Condition evaluation for cell switch

Abstract

The present disclosure is related to condition evaluation for cell switch in wireless communications. According to an embodiment of the present disclosure, a method performed by a user equipment (UE) configured to operate in a wireless communication system comprises: receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; receiving beam information for one or more beams in the set of beams for the candidate cell; evaluating the one or more event conditions based on the one or more beams related to the received beam information; and based on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.

Description

CONDITION EVALUATION FOR CELL SWITCH

[0001] The present disclosure is related to condition evaluation for cell switch in wireless communications.

[0002] 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

[0003] Work has started in International Telecommunication Union (ITU) and 3GPP to develop requirements and specifications for New Radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

[0004] The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shall be inherently forward compatible.

[0005] In communication systems, mobility procedures are often based on condition evaluation mechanisms. Condition evaluation refers to the process in which a user equipment (UE) monitors and evaluates one or more triggering conditions related to measurement results, cell quality, and / or configuration parameters. When the evaluation result indicates that the conditions are satisfied, the UE or the network initiates a mobility-related procedure.

[0006] An aspect of the present disclosure is to provide method and apparatus for condition evaluation for cell switch in a wireless communication system.

[0007] According to an embodiment of the present disclosure, a method performed by a user equipment (UE) configured to operate in a wireless communication system comprises: receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; receiving beam information for one or more beams in the set of beams for the candidate cell; evaluating the one or more event conditions based on the one or more beams related to the received beam information; and based on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0008] According to an embodiment of the present disclosure, a method performed by a network node configured to operate in a wireless communication system comprises: transmitting, to a user equipment (UE), a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; and transmitting, to the UE, beam information for one or more beams in the set of beams for the candidate cell, wherein the one or more beams related to the beam information is used for evaluating the one or more event conditions, and wherein the configuration of the candidate cell is applied for a cell switch execution to the candidate cell based on the one or more event conditions being fulfilled.

[0009] According to various embodiments, apparatuses to implement the above methods are provided.

[0010] The present disclosure may have various advantageous effects.

[0011] For example, according to various embodiments, the UE can start CLTM based on the beam shared with the network. This allows the UE to execute RACH-less CLTM with a beam shared with the network. Therefore, the network load can be reduced, as the network no longer needs to reserve resources for the entire beam set of all candidate cells for RACH-less CLTM.

[0012] Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

[0013] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0014] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0015] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0016] FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0017] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0018] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0019] FIG. 8 shows an example of a signalling procedure for LTM according to an embodiment of the present disclosure.

[0020] FIG. 9 shows an example of a method performed by a UE for condition evaluation for cell switch according to an embodiment of the present disclosure.

[0021] FIG. 10 shows an example of a signal flow between UE and network node for condition evaluation for cell switch according to an embodiment of the present disclosure.

[0022] FIG. 11 shows an example of a method for CLTM evaluation based on beam indication according to an embodiment of the present disclosure.

[0023] The following techniques, apparatuses, and systems may be applied to a variety of wireless multiple access systems. Examples of the multiple access systems include a Code Division Multiple Access (CDMA) system, a Frequency Division Multiple Access (FDMA) system, a Time Division Multiple Access (TDMA) system, an Orthogonal Frequency Division Multiple Access (OFDMA) system, a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and a Multi Carrier Frequency Division Multiple Access (MC-FDMA) system. CDMA may be embodied through radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be embodied through radio technology such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA may be embodied through radio technology 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 a part of a Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL). Evolution of 3GPP LTE includes LTE-Advanced (LTE-A), LTE-A Pro, and / or 5G New Radio (NR).

[0024] For convenience of description, implementations of the present disclosure are mainly described in regards 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, aspects of the present disclosure that are not limited to 3GPP based wireless communication system are applicable to other mobile communication systems.

[0025] For terms and technologies which are not specifically described among the terms of and technologies employed in the present disclosure, the wireless communication standard documents published before the present disclosure may be referenced.

[0026] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and / or B". For example, "A, B or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B and C".

[0027] In the present disclosure, slash ( / ) or comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Accordingly, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B or C".

[0028] In the present disclosure, "at least one of A and B" may mean "only A", "only B" or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted as same as "at least one of A and B".

[0029] 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".

[0030] Also, parentheses used in the present disclosure may mean "for example". In detail, when it is shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, "control information" in the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of "control information". In addition, even when shown as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0031] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0032] Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and / or connection (e.g., 5G) between devices.

[0033] Hereinafter, the present disclosure will be described in more detail with reference to drawings. 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 unless otherwise indicated.

[0034] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0035] The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.

[0036] Three main requirement categories for 5G include (1) a category of enhanced Mobile BroadBand (eMBB), (2) a category of massive Machine Type Communication (mMTC), and (3) a category of Ultra-Reliable and Low Latency Communications (URLLC).

[0037] Referring to FIG. 1, the communication system 1 includes wireless devices 100a to 100f, Base Stations (BSs) 200, and a network 300. Although FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system.

[0038] The BSs 200 and the network 300 may be implemented as wireless devices and a specific wireless device may operate as a BS / network node with respect to other wireless devices.

[0039] The wireless devices 100a to 100f represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication / radio / 5G devices. The wireless devices 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet-of-Things (IoT) device 100f, and an Artificial Intelligence (AI) device / server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. The vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter.

[0040] In the present disclosure, the wireless devices 100a to 100f may be called User Equipments (UEs). A 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 slate Personal Computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, 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 a financial device), a security device, a weather / environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field.

[0041] The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a beyond-5G network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., Vehicle-to-Vehicle (V2V) / Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0042] Wireless communication / connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and / or between wireless device 100a to 100f and BS 200 and / or between BSs 200. Herein, the wireless communication / connections may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or Device-to-Device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, Integrated Access and Backhaul (IAB)), etc. The wireless devices 100a to 100f and the BSs 200 / the wireless devices 100a to 100f may transmit / receive radio signals to / from each other through the wireless communication / connections 150a, 150b and 150c. For example, the wireless communication / connections 150a, 150b and 150c may transmit / receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, and resource mapping / de-mapping), and resource allocating processes, for transmitting / receiving radio signals, may be performed based on the various proposals of the present disclosure.

[0043] NR supports multiples numerologies (and / or multiple Sub-Carrier Spacings (SCS)) to support various 5G services. For example, if SCS is 15 kHz, wide area can be supported in traditional cellular bands, and if SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. If SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz can be supported to overcome phase noise.

[0044] The NR frequency band may be defined as two types of frequency range, i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2). The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter Wave (mmW).

[0045] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0046] As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).

[0047] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0048] Here, the radio communication technologies implemented in the wireless devices in the present disclosure may include NarrowBand IoT (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of 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-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in at least one of the 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-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names. For example, ZigBee technology may generate Personal Area Networks (PANs) associated with small / low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names.FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0049] In FIG. 2, The first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to use cases / services. For example, {the first wireless device 100 and the second wireless device 200} may correspond to at least one of {the wireless device 100a to 100f and the BS 200}, {the wireless device 100a to 100f and the wireless device 100a to 100f} and / or {the BS 200 and the BS 200} of FIG. 1. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / parts, and / or modules.

[0050] The first wireless device 100 may include at least one transceiver, such as a transceiver 106, at least one processing chip, such as a processing chip 101, and / or one or more antennas 108.

[0051] The processing chip 101 may include at least one processor, such a processor 102, and at least one memory, such as a memory 104. Additional and / or alternatively, the memory 104 may be placed outside of the processing chip 101.

[0052] The processor 102 may control the memory 104 and / or the transceiver 106 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 102 may process information within the memory 104 to generate first information / signals and then transmit radio signals including the first information / signals through the transceiver 106. The processor 102 may receive radio signals including second information / signals through the transceiver 106 and then store information obtained by processing the second information / signals in the memory 104.

[0053] The memory 104 may be operably connectable to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store a firmware and / or a software code 105 which implements codes, commands, and / or a set of commands that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more protocols. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more layers of the radio interface protocol.

[0054] Herein, the processor 102 and the memory 104 may be a part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each of the transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0055] The second wireless device 200 may include at least one transceiver, such as a transceiver 206, at least one processing chip, such as a processing chip 201, and / or one or more antennas 208.

[0056] The processing chip 201 may include at least one processor, such a processor 202, and at least one memory, such as a memory 204. Additional and / or alternatively, the memory 204 may be placed outside of the processing chip 201.

[0057] The processor 202 may control the memory 204 and / or the transceiver 206 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 202 may process information within the memory 204 to generate third information / signals and then transmit radio signals including the third information / signals through the transceiver 206. The processor 202 may receive radio signals including fourth information / signals through the transceiver 106 and then store information obtained by processing the fourth information / signals in the memory 204.

[0058] The memory 204 may be operably connectable to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store a firmware and / or a software code 205 which implements codes, commands, and / or a set of commands that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more protocols. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more layers of the radio interface protocol.

[0059] Herein, the processor 202 and the memory 204 may be a part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each of the transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be interchangeably used with RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0060] Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY) layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and 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 Unit (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure.

[0061] The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The 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 the one or more processors 102 and 202. For example, the one or more processors 102 and 202 may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a memory control processor.

[0062] The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104 and 204 may 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, register, cash memory, computer-readable storage medium, and / or combinations thereof. The one or more memories 104 and 204 may be located at the interior and / or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.

[0063] The one or more transceivers 106 and 206 may transmit user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.

[0064] The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208. Additionally and / or alternatively, the one or more transceivers 106 and 206 may include one or more antennas 108 and 208. The 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, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas 108 and 208 may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).

[0065] The one or more transceivers 106 and 206 may convert received user data, control information, radio signals / channels, etc., from RF band signals into baseband signals in order to process received user data, control information, radio signals / channels, etc., using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals / channels, etc., processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, the one or more transceivers 106 and 206 can up-convert OFDM baseband signals to OFDM signals by their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202 and transmit the up-converted OFDM signals at the carrier frequency. The one or more transceivers 106 and 206 may receive OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202.

[0066] Although not shown in FIG. 2, the wireless devices 100 and 200 may further include additional components. The additional components 140 may be variously configured according to types of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power unit / battery, an Input / Output (I / O) device (e.g., audio I / O port, video I / O port), a driving device, and a computing device. The additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies, such as a wired or wireless connection.

[0067] In the implementations of the present disclosure, a UE may operate as a transmitting device in Uplink (UL) and as a receiving device in Downlink (DL). In the implementations of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device 100 acts as the UE, and the second wireless device 200 acts as the BS. For example, the processor(s) 102 connected to, mounted on or launched in the first wireless device 100 may be adapted to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behavior according to an implementation of the present disclosure. The processor(s) 202 connected to, mounted on or launched in the second wireless device 200 may be adapted to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behavior according to an implementation of the present disclosure.

[0068] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0069] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0070] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0071] A UE 100 includes a processor 102, a 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 Identification Module (SIM) card 145, a speaker 146, and a microphone 147.

[0072] The processor 102 may be adapted to implement the descriptions, functions, procedures, 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, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include ASIC, other chipset, logic circuit and / or data processing device. The processor 102 may be an application processor. The processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator). An example of the processor 102 may be found in SNAPDRAGONTMseries of processors made by Qualcomm®, EXYNOSTMseries of processors made by Samsung®, A series of processors made by Apple®, HELIOTMseries of processors made by MediaTek®, ATOMTMseries of processors made by Intel®or a corresponding next generation processor.

[0073] The memory 104 is operatively coupled with the processor 102 and stores a variety of information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and / or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The modules can be stored in the memory 104 and executed by the processor 102. The memory 104 can be implemented within the processor 102 or external to the processor 102 in which case those can be communicatively coupled to the processor 102 via various means as is known in the art.

[0074] The transceiver 106 is operatively coupled with the processor 102, and transmits and / or receives a radio signal. 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 the one or more antennas 108 to transmit and / or receive a radio signal.

[0075] The power management module 141 manages power for the processor 102 and / or the transceiver 106. The battery 142 supplies power to the power management module 141.

[0076] The display 143 outputs results processed by the processor 102. The keypad 144 receives inputs to be used by the processor 102. The keypad 144 may be shown on the display 143.

