WO2020153807A1

WO2020153807A1 - Method and apparatus for load and mobility control in wireless communication system

Info

Publication number: WO2020153807A1
Application number: PCT/KR2020/001211
Authority: WO
Inventors: Jian Xu; Daewook BYUN; Seokjung KIM
Original assignee: Lg Electronics Inc.
Priority date: 2019-01-25
Filing date: 2020-01-23
Publication date: 2020-07-30

Abstract

The present disclosure relates to method and apparatus for load and mobility control in wireless communications. According to an embodiment of the present disclosure, a method performed by a radio access network (RAN) node in a wireless communication system comprises: obtaining closed access group (CAG) identities (IDs) of neighbor RAN nodes and a CAG ID of a user equipment (UE) communicating with the RAN node; determining a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE; and controlling to perform a communication between the determined neighbor RAN node and the UE.

Description

METHOD AND APPARATUS FOR LOAD AND MOBILITY CONTROL IN WIRELESS COMMUNICATION SYSTEM

The present disclosure relates to method and apparatus for load and mobility control in wireless communications.

3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible.

In a wireless communication system, there might be a case in which a service should be limited to specific area and/or specific user equipments (UEs). For example, for advanced services like industry digitalization and/or services in smart factories, such services need to be closed and/or limited in a specific area (e.g., in a factory). For another example, operators may provide a specific service layer for high-value customers to give them a higher-quality differentiated services. The limited service may comprise, for example, a service for an indoor hotspot deployment scenario, which focuses on small coverage and high user throughput or user density in buildings.

An aspect of the present disclosure is to provide method and apparatus for load and mobility control in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for load and/or mobility control in a dual connectivity (DC) situation in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for load and/or mobility control by a master node (MN) and/or a secondary node (SN) belonging to a closed access group (CAG) in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for a SN addition in DC situation in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for a handover in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for a SN change in DC situation in a wireless communication system.

According to an embodiment of the present disclosure, a method performed by a radio access network (RAN) node in a wireless communication system comprises: obtaining closed access group (CAG) identities (IDs) of neighbor RAN nodes and a CAG ID of a user equipment (UE) communicating with the RAN node; determining a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE; and controlling to perform a communication between the determined neighbor RAN node and the UE.

According to an embodiment of the present disclosure, a radio access network (RAN) node in a wireless communication system comprises: a memory; a transceiver; a backhaul communication interface; and at least one processor, operatively coupled to the memory, the transceiver and the backhaul communication interface, configured to: control the backhaul communication interface to obtain closed access group (CAG) identities (IDs) of neighbor RAN nodes and a CAG ID of a user equipment (UE) communicating with the RAN node, determine a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE, and control to perform a communication between the determined neighbor RAN node and the UE

The present disclosure can have various advantageous effects.

For example, by properly selecting MN and/or SN for a MN handover, SN change and/or SN addition based on CAG identities (IDs), advanced services can be realized in a wireless communication system (e.g., 5G NR), and/or in case of DC situation.

For advanced services like industry digitalization and smart factories, the service can be closed in factory. Or operators can provide a specific service layer for high-value customers to give them the higher-quality differentiated services. Or the service can be for the indoor hotspot deployment scenario, which focuses on small coverage and high user throughput or user density in buildings. The present disclosure provides solutions to make the services be realistic in case of MR-DC based NG-RAN architecture.

Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

FIG. 1 shows examples of 5G usage scenarios to which the technical features of the present disclosure can be applied.

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 3 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 4 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 7 shows an example of a dual connectivity (DC) architecture to which technical features of the present disclosure can be applied.

FIG. 8 shows an example of a method for load and mobility control according to an embodiment of the present disclosure.

FIG. 9 shows an example of SN addition procedure according to an embodiment of the present disclosure.

FIG. 10 shows an example of X2/Xn setup procedure between MN and SN according to an embodiment of the present disclosure.

FIG. 11 shows an example of X2/Xn setup procedure between SNs according to an embodiment of the present disclosure.

FIG. 12 shows a UE to implement an embodiment of the present disclosure.

FIG. 13 shows an example of an AI device to which the technical features of the present disclosure can be applied.

FIG. 14 shows an example of an AI system to which the technical features of the present disclosure can be applied.

The technical features described below may be used by a communication standard by the 3rd generation partnership project (3GPP) standardization organization, a communication standard by the institute of electrical and electronics engineers (IEEE), etc. For example, the communication standards by the 3GPP standardization organization include long-term evolution (LTE) and/or evolution of LTE systems. The evolution of LTE systems includes LTE-advanced (LTE-A), LTE-A Pro, and/or 5G new radio (NR). The communication standard by the IEEE standardization organization includes a wireless local area network (WLAN) system such as IEEE 802.11a/b/g/n/ac/ax. The above system uses various multiple access technologies such as orthogonal frequency division multiple access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA) for downlink (DL) and/or uplink (UL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA may be used for DL and/or UL.

In the present disclosure, “A or B” may mean “only A”, “only B”, or “both A and B”. In other words, “A or B” in the present disclosure may be interpreted as “A and/or B”. For example, “A, B or C” in the present disclosure may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”.

In the present disclosure, slash (/) or comma (,) may mean “and/or". For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”.

In the present disclosure, “at least one of A and B” may mean “only A”, “only B” or “both A and B”. In addition, the expression “at least one of A or B” or “at least one of A and/or B” in the present disclosure may be interpreted as same as “at least one of A and B”.

In addition, in the present disclosure, “at least one of A, B and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. In addition, “at least one of A, B or C” or “at least one of A, B and/or C” may mean “at least one of A, B and C”.

Also, parentheses used in the present disclosure may mean “for example”. In detail, when it is shown as “control information (PDCCH)”, "PDCCH" may be proposed as an example of “control information”. In other words, “control information” in the present disclosure is not limited to “PDCCH”, and "PDDCH" may be proposed as an example of “control information”. In addition, even when shown as “control information (i.e., PDCCH)”, “PDCCH” may be proposed as an example of “control information”.

Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

The terms used throughout the present disclosure may be defined as follows:

"closed access group (CAG)" refers to a group of RAN nodes (e.g., eNB, gNB, master node, secondary node, macro cell node, small cell node, base station and/or cell) in a PLMN which allows access to specific UEs.

"CAG identity/identifier (ID)" refers to an ID which identifies a CAG in PLMN.

"CAG ID supported by UE" refers to an ID of a CAG in a PLMN which allows access to the UE. The CAG ID supported by UE may be simply referred to as a CAG ID of the UE. A UE can support one or more CAG IDs. The CAG ID of the UE may be included in subscription information of the UE.

"CAG ID supported by a RAN node" refers to an ID of CAG in a PLMN to which the RAN node belongs. The CAG ID supported by the RAN node may be simply referred to as a CAG ID of the RAN node. A RAN node can support one or more CAG IDs.

"Access mode" of a RAN node refers to a mode indicating whether to allow access to all UEs, allow access to UEs supporting CAG ID of the RAN node, or allow access to all UEs but give a priority of using resources to UEs supporting CAG ID of the RAN node. A mode indicating to allow access to all UEs may be referred to as "open (access) mode", a mode indicating to allow access to UEs supporting CAG ID of a RAN node may be referred to as "closed (access) mode", and a mode indicating to allow access to all UEs but give a priority of using resources to UEs supporting CAG ID of the RAN node may be referred to as "hybrid (access) mode".

"Membership status" of a UE for a CAG refers to whether the UE is a member of the CAG (i.e., the CAG allows access to the UE) or is not a member of the CAG (i.e., the CAG does not allow access to the UE).

The following drawings are created to explain specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals/messages/fields shown in the drawings are provided by way of example, and thus the technical features of the present disclosure are not limited to the specific names used in the following drawings.

The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.

Referring to FIG. 1, the three main requirements areas of 5G include (1) enhanced mobile broadband (eMBB) domain, (2) massive machine type communication (mMTC) area, and (3) ultra-reliable and low latency communications (URLLC) area. Some use cases may require multiple areas for optimization and, other use cases may only focus on only one key performance indicator (KPI). 5G is to support these various use cases in a flexible and reliable way.

eMBB focuses on across-the-board enhancements to the data rate, latency, user density, capacity and coverage of mobile broadband access. The eMBB aims ~10 Gbps of throughput. eMBB far surpasses basic mobile Internet access and covers rich interactive work and media and entertainment applications in cloud and/or augmented reality. Data is one of the key drivers of 5G and may not be able to see dedicated voice services for the first time in the 5G era. In 5G, the voice is expected to be processed as an application simply using the data connection provided by the communication system. The main reason for the increased volume of traffic is an increase in the size of the content and an increase in the number of applications requiring high data rates. Streaming services (audio and video), interactive video and mobile Internet connectivity will become more common as more devices connect to the Internet. Many of these applications require always-on connectivity to push real-time information and notifications to the user. Cloud storage and applications are growing rapidly in mobile communication platforms, which can be applied to both work and entertainment. Cloud storage is a special use case that drives growth of uplink data rate. 5G is also used for remote tasks on the cloud and requires much lower end-to-end delay to maintain a good user experience when the tactile interface is used. In entertainment, for example, cloud games and video streaming are another key factor that increases the demand for mobile broadband capabilities. Entertainment is essential in smartphones and tablets anywhere, including high mobility environments such as trains, cars and airplanes. Another use case is augmented reality and information retrieval for entertainment. Here, augmented reality requires very low latency and instantaneous data amount.

mMTC is designed to enable communication between devices that are low-cost, massive in number and battery-driven, intended to support applications such as smart metering, logistics, and field and body sensors. mMTC aims ~10 years on battery and/or ~1 million devices/km2. mMTC allows seamless integration of embedded sensors in all areas and is one of the most widely used 5G applications. Potentially by 2020, internet-of-things (IoT) devices are expected to reach 20.4 billion. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture and security infrastructures.

