Multiple relay usage management

Abstract

This invention relates to a method comprising: sending, by a first wireless relay device to an access and mobility management function (AMF), a first message indicating capability of multihop relaying of the first wireless relay device; receiving, by the first wireless relay device from the AMF, a second message: authorizing multihop relaying of a service; and indicating a relay service code (RSC) for the service; receiving, by the first wireless relay device from a second wireless relay device, a sidelink announcement message comprising: an indication indicating support for multihop relaying; and the RSC; and sending, by the first wireless relay device to the second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

Description

MULTIPLE RELAY USAGE MANAGEMENTFIELD OF THE INVENTION

[0001] This invention relates to wireless communication, such as cellular communication networks. In particular, the invention relates to some protocols to establish or initiate communication with a relayed architecture.SUMMARY OF THE INVENTION

[0002] The invention aims at improving the relay management in a communication network.

[0003] In accordance with the invention, it is proposed a method and an apparatus as claimed in the appended set of claims.

[0004] In particular, in a first aspect of the invention, it is proposed a method comprising: receiving, by a first wireless relay device from a network function, a second message: authorizing multihop relaying of a service; and indicating a relay service code, RSC, for the service; and sending, by the first wireless relay device to a second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

[0005] In a variant of the first aspect, the method further comprises sending by the first wireless relay device to the network function, a first request message indicating capability of multihop relaying.

[0006] In another variant of the first aspect, the method further comprises receiving, by the first wireless relay device from the second wireless relay device, a sidelink announcement message comprising at least one of an indication indicating support for multihop relaying and the RSC.

[0007] In another variant of the first aspect, the multihop relaying is a relaying of a user data from a remote wireless device to a network, via using more than one wireless relay devices.

[0008] In another variant of the first aspect, the second message further indicates a second RSC, wherein the second RSC is used for the service when the direction connection to the cell is available.

[0009] In another variant of the first aspect, the direction connection to the cell is a connection from the first wireless relay device to the cell, without using another wireless relay device between the cell and the first wireless relay device.

[0010] In another variant of the first aspect, the method comprises sending by the firstwireless relay device to the remote wireless device, a second sidelink announcement message indicating multihop relaying. In an example, the second sidelink announcement message further indicates that the direct connection to the cell is not available.Optionally, wherein the second sidelink announcement message further indicates a number of hops to the cell. Optionally, the method may further comprise receiving by the first wireless relay device from the remote wireless device, a second sidelink connection message, wherein the second sidelink connection message indicates whether the remote wireless device supports multihop relaying.

[0011] In another variant of the first aspect, the method further comprises sending by the first wireless relay device to the remote wireless device, a sidelink connection reject message, based on that the remote wireless device does not indicate support of multihop relaying.

[0012] In another variant of the first aspect, wherein the second message further comprises one or more conditions when the first wireless relay device is authorized for multihop relaying.

[0013] In another variant of the first aspect, the method further comprises sending by the first wireless relay device, a sidelink release request, based on direct connection to a cell being available. The method may further comprise sending by the first wireless relay device to the remote wireless device, an indication that multihop relaying is not used. Additionally, the method may comprise sending by the first wireless relay device to the remote wireless device, a configuration message indicating modification of PC5 QoS parameter.

[0014] In another variant of the first aspect, the second message further indicates at least one of whether multihop relaying of the service via the plurality of wireless layer 2 relay devices is allowed, or whether multihop relaying of the service via the plurality of wireless layer 3 relay devices is allowed.

[0015] In another variant of the first aspect, the one or more conditions indicates at least one of one or more networks, one or more frequency bands, one or more geographical areas.

[0016] In another variant of the first aspect, the first request message further comprises at least one of a first indication indicating whether multihop relaying via the plurality of wireless layer 2 relay devices is supported, a second indication indicating whether multihop relaying via the plurality of wireless layer 3 relay devices is supported, a maximum number of relay hops supported, whether topmost relay operation is supported, or whether downstream relay operation is supported.

[0017] In another variant of the first aspect, the direction connection to the cell is available, if the first wireless relay device can camp on the cell or if the cell indicates multihop relaying is supported.

[0018] In accordance with a second aspect of the invention, it is proposed a method comprising: receiving, by a wireless device, one or more policy configurations comprising a first policy configuration and a second policy configuration, wherein the first policy configuration associated with multihop relaying indicates a first parameter, wherein, in multihop relaying, an intermediate relay connects to a network relay; the second policy configuration not associated with multihop relaying indicates a second parameter; and and the one or more policy configuration is associated with a first relay service; triggering, by the wireless device, a sidelink connection establishment for the first relay service; and sending, by the wireless device, a connection request message comprising: the first parameter, in response to selecting a first relay device indicating the multihop relaying; and the second parameter, in response to selecting a second relay device not indicating the multihop relaying.

[0019] In accordance with a second aspect of the invention, it is proposed a method comprising: receiving, by a network relay from a base station, a radio resource control (RRC) message indicating one or more parameters configuring relaying operation; receiving, by a network relay from a wireless device, a sidelink message associated with a multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay; and sending, by the network relay to the base station, a second RRC message indicating a type of the wireless device, wherein the type of the wireless device indicates a relay type.

[0020] In accordance with a third aspect of the invention, it is proposed a method comprising: receiving, by a first relay one or more policy configurations comprising a first policy configuration for multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay;sending, by the first relay device to a wireless device, a first message establishing a first sidelink connection; receiving, by the first relay from a second relay, a second message establishing a second sidelink connection for multihop relaying; and based on receiving the second sidelink message, sending by the first relay device to the wireless device to the wireless device, a third message indicating modification of the first sidelink.

[0021] In a variant of the second aspect of the invention, the modification indicates the multihop relaying.

[0022] In accordance with a third aspect of the invention, it is proposed a method comprising: receiving, by a wireless device, a policy configuration indicating one or more parameters for multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay; receiving, by the wireless device from one or more relays, one or more announcement messages, wherein: a first relay, of the one or more relays, transmits a first announcement message, of the one or more announcement messages, indicating multihop relaying for a service; and a second relay, of the one or more relays, transmits a second announcement message, of the one or more announcement messages, not indicating multihop relaying for the service; and sending, by the wireless device to the first relay, a sidelink connection request for the multihop relaying, based on the policy configuration and the first announcement message.

[0023] In accordance with a fourth aspect of the invention, it is proposed a method comprising: sending, by a wireless device, a first message comprising one or more parameters for indicating multihop capability of the wireless device, wherein the one or more parameters comprise at least one of: a first capability indicating whether the wireless device supports one or more first functionalities of a remote wireless device of multihop relaying; a second capability indicating whether the wireless device supports one or more second functionalities of an intermediate relay device of multihop relaying; and a third capability indicating whether the wireless device supports one or morethird functionalities of a network relay device of multihop relaying; and receiving, by the wireless device, a second message authorizing at least one of. a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

[0024] In accordance with a fifth aspect of the invention, it is proposed a method comprising: receiving, by a first base station a network function, a context management message comprising: an identifier of a wireless device; and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service; and sending, by the first base station to a second base station, a handover request message comprising the identifier and the authorization information.

[0025] In a variant of the fifth aspect, the context management message further comprises one or more capability parameters indicating that the wireless device supports the multihop relaying of a service. Optionally, the one or more capability parameters comprises at least one of: a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

[0026] In another variant of the fifth aspect, wherein the authorization information comprises at least one of: a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

[0027] In another variant of the fifth aspect, based on the context management message indicating the authorization information or based on the capability indication, the first base station determines whether to send to the wireless device, one or more radio parameters configuring the multihop relaying.

[0028] In accordance with a sixth aspect of the invention, it is proposed a method comprising: receiving, by a first base station from a wireless device and via a first relay, a radio resource control (RRC) message requesting establishment of RRC connection, wherein the RRC message indicates at least one of:- a capability information indicating that the wireless device supports multihop relaying- a request information indicating that the wireless device; receiving, by the first base station a network function, a context management message comprising authorization information authorizing the wireless device as a wireless relay device for the multihop relaying; and sending, by the first base station to the wireless device and via the first relay, based on the context management message, one or more radio parameters configuring the multihop relaying.

[0029] In accordance with a seventh aspect of the invention, it is proposed a method comprising: receiving, by a network node from a base station, a path switch request message comprising an identifier of a wireless device; and sending, by the network function to the base station, a response to the path switch request message, wherein the response comprises: an identifier of a wireless device; and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service.

[0030] In accordance with an eighth aspect of the invention, it is proposed a method comprising: receiving, by a first node managing mobility, from a wireless device, a first message comprising: an identifier associated with the wireless device; and a capability information indicating that the wireless device supports multihop relaying; and sending, by the first node to a second node managing capability, a second message comprising: the identifier; and the capability information.

[0031] In accordance with a ninth aspect of the invention, it is proposed a method comprising: receiving, by a first base station from a second base station, a handover request for a wireless device, wherein the handover request message comprises: an identifier associated with the wireless device; and a capability information indicating that the wireless device supports multihoprelaying; and sending, by the first base station to an access and mobility management node, a path switch request message; and receiving, by the first base station from the access and mobility management node, a path switch request acknowledgement message comprising: an authorization information indicating whether the UE is allowed for multihop relaying.

[0032] In accordance with a tenth aspect of the invention, it is proposed a method comprising: sending, by a wireless device, one or more registration message indicating one or more capability parameters indicating that the wireless devices supports one or more roles for multihop relaying; receiving, by a wireless device, one or more configuration message comprising one or more policy configuration parameters, where the one or more policy configuration parameters comprises at least one of: one or more relay service code for a service; and one or more conditions when the wireless device is allowed for the multihop relaying for the service, wherein the one or more conditions comprises one or more identifiers indicating one or more networks.

[0033] In accordance with an eleventh aspect of the invention, it is proposed a method comprising: sending, by a first wireless relay device to an access and mobility management function, AMF, a first message indicating capability of multihop relaying of the first wireless relay device; receiving, by the first wireless relay device from the AMF, a second message: authorizing multihop relaying of a service; and indicating a relay service code (RSC) for the service; receiving, by the first wireless relay device from a second wireless relay device, a sidelink announcement message comprising: an indication indicating support for multihop relaying; and the RSC; and sending, by the first wireless relay device to the second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

[0034] In accordance with a twelfth aspect of the invention, it is proposed an apparatus,acting as a first wireless relay device, comprising: a receiver configured to receiving from a network function, a second message: a controller configured to decide on whether authorizing multihop relaying of a service; wherein the controller is adapted to indicate a relay service code, RSC, for the service; and a transmitter configured to send to a second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

[0036] FIG. 1 A and FIG. IB illustrate example communication networks including an access network and a core network.

[0037] FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D illustrate various examples of a framework for a service-based architecture within a core network.

[0038] FIG. 3 illustrates an example communication network including core network functions.

[0039] FIG. 4A and FIG. 4B illustrate example of core network architecture with multiple user plane functions and untrusted access.

[0040] FIG. 5 illustrates an example of a core network architecture for a roaming scenario.

[0041] FIG. 6 illustrates an example of network slicing.

[0042] 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.

[0043] FIG. 8 illustrates an example of a quality of service model for data exchange.

[0044] FIG. 9A, FIG. 9B, FIG. 9C, and FIG. 9D illustrate example states and state transitions of a wireless device.

[0045] FIG. 10 illustrates an example of a registration procedure for a wireless device.

[0046] FIG. 11 illustrates an example of a service request procedure for a wireless device.

[0047] FIG. 12 illustrates an example of a protocol data unit session establishment procedure for a wireless device.

[0048] FIG. 13 illustrates examples of components of the elements in a communications network.

[0049] FIG. 14 A, 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.

[0050] FIG. 15 is a diagram of an aspect of an example embodiment of the present disclosure.

[0051] FIG. 16 is a diagram of an aspect of an example embodiment of the present disclosure.

[0052] FIG. 17 is a diagram of an aspect of an example embodiment of the present disclosure.

[0053] FIG. 18 is a diagram of an aspect of an example embodiment of the present disclosure.

[0054] FIG. 19 is a diagram of an aspect of an example embodiment of the present disclosure.

[0055] FIG. 20 is a diagram of an aspect of an example embodiment of the present disclosure.

[0056] FIG. 21 is a diagram of an aspect of an example embodiment of the present disclosure.

[0057] FIG. 22 is a diagram of an aspect of an example embodiment of the present disclosure.

[0058] FIG. 23 is a diagram of an aspect of an example embodiment of the present disclosure.

[0059] FIG. 24 is a diagram of an aspect of an example embodiment of the present disclosure.

[0060] FIG. 25 is a diagram of an aspect of an example embodiment of the present disclosure.

[0061] FIG. 26 is a diagram of an aspect of an example embodiment of the present disclosure.

[0062] FIG. 27 is a diagram of an aspect of an example embodiment of the present disclosure.

[0063] FIG. 28 is a diagram of an aspect of an example embodiment of the present disclosure.DETAILED DESCRIPTION

[0064] 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.

[0065] 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 implementdisclosed protocols.

[0066] 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.

[0067] 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.

[0068] 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”.

[0069] The term “configured” may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In 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.

[0070] 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.

[0071] 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”.

[0072] 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 Yl, Y2, and Y3, then the possible subsets of Y are {Yl, Y2, Y3}, {Yl, Y2{, {Yl, Y3{, {Y2, Y3{, {Yl }, {Y2}, and {Y3}.

[0073] FIG. 1 A 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.

[0074] The wireless device 101 may communicate with DNs 108 via AN 102 and CN 105. In the present disclosure, the term wireless device may refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (loT) device, vehicle road side unit (RSU), relay node, automobile, unmanned aerial vehicle, urban air mobility, and / or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0075] 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.

[0076] In the present disclosure, the term base station may refer to and encompass any element of AN 102 that facilitates communication between wireless device 101 and AN 102. Access networks and base stations have many different names and implementations. The base station may be a terrestrial base station fixed to the earth. The base station may be a mobile base station with a moving coverage area. The base station may be in space, for example, on board a satellite. For example, WiFi and other standards may use the term access point. As another example, the Third-Generation Partnership Project (3 GPP) has produced specifications for three generations of mobile networks, each of which uses different terminology. Third Generation (3G) and / or Universal Mobile Telecommunications System (UMTS) standards may use the term Node B. 4G, Long Term Evolution (LTE), and / or Evolved Universal Terrestrial Radio Access (E- UTRA) standards may use the term Evolved Node B (eNB). 5G and / or New Radio (NR) standards may describe AN 102 as a next-generation radio access network (NG-RAN) and may refer to base stations as Next Generation eNB (ng-eNB) and / or Generation Node B (gNB). Future standards (for example, 6G, 7G, 8G) may use new terminology to refer to the elements which implement the methods described in the present disclosure (e.g., wireless devices, basestations, 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.

[0077] 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.

[0078] 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).

[0079] FIG. IB 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. IB, 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 NodeBs (ng eNBs) 152B. The 5G-CN 155 includes one or more network functions (NFs), including control plane functions 155 A 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. 1 A, these components may represent specific implementations and / or terminology.

[0080] 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).

[0081] 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 155 A. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and / or warning message transmission. In some cases, the NG-C interface may support transmission of user data (for example, a small data transmission for an loT device).

[0082] 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 Fl 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.

[0083] The gNBs 152A and ng-eNBs 152B may provide different user plane and control plane protocol termination towards the UEs 151. For example, the gNB 154A may provide new radio(NR) protocol terminations over a Uu interface associated with a first protocol stack. The ng-eNBs 152B may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) protocol terminations over a Uu interface associated with a second protocol stack.

[0084] 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.

[0085] 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).

[0086] In the example of FIG. 2A, an NF 211 (a consumer NF in this example) may send a request 221 to an NF 212 (a producer NF). The request 221 may be a request for a particular service and may be sent based on a discovery that NF 212 is a producer of that service. The request 221 may comprise data relating to NF 211 and / or the requested service. The NF 212 may receive request 221, perform one or more actions associated with the requested service (e.g., retrieving data), and provide a response 221. The one or more actions performed by the NF 212 may be based on request data included in the request 221, data stored by NF 212, and / or data retrieved by NF 212. The response 222 may notify NF 211 that the one or more actions have been completed. The response 222 may comprise response data relating to NF 212, the one or more actions, and / or the requested service.

