Event evaluation based on multiple reference signal measurement results

Abstract

A method and apparatus for event evaluation based on multiple Reference Signal (RS) measurement results is provided. A wireless device obtains measurement results of a first set of reference signals configured for an event, and derives a representative metric for evaluation of the event based on measurement results of a second set of reference signals. The wireless device evaluates the event based on the representative metric, and transmits the measurement results of the second set of reference signals to a network based on the event being met.

Description

EVENT EVALUATION BASED ON MULTIPLE REFERENCE SIGNAL MEASUREMENT RESULTS

[0001] The present disclosure relates to event evaluation based on multiple Reference Signal (RS) measurement results.

[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] 3GPP New Radio (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. 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] 6G is the successor to 5G cellular technology. 6G networks will be able to use higher frequencies than 5G networks and provide substantially higher capacity and much lower latency. The 6G technology market is expected to facilitate large improvements in the areas of imaging, presence technology and location awareness. Working in conjunction with Artificial Intelligence (AI), the 6G computational infrastructure will be able to identify the best place for computing to occur. This includes decisions about data storage, processing and sharing.

[0005] Layer 3 based mobility has evolved over several releases. Conditional Handover (CHO) and other conditional mobility procedures (Conditional PSCell Addition and Change (CPAC), Subsequent CPAC (SCPAC)) were developed to achieve high robustness by enabling the procedure to be executed without necessitating a signaling exchange with source cell beforehand. L1 / L2 Triggered Mobility (LTM) as introduced in Rel-18 offers short interruption time but not with the same level of robustness as the conditional L3 mobility procedures. In Rel-19, enhancements should be specified so that the system can benefit from both the high robustness and short interruption.

[0006] In an aspect, a method is provided. The method comprises obtaining measurement results of a first set of reference signals configured for an event, deriving a representative metric for evaluation of the event based on measurement results of a second set of reference signals, evaluating the event based on the representative metric, and transmitting the measurement results of the second set of reference signals to a network based on the event being met.

[0007] In another aspect, an apparatus for implementing the above method is provided.

[0008] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0009] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0010] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0011] FIGS. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0012] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0013] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0014] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0015] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0016] FIG. 10 shows an example of a method to which implementations of the present disclosure are applied.

[0017] FIG. 11 shows an example of another method to which implementations of the present disclosure are applied.

[0018] FIG. 12 shows an example of applicable RS selection to which implementations of the present disclosure are applied.

[0019] FIG. 13 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0020] FIG. 14 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0021] FIG. 15 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0022] FIGS. 16 and 17 show an example of selecting synchronous RSs as applicable RSs to which implementations of the present disclosure are applied.

[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, 5G New Radio (NR) and / or 6G.

[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 are 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.

[0049] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] In the implementations of the present disclosure, a UE may operate as a transmitting device in UL and as a receiving device in 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.

[0069] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0070] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0071] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0072] 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.

[0073] 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®, DIMENSITYTMseries of processors made by MEDIATEK®, or a corresponding next generation processor.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] FIGS. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0081] 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 (i.e., a PHY layer) and Layer 2. Referring to FIG. 5, the control plane protocol stack may be divided into Layer 1 (i.e., a PHY layer), Layer 2, Layer 3 (e.g., 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).

[0082] 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.

[0083] 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.

[0084] 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.

[0085] The RLC sublayer supports three transmission modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (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).

[0086] 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.

[0087] 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.

[0088] 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 5G Core network (5GC) or Next-Generation Radio Access Network (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 Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs); mobility functions (including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility); QoS management functions; UE measurement reporting and control of the reporting; detection of and recovery from radio link failure; NAS message transfer to / from NAS from / to UE.

[0089] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0090] 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., 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 Cyclic Prefix (CP)-OFDM symbols), SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbols).

[0091] 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 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 Δf = 2u*15 kHz.

[0092] 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 Δf = 2u*15 kHz.

[0093] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0094] 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 Δf = 2u*15 kHz.

[0095] uNslotsymbNframe,uslotNsubframe,uslot212404

[0096] 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 signaling (e.g., RRC signaling), 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.

[0097] 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.

[0098] 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.

[0099] 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 Physical Uplink Control Channel (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.

[0100] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0101] 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.

[0102] 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 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.

[0103] Network controlled mobility applies to UEs in RRC_CONNECTED and is categorized into two types of mobility: cell level mobility and beam level mobility. Beam level mobility includes intra-cell beam level mobility and inter-cell beam level mobility.

[0104] Cell level mobility requires explicit RRC signaling to be triggered, i.e., handover.

[0105] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0106] For inter-gNB handover, the signaling procedures consist of at least the following elemental components described in FIG. 8.

[0107] 1. Step 1: The source gNB initiates handover and issues a HANDOVER REQUEST over the Xn interface.

[0108] 2. Step 2: The target gNB performs admission control and provides the new RRC configuration as part of the HANDOVER REQUEST ACKNOWLEDGE.

[0109] 3. Step 3: The source gNB provides the RRC configuration to the UE by forwarding theRRCReconfigurationmessage received in the HANDOVER REQUEST ACKNOWLEDGE. TheRRCReconfigurationmessage includes at least cell ID and all information required to access the target cell so that the UE can access the target cell without reading system information. For some cases, the information required for contention-based and contention-free random access can be included in theRRCReconfigurationmessage. The access information to the target cell may include beam specific information, if any.

[0110] 4. Step 4: The UE moves the RRC connection to the target gNB and replies with theRRCReconfigurationComplete.

[0111] User data may also be sent in step 4 if the grant allows.

[0112] Beam level mobility does not require explicit RRC signaling to be triggered. Beam level mobility can be within a cell, or between cells, the latter is referred to as Inter-Cell Beam Management (ICBM). For ICBM, a UE can receive or transmit UE dedicated channels / signals via a Transmission / Reception Point (TRP) associated with a Physical Cell ID (PCI) different from the PCI of a serving cell, while non-UE-dedicated channels / signals can only be received via a TRP associated with a PCI of the serving cell. The gNB provides via RRC signaling the UE with measurement configuration containing configurations of Synchronization Signal Block (SSB) / Channel State Information (CSI) resources and resource sets, reports and trigger states for triggering channel and interference measurements and reports. In case of ICBM, a measurement configuration includes SSB resources associated with PCIs different from the PCI of a serving cell. Beam level mobility is then dealt with at lower layers by means of physical layer and MAC layer control signaling, and RRC is not required to know which beam is being used at a given point in time.