[0077] The SIM card 145 is an　integrated circuit　that is intended to　securely store the　International Mobile Subscriber Identity　(IMSI) number and its related　key, which are used to identify and authenticate subscribers on　mobile telephony　devices (such as　mobile phones　and　computers). It is also possible to store contact information on many SIM cards.

[0078] The speaker 146 outputs sound-related results processed by the processor 102. The microphone 147 receives sound-related inputs to be used by the processor 102.

[0079] FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0080] In particular, FIG. 4 illustrates an example of a radio interface user plane protocol stack between a UE and a BS and FIG. 5 illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to a path through which control messages used to manage call by a UE and a network are transported. The user plane refers to a path through which data generated in an application layer, for example, voice data or Internet packet data are transported. Referring to FIG. 4, the user plane protocol stack may be divided into Layer 1 (L1, for example PHY layer) and Layer 2 (L2, for example MAC / RLC / PDCP layer). Referring to FIG. 5, the control plane protocol stack may be divided into Layer 1 (L1, for example PHY layer), Layer 2 (L2, for example MAC / RLC / PDCP layer), Layer 3 (L3, for example an RRC layer), and a non-access stratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as an access stratum (AS).

[0081] In the 3GPP LTE system, the Layer 2 is split into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 is split into the following sublayers: MAC, RLC, PDCP and SDAP. The PHY layer offers to the MAC sublayer transport channels, the MAC sublayer offers to the RLC sublayer logical channels, the RLC sublayer offers to the PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAP sublayer radio bearers. The SDAP sublayer offers to 5G core network quality of service (QoS) flows.

[0082] In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing / de-multiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in case of carrier aggregation (CA)); priority handling between UEs by means of dynamic scheduling; priority handling between logical channels of one UE by means of logical channel prioritization; padding. A single MAC entity may support multiple numerologies, transmission timings and cells. Mapping restrictions in logical channel prioritization control which numerology(ies), cell(s), and transmission timing(s) a logical channel can use.

[0083] Different kinds of data transfer services are offered by MAC. To accommodate different kinds of data transfer services, multiple types of logical channels are defined, i.e., each supporting transfer of a particular type of information. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used for the transfer of control plane information only, and traffic channels are used for the transfer of user plane information only. Broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, paging control channel (PCCH) is a downlink logical channel that transfers paging information, system information change notifications and indications of ongoing public warning service (PWS) broadcasts, common control channel (CCCH) is a logical channel for transmitting control information between UEs and network and used for UEs having no RRC connection with the network, and dedicated control channel (DCCH) is a point-to-point bi-directional logical channel that transmits dedicated control information between a UE and the network and used by UEs having an RRC connection. Dedicated traffic channel (DTCH) is a point-to-point logical channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink. In downlink, the following connections between logical channels and transport channels exist: BCCH can be mapped to broadcast channel (BCH); BCCH can be mapped to downlink shared channel (DL-SCH); PCCH can be mapped to 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 uplink, the following connections between logical channels and transport channels exist: CCCH can be mapped to uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.

[0084] The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM). The RLC configuration is per logical channel with no dependency on numerologies and / or transmission durations. In the 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include: transfer of upper layer PDUs; sequence numbering independent of the one in PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only).

[0085] 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); transfer of user data; reordering and duplicate detection; in-order delivery; PDCP PDU routing (in 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; duplication of PDCP PDUs 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; transfer of control plane data; reordering and duplicate detection; in-order delivery; duplication of PDCP PDUs and duplicate discard indication to lower layers.

[0086] In the 3GPP NR system, the main services and functions of SDAP include: mapping between a QoS flow and a data radio bearer; marking QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each individual PDU session.

[0087] 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 an RRC connection between the UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signalling 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 the reporting; detection of and recovery from radio link failure; NAS message transfer to / from NAS from / to UE.

[0088] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0089] The frame structure shown in FIG. 6 is purely exemplary and the number of subframes, the number of slots, and / or the number of symbols in a frame may be variously changed. In the 3GPP based wireless communication system, OFDM numerologies (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be differently configured between a plurality of cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for the cell, an (absolute time) duration of a time resource (e.g., a subframe, a slot, or a TTI) including the same number of symbols may be different among the aggregated cells. Herein, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).

[0090] Referring to FIG. 6, downlink and uplink transmissions are organized into frames. Each frame has Tf= 10ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5ms duration. Each half-frame consists of 5 subframes, where the duration Tsfper subframe is 1ms. Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols. The numerology is based on exponentially scalable subcarrier spacing βf = 2u*15 kHz.

[0091] Table 3 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the normal CP, according to the subcarrier spacing βf = 2u*15 kHz.

[0092] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0093] Table 4 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the extended CP, according to the subcarrier spacing βf = 2u*15 kHz.

[0094] uNslotsymbNframe,uslotNsubframe,uslot212404

[0095] A slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain. For each numerology (e.g., subcarrier spacing) and carrier, a resource grid ofNsize,ugrid,x*NRBscsubcarriers andNsubframe,usymbOFDM symbols is defined, starting at common resource block (CRB)Nstart,ugridindicated by higher-layer signalling (e.g., RRC signalling), whereNsize,ugrid,xis the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink.NRBscis the number of subcarriers per RB. In the 3GPP based wireless communication system,NRBscis 12 generally. There is one resource grid for a given antenna portp, subcarrier spacing configurationu, and transmission direction (DL or UL). The carrier bandwidthNsize,ugridfor subcarrier spacing configurationuis given by the higher-layer parameter (e.g., RRC parameter). Each element in the resource grid for the antenna portpand the subcarrier spacing configurationuis referred to as a resource element (RE) and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an indexkin the frequency domain and an indexlrepresenting a symbol location relative to a reference point in the time domain. In the 3GPP based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. As shown in FIG. 6, as SCS doubles, the slot length and symbol length are halved. For example, when SCS is 15kHz, the slot length is 1ms, which is the same as the subframe length. When SCS is 30kHz, the slot length is 0.5ms (=500us), and the symbol length is half of that when the SCS is 15kHz. When SCS is 60kHz, the slot length is 0.25ms (=250us), and the symbol length is half of that when the SCS is 30kHz. When SCS is 120kHz, the slot length is 0.125ms (=125us), and the symbol length is half of that when the SCS is 60kHz. When SCS is 240kHz, the slot length is 0.0625ms (=62.5us), and the symbol length is half of that when the SCS is 120kHz.

[0096] In the 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configurationu. The center of subcarrier 0 of CRB 0 for subcarrier spacing configurationucoincides with 'point A' which serves as a common reference point for resource block grids. In the 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and numbered from 0 toNsizeBWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRBin the bandwidth part i and the common resource block nCRBis as follows: nPRB= nCRB+NsizeBWP,i, whereNsizeBWP,iis the common resource block where bandwidth part starts relative to CRB 0. The BWP includes a plurality of consecutive RBs. A carrier may include a maximum of N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.

[0097] In the present disclosure, the term "cell" may refer to a geographic area to which one or more nodes provide a communication system, or refer to radio resources. A "cell" as a geographic area may be understood as coverage within which a node can provide service using a carrier and a "cell" as radio resources (e.g., time-frequency resources) is associated with bandwidth which is a frequency range configured by the carrier. The "cell" associated with the radio resources is defined by a combination of downlink resources and uplink resources, for example, a combination of a DL component carrier (CC) and a UL CC. The cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources. Since DL coverage, which is a range within which the node is capable of transmitting a valid signal, and UL coverage, which is a range within which the node is capable of receiving the valid signal from the UE, depends upon a carrier carrying the signal, the coverage of the node may be associated with coverage of the "cell" of radio resources used by the node. Accordingly, the term "cell" may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times.

[0098] In CA, two or more CCs are aggregated. A UE may simultaneously receive or transmit on one or multiple CCs depending on its capabilities. CA is supported for both contiguous and non-contiguous CCs. When CA is configured, the UE only has one RRC connection with the network. At RRC connection establishment / re-establishment / handover, one serving cell provides the NAS mobility information, and at RRC connection re-establishment / handover, one serving cell provides the security input. This cell is referred to as the primary cell (PCell). The PCell is a cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on UE capabilities, secondary cells (SCells) can be configured to form together with the PCell a set of serving cells. An SCell is a cell providing additional radio resources on top of special cell (SpCell). The configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of the master cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). An SpCell supports PUCCH transmission and contention-based random access, and is always activated. The MCG is a group of serving cells associated with a master node, comprised of the SpCell (PCell) and optionally one or more SCells. The SCG is the subset of serving cells associated with a secondary node, comprised of the PSCell and zero or more SCells, for a UE configured with DC. For a UE in RRC_CONNECTED not configured with CA / DC, there is only one serving cell comprised of the PCell. For a UE in RRC_CONNECTED configured with CA / DC, the term "serving cells" is used to denote the set of cells comprised of the SpCell(s) and all SCells. In DC, two MAC entities are configured in a UE: one for the MCG and one for the SCG.

[0099] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0100] Referring to FIG. 7, "RB" denotes a radio bearer, and "H" denotes a header. Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data. The MAC PDU is transmitted / received using radio resources through the PHY layer to / from an external device. The MAC PDU arrives to the PHY layer in the form of a transport block.

[0101] In the PHY layer, the uplink transport channels UL-SCH and random access channel (RACH) are mapped to their physical channels physical uplink shared channel (PUSCH) and physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to physical downlink shared channel (PDSCH), physical broadcast channel (PBCH) and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to physical uplink control channel (PUCCH), and downlink control information (DCI) is mapped to physical downlink control channel (PDCCH). A MAC PDU related to UL-SCH is transmitted by a UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCH is transmitted by a BS via a PDSCH based on a DL assignment.

[0102] Hereinafter, a description will be given of measurements on reference signals (RSs).

[0103] The UE may receive RSs through a plurality of beams from the serving cell and / or neighbor cell(s), where each of the RSs is received through a corresponding beam. There may be RSs of multiple types - for example, RSs of a first type (e.g., synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB)), and / or RSs of a second type (e.g., channel state information (CSI) - RS). That is, there may be multiple RS types comprising the first type and the second type, where RS of the first type may be SSB, and RS of the second type may be CSI-RS.

[0104] Each RS may be transmitted / received on a corresponding RS resource. For example, RS of the first type (e.g., SSB) may be transmitted / received on a resource related to the RS of the first type (e.g., SSB resource), and RS of the second type (e.g., CSI-RS) may be transmitted / received on a resource related to the RS of the second type (e.g., CSI-RS resource).

[0105] The UE may perform measurements on the RSs received through the plurality of beams from the serving cell and / or the neighbor cells, and obtain measurement results for the RSs. For example, the UE may transmit measurement report comprising the measurement results to network. For another example, the UE may perform a mobility to a target cell among the neighbor cell(s) based on the measurement results.

[0106] Further, in order to support beam management in both downlink and / or uplink transmissions, the concept of a transmission configuration indicator (TCI) has been introduced. A TCI generally represents an index associated with a specific transmission beam and / or a set of RSs, such as SSB or CSI-RS. The network may configure one or more TCI states for UE, where each TCI state corresponds to a beam identified by a RS resource.

[0107] The network may inform the UE of applicable TCI states through RRC signaling, while dynamic indication of a selected TCI state can be performed using MAC CE and / or DCI. By activating a particular TCI state, the network specifies which transmission beam is to be used for physical signals and / or data (e.g., DMRS, PTRS, PDSCH, PUSCH). Consequently, the TCI mechanism enables efficient beam correspondence between control signaling and data transmissions.

[0108] In the present disclosure, the terms "RS (e.g., SSB / CSI-RS)", "RS resource", "beam" and "TCI (or, TCI state)" can be used inter-changeably.

[0109] Hereinafter, a description will be given of mobility.

[0110] The mobility may comprise PCell change, PSCell change (or, secondary node (SN) change), and / or PSCell addition (or, SN addition).

[0111] In the present disclosure, the term "handover (HO)" may mean PCell change, or may be a broad concept that includes not only PCell change but also PSCell change / addition.

[0112] In the present disclosure, the terms "handover" and "mobility" can be used interchangeably.

[0113] In the present disclosure, the description regarding handover can also be applied to other mobility procedures (e.g., PSCell change / addition).

