Radio access network intelligent controller, E2 node and method thereof

Abstract

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system provided for supporting higher data rates beyond 4th-Generation (4G) communication systems, such as Long Term Evolution (LTE). In accordance with various embodiments of the present disclosure, a method performed by an E2 node may include receiving a Radio Access Network (RAN) Intelligent Controller (RIC) subscription request message from an RIC via an E2 interface, and the RIC subscription request message may include information representing a network interface type.

Description

[0001] This application is a divisional application of an invention patent application with an application date of September 29, 2020, application number 202080083160.0, and invention name “Device and method for subscribing to services through the E2 interface in a radio access network communication system”. Technical Field

[0002] The present disclosure generally relates to a radio access network communication system, and more particularly, to an apparatus and method for subscribing to a service of an open radio access network (O-RAN) base station using an E2 message of a radio communication system. Background Art

[0003] In order to meet the demand for increasing wireless data traffic since the deployment of the 4th generation (4G) communication system, efforts have been made to develop improved 5th generation (5G) or pre-5G (pre-5G) communication systems. Therefore, 5G or pre-5G communication systems are also called "beyond 4G networks" or "post-LTE systems."

[0004] 5G communication systems are considered to be implemented at higher frequency (mmWave) bands (e.g., 60GHz bands) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are discussed in 5G communication systems.

[0005] In addition, in the 5G communication system, development of system network improvements based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), receiving-end interference cancellation, etc. is underway.

[0006] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coded modulation (ACM) and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0007] The commercialization of 5G system, new radio or next generation radio (NR) is to meet the demand for wireless data traffic, and similar to 4G, high data rate services are provided to users through 5G system, and it is predicted that wireless communication services for various purposes such as IoT and services requiring high reliability for specific purposes may be provided. The open radio access network (O-RAN) established by operators and equipment providers in a system where the current 4G communication system and 5G system are mixed is based on the existing 3rd Generation Partnership Project (3GPP) standard, defines new network elements (NE) and interface standards, and proposes an O-RAN structure. Summary of the invention

[0008] Technical issues

[0009] With the commercialization of 4th generation (4G) / 5th generation (5G) communication systems (hereinafter referred to as 4G / 5G systems, new radio or next generation radio (NR)), virtualized networks need to provide differentiated service support for users. The Open Radio Access Network (O-RAN) redefines the existing 3rd Generation Partnership Project (3GPP) network entity (NE), radio unit (RU), distributed unit (DU), central unit (CU) control plane (CP) and CU user plane (UP) as O-RU, O-DU, O-CU-CP and O-CU-UP, respectively, and also standardizes a near real-time RAN intelligent controller (RIC). The present disclosure relates to an E2 subscription message for requesting a service from the redefined RIC to the O-DU, O-CU-CP or O-CU-UP. In addition, the present disclosure relates to a method for subdividing and processing E2 subscription messages based on user equipment (UE), group, cell and network slice. In this article, O-RU, O-DU, O-CU-CP and O-CU-UP can be understood as objects for building RAN, RAN can operate according to the O-RAN standard, and can be called E2 node.

[0010] To solve the above problems, the present invention discloses a method for a first node in a wireless communication system, including: generating and transmitting an E2 subscription request message at the RIC; at the E2NODE, setting a call processing event by receiving the E2 subscription request message by the RIC; after setting the EVENT, successfully delivering the subscription request response message to the RIC, and, if a call processing event that meets the set conditions occurs, generating an E2INDICATION / REPORT message based on the generated EVENT and delivering it to the RIC.

[0011] In addition, the E2 subscription request message can be identified based on the detailed information element of the E2 subscription request transmitted from the RIC, and the information element information can include MESSAGE TYPE identifier information, RIC REQUEST ID identifier information, E2NODEFUNCTION ID identifier information and RIC SUBSCRIPTION TYPE identifier information set based on the call processing function of the E2NODE.

[0012] In addition, the E2 subscription response message can be identified based on the detailed information element of the E2 subscription response transmitted from the RIC, and the information element information can include MESSAGE TYPE identifier information, RIC REQUEST ID identifier information, E2NODEFUNCTION ID identifier information and RIC SUBSCRIPTION RESULT identifier information set based on the call processing function of the E2 node.

[0013] Solution to the problem

[0014] According to various embodiments of the present disclosure, a method performed by an E2 node may include receiving a RIC subscription request message from a radio access network (RAN) intelligent controller (RIC) via an E2 interface, and the RIC subscription request message may include information indicating a network interface type.

[0015] According to various embodiments of the present disclosure, a method performed by the RIC may include transmitting a RIC subscription request message to an E2 node via an E2 interface, and the RIC subscription request message may include information indicating a network interface type.

[0016] According to various embodiments of the present disclosure, a device working as an E2 node may include at least one transceiver and at least one processor coupled to the at least one transceiver, the at least one processor may be configured to receive a RIC subscription request message from the RIC via the E2 interface, and the RIC subscription request message may include information representing a network interface type.

