Method and apparatus for mobility of multiple terminals for network power saving in next generation mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method and apparatus for controlling mobility of a terminal for network energy saving technology are disclosed.

Description

Technical Field

[0001] This disclosure relates to the operation of a terminal in a mobile communication system. More specifically, this disclosure relates to the mobility of a terminal for network power-saving technologies. Background Technology

[0002] 5G mobile communication technology defines wide frequency bands to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz, such as 3.5 GHz, but also in ultra-high frequency bands (“above 6 GHz”) such as 28 GHz and 39 GHz, known as millimeter wave (mmWave). Furthermore, 6G mobile communication technology, known as super 5G communication systems, is being considered for implementation in terahertz frequency bands (e.g., from 95 GHz to 3 terahertz (3 THz)) to achieve transmission speeds up to 50 times faster than 5G mobile communication technology and ultra-low latency as low as one-tenth.

[0003] The early stages of 5G mobile communication technology aim to support services such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC) while meeting their performance requirements. To achieve this goal, standardization is currently underway for the following technologies: beamforming and massive MIMO to mitigate path loss of radio waves and increase propagation range in the UHF band; support for dynamic operation of various parameter sets (such as operation of multiple subcarrier spacing) and time slot formats to effectively utilize UHF resources; initial access technologies to support multi-beam transmission and broadband; definition and operation of the bandwidth portion (BWP); new channel coding methods such as low-density parity-check (LDPC) codes for high-capacity data transmission and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing to provide dedicated networks for specific services.

[0004] Currently, discussions are underway regarding how to improve and enhance the performance of initial 5G mobile communication technologies, considering the services they are intended to support. Physical layer standardization is underway, targeting technologies such as: Vehicle-to-Everything (V2X), which assists autonomous vehicles in making driving decisions and improves user convenience based on the vehicle's own location and status information; New Radio Unlicensed (NR-U), which aims to enable system operation in unlicensed frequency bands to meet various regulatory requirements; NR UE power saving; Non-Terrestrial Networks (NTN), which is direct UE-satellite communication to ensure coverage in areas where communication with terrestrial networks is impossible; and positioning.

[0005] In addition, standardization of wireless interface architecture / protocol fields for technologies such as: smart factories (Industrial Internet of Things, IIoT) to support new services through integration and convergence with other industries; Integrated Access and Backhaul (IAB) to provide nodes to extend network service areas by integrating and supporting wireless backhaul links and access links; mobility enhancement technologies including conditional handover and dual active protocol stack (DAPS) handover; and 2-step random access (2-step RACH for NR), which simplifies the random access process; and standardization of system architecture / service fields for 5G baseline architectures (e.g., service-based architecture, service-based interfaces) to combine Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies with Mobile Edge Computing (MEC) to receive services based on UE location.

[0006] When 5G mobile communication systems become commercialized, the explosive growth of connected devices will link to these networks. Therefore, it is anticipated that there will be a need to enhance the functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices. To this end, new research is planned on the following technologies: Extended Reality (XR) for effective support of Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), etc.; 5G performance improvements and complexity reductions through the use of Artificial Intelligence (AI) and Machine Learning (ML); AI service support; Metaverse service support; and drone communication.

[0007] Furthermore, advancements in 5G mobile communication systems can not only lay the foundation for developing 6G mobile communication technologies that include: new waveforms for ensuring coverage in the terahertz band; multi-antenna transmission technologies such as full-dimensional multiple-input multiple-output (FD-MIMO), array antennas, and massive MIMO; metamaterial-based lenses and antennas for improving terahertz band signal coverage; high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM); and reconfigurable smart surfaces (RIS) technology, but also can lay the foundation for developing 6G mobile communication technologies that include: full-duplex technologies for improving frequency efficiency and enhancing system networks; AI-based communication technologies that leverage satellite and artificial intelligence (AI) from the design stage and include end-to-end AI support for system optimization; and next-generation distributed computing technologies that utilize ultra-high-performance communication and computing resources to exceed the operational limits of UEs to achieve highly complex services.

[0008] With the advancements in mobile communication systems, various services can be provided. Therefore, measures are needed to efficiently deliver these services. For example, to provide these services more efficiently, the network can operate in energy-saving mode. When the network enters energy-saving mode, the UE may be unable to send and receive normal signals. Conventionally, a method is introduced to move the UE to another network / cell, enabling normal signal transmission and reception. In this scenario, multiple UEs can be moved in this manner, and each UE is assigned specific conditions related to the signal strength of the target cell relative to the signal strength of the serving cell. Based on a signal received from the network indicating that the network has entered energy-saving mode, the UE moves to the target cell that meets the specific conditions. However, the signal indicating that the network has entered energy-saving mode does not indicate which mode the network has entered. Summary of the Invention

[0009] Technical issues

[0010] Various methods can be employed to reduce energy consumption in the aforementioned network, and these methods can be applied to UEs in specific connection modes at specific times. However, given this, the conditions for conditional handover of the UE should also be configurable to reflect various conditions for each energy-saving mode. Otherwise, for example, when a condition is uniformly applied to other modes without considering the cell signal strength of the serving cell for each mode, there may be issues where the UE might perform unnecessary handovers or fail to perform handovers when necessary.

[0011] Problem Solution

[0012] To address the aforementioned problems, according to one aspect of this disclosure, a method performed by a terminal in a wireless communication system includes: receiving from a base station a radio resource control (RRC) message containing configuration information regarding conditional handover (CHO), the configuration information including a conditional reconfiguration identifier (ID) and at least one measurement ID mapped to the conditional reconfiguration ID; performing measurements on a candidate cell using measurement configuration information associated with the at least one measurement ID; receiving from the base station control information containing an indicator associated with a network power saving (NES) specific CHO; determining whether a condition for performing CHO on the candidate cell is met based on report configuration information associated with the at least one measurement ID; and performing CHO on the candidate cell if the condition is met, wherein the indicator contains information indicating an NES mode applied to the base station, and wherein at least one measurement ID is configured for each NES mode.

[0013] According to another aspect of this disclosure, a method performed by a base station in a wireless communication system includes: sending a radio resource control (RRC) message to a terminal containing configuration information regarding conditional handover (CHO), the configuration information including a conditional reconfiguration identifier (ID) and at least one measurement ID mapped to the conditional reconfiguration ID; sending control information to the terminal containing an indicator associated with a network power saving (NES) specific CHO, wherein measurement configuration information associated with at least one measurement ID is used for measurements of candidate cells of the terminal, and reporting configuration information associated with at least one measurement ID is used to determine whether conditions for CHO of candidate cells of the terminal are met, wherein the indicator contains information indicating an NES mode applied to the base station, and wherein at least one measurement ID is configured for each NES mode.

[0014] According to another aspect of this disclosure, a terminal in a wireless communication system includes: a transceiver; and a controller configured to: control the transceiver to receive from a base station a radio resource control (RRC) message containing configuration information regarding conditional handover (CHO), the configuration information including a conditional reconfiguration identifier (ID) and at least one measurement ID mapped to the conditional reconfiguration ID; perform measurements on a candidate cell using measurement configuration information associated with the at least one measurement ID; control the transceiver to receive from the base station control information containing an indicator associated with a network power saving (NES) specific CHO; determine whether a condition for performing CHO on the candidate cell is met based on report configuration information associated with the at least one measurement ID; and, if the condition is met, perform CHO on the candidate cell, wherein the indicator contains information indicating an NES mode applied to the base station, and wherein at least one measurement ID is configured for each NES mode.