[0114] For example, there may be a mobility called L1 / L2-triggered mobility (LTM)(or, cell switch). LTM is a procedure in which a gNB receives L1 or L3 measurement report(s) from a UE, and on their basis the gNB may change UE serving cell by a cell switch command signalled via a MAC CE. The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through RRC signalling. Then the UE switches to the target configuration according to the cell switch command. The LTM procedure can be used to reduce the mobility latency.

[0115] When configured by the network, it is possible to activate TCI states of one or multiple cells that are different from the current serving cell. For instance, the TCI states of the LTM candidate cells can be activated in advance before any of those cells become the serving cell. This allows the UE to be DL synchronized with those cells, thereby facilitating a faster cell switch to one of those cells when cell switch is triggered. All the activated TCI states except those received in the cell switch command are deactivated upon LTM cell switch execution.

[0116] When configured by the network, it is possible to initiate UL TA acquisition (called early TA) procedure of one or multiple cells that are different from the current serving cells. If the cell has the same NTA as the current serving cells or NTA=0, early TA acquisition procedure is not required. The network may request the UE to perform early TA acquisition of a candidate cell before a cell switch. The early TA acquisition procedure is triggered by PDCCH order or realized through UE-based TA measurement as configured by RRC. In the former case, the gNB / gNB-DU to which the candidate cell belongs calculates the TA value and sends it to the gNB / gNB-DU to which the serving cell belongs via gNB-CU. The serving cell sends the TA value in the LTM cell switch command MAC CE when triggering LTM cell switch. In the latter case, the UE performs TA measurement for the candidate cells after being configured by RRC but the exact time the UE performs TA measurement is up to UE implementation. The UE applies the TA value measured by itself and performs RACH-less LTM upon receiving the cell switch command, if it does not include any valid TA value. The network may also send a TA value in the LTM cell switch command MAC CE without early TA acquisition.

[0117] When two TAG IDs are configured for an LTM candidate cell, the gNB-DU to which the LTM candidate cell belongs assigns the same TAG ID pointer value for each TRP to be used by the UEs.

[0118] Depending on the availability of a valid TA value, the UE performs either a RACH-less LTM or RACH-based LTM cell switch. If the valid TA value is provided in the cell switch command, the UE applies the TA value as instructed by the network. In the case where UE-based TA measurement is configured, but no valid TA value is provided in the cell switch command, the UE applies the valid TA value by itself if available. The UE performs RACH-less LTM cell switch upon receiving the cell switch command whenever a valid TA value is available. If no valid TA value is available, the UE performs RACH-based LTM cell switch.

[0119] Regardless of whether the UE is configured for UE-based TA measurement for a certain candidate cell, it will still follow the PDCCH order, which includes performing a random access procedure towards one or more candidate cells.

[0120] This also applies to the candidate cells for which the UE is capable of deriving TA values by itself. Additionally, regardless of whether the UE has already performed a random access procedure towards the candidate cells, it will still follow the UE-based measurement configuration if configured by the network.

[0121] For RACH-less LTM, the UE accesses the target cell using either a configured grant or a dynamic grant. The configured grant is provided in the LTM candidate configuration, and the UE selects the configured grant occasion associated with the beam indicated in the cell switch command. Upon initiation of LTM cell switch to the target cell, the UE starts to monitor PDCCH on the target cell for dynamic scheduling. Before RACH-less LTM procedure completion, the UE shall not trigger random access procedure if it does not have a valid PUCCH resource for triggered SRs.

[0122] The following principles apply to LTM:

[0123] - Security keys are maintained upon an LTM cell switch;

[0124] - Subsequent LTM is supported.

[0125] LTM supports both intra-gNB-DU and inter-gNB-DU mobility within the same gNB-CU. LTM supports both intra-frequency and inter-frequency mobility, including mobility to inter-frequency cell that is not a current serving cell.

[0126] LTM is supported only for licensed spectrum. The following scenarios are supported:

[0127] - PCell change in non-CA scenario and non-DC scenario;

[0128] - PCell and SCell(s) change in CA scenario;

[0129] - Dual connectivity scenario: including PCell and MCG SCell(s) change and intra-SN PSCell and SCG SCell(s) change without MN involvement. LTM for simultaneous PCell and PSCell change is not supported.

[0130] While the UE has stored LTM candidate configurations the UE can also execute any L3 handover except for DAPS handover. In the RRC message which the UE applies for any L3 handover (except DAPS), LTM candidate configurations can be added / modified / released by the target cell.

[0131] Cell switch command is conveyed in a MAC CE, which contains the necessary information to perform the LTM cell switch.

[0132] The overall procedure for LTM is shown in FIG. 8 below. Subsequent LTM is done by repeating the early synchronization, LTM cell switch execution, and LTM cell switch completion steps without the need to release, reconfigure or add other LTM candidate configurations after each LTM cell switch completion.　The general procedure over the air interface may also be applicable to SCG LTM.

[0133] FIG. 8 shows an example of a signalling procedure for LTM according to an embodiment of the present disclosure.

[0134] Referring to FIG. 8, in step S801, the UE may send aMeasurementReportmessage to the gNB. The gNB decides to configure LTM and initiates LTM preparation.

[0135] In step S803, the gNB may transmit anRRCReconfigurationmessage to the UE including the LTM candidate cell configurations of one or multiple candidate cells. TheRRCReconfigurationmessage comprise an LTM configuration / cell switch configuration (e.g.,LTM-Config) comprising a list of LTM candidate configurations (e.g.,ltm-CandidateToAddModList). That is, the network configures the UE with one or more LTM candidate configurations within theLTM-ConfigIE.

[0136] In NR-DC, the UE may receive two independentltm-Config,or anltm-Configassociated with the MCG and anltm-ConfigNRDC:

[0137] - anltm-Configassociated with the MCG that is included within anRRCReconfigurationmessage received via SRB1; and

[0138] - ether: i) anltm-Configassociated with the SCG that is included within anRRCReconfigurationmessage either received via SRB3, or, alternatively, embedded in anRRCReconfigurationmessage received via SRB1; or ii) anltm-ConfigNRDCthat is included within anRRCReconfigurationmessage received via SRB1.

[0139] The IEs in the LTM configuration / cell switch configuration (e.g.,LTM-Config) are shown in table 5:

[0140] LTM-Config-r18 ::= SEQUENCE {ltm-ReferenceConfiguration-r18 SetupRelease {ReferenceConfiguration-r18} OPTIONAL, -- Cond NR-DCltm-CandidateToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofLTM-Configs-r18)) OF LTM-CandidateId-r18 OPTIONAL, -- Need Nltm-CandidateToAddModList-r18 SEQUENCE (SIZE (1..maxNrofLTM-Configs-r18)) OF LTM-Candidate-r18 OPTIONAL, -- Need Nltm-ServingCellNoResetID-r18 INTEGER (1..maxNrofLTM-Configs-plus1-r18) OPTIONAL, -- Need Nltm-CSI-ResourceConfigToAddModList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ResourceConfigurations-r18)) OF LTM-CSI-ResourceConfig-r18OPTIONAL, -- Need Nltm-CSI-ResourceConfigToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ResourceConfigurations-r18)) OF LTM-CSI-ResourceConfigId-r18OPTIONAL, -- Need NattemptLTM-Switch-r18 ENUMERATED {true} OPTIONAL, -- Cond LTM-MCGltm-ServingCellUE-MeasuredTA-ID-r18 INTEGER (1..maxNrofLTM-Configs-plus1-r18) OPTIONAL, -- Need N...,[[ltm-ServingCellExecutionCondition-r19 SetupRelease {LTM-ExecutionConditionList-r19} OPTIONAL -- Need M]]}

[0141] In table 5

[0142] :-ltm-ReferenceConfiguration: LTM reference configuration used to provide a configuration that is common, within the same cell group, to all configured non-complete LTM candidate configurations;

[0143] -ltm-CandidateToAddModList: a list of LTM candidate configurations (e.g.,LTM-Candidate(s)) related to candidate SpCells to be added or modified for LTM;

[0144] -ltm-CandidateToReleaseList: a list of LTM candidate configuration IDs (e.g.,LTM-CandidateId(s)) related to candidate SpCells to be removed;

[0145] -ltm-ServingCellNoResetID: serving cell ID based on which the UE determines whether a L2 reset is needed or not upon an LTM cell switch procedure;

[0146] -ltm-ServingCellUE-MeasuredTA-ID: serving cell ID based on which the UE determines whether UE-based TA measurements are needed or not; and

[0147] -ltm-ServingCellExecutionCondition: This field can only be included within anltm-Configassociated with the MCG.

[0148] The IEs in the LTM configuration / cell switch configuration for NR-DC (e.g.,LTM-ConfigNRDC) are shown in table 6:

[0149] LTM-ConfigNRDC-r19 ::= SEQUENCE {ltm-ConfigurationSCG-r19 SetupRelease {LTM-Config-r18} OPTIONAL, -- Need M...}

[0150] In table 6

[0151] :-ltm-ConfigurationSCG: the network does not configure this field in anRRCReconfigurationmessage within anLTM-ConfigIE andConditionalReconfigurationIE. The network does not configure this field in anRRCReconfigurationmessage contained innr-SCGor transmitted on SRB3.

[0152] The LTM candidate configuration / candidate configuration / candidate cell configuration (e.g.,LTE-Candidate) may be related to a candidate (target) cell. The IEs in the LTM candidate configuration / candidate configuration / candidate cell configuration (e.g.,LTE-Candidate) are shown in table 7:

[0153] LTM-Candidate-r18 ::= SEQUENCE {ltm-CandidateId-r18 LTM-CandidateId-r18,ltm-CandidatePCI-r18 PhysCellId OPTIONAL, -- Need Mltm-SSB-Config-r18 LTM-SSB-Config-r18 OPTIONAL, -- Need Mltm-CandidateConfig-r18 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Need Mltm-ConfigComplete-r18 ENUMERATED {true} OPTIONAL, -- Need Rltm-EarlyUL-SyncConfig-r18 OCTET STRING (CONTAINING EarlyUL-SyncConfig-r18) OPTIONAL, -- Need Rltm-EarlyUL-SyncConfigSUL-r18 OCTET STRING (CONTAINING EarlyUL-SyncConfig-r18) OPTIONAL, -- Need Rltm-TCI-Info-r18 LTM-TCI-Info-r18 OPTIONAL, -- Need Mltm-NoResetID-r18 INTEGER (1..maxNrofLTM-Configs-plus1-r18) OPTIONAL, -- Need Mltm-UE-MeasuredTA-ID-r18 INTEGER (1..maxNrofLTM-Configs-plus1-r18) OPTIONAL, -- Need M...,[[ltm-ExecutionCondition-r19 SetupRelease {LTM-ExecutionConditionList-r19} OPTIONAL, -- Need Mltm-NZP-CSI-RS-ResourceToAddModList-r19 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceOPTIONAL, -- Need Nltm-NZP-CSI-RS-ResourceToReleaseList-r19 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceIdOPTIONAL, -- Need Nltm-NZP-CSI-RS-ResourceSetToAddModList-r19 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetOPTIONAL, -- Need Nltm-NZP-CSI-RS-ResourceSetToReleaseList-r19 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetIdOPTIONAL, -- Need Nltm-CSI-ReportConfigToAddModList-r19 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ReportConfigurations-r18)) OF LTM-CSI-ReportConfig-r18OPTIONAL, -- Need Nltm-CSI-ReportConfigToReleaseList-r19 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ReportConfigurations-r18)) OF LTM-CSI-ReportConfigId-r18OPTIONAL -- Need Nltm-CSI-IM-ResourceSetToAddModList-r19 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ReportConfigurations-r18)) OF CSI-IM-ResourceSetOPTIONAL, -- Need Nltm-CSI-IM-ResourceSetToReleaseList-r19 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ReportConfigurations-r18)) OF CSI-IM-ResourceSetIdOPTIONAL -- Need N]]}LTM-SSB-Config-r18 ::= SEQUENCE {ssb-Frequency-r18 ARFCN-ValueNR,subcarrierSpacing-r18 SubcarrierSpacing,ssb-Periodicity-r18 ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1} OPTIONAL, -- Need Rssb-PositionsInBurst-r18 CHOICE {shortBitmap BIT STRING (SIZE (4)),mediumBitmap BIT STRING (SIZE (8)),longBitmap BIT STRING (SIZE (64))} OPTIONAL, -- Need Rss-PBCH-BlockPower-r18 INTEGER (-60..50) OPTIONAL, -- Need R...}

[0154] In table 7:

[0155] -ltm-CandidateId: an ID used to identify an LTM candidate configuration;

[0156] -ltm-CandidateConfig: a configuration of the related candidate cell for LTM, comprisingRRCReconfigurationmessage to be applied when LTM / cell switch is executed;

[0157] -ltm-ConfigComplete: if included in theLTM-Candidate, the UE may consider that the relatedltm-CandidateConfigis a complete configuration of the related candidate cell for LTM;

[0158] -ltm-NoResetID: if this field is equal toltm-ServingCellNoResetID, UE may determine that L2 reset is needed upon an LTM cell switch procedure;

[0159] -ltm-UE-MeasuredTA-ID: if this field is equal toltm-ServingCellNoResetID, UE may determine that the UE-based TA measurements are needed;

[0160] -ltmExecutionCondition: this field can only be included within anltm-Configassociated with the MCG;

[0161] -ltm-NZP-CSI-RS-ResourceToAddModList: pool of CSI-RS resources sets which can be referred to inNZP-CSI-RS-ResourceSet;

[0162] -ltm-NZP-CSI-RS-ResourceSetToAddModList: pool of CSI-RS resource set which can be referred to inLTM-CSI-RS-ResourceConfig; and

[0163] -ltm-CSI-ReportConfigToAddModList: configured CSI report settings for LTM.

