Radio access network core convergence in service-based architecture

Abstract

An apparatus (700) implemented at a core network entity (408) is disclosed. The apparatus (700) is configured to receive a first service discovery request to access one or more services associated with a Core Network (CN) from a first network entity (501). The apparatus (700) is also configured to identify at least one secondary network entity (503) based on the received first service discovery request. Further, the apparatus (700) is configured to assign a token Identifier (ID) corresponding to the at least one secondary network entity (503) for a session of the first network entity. Furthermore, the apparatus (700) is configured to transmit the assigned token ID corresponding to the at least one secondary network entity (503) and a unique ID associated with a User Equipment (UE) to the first network entity and a Service-Based Interface (SBI) for providing one or more services to the UE.

Description

RADIO ACCESS NETWORK CORE CONVERGENCE IN SERVICE-BASED ARCHITECTUREFIELD

[0001] The present disclosure relates to Radio Access Network (RAN) core convergence in a service- based architecture.BACKGROUND

[0002] The information disclosed in this background section is only for enhancement of understanding of the general background of the disclosure and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

[0003] A Radio Access Network (RAN) is an important component in a telecommunications system and includes multiple network entities or network components that facilitate connections with end-user devices (user equipment). Further, a disaggregated RAN architecture is defined in 3rd Generation Partnership Project (3GPP) decomposing a gNodeB (gNB) into multiple logical entities. Further, for the gNB in 5G New Radio (NR) systems, such disaggregated entities include at least one Distributed Unit (DU) and a Centralized Unit (CU). The CU may be further split into a CU Control Plane (CP) part, also referred to as CU-C or CU-CP, and a CU User Plane (UP) part, also referred to as CU-U or CU-UP. Such a split enables the implementation of the CU-CP and CU-UP parts in different locations.

[0004] In line with the cloudifi cation and virtualization trends, the 5G system introduced a Service- Based Architecture (SBA) to transform a Core Network (CN) architecture to be cloud-friendly. Within the SBA, Network Functions (NFs) exchange information through a common interface, called Service-Based Interface (SBI). This is already specified in the 5G system for the CN. However, this is still not applicable to the RAN due to a logical barrier between the RAN and the CN.

[0005] In release 15, 3 GPP has introduced Network Function (NF) services. Particularly, each NF exposes a set of services called NF Service through a service- based interface that is consumed by other authorized NFs. NF services have the same properties as services as in a CN / RAN. Further, RAN-CN convergence is to bring certain CN functions together with RAN. A Packet Data Unit(PDU) session characteristics may determine the selection of a unified RAN-CN function or dedicated RAN, CN functions. However, the selection of network entities based on service requests is still one of the critical aspects of the RAN-CN convergence in the SBA.

[0006] Therefore, there is a need to address the above-mentioned problem(s) of the CN-RAN architecture.SUMMARY

[0007] This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the disclosure. This summary is neither intended to identify key or essential inventive concepts of the present disclosure nor is it intended to determine the scope of the disclosure.

[0008] The selection of NFs in a RAN-Core convergence solution is an important aspect of the SBA. Therefore, there is a need to optimize the selection of NF for providing one or more services to a User Equipment (UE) from the network in the SBA.

[0009] According to one embodiment of the present disclosure, an apparatus implemented at a core network entity is disclosed. The apparatus is configured to receive a first service discovery, from a first network entity. The first discovery request corresponds to a request to access one or more services associated with a Core Network (CN). The apparatus is also configured to identify at least one secondary network entity based on the received first service discovery request. Thereafter, the apparatus is configured to assign a token identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity. Furthermore, the apparatus is configured to transmit the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) to the first network entity and a Service-Based Interface (SBI). The assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with the UE is used to provide the one or more services to the UE.

[0010] According to another embodiment of the present disclosure, a method is disclosed. The method includes receiving, by the core network entity, a first service discovery request from a first network entity. The first discovery request corresponds to a request to access one or more services associated with a Core Network (CN). The method also includes identifying, by the core network entity, at least one secondary network entity based on the received first service discovery request.The method further includes assigning, by the core network entity, a token identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity. Furthermore, the method includes transmitting, by the core network entity to the first network entity and a Service-Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity. The assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with the UE is used to provide the one or more services to the UE.

[0011] According to another embodiment of the present disclosure, a non-transitory computer- readable medium storing instructions is disclosed. The instructions include one or more instructions that are executed by a core network entity comprising one or more processors. The instructions cause the one or more processors to receive, from a first network entity, a first service discovery request to access one or more services associated with a Core Network (CN). The instructions further cause the one or more processors to identify at least one secondary network entity based on the received first service discovery request. The instructions also cause the one or more processors to assign a token Identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity. Furthermore, the instructions cause the one or more processors to transmit, to the first network entity and a Service-Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity. The assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with the UE is used to provide the one or more services to the UE.