[0015] According to another aspect of this disclosure, a base station in a wireless communication system includes: a transceiver; and a controller configured to: control the transceiver to send a radio resource control (RRC) message to a terminal containing configuration information regarding conditional handover (CHO), the configuration information including a conditional reconfiguration identifier (ID) and at least one measurement ID mapped to the conditional reconfiguration ID; and control the transceiver to send control information to the terminal containing an indicator associated with a network power saving (NES) specific CHO, wherein measurement configuration information associated with at least one measurement ID is used for measurements of candidate cells of the terminal, wherein reporting configuration information associated with at least one measurement ID is used to determine whether conditions for CHO of candidate cells of the terminal are met, wherein the indicator contains information indicating an NES mode applied to the base station, and wherein at least one measurement ID is configured for each NES mode.

[0016] Advantages of the invention

[0017] According to embodiments of this disclosure, the UE can perform conditional handover by using handover conditions optimized for each type of network power saving mode. Attached Figure Description

[0018] Figure 1 This is a diagram showing the structure of a general LTE system.

[0019] Figure 2 This is a diagram illustrating the wireless protocol structure of a general LTE system.

[0020] Figure 3 This is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0021] Figure 4 This is a diagram illustrating the wireless protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0022] Figure 5 This is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure.

[0023] Figure 6 This is a block diagram illustrating the configuration of an NR base station according to an embodiment of the present disclosure.

[0024] Figure 7 This is a figure illustrating Example 1-1 of a method for configuring multiple conditions when configuring NES CHO for a UE in a network according to an embodiment of the present disclosure.

[0025] Figure 8 The figures are examples 1-2 illustrating a method for configuring multiple conditions when configuring NES CHO for a UE in a network according to embodiments of the present disclosure.

[0026] Figure 9 The figures are examples 1-3 illustrating a method for configuring multiple conditions when configuring NES CHO for a UE in a network according to embodiments of the present disclosure.

[0027] Figure 10 This is a diagram of Example 2 illustrating a method for configuring multiple conditions when configuring NES CHO for a UE in a network according to an embodiment of the present disclosure.

[0028] Figure 11 This is a diagram of Example 3 illustrating a method for configuring multiple conditions when configuring NES CHO for a UE in a network according to an embodiment of the present disclosure.

[0029] Figure 12 This is a diagram used to describe the call flow between the UE and the network for option 1 according to an example of this disclosure.

[0030] Figure 13This is a diagram used to describe the call flow between the UE and the network for option 2 according to an example of this disclosure.

[0031] Figure 14 This is a diagram used to describe the call flow between the UE and the network for option 3 according to an example of this disclosure. Detailed Implementation

[0032] The operating principles of this disclosure will be described in detail below with reference to the accompanying drawings. In the following description, detailed descriptions of known technologies or configurations related to this disclosure will be omitted where it is determined that such detailed descriptions might unnecessarily obscure the essence of this disclosure. Furthermore, the following terminology is based on the functional definition of this disclosure and may vary depending on the intent and practice of the user and operator. Therefore, the definitions of the terms should be interpreted based on the content of this specification.

[0033] In the following description, terms used to identify connected nodes, to refer to network entities, to refer to messages, to refer to interfaces between network entities, and to refer to various identifying information are merely examples for ease of description. Therefore, this disclosure is not limited to the terms described below, and other terms may be used to refer to subjects with equivalent technical meaning.

[0034] In the following description, a base station is an entity that performs resource allocation for a terminal and can be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, or node on a network. A terminal can include a user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, downlink (DL) refers to the radio transmission path of a signal from the base station to the terminal, and uplink (UL) refers to the radio transmission path of a signal from the terminal to the base station. Furthermore, although LTE or LTE-A systems may be described as examples below, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel configurations. For example, fifth-generation (5G) mobile communication technologies (New Radio, NR) developed after LTE-A can be included in systems where embodiments of this disclosure can be applied, and 5G below can also be a concept including legacy LTE, LTE-A, and similar services. Furthermore, this disclosure can be applied to other communication systems with certain modifications as determined by those skilled in the art without significantly departing from the scope of this disclosure. In this case, it will be understood that each block in the process flowchart and combinations of flowcharts can be executed by computer program instructions.

[0035] Because these computer program instructions can be mounted on the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, these computer program instructions, executed by the processor of the computer or other programmable data processing equipment, create means for performing the functions described in the blocks of the flowchart. Because these computer program instructions can also be stored in computer-usable or computer-readable memory that can instruct the computer or other programmable data processing equipment to function in a particular manner, the instructions stored in computer-usable or computer-readable memory can produce an article of art that includes instruction means for performing the functions described in the blocks of the flowchart. Because the computer program instructions can also be mounted on a computer or other programmable data processing equipment, performing a series of operational steps on the computer or other programmable data processing equipment to create a process executed by the computer, thereby executing the instructions of the computer or other programmable data processing equipment, can also provide steps for performing the functions described in the blocks of the flowchart.

[0036] Furthermore, each box may represent some of a module, segment, or code, including one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative embodiments, the functions mentioned in the boxes occur regardless of the order. For example, two boxes shown consecutively may actually be executed simultaneously, or sometimes in reverse order depending on the corresponding function. In this context, the term "~unit" as used in this embodiment means a software or hardware component such as a Field Programmable Gate Array (FPGA) or Application-Specific Integrated Circuit (ASIC), and the "~unit" performs a specific role. However, "~unit" is not intended to be limited to software or hardware. A "~unit" may be configured to be stored in an addressable storage medium or may be configured to reproduce one or more processors. Thus, by way of example, "~unit" includes components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in components and "~units" may be combined into a smaller number of components and / or "~units," or may be divided into additional components and "~units." Furthermore, components and "~units" can be implemented to reproduce one or more CPUs in a device or secure multimedia card. Additionally, in embodiments, "~units" may include one or more processors.

[0037] In the following text, for ease of explanation, this disclosure uses the terms and names defined in the 5GS and NR specifications, which are standards defined by the 3rd Generation Partnership Project (3GPP) organization in existing communication standards. However, this disclosure is not limited to these terms and names and can be applied equally to wireless communication networks conforming to other standards. For example, this disclosure can be applied to 3GPP 5GS / NR (5G mobile communication standard).

[0038] Figure 1 This is a diagram showing the structure of a general LTE system.

[0039] refer to Figure 1 The radio access network of a Long Term Evolution (LTE) system may include next-generation base stations (Evolved Node Bs (hereinafter referred to as ENBs), Node Bs or base stations) 1-05, 1-10, 1-15 and 1-20, a Mobility Management Entity (MME) 1-25 and a Serving Gateway (S-GW) 1-30. User equipment (hereinafter referred to as terminals or UEs) 1-35 accesses external networks via ENBs 1-05 to 1-20 and S-GW 1-30.

[0040] exist Figure 1 In LTE, ENBs 1-05 to 1-20 can correspond to traditional Node Bs in a UMTS (Universal Mobile Telecommunications System) system. ENBs 1-05 to 1-20 connect to UE 1-35 via a radio channel and can perform a more complex role than traditional Node Bs. In LTE systems, all user services, including real-time services via Internet Protocol (IP) such as Voice over IP (VoIP), can be served through a shared channel. Therefore, a device is needed to collect UE state information (such as buffer state, available transmit power state, and channel state) and perform scheduling, which can be handled by ENBs 1-05 to 1-20. One ENB typically controls multiple cells. For example, to achieve a transmission rate of 100 Mbps, an LTE system can use an Orthogonal Frequency Division Multiplexing (OFDM) scheme in a 20 MHz bandwidth as the radio access technology. Furthermore, an Adaptive Modulation and Coding (AMC) scheme, which determines the modulation scheme and channel coding rate based on the UE's channel state, can be applied.

