Apparatus and method for relaying service subscription events over e2 interface in radio access network communication system

Abstract

To provide 5G (5th generation) or pre-5G communication systems to support higher data transmission rates than 4G (4th generation) communication systems such as LTE (Long Term Evolution).SOLUTION: According to various embodiments of the present disclosure, a method performed by an E2 node includes a step of sending a radio access network (RAN) intelligent controller (RIC) indication message to an RIC via an E2 interface, the RIC indication message includes information regarding an indication type, which may be one of types including "insert" and "report."SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates generally to radio access network communication systems, and more particularly to an apparatus and method for transmitting a message when a service event occurs to a base station according to an open radio access network (O-RAN) standard using an E2 message in a wireless communication system. [Background technology]

[0002] 4G(4 th Since the commercialization of the 5G (5th generation) communication system, improved 5G (5G) technology has been developed to meet the increasing demand for wireless data traffic. th Efforts are being made to develop 5G (5th generation) or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are also called beyond 4G network communication systems or post-LTE (Long Term Evolution) systems.

[0003] To achieve high data transmission rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., 60 GHz bands). To mitigate the path loss of radio waves in the ultra-high frequency bands and increase the transmission distance of radio waves, technologies such as beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large scale antennas are being discussed for 5G communication systems.

[0004] In addition, to improve the system network, technologies such as advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and receiver interference cancellation are being developed for 5G communication systems.

[0005] In addition, 5G systems are being developed with advanced coding modulation (ACM) methods such as FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Code Multiple Access).

[0006] To meet the demand for wireless data traffic, 5G systems, or new radio or next radio (NR), have been commercialized, providing users with high data transmission rate services similar to 4G, and are expected to provide wireless communication services for a variety of purposes, such as the Internet of Things and services requiring high reliability for specific purposes.Currently, the open radio access network (O-RAN), established by operators and equipment providers in a system that combines 4G and 5G systems, is proposing the O-RAN architecture by defining new network element (NE) and interface standards based on the existing 3GPP (3rd Generation Partnership Project) standards. Summary of the Invention [Problem to be solved by the invention]

[0007] With the commercialization of 4th / 5th generation communication systems (hereinafter referred to as 4G / 5G systems, NR (new radio or next radio)), users are now demanding differentiated service support through virtualized networks. O-RAN defines the existing 3GPP (3rd Generation Partnership Project) NE (network element), RU (radio unit), DU (distributed unit), CU-CP (central unit-control plane), and CU-UP (central unit-user plane) as O-RU, O-DU, O-CU-CP, and O-CU-UP, respectively, and also standardizes a near-real-time RAN intelligent controller (RIC).

[0008] The present disclosure relates to an E2 Subscription message that a newly defined RIC uses to request a service from an O-RU, O-CU-CP, or O-CU-UP. The present disclosure also relates to a method for processing the E2 Subscription message by dividing it into UE units, group units, cell units, and network slice units. Here, the O-RU, O-DU, O-CU-CP, and O-CU-UP can be understood as objects constituting a RAN that can operate in accordance with the O-RAN standard, and can be referred to as E2 nodes.

[0009] The RIC generates an E2 subscription request message and transmits it to an E2 node (e.g., O-CU-CP, O-CU-UP, O-DU) to set up a call processing event, and after the event is set up, the E2 node transmits a subscription request response message to the RIC. This disclosure relates to an E2 indication message that a newly defined RIC receives in the form of a container by dividing call processing messages corresponding to E2 events that occurred in the O-DU, O-CU-CP, or O-CU-UP into an overall message set under subscription event conditions or by a specific application protocol per I / F, and by cell, group ID, network slice, or UE.

[0010] The present disclosure for solving the above problems is characterized in that, in a method for a first node in a wireless communication system, an E2 NODE classifies call processing messages received from a call processing block by I / F and by Application Protocol messages, generates the classified messages into containers for each cell, UE, Group ID, and Network slice, and transmits the E2 NODE an E2 Indication message to a RIC. In addition, the E2 Indication message can be confirmed based on a detailed Information Element of the E2 Indication transmitted from the RIC, and the Information Element information can include MESSAGE TYPE identifier information, RIC REQUEST ID identifier information, E2 NODE FUNCTION ID identifier information, and RIC SUBSCRIPTION TYPE identifier information set based on the call processing function of the E2 NODE. [Means for solving the problem]

[0011] According to various embodiments of the present disclosure, a method performed by an E2 node includes a step of sending a RIC indication message to a RAN (radio access network intelligent controller) via an E2 interface, the RIC indication message including information regarding an indication type, which may be one of types including "insert" and "report."

