Network controlled cell reselection in inactive state

Abstract

A method and apparatus for network-controlled cell reselection in inactive state is provided. A wireless device initiates small data transmission, and performs measurement reporting to a network via the small data transmission in an inactive state based on a condition for the measurement reporting in the inactive state being met. The wireless device receives an identifier of a target cell from the network via the small data transmission, and performs cell reselection to the target cell.

Description

NETWORK CONTROLLED CELL RESELECTION IN INACTIVE STATE

[0001] The present disclosure relates to network-controlled cell reselection in inactive state.

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

[0003] 3GPP New Radio (NR) targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shall be inherently forward compatible. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

[0004] 6G is the successor to 5G cellular technology. 6G networks will be able to use higher frequencies than 5G networks and provide substantially higher capacity and much lower latency. The 6G technology market is expected to facilitate large improvements in the areas of imaging, presence technology and location awareness. Working in conjunction with Artificial Intelligence (AI), the 6G computational infrastructure will be able to identify the best place for computing to occur. This includes decisions about data storage, processing and sharing.

[0005] A UE in idle state and / or inactive state performs cell reselection. The UE makes measurements of attributes of the serving and neighbor cells to enable the reselection process. Cell reselection identifies the cell that the UE should camp on. It is based on cell reselection criteria which involves measurements of the serving and neighbor cells.

[0006] In an aspect, a method is provided. The method comprises initiating small data transmission, performing measurement reporting to a network via the small data transmission in an inactive state based on a condition for the measurement reporting in the inactive state being met, receiving an identifier of a target cell from the network via the small data transmission, and performing cell reselection to the target cell.

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

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

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

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

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

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

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

[0014] FIG. 8 shows an example of an overall procedure for RA-based SDT with UE context relocation to which implementations of the present disclosure are applied.

[0015] FIG. 9 shows an example of an overall procedure for RA-based SDT without UE context relocation to which implementations of the present disclosure are applied.

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

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

[0018] FIG. 12 shows an example of a network-controlled cell reselection in an inactive state to which implementations of the present disclosure are applied.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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".

[0023] 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".

[0024] 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".

[0025] 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".

[0026] 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".

[0027] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0028] 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.

[0029] 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.

[0030] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0031] 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.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0042] 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).

[0043] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0044] 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.

[0045] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0066] FIG. 3 shows an example of UE to which implementations of the present disclosure are applied.

[0067] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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).

[0082] 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.

[0083] 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.

[0084] 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.

[0085] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0086] 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).

[0087] 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.

[0088] 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.

[0089] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0090] 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.

[0091] uNslotsymbNframe,uslotNsubframe,uslot212404

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0097] 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.

[0098] 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.

[0099] Small Data Transmission (SDT) is a procedure allowing data and / or signaling transmission while remaining in inactive state (i.e., without transitioning to connected state). SDT is enabled on a radio bearer basis and is initiated by the UE only if less than or equal to a configured amount of UL data awaits transmission across all radio bearers for which SDT is enabled, the DL Reference Signal Received Power (RSRP) is above a configured threshold, and a valid SDT resource is available. Maximum duration the SDT procedure can last is dictated by an SDT failure detection timer that is configured by the network.

[0100] SDT procedure is initiated with either a transmission over RACH (configured via system information) or over type 1 Configured Grant (CG) resources (configured via dedicated signaling in RRC release message). The SDT resources can be configured on initial BWP for both RACH and CG. RACH and CG resources for SDT can be configured on either or both of Normal UL (NUL) and Supplementary (SUL) carriers. The CG resources for SDT are valid only within the PCell of the UE when the RRC Release message with suspend indication is received. CG resources are associated with one or multiple Synchronization Signal Block(s) (SSB(s)). For RACH, the network can configure 2-step and / or 4-step RA resources for SDT. When both 2-step and 4-step RA resources for SDT are configured, the UE selects the RA type. CFRA is not supported for SDT over RACH.