[0041] The S-GW 1-30 is a device that provides data bearers and can generate or remove data bearers under the control of the MME 1-25. The MME 1-25 is a device that handles various control functions and UE mobility management functions, and can be connected to multiple base stations.

[0042] Figure 2 This is a diagram illustrating the wireless protocol structure of a traditional LTE system.

[0043] refer to Figure 2 The radio protocols of an LTE system may include Packet Data Convergence Protocol (PDCP) 2-05 and 2-40, Radio Link Control (RLC) 2-10 and 2-35, and Media Access Control (MAC) 2-15 and 2-30, respectively, in the UE and ENB. PDCP can handle operations such as Internet Protocol (IP) header compression / decompression. The main functions of PDCP can be summarized as follows.

[0044] - Header compression and decompression functions (Header compression and decompression: ROHC only)

[0045] - User data transfer function (transfer of user data)

[0046] - Sequential delivery function (sequential delivery of upper-layer PDUs during PDCP reconstruction for RLC AM)

[0047] - Reordering function (for separate bearers in DC (RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0048] - Repeat detection function (repeated detection of lower-layer SDUs during PDCP reconstruction of RLC AM)

[0049] - Retransmit function (for RLC AM, retransmit PDCP SDU during handover, and for separate bearers in DC, retransmit PDCP PDU during PDCP data recovery)

[0050] - Encryption and decryption functions (encryption and decryption)

[0051] - Timer-based SDU discarding function (timer-based SDU discarding in the uplink)

[0052] Radio Link Control (RLC) 2-10 and 2-35 can perform ARQ operations, etc., by reconfiguring PDCP Packet Data Units (PDUs) to an appropriate size. The main functions of the RLC can be summarized as follows.

[0053] - Data transmission function (transmission of upper-layer PDUs)

[0054] -ARQ function (error correction via ARQ (for AM data transmission only))

[0055] - Cascading, segmentation, and reassembly functions (cascading, segmentation, and reassembly of RLC SDUs (only for UM and AM data transmission))

[0056] - Re-segmentation function (re-segmentation of RLC data PDUs (only for AM data transmission))

[0057] - Reordering function (Reordering of RLC data PDUs (only for UM and AM data transfers))

[0058] - Duplicate detection function (Duplicate detection (only for UM and AM data transmission))

[0059] - Error detection function (protocol error detection (AM data transmission only))

[0060] -RLC SDU discard function (RLC SDU discard (only for UM and AM data transmission))

[0061] -RLC Reconstruction Function (RLC Reconstruction)

[0062] MAC 2-15 and 2-30 connect to multiple RLC layer entities configured in a UE and can perform operations such as multiplexing RLCPDUs (Protocol Data Units) into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of the MAC can be summarized as follows.

[0063] - Mapping function (mapping between logical channels and transmission channels)

[0064] - Multiplexing and demultiplexing functions (multiplexing MAC SDUs belonging to one or different logical channels into a transport block (TB) delivered to the physical layer on the transport channel / demultiplexing MAC SDUs belonging to one or different logical channels from a TB delivered from the physical layer on the transport channel)

[0065] - Scheduling information reporting function (Scheduling Information Report)

[0066] - HARQ function (error correction via HARQ)

[0067] - Priority processing function between logical channels (priority processing between logical channels of a UE)

[0068] - Priority handling function between UEs (priority handling between UEs with the help of dynamic scheduling)

[0069] -MBMS Service Identification Function (MBMS Service Identification)

[0070] -Transmission format selection function (Transmission format selection)

[0071] - Fill function (Fill)

[0072] Physical layers 2-20 and 2-25 can perform channel coding and modulation of upper-layer data, convert upper-layer data into OFDM symbols for transmission via a wireless channel, or demodulate and channel decode OFDM symbols received via a wireless channel and deliver the demodulated and channel-decoded symbols to the upper layer.

[0073] Figure 3 This is a diagram showing the structure of a next-generation mobile communication system.

[0074] refer to Figure 3 The radio access network for next-generation mobile communication systems (hereinafter referred to as NR or 5G) can consist of next-generation base stations (new radio nodes B, hereinafter referred to as NR gNB or NR base stations) 3-10 and next-generation radio core networks (new radio core networks (NR CN)) 3-05. Next-generation radio user equipment (new radio user equipment (NR UE) or UE) 3-15 can access external networks via NR gNB 3-10 and NR core networks (NR CN) 3-05.

[0075] exist Figure 3 In this context, NR gNB 3-10 can correspond to an evolved Node B (eNB) in a traditional LTE system. NR gNB 3-10 connects to NR UE 3-15 via a radio channel and can provide services superior to those of a traditional Node B. In next-generation mobile communication systems, all user services can be served via a shared channel. Therefore, a device is needed to collect UE state information (such as buffer state, available transmit power state, and channel state) and perform scheduling, which can be handled by NR gNB 3-10. One NR gNB can control multiple cells. In next-generation mobile communication systems, bandwidths exceeding the typical maximum bandwidth can be applied to achieve data transmission speeds significantly higher than typical LTE speeds. Furthermore, beamforming techniques, such as Orthogonal Frequency Division Multiplexing (OFDM), can be incorporated into radio access technologies. Additionally, adaptive modulation and coding (AMC) schemes, which determine the modulation scheme and channel coding rate based on the UE's channel state, can be applied.

[0076] The NR CN 3-05 can perform functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. The NR CN 3-05 is an apparatus for handling various control functions and UE mobility management functions, and can connect to multiple base stations. Furthermore, next-generation mobile communication systems can link to LTE systems, and the NR CN 3-05 can connect to the MME 3-25 via a network interface. The MME 3-25 can connect to the eNB 3-30, which acts as an LTE base station.

[0077] Figure 4This is a diagram illustrating the wireless protocol structure of a next-generation mobile communication system to which this disclosure can be applied.

[0078] refer to Figure 4 The radio protocols of the next-generation mobile communication system consist of NR Service Data Adaptation Protocol (SDAP) 4-01 and 4-45, NR PDCP 4-05 and 4-40, NR RLC 4-10 and 4-35, NR MAC 4-15 and 4-30, and NR PHY 4-20 and 4-25 at the UE and NB base station, respectively.

[0079] The main functions of NR SDAP 4-01 and 4-45 may include some of the following functions.

[0080] - User data transmission function (transmission of user plane data)

[0081] - Mapping function for QoS flows and data bearers for uplink and downlink (mapping between QoS flows and DRB for both DL and UL)

[0082] - A tagging function for QoS flow IDs of both uplink and downlink (tags QoS flow IDs in both DL and UL packets).

[0083] - Functionality for mapping reactive QoS flows to data bearers for uplink SDAP PDUs (reactive QoS flows to DRB mapping for UL SDAPPDUs).

[0084] For SDAP layer entities, the UE can be configured via Radio Resource Control (RRC) messages to indicate whether to use the SDAP layer entity header, or whether to enable SDAP layer entity functionality on a per PDCP layer entity, per bearer, or per logical channel basis. When the SDAP header is configured, the UE can be instructed to use a 1-bit indicator for Non-Access Stratum (NAS) Quality of Service (QoS) reflection configuration (NAS reflected QoS) and a 1-bit indicator for Access Stratum (AS) QoS reflection configuration (AS reflected QoS) in the SDAP header to update or reconfigure the mapping information of uplink and downlink QoS flows and data bearers. The SDAP header may include QoS flow ID information representing QoS. QoS information can be used as data processing priority information, scheduling information, etc., to support smooth service.