[0012] According to various embodiments of the present disclosure, a method performed by a RAN (radio access network intelligent controller) includes receiving a RIC indication message from an E2 node via an E2 interface, the RIC indication message including information regarding an indication type, which may be one of types including "insert" and "report."

[0013] According to various embodiments of the present disclosure, an apparatus functioning as an E2 node includes at least one transceiver and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to send a RIC indication message to a RAN (radio access network intelligent controller) via an E2 interface, the RIC indication message including information regarding an indication type, and the indication type may be one of types including "insert" and "report."

[0014] According to various embodiments of the present disclosure, an apparatus functioning as a RAN (radio access network) intelligent controller (RIC) includes at least one transceiver and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to receive a RIC indication message from an E2 node via an E2 interface, the RIC indication message including information regarding an indication type, which may be one of types including "insert" and "report." [Effects of the Invention]

[0015] The apparatus and method according to various embodiments of the present disclosure enable providing an effective service procedure between a near real-time (RT) RIC and an E2 node by indicating the type of RIC (RAN intelligent controller) service via an indication message from the E2 node.

[0016] The effects obtained by the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those having ordinary skill in the art to which the present disclosure pertains from the following description. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram illustrating an example of a 4G (4th generation) LTE (Long Term Evolution) core system. [Figure 2A] FIG. 1 is a diagram illustrating an example of a 5G (5th generation) NSA (non-standard alone) system. [Figure 2B] FIG. 1 illustrates an example architecture for O-RAN. [Figure 3] FIG. 2 illustrates a protocol stack for an E2 application protocol message in a radio access network according to various embodiments of the present disclosure. [Figure 4] 1 illustrates an example of a connection between a base station and a radio access network intelligence controller (RIC) in a radio access network according to various embodiments of the present disclosure. [Figure 5] FIG. 1 illustrates an arrangement of devices in a radio access network according to various embodiments of the present disclosure. [Figure 6]FIG. 2 illustrates logical functions associated with E2 messages of an E2 node and a RIC in a radio access network according to various embodiments of the present disclosure. [Figure 7A] FIG. 10 is a diagram illustrating an example of a signaling procedure between an E2 node and a RAN (radio access network) intelligent controller (RIC). [Figure 7B] A diagram showing an example of a subscription procedure between an E2 node and a RIC. [Figure 8] FIG. 10 is a diagram illustrating an example of a message used for a Message Relay procedure based on an E2 indication. [Figure 9] FIG. 10 is a diagram illustrating an example of a message used for a Message Relay procedure based on an E2 indication. [Figure 10] FIG. 10 is a diagram illustrating an example of a message used for a Message Relay procedure based on an E2 indication. [Figure 11] FIG. 10 is a diagram illustrating an example of a message used for a Message Relay procedure based on an E2 indication. [Figure 12] FIG. 10 is a diagram illustrating an example of a message used for a Message Relay procedure based on an E2 indication. DETAILED DESCRIPTION OF THE INVENTION

[0018] The terms used in this disclosure are merely used to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression can include a plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, can have the same meaning as commonly understood by a person of ordinary skill in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary can be interpreted as meanings that are the same as or similar to their meanings in the context of the relevant art, and should not be interpreted as idealized or overly formal unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure cannot be interpreted to exclude embodiments of the present disclosure.

[0019] In the various embodiments of the present disclosure described below, a hardware approach is described as an example, but since the various embodiments of the present disclosure include techniques that use both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0020] The present disclosure relates to an apparatus and method for performing a subscription procedure between devices in a radio access network (RAN) and devices controlling the RAN in a wireless communication system.

[0021] Terms used in the following description, such as those referring to signals, channels, control information, network entities, and device components, are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms used below, and other terms having equivalent technical meanings may be used.

[0022] Although the present disclosure describes various embodiments using terminology used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project)), this is merely an example for the purpose of explanation. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0023] Hereinafter, in this disclosure, uplink refers to a wireless link through which a terminal (User Equipment, UE, or Mobile Station, MS) transmits data or control signals to a base station (eNode B, or base station, BS), and downlink refers to a wireless link through which a base station transmits data or control signals to the terminal. The base station is an entity that allocates resources to the terminal and may be at least one of an eNode B, a Node B, a Base Station (BS), a generation Node B (gNB) radio access unit, a base station controller, or a node on a network. The terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions.

[0024] To meet the demand for wireless data traffic, the fifth generation communication system (hereinafter referred to as the 5G system, sometimes referred to as the NR (new radio) or next radio) system) has been commercialized. Similar to 4G, the 5G system provides users with high data transmission rate services. It is also expected that wireless communication services for various purposes, such as the Internet of Things and services requiring high reliability for specific purposes, can be provided.