[0087] In the example of FIG. 2B, an NF 231 sends a request 241 to an NF 232. In this example, part of the service produced by NF 232 is to send a request 242 to an NF 233. The NF 233 may perform one or more actions and provide a response 243 to NF 232. Based on response 243, NF 232 may send a response 244 to NF 231. It will be understood from FIG. 2B that a single NF may perform the role of producer of services, consumer of services, or both. A particular NF service may include any number of nested NF services produced by one or more other NFs.

[0088] FIG. 2C illustrates examples of subscribe-notify interactions between a consumer NF anda 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.

[0089] 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.

[0090] 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.

[0091] 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).

[0092] The NFs depicted in FIG. 3 include a user plane function (UPF) 305, an access andmobility 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 (0AM), a public warning system (PWS), a short message service function (SMSF), a unified data repository (UDR), and an unstructured data storage function (UDSF).

[0093] 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.

[0094] 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 PDUsessions 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.

[0095] 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.

[0096] 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.)

[0097] 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.

[0098] The PCF 320 may provide, to other NF s, 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 ofthose 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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).

[0104] 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.

[0105] 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.

[0106] 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.

[0107] FIGS. 4 A, 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. 4 A, 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.

[0108] FIG. 4A illustrates an example of a core network architecture 400A comprising an arrangement of multiple UPFs. Core network architecture 400 A 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.

[0109] 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 ormore 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 ethemet packet filter set), and / or an application identifier.

[0110] 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.[OHl] 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.

[0112] 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.

[0113] 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.

[0114] 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).

[0115] 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.

[0116] In the example of FIG. 4 A, 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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 AN402 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.

[0121] 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 Yl, 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 AN403 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.

[0122] 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.

[0123] 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, inparticular, 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] Network architecture 600A illustrates an un-sliced physical network corresponding to a single logical network. The network architecture 600A comprises a user plane wherein UEs 601 A, 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.

[0128] 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 ofcharacteristics 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.

[0129] Network architecture 600B is an example of a sliced physical network divided into multiple logical networks. In FIG. 6, the physical network is divided into three logical networks, referred to as slice A, slice B, and slice C. For example, UE 601 A may be served by AN 602A, UPF 605A, AMF 612, and SMF 614A. UE 601B may be served by AN 602B, UPF 605B, AMF 612, and SMF 614B. UE 601C may be served by AN 602C, UPF 605C, AMF 612, and SMF 614C. Although the respective UEs 601 communicate with different network elements from a logical perspective, these network elements may be deployed by a network operator using the same physical network elements.

[0130] 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.

[0131] 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.

[0132] 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 SMF614 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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).

[0137] 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 trafficavoidance. 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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 aPDU session, which may be a logical connection between the UE 701 and a data network (DN). The UE 701 and the DN may exchange data packets associated with the PDU session. The PDU session may comprise one or more quality of service (QoS) flows. SDAP 771 and SDAP 772 may perform mapping and / or demapping between the one or more QoS flows of the PDU session and one or more radio bearers (e.g., data radio bearers). The mapping between the QoS flows and the data radio bearers may be determined in the SDAP 772 by the gNB 702, and the UE 701 may be notified of the mapping (e.g., based on control signaling and / or reflective mapping). For reflective mapping, the SDAP 772 of the gNB 220 may mark downlink packets with a QoS flow indicator (QFI) and deliver the downlink packets to the UE 701. The UE 701 may determine the mapping based on the QFI of the downlink packets.

[0142] 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, insequence 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.

[0143] RLC 751 and RLC 752 may perform segmentation, retransmission through Automatic Repeat Request (ARQ). The RLC 751 and RLC 752 may perform removal of duplicate data units received from MAC 741 and MAC 742, respectively. The RLCs 213 and 223 may provide RLC channels as a service to PDCPs 214 and 224, respectively.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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).

[0148] 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.

[0149] 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 QoSflow 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.

[0150] 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), SI bearers between an eNB and a serving gateway (SGW), and / or an S5 / S8 bearer between an SGW and a PGW.

[0151] 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-emptionvulnerability. Based on the ARP, the AN 802 may apply admission control for the QoS flows in a case of resource limitations.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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 linkconfiguration 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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 maybe 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).

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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).

[0166] 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 thewireless device is likely to be found).

[0167] 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.

[0168] 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).

[0169] 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.

[0170] 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.

[0171] FIG. 9D is an example diagram showing CM state transitions of the wireless device (e.g., a UE), shown from a network perspective (e.g., an AMF). The CM state of the UE, as tracked by the AMF, may be in CM idle 980 (e.g., CM-IDLE) or CM connected 990 (e.g., CM- CONNECTED). When the UE transitions from CM idle 980 to CM connected 990, the AMF many establish an N2 context of the UE (N2 context establishment 989). When the UEtransitions from CM connected 990 to CM idle 980, the AMF may release the N2 context of the UE (N2 context release 998).

[0172] FIGS. 10 - 12 illustrate example procedures for registering, service request, and PDU session establishment of a UE.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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_ Communi cation_ 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.

[0177] 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 authenticationdata 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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 asession management context of the PDU session (Nsmf_PDUSession_UpdateSMContext, Nsmf_ PDUSession_ ReleaseSMContext).

[0182] 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.

[0183] 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 (3 GPP or non- 3 GPP).

[0184] 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.

[0185] At 1110, a UPF receives data. The data may be downlink data for transmission to a UE. The data may be associated with an existing PDU session between the UE and a DN. The data may be received, for example, from a DN and / or another UPF. The UPF may buffer the received data. In response to the receiving of the data, the UPF may notify an SMF of the received data. The identity of the SMF to be notified may be determined based on the received data. The notification may be, for example, an N4 session report. The notification may indicate that the UPF has received data associated with the UE and / or a particular PDU session associated with the UE. In response to receiving the notification, the SMF may send PDU session information to an AMF. The PDU session information may be sent in an N1N2 message transfer for forwarding to an AN. The PDU session information may include, for example, UPF tunnel endpoint information and / or QoS information.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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).

[0193] 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 planeresource 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.

[0194] 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.

[0195] 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.

[0196] 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 3 GPP network, or for any other suitable reason.

[0197] 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.

[0198] 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.

[0199] 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. ThePDU 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_ Create SMC ontext Response and / or aNsmf PDUSession UpdateSMContext Response. The PDU session context response may include a session management context ID.

[0200] 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.

[0201] 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).

[0202] 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.

[0203] The SMF may send PDU session management information to the AMF. The PDU session management information may be a session service request (e.g., Namf_Communication_NlN2MessageTransfer) message. The PDU session managementinformation 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.

[0204] 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.

[0205] 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.

[0206] 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 aNsmf 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.

[0207] 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.

[0208] 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 physicaldeployment 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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 processingsystem 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.

[0214] 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.

[0215] 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.

[0216] 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 system1337. The deployment 1330 may comprise one or more other elements 1339 analogous to one or more of the one or more other elements 1319.

[0217] 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.

[0218] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g. hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab and / or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise computers, microcontrollers, microprocessors, DSPs, ASICs, FPGAs, and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors may be programmed using languages such as assembly, C, C++ and / or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0219] 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, anexogenous 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.

[0220] FIGS. 14 A, 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.

[0221] 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 differentNFs 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).

[0222] 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.

[0223] 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).

[0224] For example, deployment 1410 comprises an additional network function, NF 1411 A. The NFs 1411, 1411 A may consist of multiple instances of the same NF type, co-located at a same physical location within the same deployment 1410. The NFs 1411, 1411 A may be implemented independently from one another (e.g., isolated and / or independently controlled). For example, the NFs 1411, 1411 A 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 1411 A. In an example, NFs 1411, 1411 A may be associated with different PLMNs, but deployment 1410, which implements NFs 1411, 1411 A, may be owned and / or operated by a single entity.

[0225] 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, 1411 A, 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 havingNFs 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.

[0226] 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.

[0227] FIG. 14D illustrates an example arrangement of core network deployments in which one or more network functions are implemented using a data processing service. In FIG. 14D, NFs 1411, 1411 A, 1421, 1422 are included in a deployment 1450 that is implemented as a data processing service. The deployment 1450 may comprise, for example, a cloud network and / or data center. The deployment 1450 may be owned and / or operated by a PLMN or by a non- PLMN third party. The NFs 1411, 1411 A, 1421, 1422 that are implemented using the deployment 1450 may belong to the same PLMN or to different PLMNs. The PLMN(s) may obtain (e.g., rent, lease, procure, etc.) at least a portion of the capabilities of the deployment 1450 (e.g., processing power, data storage, etc.). By providing one or more NFs using a data processing service, the mobile communications network may operate with greater speed, coverage, security, and / or efficiency.

[0228] 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.

[0229] 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 toimplement NFs and communicate with other deployments in a transparent manner. The deployment may operate in accordance with open RAN (O-RAN) standards.

[0230] One of advancement achieved by 5G system (5GS) may be to use a new frequency band that was not actively used in previous generation communication system (e.g., 4G, 3G). For example, as device components of mobile communication system begin to support higher frequencies (e.g., milli-meter waves), the 5G system can support a higher bitrate via the higher frequencies.

[0231] However, one of problems of using the higher frequencies includes that communication range supported by the higher frequencies is shorter than communication range supported by lower frequencies (e.g., centi-meter waves). As shown in the example of FIG. 15, as long as a mobile device (e.g., UE A) of a user is located inside a coverage (e.g., a signal strength of a basestation is above minimum threshold that can sustain a communication) of a cell, the user (e.g., UE A) can enjoy a higher data bitrate service. However, as communication range supported by the cell gets shorter due to use of the higher frequencies, another user (e.g., UE B) may be more likely to be located outside of the coverage of the cell, and communication service may not be provided to the another user. This may lead to reduced availability of communication service by the 5G system, and more interruptions to the communication service.

[0232] As shown in the example depicted in FIG. 16, a remote UE (e.g., remote C, remote UE C) may benefit from using a sidelink communication (e.g., PC5 communication) via a relay UE (e.g., relay A, e.g., a wireless relay device, a relay wireless device). In an example, a user of the remote UE may decide to use the relay UE. For example, when the remote UE is outside of a coverage of a base station, the remote UE (e.g., remote wireless device) may not be able to communicate directly (e.g., not using another UE in the middle) with one or more cells of the base station. Based on that the remote UE being unable to directly communicate with the base station, the user of the remote UE may decide to use a relay service (e.g., data communication between the remote UE and a network (e.g., an application server, the basestation, a UPF, and / or the like) via one or more relay UEs). To use the relay service, the remote UE may start searching for candidate relay UEs. For example, the remote UE may be configured with a first relay policy information by a configuration server (e.g., a PCF, an AF, an AMF, a SMF, and / or the like). For example, the first relay policy information may indicate (comprise) at least one of one or more relay service codes (RSCs) (e.g., RSC 1) allowed for the remote UE, an indication (e.g., authorization information) indicating whether the remote UE is allowed to use a relay service from a relay UE. Similarly, the relay UE may be configured with a second relay policy information by the configuration server. For example, the second relay policy information may indicate (comprise) at least one of the one or more relay service codes (e.g., RSC 1) allowed for the relay UE, and / or a second indication indicating whether the relay UE is allowed to provide one or more relay services (associated with the RSCs) to a remote UE. The remote UE may findone or more candidate relay UEs that can relay data traffic between the base station and the remote UE. For example, the relay UE may send a sidelink announcement message (e.g., sidelink announce message, e.g., a Prose PC5 discovery message for announcement). For example, based on that the relay UE is allowed to provide the one or more relay services, the sidelink announcement message may comprise the one or more RSCs. In an example, the remote UE may receive the sidelink announcement message. Based on the first relay policy information comprising the RSC 1, and / or based on that the sidelink announcement message comprising the RSC 1, the remote UE may determine that the remote UE can use the relay UE for the relay service (e.g., a relay service 1 associated with the RSC 1). The remote UE may select the relay UE among one or more found candidate relay UEs. For example, the remote UE may establish a sidelink connection (e.g., by sending / receiving a prose direct link connection request and / or by receiving / sending a prose direct link connection accept, and / or the like) with the relay UE. In an example, based on that the relay UE establishes the sidelink connection with the remote UE and / or based on that the remote UE indicates the RSC 1, the relay UE may establish (sending / receiving a PDU session establishment / modification message) with a SMF, a PDU session associated with the RSC 1, with the network. After the PDU session is established, the relay UE may receive one or more packets sent by the remote UE and / or may deliver the one or more packets to the network (e.g., base station, UPF). By using communication link between the remote UE and the relay UE and communication link between the relay UE and the base station, data traffic can be exchanged between the remote UE and the application server. However, this mechanism may not be able to support communication for the remote UE enough, when the one or more found candidate relay UEs are located outside of the coverage of the cell (e.g., cannot directly connect to the cell (e.g., the basestation)).

[0233] In an example as depicted in FIG. 17, different types of relay UEs may be used. For example, the different types of relay UEs may comprise one or more first-type relay UEs and / or one or more second-type relay UEs. For example, the one or more first-type relay UEs may be one or more relay UEs (e.g., Relay B) located inside of a coverage of a cell, and / or may be directly connected to the cell. For example, the one or more second-type relay UEs may be one or more UEs (e.g., Relay A) located outside of the coverage of the cell, may be indirectly connected to the cell (e.g., to the base station, to the network) via one or more other relay UEs (e.g., the one or more first-type relay UEs). For example, to relay a traffic from a remote UE to a network, the one or more second-type relay UEs may need to connect to the one or more first- type relay UEs. For example, because a second UE (e.g., Relay A) of the one or more second- type relay UEs is located outside of the coverage of the cell, the second UE may require a sidelink connection to a first UE (e.g., Relay B) of the one or more first-type relay UEs, todeliver the traffic from the remote UE (e.g., a UE that the second UE serves) to the network. For example, if the first UE receives the traffic of the remote UE via the second UE, the first UE may deliver the traffic to the network (e.g., a basestation, a UPF, a data network) via a PDU session.

[0234] In an example, a configuration server (e.g., a PCF via control plane signalling, an AMF via control plane signalling, a configuration server via user plane signalling, and / or the like) may send one or more configuration information to one or more UEs. For example, the one or more UEs may comprise one or more relay UEs (e.g., the relay A, the relay B), and / or one or more remote UEs (e.g., the remote C). For example, the one or more configuration information may comprise a first configuration, and / or a second configuration. The first configuration may comprise information for the one or more relay UEs. For example, the first configuration may indicate at least one of one or more relay service codes (RSCs) indicating one or more first relay services. For example, the first configuration may indicate that the one or more relay UEs are allowed (authorized) for relaying traffic (associated with the one or more first relay services) for one or more remote UEs. The second configuration may comprise information for one or more remote UEs (e.g., information used when the one or more remote UEs needs to use relaying service). For example, the second configuration may indicate at least one of one or more relay service codes (RSCs) indicating one or more second relay services. For example, the second configuration may indicate that the one or more remote UEs are allowed (authorized) for using the one or more second relay services. For example, the one or more first relay service may comprise a first relay service and / or a RSC for the first relay service may be RSC (1). For example, the one or more second relay service may comprise a second relay service and / or a RSC for the second relay service may be RSC (1).

[0235] In an example, the relay B may be located inside a coverage of a basestation, and / or the relay A may be located outside of the coverage of the basestation. Because the relay A is located outside of the coverage, and / or because the relay A cannot establish a direct (network) connection to the basestation, the relay A may determine to establish a sidelink connection with the relay B, to connect to the network.

[0236] In an example, the relay B may start / trigger establishment of a PDU session and / or may start / trigger modification (e.g., update) of the PDU session. For example, the PDU session may be associated with the RSC (1), and / or the PDU session may be used to relay a traffic associated with the RSC (1). For example, the PDU session may be associated with a network slice and / or a data network for which the RSC (1) is linked.

[0237] In an example, because the relay B has the PDU session associated with the RSC (1), because the relay B is authorized for relaying, and / or because the relay B has information of the RSC (1), the relay B may send a first sidelink announcement message (e.g., message 4B, step4B). For example, the first sidelink announcement message may indicate the RSC (1).