[0085] The main functions of NR PDCP 4-05 and 4-40 may include some of the following functions.

[0086] - Header compression and decompression functions (Header compression and decompression: ROHC only)

[0087] - User data transfer function (transfer of user data)

[0088] - Sequential delivery function (sequential delivery of upper-layer PDUs)

[0089] - Out-of-order delivery function (out-of-order delivery of upper-layer PDUs)

[0090] - Reordering function (PDCP PDU reordering for reception)

[0091] - Duplicate detection function (duplicate detection of lower-level SDUs)

[0092] - Retransmission function (PDCP SDU retransmission)

[0093] - Encryption and decryption functions (encryption and decryption)

[0094] - Timer-based SDU discarding function (timer-based SDU discarding in the uplink)

[0095] In the above description, the reordering function of the NR PDCP entity can refer to the function of reordering PDCP PDUs received from the lower layer in sequence based on the PDCP sequence number (PDCP SN). The reordering function of the NR PDCP entity may include: delivering data to the upper layer in the reordered order; delivering data immediately regardless of order; recording PDCP PDUs lost during the reordering process; reporting the status of lost PDCP PDUs to the transmitter; and requesting the retransmission of lost PDCP PDUs.

[0096] The main functions of NR RLC 4-10 and 4-35 may include some of the following functions.

[0097] - Data transmission function (transmission of upper-layer PDUs)

[0098] - Sequential delivery function (sequential delivery of upper-layer PDUs)

[0099] - Out-of-order delivery function (out-of-order delivery of upper-layer PDUs)

[0100] -ARQ function (error correction via ARQ)

[0101] - Cascading, segmentation, and reassembly functions (cascading, segmentation, and reassembly of RLC SDU)

[0102] - Re-segmentation function (re-segmentation of RLC data PDUs)

[0103] - Reordering function (reordering RLC data PDUs)

[0104] - Duplicate detection function (duplicate detection)

[0105] - Error detection function (protocol error detection)

[0106] -RLC SDU discard function (RLC SDU discard)

[0107] -RLC Reconstruction Function (RLC Reconstruction)

[0108] In the above description, the sequential delivery function of an NR RLC entity can refer to the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. When an RLC SDU is segmented into multiple RLC SDUs and received, the sequential delivery function of an NR RLC entity can include the function of reassembling and delivering the RLC SDUs.

[0109] The sequential delivery function of NR RLC entities may include the function of reordering received RLC PDUs based on RLC sequence number (RLC SN) or PDCP sequence number (PDCP SN); the function of recording lost RLC PDUs by reordering them; the function of reporting the status of lost RLC PDUs to the transmitter; and the function of requesting retransmission of lost RLC PDUs.

[0110] The sequential delivery function of NR RLC entities can include the ability to sequentially deliver only the RLC SDUs preceding the lost RLCSDU to the upper layer when a lost RLC SDU exists.

[0111] The sequential delivery function of NR RLC entities may include the function of sequentially delivering all RLC SDUs received before the scheduled timer starts to the upper layer, even if there are lost RLC SDUs, if the timer has expired.

[0112] The sequential delivery function of NR RLC entities may include the function of sequentially delivering all RLC SDUs received to date to the upper layer when a predetermined timer has expired, even in the presence of lost RLC SDUs.

[0113] The NR RLC entity can process RLC PDUs in the order they are received and deliver the processed RLC PDUs to the NR PDCP entity, regardless of the sequence number order (out-of-order delivery).

[0114] When a fragment is received, the NR RLC entity can receive the fragment stored in the buffer or to be received later, reconfigure the fragment into a complete RLC PDU, and then deliver the reconfigured RLC PDU to the NR PDCP entity.

[0115] The NR RLC layer may not include cascading functionality, but this functionality can be implemented in the NR MAC layer or replaced by the multiplexing functionality of the NR MAC layer.

[0116] In the above description, the out-of-order delivery function of an NR RLC entity can refer to the function of directly delivering RLC SDUs received from lower layers to upper layers regardless of their order. The out-of-order delivery function of an NR RLC entity can include the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is segmented into multiple RLC SDUs and received. The out-of-order delivery function of an NR RLC entity can include the function of storing the RL CSN or PDCP SN of received RLC PDUs and reordering them to record any lost RLC PDUs.

[0117] NR MAC 4-15 and 4-30 can connect to multiple NR RLC layer entities configured in a UE, and the main functions of NR MAC can include some of the following functions.

[0118] - Mapping function (mapping between logical channels and transmission channels)

[0119] - Multiplexing and demultiplexing functions (MAC SDU multiplexing / demultiplexing)

[0120] - Scheduling information reporting function (Scheduling Information Report)

[0121] - HARQ function (error correction via HARQ)

[0122] - Priority processing function between logical channels (priority processing between logical channels of a UE)

[0123] - Priority handling function between UEs (priority handling between UEs with the help of dynamic scheduling)

[0124] -MBMS Service Identification Function (MBMS Service Identification)

[0125] -Transmission format selection function (Transmission format selection)

[0126] - Fill function (Fill)

[0127] NR PHY layers 4-20 and 4-25 can perform operations such as channel coding and modulation of upper-layer data, conversion of upper-layer data into OFDM symbols for transmission via a radio channel, or demodulation and channel decoding of OFDM symbols received via a radio channel and delivery of the demodulated and channel-decoded symbols to the upper layer.

[0128] Figure 5This is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0129] refer to Figure 5 The terminal includes a radio frequency (RF) processing unit 5-10, a baseband processing unit 5-20, a storage unit 5-30, and a control unit 5-40.

[0130] RF processing unit 5-10 can perform functions for transmitting and receiving signals via a wireless channel, such as signal band conversion and amplification. That is, RF processing unit 5-10 can upconvert a baseband signal provided by baseband processing unit 5-20 into an RF band signal, then transmit the RF band signal via an antenna, and downconvert the RF band signal received via the antenna into a baseband signal. For example, RF processing unit 5-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), etc. Although only one antenna is shown in the figure, the terminal may have multiple antennas. Furthermore, RF processing unit 5-10 may include multiple RF chains. Additionally, RF processing unit 5-10 can perform beamforming. For beamforming, RF processing unit 5-10 can adjust the phase and amplitude of each signal transmitted and received through multiple antennas or antenna elements. Furthermore, the RF processing unit can perform multiple-input multiple-output (MIMO) and receive multiple layers during MIMO operation.

[0131] The baseband processing unit 5-20 can perform the conversion function between baseband signals and bit strings according to the physical layer specifications of the system. For example, during data transmission, the baseband processing unit 5-20 can encode and modulate the transmitted bit string to generate complex symbols. Furthermore, during data reception, the baseband processing unit 5-20 can demodulate and decode the baseband signal provided from the RF processing unit 5-10 to reconstruct the received bit string. For example, according to the Orthogonal Frequency Division Multiplexing (OFDM) scheme, during data transmission, the baseband processing unit 5-20 can encode and modulate the transmitted bit string to generate complex symbols, map the complex symbols to subcarriers, and then construct OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, during data reception, the baseband processing unit 5-20 can segment the baseband signal provided by the RF processing unit 5-10 into OFDM symbol units, reconstruct the signal mapped to the subcarrier through Fast Fourier Transform (FFT), and then reconstruct the received bit string through demodulation and decoding.