URLLC will make it possible for devices and machines to communicate with ultra-reliability, very low latency and high availability, making it ideal for vehicular communication, industrial control, factory automation, remote surgery, smart grids and public safety applications.　URLLC aims ~1ms of latency. URLLC includes new services that will change the industry through links with ultra-reliability / low latency, such as remote control of key infrastructure and self-driving vehicles. The level of reliability and latency is essential for smart grid control, industrial automation, robotics, drones control and coordination.

Next, a plurality of use cases included in the triangle of FIG. 1 will be described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) as a means of delivering streams rated from hundreds of megabits per second to gigabits per second. This high speed can be required to deliver TVs with resolutions of 4K or more (6K, 8K and above) as well as virtual reality (VR) and augmented reality (AR). VR and AR applications include mostly immersive sporting events. Certain applications may require special network settings. For example, in the case of a VR game, a game company may need to integrate a core server with an edge network server of a network operator to minimize delay.

Automotive is expected to become an important new driver for 5G, with many use cases for mobile communications to vehicles. For example, entertainment for passengers demands high capacity and high mobile broadband at the same time. This is because future users will continue to expect high-quality connections regardless of their location and speed. Another use case in the automotive sector is an augmented reality dashboard. The driver can identify an object in the dark on top of what is being viewed through the front window through the augmented reality dashboard. The augmented reality dashboard displays information that will inform the driver about the object's distance and movement. In the future, the wireless module enables communication between vehicles, information exchange between the vehicle and the supporting infrastructure, and information exchange between the vehicle and other connected devices (e.g. devices accompanied by a pedestrian). The safety system allows the driver to guide the alternative course of action so that he can drive more safely, thereby reducing the risk of accidents. The next step will be a remotely controlled vehicle or self-driving vehicle. This requires a very reliable and very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, a self-driving vehicle will perform all driving activities, and the driver will focus only on traffic that the vehicle itself cannot identify. The technical requirements of self-driving vehicles require ultra-low latency and high-speed reliability to increase traffic safety to a level not achievable by humans.

Smart cities and smart homes, which are referred to as smart societies, will be embedded in high density wireless sensor networks. The distributed network of intelligent sensors will identify conditions for cost and energy-efficient maintenance of a city or house. A similar setting can be performed for each home. Temperature sensors, windows and heating controllers, burglar alarms and appliances are all wirelessly connected. Many of these sensors typically require low data rate, low power and low cost. However, for example, real-time high-definition (HD) video may be required for certain types of devices for monitoring.

The consumption and distribution of energy, including heat or gas, is highly dispersed, requiring automated control of distributed sensor networks. The smart grid interconnects these sensors using digital information and communication technologies to collect and act on information. This information can include supplier and consumer behavior, allowing the smart grid to improve the distribution of fuel, such as electricity, in terms of efficiency, reliability, economy, production sustainability, and automated methods. The smart grid can be viewed as another sensor network with low latency.

The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine to provide clinical care in remote locations. This can help to reduce barriers to distance and improve access to health services that are not continuously available in distant rural areas. It is also used to save lives in critical care and emergency situations. Mobile communication based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring costs are high for installation and maintenance. Thus, the possibility of replacing a cable with a wireless link that can be reconfigured is an attractive opportunity in many industries. However, achieving this requires that wireless connections operate with similar delay, reliability, and capacity as cables and that their management is simplified. Low latency and very low error probabilities are new requirements that need to be connected to 5G.

Logistics and freight tracking are important use cases of mobile communications that enable tracking of inventory and packages anywhere using location based information systems. Use cases of logistics and freight tracking typically require low data rates, but require a large range and reliable location information.

NR supports multiple numerology (or, subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, wide area in traditional cellular bands may be supported. When the SCS is 30 kHz/60 kHz, dense-urban, lower latency and wider carrier bandwidth may be supported. When the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

The NR frequency band may be defined as two types of frequency range, i.e., FR1 and FR2. The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter wave (mmW).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	450MHz - 6000MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	410MHz - 7125MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.Referring to FIG. 2, the wireless communication system may include a first device 210 and a second device 220.

The first device 210 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an AR device, a VR device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

The second device 220 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

For example, the UE may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate personal computer (PC), a tablet PC, an ultrabook, a wearable device (e.g. a smartwatch, a smart glass, a head mounted display (HMD)) . For example, the HMD may be a display device worn on the head. For example, the HMD may be used to implement AR, VR and/or MR.

For example, the drone may be a flying object that is flying by a radio control signal without a person boarding it. For example, the VR device may include a device that implements an object or background in the virtual world. For example, the AR device may include a device that implements connection of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the MR device may include a device that implements fusion of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the hologram device may include a device that implements a 360-degree stereoscopic image by recording and playing stereoscopic information by utilizing a phenomenon of interference of light generated by the two laser lights meeting with each other, called holography. For example, the public safety device may include a video relay device or a video device that can be worn by the user's body. For example, the MTC device and the IoT device may be a device that do not require direct human intervention or manipulation. For example, the MTC device and the IoT device may include a smart meter, a vending machine, a thermometer, a smart bulb, a door lock and/or various sensors. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, handling, or preventing a disease. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, or correcting an injury or disorder. For example, the medical device may be a device used for the purpose of inspecting, replacing or modifying a structure or function. For example, the medical device may be a device used for the purpose of controlling pregnancy. For example, the medical device may include a treatment device, a surgical device, an (in vitro) diagnostic device, a hearing aid and/or a procedural device, etc. For example, a security device may be a device installed to prevent the risk that may occur and to maintain safety. For example, the security device may include a camera, a closed-circuit TV (CCTV), a recorder, or a black box. For example, the fin-tech device may be a device capable of providing financial services such as mobile payment. For example, the fin-tech device may include a payment device or a point of sales (POS). For example, the climate/environmental device may include a device for monitoring or predicting the climate/environment.

The first device 210 may include at least one or more processors, such as a processor 211, at least one memory, such as a memory 212, and at least one transceiver, such as a transceiver 213. The processor 211 may perform the functions, procedures, and/or methods of the present disclosure described below. The processor 211 may perform one or more protocols. For example, the processor 211 may perform one or more layers of the air interface protocol. The memory 212 is connected to the processor 211 and may store various types of information and/or instructions. The transceiver 213 is connected to the processor 211 and may be controlled to transmit and receive wireless signals.

The second device 220 may include at least one or more processors, such as a processor 221, at least one memory, such as a memory 222, and at least one transceiver, such as a transceiver 223. The processor 221 may perform the functions, procedures, and/or methods of the present disclosure described below. The processor 221 may perform one or more protocols. For example, the processor 221 may perform one or more layers of the air interface protocol. The memory 222 is connected to the processor 221 and may store various types of information and/or instructions. The transceiver 223 is connected to the processor 221 and may be controlled to transmit and receive wireless signals.

The

memory

212, 222 may be connected internally or externally to the

processor

211, 212, or may be connected to other processors via a variety of technologies such as wired or wireless connections.

The first device 210 and/or the second device 220 may have more than one antenna. For example, antenna 214 and/or antenna 224 may be configured to transmit and receive wireless signals.

According to various embodiments, the first device 210 may comprise a RAN node (e.g., gNB, eNB, MN, SN, macro cell node, small cell node, base station and/or cell). In this case, the first device 210 may further comprise a backhaul communication interface that is configured to control to perform a communication between the first device 210 and other devices (e.g., second device 220) connected to the first device 210 via backhaul. Further, the processor 211 may be configured to, or control the transceiver 213 and/or the backhaul communication interface to, perform steps/operations implemented by the RAN node as illustrated throughout the disclosure.

According to various embodiments, the second device 220 may comprise a RAN node (e.g., gNB, eNB, MN, SN, macro cell node, small cell node, base station and/or cell). In this case, the second device 220 may further comprise a backhaul communication interface that is configured to control to perform a communication between the second device 220 and other devices (e.g., first device 221) connected to the second device 220 via backhaul. Further, the processor 221 may be configured to, or control the transceiver 223 and/or the backhaul communication interface to, perform steps/operations implemented by the RAN node as illustrated throughout the disclosure.

Specifically, FIG. 3 shows a system architecture based on an evolved-UMTS terrestrial radio access network (E-UTRAN). The aforementioned LTE is a part of an evolved-UTMS (e-UMTS) using the E-UTRAN.

Referring to FIG. 3, the wireless communication system includes one or more user equipment (UE) 310, an E-UTRAN and an evolved packet core (EPC). The UE 310 refers to a communication equipment carried by a user. The UE 310 may be fixed or mobile. The UE 310 may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), and/or a wireless device, etc.

The E-UTRAN consists of one or more evolved NodeB (eNB) 320. The eNB 320 provides the E-UTRA user plane and control plane protocol terminations towards the UE 10. The eNB 320 is generally a fixed station that communicates with the UE 310. The eNB 320 hosts the functions, such as inter-cell radio resource management (RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provision, dynamic resource allocation (scheduler), etc. The eNB 320 may be referred to as another terminology, such as a base station (BS), a base transceiver system (BTS), an access point (AP), etc.

A downlink (DL) denotes communication from the eNB 320 to the UE 310. An uplink (UL) denotes communication from the UE 310 to the eNB 320. A sidelink (SL) denotes communication between the UEs 310. In the DL, a transmitter may be a part of the eNB 320, and a receiver may be a part of the UE 310. In the UL, the transmitter may be a part of the UE 310, and the receiver may be a part of the eNB 320. In the SL, the transmitter and receiver may be a part of the UE 310.

