WO2022232098A1 - Ran service-based interfaces - Google Patents

Abstract

An apparatus and system are described to provide a service-based interface between a Radio Access Network node (RANnode) central unit (CU) control plane (RANnode-CU-CP) and an access and mobility function (AMF) and a network repository function (NRF). Interactions with the AMF via an N2 interface and the NRF via a N100 interface are through at least one of request response or subscribe-notify communications for N2 interface bootstrapping, AMF selection, and N2-based handover using at least one of an internet protocol (IP) address or fully qualified domain name (FQDN) of the N2 interface as a termination point for N2 signaling for user equipment (UE) and non-UE associated procedures.

Description

RAN SERVICE-BASED INTERFACES

PRIORITY CLAIM

[0001] This application claims the benefit of priority to United States

Provisional Patent Application Serial No. 63/182,577, filed April 30, 2021, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to next generation wireless communications. In particular, some embodiments relate to service-based interfaces to a next generation (NG) radio access network (RAN) for RAN procedures.

BACKGROUND

[0003] The use and complexity of next generation (NG) or new radio

(NR) wireless systems, which include 5G networks and are starting to include sixth generation (6G) networks among others, has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. With the vast increase in number and diversity of communication devices, the corresponding network environment, including routers, switches, bridges, gateways, firewalls, and load balancers, has become increasingly complicated. As expected, a number of issues abound with the advent of any new technology.

BRIEF DESCRIPTION OF THE FIGURES [0004] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. [0005] FIG. 1 A illustrates an architecture of a network, in accordance with some aspects.

[0006] FIG. IB illustrates a non-roaming 5G system architecture in accordance with some aspects. [0007] FIG. 1C illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0008] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments.

[0009] FIG. 3 illustrates a successful operation of a NG setup in accordance with some embodiments.

[0010] FIG. 4 illustrates a distributed Next Generation NodeB (gNB) in a

5G architecture with service-based interface in accordance with some embodiments.

[0011] FIG. 5 illustrates architecture of FIG. 4 with reference point representation in accordance with some embodiments.

[0012] FIG. 6 illustrates bootstrapping of a service-based N2 interface in accordance with some embodiments.

[0013] FIG. 7 illustrates UE-associated procedures with a service-based

N2 interface in accordance with some embodiments. [0014] FIG. 8 illustrates N2-based handover in accordance with some embodiments.

[0015] FIG. 9 illustrates non-UE associated procedures in accordance with some embodiments. DETAILED DESCRIPTION

[0016] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0017] FIG. 1 A illustrates an architecture of a network in accordance with some aspects. The network 140 A includes 3 GPP LTE/4G and NG network functions that may be extended to 6G functions. Accordingly, although 5G will be referred to, it is to be understood that this is to extend as able to 6G structures, systems, and functions. A network function can be implemented as a discrete network element on a dedicated hardware, as a software instance running on dedicated hardware, and/or as a virtualized function instantiated on an appropriate platform, e.g., dedicated hardware or a cloud infrastructure.

[0018] The network 140 A is shown to include user equipment (UE) 101 and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as portable (laptop) or desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs 101 and 102 can be collectively referred to herein as UE 101, and UE 101 can be used to perform one or more of the techniques disclosed herein.

[0019] Any of the radio links described herein (e.g., as used in the network 140 A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard. Any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and other frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and other frequencies). Different Single Carrier or Orthogonal Frequency Domain Multiplexing (OFDM) modes (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.), and in particular 3 GPP NR, may be used by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0020] In some aspects, any of the UEs 101 and 102 can comprise an

Internet-of-Things (IoT) UE or a Cellular IoT (CIoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short lived UE connections. In some aspects, any of the UEs 101 and 102 can include a narrowband (NB) IoT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network includes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep alive messages, status updates, etc.) to facilitate the connections of the IoT network. In some aspects, any of the UEs 101 and 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs.

[0021] The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), aNextGen RAN (NG RAN), or some other type of RAN. The RAN 110 may contain one or more gNBs, one or more of which may be implemented by multiple units. Note that although gNBs may be referred to herein, the same aspects may apply to other generation NodeBs, such as 6^th generation NodeBs - and thus is more generally referred to as Radio Access Network node (RANnode).

[0022] Each of the gNBs may implement protocol entities in the 3GPP protocol stack, in which the layers are considered to be ordered, from lowest to highest, in the order Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Control (PDCP), and Radio Resource Control (RRC)/Service Data Adaptation Protocol (SDAP) (for the control plane/user plane). The protocol layers in each gNB may be distributed in different units - a Central Unit (CU), at least one Distributed Unit (DU), and a Remote Radio Head (RRH). The CU may provide functionalities such as the control the transfer of user data, and effect mobility control, radio access network sharing, positioning, and session management, except those functions allocated exclusively to the DU.

[0023] The higher protocol layers (PDCP and RRC for the control plane/PDCP and SDAP for the user plane) may be implemented in the CU, and the RLC and MAC layers may be implemented in the DU. The PHY layer may be split, with the higher PHY layer also implemented in the DU, while the lower PHY layer is implemented in the RRH. The CU, DU and RRH may be implemented by different manufacturers, but may nevertheless be connected by the appropriate interfaces therebetween. The CU may be connected with multiple DUs.

[0024] The interfaces within the gNB include the El and front-haul (F)

FI interface. The El interface may be between a CU control plane (gNB-CU- CP) and the CU user plane (gNB-CU-UP) and thus may support the exchange of signaling information between the control plane and the user plane through El AP service. The El interface may separate Radio Network Layer and Transport Network Layer and enable exchange of UE associated information and non-UE associated information. The El AP services may be non UE- associated services that are related to the entire El interface instance between the gNB-CU-CP and gNB-CU-UP using a non UE-associated signaling connection and UE-associated services that are related to a single UE and are associated with a UE-associated signaling connection that is maintained for the UE.

[0025] The FI interface may be disposed between the CU and the DU.