[0132] The baseband processing unit 5-20 and the RF processing unit 5-10 can transmit and receive signals, as described above. Therefore, the baseband processing unit 5-20 and the RF processing unit 5-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 can include multiple communication modules to support various radio access technologies. Additionally, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 can each include different communication modules to process signals in different frequency bands. For example, different radio access technologies can include wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Furthermore, different frequency bands can include ultra-high frequency (SHF) bands (e.g., 2.0 NRHz, NRhz) and millimeter wave (mmWave) bands (e.g., 60 GHz).

[0133] Storage unit 5-30 can store data, such as basic programs, applications, and configuration information for terminal operation. Specifically, storage unit 5-30 can store information related to a second access node performing wireless communication using a second radio access technology. Furthermore, storage unit 5-30 can provide the stored data upon request from control unit 5-40.

[0134] Control unit 5-40 controls the overall operation of the terminal. For example, control unit 5-40 can send and receive signals via baseband processing unit 5-20 and RF processing unit 5-10. Furthermore, control unit 5-40 can write data to and read data from storage unit 5-30. For this purpose, control unit 5-40 may include at least one processor. For example, control unit 5-40 may include a communication processor (CP) that performs communication control and an application processor (AP) that controls upper layers (such as applications).

[0135] Figure 6 This is a block diagram illustrating the configuration of an NR base station according to an embodiment of the present disclosure.

[0136] As shown in the figure, the base station can be configured to include an RF processing unit 6-10, a baseband processing unit 6-20, a backhaul communication unit 6-30, a storage unit 6-40, and a control unit 6-50.

[0137] RF processing unit 6-10 can perform functions for transmitting and receiving signals via a wireless channel, such as signal band conversion and amplification. That is, RF processing unit 6-10 can upconvert a baseband signal provided by baseband processing unit 6-20 into an RF band signal, then transmit the RF band signal via an antenna, and downconvert the RF band signal received via the antenna into a baseband signal. For example, RF processing unit 6-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, ADCs, etc. Although only one antenna is shown in the figure, the first access node may have multiple antennas. Furthermore, RF processing unit 6-10 may include multiple RF chains. Additionally, RF processing unit 6-10 can perform beamforming. For beamforming, RF processing unit 6-10 can adjust the phase and amplitude of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform downlink MIMO operation by transmitting one or more layers.

[0138] The baseband processing unit 6-20 can perform the conversion function between baseband signals and bit strings according to the physical layer specification of the first radio access technology. For example, during data transmission, the baseband processing unit 6-20 can encode and modulate the transmitted bit string to generate complex symbols. Furthermore, during data reception, the baseband processing unit 6-20 can demodulate and decode the baseband signal provided from the RF processing unit 6-10 to reconstruct the received bit string. For example, in the case of an OFDM scheme, during data transmission, the baseband processing unit 6-20 can encode and modulate the transmitted bit string to generate complex symbols, map the complex symbols to subcarriers, and then construct OFDM symbols through IFFT operations and CP insertion. Furthermore, during data reception, the baseband processing unit 6-20 can segment the baseband signal provided from the RF processing unit 6-10 into OFDM symbol units, reconstruct the signal mapped to the subcarriers through FFT operations, and then reconstruct the received bit string through demodulation and decoding. The baseband processing unit 6-20 and the RF processing unit 6-10 can transmit and receive signals, as described above. Therefore, the baseband processing unit 6-20 and the RF processing unit 6-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, a communication unit, or a wireless communication unit.

[0139] The backhaul communication unit 6-30 can provide an interface for communicating with other nodes within the network. That is, the backhaul communication unit 6-30 can convert bit strings sent from the primary base station to another node (such as a secondary base station, core network, etc.) into physical signals, and can also convert physical signals received from another node into bit strings.

[0140] Storage unit 6-40 can store data, such as basic procedures, application programs, and configuration information for the operation of the main base station. Specifically, storage unit 6-40 can store information related to bearers allocated to accessed terminals, measurement results reported from accessed terminals, etc. Furthermore, storage unit 6-40 can store information used as the basis for determining whether to provide or terminate multiple connections to terminals. Additionally, storage unit 6-40 can provide the stored data upon request from control unit 6-50.

[0141] Control unit 6-50 controls the overall operation of the base station. For example, control unit 6-50 can transmit and receive signals via baseband processing unit 6-20 and RF processing unit 6-10 or via backhaul communication unit 6-30. Furthermore, control unit 6-50 can write data to and read data from storage unit 6-40. For this purpose, control unit 6-50 may include at least one processor.

[0142] Meanwhile, as a method for implementing network energy saving (NES) through cells in the network, there may be power domain (PD) schemes, spatial domain (SD) schemes, cell discontinuous transmission / cell discontinuous reception (cell DTX / DRX) schemes, or cell shutdown (shutting down all receive / transmit operations of the cell) schemes.

[0143] PD is a scheme for reducing or increasing transmit power during a specific time / resource period, and SD is a scheme for turning a specific RF panel / beam / port on or off. Cell DTX / DRX has periods during which the cell does not transmit or receive within a specific time unit.

[0144] Therefore, even for the same UE, the serving cell signal strength measured by the UE will vary depending on which NES mode is operating in the corresponding cell and at which point in time. For example, when a portion of the synchronization signal block (SSB) and / or channel state information (CSI) reference signal (RS) used to specify L3 strength and / or L1 channel quality indicator (L1 CQI) corresponds to the time / space of the NES mode cycle in a specific NES mode, the signal strength of the corresponding serving cell of the UE measuring that signal will change for each measurement cycle.

[0145] The following signal strengths can serve as examples of the serving cell signal strengths that a specific UE may have for each NES mode.

[0146] Normal, meaning no NES mode: -20 dBm

[0147] Full PD NES (Power Domain): Received L1-RSRP -100 dBm

[0148] Partial PD NES: Received L1-RSRP -50 dBm

[0149] Some SD NES (spatial domain): -80 dBm

[0150] Other SD NES: -101 dBm

[0151] Community DTX activation: Expected 0 W

[0152] Community closure: Expected 0 W

[0153] If we assume a Common Conditional Handover (CHO), then the normal scenario without NES mode is assumed. For example, for the corresponding normal scenario, the required CHO condition could be that the target cell signal strength is 3 dB higher than the serving cell signal strength. However, in the case of a full PD, assuming that SSB / CSI-RS transmission is significantly omitted, the cell signal strength will be significantly reduced, so the target cell signal strength is fixed while the serving cell signal strength is reduced. Therefore, when the UE enters this mode and immediately meets the 3 dB condition, the UE can move to another cell. However, even in this case, the network may still want to configure the UE to be served in the current serving cell. Therefore, in the case of a full PD, the conditions should be configured differently from those in normal NES mode.

[0154] As another example, since cell shutdown mode completely shuts down the serving cell, even if the target cell signal strength is weak (e.g., even if the signal strength is strong enough to access the target cell), the conditions for moving to the target cell can be configured based only on a relatively small difference in signal strength compared to normal conditions. As another example, in the case of partial PD, the serving cell signal strength is not very weak. Therefore, if the UE needs to move, the above conditions can be configured only for the target cell with sufficiently good signal strength.

[0155] In this way, there should be separate conditions for each NES mode, allowing the UE to appropriately select the target cell and perform a handover by taking into account the current state of the serving cell.