[0101] Once initiated, the SDT procedure is either:

[0102] - successfully completed after the UE is directed to idle state (via RRC release message) or to continue in inactive state (via RRC release message or RRC reject message) or to connected state (via RRC resume message or RRC setup message); or

[0103] - unsuccessfully completed upon cell re-selection, expiry of the SDT failure detection timer, a MAC entity reaching a configured maximum PRACH preamble transmission threshold, an RLC entity reaching a configured maximum retransmission threshold, or integrity check failure while SDT procedure is ongoing, or expiry of SDT-specific timing alignment timer or configured grant timer while SDT procedure is ongoing over CG and the UE has not received a response from the network after the initial PUSCH transmission.

[0104] Upon unsuccessful completion of the SDT procedure, the UE transitions to idle state.

[0105] For SDT, network should not send RRC reject message in response to RRC resume request message if DL data over any radio bearer configured for SDT is transmitted.

[0106] The initial PUSCH transmission during the SDT procedure includes at least the CCCH message. When using CG resources for initial SDT transmission, the UE can perform autonomous retransmission of the initial transmission if the UE does not receive confirmation from the network (dynamic UL grant or DL assignment) before a configured timer expires. After the initial PUSCH transmission, subsequent transmissions are handled differently depending on the type of resource used to initiate the SDT procedure:

[0107] - When using CG resources, the network can schedule subsequent UL transmissions using dynamic grants or they can take place on the following CG resource occasions. The DL transmissions are scheduled using dynamic assignments. The UE can initiate subsequent UL transmission only after reception of confirmation (dynamic UL grant or DL assignment) for the initial PUSCH transmission from the network. For subsequent UL transmission, the UE cannot initiate re-transmission over a CG resource.

[0108] - When using RACH resources, the network can schedule subsequent UL and DL transmissions using dynamic UL grants and DL assignments, respectively, after the completion of the RA procedure.

[0109] When SDT procedure is initiated, AS security is applied for all the radio bearers enabled for SDT.

[0110] While the SDT procedure is ongoing, if data appears in a buffer of any radio bearer not enabled for SDT, the UE initiates a transmission of a non-SDT data arrival indication using UE assistance information message to the network and, if available, includes the resume cause.

[0111] SDT procedure over CG resources can only be initiated with valid UL timing alignment. The UL timing alignment is maintained by the UE based on a SDT-specific timing alignment timer configured by the network via dedicated signaling and, for initial CG-SDT transmission, also by DL RSRP of configured number of highest ranked SSBs which are above a configured RSRP threshold. Upon expiry of the SDT-specific timing alignment timer, the CG resources are released while maintaining the CG resource configuration.

[0112] Logical channel restrictions configured by the network while in connected state and / or in RRC release message for radio bearers enabled for SDT, if any, are applied by the UE during SDT procedure.

[0113] The network may configure UE to apply ROHC continuity for SDT either when the UE initiates SDT in the PCell of the UE when the RRC release mesasge with suspend indication was received or when the UE initiates SDT in a cell of its RAN-based Notification Area (RNA).

[0114] For SDT procedure over RACH, if the UE accesses a base station (i.e., receiving base station) other than the last serving base station, the UL SDT data / signaling is buffered at the receiving base station, and then the receiving base station triggers the retrieve UE context procedure. The receiving base station indicates SDT to the last serving base station and the last serving base station decides whether to relocate the UE context or not. Other SDT assistance information (e.g., single packet, multiple packets) may also be provided by the receiving base station to help the decision of UE context relocation.

[0115] If the last serving base station decides not to relocate the full UE context, it transfers a partial UE context containing SDT RLC context information necessary for the receiving base station to handle SDT via the partial UE context transfer procedure.

[0116] Then, in case SDT is used for user data over DRBs, UL / DL tunnels are established for DRBs configured for SDT between the receiving base station and the last serving base station. The PDCP PDU of UL / DL data is transferred over the tunnels, until the last serving base station terminates the SDT session and directs the UE to continue in inactive state by sending the RRC release message.

