Handling secondary cell setup timing in conditional mobility procedures

Abstract

The disclosure relates to handling secondary cell group (SCG) setup timing in wireless communications. According to an embodiment of the present disclosure, a user equipment (UE) may evaluate an execution condition for a conditional handover (CHO) to a primary cell (PCell) and an execution condition for conditional PSCell mobility to a first primary-secondary cell (PSCell), and when the execution condition for the CHO is satisfied and the execution condition for the conditional PSCell mobility is not satisfied, the UE may execute the CHO to the PCell, however, secondary cell group (SCG) setup to a second PSCell associated with the CHO is delayed to be performed.

Description

Technical Field

[0001] The present disclosure relates to handling secondary cell group (SCG) establishment timing in wireless communications. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology that enables high-speed packet communications. Many solutions have been proposed for LTE, including those aimed at reducing user and provider costs, improving service quality, and expanding and improving coverage and system capacity. As high-level requirements, 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of frequency bands, a simple structure, open interfaces, and appropriate power consumption of terminals.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun developing requirements and specifications for New Radio (NR) systems. 3GPP must identify and develop the technical components necessary for successful standardization of the new RAT, which will meet both immediate market needs and the longer-term requirements outlined by the ITU Radiocommunication Sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Furthermore, NR should be able to use any spectrum band available for wireless communications in the more distant future, at least up to 100 GHz.

[0004] The goal of NR is to be a single technology framework that addresses all use cases, requirements, and deployment scenarios, including enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), ultra-reliable and low-latency communications (URLLC), etc. NR should be inherently forward-compatible.

[0005] In wireless communications, a user equipment (UE) can perform conditional mobility, where the network configures the UE with multiple candidate cells and the UE determines a target cell among the multiple candidate cells that meets the mobility execution conditions. When one of the mobility execution conditions for the multiple candidate cells is met, the timing of establishing the associated secondary cell group (SCG) can be an issue. Summary of the Invention

[0006] Technical Solution

[0007] An aspect of the present disclosure is to provide a method and apparatus for handling SCG establishment timing in conditional mobility in a wireless communication system.

[0008] According to one embodiment of the present disclosure, a method performed by a user equipment (UE) configured to operate in a wireless communication system includes the following steps: receiving a configuration for conditional handover (CHO) to a target primary cell (PCell) from a network, wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is met but the execution condition for conditional PSCell mobility is not met: performing CHO to the target PCell; and delaying the execution of SCG establishment to the second target PSCell within a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0009] According to one embodiment of the present disclosure, a method performed by a network node configured to operate in a wireless communication system includes the following steps: obtaining a configuration for conditional handover (CHO) to a target primary cell (PCell), wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; sending the configuration for CHO to a target PCell to a user equipment (UE), wherein the UE is configured to perform operations including the following items: evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is met but the execution condition for conditional PSCell mobility is not met: executing CHO to the target PCell; and delaying execution of SCG establishment to the second target PSCell within a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0010] According to various embodiments, an apparatus for implementing the above method is provided.

[0011] The present disclosure may have various beneficial effects.

[0012] For example, due to conditional PSCell mobility performed immediately after CHO execution with SCG establishment, interruption / signaling can be reduced.

[0013] The beneficial effects that can be obtained by the specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, there may be various technical effects that can be understood and / or derived from the present disclosure by a person of ordinary skill in the relevant art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 An example of a communication system to which an implementation of the present disclosure is applied is shown.

[0015] Figure 2 An example of a wireless device to which an implementation of the present disclosure is applied is shown.

[0016] Figure 3 An example of a UE to which an implementation of the present disclosure is applied is shown.

[0017] Figure 4 and Figure 5 An example of a protocol stack in a 3GPP-based wireless communication system to which implementations of the present disclosure are applied is shown.

[0018] Figure 6 The frame structure in a 3GPP-based wireless communication system to which the implementation of the present disclosure is applied is shown.

[0019] Figure 7 An example of data flow in a 3GPP NR system to which an implementation of the present disclosure is applied is shown.

[0020] Figure 8 An example of a dual connectivity (DC) architecture to which the technical features of the present disclosure can be applied is shown.

[0021] Figure 9 An example of a conditional mobility procedure according to an embodiment of the present disclosure is shown.

[0022] Figure 10 An example of a method performed by a UE according to an embodiment of the present disclosure is shown.

[0023] Figure 11 An example of a signal flow between a UE and a network node according to an embodiment of the present disclosure is shown.

[0024] Figure 12 An example of an evaluation status of a CPC execution condition according to an embodiment of the present disclosure is shown.

[0025] Figure 13 An example of timer-based CPC condition evaluation according to an embodiment of the present disclosure is shown.

[0026] Figure 14An example of a method for handling SCG establishment timing according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0027] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented using radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) that uses E-UTRA. 3GPP LTE uses OFDMA in the downlink (DL) and SC-FDMA in the uplink (UL). Evolutions of 3GPP LTE include LTE-Advanced (LTE-A), LTE-A Pro, and / or 5G New Radio (NR).

[0028] For ease of description, the implementation of the present disclosure will be primarily described with respect to a 3GPP-based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP-based wireless communication system, various aspects of the present disclosure that are not limited to a 3GPP-based wireless communication system are applicable to other mobile communication systems.

[0029] For terms and techniques not specifically described among the terms and techniques employed in the present disclosure, reference may be made to wireless communication standard documents published prior to the present disclosure.

[0030] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, in the present disclosure, "A or B" may be interpreted as "A and / or B". For example, in the present disclosure, "A, B, or C" may mean "only A", "only B", "only C", or "any combination of A, B, and C".

[0031] In the present disclosure, a slash ( / ) or a comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0032] 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 being the same as “at least one of A and B”.

[0033] 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.”

[0034] In addition, the brackets used in this disclosure may mean "for example". Specifically, when "control information (PDCCH)" is shown, "PDCCH" can be cited as an example of "control information". In other words, in this disclosure, "control information" is not limited to "PDCCH", and "PDCCH" can be cited as an example of "control information". In addition, even when "control information (i.e., PDCCH)" is shown, "PDCCH" can be cited as an example of "control information".

[0035] The technical features described separately in one figure in this disclosure can be implemented separately or simultaneously.

[0036] Although not limited thereto, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein may be applied to various fields requiring wireless communication and / or connectivity (e.g., 5G) between devices.

[0037] Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings. Unless otherwise specified, the same reference numerals in the following drawings and / or descriptions may refer to the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0038] Figure 1 An example of a communication system to which an implementation of the present disclosure is applied is shown.

[0039] Figure 1 The 5G usage scenarios shown are only exemplary, and the technical features of the present disclosure can be applied to Figure 1 Other 5G usage scenarios not shown.

[0040] The three main demand categories for 5G include: (1) enhanced mobile broadband (eMBB) category, (2) massive machine type communication (mMTC) category, and (3) ultra-reliable and low-latency communication (URLLC) category.

[0041] Reference Figure 1 , the communication system 1 includes wireless devices 100a to 100f, a base station (BS) 200, and a network 300. Figure 1 A 5G network is illustrated as an example of the network of the communication system 1 , but implementations of the present disclosure are not limited to the 5G system and may be applied to future communication systems other than the 5G system.

[0042] BS 200 and network 300 may be implemented as wireless devices, and certain wireless devices may operate as BSs / network nodes relative to other wireless devices.

[0043] Wireless devices 100a to 100f represent devices that perform communication using a radio access technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication / radio / 5G devices. Wireless devices 100a to 100f may include, but are not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with wireless communication capabilities, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. A vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). XR devices may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices can include smartphones, smart tablets, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., laptops). Home appliances can include TVs, refrigerators, and washing machines. IoT devices can include sensors and smart meters.

[0044] In the present disclosure, wireless devices 100a to 100f may be referred to as user equipment (UE). UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a tablet-shaped personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving capabilities, a connected car, an 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 FinTech device (or financial device), a security device, a weather / environmental device, a device related to 5G services, or a device related to the Fourth Industrial Revolution.

[0045] Wireless devices 100a to 100f can be connected to network 300 via BS 200. AI technology can be applied to wireless devices 100a to 100f, and wireless devices 100a to 100f can be connected to AI server 400 via network 300. Network 300 can be configured using a 3G network, a 4G network (e.g., LTE), a 5G network (e.g., NR), and a beyond 5G network. While wireless devices 100a to 100f can communicate with each other via BS 200 / network 300, wireless devices 100a to 100f can perform direct communication with each other (e.g., sidelink communication) without going through BS 200 / network 300. For example, vehicles 100b-1 and 100b-2 can perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). IoT devices (e.g., sensors) can perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0046] Wireless communications / connections 150a, 150b, and 150c may be established between wireless devices 100a to 100f and / or between wireless devices 100a to 100f and BS 200 and / or between BS 200. Wireless communications / connections may be established via various RATs (e.g., 5G NR), such as uplink / downlink communication 150a, sidelink communication (or device-to-device (D2D) communication) 150b, and inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)). Wireless devices 100a to 100f and BS 200 / wireless devices 100a to 100f may transmit / receive radio signals to / from each other via wireless communications / connections 150a, 150b, and 150c. For example, wireless communications / connections 150a, 150b, and 150c may transmit / receive signals via various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of the resource allocation process can be performed based on the various proposals of the present disclosure.

[0047] NR supports multiple numerologies (and / or multiple subcarrier spacings (SCS)) to support various 5G services. For example, if the SCS is 15kHz, wide areas can be supported in traditional cellular bands, while if the SCS is 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. If the SCS is 60kHz or higher, bandwidths greater than 24.25GHz can be supported to overcome phase noise.

[0048] The NR frequency band can be defined as two types of frequency ranges, namely, frequency range 1 (FR1) and frequency range 2 (FR2). The numerical values ​​of the frequency ranges can be changed. For example, the two types of frequency ranges (FR1 and FR2) can be shown in Table 1 below. For ease of explanation, in the frequency range used in the NR system, FR1 can mean "a range below 6 GHz", FR2 can mean "a range above 6 GHz", and can be referred to as millimeter wave (mmW).

[0049] [Table 1]

[0050]

[0051]

[0052] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a frequency band of 410 MHz to 7125 MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6 GHz (or 5850 MHz, 5900 MHz, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850 MHz, 5900 MHz, 5925 MHz, etc.) or higher included in FR1 may include an unlicensed frequency band. The unlicensed frequency band can be used for various purposes, for example, for communication of vehicles (e.g., autonomous driving).