[0238] In an example, because the relay A is authorized for relaying, and / or because the relay A has information of the RSC (1), the relay A may send a second sidelink announcement message (e.g., message 4A, step 4A). For example, the second sidelink announcement message may indicate the RSC (1).

[0239] In an example, the remote C may receive the first sidelink announcement message, and / or the remote C may receive the second sidelink announcement message. Because the remote C is authorized for using relaying, because the remote C is configured with (e.g., authorized for) the RSC (1), the remote C may determine to use the relaying service associated with the RSC (1). Because the first sidelink announcement message indicates the RSC (1), the remote C may consider the relay B as a first candidate relay. Because the second sidelink announcement message indicates the RSC (1), the remote C may consider the relay A as a second candidate relay. Because there is a plurality of candidate relays, the remote C may perform selection of a relay. For example, based on that a first measured signal strength (e.g., -30 dBm RSRP) of the relay A is stronger than a second measured signal strength (e.g., -50 dBm RSRP) of the relay B, the remote C may select the relay A for the relaying service associated with the RSC (1).

[0240] In an example, the remote C may not support using a plurality of relays (e.g., multihop relaying) for relaying operation. For example, the multihop relaying may be a relaying of data of the remote UE to the network, via a series of more than one UEs (e.g., relay UE), and / or via a plurality of PC5 interfaces with one or more Uu interfaces, and / or the like. For example, the remote UE may support a singlehop relaying. For example, the singlehop relaying may be a relaying of a traffic between the remote UE and the network, using up to one UE in the middle. For example, the multihop relaying may be associated with a first path from the remote C to the base station via the relay A and the relay B. For example, the singlehop relaying may be associated with a second path from the remote C to the base station via the relay B. For example, the remote C may support only basic (e.g., singlehop) relaying, may not support advanced relaying (e.g., multihop). For example, the remote C may be a legacy UE. For example, due to subscription to basic relaying service, a home network of the remote C may not allow the remote C to use advanced relaying service (e.g., multihop relaying). In existing technologies, if the remote C selects the relay A for relaying service of the RSC (1), the remote C may not properly get the relaying service e.g., due to capability limitation and / or due to service agreement (e.g., subscription) limitation. In this case, access attempt of the remote C to the relay A may waste sidelink radio resources, and / or may impact service of other remote UEs accessing the relay A. Similar situations may occur for the relay A, if the relay A is not allowed for multihop relaying. For example, if the relay A is a low-capability UE, and / or if the relay A does not subscribe to apremium service (e.g., providing the multihop relaying), the second announcement of the relay A may cause service interruption to an advanced remote UEs (e.g., a remote UE capable of using the multihop relaying).

[0241] In example embodiments of the present disclosure, signalling may be enhanced to configure a relay UE and / or a remote UE, with information on when / how advanced relaying operation (e.g., multihop relaying) is used / allowed. This may assist the relay UE to determine when to provide the advanced relaying service, and / or may assist the remote UE to determine which relay to select based on availability of advanced relaying service. In another example, sidelink signalling may be enhanced to assist for the remote UE and / or a neighboring relay UE, to determine whether the relay UE supports the advanced relaying service. This may assist a downstream relay UE to select which upstream relay UE for the advanced relaying service. In another example, mapping information between a first RSC for the basic relaying and a second RSC for the advanced relaying may be provided. This may support service continuity when the remote UE navigates through relay UEs of different capabilities. In another example, assistance information (e.g., capability information, authorization information) may be delivered among one or more network nodes. This may assist each network node to make a proper decision on using advanced relaying operations.

[0242] In the specification, the term “5G access network” may be interpreted as, or may refer to, an access network comprising at least one of a NG-RAN and / or non-3GPP access network (AN), and connecting to a 5G core network.

[0243] In the specification, the term “5G core network” may be interpreted as, or may refer to, a core network connecting to a 5G access network. This may be 5G core (5GC).

[0244] In the specification, the term “3 GPP RAN” or “RAN” may be interpreted as, or may refer to, a radio access network using 3GPP RAT. For example, this may comprise at least one of a gNB, an eNB, a ng-eNB, an en-gNB, the like, and / or a combination thereof. For example, this may be at least one of an E-UTRAN, NG-RAN, the like, and / or a combination thereof.

[0245] In the specification, the term “NG-RAN” may be interpreted as, or may refer to, a base station, which may comprise at least one of a gNB, a ng-eNB, a relay node, a base station central unit (e.g., gNB-CU), a base station distributed unit (e.g., gNB-DU), and / or the like. This may be a radio access network that connects to 5GC, supporting at least one of NR, E-UTRA, and / or a combination thereof.

[0246] In the specification, the term “E-UTRAN” may be interpreted as, or may refer to, a base station, which may comprise at least one of an eNB, an en-gNB, and / or the like. This may be a radio access network that connects to evolved packet core (EPC), supporting at least one of NR, E-UTRA, and / or a combination thereof.

[0247] In the specification, the term “network node” may be interpreted as, or may refer to, at least one of a core network node, an access node, a UE, the like, and / or a combination thereof. A network may comprise one or more network nodes.

[0248] In the specification, the term “core network node” may be interpreted as, or may refer to, a core network device, which may comprise at least one of an AMF, a SMF, a NSSF, a UPF, a NRF a UDM, a PCF, a SoR-AF, an AF, an DDNMF, an MB-SMF, an MB-UPF, a MME, a SGW, a PGW, a SMF+PGW-C, a SMF+PGW-U, a UDM+HSS and / or the like.

[0249] In the specification, a term of a relay UE (a relay wireless device, a wireless relay device, a relay, and / or the like) may be interpreted as a U2N relay UE and / or a U2U relay UE. The relay UE may be a relay. The relay UE may be 5G Prose Relay UE.

[0250] In the specification, a term of a UE-to-Network (U2N) relay UE may be interpreted as a UE which provides a network relay service (e.g., UE-to-Network service, e.g., a data delivery from / to a network (e.g., application server, data network)) for a remote UE and / or a downstream UE (e.g., a downstream end UE, a downstream relay UE, a downstream remote UE). The U2N relay UE may be a U2N relay and / or 5G ProSe UE-to-Network Relay UE. The U2N relay UE may provides functionality to support connectivity to a network (e.g., an application server, a basestation, a UPF, a data network, and / or the like) for the downstream UE. For example, connectivity to the network for the downstream UE may be providing data delivery service of data between the downstream UE and the network (e.g., basestation, a UPF, a data network). The U2N relay UE may comprise at least a singlehop (e.g., basic) U2N relay UE and / or a multihop (e.g., evolved, advanced) U2N relay UE. The singlehop U2N relay may be directly connected to the network (e.g., direct network connection) and / or may be directly connected to the remote UE. The multihop U2N relay may be connected to the network via one or more first UEs (e.g., another first U2N relays, and / or another first U2U relays, and / or upstream relay UEs) and / or may be connected to the remote UE via one or more second UEs (e.g., another second U2N relays, and / or another second U2U relays, and / or downstream relay UEs). The U2N relay UE may comprise at least one of an edge U2N relay UE and / or interim U2N relay UE. For example, the edge U2N relay UE may directly connect to the remote UE without any UE in the middle and / or may directly connects to the cell (e.g., basestation, network) without any UE in the middle. For example, the edge U2N relay UE may comprise a first-type edge U2N relay UE (e.g., connects to directly the cell, a top relay UE) and / or a second-type edge U2N relay (e.g., connects to directly to a remote UE, a bottom relay UE). For example, the interim U2N relay UE may be a U2N relay UE which does not directly connect to the cell and / or which does not directly connect to a remote UE. An upstream relay UE may be a relay UE closer to the cell in a chain of relay UEs, and / or a downstream relay UE may be a relay UE closer to the remote UE(e.g., end UE) in the chain of relay UEs. For example, an upstream UE may be a UE closer to the cell in a chain of UEs and / or a downstream UE is a UE closer to a remote UE (e.g., an end UE) closer in a chain of UEs.

[0251] In the specification, a term of a UE-to-UE (U2N) relay UE may be interpreted as a UE which provides a UE-to-UE relay service (e.g., U2U service, a data delivery between two UEs without traversing a network / a cell / a basestation) for a remote UE (an end UE). The U2U relay UE may be a U2U relay, and / or a 5G ProSe UE-to-UE relay UE. For example, the U2U relay UE may provide data delivery service of data between a first end UE and a second end UE. The U2U relay UE may be at least a singlehop (e.g., basic) U2U relay UE and / or a multihop (e.g., evolved, advanced) U2U relay UE. The singlehop U2U UE relay may be directly connected to the first end UE and the second end UE. The multihop U2U relay UE may be connected to the first end UE via another one or more U2U relay UEs. For example, an edge U2U relay UE may be connected directly to the first end UE and / or may be connected to the second end UE via one or more UEs in the middle. For example, an interim U2U relay UE may be connected to the first end UE via one or more UEs in the middle and / or may be connected to the second end UE via one or more UEs in the middle.

[0252] In the specification, a term of sidelink may be interpreted as a direct interface between UEs. For example, the sidelink may comprise a PC5 interface. For example, a direct connection between UEs may be a sidelink connection. For example, a direct sidelink connection may be a connection between UEs without other UEs (e.g., relay UEs) in the middle. For example, an in direct sidelink connection may be a connection between UEs with one or more other UEs in the middle.

[0253] In the specification, a term of a remote UE may be interpreted as a UE which may send and / or receive traffic via one or more relay UEs, to / from the network. The remote UE may search, select and / or establish direct sidelink connection (e.g., sidelink connection, PC5 connection, D2D connection) with the relay UE. If the remote UE is out of coverage of a cell, may establish an indirect network connection to the cell via the one or more relay UEs. If a UE connects to the network via the one or more relay UEs, the UE may be interpreted as the remote UE. The remote UE and a relay UE of the one or more relay UEs may use one or more PC5 interfaces. The remote UE may receive from a network, configuration information and / or policy information for using the one or more relay UEs. The remote UE may use the configuration information and / or the policy information, when the remote UE uses the one or more relay UEs and / or when the remote UE intends to use the one or more relay UEs. For example, the remote UE may be 5G ProSe Remote UE.

[0254] In the specification, a term of an end UE may be interpreted as a UE that connects withanother end UE via one or more UE-to-UE (U2U) Relays. For example, the end UE may be 5G ProSe End UE.

[0255] In the specification, a term of relay service code (RSC) may be interpreted as a code to identify a connectivity (e.g., relay) service. The RSC may be used for the case of UE-to-Network Relay as well as for the case of UE-to-UE Relay. For the case of UE-to-UE Relay, the RSC may used to identify a connectivity service that a U2U relay provides and / or authorized users that the U2U Relay may offer service to. For the case of UE-to-Network Relay, the RSC may be used to identify a connectivity service that is associated with a PDU session, and / or that is associated with a network slice, a data network and / or the like.

[0256] In the specification, a term UE-to-UE relay service (e.g., U2U relay service) may be interpreted as a data delivery service between a first UE and a second UE via one or more third UEs in the middle. For example, the first UE may send a data to the second UE via the one or more third UEs. In this case, the one or more third UEs in the middle may provide the UE-to-UE relay (or relaying) service. When the second UE receives the data, the second UE may consume (in case of U2U relaying for U2U service) the data (e.g., a second application of the second UE process the data) and / or may forward (in case of U2U relaying for U2N service) the data to other entity (e.g., the network, the relay UE).

[0257] In the specification, a term UE-to-Network relay service (e.g., U2N relay service) may be interpreted as a data delivery service between a first UE and a network via one or more third UEs in the middle. For example, the first UE may send a data to the network via the one or more third UEs. In this case, a third UE (e.g., the UE has direct (network) connection to a cell of the network, and / or the UE has a PDU session to deliver a data for the first UE) of the one or more third UEs may receive the data from the first UE via other UEs of the one or more third UEs in the middle, and / or the third UE may forward the data to the network (and / or via zero or more upstream relay UEs) via the PDU session. The data delivery service may be the UE-to-Network relay (or relaying) service, and / or a service provided by the PDU session may be the UE-to- Network relay service.

[0258] In the specification, a term multihop may be interpreted as having more than one (link, hop, interface) between a first UE and a second UE (or a network). For example, using FIG. 17 as example, for a communication between the remote C and the network, a first path (a path involving the remote C, the relay A, the relay B and the network) may be a multihop path (e.g., not singlehop), while a second path (a path involving the remote C, the relay B and the network, and not involving the relay A) may be a singlehop path (i.e., not multihop). In other example, for a communication, if more than one relay UE (or UE) are involved, it can be interpreted as multihop. In other example, for a communication, if only one relay UE (or UE) is involved, itcan be interpreted as singlehop (relaying). Similarly, when two entities cannot directly communicate, if one relay (or a UE) is used in the middle of the two entities, a singlehop relaying may apply. When two entities cannot directly communicate, if more than one relays (or UEs) are used in the middle of the two entities, a multihop relaying may apply.

[0259] In the specification, a term direct network communication may be interpreted as one mode of communication, where there is no relay UE between a UE and a network. For example, for direct network communication, the UE and the network (e.g., a basestation) may use Uu interface, and / or may not use PC5 interface. For example, in case of direct network connection (communication), the UE may be inside a coverage of the network.

[0260] In the specification, a term indirect network communication may be interpreted as one mode of communication, where there is one or more relay UEs between a UE (a remote UE) and a network. For example, for indict network communication, the UE and a first relay UE of the one or more relay UEs may use a PC5 interface and / or the network (e.g., a basestation) and a second relay UE of the one or more relay UEs may use Uu interface.

[0261] In the specification, a term RSC (relay service code) may be interpreted as an indicator indicating a connectivity service a relay UE provides to other UE (e.g., a relay UE, a remote UE, an end UE). The RSC may be configured on the relay UE, the end UE, and / or the remote UE. The RSC may indicate whether the RSC is associated with an offering of layer-2 relay service o layer-3 relay service, the relay UE supporting multiple RSCs may advertise the RSCs using multiple discovery messages, with one or more discovery messages (e.g., announcement messages).

[0262] FIG. 18 depicts one example embodiment of the present disclosure. In an example, a UE may indicate whether the UE has a capability of supporting multihop relaying. In an example, the UE may receive an indication whether the UE is allowed to perform multihop relaying operation. This may help a network operator to control where the UE can be involved in multihop relaying. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0263] In an example, a relay UE A (e.g., a relay wireless device A, a wireless relay device A, a relay A) may send a first NAS message to an AMF. For example, the first NAS message may be at least one of a Registration Request message, UL NAS Transport message, and / or the like. For example, the first NAS message may comprise a UE Policy Container. For example, the UE policy Container may comprise a UE Policy Provisioning Request. For example, the UE Policy Provisioning Request may comprise 5G ProSe policies and / or 5G ProSe policies for multihop relaying. For example, the first NAS message may comprise an indication (e.g., multihop capability) indicating that the relay UE A has capability supporting multihop relaying and / or thatthe relay UE A has capability of performing as a multihop relay UE. For example, the first NAS message may comprise a first capability indicator indicating that the relay UE A supports a relaying operation and / or a second capability indicator indicating that the relay UE A supports a multihop relaying operation. For example, this may help a legacy AMF (e.g., not supporting multihop relaying) to interpret / use the first capability indicator, and / or may help an advanced AMF (e.g., supporting multihop relaying) to interpret / use the second capability indicator.

[0264] In an example, the AMF may receive the first NAS message. In response to receiving the first NAS message, the AMF may send a request to a UDM. For example, the request to the UDM may request for the UDM to send to the AMF, a subscription data of the relay UE A, for the multihop relaying operation. In response to the request to the UDM, the UDM may send a response to the AMF. For example, the response to the AMF may comprise the subscription data of the relay UE A, for the multihop relaying operation. For example, the subscription data of the relay UE A may comprise an indication indicating the relay UE A being allowed (authorized, subscribed) for multihop relaying and / or the relay UE A having subscription for multihop relaying.

