Retaining logged data during connection transition

Abstract

A method and apparatus for retaining logged data during a connection transition is provided. A wireless device performs a logging of measurements, and receives information related to retaining of the logged measurements from a base station. The wireless device retains the logged measurements based on the information upon execution of a handover.

Description

RETAINING LOGGED DATA DURING CONNECTION TRANSITION

[0001] The present disclosure relates to retaining logged data during a connection transition.

[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] The integration of Artificial Intelligence and Machine Learning (AI / ML) technologies has emerged as a key enabler for enhanced performance and intelligent network operation in 5G and 6G. AI / ML techniques can be applied to various aspects of wireless communications, including channel state prediction, beam management, positioning accuracy improvement, and / or network optimization. By leveraging AI / ML capabilities, communication systems can achieve improved spectral efficiency, reduced latency, and more adaptive resource management compared to conventional rule-based approaches.

[0005] In wireless communication systems incorporating AI / ML functionalities, the training and deployment of AI / ML models may involve different architectural approaches. AI / ML models may be deployed at various network entities, and the training processes can be organized in different ways depending on system architecture, operational requirements, and data management strategies.

[0006] The network-side AI / ML models may reside and operate within network infrastructure rather than at the User Equipment (UE). For the network-side AI / ML models, training data collection may be a critical component of the overall AI / ML workflow. To support effective model training and continuous model improvement, the UE may be configured by the network to perform logging operations, whereby the UE collects and records various types of measurement data, radio conditions, performance metrics, or other relevant information according to network-configured parameters.

[0007] Once the UE has collected logged data based on network configuration, this data needs to be delivered to the network so that it can be utilized for model training, validation, or refinement purposes. Under normal operational conditions, the UE may transmit the logged data to the serving cell when requested by the network or according to configured reporting conditions.

[0008] However, complications may arise in mobility scenarios, particularly during handover procedures. When a UE undergoes handover from a source cell to a target cell, there may be situations where the UE has not successfully delivered its logged data to the source cell before the handover is completed. This may occur due to various reasons such as sudden radio link quality degradation, timing constraints during the handover procedure, insufficient uplink resources before handover execution, or other operational conditions that prevent timely data delivery.

[0009] In such scenarios where logged data has not been delivered to the source cell, the UE may face an ambiguous situation regarding what should be done with the retained logged data. Specifically, the UE may need to determine whether the logged data should be delivered to the target cell after handover completion, or whether the logged data should be discarded as no longer relevant or useful.

[0010] This determination may depend on several factors that are not inherently known to the UE. For instance, AI / ML model training may be organized in different ways. It may be Operations, Administration, and Maintenance (OAM) centric, where training is coordinated centrally across multiple network nodes. Or, it may be base station (e.g., gNB) centric, where training is performed locally at individual base stations. Depending on which training approach is being used, the utility of delivering logged data to a different cell may vary significantly. In OAM-centric training scenarios, logged data from any cell may be valuable as it can be aggregated centrally for model training. In gNB-centric training scenarios, logged data might only be useful to the specific base station that configured the logging, making delivery to a different cell potentially unnecessary.

[0011] Furthermore, the ability to transfer logged data between network nodes may depend on network architecture and inter-node connectivity. For example, if the source and target base stations are connected via an Xn interface or other inter-node communication mechanisms, it may be possible for logged data delivered to the target cell to be forwarded to the source cell or to a centralized training entity. However, if such connectivity does not exist or if data transfer mechanisms are not supported, delivering logged data to the target cell may not serve any useful purpose.

[0012] The UE itself cannot autonomously determine these architectural and connectivity factors. Without explicit information or guidance from the network regarding how logged data should be handled after unsuccessful delivery during handover scenarios, the UE may make suboptimal decisions. For instance, discarding potentially valuable logged data may result in loss of training information that could have improved model performance. Conversely, attempting to deliver logged data to a target cell when it cannot be utilized may result in unnecessary signaling overhead and resource consumption.

[0013] Therefore, there may be a need for mechanisms that provide the UE with appropriate information or guidance from the network to enable informed decisions regarding handling of logged data in handover scenarios where delivery to the source cell was not completed, thereby optimizing data collection for AI / ML training while avoiding unnecessary resource waste.

[0014] In an aspect, a method performed by a wireless device is provided. The method comprises performing a logging of measurements, receiving information related to retaining of the logged measurements from a base station, and retaining the logged measurements based on the information upon execution of a handover.

[0015] In another aspect, an apparatus for implementing the above method is provided.

[0016] The present disclosure may have various advantageous effects.

[0017] For example, by having the network provide guidance regarding whether logged data management is necessary for each specific scenario, the UE can avoid unnecessary memory usage and prevent unnecessary data forwarding, while efficiently providing logged data to the network when it is actually needed.

[0018] For example, when the network explicitly indicates how logged data should be handled in different mobility scenarios, such as whether logged data should be retained and delivered to a target cell after handover, or whether it should be discarded, the UE can make informed decisions that align with the network's training architecture and data collection requirements. This coordination between the UE and network can optimize resource utilization on both sides.

[0019] For example, from the UE perspective, avoiding unnecessary retention of logged data that will ultimately not be used can free up valuable memory resources. Mobile devices often have limited storage capacity, and retaining large amounts of logged measurement data that serves no purpose can constrain the UE's ability to perform other functions or store other important information. By discarding logged data when the network indicates it is not needed, the UE can manage its memory more efficiently.