[0012] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawing. It is appreciated that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting its scope. The disclosure will be described and explained with additional specificity and detail with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Features, aspects, and advantages of embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like reference numerals denote like elements, and wherein:FIG. 1 illustrates a disaggregated architecture of a gNB, in accordance with a conventional technique;FIG. 2 illustrates a 5G architecture, in accordance with a conventional technique;FIG. 3 illustrates an end-to-end service based architecture, in accordance with a conventional technique;FIG. 4 illustrates a service-based architecture, in accordance with an embodiment of the present disclosure;FIG. 5 illustrates a sequence of operations between an UE and one or more NFs, in accordance with an embodiment of the present disclosureFIG. 6 illustrates a flow chart of an example method, in accordance with an embodiment of the present disclosure; andFIG. 7 illustrates an embodiment of an example device, in accordance with an embodiment of the present disclosure.DETAILED DESCRIPTION

[0014] The following detailed description of example embodiments refers to the accompanying drawings. The present disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modifications and variations are possible in light of the present disclosure or may be acquired from practice of the implementations. Further, one or more features or components of one embodiment may be incorporated into or combined with another embodiment (or one or more features of another embodiment). Additionally, the flowchart and description of operations provided below relate to at least one of the embodiments in the present disclosure. It should be noted that it is possible to make other embodiments that do not exactly match the flowchart and its description. It is understood that in other embodiments one or more operations may be omitted, one or moreoperations may be added, one or more operations may be performed simultaneously (at least in part).

[0015] It will be apparent that systems and / or methods, described herein, may be implemented in different forms of hardware, software, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods should not limit their implementations. Thus, the operation and behavior of the systems and / or methods are described herein without reference to specific software code. It is understood that software and hardware may be designed to implement the systems and / or methods based on the description herein.

[0016] Even though particular combinations of features are recited in the claims and / or disclosed in the specification, the particular combinations are not intended to limit the disclosure of implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and / or disclosed in the specification. Even if a dependent claim directly depends on only one claim, the present disclosure may indicate that the dependent claim is dependent on other claims in the claim set.

[0017] No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” (in other words, nouns not mentioned in the plural) are intended to include one or more items, and may be used interchangeably with “one or more.” Also, as used herein, the terms “has,” “have,” “having,” “include,” “including,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Furthermore, expressions such as “at least one of [A] and [B],” “[A] and / or [B],” or “at least one of [A] or [B]” are to be understood as including only A, only B, or both A and B.

[0018] The present disclosure may be described with reference to a network management entity associated with a RAN. The network management entity may be configured to manage services in an O-RAN. In some embodiments, the network management entity may be implemented in the form of virtualized software units in hardware or cloud environments. In some embodiments, the network management entity may be implemented as dedicated hardware units. The network management entity may be associated with an ORAN Radio Unit (0-RU), an ORAN Control Unit (O-CU), and an O-RAN Distributed Unit (O-DU) among other components of the O-RAN.

[0019] The present disclosure relates to RAN core convergence in a Service Based Architecture (SBA). Within the SBA, instead of the direct point-to-point interface, Network Functions (NF) communicate and exchange information through a common interface bus, called service-based interface (SBI). Therefore, in the SBA, SBI needs to direct a request to an NF instance effectively and efficiently. Specifically, a selection of NF to serve the UE with the requested services is one of the important aspects of the SBA. However, based on service requirements, in some special scenarios, specific network entities are selected to serve a UE’s PDU session. The present disclosure provides the assignment of a token identifier to a selected entity configured to serve the UE, such that any subsequent request directly directed to the entity by the SBI. This enables service delivery to the UE in the SBA with low latency and high efficiency.

[0020] FIG. 1 illustrates a disaggregated architecture of a gNB 100, in accordance with a conventional technique. The disaggregated architecture is defined in 3 GPP decomposing the gNB 100 into multiple logical entities. The multiple logical entities may include one or more first units 102 may be represented by at least one distributed unit (gNB-DU) and the one or more second units 104 may be represented by a centralized unit (gNB-CU). The gNB-CU may be further split into a CU Control Plane (CP) part, also referred to as gNB-CU-CP, and a CU User Plane (UP) part, also referred to as gNB-CU-UP. Such a split enables the implementation of the CU-CP and CU- UP parts in different locations. For example, such a split of the gNB 100 into the plurality of logical entities enables flexibility, scalability, and efficiency in the deployment and operation of 5G networks. The disaggregated architecture of the gNB 100 may also include a Radio Unit (gNB- RU), not shown in FIG. 1. The gNB-RU may be responsible for the radio transmission and reception of signals. The gNB-RU may include physical Radio Frequency (RF) components such as antennas, power amplifiers, and analog-to-digital converters. The gNB-RU may be located at a cell site or a radio tower, close to the antennas. Further, the gNB-DU may perform baseband processing functions such as physical layer processing, channel coding, and modulation / demodulation. Particularly, the gNB-DU may host a Radio Link Control (RLC), a Medium Access Control (MAC) layer, and a Physical (PHY) layer. The gNB-DU may also perform scheduling operations. Multiple gNB-RUs can be connected to a single gNB-DU, allowing for centralized processing of multiple radio units. The gNB-CU may be responsible for higher layer processing functions such as radio resource management, mobility management, andconnection management. The gNB-CU may provide a centralized control point for multiple gNB- DUs, enabling network-wide coordination and optimization.