[0164] The IELTM-ExecutionConditionListmay be used to configure LTM cell switch conditions, and comprises IEs as shown in table 8:

[0165] LTM-ExecutionConditionList-r19 ::= SEQUENCE (SIZE (1..maxNrofLTM-Configs-r18)) OF LTM-ExecutionCondition-r19LTM-ExecutionCondition-r19 ::= SEQUENCE {ltm-CandidateId-r19 LTM-CandidateId-r18,executionCondition-r19 CHOICE {l1-Conditions-r19 LTM-CSI-ReportConfigId-r18,l3-Conditions-r19 SEQUENCE (SIZE (1..2)) OF MeasId} OPTIONAL, -- Need R...}

[0166] The IELTM-CSI-ReportConfigIdis used to identify anLTM-CSI-ReportConfig. The IELTM-CSI-ReportConfigis used to configure gNB-scheduled measurement report on the cell in which theLTM-CSI-ReportConfigis included when the fieldltm-ReportConfigTypeis configured asperiodic / semi-persistentOnPUCCH / semi-persistentOnPUSCH / aperiodic.

[0167] The IELTM-CSI-ReportConfigis also used to configure event-triggered measurement report when the fieldltm-ReportConfigTypeis configured aseventTriggered, within which the criteria for triggering measurement report by MAC CE.

[0168] - Event LTM2: Beam of SpCell becomes worse than absolute threshold;

[0169] - Event LTM3: Beam of candidate cell becomes amount of offset better than the beam of SpCell;

[0170] - Event LTM4: Beam of candidate cell becomes better than absolute threshold;

[0171] - Event LTM5: Beam of SpCell becomes worse than absolute threshold1 AND Beam of candidate cell becomes better than another absolute threshold2.

[0172] The IEs in theLTM-CSI-ReportConfigare shown in table 9:

[0173] LTM-CSI-ReportConfig-r18 ::= SEQUENCE {ltm-CSI-ReportConfigId-r18 LTM-CSI-ReportConfigId-r18,ltm-ResourcesForChannelMeasurement-r18 LTM-CSI-ResourceConfigId-r18,ltm-ReportConfigType-r18 CHOICE {periodic-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,pucch-CSI-ResourceList-r18 SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource},semiPersistentOnPUCCH-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,pucch-CSI-ResourceList-r18 SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource},semiPersistentOnPUSCH-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,reportSlotOffsetList-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-2-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-1-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128),p0alpha P0-PUSCH-AlphaSetId},aperiodic-r18 SEQUENCE {reportSlotOffsetList-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-2-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-1-r18 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER (0..128)},...,eventTriggered-r19 SEQUENCE {eventId-r19 CHOICE {eventLTM2-r19 SEQUENCE {ltm2-Threshold-r19 MeasTriggerQuantity,hysteresis-r19 Hysteresis,timeToTrigger-r19 TimeToTrigger,...},eventLTM3-r19 SEQUENCE {ltm3-Offset-r19 MeasTriggerQuantityOffset,hysteresis-r19 Hysteresis,timeToTrigger-r19 TimeToTrigger,...},eventLTM4-r19 SEQUENCE {ltm4-Threshold-r19 MeasTriggerQuantity,hysteresis-r19 Hysteresis,timeToTrigger-r19 TimeToTrigger,...},eventLTM5-r19 SEQUENCE {ltm5-Threshold1-r19 MeasTriggerQuantity,ltm5-Threshold2-r19 MeasTriggerQuantity,hysteresis-r19 Hysteresis,timeToTrigger-r19 TimeToTrigger,...},...},ltm-CandidateReportConfigList-r19 SEQUENCE (SIZE (1.. maxNrofLTM-Configs-r18)) OF LTM-CandidateReportConfig-r19OPTIONAL, -- Need Rltm-EventTriggeredReportContent-r19 LTM-EventTriggeredReportContent-r19,reportOnLeave-r19 ENUMERATED {enabled} OPTIONAL, -- Need Rltm-EventTriggeredPeriodicReport-r19 LTM-EventTriggeredPeriodicReport-r19 OPTIONAL, -- Need S...}},ltm-ReportContent-r18 LTM-ReportContent-r18,...,[[ltm-ReportContent-v19xy LTM-ReportContent-v19xy OPTIONAL, -- Need Rltm-ResourceForInterferenceMeasurements-r19 LTM-CSI-ResourceConfigId-r18 OPTIONAL, -- Need R]]}LTM-ReportContent-r18 ::= SEQUENCE {nrOfReportedCells-r18 ENUMERATED {n1,n2,n3,n4},nrOfReportedRS-PerCell-r18 ENUMERATED {n1,n2,n3,n4},spCellInclusion-r18 ENUMERATED {true} OPTIONAL -- Need R}LTM-EventTriggeredPeriodicReport-r19 ::= SEQUENCE {reportInterval-r19 ReportInterval-r19,reportAmount-r19 ENUMERATED {r2, r4, r8, r16, r32, r64, infinity, spare1},...}LTM-EventTriggeredReportContent-r19 ::= SEQUENCE {maxNumberOfReportedBeams-r19 INTEGER (1..16),allowReportAnyBeam-r19 ENUMERATED {enabled} OPTIONAL, -- Need RreportCurrentBeam-r19 ENUMERATED {enabled} OPTIONAL, -- Need R...}LTM-CandidateReportConfig-r19 ::= SEQUENCE {ltm-CandidateReportConfigId-r19 LTM-CandidateId-r18,candidateSpecificOffset-r19 MeasTriggerQuantityOffset OPTIONAL, -- Cond notEventLTM2...}LTM-ReportContent-v19xy ::= SEQUENCE {reportQuantity-r19 ENUMERATED {cri-RSRP, ssb-index-RSRP, cri-RI-PMI-CQI, value1},...}

[0174] In table 9:

[0175] -eventId: Type of LTM event for triggering event-triggered measurement report;

[0176] -hysteresis: Hysteresis when evaluating the entering / leaving conditions for an LTM event;

[0177] -ltm-CandidateReportConfigList: List of report configurations for LTM candidate IDs;

[0178] -ltm-EventTriggeredPeriodicReport: This field indicates when an LTM event is triggered, whether the event-triggered measurement report is sent periodically. When the field is absent, the event-triggered measurement report is sent once;

[0179] -ltm-ReportConfigType: This field specifies how the UE shall report the measurement results for LTM either by gNB-scheduled measurement report or by event-triggered measurement report by MAC CE. The UE shall ignore this field is LTM-CSI-ReportConfig is configured with a LTM-Candidate IE.

[0180] -ltm-ReportContent: This field defines the content of the LTM L1 measurement report. The UE shall ignore this field is LTM-CSI-ReportConfig is configured with a LTM-Candidate IE;

[0181] -ltm-ResourcesForChannelMeasurement: This field indicates the index of SSB or CSI-RS in the field LTM-CSI-ResourceConfig;

[0182] -ltm2-Threshold, ltm4-Threshold, ltm5-Threshold1, ltm5-Threshold2: Thresholds defined in the entering / leaving conditions for different LTM events;

[0183] -ltm3-Offset: Offset for the entering / leaving condition for event LTM3. The actual value is field value * 0.5 dB;

[0184] -reportOnLeave: Indicates whether the event-triggered measurement report by MAC CE shall be triggered when leaving condition is satisfied;

[0185] -reportSlotConfig: Periodicity and slot offset;

[0186] -reportSlotOffsetList, reportSlotOffsetListDCI-0-1, reportSlotOffsetListDCI-0-2: Timing offset Y for semi persistent reporting using PUSCH and aperiodic reporting;

[0187] -nrOfReportedCells: This field defines how many cells are reported within a single L1 measurement report instance;

[0188] -nrOfReportedRS-PerCell: This field defines how many RSs per cell are reported within a single L1 measurement report instance;

[0189] -spCellInclusion: This field indicates whether the UE shall include a L1 measurement report associated to the current SpCell. This field can only be configured if the current SpCell is configured as an SpCell of an LTM candidate configuration and the LTM-CSI-ResourceConfig IE associated to the LTM-CSI-ReportConfig IE includes resources for the current SpCell;

[0190] -reportQuantity: Indicates the report quantity for the CSI report;

[0191] -allowReportAnyBeam: Indicates whether the UE can report the measurement results for the beams not satisfying the conditions of the events at least for the time durating configured by timeToTrigger;

[0192] -maxNumberOfReportedBeams: This field defines maximum number of beams whose measurements can be reported in the event-triggered measurement report by MAC CE;

[0193] -reportCurrentBeam: Indicates whether the UE is required to report the measurement result of the current beam;

[0194] -reportInterval: This field defines the periodicity of the event-triggered periodic measurement report;

[0195] -reportAmount: Number of measurement reports needs to be transmitted after the event is triggered. Value 'r2' means the report is sent twice, 'r3' means the report is sent three times, and so on;

[0196] -ltm-CandidateReportConfigId: LTM candidate cell ID for which the UE is required to measure reference signal and perform LTM event evaluation;

[0197] -candidateSpecificOffset, candidateSpecificOffsetS: Offset for event condition that is applicable for all the reference signals belonging to the candidate cell with the candidate cell ID ltm-CandidateReportConfigId. If the field is absent, the value '0dB' is applied.

[0198] In step S805, the UE may store the LTM configuration / cell switch configuration comprising the list of LTM candidate configurations, and transmit anRRCReconfigurationCompletemessage to the gNB.

[0199] In case the UE receives two independentltm-Config,or anltm-Configassociated with the MCG and anltm-ConfigNRDC:

[0200] - the UE maintains independently the twoltm-Config,or theltm-Configand theltm-ConfigNRDC;

[0201] - the UE maintains two independentVarLTM-ServingCellNoResetID, one associated with eachltm-Config,or one associated with theltm-Configand one associated with theltm-ConfigNRDC;

[0202] - the UE maintains two independentVarLTM-ServingCellUE-MeasuredTA-ID, one associated with eachltm-Config,or one associated with theltm-Configand one associated with theltm-ConfigNRDC;

[0203] - the UE independently performs all the LTM configuration and / or execution procedures for eachltm-Config,or anltm-Configand anltm-ConfigNRDC,and the associatedVarLTM-ServingCellNoResetID, andVarLTM-ServingCellUE-MeasuredTA-IDunless explicitly stated otherwise.