[0265] In an example, in response to receiving the first NAS message, in response to receiving the subscription data from the UDM, and / or in response to detecting a mobility event of the relay UE A, the AMF may send a first notification message to a PCF. For example, the first notification message to the PCF may comprise at least one of the subscription data indicating that the relay UE A has subscription for multihop relaying, an indication indicating that the relay UE A moves from a PLMN X (e.g., a cell X, a basestation X) to a PLMN Y (e.g., a cell Y, a basestation Y), the UE Policy Provisioning Request and / or that the relay UE A supports the capability of multihop relaying. For example, the first notification message may be at least one of Namf_Communication_NlMessageNotify message, Npcf_UEPolicyControl_Create request message, Npcf_AMPolicyControl_Create request message, Namf_EventNotify message, and / or the like. For example, the first Namf message may comprise at least one of the UE policy Container, the indication indicating that the relay UE A has capability supporting the multihop relaying, the subscription date, and / or the like.

[0266] In other example, when subscription of the relay UE A changes (e.g., from not subscribing to multihop relaying to subscribing to multihop relaying), the UDM may send a second notification message to the PCF (and / or via the AMF). For example, the second notification message may comprise an indication indicating that the relay UE A has the subscription for multihop relaying.

[0267] In other example, the PCF may receive a third notification message from an application server. For example, the third notification may indicate whether a UE (e.g., a remote UE, a relayUE) is allowed to use a service of the multihop relaying or not, whether the UE is allowed to act as a multihop relay, whether the UE is preferred to use (and / or provide) multihop relaying or singlehop relaying, and / or the like. Alternatively and / or additionally, when the AMF receives the first NAS message from the relay UE A, the AMF may send a fourth notification message to the application server. For example, the application server may manage (e.g., determine, authorize, and / or the like) a service (e.g., an application service, an application data flow) related to the multihop relaying of the relay UE A. In response to receiving the fourth notification message, the application server may send an updated configuration information to the PCF, via the third notification message.

[0268] In an example, the PCF may receive at least one of the first notification message, the second notification message, the third notification message, and / or the like. Because the relay UE A supports the capability of multihop relaying, and / or because the relay UE A is allowed for the multihop relaying (e.g., act / perform as a multihop relay), the PCF may determine to send a first prose policy information (e.g., Prose policy information, multihop relaying policy information, and / or the like) to the relay UE A (e.g., via the AMF, via user plane). For example, the first prose policy information may comprise the first multihop relaying provisioning information. For example, the first multihop relaying provisioning information may comprise (e.g., indicate) at least one of:

[0269] - one or more RSCs. Each RSC of the one or more RSCs may be associated a relaying service. For example, each relaying service may be associated with a specific U2N service, a specific U2U service, a specific data network, a specific application, a specific user group, a specific network slice, and / or the like. The RSC may allow to identify a specific relay service, a user, a user group, a data service, and / or the like.

[0270] - For each RSC, one or more multihop relaying conditions indicating when the UE (e.g., an entity receiving multihop provisioning information) is allowed (authorized) to act as a multihop relay UE, to use the multihop relay UE, and / or the like. For example, the one or more multihop relaying conditions may comprise at least one of one or more network identifiers (e.g., PLMN A, PLMN B, SNPN C), one or more location areas (e.g., city D, Tracking Area E, geocoordinate F), and / or one or more time periods (e.g., start time, end time, time length). For example, when the one or more multihop conditions are met, the UE may be allowed to perform as the relay UE using multihop functionalities, to provide the multihop relaying services to other UEs, and / or to use the multihop relaying service provided by other UEs. For example, when one or more multihop conditions are not met, the UE may not be allowed to perform as the relay UE using multihop functionalities, and / or to use the multihop relaying service.

[0271] - For each RSC, one or more singlehop conditions indicating when the UE is allowed(authorized) to act as a single relay UE. For example, when one or more singlehop conditions are met, the UE may be allowed to perform as a relay UE using singlehop functionalities, and / or to use a singlehop relaying service. For example, when one or more singlehop conditions are not met, the UE may not be allowed to perform as the relay UE using singlehop functionalities, and / or may not be allowed to use the singlehop relaying.

[0272] - an indicator indicating whether the UE is allowed to act as a multihop relay UE. This may indicate whether the UE is authorized to perform a role of multihop relay UE.

[0273] - an indicator indicating whether the UE is allowed to act as a singlehop relay UE. This may indicate whether the UE is authorized to perform a role of singlehop relay UE.

[0274] - an indicator indicating whether the UE is allowed to use a multihop relaying service.

[0275] - an indicator indicating whether the UE is allowed to use a singlehop relaying service.

[0276] - an indicator indicating whether the UE is allowed to provide a relaying service to other (downstream) relay UEs.

[0277] - an indicator indicating whether the UE is allowed to connect (e.g., use) an upstream relay UE as a relay UE, to provide a relaying service to other (downstream) UEs.

[0278] - an indicator indicating whether the UE is allowed to act as a multihop U2N relay UE. This may indicate whether the UE is authorized to perform a role of multihop U2N relay UE.

[0279] - an indicator indicating whether the UE is allowed to act as a multihop layer-2 U2N relay UE. This may indicate whether the UE is authorized to perform a role of multihop layer-2 U2N relay UE. For example, when layer-2 multihop relaying is used, a path from the basestation to the remote UE may be controlled by the base station.

[0280] - an indicator indicating whether the UE is allowed to act as a multihop layer-3 U2N relay UE. This may indicate whether the UE is authorized to perform a role of multihop layer-3 U2N relay UE. For example, when layer-3 multihop relaying is used, a path from a topmost relay UE to a remote UE may not be controlled by the base station, and / or the basestation may not be aware of the remote UE.

[0281] - a value indicating maximum number of hops allowed for multihop relaying. For example, this may indicate maximum number of hops (e.g., number of PC5 interfaces, number of interfaces, number of relay UEs in a path) allowed for the UE to support for multihop relaying and / or allowed for the UE to use for multihop relaying. For example, if the maximum number of hops allowed for multihop relaying is set to 5, the UE may not provide relaying service to a remote UE which requires more than 5 hops to reach a network. For example, if the maximum number of hops allowed for multihop relaying is set to 5, the UE may not use the multihop relaying service which requires more than 5 hops to reach a network.

[0282] For example, the first multihop provisioning information may indicate that RSC IB isallowed for the relay UE A for multihop relaying operation, that RSC 1 A is allowed for the relay UE A for singlehop relaying operation, and / or that RSC IB and RSC 1 A are associated for the same service (e.g., PDU session, network slice, data network). For example, if authorized, the first multihop provisioning information may comprise the RSC IB and / or the RSC 1 A. For example, if not authorized, the first multihop provisioning information may not comprise the RSC IB and / or the RSC 1A.

[0283] In an example, the PCF may send the first prose policy information for the relay UE A, to the AMF. In response to receiving the first prose policy information from the PCF, the AMF may send a second NAS message to the UE. For example, the second NAS message may be at least one of a DL NAS transport message, a registration accept message, a UE configuration update message and / or the like. For example, the second NAS message may comprise the first prose policy information.

[0284] In an example, the relay UE A may receive the second NAS message. Because the second NAS message comprises the first prose policy information, because the second NAS message indicates (e.g., comprise) the one or more RSCs allowed for multihop relaying, and / or because the second NAS message comprises the first multihop provisioning information indicating allowance of using multihop relaying, the relay UE A may determine that the relay UE A is authorized for providing multihop relaying service to other UEs.

[0285] In an example, a relay UE B may receive a second prose policy information (not shown in the figure). For example, the second prose policy information may be similar to the first prose policy information (with information relevant for the relay UE B instead of the relay UE A). For example, the relay UE B may receive the second prose policy information, in a similar way that the relay UE A receive the first prose policy information. For example, one or more network nodes (e.g., the AMF, the PCF, the UDM, the AF) may perform similar actions for constructing / delivering the second prose policy information, as the first prose policy information.

[0286] In an example, a remote UE C may receive a third prose policy information (not shown in the figure). For example, the remote UE C may receive the third prose policy information, in a similar way that the relay UE A receive the first prose policy information. For example, one or more network nodes (e.g., the AMF, the PCF, the UDM, the AF) may perform similar actions for constructing / delivering the third prose policy information, as the first prose policy information. For example, the third prose policy information may indicate whether the remote UE C is allowed to use a service via the multihop relaying. For example, the remote UE C may send a similar NAS message as the first NAS message. For example, the similar NAS message may indicate whether the remote UE C supports multihop relaying, e.g., whether the remote UE C has a capability of using a relaying service service via using multihop relaying. Similarly, the AMFmay receive from the PCF and / or the UDM, the third prose policy information. For example, the third Prose policy information may use similar format as the first Prose Policy information. For example, the third Prose Policy information may comprise (e.g., indicate) at least one of:

[0287] - one or more RSCs. This may indicate one or more RSCs that a UE (e.g., the remote UE C) is allowed to use.

[0288] - For each RSC, one or more multihop conditions indicating when the UE is allowed (authorized) to act as a multihop remote UE (e.g., a UE using a U2N service via a multiple relay UEs). For example, the one or more multihop relaying conditions (e.g., multihop conditions) may comprise at least one of one or more network identifiers (e.g., PLMN A, PLMN B, SNPN C), one or more location areas (e.g., city D, Tracking Area E, geo-coordinate F), and / or one or more time periods (e.g., start time, end time, time length). For example, when one or more multihop conditions are met, the UE may be allowed to perform as a remote UE using multihop functionalities, and / or may be allowed to use one or more multihop relays. For example, when one or more multihop conditions are not met, the UE may not be allowed to use a relay UE using multihop functionalities.

[0289] - For each RSC, one or more singlehop relaying conditions indicating when the UE is allowed (authorized) to use a singlehop relaying UE. For example, when one or more singlehop relaying conditions are met, the remote UE C may be allowed to use a relay UE using singlehop functionalities. For example, when one or more singlehop conditions are not met, the remote UE C may not be allowed to use a relay UE using singlehop functionalities.

[0290] - an indicator indicating whether the UE is allowed to act as a multihop remote UE. This may indicate whether the UE is authorized to use one or more multihop relay UEs.

[0291] - an indicator indicating whether the UE is allowed to act as a singlehop remote UE. This may indicate whether the UE is authorized to use singlehop relay UE.

[0292] - an indicator indicating whether the UE is allowed to act as a multihop U2N remote UE. This may indicate whether the UE is authorized to perform a role of multihop U2N remote UE, e.g., using one or more U2N multihop relay UEs.

[0293] - an indicator indicating whether the UE is allowed to act as a multihop layer-2 U2N remote UE. This may indicate whether the UE is authorized to perform a role of multihop layer-2 U2N remote UE, e.g., using one or more layer-2 multihop relay UEs. For example, when layer-2 multihop relaying is used, a path from the basestation to the remote UE may be controlled by the base station.

[0294] - whether the UE is allowed to act as a multihop layer-3 U2N remote UE. This may indicate whether the UE is authorized to perform a role of multihop layer-3 U2N remote UE, e.g., using one or more layer-3 multihop relay UEs. For example, when layer-3 multihoprelaying is used, a path from the top relay UE to the remote UE may not be controlled by the base station.

[0295] - maximum number of hops allowed for multihop relaying. For example, this may indicate maximum number of hops (e.g., number of PC5 interfaces, number of interfaces) allowed for the UE , when the UE uses the multihop relaying service. For example, if the maximum number of hops allowed for multihop relaying is set to 5, the UE may not use a multihop relaying service which requires more than 5 hops to reach a network.

[0296] In an example, the relay UE B may be in a second coverage of a second cell (e.g., second basestation). Because direct connection (e.g., direct network connection) to the second cell (a second network) is available, and / or because the relay UE B is allowed (authorized) for multihop relaying for other UEs (e.g., remote UEs, relay UEs) via the second prose policy information, the relay UE B may determine to provide multihop relaying service (e.g., U2N relay service, e.g., U2U relay service). For example, the relay UE B may determine to provide multihop relaying service associated with the RSC IB. For example, the relay UE B may send a sidelink message 4A. For example, the sidelink message 4A may be a PC5 message 4A. The sidelink message 4A may be at least one of Announce message 4A (e.g., PC5 Prose Discovery message for announcement 4A), ProSe Additional Parameters Announcement Response message 4A, ProSe PC5 Discovery message 4A, ProSe Direct Link Establishment message 4A, ProSe Direct Link Modification message 4A, and / or the like. The sidelink message 4A may comprise at least one of:

[0297] - Source layer-2 ID: This may indicate source layer-2 identifier of a transmitting UE (e.g., the relay UE B).

[0298] - Destination layer-2 ID: This may indicate one or more target layer-2 identifiers associated with one or more UEs, to which the sidelink message 4A is sent.

[0299] - RSC: This may identify a connectivity service the relay UE B provides to one or more remote UEs and / or one or more relay UEs. This may identify authorized users of the relay UE B. For example, this may indicate RSC IB.

[0300] - Discoverer Info: This may provide information (i.e., User Info ID) about discoverer user.

[0301] - Target Info: This may provide provides information (i.e., User Info ID) about targeted discoveree user.

[0302] - List of User Info ID: This may provide information about one or more end UEs, one or more remote UEs, one or more relay UEs.

[0303] - Support indicator of multihop: This may indicate that the transmitter (e.g., the relay UE B) supports multihop relaying, that the transmitter supports a connection (e.g., a sidelinkconnection) with another relay UE (e.g., downstream relay UEs, upstream relay UEs), that the transmitter supports (e.g., provides) multihop U2N relaying service, and / or the like.

[0304] - a first coverage indicator indicating whether the transmitter is in coverage or not.

[0305] - a second coverage indicator indicating whether the transmitter has a connection to an upstream relay UE which is in coverage.

[0306] In an example, the relay UE A (case 2) may move out of coverage of a cell. For example, the relay UE A may not be able to find a cell to camp on (due to weak signal of the cell, or a network associated with a found cell is not allowed for the relay UE A, and / or the like). Because direct connection to the cell (to the network) is not available, because the relay UE A is allowed (authorized) for multihop relaying (e.g., allowed to use / connect other relay UEs to provide connectivity service to other remote UEs), because an upstream relay UE (e.g., relay UE B) in coverage is available, because the relay UE A receives the sidelink message 4A indicating support for multihop relaying, and / or because the relay UE A is authorized (received authorization) for multihop relaying, because the relay UE A is authorized for RSC IB associated with the multihop relaying, the relay UE A may determine to participate in multihop relaying, to connect to the upstream relay UE, to establish a sidelink connection to another relay (e.g., relay UE B, for multihop relaying), and / or the like. For example, the relay UE A may send a sidelink message 4B to relay UE B, to establish a sidelink connection. For example, the sidelink message 4B may be a PC5 message 4B. For example, the sidelink message 4B may be at least one of Announce message 4B, ProSe Additional Parameters Announcement Response message 4B, ProSe PC5 Discovery message 4B, ProSe Direct Link Establishment message 4B, ProSe Direct Link Modification message 4B, Sidelink connection Establishment message, and / or the like. The sidelink message 4B may comprise at least one of

[0307] - Source layer-2 ID: This may indicate source layer-2 identifier of the transmitting UE. For example, this may indicate the relay UE A.

[0308] - Destination layer-2 ID: This may indicate one or more target layer-2 identifiers associated with one or more UEs, to which the sidelink message 4B is sent. For example, this may indicate the relay UE B.

[0309] - RSC: This may identify a connectivity service the relay UE A requests from the relay UE B, and / or may indicate that the relay UE A requests a connection with the relay UE B, to provide / use a multihop relaying service. For example, this may indicate RSC IB.

[0310] - Discoverer Info: This may provide information (i.e., User Info ID) about discoverer user.

[0311] - Target Info: This may provide provides information (i.e., User Info ID) about targeted discoveree user.

[0312] - Support indicator of multihop: This may indicate that the transmitter (e.g., the relay UE A) supports multihop relaying, that the transmitter supports connection to another relay UE, that the transmitter supports multihop relaying service, that the transmitter supports performing as a downstream relay UE, that the transmitter supports performing as an upstream relay UE, that the transmitter is authorized for multihop relaying, and / or the like.

[0313] In an example, the relay UE A may receive a sidelink message 4C (not shown in the figure) from the relay UE B. For example, the sidelink message 4C may indicate at least one of that establishment of sidelink connection is successful between the relay UE A and the relay UE B, that the relay UE A is allowed for multihop relaying, that the relay UE A is allowed as downstream relay to the relay UE B, that the multihop relaying service associated with the RSC1B is allowed to the relay UE A, that the relay UE B provides a multihop relaying service to the relay UE A, and / or the like. In an example, the relay UE B may receive from the network, an information indicating whether the relay UE A can connects to the relay UE B as the downstream relay and / or an information indicating whether the relay UE A is allowed for multihop relaying. If the information indicates that the relay UE A is allowed, the relay UE B may send the sidelink message 4C, which indicates that the relay UE A is allowed for multihop relaying.

