comprise one or more cells. For example, the one or more cells may comprise one or more type-A cells and/or one or more type-B cells. For example, the one or more type-A cells may be one or more cells of one or more MBSRs. For example, the one or more type-B cells may be one or more cells that are not operated (run, implemented, served, provided, associated) by one or more MBSRs. For example, the one or more type-A cells may comprise at least one of a cell A1 (e.g., of a MBSR A1) and a cell A2 (e.g., of a MBSR A2). For example, the one or more type-B cells may comprise at least one of a cell B1 and a cell B2. For example, if the UE is allowed to access a cell of a MBSR, the UE may be allowed to access/use the one or more type-A cells (e.g., the cell A1, the cell A2). For example, if the UE is not allowed to access a cell of a MBSR, the UE may not be allowed to access/use the one or more type-A cells (e.g., the cell A1, the cell A2) and/or may be allowed to access/use the one or more type-B cells.

FIG. 19 illustrates an example of registration of an MBSR and a UE. For illustration purposes, the figure includes a UE 3, a UE 4, an MBSR, a BS 1, and a core node.

In the figure, the MBSR may be operational. For example, the MBSR may provide a cell 1 of a TA 1. The MBSR may be connected to a gNB-CU (not shown in the figure) via F1 interface. The MBSR may broadcast a SIB via the cell 1. The SIB may indicate the TA 1 and/or that the cell 1 is a cell of a MBSR.

In the figure, the BS 1 may provide one or more cells. The one or more cells may comprise a cell 2. The cell 2 may belong to the TA 1.

In the figure, the UE 4 may camp on (connects to) the cell 2. For example, the UE 4 may be in coverage of the cell 2. The UE 4 may not be allowed to access a cell of a MBSR. For example, a cell of a MBSR may be one or more cells of one or more MBSRs. For example, the one or more cells of the one or more MBSRs may be one or more cells operated (served) by the one or more MBSRs. For example, a UE may be allowed to access a cell of a MBSR by, for example, UE being allowed to exchange data via the one or more cells of the one or more MBSRs. For example, a network operator may allow UEs with subscription to MBSR, to access a cell of a MBSR, and/or may not allow UEs without subscription to access to a cell of MBSR. In other example, the network operator may allow UEs (e.g., public safety UEs (police, firefighters, and/or the like), high capability UEs, and/or the like) with priority to access to a cell of a MBSR, and/or may not allow UEs (e.g., normal UEs, low capability UEs, without supporting IAB functionalities, legacy UE, and/or the like) without priority to access to a cell of a MBSR. For example, based on that the UE 4 does not have subscription to a cell of a MBSR, the network operator may determine that the UE 4 is not allowed to access to a cell of a MBSR. For example, the UE may not be allowed to access the cell 1.

In an example, the BS 1 may determine to handover the UE 4 to the cell 1. For example, based on the signal strength of one or more cells, the BS 1 may determine the handover. For example, if the signal of the cell 2 becomes weak (e.g., less than 1 dBm) and/or if the signal of the cell 1 becomes strong (e.g., more than 10 dBm), the BS 1 may determine to handover the UE 4 to the cell 1. Based on the determination, the BS 1 may send a handover command to the UE 4.

In an example, the UE 4 may receive the handover command and/or may access the cell 1. The UE 4 may send a RRC request message to the cell 1 and/or may request resource allocation for data communication to the cell 1. Because the UE 4 is not allowed to use a cell of a MBSR, this request may cause signaling congestion to the cell 1 and/or the UE 4 may not be able to use data communication service in the cell 1. The existing technologies causes handover of a UE to a cell for which the UE is not allowed, leading to waste of signaling resources and/or increased service interruption time.

In another example, a UE 3 may power on in coverage of the cell 1. Based on detecting the cell 1, the UE 3 may start registration procedure via the cell 1. For the registration procedure, the UE 3 may send a registration request message. The UE 3 may not be allowed to use a cell of a MBSR, e.g., due to subscription. Based on the fact that the UE 3 is not allowed to use a cell of a MBSR, and/or based on that the UE 3 is accessing a network via a cell of a MBSR, the core network node may reject the registration request, and/or may send a registration reject message to the UE 3.

In an example, the UE 3 may receive the registration reject message. Based on the fact that the UE 3 receives the registration reject message via the cell 1 of the TA 1, and/or based on that the SIB of the cell 1 indicates the TA 1, the UE 3 may consider that one or more cells of the TA 1 is restricted (not allowed) to the UE 3.

In an example, the UE 3 may move into coverage of the cell 2 from the cell 1. The UE 3 may receive a SIB broadcast by the cell 2. The SIB may indicate that the cell 2 supports the TA 1. Based on that the UE 3 received the registration reject message from one (e.g., cell 1) or more cells of the TA 1, and/or that the cell 2 belongs to the TA 1, the UE 3 may determine that access to one or more cells of the TA 1 is not allowed, and/or that the UE 3 is not allowed to request a service via the cell 2.

In an example, because the cell 2 is served by a non-IAB cell (e.g., a cell which is not provided by an IAB-node), the network operator may allow the UE 3 to access the cell 2. However, in the existing technologies, the UE may not request a service from the cell 2 and/or may experience a longer service interruption time.

Example embodiments of the present disclosure improve quality of service experience by enhancement in signaling between network nodes. In an example, a source access node may exchange with neighboring access node, configuration information associated with MBSR. This may assist the source access node to select a relevant target access node for handover. In other example, a core network node may indicate to an access node, subscription information associated with MBSR. This may assist the access node in determining which target access node can provide data communication service for the UE. For example, a first base station receives, from a core network node, an indication indicating that a wireless device is allowed to access via one or more mIAB nodes. In this example, the first base station sends, to a second base station and based on the indication, a request requesting handover of the wireless device to a cell of the second base station, wherein the cell is operated by a mIAB node. This may help in reducing service interruption time for the UE, and this may reduce unnecessary use of radio resources.

FIG. 20 illustrates an example of registration of an MBSR and a UE. For illustration purposes, the figure includes a UE 2000, an MBSR 2010, a BS 2020, an AMF 2055 (serving UE 2000), and an AMF 2060 (serving MBSR 2010).

BS 2020 may operate as an IAB-node (e.g., having DU functionality and MT functionality) or as an IAB-donor (e.g., having CU functionality and DU functionality). Although BS 2020 is illustrated as a single node, it will be understood that in some scenarios, BS 2020 may comprise one or more IAB-nodes and an IAB-donor (e.g., a chain of IAB-nodes and an IAB-donor).

Although AMF 2055 and AMF 2060 are illustrated as different AMFs, it will be understood that in some scenarios, the same AMF may serve (e.g., be selected to serve) both UE 2000 and MBSR 2010.

At 2028, MBSR 2010 accesses the network, sets up an RRC connection, and registers. During 2138/2048, MBSR 2010 may operate using IAB-MT functionality.