[0020] For example, preventing unnecessary data forwarding can reduce signaling overhead and conserve radio resources. Transmitting logged data over the air interface consumes uplink resources that could otherwise be used for user data transmission or other control signaling. When logged data delivery to a target cell would not contribute to model training or would not reach the appropriate training entity, avoiding such transmission can improve overall spectral efficiency and reduce battery consumption at the UE.

[0021] For example, by introducing clear criteria for when logged data should be kept versus discarded, the system can achieve more predictable and consistent behavior across different UE implementations and deployment scenarios. This clarity can eliminate ambiguity that might otherwise lead to inconsistent handling of logged data, where some UEs might retain data unnecessarily while others might prematurely discard valuable training information.

[0022] For example, the improved logged data management can also enhance the overall efficiency of AI / ML model training workflows. By ensuring that logged data is delivered to the network only when it can actually be utilized, the system can maximize the value obtained from data collection efforts while minimizing wasted resources.

[0023] For example, the network's ability to provide scenario-specific guidance can enable more flexible and adaptive data collection strategies. Different AI / ML use cases or training approaches may have different requirements regarding data persistence and delivery across cell boundaries. By allowing the network to configure these aspects appropriately for each scenario, the system can support diverse AI / ML deployment models without imposing unnecessary constraints on UE behavior.

[0024] 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.

[0025] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0026] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0027] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0028] 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.

[0029] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0030] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0031] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0032] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0033] FIG. 10 shows an example of applicability status reporting to which implementations of the present disclosure are applied.

[0034] FIG. 11 shows an example of retrieving logged data to which implementations of the present disclosure are applied.

[0035] FIG. 12 shows an example of a method performed by a wireless device to which implementations of the present disclosure are applied.

[0036] FIG. 13 shows an example of a method performed by a base station to which implementations of the present disclosure are applied.

[0037] FIG. 14 shows an example of managing logged data to which implementations of the present disclosure are applied.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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".

[0042] 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".

[0043] 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".

[0044] 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".

[0045] 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".

[0046] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0047] 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.

[0048] 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.

[0049] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0050] 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.

[0051] 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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).

[0060] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0061] 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).

[0062] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0063] 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.

[0064] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0085] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0086] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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).

[0101] 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.

[0102] 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.

[0103] 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.

[0104] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0105] 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).

[0106] 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.

[0107] 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.

[0108] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0109] 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.

[0110] uNslotsymbNframe,uslotNsubframe,uslot212404

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0116] 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.

[0117] 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.

[0118] Network controlled mobility applies to UEs in RRC_CONNECTED and is categorized into two types of mobility: cell level mobility and beam level mobility. Beam level mobility includes intra-cell beam level mobility and inter-cell beam level mobility.

[0119] Cell level mobility requires explicit RRC signaling to be triggered, i.e., handover.

[0120] FIG. 8 shows an example of inter-gNB handover procedures to which implementations of the present disclosure are applied.

[0121] For inter-gNB handover, the signaling procedures consist of at least the following elemental components described in FIG. 8.

[0122] 1. Step 1: The source gNB initiates handover and issues a HANDOVER REQUEST over the Xn interface.

[0123] 2. Step 2: The target gNB performs admission control and provides the new RRC configuration as part of the HANDOVER REQUEST ACKNOWLEDGE.

[0124] 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.

[0125] 4. Step 4: The UE moves the RRC connection to the target gNB and replies with theRRCReconfigurationComplete.

[0126] User data may also be sent in step 4 if the grant allows.

[0127] The handover mechanism triggered by RRC requires the UE at least to reset the MAC entity and re-establish RLC, except for Dual Active Protocol Stack (DAPS) handover, where upon reception of the handover command, the UE:

[0128] - Creates a MAC entity for target;

[0129] - Establishes the RLC entity and an associated DTCH logical channel for target for each DRB configured with DAPS;

[0130] - For each DRB configured with DAPS, reconfigures the PDCP entity with separate security and ROHC functions for source and target and associates them with the RLC entities configured by source and target respectively;

[0131] - Retains the rest of the source configurations until release of the source.

[0132] The cell switch mechanism triggered by MAC, (i.e., L1 / L2-Triggered Mobility (LTM) cell switch) requires the UE at least to reset the MAC entity. RLC and PDCP handling depends on the network configuration.

[0133] 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.

[0134] SSB-based beam level mobility is based on the Cell Defining (CD)-SSB associated to the initial DL BWP and can be configured for the initial DL BWPs, for DL BWPs containing the CD-SSB associated to the initial DL BWP, and if supported, for DL BWPs not containing the CD-SSB associated to the initial DL BWP. SSB-based beam level mobility can be also performed based on a Non-Cell Defining (NCD)-SSB, if configured for the active DL BWP. beam level mobility can be also performed based on CSI-RS, if configured for the active DL BWP.

[0135] 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.

[0136] The following principles apply to CHO:

[0137] - 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.

[0138] - 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.

[0139] - Before any CHO execution condition is satisfied, upon reception of HO command (without CHO configuration), the UE executes the HO procedure or or

[0140] LTM cell switch procedure, regardless of any previously received CHO configuration.

[0141] - While executing CHO, i.e., from the time when the UE starts synchronization with target cell, the UE does not monitor source cell.

[0142] LTM is a procedure in which a gNB receives L1 or L3 measurement report(s) from a UE, and on their basis the gNB may change UE serving cell by a cell switch command signaled via a MAC Control Element (CE). The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through RRC signaling. Then the UE switches to the target configuration according to the cell switch command. The LTM procedure can be used to reduce the mobility latency.

