Apparatus and method for service subscription using E2 interface

Abstract

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

Description

[0001] This application is a divisional application of an invention patent application with an application date of September 29, 2020, application number: 202080074541.2, and invention name: "Device and method for service subscription using E2 interface in a wireless access network communication system". Technical Field

[0002] The present disclosure relates generally to a wireless access network communication system, and in particular, to an apparatus and method for service subscription to an Open Radio Access Network (O-RAN) base station using an E2 message of a wireless communication system. Background Art

[0003] In order to meet the demand for wireless data services that has increased since the deployment of the fourth generation (4G) communication system, efforts have been made to develop improved fifth generation (5G) or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE systems."

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

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

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

[0007] In order to meet the demand for wireless data services, 5G systems or new radio or next generation radio (NR) systems have been commercialized, thereby providing users with services with high data rates by using a 5G system similar to 4G. In addition, it is expected to provide wireless communication services for various purposes, such as the Internet of Things and services requiring high reliability for specific purposes. In the current system where the 4G communication system and the 5G communication system are used together, the open radio access network (O-RAN) created by vendors and equipment providers together defines new network elements (NEs) and interface standards based on the existing third generation partnership project (3GPP) standards, and provides an O-RAN architecture. Summary of the invention

[0008] Technical issues

[0009] Since the 4th generation (4G) / 5th generation (5G) communication system (hereinafter referred to as 4G / 5G system, new radio or next generation radio (NR) system) is currently commercialized, it is necessary to support user-specific services in a virtualized network. The open radio access network (O-RAN) has newly defined the existing third generation partnership project (3GPP) network element (NE), radio unit (RU), distribution unit (DU), centralized unit (CU)-control plane (CP) and CU-user plane (UP) as O-RU, O-DU, O-CU-CP and O-CU-UP, respectively. In addition, O-RAN has standardized a near real-time RAN intelligent controller (RIC). The present disclosure relates to an E2 subscription message used by the newly defined RIC to request O-DU, O-CU-CP or O-CU-UP to provide a service. In addition, the present disclosure relates to a method for processing an E2 subscription message by dividing the E2 subscription message based on UE, group, cell and network slice. Herein, the O-RU, O-DU, O-CU-CP, and O-CU-UP may be understood as objects constituting a RAN that may operate according to the O-RAN standard, and may be referred to as an E2 node.

[0010] In order to solve the aforementioned problem, the present disclosure provides a method for a first node of a wireless communication system. The method comprises: generating an E2 subscription request message by the RIC after the establishment between the E2 node and the RIC is completed or at the same time as the establishment, and then sending the message; receiving the E2 subscription request message sent by the RIC by the E2 node, and then configuring a call processing event; after the event is configured, delivering a subscription request response message to the RIC to report that the event is successfully configured; and when a call processing event that meets the setting conditions occurs, generating an E2 indication / report message based on the event that occurs, and then delivering the message to the RIC.

[0011] In addition, the E2 subscription request message transmitted by being carried together with the E2 establishment message or sent separately can be identified based on the detailed information element of the E2 subscription request sent from the RIC, and the information element information can include message type identifier information configured based on the call processing function of the E2 node, RIC request ID identifier information, E2 node function ID identifier information and RIC subscription type identifier information.

[0012] In addition, the E2 subscription response message can be identified based on the detailed information element of the E2 subscription response sent from the RIC, and the information element information can include message type identifier information configured based on the call processing function of the E2 node, RIC request ID identifier information, E2 node function ID identifier information, and RIC subscription result identifier information.

[0013] Problem Solution

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

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

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

[0017] According to various embodiments of the present disclosure, a device acting as a RIC may include at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to send a RIC subscription request message to an E2 node through an E2 interface. The RIC subscription request message may include information indicating a network interface type.

[0018] According to various embodiments of the present disclosure, a method performed by an E2 node includes: receiving a RIC subscription request message for a RAN function supported by the E2 node from a radio access network RAN ​​intelligent controller RIC via an E2 interface, and sending a RIC subscription response message to the RIC via the E2 interface to accept the RIC subscription request message, wherein the RIC subscription request message includes information indicating a network interface type from a plurality of network interface types.

