WO2024109199A1

WO2024109199A1 - Network function determination

Info

Publication number: WO2024109199A1
Application number: PCT/CN2023/113900
Authority: WO
Inventors: Congchi ZHANG; Lizhuo ZHENG; Mingzeng Dai; Haiyan Luo
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-08-18
Filing date: 2023-08-18
Publication date: 2024-05-30

Abstract

Various aspects of the present disclosure relate to a device, a processor, and a method for network function (NF) determination, for example, in a service-based radio access network (RAN). In an aspect, an access network device receives, from a user equipment (UE), a message associated with a network function (NF) type in a core network. The access network device determines a first NF of the NF type in the core network for serving the UE. The access network device transmits the message to the first NF of the NF type. By implementing the embodiments of the present disclosure, the service-based RAN can know the selected NFs to serve the UE and communicate with them directly.

Description

NETWORK FUNCTION DETERMINATION

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to a device, a processor, and a method for network function (NF) determination, for example, in a service-based radio access network (RAN) .

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

In future 6G evolution, it is one of the visions to support service-based RAN architecture. That is, the service-based RAN could offer a service-based interface to the core network for control plane, and the service-based RAN can directly communicate with other network functions (e.g., SMF, LMF) without being forwarded by AMF anymore as in 5G. Furthermore, the service-based interface can be supported by either RAN node, in case of non-split architecture; or CU of RAN node, in case of CU-DU split RAN architecture; or CU-CP of RAN node, in case of CU-CP and CU-UP split RAN architecture, or a network function of RAN node. However, there are still some open problems related to the core network functions that will be studied in the future.

SUMMARY

The present disclosure relates to methods, apparatuses, and systems that support network function (NF) determination, for example, in a service-based radio access network (RAN) . In a first aspect of the solution, an access network device comprises: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive, via the transceiver and from a user equipment (UE) , a message associated with a network function (NF) type in a core network; determine a first NF of the NF type in the core network for serving the UE; and transmit, via the transceiver, the message to the first NF of the NF type. By performing determining the first NF of the NF type in the core network for serving the UE, the service-based RAN can know the selected NFs to serve the UE and communicate with them directly.

In some implementations of the access network device described herein, wherein the processor is further configured to: receive, via the transceiver and from the first NF, a response to the message, wherein the response comprises information related to the first NF; and forward, via the transceiver, the response to the UE.

In some implementations of the access network device described herein, wherein determining the first NF of the NF type comprises: transmitting, via the transceiver and to a second NF or a third NF in the core network, a request for determining a first NF of the NF type, wherein the second NF is responsible for UE access and mobility management, and wherein the third NF is responsible for storing information related to NF in the core network; and receiving, via the transceiver and from the second NF or the third NF, information related to the first NF of the NF type.

In some implementations of the access network device described herein, wherein the request comprises one of the following: the NF type; a requested service; or a UE identifier (ID) .

In some implementations of the access network device described herein, wherein the information comprises one of the following: the NF type; an identifier (ID) of an NF instance; an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance; or a list of service instances associated with the NF instance, wherein a service instance in the list of services instances is associated with one of a service name, an NF service instance ID, or an endpoint address.

In some implementations of the access network device described herein, wherein the information related to the first NF of the NF type is comprised in information related to at least one NF of the NF type.

In some implementations of the access network device described herein, wherein the information related to at least one NF of the NF type comprises information related to a plurality of NF candidates of the NF type selected by the second NF or discovered by the third NF for the UE, and the processor is further configured to: select the first NF of the NF type from the plurality of NF candidates.

In some implementations of the access network device described herein, wherein the processor is further configured to: receive, via the transceiver and from the second NF, updated information related to a first NF of the NF type or a plurality of NF candidates of the NF type selected by the second NF for the UE.

In some implementations of the access network device described herein, wherein the first NF of the NF type is selected from the plurality of NF candidates discovered by the third NF, and the processor is further configured to: receive, via the transceiver and from the first NF of the NF type, a request for providing information related to a further NF selected by the access network device from the plurality of NF candidates; and transmit, via the transceiver and to the first NF, the information related to the further NF.

In some implementations of the access network device described herein, wherein the message comprises a message towards NF in the core network, and wherein the message towards NF in the core network is carried in a message towards base station.

In some implementations of the access network device described herein, wherein the message towards NF in the core network comprises one of the following: a protocol data unit (PDU) session setup request message for an NF responsible for service management; a location service request message for an NF responsible for location management; and a sensing service request message for an NF responsible for sensing related functions.

In some implementations of the access network device described herein, wherein the message towards base station further comprises an indication for indicating a destination NF.

In some implementations of the access network device described herein, wherein the indication indicates one of the following: the type of the NF in a form of an enumerated value; a type of the message in a form of an enumerated value; a protocol discriminator of the message in a form of a bitmap; or an identifier (ID) or index of the NF in a form of an integer value.

In some implementations of the access network device described herein, wherein the access network device is a first access network device, and the processor is further configured to: during a handover procedure for the UE from the first access network device to a second access network device, transmit, via the transceiver, information related to the first NF or information related to a second NF to the second access network device.

In some implementations of the access network device described herein, wherein the access network device is a first access network device, the UE is a first UE, and the processor is further configured to: during a handover procedure for a second UE from a second access network device to the first access network device, receive, via the transceiver, information related to an NF serving the second UE or information related to a second NF serving the second UE from the second access network device.

In some implementations of the access network device described herein, wherein the access network device is a first access network device, the UE is a first UE, and the processor is further configured to: during a handover procedure for a second UE from a second access network device to the first access network device, receive, via the transceiver, information related to an NF serving the second UE from a second NF serving the second UE.

In a second aspect of the solution, an apparatus for performing a network function comprises: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive, via the transceiver and from an access network device, a request for determining a first network function (NF) of an NF type for serving a user equipment (UE) ; determine the first NF of the NF type; and transmit, via the transceiver and to the access network device, information related to the first NF of the NF type.

In some implementations of the apparatus for performing a network function described herein, wherein the request comprises one of the following: the NF type; a requested service; or a UE identifier (ID) .