[0117] Or in case SDT is used for signaling, SRB PDCP PDUs are transferred between the receiving base station and the last serving base station via the RRC transfer procedure, until the last serving base station terminates the SDT session and directs the UE to continue in inactive state by sending the RRC release message.

[0118] During the SDT session, in case the receiving base station detects that no more packets are to be transmitted, or radio link problem is detected, the receiving base station may also request to terminate the SDT session to the last serving base station via the UE context retrieve confirmation procedure.

[0119] FIG. 8 shows an example of an overall procedure for RA-based SDT with UE context relocation to which implementations of the present disclosure are applied.

[0120] 1. The UE sends anRRCResumeRequestmessage as well as UL SDT data and / or UL SDT signaling to the receiving gNB.

[0121] 2. The receiving gNB identifies the last serving gNB using the Inactive Radio Network Temporary Identity (I-RNTI) and retrieves the UE context by means of Xn-AP retrieve UE context procedure. The receiving gNB indicates that the UE request is for an SDT and may also provide SDT assistance information (e.g., single packet, multiple packets).

[0122] 3. The last serving gNB decides to relocate UE context and responds with the retrieve UE context response message. The UL SDT data, if any, is delivered from the receiving gNB to the User Plane Function (UPF).

[0123] 4. The receiving gNB decides to keep UE in RRC_INACTIVE state for SDT. If loss of DL user data buffered in the last serving gNB shall be prevented, the receiving gNB provides forwarding addresses via the Xn-U address indication message. The receiving gNB also initiates NGAP path switch request procedure to establish a NG UE-associated signaling connection to the Access and mobility Management Function (AMF). After the path switch request procedure, the buffered UL NAS PDU, if any, is delivered from the receiving gNB to the AMF. And then, the subsequent UL / DL SDT data and / or signaling are transferred between UE and core network (e.g., UPF) via the receiving gNB.

[0124] 5. After the SDT transmission is terminated, the receiving gNB generates and sends theRRCReleasemessage including the suspend indication to the UE to terminate the SDT procedure and continue in RRC_INACTIVE state.

[0125] In case DL non-SDT data or DL non-SDT signaling arrives, or the UE assistance information (i.e., UL non-SDT data arrival indication) is received from the UE, the receiving gNB may decide to directly send the UE to RRC_CONNECTED state by sending theRRCResumemessage.

[0126] The receiving gNB may decide to directly send the UE to RRC_CONNECTED state by sending theRRCResumemessage based on (e.g., large size of) DL SDT data or DL SDT signaling.

[0127] 4. The receiving gNB indicates to the last serving gNB to remove the UE context by sending the XnAP UE context release message. The XnAP UE context release message can be sent after step 6.

[0128] FIG. 9 shows an example of an overall procedure for RA-based SDT without UE context relocation to which implementations of the present disclosure are applied.

[0129] 1 / 2. The steps 1 / 2 are as defined in steps 1 / 2 in FIG. 8.

[0130] 3. The last serving gNB decides not to relocate the full UE context for SDT.

[0131] 4. The last serving gNB transfers a partial UE context including the SDT related RLC context.

[0132] 5. The receiving gNB acknowledges receiving the partial UE context and provides associated DL Transport Network Layer (TNL) address. The UE context is kept at the last serving gNB and the SDT related RLC context is established at the receiving gNB. Then UL / DL GPRS Tunneling Protocol (GTP)-U tunnels are established for DRBs configured for SDT, if any, and the UL SDT data and / or signaling, if any, are forwarded to the last serving gNB, and then delivered to the core network.

[0133] The DL signaling from the last serving gNB, if any, is forwarded to the receiving gNB via the RRC transfer message, for which the receiving gNB delivers it to the UE.

[0134] In case DL non-SDT data or DL non-SDT signaling arrives, or UE assistance information (i.e., UL non-SDT data arrival indication) is received from the UE, the last serving gNB terminates the SDT procedure and directs the UE to continue in RRC_INACTIVE state by sending theRRCReleasemessage.