[0019] According to various embodiments of the present disclosure, a method performed by a radio access network RAN ​​intelligent controller RIC, the method comprising: sending a RIC subscription request message for a RAN function supported by the E2 node to an E2 node via an E2 interface; and receiving a RIC subscription response message for accepting the RIC subscription request message from the E2 node via the E2 interface, wherein the RIC subscription request message includes information indicating a network interface type from a plurality of network interface types.

[0020] According to various embodiments of the present disclosure, a device used as an E2 node includes: a transceiver; a processor; and a memory storing instructions, wherein the instructions, when executed by the processor, enable the device to: receive a RIC subscription request message for a RAN function supported by the E2 node from a radio access network RAN ​​intelligent controller RIC via an E2 interface, and send a RIC subscription response message to the RIC via the E2 interface to accept the RIC subscription request message, wherein the RIC subscription request message includes information indicating a network interface type from a plurality of network interface types.

[0021] According to various embodiments of the present disclosure, a device used as a radio access network RAN ​​intelligent controller RIC, the device including: a transceiver; a processor; and a memory storing instructions, the instructions, when executed by the processor, causing the device to: send a RIC subscription request message for a RAN function supported by the E2 node to an E2 node via an E2 interface; and receive a RIC subscription response message for accepting the RIC subscription request message from the E2 node via the E2 interface, wherein the RIC subscription request message includes information indicating a network interface type from a plurality of network interface types.

[0022] Advantageous Effects of the Invention

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

[0024] The technical problems to be solved in the present disclosure are not limited to the above-mentioned technical problems, and those skilled in the art to which the present disclosure belongs can clearly understand other technical problems not mentioned herein from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0029] Figure 4 An example of a connection between a base station and a radio access network (RAN) intelligent controller (RIC) in a radio access network according to various embodiments of the present disclosure is shown;

[0030] Figure 5 shows the structure of a device according to various embodiments of the present disclosure;

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

[0032] Fig. 7A An example of the signaling process between the E2 node and the RIC is shown;

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

[0034] Figures 8 to 19 An example for a subscription process is shown. DETAILED DESCRIPTION

[0035] The terms used in the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit other embodiments. Singular expressions may include plural expressions, unless there is a clear difference in context. All terms used herein (including technical and scientific terms) have the same meanings commonly understood by those of ordinary skill in the field disclosed in the present disclosure. It will also be understood that the terms such as those defined in the commonly used dictionaries should be interpreted as having the meanings consistent with their meanings in the context of the relevant field, and unless clearly defined in this article, will not be interpreted in an idealized or overly formal sense. Optionally, the terms defined in the present disclosure should not be interpreted as excluding embodiments of the present disclosure.

[0036] For example, a hardware-based method is described in various embodiments of the present disclosure described below. However, since various embodiments of the present disclosure include technologies in which hardware and software are used simultaneously, a software-based method is not excluded in the embodiments of the present disclosure.

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

[0038] For convenience of explanation, the terms used hereinafter to refer to signals, channels, control information, messages, network entities, components of devices, etc. are exemplified. Therefore, the present disclosure is not limited to the terms described below, and thus other terms having the same technical meaning may also be used.

[0039] In addition, although the present disclosure describes various embodiments by using terms used in some communication standards (e.g., the Third Generation Partnership Project (3GPP)), this is only for exemplary purposes. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0040] In the present disclosure described below, uplink means a radio link in which a terminal (e.g., user equipment (UE) or mobile station (MS)) sends data or a control signal to a base station (e.g., eNodeB or base station (BS)), and downlink means a radio link in which a base station sends data or a control signal to a terminal. In addition, a base station is an entity that performs resource allocation of a terminal, and may be at least one of an eNodeB, a NodeB, a BS, a next generation NodeB (gNB), a radio access unit, a base station controller, and a node on a network. A terminal may include a UE, an MS, a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

[0041] In order to meet the demand for wireless data services, 5G communication systems (hereinafter, interchangeably referred to as 5G systems, new radio or next generation radio (NR) systems, etc.) have been commercialized, thereby providing users with services with high data rates by using 5G systems similar to 4G. In addition, it is expected to provide wireless communication services for various purposes, such as the Internet of Things and services requiring high reliability for specific purposes.