[0017] According to various embodiments of the present disclosure, a device working as a RIC may include at least one transceiver and at least one processor coupled to the at least one transceiver, the at least one processor being configured to transmit a RIC subscription request message to an E2 node via an E2 interface, and the RIC subscription request message may include information representing a network interface type.

[0018] According to various embodiments of the present disclosure, a method performed by an E2 node may include: receiving a RIC subscription request message from a radio access network (RAN) intelligent controller (RIC) via an E2 interface; and sending a RIC subscription response message to the RIC via the E2 interface as a response to the RIC subscription request message, wherein the RIC subscription request message includes first information representing a network interface type and second information representing a node identifier (ID), and wherein, in the case where the first information represents an X2 interface, the node ID represents one of an evolved NodeB (eNB) ID or a new radio (NR) base station ID.

[0019] According to various embodiments of the present disclosure, a method performed by a radio access network (RAN) intelligent controller (RIC) may include: sending a RIC subscription request message to an E2 node via an E2 interface; and receiving a RIC subscription response message from the E2 node via the E2 interface as a response to the RIC subscription request message, wherein the RIC subscription request message includes first information representing a network interface type and second information representing a node identifier (ID), and wherein, in the case where the first information represents an X2 interface, the node ID represents one of an evolved NodeB (eNB) ID or a new radio (NR) base station ID.

[0020] According to various embodiments of the present disclosure, an apparatus operating as an E2 node may include: a transceiver; and a controller coupled to the transceiver and configured to execute any one of the aforementioned methods.

[0021] According to various embodiments of the present disclosure, an apparatus operating as a radio access network (RAN) intelligent controller (RIC) may include: a transceiver; and a controller coupled to the transceiver and configured to perform any one of the aforementioned methods.

[0022] Beneficial Effects

[0023] The apparatus and method according to various embodiments of the present disclosure may indicate the type of network interface in a subscription request for requesting subscription to a radio access network (RAN) function of an E2 node, thereby providing an efficient subscription process between a near real-time (RT) RAN intelligent controller (RIC) and the E2 node.

[0024] Effects obtainable from the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those skilled in the art of the present disclosure through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 An example of a 4th generation (4G) long term evolution (LTE) core system is shown.

[0026] Figure 2a An example of a 5th generation (5G) non-standalone (NSA) system is shown.

[0027] Figure 2b An example of an architecture for an Open (O)-Radio Access Network (RAN) is shown.

[0028] Figure 3 A protocol stack of an E2 application protocol message in a radio access network according to various embodiments of the present disclosure is shown.

[0029] Figure 4 An example of connection between a base station and a Radio Access Network (RAN) Intelligent Controller (RIC) in a radio access network according to various embodiments of the present disclosure is shown.

[0030] Figure 5 A configuration of a device in a radio access network according to various embodiments of the present disclosure is shown.

[0031] Figure 6 1 and 2 illustrate logical functions related to E2 messages of an E2 node and an RIC in a radio access network according to various embodiments of the present disclosure.

[0032] Figure 7a An example of a signaling procedure between an E2 node and an RIC is shown.

[0033] Figure 7b An example of a subscription process between an E2 node and a RIC is shown.

[0034] Figures 8 to 14 An example of messages used for the subscription process is shown. DETAILED DESCRIPTION

[0035] The terms used in the present disclosure are only used to describe specific embodiments, and are not intended to limit the scope of other embodiments. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. The meaning of the terms (including technical or scientific terms) used herein may be the same as the meaning generally understood by those of ordinary skill in the technical field described by the present disclosure. Among the terms used in the present disclosure, the terms defined in general dictionaries may be interpreted as having the same or similar meaning as the terms in the context of the relevant art, and unless clearly defined in the present disclosure, shall not be interpreted as ideal or overly formal meanings. In some cases, even the terms defined in the present disclosure may not be interpreted as excluding embodiments of the present disclosure.

[0036] The hardware-based method will be described as an example in various embodiments of the present disclosure, which will be described below. However, various embodiments of the present disclosure include techniques using both hardware and software, and therefore, various embodiments of the present disclosure do not exclude software-based methods.

[0037] Hereinafter, a preset disclosure relates to an apparatus and method for performing a subscription procedure between a device in a Radio Access Network (RAN) and a device controlling the RAN in a wireless communication system.

[0038] For the convenience of description, terms for signals, terms representing channels, terms representing control information, terms representing network entities, and terms representing components of devices used in the following description are shown. Therefore, the present disclosure is not limited to the terms to be described, and other terms with the same technical meaning may be used.

[0039] In addition, the present disclosure uses terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP)) to explain various embodiments, but this is only an example for description. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0040] In the following, uplink refers to a radio link for transmitting data or control signals from a user equipment (UE) or a mobile station (MS) to an eNode B or a base station (BS), and downlink refers to a radio link for transmitting data or control signals from an eNodeB to a UE in the present disclosure. In addition, an eNode B is an entity that performs resource allocation for a UE, and may be at least one of an eNode B, a Node B, a BS, a next generation Node B (gNB) radio access unit, a BS controller, or a node on a network. A UE may include a UE, an MS, a cellular phone, a smart phone, a computer, or a multimedia system for performing a communication function.

