Patent Application
20220232508
The disclosure relates to a radio access network communication system. More particularly, the disclosure relates to message relay apparatus and method if a service event occurs for a base station conforming to an open radio access network (O-RAN) standard using an E2 message of the radio communication system.
To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post long term evolution (LTE) System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
The 5G system and new radio or next radio (NR) are commercialized to satisfy demand for wireless data traffic, and provide a high data rate service to a user through the 5G system like 4G, and it is also expected that wireless communication services for various purposes such as internet of things and a service requiring high reliability for a specific purpose may be provided. Open radio access network (O-RAN) established by operators and equipment providers in a system where the current 4G communication system and the 5G system are mixed defines a new network element (NE) and an interface standard based on the existing 3rd generation partnership project (3GPP) standard, and suggests an O-RAN structure.
The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.
As a 4th generation (4G)/5th generation (5G) communication system (hereafter, a 4G/5G system, new radio or next radio (NR)) is commercialized, a virtualized network requires a differentiated service support for users. Open-radio access network (O-RAN) newly defines the existing 3rd generation partnership project (3GPP) network entity (NE), radio unit (RU), distributed unit (DU), central unit (CU)-control plane (CP), and CU-user plane (UP) as O-RU, O-DU, O-CU-CP, and O-CU-UP respectively, and additionally standardizes a near-real-time RAN intelligent controller (RIC).
Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide an apparatus relaying an E2 subscription message for requesting a service from the newly defined RIC to the O-DU, the O-CU-CP or the O-CU-UP.
Another aspect of the disclosure is to provide a method for subdividing and processing an E2 subscription message based on a user equipment (UE), a group, a cell, and a network slice. Herein, the O-RU, the O-DU, the O-CU-CP, and the O-CU-UP may be understood as objects constituting the RAN which may operate according to the O-RAN standard, and may be referred to as E2 nodes.
Another aspect of the disclosure is to provide a RIC generating an E2 subscription request message, and setting a call processing EVENT by relaying it to the E2 NODE (e.g., the O-CU-CP, the O-CU-UP, the O-DU), and the E2 node relays the subscription request response message relayed to the RIC after the event setup. The disclosure relates to an E2 indication message for a newly defined RIC to divide a call processing message corresponding to an E2 event occurring in O-DU, O-CU-CP, O-CU-UP for a whole message set in a subscription event condition or for each specific application protocol per I/F, and received in a container form in a cell unit, a group ID unit, a network slice unit, and a UE unit.
Another aspect of the disclosure is to provide a method of a first node of a wireless communication system. The method includes dividing a call processing message received at an E2 NODE from a call processing block for each I/F, generating the divided message in a cell unit, a user equipment (UE) unit, a group ID unit, and a network slice unit container, and relaying an E2 indication message from the E2 node to the RIC. In addition, the E2 indication message may be identified based on a detailed information element of the E2 indication transmitted from the RIC, and 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 E2 NODE.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
In accordance with an aspect of the disclosure, a method performed by an E2 node is provided. The method includes transmitting a radio access network (RAN) intelligent controller (RIC) indication message to an RIC via an E2 interface, the RIC indication message may include indication type information, and the indication type information may indicate one of an ‘insert’ type or a ‘report’ type.
In accordance with another aspect of the disclosure, a method performed by an RIC is provided. The method includes receiving an RIC indication message from an E2 node via an E2 interface, the RIC indication message may include indication type information, and the indication type information may indicate one of an ‘insert’ type and a ‘report’ type.
In accordance with another aspect of the disclosure, an apparatus functioning as an E2 node is provided. The apparatus includes at least one transceiver, and at least one processor coupled with the at least one transceiver, the at least one processor may be configured to transmit an RIC indication message to an RIC via an E2 interface, the RIC indication message may include indication type information, and the indication type information may indicate one of an ‘insert’ type or a ‘report’ type.
In accordance with another aspect of the disclosure, an apparatus functioning as an RIC is provided. The apparatus includes at least one transceiver, and at least one processor coupled with the at least one transceiver, the at least one processor is configured to receive an RIC indication message from an E2 node via an E2 interface, the RIC indication message may include indication type information, and the indication type information may indicate one of an ‘insert’ or a ‘report’ type.
An apparatus and a method according to various embodiments of the disclosure, may indicate a type of a radio access network (RAN) intelligent controller (RIC) service through an indication message of an E2 node, and thus provide an effective service procedure between a near real time (RT) RIC and the E2 node.