[0204] The UE shall perform the following actions based on the receivedLTM-ConfigIE:

[0205] 1> if the receivedLTM-Configincludesltm-ServingCellNoResetID:

[0206] 2> if the currentVarLTM-ServingCellNoResetIDincludes anltm-ServingCellNoResetID:

[0207] 3> replace theltm-ServingCellNoResetIDvalue withinVarLTM-ServingCellNoResetIDwith the receivedltm-ServingCellNoResetID;

[0208] 2> else:

[0209] 3> store the receivedltm-ServingCellNoResetIDinVarLTM-ServingCellNoResetID;

[0210] 1> if the receivedLTM-Configincludesltm-ServingCellUE-MeasuredTA-ID:

[0211] 2> if the currentVarLTM-ServingCellUE-MeasuredTA-IDincludes anltm-ServingCellUE-MeasuredTA-ID:

[0212] 3> replace theltm-ServingCellUE-MeasuredTA-IDvalue withinVarLTM-ServingCellUE-MeasuredTA-IDwith the receivedltm-ServingCellUE-MeasuredTA-ID;

[0213] 2> else:

[0214] 3> store the receivedltm-ServingCellUE-MeasuredTA-IDinVarLTM-ServingCellUE-MeasuredTA-ID;

[0215] 1> if the receivedLTM-Configincludes theltm-CandidateToReleaseList:

[0216] 2> perform the LTM candidate configuration release;

[0217] 1> if the receivedLTM-Configincludes theltm-CandidateToAddModList:

[0218] 2> perform the LTM candidate configuration addition or modification;

[0219] 1> reconfigure the UE according to all other fields of the receivedLTM-ConfigIE.

[0220] 1> if the receivedLTM-Configincludes the fieldltm-ServingCellExecutionCondition:

[0221] 2> if LTM conditions evaluation was done based on L1 measurements:

[0222] 3> inform lower layers to stop the LTM conditions evaluation, if any, for all the LTM candidate configurations;

[0223] 2> else:

[0224] 3> stop the LTM conditions evaluation, if any, for all the LTM candidate configurations;

[0225] 2> if the fieldl3-Conditionsis included withinltm-ServingCellExecutionCondition:

[0226] 3> perform the LTM cell switch conditions evaluation based on L3 measurements according to the receivedltm-ServingCellExecutionCondition;

[0227] 2> else if the fieldl1-Conditionsis included withinltm-ServingCellExecutionCondition:

[0228] 3> inform lower layers to initiate the LTM cell switch conditions evaluation based on L1 measurements according to the received fieldltm-ServingCellExecutionCondition.

[0229] To perform the LTM candidate configuration release, The UE shall:

[0230] 1> for eachltm-CandidateIdvalue included in theltm-CandidateToReleaseListthat is part of the current UE configuration:

[0231] 2> remove the correspondingLTM-Candidate.

[0232] To perform the LTM candidate configuration addition or modification, the UE shall:

[0233] 1> for eachltm-CandidateIdvalueincluded in theltm-CandidateToAddModList:

[0234] 2> if the current UE configuration contains anLTM-Candidatewith theltm-CandidateIdvalue:

[0235] 3> reconfigure the correspondingLTM-Candidatein accordance with the receivedLTM-Candidate;

[0236] 2> else:

[0237] 3> add the receivedLTM-Candidate;

[0238] 2> if theLTM-Candidatewith the receivedltm-CandidateIdvalue includesltm-UE-MeasuredTA-ID:

[0239] 3> if the value ofltm-UE-MeasuredTA-IDis equal to the value ofltm-ServingCellUE-MeasuredTA-IDwithinVarLTM-ServingCellUE-MeasuredTA-ID:

[0240] 4> inform lower layers that the UE is configured with UE-based TA measurements for thisLTM-Candidate;

[0241] 3> else:

[0242] 4> inform lower layers that the UE is not configured with UE-based TA measurements for thisLTM-Candidate;

[0243] 2> else:

[0244] 3> inform lower layers that the UE is not configured with UE-based TA measurements for thisLTM-Candidate.

[0245] In step S807, the UE may perform DL / UL synchronization with the LTM candidate cell(s) before receiving the cell switch command.

[0246] In some implementations, the UE may perform DL synchronization with the LTM candidate cell(s) before receiving the cell switch command. The UE may activate and deactivate TCI states of LTM candidate cell(s), as triggered by the gNB.

[0247] In some implementations, the UE may perform UL synchronization with LTM candidate cell(s) before receiving the cell switch command, by using UE-based timing advance (TA) measurement, if configured, and / or by transmitting a preamble towards the candidate cell, as triggered by the gNB. When UE-based TA measurement is configured, UE acquires the TA value(s) of the candidate cell(s) by measurement. UE performs early TA acquisition with the candidate cell(s) as requested by the network before receiving the cell switch command. This is done via CFRA triggered by a PDCCH order from the source cell, following which the UE sends preamble towards the indicated candidate cell. In order to minimize the data interruption of the source cell due to CFRA towards the candidate cell(s), the UE does not receive random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell is indicated in the cell switch command. The UE does not maintain the TA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[0248] In step S809, the UE may perform L1 measurements on the configured LTM candidate cell(s) and transmit L1 measurement reports to the gNB. L1 measurement should be performed as long as RRC reconfiguration (step S803) is applicable. The UE can also perform L3 measurement reporting to the gNB, including beam level measurement results on cell(s) which are configured as LTM candidate cell(s) according to the received network configuration.

[0249] In step S811, the gNB may decide to execute cell switch to a target cell and transmit an LTM cell switch command MAC CE triggering cell switch by including a target configuration ID which indicates the index of the candidate configuration of the target cell (e.g.,ltm-CandidateId), a beam indicated with a TCI state or beams indicated with DL and UL TCI states, and a timing advance command for the target cell, if available. The UE switches to the target cell and applies the candidate configuration (e.g.,ltm-CandidateConfig) indicated by the target configuration ID.

[0250] Upon the indication by lower layers that an LTM cell switch procedure is triggered, or upon performing LTM cell switch following cell selection performed while timer T311 was running, or upon the fulfilment of LTM cell switch execution conditions, the UE shall perform the LTM cell switch execution procedure according to the followings:

[0251] 1> if this procedure is triggered due to fulfilment of LTM cell switch execution conditions:

[0252] 2> if more than one LTM candidate configuration has triggered this procedure:

[0253] 3> select one of the LTM candidate configurations as the selected cell for the LTM cell switch execution execution;

[0254] 2> if UE is performing an LTM conditions evaluation based on L1 measurements:

[0255] 3> inform lower layers to stop the LTM conditions evaluation, if any, for all the LTM candidate configurations;

[0256] 2> else:

[0257] 3> stop the LTM conditions evaluation, if any, for all the LTM candidate configurations;

[0258] 1> if the LTM cell switch is triggered on the MCG; or

[0259] 1> if the LTM cell switch is triggered on the SCG and the LTM candidate configuration to be applied is configured vialtm-ConfigNRDC:

[0260] 2> release / clear all current dedicated and common radio configurations which have neither been received via SRB1 withinmrdc-SecondaryCellGroup, nor via SRB3 except for the following:

[0261] - the radio bearer configuration (configured viaRadioBearerConfig)

[0262] - thelogicalChannelIdentityandlogicalChannelIdentityExtof RLC bearers configured inRLC-BearerConfigand the associated RLC entities, their state variables, buffers, and timers, except for triggering the associated RLC entities to reset the variable RETX_COUNT its initial value;

[0263] - thebh-LogicalChannelIdentityof BH RLC channels configured inBH-RLC-ChannelConfigand the associated RLC entities, their state variables, buffers, and timers, except for triggering the associated RLC entities to reset the variable RETX_COUNT its initial value;

[0264] - theltm-Configandltm-ConfigNRDC(if configured);

[0265] - the MCG C-RNTI;

[0266] - the AS security configurations associated with the master key;

[0267] - the logged measurement configuration;

[0268] 1> if the LTM cell switch is triggered on the SCG:

[0269] 2> release / clear all current dedicated and common radio configurations which have been received either via SRB1 withinmrdc-SecondaryCellGroup, or via SRB3 except for the following:

[0270] - the radio bearer configuration (configured viaRadioBearerConfigIE)

[0271] - thelogicalChannelIdentityandlogicalChannelIdentityExtof RLC bearers configured inRLC-BearerConfigand the associated RLC entities, their state variables, buffers, and timers, except for triggering the associated RLC entities to reset the variable RETX_COUNT its initial value;

[0272] - thebh-LogicalChannelIdentityof BH RLC channels configured inBH-RLC-ChannelConfigand the associated RLC entities, their state variables, buffers, and timers, except for triggering the associated RLC entities to reset the variable RETX_COUNT its initial value;

[0273] - the UE variablesVarLTM-ServingCellNoResetIDandVarLTM-ServingCellUE-MeasuredTA-ID;

[0274] - theltm-Config;

[0275] - the AS security configurations associated with the secondary key;

[0276] 1> for each SRB / DRB in the current UE configuration:

[0277] 2> if the LTM cell switch is triggered on the MCG and the SRB / DRB using the master key; or

[0278] 2> if the LTM cell switch is triggered on the SCG and the SRB / DRB using the secondary key:

[0279] 3> keep the associated PDCP and SDAP entities, their state variables, buffers and timers;

[0280] 3> release all fields related to the SRB / DRB configuration except forsrb-Identityanddrb-Identity;

[0281] For all radio bearers and RLC bearers included in the LTM candidate configuration to be applied at an LTM cell switch execution (i.e., as derived from the LTM reference configuration and the LTM candidate configuration), even if those radio bearers and RLC bearers were configured before the LTM cell switch execution, the network includes fields as specified for the initial setup of radio bearers and RLC bearers and sets the values previously stored by the UE for the fields that cannot be modified according to presence conditions or field descriptions.

[0282] 1> apply the default L1 parameter values as specified in corresponding physical layer specifications except for the parameters for which values are provided in SIB1;

[0283] 1> use the default values for timers T310, T311 and constants N310, N311 associated with the cell group(s) for which theRRCReconfigurationmessage is applied due to the triggered LTM cell switch procedure, where T310, N310, and N311 are for both MCG and SCG, and T311 is only for the MCG;

[0284] 1> apply the default MAC Cell Group configuration for the cell group(s) for which theRRCReconfigurationmessage is applied due to the triggered LTM cell switch procedure;

[0285] 1> for eachsrb-Identityin the current UE configuration:

[0286] 2> apply the default SRB configuration for the corresponding SRB;

[0287] 1> else if theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell does not contain the fieldltm-NoResetIDand if the UE does not have any value stored ofltm-ServingCellNoResetIDwithinVarLTM-ServingCellNoResetID; or

[0288] 1> if the value of fieldltm-NoResetIDcontained within theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell is not equal to the value ofltm-ServingCellNoResetIDwithinVarLTM-ServingCellNoResetID:

[0289] 2> for eachlogicalChannelIdentityandlogicalChannelIdentityExtthat is part of the current UE configuration for the cell group for which the LTM cell switch procedure is triggered:

[0290] 3> ifservedRadioBeareris set todrb-Identity:

[0291] 4> after the end of this procedure, re-establish the corresponding RLC entity, after applying the LTM configuration inltm-CandidateConfigwithin theLTM-CandidateIE inltm-Configorltm-ConfigNRDC;

[0292] 2> for eachbh-LogicalChannelIdentitythat is part of the current UE configuration for the cell group for which the LTM cell switch procedure is triggered:

[0293] 3> after the end of this procedure, re-establish the corresponding RLC entity, after applying the LTM configuration inltm-CandidateConfigwithin the LTM-Candidate IE inltm-Configorltm-ConfigNRDC;

[0294] 2> for eachdrb-Identityvalue that is part of the current UE configuration:

[0295] 3> if this DRB is an AM DRB:

[0296] 4> after the end of this procedure, trigger the PDCP entity of this DRB to perform data recovery, after applying the LTM configuration inltm-CandidateConfigwithinLTM-CandidateIE inltm-Configorltm-ConfigNRDC;

[0297] 2> if the value of fieldltm-NoResetIDcontained within theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell is not equal to the value ofltm-ServingCellNoResetIDwithinVarLTM-ServingCellNoResetID:

[0298] 3> replace the value ofltm-ServingCellNoResetIDinVarLTM-ServingCellNoResetIDwith the value ofltm-NoResetIDin theLTM-Candidateinltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell;

[0299] 1> if theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell contains the fieldltm-UE-MeasuredTA-ID:

[0300] 2> if the value ofltm-UE-MeasuredTA-IDis not equal to the value ofltm-ServingCellUE-MeasuredTA-IDwithinVarLTM-ServingCellUE-MeasuredTA-ID:

[0301] 3> replace the value ofltm-ServingCellUE-MeasuredTA-IDinVarLTM-ServingCellUE-MeasuredTA-IDwith the value received withinltm-UE-MeasuredTA-ID;

[0302] 3> for eachLTM-CandidateIE inltm-Configorltm-ConfigNRDCthat includes theLTM-CandidateIE indicated by lower layers or for the selected cell:

[0303] 4> if the value ofltm-UE-MeasuredTA-IDwithinLTM-CandidateIE is equal to the value ofltm-ServingCellUE-MeasuredTA-IDwithinVarLTM-ServingCellUE-MeasuredTA-ID:

[0304] 5> inform lower layers that the UE is configured with UE-based TA measurements for theLTM-Candidate;

[0305] 4> else:

[0306] 5> inform lower layers that the UE is not configured with UE-based TA measurements for theLTM-Candidate;

[0307] The UE is not expected to perform UE-based TA measurements for an SpCell.