[0135] The last serving gNB may terminate the SDT procedure and direct the UE to continue in RRC_INACTIVE state by sending theRRCReleasemessage based on (e.g., large size of) DL SDT data or DL SDT signaling.

[0136] 6. The receiving gNB detects the end of SDT session and sends the retrieve UE context confirm message including whether this is a normal end of SDT transaction or a radio link problem.

[0137] 7. Upon receiving the retrieve UE context confirm message and deciding to terminate the SDT, the last serving gNB responds to the receiving gNB with the retrieve UE context failure message including an encapsulatedRRCReleasemessage. The receiving gNB may release the established partial UE context.

[0138] 8. The receiving gNB sends theRRCReleasemessage to the UE.

[0139] 9. The UE moves to RRC_INACTIVE state if the suspend indication is included in theRRCReleasemessage. Or else, the UE moves to RRC_IDLE state.

[0140] A UE in idle state (e.g., RRC_IDLE state) and / or inactive state (RRC_INACTIVE state) autonomously selects the target cell to camp on based on the measurement results. A network may somewhat control the mobility of the UE in idle state and / or inactive state by setting and transmitting the frequency priority via system information, but may not separately configure it for each individual UE. Although the frequency priority may be provided via dedicated signaling to separately configure each individual UE, it may also have a limitation that it cannot be updated while UE is in idle state and / or inactive state.

[0141] Therefore, a method for enhancing mobility control of a UE in idle state and / or inactive state more may be required.

[0142] According to implementations of the present disclosure, while the small data transmission (e.g., SDT procedure described above in FIGS. 8 and / or 9) is available (e.g., when small data transmission is initiated), if the measurement reporting condition is met, the UE in inactive state (e.g., RRC_INACTIVE state) may report the measurement results to network via the small data transmission.

[0143] After reporting the measurement results to network via the small data transmission, the UE in inactive state (e.g., RRC_INACTIVE state) may receive the mobility command indicating a target cell via the small data transmission from the network, and perform the cell reselection to the target cell, e.g., camps on the target cell.

[0144] Transmitting of the measurement results to network via the small data transmission and / or receiving of the mobility command indicating a target cell via the small data transmission may be performed based on the SDT transmission procedure described above in FIGS. 8 and / or 9.

[0145] The UE in inactive state (e.g., RRC_INACTIVE state) may consider the small data transmission is available if all conditions for initiating the small data transmission procedure are met.

[0146] For example, a UE in inactive state may initiate the resume procedure for SDT when all of the following conditions are fulfilled:

[0147] 1> the upper layers (e.g., NAS layer) request resumption of RRC connection; and

[0148] 1>SIB1includessdt-ConfigCommon; and

[0149] 1>sdt-Configis configured; and

[0150] 1> all the pending data in UL is mapped to the radio bearers configured for small data transmission; and

[0151] 1> for a RedCap UE when RedCap-specific initial downlink BWP includes no CD-SSB,ncd-SSB-RedCapInitialBWP-SDTis configured; and

[0152] 1> lower layers (e.g., MAC layer) indicate that conditions for initiating small data transmission are fulfilled.

[0153] For example, the MAC entity may be configured by RRC with SDT and the SDT procedure may be initiated by RRC layer. The SDT procedure can be performed either by random access procedure with 2-step RA type or 4-step RA type (i.e., RA-SDT) or by configured grant type 1 (i.e., CG-SDT).

[0154] RRC configures the following parameters for SDT procedure:

[0155] -sdt-DataVolumeThreshold: data volume threshold for the UE to determine whether to perform SDT procedure;

[0156] -sdt-RSRP-Threshold: RSRP threshold for UE to determine whether to perform SDT procedure;

[0157] -cg-SDT-RSRP-ThresholdSSB: an RSRP threshold configured for SSB selection for CG-SDT.