In some implementations of the apparatus for performing a network function described herein, wherein the information comprises one of the following: the NF type; an identifier (ID) of an NF instance; an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance; or a list of service instances associated with the NF instance, wherein a service instance in the list of services instances is associated with one of a service name, an NF service instance ID, or an endpoint address.

In some implementations of the apparatus for performing a network function described herein, wherein the information related to the first NF comprises information related to a plurality of NF candidates of the NF type selected by the network function for the UE.

In some implementations of the apparatus for performing a network function described herein, wherein the processor is further configured to: transmit, via the transceiver, a message associated with the NF type to the first NF of the NF type; and receive, via the transceiver and from the first NF, a response to the message.

In some implementations of the apparatus for performing a network function described herein, wherein the processor is further configured to: transmit, via the transceiver and to the access network device, updated information related to the first NF of the NF type.

In a third aspect of the solution, a user equipment comprises: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: transmit, via the transceiver and to an access network device, a message associated with a first network function (NF) type in a core network; and receive, via the transceiver and from the access network device, a response to the message, wherein the response comprises information related to a first NF.

In some implementations of the user equipment described herein, wherein the information comprises one of the following: an identifier (ID) of an NF instance; or an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance.

In some implementations of the user equipment described herein, wherein the message comprises a message towards NF in the core network, and wherein the message towards NF in the core network is carried in a message towards base station.

In some implementations of the user equipment described herein, wherein the message towards base station further comprises an indication for indicating a destination NF.

In some implementations of the user equipment described herein, wherein the indication indicates one of the following: the type of the NF in a form of an enumerated value; a type of the message in a form of an enumerated value; a protocol discriminator of the message in a form of a bitmap; or an identifier (ID) or index of the NF in a form of an integer value.

In a fourth aspect of the solution, a processor for wireless communication comprises: at least one memory; and a controller coupled with the at least one memory and configured to cause the controller to: receive, from a user equipment (UE) , a message associated with a network function (NF) type in a core network; determine a first NF of the NF type in the core network for serving the UE; and transmit the message to the first NF of the NF type.

In a fifth aspect of the solution, a processor for wireless communication comprises: at least one memory; and a controller coupled with the at least one memory and configured to cause the controller to: receive, from an access network device, a request for determining a first network function (NF) of an NF type for serving a user equipment (UE) ; determine the first NF of the NF type; and transmit, to the access network device, information related to the first NF of the NF type.

In a sixth aspect of the solution, a processor for wireless communication comprises: at least one memory; and a controller coupled with the at least one memory and configured to cause the controller to: transmit, to an access network device, a message associated with a network function (NF) type in a core network; and receive, from the access network device, a response to the message, wherein the response comprises information related to a first NF.

In a seventh aspect of the solution, a method performed by an access network device comprises: receiving, from a user equipment (UE) , a message associated with a network function (NF) type in a core network; determining a first NF of the NF type in the core network for serving the UE; and transmitting the message to the first NF of the NF type.

In an eighth aspect of the solution, a method performed by a network function comprises: receiving, from an access network device, a request for determining a first network function (NF) of an NF type for serving a user equipment (UE) ; determining the first NF of the NF type; and transmitting, to the access network device, information related to the first NF of the NF type.

In a ninth aspect of the solution, a method performed by a user equipment comprises: transmitting, to an access network device, a message associated with a network function (NF) type in a core network; and receiving, from the access network device, a response to the message, wherein the response comprises information related to a first NF.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system that supports NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example service-based architecture in 5G core network in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example service-based architecture in 6G core network in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example signalling procedure for NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example procedure for NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 6 illustrates another example procedure for NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 7 illustrates a further example procedure for NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 8 illustrates an example RRC indication for NAS message destination in service-based RAN architecture in accordance with aspects of the present disclosure.

FIG. 9 illustrates an example procedure for transferring information related to the selected NF during handover in service-based RAN architecture in accordance with aspects of the present disclosure.

FIG. 10 illustrates another example procedure for transferring information related to the selected NF information during handover in service-based RAN architecture in accordance with aspects of the present disclosure.

FIG. 11 illustrates a further example procedure for transferring information related to the selected NF information during handover in service-based RAN architecture in accordance with aspects of the present disclosure.

FIG. 12 illustrates an example of device that support NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 13 illustrates an example of processor that support NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 14 illustrates a flowchart of a method that support NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 15 illustrates a flowchart of a method that support NF determination in service-based RAN in accordance with aspects of the present disclosure.

FIG. 16 illustrates a flowchart of a method that support NF determination in service-based RAN in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as, 5G NR, long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band internet of things (NB-IoT) , and so on. Further, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will also be future type communication technologies and systems in which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned systems.

As used herein, the term “network device” generally refers to a node in a communication network via which a terminal device can access the communication network and receive services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , a radio access network (RAN) node, an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , an infrastructure device for a V2X (vehicle-to-everything) communication, a transmission and reception point (TRP) , a reception point (RP) , a remote radio head (RRH) , a relay, an integrated access and backhaul (IAB) node, a low power node such as a femto BS, a pico BS, and so forth, depending on the applied terminology and technology.

As used herein, the term “terminal device” generally refers to any end device that may be capable of wireless communications. By way of example rather than a limitation, a terminal device may also be referred to as a communication device, a user equipment (UE) , an end user device, a subscriber station (SS) , an unmanned aerial vehicle (UAV) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA) , a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , a USB dongle, a smart device, wireless customer-premises equipment (CPE) , an internet of things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device (for example, a remote surgery device) , an industrial device (for example, a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms: “terminal device, ” “communication device, ” “terminal, ” “user equipment” and “UE, ” may be used interchangeably.

Aspects of the present disclosure are described in the context of a wireless communications system.

FIG. 1 illustrates an example of a wireless communications system 100 that supports NF determination in service-based RAN in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 102 (also referred to as network equipment (NE) ) , one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN) , a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 (such as UE 104-1 or UE 104-2) may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an internet-of-things (IoT) device, an internet-of-everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in FIG. 1. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open radio access network (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a CU, a DU, a radio unit (RU) , a RAN intelligent controller (RIC) (e.g., a near-real time RIC (Near-RT RIC) , a non-real time RIC (Non-RT RIC) ) , a service management and orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., radio resource control (RRC) , service data adaption protocol (SDAP) , packet data convergence protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a packet data network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

FIG. 2 illustrates an example service-based architecture in 5G core network in accordance with aspects of the present disclosure. In the 5G revolution, the service-based architecture for core network is a fundamental shift from the traditional network architecture used in previous generations. It introduces a service-oriented approach that enables more flexible, scalable, and efficient deployment and management of network functions and services.