[0021] According to one configuration, a gNB-DU may host multiple cells (for example, a max of 512 as per current specifications). The gNB-CU-CP may host the one or more gNB-DUs and one or more gNB-CU-UPs. Also, the gNB-CU-UP may host the Packet Data Convergence Protocol- User Plane part (PDCP-U) and Service Data Adaptation Protocols (SDAP).

[0022] More specifically, 3GPP RAN3 cardinality for the 5G gNB 100 defines that the gNB 100 may only include one gNB-CU-CP. There may be an “n” number of gNB-DUs controlled by a gNB-CU-CP. Further, there may be ‘m” number of gNB-CU-UP controlled by the gNB-CU-CP in the gNB 100. Also, one gNB-DU may be served by multiple gNB-CU-UP.

[0023] The various entities and / or network functions within the gNB 100 may communicate via one or more interfaces including an Fl-C interface, an Fl-U interface, and an El interface. The Fl-C, Fl-U, and El interfaces The Fl-C interface is a control plane interface between the gNB- CU and the gNB-DU within the gNB 100. The Fl-C interface is used for signaling and control messages related to radio resource management, mobility management, and configuration management. The Fl-C interface facilitates coordination between the gNB-CU and the gNB-DU for efficient network operation and service delivery. The Fl-U interface is a user plane interface between the gNB-CU and the gNB-DU in the gNB 100 architecture. The Fl-U is responsible for transporting user data packets between the gNB-CU and the gNB-DU. The Fl-U interface handles user plane data processing, including packet forwarding, Quality of Service (QoS) management, and encryption / decrypt! on functions. The El interface in the gNB 100 connects the entity with the gNB-CU and / or the gNB 100 to core network elements, such as the 5G Core (5GC) network functions.

[0024] FIG. 2 illustrates a 5G architecture 200 (also referred to as the architecture 200), in accordance with a conventional technique. The architecture 200 illustrates the integration of RAN CP functions and CN CP functions. The RAN CP functions include a DU, an Open RAN- Intelligent Controller (ORAN-RIC), a CU-CP, a CU-UP, and a User Plane Function (UPF). The ORAN-RIC may be defined as an open architecture framework configured to manage and orchestrate functions with an Open RAN environment. The ORAN-RIC provides interoperability, flexibility, and automation within the RAN ecosystem by providing a centralized control and management framework for network functions. Further, the UPF may be responsible for handlinguser data packets in the 5G network, including routing, forwarding, and traffic management. The CN CP functions include a Unified Data Management (UDM), a Network Data Analysis Function (NWDAF), a Policy Control Function (PCF), a Unified Data Repository (UDR), an Access and Mobility Management Function (AMF), a Session Management Function (SMF), and other NFs. centralized management of all data related to subscribers, services, and network functions. The UDM refers to the centralized management of all data related to subscribers, services, and network functions. This includes user profiles, authentication information, location data, and service preferences. The NWDAF is a function within a network architecture that is responsible for analyzing data related to network traffic, performance, and other network parameters. The PCF is a network function that is responsible for defining and enforcing policies within the network. The PCF controls access to network resources based on predefined policies and ensures that the network operates according to the desired rules and requirements. The UDR refers to a centralized storage system that collects and stores a wide range of data from various sources in a structured manner. The AMF is a network function that is responsible for managing user access and mobility within the network. The AMF is configured for authenticating users, assigning network resources, and handling mobility-related functions such as handovers and roaming. The SMF corresponds to a network function that is responsible for managing session-related activities within the network. The SMF oversees the establishment, maintenance, and termination of communication sessions between network entities, ensuring seamless connectivity and data transfer.

[0025] In the illustrated architecture 200, the CU-CP is connected to the AMF via a Next- Generation Core (NG-C) interface to communicate with the other CN NFs. The NG-C is a Peer- to-Peer (P2P) interface. Accordingly, any signaling from a UE must pass through the P2P connections from the DU to the CU-CP and then to the AMF to reach the other CN NFs. The DU, the CU-CP, and the AMF may be referred to as anchor points of such a P2P interface. Such predefined anchored points of the P2P communication cause unnecessary transmission overhead and make deployment of other NFs dependent on the location of the CU-CP and the AMF. For example, in case the UE needs to access any service via the SMF and / or other NFs associated with the CN, such a service request will be transmitted via the DU, the CU-CP, the AMF, and then to the intended NF, e.g., the SMF. The P2P interfaces also cause hardware limitations as they are accessible only between the hardware instances connecting the two endpoints.