[0158] The MAC entity may, if initiated by the upper layers (e.g., RRC layer) for SDT procedure:

[0159] 1> if the data volume of the pending UL data across all RBs configured for SDT is less than or equal tosdt-DataVolumeThreshold; and

[0160] 1> if the RSRP of the downlink pathloss reference is higher thansdt-RSRP-Thresholdor ifsdt-RSRP-Thresholdis not configured:

[0161] 2> if the serving cell is configured with supplementary uplink; and

[0162] 2> if the RSRP of the downlink pathloss reference is less thanrsrp-ThresholdSSB-SUL:

[0163] 3> select the SUL carrier.

[0164] 2> else:

[0165] 3> select the NUL carrier.

[0166] 2> if CG-SDT is configured on the selected UL carrier, and Timing Advance (TA) for CG-SDT is valid in the first available CG occasion for initial CG-SDT transmission with CCCH message; and

[0167] 2> if, for each RB having data available for transmission,configuredGrantType1Allowed, if configured for CG-SDT, is configured with valuetruefor the corresponding logical channel; and

[0168] 2> if at least one SSB configured for CG-SDT with SS-RSRP abovecg-SDT-RSRP-ThresholdSSBis available:

[0169] 3> indicate to the upper layers (e.g., RRC layer) that the conditions for initiating SDT procedure are fulfilled;

[0170] 3> perform CG-SDT procedure on the selected UL carrier.

[0171] 2> else if a set of random access resources for RA-SDT is configured and can be selected on the selected UL carrier on the BWP configured byinitialUplinkBWP-RedCap, if configured for a RedCap UE; otherwise, on the BWP configured byinitialUplinkBWP:

[0172] 3> ifcg-SDT-TimeAlignmentTimeris running, considercg-SDT-TimeAlignmentTimeras expired;

[0173] 3> indicate to the upper layers (e.g., RRC layer) that the conditions for initiating SDT procedure are fulfilled.

[0174] 2> else:

[0175] 3> indicate to the upper layers (e.g., RRC layer) that the conditions for initiating SDT procedure are not fulfilled.

[0176] 1> else:

[0177] 2> indicate to the upper layers (e.g., RRC layer) that the conditions for initiating SDT procedure are not fulfilled.

[0178] If RA-SDT is selected above and after the random access procedure is successfully completed, the UE monitors PDCCH addressed to Cell RNTI (C-RNTI) received in random access response until the RA-SDT procedure is terminated. If CG-SDT is selected above and after the initial transmission for CG-SDT is performed, the UE monitors PDCCH addressed to C-RNTI as stored in UE Inactive AS context and Configured Grant RNTI (CS-RNTI) until the CG-SDT procedure is terminated.

[0179] According to implementations of the present disclosure, if the small data transmission is available, the UE in inactive state performs the connected measurements (e.g., RRC_CONNECTED measurements).

[0180] For example, the UE performing connected measurements while in inactive state may derive cell measurement results as it derives them in connected state.

[0181] For example, for cell measurement results, e.g., RSRP or Reference Signal Received Quality (RSRQ), the UE performing connected measurements while in inactive state may apply the layer 3 filtering, before using the measured results for evaluation of reporting criteria, and / or measurement reporting.

[0182] For example, if beam measurement information is configured to be included in measurement reporting to be transmitted in inactive state, the UE may apply the layer 3 beam filtering.

[0183] According to implementations of the present disclosure, for the connected measurements (e.g., RRC_CONNECTED measurements) and / or measurement reporting in inactive state, the network may provide the measurement configuration to UE.

[0184] For example, the measurement configuration may include at least one of measurement target information, e.g., measurement object configuration, and / or measurement reporting configuration, e.g., reporting condition.

[0185] For example, the measurement configuration may be transmitted via RRC release message, RRC reconfiguration message, and / or system information.

[0186] According to implementations of the present disclosure, if the reporting condition is met while measurement reporting via the small data transmission is available, the UE may transmit the measurement report to the network using the small data transmission procedure. For this, the existing measurement report message may be used. Alternatively, a new measurement report message may be used. The existing / new measurement report message may include at least a cell identity / index and / or a measurement identity which triggers the measurement report.