As described in connection with FIG. 2, the service-based interface (SBI) is a standardized communication interface, which acts as a common language or protocol that enables different network functions to understand and communicate with each other. First, the SBI ensures interoperability and flexibility by decoupling network functions from each other, allowing for easier deployment, integration, and modification of services. With SBIs, network functions can be developed and deployed independently, and they can easily connect and form end-to-end service chains. Second, SBIs provide a standardized and well-defined set of rules, protocols, and data formats that facilitate the exchange of information, commands, and data between network functions, which enables efficient coordination and collaboration between network functions, allowing them to work together harmoniously to deliver the desired services to end-users.

On the other hand, for RAN in 5G, AMF is the only bridge to connect the RAN with other core network functions, it is also the AMF that is responsible for other network function (e.g., SMF, LMF) discovery/selection to serve the UE and any messages between UE/RAN and other NFs are forwarded by AMF.

As discussed above, in future 6G evolution, it is one of the visions to support service-based RAN architecture. As maybe the first step, the control plane of the RAN can adopt the service-based architecture as illustrated in FIG. 3.

Since the present disclosure is targeting 6G evolution (e.g., 6G computing power network) , the term “RAN” mentioned and/or used in the proposed solution (s) mainly refers to a service-based RAN, where the service-based RAN could offer a service-based interface to the core network for control plane, and the service-based RAN can directly communicate with other network functions (e.g., SMF, LMF) . Furthermore, the service-based interface can be supported by either RAN node, in case of non-split architecture; or CU of RAN node, in case of CU-DU split RAN architecture; or CU-CP of RAN node, in case of CU-CP and CU-UP split RAN architecture, or a network function of RAN node.

However, as described in connection with FIG. 3, there are two issues that might need to be further investigated. For the first issue, the service-based RAN might need to know the selected NFs to serve a UE and communicate with them directly. As a first option, it will still be AMF that selects the related NFs (e.g., SMF/LMF/PCF) , and the selection can be triggered by request from RAN explicitly, or upon AMF to determine based on the NAS message interpretation. Thereafter, AMF will inform RAN about the selected NFs, and RAN could communicate with the selected NFs directly. As a second option, it will be RAN that selects related NFs (e.g., SMF/LMF/PCF) , and communicate with them directly. But in some cases, a selected NF may need to know the existence of selected AMF or other NFs. For example, SMF may need to communicate with AMF to subscribe to the EventExposure service related to mobility. Thus, procedures are needed for a selected NF to know the existence of selected AMF or other NFs.

For the second issue, for NAS message in UL, the service-based RAN might need to know the NF (e.g., AMF/SMF/LMF) to which the NAS message from UE is to be forwarded. In legacy, when the RAN receives a NAS message from UE piggybacked in RRC message, the RAN will always forward it to AMF, and it is upon AMF to interpret and understand if the NAS message is for other NFs (e.g., SMF/LMF) . As such, additional headers/indications might be needed in the RRC message from UE when it is upon RAN to forward the NAS message to related NFs.

Therefore, the present disclosure proposes a solution to support NF determination in service-based RAN. In some embodiments of this solution, at an access network device (e.g., at RAN) , a message associated with an NF type in the core network is received from the UE, and a first NF of the NF type in the core network is determined for serving the UE. By implementing the example embodiments of the present disclosure, the service-based RAN can know the selected NFs to serve the UE and communicate with them directly.

Since the present disclosure is targeting 6G evolution (e.g., 6G computing power network) , the name of each network function is only for exemplary purposes. In 6G standardization, the network function providing the same functionality/service may be named differently. In the present disclosure, the mentioned network functions are assumed to provide at least the following concerned functionalities/services.

The Network Repository Function (NRF) supports the following functionality: supports service discovery of NRF services and their endpoint addresses by the NRF bootstrapping service; supports service discovery function; receive NF Discovery Request from NF instance or SCP, and provides the information of the discovered NF instances (be discovered) to the NF instance or SCP; maintains the NF profile of available NF instances and their supported services; maintains SCP profile of available SCP instances; supports SCP discovery by SCP instances; notifies about newly registered/updated/deregistered NF and SCP instances along with its potential NF services to the subscribed NF service consumer or SCP; and maintains the health status of NFs and SCP.

The Access and Mobility Management function (AMF) includes the following functionality. Some or all of the AMF functionalities may be supported in a single instance of an AMF. The functionalities may include: registration management; connection management; reachability management; and mobility Management. UE mobility event notification.

The Session Management function (SMF) includes the following functionality. Some or all of the SMF functionalities may be supported in a single instance of a SMF. The functionalities may include: session Management e.g. Session Establishment, modify and release, including tunnel maintain between UPF and AN node; selection and control of UP function, including controlling the UPF to proxy ARP or IPv6 Neighbour Discovery, or to forward all ARP/IPv6 Neighbour Solicitation traffic to the SMF, for Ethernet PDU Sessions; configures traffic steering at UPF to route traffic to proper destination; termination of interfaces towards Policy control functions; termination of SM parts of NAS messages; downlink Data Notification.

The Radio Access Network (RAN) hosts the following functions. Some or all of the RAN functionalities/services may be supported in a single RAN node. The functionalities may include: functions for Radio Resource Management: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both uplink and downlink (scheduling) ; IP and Ethernet header compression, uplink data decompression, encryption and integrity protection of data; connection setup and release; scheduling and transmission of paging messages; scheduling and transmission of system broadcast information (originated from the AMF or OAM) ; and measurement and measurement reporting configuration for mobility and scheduling.

In addition, the Location Management Function (LMF) supports the positioning related functions. The Sensing Function (SF) supports the sensing related functions.

FIG. 4 illustrates an example signalling procedure 400 for NF determination in service-based RAN in accordance with aspects of the present disclosure. At 410, the UE 104 may transmit, to an access network device 402 (e.g., a RAN node) , a message 412 associated with an NF type in a core network. Accordingly, at 414, the access network device 402 may receive, from the UE 104, the message 412 associated with the NF type in the core network.

