Method and apparatus for performing reconnection in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by an ambient Internet of Things (A-IoT) device in a wireless communication system, according to one embodiment of the present disclosure, comprises the steps of: transmitting, to a reader, a first message for contention-based random access (CBRA); receiving, from the reader, a second message in response to the first message; storing an access stratum (AS) ID on the basis of the second message; transmitting, to the reader, a device-to-reader (D2R) message; and receiving, from the reader, a negative acknowledgment (NACK) message including the stored AS ID, wherein the NACK message may include information indicating that a message type is NACK, size information of the NACK message, and one or more reserved bits.

Description

Method and device for performing reconnection in a wireless communication system

[0001] The present disclosure relates to a wireless communication system or a mobile communication system. Specifically, it relates to a method and apparatus for performing non-acknowledgement (NACK)-based re-access in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz (THX) band (e.g., the 3 terahertz band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) for supporting new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) for incorporating Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms to guarantee coverage in the terahertz band of 6G mobile communication technology, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas; metamaterial-based lenses and antennas to improve terahertz band signal coverage; high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum); and Reconfigurable Intelligent Surface (RIS) technology; as well as Full Duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] The present disclosure provides a method and apparatus for performing NACK (non-acknowledgement)-based re-access in a wireless communication system or a mobile communication system.

[0009] A method performed by an A-IoT (Ambient Internet of Things) device in a wireless communication system according to one embodiment of the present disclosure comprises the steps of: transmitting a first message for CBRA (Contention-Based Random Access) to a reader; receiving a second message from the reader in response to the first message; storing an AS (Access Stratum) ID based on the second message; transmitting a D2R (Device to Reader) message to the reader; and receiving a NACK (Negative Acknowledgment) message from the reader that includes the stored AS ID, wherein the NACK message may include information indicating that the message type is NACK, size information of the NACK message, and one or more reserved bits.

[0010] A method performed by a reader in a wireless communication system according to one embodiment of the present disclosure may include receiving a first message for CBRA (Contention-Based Random Access) from an A-IoT (Ambient Internet of Things) device, transmitting a second message to the A-IoT device in response to the first message, receiving a D2R (Device to Reader) message from the A-IoT device, and transmitting a NACK (Negative Acknowledgment) message including an AS (Access Stratum) ID to the A-IoT device, wherein the AS ID is stored in the A-IoT device based on the second message, and the NACK message may include information indicating that the message type is NACK, size information of the NACK message, and one or more reserved bits.

[0011] According to one embodiment of the present disclosure, an A-IoT (Ambient Internet of Things) device in a wireless communication system comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory communicatively coupled to the at least one processor for storing instructions, wherein the instructions are executed individually or in any combination by the at least one processor, so that the A-IoT device transmits a first message for CBRA (Contention-Based Random Access) to a reader, receives a second message from the reader in response to the first message, stores an AS (Access Stratum) ID based on the second message, transmits a D2R (Device to Reader) message to the reader, and receives a NACK (Negative Acknowledgment) message including the stored AS ID from the reader, wherein the NACK message indicates that the message type is NACK It may include information indicating, size information of the NACK message, and one or more reserved bits.

[0012] In a wireless communication system according to one embodiment of the present disclosure, a reader comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory communicatively coupled to the at least one processor for storing instructions, wherein the instructions are executed individually or in any combination by the at least one processor, so that the reader receives a first message for Contentation-Based Random Access (CBRA) from an Ambient Internet of Things (A-IoT) device, transmits a second message to the A-IoT device in response to the first message, receives a Device to Reader (D2R) message from the A-IoT device, and transmits a Negative Acknowledgment (NACK) message including an Access Stratum (AS) ID to the A-IoT device, wherein the AS ID is based on the second message The NACK message is stored in an A-IoT device and may include information indicating that the message type is NACK, size information of the NACK message, and one or more reserved bits.

[0013] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below.

[0014] FIG. 1a is a drawing illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0015] FIG. 1b is a diagram showing the wireless protocol structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0016] FIG. 1c is a diagram illustrating a topology and deployment scenario in which ambient IoT (Internet of Things) communication is supported in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0017] FIG. 1d is a diagram illustrating a use case in which Ambient IoT (Internet of Things) communication is applied in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0018] FIG. 1e is a diagram illustrating a procedure for inventorying Ambient IoT (Internet of Things) devices in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0019] FIG. 1f is a diagram illustrating a procedure for inventorying Ambient IoT (Internet of Things) devices in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0020] FIG. 1g is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0021] FIG. 1h is a block diagram showing the configuration of an NR base station according to one embodiment of the present disclosure.

[0022] FIG. 1i illustrates the structure of a terminal according to one embodiment of the present disclosure.

[0023] FIG. 1j illustrates the structure of a base station according to one embodiment of the present disclosure.

[0024] The operating principles of the present disclosure will be described in detail below with reference to the attached drawings. In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Furthermore, the terms described below are defined in consideration of their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0025] In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Embodiments of the present disclosure will be described below with reference to the attached drawings.

[0026] Terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc., are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0027] For convenience of explanation, the present disclosure uses terms and names defined in the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard. However, the present disclosure is not limited to the above terms and names and may be applied equally to systems conforming to other standards. In the present disclosure, eNB may be used interchangeably with gNB for convenience of explanation. That is, a base station described as an eNB may represent a gNB.

[0028] FIG. 1a is a drawing illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0029] Referring to FIG. 1a, as illustrated, the wireless access network of a next-generation mobile communication system (hereinafter NR or 2g) consists of a next-generation base station (New Radio Node B, hereinafter NR gNB or NR base station) (1a-10) and an NR CN (1a-05, New Radio Core Network). A user terminal (New Radio User Equipment, hereinafter NR UE or terminal) (1a-15) connects to an external network through the NR gNB (1a-10) and the NR CN (1a-05).

[0030] In FIG. 1a, the NR gNB (1a-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE (1a-15) via a wireless channel and can provide superior service compared to the existing Node B. In next-generation mobile communication systems, since all user traffic is serviced through a shared channel, a device is required to collect status information such as the buffer status, available transmission power status, and channel status of the UEs to perform scheduling, and this can be handled by the NR NB (1a-10). A single NR gNB can typically control multiple cells. To achieve ultra-high-speed data transmission compared to current LTE, it can have a maximum bandwidth greater than the existing maximum bandwidth, and beamforming technology can be additionally incorporated by using Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) as the wireless access technology. In addition, an Adaptive Modulation & Coding (AMC) method can be applied to determine the modulation scheme and channel coding rate according to the channel conditions of the terminal. The NR CN (1a-05) performs functions such as mobility support, bearer configuration, and QoS configuration. The NR CN is a device responsible for various control functions as well as mobility management functions for the terminal, and can be connected to multiple base stations. Furthermore, the next-generation mobile communication system can be interoperable with existing LTE systems, and the NR CN can be connected to the MME (mobility management entity) (1a-25) via a network interface. The MME can be connected to the existing base station eNB (1a-30).