The MBSR 2010 receives a system information block (SIB) 2025 from BS 2020. The SIB 2025 may indicate (e.g., comprise an indicator) that BS 2020 supports MBSR operation (e.g., supports communication via a wireless backhaul link, supports communication with an IAB-node, supports mobile IAB-node, etc.). The SIB 2025 may comprise, for example, a network identifier associated with a network of BS 2020 (e.g., PLMN ID), a tracking area identifier associated with a tracking area of BS 2020 (e.g., tracking area code (TAC), tracking area identifier (TAI) etc.), a cell identifier associated with the cell of BS 2020 (e.g., new radio cell global identifier (NCGI), NR cell identity), etc.

At 2138, MBSR 2010 performs random access (RA). The RA in the figure is illustrated as four-step random access, but it will be understood that other types of RA may be implemented. The random access at 2138 may be based on receiving the SIB 2025. The random access at 2138 may be based on the SIB 2025 indicating MBSR support and/or based on that MBSR 2010 is configured to function as a MBSR.

In the figure, to perform random access at 2138, MBSR 2010 transmits an RA preamble to BS 2020. The BS 2020 transmits an RA response to MBSR 2010. The transmitting the RA response may be based on receiving the RA preamble. The MBSR 2010 transmits a Msg3 to BS 2020. The Msg3 may comprise an RRC setup request (e.g., RRC connection setup request, RRC connection establishment request, and/or the like). The Msg3 may comprise a temporary identifier of MBSR 2010. The Msg3 may comprise an establishment cause value (e.g., an indication that RRC setup is for a mobile base station (e.g., MBSR, mIAB)). The transmitting the Msg3 may be based on receiving the RA response. The BS 2020 transmits a Msg4 to MBSR 2010. The Msg4 may comprise an RRC setup message. The transmitting the Msg4 may be based on receiving the Msg3.

At 2048, MBSR 2010 registers with the network. The registration is via BS 2020 (e.g., a distributed unit (DU) of BS 2020, a central unit (CU) of BS 2020, a cell of BS 2020, etc.). In the figure, MBSR 2010 sends a registration request to BS 2020. The registration request may be included in a NAS message.

The registration request and/or NAS message may be included in an RRC setup complete message. In an example, the RRC Setup complete message may comprise an indication that MBSR 2010 is an MBSR, and/or that MBSR 2010 wants to perform as a MBSR. After the RRC setup complete message is transmitted by MBSR 2010 and/or received by BS 2020, the MBSR 2010 may have an RRC connection with BS 2020.

The BS 2020 may select an AMF to serve the MBSR 2010. In the figure, AMF 2060 is the selected AMF. The BS 2020 sends a registration request (e.g., the registration request received from MBSR 2010) to the AMF 2060. The registration request may be included in a NAS message (e.g., the NAS message received from MBSR 2010). The registration request and/or the NAS message may be included in an N2 message (e.g., initial UE message). After receiving the registration request, the AMF 2060 may determine to accept the registration. The accepting may be based on, for example, subscription information of the MBSR 2010, etc. The AMF 2060 sends a registration accept to BS 2020. The registration accept may be included in a NAS message. The registration accept and/or the NAS message may be included in an N2 message (e.g., initial context setup message). The BS 2020 may send a registration accept (e.g., the registration accept received from AMF 2060) to the MBSR 2010. The registration accept may be included in a NAS message. The registration accept and/or the NAS message may be included in an RRC message.

MBSR 2010 may operate as an IAB-node. BS 2020 may operate as an IAB-node and/or an IAB-donor. Based on registration of MBSR 2010, a Uu interface may be used between MBSR 2010 (e.g., an MT functionality of MBSR 2010) and BS 2020 (e.g., a DU functionality of BS 2020). An F1 interface may be set up between MBSR 2010 (e.g., a DU functionality of MBSR 2010) and an IAB-donor (e.g., a CU functionality of BS 2020 or a CU functionality of an IAB-donor further upstream). The F1 interface may be set up over the Uu interface. The F1 interface may be via one or more wireless backhaul links.

The UE 2000 registers with AMF 2050 via a coverage area of MBSR 2010. For example, UE 2000 receives a SIB from MBSR 2010. Based on receiving the SIB, UE 2000 sends a registration request to MBSR 2010. MBSR 2010 sends the registration request to AMF 2050 via BS 2020. Based on receiving the registration request, AMF 2050 sends a registration accept to UE 2000 (e.g., via BS 2020 and MBSR 2010).

Based on, for example, the registration of MBSR 2010 via BS 2020 and the registration of UE 2000 via MBSR 2010/BS 2020, UE 2000 may exchange (e.g., send and/or receive) user data with a data network.

FIG. 21 illustrates an example of access control in accordance with aspects of the disclosure. For illustration purposes, the figure includes a UE 2100, an MBSR 2110, a BS 2120, a BS 2125, an AMF 2155, a UDM 2180, and a 2190.

Although BS 2120 and BS 2125 are illustrated as different BSs, it will be understood that in some scenarios, the same BS may constitute both BS 2120 and BS 2125 (e.g., BS 2120 and BS 2125 may represent different cells of a same base station rather than different base stations).

In an example, MBSR 2110 may be set up to operate as a mobile base station relay. For example, 2028 of FIG. 20 may show one example of how a MBSR is set up. Reverting back to FIG. 21, for example, the MBSR 2110 may provide a cell 1 (first cell).

In an example, the BS 2120 may establish an association with the BS 2125. For example, the BS 2125 may be one of a neighboring base stations of the BS 2120. Based on the association, the BS 2120 may handover one or more UEs to the BS 2125, and/or may add resources of the BS 2125 to the one or more UEs. To establish the association, the BS 2120 may send a Xn Setup request message to the BS 2125. For example, the Xn Setup request message may comprise an identifier of the BS 2125, information of one or more cells served by the BS 2125. For example, the information of one or more cells served by the BS 2125 may comprise, for each cell of the one or more cells, information of the cell (e.g., the cell 1) served by the MBSR 2110. For example, the information of the cell may indicate that the cell 1 is a cell of a MBSR (e.g., the cell 1 is served by a MSBR (e.g., MBSR 2110)). In response to the Xn Setup request message, the BS 2125 may send a Xn Setup response (e.g., acknowledge, accept, and/or the like) message to the BS 2120. For example, the Xn Setup response message may comprise information of cells served by the BS 2125. For example, the information of cells served by the BS 2125 may comprise information of a second cell (e.g., cell 2). For example, the information of the second cell may comprise an identifier of the second cell, a TA associated with the second cell, and/or indication indicating that the second cell is not a cell of a MBSR.

In an example, the UE 2100 may camp on the cell 2. The UE 2100 may send a RRC message to the BS 2125 via the cell 2. For example, the RRC message may comprise an identifier of the UE 2100, and/or a NAS message. For example, the NAS message may comprise an indication indicating whether the UE 2100 supports the feature (e.g., MBSR access capability) of an MBSR. For example, the feature of the MBSR may indicate whether the UE can camp on a cell of a MBSR, whether the UE can interpret/receive/process information (e.g., an information indicating that a cell is a cell of a MBSR) associated with a MBSR.

