Apparatus and method for service subscription over E2 interface in a radio access network communication system

Abstract

To provide 5G or pre-5G communication systems to support higher data transmission rates after 4G communication systems such as LTE.SOLUTION: A method performed by an E2 node includes transmitting an E2 setup request message to a radio access network (RAN) intelligent controller (RIC), and receiving an E2 setup response message from the RIC, where the E2 setup request message includes an information element (IE) related to an RIC service update request message, and where the E2 setup response message includes an IE related to an RIC service update acknowledgement message.SELECTED DRAWING: Figure 8A

Description

[Technical Field]

[0001] The present disclosure relates generally to radio access network communication systems, and more particularly to an apparatus and method for messaging during E2 setup events for an open radio access network (O-RAN) base station using E2 messages 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, O-RAN (open radio access network), which was established by operators and equipment providers in a system that is a hybrid of 4G and 5G systems, is proposing the O-RAN structure 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 in virtualized networks. O-RAN defines the existing 3GPP (registered trademark) (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). This disclosure relates to an E2 Subscription message that the newly defined RIC uses to request a service from the O-DU, O-CU-CP, or O-CU-UP. This disclosure also relates to a method for processing the E2 Subscription message by subdividing 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 according to the O-RAN standard, and can be referred to as E2 nodes.

[0008] The E2 node(s) sends an E2 SETUP REQUEST message to the RIC to initialize the service, and the RIC responds with an E2 SETUP RESPONSE message. As a next step, the E2 node transmits the call processing capabilities of its supported Radio Access Network (RAN) to the RIC using a Service Update message, and the RIC responds with a Service Update Acknowledgement message. The RIC then generates an E2 subscription request message and transmits it to the E2 node (e.g., O-CU-CP, O-CU-UP, O-DU) to set a call processing event. After the event is set, the E2 node transmits a subscription request response message to the RIC. In this case, up to six messages must be transmitted from E2 SETUP to the subscription completion step, which allows service to start. This disclosure relates to a newly defined E2 SETUP message that complements the E2 SETUP message between a RIC and an E2 node (e.g., O-DU, O-CU-CP, O-CU-UP) to complete the service update step and subscription step in the E2 SETUP step.

[0009] The present disclosure for solving the above problems is characterized in that a method in a first node of a wireless communication system includes a step in which an E2 node generates an E2 SETUP REQUEST message and includes a RIC SERVICE UPDATE Information Element (IE), a step in which the RIC generates an E2 SETUP RESPONSE message and includes a RIC SERVICE UPDATE ACKNOWLDGE Information Element (IE), a step in which the RIC includes a RIC SUBSCRIPTION Information Element (IE) in the E2 SETUP RESPONSE message, and a step in which the E2 node transmits the E2 SUBSCRIPTION RESPONSE message to the RIC. In addition, the RIC SERVICE UPDATE message and RIC SUBSCRIPTION REQUEST message with optimized message transmission can be confirmed based on the detailed Information Element of the E2 SETUP REQUEST message transmitted from the E2 node and the E2 SETUP RESPONSE message transmitted from the RIC, respectively. In the case of a RIC SERVICE UPDATE message, the Information Element information may include MESSAGE TYPE identifier information, RIC REQUEST ID identifier information, E2 NODE FUNCTION ID identifier information, SERVICES TO ADD list, and SERVICES TO DELETE list identifier information set based on the call processing function of the E2 node. In the case of a RIC SUBSCRIPTION REQUEST, the Information Element information may 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]

[0010] According to various embodiments of the present disclosure, a method performed by an E2 node includes the steps of transmitting an E2 setup request message to a RIC (RAN (radio access network) intelligent controller) and receiving an E2 setup response message from the RIC, wherein the E2 setup request message includes an IE (information element) associated with the RIC service update request message, and the E2 setup response message includes an IE associated with the RIC service update acknowledge message.

[0011] According to various embodiments of the present disclosure, a method performed by a RAN (radio access network) intelligent controller (RIC) includes the steps of receiving an E2 setup request message from an E2 node and transmitting an E2 setup response message to the E2 node, wherein the E2 setup request message includes an information element (IE) associated with the RIC service update request message, and the E2 setup response message includes an IE associated with the RIC service update acknowledge message.

[0012] 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 transmit an E2 setup request message to a RAN (radio access network intelligent controller) and receive an E2 setup response message from the RIC, wherein the E2 setup request message includes an information element (IE) associated with the RIC service update request message, and the E2 setup response message includes an IE associated with the RIC service update acknowledge message.

