Retaining triggering status of measurement reporting after transmission of truncated measurement report

Abstract

A method and apparatus for retaining a triggering status of a measurement reporting after transmission of a truncated measurement report is provided. For a measurement reporting which is triggered, the wireless device transmits at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to a base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC.

Description

RETAINING TRIGGERING STATUS OF MEASUREMENT REPORTING AFTER TRANSMISSION OF TRUNCATED MEASUREMENT REPORT

[0001] The present disclosure relates to retaining a triggering status of a measurement reporting after transmission of a truncated measurement report.

[0002] 3rd Generation Partnership Project (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.

[0003] 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.

[0004] 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.

[0005] In mobile communication systems, L1 measurement reporting is a fundamental procedure through which a User Equipment (UE) provides the network with channel quality and link performance measurements necessary for functions such as handover decisions and beam management. These measurement reports are transmitted over Uplink (UL) resources, which are allocated by the network and are inherently limited in wireless communication environments.

[0006] In certain situations, the UL resources available to the UE at the time of a measurement reporting event may be insufficient to accommodate a full-sized, normal L1 measurement report containing all required measurement information. In such cases, the UE may be required to transmit a truncated L1 measurement report that includes only essential information, omitting certain fields or measurements that would otherwise be present in a normal measurement report. While transmitting a truncated measurement report may allow the UE to convey critical measurement information within the constrained resource budget, it may result in the network receiving an incomplete picture of the radio environment, which could in turn affect the quality of network decisions.

[0007] When a truncated L1 measurement report is transmitted under such resource-constrained conditions, a further question may arise as to whether the UE should maintain the measurement reporting trigger state and subsequently transmit a normal L1 measurement report once sufficient UL resources become available. Without a clearly defined procedure governing this behavior, the UE may fail to follow up with a complete report even when resources later become available, or conversely, may retransmit unnecessarily, leading to ambiguity and inefficiency in the measurement reporting procedure.

[0008] Accordingly, there may be a need for a clearly defined mechanism that determines whether a UE, after transmitting a truncated L1 measurement report due to insufficient UL resources, should maintain the trigger state and proceed to transmit a normal L1 measurement report, thereby ensuring completeness and consistency in the L1 measurement reporting procedure.

[0009] In an aspect, a method performed by a wireless device is provided. The method includes, for a measurement reporting which is triggered, transmitting at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to a base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0010] In another aspect, a wireless device is provided. The wireless device includes 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, cause the wireless device to perform operations. The operations include, for a measurement reporting which is triggered, transmitting at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE to a base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0011] In another aspect, a processing apparatus is provided. The processing apparatus includes at least one processor that is integrated with a wireless device, and at least one memory comprising processor-executable instructions stored thereon that are configured to cause the at least one processor to perform operations. The operations include, for a measurement reporting which is triggered, generating at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0012] In another aspect, a non-transitory Computer Readable Medium (CRM) storing instructions that, based on being executed by at least one processor, cause a wireless device to perform operations is provided. The operations include, for a measurement reporting which is triggered, transmitting at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to a base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0013] In another aspect, a method performed by a base station device is provided. The method includes, for a measurement reporting which is triggered, receiving at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE from the wireless device. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0014] In another aspect, a base station is provided. The base station includes 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, cause the base station to perform operations. The operations include, for a measurement reporting which is triggered, receiving at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE from the wireless device. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0015] The present disclosure may have various advantageous effects.

[0016] For example, even when a UE has transmitted a truncated L1 measurement report MAC CE containing only essential measurement information due to insufficient uplink resources, the subsequent transmission of a normal L1 measurement report MAC CE can be guaranteed. By ensuring that the measurement reporting trigger state is maintained following a truncated transmission, the UE can proceed to transmit a complete normal L1 measurement report once adequate uplink resources become available, without the reporting procedure being prematurely terminated or abandoned.

[0017] For example, by guaranteeing the eventual delivery of a normal L1 measurement report MAC CE, the network can be ensured to ultimately receive the full set of measurement information that was not included in the truncated report. This can enable the network to make more accurate and reliable decisions in procedures that depend on L1 measurement results, such as handover control, beam management, and link adaptation, thereby contributing to improved overall system performance and user experience.

[0018] For example, by clearly defining the UE behavior following the transmission of a truncated L1 measurement report, ambiguity in the measurement reporting procedure can be eliminated. This can prevent situations where the network operates based on incomplete measurement information for an extended period, and can also prevent unnecessary repetition or omission of measurement reporting, thereby contributing to more consistent and predictable UE operation in resource-constrained environments.

[0019] 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.

[0020] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0021] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0022] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0023] 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.

[0024] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0025] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0026] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0027] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0028] FIG. 10 shows an example of a method performed by a wireless device to which the implementation 1 of the present disclosure is applied.

[0029] FIG. 11 shows an example of a method performed by a base station to which the implementation 1 of the present disclosure is applied.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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".

[0034] 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".

[0035] 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".

[0036] 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".

[0037] 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".

[0038] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0039] 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.

[0040] 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.

[0041] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0042] 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.

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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).

[0052] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0053] 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).

[0054] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0055] 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.

[0056] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0077] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0078] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0079] 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.

[0080] The processor 102 may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include ASIC, other chipset, logic circuit and / or data processing device. The processor 102 may be an application processor. The processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator). An example of the processor 102 may be found in SNAPDRAGONTMseries of processors made by QUALCOMM®, EXYNOSTMseries of processors made by SAMSUNG®, A series of processors made by APPLE®, HELIOTMseries of processors made by MEDIATEK®, ATOMTMseries of processors made by INTEL®or a corresponding next generation processor.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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).

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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).

[0093] 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.

[0094] 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.

[0095] 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.

[0096] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0101] 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.

[0102] uNslotsymbNframe,uslotNsubframe,uslot212404

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0108] 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.

[0109] 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.

[0110] Cell level mobility requires explicit RRC signaling to be triggered, i.e., handover.

[0111] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0112] For inter-gNB handover, the signaling procedures consist of at least the following elemental components described in FIG. 8.

[0113] 1. Step 1: The source gNB initiates handover and issues a HANDOVER REQUEST over the Xn interface.

[0114] 2. Step 2: The target gNB performs admission control and provides the new RRC configuration as part of the HANDOVER REQUEST ACKNOWLEDGE.

[0115] 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.

[0116] 4. Step 4: The UE moves the RRC connection to the target gNB and replies with theRRCReconfigurationComplete.

[0117] User data may also be sent in step 4 if the grant allows.

[0118] 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.

[0119] 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).

[0120] 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.

[0121] The following principles apply to CHO:

[0122] - 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.

[0123] - 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.

[0124] - 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.

[0125] - While executing CHO, i.e., from the time when the UE starts synchronization with target cell, the UE does not monitor source cell.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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).