[0143] 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. All the activated TCI states except those received in the cell switch command are deactivated upon LTM cell switch execution.

[0144] When configured by the network, it is possible to initiate UL TA acquisition (called early TA) procedure of one or multiple cells that are different from the current serving cells. If the cell has the same NTA as the current serving cells or NTA=0, early TA acquisition procedure is not required. The network may request the UE to perform early TA acquisition of a candidate cell before a cell switch. The early TA acquisition procedure is triggered by PDCCH order or realized through UE-based TA measurement as configured by RRC. In the former case, the gNB / gNB-Distributed Unit (DU) to which the candidate cell belongs calculates the TA value and sends it to the gNB / gNB-DU to which the serving cell belongs via gNB-Centralized Unit (CU). The serving cell sends the TA value in the LTM cell switch command MAC CE when triggering LTM cell switch. In the latter case, the UE performs TA measurement for the candidate cells after being configured by RRC. The UE applies the TA value measured by itself and performs RACH-less LTM upon receiving the cell switch command, if it does not include any valid TA value. The network may also send a TA value in the LTM cell switch command MAC CE without early TA acquisition.

[0145] When two TAG IDs are configured for an LTM candidate cell, the gNB-DU to which the LTM candidate cell belongs assigns the same TAG ID pointer value for each TRP to be used by the UEs.

[0146] Depending on the availability of a valid TA value, the UE performs either a RACH-less LTM or RACH-based LTM cell switch. If the valid TA value is provided in the cell switch command, the UE applies the TA value as instructed by the network. In the case where UE-based TA measurement is configured, but no valid TA value is provided in the cell switch command, the UE applies the valid TA value by itself if available. The UE performs RACH-less LTM cell switch upon receiving the cell switch command whenever a valid TA value is available. If no valid TA value is available, the UE performs RACH-based LTM cell switch.

[0147] Regardless of whether the UE is configured for UE-based TA measurement for a certain candidate cell, it will still follow the PDCCH order, which includes performing a random access procedure towards one or more candidate cells. This also applies to the candidate cells for which the UE is capable of deriving TA values by itself. Additionally, regardless of whether the UE has already performed a random access procedure towards the candidate cells, it will still follow the UE-based measurement configuration if configured by the network.

[0148] For RACH-less LTM, the UE accesses the target cell using either a configured grant or a dynamic grant. The configured grant is provided in the LTM candidate configuration, and the UE selects the configured grant occasion associated with the beam indicated in the cell switch command. Upon initiation of LTM cell switch to the target cell, the UE starts to monitor PDCCH on the target cell for dynamic scheduling. Before RACH-less LTM procedure completion, the UE shall not trigger random access procedure if it does not have a valid PUCCH resource for triggered SRs.

[0149] The following principles apply to LTM:

[0150] - Security keys are maintained upon an LTM cell switch;

[0151] - Subsequent LTM is supported.

[0152] LTM supports both intra-gNB-DU and inter-gNB-DU mobility within the same gNB-CU. LTM supports both intra-frequency and inter-frequency mobility, including mobility to inter-frequency cell that is not a current serving cell. LTM is supported only for licensed spectrum. The following scenarios are supported:

[0153] - PCell change in non-CA scenario and non-DC scenario;

[0154] - PCell and SCell(s) change in CA scenario;

[0155] - Dual connectivity scenario: including PCell and MCG SCell(s) change and intra-SN PSCell and SCG SCell(s) change without MN involvement. LTM for simultaneous PCell and PSCell change is not supported.

[0156] While the UE has stored LTM candidate configurations, the UE can also execute any L3 handover except for DAPS handover. In the RRC message which the UE applies for any L3 handover (except DAPS), LTM candidate configurations can be added / modified / released by the target cell.

[0157] FIG. 9 shows an example of signaling procedure for LTM to which implementations of the present disclosure are applied.

[0158] Cell switch command is conveyed in a MAC CE, which contains the necessary information to perform the LTM cell switch.

[0159] Subsequent LTM is done by repeating the early synchronization, LTM cell switch execution, and LTM cell switch completion steps without the need to release, reconfigure or add other LTM candidate configurations after each LTM cell switch completion. The general procedure over the air interface is applicable to SCG LTM.

[0160] The signaling procedure for LTM is as follows.

[0161] 1. Step 1: The UE sends aMeasurementReportmessage to the gNB. The gNB decides to configure LTM and initiates LTM preparation.

[0162] 2. Step 2: The gNB transmits anRRCReconfigurationmessage to the UE including the LTM candidate cell configurations.

[0163] 3. Step 3: The UE stores the LTM candidate configurations and transmits anRRCReconfigurationCompletemessage to the gNB.

[0164] 4a. Step 4a: The UE performs DL synchronization with the LTM candidate cell(s) before receiving the cell switch command. The UE may activate and deactivate TCI states of LTM candidate cell(s), as triggered by the gNB.

[0165] 4b. Step 4b: The UE may perform UL synchronization with LTM candidate cell(s) before receiving the cell switch command, by using UE-based TA measurement, if configured, and / or by transmitting a preamble towards the candidate cell, as triggered by the gNB. When UE-based TA measurement is configured, UE acquires the TA value(s) of the candidate cell(s) by measurement. UE performs early TA acquisition with the candidate cell(s) as requested by the network before receiving the cell switch command. This is done via Contention Free Random Access (CFRA) triggered by a PDCCH order from the source cell, following which the UE sends preamble towards the indicated candidate cell. In order to minimize the data interruption of the source cell due to CFRA towards the candidate cell(s), the UE does not receive random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell is indicated in the cell switch command. The UE does not maintain the TA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[0166] 5. Step 5: The UE performs L1 measurements on the configured LTM 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. The UE can also perform L3 measurement reporting to the gNB, including beam level measurement results on cell(s) which are configured as LTM candidate cell(s) according to the received network configuration.