[0031] FIG. 1b is a diagram showing the wireless protocol structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0032] Referring to Fig. 1b, the wireless protocol of the next-generation mobile communication system consists of NR SDAP (service data adaptation protocol) (1b-01, 1b-45), NR PDCP (packet data convergence protocol) (1b-05, 1b-40), NR RLC (radio link control) (1b-10, 1b-35), and NR MAC (medium access control) (1b-15, 1b-30) at the terminal and the NR base station, respectively.

[0033] The main functions of NR SDAP (1b-01, 1b-45) may include some of the following functions.

[0034] - User data transfer function (transfer of user plane data)

[0035] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink

[0036] - Marking QoS flow ID in both DL and UL packets for uplink and downlink

[0037] - Function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0038] For SDAP layer devices, the terminal may receive a setting via an RRC message regarding whether to use the SDAP layer device header or the SDAP layer device functions for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the terminal may be instructed to update or reset the mapping information for the uplink and downlink QoS flows and data bearers using the 1-bit NAS QoS reflective QoS and AS QoS reflective QoS indicators in the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used for data processing priorities, scheduling information, etc., to support seamless service.

[0039] The main functions of NR PDCP (1b-05, 1b-40) may include some of the following functions.

[0040] - Header compression and decompression features (ROHC only)

[0041] - User data transfer function (Transfer of user data)

[0042] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0043] - Out-of-sequence delivery of upper layer PDUs

[0044] - Reordering function (PDCP PDU reordering for reception)

[0045] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0046] - Retransmission of PDCP SDUs

[0047] - Encryption and decryption functions (Ciphering and deciphering)

[0048] - Timer-based SDU discard in uplink.

[0049] In one example, the reordering function of an NR PDCP device refers to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order, a function of transmitting immediately without considering the order, a function of recording lost PDCP PDUs by reordering, a function of reporting the status of lost PDCP PDUs to the transmitting side, or a function of requesting retransmission of lost PDCP PDUs.

[0050] The main functions of NR RLC(1b-10, 1b-35) may include some of the following functions.

[0051] - Data transfer function (Transfer of upper layer PDUs)

[0052] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0053] - Out-of-sequence delivery of upper layer PDUs

[0054] - ARQ function (Error Correction through ARQ)

[0055] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0056] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0057] - Reordering function (Reordering of RLC data PDUs)

[0058] - Duplicate detection

[0059] - Error detection function (Protocol error detection)

[0060] - RLC SDU discard function

[0061] RLC re-establishment function

[0062] The in-sequence delivery function of an NR RLC device refers to the function of delivering RLC SDUs received from a lower layer to an upper layer in sequence, and may include the function of reassembling and delivering them when an original RLC SDU is received divided into multiple RLC SDUs. Additionally, the sequential delivery function of the NR RLC device may include a function to rearrange the received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function to record the lost RLC PDUs by rearranging the order, a function to report the status of the lost RLC PDUs to the transmitting side, a function to request retransmission of the lost RLC PDUs, a function to deliver only the RLC SDUs up to the lost RLC SDU in order to the upper layer if there is a lost RLC SDU, a function to deliver all RLC SDUs received before the timer started in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU, or a function to deliver all RLC SDUs received up to the present in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU. In addition, the RLC PDUs mentioned above may be processed in the order they are received (regardless of the order of sequence numbers, in the order of arrival) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, segments stored in a buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and this function may be performed by the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0063] The out-of-sequence delivery function of the aforementioned NR RLC device refers to the function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order, and may include the function of reassembling and delivering them when a single RLC SDU is received divided into multiple RLC SDUs. In addition, the out-of-sequence delivery function of the NR RLC device may include the function of storing the RLC SN or PDCP SN of the received RLC PDUs and recording lost RLC PDUs by sorting their order.

[0064] The NR MAC (1b-15, 1b-30) can be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions.

[0065] - Mapping function (Mapping between logical channels and transport channels)

[0066] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)

[0067] - Scheduling information reporting function

[0068] - HARQ function (Error correction through HARQ)

[0069] - Priority handling between logical channels of one UE

[0070] - Priority handling between UEs by means of dynamic scheduling

[0071] - MBMS service identification function

[0072] - Transport format selection function

[0073] - Padding

[0074] The NR PHY layer (1b-20, 1b-25) can perform the operation of channel coding and modulating upper layer data, creating OFDM symbols and transmitting them to the wireless channel, or demodulating OFDM symbols received through the wireless channel and channel decoding them to transmit them to the upper layer.

[0075] FIG. 1c is a diagram illustrating a topology and deployment scenario in which ambient IoT (Internet of Things) communication is supported in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0076] An Ambient IoT device (or Ambient IoT device) (1c-01) according to the present disclosure is a device with very low maximum power consumption, capable of supporting a maximum peak power consumption of 1 uW or a peak power consumption of several hundred uW. The Ambient IoT device (1c-01) can basically perform uplink transmission through backscattering. That is, the Ambient IoT device (1c-01) can perform uplink transmission using an external carrier wave. When performing uplink transmission, the Ambient IoT device (1c-01) may or may not perform amplification. Of course, the Ambient IoT device (1c-01) may also generate uplink transmission internally. The Ambient IoT device (1c-01) does not have an RRC state and does not support mobility such as cell selection or cell reselection. Furthermore, the device is a low-spec device that does not support Hybrid Automatic Repeat and reQuest (HARQ) and Automatic Repeat reQuest (ARQ).

[0077] Meanwhile, the Ambient IoT device (1c-01) may be a device that uses energy harvesting to generate power and may have no battery or have a limited energy storage capacity.

[0078] An Ambient IoT device (1c-01) can perform direct bidirectional communication with a base station or a reader (1c-05). That is, the Ambient IoT device (1c-01) can transmit and receive Ambient IoT data and / or signaling (1c-20) with the base station or the reader (1c-05). For reference, the Ambient IoT device (1c-01) can transmit Ambient IoT data and / or signaling (1c-20) to the base station or the reader (1c-05) and receive Ambient IoT data and / or signaling (1c-30) to another base station or the reader (1c-10). Of course, the Ambient IoT device (1c-01) can receive Ambient IoT data and / or signaling (1c-20) to the base station or the reader (1c-05) and transmit Ambient IoT data and / or signaling (1c-30) to another base station or the reader (1c-10).