[0025] The open radio access network (O-RAN), established by operators and equipment providers in a system currently interoperating with 4G and 5G systems, is emerging through the definition of new network element (NE) and interface standards based on existing 3GPP standards. O-RAN redefines the existing 3GPP NE, radio unit (RU), distributed unit (DU), central unit (CU)-CP (control plane), and user plane (CU-UP) as O-RU, O-DU, O-CU-CP, and O-CU-UP, respectively. Additionally, O-RAN also defines near-real-time RAN intelligent controllers (RICs) and non-real-time (NRT) RICs. For example, a RIC can be a server centrally located in a single physical location. A RIC is also a logical node that can collect information at cell sites where terminals and O-DUs, O-CU-CPs, or O-CU-UPs transmit and receive data. The O-DU and RIC, the O-CU-CP and RIC, and the O-CU-UP and RIC can be connected via Ethernet. Therefore, interface standards for communication between the O-DU and RIC, the O-CU-CP and RIC, and the O-CU-UP and RIC are required, and message standards such as E2-DU, E2-CU-CP, and E2-CU-UP are required to define procedures between the O-DU, O-CU-CP, O-CU-UP, and RIC. In particular, differentiated service support is required for users in virtualized networks, and functional definitions for the E2-DU, E2-CU-CP, and E2-CU-UP messages are required to support services over a wide cell coverage area by concentrating call processing messages / functions generated in the O-RAN in the RIC.

[0026] Specifically, the RIC can set event occurrence conditions by generating and sending an E2 subscription message to the O-DU, O-CU-CP, or O-CU-UP. The O-DU, O-CU-CP, or O-CU-UP determines whether the set conditions are met, and places the 3GPP call processing message that meets the conditions in a container to the RIC, classifies it into user identifiers, cell identifiers, and network slice identifiers, and then transmits it via an E2 indication / report.

[0027] Call processing message information collected by the O-RAN based on a user identifier can be identified by the RIC as being for a specific user / specific cell / specific network slice for each I / F. The collected information may be transmitted from at least one of the (O-)CU-CP, (O-)CU-UP, and (O-)DU. The RIC can confirm that information collected from different entities based on the user identifier is for a specific user / specific cell / specific network slice, and can provide a service specialized for a specific user / specific cell / specific network slice for multiple cells / network slices based on the collected information, and can also determine the KPIs (key performance indicators) of the service provided to each user.

[0028] A typical call processing service is limited to a base station, limiting the number of cells that can be supported. Furthermore, because the collected information is limited to a specific base station, efficient monitoring of overall radio resources is not possible. According to various embodiments of the present disclosure, the RIC collects call processing messages (e.g., E1, F1, X2, XN, RRC, etc.) for each I / F or each generated by the O-RU, O-DU, O-CU-CP, or O-CU-UP, thereby efficiently providing resource optimization and user-specific or user-requested services for a specific user / specific cell / specific network slice across a wide range of cells. For example, the RIC can efficiently divide network slices or configure additional carriers so that a specific terminal can receive services through carrier aggregation for resource optimization, or configure additional cells that perform dual connectivity (DC) so that a specific terminal can receive services through dual connectivity (DC). Furthermore, the RIC can be configured to connect to a specific cell while avoiding connection to a specific cell when moving between cells. In addition, the RIC can efficiently perform resource optimization using machine learning through analysis based on the collected information. However, the resource optimization of the present disclosure is not limited to the described content. Furthermore, according to the present disclosure, it is possible to collect and analyze information not only by terminal but also by bearer.

[0029] The collected information for a particular user may be used by the collection server or RIC (near RIC) or NRT-RIC, but may also be provided to an OSS (operations support system) or / and a BSS (business support system) to provide services tailored to the user.

[0030] FIG. 1 shows an example of a 4G (4th generation) LTE (Long Term Evolution) core system.

[0031] Referring to FIG. 1, the LTE core system includes a base station 110, a terminal 120, an S-GW (serving gateway) 130, a P-GW (packet data network gateway) 140, an MME (mobility management entity) 150, an HSS (home subscriber server) 160, and a PCRF (policy and charging rule function) 170.