The EPC includes a mobility management entity (MME), a serving gateway (S-GW) and a packet data network (PDN) gateway (P-GW). The MME hosts the functions, such as non-access stratum (NAS) security, idle state mobility handling, evolved packet system (EPS) bearer control, etc. The S-GW hosts the functions, such as mobility anchoring, etc. The S-GW is a gateway having an E-UTRAN as an endpoint. For convenience, MME/S-GW 330 will be referred to herein simply as a “gateway,” but it is understood that this entity includes both the MME and S-GW. The P-GW hosts the functions, such as UE Internet protocol (IP) address allocation, packet filtering, etc. The P-GW is a gateway having a PDN as an endpoint. The P-GW is connected to an external network.

The UE 310 is connected to the eNB 320 by means of the Uu interface. The UEs 310 are interconnected with each other by means of the PC5 interface. The eNBs 320 are interconnected with each other by means of the X2 interface. The eNBs 320 are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs / S-GWs and eNBs.

Specifically, FIG. 4 shows a system architecture based on a 5G NR. The entity used in the 5G NR (hereinafter, simply referred to as "NR") may absorb some or all of the functions of the entities introduced in FIG. 3 (e.g. eNB, MME, S-GW). The entity used in the NR may be identified by the name “NG” for distinction from the LTE/LTE-A.

Referring to FIG. 4, the wireless communication system includes one or more UE 410, a next-generation RAN (NG-RAN) and a 5th generation core network (5GC). The NG-RAN consists of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the eNB 320 shown in FIG. 3. The NG-RAN node consists of at least one gNB 421 and/or at least one ng-eNB 422. The gNB 421 provides NR user plane and control plane protocol terminations towards the UE 410. The ng-eNB 422 provides E-UTRA user plane and control plane protocol terminations towards the UE 410.

The 5GC includes an access and mobility management function (AMF), a user plane function (UPF) and a session management function (SMF). The AMF hosts the functions, such as NAS security, idle state mobility handling, etc. The AMF is an entity including the functions of the conventional MME. The UPF hosts the functions, such as mobility anchoring, protocol data unit (PDU) handling. The UPF an entity including the functions of the conventional S-GW. The SMF hosts the functions, such as UE IP address allocation, PDU session control.

The gNBs 421 and ng-eNBs 422 are interconnected with each other by means of the Xn interface. The gNBs 421 and ng-eNBs 422 are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF by means of the NG-C interface and to the UPF by means of the NG-U interface.

A protocol structure between network entities described above is described. On the system of FIG. 3 and/or FIG. 4, layers of a radio interface protocol between the UE and the network (e.g. NG-RAN and/or E-UTRAN) may be classified into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied. FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

The user/control plane protocol stacks shown in FIG. 5 and FIG. 6 are used in NR. However, user/control plane protocol stacks shown in FIG. 5 and FIG. 6 may be used in LTE/LTE-A without loss of generality, by replacing gNB/AMF with eNB/MME.

Referring to FIG. 5 and FIG. 6, a physical (PHY) layer belonging to L1. The PHY layer offers information transfer services to media access control (MAC) sublayer and higher layers. The PHY layer offers to the MAC sublayer transport channels. Data between the MAC sublayer and the PHY layer is transferred via the transport channels. Between different PHY layers, i.e., between a PHY layer of a transmission side and a PHY layer of a reception side, data is transferred via the physical channels.

The MAC sublayer belongs to L2. The main services and functions of the MAC sublayer include mapping between logical channels and transport channels, multiplexing/de-multiplexing of MAC service data units (SDUs) belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling between UEs by means of dynamic scheduling, priority handling between logical channels of one UE by means of logical channel prioritization (LCP), etc. The MAC sublayer offers to the radio link control (RLC) sublayer logical channels.

The RLC sublayer belong to L2. The RLC sublayer supports three transmission modes, i.e. transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM), in order to guarantee various quality of services (QoS) required by radio bearers. The main services and functions of the RLC sublayer depend on the transmission mode. For example, the RLC sublayer provides transfer of upper layer PDUs for all three modes, but provides error correction through ARQ for AM only. In LTE/LTE-A, the RLC sublayer provides concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer) and re-segmentation of RLC data PDUs (only for AM data transfer). In NR, the RLC sublayer provides segmentation (only for AM and UM) and re-segmentation (only for AM) of RLC SDUs and reassembly of SDU (only for AM and UM). That is, the NR does not support concatenation of RLC SDUs. The RLC sublayer offers to the packet data convergence protocol (PDCP) sublayer RLC channels.

The PDCP sublayer belong to L2. The main services and functions of the PDCP sublayer for the user plane include header compression and decompression, transfer of user data, duplicate detection, PDCP PDU routing, retransmission of PDCP SDUs, ciphering and deciphering, etc. The main services and functions of the PDCP sublayer for the control plane include ciphering and integrity protection, transfer of control plane data, etc.

The service data adaptation protocol (SDAP) sublayer belong to L2. The SDAP sublayer is only defined in the user plane. The SDAP sublayer is only defined for NR. The main services and functions of SDAP include, mapping between a QoS flow and a data radio bearer (DRB), and marking QoS flow ID (QFI) in both DL and UL packets. The SDAP sublayer offers to 5GC QoS flows.

A radio resource control (RRC) layer belongs to L3. The RRC layer is only defined in the control plane. The RRC layer controls radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS. The main services and functions of the RRC layer include broadcast of system information related to AS and NAS, paging, establishment, maintenance and release of an RRC connection between the UE and the network, security functions including key management, establishment, configuration, maintenance and release of radio bearers, mobility functions, QoS management functions, UE measurement reporting and control of the reporting, NAS message transfer to/from NAS from/to UE.

In other words, the RRC layer controls logical channels, transport channels, and physical channels in relation to the configuration, reconfiguration, and release of radio bearers. A radio bearer refers to a logical path provided by L1 (PHY layer) and L2 (MAC/RLC/PDCP/SDAP sublayer) for data transmission between a UE and a network. Setting the radio bearer means defining the characteristics of the radio protocol layer and the channel for providing a specific service, and setting each specific parameter and operation method. Radio bearer may be divided into signaling RB (SRB) and data RB (DRB). The SRB is used as a path for transmitting RRC messages in the control plane, and the DRB is used as a path for transmitting user data in the user plane.

An RRC state indicates whether an RRC layer of the UE is logically connected to an RRC layer of the E-UTRAN. In LTE/LTE-A, when the RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected state (RRC_CONNECTED). Otherwise, the UE is in the RRC idle state (RRC_IDLE). In NR, the RRC inactive state (RRC_INACTIVE) is additionally introduced. RRC_INACTIVE may be used for various purposes. For example, the massive machine type communications (MMTC) UEs can be efficiently managed in RRC_INACTIVE. When a specific condition is satisfied, transition is made from one of the above three states to the other.

A predetermined operation may be performed according to the RRC state. In RRC_IDLE, public land mobile network (PLMN) selection, broadcast of system information (SI), cell re-selection mobility, core network (CN) paging and discontinuous reception (DRX) configured by NAS may be performed. The UE shall have been allocated an identifier (ID) which uniquely identifies the UE in a tracking area. No RRC context stored in the BS.

In RRC_CONNECTED, the UE has an RRC connection with the network (i.e. E-UTRAN/NG-RAN). Network-CN connection (both C/U-planes) is also established for UE. The UE AS context is stored in the network and the UE. The RAN knows the cell which the UE belongs to. The network can transmit and/or receive data to/from UE. Network controlled mobility including measurement is also performed.

Most of operations performed in RRC_IDLE may be performed in RRC_INACTIVE. But, instead of CN paging in RRC_IDLE, RAN paging is performed in RRC_INACTIVE. In other words, in RRC_IDLE, paging for mobile terminated (MT) data is initiated by core network and paging area is managed by core network. In RRC_INACTIVE, paging is initiated by NG-RAN, and RAN-based notification area (RNA) is managed by NG-RAN. Further, instead of DRX for CN paging configured by NAS in RRC_IDLE, DRX for RAN paging is configured by NG-RAN in RRC_INACTIVE. Meanwhile, in RRC_INACTIVE, 5GC-NG-RAN connection (both C/U-planes) is established for UE, and the UE AS context is stored in NG-RAN and the UE. NG-RAN knows the RNA which the UE belongs to.

NAS layer is located at the top of the RRC layer. The NAS control protocol performs the functions, such as authentication, mobility management, security control.

The physical channels may be modulated according to OFDM processing and utilizes time and frequency as radio resources. The physical channels consist of a plurality of orthogonal frequency division multiplexing (OFDM) symbols in time domain and a plurality of subcarriers in frequency domain. One subframe consists of a plurality of OFDM symbols in the time domain. A resource block is a resource allocation unit, and consists of a plurality of OFDM symbols and a plurality of subcarriers. In addition, each subframe may use specific subcarriers of specific OFDM symbols (e.g. first OFDM symbol) of the corresponding subframe for a physical downlink control channel (PDCCH), i.e. L1/L2 control channel. A transmission time interval (TTI) is a basic unit of time used by a scheduler for resource allocation. The TTI may be defined in units of one or a plurality of slots, or may be defined in units of mini-slots.

The transport channels are classified according to how and with what characteristics data are transferred over the radio interface. DL transport channels include a broadcast channel (BCH) used for transmitting system information, a downlink shared channel (DL-SCH) used for transmitting user traffic or control signals, and a paging channel (PCH) used for paging a UE. UL transport channels include an uplink shared channel (UL-SCH) for transmitting user traffic or control signals and a random access channel (RACH) normally used for initial access to a cell.