The CU may control the operation of the DU over the FI interface. As the signaling in the gNB is split into control plane and user plane signaling, the FI interface may be split into the Fl-C interface for control plane signaling between the gNB-DU and the gNB-CU-CP, and the FI -U interface for user plane signaling between the gNB-DU and the gNB-CU-UP, which support control plane and user plane separation. The FI interface may separate the Radio Network and Transport Network Layers and enable exchange of UE associated information and non-UE associated information. In addition, an F2 interface may be between the lower and upper parts of the NR PHY layer. The F2 interface may also be separated into F2-C and F2-U interfaces based on control plane and user plane functionalities.

[0026] The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a 5G protocol, a 6G protocol, and the like.

[0027] In an aspect, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink (SL) interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), a Physical Sidelink Broadcast Channel (PSBCH), and a Physical Sidelink Feedback Channel (PSFCH).

[0028] The UE 102 is shown to be configured to access an access point

(AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi®) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0029] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes 111 and 112 can be transmission/reception points (TRPs). In instances when the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 111, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112. [0030] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some aspects, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes 111 and/or 112 can be a gNB, an eNB, or another type of RAN node.

[0031] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an SI interface 113. In aspects, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the SI interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the Sl-mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121

[0032] In this aspect, the CN 120 comprises the MMEs 121, the S-GW

122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. [0033] The S-GW 122 may terminate the SI interface 113 towards the

RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawful intercept, charging, and some policy enforcement.

[0034] The P-GW 123 may terminate an SGi interface toward a PDN.

The P-GW 123 may route data packets between the CN 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks 131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 101 and 102 via the CN 120.

[0035] The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some aspects, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P-GW 123. [0036] In some aspects, the communication network 140 A can be an IoT network or a 5G or 6G network, including 5G new radio network using communications in the licensed (5GNR) and the unlicensed (5GNR-U) spectrum. One of the current enablers of IoT is the narrowband-IoT (NB-IoT). Operation in the unlicensed spectrum may include dual connectivity (DC) operation and the standalone LTE system in the unlicensed spectrum, according to which LTE-based technology solely operates in unlicensed spectrum without the use of an “anchor” in the licensed spectrum, called MulteFire. Further enhanced operation of LTE systems in the licensed as well as unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operations can include techniques for sidelink resource allocation and UE processing behaviors for NR sidelink V2X communications.

[0037] An NG system architecture (or 6G system architecture) can include the RAN 110 and a core network (CN) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The CN 120 (e.g., a 5G core network (5GC)) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some aspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces. [0038] In some aspects, the NG system architecture can use reference points between various nodes. In some aspects, each of the gNBs and the NG- eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some aspects, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

[0039] FIG. IB illustrates a non-roaming 5G system architecture in accordance with some aspects. In particular, FIG. IB illustrates a 5G system architecture 140B in a reference point representation, which may be extended to a 6G system architecture. More specifically, UE 102 can be in communication with RAN 110 as well as one or more other CN network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as an AMF 132, session management function (SMF) 136, policy control function (PCF) 148, application function (AF) 150, UPF 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM)/home subscriber server (HSS) 146. [0040] The UPF 134 can provide a connection to a data network (DN)

152, which can include, for example, operator services, Internet access, or third- party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The AMF 132 may provide UE-based authentication, authorization, mobility management, etc., and may be independent of the access technologies. The SMF 136 can be configured to set up and manage various sessions according to network policy. The SMF 136 may thus be responsible for session management and allocation of IP addresses to UEs. The SMF 136 may also select and control the UPF 134 for data transfer. The SMF 136 may be associated with a single session of a UE 101 or multiple sessions of the UE 101. This is to say that the UE 101 may have multiple 5G sessions. Different SMFs may be allocated to each session. The use of different SMFs may permit each session to be individually managed. As a consequence, the functionalities of each session may be independent of each other.

[0041] The UPF 134 can be deployed in one or more configurations according to the desired service type and may be connected with a data network. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

[0042] The AF 150 may provide information on the packet flow to the

PCF 148 responsible for policy control to support a desired QoS. The PCF 148 may set mobility and session management policies for the UE 101. To this end, the PCF 148 may use the packet flow information to determine the appropriate policies for proper operation of the AMF 132 and SMF 136. The AUSF 144 may store data for UE authentication.

[0043] In some aspects, the 5G system architecture 140B includes an IP multimedia subsystem (IMS) 168B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs).

More specifically, the IMS 168B includes a CSCF, which can act as a proxy CSCF (P-CSCF) 162BE, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not illustrated in FIG. IB), or interrogating CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain aspects of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's network for all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's service area. In some aspects, the I-CSCF 166B can be connected to another IP multimedia network 170B, e.g. an IMS operated by a different network operator.

[0044] In some aspects, the UDM/HSS 146 can be coupled to an application server (AS) 160B, which can include a telephony application server (TAS) or another application server. The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0045] A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. IB illustrates the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152),

N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM 146 and the SMF 136, not shown), Nil (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of a non-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. IB can also be used.

[0046] FIG. 1C illustrates a 5G system architecture 140C and a service- based representation. In addition to the network entities illustrated in FIG. IB, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some aspects, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces.

[0047] In some aspects, as illustrated in FIG. 1C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following service- based interfaces: Namf 158H (a service-based interface exhibited by the AMF 132), Nsmf 1581 (a service-based interface exhibited by the SMF 136), Nnef 158B (a service-based interface exhibited by the NEF 154), Npcf 158D (a service-based interface exhibited by the PCF 148), a Nudm 158E (a service- based interface exhibited by the UDM 146), Naf 158F (a service-based interface exhibited by the AF 150), Nnrf 158C (a service-based interface exhibited by the NRF 156), Nnssf 158A (a service-based interface exhibited by the NSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in FIG. 1C can also be used.

[0048] NR-V2X architectures may support high-reliability low latency sidelink communications with a variety of traffic patterns, including periodic and aperiodic communications with random packet arrival time and size.

Techniques disclosed herein can be used for supporting high reliability in distributed communication systems with dynamic topologies, including sidelink NR V2X communication systems.

[0049] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments. The communication device 200 may be a UE such as a specialized computer, a personal or laptop computer (PC), a tablet PC, or a smart phone, dedicated network equipment such as an eNB, a server running software to configure the server to operate as a network device, a virtual device, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. For example, the communication device 200 may be implemented as one or more of the devices shown in FIGS. 1 A-1C. Note that communications described herein may be encoded before transmission by the transmitting entity (e.g., UE, gNB) for reception by the receiving entity (e.g., gNB, UE) and decoded after reception by the receiving entity.