[0026] FIG. 3 illustrates an end-to-end service-based architecture 300 (also referred to as the SBA 300), in accordance with a conventional technique. In the SBA 300, each Network Function (NF) provides one or more network function services through a service- based interface that is consumed by one or more authorized NFs 302 (for example, NF#1, NF#2, NF#3, NF#4, NF#5, NF#6, NF#7, and other NFs). Each NF 302 is configured to provide a set of services (referred to as NF services) to other NFs via a Service-Based Interface (SBI) 304. The SBI 304 acts as a standardized communication interface through which NFs 302 interact with each other to deliver specific services or functionalities within the network environment. The SBI 304 enables NFs 302 to exchange information, data, and commands in a structured manner. The SBI 304 enables implementation of the service-oriented architectures 300 in NF deployments. The SBI 304 may employ standardized protocols and formats for communication and ensuring interoperability between different NFs 302. The SBI 304 may define how NFs 302 expose their capabilities, accept requests, and provide responses to fulfill specific service requirements within the network. The NF services have the same properties as services in a CN / RAN architecture. The SBA 300 may operate on three fundamental principles, such as:• Service registration: Service registration is implemented based on the service registry, which is a database of available services and their reachability (e.g. through addresses or names).• Service authorization: A service authorization mechanism is used to control whether a service can be accessed / invoked by other services.• Service discovery: A service consumer queries for a specific service in the service registry. The service registry responds to several available services and their addresses to the consumer. Load-balancing mechanisms can be used to assist in the appropriate selection of available services.

[0027] In particular, the SBA 300 was introduced in 3 GPP to improve service delivery via the NFs 302. The SBA 300 enables a RAN to communicate directly with other NFs 302 via the SBI 304. In the exemplary implementation, the NFs 302 correspond to CP entities on the network connected to each other through single-hop SBI communications. This enables any CP entity to be placed in a location suitable for its purpose more independently from the location of the other NFs, thus providing improved deployment autonomy. Therefore, contrary to the architecture 200, the SBA 300 provides more flexibility, interoperability, and scalability. The SBA 300 may also beimplemented in a cloud environment with one or more cloud-based entities. Moreover, the SBA 300 may provide stateless service.

[0028] The data service provides a unified way of accessing the UE or session data. There are multiple types of UE data such as, UE subscription, policy, mobility management, session management context-related information, etc. Such UE data also includes any UE context used only by a single service. Such data may be quite different in the sense of dynamic or static. The data service can use a unified access framework with a distributed storage manner so that the data can be close to the services that access them. Data service exposes one interface for any authorized consumer that needs to leverage the services (i.e. allowing the consumers to create, read, update, delete their data, and subscribe to notifications upon data change).

[0029] The data service provides necessary information to the control plane services. This offers the possibility to avoid a tight coupling between the services and ensures higher flexibility. The fundamental idea is to keep communication states not in the service instance. A communication state consists of all the UE state-related information mentioned above. Instead of maintaining communication states within a service, communication states are stored in a data service such as a RAN DB (whose only role is to keep and maintain communication states and user-related context information). Whenever a service becomes active and has to process such communication states, the service retrieves the information from that data service. The affected data is locked during this processing time, which means no other service is able to modify the data. Only the current service instance can store, change, or manipulate these locked communication states. After successful execution of a service, the final communication states are stored in the data service and are unlocked, to be subsequently accessible for other services. In addition, in the case a service fails, the communication states are not lost, and the end user communication is not interrupted. The data service can use a service framework in a distributed manner so that the data can be close to the services that access them.

[0030] With RAN-CN convergence, certain CN functions may be co-sited with RAN functions, such as NFs 302. This brings an advantage in latency for a category of users, for example UEs which have limited mobility. Further, Packet Data Unit (PDU) session characteristics may be utilized by the SBI 304 to select a local or unified RAN-CN function, or a dedicated RAN, CN functions.

[0031] Further, a concept of an intermediate SMF (i-SMF) is introduced to support deployment topologies with specific SMF service areas. For instance, when a UE has one or more PDU sessions that utilize a local UPF i.e., a UPF collocated with the RAN user plane entity gNB-CU-UP, for latency reasons, the i-SMF (that may be deployed locally together with the RAN) may be selected for such a PDU session. The i-SMF may then be responsible for controlling local UPF(s) that serve the specific PDU sessions. The i-SMF may also be configured to deal with IDLE-CONNECTED state transitions of the UE and / or handovers when the UE is within the service area of the i-SMF. Similarly, an i-AMF (or a local AMF) may be implemented to serve the UE along with a global AMF (i.e., the AMF located centrally) to serve the UE with specific characteristics. Such characteristics include, but are not limited to, limited mobility, less CN interaction, etc. The local AMF / SMF (i-AMF / i-SMF) may be collocated with a NG-RAN node such as, gNB-CU-CP.

[0032] The local AMF / SMF entities are configured to provide selected CN functionalities to some selected services (based on PDU session characteristics) to the UEs. In such a scenario, the global AMF performs the selection of the local AMF / SMF per PDU session based on service characteristics. The global AMF performs such selection after an initial handshake with the RAN. Therefore, collocation of control and user plane functionality of RAN and Core for selected PDU sessions benefits signaling and latency, i.e., CU-CP, i-AMF and i-SMF, UPF. However, when RAN-CN convergence is applied to an SBA architecture, the core network services including that of AMF and SMF are provided using SBIs. Also, over an SBI, when the RAN performs service discovery of the CN services (e.g.: AMF / SMF), there is no mechanism to select local or global NFs. This diminishes the benefits of the RAN-CN convergence aspects, as signaling and latency benefits from the local and global AMF / SMF cannot be realized in the subsequent attempts as the local NF selection has to be repeated all over again. In particular, in a conventional RAN-CN convergence SBA architecture, each service discovery for the same network function may return a different instance of the NF. For example, if a gNB-CU-CP performs service discovery of an AMF twice, there is no guarantee that the service will be routed / handled by the same AMF instance. This also results in complexity in the selection of local AMF / SMF for a given PDU session, and the requirement of additional signalling to perform such an operation. This leads to latency in providing the requested services to the UE.