[0041] The commercialization of the 5th generation (5G) communication system (hereinafter, may be used interchangeably with 5G system, new radio or next generation radio (NR) system) is to meet the demand for wireless data traffic, and similar to 4G, high data rate services are provided to users through the 5G system, and it is predicted that wireless communication services for various purposes such as the Internet of Things and services requiring high reliability for specific purposes may be provided.

[0042] Open-RAN (O-RAN), established by operators and equipment providers in a system where the current 4G communication system and the 5G system are mixed, defines new network elements (NEs) and interface standards based on existing 3GPP standards, thereby presenting an O-RAN structure. O-RAN redefines the existing 3GPP network entity (NE), radio unit (RU), distributed unit (DU), central unit (CU) control plane (CP) and CU user plane (UP) as O-RU, O-DU, O-CU-CP and O-CU-UP, respectively. In addition, O-RAN also standardizes near real-time RAN intelligent controller (RIC) and non-real-time (NRT) RIC. For example, RIC can be a server densely deployed in one physical place. In addition, RIC can be a logical node for collecting information about cell sites transmitted and received by UE and O-DU, O-CU-CP or O-CU-UP. O-DU and RIC, O-CU-CP and RIC, and O-CU-UP and RIC can be connected via Ethernet. To this end, the communication between O-DU and RIC, between O-CU-CP and RIC, and between O-CU-UP and RIC requires interface standards, and the message formats such as E2-DU, E2-CU-CP, E2-CU-UP require process definitions between O-DU, O-CU-CP, O-CU-UP and RIC. Specifically, users in the virtualized network require differentiated service support, and it is necessary to define the functions of the messages of E2-DU, E2-CU-CP and E2-CU-UP to support services in a wide cell coverage by centralizing the call processing message / function generation in O-RAN to RIC.

[0043] Specifically, RIC can generate and transmit an E2 subscription message to O-DU, O-CU-CP or O-CU-UP to set the event occurrence condition. O-DU, O-CU-CP or O-CU-UP can determine that the set condition is met, load the 3GPP call processing message corresponding to the satisfied condition in the container to RIC, classify it into user identifier, cell identifier, network slice identifier, etc., and then transmit it through E2 indication / report.

[0044] Call processing messages collected in O-RAN based on user identifiers can be identified as RIC for specific users / specific cells / specific network slices for each I / F. The collected information can be transmitted from at least one of (O-)CU-CP, (O-)CU-UP and (O-)DU. RIC can identify that the information collected from different entities is related to a specific user / specific cell / specific network slice based on the user identifier, provide dedicated services to specific users / specific cells / specific network slices for multiple cells / network slices based on the collected information, and determine the key performance indicators (KPIs) of the services to be provided to each user.

[0045] Since general call processing services are limited on a base station basis, the number of cells that can be supported is limited. In addition, since the collected information is limited to a specific base station, it is impossible to effectively monitor the entire radio resource. According to various embodiments of the present disclosure, RIC can collect call processing information (e.g., E1, F1, X2, XN, RRC, etc.) generated by each I / F or O-RU, O-DU, O-CU-CP or O-CU-UP, respectively, so as to effectively provide resource optimization and wide cell user-specific services or user-requested services for specific users / specific cells / specific network slices. For example, RIC can configure additional carriers to achieve resource optimization by effectively dividing network slices or by serving specific terminals via carrier aggregation, or configure additional cells for performing dual access to serve specific terminals via dual connection (DC). In addition, RIC can configure specific terminals to avoid connecting to specific cells and connect to specific cells during inter-cell mobility. In addition, RIC can effectively perform resource optimization by machine learning based on analysis of the collected information. In addition, the resource optimization of the present disclosure is not limited to the described content. Furthermore, according to the present disclosure, not only information of each terminal can be collected, but also information of each bearer can be collected and analyzed.

[0046] The collected specific user information may be used at the collection server, RIC or NRT-RIC, and may also be provided to an operation support system (OSS) or / and a business support system (BSS) to provide specialized services to the user.

[0047] Figure 1 An example of a 4th generation (4G) long term evolution (LTE) core system is shown.

[0048] refer to Figure 1The LTE core system includes a base station 110, a terminal 120, a serving gateway (S-GW) 130, a packet data network gateway (P-GW) 140, a mobility management entity (MME) 150, a home subscriber server (HSS) 160, and a policy and charging rules function (PCRF) 170.

[0049] The base station 110 is a network infrastructure for providing radio access to the terminal 120. For example, the base station 110 is a device that performs scheduling by collecting status information such as the buffer status, available transmission power, and channel status of the terminal 110. The coverage of the base station 110 is defined as a specific geographical area based on the signal transmission distance. The base station 110 is connected to the MME 150 via the S1-MME interface. In addition to the base station, the base station 110 may also be referred to as an "access point (AP)", "eNodeB (eNB)", "radio point", "transmission / reception point (TRP)" or other terms with equivalent technical meanings.