In some embodiments, the message 412 comprises a message towards NF in the core network (e.g., a non-access stratum (NAS) message) , and wherein the message towards NF in the core network is carried in a message towards base station (e.g., a radio resource control (RRC) message) . In some embodiments, the message towards NF in the core network comprises one of the following: a protocol data unit (PDU) session setup request message for an NF responsible for service management; a location service request message for an NF responsible for location management; and a sensing service request message for an NF responsible for sensing related functions.

In some embodiments, the message towards base station further comprises an indication for indicating a destination NF. Furthermore, in some embodiments, the indication indicates one of the following: the type of the NF in a form of an enumerated value; a type of the message in a form of an enumerated value; a protocol discriminator of the message in a form of a bitmap; or an identifier (ID) or index of the NF in a form of an integer value.

For example, UE generates a NAS message and sends to RAN piggybacked in RRC message. The RRC message also indicates the destination NF. The NAS message could be e.g., PDU session setup request message for SMF; Location service request message for LMF; Sensing service request message for SF.

For example, after receiving the RRC message containing a NAS message, RAN first determines if the destination NF already exists or being selected/prepared. If not, RAN will generate and send a message (e.g., Namf_NFSelection_Request/Subscribe) to AMF requesting AMF to select one or multiple NF for the RAN/UE. The message may further contain, e.g., the requested NF type (e.g., SMF/LMF/SF) , requested service, UE ID (e.g., SUPI) .

In some embodiments, at 416, the access network device 402 may transmit, to a second NF 406 (e.g., AMF) in the core network, a request 418 for determining a first NF of the NF type for serving the UE 104, wherein the second NF 406 is responsible for UE access and mobility management.

Additionally or alternatively, in some embodiments, the access network device 402 may transmit, to a third NF (e.g., NRF) in the core network, a request for determining a first NF of the NF type for serving the UE 104, wherein the third NF is responsible for storing information related to NF in the core network. For example, RAN requests NF candidates from NRF via the NF discovery service from NRF, e.g., via Nnrf_NFDiscovery_Request (and/or Nnrf_NFDiscovery_Request_Response) messages. In some embodiments, the request comprises one of the following: the NF type; a requested service; or a UE identifier (ID) .

Accordingly, at 420, the second NF 406 may receive, from the access network device 402, the request 418. Thereafter, at 422, the second NF 406 may determine the first NF 404 of the NF type. In some embodiments, the second NF 406 may transmit a message associated with the NF type to the first NF 404 of the NF type; and receive, from the first NF 404, a response to the message.

Thereafter, at 424, the second NF 406 may transmit, to the access network device 402, information 426 related to the first NF of the NF type. In some embodiments, the information 426 comprises one of the following: the NF type; an identifier (ID) of an NF instance; an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance; or a list of service instances associated with the NF instance, wherein a service instance in the list of services instances is associated with one of a service name, an NF service instance ID, or an endpoint address.

Additionally or alternatively, in some embodiments, the information 426 comprises information related to a plurality of NF candidates of the NF type selected by the second NF 406 for the UE 104. Accordingly, in some embodiments, at 428, the access network device 402 may receive, from the second NF 406, information 426 related to the first NF of the NF type. When the access network device 402 transmit, to the third NF, the request for determining a first NF of the NF type for serving the UE 104 previously, accordingly, the access network device 402 may receive, from the third NF, information related to the first NF of the NF type.

Additionally or alternatively, in some embodiments, the information 426 comprises information related to a plurality of NF candidates of the NF type selected by the second NF 406 for the UE 104. Accordingly, the access network device 402 may select the first NF 404 of the NF type from the plurality of NF candidates.

When the access network device 402 transmit, to the third NF, the request for determining a first NF of the NF type for serving the UE 104 previously, accordingly, the information related to the first NF of the NF type comprises information related to a plurality of NF candidates of the NF type discovered by the third NF for the UE 104. Accordingly, the access network device 402 may select the first NF 404 of the NF type from the plurality of NF candidates. For example, RAN makes the NF selection decision and sends the NAS message to the selected NF, while NRF only provide discovery service, not selection service.

In some embodiments, the information related to the first NF 404 of the NF type is comprised information related to at least one NF of the NF type. For example, AMF selects an NF as RAN requested. Then, AMF generates and sends a response message (e.g., Namf_NFSelection_Response/Notify) back to RAN. The message may further contain, e.g., one or a list of: NF type; NF instance ID; IP address or FQND of the NF instance; a list of services instances, each is associated with a service name, an NF service instance ID and optionally endpoint address.

At 430, the access network device 402 may determine the first NF of the NF type in the core network for serving the UE 104. Thereafter, at 432, the access network device 402 may transmit the message 434 to the first NF 404 of the NF type. Accordingly, at 436, the first NF 404 may receive the message 434 from the access network device 402. For example, according to the information of the selected NF, RAN will send the NAS message (received from UE previously) to the corresponding NF, e.g., via: Nsmf_PDUSession_CreateSMContext_Request; Nlmf_Location_DetermineLocation_Request; or Nsf_Sensing_Request.

In some embodiments, at 438, the first NF 404 may transmit, to the access network device 402, a response 440 to the message 434, wherein the response 440 comprises information related to the first NF 404. Accordingly, at 442, the access network device 402 may receive, from the first NF 404, the response 440 to the message 434, wherein the response 440 comprises information related to the first NF 404. For example, RAN may receive the response message from the NF, e.g., via: Nsmf_PDUSession_CreateSMContext_Response; Nlmf_Location_DetermineLocation_Response; or Nsf_Sensing_Response.

In some embodiments, at 444, the access network device 402 may forward the response 446 to the UE 104. Accordingly, at 448, the UE 104 may receive, from the access network device 402, the response 446 to the message 412, wherein the response comprises information related to the first NF 404. In some embodiments, the information comprises one of the following: an identifier (ID) of an NF instance; or an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance. For example, RAN will further forward the NAS message to UE piggybacked in RAN message, e.g., in the DLInformationTransfer IE. The same RRC message may further contain the ID or address information about the selected NF. As a result, UE can indicate the ID or address of the selected NF in the future UL NAS message transmission.