[0013] 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 an E2 setup request message from an E2 node and transmit an E2 setup response message to the E2 node, wherein the E2 setup request message includes an information element (IE) associated with the RIC service update request message, and the E2 setup response message includes an IE associated with the RIC service update acknowledge message. [Effects of the Invention]

[0014] The apparatus and method according to various embodiments of the present disclosure can provide an efficient procedure between a near real-time (RT) RIC (RAN intelligent controller) and an E2 node by using an information element (IE) used in a service update procedure between the E2 node and a RIC (RAN intelligent controller) in the E2 setup procedure.

[0015] 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 technical field to which the present disclosure pertains from the following description. [Brief explanation of the drawings]

[0016] [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]1 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 8A] A figure showing an example of an information element (IE) for E2 RIC service update. [Figure 8B] A figure showing an example of an information element (IE) for E2 RIC service update. [Figure 9] A figure showing an example of an information element (IE) for E2 RIC service update. [Figure 10] A figure showing an example of an information element (IE) for E2 RIC service update. [Figure 11] A figure showing an example of an information element (IE) for E2 RIC service update. DETAILED DESCRIPTION OF THE INVENTION

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 centralized 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. 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 must 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.

[0025] 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 3GPP call processing messages that meet the met conditions in a container to the RIC, classifies them into user identifiers, cell identifiers, network slice identifiers, etc., and then transmits them via an E2 indication / report.

[0026] 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.

[0027] Since general call processing services are limited to base station units, the number of cells that can be supported is limited. Furthermore, since 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 each I / F-specific or each call processing message (e.g., E1, F1, X2, XN, RRC, etc.) 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 a specific terminal moves 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.

[0028] 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.

[0029] Figure 1 shows 4G (4 th generation) LTE (Long Term Evolution) core system.

[0030] 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.

[0031] 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 buffer status, available transmission power, and channel status of the terminal 120. 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.

[0032] The terminal 120 is a device used by a user and communicates with the base station 110 via a wireless channel. In some cases, the terminal 120 may be operated without the user's involvement. That is, at least one of the terminal 120 and the S-GW 130 may be a device that performs machine-type communication (MTC) and is not carried by the user. The terminal 120 may 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 having equivalent technical meanings.

[0033] 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.

[0034] 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).

[0035] 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.

[0036] The PCRF 170 defines policies and rules for charging. The stored information is transmitted from the PCRF 170 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 170.

[0037] 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.

[0038] Dual / multi-connectivity technology (dual connectivity or multi-connectivity) is a technology that increases frequency usage efficiency from the perspective of the terminal or base station by connecting one terminal to multiple different base stations and transmitting and receiving signals simultaneously using carriers within multiple base stations located in different frequency bands. The terminal connects to a first base station (e.g., a base station that provides services using LTE technology or 4th generation mobile communication technology) and a second base station (e.g., a base station that provides services using NR (new radio) technology or 5G (5G) technology). th 5G can simultaneously connect to multiple base stations (which provide services using 5G LTE and NR mobile communication technology) to send and receive traffic. The frequency resources used by each base station may be in different bands. This method of operating based on the dual connectivity of LTE and NR can be called 5G NSA (non-stand alone).

[0039] Figure 2A shows an example of a 5G NSA system.

[0040] 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 250, and the terminal 220 can receive service from either one or both of the NR RAN 210a and 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 is referred to as a "5G node (5G)." th The NR base station may be referred to as a "next generation nodeB (gNB)," "next generation nodeB (gNB)," or other terms having an equivalent technical meaning. In addition, the NR base station may have a structure separated into a CU (central unit) and a DU (digital unit), and the CU may have a structure separated into a CU-CP (control plane) unit and a CU-UP (user plane) unit.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Figure 5 shows the configuration of an apparatus according to various embodiments of the present disclosure. The structure illustrated in Figure 5 can 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 4. As used below, the terms "module," "device," etc. refer to a unit that processes at least one function or operation, and can be embodied in hardware, software, or a combination of hardware and software.

[0050] Referring to FIG. 5, the core network device includes a communication unit 510, a storage unit 520, and a control unit 530.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 another E2 node 616 via an X2 interface or an XN interface. Alternatively, for example, the E2 node 610 can communicate with another E2 node 616 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).

[0056] 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 then transmits an E2 message including the KPI parameters to an E2 termination 642 located in 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 wireless network for terminals.

[0057] 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 642 or the xApp 646. 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.

[0058] 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 the setup procedure for the E2 I / F between the E2 node and the RIC, the subscription procedure between the E2 node and the RIC, and the procedure for providing information. FIG. 7A shows the initial SETUP procedure up to the point where the RIC is able to provide service, which is being discussed in the O-RAN standard. FIG. 7A shows the setup procedure for the E2 I / F between the E2 node and the RIC, the E2 SERVICE UPDATE procedure, and the RIC subscription message transmission procedure. E2 node 610 is exemplified as the E2 node, and RIC 640 is exemplified as the RIC.