[0042] In the current system where the 4G communication system and the 5G communication system are used together, the open radio access network (O-RAN) created by vendors and equipment providers together has an O-RAN architecture that is started according to the new network element (NE) and interface standards defined based on the existing 3GPP standard. O-RAN has newly defined the existing 3GPP NE, radio unit (RU), distribution unit (DU), centralized unit (CU)-control plane (CP) and CU-user plane (UP) as O-RU, O-DU, O-CU-CP and O-CU-UP, respectively. In addition, O-RAN has standardized near real-time RAN intelligent controller (RIC) and non-real-time (NRT) RIC. For example, RIC can be a server deployed in a centralized manner in one physical place. In addition, RIC is a logical node that can collect information in the cell site where the terminal performs transmission / reception of O-DU, O-CU-CP or O-CU-UP. The connection between O-DU and RIC, between O-CU-CP and RIC, and between O-CU-UP and RIC can be established through Ethernet. To this end, interface standards for communication between O-DU and RIC, between O-CU-CP and RIC, and between 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 the procedures between RIC and O-DU, O-CU-CP, and O-CU-UP. Specifically, user-specific services are required in virtualized networks, and the functions of messages of O-DU, O-CU-CP, O-CU-UP, and RIC need to be defined to support services for wide cell coverage by allowing call processing messages / functions generated in O-RAN to be centralized in RIC.

[0043] Specifically, RIC can configure the event occurrence conditions by generating an E2 subscription message and sending it to O-DU, O-CU-CP or O-CU-UP. O-DU, O-CU-CP or O-CU-UP can determine whether the configured conditions are met, classify the qualified 3GPP call processing messages into user identifiers, cell identifiers, network slice identifiers, etc. by carrying the message in a container, and then send it to RIC through E2 indication / report.

[0044] The call processing message information collected based on the user identifier in O-RAN can be used to identify the RIC for a specific user / specific cell / specific network time slot for each I / F. The collected information can be sent from at least one of the (O-)CU-CP, (O-)CU-UP and (O-)DU. RIC can identify that the information collected from different entities based on the user identifier is for a specific user / specific cell / specific network slice, provide services specified for a specific user / specific cell / specific network slice for multiple cells / network slices based on the collected information, and determine the key performance indicators (KPIs) of the services provided to each user.

[0045] Since general call processing services are limited to base stations, the number of cells that can be supported is limited. In addition, since the collected information is limited to a specific base station, effective monitoring of all radio resources is impossible. According to various embodiments of the present disclosure, RIC collects each call processing message (e.g., E1, F1, X2, XN, RRC, etc.) generated by each I / F or by O-RU, O-DU or O-CU-CP. Therefore, the resources of a specific user / specific cell / specific network slice of a large range of cells can be optimized, and user-specific services or user-requested services can be effectively provided. For example, in order to effectively divide network slices or optimize resources, RIC can configure additional carriers so that a specific terminal can receive services through carrier aggregation, or can configure additional cells for performing dual connectivity (DC) so that a specific terminal can receive services through DC. In addition, RIC can configure a specific terminal to connect to a specific cell while avoiding connection to a specific cell during inter-cell mobility. In addition, RIC can effectively perform resource optimization by machine learning based on analysis of the collected information. In addition, the resource optimization of the present disclosure is not limited to the described content. In addition, according to the present disclosure, it is also possible to collect and analyze information of each bearer and collect information of each terminal.

[0046] The collected information of each user can be used in a collection server or RIC (near RIC) or NRT-RIC, but can be provided to an operation support system (OSS) and / or a business support system (BSS), and thus can also be used to provide user-specific services.

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

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

[0049] The base station 110 is a network infrastructure that provides radio access to the terminal 120. For example, the base station 110 is a device that performs scheduling by collecting status information such as the buffer status, available transmission power, channel status, etc. of the terminal 110. The base station 110 has coverage defined as a specific geographical area based on the distance that a signal can be transmitted. The base station 110 is coupled to the MME 150 through an S1-MME interface. The base station 110 may be referred to not only as a base station but also as an "access point (AP)", "eNodeB (eNB)", "radio point", "transmission / reception point (TRP)" or other terms having equivalent technical meanings.

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

[0051] The S-GW 130 provides data bearers and creates or removes data bearers 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. In addition, when the terminal 120 performs a handover between base stations, the S-GW 130 may perform an anchoring role. The P-GW 140 may act as a connection point with respect to an external network (e.g., an Internet network). In addition, the P-GW 140 allocates an Internet Protocol (IP) address to the terminal 120 and performs the anchoring role of the S-GW 130. In addition, the P-GW 140 applies a Quality of Service (QoS) policy of the terminal 120 and may manage account data.