[0156] Therefore, when the network configures conditional handover for NES use for UEs based on a high level, a method can be introduced to configure conditions and / or target cells for each NES mode.

[0157] When the network sends a signal to a UE configured with an NES CHO to perform an NES CHO or to instruct the UE to enter a specific NES mode, the network can also indicate information about which NES mode the UE should enter.

[0158] After the UE receives the NES CHO configuration, the UE can receive network signals (signals used to execute the NES CHO or signals instructing the UE to enter a specific NES mode), determine the condition information related to the NES mode based on the corresponding NES mode signal, and then execute the CHO based on the corresponding condition information.

[0159] More specifically, when the network configures NES CHO for the UE, the following methods can be used as a way to configure multiple conditions.

[0160] Option 1. Multiple measIds, consisting of the traditional reportconfig and measurement objects, are assigned to each NES mode.

[0161] Option 2. reportConfig is configured to include a new, modified type containing NES mode-specific parameters. Multiple measIds configured via reportConfig are assigned to each NES mode.

[0162] Option 3. The measurement object is configured as a new, modified type containing NES mode-specific parameters. Multiple measIds configured through the measurement object are assigned to each NES mode.

[0163] Each option is described in detail below.

[0164] First, for option 1, the measId consists of the reportconfig and measObject in the UE's existing / configured measurement configuration. Therefore, regardless of the current NES mode, the UE should measure and evaluate all conditions starting from the time the condition information is received.

[0165] Conversely, for option 2, after performing a measurement without change, the UE may receive an NES CHO trigger indication signal to evaluate a specific condition. The UE can then identify the NES mode ID indicated in the corresponding indication signal and evaluate the condition associated with the corresponding NES mode ID.

[0166] For option 3, since the Measurement Object (MO) contains NES mode-specific parameters (e.g., information associated with each NES mode), even if the UE receives an NES CHO configuration based on a change in the MO, the UE will evaluate the conditions of each NES mode by modifying the measurement operation according to the time of the NES mode present in the MO. In other words, the measurement operation changes for each NES mode, while the evaluation operation remains unchanged. Furthermore, to change the MO, it is necessary to know in advance which NES mode is used by each cell at which time for each frequency. Therefore, in the network, each gNB should exchange information about the operation and time of the NES mode being used in its own cell using signals on the Xn interface or via Operation, Administration, and Maintenance (OAM) signals.

[0167] In the following text, detailed embodiments of the above options will be described with reference to each of the accompanying drawings.

[0168] In Option 1, a single measurement ID (measId) is configured for both the traditional reportConfiguration and the measurement object. The network can configure the list of measIds as a condition associated with the configuration of a specific target cell of the UE. In this case, the above condition can be associated with a specific NES mode. This association can be performed, for example, by representing the NES mode defined by the network as an ID. Here, id can be a specific natural number or integer. As a method for representing the above condition, the following can be considered: Figure 7 Option 1-1 Figure 8 Options 1-2 and Figure 9 Options 1-3 are provided.

[0169] refer to Figure 7 In option 1-1, multiple conditions corresponding to a specific target cell configuration can be represented. In this case, each condition can be represented together with an NES mode ID. In this case, a target cell configuration can be associated with a condReconfig ID. Furthermore, a single target cell configuration can be associated with multiple conditions. Here, multiple conditions can refer to conditions corresponding to multiple NES modes. Specifically, in the case of normal NES CHO conditions, a single NES mode ID may or may not be associated with the corresponding condition. When an NES mode ID is not associated with a condition, the NES CHO trigger indication signal may not contain a single NES mode ID. Conversely, when an NES mode ID is associated with a condition, and an NES CHO trigger indication signal containing the NES mode ID is sent, the UE can evaluate the condition associated with the NES mode ID. Furthermore, conditions can be associated and configured for the UE for each other NES mode ID. Figure 7As shown, multiple measIds can be associated with a single condition configuration. In this case, a condition can be determined to be met when all events of multiple measIds are satisfied, or when only a specific measId is satisfied.

[0170] like Figure 8 As shown, according to options 1-2, which are examples of this disclosure, for each specific target cell, an NES mode ID and a condition can be associated with the UE and the NES mode ID and condition can be configured for the UE. In this case, the target cell for each condition configuration ID can be the same cell, and the configurations can be the same or different. For example, as Figure 8 As shown, each condReconfig ID is associated with a specific target cell configuration and also with a single condition configuration. In this case, the condition is assigned an associated NES mode ID.

[0171] like Figure 9 As shown, according to options 1-3, which are examples of this disclosure, a list of NES conditions can be assigned to each specific target cell. That is, as... Figure 9 As shown, a target cell can be configured to be associated with an NESmodeConditionList. Here, the order of the list corresponds to the order of each NES mode ID. For example, the elements of the list above can represent NES modes 1, 2, 3, and 4 in sequence, and each element can be represented as a list of measIds.

[0172] Figure 10 The diagram is based on Option 2 of the example in this disclosure and illustrates a case where a new NES mode-specific report configuration type is defined. In this case, traditional measurement objects and the new type of reportconfig can be combined to configure a single measId, and each such configured measId can be associated with a specific target cell configuration.

[0173] For example, such as Figure 10 As shown, the new type of reportConfig can consist of a combination of the following: each NES mode ID, the event type as the condition information to be used in the corresponding mode, and the parameters required for each event type (e.g., the offset of signal strength difference, the signal strength threshold for each cell, etc.). Different condition information can be configured for each NES mode ID.

[0174] As conditional information, the event type can be an A3 event, an A4 event, or an A5 event. For an A3 event, the offset of the target cell signal strength relative to the source cell (indicating how good the target cell should be); for an A4 event, the absolute cell signal strength threshold that the target cell should exceed; and for an A5 event, the maximum threshold of the source cell signal strength (i.e., when the source cell signal is less than or equal to the maximum threshold, the signal strength is determined to be poor) (indicating when the source cell signal is poor) and the minimum threshold of the target cell signal strength (i.e., when the target cell signal strength is greater than or equal to the minimum threshold, the signal strength is determined to be good) can be configured as corresponding conditions.

[0175] According to option 2, a reportConfig can be associated with a measurement object to configure a measId. The network can configure multiple measIds as described above, associate multiple measIds with a target cell configuration, and deliver multiple measIds to the UE.

[0176] Figure 11 This diagram illustrates Option 3 of the example according to this disclosure, and shows the case where the measurement object includes parameters associated with each NES mode. In this case, the associated reportConfig may or may not include parameters associated with each NES mode ID, as described in Option 2 above. When the reportConfig includes parameters for each NES mode ID, only NES mode IDs that are identical between the MO and the reportConfig can be used together for measurement and condition evaluation.

[0177] The information indicated for each NES mode ID in the MO may include the following.

[0178] Smtc1, referenceSignalConfig absThreshSS-BlocksConsolidation absThreshCSI-RS-Consolidation nrofSS-BlocksToAverage nrofCSI-RS-ResourcesToAverage quantityConfigIndex offsetMO In addition, each of the above fields can be defined as shown in [Table 1].