Different kinds of data transfer services are offered by MAC sublayer. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels.

Control channels are used for the transfer of control plane information only. The control channels include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH) and a dedicated control channel (DCCH). The BCCH is a DL channel for broadcasting system control information. The PCCH is DL channel that transfers paging information, system information change notifications. The CCCH is a channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network. The DCCH is a point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. This channel is used by UEs having an RRC connection.

Traffic channels are used for the transfer of user plane information only. The traffic channels include a dedicated traffic channel (DTCH). The DTCH is a point-to-point channel, dedicated to one UE, for the transfer of user information. The DTCH can exist in both UL and DL.

Regarding mapping between the logical channels and transport channels, in DL, BCCH can be mapped to BCH, BCCH can be mapped to DL-SCH, PCCH can be mapped to PCH, CCCH can be mapped to DL-SCH, DCCH can be mapped to DL-SCH, and DTCH can be mapped to DL-SCH. In UL, CCCH can be mapped to UL-SCH, DCCH can be mapped to UL- SCH, and DTCH can be mapped to UL-SCH.

Referring to FIG. 7, MN 711, SN 721, and a UE 730 communicating with both the MN 711 and the SN 721 are illustrated. As illustrated in FIG. 7, DC refers to a scheme in which a UE (e.g., UE 730) utilizes radio resources provided by at least two RAN nodes comprising a MN (e.g., MN 711) and one or more SNs (e.g., SN 721). In other words, DC refers to a scheme in which a UE is connected to both the MN and the one or more SNs, and communicates with both the MN and the one or more SNs. Since the MN and the SN may be in different sites, a backhaul between the MN and the SN may be construed as non-ideal backhaul (e.g., relatively large delay between nodes).

MN (e.g., MN 711) refers to a main RAN node providing services to a UE in DC situation. SN (e.g., SN 721) refers to an additional RAN node providing services to the UE with the MN in the DC situation. If one RAN node provides services to a UE, the RAN node may be a MN. SN can exist if MN exists.

For example, the MN may be associated with macro cell whose coverage is relatively larger than that of a small cell. However, the MN does not have to be associated with macro cell - that is, the MN may be associated with a small cell. Throughout the disclosure, a RAN node that is associated with a macro cell may be referred to as 'macro cell node'. MN may comprise macro cell node.

For example, the SN may be associated with small cell (e.g., micro cell, pico cell, femto cell) whose coverage is relatively smaller than that of a macro cell. However, the SN does not have to be associated with small cell - that is, the SN may be associated with a macro cell. Throughout the disclosure, a RAN node that is associated with a small cell may be referred to as 'small cell node'. SN may comprise small cell node.

The MN may be associated with a master cell group (MCG). MCG may refer to a group of serving cells associated with the MN, and may comprise a primary cell (PCell) and optionally one or more secondary cells (SCells). User plane data and/or control plane data may be transported from a core network to the MN through a MCG bearer. MCG bearer refers to a bearer whose radio protocols are located in the MN to use MN resources. As shown in FIG. 7, the radio protocols of the MCG bearer may comprise PDCP, RLC, MAC and/or PHY.

The SN may be associated with a secondary cell group. SCG may refer to a group of serving cells associated with the SN, and may comprise a primary secondary cell (PSCell) and optionally one or more SCells. User plane data may be transported from a core network to the SN through a SCG bearer. SCG bearer refers to a bearer whose radio protocols are located in the SN to use SN resources. As shown in FIG. 7, the radio protocols of the SCG bearer may comprise PDCP, RLC, MAC and PHY.

User plane data and/or control plane data may be transported from a core network to the MN and split up/duplicated in the MN, and at least part of the split/duplicated data may be forwarded to the SN through a split bearer. Split bearer refers to a bearer whose radio protocols are located in both the MN and the SN to use both MN resources and SN resources. As shown in FIG. 7, the radio protocols of the split bearer located in the MN may comprise PDCP, RLC, MACN and PHY. The radio protocols of the split bearer located in the SN may comprise RLC, MAY and PHY.

According to various embodiments, PDCP anchor/PDCP anchor point/PDCP anchor node refers to a RAN node comprising a PDCP entity which splits up and/or duplicates data and forwards at least part of the split/duplicated data over X2/Xn interface to another RAN node. In the example of FIG. 7, PDCP anchor node may be MN.

According to various embodiments, the MN for the UE may be changed. This may be referred to as handover, or a MN handover.

According to various embodiments, a SN may newly start providing radio resources to the UE, establishing a connection with the UE, and/or communicating with the UE (i.e., SN for the UE may be newly added). This may be referred to as a SN addition.

According to various embodiments, a SN for the UE may be changed while the MN for the UE is maintained. This may be referred to as a SN change.

According to various embodiments, DC may comprise E-UTRAN NR - DC (EN-DC), and/or multi-radio access technology (RAT) - DC (MR-DC). EN-DC refers to a DC situation in which a UE utilizes radio resources provided by E-UTRAN node and NR RAN node. MR-DC refers to a DC situation in which a UE utilizes radio resources provided by RAN nodes with different RATs.

In a wireless communication system, there might be an issue regarding network discovery, selection and/or access control for non-public networks (for example, one of the key issues of 3GPP TR23.734 v1.0.0 (2018-12): Study on 5GS Enhanced support of Vertical and LAN Services). The issue may aim at studying network discovery, selection and access control for non-public networks. Solutions to this key issue are expected to address the following aspects:

- Non-public network subscriptions

- How is information identifying a non-public network provided to the UE for network discovery and selection?

- Which criteria are used by the UE for automatic selection of non-public networks

- How to support manual selection of non-public networks

- How to prevent UEs not authorized for a given non-public network from attempting to automatically select and register in that non-public network?

- How to enable the network to verify whether a UE is authorized to access a non-public network?

- Which network entities perform access control for non-public networks?

- Access barring aspects for non-public networks

- Where access restrictions are configured (e.g. subscription or configuration)?

- How to enable UEs to access non-public networks but prevent the same UEs from accessing public PLMNs?

- How to prevent UEs not supporting non-public networks from attempting to access type-a and type-b networks?

- How to prevent NG-RAN from handing over a UE to a non-public network if the UE is not permitted to access the non-public network?

The solution addressing the issue may support, but not limited to, non-stand-alone non-public networks (i.e. non-public networks that are deployed as part of a PLMN).

Also, the solution may be based on the following principles:

(1)Identities

- CAG ID uniquely identifies a closed access group (CAG) in a PLMN.

- A human-readable network name identifies the CAG. The human-readable name may be unique.

(2)The following information is broadcasted in SIB for a PLMN that supports a CAG:

- CAG indication identifying the cell as a Closed Access Group cell.

- cellReservedForOtherUse indication (to prevent non-supporting UEs from accessing the cell). UEs that support non-public networks consider a cell that broadcasts both the cellReservedForOtherUse and the CAG indication as not barred.

- CAG ID.

- (Optional) Human-readable network name.

(3)Network and cell selection

- UE maintains a white list of CAG IDs

- UE configured to only access CAG cells are not allowed to register via non-CAG cells of any PLMN.

- UE shall only automatically select and attempt to register via a CAG cell whose identity is contained in the white list.

- For manual CAG selection the UE presents the list of available CAG IDs and related human-readable names (if available). If a UE has successfully registered to a CAG which was not listed in the white list yet, the CAG ID is added to the CAG white list.

(4)Subscription

- Subscription contains the list of CAGs the UE is entitled to access

- Subscription contains indication whether the UE is only allowed to access CAG cells (UE is also configured accordingly); this is to address factory devices that are supposed to remain on the CAG cells

MR-DC architectures are adopted in a wireless communication system (e.g., 5G NR). In addition, some advance services are also to be designed for the vertical areas. For example, some advances services may be limited to, or provided based on a closed mode to specific UEs only. Or, the service may be provided based on a hybrid mode (i.e., all UEs may access and be provided with services, but if a specific UE (e.g., UE supporting CAG ID of a RAN node which provides the services) joined the services, the specific UE may have a priority to use resources).

The UE access problem can happen in case a cell has access limitation for UEs (depending on UE's subscription information, etc.). The present disclosure provides various embodiments to solve the problem and various embodiments to make the closed/limited service be realistic in case that UE is served in a way of DC.

For example, in SN change procedure, the source secondary node has to decide the target secondary node and then triggers the SN change procedure to master node. In this case, information for the source secondary node to make a correct decision of the target node may be needed.

FIG. 8 shows an example of a method for load and mobility control according to an embodiment of the present disclosure. The method may be performed by a RAN node, such as gNB, eNB, MN, SN, macro cell node, small cell node, base station and/or cell.

Referring to FIG. 8, in step S801, the RAN node may obtain CAG IDs of neighbor RAN nodes and a CAG ID of a UE communicating with the RAN node. The neighbor RAN nodes comprises at least one of neighbor RAN nodes for the RAN node (i.e., RAN nodes neighboring the RAN node) or neighbor RAN nodes for another RAN node (i.e., RAN nodes neighboring the other RAN node. The other RAN node may neighbor the RAN node). The neighbor RAN nodes for the RAN node comprises RAN nodes connected to the RAN node via X2/Xn interface. The neighbor RAN nodes for the other RAN node comprises RAN nodes connected to the other RAN node via X2/Xn interface. Each of the neighbor RAN nodes may support a list of CAG IDs, and the UE may support a list of CAG IDs.