[0079] An Ambient IoT device (1c-01) may be located indoors, and a base station (1c-05, 1c-10) may also be located indoors. Communication between the Ambient IoT device (1c-01) and the base station (1c-05, 1c-10) is not supported through the Uu interface between the conventional terminal and the base station, but can be supported through a new interface. In the present disclosure, the new interface may be referred to as the Ax interface.

[0080] FIG. 1d is a diagram illustrating a use case in which Ambient IoT (Internet of Things) communication is applied in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0081] Referring to FIG. 1d, a service may be provided to a specific Ambient IoT device (1d-10), a service may be provided to a group of Ambient IoT devices consisting of two or more Ambient IoT devices (1d-05), or a service may be provided to all Ambient IoT devices (1d-01).

[0082] 1d-01 is a figure illustrating a scenario for an automated warehouse inventory. In this scenario, various warehousing information may be generated for the transfer of goods, storage of goods, and inventory of goods. Specifically, this scenario may consist of five steps.

[0083] - Step 1: Verification and unloading of goods

[0084] - Step 2: Move items into the gate (gate-in inventory)

[0085] - Step 3: Item Inventory Management (inventory)

[0086] - Step 4: Move items out of the gate (gate-out inventory)

[0087] - Step 5: Check and Loading

[0088] In a warehouse inventory scenario, Ambient IoT devices can be attached to each item for automated warehouse inventory management. By performing an inventory procedure on all Ambient IoT devices and executing a command procedure—which involves writing and reading the characteristics of each item—warehouse inventory can be managed efficiently.

[0089] 1d-05 is a figure illustrating a scenario in which the surrounding environment is sensed through an Ambient IoT device. In this scenario, when planting orchids, an Ambient IoT device is attached to the plant to monitor the plant's surrounding environment and provide the generated monitoring information to authorized users and third parties. In this scenario of sensing the surrounding environment, plants can be managed efficiently by performing an inventory procedure on Ambient IoT devices attached to multiple plants (i.e., a group of Ambient IoT devices) and executing a command procedure, which is a procedure to activate or deactivate each Ambient IoT device.

[0090] Figure 1d-10 illustrates a scenario for managing the health of the elderly through an Ambient IoT device. In this scenario, the health status of the elderly with heart disease or chronic diseases can be continuously monitored, and the generated monitoring information can be periodically provided to an authorized user (e.g., a doctor). In this scenario for managing the health of the elderly, the health status of the elderly can be managed efficiently by performing an inventory procedure on a single Ambient IoT device attached to a specific elderly person, and then performing a command procedure, which is a procedure for reading necessary information from that Ambient IoT device.

[0091] FIG. 1e is a diagram illustrating a procedure for inventorying all Ambient IoT (Internet of Things) devices in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0092] Referring to FIG. 1e, a Core Network (hereinafter CN (1e-03)) may transmit (1e-05) a predetermined message (e.g., an Inventory request message) to a predetermined Reader (1e-02) to provide / request an AIoT service. The CN (1e-03) may refer to an Access and Mobility Management Function (AMF) for supporting AIoT communication, a new Core Network function (AIoT function, hereinafter AIoTF) that supports AIoT communication, or a new entity within the (new) Core Network. In this case, the Reader (1e-02) may refer to a Base Station (hereinafter BS) or User Equipment (hereinafter UE) that supports AIoT communication. The predetermined message may include at least one of the following information.

[0093] - Information About AIoT services

[0094] The above information may indicate which service type, Inventory or Command, is represented.

[0095] - CN correlation ID

[0096] The above CN correlation ID may refer to an identifier representing information about a specific AIoT service ID.

[0097] - Information used for reader selection

[0098] The above information may refer to one or more terminal Reader identifiers or target area information.

[0099] - Information about the target AIoT device(s)

[0100] The above information may refer to information capable of identifying a specific AIoT device, identifying a group of multiple AIoT devices, or identifying all AIoT devices. For example, the information regarding the target AIoT device(s) may include a specific AIoT device ID to identify a specific AIoT device, or filtering information that can be used in association with multiple AIoT devices to identify multiple AIoT devices, and / or an AIoT device ID or group AIoT device ID capable of identifying each AIoT device. The information regarding the target AIoT device(s) may be empty to indicate identification of all AIoT devices, or the information may include an indicator to indicate this.

[0101] - Information to be used for resource allocation

[0102] * Approximate number of AIoT devices and / or approximate D2R (Device-to-Reader) message size

[0103] In step 1e-10, Reader (1e-02) may send a predetermined message (e.g., Inventory response message) to CN (1e-03) in response to step 1e-05.

[0104] In step 1e-15, the Reader (1e-02) can transmit an AIoT paging message based on the message received in step 1e-05. The message may be transmitted as a broadcast. The AIoT paging message may include at least one of the following information.

[0105] - Information about target AIoT device(s)

[0106] * Information regarding the target AIoT device(s) may refer to the information described above in step 1e-05. For example, it may refer to one AIoT device identifier (or a temporary AIoT device ID mapped thereto) or one-group AIoT device identifier and / or filtering criteria (or a temporary AIoT group device ID and / or filtering criteria mapped thereto). The AIoT device ID cannot be decoded at the AIoT device's MAC layer and is visible only at the upper layer of the AIoT device (e.g., the NAS layer). That is, information regarding the target AIoT device(s) may be transparent to the AIoT device's MAC layer. Of course, it may be decoded at the AIoT device's MAC layer.

[0107] The above information may be empty to instruct to identify all AIoT devices. Alternatively, a separate indicator to instruct to identify all AIoT devices may be included in the above information. The information to identify all AIoT devices may be visible at the MAC layer of the AIoT device, or it may be transparent to the AIoT device MAC layer as described above.

[0108] - Resource configuration information for target AIoT device(s) to send message 1 (msg 1)

[0109] Resource configuration information for transmitting Message 1 via Frequency Division Multiple Access

[0110] ● Frequency shift and / or frequency channel resource information that enables the transmission of msg 1 in a specific frequency channel or bandwidth may be represented. For example, an AIoT device that receives frequency shift information to be used when transmitting msg 1 may determine one frequency shift value randomly from the corresponding configuration information and transmit msg 1 in the corresponding frequency channel or bandwidth.

[0111] Resource configuration information for transmitting Message 1 via Time Frequency Multiple Access

[0112] ● Resource setting information that enables the transmission of msg 1 at a specific time can be represented. For example, an AIoT device that receives time setting information that enables the transmission of msg 1 can determine a time for the transmission of msg 1 by randomly selecting one time from the setting information.