[0130] The following principles apply to LTM:

[0131] - The UE does not update its security key after an intra-gNB LTM cell switch.

[0132] - Subsequent LTM is supported.

[0133] 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:

[0134] - PCell change in non-CA scenario and non-DC scenario,

[0135] - PCell change in CA scenario,

[0136] - DC scenario, MCG PCell change and SCG PSCell change without MN involvement case (i.e., intra-SN PSCell change).

[0137] While the UE has stored LTM candidate cell configurations, the UE can also execute any L3 handover command sent by the network.

[0138] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0139] Cell switch command is conveyed in a MAC Control Element (CE), which contains the necessary information to perform the LTM cell switch.

[0140] 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.

[0141] The signaling procedure for LTM is as follows.

[0142] 1. Step 1: The UE sends aMeasurementReportmessage to the gNB. The gNB decides to configure LTM and initiates candidate cell(s) preparation.

[0143] 2. Step 2: The gNB transmits anRRCReconfigurationmessage to the UE including the LTM candidate cell configurations of one or multiple candidate cells.

[0144] 3. Step 3: The UE stores the LTM candidate cell configurations and transmits anRRCReconfigurationCompletemessage to the gNB.

[0145] 4a. Step 4a: The UE may perform DL synchronization with the candidate cell(s) before receiving the cell switch command.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] The steps 4-8 can be performed multiple times for subsequent LTM using the LTM candidate cell configuration(s) provided in step 2.

[0152] Table 5 shows an example ofLTM-ConfigInformation Element (IE). TheLTM-ConfigIE may be used to provide LTM candidate configurations.

[0153] -- ASN1START-- TAG-LTM-CONFIG-STARTLTM-Config-r18 ::= SEQUENCE {ltm-ReferenceConfiguration-r18 SetupRelease {ReferenceConfiguration-r18} OPTIONAL, -- Need Mltm-CandidateToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofLTM-Configs-r18)) OF LTM-CandidateId-r18 OPTIONAL, -- Need Nltm-CandidateToAddModList-r18 SEQUENCE (SIZE (1..maxNrofLTM-Configs-r18)) OF LTM-Candidate-r18 OPTIONAL, -- Need Nltm-ServingCellNoResetID-r18 INTEGER (1..maxNrofLTM-Configs-r18-plus-1) OPTIONAL, -- Cond FirstLTM-Onlyltm-CSI-ResourceConfigToAddModList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ResourceConfigurations-r18)) OF LTM-CSI-ResourceConfig-r18 OPTIONAL, -- Need Nltm-CSI-ResourceConfigToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-ResourceConfigurations-r18)) OF LTM-CSI-ResourceConfigId-r18 OPTIONAL, -- Need NattemptLTM-Switch-r18 ENUMERATED {true} OPTIONAL, -- Cond LTM-MCGltm-ServingCellUE-MeasuredTA-ID-r18 INTEGER (1..maxNrofLTM-Configs-r18-plus-1) OPTIONAL, -- Cond LTM...}-- TAG-LTM-CONFIG-STOP-- ASN1STOP

[0154] Table 6 shows an example ofLTM-CandidateIE. The IELTM-Candidateconcerns a LTM candidate configuration to add or modify.

[0155] -- ASN1START-- TAG-LTM-CANDIDATE-STARTLTM-Candidate-r18 ::= SEQUENCE {ltm-CandidateId-r18 LTM-CandidateId-r18,ltm-CandidatePCI-r18 PhysCellId,ltm-SSB-Config-r18 LTM-SSB-Config-r18 OPTIONAL, -- Need Mltm-CandidateConfig-r18 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Need Mltm-ConfigComplete-r18 ENUMERATED {true} OPTIONAL, -- Need Rltm-EarlyUL-SyncConfig-r18 SetupRelease { EarlyUL-SyncConfig-r18 } OPTIONAL, -- Need Mltm-EarlyUL-SyncConfigSUL-r18 SetupRelease { EarlyUL-SyncConfig-r18 } OPTIONAL, -- Need Mltm-NoResetID-r18 INTEGER (1..maxNrofLTM-Configs-r18-plus-1) OPTIONAL, -- Need Mltm-DL-OrJointTCI-StateToAddModList-r18 SEQUENCE (SIZE (1..maxNrofCandidateTCI-State-r18)) OF CandidateTCI-State-r18 OPTIONAL, -- Need Nltm-DL-OrJointTCI-StateToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofCandidateTCI-State-r18)) OF TCI-StateId OPTIONAL, -- Need Nltm-UL-TCI-StatesToAddModList-r18 SEQUENCE (SIZE (1..maxNrofCandidateUL-TCI-r18)) OF CandidateTCI-UL-State-r18 OPTIONAL, -- Need Nltm-UL-TCI-StatesToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofCandidateUL-TCI-r18)) OF TCI-UL-StateId-r17 OPTIONAL, -- Need Nltm-nzp-CSI-RS-ResourceToAddModList-r18 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-Resource OPTIONAL, -- Need Nltm-nzp-CSI-RS-ResourceToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceId OPTIONAL, -- Need Nltm-nzp-CSI-RS-ResourceSetToAddModList-r18 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSet OPTIONAL, -- Need Nltm-nzp-CSI-RS-ResourceSetToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId OPTIONAL, -- Need NpathlossReferenceRS-ToAddModList-r18 SEQUENCE (SIZE (1..maxNrofPathlossReferenceRSs-r17)) OF PathlossReferenceRS-r17 OPTIONAL, -- Need NpathlossReferenceRS-ToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofPathlossReferenceRSs-r17)) OF PathlossReferenceRS-Id-r17 OPTIONAL, -- Need Nltm-UE-MeasuredTA-ID-r18 INTEGER (1..maxNrofLTM-Configs-r18-plus-1) OPTIONAL, -- Need M...}LTM-SSB-Config-r18 ::= SEQUENCE {ssbFrequency-r18 ARFCN-ValueNR,subcarrierSpacing-r18 SubcarrierSpacing,ssb-Periodicity-r18 ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1} OPTIONAL, -- Need Rssb-PositionsInBurst-r18 CHOICE {shortBitmap BIT STRING (SIZE (4)),mediumBitmap BIT STRING (SIZE (8)),longBitmap BIT STRING (SIZE (64))} OPTIONAL, -- Need Rss-PBCH-BlockPower-r18 INTEGER (-60..50) OPTIONAL, -- Need R...}-- TAG-LTM-CANDIDATE-STOP-- ASN1STOP

[0156] Table 7 shows an example ofLTM-CandidateIdIE. The IELTM-CandidateIdis used to identify an LTM candidate configuration.