In step S803, the RAN node may determine a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE. For example, the RAN node determines a neighbor RAN node among the neighbor RAN nodes based on a match between a CAG ID of the neighbor RAN node and the CAG ID of the UE. In other words, the RAN node determines a neighbor RAN node which supports a CAG ID matching the CAG ID of the UE, among the neighbor RAN nodes.

In step 805, the RAN node may control to perform a communication between the determined neighbor RAN node and the UE. For example, the RAN node may perform MN handover, SN addition and/or SN change procedure so that the determined neighbor RAN node and the UE can communicate with each other.

According to various embodiments, the RAN node may receive a measurement report comprising a signal quality (e.g., reference signal received power (RSRP), and/or reference signal received quality (RSRQ)) for each of the neighbor RAN node. The RAN node may receive the measurement report directly from the UE, or from the UE via another RAN node. The UE may receive a signal from a neighbor RAN node, and measure a quality of the signal to obtain a signal quality for the neighbor RAN node. Also, the measurement report may comprise a signal quality for the RAN node. The UE may receive a signal from the RAN node, and measure a quality of the signal to obtain a signal quality for the RAN node.

For example, after receiving the measurement report, the RAN node may determine the neighbor RAN node among the neighbor RAN nodes based on the measurement report. The RAN node may determine, among the neighbor RAN nodes, one or more neighbor RAN nodes for which signal quality is i)higher than a threshold, ii)higher than that for the RAN node, iii)higher than that for the RAN node by an offset, or iv)higher than a first threshold while a signal quality for the RAN node is lower than a second threshold. Then, the RAN node may determine, among the one or more neighbor RAN nodes, the neighbor RAN node which supports a CAG ID matching the CAG ID of the UE.

For another example, the RAN node may determine, among the neighbor RAN nodes, one or more neighbor RAN nodes which support CAG ID matching the CAG ID of the UE. Then, after receiving the measurement report, the RAN node may determine the neighbor RAN node among the one or more neighbor RAN nodes based on the measurement report. The RAN node may determine, among the one or more neighbor RAN nodes, the neighbor RAN node for which signal quality is i)higher than a threshold, ii)higher than that for the RAN node, iii)higher than that for the RAN node by an offset, or iv)higher than a first threshold while a signal quality for the RAN node is lower than a second threshold.

According to various embodiments, the RAN node may be MN for the UE. The MN may receive, from another RAN node neighboring the MN, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node via X2/Xn interface. The other RAN node may comprise SN. For example, the message may be an acknowledgment (ACK) message for a SN addition request message (i.e., SN addition request ACK message) received from the other RAN node. The SN addition request message may be transmitted from the MN to the other RAN node. For another example, the message may be an X2/Xn setup response message or an X2/Xn setup response message received from the other RAN node. The X2/Xn setup response message may be a response message for an X2/Xn setup message transmitted from the MN to the other RAN node.

According to various embodiments, the MN may determine a target MN for a handover among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target MN. For example, the MN may determine, among the neighbor RAN nodes for the other RAN node, candidate MNs for a handover which support CAG ID matching the CAG ID of the UE. Then, the MN may determine, among the candidate MNs for a handover based on the measurement report, the target MN for a handover for which signal quality is i)higher than that for the MN, ii)higher than that for the MN by an offset, or iii)higher than a first threshold while a signal quality for the MN is lower than a second threshold. For another example, the MN may determine, among the neighbor RAN nodes for the other RAN node based on the measurement report, candidate MNs for a handover for which signal quality is i)higher than that for the MN, ii)higher than that for the MN by an offset, or iii)higher than a first threshold while a signal quality for the MN is lower than a second threshold. Then, the MN may determine, among the candidate MNs for a handover, the target MN which supports CAG ID matching the CAG ID of the UE. After determining the target MN, the MN may perform a handover (or, MN handover) of the UE from the MN to the target MN. If the UE is communicating with a SN, the SN for the UE may be maintained during and/or after the handover (or, MN handover).

According to various embodiments, the RAN node may be a SN for the UE. The SN may receive, from another RAN node neighboring the SN, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node via X2/Xn interface. The other RAN node may comprise MN for the UE, and/or another SN. For example, the message may be a SN addition request message received from a MN for the UE. For another example, the message may be an X2/Xn setup message or X2/Xn setup response message received from the other RAN node. The X2/Xn setup response message may be a response message for an X2/Xn setup request message transmitted from the SN to the other RAN node.

According to various embodiments, the SN may determine a target SN for a SN change among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target SN. For example, the SN may determine, among the neighbor RAN nodes for the other RAN node, candidate SNs for the UE which support CAG ID matching the CAG ID of the UE. Then, the SN may determine, among the candidate SNs for the UE based on the measurement report, the target SN for which a signal quality is i)higher than that for the SN, ii)higher than that for the SN by an offset, or iii)higher than a first threshold while a signal quality for the SN is lower than a second threshold. For another example, the SN may determine, among the neighbor RAN nodes for the other RAN node based on the measurement report, candidate SNs for a SN change for which signal quality is i)higher than that for the SN, ii)higher than that for the SN by an offset, or iii)higher than a first threshold while a signal quality for the SN is lower than a second threshold. Then, the SN may determine, among the candidate SNs for a SN change, the target SN which supports CAG ID matching the CAG ID of the UE. After determining the target SN, the SN may perform the SN change for the UE from the SN to the target SN. During and/or after the SN change, MN for the UE may be maintained.

According to various embodiments, the RAN node may be a MN for the UE. The MN may receive, from neighbor RAN nodes for the MN which are connected to the MN via X2/Xn interface, a message comprising CAG IDs of the neighbor RAN nodes for the MN. For example, the message may be an X2/Xn setup message received from the neighbor RAN nodes for the MN. For another example, the message may be an X2/Xn setup response message for an X2/Xn setup message transmitted from the MN to the neighbor RAN nodes for the MN.

According to various embodiments, the MN may determine a SN for the UE among the neighbor RAN nodes for the MN based on the measurement report, and a match between the CAG ID of the UE and a CAG ID of the SN. For example, the MN may determine, among the neighbor RAN nodes for the MN, candidate SNs for the UE which support CAG ID matching the CAG ID of the UE. Then, the MN may determine, among the candidate SNs for the UE based on the measurement report, the SN for the UE for which a signal quality is higher than a threshold. For another example, the MN may determine, among the neighbor RAN nodes for the MN based on the measurement report, candidate SNs for the UE for which a signal quality is higher than a threshold. Then, the MN may determine, among the candidate SNs for the UE, the SN for the UE which supports CAG ID matching the CAG ID of the UE. After determining the SN for the UE, the MN may perform SN addition procedure - that is, the MN may control to perform a communication between the SN and the UE while maintaining a communication with the UE. During the SN addition procedure and/or for the SN addition, the MN may transmit, to the target SN, SN addition request message and receive, from the target node, SN addition request ACK message for the SN addition request message.

According to various embodiments, the MN may determine a target MN for a handover among the neighbor RAN nodes for the MN based on the measurement report, and a match between the CAG ID of the UE and a CAG ID of the target MN. For example, the MN may determine, among the neighbor RAN nodes for the MN, candidate MNs for a handover which support CAG ID matching the CAG ID of the UE. Then, the MN may determine, among the candidate MNs for a handover based on the measurement report, the target MN for which a signal quality is i)higher than that for the MN, ii)higher than that for the MN by an offset, or iii)higher than a first threshold while a signal quality for the MN is lower than a second threshold. For another example, the MN may determine, among the neighbor RAN nodes for the MN based on the measurement report, candidate MNs for a handover for which a signal quality is i)higher than that for the MN, ii)higher than that for the MN by an offset, or iii)higher than a first threshold while a signal quality for the MN is lower than a second threshold. Then, the MN may determine, among the candidate MNs for a handover, the target MN which supports CAG ID matching the CAG ID of the UE. After determining the target MN, the MN may perform a handover (or, MN handover) of the UE from the MN to the target MN. If a SN for the UE exists, the SN for the UE may be maintained during and/or after the handover (or, MN handover).

According to various embodiments, the RAN node may be a SN for the UE. The SN may receive, from neighbor RAN nodes for the SN which are connected to the SN via X2/Xn interface, a message comprising CAG IDs of the neighbor RAN nodes for the SN. For example, the message may be an X2/Xn setup message received from the neighbor RAN nodes for the SN. For another example, the message may be an X2/Xn setup response message for an X2/Xn setup message transmitted from the SN to the neighbor RAN nodes for the SN.

According to various embodiments, the SN may determine a target SN for a SN change among the neighbor RAN nodes for the SN based on the measurement report, and a match between the CAG ID of the UE and a CAG ID of the target SN. For example, the SN may determine, among the neighbor RAN nodes for the SN, candidate SNs for a SN change which support CAG ID matching the CAG ID of the UE. Then, the SN may determine, among the candidate SNs for a SNS change based on the measurement report, the target SN for which signal quality is i)higher than that for the SN, ii)higher than that for the SN by an offset, or iii)higher than a first threshold while a signal quality for the SN is lower than a second threshold. For another example, the SN may determine, among the neighbor RAN nodes for the SN based on the measurement report, candidate SNs for a SN change for which signal quality is i)higher than that for the SN, ii)higher than that for the SN by an offset, or iii)higher than a first threshold while a signal quality for the SN is lower than a second threshold. Then, the SN may determine, among the candidate SNs for a SN change, the target SN which supports CAG ID matching the CAG ID of the UE. After determining the target SN, the SN may perform the SN change for the UE from the SN to the target SN. During and/or after the SN change, MN for the UE may be maintained.