[0050] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0051] Accordingly, the term “module” (and “component”) is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0052] The communication device 200 may include a hardware processor (or equivalently processing circuitry) 202 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The main memory 204 may contain any or all of removable storage and non-removable storage, volatile memory or non-volatile memory. The communication device 200 may further include a display unit 210 such as a video display, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The communication device 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 200 may further include an output controller, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0053] The storage device 216 may include a non-transitory machine readable medium 222 (hereinafter simply referred to as machine readable medium) on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, completely or at least partially, within the main memory 204, within static memory 206, and/or within the hardware processor 202 during execution thereof by the communication device 200. While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224.

[0054] The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 200 and that cause the communication device 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks.

[0055] The instructions 224 may further be transmitted or received over a communications network using a transmission medium 226 via the network interface device 220 utilizing any one of a number of wireless local area network (WLAN) transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks. Communications over the networks may include one or more different protocols, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, IEEE 802.16 family of standards known as WiMax, IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, a next generation (NG)/5^th generation (5G) standards among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the transmission medium 226.

[0056] Note that the term “circuitry” as used herein refers to, is part of, or includes hardware components such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group), an Application Specific Integrated Circuit (ASIC), a field-programmable device (FPD) (e.g., a field-programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high-capacity PLD (HCPLD), a structured ASIC, or a programmable SoC), digital signal processors (DSPs), etc., that are configured to provide the described functionality. In some embodiments, the circuitry may execute one or more software or firmware programs to provide at least some of the described functionality. The term “circuitry” may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) with the program code used to carry out the functionality of that program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuitry.

[0057] The term “processor circuitry” or “processor” as used herein thus refers to, is part of, or includes circuitry capable of sequentially and automatically carrying out a sequence of arithmetic or logical operations, or recording, storing, and/or transferring digital data. The term “processor circuitry” or “processor” may refer to one or more application processors, one or more baseband processors, a physical central processing unit (CPU), a single- or multi-core processor, and/or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, and/or functional processes.

[0058] Any of the radio links described herein may operate according to any one or more of the following radio communication technologies and/or standards including but not limited to: a Global System for Mobile Communications (GSM) radio communication technology, a General Packet Radio Service (GPRS) radio communication technology, an Enhanced Data Rates for GSM Evolution (EDGE) radio communication technology, and/or a Third Generation Partnership Project (3GPP) radio communication technology, for example Universal Mobile Telecommunications System (UMTS), Freedom of Multimedia Access (FOMA), 3GPP Long Term Evolution (LTE), 3GPP Long Term Evolution Advanced (LTE Advanced), Code division multiple access 2000 (CDMA2000), Cellular Digital Packet Data (CDPD), Mobitex, Third Generation (3G), Circuit Switched Data (CSD), High-Speed Circuit-Switched Data (HSCSD), Universal Mobile Telecommunications System (Third Generation) (UMTS (3G)), Wideband Code Division Multiple Access (Universal Mobile Telecommunications System) (W-CDMA (UMTS)), High Speed Packet Access (HSPA), High-Speed Downlink Packet Access (HSDPA), High-Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+), Universal Mobile Telecommunications System-Time-Division Duplex (UMTS-TDD), Time Division-Code Division Multiple Access (TD-CDMA), Time Division- Synchronous Code Division Multiple Access (TD-CDMA), 3rd Generation Partnership Project Release 8 (Pre-4th Generation) (3 GPP Rel. 8 (Pre-4G)), 3GPP Rel. 9 (3rd Generation Partnership Project Release 9), 3GPP Rel. 10 (3rd Generation Partnership Project Release 10) , 3GPP Rel. 11 (3rd Generation Partnership Project Release 11), 3GPP Rel. 12 (3rd Generation Partnership Project Release 12), 3GPP Rel. 13 (3rd Generation Partnership Project Release 13), 3GPP Rel. 14 (3rd Generation Partnership Project Release 14), 3GPP Rel.

15 (3rd Generation Partnership Project Release 15), 3GPP Rel. 16 (3rd Generation Partnership Project Release 16), 3GPP Rel. 17 (3rd Generation Partnership Project Release 17) and subsequent Releases (such as Rel. 18, Rel. 19, etc ), 3 GPP 5G, 5G, 5G New Radio (5G R), 3 GPP 5G New Radio, 3 GPP LTE Extra, LTE-Advanced Pro, LTE Licensed-Assisted Access (LAA), MuLTEfire, UMTS Terrestrial Radio Access (UTRA), Evolved UMTS Terrestrial Radio Access (E-UTRA), Long Term Evolution Advanced (4th Generation) (LTE Advanced (4G)), cdmaOne (2G), Code division multiple access 2000 (Third generation) (CDMA2000 (3G)), Evolution-Data Optimized or Evolution-Data Only (EV-DO), Advanced Mobile Phone System (1st Generation) (AMPS (1G)), Total Access Communication System/Extended Total Access Communication System (TACS/ETACS), Digital AMPS (2nd Generation) (D-AMPS (2G)), Push-to-talk (PTT), Mobile Telephone System (MTS), Improved Mobile Telephone System (IMTS), Advanced Mobile Telephone System (AMTS), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD (Swedish abbreviation for Mobiltelefonisystem D, or Mobile telephony system D), Public Automated Land Mobile (Autotel/PALM), ARP (Finnish for Autoradiopuhelin, "car radio phone"), NMT (Nordic Mobile Telephony), High capacity version of NTT (Nippon Telegraph and Telephone) (Hicap), Cellular Digital Packet Data (CDPD), Mobitex, DataTAC, Integrated Digital Enhanced Network (iDEN), Personal Digital Cellular (PDC), Circuit Switched Data (CSD), Personal Handy- phone System (PHS), Wideband Integrated Digital Enhanced Network (WiDEN), iBurst, Unlicensed Mobile Access (UMA), also referred to as also referred to as 3 GPP Generic Access Network, or GAN standard), Zigbee, Bluetooth(r), Wireless Gigabit Alliance (WiGig) standard, mmWave standards in general (wireless systems operating at 10-300 GHz and above such as WiGig, IEEE 802. llad, IEEE 802.1 lay, etc.), technologies operating above 300 GHz and THz bands, (3GPP/LTE based or IEEE 802.1 lp or IEEE 802.1 lbd and other) Vehi cl e-to- Vehicle (V2V) and Vehicle-to-X (V2X) and Vehicle-to- Infrastructure (V2I) and Infrastructure-to- Vehicle (12 V) communication technologies, 3GPP cellular V2X, DSRC (Dedicated Short Range Communications) communication systems such as Intelligent-Transport-Systems and others (typically operating in 5850 MHz to 5925 MHz or above (typically up to 5935 MHz following change proposals in CEPT Report 71)), the European ITS-G5 system (i.e. the European flavor of IEEE 802.1 lp based DSRC, including ITS-G5A (i.e., Operation of ITS-G5 in European ITS frequency bands dedicated to ITS for safety re-lated applications in the frequency range 5,875 GHz to 5,905 GHz), ITS-G5B (i.e., Operation in European ITS frequency bands dedicated to ITS non- safety applications in the frequency range 5,855 GHz to 5,875 GHz), ITS-G5C (i.e., Operation of ITS applications in the frequency range 5,470 GHz to 5,725 GHz)), DSRC in Japan in the 700MHz band (including 715 MHz to 725 MHz), IEEE 802.1 lbd based systems, etc.