[0157] -- ASN1START-- TAG-LTM-CANDIDATEID-STARTLTM-CandidateId-r18 ::= INTEGER (1..maxNrofLTM-Configs-r18)-- TAG-LTM-CANDIDATEID-STOP-- ASN1STOP

[0158] Table 8 shows an example ofLTM-CSI-ReportConfigIE. The IELTM-CSI-ReportConfigis used to configure report on the cell in which theLTM-CSI-ReportConfigis included.

[0159] -- ASN1START-- TAG-LTM-CSI-REPORTCONFIG-STARTLTM-CSI-ReportConfig-r18 ::= SEQUENCE {ltm-CSI-ReportConfigId-r18 LTM-CSI-ReportConfigId-r18,ltm-ResourcesForChannelMeasurement-r18 LTM-CSI-ResourceConfigId-r18,ltm-ReportConfigType-r18 CHOICE {periodic-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,pucch-CSI-ResourceList-r18 SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource},semiPersistentOnPUCCH-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,pucch-CSI-ResourceList-r18 SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource},semiPersistentOnPUSCH-r18 SEQUENCE {reportSlotConfig-r18 CSI-ReportPeriodicityAndOffset,reportSlotOffsetList-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-2-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-1-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128),p0alpha P0-PUSCH-AlphaSetId},aperiodic-r18 SEQUENCE {reportSlotOffsetList-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-2-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128),reportSlotOffsetListDCI-0-1-r18 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER (0..128)}},ltm-ReportContent-r18 LTM-ReportContent-r18,...}LTM-ReportContent-r18 ::= SEQUENCE {nrOfReportedCells-r18 ENUMERATED {n1,n2,n3,n4},nrOfReportedRS-PerCell-r18 ENUMERATED {n1,n2,n3,n4},spCellInclusion-r18 ENUMERATED {true} OPTIONAL -- Need R}-- TAG-LTM-CSI-REPORTCONFIG-STOP-- ASN1STOP

[0160] Table 9 shows an example ofLTM-CSI-ReportConfigIdIE. The IELTM-CSI-ReportConfigIdis used to identify anLTM-CSI-ReportConfig.

[0161] -- ASN1START-- TAG-LTM-CSI-REPORTCONFIGID-STARTLTM-CSI-ReportConfigId-r18 ::= INTEGER (0..maxNrofLTM-CSI-ReportConfigurations-1-r18)-- TAG-LTM-CSI-REPORTCONFIGID-STOP-- ASN1STOP

[0162] Table 10 shows an example ofLTM-CSI-ResourceConfigIE. TheLTM-CSI-ResourceConfigIE defines a group of one or more CSI resources for one or more LTM candidate configurations.

[0163] -- ASN1START-- TAG-LTM-CSI-RESOURCECONFIG-STARTLTM-CSI-ResourceConfig-r18 ::= SEQUENCE {ltm-CSI-ResourceConfigId-r18 LTM-CSI-ResourceConfigId-r18,ltm-CSI-SSB-ResourceSet-r18 LTM-CSI-SSB-ResourceSet-r18,...}LTM-CSI-SSB-ResourceSet-r18 ::= SEQUENCE {ltm-CSI-SSB-ResourceList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-SSB-ResourcesPerSet-r18)) OF SSB-Index,ltm-CandidateIdList-r18 SEQUENCE (SIZE (1..maxNrofLTM-CSI-SSB-ResourcesPerSet-r18)) OF LTM-CandidateId-r18,...}-- TAG-LTM-CSI-RESOURCECONFIG-STOP-- ASN1STOP

[0164] Table 11 shows an example ofLTM-CSI-ResourceConfigIdIE. The IELTM-CSI-ResourceConfigIdis used to identify anLTM-CSI-ResourceConfig.

[0165] -- ASN1START-- TAG-LTM-CSI-RESOURCECONFIGID-STARTLTM-CSI-ResourceConfigId-r18 ::= INTEGER (0..maxNrofLTM-CSI-ResourceConfigurations-r18-1)-- TAG-LTM-CSI-RESOURCECONFIGID-STOP-- ASN1STOP

[0166] The UE may be configured with one or more measurement resources / targets / objects (e.g., cell, beam, RS, etc.). The UE may be configured with one or more report conditions. Each report condition may be associated with at least one measurement resource. The UE may evaluate the report condition by performing measurement of the associated measurement resource. If the report condition is met for the associated measurement resource, the UE may trigger a measurement report procedure. Upon initiating the measurement report, the UE may transmit a measurement report including measurement results related to the measurement resource. For example, the measurement results related to the measurement resource may include beam identifier, beam quality and / or report condition information.

[0167] To achieve a fast cell switch, LTM is introduced in 5G NR Rel-18. For example, the UE may be configured with an LTM configuration related to one or more candidate cells in advance, and the LTM configuration for a candidate cell may include one or more conditions. When a condition related to a candidate cell is met, the UE may transmit measurement report to a serving cell.

[0168] To achieve high robustness and short interruption for mobility, a Conditional LTM (CLTM) will be introduced in 5G NR Rel-19. For example, the UE may be configured with a CLTM configuration related to one or more candidate cells in advance, and the CLTM configuration for a candidate cell may include one or more execution conditions. When an execution condition related to a candidate cell is met, the UE may execute the CLTM cell switch toward the candidate cell (i.e., target cell).

[0169] Regarding event triggered LTM measurement report, the followings have been discussed and / or agreed.

[0170] - Time-To-Trigger (TTT) may be evaluated per beam, and measurement report may only be triggered by beam that has satisfied the (entering / leaving) condition for the whole duration of TTT.

[0171] - TTT timer may not be restarted if the current beam changes and the entering condition is still met with the new current beam.

[0172] - TTT may be applied to the leaving condition.

[0173] - Network may configure which RS type (e.g., SSB or CSI-RS) is used for LTM event evaluation.

[0174] - Either CSI-RS or SSB may be configured as candidate beam and the measurement RS of the serving cell beam may be determined based on the candidate beam to ensure same RS type. For example, the RS for current beam of serving cell may be same as or Quasi-Co-Located (QCL-ed) with the QCL RS of the indicated Transmission Configuration Indicator (TCI) state.

[0175] - SSB Resource Indicator (SSBRI) and CSI-RS Resource Indicator (CRI) may be used to represent the candidate beam ID in the measurement report MAC CE.

[0176] - For event-triggered L1 LTM measurement reporting, maximum number N may be a total number of all beams included into the measurement report MAC CE.

[0177] - For event-triggered L1 LTM measurement reporting, the network may control if the beam(s) not satisfying the event could be reported according to N beams in the measurement report MAC CE.

[0178] - A single MAC CE format for the event-triggered L1 measurement report may be used for both the SSB and CSI-RS.

[0179] - The truncated measurement report MAC CE may be supported.