In an example, the BS 2125 may receive the RRC message. Based on that the RRC message comprises the NAS message, the BS 2125 may send a N2 request message (e.g., initial UE message, UL NAS transfer, and/or the like) to the AMF 2155. For example, the N2 request message may comprise the NAS message.

In an example, the AMF 2155 may receive the N2 request message. Based on the N2 request message, the AMF 2155 may determine to retrieve subscription information of the UE 2100. For example, the AMF 2155 may send the Nudm service request message to a UDM 2180. This may assist the AMF to determine whether the UE is eligible for using a cell of a MBSR. For example, the Nudm service request message may be a Nudm_SDM_Get request and/or the like. The Nudm service request message may comprise an identifier of the UE 2100. In response to the Nudm service request, the UDM 2180 may respond to the AMF 2155, with a Nudm service response. The Nudm service response may be a Nudm_SDM_Get response and/or the like. The Nudm service response may comprise subscription information (e.g., MBSR access subscription information and/or the like) associated with the MBSR. For example, the MBSR access subscription information may indicate whether the UE 2100 has a subscription for the feature of the MBSR (or mobile IAB), and/or whether the UE is allowed to access one or more cells provided one or more MBSR (e.g., mobile IAB nodes). The AMF may receive the Nudm service response. Based on the MBSR access subscription information of the Nudm service response, the AMF may determine whether to send to the BS 2125, a MBSR access restriction information (and/or the like). For example, the MBSR access restriction information may indicate whether the UE 2110 is allowed to use a cell of a MBSR. For example, based on the fact that the MBSR access subscription information indicates that the UE 2110 has a subscription, the MBSR access restriction information may indicate that the UE 2110 is allowed to use a cell of a MBSR. For example, based on the fact that the MBSR access subscription information does not indicate that the UE 2110 has a subscription, the MBSR access restriction information may indicate that the UE 2110 is not allowed to use a cell of a MBSR.

In an example, based on receiving the N2 request message, the AMF 2155 may send a Npcf service request message to a PCF 2190, to determine whether a policy for the UE allows the UE 2100 to use a cell of a MBSR. For example, the Npef service request message may be a Npcf_AMPolicyControl_Create request, Npcf_UEPolicyControl_Create request, and/or the like. The Npcf service request message may comprise at least one of the identifier of the UE, a subscription information (e.g., MBSR access subscription information) of the UE. In response to the Npcf service request, the PCF 2190 may respond to the AMF 2150, with a Npcf service response. The Npcf service response may be a Npcf_AMPolicyControl_Create response, a Npcf_UEPolicyControl_Create response, and/or the like. The Npef service response may comprise a MBSR access policy information for the UE. For example, the MBSR access policy information may indicate whether the UE is allowed to use a cell of a MBSR. The AMF may receive the Npcf service response. Based on the MBSR access policy information, the AMF may determine the MBSR access restriction information. For example, based on that the MBSR access policy information indicates that the UE is allowed to use a cell of a MBSR, the MBSR access restriction information may be set to indicate that the UE 2110 is allowed to use a cell of a MBSR. For example, based on that the MBSR access policy information does not indicate that the UE is allowed to use a cell of a MBSR, the MBSR access restriction information may not be set to indicate that the UE 2110 is allowed to use a cell of a MBSR.

In an example, the AMF 2155 may send the N2 response to the BS 2125. The N2 response may comprise the MBSR access restriction information and/or the NAS response message. For example, in response to the received NAS message from the UE 2100, the AMF 2155 may send the NAS response message, to the UE 2100.

In an example, the BS 2125 may determine whether to handover the UE 2100 to another cell. For example, if the signal quality of the cell 2 for the UE 2100 gets weak (e.g., below 1 dBm), the BS 2125 may determine to handover the UE 2100 to the other cell. For example, the BS 2125 may receive from the UE 2100, a measurement report indicating the signal quality and/or the BS 2125 may measure uplink signal of the UE 2100.

In an example, based on the determination to handover the UE 2100 to the other cell, the BS 2125 may determine a target cell to which the UE is handed over. For example, the BS 2125 may consider one or more candidate cells for handover. For example, the one or more candidate cells may be selected, based on that signal quality of the one or more candidate cell meets a minimum requirement (e.g., higher than 5 dBm). For example, the BS 2125 may remove one or more cells from the one or more candidate cells, based on the MBSR access restriction information. For example, if the MBSR access restriction information indicates that the UE 2100 is not allowed to use a cell of a MBSR, the BS 2125 may remove one or more cells (e.g., type-A cells, cells that are provided by one or more MBSR) from the one or more candidate cells. For example, if the MBSR access restriction information indicates that the UE 2100 is allowed to use a cell of a MBSR, the BS 2125 may not remove one or more cells (e.g., type-A cells, cells that are provided by one or more MBSR) from the one or more candidate cells. For example, if the UE 2100 is allowed to use a cell of a MBSR, the cell 1 may be considered as a candidate cell for a handover. For example, if the UE 2100 is not allowed to use a cell of a MBSR, the cell 1 may not be considered as a candidate cell for handover. The BS 2125 may select one or more target cells for handover, among the remaining one or more candidate cells. For example, based on that the UE 2100 is allowed to use a cell of a MBSR, and/or based on that the cell 1 is a cell of a MBSR, the BS 2125 may determine to handover the UE 2100 to the cell 1 (which is operated by the MBSR 211). Based on the determination, the BS 2125 may send a handover request message to the BS 2120. By using the MBSR access restriction information, a BS (e.g., a gNB, a NG-RAN) may avoid handing over a UE to a cell which the UE is not allowed to use.

In an example above, the BS 2125 may send a measurement configuration to the UE 2100 to receive the measurement report. For example, the measurement configuration may indicate whether the UE needs to measure a cell of a MBSR or not, or whether the UE needs to report a cell of a MBSR via measurement report. For example, if the measurement configuration indicates to measure a cell of a MBSR, the UE 2100 may measure one or more cells of one or more MBSRs, and/or may include measured result of the one or more cells of the one or more MBSRs in the measurement report. For example, if the measurement configuration indicates not to measure a cell of a MBSR, the UE 2100 may not measure one or more cells of one or more MBSRs, and/or may not include measured result of the one or more cells of the one or more MBSRs in the measurement report. This may assist the UE save battery power, by reducing unnecessary measurement.

FIG. 22 illustrates an example of access control in accordance with aspects of the disclosure. Similar to previous figures, a BS 2225 may receive the MBSR access restriction information from a core network. For illustration purposes, the figure includes a UE 2200, an MBSR 2210, a BS 2220, the BS 2225, an AMF 2255, a UDM 2280, and a 2290. These elements may be similar to the elements illustrated in previous figures. For brevity, redundant details will be omitted. The figure illustrates another base station, BS 2227.