FIG. 9 shows an example of SN addition procedure according to an embodiment of the present disclosure. The procedure may be used to help a SN to make a decision on a SN change. The procedure may be also used to help a MN to make a decision on a handover while maintaining a SN. The procedure may also be applied to other procedures. In FIG. 9, after the SN addition procedure, both of the MN and the SN1 are assumed to provide radio resources to the UE (i.e., UE in MN-SN1 DC situation).

Referring to FIG. 9, in step S901, UE may transmit a measurement report to a MN. The measurement report may comprise a signal quality for the MN, and a signal quality for each of neighbor RAN nodes (e.g., SN1, SN2). When the MN receives the measurement report on the neighbor RAN nodes, the MN may decide to offload services of the UE to one of the neighbor RAN nodes for the MN (e.g., target SN for SN addition). In the SN addition procedure illustrated in FIG. 9, the target SN for SN addition is assumed to be SN1.

In step S903, the MN may transmit, to the SN1, a SN addition request message. The SN addition request message may comprise at least one of:

1)A list of neighbor RAN nodes connected through X2/Xn interface with the MN. The list of neighbor RAN nodes can be expressed as a list of eNB IDs, gNB IDs, and/or cell IDs of the neighbor RAN nodes. The neighbor RAN nodes may comprise at least one of neighbor SNs (e.g., SN2) for the MN or neighbor MNs for the MN. The SN addition request message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor RAN nodes. The list of neighbor RAN nodes and/or the list of CAG IDs of each of the neighbor RAN nodes may be used to facilitate the SN1 to trigger a SN change procedure in a future mobility, which is a reference for the SN1 to make a decision on which SN is suitable for the SN change procedure.

According to various embodiments, the list of neighbor RAN nodes, the list of CAG IDs of each of the neighbor RAN nodes and/or the access mode of each of the neighbor RAN nodes may be obtained by the MN through X2/Xn setup procedure between the MN and neighbor RAN nodes (e.g., SNs) for the MN.

According to various embodiments, the SN addition request message may further comprise a list of CAG IDs supported by the UE and/or CAG membership information indicating a membership status of the UE. The receiving node (i.e., SN1) may take the information (i.e., the list of CAG IDs supported by the UE and/or CAG membership information indicating a membership status of the UE) to decide how to perform resource allocation, and/or how to treat the UE as a member or not.

2)Roaming information and/or access restriction information for the UE, which may be also used as a reference for the SN1 for future mobility.

3)A list of neighbor MNs for the MN, connected through X2/Xn interface with the MN.

According to various embodiments, some contents of the SN addition request message may be included in the measurement report from the UE. For example, the UE may transmit the measurement report comprising a list of CAG IDs and/or an access mode of each of the neighbor RAN nodes (e.g., SN2).

When receiving the SN addition request message, the SN1 (e.g., gNB or enhanced eNB) may store the contents of the SN addition request message and take the contents into account for the future mobility, for example, SN change and/or handover to another MN. The stored information may be important for the SN1 to decide the potential target nodes for SN change (e.g., SN2), SN addition and/or handover. For example, the SN1 may select a target SN for SN change (e.g., SN2) which satisfies a SN change condition. The SN change condition may comprise at least one of:

- the target SN should support the CAG ID of the UE; or

- a signal quality for the target SN should be i)higher than that for the SN1, ii)higher than that for the SN1 by an offset, or iii)higher than a first threshold while a signal quality for the SN1 is lower than a second threshold.

In step S905, the SN1 transmit, to the MN, a SN addition request ACK message. The SN addition request ACK message may comprise at least one of:

1)a list of neighbor MNs connected through X2/XN interface with the SN1 neighboring the SN1. The list of neighbor MNs for the SN1 may be expressed as a list of eNB IDs, gNB IDs, and/or cell IDs of the neighbor MNs for the SN1. Also, the SN addition request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor MNs. According to various embodiments, these lists can be obtained by the SN1 through X2/Xn setup procedure between the SN1 and the neighbor MNs for the SN1.

2)a list of neighbor SNs which are connected through X2/Xn interface with the SN1. The list of neighbor SNs for the SN1 may be expressed as a list of eNB IDs, gNB IDs, and/or cell IDs of the neighbor SNs for the SN1. Also, the SN addition request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor SNs. According to various embodiments, these lists can be obtained by the SN1 through X2/Xn setup procedure between the SN1 and the neighbor SNs for the SN1.

After the step S905, when the MN receives the SN addition request ACK message, the contents of the SN addition request ACK message may be used to help the MN to make a decision on a handover to another MN, which the SN1 for the UE is kept. For example, the MN may select a target MN for a handover which satisfies a handover condition. The handover condition may comprise at least one of:

- the target MN should support the CAG ID of the UE; or

- a signal quality for the target MN should be i)higher than that for the MN, ii)higher than that for the MN by an offset, or iii)higher than a first threshold while a signal quality for the MN is lower than a second threshold.

In FIG. 9, the SN1 may obtain a list of CAG IDs and/or an access mode of the target SN for SN change (e.g., SN2) by a message received from the MN (e.g., SN addition request message). However, the UE may also report a list of CAG IDs and/or an access mode of each of the neighbor RAN nodes (e.g., SN2), to the SN1 through the measurement report, and the SN1 may obtain the list of CAG IDs and/or an access mode of the SN2 from the measurement report. In other words, the list of CAG IDs and/or an access mode of the SN2 may be reported by the UE directly to the SN1 by the measurement report, or the measurement report comprising the list of CAG IDs and/or an access mode of the SN2 may be sent to the MN and then forwarded from the MN to the SN1 via, for example, the SN addition request message. The list of CAG IDs and/or an access mode of each of the neighbor RAN nodes may be used by the SN1 to select a target SN during a SN change procedure.

FIG. 10 shows an example of X2/Xn setup procedure between MN and SN according to an embodiment of the present disclosure. The procedure may be used to help a SN to make a decision on a SN change. The procedure may be also used to help a MN to make a decision on a handover while maintaining a SN. The procedure may also be applied to other procedures. In FIG. 10, both of the MN and the SN1 are assumed to provide radio resources to a UE (i.e., UE in MN-SN1 DC situation).

Referring to FIG. 10, in step S1001, a MN may transmit, to a SN1, an X2/Xn setup request message (or, simply X2/Xn setup message). The X2/Xn setup request message may comprise at least one of:

1)A list of neighbor SNs (e.g., SN2) connected through X2/Xn interface with the MN. The list of neighbor SNs may be expressed as a list of eNB IDs, gNB IDs, and/or cell IDs of the neighbor SNs for the MN. The X2/Xn setup request message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor SNs for the MN. The list of neighbor SNs and/or the list of CAG IDs of each of the neighbor SNs may be used to facilitate the SN1 to trigger a SN change procedure in a future mobility, which may be a reference for the SN1 to make a decision on which SN is suitable for SN change. According to various embodiments, these lists can be obtained by the MN through X2/Xn setup procedure between the MN and the neighbor SNs for the MN.

2)A list of neighbor MNs connected through X2/XN interface with the MN. The list of neighbor MNs may be expressed as a list of eNB IDs, gNB IDs, and/or cell IDs of the neighbor MNs for the MN. The X2/Xn setup request message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor MNs for the MN. According to various embodiments, these lists can be obtained by the MN through X2/Xn setup procedure between the MN and the neighbor MNs for the MN.

When receiving the X2/Xn setup message, the SN1 (gNB or enhanced eNB) store the contents of the X2/Xn setup message and take the stored information into account for a future mobility, for example, SN change, or handover to another MN. The stored information is important for the SN1 to decide the potential target nodes for SN change (e.g., SN2), SN addition and/or handover. For example, the SN1 may select a target SN for SN change (e.g., SN2) which satisfies a SN change condition. The SN change condition may comprise at least one of:

- the target SN should support the CAG ID of the UE; or

In step S1003, the SN1 may transmit, to the MN, an X2/Xn setup request ACK message. The X2/Xn setup request ACK message may comprise at least one of:

1)A list of neighbor MNs connected through X2/Xn interface with the SN1. The list of neighbor MNs may be expressed as a list of eNB IDs, gNB IDs and/or cell IDs of the neighbor MNs for the SN1. The X2/Xn setup request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor MNs for the SN1. According to various embodiments, these lists can be obtained by the SN1 through X2/Xn setup procedure between the SN1 and the neighbor MNs for the SN1.

2)A list of neighbor SNs connected through X2/Xn interface with the SN1. The list of neighbor SNs may be expressed as a list of eNB IDs, gNB IDs and/or cell IDs of the neighbor SNs for the SN1. The X2/Xn setup request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor SNs for the SN1. According to various embodiments, these lists can be obtained by the SN1 through X2/Xn setup procedure between the SN1 and the neighbor SNs for the SN1.

After the step S1003, when the MN receives the list of neighbor RAN nodes (e.g., neighbor MNs and/or neighbor SNs) for the SN1, the list of CAG IDs of each of the neighbor RAN nodes for the SN1, and/or an access mode of each of the neighbor RAN nodes for the SN1, the received information may be used to help the MN to make a decision on a handover to another master node while the SN1 for the UE can be kept. For example, the MN may select a target MN for a handover which satisfies a handover condition. The handover condition may comprise at least one of:

- the target MN should support the CAG ID of the UE; or

FIG. 11 shows an example of X2/Xn setup procedure between SNs according to an embodiment of the present disclosure. The procedure may be used to help a SN to make a decision on a SN change. The procedure may also be applied to other procedures. In FIG. 11, both of the MN and the SN1 are assumed to provide radio resources to a UE (i.e., UE in MN-SN1 DC situation).