[0179] [Table 1]

[0180] When a UE is configured with a measId (which is configured with an MO) as conditional information, if the NES mode ID is transmitted via a NESCHO trigger indication signal, the UE can consider restarting the measurement with the measurement parameters associated with the corresponding NES mode ID. When the reportConfig associated with the MO contains conditional information associated with the NES mode ID, the UE can perform conditional evaluation using events, etc., associated with the corresponding NES mode ID. Furthermore, NES mode-specific parameters in the MO can be indicated by separate indicators whether they are parameters used for source cell measurements (i.e., whether they are parameters used for target cell or neighboring cell measurements). When this information is available, the UE can perform measurements using separate parameters corresponding to each cell during source cell and target cell measurements.

[0181] In addition to the NES mode-specific parameters, the MO can also include existing MO parameters. In this case, without an NES mode indication, the UE can perform measurements at the corresponding frequency based on the corresponding MO parameters.

[0182] In another scenario, traditional MOs and new-type MOs can coexist independently. For example, even if both the new-type MO and the traditional MO measure the same frequency, they can each be configured with a specific measurement ID. This differs from the traditional scenario, where an MO exists only for a Synchronization Signal Block (SSB) frequency. In this case, for example, when the network does not send an NES CHO trigger indication signal, the UE performs measurements based on the traditional MO. However, when the network sends an NES CHO trigger indication signal, the UE can consider performing measurements with the NES mode parameters within the new-type MO (not the traditional MO) corresponding to the NES mode ID indicated by the corresponding indication signal. In another example, when the network sends an NES CHO trigger indication signal, the UE can perform measurements based on both the traditional MO and the new-type MO simultaneously.

[0183] Figure 12 This is a diagram used to describe the call flow between the UE and the network for option 1 according to an example of this disclosure.

[0184] Figure 12 The operation of the UE and base station is illustrated according to an example of this disclosure when multiple conditions are configured. More specifically, refer to... Figure 12According to the examples of this disclosure, UE 120 can receive an RRC message (e.g., an RRCReconfiguration message) (S1200) from serving gNB 121 for configuring NES conditional switching for NES. Here, the RRC message may contain at least one of the following: configuration information regarding the NES CHO, information regarding the conditions for each NES mode, and a Radio Network Temporary Identifier (RNTI) for triggering the CHO via downlink control information (DCI). For example, the RRC message may configure the CHO for NES for the UE using the scheme according to Option 1 above.

[0185] Having received the RRC message, UE 120 can send an RRC reconfiguration complete message to serving gNB 121 (S1210), and then perform measurement and evaluation operations on the RS (SSB / CSI-RS) transmitted together from serving gNB 121 and target base station 122 based on the information contained in the RRC message (S1220). In this case, the RS from each base station is a reference signal transmitted for general conditional handover or general radio resource management (RRM) measurement purposes, and UE 120 can measure and evaluate the RS for each NES mode.

[0186] Subsequently, the serving gNB 121 can determine the change of the NES mode configured for UE 120 (S1230). In addition, the serving gNB 121 can send an NES CHO trigger indicator containing the NES mode ID corresponding to the changed NES mode to UE 120 (S1240).

[0187] Based on the received indicator, UE 120 can operate to perform measurement and evaluation operations only on the report configuration (reportConfig) corresponding to the NES mode ID indicated in the indicator (S1250). Furthermore, when the measurement and evaluation operations determine that a predetermined condition is met, UE 120 can perform an NES CHO on the target cell 122 associated with the condition being met (S1260).

[0188] UE 120 can send a message (RRCReconfigComplete message) to target cell 122 to complete NES CHO for target cell 122 (S1270).

[0189] Figure 13 This is a diagram used to describe the call flow between the UE and the network for option 2 according to an example of this disclosure.

[0190] refer to Figure 13According to the example of this disclosure, UE 130 can receive RRC messages (e.g., RRCReconfiguration messages) for configuring NES conditional handover from serving gNB 131 (S1300). Here, as Figure 12 As shown, the RRC message may contain at least one of the following: configuration information about the NES CHO, information about the conditions for each NES mode, and a Radio Network Temporary Identifier (RNTI) for triggering the downlink control information (DCI) for the CHO. For example, based on option 2 above, the RRC message can configure the NES CHO of UE 130 by including a new type of reportConfig containing parameters for each NES mode.

[0191] Having received the RRC message, UE 130 can send an RRC reconfiguration complete message to serving gNB 131 (S1310), and then perform a measurement operation on the RS (SSB / CSI-RS) sent from serving gNB 131 and target base station 132 based on the information contained in the RRC message (S1320). That is, in this embodiment, with... Figure 12 Unlike other systems, UE 130 can prioritize performing measurement operations based solely on RRC messages without requiring evaluation operations on RS.

[0192] Subsequently, the serving gNB 131 can determine the change of the NES mode configured for UE 130 (S1330). In addition, the serving gNB 131 can send an NES CHO trigger indicator containing the NES mode ID corresponding to the changed NES mode to UE 130 (S1340).

[0193] Based on the received indicator, UE 130 can operate to perform an evaluation operation on the report configuration (reportConfig) corresponding to the NES mode ID indicated in the indicator (S1350). Therefore, when it is determined that the predetermined conditions are met, UE 130 can perform an NES CHO on the target cell 132 associated with the condition being met (S1360).

[0194] UE 130 can send a message (RRCReconfigComplete message) to target cell 132 to complete NES CHO for target cell 132 (S1370).

[0195] Figure 14 This is a diagram used to describe the call flow between the UE and the network for option 3 according to an example of this disclosure.

[0196] refer to Figure 14According to the example of this disclosure, UE 140 can receive RRC messages (e.g., RRCReconfiguration messages) for configuring NES conditional handover from serving gNB 141 (S1400). Here, as Figure 12 As shown, the RRC message may contain at least one of the following: configuration information for the NES CHO, information about the conditions for each NES mode, and a Radio Network Temporary Identifier (RNTI) for triggering the CHO via Downlink Control Information (DCI). For example, based on option 3 above, the RRC message may configure the NES CHO for UE140 by including a new type of Measurement Object (MO) containing parameters for each NES mode.

[0197] Once the UE 140 has received the RRC message, it can send an RRC reconfiguration complete message to the serving gNB 141 (S1410), and then initiate a measurement operation on the RS (SSB / CSI-RS) sent from the serving gNB 141 and the target base station 142 based on the information contained in the RRC message (S1420).

[0198] Subsequently, the serving gNB 141 can determine the change of the NES mode configured for UE 140 (S1430). In addition, the serving gNB 141 can send an NES CHO trigger indicator containing the NES mode ID corresponding to the changed NES mode to UE 140 (S1440).

[0199] UE 140 can initiate a measurement of the MO, which includes a specific portion of the NES mode corresponding to the NES mode ID indicated in the indicator (e.g., the time / frequency portion associated with the measurement of the corresponding NES mode). Furthermore, UE 140 can initiate an evaluation operation regarding the conventional or new reportConfig indicated by the NES mode ID (S1450). The measurement and evaluation operations described herein can be performed based on the RS transmitted from the serving gNB 141 and the target cell 142 after the indicator is sent.

[0200] Subsequently, when the predetermined conditions are determined to be met according to the evaluation operation, UE 140 can perform NES CHO on the target cell 142 related to the conditions (S1460) and send an NES CHO completion message (RRCReconfigComplete message) to the target cell 142 (S1470).

[0201] The methods described in the embodiments of the claims or this disclosure can be implemented in hardware, software, or a combination of hardware and software.

[0202] When implemented as software, a computer-readable storage medium may be provided storing one or more programs (software modules). The one or more programs stored in the computer-readable storage medium are configured to be executable by one or more processors within an electronic device. The one or more programs include instructions to cause the electronic device to perform a method according to an embodiment described in the claims or specification of this disclosure.