[0167] 6. Step 6: The gNB decides to execute cell switch to a target cell and transmits an LTM cell switch command MAC CE triggering cell switch by including a target configuration ID which indicates the index of the candidate configuration of the target cell, a beam indicated with a TCI state or beams indicated with DL and UL TCI states, and a timing advance command for the target cell, if available. The UE switches to the target cell and applies the candidate configuration indicated by the target configuration ID.

[0168] 7. Step 7: The UE performs the random access procedure towards the target cell, if UE does not have valid TA of the target cell.

[0169] 8. Step 8: The UE completes the LTM cell switch procedure by sendingRRCReconfigurationCompletemessage to target cell. If the UE has performed a RA 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.

[0170] The steps 4-8 can be performed multiple times for subsequent LTM cell switch executions using the LTM candidate configuration(s) provided in step 2.

[0171] Data collection may play a fundamental role in supporting Artificial Intelligence (AI) / Machine Learning (ML) functionalities throughout their lifecycle. For AI / ML models deployed in network infrastructure, training data needs to be collected from UEs operating under various radio conditions, mobility scenarios, and service configurations.

[0172] The 3GPP framework has defined mechanisms for network-configured data logging, where UEs can be instructed to collect and record specific types of information relevant to AI / ML training purposes. This logged data may include channel measurements, signal quality metrics, beam information, positioning measurements, or other radio-related parameters. The UE performs logging operations according to network configuration and subsequently delivers the collected data to the network when requested or when certain reporting conditions are met.

[0173] Data collection for AI / ML can support various operational phases including initial model training, model validation, and ongoing model refinement. The collected data may be used at different network entities depending on the training architecture―for example, at individual base stations for localized model training, or at centralized network functions for training models that will be deployed across multiple network nodes.

[0174] More specifically, AI / ML-based beam management utilizes intra-cell downlink beam prediction of the serving cell to reduce measurement / RS overhead and to improve the accuracy of beam selection. Two types of beam prediction are supported:

[0175] - Spatial-domain downlink transmission beam prediction for one set of beams based on measurement results of another set of beams; and

[0176] - Temporal-domain downlink transmission beam prediction for one set of beams based on historic measurement results of another set of beams (these two sets may be different).

[0177] For AI / ML-based beam management, both NW-side model and UE-side model are supported.

[0178] NW-side data collection for NW-side model training can be initiated by OAM or by gNB. The following enablers are introduced for NW-side data collection for NW-side model over air interface:

[0179] - The UE can be configured by gNB to log L1 measurements in the AS buffer and report them via a RRC message(s).

[0180] - Both periodic and L3 measurement event-triggered data loggings are supported. The UE stores the logged data at the AS buffer. When the AS buffer for storing logged data becomes full, the UE stops measurement and logging for data collection. When the AS buffer reserved for storing logged data becomes full or reaches an absolute threshold (if configured), the UE indicates data availability to the network.

[0181] - When low power state is detected, the UE can indicate the low power state to the network. Upon reception of the low power state indication, the network should release the UE data collection configuration for NW-side model.

[0182] For UE-side data collection for UE-side model training, the network can configure whether UE is allowed to initiate a request for data collection configuration (e.g., UE's preference to start or to stop data collection, preferred configuration from a list of candidate configurations provided by network). The network can also provide UE with data collection configuration or release the data collection configuration at any point in time, with or without UE request.

[0183] The integration of AI / ML techniques for CSI operations has been under active discussion. AI / ML-based CSI feedback enhancement has been identified as one of the key use cases where AI / ML technologies can be applied to improve system performance.

[0184] AI / ML techniques may be utilized for various CSI-related operations, including CSI prediction, CSI compression, and CSI reconstruction. For instance, AI / ML models may be deployed to predict future channel states based on historical channel measurements, and / or to compress CSI feedback information into a more compact representation that can be transmitted with reduced overhead. The network may then use AI / ML models to reconstruct the full CSI from the compressed feedback.

[0185] AI / ML functionalities for CSI operations may involve procedures such as model delivery, applicability reporting, and activation signaling. The UE may report whether a particular AI / ML functionality is applicable under current conditions, and the network may configure and activate the functionality accordingly. Various signaling mechanisms and reporting formats have been discussed to support AI / ML-enhanced CSI operations.

[0186] FIG. 10 shows an example of applicability status reporting to which implementations of the present disclosure are applied.

[0187] 1. Step 1:

[0188] The network may enquire about the UE capability information.

[0189] 2. Step 2:

[0190] The UE may indicate its supported functionalities to the network viaUECapabilityInformationmessage.

[0191] 3. Step 3:

[0192] The network may provide inference configuration with NW-side additional conditions (e.g., associated ID) to UE via CSI report configuration or inference related parameters configuration viaOtherConfig.

[0193] 4. Step 4:

[0194] The UE may determine the applicable AI / ML functionalities based on at least one of NW-side additional conditions (if provided), UE-side additional conditions (internally known by UE) or model availability in the UE. The UE may report its functionality applicability to the network.