[0187] If the small data transmission procedure is not on-going when the reporting condition is met, the UE may initiate the resume procedure for small data transmission.

[0188] According to implementations of the present disclosure, the UE may receive a mobility command from the network via the small data transmission. The mobility command may include at least a target cell identity.

[0189] According to implementations of the present disclosure, the measurement configuration may be updated via the small data transmission. If the measurement configuration is received via the small data transmission, the UE may perform the connected measurements and / or measurement reporting according to the updated measurement configuration.

[0190] According to implementations of the present disclosure, network-controlled cell reselection proposed by the present disclosure and legacy cell reselection may be co-existed or not.

[0191] For example, network-controlled cell reselection and legacy cell reselection may be mutually exclusive. For example, if the small data transmission resource is configured and available, the UE in inactive state may not perform the normal cell reselection which is the cell reselection procedure performed based on cell-ranking criterion and reselection priorities. For example, if the small data transmission resource is not available, the UE in inactive state may perform the normal cell reselection.

[0192] For example, network-controlled cell reselection and legacy cell reselection may be co-existed. For example, even though the small data transmission resource is configured and available, the UE may also perform the normal cell reselection procedure. If the UE finds a neighbor cell which satisfies the cell reselection condition, the UE may perform the cell reselection to the neighbor cell without measurement reporting and the mobility command via the small data transmission.

[0193] 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.

[0194] FIG. 10 shows an example of a method to which implementations of the present disclosure are applied.

[0195] In step S1000, the method comprises receiving a release message including a suspend configuration from a network.

[0196] In step S1010, the method comprises entering an inactive state based on the suspend configuration.

[0197] In some implementations, the inactive state may be an RRC_INACTIVE state.

[0198] In step S1020, the method comprises receiving a small data transmission configuration from the network.

[0199] In step S1030, the method comprises receiving information related to a condition for measurement reporting in the inactive state from the network.

[0200] In step S1040, the method comprises initiating small data transmission based on the small data transmission configuration.

[0201] In some implementations, the small data transmission may be initiated based on conditions for initiating the small data transmission being fulfilled.

[0202] In step S1050, the method comprises performing the measurement reporting to the network via the small data transmission in the inactive state based on the condition being met.

[0203] In step S1060, the method comprises receiving an identifier of a target cell from the network via the small data transmission.

[0204] In some implementations, the identifier of the target cell may be received in a mobility command.

[0205] In step S1070, the method comprises performing cell reselection to the target cell.

[0206] In some implementations, connected measurements may be performed in the inactive state based on initiating the small data transmission. performing of the connected measurements may include deriving cell measurement results. The cell measurement results may include at least one of RSRP, RSRQ or SINR of a cell. Layer 3 filtering may be applied to the cell measurement results before transmitting the measurement results. The measurement reporting may include the cell measurements results.

[0207] In some implementations, the measurement reporting may include beam measurements results. Layer 3 beam filtering may be applied to the beam measurements results.

[0208] In some implementations, the measurement reporting may include at least one of a cell identity or a measurement identity which triggers the measurement reporting.

[0209] In some implementations, a resume procedure for the small data transmission may be initiated based on i) the condition being met, and ii) the small data transmission not being on-going.

[0210] In some implementations, a measurement configuration may be received / updated via the small data transmission.

[0211] In some implementations, the cell reselection may not include a normal cell reselection based on cell ranking criterion and reselection priorities.

[0212] In some implementations, the method may be performed by a wireless device. The wireless device may be in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the first wireless device.

[0213] Furthermore, the method described above in FIG. 10 may be performed by a wireless device. 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.

[0214] The wireless device comprises at least one transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform the method described in FIG. 10.

[0215] More specifically, the wireless device receives a release message including a suspend configuration from a network.

[0216] The wireless device enters an inactive state based on the suspend configuration.

[0217] In some implementations, the inactive state may be an RRC_INACTIVE state.