[0113] - Transaction ID

[0114] * An ID generated from the CN correlation ID received from CN(1e-03), which can be composed of fewer bit values ​​than the CN correlation ID.

[0115] - Indicators or information indicating whether the inventory procedure should be performed using contention-based random access or contention-free random access.

[0116] If information for only one AIoT device is included in the AIoT paging, or if only one Msg1 resource is included (for one AIoT device), the corresponding AIoT device can perform the inventory procedure via contention-free random access. Of course, this can also be indicated through a separate directive.

[0117] If information regarding at least two AIoT devices is included in the AIoT paging (for example, if information about a group of devices consisting of two or more AIoT devices is included, or if information is included instructing all AIoT devices to perform an inventory procedure), those AIoT devices may perform the inventory procedure via contention-based random access. Of course, this can also be instructed through a separate indicator.

[0118] In step 1e-20, the AIoT device (1e-01) can determine whether there is information in the AIoT paging received through step 1e-15 that directs the AIoT device (1e-01). That is, the MAC layer device of the AIoT device can forward information about the target AIoT device(s) contained in the AIoT paging to the upper layer of the AIoT device (e.g., NAS layer). The upper layer of the AIoT device can determine that the AIoT device (1e-01) must perform an inventory procedure if it contains a paging identifier directing the AIoT device (1e-01), or a group paging identifier and / or filtering criteria to which the AIoT device (1e-01) belongs, or information that all AIoT devices must perform an inventory procedure (e.g., if the indicator indicating this or the information about the target AIoT device(s) is empty). For reference, if the MAC layer of the AIoT device can decode information about the target AIoT device(s) (e.g., information that all AIoT devices must perform an inventory procedure), the MAC layer of the AIoT device may notify the upper layer of the AIoT device that the inventory procedure must be performed, or may notify it when necessary (e.g., when receiving necessary information from the upper layer of the AIoT device (e.g., when message 3 needs to be transmitted).

[0119] In step 1e-25, the AIoT device (1e-01) triggered to perform the inventory procedure may initiate a random access procedure (contention-based random access or contention-free random access) according to the AIoT paging received in step 1e-15.

[0120] In step 1e-30, the AIoT device (1e-01) can receive an R2D message from the Reader (1e-02) that determines the resource for transmitting Msg1 (e.g., AIoT paging that does not contain information about the target AIoT device(s) or a new R2D message, e.g., a QueryRep-like message).

[0121] In step 1e-35, the AIoT device (1e-01) can transmit Msg1. Specifically, the AIoT device that triggered contention-based random access can transmit Msg1 containing a randomly generated 16-bit value consisting of a specific number of bits (e.g., 16 bits).

[0122] In step 1e-40, the Reader (1e-02) that receives Msg1 containing a random value composed of 16 bits can transmit Msg2. That is, the Reader (1e-02) can transmit Msg2 by including the same 16-bit value contained in Msg1 in Msg2. Of course, the Reader (1e-02) may also transmit Msg2 that includes the same 16-bit value contained in the received Msg1 and an AS ID that is intended to be used separately for AIoT data communication with the AIoT device (1e-01) in the future. The Msg2 is an R2D message and may consist of at least one of the following fields as a header.

[0123] - Message type representing Msg2

[0124] - Length of the SDU (Service Data Unit) of Msg2

[0125] - An indicator indicating whether to use the value included in Msg1 as the AS ID or a newly assigned AS ID. Since the Reader can transmit only one Msg2 after receiving Msg1 from multiple AIoT devices, the above indicator can be configured for each Msg1.

[0126] - An indicator indicating whether a Msg3 resource exists. Since the Reader can transmit only one Msg2 after receiving Msg1 from multiple AIoT devices, the indicator can be configured for each Msg1. For reference, if a resource for Msg3 is not allocated to a specific AIoT device, that AIoT device may not transmit Msg3. In other words, this is because it is intended only to check the existence of the AIoT device.

[0127] - Information indicating how many Msg1s to multiplex and include in Msg2

[0128] - One or more Reserved bit(s) for future use

[0129] The above Msg2 may include an SDU composed of at least one ID. Specifically,

[0130] - When the Reader (1e-02) receives one Msg1 and transmits Msg2 in response thereto, at least one of the following may be included in Msg2.

[0131] The same value included in Msg1 (i.e., a 16-bit random number) or, in the case of a terminal already assigned an AS ID, the previously assigned AS ID

[0132] ● If Reader (1e-02) wants to assign a new AS ID, the AS ID may also be included. The AS ID may consist of specific bits (e.g., may be the same as or different from the 16-bit value included in Msg1).

[0133] Resource configuration information required to send Msg3

[0134] ● If the relevant resource configuration information is missing, the AIoT device may not send Msg3.

[0135] - When the above Reader (1e-02) receives a plurality of Msg1s (assuming two Msg1s for convenience of explanation) and transmits one Msg2 in response, at least one of the following may be included in Msg2.

[0136] For the first Msg1,

[0137] ● The same value included in Msg1 (i.e., a 16-bit random number) or, in the case of a terminal already assigned an AS ID, the previously assigned AS ID

[0138] If Reader (1e-02) wants to assign a new AS ID, the AS ID may also be included. The AS ID may consist of specific bits (e.g., may be the same as or different from the 16-bit value included in Msg1).

[0139] ● Resource configuration information required to send Msg3

[0140] If the relevant resource configuration information is missing, the AIoT device may not send Msg3.

[0141] Regarding the second Msg2,

[0142] ● The same value included in Msg1 (i.e., a 16-bit random number) or, in the case of a terminal already assigned an AS ID, the previously assigned AS ID

[0143] · If Reader (1e-02) wants to assign a new AS ID, the AS ID may also be included. The AS ID may consist of specific bits (e.g., may be the same as or different from the 16-bit value included in Msg1).

[0144] ● Resource configuration information required to send Msg3

[0145] If the relevant resource configuration information is missing, the AIoT device may not send Msg3.

[0146] Of course, it may also be configured to include the same value contained in Msg1 for the first Msg1 (i.e., a random number value consisting of 16 bits) (or the previously assigned AS ID in the case of a terminal that has already been assigned an AS ID) and the same value in Msg2 for the second Msg1 (i.e., a random number value consisting of 16 bits) (or the previously assigned AS ID in the case of a terminal that has already been assigned an AS ID), sequentially include a new AS ID if one exists for each Msg1, and include necessary resource configuration information to transmit Msg3 for each Msg1.

[0147] In step 1e-45, the AIoT device (1e-01) may determine that contention resolution has been successful if the Msg2 received in step 1e-40 contains a value identical to the random number value transmitted in step 1e-35. Of course, the AIoT device (1e-01) may also determine that contention resolution has been successful only if the Msg2 contains resource configuration information that allows it to transmit Msg3. The AIoT device may store an AS ID that can identify itself (a 16-bit random number value transmitted in Msg1 or a new ID assigned to Msg2).