[0033] FIG. 4 illustrates a service-based architecture 400 (hereafter referred to as the SBA 400), in accordance with an embodiment of the present disclosure. The SBA 400 may include a UE 402,a gNB 404, and one or more core network entities such as, an AMF 408, a SMF 410, a UPF 412, and other NFs 414. The one or more core network entities may be interconnected with each other and / or the gNB 404 via a SBI message bus 406 (hereinafter referred to as the SBI 406). The different NFs of a gNB may also be interconnected in the same way over the SBI 406.

[0034] The gNB 404 may be implemented in a disaggregated manner to include one or more gNB- CU-CPs and a gNB-DU. Moreover, as discussed above, a local SMF (an intermediate SMF), and a local AMF (an intermediate AMF) may be collocated with one of the gNB-CU-CP of the gNB 404. Similarly, a local UPF may be collocated with another gNB-CU-UP of the gNB 404. The gNB may also be referred to as a NG-RAN node.

[0035] The AMF 408, the SMF 410, the UPF 412, and other NFs 414 implemented as the core network entities may be located centrally, which serves a large number of NG-RAN nodes and hence will have a broader service coverage. Therefore, such an AMF 408 may be referred to as a global AMF. Similarly, the SMF implemented centrally may be referred to as a global SMF.

[0036] In an exemplary embodiment, even in the SBA 400, the global and local AMF / SMF may be located, realized, and / or implemented as in a non-SBA framework. For example, the global AMF / SMF may be serving a host of RAN nodes, while the local AMFs / SMFs may be collocated with the RAN node or serving a few RAN nodes.

[0037] During a CN service discovery i.e., during an initial handshake between the RAN and the CN to select AMF / SMF, the gNB-CU-CP (or its equivalent in the 6G network) may indicate the PDU session being established. The CN service discovery may be performed with a service discovery request from the gNB-CU-CP. In the SBA 400, the service discovery request may be initiated to dynamically discover and identify NFs that may comply with desired functionalities and / or can provide required resources and services. In the SBA 400, the SBI 406 may be configured to identify the core network entity corresponding to the service discovery request based on user and / or session characteristics. The SBI 406 may also be configured to route the service discovery request to the identified core network entity.

[0038] When a service discovery request is intended for the AMF 408 and the default AMF (eg: global AMF) is selected by the SBI 406, the default AMF 408 may select at least one of the global AMF / SMF or a local AMF / SMF based on one or more RRM criteria. Such one or more criteria may include user and / or session characteristics, such as a location of the user, mobility speed of the user, session service requirements, session type, user subscription, and so forth.

[0039] In an exemplary embodiment, when the AMF 408 may identify / select a local AMF / SMF, the AMF 408 may assign a token identifier (ID) (also referred to as a token) corresponding to the identified / selected local AMF / SMF for a given PDU session. The AMF 408 may transmit the assigned token ID corresponding to the identified / selected local AMF / SMF to the gNB-CU-CP of the gNB 404 via the SBI 406. The SBI 406 may also store the assigned token ID corresponding to the identified / selected local AMF / SMF along with a PDU session ID and a UE ID. Therefore, the SBI 406 may be effectively able to select the local NF (i.e., the identified / selected local AMF / SMF), whenever the service discovery request by the UE 402 includes the corresponding token ID.

[0040] Moreover, during any subsequent requests for service discovery against the same NF, the gNB-CU-CP may include the assigned token ID to indicate the PDU session and the SBI 406 may ensure that the corresponding NF is selected. This reduces transmission overhead over the anchored nodes such as, the global AMF 408. Further, this provides low-latency service discovery and processing in the SBA 400. Alternatively, during subsequent attempts, if the SBI is not used for service discovery, the gNB-CU-CP may be authorized for this particular PDU session to establish communication with the local AMF / SMF using a P2P interface to enable faster communication.

[0041] FIG. 5 illustrates a sequence of operations between the UE 402 and one or more NFs, in accordance with an embodiment of the present disclosure.

[0042] At operation 502, the UE 402 may transmit a service request to an NG-RAN node 501. The NG-RAN node 501 may correspond to the gNB-CU-CP of the gNB 404, as shown in FIG. 4. Examples of such service requests may include, but are not limited to, a RRC Connection Setup request, a registration request, a session management request, a mobility management request, a network slice selection request, and so forth.

[0043] In response to the received service request, at operation 504, the NG-RAN node 501 may transmit a first service discovery request to the SBA framework (i.e., the SBI 406) and request AMF service from the SBI. Specifically, the NG-RAN node 501 may perform the initial handshake between the RAN and the CN to provide the requested service to the UE 402.

[0044] Upon receiving the service discovery request, the SBI 406, may perform the AMF service discovery and route the service request to the global AMF 408.