[0308] 1> else if theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell does not contain the fieldltm-UE-MeasuredTA-ID:

[0309] 2> inform lower layers that the UE is not configured with UE-based TA measurements for theLTM-Candidate.

[0310] 1> ifltm-ConfigCompleteis not included within theLTM-CandidateIE inltm-Configorltm-ConfigNRDCindicated by lower layers or for the selected cell:

[0311] 2> considerltm-ReferenceConfigurationinltm-Configorltm-ConfigNRDC, associated with the cell group for which the LTM cell switch procedure is triggered, to be the current UE configuration for the fields and configurations to be released by the actions above in this procedure;

[0312] 2> ifmeasConfigis included withinltm-ReferenceConfigurationinltm-Configorltm-ConfigNRDC;

[0313] 3> perform the measurement configuration procedure by considering themeasConfigwithinltm-ReferenceConfigurationinltm-Configorltm-ConfigNRDCas the receivedmeasConfig:

[0314] When the UE considers the reference configuration to be the current UE configuration, the UE should store fields and configurations that are part of the reference configuration but should not execute any actions or procedures triggered by the reception of anRRCReconfigurationmessage, unless specified otherwise in this clause.

[0315] 1> if the LTM cell switch is triggered by an indication from lower layers:

[0316] 2> apply theRRCReconfigurationmessage inltm-CandidateConfigwithinLTM-CandidateIE inltm-Configorltm-ConfigNRDCidentified by the LTM candidate configuration identity received from lower layers;

[0317] 1> else (LTM cell switch triggered upon cell selection performed while timer T311 was running or upon the fulfilment of LTM cell switch execution conditions):

[0318] 2> apply theRRCReconfigurationmessage inltm-CandidateConfigwithinLTM-CandidateIE inltm-Configrelated to the LTM candidate configuration identity for the selected cell;

[0319] 1> release the radio bearer(s) and the logical channel(s) that were part of the UE configuration before of this LTM cell switch procedure but not part of the LTM candidate configuration either indicated by lower layers or for the selected cell, or the LTM reference configuration (in case the LTM candidate configuration does not includeltm-ConfigComplete).

[0320] 1> ifltm-ExecutionConditionis configured within theLTM-CandidateIE for the selected LTM candidate configuration:

[0321] 2> if the fieldl3-Conditionsis included withinltm-ExecutionCondition:

[0322] 3> perform the LTM cell switch conditions evaluation based on L3 measurements according to the receivedltm-ExecutionConditiononce this procedure is completed;

[0323] 2> else if the fieldl1-Conditionsis included withinltm-ExecutionCondition:

[0324] 3> inform lower layers to initiate the LTM cell switch conditions evaluation based on L1 measurements according to the received fieldltm-ExecutionConditiononce this procedure is completed.

[0325] Whenltm-ConfigCompleteis not included for an LTM candidate configuration, before an LTM cell switch is triggered a UE implementation may generate and store anRRCReconfigurationmessage by applying the received LTM candidate configuration on top of the LTM reference configuration, and the storedRRCReconfigurationmessage is applied when the LTM cell switch is triggered. It is up to the UE to ensure that the RRC reconfiguration applied at the time of LTM cell switch is in accordance with the latest LTM reference configuration and LTM candidate configuration.

[0326] The UE shall perform the LTM cell switch conditions evaluation based on L3 measurements according to the followings:

[0327] 1> for each entry within theLTM-ExecutionConditionListwhich has thel3-Conditionsconfigured:

[0328] 2> for eachmeasIdindicated in thel3-Conditionswhich has a correspondingmeasIdin theVarMeasConfigassociated with the MCGmeasConfig:

[0329] 3> if thecondEventIdrelated to thismeasIdis associated withcondEventA3orcondEventA5, and if the entry condition(s) applicable for this event is fulfilled for theltm-CandidatePCIandltm-SSB-Configrelated to theltm-CandidateIdfor all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event:

[0330] 4> consider the event associated to thismeasIdto be fulfilled for theltm-CandidateIdassociated to themeasId;

[0331] That is, according to various embodiments, the mobility execution condition may be fulfilled (or, satisfied / met) when an entry condition (or, entering condition) for the mobility execution condition is fulfilled for at least a time-to-trigger (TTT) for the mobility execution condition. The entry condition / entering condition may mean that the mobility execution condition is initially met. Once the entry condition is met, the mobility execution condition will be considered to be met if the entry condition is met for time duration TTT continuously.

[0332] 3> if thecondEventIdrelated to thismeasIdis associated withcondEventA3orcondEventA5, and if the leaving condition(s) applicable for this event is fulfilled for theltm-CandidatePCIandltm-SSB-Configrelated to theltm-CandidateIdfor all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event:

[0333] 4> consider the event associated to thismeasIdto be not fulfilled for theltm-CandidateIdassociated to themeasId;

[0334] 1> if event(s) associated with allmeasId(s)for anltm-CandidateIdwithin theLTM-ExecutionConditionListIE are fulfilled:

[0335] 2> perform the LTM cell switch procedure for the LTM candidate configuration associated to theltm-CandidateId.

[0336] In step S813, the UE may perform the random access procedure towards the target cell, if UE does not have valid TA of the target cell. If UE has valid TA of the target cell, the UE may skip the random access procedure towards the target cell (i.e., RACH-less LTM).

[0337] When performing the random access procedure / RACH procedure: i) the UE may perform a contention-free random access (CFRA) if CFRA resources / dedicated RACH configuration is available to the UE; and ii) the UE may perform a contention-based random access (CBRA) if CFRA resources / dedicated RACH configuration is not available to the UE.

[0338] For the CBRA, the UE may transmit a random access preamble in uplink, to a RAN node. The UE may transmit a message 1 (MSG1) comprising the random access preamble to the RAN node. The random access preamble may be associated with a random access - radio resource temporary identifier (RA-RNTI). The random access preamble may be selected based on the selected RACH resources, and transmitted through a time / frequency resources identified by the selected RACH resources.

[0339] For the CFRA, the UE may transmit a dedicated random access preamble in uplink, to a RAN node. The UE may transmit an MSG1 comprising the dedicated random access preamble to the RAN node. The dedicated random access preamble may be associated with a RA-RNTI. The dedicated random access preamble may be selected based on the CFRA resources / dedicated RACH configuration, and transmitted through a time / frequency resources identified by the CFRA resources / dedicated RACH configuration.

[0340] In step S815, the UE may complete the LTM cell switch procedure by sendingRRCReconfigurationCompletemessage to target cell. If the UE has performed a RA procedure in step S813, the UE considers that LTM cell switch execution is successfully completed when the random access procedure is successfully completed. For RACH-less LTM, the UE considers that LTM cell switch execution is successfully completed when the UE determines that the network has successfully received its first UL data.

[0341] The steps S807 to S815 can be performed multiple times for subsequent LTM cell switch executions using the LTM candidate configuration(s) provided in step S803.

[0342] The procedure over the air interface described in FIG. 8 is applicable to both intra-gNB-DU LTM and inter-gNB-DU LTM.

[0343] In the present disclosure, subsequent mobility (e.g., subsequent LTM / CLTM) is described. The subsequent mobility may refer to a mobility that is done by repeating a mobility execution / completion after each mobility execution / completion based on a corresponding candidate configuration without releasing other candidate configurations. That is, the subsequent mobility may refer to a mobility that is performed without reconfiguration and / or re-initialization on the mobility preparation from a network after a previous mobility. For example, when a UE has received a plurality of candidate configurations, after the UE performs a mobility based on a corresponding candidate configuration, the UE does not release other candidate configurations, and may perform a subsequent mobility based on a corresponding candidate configuration among the already received plurality of candidate configurations without reconfiguration and / or re-initialization on the mobility preparation from the network (or, without receiving new candidate configurations from the network). This results in a reduction of the signalling overhead and / or interrupting time for mobility.

[0344] Meanwhile, to execute L1 / L2 triggered mobility (LTM), the UE may perform L1 measurements, and when one or more L1 measurement events are configured for the UE, the UE may send an L1 measurement report to the network if at least one of report conditions for the one or more L1 measurement events is satisfied. Based on the received measurement report, the network may decide a candidate cell to which the network sends the LTM cell switch command. The UE may send the L1 measurement report if any beam from the beam set provided for the candidate cell satisfies the report condition.

[0345] In conditional LTM (CLTM), the UE may execute LTM without reception of an execution command (e.g., LTM cell switch command) from the network. Thus, for the execution of CLTM, when one or more L1 measurement event are configured, the UE may perform CLTM based on any beam from the beam set configured for the candidate cell satisfying the L1 measurement event condition.

[0346] The problem is that when the UE performs RACH-less CLTM based on a beam that satisfies the L1 measurement event / report condition, the network is unable to know which beam is selected to transmit the first DL / UL data transmission on the target cell. This is because the UE performs RACH-less CLTM based on a certain beam that satisfied the configured L1 measurement event for CLTM, and the network does not receive the L1 measurement report for this beam before the RACH-less CLTM execution. To address this issue, the network may reserve all resources based on / related to all beam sets for the L1 measurement events configured for all candidate cells, which leads to inefficiency in terms of the network resource usage.

[0347] Therefore, the present disclosure provides various embodiments related to condition evaluation for cell switch.

[0348] FIG. 9 shows an example of a method performed by a UE for condition evaluation for cell switch according to an embodiment of the present disclosure.

[0349] Referring to FIG. 9, in step S901, the UE may receive a configuration of a candidate cell (e.g.,LTM-Candide / LTM-CandidateConfigcomprisingRRCReconfigurationfor the candidate cell), and configurations for one or more event conditions (e.g.,LTM-ExecutionCondition / LTM-ExecutionConditionList) related to a set of beams for the candidate cell.

[0350] In step S903, the UE may receive beam information for one or more beams in the set of beams for the candidate cell.

[0351] In step S905, the UE may evaluate the one or more event conditions based on the one or more beams related to the received beam information.

[0352] In step S907, based on the one or more event conditions being fulfilled, the UE may apply the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0353] According to various embodiments, the UE may initiate the evaluation of the one or more event conditions based on receiving a network signalling comprising the beam information.

[0354] According to various embodiments, the network signalling may be received separately from receiving the configurations for the one or more event conditions.

[0355] According to various embodiments, the network signalling may be included in the configurations for the one or more event conditions.

[0356] According to various embodiments, the network signalling may be a signalling comprising at least one of a radio resource control (RRC) signalling, media access control (MAC) control element (CE) signalling, or downlink control information (DCI).

[0357] According to various embodiments, the MAC CE signalling may comprise a layer 1 / layer 2 triggered mobility (LTM) cell switch command.

[0358] According to various embodiments, the set of beams may comprise at least one beam not related to the received beam information. The at least one beam not related to the received beam information may be unused for evaluating the one or more event conditions.