[0113] SSB-based beam level mobility is based on　the SSB associated to the initial DL BWP and can only be　configured for　the initial DL BWPs and for　DL BWPs　containing the SSB associated to the initial DL BWP. For　other DL BWPs, beam level mobility can only be performed based on CSI-Reference Signal (RS).

[0114] A Conditional Handover (CHO) is defined as a handover that is executed by the UE when one or more handover execution conditions are met. The UE starts evaluating the execution condition(s) upon receiving the CHO configuration, and stops evaluating the execution condition(s) once a handover is executed.

[0115] The following principles apply to CHO:

[0116] - The CHO configuration contains the configuration of CHO candidate cell(s) generated by the candidate gNB(s) and execution condition(s) generated by the source gNB.

[0117] - An execution condition may consist of one or two trigger condition(s) (CHO events A3 / ). Only single RS type is supported and at most two different trigger quantities (e.g., Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ), RSRP and Signal-to-Interference plus Noise Ratio (SINR), etc.) can be configured simultaneously for the evaluation of CHO execution condition of a single candidate cell.

[0118] - Before any CHO execution condition is satisfied, upon reception of HO command (without CHO configuration), the UE executes the HO procedure, regardless of any previously received CHO configuration.

[0119] - While executing CHO, i.e., from the time when the UE starts synchronization with target cell, the UE does not monitor source cell.

[0120] L1 / L2 Triggered Mobility (LTM) is a procedure in which a gNB receives L1 measurement report(s) from a UE, and on their basis the gNB changes UE's serving cell by a cell switch command signaled via a MAC CE. The cell switch command indicates an LTM candidate cell configuration that the gNB previously prepared and provided to the UE through RRC signaling. Then the UE switches to the target cell according to the cell switch command. The LTM procedure can be used to reduce the mobility latency.

[0121] When configured by the network, it is possible to activate Transmission Configuration Index (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.

[0122] When configured by the network, it is possible to initiate UL Timing Advance (TA) acquisition procedure to one or multiple cells that are different from the current serving cell. For instance, the network may request the UE to perform early TA acquisition of a candidate cell before a cell switch. The early TA acquisition is triggered by PDCCH order or realized through UE-based TA measurement. In the former case, the gNB to which the candidate cell belongs calculates the TA value and sends it to the gNB to which the serving cell belongs. 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 applies the TA value measured by itself and performs RACH-less LTM upon receiving the cell switch command.

[0123] If UE-based TA measurement is configured, the UE performs RACH-less LTM upon receiving the cell switch command. Otherwise, the UE determines whether to access the target cell with the RA procedure depending on whether a TA value is provided in the cell switch command. For RACH-less LTM, the UE accesses the target cell via a configured grant provided in the LTM candidate cell configuration and selects the configured grant occasion associated with the beam indicated in the cell switch command. If the LTM candidate cell configuration does not include a configured grant, the UE may monitor PDCCH for dynamic scheduling from the target cell upon LTM cell switch. Before RACH-less LTM procedure completion, the UE may not trigger random access procedure if it does not have a valid PUCCH resource for triggered Scheduling Requests (SRs).

[0124] The following principles apply to LTM:

[0125] - The UE does not update its security key after an intra-gNB LTM cell switch.

[0126] - Subsequent LTM is supported.

[0127] LTM supports both intra-gNB-Distributed Unit (DU) and intra-gNB-Centralized Unit (CU) inter-gNB-DU mobility. LTM supports both intra-frequency and inter-frequency mobility, including mobility to inter-frequency cell that is not a current serving cell. The following scenarios are supported:

[0128] - PCell change in non-CA scenario and non-DC scenario,

[0129] - PCell change in CA scenario,

[0130] - DC scenario, MCG PCell change and SCG PSCell change without MN involvement case (i.e., intra-SN PSCell change).

[0131] While the UE has stored LTM candidate cell configurations, the UE can also execute any L3 handover command sent by the network.

[0132] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0133] Cell switch command is conveyed in a MAC Control Element (CE), which contains the necessary information to perform the LTM cell switch.

[0134] Subsequent LTM is done by repeating the early synchronization, LTM cell switch execution, and LTM cell switch completion steps without releasing other LTM candidate cell configurations after each LTM cell switch completion.

[0135] The signaling procedure for LTM is as follows.

[0136] 1. Step 1: The UE sends aMeasurementReportmessage to the gNB. The gNB decides to configure LTM and initiates candidate cell(s) preparation.

[0137] 2. Step 2: The gNB transmits anRRCReconfigurationmessage to the UE including the LTM candidate cell configurations of one or multiple candidate cells.

[0138] 3. Step 3: The UE stores the LTM candidate cell configurations and transmits anRRCReconfigurationCompletemessage to the gNB.

[0139] 4a. Step 4a: The UE may perform DL synchronization with the candidate cell(s) before receiving the cell switch command.

[0140] 4b. Step 4b: When UE-based TA measurement is configured, the UE may acquire the TA value(s) of the candidate cell(s) by measurement. Otherwise, the UE may perform early TA acquisition with the candidate cell(s) as requested by the network before receiving the cell switch command. This may be done via Contention-Free Random Access (CFRA) triggered by a PDCCH order from the source cell, following which the UE may send 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 may 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 may not maintain the TA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[0141] 5. Step 5: The UE performs L1 measurements on the configured candidate cell(s) and transmits L1 measurement reports to the gNB. L1 measurement should be performed as long as RRC reconfiguration (step 2) is applicable.

[0142] 6. Step 6: The gNB decides to execute cell switch to a target cell and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell. The UE switches to the target cell and applies the configuration indicated by candidate configuration index.

[0143] 7. Step 7: The UE may perform the random access procedure towards the target cell, if the UE does not have valid TA of the target cell. The UE may perform CFRA if the LTM cell switch command MAC CE contains information for CFRA.

[0144] 8. Step 8: The UE completes the LTM cell switch procedure by sendingRRCReconfigurationCompletemessage to target cell. If the UE has performed a random access procedure in step 7, 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. The UE determines successful reception of its first UL data by receiving a PDCCH addressing the UE's Cell Radio Network Temporary Identity (C-RNTI) in the target cell, which schedules a new transmission following the first UL data. The PDCCH carries either a DL assignment or an UL grant addressing the same HARQ process as the first UL data.

[0145] The steps 4-8 can be performed multiple times for subsequent LTM using the LTM candidate cell configuration(s) provided in step 2.