[0059] Aspects described herein can be used in the context of any spectrum management scheme including dedicated licensed spectrum, unlicensed spectrum, license exempt spectrum, (licensed) shared spectrum (such as LSA = Licensed Shared Access in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz and further frequencies and SAS = Spectrum Access System / CBRS = Citizen Broadband Radio System in 3.55-3.7 GHz and further frequencies). Applicable spectrum bands include IMT (International Mobile Telecommunications) spectrum as well as other types of spectrum/bands, such as bands with national allocation (including 450 - 470 MHz, 902-928 MHz (note: allocated for example in US (FCC Part 15)), 863-868.6 MHz (note: allocated for example in European Union (ETSI EN 300220)), 915.9-929.7 MHz (note: allocated for example in Japan), 917-923.5 MHz (note: allocated for example in South Korea), 755-779 MHz and 779-787 MHz (note: allocated for example in China), 790 - 960 MHz, 1710 - 2025 MHz, 2110 - 2200 MHz, 2300 - 2400 MHz, 2.4-2.4835 GHz (note: it is an ISM band with global availability and it is used by Wi-Fi technology family (1 lb/g/n/ax) and also by Bluetooth), 2500 - 2690 MHz, 698-790 MHz, 610 - 790 MHz, 3400 - 3600 MHz, 3400 - 3800 MHz, 3800 - 4200 MHz, 3.55- 3.7 GHz (note: allocated for example in the US for Citizen Broadband Radio Service), 5.15-5.25 GHz and 5.25-5.35 GHz and 5.47-5.725 GHz and 5.725-5.85 GHz bands (note: allocated for example in the US (FCC part 15), consists four U-NII bands in total 500 MHz spectrum), 5.725-5.875 GHz (note: allocated for example in EU (ETSI EN 301 893)), 5.47-5.65 GHz (note: allocated for example in South Korea, 5925-7125 MHz and 5925-6425MHz band (note: under consideration in US and EU, respectively. Next generation Wi-Fi system is expected to include the 6 GHz spectrum as operating band but it is noted that, as of December 2017, Wi-Fi system is not yet allowed in this band. Regulation is expected to be finished in 2019-2020 time frame), IMT-advanced spectrum, IMT-2020 spectrum (expected to include 3600-3800 MHz, 3800 - 4200 MHz, 3.5 GHz bands, 700 MHz bands, bands within the 24.25-86 GHz range, etc.), spectrum made available under FCC's "Spectrum Frontier" 5G initiative (including 27.5 - 28.35 GHz, 29.1 - 29.25 GHz, 31 - 31.3 GHz, 37 - 38.6 GHz, 38.6 - 40 GHz, 42 - 42.5 GHz, 57 - 64 GHz, 71 - 76 GHz, 81 - 86 GHz and 92 - 94 GHz, etc), the ITS (Intelligent Transport Systems) band of 5.9 GHz (typically 5.85-5.925 GHz) and 63-64 GHz, bands currently allocated to WiGig such as WiGig Band 1 (57.24-59.40 GHz), WiGig Band 2 (59.40-61.56 GHz) and WiGig Band 3 (61.56-63.72 GHz) and WiGig Band 4 (63.72-65.88 GHz), 57- 64/66 GHz (note: this band has near-global designation for Multi-Gigabit Wireless Systems (MGWS)/WiGig . In US (FCC part 15) allocates total 14 GHz spectrum, while EU (ETSI EN 302 567 and ETSI EN 301 217-2 for fixed P2P) allocates total 9 GHz spectrum), the 70.2 GHz - 71 GHz band, any band between 65.88 GHz and 71 GHz, bands currently allocated to automotive radar applications such as 76-81 GHz, and future bands including 94-300 GHz and above. Furthermore, the scheme can be used on a secondary basis on bands such as the TV White Space bands (typically below 790 MHz) where in particular the 400 MHz and 700 MHz bands are promising candidates. Besides cellular applications, specific applications for vertical markets may be addressed such as PMSE (Program Making and Special Events), medical, health, surgery, automotive, low-latency, drones, etc. applications.

[0060] Aspects described herein can also implement a hierarchical application of the scheme is possible, e.g., by introducing a hierarchical prioritization of usage for different types of users (e.g., low/medium/high priority, etc.), based on a prioritized access to the spectrum e.g., with highest priority to tier-1 users, followed by tier-2, then tier-3, etc. users, etc.

[0061] Aspects described herein can also be applied to different Single

Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3 GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0062] 5G networks extend beyond the traditional mobile broadband services to provide various new services such as internet of things (IoT), industrial control, autonomous driving, mission critical communications, etc. that may have ultra-low latency, ultra-high reliability, and high data capacity requirements due to safety and performance concerns. Some of the features in this document are defined for the network side, such as APs, eNBs, NR or gNBs - note that this term is typically used in the context of 3GPP 5G and 6G communication systems, etc. Still, a UE may take this role as well and act as an AP, eNB, or gNB; that is some or all features defined for network equipment may be implemented by a UE.