[0050] The terminal 120 is a device used by a user and performs communication with the base station 110 on a radio channel. In some cases, the terminal 120 can operate without user participation. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by the user. In addition to the terminal, the terminal 120 may be referred to as a "UE", "mobile station", "user station", "user premises equipment (CPE)", "remote terminal", "wireless terminal" or "user device" or other terms with equivalent technical meanings.

[0051] The S-GW 130 provides a data bearer and generates or controls the data bearer under the control of the MME 150. For example, the S-GW 130 processes a packet arriving from the base station 110 or a packet to be forwarded to the base station 110. In addition, the S-GW 130 can perform an anchoring role in the handover of the terminal 120 located between base stations. The P-GW 140 can work as a connection point with an external network (e.g., an Internet network). In addition, the P-GW 140 assigns an Internet Protocol (IP) address to the terminal 120 and serves as an anchor point for the S-GW 130. In addition, the P-GW 140 can apply a Quality of Service (QoS) policy for the terminal 120 and manage account data.

[0052] The MME 150 manages the mobility of the terminal 120. In addition, the MME 150 may perform authentication, bearer management, etc. for the terminal 120. That is, the MME 150 is responsible for the mobility management and various control functions of the terminal. The MME 150 may cooperate with a serving general packet radio service (GPRS) support node (SGSN).

[0053] The HSS 160 stores key information and user profile used for authentication of the terminal 120. If the terminal 120 accesses the network, the key information and user profile are transmitted from the HSS 160 to the MME 150.

[0054] PCRF 170 defines policies and charging rules. The stored information is forwarded from PCRF 180 to P-GW 140, and P-GW 140 may control terminal 120 (eg, QoS management, charging, etc.) based on the information provided from PCRF 180.

[0055] Carrier aggregation (hereinafter referred to as "CA") technology is a technology that combines multiple component carriers, and uses multiple component carriers to transmit and receive signals at one terminal at the same time, thereby improving the frequency utilization efficiency of the terminal or the base station. Specifically, according to the CA technology, the terminal and the base station can use broadband transmission and reception signals using multiple component carriers in the uplink (UL) and downlink (DL), wherein the component carriers are located in different frequency bands, respectively. Thereafter, UL represents a communication link through which the terminal transmits a signal to the base station, and DL represents a communication link through which the base station transmits a signal to the terminal. At this time, the number of uplink component carriers and downlink component carriers may be different.

[0056] Dual connectivity or multi-connectivity is a technology used to improve the frequency usage efficiency of terminals or base stations, in which a terminal is connected to multiple different base stations and uses carriers in multiple base stations located in different frequency bands to simultaneously transmit and receive signals. The terminal can be simultaneously connected to a first base station (for example, a base station providing services using LTE technology or 4G mobile communication technology) and a second base station (for example, a base station providing services using NR technology or 5G mobile communication technology) to transmit and receive traffic. In this case, the frequency resources used by each base station may be located in different frequency bands. Therefore, the operating scheme of the dual connectivity scheme based on LTE and NR can be called 5G non-independent (NSA).

[0057] Figure 2a An example of a 5G NSA system is shown.

[0058] refer to Figure 2a, the 5G NSA system includes NR RAN 210a, LTE RAN 210b, terminal 220 and evolved packet core network (EPC) 250. NR RAN 210a and LTE RAN 210b are connected to EPC 150, and terminal 220 can be served by any one or both of NR RAN 210a and LTE RAN 210b at the same time. NR RAN 210a includes at least one NR base station, and LTE RAN 210b includes at least one LTE base station. In this document, NR base stations may be referred to as "5G nodes", "gNBs" or other terms with equivalent technical meanings. In addition, the NR base station may have a structure divided into CU and DU, and the CU may also have a structure divided into CU-CP units and CU-UP units.

[0059] In the structure shown in Figure 2, the terminal 220 can perform radio resource control (RRC) access through a first base station (e.g., a base station belonging to LTE RAN210b), and can provide services with functions provided in the control plane (e.g., connection management, mobility management, etc.). In addition, the terminal 220 can receive additional radio resources for transmitting and receiving data via a second base station (e.g., a base station belonging to NR RAN 210a). This dual connection technology using LTE and NR can be called Evolved Universal Terrestrial Radio Access (E-UTRA)-NR (EN)-dual connection (DC). Similarly, the dual connection technology in which the first base station uses NR technology and the second base station uses LTE technology is called NR-E-UTRA (NE)-DC. In addition, various embodiments can be applied to various types of multi-connection and CA technologies. In addition, even if the first system using the first communication technology and the second system using the second communication technology are implemented in one device, or if the first base station and the second base station are located in the same geographical location, the various embodiments may also be applicable.

[0060] Figure 2b An example architecture of O-RAN is shown. For the purpose of E2-SM-KPI Monitoring (KPIMON) of the E2 service model, O-RAN non-standalone in multi-connectivity operation using E-UTRA and NR radio access technologies is considered, while the E2 nodes can be assumed to be in O-RAN standalone mode.