[0146] Measurement reports may be triggered when one beam satisfies the event condition. As a result, measurement reports may be triggered frequently. Furthermore, even when only one specific beam among beams transmitted by the neighbor cell has good quality and the other beams have bad quality, measurement reports may be triggered. When mobility is performed towards such a cell, beam failure may occur in that cell and / or another mobility may occur within a short period of time (i.e., causing ping-pong, etc.).

[0147] To address the above-mentioned problem, in the present disclosure, a method for L1 event-triggered operation based on deriving a representative metric (or consolidated metric) of multiple RS measurement results for event evaluation is proposed.

[0148] According to implementations of the present disclosure, for L1 event evaluation based on representative metric of multiple RSs of a cell, the event evaluation may be executed based on representative metric of measurement result(s) of multiple RSs configured for a cell (serving or candidate cell).

[0149] For example, if four RSs are configured to a UE for LTM candidate cell with an L1 event for the candidate cell, the event may take all (or a subset of) the RSs for evaluation of the event. Such consolidated L1 event may be useful for network's cell-level decision. For instance, if the L1 event indicates that a consolidated result of a candidate cell is reasonably good, the network may decide to actually prepare candidate cell resources towards the reported candidate cell in preparation of potential LTM, or the network may choose an appropriate candidate cell based on the provided L1 report(s), or the network may directly decide to execute LTM to the reported candidate directly based on the consolidated L1 report.

[0150] For example, operations related to the representative metric according to implementations of the present disclosure may be as follows.

[0151] (1) The UE may obtain measurement results of 'M' number of RSs configured for cell A. The UE may obtain measurement results of 'N' number of RSs configured for cell B.

[0152] (2-1) The network may configure the minimum number of RSs, 'J', for the event to the UE.

[0153] If J is applicable for cell A and M<J (i.e., the number of RSs for which measurement results are obtained for cell A is less than the minimum number of RSs), the UE may consider that the event is not met. If J is applicable for cell B and N<J (i.e., the number of RSs for which measurement results are obtained for cell B is less than the minimum number of RSs), the UE may consider that the event is not met.

[0154] The UE may determine whether J is applicable for cell A or cell B based on configuration. For different cells, different J values may be configured.

[0155] (3-1) Else if M=>J for cell A (i.e., the number of RSs for which measurement results are obtained for cell A is not less than the minimum number of RSs), and / or N=>J for cell B (i.e., the number of RSs for which measurement results are obtained for cell B is not less than the minimum number of RSs), 'K' may be configured. K may be equal to and / or less than J. K may correspond to the number of RSs having best measurement results among measurement results of M number of RSs configured for cell A and / or measurement results of 'N' number of RSs configured for cell B. For different cells, different K values may be configured.

[0156] (4) If K is configured, and K is applicable for cell A, the UE may derive representative metric for event evaluation based on best K measurement results for cell A. Else if K is not applicable for cell A, the UE may derive representative metric for event evaluation based on best J measurement results for cell A.

[0157] If K is configured, and K is applicable for cell B, the UE may derive representative metric for event evaluation based on best K measurement results for cell B. Else if K is not applicable for cell A, the UE may derive representative metric for event evaluation based on best J measurement results for cell B.

[0158] (5) The UE may evaluate the event based on the representative metric(s).

[0159] (6) The network may configure the minimum reference signal quality threshold, 'L', for the event. If L is configured, if any measurement result of the best K RS is below L, the UE may consider that the event is not met. L may be applicable for the event that is configured to detect a better cell and / or beam.

[0160] (3-2) Else if J is configured but K is not configured, the UE may derive representative metric for event evaluation based on best J measurement results for a concerned cell, and evaluate the event based on the representative metric(s).

[0161] (2-2) Else if J is not configured, the UE may derive representative metric for event evaluation based on obtained measurement results for a concerned cell, and evaluate the event based on the representative metric(s).

[0162] According to implementations of the present disclosure, if there are multiple applicable RSs, the UE may derive a representative metric of the multiple applicable RSs, based on the configuration of the event. Then, the UE may use the representative metric as the quality of representative applicable RS for event evaluation.

[0163] For example, the quality of best RS among the multiple RSs may be considered as the representative metric. For example, the quality of best N RSs among the multiple RSs may be considered as the representative metric. For example, the average quality of the multiple RSs may be considered as the representative metric.

[0164] According to implementations of the present disclosure, L1 event-triggered operation may be event-triggered measurement reporting or L1 event-triggered mobility execution. The UE may be configured with at least one event for the L1-event triggered operation. The event may be associated with a certain RS set. The associated RSs may be used for evaluation of the event. At least one condition related to radio quality of the associated RSs may be configured for the event evaluation. If multiple conditions are defined for the event, the event may be considered to be met when all of the conditions are met. Alternatively, if multiple conditions are defined for the event, the event may be considered to be met when at least one condition is met. Different event may be associated with different RS set.

[0165] According to implementations of the present disclosure, for event evaluation, the UE may select one or more applicable RSs among the associated RS set based on network indication. Then, the UE may consider the selected applicable RS(s) for the event evaluation. If the applicable RS(s) satisfy the condition(s) of the event, the UE may consider that the event is met. If the applicable RS does not satisfy the condition(s) of the event, the UE may not consider that the event is met, even if other RS included in the associated RS set satisfies the condition of the event.

[0166] According to implementations of the present disclosure, if the event is defined for event-triggered measurement reporting, and if the event is met, the UE may transmit measurement result of the applicable RS. If the event is defined for event-triggered mobility execution for a target cell and the UE is configured with a configuration of the target cell, and if the event is met, the UE may initiate execution of mobility to a target cell associated with the event.

[0167] According to implementations of the present disclosure, the UE may receive an indication (i.e., network indication) for an event of event-triggered L1 reporting.

[0168] For example, the indication may include event ID. The event ID may indicate an event for which the indication needs to be applied.

[0169] For example, the indication may include association ID. The association ID may indicate an association for which the indication needs to be applied. The association may associate a measurement target (e.g., a RS measurement object) specifying a list of RSs and an event specifying the event condition, as required for event evaluation.

[0170] For example, the indication may include a candidate cell ID (or candidate cell configuration ID). The candidate cell ID may indicate a candidate cell for which the indication needs to be applied. If the candidate cell ID is indicated, the UE may consider all configured CSI resources for the candidate cell as candidates of applicable RS.

[0171] For example, the indication may include a CSI resource set ID (or candidate cell configuration ID). The CSI resource set ID may indicate a CSI resource set for which the indication needs to be applied. If the CSI resource set ID is indicated, the UE considers that CSI resources included in the indicated CSI resource set among the RSs configured for the candidate cell as candidates of applicable RS.