[0148] In step 1e-50, the AIoT device (1e-01) may transmit a Msg3 containing a (temporary) device ID that can identify the AIoT device. The AIoT device (1e-01) may store in memory that it has successfully performed an inventory procedure or a random access procedure if it does not receive a NACK-based R2D message (e.g., an AS ID (16-bit random number or assigned AS ID in Msg2) indicating that the Reader (1e-02) did not receive the Msg3 (for a certain period of time) or immediately after transmitting the Msg3 (after a certain period of time has passed since transmitting the Msg3). This is to prevent the random access procedure from being performed redundantly in response to AIoT paging coming from the Reader (1e-02) in the future.

[0149] In step 1e-55, the Reader (1e-02) may determine that it has not successfully received Msg3 from the AIoT device (1e-01).

[0150] In step 1e-60, the Reader (1e-02) may transmit a NACK-based R2D message indicating that Msg3 was not successfully received. The R2D message may be the same R2D message as described in step 1e-40 (or may be the same as the NACK-based message, with only the type of message indicating that Msg3 was not successfully received differing, and / or may not include some of the information described in step 1e-40 (e.g., information on resource configuration for transmitting Msg3 is not included) and / or may differ only in definition (e.g., information indicating how many Msg3s are sent as NACK-based R2D messages) and the rest may be the same). For reference, if step 1e-40 is a message transmitted by the Reader for AIoT device(s) that successfully received Msg1, step 1e-60 is a message transmitted by the Reader for AIoT device(s) that did not successfully receive Msg3. Of course, the R2D message may be a new R2D message different from Msg2. For example, the R2D message may include at least one of the following information.

[0151] - Message type indicating that at least one Msg3 was not successfully received (e.g., NACK)

[0152] - Length of the SDU (Service Data Unit) of the R2D message

[0153] - If one AIoT device or all AIoT devices transmit Msg3, a 1-bit indicating that it was not successfully received.

[0154] In such cases, it may not necessarily be an R2D message.

[0155] - One or more Reserved bit(s) for future use

[0156] - Information on whether to trigger re-access in AIoT paging by including the AS ID or the paging identifier in the future

[0157] - Information indicating how many Msg3s to multiplex and include in the above R2D message

[0158] Information indicating multiplexing for two Msg3s

[0159] - Information indicating whether to send Msg1 or Msg3 upon receiving AIoT paging later

[0160] * Resource configuration information for Msg1 or resource configuration information for Msg3 may be included for each AS ID (i.e., AS ID used after contention resolution).

[0161] The R2D message may contain an SDU consisting of at least one ID. Specifically,

[0162] - If the Reader (1e-02) has not successfully received one Msg3, at least one of the following may be included.

[0163] The same value included in Msg2

[0164] - If Reader (1e-02) fails to successfully receive multiple Msg3s (assuming 2 Msg3s for convenience of explanation), at least one of the following may be included in the R2D message.

[0165] For the first Msg3,

[0166] ● The same value included in Msg2 (i.e., a 16-bit random value)

[0167] Regarding the second Msg3,

[0168] ● The same value included in Msg2 (i.e., a 16-bit random value)

[0169] In step 1e-65, the AIoT device (1e-01) may determine that it needs to perform re-access if it receives the R2D message described above in step 1e-60. Unlike in step 1e-20, the MAC layer device of the AIoT device may not transmit the AS ID to the AIoT upper layer device. Alternatively, the MAC layer device of the AIoT device may transmit information to the AIoT upper layer device that re-access has been triggered. The AIoT device may change the state of having successfully performed the inventory procedure or the random access procedure to a state of not having done so and store it in memory. Of course, if the AIoT device has not stored in memory the state of having successfully performed the inventory procedure or the random access procedure, it may not perform any separate action or may store in memory the state that re-access needs to be performed.

[0170] In step 1e-70, the Reader (1e-02) may send an AIoT paging message to trigger re-access to a specified AIoT device. The AIoT paging message may include the AS ID(s) included in step 1e-60 to trigger re-access for the AIoT device(s) mapped to those AS ID(s). That is, re-access may be triggered with fewer bits than the ID included in step 1e-15. Unlike in step 1e-20, the MAC layer device of the AIoT device may not transmit the AS ID to the AIoT upper layer device. Alternatively, the MAC layer device of the AIoT device may transmit information to the AIoT upper layer device that re-access has been triggered. Additionally, information or instructions regarding whether to send Msg1 or Msg3 for each AS ID or all AS IDs may also be included. The resource configuration information described in step 1e-15 may be applied commonly to Msg3, or resources may be configured separately for the Msg3 resource. Of course, it may also include information about the target AIoT device(s) to trigger re-access, just as in step 1e-15. If the AIoT device has stored an AS ID capable of identifying itself (a 16-bit random value transmitted in Msg1 or a new ID assigned to Msg2), it may release the AS ID if there is information representing itself among the information about the target AIoT device(s) in the same form as in step 1e-15, rather than the AS ID. The AIoT device may change the state of having successfully performed the inventory procedure or the random access procedure to a state of not having successfully performed it and store it in memory.Of course, if the above AIoT device has not stored in memory the state in which it has successfully performed the inventory procedure or the random access procedure, it may not perform any separate action or may store in memory the state that it needs to re-access. For reference, AIoT device(s) that have not received a NACK-based R2D message through step 1e-70 may be instructed to re-access when they receive AIoT paging later.

[0171] If the AIoT device (1e-01) is instructed to transmit Msg3 via step 1e-70 or to transmit Msg1 via contention-free random access (or fails to receive the message of step 1e-60), the AIoT device (1e-01) may transmit a message (1e-71) containing a (temporary) device ID that can identify itself. Upon receiving this, the Reader (1e-02) may transmit an Inventory report message (1e-72) containing the device ID to the CN (1e-03).

[0172] If the AIoT device (1e-01) is instructed to transmit Msg1 (based on contention-based random access) through step 1e-70, the AIoT device (1e-01) may transmit Msg1 in step 1e-75. Msg1 may contain the AS ID that was determined to have successfully performed contention resolution in step 1e-45, or it may contain a randomly generated 16-bit value consisting of a specific number of bits (e.g., 16 bits).

[0173] In step 1e-80, the Reader (1e-02) that received Msg1 may transmit Msg2 containing the AS ID included in Msg1. This may follow the aforementioned step 1e-40.

[0174] In step 1e-85, the AIoT device (1e-01) can determine that contention resolution has been successful if the AS ID value transmitted in step 1e-75 is included in the Msg2 received in step 1e-80.