[0063] As above, one innovation in the 5GS defined by 3 GPP is the service-based architecture (SBA) for the CN network shown in FIG. 1C. The SBA allows for network functions (such as the AMF, SMF, PCF shown) to be implemented as a set of software-defined services. Each service is provided by a service producer and can be consumed by one or more service consumers. SBA is a paradigm change compared to the previous peer-to-peer model where each pair of network functions (NFs) communicated with each other using a pre- established peer-to-peer (P2P) signalling interface, typically based on the GTP-C protocol defined by 3GPP. Whenever a new function is introduced in the system of a previous generation, the existing network functions was enhanced to support the new functionality, and also a new P2P interface was defined between the new function and the existing NFs that communicate with the new function. In contrast, with the SBA the services provided by a service producer, although initially defined for a specific service consumer (or a set of service consumers), can later also be made accessible to additional consumers, if such need arises. [0064] Consider an example of the above: UE location as a service. The

AMF is aware of the UE location (with the granularity of a Tracking Area or a cell, depending on the UE state) and can act as service producer; i.e., the AMF can provide this information to any entity that to which the information is to be provided. In Rel-15 this service was consumed by the PCF, but in later releases additional functions were defined (e.g., Network Analytics Data Function (NWDAF)) that act as service consumers for the UE location, without having to make any changes to the service producer (i.e., the AMF). Compare this with a system of a previous generation where a new P2P interface would have had to be defined between the AMF and the newly introduced NF.

[0065] When extending an existing service to additional service consumers there is typically no need to make any enhancements to the service producer. Of course, the new service consumer may request authorizing for access to the services of the service producer, but this is done using the existing service-based framework.

[0066] Another intrinsic SBA feature is that SBA copes with load distribution by design. For instance, a specific NF can be implemented as a set of virtualized compute resources. When this NF is invoked for a specific task, the SBA architecture allows for selecting a specific compute resource taking into account the current compute load of the individual compute resources.

[0067] All intra-5GC interfaces for control-plane functionality have been defined as service-based interfaces. The only interfaces that are still implemented as legacy (P2P) interfaces are the following: N2 - the interface between the 5GC control plane and the NG-RAN; N4 - the interface between the 5GC control plane and the 5GC user plane; N26 - the interface between the 5GC control plane and the core network of 4^th generation (EPC). On the NG- RAN side, 3GPP has also defined a distributed RAN architecture with the split of the gNB into the gNB-CU and gNB-DUs, and split of the central unit into a control plane and user plane parts (gNB-CU-CP and gNB-CU-UP, respectively) as described above. This CU-DU split allows for development of a logical gNB that can be much bigger compared to a monolithic gNB. On the other hand, the C-plane/U-plane split allows for relocating the C-plane part (i.e., gNB-CU-CP) into a centralized cloud environment, similar to the environment in which 5GC functionality is implemented.

[0068] Assuming that the gNB-CU-CP resides in a centralized location together with the 5GC network functions, the non-service based N2 interface appears as an intruder in what otherwise is a pure service-based environment, as shown in FIG. 1C.

[0069] The continued use of the existing N2 control protocol (NG

Application Protocol (NGAP)) with the underlying protocol stack based on transport network layer (TNL) associations based on the SCTP protocol becomes questionable in this environment. Given that gNB-CU-CP is a pure C-plane function comparable to the 5GC NFs there is no clear motivation to continue the use of a p2p protocol like NGAP where a service-based interface seems to be a more appropriate candidate. Note that although 5G terms are used, this may apply to 6G and later generation technologies as well.

[0070] Thus, the embodiments herein enable the use of a service-based interface between the gNB-CU-CP and the AMF. For simplicity, below the term gNB is used as shorthand for the gNB-CU-CP function. Specifically, how to bootstrap a service-based N2 interface is described (i.e., what is the equivalent to the existing N2 interface management procedures (NG Setup, RAN Configuration Update, AMF Configuration Update) procedures defined in 3 GPP TS 38.413 clause 8.7). In addition, the manner of performing AMF selection and other UE-specific N2 procedures are described. Only the mechanisms for enabling the basic functionality on a service-based N2 interface without any changes to the CN-RAN functional split are described, however. To this end, the NG-RAN control plane functionality may be located in the same location (e.g., data center) as the 5GC network functions and the 5GC service-based framework may be used for interaction with the 5GC network functions (primarily the AMF and the NRF).

[0071] FIG. 3 illustrates a successful operation of a NG setup in accordance with some embodiments. The N2 interface in the 5G System is established using the NG Setup procedure defined in 3GPP TS 38.413 clause 8.7. The NG Setup procedure is the first NGAP procedure triggered after the TNL association has become operational. The TNL association (an SCTP connection) between the gNB and the 5GC is itself established by means that are not specified by 3GPP (e.g., by the Operations Administration and Maintenance (OAM)).

[0072] In the NG SETUP REQUEST message of FIG. 3 , the gNB indicates to the AMF specific information (e.g., Global RAN Node ID, Tracking Area Codes (TACs) including PLMN Identity, Default Paging DRX) that is essential for bootstrapping of the N2 interface. In the NG SETUP RESPONSE message, the AMF indicates to the gNB other specific information (e.g., AMF Name, Served Globally Unique AMF ID (GUAMIs) (i.e., served “logical” AMFs), Supported PLMN Identities) that are used for bootstrapping of the N2 interface.

[0073] In subsequent interface management procedures (RAN

Configuration Update, AMF Configuration Update) the gNB and AMF can exchange further information e.g., addition or deletion of TNL associations with corresponding TNL address weight factors. When a UE connects to the gNB, the gNB performs initial selection of an AMF (i.e., selects a GUAMI): if the UE connects for a first time, the gNB can select any of the GUAMIs serving the gNB, possibly using preconfigured weight factors associated with each GUAMI; otherwise, the gNB uses the UE’s temporary identifier to select the GUAMI that is already in charge of this UE. The gNB then creates an NGAP UE-TLNA binding for the UE by selecting the TNL association of the selected GUAMI. If there are multiple TNL associations associated with the same GUAMI, the gNB also selects a TNL association, possibly using preconfigured TNL address weight factors. Once the UE-specific CN-RAN association (using the NGAP UE-TLNA binding) is established over N2, the gNB and the AMF can trigger UE-specific N2 transactions. The weight factor may be used for load balancing among the AMFs.