[0045] At operation 508, the global AMF 408 performs the selection of AMF and / or the SMF. If a local AMF / SMF is suitable for a current PDU session, the global AMF 408 may select such local AMF / SMF. For instance, the global AMF 408 may identify and select a local AMF 503 to serve the UE 402 for the given UE or PDU session. Further at operation 508, the global AMF 408 may assign a token ID (or token) to the selected local AMF 503 for the given PDU session. In one embodiment, the assigned token ID may correspond to an identity of the selected local AMF 503. At operation 510, the global AMF 408 may share the assigned token ID along with at least one of the UE ID corresponding to the UE 402 or a PDU session ID and a communication address of the selected AMF, to the NG-RAN node 501. In one embodiment, the SBI 406 may also be provided with the assigned token ID and a communication address corresponding to the local AMF 503, the UE ID corresponding to the UE 402, and / or the PDU session ID. The SBI 406 may store the shared information. In one embodiment, the global AMF 408 may share the assigned token ID corresponding to the local AMF 503, the UE ID corresponding to the UE 402, and / or the PDU session ID with the NG-RAN node 501 and / or the SBI 406 via one or more protocol messages.

[0046] At operations 511 and 512, the local AMF 503 may provide the requested service to the UE 402 via the NG-RAN node 501.

[0047] In the subsequent operations, at operation 514, a second communication message for the same PDU session is transmitted by the UE 402 to the NG-RAN node 501 or alternatively, the NG-RAN node 501 may initiate a second service request to the SBI as part of the same communication procedure. At operation 516, the NG-RAN node 501 may identify the second service request to be intended for the local AMF 503, and therefore the NG-RAN node 501 may include the assigned token ID for the local AMF 503 in the second service discovery request to the SBI 406. The NG-RAN node 501 may also include the UE ID corresponding to the UE 402 and / or the session ID corresponding to the previous session. Based on the received second service discovery request, at operation 518, the SBI 406 may directly route the request to the local AMF 503. In response, at operation 520, the local AMF 503 may serve the UE 402 with the requested service. In one embodiment, if the NG-RAN node 501 is provided a communication address of the local AMF 503 for direct P2P communication for the given UE / PDU session. The NG-RAN node 501 may transmit the second communication message directly to the local AMF 503 instead of sending a service request to the SBI 406.

[0048] Thus, the present disclosure reduces transmission overhead in a service-based architecture with RAN-CN convergence.

[0049] FIG. 6 illustrates a flow chart of an example method 600, in accordance with an embodiment of the present disclosure; and

[0050] At step 602, the method 600 comprises receiving, by the core network entity 408, from a first network entity 501 (for example, the NG-RAN node 501), a first service discovery request to access one or more services associated with a Core Network (CN).

[0051] At step 604, the method 600 comprises identifying, by the core network entity 408, at least one secondary network entity based on the received first service discovery request.

[0052] At step 606, the method 600 comprises assigning, by the core network entity 408, a token Identifier (ID) corresponding to the at least one secondary network entity (for example, the local AMF 503) for a session of the first network entity 501.

[0053] At step 608, the method 600 comprises transmitting, by the core network entity 408 to the first network entity 501 and a Service-Based Interface (SBI) 406, the assigned token ID corresponding to the at least one secondary network entity 503 and a unique ID associated with a User Equipment (UE) 402 connected to the first network entity for providing the one or more services to the UE 402.

[0054] In one embodiment, the core network entity corresponds to one of a global Access and Mobility Management Function (AMF) or a global Session Management Function (SMF) and the at least one secondary network entity corresponds to one of a local AMF or a local SMF.

[0055] FIG. 7 illustrates an embodiment of an example device 700 (may also be referred to as the apparatus 700), in accordance with an embodiment of the present disclosure. As shown in FIG. 7, the device 700 includes a processor 710, a memory 720, a storage component 730, an input component 740, an output component 750, a communication interface 760, and a bus 770. The device / apparatus 700 may be implemented at any of the UE 402, the gNB 404, and the one or more core network entities such as, the AMF 408, the SMF 410, the UPF 412, and other NFs 414.

[0056] The processor 710, as used herein, means any type of computational circuit that may comprise hardware elements and software elements. The processor 710 may be embodied as a multi-core processor, a single core processor, or a combination of one or more multi-core processors and / or one or more single core processors, a distributed processing system, or the like. The processor 710 may be a Central Processing Unit (CPU), a graphics processing unit (GPU), anaccelerated processing unit (APU), an application-specific integrated circuit (ASIC), or another type of processing component. In one non-limiting example, the processor 710 may be configured to perform one or more functionalities of the core network entity (for example, the AMF 408).

[0057] The memory 720 includes a non-transitory computer readable medium. The memory 720 includes a random-access memory (RAM), a read only memory (ROM), and / or another type of dynamic or static storage device (e.g., a flash memory, a magnetic memory, and / or an optical memory) that stores information and / or instructions for use by processor 710. The memory 720 comprises machine-readable instructions which are executable by the processor 710. These machine-readable instructions when executed by the processor 710 cause the processor 710 to perform one or more method steps of an embodiment described above.