[0180] - For measurement resource configuration, Rel-18 LTM CSI resource configuration (e.g.,LTM-CSI-ResourceConfig) may be reused.

[0181] - The bits for SSB resource set may be carried when CSI-RS resource set is configured.

[0182] - For measurement reporting configuration, Rel-18 LTM CSI report configuration (e.g.,LTM-CSI-ReportConfig) may be reused.

[0183] - The existing RSRP values and RSRP offset values for event-triggered measurement report may be reused.

[0184] -TimeToTriggerandreportIntervalof L3 measurement report may be reused.

[0185] - Cell specific offset may not be supported for LTM L1 event evaluation.

[0186] - The trigger quantity for LTM L1 event triggered measurement may be the same as the report quantity.

[0187] - Explicit indication in measurement report MAC CE to inform which beam(s) meets the event condition with TTT.

[0188] - Explicit indication in measurement report MAC CE to inform the leaving event condition is met.

[0189] - LTM measurement report MAC CE may only include one triggered measurement event and the LTM measurement report MAC CE may be multiplexed in any available UL grant.

[0190] - Truncated measurement report MAC CE may include the triggered beam information: i) One report configuration ID (event config ID), and ii) at least one triggered beam ID (SSBRI or CRI) + L1 RSRP

[0191] - Common format for normal measurement report MAC CE and truncated measurement report MAC CE may be used.

[0192] - For truncated LTM measurement report MAC CE, an LCID separate from that for normal LTM measurement report MAC CE may be used.

[0193] From the discussions and / or agreements mentioned above, the followings problems may arise.

[0194] For example, when the UE receives a UL grant, the UE may already have more than one pending L1 measurement report MAC CEs to be transmitted. If the UL grant is insufficient to transmit all the pending L1 measurement report MAC CEs, the UE may need to decide which L1 measurement report MAC CE MR(s) to transmit first. In addition, the UE may need to be able to determine which L1 measurement report MAC CE(s) have to remain as pending MAC CE(s).

[0195] For example, considering multiple L1 measurement report MAC CEs are triggered by different LTM events, it may be unclear in which condition the UE is allowed to transmit truncated L1 measurement report MAC CE. It may also be undefined, upon transmitting truncated L1 measurement report MAC CE, whether to further transmit normal L1 measurement report MAC CE.

[0196] Hereinafter, various implementations related to the event triggered LTM measurement report are described.

[0197] In the present disclosure, a Measurement Target Resource (MTR) may be defined. An RS may be MTR. Additionally and / or alternatively, a set of RSs may be MTR. Additionally and / or alternatively, a beam may be MTR. Additionally and / or alternatively, a set of beams may be MTR. Additionally and / or alternatively, a cell may be MTR. Additionally and / or alternatively, a set of cells may be MTR. The MTR may be replaced with other names, such as a measurement target, a measurement resource, or a measurement object.

[0198] 1. Implementation 1: Truncated L1 measurement MAC CE

[0199] If there are more than one triggering beam and UL grant is insufficient to transmit all the triggering beams and other beam results, up to the predefined number of max beams in total, within normal L1 measurement report MAC CE (i.e., non-truncated L1 measurement report MAC CE), the UE may need to be able to determine whether the UE can use truncated L1 measurement report MAC CE or not.

[0200] For the determination, the following two options may be considered.

[0201] - Option 1: If the UL grant is sufficient to carry beam information of predefined number of beams, the UE may be allowed to use a truncated format for the L1 measurement report MAC CE. If the UL grant is not sufficient to carry beam information of predefined number of beams, the UE may not be allowed to use a truncated format for the L1 measurement report MAC CE.

[0202] For example, if the predefined number is 2, then UE may use a truncated format for the L1 measurement report MAC CE if the UL grant can accommodate beam information of two beams (here, the number of actual triggered beam for the event may be less than 2) but cannot accommodate beam information of all triggered beams and other non-triggered beams, up to the maximum number of beams in total, as required in a normal format for the L1 measurement report MAC CE.

[0203] - Option 2: If the UL grant is sufficient to carry beam information of all triggered beams, the UE may be allowed to use a truncated format for the L1 measurement report MAC CE. If the UL grant is not sufficient to carry beam information of all triggered beams, the UE may not be allowed to use a truncated format for the L1 measurement report MAC CE. After transmission of the truncated measurement report MAC CE, the triggered measurement reporting may be canceled.

[0204] For example, if the number of triggered beams is 3, then UE may use a truncated format for the L1 measurement report MAC CE if the UL grant can accommodate beam information of all three beams but cannot accommodate beam information of all three beams and other non-triggered beams, up to the maximum number of beams in total, as required in a normal format for the L1 measurement report MAC CE.

[0205] Upon transmitting the truncated L1 measurement report MAC CE triggered by an event, it should be decided i) whether the UE should keep attempting to transmit the normal L1 measurement report MAC CE for the event, or ii) whether the UE should refrain from transmitting the normal L1 measurement report MAC CE.

[0206] Considering that the truncated L1 measurement report MAC CE may include beam information of triggered beam(s) only, the following may be considered as network implementations.

[0207] - a) the network may want to further receive the normal L1 measurement report MAC CE for better understanding on status of beams before making mobility decision; or

[0208] - b) the network may make decisions based on the received truncated L1 measurement report MAC CEs without waiting for the normal L1 measurement report MAC CE.

[0209] It may seem reasonable for the network to be able to configure the UE whether to keep the normal L1 measurement report MAC CE as pending, upon transmitting the truncated L1 measurement report MAC CE. In other words, as subsequent UE behavior upon transmitting the truncated L1 measurement report MAC CE triggered by event for a beam, the network may configure the UE with either of i) keeping the normal L1 measurement report MAC CE triggered by the event for the beam as pending, or ii) refraining from transmitting the normal L1 measurement report MAC CE triggered by the event for the beam.

[0210] Alternatively, the transmission of the normal L1 measurement report MAC CE may be guaranteed subsequent to the transmission of the truncated L1 measurement report MAC CE. In other words, even after the transmission of the truncated L1 measurement report MAC CE, the triggering status of the L1 measurement reporting may be retained as pending. The triggered L1 measurement reporting may be canceled only after the transmission of the normal L1 measurement report MAC CE. By ensuring that the measurement reporting trigger state is maintained following a truncated transmission, the UE can proceed to transmit a complete normal L1 measurement report once adequate uplink resources become available, without the reporting procedure being prematurely terminated or abandoned.

[0211] For evaluation of LTM event associated with multiple RSs, for eachreportID(associated with event), report may be triggered if any beam (associated with thisreportID) fulfils the event by evaluating all beams associated with the event during TTT for each beam.