[0175] In step 1e-90, the AIoT device (1e-01) can transmit a Msg3 containing a (temporary) device ID that can identify the AIoT device. Upon receiving this, the Reader (1e-02) can transmit an Inventory report message containing the device ID to the CN (1e-03) (1e-91).

[0176] FIG. 1f is a diagram illustrating a procedure for inventorying all Ambient IoT (Internet of Things) devices in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0177] Referring to FIG. 1f, a Core Network (hereinafter CN (1f-03)) may transmit (1f-05) a predetermined message (e.g., an Inventory request message) to a predetermined Reader (1f-02) to provide / request an AIoT service. CN (1f-03) may refer to an Access and Mobility Management Function (AMF) for supporting AIoT communication, a new Core Network function (AIoT function, hereinafter AIoTF) that supports AIoT communication, or a new entity within the (new) Core Network. The Reader (1f-02) may refer to a Base Station (hereinafter BS) or User Equipment (hereinafter UE) that supports AIoT communication. The predetermined message (e.g., an Inventory request message) may include at least one of the following information.

[0178] - Information About AIoT services

[0179] The above information may refer to information regarding which service type, Inventory or Command, is represented.

[0180] - CN correlation ID

[0181] The above CN correlation ID may refer to an identifier representing information about a specific AIoT service ID.

[0182] - Information used for reader selection

[0183] The above information may refer to one or more terminal Reader identifiers or target area information.

[0184] - Information about the target AIoT device(s)

[0185] The above information may refer to information capable of identifying a specific AIoT device, identifying a group of multiple AIoT devices, or identifying all AIoT devices. For example, the above information may include a specific AIoT device ID to identify a specific AIoT device, or filtering information that can be used in association with multiple AIoT devices to identify multiple AIoT devices, and / or an AIoT device ID or group AIoT device ID capable of identifying each AIoT device. The above information may be empty to indicate identification of all AIoT devices, or the above information may include an indicator to indicate this.

[0186] - Information to be used for resource allocation

[0187] * Approximate number of AIoT devices and / or approximate D2R (Device-to-Reader) message size

[0188] In step 1f-10, Reader (1f-02) may send a predetermined message (e.g., Inventory response message) to CN (1f-03) in response to step 1f-05.

[0189] In step 1f-15, the Reader (1f-02) can transmit an AIoT paging message based on the message received in step 1f-05. The message is transmitted as a broadcast. The message may include at least one of the following information.

[0190] - Information about target AIoT device(s)

[0191] * Information regarding the target AIoT device(s) may refer to the information described above in step 1f-05. For example, it may refer to one AIoT device identifier (or a temporary AIoT device ID mapped thereto) or one-group AIoT device identifier and / or filtering criteria (or a temporary AIoT group device ID mapped thereto) and / or filtering criteria. The AIoT device ID cannot be decoded at the AIoT device's MAC layer and is only visible at the upper layer of the AIoT device (e.g., the NAS layer). That is, information regarding the target AIoT device(s) may be transparent to the AIoT device's MAC layer. Of course, it may be decoded at the AIoT device's MAC layer.

[0192] The above information may be empty to instruct to identify all AIoT devices. Alternatively, a separate indicator to instruct to identify all AIoT devices may be included in the information for get AIoT device(s). The information to identify all AIoT devices may be visible at the MAC layer of the AIoT device or may be transparent to the AIoT device MAC layer as described above.

[0193] - Resource configuration information for target AIoT device(s) to send message 1 (msg 1)

[0194] Resource configuration information for transmitting Message 1 via Frequency Division Multiple Access

[0195] ● Frequency shift and / or frequency channel resource information that enables the transmission of msg 1 in a specific frequency channel or bandwidth. For example, an AIoT device that receives frequency shift information to be used when transmitting msg 1 can determine one frequency shift value randomly from the setting information and transmit msg 1 in the corresponding frequency channel or bandwidth.

[0196] Resource configuration information for transmitting msg 1 via Time Frequency Multiple Access

[0197] ● Resource configuration information that enables the transmission of msg 1 at a specific time. For example, an AIoT device that receives time configuration information that enables the transmission of msg 1 can determine the time for transmitting msg 1 by randomly selecting one time from the configuration information.

[0198] - Transaction ID

[0199] * An ID generated from the CN correlation ID received from CN(1f-03), which can be composed of fewer bit values ​​than the CN correlation ID.

[0200] - Indicators or information indicating whether the inventory procedure should be performed using contention-based random access or contention-free random access.

[0201] If information for only one AIoT device is included in the AIoT paging, or if only one Msg1 resource is included (for one AIoT device), the corresponding AIoT device can perform the inventory procedure via contention-free random access. Of course, this can also be indicated through a separate directive.

[0202] If information regarding at least two AIoT devices is included in the AIoT paging (for example, if information about a group of devices consisting of two or more AIoT devices is included, or if information is included instructing all AIoT devices to perform an inventory procedure), those AIoT devices may perform the inventory procedure via contention-based random access. Of course, this can also be instructed through a separate indicator.

[0203] In step 1f-20, the AIoT device (1f-01) can determine whether there is information in the AIoT paging received through step 1f-15 that indicates the AIoT device (1f-01). That is, the MAC layer device of the AIoT device can forward information about the target AIoT device(s) contained in the AIoT paging to the upper layer (e.g., NAS layer) of the AIoT device. If the upper layer of the AIoT device contains a paging identifier indicating the AIoT device (1f-01), or a group paging identifier and / or filtering criteria to which the AIoT device (1f-01) belongs, or information indicating that all AIoT devices must perform an inventory procedure (e.g., an indicator indicating this or information about the target AIoT device(s) is empty), the AIoT device (1f-01) can determine that it must perform an inventory procedure. For reference, if the MAC layer of the AIoT device can decode information about the target AIoT device(s) (e.g., information that all AIoT devices must perform an inventory procedure), the MAC layer of the AIoT device may notify the upper layer of the AIoT device that the inventory procedure must be performed, or may notify it when necessary (e.g., when receiving necessary information from the upper layer of the AIoT device (e.g., when message 3 needs to be transmitted).

[0204] In step 1f-25, the AIoT device (1f-01) triggered to perform the inventory procedure may initiate a random access procedure (contention-based random access or contention-free random access) according to the AIoT paging received in step 1f-15.

[0205] In step 1f-30, the AIoT device (1f-01) can receive an R2D message from the Reader (1f-02) that determines the resource for transmitting Msg1 (e.g., AIoT paging or a new R2D message, e.g., a QueryRep-like message, which does not contain information about the target AIoT device(s).