Furthermore, in some embodiments, the access network device 402 may receive, from the second NF 406, updated information related to a first NF of the NF type or a plurality of NF candidates of the NF type selected by the second NF 406 for the UE 104. For example, AMF may update RAN about the selected NF information in the future, e.g., via Namf_NFSelection_Notify message. The message may further contain the information as listed above. The update of the selected NF information could be based on a previously received subscription message.

Furthermore, in some embodiments, when the first NF 404 of the NF type is selected from the plurality of NF candidates discovered by the third NF, the access network device 402 may receive, from the first NF 404 of the NF type, a request for providing information related to a further NF selected by the access network device 402 from the plurality of NF candidates; and transmit, to the first NF 404, the information related to the further NF.

For example, an NF that has been selected to serve the RAN/UE, may generate and send a message (e.g., Nran_NFInfo_Request/Subscribe message) to RAN to query information about another selected NF. For example, a SMF may request the RAN to provide information about the selected AMF for a UE. The message may further contain UE ID (e.g., SUPI) , and interested NF type. Thereafter, RAN will generate and send a message (e.g., Nran_NFInfo_Response/Notify message) back to the NF providing the requested information such as NF type, NF instance ID, FQDN or IP address (es) of the NF instance. In one example, the SMF may be interested to know the AMF that serves a particular UE, then SMF may communicate to the AMF directly and retrieve information related to UE mobility.

Furthermore, in some embodiments, when the access network device 402 is a first access network device, and the access network device 402 may, during a handover procedure for the UE 104 from the first access network device to a second access network device, transmit information related to the first NF 404 or information related to a second NF to the second access network device.

Additionally or alternatively, in some embodiments, when the access network device 402 is a first access network device, the UE 104 is a first UE, and the access network device 402 may, during a handover procedure for a second UE from a second access network device to the first access network device, receive information related to a first NF serving the second UE or information related to a second NF serving the second UE from the second access network device. For example, if the source RAN and the target RAN has direct connection, the NF information may be sent by the source RAN to the target RAN via a handover request message (e.g., Nran_Handover_Request) .

Additionally or alternatively, for example, in one possible case, the source RAN may inform the target RAN the NF information only about the selected AMF. Then, it is AMF that provides the other NF information to the target gNB after the target gNB notifying the AMF about the handover completion (e.g., Namf_Handover_Notify, or Namf_PathSwitch_Request) .

Additionally or alternatively, in some embodiments, when the access network device 402 is a first access network device, the UE 104 is a first UE, and the access network device 402 may, during a handover procedure for a second UE from a second access network device to the first access network device, receive information related to an NF serving the second UE from a second NF serving the second UE. For example, if the source RAN and the target RAN does not have direct connection, the source RAN may request the AMF to assist with the handover, and the AMF may generate and send a handover request message to the target RAN wherein the selected NFs information (other than AMF) will be contained.

Regarding NF determination in service-based RAN proposed by the present disclosure, two options might be supported. For option 1, it will still be AMF that selects the related NFs. That is, RAN requests the AMF to select NFs in need (as illustrated in FIGS. 5 and 6) . Moreover, for option 2, it will be RAN that selects related NFs. That is, RAN selects NFs in need by itself (as illustrated in FIG. 7) .

For option 1, after the registration and service request procedure where RAN has selected an AMF, when RAN receives a NAS message from UE indicating a destination NF which has not been prepared yet, the service-based RAN will trigger a procedure towards AMF via the service-based interface requesting the selection/discovery of an NF. Once AMF selects/discovers the corresponding NF and sends the related information to RAN, RAN will communicate with the selected NF directly without the involvement of AMF. AMF in this option supports network function selection/discovery service for a RAN node/function.

FIG. 5 illustrates an example procedure 500 for NF determination in service-based RAN in accordance with aspects of the present disclosure, where RAN 501 requests the AMF 502 to select NFs in need, and AMF 502 selects/discovers the NF for UE/RAN based on explicit request from RAN 501. In FIG. 5, it is assumed that RAN 501 has selected 508 an AMF 502 to serve the UE 104 during the UE registration procedure and service request procedure.

At 510, UE 104 generates a NAS message and sends to RAN 501 piggybacked in RRC message. The RRC message also indicates the destination NF as further explained below. The NAS message could be e.g., a) PDU session setup request message for SMF; b) Location service request message for LMF; c) Sensing service request message for SF.

At 520, after receiving the RRC message containing a NAS message, RAN 501 first determines if the destination NF already exists or being selected/prepared. If not, RAN 501 will generate and send a message (e.g., Namf_NFSelection_Request/Subscribe) to AMF 502 requesting AMF 502 to select one or multiple NF for the RAN/UE. The message may further contain, e.g., the requested NF type (e.g., SMF/LMF/SF) , requested service, UE ID (e.g., SUPI) .

At 522, AMF 502 selects an NF 503-505 as RAN requested. Then, at 530, AMF 502 generates and sends a response message (e.g., Namf_NFSelection_Response/Notify) back to RAN 501. The message may further contain, e.g., one or a list of: a) NF type; b) NF instance ID; c) IP address or FQND of the NF instance; d) a list of services instances, each is associated with a service name, an NF service instance ID and optionally endpoint address.

At 540, according to the information of the selected NF 503-505, RAN 501 will send the NAS message (received from UE in 510) to the corresponding NF 503-505, e.g., via: a) Nsmf_PDUSession_CreateSMContext_Request; b) Nlmf_Location_DetermineLocation_Request; c) Nsf_Sensing_Request.

At 550, RAN 501 may receive the response message from the NF 503-505, e.g., via: a) Nsmf_PDUSession_CreateSMContext_Response; b) Nlmf_Location_DetermineLocation_Response; c) Nsf_Sensing_Response.

At 560, RAN 501 will further forward the NAS message to UE 104 piggybacked in RAN message, e.g., in the DLInformationTransfer IE. The same RRC message may further contain the ID or address information about the selected NF. UE 104 can indicate the ID or address of the selected NF in the future UL NAS message transmission.

At 570, AMF 502 may update RAN 501 about the selected NF information in the future, e.g., via Namf_NFSelection_Notify message. The message may further contain the information as listed in 530. The update of the selected NF information could be based on a previously received subscription message.