[0053] [Table 2]

[0054] Frequency range name Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0055] Here, the radio communication technology implemented in the wireless device in the present disclosure may include narrowband Internet of Things (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of a low-power wide area network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the above names. Additionally and / or alternatively, the radio communication technology implemented in the wireless device in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of an LPWAN technology and may be referred to by various names such as enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in at least one of various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication and / or 7) LTE M, and may not be limited to the above names. Additionally and / or alternatively, the radio communication technology implemented in the wireless device of the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN considering low-power communication, and may not be limited to the above names. For example, ZigBee technology can generate a personal area network (PAN) associated with small / low-power digital communication based on various specifications (such as IEEE 802.15.4) and may be referred to by various names. Figure 2 An example of a wireless device to which an implementation of the present disclosure is applied is shown.

[0056] exist Figure 2 In the embodiment, the first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to the use case / service. For example, {the first wireless device 100 and the second wireless device 200} may correspond to Figure 1At least one of {wireless devices 100a to 100f and BS 200}, {wireless devices 100a to 100f and wireless devices 100a to 100f} and / or {BS 200 and BS 200}. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / components and / or modules.

[0057] The first wireless device 100 may include at least one transceiver (eg, transceiver 106 ), at least one processing chip (eg, processing chip 101 ), and / or one or more antennas 108 .

[0058] The processing chip 101 may include at least one processor (eg, processor 102 ) and at least one memory (eg, memory 104 ). Additionally and / or alternatively, the memory 104 may be located outside the processing chip 101 .

[0059] The processor 102 may control the memory 104 and / or the transceiver 106 and may be adapted to implement the descriptions, functions, processes, suggestions, methods, and / or operational flow charts described in the present disclosure. For example, the processor 102 may process information in the memory 104 to generate first information / signals, and then transmit a radio signal including the first information / signals through the transceiver 106. The processor 102 may receive a radio signal including second information / signals through the transceiver 106, and then store information obtained by processing the second information / signals in the memory 104.

[0060] Memory 104 may be operatively connected to processor 102. Memory 104 may store various types of information and / or instructions. Memory 104 may store firmware and / or software code 105 that implements codes, commands, and / or command sets that, when executed by processor 102, perform the descriptions, functions, procedures, suggestions, methods, and / or operational flow charts disclosed herein. For example, firmware and / or software code 105 may implement instructions that, when executed by processor 102, perform the descriptions, functions, procedures, suggestions, methods, and / or operational flow charts disclosed herein. For example, firmware and / or software code 105 may control processor 102 to execute one or more protocols. For example, firmware and / or software code 105 may control processor 102 to execute one or more layers of a wireless interface protocol.

[0061] In this document, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals via one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In this disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0062] The second wireless device 200 may include at least one transceiver (eg, transceiver 206 ), at least one processing chip (eg, processing chip 201 ), and / or one or more antennas 208 .

[0063] The processing chip 201 may include at least one processor (eg, processor 202 ) and at least one memory (eg, memory 204 ). Additionally and / or alternatively, the memory 204 may be located outside the processing chip 201 .

[0064] The processor 202 may control the memory 204 and / or the transceiver 206 and may be adapted to implement the descriptions, functions, processes, suggestions, methods, and / or operational flow charts described in the present disclosure. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 106, and then store information obtained by processing the fourth information / signals in the memory 204.

[0065] Memory 204 may be operatively connected to processor 202. Memory 204 may store various types of information and / or instructions. Memory 204 may store firmware and / or software code 205 that implements code, commands, and / or command sets that, when executed by processor 202, perform the descriptions, functions, procedures, suggestions, methods, and / or operational flow charts disclosed herein. For example, firmware and / or software code 205 may implement instructions that, when executed by processor 202, perform the descriptions, functions, procedures, suggestions, methods, and / or operational flow charts disclosed herein. For example, firmware and / or software code 205 may control processor 202 to execute one or more protocols. For example, firmware and / or software code 205 may control processor 202 to execute one or more layers of a wireless interface protocol.

[0066] In this document, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals via one or more antennas 208. Each of the transceivers 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In this disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0067] In the following, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP) layer). The one or more processors 102 and 202 may generate one or more protocol data units (PDUs), one or more service data units (SDUs), messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure and provide the generated signal to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from the one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure.

[0068] One or more processors 102 and 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. For example, one or more processors 102 and 202 may be configured by a group of communication control processors, application processors (APs), electronic control units (ECUs), central processing units (CPUs), graphics processing units (GPUs), and memory control processors.

[0069] One or more memories 104 and 204 can be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions and / or commands. One or more memories 104 and 204 can be configured by random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EPROM), flash memory, volatile memory, non-volatile memory, hard drive, registers, cache memory, computer-readable storage media and / or combinations thereof. One or more memories 104 and 204 can be located inside and / or outside of one or more processors 102 and 202. One or more memories 104 and 204 can be connected to one or more processors 102 and 202 via various technologies such as wired connections or wireless connections.

[0070] One or more transceivers 106 and 206 can transmit user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in this disclosure to one or more other devices. One or more transceivers 106 and 206 can receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in this disclosure from one or more other devices. For example, one or more transceivers 106 and 206 can be connected to one or more processors 102 and 202 and transmit and receive radio signals. For example, one or more processors 102 and 202 can execute control so that one or more transceivers 106 and 206 can transmit user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 can execute control so that one or more transceivers 106 and 206 can receive user data, control information, or radio signals from one or more other devices.

[0071] One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208. Additionally or alternatively, one or more transceivers 106 and 206 may include one or more antennas 108 and 208. One or more transceivers 106 and 206 may be adapted to transmit and receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure through one or more antennas 108 and 208. In the present disclosure, one or more antennas 108 and 208 may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0072] The one or more transceivers 106 and 206 may convert received user data, control information, radio signals / channels, etc. from RF band signals to baseband signals so that the received user data, control information, radio signals / channels, etc. may be processed by the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed by the one or more processors 102 and 202 from baseband signals to RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, under the control of the one or more processors 102 and 202, the one or more transceivers 106 and 206 may up-convert an OFDM baseband signal into an OFDM signal through their (analog) oscillators and / or filters and transmit the up-converted OFDM signal at the carrier frequency. One or more transceivers 106 and 206 may receive an OFDM signal at a carrier frequency and down-convert the OFDM signal to an OFDM baseband signal through their (analog) oscillators and / or filters under the control of one or more processors 102 and 202 .

[0073] although Figure 2 Although not shown in the figures, the wireless devices 100 and 200 may further include additional components. The additional components 140 may be configured differently depending on the type of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power supply unit / battery, an input / output (I / O) device (e.g., an audio I / O port, a video I / O port), a drive device, and a computing device. The additional components 140 may be coupled to one or more processors 102 and 202 via various technologies, such as a wired or wireless connection.

[0074] In implementations of the present disclosure, a UE may function as a transmitting device in the uplink (UL) and a receiving device in the downlink (DL). In implementations of the present disclosure, a base station (BS) may function as a receiving device in the UL and a transmitting device in the DL. Hereinafter, for ease of description, it is primarily assumed that a first wireless device 100 functions as a UE and a second wireless device 200 functions as a base station (BS). For example, a processor 102 connected to, installed on, or activated in the first wireless device 100 may be adapted to perform UE behavior according to implementations of the present disclosure or to control a transceiver 106 to perform UE behavior according to implementations of the present disclosure. A processor 202 connected to, installed on, or activated in the second wireless device 200 may be adapted to perform BS behavior according to implementations of the present disclosure or to control a transceiver 206 to perform BS behavior according to implementations of the present disclosure.

[0075] In this disclosure, a BS is also referred to as a Node B (NB), an eNode B (eNB), or a gNB.

[0076] Figure 3 An example of a UE to which an implementation of the present disclosure is applied is shown.

[0077] Reference Figure 3 , UE 100 may correspond to Figure 2 The first wireless device 100 is configured to:

[0078] UE 100 includes a processor 102 , memory 104 , a transceiver 106 , one or more antennas 108 , a power management module 141 , a battery 142 , a display 143 , a keypad 144 , a subscriber identity module (SIM) card 145 , a speaker 146 , and a microphone 147 .

[0079] The processor 102 may be adapted to implement the descriptions, functions, processes, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, processes, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The radio interface protocol layer may be implemented in the processor 102. The processor 102 may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor 102 may be an application processor. The processor 102 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). Examples of the processor 102 may be SNAPDRAGON MANUFACTURED TM series processors, Manufactured by EXYNOS TM series processors, A series of processors manufactured by Manufactured by HELIO TM series processors, ATOM manufactured TM series processors or the corresponding next-generation processors.

[0080] The memory 104 is coupled to the processor 102 during operation and stores various information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, a memory card, a storage medium, and / or other storage devices. When the embodiment is implemented in software, the technology described herein may be implemented using modules (e.g., processes, functions, etc.) that execute the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in this disclosure. The modules may be stored in the memory 104 and implemented by the processor 102. The memory 104 may be implemented within the processor 102 or external to the processor 102 (in which case, the memory may be communicatively coupled to the processor 102 via various means known in the art).

[0081] The transceiver 106 is coupled to the processor 102 during operation and transmits and / or receives radio signals. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include baseband circuitry to process radio frequency signals. The transceiver 106 controls one or more antennas 108 to transmit and / or receive radio signals.

[0082] The power management module 141 manages the power of the processor 102 and / or the transceiver 106. The battery 142 provides power to the power management module 141.

[0083] The display 143 outputs a result processed by the processor 102. The keypad 144 receives an input to be used by the processor 102. The keypad 144 may be displayed on the display 143.

[0084] The SIM card 145 is an integrated circuit designed to securely store an International Mobile Subscriber Identity (IMSI) number and its associated keys, which are used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0085] The speaker 146 outputs sound-related results processed by the processor 102. The microphone 147 receives sound-related input to be used by the processor 102.

[0086] Figure 4 and Figure 5 An example of a protocol stack in a 3GPP-based wireless communication system to which implementations of the present disclosure are applied is shown.

[0087] Specifically, Figure 4 An example of a radio interface user plane protocol stack between a UE and a BS is illustrated, and Figure 5 An example of a radio interface control plane protocol stack between a UE and a BS is illustrated. The control plane refers to a path for transmitting control messages used by the UE and the network to manage calls. The user plane refers to a path for transmitting data generated in the application layer (for example, voice data or Internet packet data). Figure 4 , the user plane protocol stack can be divided into layer 1 (L1, for example, PHY layer) and layer 2 (L2, for example, MAC / RLC / PDCP layer). Figure 5 The control plane protocol stack can be divided into Layer 1 (L1, e.g., PHY layer), Layer 2 (L2, e.g., MAC / RLC / PDCP layer), Layer 3 (L3, e.g., RRC layer), and Non-Access Stratum (NAS) layer. Layer 1, Layer 2, and Layer 3 are called Access Stratum (AS).