[0212] Depending on UE measurement and processing capabilities, the number of beams that can be measured may vary. If the network does not know how many beams the UE can measure within a unit time, the network cannot properly configure number of beams to be evaluated for the event and improper value of TTT value may be configured. To avoid these issues, a new UE capability signaling may be introduced to indicate the number of beams the UE can measure within a unit time.

[0213] 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.

[0214] 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.

[0215] FIG. 10 shows an example of a method performed by a wireless device to which the implementation 1 of the present disclosure is applied.

[0216] In step S1000, the method includes receiving one or more RS resources and one or more event conditions related to the one or more RS resources from a base station.

[0217] In some implementations, the one or more RS resources and the one or more event conditions may be received via a report configuration.

[0218] In step S1010, the method includes performing measurements based on one or more RS. A measurement reporting is triggered based on an event condition related to at least one RS being fulfilled.

[0219] In some implementations, the one or more RS may relate to at least one of a serving cell or a neighbor cell.

[0220] In step S1020, for the measurement reporting which is triggered, the method includes transmitting at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE to the base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0221] In some implementations, the truncated measurement report MAC CE may include information related to the at least one RS for which the event condition is fulfilled. The information related to the at least one RS may include information related to all RSs for which the event condition is fulfilled or information related to N number of RSs for which the event condition is fulfilled. The information related to the at least one RS may include an RS identity and an RS quality. The truncated measurement report MAC CE may further include a report identity related to the event condition.

[0222] In some implementations, the truncated measurement report MAC CE may be transmitted based on an UL resource being able to accommodate the truncated measurement report MAC CE.

[0223] In some implementations, the measurement reporting which has been triggered may not be canceled based on a transmission of the truncated measurement report MAC CE.

[0224] In some implementations, the normal measurement report MAC CE may include i) information related to the at least one RS for which the event condition is fulfilled, and / or ii) information related to at least one other RS for which the event condition is not fulfilled. The normal measurement report MAC CE may comprise information related to all RSs or up to N number of RSs, whichever is smaller.

[0225] In some implementations, the normal measurement report MAC CE may be transmitted based the measurement reporting not being canceled.

[0226] In some implementations, the method may further include selecting a format of a measurement report MAC CE to be carried in a MAC PDU from the truncated measurement report MAC CE or the normal measurement report MAC CE. For example, the normal measurement report MAC CE may be selected if a UL grant can accommodate the normal measurement report MAC CE. For example, the truncated measurement report MAC CE may be selected if the UL grant cannot accommodate the normal measurement report MAC CE but accommodate the truncated measurement report MAC CE.

[0227] Alternatively, for the L1 measurement reporting which is triggered, the truncated measurement report MAC CE may be transmitted to the base station, and for the L1 measurement reporting which has been triggered and not canceled, the normal measurement report MAC CE may be transmitted to the base station.

[0228] Furthermore, the wireless device may be implemented by the first wireless device 100 shown in FIG. 2 and / or the UE 100 shown in FIG. 3. The wireless device may be in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the wireless device.

[0229] The wireless device may comprise 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, cause the wireless device to perform the method described in FIG. 10.

[0230] More specifically, the wireless device receives one or more RS resources and one or more event conditions related to the one or more RS resources from a base station.

[0231] In some implementations, the one or more RS resources and the one or more event conditions may be received via a report configuration.

[0232] The wireless device performs measurements based on one or more RS. A measurement reporting is triggered based on an event condition related to at least one RS being fulfilled.

[0233] In some implementations, the one or more RS may relate to at least one of a serving cell or a neighbor cell.

[0234] For the measurement reporting which is triggered, the wireless device transmits at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE to the base station. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0235] In some implementations, the truncated measurement report MAC CE may include information related to the at least one RS for which the event condition is fulfilled. The information related to the at least one RS may include information related to all RSs for which the event condition is fulfilled or information related to N number of RSs for which the event condition is fulfilled. The information related to the at least one RS may include an RS identity and an RS quality. The truncated measurement report MAC CE may further include a report identity related to the event condition.

[0236] In some implementations, the truncated measurement report MAC CE may be transmitted based on an UL resource being able to accommodate the truncated measurement report MAC CE.

[0237] In some implementations, the measurement reporting which has been triggered may not be canceled based on a transmission of the truncated measurement report MAC CE.

[0238] In some implementations, the normal measurement report MAC CE may include i) information related to the at least one RS for which the event condition is fulfilled, and ii) information related to at least one other RS for which the event condition is not fulfilled. The normal measurement report MAC CE may comprise information related to all RSs or up to N number of RSs, whichever is smaller.

[0239] In some implementations, the normal measurement report MAC CE may be transmitted based the measurement reporting not being canceled.

[0240] In some implementations, the wireless device may select a format of a measurement report MAC CE to be carried in a MAC PDU from the truncated measurement report MAC CE or the normal measurement report MAC CE. For example, the normal measurement report MAC CE may be selected if a UL grant can accommodate the normal measurement report MAC CE. For example, the truncated measurement report MAC CE may be selected if the UL grant cannot accommodate the normal measurement report MAC CE but accommodate the truncated measurement report MAC CE.

[0241] Furthermore, the method described above in FIG. 10 may be performed by control of a processing apparatus. The processing apparatus may be implemented by the processor 102 included in the first wireless device 100 shown in FIG. 2 and / or the processor 102 included in the UE 100 shown in FIG. 3.

[0242] The processing apparatus comprises at least one processor that is integrated with a wireless device, and at least one memory comprising processor-executable instructions stored thereon that are configured to cause the at least one processor to perform the method described in FIG. 10.

[0243] Furthermore, the method 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.

[0244] 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.

[0245] 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.

[0246] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] FIG. 11 shows an example of a method performed by a base station to which the implementation 1 of the present disclosure is applied.

[0251] In step S1100, the method includes transmitting one or more RS resources and one or more event conditions related to the one or more RS resources to a wireless device. Measurements are performed based on one or more RS. A measurement reporting is triggered based on an event condition related to at least one RS being fulfilled.

[0252] In step S1110, for the measurement reporting which is triggered, the method includes receiving at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE from the wireless device. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0253] Furthermore, the base station may be implemented by the second wireless device 200 shown in FIG. 2.

[0254] The base station may comprise 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, cause the base station to perform the method described in FIG. 11.

[0255] More specifically, the base station transmits one or more RS resources and one or more event conditions related to the one or more RS resources to a wireless device. Measurements are performed based on one or more RS. A measurement reporting is triggered based on an event condition related to at least one RS being fulfilled.

[0256] For the measurement reporting which is triggered, the base station receives at least one of a truncated measurement report MAC CE or a normal measurement report MAC CE from the wireless device. The measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

[0257] According to implementations of the present disclosure, the followings may be provided.