[0203] Such programs (software modules, software) can be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, optical disc-ROM (CD-ROM), digital versatile optical disc (DVD), or any other form of optical storage device, as well as magnetic tape cassettes. Alternatively, they can be stored in a combination of some or all of the memories. Furthermore, each memory component can be included in a plural form.

[0204] Furthermore, the program can be stored in an attachable storage device that can be accessed via a communication network, such as the Internet, intranet, local area network (LAN), wide area network (WLAN), or storage area network (SAN) or a combination thereof. Such a storage device can be connected to an apparatus implementing embodiments of this disclosure via an external port. Additionally, a separate storage device on the communication network can be connected to an apparatus implementing embodiments of this disclosure.

[0205] In the specific embodiments of this disclosure described above, the components included in this disclosure are represented as singular or plural, according to the presented specific embodiments. However, for ease of description, singular or plural expressions have been suitably chosen for the presented context, and this disclosure is not limited to singular or plural components, and even if a component is represented as plural, the component may be configured as singular, or even if a component is represented as singular, the component may be configured as plural.

[0206] While this disclosure has been described in conjunction with its exemplary embodiments, various modifications and changes can be made without departing from the scope of this disclosure. Therefore, the scope of the invention should not be construed as limited to the described exemplary embodiments, but is defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: Receive a Radio Resource Control (RRC) message from the base station containing configuration information about Conditional Handover (CHO), the configuration information including a Conditional Reconfiguration Identifier (ID) and at least one measurement ID mapped to the Conditional Reconfiguration ID; Measurements are performed on candidate cells using measurement configuration information associated with the at least one measurement ID; Receive control information from the base station containing an indicator associated with a specific CHO for Network Energy Saving (NES); The conditions for performing the CHO to the candidate cell are determined based on the report configuration information associated with the at least one measurement ID. as well as If the conditions are met, the CHO is executed for the candidate cell. The indicator contains information indicating the NES mode applied to the base station, and The at least one measurement ID is configured for each NES mode.

2. The method as described in claim 1, The NES mode includes at least one of the following: Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) mode, Power Domain (PD) mode, Spatial Domain (SD) mode, or Cell Shutdown mode. The information indicating the NES mode includes the NES mode ID corresponding to the NES mode, and The at least one measurement ID is mapped to each of at least one NES mode ID associated with the condition reconfiguration ID.

3. The method as described in claim 2, The report configuration information includes information related to the event type mapped to each of the at least one NES pattern ID, and Determining whether the conditions for the NES-specific CHO are met includes determining whether the measurement results meet the conditions associated with the event type corresponding to the NES pattern ID.

4. The method as described in claim 2, The measurement configuration information includes the MO ID for identifying the measurement object MO and the configuration information of the MO, and The configuration information of the MO includes the configuration of the measurement reference signal corresponding to each of the at least one NES mode ID.

5. A method performed by a base station in a wireless communication system, the method comprising: Send a Radio Resource Control (RRC) message to the terminal containing configuration information about Conditional Handover (CHO), the configuration information including a Conditional Reconfiguration Identifier (ID) and at least one measurement ID mapped to the Conditional Reconfiguration ID; as well as Send control information to the terminal containing an indicator associated with a specific CHO for Network Energy Saving (NES). The measurement configuration information associated with the at least one measurement ID is used for the measurement of candidate cells of the terminal. The report configuration information associated with the at least one measurement ID is used to determine whether the conditions for performing the CHO to the candidate cell of the terminal are met. The indicator contains information indicating the NES mode applied to the base station, and The at least one measurement ID is configured for each NES mode.

6. The method as described in claim 5, The NES mode includes at least one of the following: Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) mode, Power Domain (PD) mode, Spatial Domain (SD) mode, or Cell Shutdown mode. The information indicating the NES mode includes the NES mode ID corresponding to the NES mode, and The at least one measurement ID is mapped to each of at least one NES mode ID associated with the condition reconfiguration ID.

7. The method of claim 6, wherein the report configuration information associated with the at least one measurement ID includes information relating to the event type mapped to each of the at least one NES mode ID.

8. The method as described in claim 6, The measurement configuration information includes the MO ID for identifying the measurement object MO and the configuration information of the MO, and The configuration information of the MO includes the configuration of the measurement reference signal corresponding to each of the at least one NES mode ID.

9. A terminal in a wireless communication system, the terminal comprising: transceiver; as well as The controller is configured as follows: The transceiver is controlled to receive from the base station a Radio Resource Control (RRC) message containing configuration information regarding Conditional Handover (CHO), the configuration information including a Conditional Reconfiguration Identifier (ID) and at least one measurement ID mapped to the Conditional Reconfiguration ID. Measurements are performed on candidate cells using measurement configuration information associated with the at least one measurement ID. The transceiver is controlled to receive control information from the base station containing an indicator associated with a specific CHO (Content Message for Network Energy Saving) for NES (Network Energy Saving System). The criteria for CHO to the candidate cell are determined based on the report configuration information associated with the at least one measurement ID, and If the conditions are met, the CHO is executed for the candidate cell. The indicator contains information indicating the NES mode applied to the base station, and The at least one measurement ID is configured for each NES mode.

10. The terminal as described in claim 9, The NES mode includes at least one of the following: Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) mode, Power Domain (PD) mode, Spatial Domain (SD) mode, or Cell Shutdown mode. The information indicating the NES mode includes the NES mode ID corresponding to the NES mode, and The at least one measurement ID is mapped to each of at least one NES mode ID associated with the condition reconfiguration ID.

11. The terminal as described in claim 10, The report configuration information includes information related to the event type mapped to each of the at least one NES pattern ID, and The controller is further configured to determine whether the result of the measurement satisfies the conditions associated with the event type corresponding to the NES mode ID.

12. The terminal as described in claim 10, The measurement configuration information includes the MO ID for identifying the measurement object MO and the configuration information of the MO, and The configuration information of the MO includes the configuration of the measurement reference signal corresponding to each of the at least one NES mode ID.

13. A base station in a wireless communication system, the base station comprising: transceiver; as well as The controller is configured as follows: The transceiver is controlled to send a Radio Resource Control (RRC) message to the terminal containing configuration information about Conditional Handover (CHO), including a Conditional Reconfiguration Identifier (CHO) ID and at least one measurement ID mapped to the CHO ID, and... The transceiver is controlled to send control information to the terminal, including an indicator associated with a specific CHO associated with Network Energy Saving (NES). The measurement configuration information associated with the at least one measurement ID is used for the measurement of candidate cells of the terminal. The report configuration information associated with the at least one measurement ID is used to determine whether the conditions for performing the CHO to the candidate cell of the terminal are met. The indicator contains information indicating the NES mode applied to the base station, and The at least one measurement ID is configured for each NES mode.

14. The base station as described in claim 13, The NES mode includes at least one of the following: Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) mode, Power Domain (PD) mode, Spatial Domain (SD) mode, or Cell Shutdown mode. The information indicating the NES mode includes the NES mode ID corresponding to the NES mode, and The at least one measurement ID is mapped to each of at least one NES mode ID associated with the condition reconfiguration ID.

15. The base station of claim 14, wherein the report configuration information associated with the at least one measurement ID includes information relating to the event type mapped to each of the at least one NES mode ID. The measurement configuration information includes the MO ID for identifying the measurement object MO and the configuration information of the MO, and The configuration information of the MO includes the configuration of the measurement reference signal corresponding to each of the at least one NES mode ID.

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