[0195] 5. Step 5: RRC Reconfiguration

[0196] Based on the applicability reporting, the network may provide inference configuration inRRCReconfigurationCompletemessage.

[0197] 6. Step 6: Activation / Deactivation / Inference / Monitoring

[0198] When the inference configuration consists of periodic CSI report configuration, upon reporting the applicable functionalities, the UE may autonomously activate the applicable AI / ML functionalities. When the inference configuration consists with semi-persistent CSI and / or aperiodic CSI report configuration, upon reporting the applicable AI / ML functionalities, applicable AI / ML functionality activation can be activated by MAC Control Element (CE) / DCI and aperiodic CSI reporting can be activated by DCI.

[0199] When the network enables applicability reporting viaOtherConfig, and applicability of the functionality changes, the UE can report updated functionality applicability status inUEAssistanceInformationmessage. When an activated AI / ML functionality becomes inapplicable, the UE may not autonomously deactivate it, but the UE may indicate to the network the change in the applicability. Upon reception of UE indication of the functionality becoming inapplicable, the network should deactivate or release this activated functionality.

[0200] Upon receiving one or more inference configuration(s), the UE may maintain all the inference configuration(s) no matter the inference configuration is applicable or inapplicable until the network releases it.

[0201] For NW-side model, the CSI measurement and reporting may be used to acquire input data for inference.

[0202] For NW-side model, the gNB may be responsible for performance monitoring (i.e., calculates performance metrics). There may be no additional impacts on the UE for monitoring and management, except for being configured to provide the required measurement / data. Additionally, the UE may not be informed about any gNB-side management decision.

[0203] For UE-side model, the network may initiate performance monitoring, and make management decisions based on the performance monitoring results. The UE can be configured to send either the measurement reports or the calculated performance metrics.

[0204] UE behavior during Handover (HO), RRC state transitions, and RRC re-establishment should be clarified. The following scenarios may be considered.

[0205] (1) Scenario 1:

[0206] There may be no guarantee that the UE can transmit logged data to the gNB that has configured logging. Specifically, during handover processes, transmission of logged data might fail due to radio quality issues in the serving cell before the handover is completed. If the UE discards such logged data during handover, it would be inefficient given the resources (memory and power) consumed by the UE in collecting this data. Therefore, the UE may need to retain logged data during handover processes and indicate availability of logged data to the target gNB during handover.

[0207] (2) Scenario 2:

[0208] When transitioning to RRC idle or RRC inactive states, the network might face challenges in retrieving logged data due to constraints such as high network load. Additionally, during RRC re-establishment procedures, which often occur due to abnormal UE conditions (e.g., Radio Link Failure (RLF), invalid configuration, etc.), transmitting logged data to the network may also be problematic. Therefore, to mitigate these issues, the UE may need to retrain logged data during transitions to RRC Idle / Inactive states or during RRC re-establishment procedures. Then, the UE may indicate availability of logged data to the network during RRC connection establishment procedure (e.g., RRC setup, RRC resume, or RRC re-establishment procedure).

[0209] If the UE sends a data availability indication to a new gNB / cell in scenario 1 or scenario 2, the new gNB / cell may retrieve the logged data from the UE.

[0210] FIG. 11 shows an example of retrieving logged data to which implementations of the present disclosure are applied.

[0211] There may be the following options where the logged data is finally delivered.

[0212] - Option 1: If the training location is a server, such as OAM or Trace Collection Entity (TCE), the logged data collected by the new gNB / cell can eventually be aggregated on the server.

[0213] - Option 2: If the training location is a gNB, the logged data collected by the new gNB / cell can be delivered to the original gNB / cell that configured the logging.

[0214] Option 1 may already be achieved through legacy operations, such as Minimization of Drive Tests (MDT). However, to achieve Option 2, there may be the two following approaches

[0215] - Case 1: Direct delivery from the new gNB / cell to the original gNB / cell; or

[0216] - Case 2: Indirect delivery, where the new gNB / cell first sends the data to the server, which then forwards it to the original gNB / cell.

[0217] However, both cases may have the following limitations under the current specifications:

[0218] - For case 1, the current specification only considers cases where the gNB collects data directly from the UE. That is, there is no existing data flow that allows data collected after the UE moves to a different gNB to be forwarded to the original gNB. It is unclear how long the original gNB should maintain the UE context for such data transfer.

[0219] - For case 2, if the server is a TCE, there is no existing mechanism for the TCE to send control signaling or user plane data back to the gNB that originally requested logging, which would require defining a new mechanism. If the server is an OAM, discussions are needed on how the OAM should deliver the logged data to the requesting gNB. This may include considering whether to use HyperText Transfer Protocol (HTTP) based on the requesting gNB's IP address, whether to use file transfer, or What type of control signaling should be used for logged data transmission.

[0220] The ability of the network to deliver logged data to the original gNB / cell may depend on the training location. Therefore, in situations where the serving network may change, such as during handover, RRC state transition, or RRC re-establishment, maintaining logged data at all times may be unnecessary depending on the training location.

[0221] To address the problem mentioned above, the present disclosure provides a method for determining whether logged data should be retained during a connection transition (e.g., handover, RRC state transition, or RRC re-establishment). To achieve this, the network may configure an indication indicating and / or specifying whether the logged data should be retained during a connection transition. The UE may determine whether to retain or discard logged data during a connection transition based on the indication.

[0222] For example, the indication may be determined by the network based on at least one of various factors, such as training location, training type (e.g., online / offline training, reinforcement learning, federated learning, etc.), connectivity between gNB / cell (e.g., Xn interface), and so on.