In an example, at 2228, MBSR 2210 may be set up to operate as a mobile base station relay. For example, the MBSR 2210 may provide a cell 1 (first cell).

In an example, the BS 2225 may establish an association (not shown in the figure) with the BS 2220. For example, the BS 2220 may be one of a neighboring base station (NG-RAN) of the BS 2225. To establish the association, the BS 2225 may send the Xn Setup request message to the BS 2220. For example, the Xn Setup request message may comprise the information of the second cell (e.g., cell 2) of the BS 2225. For example, the information of the second cell may comprise the indication indicating that the second cell is not a cell of a MBSR. In response to the Xn Setup request message, the BS 2220 may send the Xn Setup response (e.g., acknowledge, accept, and/or the like) message to the BS 2225. The Xn Setup response message may indicate that the first cell (cell 1) of the BS 2220 is a cell of a MBSR.

In an example, the BS 2225 may establish an association (not shown in the figure) with the BS 2227. For example, the BS 2227 may be one of a neighboring base station (NG-RAN) of the BS 2225. To establish the association, the BS 2225 may send the Xn Setup request message to the BS 2227. In response to the Xn Setup request message, the BS 2227 may send a second Xn Setup response message to the BS 2225. For example, the second Xn Setup response message may comprise the information of a third cell (e.g., cell 3). For example, the information of the third cell may comprise the indication indicating that the third cell is not a cell of a MBSR.

In an example, the UE 2200 may camp on the cell 2. The BS 2225 may send the N2 request message to the AMF 2255. In an example, the AMF 2255 may receive the N2 request message. Based on the N2 request message, the AMF 2255 may determine to retrieve subscription information of the UE 2200. In an example, based on receiving the N2 request message, the AMF 2255 may send the Npcf service request message to the PCF 2290. In response to the Npcf service request, the PCF 2290 may respond to the AMF 2250, with the Npcf service response. The AMF may receive the Npcf service response. Based on the MBSR access policy information of the Npcf service response, the AMF may determine the MBSR access restriction information. In an example, the AMF 2255 may send the N2 response to the BS 2225. The N2 response may comprise the MBSR access restriction information and/or the NAS response message.

In an example, the BS 2225 may determine whether to handover the UE 2200 to another cell. For example, if the signal quality of the cell 2 for the UE 2100 gets weak (e.g., below 2 dBm), the BS 2225 may determine to handover the UE 2200 to the other cell.

In an example, based on the determination to handover the UE 2200 to the other cell, the BS 2225 may determine a target cell to which the UE is handed over. For example, the BS 2125 may consider one or more candidate cells for handover. For example, the BS 2225 may remove one or more cells from the one or more candidate cells, based on the MBSR access restriction information. For example, if the UE 2200 is not allowed to use a cell of a MBSR, the cell 1 may not be considered as a candidate for a handover and/or the cell 3 may be considered as a candidate. The BS 2225 may select one or more target cells for handover, among the remaining one or more candidate cells. For example, based on that the UE 2200 is not allowed to use a cell of a MBSR, and/or based on that the cell 3 is not a cell of a MBSR, the BS 2225 may select the cell 3 as a target cell. For example, the BS 2225 may send a handover request message to the BS 2227.

FIG. 23 illustrates an example of access control in accordance with aspects of the disclosure. One or more base stations may exchange with other one or more base stations, information of one or more serving cells and/or information of whether the one or more cells are associated with one or more MBSRs. For brevity, redundant details will be omitted.

In an example, the BS 2320 may update an association with the BS 2325. For example, based on activation of a cell of a MBSR, the BS 2320 may determine to update the association with the BS 2325. For example, the BS 2325 may be one of a neighboring base station (NG-RAN) of the BS 2320. To update the association, the BS 2320 may send a Xn request message to the BS 2325. For example, the Xn request message may be NG-RAN node configuration update request message. For example, the Xn request message may comprise at least one of:

- TAI support list. This may indicate TAs supported by the BS 2325.
- Global NG-RAN node ID. This may be an identifier of the BS 2325,
- Served cells to update. This may comprise information of one or more cells that are served by the BS 2325. For example, for each cell of the one or more cells, this may indicate a cell identifier, a PCI, a TAC, a PLMN, a UL frequency, a DL frequency, and/or the like. For example, this may comprise indication of a type of a cell. For example, for a cell, the type of a cell may indicate whether the cell is a cell of a MBSR or not. For example, the BS 2320 may indicate the cell 1 and/or that the cell 1 is a cell of a MBSR.

For example, the BS 2320 may determine to send the Xn request message, based on that a cell (e.g., cell 1) of a MBSR (e.g., MBSR 2310) becomes operational, and/or that the cell (cell 1) of the MBSR (MBSR 2310) is added to the BS 2320.

In an example, the BS 2325 may receive the Xn request message. In response to the Xn request message, the BS 2325 may send a Xn response message to the BS 2320. For example, the Xn response message may be NG-RAN node configuration update acknowledge message. For example, the Xn response message may comprise information of cells served by the BS 2325 and/or may acknowledge the reception of the Xn request message.

FIG. 24 illustrates an example of access control in accordance with aspects of the disclosure. One or more base stations may handover a UE to other base stations, with information of whether the UE is allowed to access a cell of a MBSR. For brevity, redundant details will be omitted.

In an example, a BS 2420 may determine whether to handover the UE 2400 to another cell. For example, if the signal quality of a cell 4 for the UE 2400 gets weak (e.g., below 1 dBm), the BS 2420 may determine to handover the UE 2400 to the other cell. For example, the BS 2420 may receive from the UE 2400, a measurement report indicating the signal quality and/or the BS 2420 may measure uplink signal of the UE 2400.

In an example, based on the determination to handover the UE 2400 to the other cell, the BS 2420 may determine a target cell to which the UE is handed over. For example, based on that the signal quality of a cell 5 of BS 2425 is strong (e.g., above 12 dBm), the BS 2420 may determine the cell 5 as the target cell. Based on determining the target cell, the BS 2420 may send a handover request message to the BS 2425 which serves the cell 5. For example, the handover request message may comprise at least one of:

- Target Cell Global ID. This may indicate an identifier of a target cell, to which the UE is handed over. For example, this may indicate the cell 5.
- Cause. This may indicate a reason of handover.
- PDU session resources to be setup list. This may indicate information of one or more PDU sessions which are activated for the UE.
- RRC context. This may indicate one or more configuration and parameters for the UE.
- MBSR Services Authorized. This may indicate whether the UE is allowed to use a cell of a MBSR and/or which one or more MBSRs the UE is allowed to use. For example, this may be the MBSR access restriction information. For example, this may comprise one or more MBSR closed access group (CAG) identifiers (e.g., first MBSR CAG identifiers). The first MBSR CAG identifiers may indicate one or more MBSRs for which the UE is allowed to use/access and/or may indicate one or more CAGs accessible via MBSR for the UE. For example, a fifth MBSR (or, a cell of the fifth MBSR) may be configured with one or more MBSR CAG identifiers (e.g., second MBSR CAG identifiers). The second MBSR CAG identifiers may indicate which (MBSR) CAGs are supported by the fifth MBSR. For example, if the first MBSR CAG identifiers comprise a first identifier and/or if the second MBSR CAG identifiers comprises the first identifier, the UE may be allowed to access the fifth MBSR. For example, if the first MBSR CAG identifiers comprise the first identifier and/or if the second MBSR CAG identifiers does not comprise the first identifier, the UE may not be allowed to access the fifth MBSR (or one or more cells of the fifth MBSR).
- Mobility restriction list container. This may comprise one or more area information where the UE is not allowed to use services. This may further comprise MBSR Service Authorized.