[0088] In 3GPP LTE systems, Layer 2 is divided into the following sublayers: MAC, RLC, and PDCP. In 3GPP NR systems, Layer 2 is divided into the following sublayers: MAC, RLC, PDCP, and SDAP. The PHY layer provides transport channels to the MAC sublayer, the MAC sublayer provides logical channels to the RLC sublayer, the RLC sublayer provides RLC channels to the PDCP sublayer, and the PDCP sublayer provides radio bearers to the SDAP sublayer. The SDAP sublayer provides Quality of Service (QoS) flows to the 5G core network.

[0089] In 3GPP NR systems, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing MAC SDUs belonging to one or different logical channels into / demultiplexing transport blocks (TBs) delivered to / from the physical layer on the transport channel; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in the case of carrier aggregation (CA); priority handling between UEs with dynamic scheduling; priority handling between logical channels of a UE with logical channel prioritization; and padding. A single MAC entity can support multiple parameter sets, transmission timings, and cells. Mapping restrictions in logical channel prioritization control which parameter set(s), cell, and transmission timing can be used by a logical channel.

[0090] MAC provides different types of data transmission services. In order to accommodate different types of data transmission services, multiple types of logical channels are defined, that is, each logical channel supports the transmission of a specific type of information. Each logical channel type is defined by what type of information is transmitted. Logical channels are divided into two groups: control channels and traffic channels. Control channels are only used for the transmission of control plane information, and traffic channels are only used for the transmission of user plane information. The Broadcast Control Channel (BCCH) is a downlink logical channel used to broadcast system control information, the Paging Control Channel (PCCH) is a downlink logical channel that transmits paging information, system information change notifications, and indications of ongoing Public Warning Service (PWS) broadcasts, the Common Control Channel (CCCH) is a logical channel used to send control information between the UE and the network and is used for UEs that do not have an RRC connection with the network, and the Dedicated Control Channel (DCCH) is a point-to-point bidirectional logical channel that sends dedicated control information between the UE and the network and is used by UEs with an RRC connection. The Dedicated Traffic Channel (DTCH) is a point-to-point logical channel dedicated to one UE, which is used to transmit user information. The DTCH can exist in both the uplink and downlink. In the downlink, the following connections exist between logical channels and transport channels: BCCH can be mapped to the broadcast channel (BCH); BCCH can be mapped to the downlink shared channel (DL-SCH); PCCH can be mapped to the paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH. In the uplink, the following connections exist between logical channels and transport channels: CCCH can be mapped to the uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.

[0091] The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). RLC configuration is specific to each logical channel and is independent of the parameter set and / or transmission duration. In 3GPP NR systems, the main services and functions of the RLC sublayer depend on the transmission mode and include: delivery of upper layer PDUs; sequence numbering independent of either PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDUs (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; and protocol error detection (AM only).

[0092] In the 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression using Robust Header Compression (ROHC); delivery of user data; reordering and duplicate detection; in-sequence delivery; PDCP PDU routing (in the case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering, and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; PDCP PDU duplication and duplicate discard indication to lower layers. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering, and integrity protection; delivery of control plane data; reordering and duplicate detection; in-sequence delivery; PDCP PDU duplication and duplicate discard indication to lower layers.

[0093] In 3GPP NR systems, the main services and functions of SDAP include: mapping between QoS flows and data radio bearers; marking QoS flow IDs (QFIs) in both DL and UL packets; and configuring a single SDAP protocol entity for each individual PDU session.

[0094] In the 3GPP NR system, the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by 5GC or NG-RAN; establishment, maintenance and release of RRC connection between UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility); QoS management functions; UE measurement reporting and control of reporting; detection and repair of radio link failure; transmission of NAS messages from UE to NAS / from NAS to UE.

[0095] Figure 6 The frame structure in a 3GPP-based wireless communication system to which the implementation of the present disclosure is applied is shown.

[0096] Figure 6The frame structure shown is only exemplary, and the number of subframes, the number of time slots and / or the number of symbols in a frame may vary. In a 3GPP-based wireless communication system, OFDM parameter sets (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be configured differently between multiple cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for a cell, the (absolute time) duration of time resources (e.g., subframes, time slots, or TTIs) comprising the same number of symbols may be different among the aggregated cells. In this document, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).

[0097] Reference Figure 6 , downlink and uplink transmissions are organized into frames. Each frame has T f =10ms duration. Each frame is divided into two half-frames, where each half-frame has a duration of 5ms. Each half-frame includes 5 sub-frames, where the duration of each sub-frame is T sf is 1 ms. Each subframe is divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on the cyclic prefix (CP). In normal CP, each slot includes 14 OFDM symbols, and in extended CP, each slot includes 12 OFDM symbols. The parameter set is based on an exponentially scalable subcarrier spacing βf=2 u *15kHz.

[0098] Table 3 shows the subcarrier spacing βf=2 u *N number of OFDM symbols per slot for normal CP of 15 kHz slot symb , the number of time slots per frame N frame，u slot and the number of time slots per subframe N subframe，u slot .

[0099] [Table 3]

[0100] u <![CDATA[N slot symb ]]> <![CDATA[N fame，u slot ]]> <![CDATA[N subframe，u slot ]]> 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

[0101] Table 4 shows the subcarrier spacing βf=2 u *N number of OFDM symbols per slot for extended CP of 15 kHz slot symb , the number of time slots per frame N frame，u slot and the number of time slots per subframe Nsubframe，u slot .

[0102] [Table 4]

[0103] u <![CDATA[N slot symb ]]> <![CDATA[N fram，u slot ]]> <![CDATA[N subframe，u slot ]]> 2 12 40 4

[0104] A slot includes a plurality of symbols (e.g., 14 or 12 symbols) in the time domain. For each parameter set (e.g., subcarrier spacing) and carrier, a common resource block (CRB) N indicated by higher layer signaling (e.g., RRC signaling) is defined. start,u grid Starting N size,u grid,x *N RB sc subcarriers and N subframe,u symb OFDM symbol resource grid, where N size,u grid,x is the number of resource blocks (RBs) in the resource grid, and the subscript x is DL for the downlink and UL for the uplink. N RB sc is the number of subcarriers per RB. In 3GPP-based wireless communication systems, N RB sc Typically 12. For a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N for subcarrier spacing configuration u size,u grid Given by high-level parameters (e.g., RRC parameters). Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex symbol can be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l in the time domain that represents the symbol position relative to a reference point. In a 3GPP-based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. Figure 6As shown in the figure, as the SCS is doubled, the slot length and symbol length are halved. For example, when the SCS is 15kHz, the slot length is 1ms, which is the same as the subframe length. When the SCS is 30kHz, the slot length is 0.5ms (=500us), and the symbol length is half of the symbol length when the SCS is 15kHz. When the SCS is 60kHz, the slot length is 0.25ms (=250us), and the symbol length is half of the symbol length when the SCS is 30kHz. When the SCS is 120kHz, the slot length is 0.125ms (=125us), and the symbol length is half of the symbol length when the SCS is 60kHz. When the SCS is 240kHz, the slot length is 0.0625ms (=62.5us), and the symbol length is half of the symbol length when the SCS is 120kHz.

[0105] In 3GPP NR systems, RBs are classified into CRBs and physical resource blocks (PRBs). For subcarrier spacing configuration u, CRBs are numbered from 0 upwards in the frequency domain. The center of subcarrier 0 of CRB0 for subcarrier spacing configuration u coincides with "point A", which is used as a common reference point for the resource block grid. In 3GPP NR systems, PRBs are defined within a bandwidth part (BWP) and are numbered from 0 to N. size BWP,i -1 numbering, where i is the number of bandwidth parts. Physical resource blocks n in bandwidth part i PRB With public resource block n CRB The relationship between them is as follows: PRB =n CRB +N size BWP,i , where N size BWP,i A BWP is a common resource block where the bandwidth portion begins relative to CRB0. A BWP consists of multiple contiguous RBs. A carrier can include up to N (e.g., 5) BWPs. A UE can be configured with one or more BWPs on a given component carrier. Only one BWP configured for a UE can be active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.

[0106] In the present disclosure, the term "cell" may refer to a geographical area in which one or more nodes provide a communication system or to a radio resource. A "cell" as a geographical area may be understood as a coverage area within which a node can provide services using a carrier, and a "cell" as a radio resource (e.g., a time-frequency resource) is associated with a bandwidth that is a frequency range configured by a carrier. A "cell" associated with a radio resource is defined by a combination of downlink resources and uplink resources (e.g., a combination of a DL component carrier (CC) and a ULCC). A cell may be configured only by downlink resources, or may be configured by downlink resources and uplink resources. Since the DL coverage (which is the range within which a node can send a valid signal) and the UL coverage (which is the range within which a node can receive a valid signal from a UE) depend on the carrier that carries the signal, the coverage of a node may be associated with the coverage of a "cell" of the radio resource used by the node. Therefore, the term "cell" may sometimes be used to refer to the service coverage of a node, at other times to refer to a radio resource, or at other times to refer to a range within which a signal using a radio resource can reach with effective strength.

[0107] In CA, two or more CCs are aggregated. The UE can receive or transmit on one or more CCs simultaneously depending on its capabilities. CA is supported for both contiguous CCs and non-contiguous CCs. When CA is configured, the UE has only one RRC connection with the network. During RRC connection establishment / reestablishment / handover, one serving cell provides NAS mobility information, and during RRC connection reestablishment / handover, one serving cell provides security input. This cell is called a primary cell (PCell). A PCell is a cell operating on the primary frequency, where the UE performs an initial connection establishment procedure or initiates a connection reestablishment procedure. Depending on the UE capabilities, a secondary cell (SCell) can be configured to form a set of serving cells together with the PCell. An SCell is a cell that provides additional radio resources on top of a special cell (SpCell). Therefore, the set of serving cells configured for a UE always consists of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of a primary cell group (MCG) or the primary SCell (PSCell) of a secondary cell group (SCG). SpCell supports PUCCH transmission and contention-based random access and is always activated. MCG is a group of serving cells associated with a master node, which includes SpCell (PCell) and optionally one or more SCells. For UEs configured with DC, SCG is a subset of serving cells associated with a secondary node, which includes PSCell and zero or more SCells. For RRC_CONNECTED UEs not configured with CA / DC, there is only one serving cell consisting of PCell. For RRC_CONNECTED UEs configured with CA / DC, the term "serving cell" is used to refer to a set of cells consisting of SpCell and all SCells. In DC, two MAC entities are configured in the UE: one for MCG and one for SCG.