[0059] 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 can search for the RIC using the RIC IP address configured in OAM (Operations, administration and management) and transmit the E2 SET UP REQUEST message.

[0060] In step 703, the RIC can transmit an E2 setup response message to the E2 node. If the RIC can accept the E2 SETUP REQUEST message transmitted by the E2 NODE, it can send an E2 SETUP RESPONSE message.

[0061] In step (705), the E2 node can send a RIC service update message to the RIC. The E2 node can create a list of function capabilities that the E2 node can support using the E2 FUNCTION ID. The E2 node can create a list using the RIC SERVICE UPDATE ID. The E2 node can then send the created results to the RIC in an E2 SERVICE UPDATE.

[0062] In step 707, the RIC can transmit a RIC service update acknowledgement message to the E2 node. If the E2 NODE FUNCTION ID value in the E2 SERVICE UPDATE message transmitted by the E2 NODE is acceptable, the RIC can transmit an E2 SERVICE UPDATE ACKNOWLEDGEMENT message.

[0063] In step 709, the RIC can transmit a service subscription request message to the E2 node. A specific xApp located in the RIC can request a subscription (or subscription) from the RIC E2 termination function for a specific E2 NODE FUNCTION function supported by the E2.

[0064] In step 711, the E2 node can transmit a service subscription response message to the RIC. The E2 node function can decode the SUBSCRIPTION REQUEST message. After the RIC successfully sets the event condition requested by the E2 node function, the E2 node function can send a SUBSCRIPTION RESPONSE to the RIC indicating that the event trigger condition has been successfully set.

[0065] 7B shows an example of a subscription procedure between an E2 node and a RIC. Also, in FIG. 7B, an example of an E2 SETUP procedure proposed by the present invention is shown. An E2 node 610 is exemplified as an E2 node, and a RIC 640 is exemplified as a RIC.

[0066] Referring to FIG. 7B, in step 751, the E2 node may transmit an E2 setup request message to the RIC. The E2 node searches for the RIC using the RIC IP address configured in the OAM to create an E2 connection with the RIC, and transmits the E2 SET UP REQUEST message. According to one embodiment, the E2 node may add and transmit a RIC SERVICE UPDATE Information Element, which is being discussed in existing standards, when transmitting the E2 SET UP REQUEST message. That is, the E2 node may include a RIC SERVICE UPDATE IE in the E2 setup request message. The detailed contents of the RIC SERVICE UPDATE IE are illustrated in FIG. 8A.

[0067] In step 753, the RIC can transmit an E2 setup response message to the E2 node. If the E2 setup request message is a normal message, the RIC E2 termination function can establish an E2 connection and generate and transmit an E2 setup response message to the E2 node. According to one embodiment, the E2 setup response message can optionally carry a RIC subscription request message information element. The details of the RIC subscription request information element are illustrated in FIG. 8B. When the E2 node receives the E2 setup response message, it can set up an E2 connection. If the RIC subscription request message information element is carried in the E2 setup response message, the E2 node function can decode the message and perform the RIC subscription procedure.

[0068] In step 755, the E2 node can transmit a RIC subscription response message to the RIC. After the E2 node successfully sets the event condition defined by the RIC subscription, it can transmit a subscription response to the RIC. At this time, the subscription response informs the RIC that the event trigger condition has been successfully set.

[0069] In addition to the above, some of the content described with reference to FIG. 8A may also be applied to FIG. 8B in the same or similar manner.

[0070] Figure 8A shows the IE (Information Element) of E2 RIC SERVICE UPDATE. The first IE is Message Type, which has a unique value for each E2 message. The detailed contents of the Message Type are shown in Figure 9. The second IE is RIC REQUEST ID, which specifies a specific xApp. The detailed contents of the message are shown in Figure 10. The third IE is E2 NODE FUNCTION ID. The E2 NODE FUNCTION ID has a range value for each E2 NODE, allowing a specific E2 NODE FUNCTION to be specified for a specific E2 NODE. The detailed contents of the message are shown in Figure 11.

[0071] The fourth IE is the SERVICES TO ADD list. The SERVICES TO ADD list is a list of call processing functions supported by the E2 node. Each call processing function can include an E2 NODE FUNCTION ID value and an E2 NODE FUNCTION NAME. The E2 NODE FUNCTION ID value and E2 NODE FUNCTION NAME can be configured by OAM. For example, the X2 HANDOVER function has an E2 NODE FUNCTION ID value of 21 and an E2 NODE FUNCTION NAME of X2 HANDOVER. A maximum of 4096 SERVICES TO ADD lists can be configured.