[0061] refer to Figure 2b When deploying O-RAN non-standalone mode, the eNB is connected to the EPC via the S1-C / S1-U interface and to the O-CU-CP via the X2 interface. The O-CU-CP for deploying O-RAN standalone mode can be connected to the 5G core (5GC) via the N2 / N3 interface.

[0062] Figure 3FIG. 2 shows a protocol stack of an E2 application protocol message in a radio access network according to various embodiments of the present disclosure. Figure 3 , the control plane includes a transport network layer and a radio network layer. The transport network layer includes a physical layer 310 , a data link layer 320 , an IP 330 , and a stream control transmission protocol (SCTP) 340 .

[0063] The radio network layer includes E2AP 350. E2AP 350 is used to deliver a subscription message, an indication message, a control message, a service update message, and a service query message, and is transmitted in an upper layer of SCTP 340 and IP 330.

[0064] Figure 4 An example of connection between a base station and an RIC in a radio access network according to various embodiments of the present disclosure is shown.

[0065] refer to Figure 4 , RIC 440 is connected to O-CU-CP 420, O-CU-UP 410 and O-DU 430. RIC 440 is a device for controlling RAN nodes (or a device for performing RAN functions, such as O-CU-CP 420, O-CU-UP 410 and O-DU430). RIC 440 can be defined as a device for customizing RAN functions for new services or regional resource optimization. RIC 440 can provide functions such as network intelligence (e.g., policy execution, switching optimization), resource guarantee (e.g., radio link management, advanced self-organizing network (SON)), resource control (e.g., load balancing, slicing strategy). RIC 440 can communicate with O-CU-CP420, O-CU-UP 410 and O-DU 430. RIC 440 can be connected to each node via E2-CP, E2-UP and E2-DU interfaces. In addition, the interface between O-CU-CP and DU and between O-CU-UP and DU can be referred to as F1 interface. In the following description, DU and O-DU, CU-CP and O-CU-CP, and CU-UP and O-CU-UP may be used interchangeably.

[0066] Although Figure 4 One RIC 440 is shown, but according to various embodiments, there may be multiple RICs. The multiple RICs may be implemented with multiple hardware located in the same physical location, or may be implemented through virtualization using a single hardware.

[0067] Figure 5 The configuration of the device according to various embodiments of the present disclosure is shown. Figure 5 The structure shown can be understood as having Figure 5The term "unit" or "device" used hereinafter refers to a unit for processing at least one function or operation and can be implemented using hardware, software, or a combination of hardware and software.

[0068] refer to Figure 5 The core network device includes a communication unit 510, a storage unit 520 and a control unit 530.

[0069] The communication unit 510 provides an interface for performing communication with other devices in the network. That is, the communication unit 510 converts the bit string transmitted from the core network device to the other devices into a physical signal, and converts the physical signal received from the other devices into a bit string. In other words, the communication unit 510 can transmit and receive signals. Therefore, the communication unit 510 can be referred to as a modem, a transmitter, a receiver, or a transceiver. In this case, the communication unit 510 enables the core network device to communicate with other devices or systems via a backhaul connection (e.g., a wired backhaul or a wireless backhaul) or on a network.

[0070] The storage unit 520 stores data such as basic programs, application programs, and setting information for the operation of the core network device. The storage unit 520 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 520 provides the stored data according to a request of the control unit 530.

[0071] The control unit 530 controls the general operation of the core network device. For example, the control unit 530 transmits and receives signals through the communication unit 510. In addition, the control unit 530 records data in the storage unit 520 and reads data from the storage unit 520. To this end, the control unit 530 may include at least one processor. According to various embodiments, the control unit 530 may control the device to perform operations according to various embodiments described in the present disclosure.

[0072] Figure 6 1 and 2 illustrate logical functions related to E2 messages of an E2 node and an RIC in a radio access network according to various embodiments of the present disclosure.

[0073] refer to Figure 6, the RIC 640 and the E2 node 610 can transmit or receive E2 messages to each other. For example, the E2 node 610 can be an O-CU-CP, an O-CU-UP, an O-DU, or a base station. The communication interface of the E2 node can be determined according to the type of the E2 node 610. For example, the E2 node 610 can communicate with another E2 node 616 through an E1 interface or an F1 interface. Alternatively, for example, the E2 node 610 can communicate with the E2 node 616 through an X2 interface or an XN interface. Alternatively, for example, the E2 node 610 can perform communication through an S1 interface or a Next Generation Application Protocol (NGAP) interface (i.e., an interface between a Next Generation (NG) RAN node and an AMF).

[0074] The E2 node 610 may include an E2 node function 612. The E2 node function 612 is a function corresponding to a specific xApp (application S / W) 646 installed in the RIC 640. For example, in KPI monitoring, the KPI monitoring collection S / W may be installed in the RIC 640, and the E2 node 610 may include an E2 node function 612 that generates KPI parameters and then forwards an E2 message including the KPI parameters to an E2 terminal 642 located at the RIC 640. The E2 node 610 may include a radio resource management (RRM) 614. The E2 node 610 may manage resources provided to a radio network for a terminal.