[0032] The base station 110 is a network infrastructure that provides wireless connectivity to the terminal 120. For example, the base station 110 is a device that performs scheduling by aggregating status information such as the buffer status, available transmission power, and channel status of the terminal 110. The base station 110 has coverage defined in a predetermined geographical area based on the distance over which a signal can be transmitted. The base station 110 is connected to the MME 150 via an S1-MME interface. In addition to being called a base station, the base station 110 may also be called an "access point (AP)," "eNodeB (eNB)," "wireless point," "transmission / reception point (TRP)," or other terms with equivalent technical meanings.

[0033] Terminal 120 is a device used by a user and communicates with base station 110 via a wireless channel. In some cases, terminal 120 may be operated without user involvement. That is, at least one of terminal 120 and terminal 130 may be a device that performs machine-type communication (MTC) and is not carried by a user. Terminal 120 may also be referred to as a "user equipment (UE)," a "mobile station," a "subscriber station," a "customer-premises equipment (CPE)," a "remote terminal," a "wireless terminal," or a "user device," or other terms with equivalent technical meanings.

[0034] 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 packets arriving from the base station 110 or packets to be forwarded to the base station 110. The S-GW 130 can also act as an anchor during inter-base station handover of the terminal 120. The P-GW 140 can function as a connection point with an external network (e.g., the Internet network). The P-GW 140 can also assign an Internet Protocol (IP) address to the terminal 120 and act as an anchor for the S-GW 130. The P-GW 140 can also apply a Quality of Service (QoS) policy to the terminal 120 and manage account data.

[0035] The MME 150 manages the mobility of the terminal 120. The MME 150 can also perform authentication and bearer management for the terminal 120. That is, the MME 150 is responsible for mobility management and various control functions for the terminal. The MME 150 can interface with an SGSN (serving GPRS support node).

[0036] The HSS 160 stores key information and a subscriber profile for authentication of the terminal 120. The key information and the subscriber profile are transferred from the HSS 160 to the MME 150 when the terminal 120 connects to the network.

[0037] The PCRF 170 defines policies and rules for charging. The stored information is transmitted from the PCRF 180 to the P-GW 140, and the P-GW 140 can perform control (e.g., QoS management, charging, etc.) on the terminal 120 based on the information provided by the PCRF 180.

[0038] Carrier aggregation (hereinafter referred to as "CA") technology is a technology that increases frequency utilization efficiency from the perspective of a terminal or a base station by combining multiple component carriers and allowing one terminal to transmit and receive signals using these multiple component carriers simultaneously. Specifically, with CA technology, a terminal and a base station can transmit and receive wideband signals using multiple component carriers in the uplink (UL) and downlink (DL), respectively, where each component carrier is located in a different frequency band. Hereinafter, uplink refers to a communication link through which a terminal transmits signals to a base station, and downlink refers to a communication link through which a base station transmits signals to a terminal. Herein, the number of uplink component carriers and downlink component carriers may differ.

[0039] Dual / multi-connectivity technology (dual connectivity or multi-connectivity) is a technology that increases frequency utilization efficiency from the perspective of the terminal or base station by allowing a single terminal to connect to multiple different base stations and simultaneously transmit and receive signals using carriers within the multiple base stations located in different frequency bands. A terminal can simultaneously connect to a first base station (e.g., a base station providing services using LTE technology or fourth-generation mobile communication technology) and a second base station (e.g., a base station providing services using new radio (NR) technology or fifth-generation (5G) mobile communication technology) to transmit and receive traffic. The frequency resources used by each base station may be located in different bands. This type of operation based on the dual connectivity method of LTE and NR can be referred to as 5G non-standalone (NSA).

[0040] Figure 2A shows an example of a 5G NSA system.

[0041] Referring to FIG. 2A, the 5G NSA system includes an NR RAN 210a, an LTE RAN 210b, a terminal 220, and an EPC 250. The NR RAN 210a and the LTE RAN 210b are connected to the EPC 150, and the terminal 220 can be served by either the NR RAN 210a or the LTE RAN 210b simultaneously. The NR RAN 210a includes at least one NR base station, and the LTE RAN 210b includes at least one LTE base station. Here, the NR base station may be referred to as a "5th generation Node B (gNB)," a "next generation Node B (gNB)," or other terms having equivalent technical meanings. The NR base station may have a structure separated into a central unit (CU) and a digital unit (DU), and the CU may have a structure separated into a CU-control plane (CP) unit and a CU-user plane (UP) unit.