[0058] The storage component 730 stores information and / or software related to the operation and use of the device 700. For example, storage component 730 may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, and / or a solid-state disk), a compact disc (CD), a digital versatile disc (DVD), a floppy disk, a cartridge, a magnetic tape, and / or another type of non-transitory computer-readable medium, along with a corresponding drive.

[0059] The input component 740 is configured to receive information, such as user input. For example, the input component 740 may include, but not be limited to, a touch screen display, a keyboard, a keypad, a mouse, a button, a switch, and / or a microphone. Additionally, or alternatively, the input component 740 may include a sensor for sensing information (e.g., a global positioning system (GPS), an accelerometer, a gyroscope, and / or an actuator).

[0060] The output component 750 is configured to provide output information from the device 700. For example, the output component 750 may be, but not limited to, a display, a speaker, an instruction device to an external device, and / or one or more light-emitting diodes (LEDs).

[0061] The communication interface 760 is an interface that provides a communication connection to other devices, such as external devices and internal devices. The connection by the communication interface 760 can be a wired connection, a wireless connection, or a combination of wired and wireless connections, and can be a direct connection or an indirect connection via a communication network that exists between the device 700 and other devices. In other words, the standard of the communication interface 760 is not limited.

[0062] The bus 770 acts as an interconnect between the processor 710, the memory 720, the storage component 730, the input component 740, the output component 750, and the communicationinterface 760 of the device 700. The bus 770 may include a wired interconnection or a wireless interconnection.

[0063] Thus, the present disclosure provides low-latency services in an SBA with RAN-CN convergence. The present disclosure reduces the transmission overhead of the SBA.

[0064] The number and arrangement of components are shown in FIG. 7 are provided as an example. In practice, device 700 may include additional components, fewer components, different components, or differently arranged components than those shown in FIG. 7. Additionally, or alternatively, a set of components (e.g., one or more components) of the device 700 may perform one or more functions described as being performed by another set of components of the device 700. Further, one or more method steps described in any of the embodiments may be performed utilizing a plurality of devices 700 in communication with one another.[1] An apparatus implemented at a core network entity, configured to: receive, from a first network entity, a first service discovery request to access one or more services associated with a Core Network (CN); identify at least one secondary network entity based on the received first service discovery request; assign a token Identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity; and transmit, to the first network entity and a Service-Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity for providing the one or more services to the UE.[2] The apparatus as described in [1], wherein the core network entity corresponds to one of a global Access and Mobility Management Function (AMF) or a global Session Management Function (SMF) and the at least one secondary network entity corresponds to one of a local AMF or a local SMF.[3] The apparatus described in any one of

[0001] -[2], wherein the apparatus is configured to select the at least one secondary network entity based on the user and / or session characteristics requested by the first network entity in the first service discovery request.[4] The apparatus described in any one of [l]-[3], wherein the first network entity corresponds to a gNB-Control Unit-Control Plane (gNB-CU-CP) of a Next Generation-Radio Access Network (NG-RAN) node.[5] The apparatus described in any one of [l]-[4], wherein the core network entity provides to the first network entity of the NG-RAN node, an address of the at least one secondary network entity for direct communication of any subsequent service requests.[6] A method comprising: receiving, by the core network entity, from a first network entity, a first service discovery request to access one or more services associated with a Core Network (CN); identifying, by the core network entity, at least one secondary network entity based on the received first service discovery request; assigning, by the core network entity, a token Identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity; and transmitting, by the core network entity to the first network entity and a Service- Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity for providing the one or more services to the UE.[7] The method described in [6] , wherein the core network entity corresponds to one of a global Access and Mobility Management Function (AMF) or a global Session Management Function (SMF) and the at least one secondary network entity corresponds to one of a local AMF or a local SMF.[8] The method described in any one of [6] - [7] , wherein receiving, from the first network entity at the core network entity, the first service discovery request comprises: receiving, at the SBI from a User Equipment via the first network entity, the first service discovery request to access one or more services from a network entity associated with a Core Network (CN); identifying, by the SBI, the core network entity to serve the received first service discovery request from the first network entity; transmitting, by the SBI, the received first service discovery request from the first network entity to the core network entity.[9] The method described in any one of [6]-[8], comprising:receiving, by the first network entity from the UE, a second service discovery request to select a network entity associated with the CN, wherein the second service discovery request comprises an indication associated with the one or more services requested by the UE; transmitting, by the first network entity to the SBI, the second service discovery request along with the assigned token ID of the at least one secondary network entity and the unique ID associated with the UE; and serving, by the SBI via the at least one secondary network entity, the one or more services indicated by the second service discovery request, to the first network entity.

[0010] The method described in any one of [6] -[9], wherein the at least one secondary network entity is selected based on the user and / or session characteristics requested by the first network entity in the first service discovery request.

[0011] The method described in any one of [6] -

[0010] , wherein the first network entity corresponds to a gNB-Control Unit-Control Plane (gNB-CU-CP) of a Next Generation-Radio Access Network (NG-RAN) node.

[0012] The method described in any one of [6]-[l 1], wherein the core network entity provides to the first network entity of the NG-RAN node, an address of the at least one secondary network entity for direct communication of any subsequent service requests.