[0172] For example, the indication may include a RS selection method field. The RS selection method field may indicate at least two of value A or value B or value C. Absence of this filed may correspond to either value A or value B or value C. When the indication includes the RS selection method field, the indication may further indicate the RS selection method field separately for serving cell RS selection and for candidate cell RS selection. In this case, the indication may include a flag to distinguish whether the indication is for serving cell RS selection or for candidate cell RS selection or for both selections.

[0173] For example, if the RS selection method field is set to value A or equivalent to value A (e.g., first value), the UE may use Quasi-Co-Located (QCL) RS of the indicated TCI state of the concerned serving cell as applicable RS for evaluation of the event.

[0174] For example, if the RS selection method field is set to value B equivalent to value B (e.g., second value), the UE may use QCL RS(s) of the activated TCI states of the concerned cell (serving cell or candidate cell) as applicable RS for evaluation of the event.

[0175] For example, if the RS selection method field is set to value C equivalent to value C (e.g., third value), the UE may use configured RSs of the concerned cell (serving cell or candidate cell) as applicable RS for evaluation of the event.

[0176] For example, the indication may be transmitted via DCI or MAC CE. Or, the indication may be transmitted via RRC control signaling.

[0177] For example, the indication may be used to indicate activation and / or deactivation of event(s) by including an activation flag and / or a deactivation flag. The indication may indicate the event ID or association ID to activate or deactivate.

[0178] According to implementations of the present disclosure, if the quality of the applicable RS satisfies the event, the UE may transmit measurement report including at least one of the quality of the applicable RSs or RS identification information (e.g., RS index or event ID or association ID).

[0179] According to implementations of the present disclosure, the event-triggered L1 report may be transmitted as MAC CE. The MAC CE triggered by the event may include the quality of the RS satisfying the event.

[0180] The following drawings are created to explain specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals / messages / fields shown in the drawings are provided by way of example, and thus the technical features of the present disclosure are not limited to the specific names used in the following drawings.

[0181] An embodiment of the present disclosure related to a specific drawing described below may be combined with various embodiments of the present disclosure related to other drawings, and some descriptions, functions, procedures, proposals, methods and / or operations of the embodiment may be omitted.

[0182] FIG. 10 shows an example of a method to which implementations of the present disclosure are applied.

[0183] In step S1000, the method comprises obtaining measurement results of a first set of reference signals configured for an event.

[0184] In step S1010, the method comprises deriving a representative metric for evaluation of the event based on measurement results of a second set of reference signals.

[0185] In step S1020, the method comprises evaluating the event based on the representative metric.

[0186] In step S1030, the method comprises transmitting the measurement results of the second set of reference signals to a network based on the event being met.

[0187] In some implementations, the first set of reference signals may be associated with one or more configured candidate cells. Each reference signal of the first set of reference signals may be respectively associated with each candidate cell of the one or more configured candidate cells. Each reference signal of the first set of reference signals may be configured as a channel state information (CSI) resource.

[0188] In some implementations, the method may further comprise receiving a configuration for a number of reference signals included in the second set of reference signals from the network. The number of reference signals included in the second set of reference signals may be differently configured for different cells.

[0189] In some implementations, the second set of reference signals may be a subset of the first set of reference signals, and the measurement results of the second set of reference signals may correspond to best measurement results among the measurement results of the first set of reference signals.

[0190] In some implementations, the method may further comprise receiving a configuration for a minimum number of reference signals from the network. The method may further comprise determining that the event is not met based on a number of reference signals included in the first set of reference signals being less than the minimum number of reference signals. The method may further comprise determining whether the minimum number of reference signals is applicable for a cell based on the configuration. The minimum number of reference signals may be differently configured for different cells. A number of reference signals included in the second set of reference signals may be equal to or less than the minimum number of reference signals. A number of reference signals included in the second set of reference signals may be equal to the minimum number of reference signals, based on a number of reference signals included in the second set of reference signals not being configured.

[0191] In some implementations, the method may further comprise receiving a configuration for a minimum quality threshold from the network. The method may further comprise determining that the event is not met based on the measurement results of the second set of reference signals being below the minimum quality threshold.

[0192] In some implementations, at least one best measurement result among the measurement results of the second set of reference signals may be considered as the representative metric. Or, an average of the measurement results of the second set of reference signals may be considered as the representative metric.

[0193] In some implementations, the method may be performed by a wireless device in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the wireless device.

[0194] Furthermore, the method in perspective of the wireless device described above in FIG. 10 may be performed by the first wireless device 100 shown in FIG. 2 and / or the UE 100 shown in FIG. 3.

[0195] The wireless device comprises at least one transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform the method described in FIG. 10.

[0196] More specifically, the wireless device obtains measurement results of a first set of reference signals configured for an event.

[0197] The wireless device derives a representative metric for evaluation of the event based on measurement results of a second set of reference signals.

[0198] The wireless device evaluates the event based on the representative metric.

[0199] The wireless device transmits, via the at least one transceiver, the measurement results of the second set of reference signals to a network based on the event being met.

[0200] In some implementations, the first set of reference signals may be associated with one or more configured candidate cells. Each reference signal of the first set of reference signals may be respectively associated with each candidate cell of the one or more configured candidate cells. Each reference signal of the first set of reference signals may be configured as a channel state information (CSI) resource.In some implementations, the wireless device may receive a configuration for a number of reference signals included in the second set of reference signals from the network. The number of reference signals included in the second set of reference signals may be differently configured for different cells.

[0201] In some implementations, the second set of reference signals may be a subset of the first set of reference signals, and the measurement results of the second set of reference signals may correspond to best measurement results among the measurement results of the first set of reference signals.

[0202] In some implementations, the wireless device may receive a configuration for a minimum number of reference signals from the network. The wireless device may determine that the event is not met based on a number of reference signals included in the first set of reference signals being less than the minimum number of reference signals. The wireless device may determine whether the minimum number of reference signals is applicable for a cell based on the configuration. The minimum number of reference signals may be differently configured for different cells. A number of reference signals included in the second set of reference signals may be equal to or less than the minimum number of reference signals. A number of reference signals included in the second set of reference signals may be equal to the minimum number of reference signals, based on a number of reference signals included in the second set of reference signals not being configured.

[0203] In some implementations, the wireless device may receive a configuration for a minimum quality threshold from the network. The wireless device may determine that the event is not met based on the measurement results of the second set of reference signals being below the minimum quality threshold.