[0359] According to various embodiments, the set of beams may comprise at least one beam not related to the received beam information. The at least one beam not related to the received beam information may be used for evaluating the one or more event conditions. The configuration of the candidate cell may be applied based on the one or more event conditions being fulfilled for the one or more beams related to the received beam information. The configuration of the candidate cell may not be applied based on the one or more event conditions being fulfilled for the at least one beam not related to the received beam information.

[0360] According to various embodiments, the UE may evaluate the one or more event conditions based on the set of beams. Based on the one or more event conditions being fulfilled, the UE may transmit information for measurement results of beams in the set of beams.

[0361] According to various embodiments, the configuration of the candidate cell may be applied based on at least one of: the one or more event conditions being fulfilled for a beam among the one or more beams related to the received beam information; the one or more event conditions being fulfilled for N beams among the one or more beams related to the received beam information, wherein the N is preconfigured or configured by a network; or the one or more event conditions being fulfilled for all of the one or more beams related to the received beam information.

[0362] According to various embodiments, the configurations for the one or more event conditions comprise one or more identifiers (IDs) of beam-based report configurations for cell switch (e.g.,LTM-CSI-ReportConfig). The one or more event conditions may be included in the beam-based report configurations. The one or more event conditions may comprise at least one of: a first event condition that beam quality of a source cell becomes worse than a threshold (e.g., event LTM2); a second event condition that beam quality of the candidate cell becomes amount of offset better than that of the source cell (e.g., event LTM3); a third event condition that am quality of the candidate cell becomes better than a threshold (e.g., event LTM4); or a fourth event condition that beam quality of the source cell becomes worse than a first threshold, and beam quality of the candidate cell becomes better than a second threshold (e.g., event LTM5).

[0363] According to various embodiments, before the cell switch execution, the UE may obtain a synchronization for the candidate cell. The UE may transmit a message related to a completion of the cell switch execution without performing a random access towards the candidate cell, based on the synchronization for the candidate cell obtained before the cell switch execution.

[0364] According to various embodiments, the message related to the completion of the cell switch execution may be transmitted based on the one or more beams related to the received beam information.

[0365] According to various embodiments, the beam set may comprise at least one of one or more channel state information (CSI) - reference signal (RS) resources, or one or more synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) resources.

[0366] FIG. 10 shows an example of a signal flow between UE and network node for condition evaluation for cell switch according to an embodiment of the present disclosure.

[0367] Referring to FIG. 10, in step S1001, the network node may transmit, to a user equipment (UE), a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell.

[0368] In step S1003, the network node may transmit, to the UE, beam information for one or more beams in the set of beams for the candidate cell.

[0369] In step S1005, the UE may evaluate the one or more event conditions based on the one or more beams related to the received beam information.

[0370] In step S1007, based on the one or more event conditions being fulfilled, the UE may apply the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0371] Hereinafter, detailed descriptions regarding condition evaluation for cell switch will be provided.

[0372] According to implementations of the present disclosure, the UE may be configured with one or more candidate cells, and the UE may be configured with one or more CLTM execution conditions (e.g.,LTM-ExecutionConditionList / LTM-ExecutionCondition) for at least one candidate cell. The UE may be configured with a set of beams (e.g., CSI-RS resources and / or SSB resources) associated with at least one candidate cell. Based on the associations, each candidate cell may be associated with a set of beams, and each CLTM execution condition(s) may be also associated with a set of beams.

[0373] The UE doesn't start the evaluation of the execution conditions upon reception of (pre-)configuration for CLTM (e.g.,LTM-Config). The UE may start evaluation of the CLTM execution condition(s) based on network signalling. For example, the network signalling may be transmitted to the UE separately from the (pre-)configuration of the CLTM execution conditions (e.g.,LTM-ExecutionConditionList / LTM-ExecutionCondition). For example, the network signalling may be transmitted to the UE within the configuration of the CLTM execution conditions.

[0374] For the evaluation of the CLTM execution condition(s), the UE may evaluate the execution conditions based on beam information included in the network signalling. The beam information may indicate one or more beams associated with a candidate cell. The network signalling may include beam information for one or more candidate cells. Specifically, the UE may perform the evaluation of the CLTM execution condition(s) only for the indicated beams, and the UE does not perform the evaluation for other non-indicated beams even if these beams are potentially associated with the CLTM execution condition(s). That is, the UE may consider that the CLTM execution condition(s) is fulfilled only if the CLTM execution condition(s) is fulfilled for the indicated beam(s).

[0375] If the CLTM execution condition(s) is fulfilled, the UE may execute CLTM to the candidate cell associated with the CLTM execution condition(s) that is fulfilled. While executing CLTM, the UE may perform RACH-less CLTM based on the indicated beam if valid UL timing synchronization information status with respect to the candidate cell is available.

[0376] The (network) signalling may be a new type of lower layer signalling (e.g., DCI, MAC CE) and / or RRC dedicated message. Also, the (network) signalling may be existing lower layer signalling such as LTM cell switch command (e.g., MAC CE). In the (network) signalling, beam information may be included for execution conditions of CLTM. The beam information may mean all beam set and / or partial beams for each execution condition(s) included in the (pre-)configuration for CLTM. This beam information may refer to the SSB and / or CSI-RS associated with the transmission configuration indicator (TCI) indicated for the UE to perform DL / UL transmission in the relevant candidate cell.

[0377] The UE may receive (pre-)configuration for CLTM (e.g.,LTM-Config) from the network. This (pre-)configuration may include cell configurations related to the candidate cell list for performing CLTM. Additionally, the (pre-)configuration may include execution conditions to execute CLTM. If there is a reference configuration that can be commonly applied to all or some of the candidate cells, the complete cell configuration may be generated by combining both the candidate cell configuration and the reference configuration.

[0378] The UE may also receive execution conditions corresponding to each candidate cell in the (pre-)configuration for CLTM. These execution conditions can be configured with a beam set. The UE can consider the CLTM execution condition(s) as being met if any beam from the beam set configured for the corresponding candidate cell satisfies the execution condition(s) unless the UE receives (or doesn't receive) the (network) signalling from the network to allow executing CLTM with the beam information.

[0379] The UE doesn't start evaluation for CLTM before the UE receives a (network) signalling from the network to allow the CLTM execution. Instead, the UE may perform L1 measurement and evaluate the execution condition(s) as reporting condition. Thus, the UE may send L1 measurement reporting via lower layer signalling (e.g., UCI and / or MAC CE) when the execution condition(s) is met but the UE hasn't received the (network) signalling from the network to allow the CLTM execution. The L1 measurement reporting may indicate that the UE is ready to execute CLTM towards one or more candidate cells but the UE doesn't execute CLTM. The L1 measurement reporting may comprise information for measurement results of beams in the beam set.

[0380] The UE may start evaluation for CLTM upon reception of the (network) signalling from the network to allow the CLTM execution. The UE may evaluate execution condition(s) of the candidate cells which have the beam information in the (network) signalling. That is, the UE may not evaluate (or, ignore) execution condition(s) of the candidate cells if the beam information in the (network) signalling doesn't include any beam for the candidate cells.

[0381] Additionally, the UE may perform early DL synchronization for the candidate cell related to the beam information in the (network) signalling while evaluating the execution condition(s) for CLTM. For the early DL synchronization, the UE may activate TCI associated with the beam or beam set of the candidate cell in the (network) signalling.

[0382] The UE may also receive one or more timing advance (TA) values and / or TA offset values for early UL synchronization with candidate cells when receiving the (network) signalling including the beam information. For the early UL synchronization with candidate cells, the UE may perform RACH procedure on the candidate cells based on the network command and / or UE decision. In this RACH procedure for the early UL synchronization, the UE may terminate the RACH procedure without reception of RA response because this RACH procedure aims for sharing exact TA values between the current serving cell and the candidate cell.

[0383] For example, beam-based event evaluation may comprise at least one of:

[0384] A) single beam based evaluation: If at least one indicated beam satisfies the condition, the UE may consider the event to be fulfilled; and

[0385] B) Multi-beam based evaluation:

[0386] B1) If N beams of the indicated beams satisfy the condition, the UE may consider the event to be fulfilled; and / or

[0387] B2) If all indicated beams satisfy the condition, the UE may consider the event to be fulfilled.

[0388] When performing CLTM execution, if the early UL and / or DL synchronization of the candidate cell is valid, the UE may perform RACH-less CLTM. If the RA procedure is skipped during CLTM execution and if the uplink scheduling information (e.g., configured grant (CG)) is included in the candidate cell configuration associated with the target cell, the UE may transmit to the target cell the message for CLTM completion based on the uplink scheduling information provided in the candidate cell configuration. If the UE receives UE dedicated DL signal after transmitting the message for CLTM completion, the UE may consider that the CLTM execution is successfully completed.

[0389] According to implementations of the present disclosure, the UE may be configured with one or more candidate cells, and the UE may be configured with one or more measurement reporting conditions for at least one candidate cell. The UE may be configured with a set of beams associated with at least one candidate cell. Based on the associations, each candidate cell may be associated with a set of beams, and each measurement reporting condition may be also associated with a set of beams. The UE may start evaluation of the measurement reporting condition(s) based on network signalling. The UE doesn't start the evaluation of the execution condition(s) upon reception of (pre-)configuration for measurement reporting. For the evaluation of the measurement reporting condition, the UE may evaluate the measurement reporting conditions based on beam information included in the network signalling. The beam information may indicate one or more beams associated with a candidate cell. The network signalling may include beam information for one or more candidate cells. Specifically, the UE may perform the evaluation of the measurement reporting condition only for the indicated beams, and the UE does not perform the evaluation for other non-indicated beams even if these beams are potentially associated with the measurement reporting condition. That is, the UE may consider that the measurement reporting condition is fulfilled only if the measurement reporting condition is fulfilled for the indicated beam(s). If the measurement reporting condition is fulfilled, the UE may trigger measurement reporting to report the quality of the beam that has fulfilled the measurement reporting condition.

[0390] FIG. 11 shows an example of a method for CLTM evaluation based on beam indication according to an embodiment of the present disclosure.

[0391] Referring to FIG. 11, in step S1101, the UE may receive a (subsequent) LTM configuration (e.g.,LTM-Config) from the cell 0. For example, the cell 0 may be the source cell for CLTM and / or the serving cell. The cell 0 may configure 3 cell configurations of candidate cells (i.e., cell 1, cell 2, and cell 3) for the (subsequent) LTM cell switching. In the (subsequent) LTM configuration, conditional LTM (CLTM) execution conditions (e.g., event LTM2 / LTM3 / LTM4 / LTM5) for each candidate cell and cell configurations for candidate cells (i.e., cell 1, cell 2, and cell 3) may be included together with L1 measurement configuration. For the L1 measurement configuration, one or more SSB resource configurations and / or one or more CSI-RS resource configurations (e.g., beam set) per candidate cell may be included, and the one or more SSB resource configurations and / or the one or more CSI-RS resource configurations may be associated with TCI states. Also, in the (subsequent) LTM configuration, other execution conditions for L1 measurement reporting and / or related measurement configuration can be included.

[0392] In step S1103, the UE may perform L1 measurement for all or part of candidate cells. For example, the UE may evaluate the L1 measurement execution condition(s) for all candidate cells based on the L1 measurement. The UE may evaluate execution conditions for L1 measurement reporting for the candidate cells. The UE may report L1 measurement reporting whenever one or more execution conditions for the L1 measurement reporting are satisfied.

[0393] Additionally, the UE may check whether all configured CLTM execution conditions are satisfied based on all configured SSB and / or CSI-RS resource configurations for all candidate cells. The UE may report L1 measurement reporting whenever one or more CLTM execution condition(s) is satisfied based on any beam of the candidate cells. However, the UE doesn't initiate CLTM based on the satisfied execution condition(s) for CLTM.

[0394] Upon the UE receiving a signalling from the cell 1 to activate a TCI state for the cell 1, the UE may activate the TCI and the UE may perform DL synchronization with the cell 1.

[0395] While performing the L1 measurement, the UE may receive a PDCCH order to perform early UL synchronisation (i.e., early TA) with the cell 1. Then, the UE may perform RACH procedure on the cell 1. The UE may transmit RA preamble to the cell 1 and terminate RACH procedure.