[0013] A non-transitory computer- readable medium storing instructions, the instructions comprising: one or more instructions that, when executed by a core network entity comprising one or more processors, cause the one or more processors to: receive, from a first network entity, a first service discovery request to access one or more services associated with a Core Network (CN); identify at least one secondary network entity based on the received first service discovery request; assign a token Identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity; and transmit, to the first network entity and a Service-Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity for providing the one or more services to the UE.

[0065] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements can be at least one of a hardware device or a combination of hardware devices and software modules.

[0066] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0067] The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein.

[0068] Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

[0069] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

[0070] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodiments herein have been described in terms of at least one embodiment, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

WE CLAIM:

1. An apparatus (700) implemented at a core network entity (408), configured to: receive, from a first network entity (501), a first service discovery request to access one or more services associated with a Core Network (CN); identify at least one secondary network entity (503) based on the received first service discovery request; assign a token Identifier (ID) corresponding to the at least one secondary network entity (503) for a session of the first network entity (501); and transmit, to the first network entity (501) and a Service-Based Interface (SBI) (406), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) (402) connected to the first network entity for providing the one or more services to the UE (402).

2. The apparatus (700) as claimed in claim 1 , wherein the core network entity 408 corresponds to one of a global Access and Mobility Management Function (AMF) or a global Session Management Function (SMF) and the at least one secondary network entity (503) corresponds to one of a local AMF or a local SMF.

3. The apparatus (700) as claimed in claim 1, wherein the apparatus (700) is configured to select the at least one secondary network entity (503) based on the user and / or session characteristics requested by the first network entity (501) in the first service discovery request.

4. The apparatus (700) as claimed in claim 1, wherein the first network entity (501) corresponds to a gNB-Control Unit-Control Plane (gNB-CU-CP) of a Next Generation-Radio Access Network (NG-RAN) node.

5. The apparatus (700) as claimed in the claim 1, wherein the core network entity (408) provides to the first network entity of the NG-RAN node, an address of the at least one secondary network entity (503) for direct communication of any subsequent service requests.

6. A method (600) comprising: receiving (602), by the core network entity (408), from a first network entity (501), a first service discovery request to access one or more services associated with a Core Network (CN); identifying (604), by the core network entity (408), at least one secondary network entity (503) based on the received first service discovery request; assigning (606), by the core network entity (408), a token Identifier (ID) corresponding to the at least one secondary network entity (503) for a session of the first network entity (501); and transmitting (608), by the core network entity (408) to the first network entity (501) and a Service-Based Interface (SBI) (406), the assigned token ID corresponding to the at least one secondary network entity (503) and a unique ID associated with a User Equipment (UE) (402) connected to the first network entity (501) for providing the one or more services to the UE (402).

7. The method (600) as claimed in claim 6, wherein the core network entity (408) corresponds to one of a global Access and Mobility Management Function (AMF) or a global Session Management Function (SMF) and the at least one secondary network entity (503) corresponds to one of a local AMF or a local SMF.

8. The method (600) as claimed in claim 6, wherein receiving, from the first network entity (501) at the core network entity (408), the first service discovery request comprises: receiving, at the SBI (406) from the UE (402) via the first network entity (501), the first service discovery request to access one or more services from a network entity associated with a Core Network (CN); identifying, by the SBI (406), the core network entity to serve the received first service discovery request from the first network entity (501); transmitting, by the SBI (406), the received first service discovery request from the first network entity (501) to the core network entity.

9. The method (600) as claimed in claim 6, comprising: receiving, by the first network entity (501) from the UE (402), a second service discovery request to select a network entity associated with the CN, wherein the second service discovery request comprises an indication associated with the one or more services requested by the UE; transmitting, by the first network entity (501) to the SBI (406), the second service discovery request along with the assigned token ID of the at least one secondary network entity and the unique ID associated with the UE (402); and serving, by the SBI (406) via the at least one secondary network entity (503), the one or more services indicated by the second service discovery request, to the first network entity (501).

10. The method (600) as claimed in claim 6, wherein the at least one secondary network entity (503) is selected based on the user and / or session characteristics requested by the first network entity in the first service discovery request.

11. The method (600) as claimed in claim 6, wherein the first network entity (501) corresponds to a gNB-Control Unit-Control Plane (gNB-CU-CP) of a Next Generation-Radio Access Network (NG-RAN) node.

12. The method (600) as claimed in the claim 6, wherein the core network entity provides to the first network entity of the NG-RAN node, an address of the at least one secondary network entity for direct communication of any subsequent service requests.

13. A non-transitory computer-readable medium storing instructions, the instructions comprising: one or more instructions that, when executed by a core network entity (408) comprising one or more processors (710), cause the one or more processors (710) to: receive, from a first network entity, a first service discovery request to access one or more services associated with a Core Network (CN); identify at least one secondary network entity based on the received first service discovery request;assign a token Identifier (ID) corresponding to the at least one secondary network entity for a session of the first network entity; and transmit, to the first network entity and a Service-Based Interface (SBI), the assigned token ID corresponding to the at least one secondary network entity and a unique ID associated with a User Equipment (UE) connected to the first network entity for providing the one or more services to the UE.

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