[0223] For example, the indication may explicitly specify at least one of training location, training type, or other relevant parameters.

[0224] In the present disclosure, "function", "functionality", "inference function", "model inference function", "AI / ML model inference function", "model", "AI / ML model" may be used interchangeably.

[0225] In the present disclosure, "model", "AI / ML model" may be sub-group of "function", "functionality", "inference function", "model inference function", "AI / ML model inference function". For example, multiple models may belong to and / or may be linked to a specific function.

[0226] 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.

[0227] 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.

[0228] FIG. 12 shows an example of a method performed by a wireless device to which implementations of the present disclosure are applied.

[0229] In step S1200, the method comprises receiving a logged measurement configuration from a base station.

[0230] In some implementations, the logged measurement configuration may include information related to at least one of a logging object or a logging condition.

[0231] In some implementations, the logged measurement configuration may include information related to a functionality, a model, or a use case.

[0232] In step S1210, the method comprises performing a logging of measurements based on the logged measurement configuration.

[0233] In step S1220, the method comprises receiving information related to retaining of the logged measurements from the base station.

[0234] In some implementations, the information related to retaining of the logged measurements may inform that the wireless device should retain the logged measurement available upon execution of the handover.

[0235] In some implementations, the information related to retaining of the logged measurements may further include information related to a training. The information related to a training may include at least one of a training location, a training type, a connectivity between network nodes, or a logging type.

[0236] In some implementations, the information related to retaining of the logged measurements may further include information related to a situation in which the logged measurements are retained. The situation may include at least one of the handover, a radio resource control (RRC) state transition, an RRC re-establishment, a radio link failure (RLF), or a beam failure (BF).

[0237] In some implementations, the information related to retaining of the logged measurements may inform an OAM or CN-centric training.

[0238] In some implementations, the information related to retaining of the logged measurements may inform an offline training.

[0239] In step S1230, the method comprises retaining the logged measurements based on the information upon execution of a handover.

[0240] In some implementations, the method may further comprise transmitting an indication indicating that the wireless device has the logged measurements to a target base station of the handover. Furthermore, the method may further comprise transmitting the logged measurements to the target base station after transmitting the indication.

[0241] 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.

[0242] 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. 12.

[0243] More specifically, the wireless device receives a logged measurement configuration from a base station.

[0244] In some implementations, the logged measurement configuration may include information related to at least one of a logging object or a logging condition.

[0245] In some implementations, the logged measurement configuration may include information related to a functionality, a model, or a use case.

[0246] The wireless device performs a logging of measurements based on the logged measurement configuration.

[0247] The wireless device receives information related to retaining of the logged measurements from the base station.

[0248] In some implementations, the information related to retaining of the logged measurements may inform that the wireless device should retain the logged measurement available upon execution of the handover.

[0249] In some implementations, the information related to retaining of the logged measurements may further include information related to a training. The information related to a training may include at least one of a training location, a training type, a connectivity between network nodes, or a logging type.

[0250] In some implementations, the information related to retaining of the logged measurements may further include information related to a situation in which the logged measurements are retained. The situation may include at least one of the handover, a radio resource control (RRC) state transition, an RRC re-establishment, a radio link failure (RLF), or a beam failure (BF).

[0251] In some implementations, the information related to retaining of the logged measurements may inform an OAM) or CN-centric training.

[0252] In some implementations, the information related to retaining of the logged measurements may inform an offline training.

[0253] The wireless device retains the logged measurements based on the information upon execution of a handover.

[0254] In some implementations, the wireless device may transmit an indication indicating that the wireless device has the logged measurements to a target base station of the handover. Furthermore, the wireless device may transmit the logged measurements to the target base station after transmitting the indication.

[0255] Furthermore, the method described above in FIG. 12 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.

[0256] 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. 12.

[0257] Furthermore, the method described above in FIG. 12 may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.

[0258] 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.

[0259] 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.

[0260] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0261] 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.

[0262] 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.

[0263] 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. 12.

[0264] FIG. 13 shows an example of a method performed by a base station to which implementations of the present disclosure are applied.

[0265] In step S1300, the method comprises transmitting a logged measurement configuration to a wireless device. A logging of measurements is performed based on the logged measurement configuration.

[0266] In step S1310, the method comprises transmitting information related to retaining of the logged measurements to the wireless device. The logged measurements are retained based on the information upon execution of a handover.

[0267] Furthermore, the base station may be implemented by the second wireless device 200 shown in FIG. 2.

[0268] 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. 13.

[0269] More specifically, the base station transmits a logged measurement configuration to a wireless device. A logging of measurements is performed based on the logged measurement configuration.

[0270] The base station transmits information related to retaining of the logged measurements to the wireless device. The logged measurements are retained based on the information upon execution of a handover.

[0271] According to implementations of the present disclosure with reference of FIGS. 11 and 12, the information related to retaining of the logged measurements may be implemented byretainLoggedMeasurementsInformation Element (IE).

[0272] Table 5 shows an example of a part ofRRCReconfigurationmessage according to implementations of the present disclosure.