Effects obtainable from the disclosure are not limited to the above-mentioned effects, and other effects which are not mentioned may be clearly understood by those skilled in the art of the disclosure through the following descriptions.
Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
The same reference numerals are used to represent the same elements throughout the drawings.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
Terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
Among the terms used in the disclosure, terms defined in a general dictionary may be interpreted as having the same or similar meanings as those in the context of the related art, and unless explicitly defined in the disclosure, may not be interpreted as ideal or excessively formal meanings. In some cases, even terms defined in the disclosure may not be interpreted to exclude embodiments of the disclosure.
A hardware-based approach will be described as an example in various embodiments of the disclosure to be described hereafter. However, various embodiments of the disclosure include technology which uses both hardware and software, and accordingly various embodiments of the disclosure do not exclude a software-based approach.
Hereafter, the disclosure relates to an apparatus and a 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.
Terms for signals, terms indicating channels, terms indicating control information, terms indicating network entities, and terms indicating components of a device used in the following explanation are illustrated for convenience of description. Accordingly, the disclosure is not limited to the terms to be described, and other terms having the same technical meaning may be used.
In addition, the disclosure describes various embodiments using terms used in some communication standard (e.g., 3rd generation partnership project (3GPP)), but this is only an example for description. Various embodiments of the disclosure may be easily modified and applied in other communication systems.
Hereafter, an uplink indicates a radio link for transmitting data or a control signal from a user equipment (UE) or a mobile station (MS) to an eNode B or a base station (BS), and a downlink indicates a radio link for transmitting data or a control signal from the eNode B to the UE in the disclosure. Also, the eNode B is an entity which performs resource allocation of the UE, and may be at least one of an eNode B, a Node B, a BS, a generation node B (gNB) radio access unit, a BS controller, or a node on the network. The UE may include a UE, an MS, a cellular phone, a smart phone, a computer, or a multimedia system for performing a communication function.
A 5th generation (5G) communication system (hereafter, may be used interchangeably with a 5G system, a new radio or next radio (NR) system) is commercialized to satisfy demand for wireless data traffic, and provides a high data rate service to users through the 5G system like 4G, and it is also predicted that wireless communication services for various purposes such as internet of things and a service requiring high reliability for specific purposes may be provided.
Open-RAN (O-RAN) established by operators and equipment providers in a system where the current 4G communication system and the 5G system are mixed defines a new network element (NE) and an interface standard based on the existing 3GPP standard, and thus presents an O-RAN structure. The O-RAN newly defines the existing 3GPP network entity (NE), radio unit (RU), distributed unit (DU), central unit (CU)-control plane (CP), and CU-user plane (UP) as O-RU, O-DU, O-CU-CP, and O-CU-UP respectively, and besides, the O-RAN has standardized a near-real-time RAN intelligent controller (RIC) and a non-real-time (NRT) RIC. For example, the RIC may be a server intensively deployed at one physical place. In addition, the RIC may be a logical node for collecting information on a cell site transmitted and received by a UE and the O-DU, the O-CU-CP or the O-CU-UP. The O-DU and the RIC, the O-CU-CP and the RIC, and the O-CU-UP and the RIC may be connected via Ethernet. For doing so, an interface standard for communications between the O-DU and the RIC, between the O-CU-CP and the RIC, and between the O-CU-UP and the RIC are required, and message formats such as E2-DU, E2-CU-CP, E2-CU-UP requires defining procedures between the O-DU, the O-CU-CP, the O-CU-UP and the RIC. In particular, differentiated service support is required for users in a virtualized network, and it is necessary to define functions of messages of E2-DU, E2-CU-CP and E2-CU-UP to support a service for wide cell coverage, by concentrating a call processing message/function generating in the O-RAN on the RIC.
Specifically, the RIC may generate and transmit an E2 subscription message to the O-DU, the O-CU-CP, or the O-CU-UP and thus set an event occurrence condition. The O-DU, the O-CU-CP, or the O-CU-UP may determine that the set condition is satisfied, load a 3GPP call processing message corresponding to the satisfied condition in a container to the RIC, classify into a user identifier, a cell identifier, a network slice identifier and so on, and then transmit through an E2 indication/report.
Call processing message information collected in the O-RAN based on the user identifier may be identified that the RIC is for a specific user/specific cell/specific network slice per I/F. The collected information may be transmitted from at least one of the (O-)CU-CP, the (O-)CU-UP, and the (O-)DU. The RIC may identify based on the user identifier that information collected from different entities is related to one specific user/specific cell/specific network slice, provide a specialized service for the specific user/specific cell/specific network slice with respect to a plurality of cells/network slices based on the collected information, and determine a key performance indicator (KPI) of the service provided to each user.