[0108] Figure 7 An example of data flow in a 3GPP NR system to which an implementation of the present disclosure is applied is shown.

[0109] Reference Figure 7 "RB" stands for radio bearer, and "H" stands for header. Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data. MAC PDUs are transmitted and received to and from external devices via the PHY layer using radio resources. MAC PDUs arrive at the PHY layer in the form of transport blocks.

[0110] In the PHY layer, the uplink transport channel UL-SCH and the random access channel (RACH) are mapped to their physical channels, the physical uplink shared channel (PUSCH) and the physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to the physical downlink shared channel (PDSCH), the physical broadcast channel (PBCH) and the PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to the physical uplink control channel (PUCCH), and downlink control information (DCI) is mapped to the physical downlink control channel (PDCCH). The UE sends a MAC PDU related to the UL-SCH via the PUSCH based on the UL grant, and the BS sends a MAC PDU related to the DL-SCH via the PDSCH based on the DL assignment.

[0111] Figure 8 An example of a dual connectivity (DC) architecture to which the technical features of the present disclosure can be applied is shown.

[0112] Reference Figure 8 , illustrates MN 811, SN 821, and UE 830 communicating with both MN 811 and SN 821. Figure 8 As shown, DC refers to a scheme in which a UE (e.g., UE 830) utilizes radio resources provided by at least two RAN nodes, including a MN (e.g., MN 811) and one or more SNs (e.g., SN 821). In other words, DC refers to a scheme in which a UE is connected to and communicates with both the MN and one or more SNs. Since the MN and SNs may be in different sites, the backhaul between the MN and the SNs may be interpreted as a non-ideal backhaul (e.g., a relatively large delay between the nodes).

[0113] The MN (e.g., MN 811) refers to the primary RAN node that provides services to the UE in a DC scenario. The SN (e.g., SN 821) refers to an additional RAN node that utilizes the MN to provide services to the UE in a DC scenario. If a RAN node provides services to the UE, the RAN node may be the MN. If an MN exists, an SN may also exist.

[0114] For example, a MN may be associated with a macro cell whose coverage is relatively larger than that of a small cell. However, a MN does not necessarily have to be associated with a macro cell; that is, a MN may be associated with a small cell. Throughout this disclosure, a RAN node associated with a macro cell may be referred to as a "macro cell node." A MN may include a macro cell node.

[0115] For example, an SN may be associated with a small cell (e.g., a microcell, picocell, or femtocell) whose coverage is relatively smaller than that of a macrocell. However, an SN need not be associated with a small cell—that is, an SN may be associated with a macrocell. Throughout this disclosure, a RAN node associated with a small cell may be referred to as a "small cell node." An SN may include a small cell node.

[0116] A MN may be associated with a Master Cell Group (MCG). An MCG may refer to a group of serving cells associated with a MN and may include a primary cell (PCell) and optionally one or more secondary cells (SCells). User plane data and / or control plane data may be transmitted from the core network to the MN via an MCG bearer. An MCG bearer refers to a bearer where the radio protocol resides in the MN to use MN resources. Figure 8 As shown, the radio protocols carried by the MCG may include PDCP, RLC, MAC and / or PHY.

[0117] SN can be associated with a secondary cell group (SCG). SCG can refer to a group of serving cells associated with an SN and can include a primary secondary cell (PSCell) and optionally one or more SCells. User plane data can be transmitted from the core network to the SN via an SCG bearer. An SCG bearer refers to a bearer where the radio protocol is located in the SN to use SN resources. Figure 8 As shown, the radio protocols carried by the SCG may include PDCP, RLC, MAC, and PHY.

[0118] User plane data and / or control plane data may be transmitted from the core network to the MN and split / copied in the MN, and at least a portion of the split / copied data may be forwarded to the SN via a split bearer. A split bearer is a bearer in which the radio protocol is located in both the MN and the SN to use both MN resources and SN resources. Figure 8 As shown, the radio protocols of the split bearer located in the MN may include PDCP, RLC, MAC and PHY. The radio protocols of the split bearer located in the SN may include RLC, MAC and PHY.

[0119] According to various embodiments, a PDCP anchor point / PDCP anchor point / PDCP anchor node refers to a RAN node that includes a PDCP entity that splits and / or copies data and forwards at least a portion of the split / copied data to another RAN node via an X2 / Xn interface. Figure 8 In the example, the PDCP anchor node may be a MN.

[0120] According to various embodiments, the MN for a UE may be changed. This may be referred to as a handover or MN handover.

[0121] According to various embodiments, the SN may newly start providing radio resources to the UE, establishing a connection with the UE, and / or communicating with the UE (ie, a new SN for the UE may be newly added). This may be referred to as SN addition.

[0122] According to various embodiments, the SN for a UE may be changed while maintaining its MN. This may be referred to as an SN change.

[0123] According to various embodiments, DC may include E-UTRAN NR-DC (EN-DC) and / or Multi-Radio Access Technology (RAT)-DC (MR-DC). EN-DC refers to a DC scenario in which a UE utilizes radio resources provided by both an E-UTRAN node and an NR RAN node. MR-DC refers to a DC scenario in which a UE utilizes radio resources provided by RAN nodes with different RATs.

[0124] Hereinafter, contents regarding mobility are described.

[0125] Mobility may include PCell change, PSCell change (or Secondary Node (SN) change) and / or PSCell addition (or SN addition).

[0126] There may be at least two types of mobility: network-controlled mobility (or legacy mobility) and UE-based mobility (or conditional mobility).

[0127] Network-controlled mobility (or legacy mobility) is a method in which the network determines a target cell for mobility and configures the UE with the target cell's mobility. The network may send an RRCReconfiguration message to the UE including the configuration for the target cell. Upon receiving the cell configuration for the target cell, the UE may perform mobility to the target cell / apply the configuration for the target cell.

[0128] UE-based mobility (or conditional mobility) means that the network configures the UE with multiple candidate cells and the UE determines the mobility of the target cell among the multiple candidate cells that meets the mobility execution condition. Conditional mobility may include at least one of conditional PCell change / conditional handover (CHO) or conditional PSCell mobility. Conditional PSCell mobility may include conditional PSCell addition / change (CPAC), including conditional PSCell addition (CPA) and / or conditional PSCell change (CPC). The network may send an RRCReconfiguration message including a ConditionalReconfiguration information element (IE) to the UE, which includes a list of conditional reconfigurations for multiple candidate cells. Conditional reconfiguration for a candidate cell may include an identifier for the conditional reconfiguration, a mobility execution condition for the candidate cell, and a configuration for the candidate cell. The UE may evaluate mobility execution conditions for multiple candidate cells, and when the mobility execution conditions for the candidate cells are met, the UE may regard the candidate cells as target cells and perform mobility to the target cells / apply configurations for the target cells.

[0129] According to various embodiments, a mobility execution condition may be met or satisfied when an entry condition (or entering condition) for the mobility execution condition is met or satisfied at least within a time to trigger (TTT) for the mobility execution condition. The entry condition or entering condition may mean that the mobility execution condition is initially satisfied. Once the entry condition is satisfied, if the entry condition is continuously satisfied for a duration of TTT, the mobility execution condition is considered satisfied.

[0130] In the present disclosure, the term "handover (HO)" may mean a PCell change, or may be a broad concept including not only a PCell change but also a PSCell change / addition.

[0131] In this disclosure, the terms "handover", "mobility" and "cell handover" may be used interchangeably.

[0132] In the present disclosure, the description about handover may also be applied to other mobility procedures (eg, PSCell change / addition).

[0133] Figure 9 An example of a conditional mobility procedure according to an embodiment of the present disclosure is shown.

[0134] exist Figure 9 middle:

[0135] - The serving BS may be associated with a PCell, which may be the source PCell for the CHO;

[0136] - The serving BS may be a MN associated with a SN in DC, where the SN may be related to the source PSCell for CPC; and

[0137] -The target cell can be the target PCell for CHO, or the target PSCell for CPA / CPC.

[0138] Reference Figure 9 In step S901, the UE may receive an RRCReconfiguration message including a conditional reconfiguration information element (IE) (i.e., ConditionalReconfiguration) from the serving BS. The conditional reconfiguration IE may include a list of conditional reconfigurations for candidate cells including a target cell. Each conditional reconfiguration in the list may be associated with a corresponding candidate cell and include i) an identifier of the corresponding conditional reconfiguration (i.e., condReconfigId), ii) one or more execution conditions (i.e., condExecutionCond) for the corresponding candidate cell, and / or iii) an RRC reconfiguration for the corresponding candidate cell including a cell configuration for the corresponding candidate cell (i.e., condRRCReconfigi). The one or more execution conditions may include a CHO execution condition, a CPA execution condition, and / or a CPC execution condition.

[0139] In step S903, the UE may start evaluating one or more execution conditions for the candidate cells. Figure 9 In the example, it is assumed that the target cell meets the corresponding execution conditions.

[0140] At step S905, the UE may detach from the source PCell / PSCell (for the case of CHO / CPC), apply RRC reconfiguration for the target cell including the cell configuration for the target cell, and / or synchronize to the target cell. If timing advance (TA) information for the target cell is available, the UE may skip random access towards the target cell - otherwise, the UE shall perform random access (e.g., contention-free random access (CFRA) and / or contention-based random access (CBRA)) towards the target cell.

[0141] In step S907, the UE may complete the conditional mobility procedure by sending an RRCReconfigurationComplete message to the target cell.

[0142] In some implementations, the UE may release the conditional reconfiguration after the conditional mobility procedure completes successfully.

[0143] In the following, the simultaneous evaluation of CHO and CPAC is described.

[0144] In a wireless communication system, CHO including a target MCG and a target SCG may be supported, and CHO configuration referring to or including CPC / CPA configuration (intended to be applicable together) may be supported. When CHO is triggered, the UE may perform CPC / CPA configuration to start CPC / CPA evaluation. CHO evaluation and CPC / CPA evaluation may be concurrent or sequential.

[0145] As mentioned above, CHO with SCG configuration is already supported. However, CHO with SCG configuration is still triggered under normal CHO triggering conditions (e.g., CondEventA3, CondEventA5) based solely on the quality of the target / source PCell. The disadvantage is that the target SCG (PSCell) is blindly added without considering its quality (or / and the source PSCell). Doing so may result in the addition of an SCG in poor radio conditions, followed by SCG failure, SCG failure recovery, and reconfiguration.