In an example, the BS 2420 may receive from the core network node, the MBSR access restriction information, as shown in the example of FIG. 21. Reverting to FIG. 24, the BS 2420 may construct the handover request message, based on the MBSR access restriction information.

In an example, the BS 2425 may receive the handover request message from the BS 2420. In an example, the BS 2425 may determine to accept the handover request message. In response to the determination, the BS 2425 may send a handover (request) acknowledgement message to the BS 2420. The handover acknowledgement message may comprise at least one of:

- PDU session resources admitted list. This may indicate one or more PDU sessions which the BS 2425 accepts for the UE. The one or more PDU sessions may be handed-over to the NG-RAN2.
- PDU session resources not admitted list. This may indicate one or more PDU sessions which the BS 2425 rejects for the UE. The one or more PDU sessions may not be handed over to the BS 2425.
- Target NG-RAN node to Source NG-RAN node transparent container. This may comprise a RRC message (e.g., RRC reconfiguration message) that the BS 2425 sends to the UE 2400 via the BS 2420.

In an example, the BS 2420 may receive the handover acknowledge message. The BS 2420 may send the RRC message of the handover acknowledge message to the UE 2400.

In an example, the UE 2400 may receive the RRC message from the BS 2420. Based on the RRC message, the 2400 UE may perform handover procedure and select the cell 5 of the BS 2425. After selecting the cell 5 of the BS 2425, the UE 2400 may send a RRC response message (e.g., RRC reconfiguration complete message).

In an example, the BS 2425 may receive the RRC response message from the UE 2400. Based on receiving the RRC response message, the BS 2425 may determine that the UE 2400 is in the cell 5, and/or that the UE successfully completed handover, and/or the like.

In an example, based on that the BS 2425 determines that the UE 2400 is in the cell 5, the BS 2425 may send a path switch request message to the AMF 2455. For example, the path switch request message may indicate to the AMF 2455 that a serving NG-RAN for the UE has changed, that the serving NG-RAN for the UE is the BS 2425, that some NG-U DL tunnel termination points need to be transferred from the BS 2420 to the BS 2425, that the UE 2400 changes a location, that a handover is performed for the UE 2400, and/or the like. For example, the path switch request message may comprise at least one of:

- RAN UE NGAP ID. This may identify the UE association over the NG interface (e.g., between an access network and a core network) within the NG-RAN (e.g., BS 2420, BS 2425).
- AMF UE NGAP ID. This may uniquely identify the UE association over the NG interface.
- User Location Information. This may indicate current location of the UE.
- UE security capabilities. This may indicate capability of the UE for security handling.
- PDU session resources to be switched in downlink list. This may indicate one or more PDU sessions to be switched from a source NG-RAN (e.g., BS 2420) to a target NG-RAN (e.g., BS 2425). This may comprise at least one or more identifiers of one or more PDU sessions.
- PDU session resource failed to setup list. This may indicate one or more PDU sessions which are not transferred from the source NG-RAN to the target NG-RAN. This may comprise at least one or more identifiers of one or more PDU sessions and/or the capability indicator for partly slices.
- MBSR supported Indicator. This may indicate whether the target NG-RAN (e.g., BS 2425) supports the feature of MBSR. For example, this may indicate at least one of whether the target NG-RAN is able to interpret (receives, processes, and/or the like) information associated with MBSR (e.g., MBSR access restriction information). For example, when the target NG-RAN supports the feature of MBSR, the target NG-RAN may set this to ‘supported’. For example, when the target NG-RAN does not support the feature of MBSR, the target NG-RAN may not send the MBSR supported indicator. For example, this field may be present in the N2 request message.

In an example, the AMF 2455 may receive the path switch request. In response to the path switch request, the AMF 2455 may send to the BS 2425, the path switch request acknowledge message. The path switch request acknowledge message may comprise at least one of:

- AMF UE NGAP ID
- RAN UE NGAP ID
- Security context. This may indicate one or more parameters for security between the UE and the network.
- PDU session resource switched list. This may indicate one or more PDU sessions which are switched from a source NG-RAN to a target NG-RAN (e.g., BS 2425).
- PDU session resource released list. This may indicate one or more PDU sessions released.
- Allowed slices. This may be an allowed NSSAI.
- Core Network Assistance Information for RRC INACTIVE. This may be one or more parameters that assist the NG-RAN for configuration of UE for RRC inactive state.
- CN Assisted RAN Parameters Tuning. This may be one or more parameters to assist a NG-RAN.
- MBSR access restriction information.

In an example, the BS 2425 may receive the path switch request acknowledge message. Based on the path switch request acknowledge message, the BS 2425 may store information delivered by the path switch acknowledge message, and/or may update configuration for the UE based on the information.

In an example, a BS 2425 may determine whether to handover the UE 2400 to another cell (e.g., cell 6). Based on the determination to handover the UE 2400 to the cell 6, the BS 2425 may send a handover request message to the BS 2427 which serves the cell 6. For example, the handover request message may comprise the MBSR access restriction information (that may be received from BS 2420 or AMF 2455). This may assist a subsequent base stations (e.g., BS 2427) to determine which cell is allowed for the UE, and/or which can be a target cell (of handover) for the UE.

FIG. 25 illustrates an example of access control in accordance with aspects of the disclosure. One or more base stations may handover a UE to other base stations, with information of whether the UE is allowed to access a cell of a MBSR. For brevity, redundant details will be omitted.

In an example, the UE 2500 may camp on a cell 7. For example, the cell 7 may be a cell of a MBSR (e.g., MBSR 2510). The UE 2500 may send a RRC message to the BS 2520 via the cell 7. For example, the RRC message may comprise an identifier of the UE 2500, and/or a NAS message. For example, the NAS message may comprise an indication indicating whether the UE 2500 supports the feature (e.g., MBSR access capability) of an MBSR. For example, the feature of the MBSR may indicate whether the UE 2500 can interpret/receive/process information associated with a MBSR. For example, the information associated with a MBSR may be one or more cause value associated with a MBSR. For example, the one or more cause value associated with a MBSR may be that a registration is rejected due to MBSR, and/or that a UE is not allowed to use a cell of a MBSR.

In an example, the BS 2520 may receive the RRC message. Based on that the RRC message comprises the NAS message, the BS 2520 may send a N2 request message to the AMF 2555. For example, the N2 request message may comprise the NAS message.