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

[0053] The HSS 160 stores a subscriber profile and key information used for authentication of the terminal 120. The subscriber profile and key information are transferred from the HSS 160 to the MME 150 when the terminal 120 accesses the network.

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

[0055] Carrier aggregation (hereinafter referred to as "CA") is a technology in which multiple component carriers are aggregated so that one terminal sends / receives signals by using multiple component carriers at the same time, thereby increasing the frequency usage efficiency on the terminal or base station side. Specifically, according to the CA technology, the terminal and the base station can use multiple component carriers in each of the uplink (UL) and downlink (DL) to send / receive broadband signals. In this case, each of the component carriers is located in a different frequency band. In the following, UL means a communication link for a terminal to send a signal to a base station, and DL means a communication link for a base station to send a signal to a terminal. In this case, the number of UL component carriers and the number of DL component carriers may be different from each other.

[0056] Dual connection or multi-connection technology is a technology in which a terminal is coupled to multiple different base stations to send / receive signals by simultaneously using carriers located in different frequency bands in each of the multiple base stations, thereby increasing the frequency usage efficiency of the terminal or base station. The terminal can send / receive services by simultaneously coupling to a first base station (for example, a base station that provides services using LTE technology or 4G mobile communication technology) and a second base station (for example, a base station that provides services using new radio (NR) technology or 5G mobile communication technology). In this case, the frequency resources used by each base station can be located in different frequency bands. A scheme that operates based on dual connection technology of LTE and NR can be referred to as 5G non-independent (NSA).

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

[0058] refer to Figure 2A, the 5G NSA system includes NR RAN 210a, LTE RAN 210b, terminal 220 and EPC 250. NRRAN 210a and LTE RAN 210b can be coupled to EPC 150, and terminal 220 can receive services from any one of NR RAN 210a and LTE RAN 210b or from both at the same time. NR RAN 210a includes at least one NR base station, and LTERAN 210b includes at least one LTE base station. In this document, NR base stations may be referred to as "5th generation nodes", "next generation node B (gNB)" or other terms with equivalent technical meanings. In addition, the NR base station may have a structure divided into a centralized unit (CU) and a digital unit (DU), and the CU may have a structure divided into a CU-control plane (CP) unit and a CU-user plane (UP) unit.

[0059] In the structure of FIG. 2 , the terminal 220 can perform radio resource control (RRC) access through a first base station (e.g., a base station belonging to LTE RAN 210b), and can be provided with services of functions provided in the control plane (e.g., connection management, mobility management, etc.). In addition, additional radio resources for sending / receiving data can be provided to the terminal 220 through a second base station (e.g., a base station belonging to NR RAN 210a). The dual connection technology using LTE and NR can be referred to as Evolved Universal Terrestrial Radio Access (E-URAN)-NR Dual Connection (DC) (EN-DC). Similarly, the dual connection technology in which the first base station uses NR technology and the second base station uses LTE technology is referred to as NR-E-UTRA Dual Connection (NE-DC). In addition, various embodiments can be applied to various types of multi-connection and carrier aggregation technologies. In addition, various embodiments can also be applied to the case where a first system using a first communication technology and a second system using a second communication technology are implemented in one device, or the case where the first base station and the second base station are located in the same geographical location.

[0060] Figure 2B An example of an architecture of O-RAN is shown. For the purpose of E2-SM-Key Performance Indicator (KPI) Monitoring (KPIMON) of the E2 service model, O-RAN non-standalone mode in multi-connectivity operation using E-UTRA and NR radio access technologies may be considered. At the same time, it may be assumed that the E2 node is in O-RAN standalone mode.

[0061] refer to Figure 2BIn O-RAN standalone mode deployment, the eNB is coupled to the EPC through the S1-C / S1-U interface and to the O-CU-CP through the X2 interface. The O-CU-CP for O-RAN standalone mode deployment can be coupled to the 5G core (5GC) through the N2 / N3 interface.

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

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

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

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

[0066] Although, for example, Figure 4One RIC 440 is shown in FIG. 4 , but according to various embodiments, there may be multiple RICs. Multiple RICs may be implemented using multiple hardware entities located at the same physical location, or may be implemented by using virtualization of one hardware entity.