[0314] In an example, the relay UE A may send a sidelink message 5B to one or more remote UEs (e.g., remote UE C). For example, based on that the relay UE A establishes the sidelink connection to the upstream relay (e.g., relay UE B), based on that the relay UE A receives an indication of allowing multihop relaying from the relay UE B, based on that the relay UE A receives an indication that the RSC IB (configured for multihop operation) is allowed / established with the relay UE B, based on that the relay UE A receives an allowance of the relay UE A as the downstream relay, and / or based on that the relay UE A is out of coverage, the relay UE A may determine that the relay UE A can act as a downstream relay, the relay UE A can perform as a multihop relay UE, and / or the relay UE A may send the sidelink message 5B. For example, the sidelink message 5B may be a PC5 message 5B. The sidelink message 5B may be at least one of Announce message, ProSe Additional Parameters Announcement Response message, ProSe PC5 Discovery message, ProSe Direct Link Establishment, Response message, ProSe Direct Link Modification message, and / or the like. The sidelink message 5B may comprise at least one of:

[0315] - Source layer-2 ID: This may indicate source layer-2 identifier of the transmitting UE. For example, this may indicate the relay UE A.

[0316] - Destination layer-2 ID: This may indicate target layer-2 identifier associated with one or more UEs, to which the sidelink message 5BB is sent. For example, this may indicate one ormore remote UEs (end UEs) and / or one or more downstream relay UEs.

[0317] - RSC: This may identify the connectivity service the relay UE A provides, and / or indicate that the relay UE A provides a multihop relaying from the relay UE A. For example, this may indicate RSC IB.

[0318] - Discoverer Info: This may provide information (i.e., User Info ID) about discoverer user.

[0319] - Target Info: This may provide provides information (i.e., User Info ID) about targeted discoveree user.

[0320] - Support indicator of multihop: This may indicate at least one of that the transmitter (e.g., the relay UE A) supports multihop relaying, that the transmitter supports connection to another relay UE, that the transmitter supports multihop relaying service (e.g., U2N relay service, U2U relay service), that multihop relaying is used by the transmitter, that the connectivity service associated with the RSC (e.g., RSC IB) is provided via multihop relaying, that the transmitter is a downstream relay UE, that the transmitter is an interim relay UE, that the transmitter is connected to an upstream relay UE and / or the like.

[0321] In an example, the relay UE A (case 1) may move into a first coverage of a first cell (of a first basestation, of a first network). Because direct connection to the first cell (the first network) is available, and / or because the relay UE A is allowed (authorized) for (singlehop) relaying for other remote UEs, the relay UE A may determine to provide a relaying service (e.g., UE-to- Network relay service), the relay UE A may determine to act as a singlehop relay UE and / or the relay UE A may determine to act as a (topmost) edge relay UE. For example, the relay UE A may determine to provide (singlehop) relaying service associated with the RSC 1 A, and / or the relay UE A may determine not to provide (multihop) relaying service associated with the RSC IB. For example, the relay UE A may send a sidelink message 5A. For example, the sidelink message 5A may be a PC5 message 5A. The sidelink message 5A may be at least one of Announce message, ProSe Additional Parameters Announcement Response message, ProSe PC5 Discovery message, ProSe Direct Link Establishment, Response message, ProSe Direct Link Modification message, and / or the like. The sidelink message 5A may comprise at least one of:

[0322] - Source layer-2 ID: This may indicate source layer-2 identifier of the transmitting UE. E.g., this may indicate the relay UE A.

[0323] - Destination layer-2 ID: This may indicate target layer-2 identifier associated with one or more UEs, to which the sidelink message 5A is sent.

[0324] - RSC: This may identify a connectivity service the relay UE A provides to one or more remote UEs and / or one or more relay UEs. This may identify authorized users of the relay UE A. For example, this may indicate RSC 1 A. For example, this may indicate that a singlehop relayservice is provided.

[0325] - Discoverer Info: This may provide information (i.e. User Info ID) about discoverer user.

[0326] - Target Info: This may provide provides information (i.e. User Info ID) about targeted discoveree user.

[0327] - List of User Info ID: This may provide information about one or more end UEs, one or more remote UEs, one or more relay UEs.

[0328] - Indication of single hop relaying: This may indicate whether multihop relaying is used (or supported) by the transmitter, whether the transmitting UE is a topmost edge relay UE, whether the transmitting UE is an interim relay UE, whether the transmitting UE is directly connected to a network, whether the transmitting UE is inside a coverage, and / or whether singlehop relaying is used (or supported) by the transmitter. For example, this may indicate that singlehop relaying is used and / or that multihop relaying is not used.

[0329] In an example, the remote UE C may receive the sidelink message 5B (case 2). Based on the third prose policy information, the remote UE C may determine which relay UE to use, and / or whether to use multihop relaying service or not. For example, if the third prose policy information indicates that the remote UE C is allowed to use multihop relaying service, if the third prose policy information comprises the RSC IB, if the relay UE A indicates supports of multihop relaying and / or if the relay UE A sends the sidelink message 5B, the remote UE A may select the relay UE A, and / or send a first request message (for establishment of sidelink connection) to the relay A. The first request message may indicate (e.g., comprise) the RSC IB, may comprise an indicator indicating that the remote UE C requests a multihop relaying service, and / or may indicate (e.g., comprise an indicator indicating) that the remote UE C supports the multihop relaying.

[0330] In an example, the remote UE C may receive the sidelink message 5A (case 1). Based on the third prose policy information, the remote UE C may determine which relay UE to use, and / or whether to use multihop relaying service or not. For example, if the third prose policy information indicates that the remote UE C is not allowed to use multihop relaying service, if the third prose policy information does not comprise the RSC IB, if the third prose policy information comprises the RSC 1 A, if the relay UE A does not indicate support of multihop relaying and / or if the relay UE A sends the sidelink message 5A, the remote UE A may select the relay UE A, and may send a second request message (for establishment of sidelink connection) to the relay A. The second request message may comprise the RSC 1 A, may not comprise an indicator requesting multihop relaying service, and / or may indicate that the remote UE C does not support the multihop relaying.

[0331] The example of FIG. 18 may assist a UE when to use a multihop relaying service.

[0332] FIG. 19 depicts one example embodiment of the present disclosure. Similar to FIG. 18, the relay UE A may indicate support for multihop relaying. Reverting to FIG. 19, in an example, the relay UE A may receive an indication that the relay UE A is not allowed to perform multihop relaying. This may help a UE to determine which relay to select. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0333] In an example, the relay UE A may send the first NAS message to the AMF.

[0334] In an example, the PCF may send a fourth prose policy information for the relay UE A, to the AMF. The fourth prose policy information may be similar to the first prose policy information, except that the fourth prose policy information may not comprise information of the RSC IB, and / or except that the fourth prose policy information may indicate that the relay UE A is not allowed for the multihop relaying. In response to receiving the fourth prose policy information from the PCF, the AMF may send a third NAS message to the UE. The third NAS message may be similar to the second NAS message, except that the third NAS message may comprise the fourth prose policy information. For example, the fourth prose policy information may indicate RSC 1 for a relay service allowed for the relay UE A.

[0335] In an example, the relay UE A may receive the third NAS message. Because the third NAS message comprises the fourth prose policy information, because the third NAS message does not comprise one or more RSCs allowed for multihop relaying, because the third NAS message indicates that the relay UE A is not allowed to provide a multihop relaying service for RSC 1, and / or because the third NAS message comprises the fourth multihop provisioning information not indicating allowance of using multihop relaying (e.g., not comprising an indicator allowing the multihop relaying), the relay UE A may determine that the relay UE A is not authorized for providing multihop relaying to other UEs.

[0336] In an example, the relay UE B may be in the second coverage of the second cell. The relay UE B may receive the second prose policy information. For example, the second prose policy information may comprise an indication that the relay UE B is allowed to provide multihop relay service for the RSC 1. For example, the relay UE B may determine to provide multihop relaying service associated with the RSC 1. For example, the relay UE B may send the sidelink message 4A. The sidelink message 4A may comprise an indicator that the relay UE B provides multihop relay service for RSC 1.

[0337] In an example, the relay UE A (case 2) may move out of the coverage of the network. For example, because the relay UE A is not able to find a cell to camp on, because direct connection to the cell (the network) is not available, because the relay UE A is not allowed (authorized) for multihop relaying (e.g., not allowed to connect to other relay UEs to provide connectivity service to other remote UEs), because the relay UE (e.g., the relay UE B) in the coverage isavailable, because the relay UE A receives the sidelink message 4 A indicating the RSC 1, because the relay UE A is not authorized (received authorization) for multihop relaying, because the relay UE A is authorized for singlehop relaying for the RSC 1, the relay UE A may determine to establish a sidelink connection with the relay UE (e.g., relay UE B) as a remote UE and / or the relay UE A may determine to establish a singlehop relaying connection toward the relay UE. For example, the relay UE A may determine not to provide a relay service (e.g., for RSC 1) for other remote UE, the relay UE A may use the relay UE B to transport the relay UE A’s own traffic, and / or the relay UE A may determine not to relay other remote UE’s traffic toward the relay UE B, and / or the like. For example, the relay UE A may send a sidelink message 4B1 to relay UE B. The sidelink message 4B1 may be similar to the sidelink message 4B, except that the sidelink message 4B 1 may not indicate that the relay UE A is capable of the multihop relaying, except that the sidelink message 4B1 may not indicate that the relay UE A is requesting the multihop relaying service. For example, the sidelink message 4B1 may indicate the RSC 1.

[0338] In an example, the relay UE A may receive a sidelink message 4C1 from the relay UE B. For example, the sidelink message 4C1 may be similar to the sidelink message 4C, with small difference. For example, the sidelink message 4C1 may indicate that the relay UE A is not allowed to act as a relay, that the relay UE A is not allowed for providing the multihop relaying service, that the relay UE A is not allowed as a downstream relay to the relay UE B, that the relay UE A needs to act as a remote UE, and / or the like.

[0339] In an example, the relay UE A may send a sidelink message 5B1 to one or more remote UEs (e.g., remote UE C). For example, based on that the relay UE A establishes a sidelink connection to the relay (e.g., relay UE B) UE as a remote UE, based on that the relay UE A does not receive an indication of allowing multihop relaying, based on that the relay UE A is not allowed for multihop relaying, and / or based on that the relay UE A is out of coverage, the relay UE A may send the sidelink message 5B1, and / or the sidelink message 5B1 may not indicate (e.g., may not comprise an indication) that the relay UE A supports (or provides) a (multihop) relaying service. Alternatively, the relay UE A may not send the sidelink message 5B and / or the relay UE A may not send the sidelink message 5B. For example, because the relay UE A does not act as a relay UE, the relay UE A may be a remote UE.

[0340] In an example, the relay UE A (case 1) may move into the first coverage of the first cell (of a first basestation, of a first network). Because direct connection to the first cell (the first network) is available, and / or because the relay UE A is allowed (authorized) for (singlehop) relaying for other remote UEs, the relay UE A may determine to provide relaying service (e.g., UE-to-Network relay service). For example, the relay UE A may determine to provide(singlehop) relaying service associated with the RSC 1. For example, the relay UE A may send a sidelink message 5 Al. For example, the sidelink message 5 Al may be similar to the sidelink message 5 A. For example, the sidelink message 5 A may comprise the RSC 1, based on the fourth prose policy information.

[0341] FIG. 20 depicts one example embodiment of the present disclosure. For example, the relay UE A may receive one or more announcements (e.g., announcement messages, e.g., discovery messages for announcement) from one or more neighboring relay UEs. Based on information of the one or more announcements, the relay UE A may determine an upstream relay UE. The upstream relay UE may indicate the relay UE A to the base station. This may reduce unnecessary attempt of a sidelink connection establishment. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0342] In an example, the relay UE A may receive the first prose policy information and / or the first prose policy information may indicate that the relay UE A is allowed for providing multihop relaying service for RSC 1. In an example, the relay UE B may receive the second prose policy information and / or the second prose policy information may indicate that the relay UE B is allowed for providing multihop relaying service for RSC 1. In an example, a relay UE F may receive a fifth prose policy information. In an example, a relay UE D may receive a sixth prose policy information. For example, the fifth prose policy information may use similar structure as the first prose policy information, and / or the fifth prose policy information may indicate that the relay UE F is not allowed for multihop relaying and / or that the relay UE F is allowed to provide a (singlehop) relay service associated with RSC 1. For example, the sixth prose policy information may use similar structure as the first prose policy information, and / or the sixth prose policy information may indicate that the relay UE D is not allowed for multihop relaying and / or that the relay UE D is allowed to provide a (singlehop) relay service associated with RSC 1.

[0343] In an example, the relay UE F may transmit a sidelink message 4A2. For example, the sidelink message 4A2 may have a similar structure (and / or purpose of contents) as the sidelink message 4A, and / or may have information relevant for the relay UE F. For example, based on that the fifth prose policy information indicates that the relay UE F is not allowed for multihop relaying, the sidelink message 4A2 may not indicate (e.g., may not comprise an information indicating) that the relay UE F provides the multihop relaying service for the RSC 1, that the relay UE F provides a (singlehop) relaying service for the RSC 1 for a remote UE, and / or that the relay UE F may not provide a relaying service for the RSC 1 for a downstream relay UE.

[0344] In an example, the relay UE B may transmit a sidelink message 4A3. the sidelink message 4A3 may have similar contents as the sidelink message 4A. For example, based on that the second prose policy information indicates that the relay UE B is allowed for multihoprelaying, because an upstream relay to which the relay UE B is connected supports multihop relaying, and / or because the direct connection to the cell is available to the relay UE B, the sidelink message 4A3 may indicate that the relay UE B provides multihop relaying service for the RSC 1, may indicate that the relay UE B supports multihop relaying, may indicate that the relay UE B may provide a relaying service for the RSC 1 for a remote UE, and / or that the relay UE B may provide a relaying service for the RSC 1 for a downstream relay UE.

[0345] In an example, the relay UE D may transmit a sidelink message 4A4. The sidelink message 4A4 may have a similar structure as the sidelink message 4 A. For example, based on that the sixth prose policy information indicates that the relay UE D is not allowed for multihop relaying, and / or because the relay UE D does not have a direct connection to a cell (e.g., out of coverage), the sidelink message 4A4 may not indicate that the relay UE D provides multihop relaying service for the RSC 1, may not indicate that the relay UE D provides a relaying service for the RSC 1, and / or the like.

[0346] In an example, the relay UE A may select an upstream relay UE. For example, based on that the relay UE A is authorized for multihop relaying, based on that the relay UE A is outside of a coverage of a cell, based on that the relay UE A is authorized for RSC 1, based on that the upstream relay UE that provides connection a network (a cell, a basestation) is available, and / or based on that relay UE B indicates that the relay UE B supports multihop relaying for RSC 1, the relay UE A may select the relay UE B. For example, the relay UE B may provide to the relay UE A, a connectivity to the cell (a network, a basestation), and / or the relay UE B may be able to act as the upstream relay UE of the relay UE A.

[0347] In an example, based on selecting the relay UE B, the relay UE A may send a sidelink message 4B1. For example, the sidelink message 4B1 may be similar to the sidelink message 4B. For example, the sidelink message 4B1 may indicate (e.g., comprise an indicator / information indicating) that the relay UE A requests a multihop relaying service, that the relay UE A requests the relay UE B to act as an upstream relay UE, that the relay UE A supports the multihop relaying capability, that the relay UE A can act as a downstream relay UE for the RSC 1, that a multihop relaying service is requested, that the RSC 1 is requested, that the relay UE A is out of coverage of the network, and / or the like.