[0258] The network may configure an RRC_CONNECTED UE to perform L1 beam level measurements for LTM candidate cell(s) and / or serving cell, and report the corresponding measurement results in accordance with the event triggered L1 measurement configuration. The measurement report is used for indicating to serving gNB of the L1 measurement results from the serving cell and / or candidate cell(s). The measurement configuration is provided by means of RRC dedicated signaling.

[0259] The network may configure the UE to report the following measurement information based on SS / PBCH block(s):

[0260] - Measurement results per SS / PBCH block;

[0261] - SS / PBCH block(s) resource indicator (SSBRI).

[0262] The network may configure the UE to report the following measurement information based on CSI-RS resources: - Measurement results per CSI-RS resource;

[0263] - CSI-RS resource indicator (CRI).

[0264] RRC configures the following parameters in theLTM-CSI-ReportConfigfor L1 measurement and event triggered L1 measurement reporting:

[0265] -ltm-ResourcesForChannelMeasurementfor the LTM resource configuration containing the RS(s) of LTM candidate cell(s) that may be measured for the event;

[0266] -eventTriggeredfor the event-triggered measurement report;

[0267] -eventLTM2,eventLTM3,eventLTM4,eventLTM5: events for the event-triggered measurement report;

[0268] -timeToTrigger(TTT): time during which an entering / leaving condition needs to be consistently satisfied for reporting event triggered L1 measurement report or for cell switch execution to be met;

[0269] -ltm-CandidateReportConfigList: List of report configurations for LTM candidate IDs;

[0270] -ltm-EventTriggeredPeriodicReport: whether the event triggered L1 measurement report is sent periodically if an LTM event is triggered;

[0271] -reportOnLeave: whether the event triggered L1 measurement report shall be triggered when the leaving condition for an event is satisfied;

[0272] -ltm-EventTriggeredReportContent: the content of the event triggered L1 measurement report;

[0273] -candidateSpecificOffset: offset for event condition that is applicable for all the reference signals belonging to the candidate cell with the candidate cell IDltm-CandidateReportConfigId;

[0274] -servingSpecificOffsetS: offset for event condition that is applicable for all the reference signals belonging to the serving cell.

[0275] For L1 measurement and event triggered L1 measurement reporting, if anltm-CSI-ReportConfigor anltm-CSIResourceConfigassociated with thatltm-CSI-ReportConfigis removed or modified from the current UE configuration, the MAC entity shall:

[0276] 1> remove the measurement reporting entry for the correspondingltm-CSI-ReportConfigIdfrom theMR_LIST, if included;

[0277] 1> stop the periodical reporting timer, if running, and reset the associated information (e.g. TTT and variables) for the correspondingltm-CSI-ReportConfigId;

[0278] 1> cancel, if any, triggered event triggered L1 measurement report for the correspondingltm-CSI-ReportConfigId.

[0279] An RRC_CONNECTED UE obtains L1 beam level measurement results by measuring one or multiple RSs as configured by the network for the LTM candidate cell(s) with the candidate ID configured inltm-CandidateReportConfigListfor evaluation of reporting criteria or evaluation of execution condition.

[0280] For L1 measurements performed for evaluation of reporting criteria or evaluation of execution condition, the MAC entity shall:

[0281] - apply the layer 1 filtering by implementation, before using the measured results for evaluation of reporting criteria and measurement reporting or evaluation of execution condition.

[0282] - when the UE has two indicatedTCI-states, use the best beam of the serving cell.

[0283] The purpose of the measurement report procedure is to transfer L1 measurement results from the UE to the network. RRC controls the event triggered L1 beam level measurement reporting by configuring the following parameter:

[0284] -reportInterval: the periodicity of the event-triggered periodic measurement report;

[0285] -reportAmount: number of measurement reports needs to be transmitted after the event is triggered;

[0286] -maxNumberOfReportedBeams: number of beams whose measurements can be reported in the event triggered L1 measurement report by MAC CE regardless whether or not the report includes the current beam;

[0287] -allowReportAnyBeam: whether the UE can report the measurement results for the beams not satisfying the conditions of the events;

[0288] -reportCurrentBeam: whether the UE is required to report the measurement result of the current beam;

[0289] -ltm-CandidateReportConfigId: LTM candidate cell ID for which the UE is required to measure reference signal and perform LTM event evaluation;

[0290] -reportQuantity: the report quantity for the CSI report.

[0291] For eachltm-CSI-ReportConfigIdincluded in the SpCell cell for L1 measurement and event triggered measurement report, the MAC entity shall:

[0292] 1> if at least one L1 measurement report has been triggered for theltm-CSI-ReportConfigIdand not cancelled:

[0293] 2> if UL-SCH resources are available for a new transmission in the serving cell and these UL-SCH resources can accommodate the event triggered L1 measurement report MAC CE plus its subheader as a result of logical channel prioritization:

[0294] 3> instruct the Multiplexing and Assembly procedure to generate the event triggered L1 measurement report MAC CE associated with theltm-CSI-ReportConfigIdaccording to the measurement report information in theMR_LIST;

[0295] 3> ifreportAmountis configured in theLTM-EventTriggeredPeriodicReportby RRC:

[0296] 4> if at least one L1 measurement report associated with theltm-CSI-ReportConfigIdhas been triggered due to the reason other than the expiry of the periodical reporting timer and the L1 measurement report is not cancelled:

[0297] 5> set the MR_SENT_COUNTER to 0 for thisltm-CSI-ReportConfigId;

[0298] 4> increment theMR_SENT_COUNTERassociated with theltm-CSI-ReportConfigIdby 1;

[0299] 4> stop the periodical reporting timer, if running;

[0300] 4> ifreportAmountis configured in RRC, and theMR_SENT_COUNTERas defined for thisltm-CSIReportConfigIdis less thanreportAmount:

[0301] 5> restart the periodical reporting timer with the value ofreportIntervalfor thisltm-CSIReportConfigIdas defined within the correspondingLTM-CSI-reportConfig;

[0302] 3> include the SSBRI or CRI in theBEAM_ENTERING_LISTfor thisltm-CSI-ReportConfigId, if any, into theBEAM_REPORTED_LISTfor thisltm-CSI-ReportConfigId;

[0303] 3> clear theBEAM_ENTERING_LISTfor thisltm-CSI-ReportConfigId;

[0304] 3> clear theBEAM_LEAVING_LISTfor thisltm-CSI-ReportConfigId;

[0305] 3> if theBEAM_REPORTED_LISTfor thisltm-CSI-ReportConfigIdis empty:

[0306] 4> remove the measurement reporting entry within theMR_LISTfor thisltm-CSI-ReportConfigId;

[0307] 4> stop the periodical reporting timer for thisltm-CSI-ReportConfigId, if running.

[0308] 3> cancel the triggered L1 measurement report.