In an example, the AMF 2555 may receive the N2 request message. Based on the N2 request message, the AMF 2555 may determine to retrieve subscription information of the UE 2500. For example, the AMF 2555 may send the Nudm service request message to a UDM 2580. This may assist the AMF to determine whether the UE is eligible for using a cell of a MBSR. For example, the Nudm service request message may be a Nudm_SDM_Get request and/or the like. The Nudm service request message may comprise an identifier of the UE 2500. In response to the Nudm service request, the UDM 2580 may respond to the AMF 2555, with a Nudm service response. The Nudm service response may be a Nudm_SDM_Get response and/or the like. The Nudm service response may comprise subscription information (e.g., MBSR access subscription information and/or the like) associated with the MBSR. For example, the MBSR access subscription information may indicate that the UE 2500 does not have a subscription for the feature of the MBSR (or mobile IAB), and/or that the UE is not allowed to access one or more cells provided one or more MBSR (e.g., mobile IAB nodes). The AMF may receive the Nudm service response. Based on the MBSR access subscription information, the AMF may determine to send to the BS 2520, a MBSR access restriction information (and/or the like). For example, the MBSR access restriction information may indicate that the UE 2500 is not allowed to use a cell of a MBSR. For example, based on that the MBSR access subscription information does not indicate that the UE 2500 has a subscription for using a cell of a MBSR, the MBSR access restriction information may indicate that the UE 2500 is not allowed to use a cell of a MBSR.

In an example, based on receiving the N2 request message, the AMF 2555 may send a Npcf service request message to a PCF 2590, to determine whether a policy for the UE allows the UE 2500 to use a cell of a MBSR. For example, the Npcf service request message may be a Npcf_AMPolicyControl_Create request, Npcf_UEPolicyControl_Create request, and/or the like. The Npcf service request message may comprise at least one of the identifier of the UE, a subscription information (e.g., MBSR access subscription information) of the UE. In response to the Npcf service request, the PCF 2590 may respond to the AMF 2550, with a Npcf service response. The Npcf service response may be a Npcf_AMPolicyControl_Create response, a Npcf_UEPolicyControl_Create response, and/or the like. The Npcf service response may comprise a MBSR access policy information for the UE. For example, the MBSR access policy information may indicate that the UE is not allowed to use a cell of a MBSR. The AMF may receive the Npcf service response. Based on the MBSR access policy information, the AMF may determine the MBSR access restriction information. For example, based on the fact that the MBSR access policy information does not indicate that the UE is allowed to use a cell of a MBSR, the MBSR access restriction information may not be set to indicate that the UE 2500 is allowed to use a cell of a MBSR.

In an example, in response to the received NAS message from the UE 2500, the AMF 2555 may send the NAS response (e.g., registration reject, service reject) message, to the UE 2500. The NAS response message may comprise a cause value. For example, the AMF 2555 may determine the cause value, based on the MBSR access subscription information and/or MBSR access policy information, the MBSR access restriction information and/or the like. For example, based on that the MBSR access policy information does not indicate that the UE 2500 is allowed to use a cell of a MBSR, and/or based on that the MBSR access subscription information does not indicate that the UE 2500 has a subscription for using a cell of a MBSR, the AMF 2555 may set the cause value. For example, the cause value may indicate that the UE is not allowed to use a cell of a MBSR, that the UE is rejected for service via a cell of a MBSR, that the UE is rejected for registration via a cell of a MBSR, that the UE is not allowed for MBSR, and/or the like.

In an example, the AMF 2555 may send the N2 response to the BS 2520. The N2 response may comprise the MBSR access restriction information and/or the NAS response message. The BS 2520 may receive the N2 response. Based on that the N2 response message comprises the NAS response message, the BS 2520 may send to the UE 2500, a RRC response message comprising the NAS response message.

In an example, the UE 2500 may receive the NAS response message. Based on that the NAS response message comprises the cause value indicating that the UE is not allowed to use a cell of a MBSR, the UE 2500 may perform cell reselection and/or network reselection. For example, if the current cell (e.g., the cell 7) is a cell of a MBSR, the UE 2500 may measure one or more neighboring cells. For example, the UE 2500 may determine whether a cell of the one or more neighboring cells is a cell of a MBSR or not, based on a SIB of the cell. For example, the SIB of the cell may indicate whether the cell is a cell of a MBSR or not. For example, among the one or more neighboring cells, the UE may select a cell which is not a cell of a MBSR. For example, the UE 2500 may select a cell 8 of a BS 2525. The cell 8 may not send an indication that the cell 8 is a cell of a MBSR. The UE 2500 may send a RRC message comprising a NAS message, to BS 2520.

FIG. 26 illustrates an example of access control in accordance with aspects of the disclosure.

In an example, a first NG-RAN (e.g., a base station, gNB, gNB-CU, and/or the like) may receive from a second NG-RAN, a Xn message (e.g., Xn Setup message, NG-RAN node configuration update, and/or the like) indicating one or more serving cells of the second NG-RAN. For example, the one or more serving cells of the second NG-RAN may comprise a first cell. For example, the first cell may be a cell of a MBSR. For example, the first cell may be provided (served, operated) by a first MBSR.

In an example, the first NG-RAN, may receive from a core network node (e.g., an AMF), a NG message (e.g., Initial UE Context request message, Path Switch acknowledgement message, Handover Request message, and/or the like). For example, the NG message may comprise a MBSR access restriction information for a UE. For example, the MBSR access restriction information may indicate whether the UE is allowed to access (use, connect) to a MBSR. For example, to access to a MBSR may be to use/connect one or more cells of one or more MBSRs.

In an example, the first NG-RAN may receive a measurement report message from the UE. For example, the measurement report message from the UE may indicate quality of one or more cells. Based on the measurement report message, the first NG-RAN may determine to hand “the UE.

In an example, the first NG-RAN may select a target cell for handover, based on the MBSR access restriction information. For example, if the MBSR access restriction information indicates that the UE is allowed to access a cell of a MBSR, the first NG-RAN may select the target cell for handover, among one or more first-type cells and/or one or more second-type cells. For example, the one or more first-type cells may be one or more cells of one or more MBSRs. For example, the one or more second-type cells may not be one or more cells of one or more MBSRs. For example, the one or more second-type cells are not operated by MBSRs. For example, the one or more second-type cells may be one or more cells operated by a second-type gNB-DU. For example, the second-type gNB-DUs may be connected to a gNB-CU without signaling/data passing through one or more IAB nodes. For example, if the MBSR access restriction for the UE does not indicate that the UE is allowed to access a cell of a MBSR, the first NG-RAN may select the target cell for handover among the one or more second-type cells.

In an example, based on selecting the target cell for handover, the first NG-RAN may send a handover request message to a NG-RAN serving the target cell.

FIG. 27 illustrates an example of access control in accordance with aspects of the disclosure.