[0042] In the structure shown in FIG. 2, the terminal 220 performs radio resource control (RRC) connection through a first base station (e.g., a base station belonging to the LTE RAN 210b) and may be served with functions (e.g., connection management, mobility management, etc.) provided by a control plane. The terminal 220 may also be provided with additional radio resources for transmitting and receiving data through a second base station (e.g., a base station belonging to the NR RAN 210a). This dual connectivity technology using LTE and NR may be referred to as EN-DC (evolved universal terrestrial radio access (E-UTRA) - NR dual connectivity). Similarly, a dual connectivity technology in which the first base station uses NR technology and the second base station uses LTE technology is referred to as NE-DC (NR - E-UTRA dual connectivity). Various embodiments may also be applied to various other types of multi-connectivity and carrier aggregation technologies. In addition, various embodiments may also be applied when a first system using a first communication technology and a second system using a second communication technology are embodied in one device, or when a first base station and a second base station are located in the same geographical location.

[0043] Figure 2B shows an example architecture for O-RAN. For purposes of E2-SM-KPIMON (key performance indicator monitoring) of the E2 service model, the E2 node may be assumed to be in O-RAN Stand alone mode, while O-RAN Non-stand alone mode within multi-connectivity operation using E-UTRA and NR radio access technologies is considered.

[0044] Referring to Figure 2B, in an O-RAN non-standalone mode deployment, 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 an O-RAN standalone mode deployment can be connected to the 5GC (5G core) via the N2 / N3 interface.

[0045] 3 illustrates a protocol stack for E2 application protocol messages in a wireless access network according to various embodiments of the present disclosure. Referring to FIG. 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 Internet Protocol (IP) 330, and a stream control transmission protocol (SCTP) 340.

[0046] The wireless network layer includes the E2AP 350. The E2AP 350 is used to transmit subscription messages, indication messages, control messages, service update messages, and service query messages, and is transmitted at a higher layer than the SCTP 340 and IP 330.

[0047] FIG. 4 illustrates an example of a connection between a base station and a radio access network intelligence controller (RIC) in a radio access network according to various embodiments of the present disclosure.

[0048] Referring to FIG. 4, the RIC 440 is connected to the O-CU-CP 420, the O-CU-UP 410, and the O-DU 430. The RIC 440 is responsible for controlling the RAN node (or a device performing a RAN function, for example, the O-CU-CP 420, the O-CU-UP 410, and the O-DU 430). The RIC 440 may be defined as a device for customizing RAN functionality for new services or regional resource optimization. The RIC 440 can provide functions such as network intelligence (e.g., policy enforcement, handover optimization), resource assurance (e.g., radio-link management, advanced self-organized network (SON)), and resource control (e.g., load balancing, slicing policy). The RIC 440 can communicate with the O-CU-CP 420, O-CU-UP 410, and O-DU 430. The RIC 440 can be connected to each node via the E2-CP, E2-UP, and E2-DU interfaces. The interfaces between the O-CU-CP and DU, and between the O-CU-UP and DU can be referred to as F1 interfaces. In the following description, the terms DU and O-DU, CU-CP and O-CU-CP, and CU-UP and O-CU-UP can be used interchangeably.

[0049] 4 illustrates one RIC 440, there may be multiple RICs according to various embodiments, which may be implemented in multiple pieces of hardware located in the same physical location or may be implemented by virtualization using a single piece of hardware.

[0050] Figure 5 shows the configuration of an apparatus according to various embodiments of the present disclosure. The structure illustrated in Figure 5 may be understood as the configuration of an apparatus having at least one function of the RIC, O-CU-CP, O-CU-UP, and O-DU of Figure 5. As used below, the terms "module," "device," etc. refer to a unit that processes at least one function or operation, and may be embodied in hardware, software, or a combination of hardware and software.

[0051] Referring to FIG. 5, the core network device includes a communication unit 510, a storage unit 520, and a control unit 530.

[0052] The communication unit 510 provides an interface for communicating with other devices in the network. That is, the communication unit 510 converts bit streams transmitted from the core network device to other devices into physical signals, and converts physical signals received from other devices into bit streams. That is, the communication unit 510 can transmit and receive signals. Therefore, the communication unit 510 can be referred to as a modem, transmitter, receiver, or transceiver. In this regard, the communication unit 510 enables the core network device to communicate with other devices or systems via a backhaul connection (e.g., wired backhaul or wireless backhaul) or via a network.

[0053] The memory unit 520 stores data such as basic programs, application programs, and configuration information for the operation of the core network device. The memory unit 520 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. The memory unit 520 provides the stored data in response to a request from the control unit 530.

[0054] The controller 530 controls the overall operation of the core network device. For example, the controller 530 transmits and receives signals via the communication unit 510. The controller 530 also stores and reads data in the memory unit 520. To this end, the controller 530 may include at least one processor. According to various embodiments, the controller 530 may control the device to perform operations according to various embodiments described in this disclosure.