[0206] In step 1f-35, the AIoT device (1f-01) may transmit Msg1. Specifically, the AIoT device that triggered the contention-free random access may transmit Msg1 containing a (temporary) device ID that can identify itself. The AIoT device (1f-01) may store in memory the state that the inventory procedure or random access procedure was successfully performed if it does not receive a Command message for the AIoT device from the Reader (1f-02) (within a certain time) or receive a NACK indicating that Msg1 was not received or a NACK-based R2D message indicating this. This is to prevent the random access procedure from being performed redundantly in response to AIoT paging coming from the Reader (1f-02) in the future.

[0207] In step 1f-40, the Reader (1f-02) may determine that it has not successfully received Msg1 from the AIoT device (1f-01).

[0208] In step 1f-45, the Reader (1f-02) may transmit a NACK or a NACK-based R2D message indicating that Msg1 was not successfully received. A NACK is a message indicating that Msg1 was not successfully received and does not require the AIoT device (1f-01) to be separately directed. A NACK-based R2D message is a message transmitted by the Reader for the AIoT device(s) that did not successfully receive Msg1. The R2D message may include at least one of the following information.

[0209] - Message type indicating that at least one Msg1 was not successfully received (e.g., NACK)

[0210] - Length of the SDU (Service Data Unit) of the R2D message

[0211] - If one AIoT device or all AIoT devices transmit Msg1, a 1-bit indicating that it was not successfully received.

[0212] - One or more Reserved bit(s) for future use

[0213] - Information on which AIoT device(s) will trigger re-access by including the AS ID, (temporary) device ID, or paging identifier in AIoT paging in the future

[0214] - Information indicating how many Msg1s to multiplex and include in the above R2D message

[0215] Information indicating multiplexing for two Msg1s

[0216] - Information indicating whether to send Msg1 or Msg3 upon receiving AIoT paging later

[0217] * Resource configuration information for Msg1 or resource configuration information for Msg3 may be included for each AS ID (i.e., AS ID used after contention resolution).

[0218] The above R2D message may include an SDU composed of at least one ID. Specifically,

[0219] - If Reader (1f-02) has not successfully received one Msg1, at least one of the following may be included.

[0220] paging identifier or AS ID included in AIoT paging

[0221] If Reader (1f-02) fails to successfully receive multiple Msg1s (assuming there are 2 Msg1s for convenience of explanation), at least one of the following may be included in the R2D message.

[0222] For the first Msg1,

[0223] ● Paging identifier or AS ID included in AIoT paging

[0224] For the second Msg1,

[0225] ● Paging identifier or AS ID included in AIoT paging

[0226] In step 1f-50, the AIoT device (1f-01) may determine that it needs to perform re-access if it receives the NACK or NACK-based R2D message described in step 1f-45. The AIoT device may change the state of having successfully performed the inventory procedure or the random access procedure to a state of not having performed it and store it in memory. Of course, if the AIoT device has not stored the state of having successfully performed the inventory procedure or the random access procedure in memory, it may not perform any separate action or may store the state of needing to perform re-access in memory. If the AS ID is stored, the AIoT device may release it.

[0227] In step 1f-55, the Reader (1f-02) may send an AIoT paging message to trigger re-access to a specified AIoT device. The AIoT paging message may include a paging identifier or AS ID(s) included in step 1f-45 or 1f-15 to trigger re-access for the AIoT device(s) mapped to those ID(s). Additionally, information or instructions regarding whether to send Msg1 or Msg3 for each ID or all AS IDs may be included. The resource configuration information described in step 1f-15 may be applied commonly to Msg3, or resources may be configured separately for the Msg3 resource. Of course, information regarding target AIoT device(s) for triggering re-access may also be included, in the same way as in step 1f-15. The above AIoT device may change the state of having successfully performed the inventory procedure or the random access procedure to a state of not having performed it and store it in memory. Of course, if the above AIoT device has not stored the state of having successfully performed the inventory procedure or the random access procedure in memory, it may store the state in memory where no separate action is performed or where re-access is required. If an AS ID is stored, the AIoT device may release it. If there is a stored AS ID, the above AIoT device may release it.

[0228] For reference, AIoT device(s) that did not receive NACK-based R2D messages through step 1f-45 may be instructed to re-access when receiving AIoT paging later.

[0229] If the AIoT device (1f-01) is instructed to transmit Msg1 by contention-free random access through step 1f-55, the AIoT device (1f-01) may transmit a message (1f-56) containing a (temporary) device ID that can identify itself. Upon receiving this, the Reader (1f-02) may transmit an Inventory report message containing the device ID to the CN (1f-03) (1f-57).

[0230] If the AIoT device (1f-01) is instructed to transmit Msg1 (according to contention-based random access) through step 1f-55, the AIoT device (1f-01) may transmit Msg1 in step 1f-60. Msg1 may contain a randomly generated 16-bit value consisting of specific bits (e.g., 16 bits). If there is a stored AS ID, the AIoT device may release it.

[0231] In step 1f-65, the Reader (1f-02) that received Msg1 may transmit Msg2 containing the same random number value contained in Msg1. This may follow step 1e-40 of the above-described embodiment.

[0232] In step 1f-70, the AIoT device (1f-01) can determine that contention resolution has been successful if the AS ID value transmitted in step 1f-60 is included in the Msg2 received in step 1f-65.

[0233] In step 1f-75, the AIoT device (1f-01) can transmit a Msg3 containing a (temporary) device ID that can identify the AIoT device. Upon receiving this, the Reader (1f-02) can transmit an Inventory report message containing the device ID to the CN (1f-03) (1f-76).

[0234] FIG. 1g is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0235] Referring to FIG. 1g, the terminal includes an RF (Radio Frequency) processing unit (1g-10), a baseband processing unit (1g-20), a storage unit (1g-30), and a control unit (1g-40). Meanwhile, the terminal of the present disclosure may refer to the A-IoT device described above.

[0236] The RF processing unit (1g-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1g-10) up-converts a baseband signal provided by the baseband processing unit (1g-20) into an RF band signal, transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1g-10) may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC (digital to analog converter), an ADC (analog to digital converter), etc. Although only one antenna is shown in FIG. 1g, the terminal may be equipped with multiple antennas. In addition, the RF processing unit (1g-10) may include multiple RF chains. Furthermore, the RF processing unit (1g-10) may perform beamforming. For beamforming, the RF processing unit (1g-10) can adjust the phase and magnitude of each of the signals transmitted and received through multiple antennas or antenna elements. Additionally, the RF processing unit can perform MIMO and can receive multiple layers when performing MIMO operation.