[0067] Figure 5 The structure of a device according to various embodiments of the present disclosure is shown. Figure 5 The exemplary structure can be understood as executing Figure 5 The structure of a device that performs at least one function among the RIC, O-CU-CP, O-CU-UP and O-DU. Hereinafter, the terms "... unit", "... device" and the like mean a unit that processes at least one function or operation, and can be implemented in hardware or software or a combination of hardware and software.

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

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

[0070] The storage unit 520 stores basic programs, applications, setting information, etc. for the operation of the core network device. The storage unit 520 may be composed of a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 520 provides the stored data at the request of the control unit 530.

[0071] The control unit 530 controls the overall operation of the core network device. For example, the control unit 530 sends and receives signals via the communication unit 510. In addition, the communication unit 530 writes data to the storage unit 520 and reads data. To this end, the control unit 530 may include at least one processor. According to various embodiments, the control unit 530 may control the core network device to perform operations according to the various embodiments described below.

[0072] Figure 6 Logical functions related to E2 messages of an E2 node and an RIC in a radio access network according to various embodiments of the present disclosure are shown.

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

[0074] The E2 node 610 may include an E2 node function 612. The E2 node function 612 is a function corresponding to a specific application S / W (xApp) 646 installed in the RIC 640. For example, in the case of a KPI monitor, the KPI monitor set S / W is installed in the RIC 640, and the E2 node 610 may include an E2 node function 612 that generates a KPI parameter and then delivers an E2 message including the KPI parameter to an E2 terminal 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 radio network for a terminal.

[0075] The E2 terminal 642 located in the RIC 640 is a terminal of the RIC 640 for E2 messages, and performs a function of interpreting the E2 message transferred by the E2 node 610 and then transferring it to the xApp 646. The database (DB) 644 located in the RIC 640 can be used for the E2 terminal 624 or the xApp 646. Figure 6 The E2 node 610 is an end of at least one interface and may be understood as an end of a message to be delivered to a terminal, a neighboring base station, and a core network.

[0076] Fig. 7A An example of the signaling process between the E2 node and the RIC is shown. Specifically, Fig. 7A The RIC subscription message delivery process and the E2 I / F establishment process between the E2 node and the RIC are shown. The E2 node 610 is illustrated as an E2 node, and the RIC 640 is illustrated as a RIC.

[0077] refer to Fig. 7AIn step 701, the E2 node may send an E2 setup request message to the RIC. The E2 node function located in the E2 node finds the RIC by using the RIC IP address set to Operation, Administration and Maintenance (OAM), and sends the E2 setup request message. The E2 setup request message includes a RAN function definition defining the functions of the RAN supported by the E2 node, E2 node ID information, etc. The RAN function definition value is a value set to OAM, and information about the value set to OAM in the RIC is received as the RAN function definition value to determine which call processing function the E2 node supports.

[0078] The RIC may receive an E2 setup response message from the E2 node in step 703. If the E2 setup request message sent by the E2 node is acceptable, the RIC may send an E2 setup response message.

[0079] In step 705, the RIC may send a subscription request message to the E2 node. A specific xApp located in the RIC requests the RIC E2 end function to subscribe to a specific RAN function definition function supported in the E2. In this document, according to an embodiment, the subscription request message in step 705 may be sent together by being included in the E2 setup response message. For example, the RAN function may include functions of X2AP, F1AP, E1AP, S1AP, and NGAP interfaces or internal RAN functions for controlling UEs or cells.

[0080] In step 707, the E2 node may send a subscription request response to the RIC. The E2 node function of the E2 node decodes the subscription request message, successfully configures the event condition requested by the RIC to the E2 node function, and then delivers a subscription response to the RIC to report that the event trigger condition is successfully configured.

[0081] In step 709, the E2 node may send 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.

[0082] In step 711, the E2 node may send a service update message to the RIC. When the E2 node functional capability information element (E2 NodeCapa) is changed, the E2 node sends the changed E2 NodeCapa to the RIC in the E2 service update.

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

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

[0085] refer to Figure 7B In step 751, the RIC may request the E2 end to subscribe. For example, the E2 relay xApp in the RIC may request the RIC E2 end function to subscribe to the E2 relay message function, and may request the NGAP I / F to subscribe to the initial UE message.