[0074] As above, the gNB-CU-CP functionality is connected to the 5GC service-based architecture. FIG. 4 illustrates a distributed gNB in a 5G architecture with service-based interface in accordance with some embodiments. As shown in FIG. 4, the gNB-CU-CP exhibits a service-based interface called Ngnb and interacts with the NRF and AMF, and possibly other functions.

[0075] FIG. 5 illustrates architecture of FIG. 4 with reference point representation in accordance with some embodiments. FIG. 5 illustrates the actual interactions between specific pairs of network functions. For simplicity, the RAN has been collapsed into a single box, however the new interfaces (N100 and N102) are all terminated at the gNB-CU-CP function of the gNB. Specifically, the N100 interface is between the gNB-CU-CP and the NRF, the N101 interface is between the UPF and the NRF (depicted for completeness in case the N4 interface should also be replaced with a service-based interface, which is not discussed herein), and the N102 interface between two gNB-CU-CP functions (depicted for completeness but is not discussed herein).

[0076] FIG. 6 illustrates bootstrapping of a service-based N2 interface in accordance with some embodiments. In particular, the N2 bootstrapping procedure for a service-based interface is shown in FIG. 6. In operations 1 and 2, the AMF subscribes with the NRF for notifications when a gNB with a specific profile registers with the NRF using the existing Nnrf_NFManagement_NF Status service. The gNB profile specifically includes: supported PLMN(s) and a list of supported TACs. Upon subscription with the NRF, the AMF may also include its own profile including, e.g., the following parameters: supported GUAMI list, supported PLMN list, supported Network Slice Selection Assistance Information (NSSAIs), Integrated Access and Backhaul (IAB)-Support, AMF Name and address (IP address or fully qualified domain name (FQDN)). This information can be used for AMF selection via the NRF, as described in FIG. 7 step la.

[0077] At operation 3, a new gNB is deployed and provisioned via OAM with, e.g., the following information: Global RAN Node ID, Supported PLMN(s), a list of supported TACs, RAT information, FQDN or IP address for the transport termination point for N2 signalling, and NRF identity with which to register.

[0078] At operation 4, the gNB registers with the NRF using the provisioning information configured in operation 3. [0079] At operation 5, the AMF is notified (using a

Nnrf_NFManagement_NF Status service notification) that a new gNB with a matching profile has registered, including the FQDN or IP address of its N2 interface and the gNB Provisioning Information configured in operation 3.

[0080] At operation 6, the AMF triggers the establishment of the N2 interface (corresponding to the “NG Setup” procedure in TS 38.413) using a service-based interface (Ngnb_NFManagement_NGSetup service) and provides the supported GUAMI list, supported PLMN list, IAB-Support, AMF Name and address (IP address or FQDN). As part of the establishment of the N2 interface the AMF stores the gNB profile for future use (e.g., for selection of the target gNB upon handover).

[0081] In an alternative embodiment, the gNB subscribes with the NRF to be notified when a new AMF with matching profile is instantiated. Upon reception of a notification from the NRF about instantiation of a new AMF with a matching profile the gNB initiates an NG setup request with the new AMF. In another embodiment, the gNB makes an inquiry with the NRF about the presence of deployed AMF with a matching profile. The new gNB then initiates an NG setup request with the selected AMF(s).

[0082] FIG. 7 illustrates UE-associated procedures with a service-based

N2 interface in accordance with some embodiments. In particular, FIG. 7 shows a procedure for AMF selection and other UE-associated procedures with the service-based N2 interface.

[0083] AMF selection:

[0084] At operation la, when the gNB receives from the radio interface the initial uplink UE N1 (NAS) message, the gNB queries the NRF for AMF selection (using a Nnrf_NFDiscovery service via a Nnrf_NFDiscovery_Request) including one or more of the following query parameters in the request: UE’s GUAMI, Requested NSSAI, 5G CIoT features indicated in RRC signalling by the UE, IAB Node Indication, CE-mode-B Support Indicator, LTE-M indication, Non-Public Network (NPN) Access Information. The query is performed using an HTTP GET request to the resource URI "nf-instances" as defined in 3GPP TS 29.510 clause 53.2.2.2. [0085] At operation lb, the NRF replies with a success message

(Nnrf NFDiscovery Response), including information for the selected AMF, e.g., AMF Name and address (IP address or FQDN). The NRF may take into account the current processing load of individual AMFs when selecting the AMF. Another option for AMF selection is for the gNB to select the AMF locally (without NRF interaction) based on GUAMI list, supported PLMN list and IAB-Support as provided by the AMF(s) during the establishment of the N2 interface (see FIG. 6, operation 6).

[0086] Establishment of UE-specific RAN-CN association:

[0087] At operation 2a, the gNB then uses a new AMF service

(Namf_UEN2_CreateContext) to establish the UE-specific RAN-CN association. The gNB includes in the request the initial UE NAS message, user location information, RRC establishment cause and other parameters available in the gNB (similar to TS 38.413 clause 9.2.5.1 INITIAL UE MESSAGE).

[0088] At operation 2b, in case the request is accepted by the AMF, the

AMF includes a handle for the created UE N2 context in the response message. The gNB creates a UE-specific RAN-CN association and binds the UE-specific RAN-CN association to the UE N2 context handle.

[0089] AMF-initiated transactions on established UE-specific RAN-

CN association (subscription):

[0090] At operation 3, the gNB subscribes for AMF-initiated transactions over the newly established UE-specific RAN-CN association (e.g., downlink NAS message events, PDU Session management related information events, etc.) by using the Namf_UEN2_DownlinkMessageSubscribe operation.