FIG. 6 illustrates another example procedure 600 for NF determination in service-based RAN in accordance with aspects of the present disclosure, where RAN 601 requests the AMF 602 to select NFs in need, and by default it is still AMF 602 that responsible of NAS message transfer between RAN 601 and other NFs, while AMF 602 could decide to provide the information of selected NF to RAN 601 to enable future direct communication between RAN 601 and NFs. In FIG. 6, it is assumed that RAN 601 has selected 608 an AMF 602 to serve the UE 104 during the UE registration procedure and service request procedure.

At 610, UE 104 generates a NAS message and sends to RAN 601 piggybacked in RRC message. The RRC message also indicates the destination NF as further explained below. The NAS message could be e.g., a) PDU session setup request message for SMF; b) Location service request message for LMF; c) Sensing service request message for SF.

At 620, after receiving the RRC message containing a NAS message, RAN 601 first determines if the destination NF already exists or being selected/prepared and the related information (e.g., the IP address or FQDN) is available. If not, RAN 601 will send the NAS message to AMF 602 (e.g., via Namf_NASmessage_transfer message) . The message to AMF 602 may further indicate the destination NF.

At 622, AMF 602 selects an NF 603-605 as RAN requested if the NF has not been selected. Then, at 630, AMF 602 will send the NAS message to the destination selected NF 603-605, e.g., via: a) Nsmf_PDUSession_CreateSMContext_Request; b) Nlmf_Location_DetermineLocation_Request; c) Nsf_Sensing_Request.

At 640, AMF 602 may receive the response message from the NF 603-605, e.g., via: a) Nsmf_PDUSession_CreateSMContext_Response; b) Nlmf_Location_DetermineLocation_Response; c) Nsf_Sensing_Response.

At 650, AMF 602 forwards the received NAS message to RAN 601 (e.g., via Nran_NASmessage_transfer message) . Optionally, the message may further contain the information related to the selected NF such as: a) NF type; b) NF instance ID; c) IP address or FQND of the NF instance; d) a list of services instances, each is associated with a service name, an NF service instance ID and optionally endpoint address.

At 660, optionally, AMF 602 may generate and end another message to RAN 601 notifying RAN 601 about the selected NF information as listed in 650. If the selected NF related information is provided in 650 or 660, RAN 601 could directly communicate with the NF 603-605 e.g., by sending the message to the related IP/FQDN. The update of the selected NF information could be based on a previously received subscription message.

At 670, RAN 601 will further forward the NAS message to UE 104 piggybacked in RAN message, e.g., in the DLInformationTransfer IE. The same RRC message may further contain the ID or address information about the selected NF. UE 104 can indicate the ID or address of the selected NF in the future UL NAS message transmission.

For option 2 as mentioned above, it is the service-based RAN itself to select needed NFs based on NF information provided from NRF (e.g., via the NF discovery service from NRF) and starts the direct communication with the selected NFs via the service-based interface. The selected NF may also query RAN about the information about other NFs being selected, such that different NFs serving the same UE or RAN could directly communicate to each other as well. In this option, RAN will provide NF query service to provide and update the selected NF information to consumers, e.g., other NFs.

FIG. 7 illustrates a further example procedure 700 for NF determination in service-based RAN in accordance with aspects of the present disclosure, where RAN 701 selects NFs in need by itself.

Steps 710-760 in FIG. 7 are similar with steps 510-560 in FIG. 5, with the following differences: first, RAN 701 requests NF candidates from NRF 702 via the NF discovery service 722 from NRF 702, e.g., via Nnrf_NFDiscovery_Request (and/or Nnrf_NFDiscovery_Request_Response) messages; second, RAN 701 makes the NF selection decision and sends the NAS message to the selected NF 703-705, in other words, NRF 702 only provide discovery service, not selection service.

Furthermore, at 770, an NF 703-705 that has been selected to serve the RAN/UE, may generate and send a message (e.g., Nran_NFInfo_Request/Subscribe message) to RAN 701 to query information about another selected NF. For example, a SMF 703 may request the RAN 701 to provide information about the selected AMF for a UE. The message may further contain UE ID (e.g., SUPI) , and interested NF type.

At 780, RAN 701 will generate and send a message (e.g., Nran_NFInfo_Response/Notify message) back to the NF 703-705 providing the requested information such as NF type, NF instance ID, FQDN or IP address (es) of the NF instance. In one example, the SMF 703 may be interested to know the AMF that serves a particular UE, then SMF 703 may communicate to the AMF directly and retrieve information related to UE mobility.

FIG. 8 illustrates an example RRC indication 800 for NAS message destination in service-based RAN architecture in accordance with aspects of the present disclosure. As described in connection with FIG. 8, when UE sends NAS message in UL carried in a RRC message IE, a new RRC indication is added in the RRC message IE associated with the carried NAS message, wherein the new indication indicates the NAS message should be transmitted by the service-based RAN to which core network function (e.g., AMF/SMF/LMF/SF) via the service-based interface. The service-based RAN will determine the destination NF from the RRC indication without interpreting the NAS message OCTET STRING, and forward the NAS message to the destination NF.

It is assumed that UE has end to end NAS protocol layer with the destination network function (e.g., AMF/SMF/LMF/SF) .

In some embodiments, the indication of the destination core network function can be in the form of any of the following: 1) NF type in enumerated values, e.g., AMF, SMF, LMF, SF; 2) Message type information in enumerated values, e.g., session management, mobility management, location service, sensing service; 3) Protocol discriminator in bitmap, e.g., 00101110 indicates 5GS session management messages for SMF; 01111110 indicates 5GS mobility management messages for AMF; 00001110 indicates location service messages for LMF; 00011110 indicates sensing service messages for SF; 4) ID or Index value in integer, where the association between the ID/Index and core network function is defined in the specification or configured by RAN; 5) Address information, e.g., IP address or FQDN.

In one possible case, the protocol discriminator is the same as the protocol discriminator in the NAS message. UE copy and paste the NAS protocol discriminator as an RRC field when generating the RRC message.