[0055] FIG. 6 illustrates logical functions associated with E2 messages of an E2 node and a RIC in a radio access network according to various embodiments of the present disclosure.

[0056] 6, the RIC 640 and the E2 node 610 can transmit or receive E2 messages to or from 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 by the type of the E2 node 610. For example, the E2 node 610 can communicate with another E2 node 616 via an E1 interface or an F1 interface. Alternatively, for example, the E2 node 610 can communicate with an E2 node 616 via an X2 interface or an XN interface. Alternatively, for example, the E2 node 610 can communicate via 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).

[0057] 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 the case of a KPI monitor, KPI monitor collection software is installed in the RIC 640, and the E2 node 610 may include an E2 node function 612 that generates KPI parameters and transmits an E2 message including the KPI parameters to an E2 termination 642 located in the RIC 640. The E2 node has an E2 node function 612 that generates KPI parameters, places them in an E2 indication message, and transmits it to an E2 termination 624 function located in the RIC. The E2 termination function 624 located in the RIC can analyze an E2 report / insert message transmitted by the E2 node to the RIC 640 as the termination of the E2 message, and transmit it to the xApp 646. The E2 node 610 may include a radio resource management (RRM) 614. The E2 node 610 may manage resources provided to the wireless network for the terminal.

[0058] The E2 termination 642 located in the RIC 640 is the termination of the RIC 640 for the E2 message, and performs the function of analyzing the E2 message transmitted by the E2 node 610 and transmitting it to the xApp 646. A DB (database) 644 located in the RIC 640 can be used for the E2 termination 624 or the xApp 616. The E2 node 610 shown in FIG. 6 is the termination of at least one interface and can be understood as the termination of messages transmitted to a terminal, a neighboring base station, and a core network.

[0059] FIG. 7A shows an example of a signaling procedure between an E2 node and a RIC (RAN (radio access network) intelligent controller). Specifically, FIG. 7A shows an E2 I / F setup procedure and a RIC subscription message transmission procedure between the E2 node and the RIC. An E2 node 610 is exemplified as an E2 node, and a RIC 640 is exemplified as an RIC.

[0060] Referring to Figure 7A, in step 701, the E2 node can transmit an E2 setup request message to the RIC. The E2 NODE FUNCTION function located in the E2 node searches for the RIC using the RIC IP address configured by OAM (Operations, administration, and management) and transmits an E2 SETUP REQUEST message. The E2 SETUP REQUEST message includes RAN Function Definition, which defines the RAN functions supported by the E2 node, E2 NODE ID information, etc. The RAN Function Definition value is a value configured by OAM, and the RIC receives information about the setting value from OAM and can determine which call processing functions the E2 node supports based on the RAN Function Definition value.

[0061] In step 703, the RIC receives an E2 setup response message from the E2 node. If the RIC accepts the E2 SETUP REQUEST message sent by the E2 node, it sends an E2 SETUP RESPONSE message.

[0062] 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 Termination function to subscribe to a specific RAN Function Definition function supported by the E2. Here, according to one embodiment, the subscription request message in step 705 may be transmitted together with the E2 SETUP RESPONSE message in step 703. For example, the RAN function may include functions of the X2AP, F1AP, E1AP, S1AP, and NGAP interfaces, or an internal RAN function for controlling a UE or a cell.

[0063] In step 707, the E2 node can transmit a subscription request response to the RIC. The E2 Node Function of the E2 node decodes the Subscription Request Message and successfully sets the Event condition requested by the RIC to the E2 Node Function, and then notifies the RIC in the Subscription Response that the Event trigger condition has been successfully set.

[0064] In step 709, the E2 node can transmit an E2 RIC indication message to the RIC. When a specific event condition occurs, the E2 node transmits the E2 RIC indication message to the RIC.

[0065] In step 711, the E2 node can transmit a service update message to the RIC. If a change occurs in the E2 NODE function capability information element (E2 NODECapa), the E2 node sends the changed E2 NODECapa to the RIC in an E2 SERVICE UPDATE.

[0066] Although FIG. 7A describes the SETUP procedure, RIC subscription procedure, RIC Indication procedure, and update message transmission procedure in this order, various embodiments of the present disclosure are not limited to the above order and procedures. That is, in some embodiments, the E2 node and the RIC may independently perform the E2 configuration procedure in steps (701) through (703). In some embodiments, the E2 node and the RIC may independently perform the join procedure in steps (709) through (707). Meanwhile, according to another embodiment, as described above, the E2 configuration response message may include a join request message. In some embodiments, the E2 node and the RIC may independently perform the RIC indication procedure in step (709). In addition, in some embodiments, the E2 node and the RIC may independently perform the RIC indication procedure in step (709). In addition, the E2 node and the RIC may independently perform at least some of the above procedures.