[0204] In some implementations, at least one best measurement result among the measurement results of the second set of reference signals may be considered as the representative metric. Or, an average of the measurement results of the second set of reference signals may be considered as the representative metric.

[0205] Furthermore, the method in perspective of the wireless device described above in FIG. 10 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.

[0206] A processing apparatus adapted to control a wireless device comprises at least one processor, and at least one memory operably connectable to the at least one processor. The at least one processor is adapted to perform the method described in FIG. 10.

[0207] Furthermore, the method in perspective of the wireless device described above in FIG. 10 may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.

[0208] The technical features of the present disclosure may be embodied directly in hardware, in a software executed by a processor, or in a combination of the two. For example, a method performed by a wireless device in a wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, a software may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other storage medium.

[0209] Some example of storage medium may be coupled to the processor such that the processor can read information from the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. For other example, the processor and the storage medium may reside as discrete components.

[0210] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0211] For example, non-transitory computer-readable media may include RAM such as Synchronous DRAM (SDRAM), ROM, Non-Volatile RAM (NVRAM), EEPROM, flash memory, magnetic or optical data storage media, or any other medium that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the above.

[0212] In addition, the method described herein may be realized at least in part by a computer-readable communication medium that carries or communicates code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer.

[0213] According to some implementations of the present disclosure, a non-transitory Computer-Readable Medium (CRM) stores instructions that, based on being executed by at least one processor, perform the method described in FIG. 10.

[0214] FIG. 11 shows an example of another method to which implementations of the present disclosure are applied.

[0215] In step S1100, the method comprises receiving measurement results of a second set of reference signals from a wireless device based on an event being met. Measurement results of a first set of reference signals configured for the event are obtained. A representative metric for evaluation of the event is derived based on measurement results of the second set of reference signals. The event is evaluated based on the representative metric.

[0216] Furthermore, the method in perspective of the base station described above in FIG. 11 may be performed by the second wireless device 200 shown in FIG. 2.

[0217] The base station comprises at least one transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform the method described in FIG. 11.

[0218] More specifically, the base station receives, via the at least one transceiver, measurement results of a second set of reference signals from a wireless device based on an event being met. Measurement results of a first set of reference signals configured for the event are obtained. A representative metric for evaluation of the event is derived based on measurement results of the second set of reference signals. The event is evaluated based on the representative metric.

[0219] FIG. 12 shows an example of applicable RS selection to which implementations of the present disclosure are applied.

[0220] An embodiment described in FIG. 12 may be related to dynamic event activation / deactivation with association between RS Measurement Objects (MO) and Report Configuration (RC). In FIG. 12, when activating a certain event for a certain RS set, the indication MAC CE may be transmitted. The indication MAC CE may indicate a new association ID, RS MO ID and / or RS RC ID. Then, the indicated RS MO and RS RC may be associated, and this measurement reporting may be identified by the indicated association ID. When transmitting measurement report upon meeting the event associated with the association ID, the UE may include the associated ID and measurement results.

[0221] In step S1200, the UE may be configured with RS MO list and RS RC list via RRC signaling.

[0222] For example, in the RS MO list, MO#1, MO#2, MO#3, MO#4 and MO#5 may be configured. MO#1 may be associated to RS set1 for cell#1, MO#2 may be associated to RS set1 for cell#2, MO#3 may be associated to RS set3 for cell#2, MO#4 may be associated to RS set4 for cell#3, and MO#5 may be associated to RS set5 for cell#3.

[0223] For example, in the RS RC list, RC#1, RC#2, RC#3, RC#4 and RC#5 may be configured. RC#1 may be associated to event config1, RC#2 may be associated to event config2, RC#3 may be associated to event config3, RC#4 may be associated to event config4, and RC#5 may be associated to event config5.

[0224] In step S1210, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#1, MO#1 and RC#1.

[0225] In step S1212, the UE may evaluate RSs in MO#1 based on event config1.

[0226] In step S1230, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate deactivation of association ID#3. The indication MAC CE may further indicate activation related to association ID#4, MO#4 and RC#4. The indication MAC CE may further indicate activation related to association ID#5, MO#5 and RC#5.

[0227] In step S1232, the UE may evaluate RSs in MO#1, MO#2, MO#4 and MO#5 based on event config1, event config2, event config4 and event config5, respectively.

[0228] FIG. 13 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0229] An embodiment described in FIG. 13 may be related to dynamic activation / deactivation with RS selection based on value A / B / C. In FIG. 13, when activating a certain association, the indication MAC CE may be transmitted. The indication MAC CE may indicate the association ID. Then, the UE may perform measurement of the RS set associated with the association ID and evaluate the event associated with the association ID. When transmitting measurement report upon meeting the event associated with the association ID, the UE may include the associated ID and measurement results.

[0230] In step S1300, the UE may be configured with RS MO list, RS RC list and association between RS MO and RS RC via RRC signaling.

[0231] For example, in the RS MO list, MO#1, MO#2, MO#3, MO#4 and MO#5 may be configured. MO#1 may be associated to RS set1 for cell#1, MO#2 may be associated to RS set1 for cell#2, MO#3 may be associated to RS set3 for cell#2, MO#4 may be associated to RS set4 for cell#3, and MO#5 may be associated to RS set5 for cell#3.

[0232] For example, in the RS RC list, RC#1, RC#2, RC#3, RC#4 and RC#5 may be configured. RC#1 may be associated to event config1, RC#2 may be associated to event config2, RC#3 may be associated to event config3, RC#4 may be associated to event config4, and RC#5 may be associated to event config5.

[0233] For example, in the association between the RS MO and RS RC, ID#1, ID#2, ID#3, ID#4 and ID#5 may be configured. ID#1 may associate MO#1 and RC#1, ID#2 may associate MO#2 and RC#2, ID#3 may associate MO#3 and RC#3, ID#4 may associate MO#4 and RC#4, and ID#5 may associate MO#5 and RC#5.

[0234] In step S1310, the serving cell may transmit a TCI indication command for cell 1 to the UE. The TCI indication command may indicate a TCI state to be indicated.

[0235] In step S1312, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#1 and value A.

[0236] In step S1314, the UE may evaluate QCL RS of indicated TCI for cell 1 based event config1.

[0237] In step S1320, the serving cell may transmit a TCI indication command for cell 3 to the UE. The TCI indication command may indicate a list of DCI states to be activated.

[0238] In step S1322, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#2 and value B. The indication MAC CE may further indicate activation related to association ID#5 and value C.

[0239] In step S1324, the UE may evaluate QCL RS of activated TCIs for cell 2 based event config2. The UE may evaluate RSs in MO#5 for cell 3 based event config5.