[0075] The E2 terminal 624 located in the RIC 640 is a terminal of the RIC 640 for E2 messages, and can perform a function of interpreting the E2 message forwarded by the E2 node 610 and then transmit it to the xApp 646. The database (DB) 644 located in the RIC 640 can be used for the E2 terminal 624 or the xApp 616. Figure 6 The illustrated E2 node 610 is a terminal of at least one interface and may be understood as a terminal of messages transmitted to terminals, neighboring base stations, and a core network.

[0076] Figure 7a An example of the signaling process between the E2 node and the RIC is shown. Specifically, Figure 7a The establishment process of E2I / F between the E2 node and the RIC and the RIC subscription message relay process are shown. The E2 node 610 is shown as the E2 node, and the RIC 640 is shown as the RIC.

[0077] refer to Figure 7aIn step 701, the E2 node 610 may transmit an E2 SET UP REQUEST message to the RIC 640. The E2 NODE FUNCTION function located in the E2 node 610 finds the RIC using the RIC IP address set to operation, administration, and management (OAM), and transmits an E2 SET UP REQUEST message. The E2 SET UP REQUEST message includes a RAN function definition, which defines the functions of the RAN supported by the E2 node, E2 node ID information, etc. The RAN function definition value is a value set to OAM, and the RIC may receive information of the value set with OAM, and determine which call processing function the E2 node supports with the RAN function definition value.

[0078] The RIC may receive an E2 setup response message from the E2 node in step 703. If the E2 SETUP REQUEST message transmitted by the E2 node is accepted, the RIC may transmit an E2 SETUP RESPONSE message.

[0079] In step 705, the RIC may transmit a subscription request message to the E2 node. A specific xApp located in the RIC requests the RIC E2 terminal function to subscribe (or register) a specific RAN function definition function supported by the E2. In this document, according to an embodiment, the subscription request message of step 705 may be included in the E2SETUP RESPONSE message of step 703 and transmitted together. For example, the RAN function may include functions of X2AP, F1AP, E1AP, S1AP, and NGAP interfaces, or include internal RAN functions for controlling UEs or cells.

[0080] In step 707, the E2 node may transmit the subscription request response to the RIC. The E2 node function of the E2 node decodes the subscription request message, successfully sets the event condition requested by the RIC to the E2 node function, and then transmits the subscription response of the successfully set event trigger condition to the RIC.

[0081] In step 709, the E2 node may transmit an E2RIC indication message to the RIC. If a specific event condition occurs, the E2 node transmits the E2RIC indication message to the RIC.

[0082] The E2 node may transmit a service update message to the RIC in step 711. If the E2NODE functional capability information element (E2NodeCapa) is changed, the E2 node transmits the changed E2NodeCapa in E2SERVICEUPDATE to the RIC.

[0083] exist Figure 7a, the SET UP process, the RIC subscription process, the RIC indication process and the update message transmission process are described in sequence, but the various embodiments of the present disclosure are not limited to the above order and process. That is, in some embodiments, the E2 node and the RIC can independently perform the E2 establishment process of steps 701 to 703. In some embodiments, the E2 node and the RIC can independently perform the subscription process of steps 705 to 707. At the same time, according to another embodiment, the E2 establishment response message may include the subscription request message as described above. In some embodiments, the E2 node and the RIC can independently perform the RIC indication process of step 709. In addition, in some embodiments, the E2 node and the RIC can independently perform the RIC indication process of step 709. In addition, the E2 node and the RIC can perform at least some of the above processes together or separately.

[0084] Figure 7b An example of a subscription process between an E2 node and a RIC is shown. The E2 node 610 is shown as an E2 node, and the RIC 640 is shown as a RIC.

[0085] refer to Figure 7b In step 751, the RIC may request a subscription from the E2 terminal. For example, the E2 relay xApp located in the RIC may request a subscription from the RIC E2 terminal function to the initial UE message in the NGAP I / F for the E2 relay message function.

[0086] In step 753, the RIC may transmit the RIC subscription request to the E2 node. For example, the RIC E2 terminal function generates an initial UE message relay message for the NGAP I / F requested in step 751 as an E2 subscription request message and transmits it to the E2 node.

[0087] In step 755, the E2 node may transmit the RIC subscription response to the RIC. Specifically, the E2 node function of the E2 node that receives the E2 subscription request message may decode the message, successfully set the event condition for transmission to the RIC in a container including the RIC indication message for each UE, each cell, or each network slice (if the initial UE message occurs in the NGAP I / F), and then transmit the subscription response for successfully setting the event trigger condition to the RIC.

[0088] In step 757, the E2 node may transmit the RIC indication to the RIC. If the UE initiates an initial UE message in NGAP I / F, the E2 node may transmit an E2RIC indication message including the NGAP initial UE message in a container to the RIC.

[0089] Figure 7aSome of the content described can be applied in the same or similar manner to Figure 7b .

[0090] Figure 8 The IEs of the E2 subscription request message are shown. The first IE is the message type, and the message type has a unique value for each E2 message. The details of the message type are in Fig. 9 Displayed in.

[0091] The second IE specifies the specific xApp with the RIC REQUEST ID. The message details are in Fig.10 Displayed in.