[0348] In an example, after receiving the sidelink message 4B1, the relay UE B may send a RRC message to the basestation. For example, the basestation may have a RRC connection with the relay UE B. For example, the relay UE B may be a topmost edge relay UE (e.g., a relay UE which has a direct connection to the basestation, among the chain of relay UEs associated with the relay UE A). For example, the RRC message may be at least one of UE information message, RRC setup request message, RRC setup complete message, RRC reconfiguration message, RRCconfiguration message, UL RRC transfer message, and / or the like. For example, the RRC message may comprise at least one of an identifier of the relay UE B, an identifier of the relay UE A, an indication indicating that the relay UE B supports the multihop relaying capability, an indication indicating that the relay UE A supports the multihop relaying capability, an indication indicating that the relay UE A is a downstream relay UE of the relay UE B, an indication indicating that the relay UE A is requesting a multihop relaying service, and / or the like. For example, based on the RRC message, the basestation may update configuration of the relay UE B. For example, based on the RRC message, the basestation may send a response (e.g., a RRC message) to the relay UE B. For example, the response to the relay UE B may indicate that the relay UE A is allowed to perform (connect) as the downstream relay UE, that the relay UE A is allowed for multihop relaying operation, and / or that the connection of the relay UE A to the relay UE B is allowed.

[0349] In an example, the relay UE B may receive the response from the basestation. Based on the response, because the response allows the relay UE A, the relay UE B may send a sidelink response (e.g., the sidelink message 4C) to the relay UE A. For example, the sidelink response may indicate that the relay UE A is allowed to act as a downstream relay UE, that the relay UE A is allowed for multihop relaying, that the connection between the relay UE A and the relay UE B is allowed and / or the like.

[0350] In an example, based on the sidelink response, the relay UE A may transmit the sidelink message 5B5. For example, the sidelink message 5B5 may indicate that the relay UE A provides a relaying service for the RSC 1. For example, because the sidelink response indicates that the relay UE A is allowed for providing a (multihop) relaying service, the relay UE A may send the sidelink message 5B5 and / or the sidelink message 5B5 may indicate a relaying service for the RSC 1. For example, the sidelink message 5B5 may indicate a relay type. For example, the relay type may be at least one of a layer-3 (normal, singlehop) U2N relay, a layer-3 (advanced, multihop) U2N relay, a multihop relay, a singlehop relay, a layer-2 (normal, singlehop) U2N relay, a layer-2 (advanced, multihop) U2N relay, and / or the like. For example, the relay type may indicate to a receiver, a type of the relay UE A, and / or a type of provided relaying service.

[0351] FIG. 21 depicts one example embodiment of the present disclosure. For example, as a remote UE C moves, available relay UEs for the remote UE C may change. Based on prose policy information, the remote UE C may select a relay for service continuity. This may reduce service interruption time for the remote UE C. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0352] In an example, the remote UE C may receive the third prose policy information. For example, the third prose policy information may indicate that the RSC 1 A is for a singlehoprelaying service, the RSC IB is for a multihop relaying service, that the RSC1 A is mapped to the RSC IB, that the RSC IB is mapped to the RSC1A, and / or that the RSC 1 A and the RSC IB are associated with a same service (e.g., a network slice, a data network, an application, a user group, and / or the like). Similar information may be delivered to the relay UE F, the relay UE A and / or the relay UE B.

[0353] In an example, the remote UE C may be out of coverage and / or may search for a relay UE. For example, based on that the remote UE C is out of coverage, based on that the remote UE C is allowed for the RSC IB, based on that the remote UE C is allowed for using a multihop relay UE, based on that the sidelink message 5B received from the relay UE A indicates the RSC IB and / or based on that the relay UE A indicates supports of multihop relaying, the remote UE C may select the relay UE A. For example, based on selecting the relay UE A, the remote UE C may establish a sidelink connection with the relay UE A and / or may use multihop relaying via the relay UE A, and / or may use a service of the RSC IB via the relay UE A.

[0354] In an example, the remote UE C may move from an area covered by the relay UE A to an area covered by the relay UE F. For example, the relay UE F may be in a coverage area of a cell. For example, the relay UE F may send a sidelink message 4A5. For example, the sidelink message 4A5 may indicate that the relay UE F may provide relaying service and / or that the relay UE F may supports the RSC 1 A.

[0355] In an example, the remote UE C may receive the sidelink message 4A5. Because the remote UE C is allowed to use a service associated with the RSC 1 A, and / or based on signal strength of the relay UE F being better than that of the relay UE A, the remote UE C may select (or switch to) the relay UE F. Based on selecting the relay UE F, the remote UE C may establish a sidelink connection with the relay UE F, for the RSC 1 A. For example, based on the third prose policy information, the remote UE A may determine that the RSC IB is mapped to the RSC 1 A, the remote UE may determine that a traffic communicated via the RSC IB can be delivered via the RSC 1 A, and / or the remote UE C may switch from using the RSC IB for the service to the RSC 1 A for the service. For example, based on switching, the remote UE C may stop using multihop relaying of the RSC IB, and / or may start using singlehop relaying of the RSC 1 A. For example, based on the mapping between a first RSC for a singlehop relaying and a second RSC for a multihop relaying, the remote UE C may determine which RSCs are compatible (e.g., may be used for a same service), may determine a traffic of which service can be delivered either via the first RSC or via the second RSC, and / or may determine whether a relay UE for service continuity is available or not. For example, a remote UE may receive a traffic from upper layer. Based on the traffic and / or based on the third prose policy information, the UE may determine the first RSC which can be used when singlehop relay is available and / or the second RSC whichcan be used when multihop relay is available. Based on availability of nearby relay UEs and / or one or more RSCs supported by the nearby relay UEs, the remote UE may establish connection to either a first relay UE providing the first RSC or a second relay UE providing the second RSC. For example, after establishing a connection to the first relay UE for the first RSC, and if the first relay UE is not available and / or if the second relay UE is available, the remote UE may use the relaying services of the second relay UE for the second RSC instead of the first relay UE for the first RSC. By providing the mapping information between a RSC for a singlehop relaying and a RSC for a multihop relaying, a service interruption can be minimized.

[0356] FIG. 22 depicts one example embodiment of the present disclosure. For example, as a relay UE A moves, the relay UE A may move into a coverage of a cell and / or may move out of the coverage of the cell. If a remote UE connected to the relay UE A, the relay UE A may perform sidelink modification procedure to support service continuity. This may reduce service interruption time for the remote UE C. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0357] In an example, the remote UE C may receive the third prose policy information. For example, the third prose policy information may indicate that the RSC 1 A is for a singlehop relaying service, the RSC IB is for a multihop relaying service, that the RSC1 A is mapped to the RSC IB, that the RSC IB is mapped to the RSC1A, and / or that the RSC 1 A and the RSC IB are associated with a same service. Similar information may be delivered to the relay UE A and / or the relay UE B.

[0358] In an example, the relay UE A may be connected to the relay UE B. For example, the relay UE A may be out of the coverage and / or the relay UE B may be in coverage of the cell. Because the relay UE B supports / provides multihop relaying and / or because the relay UE A supports / provides multihop relaying, the relay UE A may establish a sidelink connection to the relay UE B and / or the relay UE A may provide a relaying service to the remote UE C via the relay UE B. The remote UE C may establish a sidelink connection to the relay UE A for multihop relaying service. For example, for the sidelink connection between the relay UE A and the remote UE C, the RSC IB may be used and / or the remote UE C and the relay UE A may exchange the RSC IB.

[0359] In an example, the relay UE A may move into a coverage of the cell. Based on the availability of the coverage, and / or based on that the relay UE A is allowed for singlehop relaying for the RSC 1 A, the relay UE A may release a connection (e.g., by sending a PC5 direct connection release message) to the relay UE B, the relay UE A may switch from multihop relaying mode to singlehop relaying mode, the relay UE A may stop acting as a downstream relay UE, the relay UE A may send to the relay UE B an indication indicating availability of adirect network connection, and / or the relay UE A may establish a RRC connection with the cell (the basestation).

[0360] In an example, based on that the RSC IB is mapped to the RSC 1 A, the relay UE A may start to provide a relaying service for the RSC 1 A, and / or may stop providing a service for the RSC IB (e.g., an announcement message transmitted by the relay UE A may not further comprise the RSC IB and / or may comprise the RSC 1 A). For example, based on availability of direction connection to the cell, the relay UE A may send a sidelink (direct) connection modification message to the remote UE C. For example, the sidelink connection modification message may indicate that the RSC IB is not used anymore, that the RSC 1 A is available, that a service via the RSC IB is mapped to the RSC 1 A, that an associated RSC for a PC5 QoS flow changed from the RSC IB to RSC 1 A and / or that the RSC IB is switched to the RSC 1 A.

[0361] In an example, the remote UE C may receive from the relay UE A, the sidelink connection modification message. For example, based on the sidelink connection modification message, and / or based on that the RSC IB is switched to the RSC 1 A, the remote UE C may update sidelink configuration and / or may start to send a traffic of a service (which was transported via the RSC IB) via the relaying service associated with the RSC 1 A.

[0362] FIG. 23 depicts one example embodiment of the present disclosure. For example, one or more relay UEs may provide a service for a RSC, and each of the one or more relay UEs may indicate (e.g., send a message comprising an indicator / information indicating) whether the each of the one or more relay UEs provides the service using a multihop relaying or not. This may assist a remote UE to configure radio parameters. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0363] In an example, the remote UE C may receive a seventh prose policy information. For example, the seventh prose policy information may indicate that the RSC 1 (e.g., a service associated with the RSC 1) is allowed for the remote UE C. For example, the delivery of the seventh prose information to the remote UE C may use a similar mechanism as used for the delivery of the third prose policy information. For example, the seventh prose policy information may indicate whether the remote UE C is allowed to use multihop relaying service offered by other relay UEs. For example, the seventh prose policy information may indicate that the remote UE C is allowed to use the RSC 1 for multihop relaying service (e.g., via one or more relay UEs providing the multihop relaying service).

[0364] In an example, the relay UE A may be connected to the relay UE B. For example, the relay UE A and the relay UE B may provide multihop relaying service. For example, based on that the relay UE A is connected to the network via other relay UEs (e.g., relay UE B), based on that the relay UE A is allowed for using multihop relaying functionality for the RSC 1, and / orbased on that the relay UE A is allowed for the RSC 1, the relay UE A may transmit the sidelink message 5B5. For example, the sidelink message 5B5 may indicate (e.g., comprise, comprise an indicator indicating) the RSC 1, that the relay UE A provides a multihop relaying service, that the relay UE A provides a relaying service for the RSC 1, that multihop relaying is provided for the RSC 1, that the relay UE A is connected to the network via one or more upstream relay UEs, and / or the like.

[0365] In an example, the remote UE C may be out of coverage and / or may search for a relay UE. For example, based on that the remote UE C is out of coverage, based on that the remote UE C is allowed for the RSC 1, based on that the remote UE C is allowed for using one or more multihop relay UEs, based on that the remote UE C is allowed to use multihop relaying service, based on that the sidelink message 5B5 received from the relay UE A indicates the RSC 1 and / or based on that the relay UE A indicates supports of multihop relaying, the remote UE C may select the relay UE A. For example, based on selecting the relay UE A, the remote UE C may establish a sidelink connection with the relay UE A, may use multihop relaying via the relay UE A, may use a configuration parameter of multihop relaying, may activate multihop relaying functionality, and / or may use a service of the RSC 1 via the relay UE A.

[0366] In an example, the remote UE C may move from the area covered by the relay UE A to an area covered by the relay UE F. For example, the relay UE F may be in a coverage area of a cell. For example, the relay UE F may send the sidelink message 4A5. For example, the sidelink message 4A5 may indicate (e.g., comprise an indicator indicating) that the relay UE F may provide relaying service and / or may not indicate that multihop relaying is used by the relay UE F, and / or may not indicate that multihop relaying is supported by the relay UE F, and / or may indicate the RSC 1. For example, the sidelink message 4A5 may not comprise an indicator indicating that the multihop relaying is supported by the relay UE F and / or the sidelink message 4A5 may comprise an indicator indicating that the multihop relaying is not supported.

[0367] In an example, the remote UE C may receive the sidelink message 4A5. Because the remote UE C is allowed for the RSC 1, because the remote UE C uses a service associated with the RSC 1 via the relay UE A, because the relay UE F provides a service of the RSC 1, and / or based on signal strength of the relay UE F being better than the relay UE A, the remote UE C may select the relay UE F to continue to use a service of the RSC 1. Based on selecting the relay UE F, the remote UE C may establish a sidelink connection with the relay UE F, for the RSC 1. For example, based on the seventh prose policy information that indicates the RSC 1 is allowed for the remote UE C, the remote UE C may select or reselect the relay UE F. Because the sidelink message 4A5 does not indicate multihop relaying, the remote UE C may switch off the multihop relaying functionality and / or may use the relay UE F as a singlehop relaying for theRSC 1. This may reduce the time that the remote UE C stays out of the service.

[0368] FIG. 24 depicts one example embodiment of the present disclosure. For example, a UE may send a capability information regarding multihop relaying and a network node (e.g., a first (e.g., source) AMF, a first (e.g., source) basestation) may deliver authorization information of the multihop relaying and / or the capability information to other network node (e.g., a second (e.g., target) AMF, a second (e.g., target) basestation). This may reduce signalling load and may assist the other network node to determine whether to provide multihop relaying service. For brevity, based on the other part of the present disclosure, redundant details will be omitted.

[0369] In an example, a relay UE B may establish a first RRC connection with a first base station. For example, the relay UE B may send a RRC message 1 A to the first base station. For example, to establish the first RRC connection, the RRC message 1 A may be at least one of an uplink (RRC) transfer message, a RRC setup request, a RRC resume request, a RRC connection setup complete message, a RRC resume complete message, a RRC reconfiguration complete message, a UE information message, and / or the like. For example, in response to receiving the RRC message 1 A, the first base station may send a RRC message IB to the relay UE B, to setup the first RRC connection.

[0370] In an example, the relay UE B may send a NAS message 1 A to an AMF via the first base station over the first RRC connection. For example, the NAS message 1 A may be at least one of Registration Request message, Service Request Message, UL NAS Transfer message and / or the like. For example, the NAS message 1 A may comprise a second multihop capability information. The second multihop capability information may indicate (e.g., comprise one or more indicators indicating):

[0371] - a first capability indicating whether a UE (e.g., the relay UE B) supports multihop relaying. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay of the multihop relaying.

[0372] - a second capability indicating whether the UE supports multihop relaying for other UEs. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay of the multihop relaying for other UEs.

[0373] - a third capability indicating whether the UE supports using a relaying service via multihop relaying (e.g., as a remote UE). This may further indicate whether the UE supports as a layer-2 remote UE and / or layer-3 remote UE, of the multihop relaying.

[0374] - a fourth capability indicating whether the UE supports multihop relaying, as an upstream relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0375] - a fifth capability indicating whether the UE supports multihop relaying, as adownstream relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay, of the downstream relay UE.

[0376] - a sixth capability indicating whether the UE supports multihop relaying, as an edge relay UE. This may further indicate whether the UE can function as a top edge relay UE and / or a bottom edge relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay, of the top edge relay UE and / or the bottom edge relay UE.

[0377] - a seventh capability indicating whether the UE supports multihop relaying, as an interim relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay of the interim relay UE.

[0378] - one or more capability indicators indicating at least one of,

[0379] For example, the first basestation may deliver the NAS message 1 A to the AMF, via using a first NG interface message (e.g., step 2A). For example, the NG interface message may be an initial UE message.

[0380] In an example, the AMF may receive the NAS message 1 A. The AMF may check with the PCF, and the UDM. For example, the AMF may receive from PCF, a second multihop authorization information. For example, the second multihop authorization information may be similar information as the second prose policy information (using similar delivery mechanism as shown in the example of FIG. 18). For example, the AMF may receive from the UDM, the subscription data of the relay UE B. In other example, the AMF may send a first Nucmf message to a UCMF (UE radio Capability Management Function). For example, the first Nucmf message may be a Nucmf_provisioning create message and / or the like. For example, the first Nucmf message may comprise the second multihop capability information and / or the identifier of the UE (e.g., the relay UE B). For example, the UCMF may store the identifier of the UE and / or the second multihop capability information. This may help the AMF when the relay UE B does not send the second multihop capability information. For example, when the NAS message 1 A does not comprise the second multihop capability information, the AMF may retrieve (e.g., via sending / receiving Nucmf_UEcapabilityManagement message to / from the UCMF) the second multihop capability information from the UCMF.