[0240] FIG. 14 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0241] An embodiment described in FIG. 14 may be related to dynamic activation / deactivation of event with cell indication. In FIG. 14, when activating a certain association, the indication MAC CE may be transmitted. The indication MAC CE may indicate the association ID. For example, if at least one TCI state is activated or indicated for a cell (serving cell or candidate cell), the indication MAC CE may further indicate that QCL RS of the indicated TCI state of the cell is the applicable RS for the event associated with the association ID, by indicating value A. For example, the indication MAC CE may further indicate that QCL RS of the activated TCI state of the cell is the applicable RS for the event associated with the association ID, by indicating value B. For example, the indication MAC CE may further indicate that all the RSs included in the RS set associated with the association ID are applicable RSs for the event associated with the association ID. For example, if there is no TCI state activated or indicated for a cell (serving cell or candidate cell), the indication MAC CE may further indicate that all the RSs included in the RS set associated with the association ID are applicable RSs for the event associated with the association ID. Then, the UE may perform measurement of the applicable RS(s) and evaluate the event associated with the association ID. When transmitting measurement report upon meeting the event associated with the association ID, the UE may include the associated ID and measurement results.

[0242] In step S1400, the UE may be configured with RS MO list, RS RC list and association between RS MO and RS RC via RRC signaling.

[0243] For example, in the RS MO list, MO#1, MO#2, MO#3, MO#4 and MO#5 may be configured. MO#1 may be associated to RS set1 for cell#1, MO#2 may be associated to RS set1 for cell#2, MO#3 may be associated to RS set3 for cell#2, MO#4 may be associated to RS set4 for cell#3, and MO#5 may be associated to RS set5 for cell#3.

[0244] For example, in the RS RC list, RC#1, RC#2, RC#3, RC#4 and RC#5 may be configured. RC#1 may be associated to event config1, RC#2 may be associated to event config2, RC#3 may be associated to event config3, RC#4 may be associated to event config4, and RC#5 may be associated to event config5.

[0245] For example, in the association between the RS MO and RS RC, ID#1, ID#2, ID#3, ID#4 and ID#5 may be configured. ID#1 may associate MO#1 and RC#1, ID#2 may associate MO#2 and RC#2, ID#3 may associate MO#3 and RC#3, ID#4 may associate MO#4 and RC#4, and ID#5 may associate MO#5 and RC#5.

[0246] In step S1410, the serving cell may transmit a TCI indication command for cell 1 to the UE. The TCI indication command may indicate a TCI state to be indicated.

[0247] In step S1412, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#1.

[0248] In step S1414, the UE may evaluate RSs in MO#1 for cell 1 based event config1.

[0249] In step S1420, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate cell1 and value A.

[0250] In step S1422, the UE may evaluate QCL RSs of indicated TCI for cell 1 based on event config1.

[0251] In step S1430, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#5.

[0252] In step S1432, the UE may evaluate QCL RSs of indicated TCI for cell 1 based on event config1. The UE may further evaluate RSs in MO#5 for cell 3 based on event config5.

[0253] In step S1440, the serving cell may transmit a TCI indication command for cell 3 to the UE. The TCI indication command may indicate a list of DCI states to be activated.

[0254] In step S1442, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate cell3 and value B.

[0255] In step S1444, the UE may evaluate QCL RSs of indicated TCI for cell 1 based on event config1. The UE may further evaluate QCL RS of activated TCIs for cell 3 based on event config5.

[0256] FIG. 15 shows another example of applicable RS selection to which implementations of the present disclosure are applied.

[0257] An embodiment described in FIG. 15 may be related to dynamic activation / deactivation of event with RS selection via bitmap. In FIG. 15, when activating a certain association, the indication MAC CE may be transmitted. The indication MAC CE may indicate a certain association ID, and the indication MAC CE may further indicate a RS selection bitmap. The RS selection bitmap may indicate which RS included in the RS set associated with the association ID should not be considered as applicable RS for the event associated with the association ID. The size of the bitmap may be equal to the number of RSs included in the RS set, and the first bit of the bitmap corresponds to the first RS entry of the RS set, the second bit of the bitmap corresponds to the second RS entry of the RS set, and so forth. If the bit is zero, the corresponding RS may not be considered as applicable RS. If the bit is one, the corresponding RS may be considered as applicable RS, until further restriction to exclude the RS from the applicable RS set is enforced.

[0258] In step S1500, the UE may be configured with RS MO list, RS RC list and association between RS MO and RS RC via RRC signaling.

[0259] For example, in the RS MO list, MO#1, MO#2 and MO#3 may be configured. MO#1 may be associated to RS set1 for cell#1, MO#2 may be associated to RS set1 for cell#2, and MO#3 may be associated to RS set3 for cell#2.

[0260] For example, in the RS RC list, RC#1, RC#2 and RC#3 may be configured. RC#1 may be associated to event config1, RC#2 may be associated to event config2, and RC#3 may be associated to event config3.

[0261] For example, in the association between the RS MO and RS RC, ID#1, ID#2 and ID#3 may be configured. ID#1 may associate MO#1 and RC#1, ID#2 may associate MO#2 and RC#2, and ID#3 may associate MO#3 and RC#3.

[0262] In step S1510, the serving cell may transmit a TCI indication command for cell 1 to the UE. The TCI indication command may indicate a TCI state to be indicated.

[0263] In step S1512, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#1 and value A.

[0264] In step S1514, the UE may evaluate QCL RSs of indicated TCI for cell 1 based on event config1.

[0265] In step S1520, the serving cell may transmit the indication MAC CE. The indication MAC CE may indicate activation related to association ID#2 and RS selection bitmap.

[0266] In step S1522, the UE may evaluate BIT1 RSs in MO#2 for cell 2 based on event config2.

[0267] In the description above, various implementations related to selection of applicable RSs for event evaluation based on network indication have been described. Furthermore, according to implementations of the present disclosure, once applicable RSs are selected based on network indication, the selected applicable RSs may be further down-selected based on the method to be described below. If the further down-selection is performed, the UE may consider the down-selected RSs as applicable RSs.

[0268] The UE may be configured with multiple RSs for serving cell and candidate cells.

[0269] The UE may be configured with one or multiple report configurations for L1 reporting. The L1 reporting may be CSI reporting or beam-related status / quality reporting. The report configuration may include one or more events. The event may be associated with one or multiple RSs, and / or a RS set. The event may be related to evaluation of measurement result of the associated RSs and / or CSI metric derived based on measurement result. If the event is met, the UE may transmit L1 report including the measurement result of the associated RS(s) related to the event and / or the CSI metric related RS.