FIGS. 9-11 relate to transferring information related to the selected NF during handover in service-based RAN architecture. As described in connection with FIGS. 9-11, during the UE handover procedure, the target RAN will be notified about the selected NFs information for the UE being handed over. It could be any of the following for a selected AMF/SMF/LMF/UPF: NF type; NF instance ID; IP address or FQND of the NF instance; and/or a list of services instances, each is associated with a service name, an NF service instance ID and optionally endpoint address.

As illustrated in FIG. 9, if the source RAN 901 and the target RAN 902 have direct connection, the NF information may be sent by the source RAN 901 to the target RAN 902 via a handover request message (e.g., Nran_Handover_Request at 910) . Accordingly, at 920, the target RAN 902 may transmit subsequent messages to NF (s) AMF/SMF/UPF 903.

As illustrated in FIG. 10, in one possible case, at 1010, the source RAN 1001 may inform the target RAN 1002 the NF information only about the selected AMF 1003. Then, at 1030, it is AMF 1003 that provides the other NF information to the target RAN 1002 after the target RAN 1002 notifying the AMF 1003 about the handover completion (e.g., Namf_Handover_Notify, or Namf_PathSwitch_Request at 1020) . Accordingly, at 1040, the target RAN 1002 may transmit subsequent messages to NF (s) SMF/LMF/UPF 1004.

As illustrated in FIG. 11, if the source RAN 1101 and the target RAN 1102 do not have direct connection, then at 1110, the source RAN 1101 may request the AMF 1103 to assist with the handover, and at 1120, the AMF 1103 may generate and send a handover request message to the target RAN 1102 where the selected NFs information (other than AMF) will be contained.

Accordingly, as further illustrated in FIG. 11, at 1130, the target RAN 1102 may generate and send, e.g., Nran_Handover_Request_Acknowledge, to the AMF 1103; and at 1140, the AMF 1103 may generate and send, e.g., Nran_Handover_Command, to the source RAN 1101. Thereafter, at 1150, the target RAN 1102 may transmit subsequent messages to NF (s) SMF/LMF/UPF 1104.

FIG. 12 illustrates an example of a device 1200 that support NF determination in service-based RAN in accordance with aspects of the present disclosure. The device 1200 may be an example of a UE 104-1 as described herein. The device 1200 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 1200 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 1202, a memory 1204, a transceiver 1206, and, optionally, an I/O controller 1208. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1202, the memory 1204, the transceiver 1206, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 1202, the memory 1204, the transceiver 1206, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 1202, the memory 1204, the transceiver 1206, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 1202 and the memory 1204 coupled with the processor 1202 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 1202, instructions stored in the memory 1204) .

For example, the processor 1202 may support wireless communication at the device 1200 in accordance with examples as disclosed herein. The processor 1202 may be configured to operable to support means for receiving, via the transceiver, a message associated with an NF type in a core network; means for determining a first NF of the NF type in the core network for serving the UE; and means for transmitting, via the transceiver, the message to the first NF of the NF type.

The processor 1202 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 1202 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 1202. The processor 1202 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1204) to cause the device 1200 to perform various functions of the present disclosure.

The memory 1204 may include random access memory (RAM) and read-only memory (ROM) . The memory 1204 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1202 cause the device 1200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 1202 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 1204 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 1208 may manage input and output signals for the device 1200. The I/O controller 1208 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 1208 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 1208 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 1208 may be implemented as part of a processor, such as the processor 1206. In some implementations, a user may interact with the device 1200 via the I/O controller 1208 or via hardware components controlled by the I/O controller 1208.

In some implementations, the device 1200 may include a single antenna 1210. However, in some other implementations, the device 1200 may have more than one antenna 1210 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1206 may communicate bi-directionally, via the one or more antennas 1210, wired, or wireless links as described herein. For example, the transceiver 1206 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1206 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1210 for transmission, and to demodulate packets received from the one or more antennas 1210. The transceiver 1206 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 1210 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 1210 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 13 illustrates an example of a processor 1300 that supports NF determination in service-based RAN in accordance with aspects of the present disclosure. The processor 1300 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1300 may include a controller 1302 configured to perform various operations in accordance with examples as described herein. The processor 1300 may optionally include at least one memory 1304, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 1300 may optionally include one or more arithmetic-logic units (ALUs) 1300. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1300 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1300) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 1302 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1300 to cause the processor 1300 to support various operations of a base station in accordance with examples as described herein. For example, the controller 1302 may operate as a control unit of the processor 1300, generating control signals that manage the operation of various components of the processor 1300. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1302 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1304 and determine subsequent instruction (s) to be executed to cause the processor 1300 to support various operations in accordance with examples as described herein. The controller 1302 may be configured to track memory address of instructions associated with the memory 1304. The controller 1302 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1302 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1300 to cause the processor 1300 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1302 may be configured to manage flow of data within the processor 1300. The controller 1302 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 1300.

The memory 1304 may include one or more caches (e.g., memory local to or included in the processor 1300 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 1304 may reside within or on a processor chipset (e.g., local to the processor 1300) . In some other implementations, the memory 1304 may reside external to the processor chipset (e.g., remote to the processor 1300) .

The memory 1304 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1300, cause the processor 1300 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1302 and/or the processor 1300 may be configured to execute computer-readable instructions stored in the memory 1304 to cause the processor 1300 to perform various functions. For example, the processor 1300 and/or the controller 1302 may be coupled with or to the memory 1304, and the processor 1300, the controller 1302, and the memory 1304 may be configured to perform various functions described herein. In some examples, the processor 1300 may include multiple processors and the memory 1304 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 1300 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 1300 may reside within or on a processor chipset (e.g., the processor 1300) . In some other implementations, the one or more ALUs 1300 may reside external to the processor chipset (e.g., the processor 1300) . One or more ALUs 1300 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1300 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1300 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1300 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1300 to handle conditional operations, comparisons, and bitwise operations.

The processor 1300 may support wireless communication in accordance with examples as disclosed herein. The processor 1300 may be configured to or operable to support means for receiving, via the transceiver, a message associated with an NF type in a core network; means for determining a first NF of the NF type in the core network for serving the UE; and means for transmitting, via the transceiver, the message to the first NF of the NF type.

FIG. 14 illustrates a flowchart of a method 1400 that supports NF determination in service-based RAN in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a device or its components as described herein. For example, the operations of the method 1400 may be performed by an access network device 410 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1410, the method may include receiving a message associated with an NF type in a core network. The operations of 1410 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1410 may be performed by a device as described with reference to FIG. 1.