[0396] In step S1105, the UE may receive MAC CE information from the network. The MAC CE information may comprise at least one of indication to allow CLTM execution, specific beam information (e.g., one or more SSB / CSI-RS resources) for the cell 1 and / or cell 2, or TA value for the cell 1.

[0397] In step S1107, upon reception of the MAC CE information, the UE may start evaluating the CLTM execution condition(s) of the cell 1 and cell 2 to execute CLTM. The UE may evaluate the execution conditions for the cell 1 and cell 2 not based on all beam set for the cell 1 / cell 2, but only based on the specific beam(s) in the MAC CE information. The UE still doesn't evaluate other execution condition(s) for the cell 3 to execute CLTM but the UE may evaluate other execution condition(s) for the cell 3 to report L1 measurement results. If the UE didn't success to activate TCI which may be associated with the specific beam in the MAC CE information, the UE may activate the associated TCIs for the cell 1 and cell 2.

[0398] The UE may check (or, evaluate) if the execution condition(s) for the cell 1 is met based on the specific beam and the UE may confirm that the execution condition(s) for the cell 1 is met based on the specific beam.

[0399] In step S1109, the UE may initiate to execute CLTM from the cell 0 to the cell 1. After the UE checked that the DL / UL early synchronization is still available (or, the UE has still valid activated TCI and / or TA value for the cell 1), the UE may perform RACH-less LTM towards the cell 1. If the uplink scheduling information (e.g., CG) is included in the cell configuration of the cell 1 in the (pre-)configuration, the UE may transmit to the cell 1 the message for CLTM completion (e.g., RRC reconfiguration complete message) based on the uplink scheduling information provided in the cell configuration of the cell 1. Otherwise (e.g., UL grant is provided based on dynamic grant (DG)), the UE may monitor PDCCH order in the cell 1 to acquire UL grant to transmit to the cell 1 the message for CLTM completion.

[0400] If the UE receives UE dedicated DL signal after transmitting the message for CLTM completion, the UE may consider that the CLTM execution is successfully completed. After CLTM execution is completed, the UE may stop evaluating the CLTM execution conditions for the cell 2 while the UE can evaluate the L1 measurement reporting / execution condition(s) for the L1 measurement reporting for all candidate cells.

[0401] In step S1111, the UE may perform L1 measurement for all or part of candidate cells. Additionally, the UE may check whether all configured CLTM execution conditions are satisfied based on all configured SSB / CSI-RS resource configurations for all candidate cells. The UE may report L1 measurement reporting whenever one or more CLTM execution condition(s) are satisfied based on any beam of the candidate cells. However, the UE doesn't initiate CLTM based on the satisfied execution condition(s) for CLTM.

[0402] In step S1113, the UE may receive MAC CE information from the network. The MAC CE information may comprise at least one of an indication to allow CLTM execution or specific beam information (e.g., a SSB / CSI-RS resource) for cell 2. However, TA value for the cell 2 may not be included in the MAC CE information.

[0403] In step S1115, upon reception of the MAC CE information, the UE may start evaluating the CLTM execution condition(s) for the cell 2 to execute CLTM. The UE may evaluate the execution conditions for the cell 2 not based on all beam set for the cell 1, but only based on the specific beam in the MAC CE information. The UE still doesn't evaluate other execution condition(s) for the cell 3 to execute CLTM but the UE may evaluate other execution condition(s) for the cell 3 to report L1 measurement results. If the UE didn't success to activate TCI which may be associated with the specific beam in the MAC CE information, the UE may activate the associated TCIs for the cell 2.

[0404] The UE may check (or, evaluate) whether the execution condition(s) for the cell 2 is met based on the specific beam and the UE may confirm that the execution condition(s) for the cell 2 is met based on the specific beam.

[0405] In step S1117, the UE may initiate to execute CLTM from the cell 1 to the cell 2. After the UE confirmed that there are no available TA values for the cell 2 and no activated TCI for the cell 2, the UE may perform RACH based CLTM towards the cell 2.

[0406] According to various embodiments, the UE may receive a configuration of a candidate cell and beam-based event condition for a set of beams of the candidate cell. The UE may receive indication of a beam for the candidate cell. Upon receiving the indication, the UE may start evaluation of the beam-based event condition based on the indicated beam. Upon the beam-based event condition being fulfilled, the UE may execute a cell switch to the candidate cell based on the indicated beam and the configuration of the candidate cell.

[0407] According to various embodiments, the beam included in the indication may be one of the beams configured for the candidate cell.

[0408] According to various embodiments, upon receiving the indication, the UE may activate the beam.

[0409] According to various embodiments, the indication may include timing advance (TA) value for the candidate cell.

[0410] According to various embodiments, upon execution of the cell switch, the UE may transmit a message indicating cell switch completion based on the beam. The beam may be used for monitoring PDCCH scheduling UL resource for the message, or the beam may be used for transmitting the message based on preconfigured UL resource associated with the beam.

[0411] Furthermore, the method in perspective of the communication device / UE described in the present disclosure (e.g., in FIG. 9) may be performed by the first wireless device 100 shown in FIG. 2 and / or the UE 100 shown in FIG. 3.

[0412] More specifically, the communication device / UE comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.

[0413] The operations comprise: receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; receiving beam information for one or more beams in the set of beams for the candidate cell; evaluating the one or more event conditions based on the one or more beams related to the received beam information; and based on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0414] Furthermore, the method in perspective of the communication device / UE described in the present disclosure (e.g., in FIG. 9) may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.

[0415] More specifically, at least one computer readable medium (CRM) stores instructions that, based on being executed by at least one processor, perform operations comprising: receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; receiving beam information for one or more beams in the set of beams for the candidate cell; evaluating the one or more event conditions based on the one or more beams related to the received beam information; and based on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0416] Furthermore, the method in perspective of the communication device / UE described in the present disclosure (e.g., in FIG. 9) may be performed by control of the processor 102 included in the first wireless device 100 shown in FIG. 2 and / or by control of the processor 102 included in the UE 100 shown in FIG. 3.

[0417] More specifically, an apparatus configured to / adapted to operate in a wireless communication system (e.g., communication device / UE) comprises at least processor, and at least one computer memory operably connectable to the at least one processor. The at least one processor is configured to / adapted to perform operations comprising: receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; receiving beam information for one or more beams in the set of beams for the candidate cell; evaluating the one or more event conditions based on the one or more beams related to the received beam information; and based on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.

[0418] Furthermore, the method in perspective of a network node described in the present disclosure (e.g., in FIG. 10) may be performed by the second wireless device 200 shown in FIG. 2. The network node may be related to a serving cell.

[0419] More specifically, the network node comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.

[0420] The operations comprise: transmitting, to a user equipment (UE), a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; and transmitting, to the UE, beam information for one or more beams in the set of beams for the candidate cell, wherein the one or more beams related to the beam information is used for evaluating the one or more event conditions, and wherein the configuration of the candidate cell is applied for a cell switch execution to the candidate cell based on the one or more event conditions being fulfilled.

[0421] The present disclosure may have various advantageous effects.

[0422] For example, according to various embodiments, the UE can start CLTM based on the beam shared with the network. This allows the UE to execute RACH-less CLTM with a beam shared with the network. Therefore, the network load can be reduced, as the network no longer needs to reserve resources for the entire beam set of all candidate cells for RACH-less CLTM.

[0423] Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

[0424] Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

1.A method comprising:receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell;receiving beam information for one or more beams in the set of beams for the candidate cell;evaluating the one or more event conditions based on the one or more beams related to the received beam information; andbased on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.2.The method of claim 1, further comprising:initiating the evaluation of the one or more event conditions based on receiving a network signalling comprising the beam information.3.The method of claim 2, wherein the network signalling is received separately from receiving the configurations for the one or more event conditions.4.The method of claim 2, wherein the network signalling is included in the configurations for the one or more event conditions.5.The method of claim 2, wherein the network signalling is a signalling comprising at least one of a radio resource control (RRC) signalling, media access control (MAC) control element (CE) signalling, or downlink control information (DCI).6.The method of claim 5, wherein the MAC CE signalling comprises a layer 1 / layer 2 triggered mobility (LTM) cell switch command.7.The method of claim 1, wherein the set of beams comprise at least one beam not related to the received beam information, andwherein the at least one beam not related to the received beam information is unused for evaluating the one or more event conditions.8.The method of claim 1, wherein the set of beams comprise at least one beam not related to the received beam information,wherein the at least one beam not related to the received beam information is used for evaluating the one or more event conditions,wherein the configuration of the candidate cell is applied based on the one or more event conditions being fulfilled for the one or more beams related to the received beam information, andwherein the configuration of the candidate cell is not applied based on the one or more event conditions being fulfilled for the at least one beam not related to the received beam information.9.The method of claim 1, further comprising:evaluating the one or more event conditions based on the set of beams; andbased on the one or more event conditions being fulfilled, transmitting information for measurement results of beams in the set of beams.10.The method of claim 1, wherein the configuration of the candidate cell is applied based on at least one of:the one or more event conditions being fulfilled for a beam among the one or more beams related to the received beam information;the one or more event conditions being fulfilled for N beams among the one or more beams related to the received beam information, wherein the N is preconfigured or configured by a network; orthe one or more event conditions being fulfilled for all of the one or more beams related to the received beam information.11.The method of claim 1, wherein the configurations for the one or more event conditions comprise one or more identifiers (IDs) of beam-based report configurations for cell switch,wherein the one or more event conditions are included in the beam-based report configurations, andwherein the one or more event conditions comprise at least one of:a first event condition that beam quality of a source cell becomes worse than a threshold;a second event condition that beam quality of the candidate cell becomes amount of offset better than that of the source cell;a third event condition that am quality of the candidate cell becomes better than a threshold; ora fourth event condition that beam quality of the source cell becomes worse than a first threshold, and beam quality of the candidate cell becomes better than a second threshold.12.The method of claim 1, further comprising:before the cell switch execution, obtaining a synchronization for the candidate cell; andtransmitting a message related to a completion of the cell switch execution without performing a random access towards the candidate cell, based on the synchronization for the candidate cell obtained before the cell switch execution.13.The method of claim 2, wherein the message related to the completion of the cell switch execution is transmitted based on the one or more beams related to the received beam information.14.The method of claim 1, wherein the beam set comprises at least one of one or more channel state information (CSI) - reference signal (RS) resources, or one or more synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) resources.15.The method of claims 1, wherein the method is performed by a user equipment (UE) in communication with at least one of a mobile device, a network, or autonomous vehicles.16.A user equipment (UE) comprising:at least one transceiver;at least one processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell;receiving beam information for one or more beams in the set of beams for the candidate cell;evaluating the one or more event conditions based on the one or more beams related to the received beam information; andbased on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.17.An apparatus comprising:at least processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell;receiving beam information for one or more beams in the set of beams for the candidate cell;evaluating the one or more event conditions based on the one or more beams related to the received beam information; andbased on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.18.A non-transitory computer readable medium (CRM) having stored thereon a program code implementing instructions that, based on being executed by at least one processor, perform operations comprising:receiving a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell;receiving beam information for one or more beams in the set of beams for the candidate cell;evaluating the one or more event conditions based on the one or more beams related to the received beam information; andbased on the one or more event conditions being fulfilled, applying the configuration of the candidate cell for a cell switch execution to the candidate cell.19.A method comprising:transmitting, to a user equipment (UE), a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; andtransmitting, to the UE, beam information for one or more beams in the set of beams for the candidate cell,wherein the one or more beams related to the beam information is used for evaluating the one or more event conditions, andwherein the configuration of the candidate cell is applied for a cell switch execution to the candidate cell based on the one or more event conditions being fulfilled.20.A network node comprising:at least one transceiver;at least one processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:transmitting, to a user equipment (UE), a configuration of a candidate cell, and configurations for one or more event conditions related to a set of beams for the candidate cell; andtransmitting, to the UE, beam information for one or more beams in the set of beams for the candidate cell,wherein the one or more beams related to the beam information is used for evaluating the one or more event conditions, andwherein the configuration of the candidate cell is applied for a cell switch execution to the candidate cell based on the one or more event conditions being fulfilled.

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