[0146] Therefore, a more optimized approach also considers the conditions of the target / source PSCell. That is:

[0147] - The UE may be configured with CHO and associated SCG and configured to consider triggering conditions on the source / target PCell and source / target PSCell; and / or

[0148] - The UE shall monitor two trigger conditions and perform CHO with the associated SCG only if both trigger conditions are met.

[0149] In some scenarios, there may be several candidate PSCells for a particular PCell. This can be achieved by configuring a CHO with an associated SCG for each possible PSCell. However, this is inefficient signaling because the MCG configuration is repeated in each configuration. A more optimal solution is to have a CHO that can be configured with / associated with multiple SCGs, each with its own triggering conditions. For example, a CHO can be associated with multiple SCGs, each with different triggering conditions.

[0150] For example, a UE may be configured with a CHO configuration with two associated SCGs (SCG1 and SCG2). If the triggering conditions for PCell and PSCell1 are met, the UE will perform CHO with SCG1. If the triggering conditions for PCell and PSCell2 are met, the UE will perform CHO with SCG2. Releasing all conditional reconfigurations while another conditional reconfiguration is being performed would result in unnecessary reconfigurations. Therefore, it is proposed that when a UE performs CHO with multiple SCGs associated with it, the UE may be configured to maintain the other SCG configurations associated with the SCG and keep monitoring their triggering conditions.

[0151] Regarding the RRC signaling structure design, there are two main possibilities:

[0152] a) CHO contains MCG configuration (and trigger conditions) and associated SCG configuration (and SCG trigger conditions)

[0153] b) CHO contains only the MCG configuration (and PCell change trigger conditions), a separate configuration for each SCG (i.e., CPC with SCG configuration and PSCell change trigger conditions), and a configuration that associates CHO with the SCG configuration (e.g., in a similar way that measurement ID associates measurement objects with measurement reporting configuration).

[0154] That is, at least one of the following structures for defining a CHO with an associated SCG may be considered:

[0155] a) a CHO configuration that includes all MCG configurations, SCG configurations, and trigger conditions for PCell change and PSCell change; and / or

[0156] b) Separate CHO and CPAC configurations, and configurations that associate CHO with CPAC configurations.

[0157] According to various embodiments, the UE may receive a conditional reconfiguration list (i.e., CondReconfigToAddModList IE) from the network. The IE CondReconfigToAddModList relates to a list of conditional reconfigurations to be added or modified, wherein each entry includes condReconfigId and associated fields, as shown in Table 5 below:

[0158] [Table 5]

[0159]

[0160]

[0161] In Table 5: - condExecutionCond (e.g., the second type of execution condition for the target PSCell) is an execution condition that needs to be met in order to trigger the execution of conditional reconfiguration for CHO, CPA, intra-SN CPC without MN participation, MN-initiated inter-SN CPC, or intra-SN subsequent CPAC initiated by SN without MN participation. When 2 triggering events (Meas Id) for a candidate cell are configured, the network ensures that both refer to the same measObject. For CHO, if the network configures condEventD1 or condEventT1 for a candidate cell, the network configures a second triggering event condEventA3, condEventA4, or condEventA5 for the same candidate cell. The network does not configure both condEventD1 and condEventT1 for the same candidate cell. For CHO in terrestrial networks, the network does not indicate the MeasId associated with condEventA4. For CPA and MN-initiated inter-SN CPC, the network only indicates the MeasId associated with condEventA4. For intra-SN CPC and intra-SN subsequent CPAC, the network only indicates the MeasId associated with condEventA3 or condEventA5;

[0162] -condExecutionCondPSCell (i.e., the first type of execution condition for the target PSCell) is the execution condition that needs to be satisfied for the associated PSCell in order to trigger the execution of the conditional reconfiguration for the CHO with the candidate SCG. MeasId refers to the measConfig associated with the MCG. When configuring two triggering events (MeasId) for a candidate cell, the network ensures that both refer to the same measObject. The network only indicates the MeasId associated with condEventA4;

[0163] -condExecutionCondSCG contains the execution conditions that need to be met in order to trigger the execution of conditional reconfiguration for SN-initiated inter-SN CPC, SN-initiated inter-SN subsequent CPAC, SN-initiated intra-SN subsequent CPAC with MN participation, or MN-initiated inter-SN subsequent CPAC. Meas Id refers to the measConfig associated with the SCG. When configuring 2 triggering events (Meas Id) for a candidate cell, the network ensures that both refer to the same measObject. For each condReconfigId, the network always configures either condExecutionCond or condExecutionCondSCG (not both). The network only indicates the MeasId associated with condEventA3 or condEventA5;

[0164] -condRRCReconfig is an RRCReconfiguration message that includes the cell configuration for the corresponding target cell to be applied when the condition is met. The RRCReconfiguration message included in condRRCReconfig must not include the field conditionalReconfiguration or the field daps-Config;

[0165] -scpac-ConfigComplete indicates whether the configuration contained in condRRCReconfig for the subsequent CPAC is a complete configuration; and

[0166] -subsequentCondReconfi contains the execution conditions that need to be met to trigger the execution of a subsequent CPAC (e.g., a second type of execution condition for the target PSCell). If this field is configured, configuration of candidate PSCells for subsequent CPAC is supported. When the RRCReconfiguration message contained in condRRCReconfig has been applied, the subsequent execution conditions are used for conditional reconfiguration evaluation of other candidate cells.

[0167] After receiving the conditional reconfiguration list, the UE may perform conditional reconfiguration evaluation. The UE shall:

[0168] 1>For each condReconfigId in VarConditionalReconfig:

[0169] 2> If RRCReconfiguration within condRRCReconfig includes a masterCellGroup that includes reconfigurationWithSync, then:

[0170] 3>If the associated condExecutionCondPSCell is configured, then:

[0171] 4> consider cells having physical cell identities matching the values ​​indicated in ServingCellConfigCommon included in reconfigurationWithSync within masterCellGroup in the received condRRCReconfig as applicable cells; and

[0172] 4> The cell having a physical cell identity matching the value indicated in ServingCellConfigCommon included in reconfigurationWithSync in secondaryCellGroup in nr-SCG in the received condRRCReconfig is regarded as an applicable cell;

[0173] 3> Otherwise:

[0174] 4> Treat cells with physical cell identities matching the value indicated in ServingCellConfigCommon included in reconfigurationWithSync within masterCellGroup in the received condRRCReconfig as applicable cells;

[0175] 2> Otherwise, if the RRCReconfiguration within condRRCReconfig includes a secondyCellGroup that includes reconfigurationWithSync:

[0176] 3> If the cell with a physical cell identity matching the value indicated in ServingCellConfigCommon included in reconfigurationWithSync within secondaryCellGroup within the received condRRCReconfig is not a PSCell, then:

[0177] 4> The cell is considered to be an applicable cell;

[0178] 2>If condExecutionCondSCG is configured, then:

[0179] 3> In the rest of the process, each measId indicated in condExecutionCondSCG is treated as a measId in the VarMeasConfig associated with the SCG measConfig;

[0180] 2>If condExecutionCondPSCell is configured, then:

[0181] 3> In the rest of this process, each measId indicated in condExecutionCondPSCell is treated as a measId in the VarMeasConfig associated with the MCG measConfig;

[0182] 2>If condExecutionCond is configured, then:

[0183] 3> If it is configured via SRB3 or configured via SRB1 within nr-SCG or nr-SecondaryCellGroupConfig, then:

[0184] 4> In the rest of the process, each measId indicated in condExecutionCond is treated as a measId in the VarMeasConfig associated with SCGmeasConfig;

[0185] 3> Otherwise:

[0186] 4> In the rest of the process, each measId indicated in condExecutionCond is treated as a measId in the VarMeasConfig associated with MCGmeasConfig;

[0187] 2> For each measId included in the measIdList within the VarMeasConfig indicated in the condExecutionCond, condExecutionCondSCG, or condExecutionCondPSCell associated with condReconfigId, then:

[0188] 3> if condEventId is associated with condEventT1, and if the entry conditions applicable to the event associated with condReconfigId (i.e., the event corresponding to the condEventId of the corresponding condTriggerConfig within VarConditionalReconfig) are met for the applicable cell; or

[0189] 3> if condEventId is associated with condEventD1, and if the entry conditions applicable to the event are met for the applicable cell during the corresponding timeToTrigger defined within VarConditionalReconfig for the event associated with condReconfigId (i.e., the event corresponding to condEventId of the corresponding condTriggerConfig within VarConditionalReconfig); or

[0190] 3> If condEventId is associated with condEventA3, condEventA4, or condEventA5, and if the entry conditions applicable to the event are met for the applicable cell for all measurements after layer 3 filtering taken during the corresponding timeTotrigger defined for that event within VarConditionalReconfig (i.e., the event corresponding to the condEventId of the corresponding condTriggerConfig within VarConditionalReconfig), then:

[0191] 4> The event associated with the measId is considered to be satisfied;

[0192] 3> If the measId associated with the event condReconfigId has been modified; or

[0193] 3> if condEventId is associated with condEventT1, and if the leaving condition applicable to the event associated with condReconfigId (i.e., the event corresponding to the condEventId of the corresponding condTriggerConfig within VarConditionalReconfig) is met for the applicable cell; or

[0194] 3> if condEventId is associated with condEventD1, and if the leave condition applicable to the event is met for the applicable cell during the corresponding timeToTrigger defined within VarConditionalReconfig for the event associated with condReconfigId (i.e., the event corresponding to condEventId of the corresponding condTriggerConfig within VarConditionalReconfig); or

[0195] 3> If condEventId is associated with condEventA3, condEventA4, or condEventA5, and if the leaving condition applicable to the event is met for the applicable cell for all measurements after layer 3 filtering taken during the corresponding timeTotrigger defined for that event within VarConditionalReconfig (i.e., the event corresponding to the condEventId of the corresponding condTriggerConfig within VarConditionalReconfig), then:

[0196] 4> The event associated with the measId is not considered to be satisfied;

[0197] 2>If condExecutionCondPSCell is not configured, then:

[0198] 3> If the events associated with all measIds within the condTriggerConfig for the applicable cell are met, then:

[0199] 4> Treat the applicable cell associated with the condReconfigId as the triggered cell;

[0200] 4>Initiate conditional reconfiguration execution;

[0201] 2> Otherwise:

[0202] 3> If the events associated with all measIds as indicated in condExecutionCond and condExecutionCondPSCell in the condTriggerConfig for the target candidate cell in the stored condRRCReconfig are met, then:

[0203] 4> The target candidate PCell associated with the condReconfigId in the stored condRRCReconfig is regarded as the triggering PCell;

[0204] 4> The target candidate PSCell associated with the condReconfigId in the stored condRRCReconfig is regarded as the triggered PSCell;

[0205] 4>Initiate conditional reconfiguration execution.