[0092] The third IE is the E2NODE FUNCTION ID. The E2NODE FUNCTION ID can be divided into range values ​​for each E2 node, thereby assigning a specific E2NODE FUNCTION to a specific E2 node. The details of the message are in Fig.11 Displayed in.

[0093] The fourth IE is RIC SUBSCRIPTION TYPE, and event trigger conditions can be set by adding various types to the E2 node. The details of the event trigger condition types are in Fig.12 , and the E2 message relay defined in this disclosure is one of the event trigger condition types, and the details of the message are shown in Fig.13 show.

[0094] Fig. 9 It is the details of the message type IE. The procedure code value as the first IE is an integer in the range of 0 to 255, and a specific MESSAGE TYPE (PROCEDURE CODE) is set. For example, the procedure code value 0 can be set to subscription, the procedure code value 1 can be set to E2SETUP configuration, and the procedure code value 2 can be set to the indication request message value of 0 to 255, that is, a total of 256 message value configurations. For example, O-RAN defines [Table 1], as follows.

[0095]

Table 1

[0096]

[0097]

[0098] The type of the message as the second IE in the message type indicates the message type, and can define a start, success, or unsuccessful message.

[0099] Fig.10It is the RIC REQUEST ID value. The RIC REQUEST ID value is an integer in the range of 0 to 65535, and a value unique to a specific xApp can be set.

[0100] Fig.11 Is the E2NODE FUNCTION ID value. The E2NODE FUNCTION ID value is an integer value in the range of 0 to 4095, and can be set by dividing the range value of each E2 node.

[0101]

Table 2

[0102]

[0103] Values ​​after 2048 are reserved and may be set if additional E2 nodes are added.

[0104] Fig.12 It is a RIC SUBSCRIPTION TYPE value. The RIC SUBSCRIPTION TYPE value is an integer in the range of 0 to 255 and can be defined as a trigger value for a specific function of a specific E2NODEFUNCTION of an E2 node. For example, an I / F-based message relay function can be defined as RIC SUBSCRIPTION TYPE 0.

[0105] Fig.13 is an example of a detailed message used for the E2 message relay function proposed in the present disclosure.

[0106] The first IE INTERFACE AP ID is an integer ranging from 1 to 32 and specifies a specific I / F. For example, up to 32 I / Fs can be defined, in order: the setting value of LTE-RRC of the UU interface between the UE and the LTE eNB is '0', the setting value of NRRRC of the UU interface between the 5G NR O-CU-CP and the terminal is '1', the F1 interface is '2', the E1 interface is '3', the X2 interface is '4', the XN interface is '5', the NGAP interface is '6', and the S1 interface is '7'.

[0107] The second IE Global Node ID is an optional IE, and if the X2 of LTE and the XN I / F messages of 5G-NR are relayed and delivered, the other base station that forwards the X2 message is set to be an LTE macro base station, a home eNB (HeNB) base station, or a 5G-NR base station.

[0108] The third IE is the MESSAGE PROCOL ID list, which can be classified into two types: an "all messages" IE that specifies relays for all messages of each I / F and a partial message list IE that specifies relays only for specific messages of each I / F. The partial message list can specify up to 256 messages, and each message can be defined with a message ID and an optional interface direction defined in the subscription message information. The message ID is a unique value defined for the I / F in each LTE base station and 5G NR base station in 3GPP, and if the MESSAGE TYPE (PROCEDURE CODE) value of 3GPP can be used, the value additionally defined by O-RAN can also be used. Examples of values ​​defined in 3GPP are shown in [Table 3] below.

[0109]

Table 3

[0110]

[0111] The interface direction defined as an optional IE can be set for I / F messages that can be forwarded bidirectionally (such as X2 / XN), and can set whether the I / F message requesting RIC relay is an incoming message or an outgoing message from other E2 nodes (e.g., eNB, O-CU-CP).

[0112] Fig.14 It is an example of a detailed message used for the E2 relay subscription response function proposed by the present invention.

[0113] The first IE is the message type and has a unique value for each E2 message. Details of the message type are in Fig. 9 Displayed in.

[0114] The second IE specifies a specific xApp with the RIC REQUEST ID. The details of the message are in Fig.10 Displayed in.

[0115] The third IE is the E2NODE FUNCTION ID. The E2NODE FUNCTION ID is divided into range values ​​for each E2 node to assign a specific E2NODE FUNCTION to a specific E2 node. The details of the message are in Fig.11 Displayed in.

[0116] The fourth IE is the subscription message condition, and it is (multiple) IEs, and if the subscription process fails, it sets the failure message ID; if all messages are set, it means that the I / F set in the E2 subscription request message INTERFACE AP ID is not available for subscription, and if a partial message list is set, subscription cannot be made because the subscription is limited to specific application protocol messages set in the list of message IDs.

[0117] Through various embodiments of the present disclosure, event conditions (each I / F, each call processing function) can be set in the call processing function of the O-RU, O-DU, O-CU-CP or O-CU-UP (i.e., the E2 node using the E2SUBSCRIPTION message) to transmit the 3GPP message to the RIC by including the 3GPP message in a specific call processing function generated for each I / F or a container for each call processing function, thereby effectively providing the call processing request service of the RIC.