[0270] The RSs configured to the UE may be divided into separate RS sets, depending on the properties or status of each RS, as determined by the UE.

[0271] For example, the UE may identify a synchronous RS set and an un-synchronous RS set. For a RS, the UE may consider that the RS belongs to the synchronous RS set if all or some of the following conditions are met (depending on embodiments):

[0272] - The UE has detected the RS;

[0273] - The UE has detected the RS within a period of time with respect to the current time;

[0274] - The UE has measured the RS within a period of time with respect to the current time;

[0275] - The RS quality (RSRP / Signal-to-Noise Ratio (SNR)) is beyond a threshold;

[0276] - The RS is associated with a candidate cell for which timing advance is known to the UE;

[0277] - The RS is associated with a candidate cell for which UE transmitted PRACH within a period of time with respect to the current time.

[0278] Otherwise, the UE may consider that the RS belongs to the un-synchronous RS set.

[0279] The RSs configured to the UE may be divided into separate RS sets, depending on the properties or status of each RS, as dynamically indicated by the network. The network may dynamically indicate RS(s) to be applicable among the associated RSs. For example, the network may indicate via MAC CE which RS(s), among the associated RSs, to be considered applicable for the event. For this purpose, the MAC CE may indicate the event identification information and the information indicating the applicable RS(s) for the event. DCI may be used, as similar to the MAC CE. For the indication the applicable RS(s) for the event via MAC CE / DCI, the network may indicate a bitmap where each bit corresponds to a specific RS among the configured RSs. To address the case where the number of configured RSs exceeds the size of the bitmap, the correspondence between the bitmap and the corresponding RSs may be also configured or indicated by the network.

[0280] The RSs configured to the UE may be divided into separate RS sets, depending on the properties or status of candidate cell associated with the event, as dynamically indicated by the network. The network may dynamically indicate candidate cell(s) to be applicable among the configured candidate cells. If a RS is associated with event and the event is associated with a candidate cell for which the network has indicated as applicable cell, the UE may consider the RS to be applicable for the event.

[0281] The RSs configured to the UE may be divided into separate RS sets, depending on the properties or status of candidate cell associated with the event, as dynamically determined by the UE. The UE may dynamically select one or more applicable candidate cell among the configured candidate cells. The UE may perform the selection based on L3 measurement quality, and select a candidate cell as applicable candidate cell if the L3 measurement quality of the cell exceeds a threshold and / or if the L3 measurement quality is better than the quality of the current serving cell. If a RS is associated with event and the event is associated with a candidate cell for which the UE has selected as applicable cell, the UE may consider the RS to be applicable for the event.

[0282] The UE may perform measurements of the configured RSs.

[0283] For a concerned event for L1 event-triggered report, the UE may consider a RS belonging to a particular RS set, to be applicable for the event. Then, the event may be met only by the particular RS set. When the network configures the L1 event to the UE, the network may indicate the particular RS set to be considered by the UE for the evaluation of the event.

[0284] For example, the UE may be configured with a L1 event, where the event is met if the quality of the associated RS is higher than a threshold1. Then, in case quality of a RS is higher than the threshold1, the UE may only consider the event to be met, only if the RS belongs to the synchronous RS set, not in the un-synchronous RS set. That is, even if a RS belonging to the un-synchronous RS set meets the quality-criterion of the event, the UE may not consider that the event is met by the RS.

[0285] For example, the UE may be configured with a L1 event, where the event is met if the quality of the associated RS is higher than a threshold2. Then, in case quality of a RS is higher than the threshold2, the UE may only consider the event to be met, only if the RS belongs to the un-synchronous RS set, not in the synchronous RS set. That is, even if a RS belonging to the synchronous RS set meets the quality-criterion of the event, the UE may not consider that the event is met by the RS.

[0286] FIGS. 16 and 17 show an example of selecting synchronous RSs as applicable RSs to which implementations of the present disclosure are applied.

[0287] In FIGS. 16 and 17, the UE may select synchronous RSs as applicable RSs for the event, and evaluate the event. If the event is met, the UE may transmit measurement result of the RSs. Specifically, FIG. 17 shows synchronization status and measured quality of each RS over time.

[0288] In step S1600, the UE may be configured with two RS sets, i.e., RS set#1 and RS set#2. RS set#1 may comprise RS1, RS2, RS3 and RS4. RS set#2 may comprise RS5 and RS6.

[0289] In step S1610, the UE may be configured with L1 event-triggered report configuration. The L1 event-triggered report configuration may include event1 and event2. Event1 may be considered to be met, if the quality of the measured RS of associated RS is higher than threshold1. Event2 may be considered to be met, if the quality of the measured RS of associated RS is higher than threshold2. Event1 may be associated with synchronous RSs of the RS set#1, and event2 may be associated with un-synchronous RSs of the RS set#1.

[0290] The UE may perform measurements of configured RSs. The UE may also identify the status of the configured RS. The UE may evaluate event1 and event2.

[0291] At t1 (referring to FIG. 17):

[0292] - RS1 and RS2 are identified as synchronous RS, and RS3 and RS4 are identified as un- synchronous RS.

[0293] - The quality of RS1 and RS2 exceeds threshold2, but event2 is not met since the RS1 and RS2 are not un-synchronous RS. Therefore, L1 event-triggered report is not triggered by event2.

[0294] - The quality of all RSs is below threshold1, so event1 is not met. Therefore, L1 event-triggered report is not triggered by event1.

[0295] At t2 (referring to FIG. 17):

[0296] - RS1 and RS2 are identified as synchronous RS, and RS3 and RS4 are identified as un-synchronous RS.

[0297] - The quality of RS1, RS2 and RS3 exceeds threshold2. Event2 is met by the RS3. Therefore, L1 event-triggered report is triggered by event2. The L1 event-triggered report includes CSI of RS3 as a triggering RS (or applicable RS).

[0298] - The L1 event-triggered report may also include CSI of RS1 and RS2, as they also satisfy quality criterion of the event. In this case, the L1 event-triggered report may need to make sure that this RS is not a triggering RS via indication or separate reporting placeholder.

[0299] - The L1 event-triggered report may also include CSI of RS4, as the RS#4 is also un-synchronous RS. In this case, the L1 event-triggered report may need to make sure that this RS is not a triggering RS via indication or separate reporting placeholder.

[0300] - The quality of all RSs is below threshold1, so event1 is not met. Therefore, L1 event-triggered report is not triggered by event1.