Since a general call processing service is restricted to a base station basis, the number of supportable cells is limited. In addition, since the collected information is limited to a specific base station, efficient monitoring on radio resources for the whole was not possible. According to various embodiments of the disclosure, the RIC may collect call processing messages (e.g., E1, F1, X2, XN, RRC, etc.) per I/F or respectively generated by the O-RU, the O-DU, the O-CU-CP or the O-CU-UP, and thus efficiently provide resource optimization and a user specific service or a user requested service with respect to the specific user/specific cell/specific network slices for wide cells. For example, the RIC may configure an additional carrier by efficiently dividing the network slice or by serving a specific terminal through carrier aggregation for the resource optimization, or configure an additional cell for performing dual access to serve a specific terminal through dual connectivity (DC). In addition, the RIC may configure a specific terminal to avoid connection with a specific cell and to connect with a specific cell in inter-cell movement. In addition, the RIC may efficiently perform the resource optimization through machine learning through analysis based on the collected information. In addition, the resource optimization of the disclosure is not limited to the described content. Also, according to the disclosure, it is possible not only to collect information per terminal but also to collect and analyze information per bearer.
The collected information of the specific user may be used at a collection server, the RIC or the NRT-RIC but may be also provided to an operations support system (OSS) or/and a business support system (BSS) to provide the specialized service to the user.
Referring to
The base station 110 is a network infrastructure for providing radio access to the terminal 120. For example, the base station 110 is a device which performs scheduling by collecting status information such as a buffer status, an available transmission power, and a channel status of the terminal 120. The base station 110 has coverage defined as a specific geographic region based on a signal transmission distance. The base station 110 is connected to the MME 150 via an S1-MME interface. Besides the base station, the base station 110 may be referred to as an ‘access point (AP)’, an ‘eNodeB (eNB)’, a ‘wireless point’, and a ‘transmission/reception point (TRP)’ or other term having the equivalent technical meaning.
The terminal 120 is a device used by the user, and performs communication with the base station 110 over a radio channel. In some cases, the terminal 120 may be operated without user's involvement. That is, the terminal 120 may be a device which performs machine type communication (MTC), and may not be carried by the user. The terminal 120 may be referred to as a user equipment or ‘UE’, a ‘mobile station’, a ‘subscriber station’, a ‘customer-premises equipment (CPE)’, a ‘remote terminal’, a ‘wireless terminal’, or a ‘user device’, or other term having the equivalent technical meaning.
The S-GW 130 provides a data bearer, and generates or controls the data bearer under control of the MME 150. For example, the S-GW 130 processes a packet arriving from the base station 110 or a packet to be forwarded to the base station 110. In addition, the S-GW 130 may perform an anchoring role in handover of the terminal 120 between base stations. The P-GW 140 may function as a connection point 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 serves as an anchor for the S-GW 130. In addition, the P-GW 140 may apply quality of service (QoS) policy of the terminal 120, and manage account data.
The MME 150 manages mobility of the terminal 120. In addition, the MME 150 may perform authentication, bearer management, and the like on the terminal 120. That is, the MME 150 is responsible for mobility management and various control functions of the terminal. The MME 150 may interwork with a serving general packet radio service (GPRS) support node (SGSN) 155.
The HSS 160 stores key information and a subscriber profile for the authentication of the terminal 120. The key information and the subscriber profile are transmitted from the HSS 160 to the MME 150 if the terminal 120 accesses the network.
The PCRF 170 defines a policy and a charging rule. The stored information is forwarded from the PCRF 170 to the P-GW 140, and the P-GW 140 may control the terminal 120 (e.g., QoS management, charging, etc.) based on the information provided from the PCRF 170.
Carrier aggregation (hereafter, ‘CA’) technology is a technology which combines a plurality of component carriers, and transmits and receives at one terminal a signal using the plurality of the component carriers at the same time and thus increases frequency use efficiency in terms of the terminal or the base station. Specifically, according to the CA technology, the terminal and the base station may transmit and receive signals using a broadband using the plurality of the component carriers in the uplink (UL) and the downlink (DL), wherein the component carriers are located in different frequency bands respectively. Hereafter, the UL indicates a communication link through which the terminal transmits a signal to the base station, and the DL indicates a communication link through which the base station transmits a signal to the terminal. At this time, the numbers of uplink component carriers and downlink component carriers may be different.