In an example, a first NG-RAN may establish a RRC connection with a UE. For example, if the UE sends a RRC connection request message to the first NG-RAN, the first NG-RAN may accept the request, the first NG-RAN may send an RRC connection setup message, and/or establishes the RRC connection.

In an example, the first NG-RAN, may receive from a core network node (e.g., an AMF), a NG message. For example, the NG message may comprise a MBSR access restriction information for the UE. For example, the MBSR access restriction information may indicate whether the UE is allowed to access (use, connect) to a MBSR. For example, to access to a MBSR may be to use/connect one or more cells of one or more MBSRs.

In an example, the first NG-RAN may determine to handover the UE to a target cell. For example, based on the measurement report message, the first NG-RAN may select the target cell.

In an example, based on selecting the target cell for handover, the first NG-RAN may send a handover request message to a NG-RAN serving the target cell. For example, the handover request message may comprise at least one of an identifier of the UE, the MBSR access restriction information.

In an example, a first NG-RAN (e.g., base station, gNB-CU, IAB doner-CU, and/or the like) may receive from a second NG-RAN, a Xn message (e.g., Xn setup request message, Xn setup response message). For example, the Xn message may comprise information of one or more serving cells of the second NG-RAN (e.g., base station, gNB-CU, IAB doner-CU, and/or the like). For example, the one or more serving cells may comprise a first cell. For example, the first cell may be a cell operated by a MBSR (or mIAB node). For example, the first cell may be operated/provided/served/managed by a first MBSR, and/or may provide a Uu interface (e.g., a first Uu interface) to one or more UEs. For example, the MBSR may be connected to a second cell via a Uu interface (e.g., a second Uu interface), may be connected to a doner gNB (or doner gNB-CU) via a F1 interface, and/or may comprise a gNB-DU. For example, each of the information of one or more serving cells may comprise at least one of an identifier of a cell, an information of a tracking area of the cell, an indication indicating whether the cell is a cell of a MBSR, and/or a frequency of the cell.

In an example, the first NG-RAN may receive from a core network node (e.g., an access and mobility management function (AMF)), a NG message (e.g., Initial context setup request message, Path switch request acknowledge message, and/or the like). For example, the NG message may comprise information indicating that a UE (e.g., a wireless device) of the one or more UEs is allowed to access (or use) one or more MBSRs (e.g., mobile IAB nodes, mIAB nodes, mIABs and/or the like) and/or information indicating whether the UE is restricted from using/accessing a cell of a MBSR. For example, that the UE is allowed to access one more MBSRs may be implemented in an embodiment in which the UE is allowed to use/camp/access one or more cells served by the one or more MBSRs.

In an example, the first NG-RAN may determine, based on the information received from the core network node, to handover the UE to the first cell. For example, based on measurement report received from the UE, the first NG-RAN may determine to handover. For example, the measurement report may indicate a cell quality of a cell. For example, the cell quality may indicate that quality of signal of the first cell is above threshold (e.g., 6 dBm). For example, based on the cell quality of the first cell, based on that the first cell is a cell of a MBSR, and/or that the UE is allowed to access a cell of a MBSR, the first NG-RAN may determine the first cell as a target cell for handover.

In an example, based on the determination, the first NG-RAN may send to the second NG-RAN, a handover request message. The handover request message may request handover of the UE to the first cell. For example, the handover request message may comprise at least one of an identifier of the UE, an identifier of the first cell, and/or information indicating that the UE is allowed to access one or more cells of one or more MBSRs and/or one or more MBSRs.

In an example, in response to sending the handover request message, the first NG-RAN may receive from the second NG-RAN, a handover request acknowledgement message. For example, the handover request acknowledgement message may comprise an RRC reconfiguration message. Based on receiving the RRC reconfiguration message, the first NG-RAN may send the RRC reconfiguration message to the UE.

In an example, the first NG-RAN may determine, based on the information received from the core network node, to handover the UE to a third cell. For example, based on measurement report received from the UE, the first NG-RAN may determine to handover. For example, the measurement report may indicate that quality of signal of the third cell is above threshold (e.g., 5 dBm). For example, based on the cell quality of the third cell, based on that the third cell is not a cell of a MBSR, and/or that the UE is not allowed to access a cell of a MBSR, the first NG-RAN may determine the third cell as a target cell for handover. In an example, based on the determination, the first NG-RAN may send to a third NG-RAN, a second handover request message.

In an example, a first NG-RAN (e.g., base station, gNB-CU, IAB doner-CU, and/or the like) may receive from a core network node (e.g., AMF), a message (e.g., NG message) indicating that a UE is allowed to access a MBSR (or a mIAB node). The first NG-RAN may send to a second NG-RAN, a handover request message requesting handover of the UE to a cell of a MBSR.

In an example, a first NG-RAN (e.g., base station, gNB-CU, IAB doner-CU, and/or the like) may receive from a second NG-RAN, an Xn request message comprising one or more serving cell information. For example, each of the one or more serving cell information may comprise at least one of an identifier of a cell, and/or information indicating whether the cell is a cell of mIAB node. The first NG-RAN may send to the second NG-RAN, a Xn Response message acknowledging the Xn Request message.

In an example, a first NG-RAN may receive from a second NG-RAN, a handover request message for a UE. The first NG-RAN may send to a core network node (e.g., an AMF), a message indicating path switch of the UE. The first NG-RAN may receive from the core network node, a response message indicating whether the UE is allowed to access a cell of mIAB node.

In an example, a first NG-RAN may receive from a second NG-RAN, a handover request message for a UE. The handover request message may comprise an indicator indicating whether the UE is allowed to access a cell of mIAB node. The first NG-RAN may send to the second NG-RAN, a message indicating a handover request acknowledge.

In an example, a UE may send a first registration request message. The UE may receive a registration response message indicating that the UE is not allowed to access from a cell of mIAB node. The UE may send a second registration request message, via a cell which is not a cell of mIAB node.

Clause 1. A method comprising: receiving, by a base station (BS) from a second BS, a first message indicating that a first cell of the second BS is operated by a first mobile integrated access and backhaul (mIAB) node; receiving, by the BS from a core network node, a second message comprising an authorization information indicating that a wireless device is authorized to access a cell operated by a mIAB node; and sending, by the BS to the second BS, a handover request message requesting a handover of the wireless device to the first cell, wherein the handover request message comprises the authorization information.

Clause 2. A method comprising: sending, by a base station (BS) to a second BS, a message comprising an authorization information indicating that a wireless device is authorized to access a cell operated by a mobile integrated access and backhaul (mIAB) node.

Clause 3. The method of clause 2, further comprising receiving by the BS from the second BS, a first message indicating a first cell of the second BS being operated by a first mIAB node.

Clause 4. The method of clause 2-3, wherein the first mIAB node provides a first Uu interface to one or more wireless device, via the first cell.

Clause 5. The method of clause 2-4, wherein the first mIAB node connects to the second BS via a second Uu interface of a second cell of the second BS, and exchanges one or more F1 interface messages with the second BS.