[0309] 2> else if the UL-SCH resources are available for a new transmission in the serving cell and these UL-SCH resources can accommodate the Truncated event triggered L1 measurement report MAC CE plus its subheader as a result of logical channel prioritization:

[0310] 3> instruct the Multiplexing and Assembly procedure to generate the Truncated event triggered L1 measurement report MAC CE associated with theltm-CSI-ReportConfigIdaccording to the measurement report information in theMR_LISTby selecting the RS(s) based on a decreasing order of the priority for the type of beam: RS(s) inBEAM_ENTERING_LIST, RS(s) inBEAM_LEAVING_LIST, RS(s) inBEAM_REPORTED_LIST, and other RS(s) not in these three lists.

[0311] 2> else:

[0312] 3> trigger the SR for event triggered L1 measurement report;

[0313] 3> stop the periodical reporting timer for thisltm-CSI-ReportConfigId, if running.

[0314] After sending a Truncated event triggered L1 measurement report MAC CE, if the subsequent UL grant is still not big enough to fit all the remaining beams, it is up to UE implementation to select the beam(s) which were not included in the previous MAC CE.

[0315] If more than one triggering events for L1 measurement report are pending and the UL grant is not sufficient for all regular event triggered L1 measurement report MAC CEs, it is up to UE implementation how to handle / include the event triggered L1 measurement report MAC CEs and / or Truncated event triggered L1 measurement report MAC CE.

[0316] When a measurement report is triggered by entry condition for one or more RS(s), and included in theBEAM_ENTERING_LIST, another measurement report is triggered by leaving condition for the same RS(s), the UE considers the corresponding measurement report(s) as cancelled. When a measurement report is triggered by leaving condition for one or more RS(s), and included in theBEAM_LEAVING_LIST, another measurement report is triggered by entry condition for the same RS(s), the UE considers the corresponding measurement report(s) as cancelled.

[0317] 2. Implementation 2: Handling of multiple pending L1 measurement report MAC CEs

[0318] When the UE receives the UL grant, the UE may already have more than one pending L1 measurement report MAC CEs to be transmitted. If the UL grant is insufficient to transmit all pending L1 measurement report MAC CEs, the UE may need to decide which L1 measurement report MAC CE MR(s) to send first. Then the UE may need to be able to determine which L1 measurement report MAC CE(s) have to remain as pending MAC CE(s). The expected UE behaviors may be different depending on whether those pending L1 measurement report MAC CEs are triggered by the same or different event IDs.

[0319] (1) Case #1: A case where two L1 measurement report MAC CEs were triggered by different LTM report configuration IDs and these two MAC CEs are pending

[0320] If the received UL grant is sufficient to transmit both L1 measurement report MAC CEs, the UE may send both MAC CEs in one MAC PDU. If the received UL grant is insufficient to transmit both L1 measurement report MAC CEs, the UE may select only one measurement report MAC CE to transmit with UL grant.

[0321] For the selection, if First-In First-Out (FIFO) is be applied, the UE may prioritize the L1 measurement report MAC CE that was triggered earlier. If Last-In First-Out (LIFO) is be applied, the UE may prioritize the L1 measurement report MAC CE that was triggered later. However, it may not be clear which one of the two L1 measurement report MAC CEs is more urgent because there are triggered by different events. In other words, it may not really matter which principle among FIFO and LIFO is applied to this case. Therefore, it may be left to UE implementation how to select L1 measurement report MAC CEs to transmit first among L1 measurement report MAC CEs triggered by different LTM report configuration IDs.

[0322] After transmission of the selected L1 measurement report MAC CE, the UE may await another UL grant to transmit remaining (i.e., pending) L1 measurement report MAC CE. Since those two L1 measurement report MAC CEs were triggered by different LTM report configuration IDs, transmission of one L1 measurement report MAC CE may not affect transmission of the other L1 measurement report MAC CE.

[0323] In summary, for the case #1, for UE having more than one pending L1 measurement report MAC CEs triggered by different LTM report configuration IDs, if the UE receives UL grant which is insufficient to transmit all pending L1 measurement report MAC CEs, it may be up to UE implementation which L1 measurement report MAC CEs to select and transmit first. Upon transmitting the selected L1 measurement report MAC CE(s), the UE may not discard other pending L1 measurement report MAC CEs triggered by different LTM report configuration ID(s).

[0324] (2) Case #2: A case where two L1 measurement report MAC CEs were triggered by the same LTM report configuration ID and these two MAC CEs are pending

[0325] If the received UL grant is not sufficient to transmit both L1 measurement report MAC CEs, the UE may select only one to transmit with UL grant. For the selection, it may be reasonable to select the L1 both L1 measurement report MAC CEs MAC CE that was triggered more recently, because the latest one is only meaningful from network side.

[0326] This may imply that even if the UL grant were sufficient to transmit both measurement report MAC CEs, it would suffice for the UE to transmit only one L1 measurement report MAC CE that was triggered more recently. If the UE then transmits the other pending L1 measurement report MAC CE with another UL grant later, it may confuse the network because the network would consider the other L1 measurement report MAC CE as the latest one, unless these L1 measurement report MAC CEs contain information indicating the sequence of the triggering. To avoid such confusion, once the UE selects a latest L1 measurement report MAC CE among those triggered by the same LTM report configuration ID and transmits the selected one measurement report MAC CE, the UE may discard the other remaining pending L1 measurement report MAC CE(s).

[0327] Case #2 may not occur at the first place if triggering of L1 measurement report MAC CE by an LTM report configuration ID discards all the pending L1 measurement report MAC CE(s) previously triggered by the same LTM report configuration ID.

[0328] In summary, for the case #1, to handle multiple pending L1 measurement report MAC CEs triggered by the same LTM report configuration ID, one of the following two alternatives may be selected:

[0329] - Alt1: For UE having more than one pending L1 measurement report MAC CEs triggered by same LTM report configuration ID, the UE may select the latest L1 measurement report MAC CE(s) triggered by the LTM report configuration ID and transmits the selected L1 measurement report MAC CE. Upon transmitting the selected L1 measurement report MAC CE(s), the UE may discard other pending L1 measurement report MAC CEs previously triggered by the same LTM report configuration ID. The discard operation may be skipped if the latest L1 measurement report MAC CE is transmitted in a truncated format.

[0330] - Alt2: If one L1 measurement report MAC CE is triggered by an LTM report configuration ID, the UE may discard all the pending L1 measurement report MAC CEs previously triggered by the same LTM report configuration ID.