[0118] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in software, hardware, or a combination of hardware and software.

[0119] For software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors of an electronic device. One or more programs may include instructions for controlling an electronic device to perform a method according to an embodiment described in the claims or specification of the present disclosure.

[0120] Such a program (software module, software) may be stored in a random access memory, a non-volatile memory (including a flash memory, a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), a magnetic disk storage device, a compact disk (CD)-ROM, a digital versatile disk (DVD) or other optical storage device), and a magnetic tape. Alternatively, such a program may be stored in a memory that combines some or all of these recording media. A plurality of memories may be included.

[0121] In addition, the program can be stored in an attachable storage device, which can be accessed via a communication network (such as the Internet, an intranet, a local area network (LAN), a wide area network (WLAN), or a storage area network (SAN) or a communication network combining these networks). Such a storage device can access the device that performs the embodiments of the present disclosure through an external port. In addition, a separate storage device on the communication network can access the device that performs the embodiments of the present disclosure.

[0122] In the specific embodiments of the present disclosure, the components included in the present disclosure are expressed in singular or plural form. However, the singular or plural expression is appropriately selected for convenience of explanation according to the proposed situation, and the present disclosure is not limited to a single component or multiple components. The component expressed in plural form can be configured as a single component, and the component expressed in singular form can be configured as multiple components.

[0123] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it should be noted that various changes may be made to the specific embodiments without departing from the scope of the present disclosure.

Claims

1. A method performed by an E2 node, the method comprising: receiving a RIC subscription request message from a radio access network (RAN) intelligent controller (RIC) via an E2 interface; as well as Send a RIC subscription response message to the RIC via the E2 interface as a response to the RIC subscription request message, The RIC subscription request message includes first information indicating a network interface type and second information indicating a node identifier (ID), and In the case where the first information indicates an X2 interface, the node ID indicates one of an evolved NodeB (eNB) ID or a new radio (NR) base station ID.

2. The method according to claim 1, wherein: The network interface type includes at least one of an F1 interface, an E1 interface, an X2 interface, an XN interface, an NG interface, or an S1 interface.

3. The method according to claim 1, in, The RIC Subscription Request message includes the RAN Function ID, and The RIC subscription request message is a message used to subscribe to a function corresponding to the RAN function ID of the E2 node.

4. The method according to claim 1, in, The RIC subscription request message further includes third information indicating a message protocol ID and fourth information indicating an interface direction, and The interface direction includes at least one of incoming and outgoing.

5. The method according to claim 1, wherein: In case that the RIC subscription response message is sent to notify that the RIC subscription request message fails, the RIC subscription response message includes the ID of the RIC subscription request message.

6. The method according to claim 1, in, The RIC is a near real-time (RT) RIC, and Among them, the E2 node includes the O-RAN distributed unit (O-DU), the O-RAN central unit control plane (O-CU-CP), the O-RAN central unit user plane (O-CU-UP) or the O-RAN eNodeB (O-eNB).

7. A method performed by a Radio Access Network (RAN) Intelligent Controller (RIC), the method comprising: Sending a RIC subscription request message to the E2 node via the E2 interface; as well as receiving a RIC subscription response message from the E2 node via the E2 interface as a response to the RIC subscription request message, The RIC subscription request message includes first information indicating a network interface type and second information indicating a node identifier (ID), and In the case where the first information indicates an X2 interface, the node ID indicates one of an evolved NodeB (eNB) ID or a new radio (NR) base station ID.

8. The method according to claim 7, wherein: The network interface type includes at least one of an F1 interface, an E1 interface, an X2 interface, an XN interface, an NG interface, or an S1 interface.

9. The method according to claim 7, in, The RIC Subscription Request message includes the RAN Function ID, and The RIC subscription request message is a message used to subscribe to a function corresponding to the RAN function ID of the E2 node.

10. The method according to claim 7, in, The RIC subscription request message further includes third information indicating a message protocol ID and fourth information indicating an interface direction, and The interface direction includes at least one of incoming and outgoing.

11. The method according to claim 7, wherein: In case that the RIC subscription response message is sent to notify that the RIC subscription request message fails, the RIC subscription response message includes the ID of the RIC subscription request message.

12. The method according to claim 7, in, The RIC is a near real-time (RT) RIC, and The E2 nodes include the O-RAN distributed unit (O-DU), the O-RAN central unit control plane (O-CU-CP), the O-RAN central unit user plane (O-CU-UP) or the O-RAN eNodeB (O-eNB).

13. A device operating as an E2 node, the device comprising: Transceiver; as well as A controller is coupled to the transceiver and is configured to perform the method of any one of claims 1 to 6.

14. An apparatus operating as a Radio Access Network (RAN) Intelligent Controller (RIC), the apparatus comprising: Transceiver; as well as A controller is coupled to the transceiver and is configured to perform the method of any one of claims 7 to 12.

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