[0206] If condExecutionCondPSCell is not configured, up to two MeasIds can be configured for each condReconfigId. The conditional reconfiguration events of the two MeasIds can have the same or different event conditions, trigger amounts, trigger times, and trigger thresholds.

[0207] For a CHO with a candidate SCG, up to 2 Measlds may be configured for a condExecutionCond, and up to 2 Measlds may be configured for a condExecutionCondPSCell for each condReconfigId.

[0208] When conditional reconfiguration is performed, the UE shall:

[0209] 1> If there is more than one pair of triggered PCell and associated triggered PSCell, then:

[0210] 2> Select one of the triggered PCell and the associated triggered PSCell as the selected cell for conditional reconfiguration execution;

[0211] 1> Otherwise, if there is only one pair of triggered PCell and associated triggered PSCell, then:

[0212] 2> Treat the triggered PCell and the associated triggered PSCell as the selected cells for conditional reconfiguration execution;

[0213] 1> Otherwise, if there is more than one triggered cell, then:

[0214] 2> Select one of the triggered cells as the selected cell for conditional reconfiguration execution;

[0215] 1> Otherwise:

[0216] 2> Treat the triggered cell as the selected cell for conditional reconfiguration execution;

[0217] 1>Selected cells for conditional reconfiguration execution:

[0218] 2> If subsequentCondReconfig is included in the entry in VarConditionalReconfig containing the RRCReconfiguration message for the selected cell, then:

[0219] 3>Execute subsequent CPAC execution;

[0220] 2> Otherwise:

[0221] 3> Apply the stored condRRCReconfig of the selected cell and apply the RRCReconfiguration in condRRCReconfig.

[0222] If multiple NR cells are triggered in the conditional reconfiguration execution, the UE can select one of them. For example, the UE can consider the beam and / or beam quality to select one of the triggered cells for execution.

[0223] When performing conditional reconfiguration for subsequent CPAC, the UE shall:

[0224] 1> If the selected subsequent CPAC candidate configuration is stored in MCG VarConditionalReconfig, then:

[0225] 2> Release / clear all current dedicated radio configurations except for the following:

[0226] -MCG C-RNTI;

[0227] -AS security configuration associated with the primary and secondary keys;

[0228] -For each SRB / DRB in the current UE configuration:

[0229] - Maintain associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0230] - Release all fields related to SRB / DRB configuration except srb-Identity and drb-Identity;

[0231] -UE variables VarConditionalReconfig and VarServingSecurityCellSetID.

[0232] 2> Release / clear all current public radio configurations;

[0233] 1> Otherwise:

[0234] 2> Release / clear all current dedicated radio configurations associated with the SCG except for the following:

[0235] -AS security configuration associated with the secondary key;

[0236] - For each SRB / DRB in the current UE configuration using secondary keys:

[0237] - Maintain associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0238] - Release all fields related to SRB / DRB configuration except srb-Identity and drb-Identity;

[0239] -UE variable VarConditionalReconfig

[0240] 2> Release / clear all current public radio configurations associated with the SCG;

[0241] 1> Use the default values ​​for timers T310, T311 and constants N310, N311 for the cell group that triggers the subsequent CPAC cell handover process;

[0242] 1> If securityCellSetId is included in the entry in VarConditionalReconfig containing the RRCReconfiguration message, then: 2> If servingSecurityCellSetId is not included in VarServingSecurityCellSetID; or

[0243] 2> If the value of securityCellSetId is not equal to the value of servingSecurityCellSetId in VarServingSecurityCellSetID, then:

[0244] 3> Treat the first sk-Counter value in the sk-CounterList associated with the securityCellSetId in VarConditionalReconfig as the selected sk-Counter value and perform the security key update procedure;

[0245] 3> Remove the selected sk-Counter value from the sk-CounterList associated with the securityCellSetId in VarConditionalReconfig;

[0246] 3>If the current VarServingSecurityCellSetID includes servingSecurityCellSetId, then:

[0247] 4>Replace the value of servingSecurityCellSetId in VarServingSecurityCellSetID with the value of securityCellSetId associated with the selected cell;

[0248] 3> Otherwise:

[0249] 4> Store servingSecurityCellSetId in VarServingSecurityCellSetID, where servingSecurityCellSetId has the value of securityCellSetId associated with the selected cell;

[0250] 1> If the selected subsequent CPAC candidate configuration is stored in SCG VarConditionalReconfig, then:

[0251] 2> for the secondary key (SK indicated by keyToUse as part of the current UE configuration gNB ) for each drb-Identity value included in the associated RadioBearerConfig:

[0252] 3> Trigger the PDCP entity of the AM DRB to perform PDCP data recovery;

[0253] 3>Rebuild the corresponding RLC entity;

[0254] 1> Otherwise:

[0255] 2> For each drb-Identity value included in the RadioBearerConfig as part of the current UE configuration:

[0256] 3>If a different keyToUse value is configured; or

[0257] 3> If a new sk-Counter value is chosen due to conditional reconfiguration execution for a subsequent CPAC, then:

[0258] 4> Trigger the bearer PDCP entity to perform PDCP re-establishment;

[0259] 3> Otherwise:

[0260] 4> Trigger the PDCP entity of the AM DRB to perform PDCP data recovery;

[0261] 4>Rebuild the corresponding RLC entity;

[0262] 1> If scpac-ConfigComplete is not included in the VarConditionalReconfig for the selected cell, then:

[0263] 2> If the subsequent CPAC candidate cell configuration is stored in MCG VarConditionalReconfig, then:

[0264] 3> Treat the scpac-ReferenceConfiguration in MCG VarConditionalReconfig as the current UE configuration;

[0265] 2> Otherwise:

[0266] 3> Treat scpac-ReferenceConfiguration in SCG VarConditionalReconfig as the current SCG configuration;

[0267] When the UE considers the reference configuration to be the current UE configuration, the UE shall store the fields and configurations that are part of the reference configuration, but shall not perform any actions or procedures triggered by the reception of the RRCReconfiguration message.

[0268] 1> Apply the stored condRRCReconfig of the selected cell and apply the RRCReconfiguration in condRRCReconfig.

[0269] 1> Release the radio bearers and associated logical channels that are part of the current UE configuration but not part of the subsequent CPAC candidate configuration or the subsequent CPAC reference configuration (in the case that the subsequent CPAC candidate configuration does not include scpac-ConfigComplete) for the selected cell.

[0270] When scpac-ConfigComplete is not included for the selected cell, before subsequent CPAC execution, the UE implementation may generate and store an RRC reconfiguration message by applying the received subsequent CPAC candidate configuration to the subsequent CPAC reference configuration, and the stored RRC reconfiguration message is applied to the subsequent CPAC execution.

[0271] In addition, the UE may be configured with CHO and an SCG for dual connectivity (DC) to be established when CHO is executed. The UE may also be configured with a CPC configuration, where the CPC configuration begins to apply after CHO execution and SCG establishment.

[0272] The UE may then evaluate the CHO execution conditions. If the CHO execution conditions are met, the UE may perform CHO for PCell switching and then establish an SCG to enable DC. After the SCG is established, the UE may start evaluating the CPC execution conditions, and if the CPC execution conditions are met, the UE may perform an SCG change (or, PSCell change / SN change) by establishing a new SCG. During the sequence of process flows, the UE has performed CHO once and performed SCG establishment twice. The first SCG establishment is to establish SCG1 (i.e., SCG addition), and the second SCG establishment is to replace SCG1 with a new one (SCG2) (i.e., SCG change). If the UE can directly establish SCG2 without establishing SCG1, the first SCG establishment for SCG addition can be avoided.

[0273] In order to achieve direct SCG change without performing SCG addition during CHO, the UE can be configured to evaluate the CHO execution condition as well as the CPC execution condition so that CHO and CPC are jointly evaluated. Based on the joint evaluation result, the UE can only perform CHO or can jointly perform CHO and CPC. In order to avoid redundant SCG addition, if there is a suitable CPC candidate at the same time as CHO is to be performed, it is expected to directly perform CPC without SCG addition. However, since the CHO execution condition and the CPC execution condition are independent, the UE cannot know when or whether the CPC execution condition will be met. This makes it difficult for the UE to determine when / whether to perform only CHO or perform CHO and CPC together at the appropriate timing.

[0274] Therefore, the present disclosure provides various embodiments to handle when / whether to perform only CHO or perform CHO and SCG establishment / CPC together at the appropriate timing.

[0275] Figure 10 An example of a method performed by a UE according to an embodiment of the present disclosure is shown. The method may also be performed by a wireless device.

[0276] Reference Figure 10 In step S1001, the UE may receive a configuration for CHO to a target PCell from the network. The configuration for CHO may include execution conditions for CHO and execution conditions for conditional PSCell mobility to a first target PSCell. The configuration for CHO may be related to the configuration for conditional PSCell mobility and the configuration for SCG establishment to a second target PSCell.

[0277] In step S1003 , the UE may evaluate an execution condition for CHO while evaluating an execution condition for conditional PSCell mobility.

[0278] In step S1005 , after the execution conditions for CHO are met but the execution conditions for conditional PSCell mobility are not met, the UE may: perform CHO to the target PCell; and delay performing SCG establishment to the second target PSCell for a period of time.

[0279] In step S1007 , the UE may evaluate execution conditions for conditional PSCell mobility during the time period.

[0280] According to various embodiments, based on the execution condition for CHO being satisfied only within a portion of the TTT of the execution condition for PSCell mobility while also satisfying the entry condition for conditional PSCell mobility, the UE may determine whether to delay performing SCG establishment based on an evaluation status of the execution condition for conditional PSCell mobility. The evaluation status may be determined based on at least one of a remaining TTT of the execution condition for conditional PSCell mobility after the execution condition for CHO is satisfied or a threshold value.

[0281] According to various embodiments, the UE may delay performing SCG establishment based on the remaining TTT of the execution condition for conditional PSCell mobility being less than a threshold.

[0282] According to various embodiments, based on the remaining TTT for the execution condition for conditional PSCell mobility being less than a threshold, the UE may start a timer with a timer value. The UE may delay performing SCG establishment while the timer is running. The timer value may be set to a time period greater than the remaining TTT for the execution condition for conditional PSCell mobility.

[0283] According to various embodiments, based on satisfying an entry condition for conditional PSCell mobility after satisfying an entry condition for CHO, the UE may determine whether to delay performing SCG establishment based on an evaluation status of an execution condition for CHO. The evaluation status may be determined based on at least one of: a remaining TTT of the execution condition for CHO after satisfying the entry condition for conditional PSCell mobility, or a threshold.