[0301] In summary, in step S1620, the UE may transmit L1 measurement report triggered by event2 which is met by RS3. The L1 measurement report may include CSI of RS1, RS2 and RS3.

[0302] At t3 (referring to FIG. 17):

[0303] - RS1 and RS2 are identified as synchronous RS, and RS3 and RS4 are identified as un-synchronous RS.

[0304] - The quality of RS1, RS2 and RS3 exceeds threshold2, but the set of RSs satisfying event2 is same as those for previous L1 event-triggered report triggered by event2 (i.e., step S1620), so no L1 event-triggered report is triggered again.

[0305] - The quality of RS1 exceeds threshold1, so event1 is met. Therefore, L1 event-triggered report is triggered by event1. The L1 event-triggered report includes CSI of RS1 as a triggering RS.

[0306] - The L1 event-triggered report may also include CSI of RS2, as RS2 is also synchronous RS. In this case, the L1 event-triggered report may need to make sure that this RS is not a triggering RS via indication or separate reporting placeholder.

[0307] In summary, in step S1630, the UE may transmit L1 measurement report triggered by event1 which is met by RS1. The L1 measurement report may include CSI of RS1 and RS2.

[0308] At t4 (referring to FIG. 17):

[0309] - RS1 and RS2 are identified as synchronous RS, and RS3 and RS4 are identified as un-synchronous RS.

[0310] - The quality of RS1, RS2 and RS3 exceeds threshold2, but the set of RSs satisfying event2 is same as those for previous L1 event-triggered report triggered by event2, so no L1 event-triggered report is triggered again.

[0311] - The quality of RS3 exceeds threshold1, but event1 is not met since the RS#3 is un-synchronous RS. The set of RSs satisfying event1 is same as those for previous L1 event-triggered report triggered by event1. Therefore, L1 event-triggered report is not triggered by event1.

[0312] - The quality of RS1, RS2 and RS3 exceeds threshold2, and the RS3 is un-synchronous RS, but event2 is not met by RS3 as the set of RSs satisfying event2 is same as those for previous L1 event-triggered report triggered by event2.

[0313] At t5 (referring to FIG. 17):

[0314] - The RS3 is identified as synchronous RS. With this change, the L1 event-triggered report is triggered by event1 for RS3.

[0315] To further reduce measurement overhead, the UE may select RSs of a candidate cell to measure based on whether the UE may assume that a valid UL timing value is available for the candidate cell (e.g., timing advance based on UE-based TA calculation) or the UE can expect that network may have a valid UL timing value (e.g., the UE has transmitted PRACH within a period of time). If the valid UL timing value is not available, the UE may skip performing the measurement of the RSs of the candidate cell or the UE may perform measurement only on a subset of the RSs of the candidate cell, where the subset of the RSs may be (pre)configured by the network.

[0316] The present disclosure may have various advantageous effects.

[0317] For example, by performing event evaluation using a metric that reflects the quality of multiple beams, frequent measurement reports can be prevented and mobility triggered to cells with good quality only for specific beams can also be prevented.

[0318] 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.

[0319] 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:obtaining measurement results of a first set of reference signals configured for an event;deriving a representative metric for evaluation of the event based on measurement results of a second set of reference signals;evaluating the event based on the representative metric; andtransmitting the measurement results of the second set of reference signals to a network based on the event being met.2.The method of claim 1, wherein the first set of reference signals is associated with one or more configured candidate cells,wherein each reference signal of the first set of reference signals is respectively associated with each candidate cell of the one or more configured candidate cells, andwherein each reference signal of the first set of reference signals is configured as a channel state information (CSI) resource.3.The method of claim 1 or 2, wherein the method further comprises receiving a configuration for a number of reference signals included in the second set of reference signals from the network.4.The method of claim 3, wherein the number of reference signals included in the second set of reference signals is differently configured for different cells.5.The method of any claims 1 to 4, wherein the second set of reference signals is a subset of the first set of reference signals, andwherein the measurement results of the second set of reference signals correspond to best measurement results among the measurement results of the first set of reference signals.6.The method of any claims 1 to 5, wherein the method further comprises receiving a configuration for a minimum number of reference signals from the network.7.The method of claim 6, wherein the method further comprises determining that the event is not met based on a number of reference signals included in the first set of reference signals being less than the minimum number of reference signals.8.The method of claim 6 or 7, wherein the method further comprises determining whether the minimum number of reference signals is applicable for a cell based on the configuration.9.The method of any claims 6 to 8, wherein the minimum number of reference signals is differently configured for different cells.10.The method of any claims 6 to 9, wherein a number of reference signals included in the second set of reference signals is equal to or less than the minimum number of reference signals.11.The method of any claims 5 to 10, wherein a number of reference signals included in the second set of reference signals is equal to the minimum number of reference signals, based on a number of reference signals included in the second set of reference signals not being configured.12.The method of any claims 1 to 11, wherein the method further comprises receiving a configuration for a minimum quality threshold from the network.13.The method of claim 12, wherein the method further comprises determining that the event is not met based on the measurement results of the second set of reference signals being below the minimum quality threshold.14.The method of any claims 1 to 13, wherein at least one best measurement result among the measurement results of the second set of reference signals is considered as the representative metric.15.The method of any claims 1 to 14, wherein an average of the measurement results of the second set of reference signals is considered as the representative metric.16.The method of any claims 1 to 15, wherein the method is performed by a wireless device in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the wireless device.17.A wireless device comprising:at least one transceiver;at least one memory; andat least one processor operably connectable to the at least one memory and the at least one transceiver,wherein the at least one memory stores instructions that, based on being executed by the at least one processor, cause the wireless device to perform the method of any claims 1 to 16.18.A processing apparatus comprising:at least one processor; andat least one memory operably connectable to the at least one processor,wherein the at least one processor is adapted to perform the method of any claims 1 to 16.19.A non-transitory Computer Readable Medium (CRM) storing instructions that, based on being executed by at least one processor, perform the method of any claims 1 to 16.20.A method comprising:receiving measurement results of a second set of reference signals from a wireless device based on an event being met,wherein measurement results of a first set of reference signals configured for the event are obtained,wherein a representative metric for evaluation of the event is derived based on measurement results of the second set of reference signals, andwherein the event is evaluated based on the representative metric.21.A base station comprising:at least one transceiver;at least one memory; andat least one processor operably connectable to the at least one memory and the at least one transceiver,wherein the at least one memory stores instructions that, based on being executed by the at least one processor, cause the base station to perform the method of claim 20.

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