Clause 6. The method of clause 2-5, further comprising, receiving by the BS from a core network node, a second message comprising the authorization information, wherein the core network node comprises at least one of a mobility management node or an access and mobility function (AMF).

Clause 7. The method of clause 2-6, wherein the message is a handover request message indicating a handover of the wireless device to the first cell, based on the authorization information indicating the wireless device being allowed for the mIAB node.

Clause 8. The method of clause 2-7, further comprising, sending by the BS to a third BS, a second handover request message requesting handover of a second wireless device, to a third cell not associated with the mIAB node, based on the second wireless device not being authorized to access the mIAB node.

Clause 9. The method of clause 2-8, wherein the authorization information indicates one or more mIAB access groups for which the wireless device is allowed to access.

Clause 10. The method of clause 2-9, further comprising receiving by the BS from the second BS, an information indicating one or more second mIAB access groups associated with the first mIAB node of the second BS.

Clause 11. The method of clause 2-10, wherein the BS sends the handover request, based on the one or more second mIAB access groups comprising at least one of the one or more mIAB access group for which the wireless device is allowed to access.

Clause 12. The method of clause 2-11, further comprising sending by the BS, a system information block indicating whether the BS supports a feature of mIAB.

Clause 13. The method of clause 2-12, further comprising receiving by the BS, a third message indicating whether the wireless device supports the feature of mIAB.

Clause 14. The method of clause 2-13, wherein the feature of mIAB comprises at least one of receiving information associated with mIAB, sending information associated with mIAB, handling information associated with mIAB, managing a cell associated with mIAB.

Clause 15. The method of clause 2-14, further comprising receiving by the BS from the second BS, a mIAB support indicator indicating whether the second BS supports the feature of mIAB.

Clause 16. The method of clause 2-15, further comprising sending by the BS to the core network node, a path switch request message, based on the wireless device being handed over to the BS from a fourth BS, wherein the path switch request comprises an indication indicating whether the BS supports the feature of mIAB.

Clause 17. The method of clause 2-16, wherein the BS receives the second message, in response to sending the path switch request message, wherein the second message is a path switch request acknowledgement message.

Clause 18. The method of clause 2-17, further comprising sending by the BS to the wireless device and based on the authorization information, a measurement configuration requesting a measurement of one or more cells of one or more mIAB nodes.

Clause 19. The method of clause 2-18, further comprising receiving by the BS from the second BS, a first message indicating a type of the first cell, wherein the type indicates at least one of a mIAB type cell or a non-mIAB type cell.

Clause 20. The method of clause 2-19, the message further indicates at least one of one or more mIAB access group identifiers allowed for the wireless device, one or more mIAB identifiers allowed for the wireless device.

Clause 21. A method comprising: receiving, by a first base station from a core network node, a message comprising an information element indicating that a wireless device is authorized to access a cell operated by a mobile integrated access and backhaul (mIAB) node; and sending, by the first base station to a second base station, a handover request message requesting a handover of the wireless device to a first cell, of the second base station, operated by the mIAB node.

Clause 22. A method comprising: receiving, by a first base station from a second base station, a handover request message for a wireless device; sending, by the first base station to a core network node, a message indicating path switch of the wireless device; and receiving, by the first base station from the core network node, a response message indicating whether the wireless device is allowed to access a cell of mobile integrated access and backhaul (mIAB) node.

Clause 23. A method comprising: receiving, by a wireless device via a cell of a base station, a system information block message indicating the cell supporting a mobile integrated access and backhaul (mIAB); and sending, by a wireless device to the base station and based on the system information block, a radio resource control (RRC) connection message comprising an indication indicating the mIAB.

Clause 24. A method comprising: sending, by a base station to a wireless device via a cell of the base station, a system information block message indicating the cell supporting a mobile integrated access and backhaul (mIAB); and receiving, by the base station from the wireless device, a radio resource control (RRC) connection request message, wherein an establishment cause of the RRC connection request message comprises an indication indicating the mIAB.

Clause 25. A method comprising: receiving, by a wireless device from a base station, a measurement configuration indicating measuring a cell of a mobile integrated access and backhaul (mIAB) node; and sending, by the wireless device, a measurement result of a first cell of a first mIAB node.

Clause 26. A method comprising: receiving, by a core network node, a subscription information indicating a wireless subscribing use of a mobile integrated access and backhaul (mIAB) node; and sending, by the core network node to a base station, an mIAB authorization information.

Clause 27. A method comprising: receiving, by an access and mobility management function (AMF) from a unified data management function, a subscription information indicating that a wireless device is allowed to use a mobile integrated access and backhaul (mIAB); and sending, by the AMF to a base station and based on the subscription information, an authorization information indicating the wireless device being allowed for a cell of a mIAB node.

Clause 28. A method comprising: receiving, by a core network node from a policy control node, a policy information indicating use of a mobile integrated access and backhaul (mIAB) node not being allowed for a wireless device; and sending, by the core network node to the wireless device and via a first cell of a first mIAB node, based on the policy information, a registration reject message indicating use of mIAB not being allowed.

Clause 29. A method comprising: receiving, by an access and mobility management function (AMF) from a policy control function, a policy information indicating that a wireless device is allowed to use a mobile integrated access and backhaul (mIAB); and sending, by the AMF to a base station and based on the policy information, an authorization information indicating the wireless device being authorized for a cell of a mIAB node.

Clause 30. A method comprising: sending, by a wireless device, a first registration request message; receiving, by the wireless device, a registration response message indicating that the wireless device is not allowed to access from a cell of mobile integrated access and backhaul (mIAB) node; and sending, by the wireless device, a second registration request message, via a cell which is not a cell of mIAB node.

Clause 31. A method comprising: sending, by a wireless device, a first registration request message indicating that the wireless device supports access to a cell of mobile integrated access and backhaul (mIAB) node; and receiving, by the wireless device, a registration response.

Clause 32. A method comprising: sending, by a wireless device, a first registration request message indicating that the wireless device supports access to a mobile integrated access and backhaul (mIAB) node; and receiving, by the wireless device, a registration reject message, wherein the registration reject message indicates that the wireless device is not allowed to use a cell of the mIAB.

Clause 33. A method comprising: receiving, by the wireless device, a non-access stratum message indicating that the wireless device is not allowed to access from a cell of mobile integrated access and backhaul (mIAB) node; and selecting, by the wireless device and based on the non-access stratum message, a first cell which is not associated with a mIAB node.

Clause 34. A method comprising: receiving, by a first base station from a second base station, a Xn Request message comprising one or more serving cell information, wherein a serving cell information of the one or more serving cell information comprises at least one of an identifier of a cell and information indicating whether the cell is a cell of mobile integrated access and backhaul (mIAB) node; and sending, by the first base station to the second base station, a Xn Response message acknowledging the Xn Request message.

Each of the embodiments described in the above clauses can be implemented as a device, software, or the like. Each of the embodiments in the above clauses can be combined with one another and used both alone and in combination and in any permutation or subcombination.

Mobile Base Station Relay Access

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