[0331] (3) Case #3: A case where the UE has K pending L1 measurement report MAC CEs, and the UE receives UL grant which can accommodate up to M normal L1 measurement report MAC CEs or up to N truncated L1 measurement report MAC CEs with N>M and M, N<K

[0332] In this case, the UE may decide which format (normal format or truncated format) to use for each L1 measurement report MAC CE to transmit. If a truncated measurement report MAC CE format is used, the UE can transmit a larger number of L1 measurement report MAC CEs with the UL grant. On the other hand, if a normal measurement report MAC CE format is used, the UE can transfer more complete beam quality status related to the selected L1 measurement report MAC CE to network.

[0333] For example, the UE may have two pending L1 measurement report MAC CEs triggered by different events and the UL grant may be fit to transmit either one normal L1 measurement report MAC CE or two truncated L1 measurement report MAC CEs. Then, the UE may have to decide whether to transmit either one L1 normal measurement report MAC CE or two truncated L1 measurement report MAC CE with the UL grant.

[0334] For example, the UE may have three pending L1 measurement report MAC CEs triggered by different events and the UL grant may be fit to transmit either {one normal L1 measurement report MAC CE + one truncated L1 measurement report MAC CE} or {three truncated L1 measurement report MAC CEs}. Given such possible combinations, it may not be straightforward to mandate a specific combination. For this example, it is mandated to transmit {one normal L1 measurement report MAC CE + one truncated L1 measurement report MAC CE} instead of {three truncated L1 measurement report MAC CEs}, the UE may still have to decide which L1 measurement report MAC CE to transmit as a normal format and other measurement report MAC CEs as a truncated format accordingly.

[0335] The network may explicitly configure the UE with priority for each event configuration such that L1 measurement report MAC CE triggered by event configuration with a higher priority is prioritized for transmission in a normal format. Or, the network may explicitly configure the UE with some prioritization rule such as maximal number of MAC CE(s) in a normal format (leading to the UE to construct MAC PDU by maximizing the number of MAC CEs of normal format) or maximal number of MAC CE(s) in a truncated format (leading to the UE to construct MAC PDU by maximizing the number of MAC CEs of truncated format. Such prioritization may allow the network to control MAC PDU construction in terms of MAC CE format, but UE complexity may increase accordingly.

[0336] The present disclosure may have various advantageous effects.

[0337] For example, even when a UE has transmitted a truncated L1 measurement report MAC CE containing only essential measurement information due to insufficient uplink resources, the subsequent transmission of a normal L1 measurement report MAC CE can be guaranteed. By ensuring that the measurement reporting trigger state is maintained following a truncated transmission, the UE can proceed to transmit a complete normal L1 measurement report once adequate uplink resources become available, without the reporting procedure being prematurely terminated or abandoned.

[0338] For example, by guaranteeing the eventual delivery of a normal L1 measurement report MAC CE, the network can be ensured to ultimately receive the full set of measurement information that was not included in the truncated report. This can enable the network to make more accurate and reliable decisions in procedures that depend on L1 measurement results, such as handover control, beam management, and link adaptation, thereby contributing to improved overall system performance and user experience.

[0339] For example, by clearly defining the UE behavior following the transmission of a truncated L1 measurement report, ambiguity in the measurement reporting procedure can be eliminated. This can prevent situations where the network operates based on incomplete measurement information for an extended period, and can also prevent unnecessary repetition or omission of measurement reporting, thereby contributing to more consistent and predictable UE operation in resource-constrained environments.

[0340] 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.

[0341] Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

1.A method comprising:receiving, by a wireless device, one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources from a base station;performing, by the wireless device, measurements based on one or more RS,wherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, transmitting, by the wireless device, at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to the base station,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.2.The method of claim 1, wherein the truncated measurement report MAC CE comprises information related to the at least one RS for which the event condition is fulfilled.3.The method of claim 2, wherein the information related to the at least one RS comprises information related to all RSs for which the event condition is fulfilled or information related to N number of RSs for which the event condition is fulfilled.4.The method of claim 2, wherein the information related to the at least one RS comprises an RS identity and an RS quality.5.The method of claim 2, wherein the truncated measurement report MAC CE further comprises a report identity related to the event condition.6.The method of claim 1, wherein the truncated measurement report MAC CE is transmitted based on an uplink (UL) resource being able to accommodate the truncated measurement report MAC CE.7.The method of claim 1, wherein the normal measurement report MAC CE comprises i) information related to the at least one RS for which the event condition is fulfilled, and / or ii) information related to at least one other RS for which the event condition is not fulfilled.8.The method of claim 7, wherein the normal measurement report MAC CE comprises information related to all RSs or up to N number of RSs, whichever is smaller.9.The method of claim 1, wherein the normal measurement report MAC CE is transmitted based the measurement reporting not being canceled.10.The method of claim 1, wherein the one or more RS resources and the one or more event conditions are received via a report configuration.11.The method of claim 1, wherein the method further comprises selecting a format of a measurement report MAC CE to be carried in a MAC protocol data unit (PDU) from the truncated measurement report MAC CE or the normal measurement report MAC CE.12.The method of claim 11, wherein the normal measurement report MAC CE is selected if a UL grant can accommodate the normal measurement report MAC CE, andwherein the truncated measurement report MAC CE is selected if the UL grant cannot accommodate the normal measurement report MAC CE but accommodate the truncated measurement report MAC CE.13.The method of claim 1, wherein the one or more RS relates to at least one of a serving cell or a neighbor cell.14.A wireless device comprising:at least one transceiver;at least one processor; andat 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, cause the wireless device to perform operations comprising:receiving one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources from a base station;performing measurements based on one or more RS,wherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, transmitting at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to the base station,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.15.A processing apparatus comprising:at least one processor that is integrated with a wireless device; andat least one memory comprising processor-executable instructions stored thereon that are configured to cause the at least one processor to perform operations comprising:obtaining one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources;performing measurements based on one or more RS,wherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, generating at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.16.A non-transitory Computer Readable Medium (CRM) storing instructions that, based on being executed by at least one processor, cause a wireless device to perform operations comprising:receiving one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources from a base station;performing measurements based on one or more RS,wherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, transmitting at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE to the base station,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.17.A method comprising:transmitting, by a base station, one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources to a wireless device,wherein measurements are performed based on one or more RS, andwherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, receiving, by the base station, at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE from the wireless device,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.18.A base station comprising:at least one transceiver;at least one processor; andat 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, cause the base station to perform operations comprising:transmitting one or more reference signal (RS) resources and one or more event conditions related to the one or more RS resources to a wireless device,wherein measurements are performed based on one or more RS, andwherein a measurement reporting is triggered based on an event condition related to at least one RS being fulfilled; andfor the measurement reporting which is triggered, receiving at least one of a truncated measurement report media access control (MAC) control element (CE) or a normal measurement report MAC CE from the wireless device,wherein the measurement reporting which has been triggered is canceled based on a transmission of the normal measurement report MAC CE.

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