[0273] RRCReconfiguration-v1900-IEs ::= SEQUENCE {n3c-ExtIndirectPathAddChange-r19 SetupRelease { N3C-ExtIndirectPathAddChange-r19 } OPTIONAL, -- Need MotherConfig-v1900 OtherConfig-v1900 OPTIONAL, -- Need MonDemandPosSIB-RequestCtrlParam-r19 ENUMERATED { enabled } OPTIONAL, -- Need RretainLoggedMeasurements-r19 ENUMERATED {true} OPTIONAL, -- Cond Syncltm-ConfigNRDC-r19 SetupRelease {LTM-ConfigNRDC-r19} OPTIONAL, -- Need MnonCriticalExtension SEQUENCE {} OPTIONAL}

[0274] Referring to Table 5, theretainLoggedMeasurementsIE indicates that the UE retains the logged measurements available inVarCSI-LogMeasReportupon execution of thisRRCReconfigurationmessage including thereconfigurationWithSync. Since theRRCReconfigurationmessage including thereconfigurationWithSyncmay be interpreted as a handover command, theretainLoggedMeasurementsIE may indicate that the UE retains the logged measurements available inVarCSI-LogMeasReportupon execution the handover.

[0275] The relevant UE operation may be as follows.

[0276] 1> set the content of theRRCReconfigurationCompletemessage as follows:

[0277] 2> if theRRCReconfigurationincludes thereconfigurationWithSyncinspCellConfigof an MCG:

[0278] 3> if theRRCReconfigurationincludesretainLoggedMeasurements:

[0279] 4> if the UE has logged measurement entries available inVarCSI-LogMeasReport:

[0280] 5> includecsi-LogMeasAvailablein theRRCReconfigurationCompletemessage;

[0281] 3> else:

[0282] 4> discard the logged measurement entries and entries associated with configuration and cell information included inVarCSI-LogMeasReport,if any;

[0283] FIG. 14 shows an example of managing logged data to which implementations of the present disclosure are applied.

[0284] In step S1400, the network may configure a logging configuration.

[0285] The logging configuration may include at least one of the following information.

[0286] (1) The logging configuration may include logging object information, e.g., information related to a logging object to be measured. For example, the logging object may be at least one of a target synchronization signal (e.g., SSB) or a reference signal (e.g., CSI-RS, Sounding RS (SRS), Demodulation RS (DM-RS), Phase Tracking RS (PT-RS), etc.). For example, the logging object may be a target configuration (e.g., frequency, sub-carrier spacing, SSB / CSI-RS for measurement).

[0287] (2) The logging configuration may include an indication related to logged data management.

[0288] The indication may indicate whether the UE should retain or discard logged data in a certain situation. Alternatively and / or additionally, the indication may include information related to a certain situation where the indication is applied. For example, the certain situation may include at least one of a handover, RRC state transition, RRC reestablishment, RLF, BF, etc.

[0289] The indication may include training related information. For example, the training related information may include at least one of the following information.

[0290] - training location (e.g., gNB, OAM, CN, etc.)

[0291] - training type (e.g., online / offline training, federated training, reinforcement training, etc.)

[0292] - connectivity between network nodes (e.g., indication whether the current gNB has Xn interface with different gNBs, gNB IDs which is associated with the current gNB, associated ID to indicate association group, network topology information, network operator configuration, etc.)

[0293] - logging type (e.g., signalling based logging, management based logging, etc.)

[0294] The indication may be configured for a logging object or for multiple logging objects.

[0295] (3) The logging configuration may include logging condition information. For example, the logging condition information may include at least one of a logging type (e.g., periodic and event-based logging), a logging interval, a logging amount, event related information (e.g., logging condition with threshold value like A1-A6 HO event, logging condition with a specific condition (e.g., link / beam failure, out-of-sync, etc.))

[0296] (4) The logging configuration may include at least one of functionality / model related information or use case related information (e.g., beam management, CSI compression, CSI feedback, Radio Resource Management (RRM) measurement prediction, etc.).

[0297] In step S1410, the UE may perform logging operation based on the logging configuration.

[0298] For example, the UE may determine whether to perform a logging operation based on a logging condition. That is, if the logging condition is satisfied, the UE may trigger logging.

[0299] For example, the UE may perform logging operation per logging interval.

[0300] For example, the UE may perform logging operation as much as logging amount

[0301] In step S1420, the UE may determine a current connection state.

[0302] The current connection state may be determined based on at least one of a cell change, RRC state transition, link status change, etc. For example, the current connection state may be determined based on whether the handover happens (i.e., gNB / cell change). For example, the current connection state may be determined based on RRC state transition (e.g., from RRC connected state to RRC idle / inactive state). For example, the current connection state may be determined based on at least one of an RRC re-establishment, a Radio link failure (RLF), or a Beam failure (BF).

[0303] The current connection state may be determined based on a certain situation included in the indication, if any. The UE may declare connection state changes only if the current situation is the certain situation.

[0304] In step S1440, if connection state changes, the UE may manage logged data based on the indication.

[0305] (1) For example, if the indication indicates "retaining", the UE may retain the logged data during connection state change. If the indication indicates "discarding", the UE may discard the logged data during connection state change.

[0306] (2) For example, if the indication includes training related information, the UE may manage logged data based on the training related information as follows.

[0307] - If the indication indicates gNB-centric training, the UE may discard the logged data during connection state change.