Dual connectivity or multi connectivity is a technology for increasing the frequency use efficiency in terms of the terminal or the base station, in which one terminal is connected to a plurality of different base stations and transmits and receives signals simultaneously using carriers within the plurality of the base stations positioned in different frequency bands. The terminal may be connected to a first base station (e.g., a base station which provides services using the LTE technology or the 4G mobile communication technology) and a second base station (e.g., a base station which provides services using the NR technology or 5G mobile communication technology) at the same time to transmit and receive traffic. In this case, frequency resources used by each base station may be positioned in different bands. As such, the operation scheme based on the dual connectivity scheme of the LTE and the NR may be referred to as 5G non-standalone (NSA).
Referring to
In the structure shown in
Referring to
Referring to
The radio network layer includes an E2AP 350. The E2AP 350 is used to deliver a subscription message, an indication message, a control message, a service update message, and a service query message, and is transmitted in a higher layer of the SCTP 340 and the IP 330.
Referring to
While
Referring to
The communication unit 510 provides an interface for performing communication with other devices in the network. That is, the communication unit 510 converts a bit string transmitted from the core network device to another device into a physical signal, and converts a physical signal received from another device into a bit string. That is, the communication unit 510 may transmit and receive signals. Accordingly, the communication unit 510 may be referred to as a modem, a transmitter, a receiver, or a transceiver. In this case, the communication unit 510 enables the core network device to communicate with other devices or systems via a backhaul connection (e.g., wired backhaul or wireless backhaul) or over the network.
The storage unit 520 stores data such as a basic program, an application program, and setting information for the operations of the core network device. The storage unit 520 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 520 provides the stored data according to a request of the control unit 530.
The control unit 530 controls general operations of the core network device. For example, the control unit 530 transmits and receives signals through the communication unit 510. In addition, the control unit 530 records and reads data in and from the storage unit 520. For doing so, the control unit 530 may include at least one processor. According to various embodiments, the control unit 530 may control the device to carry out operations according to various embodiments explained in the disclosure.
Referring to
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 KPI monitor, KPI monitor collection S/W may be installed in the RIC 640, and the E2 node 610 may include the E2 node function 612 which generates KPI parameters, and then forwards an E2 message including the KPI parameters to an E2 termination 642 positioned at the RIC 640. The E2 node 610 may include the E2 node function 612 which generates KPI parameters and relays an E2 message including the KPI parameters to the E2 termination 642 positioned at the RIC 640. The E2 termination 642 positioned in the RIC 640, which is a termination of the RIC 640 for the E2 message, may perform a function of interpreting E2 report/insert messages relayed by the E2 node 610 and relaying them to the xApp 646. The E2 node 610 may include a radio resource management (RRM) 614. The E2 node 610 may manage resources provided to the radio network for the terminal.
The E2 termination 642 positioned in the RIC 640, which is the termination of the RIC 640 for the E2 message, may perform a function of interpreting the E2 message forwarded by the E2 node 610 and then relaying it to the xApp 646. A database (DB) 644 positioned in the RIC 640 may be used for the E2 termination 642 or the xApp 646. The E2 node 610 shown in
Referring to
In operation 703, the RIC may receive an E2 setup response message from the E2 node. If accepting the E2 SETUP REQUEST message transmitted by the E2 node, the RIC may transmit the E2 SETUP RESPONSE message.
In operation 705, the RIC may transmit a subscription request message to the E2 node. A specific xApp positioned in the RIC requests the RIC E2 termination function to subscribe (or unsubscribe) for a specific RAN function definition function supported by E2. Herein, the subscription request message of operation 705 may be included in the E2 SETUP RESPONSE message of operation 703 and transmitted together, according to an embodiment. For example, the RAN function may include functions of X2AP, F1AP, E1AP, S1AP, and NGAP interfaces, or an internal RAN function for controlling UEs or cells.
In operation 707, the E2 node may transmit a subscription request response to the RIC. The E2 node function of the E2 node decodes the subscription request message, successfully sets the event condition requested by the RIC to the E2 node function and then relays the subscription response to the RIC that the event trigger condition is successfully set.
In operation 709, the E2 node may transmit an E2 RIC indication message to the RIC. If a specific event condition occurs, the E2 node relays the E2 RIC indication message to the RIC.