[0091] AMF-initiated transactions on established UE-specific RAN-

CN association [notification):

[0092] At operation 4, if the AMF needs to initiate a UE-specific transaction on an established RAN-CN association (e.g., send a downlink NAS message to the UE, send PDU Session management related information to gNB, etc.), the AMF notifies the gNB by invoking the

NamF_UEN2_DownlinkMessageNotify operation. The AMF includes the downlink NAS message and/or PDU Session management related information in the notification message. [0093] gNB-initiated transactions on established UE-specific RAN-

CN association:

[0094] At operation 5, if the gNB is to initiate a UE-specific transaction on an established RAN-CN association (e.g., forward a NAS message received from the UE, or the gNB is to send PDU Session management related information to the AMF), the gNB uses the AMF service operation NamF_UEN2_UplinkMessage and includes the uplink NAS message and/or PDU Session management related information in the request.

[0095] Release of UE-specific RAN-CN association: [0096] At operation 6, if the gNB is to release the UE-specific RAN-CN association (e.g., due to RRC release), the gNB uses the AMF service operation NamF_UEN2_ReleaseContext and includes the UE N2 context handle in the request.

[0097] FIG. 8 illustrates N2-based handover in accordance with some embodiments. FIG. 8 depicts both the procedure for N2-based handover and a UE-associated procedure with a service-based N2 interface.

[0098] HO initiation: At operation 1, the gNB initiates the N2-based handover procedure using the Namf_UEN2_UplinkMessage service (including information as in the HANODOVER REQUEST message defined in TS 38.413).

[0099] Target gNB selection: At operation 2a, the AMF selects the target gNB based on the Global RAN Node ID parameter received in operation 1. If the AMF has no stored information about the target gNB, the AMF makes a query with the NRF using the Global RAN Node ID as the query parameter. The NRF responds with the IP address or FQDN of the target gNB. The AMF then receives a response from the NRF at operation 2b.

[00100] Establishment of UE-specific RAN-CN association:

[00101] At operation 3a, the AMF then uses a new gNB service (Ngnb_UEN2_CreateContext) to establish the UE-specific RAN-CN association. The request message includes information as in the HANDOVER REQUEST message defined in TS 38.413.

[00102] At operation 3b, in case the request is accepted by the gNB, the gNB includes a handle for the created UE N2 context in the response message. AMF creates a UE-specific RAN-CN association and binds the UE-specific RAN-CN association to the UE N2 context handle.

[00103] AMF-initiated transactions on established UE-specific RAN- CN association [subscription]: [00104] At operation 4, the gNB subscribes for AMF-initiated transactions over the newly established UE-specific RAN-CN association (e.g., downlink NAS message events, PDU Session management related information events, etc.) by using the Namf_UEN2_DownlinkMessageSubscribe operation.

[00105] HO Execution: [00106] At operation 5, the AMF triggers the handover execution by invoking the NamF_UEN2_DownlinkMessageNotify operation service with the source gNB. Once the UE has established connection with the target gNB, the target gNB notifies the AMF of the HO completion using the NamF_UEN2_UplinkMessage service operation at operation 6. [00107] Release of UE-specific RAN-CN association:

[00108] At operation 7, the AMF releases the UE-specific RAN-CN association with the source gNB using the gNB service operation Ngnb_UEN2_ReleaseContext and includes the UE N2 context handle in the request. [00109] FIG. 9 illustrates non-UE associated procedures in accordance with some embodiments. FIG. 9 depicts a high-level procedure for the non-UE associated procedures on a service-based N2 interface. For instance, the N2 Paging procedure defined in TR 38.413 may be implemented with an AMF service of subscribe-notify type. The subscription for Paging events (operation 1 in FIG. 9) can be implicit. Other non-UE associated N2 procedures can be implemented as AMF service or gNB services of request/response type (operation 2 in FIG. 9).

[00110] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00111] The subject matter may be referred to herein, individually and/or collectively, by the term “embodiment” merely for convenience and without intending to voluntarily limit the scope of this application to any single inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. [00112] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. [00113] The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus of a Radio Access Network node (RANnode) central unit (CU) control plane (RANnode-CU-CP) of a RANnode, the apparatus comprising: processing circuitry configured to: interact with: an access and mobility function (AMF) of a core network (CN) via an N2 interface, and a network repository function (NRF) of a core network (CN) via a N100 interface, wherein the interactions with each of the AMF and NRF comprise using at least one of request-response or subscribe-notify communications, the interactions including N2 interface bootstrapping, AMF selection, N2-based handover, and non-user equipment (UE) associated procedures; and memory configured to store the at least one of the request-response or subscribe-notify communications.

2. The apparatus of claim 1, wherein the processing circuitry is configured to register a specific RANnode profile with the NRF using an Nnrf_NFManagement_NFRegister service, and interact with the AMF based on whether the AMF has subscribed to the NRF to be notified when any RANnode- CU-CP with the specific RANnode profile is registered and the AMF has been notified by the NRF of registration of the RANnode-CU-CP.

3. The apparatus of claim 2, wherein the specific RANnode profile includes at least one of a list of supported public land mobile network (PLMN) identities and a list of tracking area codes (TACs).

4. The apparatus of claim 3, wherein the specific RANnode profile further includes Radio Access Technology (RAT) information and at least one of an internet protocol (IP) address or fully qualified domain name (FQDN) for a termination point for N2 signaling.

5. The apparatus of claim 2, wherein an AMF profile in a subscription request from the AMF to the NRF includes an AMF profile that contains an AMF Name, a list of supported Globally Unique AMF identifiers (GUAMIs), a list of supported public land mobile network (PLMN) identities, a list of supported Network Slice Selection Assistance Information (NSSAIs), Integrated Access and Backhaul (IAB)-Support, and AMF address that includes at least one of internet protocol (IP) address or fully qualified domain name (FQDN).

6. The apparatus of claim 2, wherein the processing circuitry is configured to establish an N2 association with the AMF using a service-based interface service, the service-based interface service including an Ngnb_NFManagement_NGSetup service.

7. The apparatus of claim 1, wherein the processing circuitry is configured to: subscribe to the NRF to be notified when an AMF with a matching profile is instantiated; and in response to reception, from the NRF, of a notification that a new AMF with the matching profile has been instantiated, initiate a setup request with the new AMF.

8. The apparatus of claim 1, wherein the processing circuitry is configured to: decode, from a UE, an initial UE message to connect to the RANnode; in response to reception of the initial UE message, encode, for transmission to the NRF, a query for an AMF for the UE; and decode, in response to transmission of the query, a response from the NRF containing a selected AMF.