[0308] - If the indication indicates gNB-centric training, the UE may discard the logged data if a selected cell is different from the previous cell after connection state change

[0309] - If the connectivity between network nodes is configured, the UE may determine whether to discard the logged data. For example, if the previous cell does not have Xn interface with different gNBs, the UE may discard the logged data during connection state change. For example, if gNB ID of the selected cell is not associated with gNB ID of previous cell, the UE may discard the logged data during connection state change. For example, if the gNB group of the selected cell is different from the gNB group of the previous cell (e.g., determination whether the associated ID is the same between the selected cell and the previous cell), the UE may discard the logged data during connection state change. The selected cell may be determined by at least one of a network topology or a network operator configuration. The previous cell may be a cell which configures the logging configuration and / or where the UE performed logging operation. The selected cell may be a cell where the UE selected cell through cell (re)selection or whether network indicated for mobility. The selected cell may be a cell where the UE intended to connect (e.g., RRC connection establishment) after connection state change.

[0310] - If the indication indicates OAM / CN-centric training, the UE may retain the logged data during connection state change.

[0311] - If the indication indicates online training, the UE may discard the logged data during connection state change.

[0312] - If the indication indicates offline training, the UE may retain the logged data during connection state change.

[0313] - If the indication indicates that there is no connectivity between network nodes (e.g., gNBs), the UE may discard the logged data during connection state change.

[0314] The UE may indicate logging related information (e.g., indication indicating that there is available logged data, or an actual data) after the connection state changes. The UE may indicate corresponding information only when the selected cell supports logging target functionality / model or use case.

[0315] The present disclosure may have various advantageous effects.

[0316] For example, by having the network provide guidance regarding whether logged data management is necessary for each specific scenario, the UE can avoid unnecessary memory usage and prevent unnecessary data forwarding, while efficiently providing logged data to the network when it is actually needed.

[0317] For example, when the network explicitly indicates how logged data should be handled in different mobility scenarios, such as whether logged data should be retained and delivered to a target cell after handover, or whether it should be discarded, the UE can make informed decisions that align with the network's training architecture and data collection requirements. This coordination between the UE and network can optimize resource utilization on both sides.

[0318] For example, from the UE perspective, avoiding unnecessary retention of logged data that will ultimately not be used can free up valuable memory resources. Mobile devices often have limited storage capacity, and retaining large amounts of logged measurement data that serves no purpose can constrain the UE's ability to perform other functions or store other important information. By discarding logged data when the network indicates it is not needed, the UE can manage its memory more efficiently.

[0319] For example, preventing unnecessary data forwarding can reduce signaling overhead and conserve radio resources. Transmitting logged data over the air interface consumes uplink resources that could otherwise be used for user data transmission or other control signaling. When logged data delivery to a target cell would not contribute to model training or would not reach the appropriate training entity, avoiding such transmission can improve overall spectral efficiency and reduce battery consumption at the UE.

[0320] For example, by introducing clear criteria for when logged data should be kept versus discarded, the system can achieve more predictable and consistent behavior across different UE implementations and deployment scenarios. This clarity can eliminate ambiguity that might otherwise lead to inconsistent handling of logged data, where some UEs might retain data unnecessarily while others might prematurely discard valuable training information.

[0321] For example, the improved logged data management can also enhance the overall efficiency of AI / ML model training workflows. By ensuring that logged data is delivered to the network only when it can actually be utilized, the system can maximize the value obtained from data collection efforts while minimizing wasted resources.

[0322] For example, the network's ability to provide scenario-specific guidance can enable more flexible and adaptive data collection strategies. Different AI / ML use cases or training approaches may have different requirements regarding data persistence and delivery across cell boundaries. By allowing the network to configure these aspects appropriately for each scenario, the system can support diverse AI / ML deployment models without imposing unnecessary constraints on UE behavior.

[0323] 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.

[0324] 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, a logged measurement configuration from a base station;performing, by the wireless device, a logging of measurements based on the logged measurement configuration;receiving, by the wireless device, information related to retaining of the logged measurements from the base station; andretaining, by the wireless device, the logged measurements based on the information upon execution of a handover.2.The method of claim 1, wherein the information related to retaining of the logged measurements informs that the wireless device should retain the logged measurement available upon execution of the handover.3.The method of claim 1, wherein the method further comprises transmitting an indication indicating that the wireless device has the logged measurements to a target base station of the handover.4.The method of claim 3, wherein the method further comprises transmitting the logged measurements to the target base station after transmitting the indication.5.The method of claim 1, wherein the logged measurement configuration includes information related to at least one of a logging object or a logging condition.6.The method of claim 1, wherein the logged measurement configuration includes information related to a functionality, a model, or a use case.7.The method of claim 1, wherein the information related to retaining of the logged measurements further includes information related to a training.8.The method of claim 7, wherein the information related to a training includes at least one of a training location, a training type, a connectivity between network nodes, or a logging type.9.The method of claim 1, wherein the information related to retaining of the logged measurements further includes information related to a situation in which the logged measurements are retained.10.The method of claim 9, wherein the situation includes at least one of the handover, a radio resource control (RRC) state transition, an RRC re-establishment, a radio link failure (RLF), or a beam failure (BF).11.The method of claim 1, wherein the information related to retaining of the logged measurements informs an Operation Administration Maintenance (OAM) or Core Network (CN)-centric training.12.The method of claim 1, wherein the information related to retaining of the logged measurements informs an offline training.13.The method of claim 1, wherein the wireless device is in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the wireless device.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 the method of any claims 1 to 13.15.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 the method of any claims 1 to 13.16.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 the method of any claims 1 to 13.17.A method comprising:transmitting, by a base station, a logged measurement configuration to a wireless device, wherein a logging of measurements is performed based on the logged measurement configuration; andtransmitting, by the base station, information related to retaining of the logged measurements to the wireless device,wherein the logged measurements are retained based on the information upon execution of a handover.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 the method of claim 17.

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