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

[0087] In step 755, the E2 node may send a RIC subscription response to the RIC. Specifically, the E2 node function that has received the E2 subscription request message may decode the message, and if the initial UE message is generated in the NGAP I / F, the event condition to be sent to the RIC by carrying it using a container in the RIC indication message may be successfully configured for each UE or each cell or each network slice, and then the subscription response may be delivered to the RIC to report that the event triggering condition is successfully configured.

[0088] In step 757, the E2 node may send a RIC indication to the RIC. When the initial UE message is generated by the UE in the NGAP I / F, the E2 node may deliver the NGAP initial UE message to the RIC by carrying it using a container in the E2 RIC indication message.

[0089] Fig. 7APart of the content described in may also be applied in the same or similar manner to Figure 7B middle.

[0090] Figure 8 The information elements (IE) of the E2 subscription request message are shown. The first IE is the message type, and the message type has a unique value for each E2 message. Fig. 9 Details of the message types are shown in .

[0091] The second IE is the RIC Request ID and specifies a specific xApp. Fig.10 The details of the message are shown in .

[0092] The third IE is the E2 node function ID. The E2 node function ID can specify a specific E2 node function to a specific E2 node because the range value is divided for each E2 node. Fig.11 The details of the message are shown in .

[0093] The fourth IE is the RIC subscription type and can configure event trigger conditions, as several types can be added to the E2 node. Fig.12 The details of the event trigger condition type are shown in FIG. The E2 message relay defined in this disclosure is one type of event trigger condition type and is Fig.13 The details of the message are shown in .

[0094] Fig. 9 The details of the message type IE are shown. The first IE is a procedure code value as an integer value in the range of 0 to 255, and a specific message type (procedure code) is set. For example, a procedure code value 0 can be set to a subscription, a procedure code value 1 can be set to an E2 establishment, and a procedure code value 2 can be set to an indication request message value in the range of 0 to 255, etc., i.e., 256 message values. For example, it is defined in O-RAN as shown in Table 1 below.

[0095] [Table 1]

[0096]

[0097] The type of the message as the second IE in the message type IE indicates a message type, and may define initiated, successful, and unsuccessful messages.

[0098] Fig.10 The RIC request ID value is shown. The RIC request ID value is an integer value in the range of 0 to 65535, and can be set to a unique value of a specific xApp.

[0099] Fig.11An E2 node function ID value is shown. The E2 node function ID value is an integer value in the range of 0 to 4095, and can be set by dividing each range value for each E2 node.

[0100] [Table 2]

[0101]

[0102] Values ​​after 2048 are reserved and may be set when additional E2 nodes are added.

[0103] Fig.12 The RIC subscription type value is shown. The RIC subscription type value is an integer value in the range of 0 to 255, and can be defined as a trigger value in a specific E2 node function of the E2 node. For example, an I / F-based message relay function can be defined as RIC subscription type 0.

[0104] Fig.13 An example of detailed messages of the E2 message relay function proposed in the present disclosure is shown.

[0105] The first IE is an interface AP ID which is an integer value in the range of 1 to 32, and specifies a specific I / F. For example, up to 32 I / F definitions are possible in the order of "0" for the setting value of LTE RRC for the UU interface between the terminal and the LTE eNB, "1" for the setting value of NR RRC for the UU interface between the 5G NR O-CU-CP and the terminal, "2" for the F1 interface, "3" for the E1 interface, "4" for the X2 interface, "5" for the XN interface, "6" for the NGAP interface, and "7" for the S1 interface.

[0106] The second IE is a global node ID as an optional IE, and determines whether the peer base station that has delivered the X2 message is an LTE macro base station, a home eNB (HeNB) base station, or a 5G-NR base station when the X2 of LTE and the XN I / F message of 5G-NR are relayed and delivered. Fig.14 The detailed IE is shown in .

[0107] The third IE is a message protocol ID list that can be divided into two types, namely, an "all messages" IE that specifies relays for all messages per I / F and a partial message list IE that specifies relays for only specific messages per I / F. The partial message list can specify up to 256 messages, and each message can be defined by a message ID and an optional interface direction defined in the subscription message information. The message ID is a unique value defined in 3GPP for the I / F in each of the LTE base station and the 5G NR base station, and if the message type (procedure code) value of 3GPP is available, the value additionally defined by O-RAN can be used. For example, the values ​​defined in 3GPP are shown in Table 3 below.