[0284] According to various embodiments, based on the remaining TTT for the execution condition of CHO being greater than or equal to a threshold, the UE may delay performing SCG establishment.

[0285] According to various embodiments, based on the remaining TTT of the execution condition for CHO being greater than or equal to a threshold, the UE may start a timer with a timer value. The UE may delay performing SCG establishment while the timer is running. The timer value may be set to a time period and may be equal to the TTT of the execution condition for conditional PSCell mobility. The start time of the timer may be equal to the start time of the TTT of the execution condition for conditional PSCell mobility.

[0286] According to various embodiments, based on the execution condition for conditional PSCell mobility being met during the time period, the UE may perform conditional PSCell mobility to the first target PSCell. Based on the execution condition for conditional PSCell mobility not being met during the time period, the UE may perform SCG establishment to the second target PSCell.

[0287] According to various embodiments, based on the execution condition for conditional PSCell mobility being met while the timer is running, the UE may perform conditional PSCell mobility to the first target PSCell.Based on the execution condition for conditional PSCell mobility not being met while the timer is running, the UE may perform SCG establishment to the second target PSCell.

[0288] According to various embodiments, the UE may perform SCG establishment upon expiration of a timer.

[0289] According to various embodiments, the UE may stop the timer based on not meeting an entry condition for conditional PSCell mobility while the timer is running. The UE may perform SCG establishment when stopping the timer.

[0290] According to various embodiments, the configuration for CHO may include RRC reconfiguration for the target PCell. The RRC reconfiguration for the target PCell may include configuration for SCG establishment to the second target PSCell. To perform CHO while delaying SCG establishment, the UE may apply configurations in the RRC reconfiguration for the target PCell, except for the configuration for SCG establishment, to the second target PSCell.

[0291] According to various embodiments, conditional PSCell mobility may include at least one of CPC or CPA.

[0292] Figure 11 An example of a signal flow between a UE and a network node according to an embodiment of the present disclosure is shown. The network node may include a BS.

[0293] Reference Figure 11In step S1101, the network node may obtain a configuration for CHO to a target PCell. The configuration for CHO may include execution conditions for CHO and execution conditions for conditional PSCell mobility to a first target PSCell. The configuration for CHO may be related to the configuration for conditional PSCell mobility and the configuration for SCG establishment to a second target PSCell.

[0294] In step S1103 , the network node may send the configuration for CHO to the target PCell to the UE.

[0295] In step S1105 , the UE may evaluate an execution condition for CHO while evaluating an execution condition for conditional PSCell mobility.

[0296] In step S1107 , after the execution conditions for CHO are met but the execution conditions for conditional PSCell mobility are not met, the UE may: perform CHO to the target PCell; and delay performing SCG establishment to the second target PSCell for a period of time.

[0297] At step S1109 , the UE may evaluate execution conditions for conditional PSCell mobility during the time period.

[0298] In the present disclosure, the UE may be configured with a configuration for SCG establishment to be initiated / performed at CHO, but the UE may decide to delay SCG establishment at CHO execution based on the evaluation status of the CPC execution condition.

[0299] According to various embodiments, the evaluation status of an execution condition may indicate:

[0300] - Whether the entry conditions for the execution conditions are met;

[0301] - whether the execution conditions are met; and / or

[0302] -For the execution condition, how long is the time in TTT during which the entry condition is met, or how short is the remaining duration after the duration during which the entry condition is met.

[0303] Evaluation status can be defined in various ways, and examples of evaluation status are given in Figure 12 Example in.

[0304] Figure 12 An example of an evaluation status of a CPC execution condition according to an embodiment of the present disclosure is shown.

[0305] Reference Figure 12, the CHO execution condition is met at T_c. The UE may then evaluate R calculated as R=T_d-T_c, where T_d is the expected time within the TTT that the CPC execution condition is met (or the time when the TTT for the CPC execution condition ends).

[0306] If R is less than the threshold (ie, R<threshold), the UE may perform CHO but may not immediately establish an SCG during / after the CHO (ie, the UE may delay SCG establishment).

[0307] If R is higher than or equal to the threshold (ie, R≥threshold), the UE may perform CHO and establish an SCG during / after CHO.

[0308] When SCG establishment is delayed, the UE may perform the following operations: Figure 13 The action shown.

[0309] Figure 13 An example of timer-based CPC condition evaluation according to an embodiment of the present disclosure is shown.

[0310] Reference Figure 13 , the UE may identify that the CHO execution condition is satisfied (or that the CHO entry condition is satisfied within the TTT). The UE may then check whether the CPC entry condition for CPC is satisfied. If the CPC entry condition is satisfied, the UE may start a timer.

[0311] When the timer is started and / or when the CPC entry conditions and / or CHO execution conditions are met, the UE may perform CHO. If the timer runs during / after CHO, the UE does not establish an SCG (i.e., the UE delays SCG establishment). While the timer is running, if the CPC execution conditions are met (i.e., the CPC entry conditions are met within the TTT), the UE may perform CPC without SCG addition / establishment (i.e., establishing an SCG with a CPC candidate cell as a PSCell). If the timer expires, the UE may perform SCG addition / establishment (i.e., establishing an SCG according to the SCG configured for CHO).

[0312] Figure 14 An example of a method for handling SCG establishment timing according to an embodiment of the present disclosure is shown.

[0313] Reference Figure 14 In step S1401, the UE may apply the configuration for PCell1 and the configuration for SCG1 including PSCell1. That is, the UE may be configured with PCell1 and SCG1 including PSCell1.

[0314] In step S1403 , the UE may receive CHO configuration, configuration for SCG2, and CPC configuration.

[0315] The UE may be configured with a CHO configuration, where the CHO configuration may include a configuration for PCell2 (which is a CHO candidate cell), an MCG configuration for the CHO candidate cell, and / or a CHO execution condition for the CHO candidate cell.

[0316] The UE may also be configured with a configuration for SCG2 to be established when CHO to the CHO candidate cell is performed, wherein the configuration for SCG2 may include a SpCell configuration of PSCell2 related to SCG2.

[0317] The UE may also be configured with a CPC configuration, where the CPC configuration may include a configuration for PSCell3 as a CPC candidate cell, a configuration for SCG3 related to the CPC candidate cell, and / or a CPC execution condition for the CPC candidate cell.

[0318] In step S1405, the UE may evaluate the CHO execution condition and the CPC execution condition. The UE may evaluate the CHO execution condition and the CPC execution condition simultaneously. The UE may evaluate the CHO execution condition while evaluating the CPC execution condition.

[0319] In step S1407 , the UE may perform an action based on the evaluation status of the CHO execution condition and / or the CPC execution condition.

[0320] If the entry condition for the CHO execution condition is satisfied, the UE may start TTT for the CHO execution condition.

[0321] In some implementations, if the entry condition for the CPC execution condition is met, the UE may start TTT for the CPC execution condition.

[0322] When the TTT for the CHO execution condition expires (ie, the entry condition of the CHO execution condition is satisfied within the TTT), the UE may compare the remaining TTT for the CPC execution condition with a threshold.

[0323] If the remaining TTT for the CPC execution condition is less than the threshold, the UE may:

[0324] - Starting a first timer, wherein the first timer value may be set to the remaining TTT value, or the remaining TTT value + a non-negative value.

[0325] - Perform CHO to the CHO candidate cell PCell2 (PCell2 thus becomes the serving PCell); and

[0326] -Establish the MCG of the CHO candidate cell PCell2.

[0327] If the first timer is running during / after CHO, the UE may delay establishing SCG2 according to the configuration for SCG2 during / after CHO (ie, PSCell2 does not immediately become the serving PSCell after CHO).

[0328] Otherwise, the first timer is not running during / after CHO (i.e., the first timer expires, or the first timer stops), the UE can establish SCG2 according to the configuration for SCG2 during / after CHO (i.e., PSCell2 becomes the serving PSCell after CHO).

[0329] If the CPC execution condition is met while the first timer is running (i.e., the CPC entry condition is met within the TTT), the UE can perform CHO execution and / or CPC execution according to the CPC configuration (i.e., establish SCG3 according to the configuration for SCG3 related to PSCell3, so that PSCell3 becomes the serving PSCell).

[0330] When the first timer expires (ie, the CPC execution condition is not met while the first timer is running), the UE may establish SCG2 according to the configuration for SCG2 (so that PSCell2 becomes the serving PSCell).

[0331] When the first timer is running, if the CPC execution condition / CPC entry condition is no longer met, the UE may stop the first timer. When stopping the first timer, the UE may establish SCG2 according to the configuration for SCG2 (so that PSCell2 becomes the serving PSCell).

[0332] In some implementations, if the entry condition for the CPC execution condition is met, the UE may compare the remaining TTT for the CHO execution condition with a threshold.

[0333] If the remaining TTT for the CHO execution condition is less than the threshold, the UE does not start the TTT for the CPC execution condition.

[0334] If the remaining TTT for the CHO execution condition is not less than the threshold (i.e., greater than or equal to the threshold), the UE may start the TTT for the CPC execution condition and start a second timer. The second timer value may be set to the TTT for the CPC execution condition, or the TTT for the CPC execution condition + a non-negative value.

[0335] When the TTT for the CHO execution condition expires (i.e., the entry condition of the CHO execution condition is met within the TTT), the UE may:

[0336] - Perform CHO execution to the CHO candidate cell PCell2 (so PCell2 becomes the serving PCell);

[0337] - Establish the MCG of the CHO candidate cell PCell2;

[0338] - if the TTT for CPC is running (or if the second timer is running), the UE does not immediately establish SCG2 while the second timer is running (i.e., the UE may delay SCG establishment); and

[0339] - Otherwise, if TTT for CPC is not running (or if the second timer expires), the UE may establish SCG2 according to the configuration for SCG2 during / after CHO (so PSCell2 becomes the serving PSCell after CHO).

[0340] If the CPC execution condition is met while the second timer is running, the UE may perform CPC execution according to the CPC configuration (ie, establish SCG3 according to the configuration for SCG3 related to PSCell3, so that PSCell3 becomes the serving PSCell).

[0341] When the second timer expires (ie, the CPC execution condition is not met while the second timer is running), the UE may establish SCG2 according to the configuration for SCG2 (so PSCell2 becomes the serving PSCell).

[0342] In addition, in this disclosure (for example, Figure 10 The method described from the perspective of UE can be Figure 2 The first wireless device 100 and / or Figure 3 The UE 100 shown in FIG.

[0343] More specifically, the UE includes at least one transceiver, at least one processor, and at least one computer memory operatively connected to the at least one processor and storing instructions that perform operations upon execution by the at least one processor.