[0218] The wireless device receives a small data transmission configuration from the network.

[0219] The wireless device receives information related to a condition for measurement reporting in the inactive state from the network.

[0220] The wireless device initiates small data transmission based on the small data transmission configuration.

[0221] In some implementations, the small data transmission may be initiated based on conditions for initiating the small data transmission being fulfilled.

[0222] The wireless device performs the measurement reporting to the network via the small data transmission in the inactive state based on the condition being met.

[0223] The wireless device receives an identifier of a target cell from the network via the small data transmission.

[0224] In some implementations, the identifier of the target cell may be received in a mobility command.

[0225] The wireless device performs cell reselection to the target cell.

[0226] In some implementations, connected measurements may be performed in the inactive state based on initiating the small data transmission. performing of the connected measurements may include deriving cell measurement results. The cell measurement results may include at least one of RSRP, RSRQ or SINR of a cell. Layer 3 filtering may be applied to the cell measurement results before transmitting the measurement results. The measurement reporting may include the cell measurements results.

[0227] In some implementations, the measurement reporting may include beam measurements results. Layer 3 beam filtering may be applied to the beam measurements results.

[0228] In some implementations, the measurement reporting may include at least one of a cell identity or a measurement identity which triggers the measurement reporting.

[0229] In some implementations, a resume procedure for the small data transmission may be initiated based on i) the condition being met, and ii) the small data transmission not being on-going.

[0230] In some implementations, a measurement configuration may be received / updated via the small data transmission.

[0231] In some implementations, the cell reselection may not include a normal cell reselection based on cell ranking criterion and reselection priorities.

[0232] Furthermore, the method described above in FIG. 10 may be performed by control of a processing apparatus adapted to control a wireless device. 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.

[0233] The processing apparatus adapted to control the wireless device comprises at least one processor, and at least one memory operably connectable to the at least one processor. The at least one processor is adapted to perform the method described in FIG. 10.

[0234] Furthermore, the method described above in FIG. 10 may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.

[0235] 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.

[0236] 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.

[0237] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0238] 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.

[0239] 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.

[0240] According to some implementations of the present disclosure, a non-transitory Computer-Readable Medium (CRM) stores instructions that, based on being executed by at least one processor, perform the method described in FIG. 10.

[0241] FIG. 11 shows an example of another method to which implementations of the present disclosure are applied.

[0242] In step S1100, the method comprises transmitting a release message including a suspend configuration to a wireless device.

[0243] In step S1110, the method comprises transmitting a small data transmission configuration to the wireless device.

[0244] In step S1120, the method comprises transmitting information related to a condition for measurement reporting in an inactive state to the wireless device.

[0245] In step S1130, the method comprises receiving the measurement reporting from the wireless device via the small data transmission in an inactive state based on the condition being met.

[0246] In step S1140, the method comprises transmitting an identifier of a target cell to the wireless device via the small data transmission.

[0247] Furthermore, the method described above in FIG. 11 may be performed by a base station. The base station may be implemented by the second wireless device 200 shown in FIG. 2.

[0248] The base station comprises at least one transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform the method described in FIG. 11.

[0249] More specifically, the base station transmits a release message including a suspend configuration to a wireless device.

[0250] The base station transmits a small data transmission configuration to the wireless device.

[0251] The base station transmits information related to a condition for measurement reporting in an inactive state to the wireless device.

[0252] The base station receives the measurement reporting from the wireless device via the small data transmission in an inactive state based on the condition being met.

[0253] The base station transmits an identifier of a target cell to the wireless device via the small data transmission.

[0254] FIG. 12 shows an example of a network-controlled cell reselection in an inactive state to which implementations of the present disclosure are applied.

[0255] 1. A UE in RRC_CONNECTED state receives RRC release message (e.g.,RRCReleasemessage) with suspend configuration (e.g.,suspendConfig) including SDT configuration (e.g.,SDT-Config) and the measurement configuration, and enters RRC_INACTIVE state. The measurement configuration may indicate target cell for which the UE should perform the RRC_CONNECTED measurement, and include the reporting condition.