At 1420, the method may include determining a first NF of the NF type in the core network for serving the UE. The operations of 1420 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1420 may be performed by a device as described with reference to FIG. 1.

At 1430, the method may include transmitting the message to the first NF of the NF type. The operations of 1430 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1420 may be performed by a device as described with reference to FIG. 1.

FIG. 15 illustrates a flowchart of a method 1500 that supports NF determination in service-based RAN in accordance with aspects of the present disclosure. The operations of the method 1500 may be implemented by a device or its components as described herein. For example, the operations of the method 1500 may be performed by a second NF 406 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1510, the method may include receiving a request for determining a first NF of an NF type for serving a UE. The operations of 1510 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1510 may be performed by a device as described with reference to FIG. 1.

At 1520, the method may include determining the first NF of the NF type. The operations of 1520 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1520 may be performed by a device as described with reference to FIG. 1.

At 1530, the method may include transmitting information related to the first NF of the NF type. The operations of 1530 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1520 may be performed by a device as described with reference to FIG. 1.

FIG. 16 illustrates a flowchart of a method 1600 that supports NF determination in service-based RAN in accordance with aspects of the present disclosure. The operations of the method 1600 may be implemented by a device or its components as described herein. For example, the operations of the method 1600 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1610, the method may include transmitting a message associated with an NF type in a core network. The operations of 1610 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1610 may be performed by a device as described with reference to FIG. 1.

At 1620, the method may include receiving a response to the message, wherein the response comprises information related to the first NF. The operations of 1620 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1620 may be performed by a device as described with reference to FIG. 1.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

An access network device, comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

receive, via the transceiver and from a user equipment (UE) , a message associated with a network function (NF) type in a core network;

determine a first NF of the NF type in the core network for serving the UE; and

transmit, via the transceiver, the message to the first NF of the NF type.
The access network device of claim 1, wherein the processor is further configured to:

receive, via the transceiver and from the first NF, a response to the message, wherein the response comprises information related to the first NF; and

forward, via the transceiver, the response to the UE.
The access network device of claim 1, wherein determining the first NF of the NF type comprises:

transmitting, via the transceiver and to a second NF or a third NF in the core network, a request for determining a first NF of the NF type, wherein the second NF is responsible for UE access and mobility management, and wherein the third NF is responsible for storing information related to NF in the core network; and

receiving, via the transceiver and from the second NF or the third NF, information related to the first NF of the NF type.
The access network device of claim 3, wherein the request comprises one of the following:

the NF type;

a requested service; or

a UE identifier (ID) .
The access network device of claim 3, wherein the information comprises one of the following:

the NF type;

an identifier (ID) of an NF instance;

an internet protocol (IP) address or a fully qualified domain name (FQDN) of the NF instance; or

a list of service instances associated with the NF instance, wherein a service instance in the list of services instances is associated with one of a service name, an NF service instance ID, or an endpoint address.
The access network device of claim 3, wherein the information related to the first NF of the NF type is comprised in information related to at least one NF of the NF type.
The access network device of claim 6, wherein the information related to at least one NF of the NF type comprises information related to a plurality of NF candidates of the NF type selected by the second NF or discovered by the third NF for the UE, and the processor is further configured to:

select the first NF of the NF type from the plurality of NF candidates.
The access network device of claim 3, wherein the processor is further configured to:

receive, via the transceiver and from the second NF, updated information related to a first NF of the NF type or a plurality of NF candidates of the NF type selected by the second NF for the UE.
The network device of claim 7, wherein the first NF of the NF type is selected from the plurality of NF candidates discovered by the third NF, and the processor is further configured to:

receive, via the transceiver and from the first NF of the NF type, a request for providing information related to a further NF selected by the access network device from the plurality of NF candidates; and

transmit, via the transceiver and to the first NF, the information related to the further NF.
The access network device of claim 1, wherein the message comprises a message towards NF in the core network, and wherein the message towards NF in the core network is carried in a message towards base station.
The access network device of claim 10, wherein the message towards NF in the core network comprises one of the following:

a protocol data unit (PDU) session setup request message for an NF responsible for service management;

a location service request message for an NF responsible for location management; and

a sensing service request message for an NF responsible for sensing related functions.
The access network device of claim 10, wherein the message towards base station further comprises an indication for indicating a destination NF.
The access network device of claim 12, wherein the indication indicates one of the following:

the type of the NF in a form of an enumerated value;

a type of the message in a form of an enumerated value;

a protocol discriminator of the message in a form of a bitmap; or

an identifier (ID) or index of the NF in a form of an integer value.
The access network device of claim 1, wherein the access network device is a first access network device, and the processor is further configured to:

during a handover procedure for the UE from the first access network device to a second access network device, transmit, via the transceiver, information related to the first NF or information related to a second NF to the second access network device.
The access network device of claim 1, wherein the access network device is a first access network device, the UE is a first UE, and the processor is further configured to:

during a handover procedure for a second UE from a second access network device to the first access network device, receive, via the transceiver, information related to an first NF serving the second UE or information related to a second NF serving the second UE from the second access network device.
The access network device of claim 1, wherein the access network device is a first access network device, the UE is a first UE, and the processor is further configured to:

during a handover procedure for a second UE from a second access network device to the first access network device, receive, via the transceiver, information related to an first NF serving the second UE from a second NF serving the second UE.
An apparatus for performing a network function, comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

receive, via the transceiver and from an access network device, a request for determining a first network function (NF) of an NF type for serving a user equipment (UE) ;

determine the first NF of the NF type; and

transmit, via the transceiver and to the access network device, information related to the first NF of the NF type.
A user equipment, comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

transmit, via the transceiver and to an access network device, a message associated with a network function (NF) type in a core network; and

receive, via the transceiver and from the access network device, a response to the message, wherein the response comprises information related to a first NF.
The user equipment of claim 18, wherein the message towards base station further comprises an indication for indicating a destination NF.
A method performed by an access network device, the method comprising:

receiving, from a user equipment (UE) , a message associated with a network function (NF) type in a core network;

determining a first NF of the NF type in the core network for serving the UE; and

transmitting the message to the first NF of the NF type.