[0344] The operation includes: receiving a configuration for conditional handover (CHO) to a target primary cell (PCell) from a network, wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is met and the execution condition for conditional PSCell mobility is not met: performing CHO to the target PCell; and delaying the execution of SCG establishment to the second target PSCell within a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0345] In addition, in this disclosure (for example, Figure 10 The method described from the perspective of the UE can be stored in Figure 2 The first wireless device 100 is shown as being executed by software code 105 in a memory 104 included in the first wireless device 100 .

[0346] More specifically, at least one computer-readable medium (CRM) stores instructions that perform operations based on execution by at least one processor, the operations including: receiving a configuration for conditional handover (CHO) to a target primary cell (PCell) from a network, wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is met and the execution condition for conditional PSCell mobility is not met: performing CHO to the target PCell; and delaying the execution of SCG establishment to the second target PSCell within a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0347] In addition, in this disclosure (for example, Figure 10 The method described from the perspective of UE can be Figure 2 The processor 102 included in the first wireless device 100 is controlled and / or Figure 3 The processing is executed under the control of the processor 102 included in the UE 100 shown.

[0348] More specifically, an apparatus (e.g., a wireless device / UE) configured / adapted to operate in a wireless communication system includes at least one processor and at least one computer memory operatively connected to the at least one processor. The at least one processor is configured / adapted to perform operations comprising: receiving a configuration for conditional handover (CHO) to a target primary cell (PCell) from a network, wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is satisfied but the execution condition for conditional PSCell mobility is not satisfied: performing CHO to the target PCell; and delaying performing SCG establishment to the second target PSCell for a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0349] In addition, in this disclosure (for example, Figure 11 The method described from the perspective of network nodes can be represented by Figure 2 The second wireless device 200 shown in FIG.

[0350] More specifically, the network node includes at least one transceiver, at least one processor, and at least one computer memory operatively connected to the at least one processor and storing instructions that perform operations upon execution by the at least one processor.

[0351] The operations include: obtaining a configuration for conditional handover (CHO) to a target primary cell (PCell), wherein the configuration for CHO includes an execution condition for CHO and an execution condition for conditional PSCell mobility to a first target primary secondary cell (PSCell), and wherein the configuration for CHO is related to the configuration for conditional PSCell mobility and the configuration for secondary cell group (SCG) establishment to a second target PSCell; sending the configuration for CHO to a target PCell to a user equipment (UE), wherein the UE is configured to perform operations including: evaluating the execution condition for CHO while evaluating the execution condition for conditional PSCell mobility; after the execution condition for CHO is met but the execution condition for conditional PSCell mobility is not met: performing CHO to the target PCell; and delaying the execution of SCG establishment to the second target PSCell within a time period; and evaluating the execution condition for conditional PSCell mobility during the time period.

[0352] The present disclosure may have various beneficial effects.

[0353] For example, due to conditional PSCell mobility performed immediately after CHO execution with SCG establishment, interruption / signaling can be reduced.

[0354] The beneficial effects that can be obtained by the specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, there may be various technical effects that can be understood and / or derived from the present disclosure by a person of ordinary skill in the relevant art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure.

[0355] The claims in this disclosure may be combined in various ways. For example, the technical features in the method claims of this disclosure may be combined to be implemented or performed in a device, and the technical features in the device claims may be combined to be implemented or performed in a method. Furthermore, the technical features in the method claims and the device claims may be combined to be implemented or performed in a device. Furthermore, the technical features in the method claims and the device claims may be combined to be implemented or performed in a method. Other implementations are within the scope of the appended claims.

Claims

1. A method performed by a user equipment (UE) configured to operate in a wireless communication system, the method comprising the following steps: Receive the configuration of conditional handover (CHO) to the target primary cell (PCell) from the network, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group (SCG) to a second target PSCell; evaluating an execution condition for the CHO while evaluating an execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and The execution condition for the conditional PSCell mobility is evaluated during the time period.

2. The method according to claim 1, further comprising the steps of: determining whether to delay execution of the SCG establishment based on an evaluation status of the execution condition for the conditional PSCell mobility, based on the execution condition for the CHO being satisfied while an entry condition for the conditional PSCell mobility being satisfied only within a portion of a triggering time TTT of the execution condition for the PSCell mobility; The evaluation status is determined based on at least one of the following: a remaining TTT for the execution condition for the conditional PSCell mobility after the execution condition for the CHO is satisfied; or Threshold.

3. The method according to claim 2, wherein: The step of delaying execution of the SCG establishment includes delaying execution of the SCG establishment based on the remaining TTT of the execution condition for the conditional PSCell mobility being less than the threshold.

4. The method according to claim 2, further comprising the steps of: starting a timer having a timer value based on the remaining TTT for the execution condition of the conditional PSCell mobility being less than the threshold, Wherein, the step of delaying the execution of the SCG establishment comprises: delaying the execution of the SCG establishment while the timer is running, and The timer value is set to the time period and is greater than the remaining TTT of the execution condition for the conditional PSCell mobility.

5. The method according to claim 1, further comprising the steps of: determining whether to delay execution of the SCG establishment based on an evaluation status of the execution condition for the CHO, based on satisfying an entry condition for the conditional PSCell mobility after satisfying an entry condition for the CHO, The evaluation status is determined based on at least one of the following: a remaining triggering time TTT of the execution condition for the CHO after the entry condition for the conditional PSCell mobility is satisfied; or Threshold.

6. The method according to claim 5, wherein: The step of delaying execution of the SCG establishment includes delaying execution of the SCG establishment based on the remaining TTT of the execution condition for the CHO being greater than or equal to the threshold.

7. The method according to claim 5, further comprising the steps of: Based on the remaining TTT for the execution condition of the CHO being greater than or equal to the threshold, starting a timer having a timer value, The step of delaying the execution of the SCG establishment includes: delaying the execution of the SCG establishment while the timer is running, wherein the timer value is set to the time period and is equal to the TTT of the execution condition for the conditional PSCell mobility, and The start time of the timer is equal to the start time of the TTT of the execution condition for the conditional PSCell mobility.

8. The method according to claim 1, further comprising the steps of: performing the conditional PSCell mobility to the first target PSCell based on the execution condition for the conditional PSCell mobility being satisfied during the time period; as well as Based on the execution condition for the conditional PSCell mobility not being satisfied during the time period, the SCG establishment to the second target PSCell is performed.

9. The method according to claim 4 or 7, further comprising the steps of: performing the conditional PSCell mobility to the first target PSCell based on the execution condition for the conditional PSCell mobility being satisfied while the timer is running; as well as Based on the execution condition for the conditional PSCell mobility not being satisfied while the timer is running, the SCG establishment to the second target PSCell is performed.

10. The method according to claim 9, wherein: The step of performing the SCG establishment includes performing the SCG establishment in the following situations: expiry of the timer; or The timer stops, Wherein, based on the entry condition for the conditional PSCell mobility not being met while the timer is running, the timer is stopped.

11. The method according to claim 1, wherein The configuration for the CHO includes a radio resource control (RRC) reconfiguration for the target PCell, wherein the RRC reconfiguration for the target PCell includes configuration for the SCG establishment to the second target PSCell, and The step of performing the CHO while delaying the SCG establishment includes applying the configuration of the RRC reconfiguration for the target PCell except the configuration for the SCG establishment to the second target PSCell.

12. The method according to claim 1, wherein The conditional PSCell mobility includes at least one of conditional PSCell change CPC or conditional PSCell addition CPA.

13. The method according to claim 1, wherein The UE communicates with at least one of a mobile device, a network, or an autonomous vehicle.

14. A user equipment (UE) configured to operate in a wireless communication system, the UE comprising: at least one transceiver; at least one processor; as well as at least one memory operatively coupled to the at least one processor and storing instructions that, upon execution by the at least one processor, perform operations comprising: Receive the configuration of conditional handover (CHO) to the target primary cell (PCell) from the network, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group (SCG) to a second target PSCell; evaluating the execution condition for the CHO while evaluating the execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and An execution condition for the conditional PSCell mobility is evaluated during the time period.

15. The UE according to claim 14, wherein: The UE is arranged to implement the method according to one of claims 2 to 13.

16. A network node configured to operate in a wireless communication system, the network node comprising: at least one transceiver; at least one processor; as well as at least one memory operatively coupled to the at least one processor and storing instructions that, upon execution by the at least one processor, perform operations comprising: Get the configuration of conditional handover CHO to the target primary cell PCell, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group (SCG) to a second target PSCell; sending the configuration for the CHO to the target PCell to a user equipment UE, The UE is configured to perform operations including the following: evaluating the execution condition for the CHO while evaluating the execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and An execution condition for the conditional PSCell mobility is evaluated during the time period.

17. A method performed by a network node configured to operate in a wireless communication system, the method comprising the steps of: Get the configuration of conditional handover CHO to the target primary cell PCell, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group (SCG) to a second target PSCell; sending the configuration for the CHO to the target PCell to a user equipment UE, The UE is configured to perform operations including the following: evaluating the execution condition for the CHO while evaluating the execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and The execution condition for the conditional PSCell mobility is evaluated during the time period.

18. The method according to claim 17, wherein The UE is arranged to implement the method according to one of claims 1 to 13.

19. A device adapted to operate in a wireless communication system, the device comprising: at least one processor; as well as at least one memory operatively coupled to the at least one processor and storing instructions that, upon execution by the at least one processor, perform operations comprising: Receive the configuration of conditional handover (CHO) to the target primary cell (PCell) from the network, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group SCG to the second target PSCell; evaluating the execution condition for the CHO while evaluating the execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and The execution condition for the conditional PSCell mobility is evaluated during the time period.

20. A non-transitory computer readable medium (CRM) having program code stored thereon implementing instructions, wherein the instructions, upon execution by at least one processor, perform operations comprising: Receive the configuration of conditional handover (CHO) to the target primary cell (PCell) from the network, The configuration for the CHO includes an execution condition for the CHO and an execution condition for conditional PSCell mobility to the first target primary and secondary cell PSCell, and The configuration for the CHO is related to the configuration for the conditional PSCell mobility and the configuration for establishing a secondary cell group SCG to the second target PSCell; evaluating the execution condition for the CHO while evaluating the execution condition for the conditional PSCell mobility; After the execution condition for the CHO is satisfied but the execution condition for the conditional PSCell mobility is not satisfied: performing the CHO to the target PCell; and delaying execution of the SCG establishment to the second target PSCell for a period of time; and The execution condition for the conditional PSCell mobility is evaluated during the time period.

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