[0381] In an example, the AMF may send a second NG message to the first basestation. For example, the second NG message may be at least one of Initial UE context setup message, UE configuration message, DL transfer message, Path switch acknowledgement message, and / or the like. For example, the second NG message (e.g., step 2B) may comprise at least one of the second multihop authorization information, the second multihop capability information, and / or the like. For example, the second multihop authorization information may indicate (e.g., comprise one or more indicators indicating) at least one of:

[0382] - a first authorization information indicating whether a UE (e.g., the relay UE B) is allowed to provide / use multihop relaying service (functionality). This may further indicate whether the UE is allowed / authorized as a layer-2 relay and / or layer-3 relay.

[0383] - a second authorization information indicating whether the UE is allowed to provide multihop relaying service for other UEs (e.g., remote UE, end UE, downstream UE). This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0384] - a third authorization information indicating whether the UE is allowed for using relaying service via multihop relaying (e.g., as a remote UE, as a end UE, as a downstream UE). This may further indicate whether the UE supports as a layer-2 remote UE and / or layer-3 remote UE.

[0385] - a fourth authorization information indicating whether the UE is allowed for providing multihop relaying, as an upstream relay UE, to a downstream UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0386] - a fifth authorization information indicating whether the UE is allowed for multihop relaying, as a downstream relay UE and / ow whether the UE is allowed to connect to an upstream relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0387] - a sixth authorization information indicating whether the UE is allowed for multihop relaying, as an edge relay UE. This may further indicate whether the UE can function as a top edge relay UE and / or a bottom edge relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0388] - a seventh authorization information indicating whether the UE is allowed for multihop relaying, as an interim relay UE. This may further indicate whether the UE supports as a layer-2 relay and / or layer-3 relay.

[0389] In an example, the first basestation may receive the second NG message. Based on the information received by the second NG message, the first basestation may configure the relay UE B. For example, if the second multihop authorization information indicates that the relay UE B is allowed for multihop operation, the first basestation may send a third RRC message (e.g., configuration update) to the relay UE B. For example, the third RRC message may indicate (e.g., comprise information of) at least one of one or more sidelink resources for multihop relaying operation, an indicator indicating that the relay UE B is allowed for multihop relaying operation, and / or one or more information elements based on (e.g., of) the second multihop authorization information. For example, if the second multihop capability information indicates that the relay UE B supports the multihop relaying operation, the first basestation may send the third RRC message. For example, the third RRC message may indicate at least one of one or more sidelinkresources for multihop relaying operation, an indication indicating that the relay UE B is allowed for multihop relaying operation, and / or one or more information elements based on the second multihop capability information. For example, the third RRC message may indicate whether the relay UE B can act as at least one of an edge multihop relay UE, an interim multihop relay UE, an multihop remote UE, an multihop relaying end UE, and / or the like. For example, if the second NG message does not comprise information indicating that the relay UE B supports the capability of multihop relaying operation, the third RRC message may not comprise configuration information of multihop operation.

[0390] For example, the relay UE B may receive the third RRC message. Because the third RRC message indicates that the relay UE B is allowed for multihop relaying operation, the relay UE B may send the sidelink message 5B5. For example, the sidelink message 5B5 may indicate that the relay UE B provides the multihop relaying service.

[0391] In an example, the first base station may determine to handover the relay UE B from the first base station to a second basestation. For example, the first basestation may send to the second basestation, a handover request message over Xn interface. For example, the handover request message may comprise at least one of an identifier of a target cell of the second base station, an identifier of the relay UE B (e.g., C-RNTI, Xn UE ID, and / or the like), the second multihop authorization information, and / or the second multihop capability information.

[0392] In an example, the second base station may receive the handover request. In response to receiving the handover request, and / or based on whether the second basestation supports multihop relaying, the second basestation may send a handover response to the first basestation. For example, the handover response may comprise a RRC message container. For example, the RRC message container may indicate whether the relay UE B is allowed for multihop relaying operation after handover to the second basestation. For example, if the second basestation supports multihop relaying operation, if the second multihop authorization information indicates that the relay UE B is allowed for multihop relaying, if the second multihop capability information indicates that the relay UE B supports the capability of multihop relaying, and / or if the second basestation allows the relay UE B to use multihop relaying operation, the second basestation may determine to allow the relay UE B to act as a multihop relay. For example, based on the determination, the RRC message container may comprise information of multihop relaying operation. For example, the RRC message container may be a RRC reconfiguration message.

[0393] In an example, based on receiving the handover response, the first basestation may send the RRC message container to the relay UE B. For example, if the RRC message container does not indicate that the relay UE B is allowed for multihop operation, after handover (e.g., afteraccessing the second base station), the relay UE B may stop using the multihop operation. For example, if the RRC message container indicates that the relay UE B is allowed for multihop operation, after handover (e.g., after accessing the second base station), the relay UE B may start (or continue) using the multihop operation, e.g., continue to server a downstream UE.

[0394] In other example, if the first base station does not support multihop relaying operation, the first base station may not send the second multihop capability information and / or the second multihop authorization information to the second base station. In this case, after the handover, the second basestation may send a request to the relay UE B to send multihop capability information. In response, the relay UE B may send the second multihop capability information to the second basestation.

[0395] In an example, based on the RRC message container, the relay UE B may perform handover procedure. For example, the relay UE B may send a RRC reconfiguration complete message to indicate that the relay UB B accesses the second basestation.

[0396] In an example, in response to receiving the RRC reconfiguration complete message, the second basestation may send a path switch request message to the AMF. For example, the path Switch request message may indicate (e.g., comprise information indicating) whether the second basestation supports the multihop relaying operation, that the relay UE B is served by the second basestation, and / or the identifier of the relay UE B.

[0397] In an example, the AMF may receive the path switch request message. In response to receiving the path switch request message, the AMF may send path switch response message. For example, the path switch response message may comprise at least one of the second multihop authorization information and / or the second multihop capability information. In other example, each of the second multihop authorization information of the path switch response message may be updated / modified compared that of the second NG message. For example, based on subscription change of the relay UE B, based on change of location area of the relay UE B, and / or based on support of one or more base station for multihop relaying operation, the AMF may determine to update the contents of the second multihop authorization information (e.g., from allowed to not allowed, and / or vice versa). In other example, the relay UE B may be handed over from a basestation not supporting multihop operation to the second basestation supporting the multihop operation. In this case, sending of the path switch response message comprising the second multihop authorization information may help proper operation of the second base station.

[0398] In an example, the second base station may receive the path switch response message. Based on the path switch response message, the second base station may send a RRC message 3B. For example, the RRC message 3B may indicate whether the relay UE B is allowed formultihop relaying operation or not. For example, if the RRC message 3B does not comprise an indicator indicating that multihop operation is allowed, and / or if the RRC message 3B does not comprise a radio resource configuration for multihop operation, the relay UE B may consider that multihop operation is not allowed and / or may not send an announcement message indicating that the relay UE B provides a multihop relaying service.

[0399] In an example, the relay UE B may send the sidelink message 5B. For example, if the relay UE B is allowed for multihop operation, the relay UE B may send the sidelink message 5B indicating support of multihop relaying.

[0400] In an example, the relay UE A (or remote UE C) may establish a sidelink connection with the relay UE B. The relay UE A may send a RRC message 6 A to the second basestation via the relay UE B (and / or via one or more upstream relay UEs). For example, the RRC message 6A may indicate to the second basestation, whether the relay UE A (or remote UE C) supports multihop relaying operation, whether the relay UE A requests to perform as a multihop relay, whether the remote UE C requests to use a multihop relaying service and / or the like.

[0401] In an example, the second basestation may receive the RRC message 6 A. For example, based on an identifier of the relay UE A, the second basestation may send a request to the AMF, to request a context information of the relay UE A. For example, a similar mechanism used above for the relay UE B may be used. For example, the AMF may receive from the second (or the first) basestation, a NG message 5A indicating the relay UE A. For example, the AMF may send to the second (or the first) basestation, a NG message 5B comprising a first multihop authorization information and / or a first multihop capability information. The first multihop authorization information may use a similar structure as the second multihop authorization information, and may indicate one or more authorization information relevant for the relay UE A. The first multihop capability information may use a similar structure as the second multihop capability information, and may indicate one or more authorization information relevant for the relay UE A. In other example, the AMF may retrieve the second multihop capability information from the UCMF. This may help in reducing overhead over Uu interface.

[0402] In an example, the second (or the first) basestation may receive the NG message 5B. Based on the first multihop authorization information (e.g., indicating the relay A is allowed for multihop operation) and / or the first multihop capability information, the second (or the first) basestation may determine one or more RRC parameters for the relay UE A, and / or one or more RRC parameters of one or more downstream relay UEs of the relay UE A, and / or one or more RRC parameters of one or more upstream relay UEs of the relay UE A. Based on the determination of the one or more RRC parameters, the second basestation may send one or more RRC messages to the relay UE A, the one or more downstream relay UEs, and / or the one ormore upstream relay UEs.

[0403] In an example, a remote UE may send a connection request to the second basestation, via one or more relay UEs supporting multihop operation. In response to receiving the connection request, the second basestation may receive from the AMF, a multihop authorization information for the remote UE and / or a multihop capability information for the remote UE. The method described earlier for the relay UE A, and / or the relay UE B, may be applicable to the remote UE, in configuring the remote UE, and / or in determining configuration for the remote UE.

[0404] For example, the example of FIG. 24 may help in reducing signalling load over air interface and / or in handling heterogeneous support by different entities for multihop relaying.

[0405] FIG. 25 depicts one example embodiment of the present disclosure. For example, each UE may perform multiple roles.

[0406] In an example, a first UE (e.g., U2N relay LI) may perform as one of upstream relay UEs for a second UE (e.g., U2N relay L2) or for a third UE (e.g., U2N relay L3). The first UE may perform as an edge U2N relay UE, as a topmost edge U2N relay UE, as a topmost U2N relay UE, and / or the like.

[0407] In an example, the second UE (e.g., U2N relay L2) may perform as one of upstream relay UEs for the third UE (e.g., U2N relay L3). The second UE may perform as one of downstream relay UEs for the first UE. The second UE may perform as one of interim relay UEs between a remote UE and the topmost edge relay UE.

[0408] In an example, the third UE (e.g., U2N relay L3) may not perform as one of upstream relay UEs for other relay UEs and / or may perform as one of upstream relays for a remote UE. The third UE may perform as one of downstream relay UEs for the first UE and / or for the second UE. The third UE may perform as an edge U2N relay UE, as a bottommost edge U2N relay UE, as a bottom U2N relay UE, and / or the like.

[0409] In an example, the remote UE may use a multihop U2N relay services via one or more U2N relays (e.g., U2N relay LI, U2N relay L2, U2N relay L3).

[0410] In an example, a downstream UE may comprise a downstream relay UE and / or a remote UE. In an example, an upstream UE may comprise an upstream relay UE.

[0411] FIG. 26 depicts one example embodiment of the present disclosure. For example, a prose policy information may comprise at least one of a prose policy information for relay (e.g., used when a UE acts a role of a relay UE) and / or a prose policy information for remote UE (e.g., used when a UE acts a role of a remote UE). For example, the prose policy information for relay may comprise the first multihop policy information and / or the second policy information. For example, the prose policy information for remote may comprise the third multihop policy information.

[0412] For example, a criterion (e.g., one or more condition) may indicate one or more conditions for which the remote UE can use multihop relaying and / or for which the relay can provide multihop relaying service. The criterion may be used by a UE, to determine when the UE is allowed for multihop relaying operation.

[0413] FIG. 27 depicts one example embodiment of the present disclosure.

[0414] In an example, a UE may send a first RRC message to a basestation. For example, the first RRC message may comprise a multihop capability information. For example, the multihop capability information may comprise at least one of an access stratum multihop capability information (e.g., relevant for RRC layer, base station) indicating that the UE supports multihop relaying operation, and / or a non-access stratum multihop capability information (e.g., relevant for NAS layer, core network) indicating that the UE supports multihop relaying operation. For example, the access stratum capability information may indicate to a basestation, whether the UE supports the multihop relaying operation. For example, the non-access stratum capability information may indicate to one or more core network nodes, whether the UE supports the multihop relaying operation.

[0415] In an example, the UE may receive a second RRC message from the basestation. For example, the second RRC message may indicate (e.g., comprise an indication indicating) whether the UE is allowed for multihop relaying operation and / or one or more parameters (e.g., QoS, radio resource) for multihop relaying operation.

[0416] In an example, the UE may search for one or more cells, one or more networks to camp on.

[0417] In an example, the UE may determine whether a direct connection to a cell is available. For example, based on the cell not being available for camping on, based on the UE being allowed for using a relay UE, the UE may search for one or more candidate relay UEs. For example, the UE may find the one or more candidate relay UEs. For example, the UE may receive one or more sidelink announcement messages from the one or more candidate relay UEs. For example, based on the one or more sidelink announcement messages, the UE may determine whether there is a relay UE providing a connection to a network.

[0418] In an example, the UE may determine that the relay UE providing the connection to the network is available, based on the one or more sidelink announcement message. The UE may determine whether the relay UE supports multihop relaying. If the relay UE supports the multihop relaying and / or if the UE is authorized for multihop relaying, the UE may select the relay UE. For example, based on selecting the relay UE, may establish a sidelink connection to the relay UE, may indicate to the relay UE that the UE supports multihop relaying, may indicate to the relay UE that the UE requests multihop relaying, and / or the like. Alternatively, if the relayUE does not indicate support of multihop relaying, the UE may establish the sidelink connection with the relay UE, as a remote UE.

[0419] In an example, the UE may establish the sidelink connection to the relay UE for multihop relaying. Based on establishing the sidelink connection, the UE may send a second sidelink announcement message. For example, the second sidelink announcement message may indicate the UE provides multihop relaying service and / or that the UE provides a U2N service.

[0420] In an example, alternatively, if the UE finds the cell to camp on and / or if the cell supports relaying operation, the UE may act as a topmost edge relay UE (e.g., a topmost relay UE) and / or may stop multihop relaying operation. For example, the UE may establish a Uu connection to the cell (e.g., basestation), may provide a relaying service to a remote UE, and / or may establish a sidelink connection with one or more downstream relay UEs. The establishment of the sidelink connection with the one or more downstream relay UEs may allow provision of multihop relaying service to one or more downstream UEs.

[0421] FIG. 28 depicts one example embodiment of the present disclosure.

[0422] In an example, a basestation may receive a RRC connection request message from a UE. In response to receiving the RRC connection request message, the basestation may send to an AMF, a first NG message (e.g., an initial UE message). For example, the initial UE message may indicate the basestation supports multihop relaying operation and / or an identifier of the UE.

[0423] In an example, the basestation may receive from the AMF, a second NG message. For example, the second NG message may be at least one of initial UE context message, a path switch acknowledge message, and / or the like. For example, the second NG message may comprise at least one of a multihop authorization information and / or a multihop capability information. For example, the multihop authorization information may indicate whether the UE is allowed to provide multihop relaying service and / or whether the UE is allowed to use multihop relaying service. For example, the multihop capability information may indicate whether the UE supports the multihop relaying functionality.

[0424] In an example, based on the second NG message, the basestation may configure the UE. For example, the basestation may send a RRC configuration message to the UE. For example, the RRC configuration message may indicate one or more radio resources for multihop relaying, one or more information of relay UEs (e.g., downstream relay UEs, upstream relay UEs) involved in multihop relay operations.

[0425] In an example, the basestation may receive a measurement report from the UE and / or the basestation may determine to handover the UE to other basestation. For example, the basestation may send a handover request message to a second basestation. For example, the handover request message may comprise at least one of the multihop authorization information and / or themultihop capability information.