Referring to FIG. 11, in step S1101, a source SN (i.e., SN1) may transmit, to a neighbor SN (e.g., SN2), an X2/Xn setup request message. The X2/Xn setup request message may comprise at least one of:

When receiving the X2/Xn setup request message, the SN2 (e.g., gNB or enhanced gNB) may store the contents of the X2/XN setup request message and take the stored information into account for future mobility, for example, SN change. The stored information is important for the SN2 to decide the potential target nodes for SN change, SN addition, and/or handover. For example, the SN2 may select a target SN for SN change which satisfies a SN change condition. The SN change condition may comprise at least one of:

- The target SN should support the CAG ID of the UE; or

- a signal quality for the target SN should be i)higher than that for the SN2, ii)higher than that for the SN2 by an offset, or iii)higher than a first threshold while a signal quality for the SN2 is lower than a second threshold.

In step S1103, the SN2 transmit, to the SN1, an X2/Xn setup request ACK message (i.e., X2/Xn setup request response message or X2/Xn setup response message). The X2/Xn setup request ACK message may comprise at least one of:

1)A list of neighbor MNs connected through X2/Xn interface with the SN2. The list of neighbor MNs may be expressed as a list of eNB IDs, gNB IDs and/or cell IDs of the neighbor MNs for the SN2. The X2/Xn setup request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor MNs for the SN2. According to various embodiments, these lists can be obtained by the SN2 through X2/Xn setup procedure between the SN2 and the neighbor MNs for the SN2.

2)A list of neighbor SNs connected through X2/Xn interface with the SN2. The list of neighbor SNs may be expressed as a list of eNB IDs, gNB IDs and/or cell IDs of the neighbor SNs for the SN2. The X2/Xn setup request ACK message may further comprise a list of CAG IDs and/or an access mode of each of the neighbor SNs for the SN2. According to various embodiments, these lists can be obtained by the SN2 through X2/Xn setup procedure between the SN2 and the neighbor SNs for the SN2.

When the SN1 receives the X2/Xn setup response message, the list of neighbor RAN nodes (e.g., neighbor MNs, neighbor SNs) for the SN2, the list of CAG IDs of each of the neighbor RAN nodes for the SN2, and/or an access mode of each of the neighbor RAN nodes for the SN2 can be used to help the SN1 to make a decision on future mobility, for example, SN change. The list of neighbor RAN nodes (e.g., neighbor MNs, neighbor SNs) for the SN2, the list of CAG IDs of each of the neighbor RAN nodes for the SN2, and/or an access mode of each of the neighbor RAN nodes for the SN2 may be important for the SN1 to decide the potential target nodes for SN addition, SN change and/or handover. For example, the SN1 may select a target SN for SN change which satisfies a SN change condition. The SN change condition may comprise at least one of:

- the target SN should support the CAG ID of the UE; or

According to various embodiments, as two SNs exchange a list of neighbor MNs to which each SN is connected with each other, each SN may know whether the two SNs share the same MN or not. If the two SNs share the same MN, this can make sure that each SN makes a decision on triggering the direct SN change procedure to noes that they share the same MN.

FIG. 12 shows a UE to implement an embodiment of the present disclosure. The present disclosure described above for UE side may be applied to this embodiment.

A UE includes a processor 1210, a power management module 1211, a battery 1212, a display 1213, a keypad 1214, a subscriber identification module (SIM) card 1215, a memory 1220, a transceiver 1230, one or more antennas 1231, a speaker 1240, and a microphone 1241.

The processor 1210 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of the radio interface protocol may be implemented in the processor 1210. The processor 1210 may include application-specific integrated circuit (ASIC), other chipset, logic circuit and/or data processing device. The processor 1210 may be an application processor (AP). The processor 1210 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), a modem (modulator and demodulator). An example of the processor 1210 may be found in SNAPDRAGONTM series of processors made by Qualcomm®, EXYNOSTM series of processors made by Samsung®, A series of processors made by Apple®, HELIOTM series of processors made by MediaTek®, ATOMTM series of processors made by Intel® or a corresponding next generation processor.

The processor 1210 may be configured to, or configured to control the transceiver 1230 to, perform operations/steps implemented by the UE as illustrated throughout the disclosure.

The power management module 1211 manages power for the processor 1210 and/or the transceiver 1230. The battery 1212 supplies power to the power management module 1211. The display 1213 outputs results processed by the processor 1210. The keypad 1214 receives inputs to be used by the processor 1210. The keypad 1214 may be shown on the display 1213. The SIM card 1215 is an　integrated circuit　that is intended to　securely store the　international mobile subscriber identity　(IMSI) number and its related　key, which are used to identify and authenticate subscribers on　mobile telephony　devices (such as　mobile phones　and　computers). It is also possible to store contact information on many SIM cards.

The memory 1220 is operatively coupled with the processor 1210 and stores a variety of information to operate the processor 1210. The memory 1220 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and/or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the memory 1220 and executed by the processor 1210. The memory 1220 can be implemented within the processor 1210 or external to the processor 1210 in which case those can be communicatively coupled to the processor 1210 via various means as is known in the art.

The transceiver 1230 is operatively coupled with the processor 1210, and transmits and/or receives a radio signal. The transceiver 1230 includes a transmitter and a receiver. The transceiver 1230 may include baseband circuitry to process radio frequency signals. The transceiver 1230 controls the one or more antennas 1231 to transmit and/or receive a radio signal.

The speaker 1240 outputs sound-related results processed by the processor 1210. The microphone 1241 receives sound-related inputs to be used by the processor 1210.

The present disclosure may be applied to various future technologies, such as AI, robots, autonomous-driving/self-driving vehicles, and/or extended reality (XR).

<AI>

AI refers to artificial intelligence and/or the field of studying methodology for making it. Machine learning is a field of studying methodologies that define and solve various problems dealt with in AI. Machine learning may be defined as an algorithm that enhances the performance of a task through a steady experience with any task.

An artificial neural network (ANN) is a model used in machine learning. It can mean a whole model of problem-solving ability, consisting of artificial neurons (nodes) that form a network of synapses. An ANN can be defined by a connection pattern between neurons in different layers, a learning process for updating model parameters, and/or an activation function for generating an output value. An ANN may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may contain one or more neurons, and an ANN may include a synapse that links neurons to neurons. In an ANN, each neuron can output a summation of the activation function for input signals, weights, and deflections input through the synapse. Model parameters are parameters determined through learning, including deflection of neurons and/or weights of synaptic connections. The hyper-parameter means a parameter to be set in the machine learning algorithm before learning, and includes a learning rate, a repetition number, a mini batch size, an initialization function, etc. The objective of the ANN learning can be seen as determining the model parameters that minimize the loss function. The loss function can be used as an index to determine optimal model parameters in learning process of ANN.

Machine learning can be divided into supervised learning, unsupervised learning, and reinforcement learning, depending on the learning method. Supervised learning is a method of learning ANN with labels given to learning data. Labels are the answers (or result values) that ANN must infer when learning data is input to ANN. Unsupervised learning can mean a method of learning ANN without labels given to learning data. Reinforcement learning can mean a learning method in which an agent defined in an environment learns to select a behavior and/or sequence of actions that maximizes cumulative compensation in each state.

Machine learning, which is implemented as a deep neural network (DNN) that includes multiple hidden layers among ANN, is also called deep learning. Deep learning is part of machine learning. In the following, machine learning is used to mean deep learning.

The AI device 1300 may be implemented as a stationary device or a mobile device, such as a TV, a projector, a mobile phone, a smartphone, a desktop computer, a notebook, a digital broadcasting terminal, a PDA, a PMP, a navigation device, a tablet PC, a wearable device, a set-top box (STB), a digital multimedia broadcasting (DMB) receiver, a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, etc.

Referring to FIG. 13, the AI device 1300 may include a communication part 1310, an input part 1320, a learning processor 1330, a sensing part 1340, an output part 1350, a memory 1360, and a processor 1370.

The communication part 1310 can transmit and/or receive data to and/or from external devices such as the AI devices and the AI server using wire and/or wireless communication technology. For example, the communication part 1310 can transmit and/or receive sensor information, a user input, a learning model, and a control signal with external devices. The communication technology used by the communication part 1310 may include a global system for mobile communication (GSM), a code division multiple access (CDMA), an LTE/LTE-A, a 5G, a WLAN, a Wi-Fi, BluetoothTM, radio frequency identification (RFID), infrared data association (IrDA), ZigBee, and/or near field communication (NFC).

The input part 1320 can acquire various kinds of data. The input part 1320 may include a camera for inputting a video signal, a microphone for receiving an audio signal, and a user input part for receiving information from a user. A camera and/or a microphone may be treated as a sensor, and a signal obtained from a camera and/or a microphone may be referred to as sensing data and/or sensor information. The input part 1320 can acquire input data to be used when acquiring an output using learning data and a learning model for model learning. The input part 1320 may obtain raw input data, in which case the processor 1370 or the learning processor 1330 may extract input features by preprocessing the input data.

The learning processor 1330 may learn a model composed of an ANN using learning data. The learned ANN can be referred to as a learning model. The learning model can be used to infer result values for new input data rather than learning data, and the inferred values can be used as a basis for determining which actions to perform. The learning processor 1330 may perform AI processing together with the learning processor of the AI server. The learning processor 1330 may include a memory integrated and/or implemented in the AI device 1300. Alternatively, the learning processor 1330 may be implemented using the memory 1360, an external memory directly coupled to the AI device 1300, and/or a memory maintained in an external device.

The sensing part 1340 may acquire at least one of internal information of the AI device 1300, environment information of the AI device 1300, and/or the user information using various sensors. The sensors included in the sensing part 1340 may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, a light detection and ranging (LIDAR), and/or a radar.