[0072] The fifth IE is the SERVICES TO DELETE list. SERVICES TO DELETE is a list of call processing functions that were already supported by the E2 NODE but have become unsupported due to changes in the environment. A maximum of 4096 items can be set in the SERVICES TO DELETE list. As with the SERVICES TO ADD list, each call processing function in the SERVICES TO DELETE list can include an E2 NODE FUNCTION ID value and an E2 NODE FUNCTION NAME.

[0073] Figure 8B shows the Information Element (IE) of an E2 subscription request message. The first IE is Message Type, which has a unique value for each E2 message. The detailed contents of the Message Type are shown in Figure 9. The second IE is RIC REQUEST ID, which specifies a specific xApp. The detailed contents of the message are shown in Figure 10. The third IE is E2 NODE FUNCTION ID. The E2 NODE FUNCTION ID has a range value for each E2 NODE, allowing a specific E2 NODE FUNCTION to be specified for a specific E2 NODE. The detailed contents of the message are shown in Figure 1. The fourth IE is RIC SUBSCRIPTION TYPE, which allows various types to be added to the E2 NODE and allows event trigger conditions to be set.

[0074] 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.

[0075] [Table 1]

[0076] The second IE in the Message Type IE, Type of message, indicates the type of message and can define Initiating, Successful, and Unsuccessful messages.

[0077] 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.

[0078] 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.

[0079] [Table 2]

[0080] Values ​​after 2048 are reserved values ​​and can be set when adding additional E2 nodes.

[0081] According to the above embodiment, the service subscription procedure for the operation of the RIC may be performed in combination with the E2 setup procedure. That is, the E2 setup response (SETUP RESPONSE) message may optionally include a RIC subscription request (SUBSCRIPTION REQUEST) message information element (IE). Also, according to one embodiment, the service subscription procedure for the operation of the RIC may be performed in combination with a service update procedure associated with the RIC. In this case, the RIC service update acknowledgement (RIC SERVICE UPDATE ACKNOWLEDGEMENT) message may optionally include a RIC subscription request (SUBSCRIPTION REQUEST) message information element (IE).

[0082] 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.

[0083] 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.

[0084] 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 discs (DVDs) or other forms of optical storage, magnetic cassette, or in memory configured as a combination of some or all of these. Each of these memory configurations may also include multiple instances.

[0085] 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.

[0086] In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in the singular or plural form according to the specific embodiments presented. However, the expressions "singular" or "plural" are selected to suit the presented circumstances for the convenience of explanation, and the present disclosure is not limited to 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.

[0087] Meanwhile, although the detailed description of the present disclosure has been given with reference to specific embodiments, it goes without saying that various modifications can be made without departing from the scope of the present disclosure. [Explanation of symbols]

[0088] 110 base station 120 terminals 220 terminals 310 Physical layer 320 Data Link Layer 510 Communications Department 520 Storage section 530 Control Unit 612 E2 node function 616 Other E2 Node Features

Claims

1. A method performed by an E2 node, comprising: transmitting an E2 setup request message to a radio access network (RAN) intelligent controller (RIC), the E2 setup request message including information regarding a list of one or more functions to be added to the E2 node; The method includes receiving an E2 setup response message from the RIC, the E2 setup response message including information related to a list of one or more functions to be added to the E2 node.

2. The method described in claim 1, wherein the information relating to the list of one or more functions to be added to the E2 node includes results regarding one or more functions to be added by the RIC.

3. The method of claim 1, wherein the list includes one or more identifiers (IDs) for each of the one or more E2 node functions.

4. The E2 configuration request message includes information regarding a message type, The method of claim 1, wherein the message type indicates a procedure code and a message type.

5. The RIC is a near real time (near RT) RIC, 2. The method of claim 1, wherein the E2 node 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), comprising: receiving an E2 setup request message from an E2 node, the E2 setup request message including information related to a list of one or more functions to be added to the E2 node; The method includes transmitting to the E2 node an E2 setup response message including information related to a list of one or more functions to be added to the E2 node.

7. The method described in claim 6, wherein the information relating to the list of one or more functions to be added to the E2 node includes results regarding one or more functions to be added by the RIC.

8. The method of claim 6, wherein the list includes one or more identifiers (IDs) for each of the one or more E2 node functions.

9. The E2 setup request message includes information about a message type; The method of claim 6, wherein the message type indicates a procedure code and a message type.

10. The RIC is a near real time (near RT) RIC, 7. The method of claim 6, wherein the E2 node 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. A device that functions as an E2 node, 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. A device that functions as a RIC (RAN (radio access network) intelligent controller), 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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