[0426] In an example, indication (e.g., indicate) may be achieved in various ways. For example, a first indication may be done via a first field in a first signalling (e.g., a message). Alternatively and / or additional, a second indication may be done by not including the first field in the first signalling. For example, if a first message comprises the first field, the first indication may be done (e.g., achieved, delivered from a sender to a receiver). For example, if the first field in the first message is set to a value A, a third indication may be done. For example, if the first message does not comprise the first field, the second indication may be done. In other example, a fourth indication may be done by sending a second signalling. Alternatively and / or additionally, a fifth indication may be done by not sending the second signalling (e.g., a message). For example, the sender can indicate something, by sending a message comprising an indicator (e.g., an information element) indicating the information. For example, when a first entity indicates to a second entity about first something, the first entity may send to the second entity, an indicator (e.g., an information element) indicating the first something, and / or may send to the second entity, a message comprising the indicator. In other example, when a first entity does not indicate to a second entity about second something, the first entity may not send to the second entity, a first indicator (e.g., an information element) indicating the second something, may not send to the second entity, a message comprising the first indicator, and / or may send to the second entity, a second indicator indicating that the second something does not apply.

[0427] In an example, a first wireless relay device (e.g., a relay UE A, a downstream relay UE) may send to an access and mobility management function (AMF), a first message indicating capability of multihop relaying of the first wireless relay device. The first wireless relay device may receive from the AMF, a second message. The second message may authorize the first wireless device to provide multihop relaying of a service. The second message may indicate (e.g., comprise) a relay service code (RSC) for the service. The first wireless relay device may receive from a second wireless relay device (e.g., a relay B, a upstream relay UE), a sidelink announcement message. The sidelink announcement message may comprise an indication indicating support for multihop relaying, and / or the RSC (e.g., RSC associated with multihop relaying, RSC allowed for multihop relaying). The first wireless relay device may send to the second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC.

[0428] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device,a sidelink connection request message requesting multihop relaying for the RSC.

[0429] In an example, a first wireless relay device may send to the AMF, a first request message indicating capability of multihop relaying. The first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC.

[0430] In an example, a first wireless device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may receive from a second wireless relay device, a sidelink announcement message comprising at least one of an indication indicating support for multihop relaying and the RSC. The first wireless relay device may send to the second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC.

[0431] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The multihop relaying may be a relaying of a user data from a remote wireless device to a network, via using more than one wireless relay devices. For example, the more than one wireless relay devices may comprise at least the first wireless relay device and / or the second wireless relay device.

[0432] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The second message may comprise a second RSC, wherein the second RSC is used for the service when a direction connection to a cell is available and / or when a singlehop relaying is used. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC.

[0433] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The second message may comprise a second RSC, wherein the second RSC is used for the service when a direction connection to a cell is available for the first wirelessrelay device and / or when a singlehop relaying is used. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The direction connection to the cell for a wireless device may be a connection from the wireless device (e.g., the first wireless relay device) to the cell, without using another wireless relay device between the cell and the first wireless relay device.

[0434] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send to the remote wireless device, a second sidelink announcement message indicating multihop relaying.

[0435] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send to the remote wireless device, a second sidelink announcement message indicating multihop relaying. The second sidelink announcement message may indicate that the direct connection to the cell is not available for the second wireless relay device.

[0436] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send to the remote wireless device, a second sidelink announcement message indicating multihop relaying. The second sidelink announcement message may indicate a number of hops (e.g., interfaces, links) to the cell (e.g., from the first wireless relay device, from the second wireless relay device, from the remote wireless device, and / or the like).

[0437] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send to the remote wireless device, a second sidelink announcementmessage indicating multihop relaying. The first wireless relay device may receive from the remote wireless device, a second sidelink connection message, wherein the second sidelink connection message indicates whether the remote wireless device supports multihop relaying.

[0438] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send to a fifth remote wireless device, a second sidelink announcement message indicating multihop relaying. The first wireless relay device may send to a fifth remote wireless device, a sidelink connection reject message, based on that the fifth remote wireless device does not indicate support of multihop relaying.

[0439] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The second message may further comprise one or more conditions when the first wireless relay device is authorized for multihop relaying.

[0440] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The second message may further comprise one or more conditions when the first wireless relay device is authorized for multihop relaying. The one or more conditions may indicate at least one of one or more networks, one or more frequency bands, one or more geographical areas.

[0441] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send a sidelink release request to the first wireless device, based on at least one of direct connection to a cell being available, change (addition, removal) of one or more upstream relay wireless devices.

[0442] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send a sidelink release request to the first wireless device, based on at least one of direct connection to a cell being available, change (addition, removal) of one or more upstream relay wireless devices. The first wireless relay device may send to the remote wireless device, an indication that multihop relaying is not used.

[0443] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first wireless relay device may send a sidelink release request to the first wireless device, based on at least one of direct connection to a cell being available, change (addition, removal) of one or more upstream relay wireless devices. The first wireless relay device may send to the remote wireless device, a configuration message indicating modification of PC5 QoS parameter.

[0444] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The second message may further indicate at least one of whether multihop relaying of the service via the plurality of wireless layer 2 relay devices is allowed, or whether multihop relaying of the service via the plurality of wireless layer 3 relay devices is allowed.

[0445] In an example, a first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The second message may comprise a second RSC, wherein the second RSC is used for the service when a direction connection to a cell is available for the first wireless relay device and / or when a singlehop relaying is used. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The direction connection to the cell for a wireless device may be a connection from the wireless device (e.g., the first wireless relay device) to the cell, withoutusing another wireless relay device between the cell and the first wireless relay device. The first wireless relay device may determine that the direction connection to the cell is available, if the first wireless relay device can camp on the cell or if the cell does not indicate that multihop relaying is supported.

[0446] In an example, a first wireless relay device may send to the AMF, a first request message indicating capability of multihop relaying. The first wireless relay device may receive from a network function, a second message. The second message may authorize the first wireless relay device for multihop relaying of a service. The second message may comprise an indication of a relay service code (RSC) for the service. The first wireless relay device may send to a second wireless relay device, a sidelink connection request message requesting multihop relaying for the RSC. The first request message may further comprise at least one of a first indication indicating whether multihop relaying via the plurality of wireless layer 2 relay devices is supported, a second indication indicating whether multihop relaying via the plurality of wireless layer 3 relay devices is supported, a maximum number of relay hops supported, whether topmost relay operation is supported, or whether downstream relay operation is supported.

[0447] In an example, a first basestation a network function may receive a context management message comprising an identifier of a wireless device and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service. The first basestation may send to a second basestation, a handover request message comprising the identifier and the authorization information.

[0448] In an example, a network node may receive from a basestation, a path switch request message comprising an identifier of a wireless device. The network node may send to the basestation, a response to the path switch request message, wherein the response comprises an identifier of a wireless device and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service.

[0449] In an example, a network node may receive from a first basestation, a first message comprising an identifier of a wireless device and a capability information indicating that the wireless device supports multihop relaying. The network node may send to a second basestation, a second message comprising the identifier of a wireless device and the capability information.

[0450] One or more embodiments of the present disclosure may be applicable to U2U relaying service. E.g., examples are described for providing a U2N service (e.g., a data traffic between a UE and an application server (network). The descriptions and / or examples may be applicable to a U2U service (e.g., data traffic among UEs, without traversing an application server (network)) by replacing the U2N service to the U2U service.

Claims

CLAIMS1. A method comprising: receiving, by a first wireless relay device from a network function, a second message: authorizing multihop relaying of a service; and indicating a relay service code, RSC, for the service; and sending, by the first wireless relay device to a second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

2. The method of claim 1, further comprising sending by the first wireless relay device to the network function, a first request message indicating capability of multihop relaying.

3. The method of claim 1 or 2, further comprising receiving, by the first wireless relay device from the second wireless relay device, a sidelink announcement message comprising at least one of an indication indicating support for multihop relaying and the RSC.

4. The method of any of the previous claims, wherein the multihop relaying is a relaying of a user data from a remote wireless device to a network, via using more than one wireless relay devices.

5. The method of any of the previous claims, wherein the second message further indicates a second RSC, wherein the second RSC is used for the service when the direction connection to the cell is available.

6. The method of any of the previous claims, wherein the direction connection to the cell is a connection from the first wireless relay device to the cell, without using another wireless relay device between the cell and the first wireless relay device.

7. The method of any of the previous claims, further comprising sending by the first wireless relay device to the remote wireless device, a second sidelink announcement message indicating multihop relaying.

8. The method of claim 7, wherein the second sidelink announcement message further indicates that the direct connection to the cell is not available.

9. The method of claim 7, wherein the second sidelink announcement message further indicates a number of hops to the cell.

10. The method of claim 7 or 8 or 9, further comprising receiving by the first wireless relay device from the remote wireless device, a second sidelink connection message, wherein the second sidelink connection message indicates whether the remote wireless device supports multihop relaying.

11. The method of claim 7-10, further comprising sending by the first wireless relay device to the remote wireless device, a sidelink connection reject message, based on that the remote wireless device does not indicate support of multihop relaying.

12. The method of any of the previous claims, wherein the second message further comprises one or more conditions when the first wireless relay device is authorized for multihop relaying.

13. The method of any of the previous claims, further comprising sending by the first wireless relay device, a sidelink release request, based on direct connection to a cell being available.

14. The method of claim 13, further comprising sending by the first wireless relay device to the remote wireless device, an indication that multihop relaying is not used.

15. The method of claim 14, further comprising sending by the first wireless relay device to the remote wireless device, a configuration message indicating modification of PC5 QoS parameter.

16. The method of any of the previous claims, wherein the second message further indicates at least one of whether multihop relaying of the service via the plurality of wireless layer 2 relay devices is allowed, or whether multihop relaying of the service via the plurality of wireless layer 3 relay devices is allowed.

17. The method of any of the previous claims, wherein the one or more conditions indicates at least one of one or more networks, one or more frequency bands, one or more geographical areas.

18. The method of claim 2, wherein the first request message further comprises at least one of a first indication indicating whether multihop relaying via the plurality of wireless layer 2 relay devices is supported, a second indication indicating whether multihop relaying via the plurality of wireless layer 3 relay devices is supported, a maximum number of relay hops supported, whether topmost relay operation is supported, or whether downstream relay operation is supported.

19. The method of any of the previous claims, wherein the direction connection to the cell is available, if the first wireless relay device can camp on the cell or if the cell indicates multihop relaying is supported.

20. A method comprising: receiving, by a wireless device, one or more policy configurations comprising a first policy configuration and a second policy configuration, wherein the first policy configuration associated with multihop relaying indicates a first parameter, wherein, in multihop relaying, an intermediate relay connects to a network relay; the second policy configuration not associated with multihop relaying indicates a second parameter; and and the one or more policy configuration is associated with a first relay service; triggering, by the wireless device, a sidelink connection establishment for the first relay service; and sending, by the wireless device, a connection request message comprising: the first parameter, in response to selecting a first relay device indicating the multihop relaying; and the second parameter, in response to selecting a second relay device not indicating the multihop relaying.

21. A method compri sing : receiving, by a network relay from a base station, a radio resource control (RRC) message indicating one or more parameters configuring relaying operation;receiving, by a network relay from a wireless device, a sidelink message associated with a multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay; and sending, by the network relay to the base station, a second RRC message indicating a type of the wireless device, wherein the type of the wireless device indicates a relay type.

22. A method comprising: receiving, by a first relay one or more policy configurations comprising a first policy configuration for multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay; sending, by the first relay device to a wireless device, a first message establishing a a first sidelink connection; receiving, by the first relay from a second relay, a second message establishing a second sidelink connection for multihop relaying; and based on receiving the second sidelink message, sending by the first relay device to the wireless device to the wireless device, a third message indicating modification of the first sidelink.

23. The method of claim 22, wherein the modification indicates the multihop relaying.

24. A method comprising: receiving, by a wireless device, a policy configuration indicating one or more parameters for multihop relaying, wherein, in multihop relaying, an intermediate relay connects to a network relay; receiving, by the wireless device from one or more relays, one or more announcement messages, wherein: a first relay, of the one or more relays, transmits a first announcement message, of the one or more announcement messages, indicating multihop relaying for a service; and a second relay, of the one or more relays, transmits a second announcement message, of the one or more announcement messages, not indicating multihop relaying for the service; and sending, by the wireless device to the first relay, a sidelink connection request for the multihop relaying, based on the policy configuration and the first announcement message.

25. A method comprising: sending, by a wireless device, a first message comprising one or more parameters for indicating multihop capability of the wireless device, wherein the one or more parameters comprise at least one of a first capability indicating whether the wireless device supports one or more first functionalities of a remote wireless device of multihop relaying; a second capability indicating whether the wireless device supports one or more second functionalities of an intermediate relay device of multihop relaying; and a third capability indicating whether the wireless device supports one or more third functionalities of a network relay device of multihop relaying; and receiving, by the wireless device, a second message authorizing at least one of. a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

26. A method comprising: receiving, by a first base station a network function, a context management message comprising: an identifier of a wireless device; and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service; and sending, by the first basestation to a second basestation, a handover request message comprising the identifier and the authorization information.

27. The method of claim 26, wherein the context management message further comprises one or more capability parameters indicating that the wireless device supports the multihop relaying of a service.

28. The method of claim 27, wherein the one or more capability parameters comprises at least one of: a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

29. The method of claim 26 or 27 or 28, wherein the authorization information comprises at least one of: a first authorization for the remote wireless device of multihop relaying; a second authorization for the intermediate relay device of multihop relaying; and a third authorization for the network relay device of multihop relaying.

30. The method of any of claims 26-29, wherein based on the context management message indicating the authorization information or based on the capability indication, the first base station determines whether to send to the wireless device, one or more radio parameters configuring the multihop relaying.

31. A method comprising: receiving, by a first base station from a wireless device and via a first relay, a radio resource control (RRC) message requesting establishment of RRC connection, wherein the RRC message; indicates at least one of:- a capability information indicating that the wireless device supports multihop relaying- a request information indicating that the wireless device receiving, by the first base station a network function, a context management message comprising authorization information authorizing the wireless device as a wireless relay device for the multihop relaying; and sending, by the first base station to the wireless device and via the first relay, based on the context management message, one or more radio parameters configuring the multihop relaying.

32. A method comprising: receiving, by a network node from a base station, a path switch request message comprising an identifier of a wireless device; and sending, by the network function to the base station, a response to the path switch request message, wherein the response comprises: an identifier of a wireless device; and authorization information authorizing the wireless device as a wireless relay device for multihop relaying of a service.

33. A method compri sing :receiving, by a first node managing mobility, from a wireless device, a first message comprising: an identifier associated with the wireless device; and a capability information indicating that the wireless device supports multihop relaying; and sending, by the first node to a second node managing capability, a second message comprising: the identifier; and the capability information.

34. A method comprising: receiving, by a first base station from a second base station, a handover request for a wireless device, wherein the handover request message comprises: an identifier associated with the wireless device; and a capability information indicating that the wireless device supports multihop relaying; and sending, by the first base station to an access and mobility management node, a path switch request message; and receiving, by the first base station from the access and mobility management node, a path switch request acknowledgement message comprising: an authorization information indicating whether the UE is allowed for multihop relaying.

35. A method compri sing : sending, by a wireless device, one or more registration message indicating one or more capability parameters indicating that the wireless devices supports one or more roles for multihop relaying; receiving, by a wireless device, one or more configuration message comprising one or more policy configuration parameters, where the one or more policy configuration parameters comprises at least one of: one or more relay service code for a service; and one or more conditions when the wireless device is allowed for the multihop relaying for the service, wherein the one or more conditions comprises one or more identifiers indicating one or more networks.

36. A method comprising:sending, by a first wireless relay device to an access and mobility management function, AMF, a first message indicating capability of multihop relaying of the first wireless relay device; receiving, by the first wireless relay device from the AMF, a second message: authorizing multihop relaying of a service; and indicating a relay service code (RSC) for the service; receiving, by the first wireless relay device from a second wireless relay device, a sidelink announcement message comprising: an indication indicating support for multihop relaying; and the RSC; and sending, by the first wireless relay device to the second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

37. An apparatus, acting as a first wireless relay device, comprising: a receiver configured to receiving from a network function, a second message: a controller configured to decide on whether authorizing multihop relaying of a service; wherein the controller is adapted to indicate a relay service code, RSC, for the service; and a transmitter configured to send to a second wireless relay device and based on the second message, a sidelink connection request message requesting multihop relaying for the RSC.

38. A computer program product comprising instructions to perform the steps of the method of claims 1-34.

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