[0108] [Table 3]

[0109]

[0110] The interface direction defined as an optional IE can be determined for bidirectionally transmittable I / F messages such as X2 / XN, and can determine whether the I / F message for which RIC is requested to relay is an incoming message or an outgoing message from another E2 node (e.g., eNB, O-CU-CP).

[0111] The fourth IE is the subscription condition. It defines the group elements of messages to be relayed to the RIC. The TargetUE list is a list of UE identifiers and its details are in Fig.15 The TargetSlice list is a list of slices, and its details are in Fig.16 The TargetCell list is a list of cells and its details are in Fig.17 Defined in.

[0112] Fig.14 A global node IE is defined as an optional IE limited to X2 / XN messages. Unlike other I / Fs, X2 / XN has bidirectionality, and the I / F can be configured between macro cell LTE base stations, small cell LTE base stations, and 5G NR base stations. Therefore, since various combinations of connections are possible, the other party's global ID is important in X2 message transmission. The global node ID IE can be divided into macro eNB ID, home eNB ID, short macro eNB ID, long macro eNB ID, 5G-NR gNB ID, etc.

[0113] Fig.15 The Target UE List IE used when the RIC requests the E2 node to send a Relay Request message based on the UE is shown. The Target UE List is a list of RAN UE IDs defined in 3GPP. Up to UEMAX (e.g., 1024) RAN UE IDs can be configured and then sent.

[0114] Fig.16 The target slice list IE used when the RIC requests the E2 node to send a relay request message based on the network slice is shown. The target slice list is a list of single (S)-network slice selection assistance information (NSSAI) defined in 3GPP. Up to S-NSSAIMAX (e.g., 1024) S-NSSAIs can be configured and then sent. NSSAI includes multiple parameters required to select network slice instances belonging to RAN and CN, and is used to select CCNF and NFI as well as UE capabilities, subscription data, etc.

[0115] Fig.17 The target cell list IE used when the RIC requests the E2 node to send a relay request message on a cell basis is shown. The target cell list is a list of EUTRAN cell IDs and NR cell IDs defined in 3GPP. Up to 1024 cell IDs can be configured and then sent.

[0116] Fig.18 The target group ID list IE used when the RIC requests the E2 node to send a relay request message on a group basis is shown. The target group ID list is a list of subscriber profile IDs (SPIDs) or additional RRM policy IDs (ARPIs) defined in 3GPP. Up to 256 group IDs can be configured and then sent.

[0117] Fig.19 It is an example of a detailed message of the E2 relay subscription response function proposed in the present disclosure.

[0118] The first IE is the message type and has a unique value for each E2 message. Fig. 9 Details of the message types are shown in .

[0119] The second IE is the RIC Request ID and specifies a specific xApp. Fig.10 The details of the message are shown in .

[0120] The third IE is the E2 node function ID. The E2 node function ID can specify a specific E2 node function to a specific E2 node because the range value is divided for each E2 node. Fig.11 The details of the message are shown in .

[0121] The fourth IE is the subscription result. It defines the group element of the message to be relayed to the RIC. The TargetUE list is a list of UE identifiers and its details are in Fig.15 The TargetGroup list is a list of cells and its details are in Fig.18 The TargetCell list is a list of cells and its details are in Fig.17The TargetSlice list is a list of slices, and its details are in Fig.16 Defined in.

[0122] The fifth IE is a subscription message condition, and is an IE (multiple) that sets a failure message ID when the subscription process fails. When set to all messages, it means that subscription is not possible in the I / F configured in the E2 subscription request message interface AP ID. When set to a partial message list, it means that subscription is limitedly impossible for a specific application protocol message configured in the message ID list.

[0123] According to various embodiments of the present disclosure, the E2 subscription message is used to configure the event condition in the call processing function of the O-RU, O-DU, O-CU-CP or O-CU-UP (for each I / F, for each call processing function), and the 3GPP message can be delivered to the RIC by packaging in a specific call processing function or all call processing functions generated for each I / F. Therefore, the call processing request service of the RIC can be effectively provided.

[0124] The methods according to the embodiments disclosed in the claims and / or the specification of the present disclosure may be implemented in hardware, software, or a combination of both.

[0125] When implemented in software, a computer-readable recording medium for storing one or more programs (i.e., software modules) may be provided. One or more programs stored in the computer-readable recording medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions for allowing an electronic device to execute the method according to the embodiments disclosed in the claims and / or specification of the present disclosure.