[0067] 7B shows an example of a subscription procedure between an E2 node and a RIC, where E2 node 610 is exemplified as the E2 node and RIC 640 is exemplified as the RIC.

[0068] 7B, in step 751, the RIC can request a subscription from an E2 termination. For example, the E2 Relay xApp located in the RIC can request a subscription for an Initial UE message from the NGAP I / F to the E2 Relay message function of the RIC E2 Termination function.

[0069] In step 753, the RIC can transmit a RIC subscription request to the E2 node. For example, the RIC E2 Termination 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.

[0070] In step 755, the E2 node can transmit a RIC subscription response to the RIC. Specifically, the E2 Node Function of the E2 node that received the E2 Subscription Request Message decodes the message and, when an Initial UE message occurs in the NGAP I / F, successfully sets the Event condition to be transmitted to the RIC in a container in a RIC indication message for each UE, cell, or network slice, and then notifies the RIC that the Event trigger condition has been successfully set in the Subscription Response.

[0071] In step 757, the E2 node can transmit a RIC indication to the RIC. If an Initial UE message is generated by the UE in the NGAP I / F, the E2 node can transmit the NGAP Initial UE message in a container in an E2 RIC Indication message to the RIC.

[0072] Some of the content described in FIG. 7A may also be applied to FIG. 7B in the same or similar manner.

[0073] Figure 8 shows the IE (Information Element) of the E2 Indication message. The first IE is Message Type, which has a unique value for each E2 message. The details of the Message Type are shown in Figure 9.

[0074] The second IE is the RIC REQUEST ID, which specifies a specific xApp. The details of the message are shown in Figure 10.

[0075] The third IE is the E2 NODE FUNCTION ID. The E2 NODE FUNCTION ID has a range value for each E2 node, allowing you to specify a specific E2 NODE FUNCTION for a specific E2 node. The details of the message are shown in Figure 11.

[0076] The fourth IE is the RIC INDICATION TYPE (or sometimes referred to as E2 INDICATION TYPE). The RIC INDICATION TYPE specifies to the E2 node whether the INDICATION occurrence is a REPORT of a specific process or an addition to a message of an existing process. The details of the Indication type are illustrated in Figure 12.

[0077] The fifth IE is the E2 Message Relay Container (or may be referred to as RELAY CONTAINER) Octet string defined in this disclosure and is capable of transmitting all types of messages specified in the Subscription message.

[0078] 8, all IEs are shown as mandatory, but the embodiments of the present disclosure are not limited thereto. According to another embodiment, at least one of the illustrated IEs functions as optional, and for example, the corresponding IE may be omitted from the RIC indication message.

[0079] Figure 9 shows the details of the Message Type IE. The Procedure Code value, which is the first IE, is an integer value ranging from 0 to 255, and a specific MESSAGE TYPE (PROCEDURE CODE) is set. For example, Procedure Code value 0 is set to Subscription, Procedure Code value 1 is E2 SETUP setting, Procedure Code value 2 is Indication Request Message value, etc., and a total of 256 message values can be set from 0 to 255. For example, they are defined in O-RAN as shown in Table 1 below.

[0080] [Table 1]

[0081] The second IE in the Message Type IE, Type of message, indicates the type of message and can define Initiating, Successful, and Unsuccessful messages.

[0082] The RIC REQUEST ID value is shown in Figure 10. The RIC REQUEST ID value is an integer value ranging from 0 to 65535, and a value unique to a specific xApp can be set.

[0083] Figure 11 shows the E2 NODE FUNCTION ID value. The E2 NODE FUNCTION ID value is an integer value ranging from 0 to 4095, and can be set with different range values for each E2 node.

[0084] [Table 2]

[0085] Values after 2048 are reserved values and can be set when adding additional E2 nodes.

[0086] Figure 12 shows the E2 INDICATION TYPE value. The E2 INDICATION TYPE value is a string value in the range of "Insert" and "Report" and can be defined as a service value of an indication message for a specific function of a specific E2 NODE FUNCTION of an E2 node. For example, an I / F-based message relay function can be defined as a REPORT message.

[0087] According to various embodiments of the present disclosure, an event condition (per I / F, per call processing function) can be set in the call processing function of the O-RU, O-DU, O-CU-CP, or O-CU-UP in the E2 SUBSCRIPTION message, and all call processing functions that occur per specific call processing function or per I / F can be delivered to the RIC by packaging 3GPP messages in a Container, thereby making it possible to efficiently provide call processing request services of the RIC.