In operation 711, the E2 node may transmit an E2 service update message to the RIC. If a change occurs in an E2 NODE function capability information element (E2 NodeCapa), the E2 node transmits the changed E2 NodeCapa in the E2 SERVICE UPDATE to the RIC.
Referring to
Referring to
In operation 753, the RIC may transmit an RIC subscription request to the E2 node. For example, the RIC E2 termination function generates an initial UE message relay message for the NGAP I/F requested in operation 751 as an E2 subscription request message and relays it to the E2 node.
In operation 755, the E2 node may transmit an RIC subscription response to the RIC. Specifically, the E2 node function of the E2 node receiving the E2 subscription request message may decode the message, successfully set the event condition for transmitting to the RIC in a container including the RIC indication message per UE, per cell or per network slice if the initial UE message occurs in the NGAP I/F, and then relay the subscription response to the RIC that the event trigger condition is successfully set.
In operation 757, the E2 node may transmit an RIC indication to the RIC. If an Initial UE message occurs in the NGAP I/F by the UE, the E2 node may relay the E2 RIC Indication message including the NGAP Initial UE message in the container to the RIC.
Some contents described in
The second IE designates a specific xApp with RIC REQUEST ID. Message details are shown in
The third IE is E2 NODE FUNCTION ID. The E2 NODE FUNCTION ID may divide the range value for each E2 node and thus designate a specific E2 NODE FUNCTION to a specific E2 node. Message details are shown in
The fourth IE is RIC INDICATION TYPE (or may be expressed as E2 INDICATION TYPE). The RIC INDICATION TYPE designates whether the INDICATION occurrence in the E2 node is REPORT of a specific process or an addition to a message of an existing process. Details of the indication type are shown in
The fifth IE allows the E2 message relay container (or may be expressed as RELAY CONTAINER) defined in the disclosure to transmit any type of the message designated in the subscription message in the form of an Octet string.
Referring to
Referring to
Type of message which is the second IE in Message Type indicates the Message type, and may define initiating, successful, unsuccessful messages.
The value after 2048 is the reserved value and may be set if an additional E2 node is added.
Various embodiments of the disclosure may set the event condition in the call processing function (per I/F, per call processing function) of the O-RU, the O-DU, the O-CU-CP or the O-CU-UP with the E2 SUBSCRIPTION message, relay it to the RIC by including the 3GPP message in the container for a specific call processing function or every call processing function generated for each I/F, and thus efficiently provide the call processing request service of the RIC.
The methods according to the embodiments described in the claims or the specification of the disclosure may be implemented in software, hardware, or a combination of hardware and software.
As for the software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors of an electronic device. One or more programs may include instructions for controlling an electronic device to execute the methods according to the embodiments described in the claims or the specification of the disclosure.
Such a program (software module, software) may be stored to a random access memory, a non-volatile memory including a flash memory, a read only memory (ROM), an electrically erasable programmable ROM (EEPROM), a magnetic disc storage device, a compact disc (CD)-ROM, digital versatile discs (DVDs) or other optical storage devices, and a magnetic cassette. Alternatively, it may be stored to a memory combining part or all of those recording media. A plurality of memories may be included.
Also, the program may be stored in an attachable storage device accessible via a communication network such as internet, intranet, local area network (LAN), wide LAN (WLAN), or storage area network (SAN), or a communication network by combining these networks. Such a storage device may access a device which executes an embodiment of the disclosure through an external port. In addition, a separate storage device on the communication network may access the device which executes an embodiment of the disclosure.
In the specific embodiments of the disclosure, the components included in the disclosure are expressed in a singular or plural form. However, the singular or plural expression is appropriately selected according to a proposed situation for the convenience of explanation, the disclosure is not limited to a single component or a plurality of components, the components expressed in the plural form may be configured as a single component, and the components expressed in the singular form may be configured as a plurality of components.
While the disclosure has been shown and described with reference to various 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 disclosure as defined by the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0130501 | Oct 2020 | KR | national |
This application is a continuation application, claiming priority under § 365(c), of an International application No. PCT/KR2020/013816, filed on Oct. 8, 2020, which is based on and claims the benefit of a U.S. Provisional application Ser. No. 62/912,237, filed on Oct. 8, 2019, in the U.S. Patent and Trademark Office, and of a Korean patent application number 10-2020-0130501, filed on Oct. 8, 2020, in the Korean Intellectual Property Office, the disclosure of each of which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62912237 | Oct 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2020/013816 | Oct 2020 | US |
| Child | 17716761 | US |