[0126] The program (i.e., software module or software) may be stored in a random access memory, a non-volatile memory including a flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a compact disk-ROM (CD-ROM), a digital versatile disk (DVD) or other forms of optical storage devices, and a magnetic tape cassette. Alternatively, the program may be stored in a memory configured with a combination of all or some of these storage media. In addition, the configured memory may be plural in number.

[0127] In addition, the program can be stored in an attachable storage device that can access the electronic device through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WLAN), or a storage area network (SAN), or a communication network configured by combining these networks. The storage device can access the device for executing the embodiments of the present disclosure via an external port. In addition, an additional storage device on the communication network can access the device for executing the embodiments of the present disclosure.

[0128] In the foregoing specific embodiments of the present disclosure, the components included in the present disclosure are expressed in singular or plural form according to the specific embodiments proposed herein. However, for the situation proposed for the convenience of explanation, singular or plural expression is appropriately selected, so the various embodiments of the present disclosure are not limited to single or multiple components. Therefore, the components expressed in plural form can also be expressed in singular form, and vice versa.

[0129] While the present disclosure has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims.

Claims

1. A method performed by an E2 node, the method include: receiving, via an E2 interface, from a Radio Access Network RAN ​​intelligent controller RIC, a RIC subscription request message for a RAN function supported by an E2 node, Sending a RIC subscription response message to the RIC via the E2 interface to accept the RIC subscription request message, The RIC subscription request message includes information indicating a network interface type from among a plurality of network interface types.

2. The method according to claim 1, in, The network interface type includes at least one of an F1 interface, an E1 interface, an X2 interface, an XN interface, a next generation (NG) interface, and an S1 interface.

3. The method according to claim 1, in, The RIC subscription request message includes information indicating a group identifier ID list for RAN functions supported by the E2 node, and Here, a maximum number of at least one group ID included in the group ID list is 256.

4. The method according to claim 1, in, The RIC subscription request message includes a node identifier ID, and The node identifier indicates at least one of an evolved NodeB (eNB) ID or a next generation NodeB (gNB) ID.

5. The method according to claim 1, in, The RIC subscription request message also includes an interface direction information element IE, and The interface direction IE indicates at least one of incoming and outgoing.

6. The method according to claim 1, further comprising: include: A service update message associated with the modified E2 node functionality is sent to the RIC via the E2 interface.

7. A method performed by a radio access network RAN ​​intelligent controller RIC, the method include: sending, via an E2 interface, to the E2 node a RIC subscription request message for a RAN function supported by the E2 node; as well as receiving, via the E2 interface, a RIC subscription response message from the E2 node for accepting the RIC subscription request message, The RIC subscription request message includes information indicating a network interface type from among a plurality of network interface types.

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

9. The method according to claim 7, in, The RIC subscription request message includes information indicating a group identifier ID list for RAN functions supported by the E2 node, and Here, a maximum number of at least one group ID included in the group ID list is 256.

10. The method according to claim 7, in, The RIC subscription request message includes a node identifier ID, and The node identifier indicates at least one of an evolved NodeB (eNB) ID or a next generation NodeB (gNB) ID.

11. The method according to claim 7, in, The RIC subscription request message also includes an interface direction information element IE, and The interface direction IE indicates at least one of incoming and outgoing.

12. The method according to claim 7, further comprising: include: A service update message associated with the modified E2 node functionality is sent to the RIC via the E2 interface.

13. A device used as an E2 node, the device include: Transceiver; processor; as well as a memory storing instructions that, when executed by the processor, cause the apparatus to: receiving, via an E2 interface, from a Radio Access Network RAN ​​intelligent controller RIC, a RIC subscription request message for a RAN function supported by an E2 node, Sending a RIC subscription response message to the RIC via the E2 interface to accept the RIC subscription request message, The RIC subscription request message includes information indicating a network interface type from among a plurality of network interface types.

14. A device used as a radio access network RAN ​​intelligent controller RIC, the device include: Transceiver; processor; as well as a memory storing instructions that, when executed by the processor, cause the apparatus to: sending a RIC subscription request message for a RAN function supported by the E2 node to the E2 node via an E2 interface; and receiving, via the E2 interface, a RIC subscription response message from the E2 node for accepting the RIC subscription request message, The RIC subscription request message includes information indicating a network interface type from among a plurality of network interface types.

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