9. The apparatus of claim 8, wherein the query includes a Globally Unique AMF identifier (GUAMI), a requested Network Slice Selection Assistance Information (NSSAI), Cellular Intemet-of-Things (CIoT) features indicated in radio resource control signaling (RRC) by the UE, an Integrated Access and Backhaul (LAB) node indication, a control element (CE)-mode-B Support Indicator, a long term evolution (LTE)-M indication, and Non-Public Network (NPN) Access Information, and wherein the query is performed by sending a hypertext transfer protocol (HTTP) GET request to a resource uniform resource indicator (URI) "nf-instances".

10. The apparatus of claim 8, wherein the response includes at least one of internet protocol (IP) address or fully qualified domain name (FQDN) of the selected AMF.

11. The apparatus of claim 10, wherein the selected AMF is selected based on current processing load among a group of AMFs.

12. The apparatus of claim 8, wherein after reception of the response, the processing circuitry is configured to: encode, for transmission to the selected AMF, a Namf_UEN2_CreateContext AMF request to establish a UE-specific radio access network (RAN)-core network (CN) association for the UE, the Namf_UEN2_CreateContext request including an initial UE non-access stratum (NAS) message, user location information, and radio resource control (RRC) establishment cause; decode, in response to transmission of the Namf_UEN2_CreateContext request, aNamf_UEN2_CreateContext response from the selected AMF, the Namf_UEN2_CreateContext response including information for a UE N2 context handle; and create a UE-specific RAN-CN association and bind the UE-specific RAN-CN association to the UE N2 context handle.

13. The apparatus of claim 12, wherein the processing circuitry is configured to: subscribe to AMF-initiated transactions over the UE-specific RAN-CN association, the AMF-initiated transactions including downlink NAS message events and packet data unit (PDU) Session management related information events, etc.) via aNamf_UEN2_DownlinkMessageSubscribe operation to the selected AMF; and decode, after subscription to the AMF-initiated transactions using the Namf_UEN2_DownlinkMessageSubscribe operation, a notification from the selected AMF via a NamF_UEN2_DownlinkMessageNotify operation, the notification including at least one of downlink NAS message or PDU Session management-related information.

14. The apparatus of claim 12, wherein the processing circuitry is configured to use an AMF service operation NamF_UEN2_UplinkMessage request to initiate a UE-specific transaction on the UE-specific RAN-CN association, the NamF_UEN2_UplinkMessage request including at least one of an uplink NAS message or PDU Session management related information in the NamF_UEN2_UplinkMessage request.

15. The apparatus of claim 12, wherein the processing circuitry is configured to release the UE-specific RAN-CN association via an AMF service operation NamF_UEN2_ReleaseContext request that includes the UE N2 context handle.

16. The apparatus of claim 1, wherein the processing circuitry is configured to: decode, from a UE, an initial UE message to connect to the RANnode; in response to reception of the initial UE message, select, without interaction with the NRF, a UE AMF for the UE based on a list of supported Globally Unique AMF identifiers (GUAMIs), a list of supported public land mobile network (PLMN) identities, and Integrated Access and Backhaul (IAB)- Support provided by the UE AMF during establishment of the N2 interface with the UE AMF.

17. An apparatus of a network repository function (NRF), the apparatus comprising: processing circuitry configured to: decode, from an access and mobility function (AMF) of a core network (CN), aNnrf_NFManagement_NFStatusSubscribe message to subscribe to notification in response to registration of a Radio Access Network node (RANnode) having a RANnode profile that includes at least one of a list of supported public land mobile network (PLMN) identities and a list of tracking area codes (TACs); decode, from a new RANnode via an N100 interface, an Nnrf_NFManagement_NFRegister message indicating that the RANnode has the RANnode profile; encode, for transmission to the AMF, a Nnrf_NFManagement_NFStatusNotify message indicating that the new RANnode has registered, the Nnrf_NFManagement_NFStatusNotify message including at least one of an internet protocol (IP) address or fully qualified domain name (FQDN) of an N2 interface of the RANnode; and memory configured to store the RANnode profile.

18. The apparatus of claim 17, wherein the processing circuitry is configured to: in response to reception of an initial message from a user equipment (UE) to the RANnode, decode, from the RANnode, a

Nnrf_NFDiscovery_Request request for an AMF for the UE, the Nnrf_NFDiscovery_Request request including a Globally Unique AMF identifier (GUAMI), a requested Network Slice Selection Assistance Information (NSSAI), Cellular Intemet-of-Things (CIoT) features indicated in radio resource control signaling (RRC) by the UE, an Integrated Access and Backhaul (LAB) node indication, a control element (CE)-mode-B Support Indicator, a long term evolution (LTE)-M indication, and Non-Public Network (NPN) Access Information, and the Nnrf_NFDiscovery_Request request is performed by transmission of a hypertext transfer protocol (HTTP) GET request to a resource uniform resource indicator (URI) "nf-instances"; select a selected AMF based on processing load of individual AMFs; and encode, in response to reception of the Nnrf NFDiscovery Request request, aNnrf_NFDiscovery_Response response containing the selected AMF, the Nnrf NFDiscovery Response response including AMF Name and IP address or FQDN of the selected AMF.

19. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a Radio Access Network node (RANnode) central unit (CU) control plane (RANnode-CU-CP), the one or more processors to configure the RANnode-CU-CP to, when the instructions are executed: interact with an access and mobility function (AMF) of a core network (CN) via an N2 interface and with a network repository function (NRF) of a core network (CN) via a N100 interface through at least one of request-response or subscribe-notify communications for N2 interface bootstrapping, AMF selection, and N2-based handover using at least one of an internet protocol (IP) address or fully qualified domain name (FQDN) of the N2 interface as a termination point for N2 signaling for user equipment (UE) and non-UE associated procedures.

20. The non-transitory computer-readable storage medium of claim 19, wherein the one or more processors further configure the RANnode-CU-CP to, when the instructions are executed: decode, from a UE, an initial UE message to connect to the RANnode- CU-CP; in response to reception of the initial UE message, encode, for transmission to the NRF, a query for an AMF for the UE; and decode, in response to transmission of the query, a response from the NRF containing a selected AMF. the response including at least one of internet protocol (IP) address or fully qualified domain name (FQDN) of the selected AMF.