[0256] 2. The UE in RRC_INACTIVE state performs the RRC_CONNECTED measurement while the SDT resource is available.

[0257] 3. If the reporting condition configured by the RRC release message with suspend configuration is met, the UE in RRC_INACTIVE state transmits the measurement report via SDT procedure.

[0258] 4. The UE in RRC_INACTIVE state receives a mobility command from the network, which indicates target cell.

[0259] 5. The UE in RRC_INACTIVE state performs cell reselection to the target cell indicated by the mobility command.

[0260] The present disclosure may have various advantageous effects.

[0261] For example, the network can enhance the ability to control the mobility of UE in idle state and / or inactive state, and can more aggressively make UE transition to inactive state.

[0262] For example, the UE can move to and camp on a cell which is suitable for on-going session that the UE has or UE capability.

[0263] 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.

[0264] Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

1.A method comprising:receiving a release message including a suspend configuration from a network;entering an inactive state based on the suspend configuration;receiving a small data transmission configuration from the network;receiving information related to a condition for measurement reporting in the inactive state from the network;initiating small data transmission based on the small data transmission configuration;performing the measurement reporting to the network via the small data transmission in the inactive state based on the condition being met;receiving an identifier of a target cell from the network via the small data transmission; andperforming cell reselection to the target cell.2.The method of claim 1, wherein the inactive state is a Radio Resource Control (RRC) inactive state (RRC_INACTIVE state).3.The method of claim 1 or 2, wherein the small data transmission is initiated based on conditions for initiating the small data transmission being fulfilled.4.The method of any claims 1 to 3, wherein connected measurements are performed in the inactive state based on initiating the small data transmission.5.The method of claim 4, wherein performing of the connected measurements include deriving cell measurement results.6.The method of claim 5, wherein the cell measurement results includes at least one of a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ) or a Signal-to-Interference and Noise Ratio (SINR) of a cell.7.The method of claim 6, wherein layer 3 filtering is applied to the cell measurement results before transmitting the measurement results.8.The method of any claims 5 to 7, wherein the measurement reporting includes the cell measurements results.9.The method of any claims 1 to 8, wherein the measurement reporting includes beam measurements results.10.The method of claim 9, wherein layer 3 beam filtering is applied to the beam measurements results.11.The method of any claims 1 to 10, wherein the measurement reporting includes at least one of a cell identity or a measurement identity which triggers the measurement reporting.12.The method of any claims 1 to 11, wherein a resume procedure for the small data transmission is initiated based on i) the condition being met, and ii) the small data transmission not being on-going.13.The method of any claims 1 to 12, wherein the identifier of the target cell is received in a mobility command.14.The method of any claims 1 to 13, wherein a measurement configuration is updated via the small data transmission.15.The method of any claims 1 to 14, wherein the cell reselection does not include a normal cell reselection based on cell ranking criterion and reselection priorities.16.The method of any claims 1 to 15, wherein the method is performed by a wireless device.17.The method of any claims 1 to 16, wherein the wireless device is in communication with at least one of a mobile device, a network, and / or autonomous vehicles other than the first wireless device.18.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, perform the method of any claims 1 to 17.19.A processing apparatus adapted to control a wireless device comprising:at least one processor; andat least one memory operably connectable to the at least one processor,wherein the at least one processor is adapted to perform the method of any claims 1 to 17.20.A non-transitory Computer Readable Medium (CRM) storing instructions that, based on being executed by at least one processor, perform the method of any claims 1 to 17.21.A method comprising:transmitting a release message including a suspend configuration to a wireless device;transmitting a small data transmission configuration to the wireless device;transmitting information related to a condition for measurement reporting in an inactive state to the wireless device;receiving the measurement reporting from the wireless device via the small data transmission in an inactive state based on the condition being met; andtransmitting an identifier of a target cell to the wireless device via the small data transmission.22.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, perform the method of claim 21.

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