[0088] The methods according to the embodiments described in the claims or specification of the present disclosure can be implemented in the form of hardware, software, or a combination of hardware and software.

[0089] In the case of a software implementation, a computer-readable storage medium may be provided that stores one or more programs (software modules). The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform a method according to the embodiments described in the claims or specification of the present disclosure.

[0090] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile disc (DVD) or other form of optical storage device, magnetic cassette, or in memory configured as a combination of some or all of these. Also, each of the constituent memories may include multiple units.

[0091] The program may also be stored in an attachable storage device accessible through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device that performs an embodiment of the present disclosure through an external port. Alternatively, a separate storage device on the communication network may be connected to a device that performs an embodiment of the present disclosure.

[0092] In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in the singular or plural form depending on the specific embodiment presented. However, the expressions in the singular or plural form are selected to suit the presented situation for the convenience of explanation, and the present disclosure is not limited to the singular or plural elements, and elements expressed in the plural form may be composed in the singular form, and elements expressed in the singular form may be composed in the plural form.

[0093] Meanwhile, although the detailed description of the present disclosure has been given with reference to specific embodiments, it goes without saying that various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0094] 110 base station 120 terminals 130 S-GW 140 P-GW 150 MME 160 HSS 170 PCRF 210a NR RAN 210b LTE RAN 220 terminals 250 EPC 310 Physical layer 320 Data Link Layer 330 IP 340 SCTP 350 E2AP 410 O-CU-UP 420 O-CU-CP 430 O-DU 440 RIC 510 Communications Department 520 Storage section 530 Control Unit 610 E2 nodes 612 E2 node function 614 RRM 616 other E2 nodes 640 RIC 642 E2 termination 644 DB 646 xApp

Claims

1. A method performed by an E2 node (610) of an open-radio access network (O-RAN), comprising: and transmitting an RIC indication message including message type information to a radio access network (RAN) intelligent controller (RIC) 640 via an E2 interface of the O-RAN; The message type information includes a procedure code value and a type of the message, The procedure code value indicates RIC subscription, setup, RIC indication, RIC control, RIC service update, or RIC service query; The method, wherein the type of the message indicates initial, success, or failure.

2. The method of claim 1, wherein the RIC indication message includes indication type information indicating a type of RIC service corresponding to a RAN function ID of the E2 node.

3. The method of claim 1 , wherein the RIC service types include "insert" and "report."

4. The method of claim 1 , wherein the RIC indication message further includes a RIC request ID and a RAN function ID.

5. The RIC (640) is a near RT (realtime) RIC, 2. The method of claim 1, wherein the E2 node (610) comprises an O-RAN distributed unit (O-DU), an O-RAN central unit - control plane (O-CU-CP), an O-RAN central unit - user plane (O-CU-UP), or an O-RAN eNodeB (O-eNB).

6. A method performed by a radio access network (RAN) intelligent controller (RIC) (640) of an open-radio access network (O-RAN), comprising: receiving an RIC indication message including message type information from a radio access network (RAN) intelligent controller (RIC) 640 via an E2 interface of the O-RAN; The message type information includes a procedure code value and a type of the message, The procedure code value indicates RIC subscription, setup, RIC indication, RIC control, RIC service update, or RIC service query; The method, wherein the type of the message indicates initial, success, or failure.

7. The method of claim 6, wherein the RIC indication message includes indication type information indicating a type of RIC service corresponding to a RAN function ID of the E2 node.

8. The method of claim 6, wherein the RIC service types include "insert" and "report."

9. The method of claim 6 , wherein the RIC indication message further includes a RIC request ID and a RAN function ID.

10. The RIC (640) is a near RT (realtime) RIC, 7. The method of claim 6, wherein the E2 node (610) comprises an O-RAN distributed unit (O-DU), an O-RAN central unit - control plane (O-CU-CP), an O-RAN central unit - user plane (O-CU-UP), or an O-RAN eNodeB (O-eNB).

11. An apparatus that functions as an E2 node (610) of an O-RAN (open-radio access network), comprising: at least one transceiver; at least one processor coupled to the at least one transceiver; 6. An apparatus, wherein the at least one processor is configured to perform the method of any one of claims 1 to 5.

12. An apparatus that functions as a radio access network (RAN) intelligent controller (RIC) (640) of an open-radio access network (O-RAN), comprising: at least one transceiver; at least one processor coupled to the at least one transceiver; 11. Apparatus, wherein the at least one processor is configured to perform the method of any one of claims 6 to 10.

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