The output part 1350 may generate an output related to visual, auditory, tactile, etc. The output part 1350 may include a display unit for outputting visual information, a speaker for outputting auditory information, and/or a haptic module for outputting tactile information.

The memory 1360 may store data that supports various functions of the AI device 1300. For example, the memory 1360 may store input data acquired by the input part 1320, learning data, a learning model, a learning history, etc.

The processor 1370 may determine at least one executable operation of the AI device 1300 based on information determined and/or generated using a data analysis algorithm and/or a machine learning algorithm. The processor 1370 may then control the components of the AI device 1300 to perform the determined operation. The processor 1370 may request, retrieve, receive, and/or utilize data in the learning processor 1330 and/or the memory 1360, and may control the components of the AI device 1300 to execute the predicted operation and/or the operation determined to be desirable among the at least one executable operation. The processor 1370 may generate a control signal for controlling the external device, and may transmit the generated control signal to the external device, when the external device needs to be linked to perform the determined operation. The processor 1370 may obtain the intention information for the user input and determine the user's requirements based on the obtained intention information. The processor 1370 may use at least one of a speech-to-text (STT) engine for converting speech input into a text string and/or a natural language processing (NLP) engine for acquiring intention information of a natural language, to obtain the intention information corresponding to the user input. At least one of the STT engine and/or the NLP engine may be configured as an ANN, at least a part of which is learned according to a machine learning algorithm. At least one of the STT engine and/or the NLP engine may be learned by the learning processor 1330 and/or learned by the learning processor of the AI server, and/or learned by their distributed processing. The processor 1370 may collect history information including the operation contents of the AI device 1300 and/or the user's feedback on the operation, etc. The processor 1370 may store the collected history information in the memory 1360 and/or the learning processor 1330, and/or transmit to an external device such as the AI server. The collected history information can be used to update the learning model. The processor 1370 may control at least some of the components of AI device 1300 to drive an application program stored in memory 1360. Furthermore, the processor 1370 may operate two or more of the components included in the AI device 1300 in combination with each other for driving the application program.

Referring to FIG. 14, in the AI system, at least one of an AI server 1420, a robot 1410a, an autonomous vehicle 1410b, an XR device 1410c, a smartphone 1410d and/or a home appliance 1410e is connected to a cloud network 1400. The robot 1410a, the autonomous vehicle 1410b, the XR device 1410c, the smartphone 1410d, and/or the home appliance 1410e to which the AI technology is applied may be referred to as AI devices 1410a to 1410e.

The cloud network 1400 may refer to a network that forms part of a cloud computing infrastructure and/or resides in a cloud computing infrastructure. The cloud network 1400 may be configured using a 3G network, a 4G or LTE network, and/or a 5G network. That is, each of the devices 1410a to 1410e and 1420 consisting the AI system may be connected to each other through the cloud network 1400. In particular, each of the devices 1410a to 1410e and 1420 may communicate with each other through a base station, but may directly communicate with each other without using a base station.

The AI server 1420 may include a server for performing AI processing and a server for performing operations on big data. The AI server 1420 is connected to at least one or more of AI devices constituting the AI system, i.e. the robot 1410a, the autonomous vehicle 1410b, the XR device 1410c, the smartphone 1410d and/or the home appliance 1410e through the cloud network 1400, and may assist at least some AI processing of the connected AI devices 1410a to 1410e. The AI server 1420 can learn the ANN according to the machine learning algorithm on behalf of the AI devices 1410a to 1410e, and can directly store the learning models and/or transmit them to the AI devices 1410a to 1410e. The AI server 1420 may receive the input data from the AI devices 1410a to 1410e, infer the result value with respect to the received input data using the learning model, generate a response and/or a control command based on the inferred result value, and transmit the generated data to the AI devices 1410a to 1410e. Alternatively, the AI devices 1410a to 1410e may directly infer a result value for the input data using a learning model, and generate a response and/or a control command based on the inferred result value.

Various embodiments of the AI devices 1410a to 1410e to which the technical features of the present disclosure can be applied will be described. The AI devices 1410a to 1410e shown in FIG. 14 can be seen as specific embodiments of the AI device 1300 shown in FIG. 13.

The present disclosure can have various advantageous effects.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

A method performed by a radio access network (RAN) node in a wireless communication system, the method comprising:

obtaining closed access group (CAG) identities (IDs) of neighbor RAN nodes and a CAG ID of a user equipment (UE) communicating with the RAN node;

determining a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE; and

controlling to perform a communication between the determined neighbor RAN node and the UE.
The method of claim 1, further comprising:

receiving a measurement report comprising a signal quality for each of the neighbor RAN nodes,

wherein the determining the neighbor RAN node comprises determining the neighbor RAN node among the neighbor RAN nodes based on the measurement report.
The method of claim 1, wherein the RAN node is a master node (MN) for the UE,

wherein the obtaining the CAG IDs of neighbor RAN nodes comprises receiving, from another RAN node, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node,

wherein the determining of the neighbor RAN node comprises determining a target MN for a handover among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target MN, and

wherein the controlling to perform the communication comprises performing the handover of the UE from the MN to the target MN.
The method of claim 3, wherein the message is acknowledgement (ACK) message for a secondary node (SN) addition request message received from the other RAN node, and

wherein the SN addition request message is transmitted from the MN to the other RAN node.
The method of claim 3, wherein the message is an Xn setup message or an Xn setup response message received from the other RAN node, and

wherein the Xn setup response message is a response message for an Xn setup message transmitted from the MN to the other RAN node.
The method of claim 1, wherein the RAN node is a secondary node (SN) for the UE,

wherein the obtaining of the CAG IDs of neighbor RAN nodes comprises receiving, from another RAN node, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node,

wherein the determining the neighbor RAN node comprises determining a target SN for a SN change among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target SN,

wherein the controlling to perform the communication comprises performing the SN change for the UE from the SN to the target SN, and

wherein a master node (MN) for the UE is maintained after the SN change.
The method of claim 6, wherein the message is a secondary node (SN) addition request message received from the MN.
The method of claim 6, wherein the message is an Xn setup message or an Xn setup response message received from the other RAN node, and

wherein the Xn setup response message is a response message for an Xn setup message transmitted from the SN to the other RAN node.
The method of claim 1, wherein the RAN node is a master node (MN) for the UE,

wherein the obtaining of the CAG IDs of the neighbor RAN nodes comprises receiving, from neighbor RAN nodes for the MN which are connected to the MN, a message comprising CAG IDs of the neighbor RAN nodes for the MN,

wherein the determining of the neighbor RAN node comprises determining a SN for the UE among the neighbor RAN nodes for the MN based on a match between the CAG ID of the UE and a CAG ID of the SN, and

wherein the controlling to perform the communication comprises controlling to perform the communication between the SN and the UE while maintaining a communication with the UE.
The method of claim 1, wherein the RAN node is a master node (MN) for the UE,

wherein the obtaining of the CAG IDs of the neighbor RAN nodes comprises receiving, from neighbor RAN nodes for the MN which are connected to the MN, a message comprising CAG IDs of the neighbor RAN nodes for the MN,

wherein the determining of the neighbor RAN node comprises determining a target MN for a handover among the neighbor RAN nodes for the MN based on a match between the CAG ID of the UE and a CAG ID of the target MN, and

wherein the controlling to perform the communication comprises performing the handover of the UE from the MN to the target MN.
The method of claim 1, wherein the RAN node is a secondary node (SN) for the UE,

wherein the obtaining of the CAG IDs of the neighbor RAN nodes comprises receiving, from neighbor RAN nodes for the SN which are connected to the SN, a message comprising CAG IDs of the neighbor RAN nodes for the SN,

wherein the determining of the neighbor RAN node comprises determining a target SN for a SN change among the neighbor RAN nodes for the SN based on a match between the CAG ID of the UE and a CAG ID of the target SN,

wherein the controlling to perform the communication comprises performing the SN change for the UE from the SN to the target SN, and

wherein a master node (MN) for the UE is maintained after the SN change.
A radio access network (RAN) node in a wireless communication system comprising:

a memory;

a transceiver;

a backhaul communication interface; and

at least one processor, operatively coupled to the memory, the transceiver and the backhaul communication interface, configured to:

control the backhaul communication interface to obtain closed access group (CAG) identities (IDs) of neighbor RAN nodes and a CAG ID of a user equipment (UE) communicating with the RAN node,

determine a neighbor RAN node among the neighbor RAN nodes based on the CAG IDs of neighbor RAN nodes and the CAG ID of the UE, and

control to perform a communication between the determined neighbor RAN node and the UE
The RAN node of claim 12, wherein the transceiver is further configured to receive a measurement report comprising a signal quality for each of the neighbor RAN nodes, and

wherein the at least one processor is further configured to determine the neighbor RAN node among the neighbor RAN nodes based on the measurement report.
The RAN node of claim 12, wherein the RAN node is a master node (MN) for the UE, and

wherein the at least one processor is further configured to:

control the backhaul communication interface to receive, from another RAN node, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node,

determine a target MN for a handover among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target MN, and

perform the handover of the UE from the MN to the target MN.
The method of claim 12, wherein the RAN node is a secondary node (SN) for the UE, and

wherein the at least one processor is further configured to:

control the backhaul communication interface to receive, from another RAN node, a message comprising CAG IDs of neighbor RAN nodes for the other RAN node which are connected to the other RAN node,

determine a target SN for a SN change among the neighbor RAN nodes for the other RAN node based on a match between the CAG ID of the UE and a CAG ID of the target SN, and

perform the SN change for the UE from the SN to the target SN, and

wherein a master node (MN) for the UE is maintained after the SN change.