[0237] The baseband processing unit (1g-20) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1g-20) can generate complex symbols by encoding and modulating the transmitted bit sequence. Additionally, when receiving data, the baseband processing unit (1g-20) restores the received bit sequence by demodulating and decoding the baseband signal provided by the RF processing unit (1g-10). For example, in the case of following the orthogonal frequency division multiplexing (OFDM) method, when transmitting data, the baseband processing unit (1g-20) generates complex symbols by encoding and modulating the transmitted bit sequence, maps the complex symbols to subcarriers, and then constructs the OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. Additionally, upon receiving data, the baseband processing unit (1g-20) divides the baseband signal provided by the RF processing unit (1g-10) into OFDM symbol units, restores the signals mapped to subcarriers through a fast Fourier transform (FFT), and then restores the received bit sequence through demodulation and decoding.

[0238] The baseband processing unit (1g-20) and the RF processing unit (1g-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1g-20) and the RF processing unit (1g-10) may be referred to as a transmitting unit, a receiving unit, a transmitting and receiving unit, or a communication unit. Furthermore, at least one of the baseband processing unit (1g-20) and the RF processing unit (1g-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. Additionally, at least one of the baseband processing unit (1g-20) and the RF processing unit (1g-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. In addition, the above different frequency bands may include super high frequency (SHF) bands (e.g., 2 NRHz, NRHz) and millimeter wave (e.g., 60 GHz) bands.

[0239] The storage unit (1g-30) stores data such as basic programs, application programs, and configuration information for the operation of the terminal. In particular, the storage unit (1g-30) can store information related to a second connection node that performs wireless communication using the second wireless connection technology. Additionally, the storage unit (1g-30) provides the stored data upon the request of the control unit (1g-40).

[0240] The control unit (1g-40) controls the overall operations of the terminal. For example, the control unit (1g-40) transmits and receives signals through the baseband processing unit (1g-20) and the RF processing unit (1g-10). Additionally, the control unit (1g-40) writes and reads data to and from the storage unit (1g-40). To this end, the control unit (1g-40) may include at least one processor. For example, the control unit (1g-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications.

[0241] FIG. 1h is a block diagram showing the configuration of an NR base station according to one embodiment of the present disclosure.

[0242] As illustrated in FIG. 1h, the base station is configured to include an RF processing unit (1h-10), a baseband processing unit (1h-20), a backhaul communication unit (1h-30), a storage unit (1h-40), and a control unit (1h-50). Meanwhile, the base station of the present disclosure may refer to the Reader or intermediate UE described above.

[0243] The RF processing unit (1h-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1h-10) upconverts the baseband signal provided by the baseband processing unit (1h-20) into an RF band signal, transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1h-10) may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although only one antenna is shown in FIG. 1h, the first connection node may be equipped with multiple antennas. Additionally, the RF processing unit (1h-10) may include multiple RF chains. Furthermore, the RF processing unit (1h-10) may perform beamforming. For beamforming, the RF processing unit (1h-10) may adjust the phase and magnitude of each of the signals transmitted and received through multiple antennas or antenna elements. The above RF processing unit can perform down-to-down MIMO operation by transmitting one or more layers.

[0244] The baseband processing unit (1h-20) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (1h-20) can generate complex symbols by encoding and modulating the transmitted bit sequence. Additionally, when receiving data, the baseband processing unit (1h-20) restores the received bit sequence by demodulating and decoding the baseband signal provided by the RF processing unit (1h-10). For example, in the case of following the OFDM method, when transmitting data, the baseband processing unit (1h-20) generates complex symbols by encoding and modulating the transmitted bit sequence, maps the complex symbols to subcarriers, and then constructs OFDM symbols through IFFT operation and CP insertion. Additionally, upon receiving data, the baseband processing unit (1h-20) divides the baseband signal provided by the RF processing unit (1h-10) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operations, and then restores the received bit sequence through demodulation and decoding. The baseband processing unit (1h-20) and the RF processing unit (1h-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1h-20) and the RF processing unit (1h-10) may be referred to as a transmitting unit, a receiving unit, a transmitting and receiving unit, a communication unit, or a wireless communication unit.

[0245] The backhaul communication unit (1h-30) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (1h-30) converts a bit sequence transmitted from the main base station to other nodes, such as an auxiliary base station or a core network, into a physical signal, and converts a physical signal received from other nodes into a bit sequence.

[0246] The storage unit (1h-40) stores data such as basic programs, application programs, and configuration information for the operation of the main station. In particular, the storage unit (1h-40) can store information regarding bearers assigned to connected terminals, measurement results reported from connected terminals, etc. Additionally, the storage unit (1h-40) can store information that serves as a criterion for determining whether to provide multiple connections to the terminal or to disconnect them. Furthermore, the storage unit (1h-40) provides the stored data upon the request of the control unit (1h-50).

[0247] The control unit (1h-50) controls the overall operations of the main station. For example, the control unit (1h-50) transmits and receives signals through the baseband processing unit (1h-20) and the RF processing unit (1h-10) or through the backhaul communication unit (1h-30). Additionally, the control unit (1h-50) writes and reads data to and from the storage unit (1h-40). To this end, the control unit (1h-50) may include at least one processor.

[0248] FIG. 1i illustrates the structure of a base station according to various embodiments of the present disclosure.

[0249] Referring to FIG. 1i, a base station may include a transceiver (1i-10), a control unit (1i-20), and a storage unit (1i-30). The transceiver (1i-10), the control unit (1i-20), and the storage unit (1i-30) may operate according to the communication method of the base station described above. A network device may also correspond to the structure of the base station. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. For example, the base station may include a transceiver (1i-10) and a control unit (1i-20). Furthermore, the transceiver (1i-10), the control unit (1i-20), and the storage unit (1i-30) may be implemented in the form of a single chip.

[0250] The transceiver unit (1i-10) collectively refers to the receiver unit and the transmitter unit of a base station and can transmit and receive signals with a terminal, another base station, or other network devices. At this time, the signals transmitted and received may include control information and data. For example, the transceiver unit (1i-10) can transmit system information to a terminal and can transmit a synchronization signal or a reference signal. To this end, the transceiver unit (1i-10) may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver unit (1i-10), and the components of the transceiver unit (1i-10) are not limited to an RF transmitter and an RF receiver. The transceiver unit (1i-10) may include a wired / wireless transceiver unit and may include various configurations for transmitting and receiving signals. Additionally, the transceiver (1i-10) can receive a signal through a communication channel (e.g., a wireless channel) and output it to a control unit (1i-20), and transmit the signal output from the control unit (1i-20) through the communication channel. Additionally, the transceiver (1i-10) can receive a communication signal and output it to a processor, and transmit the signal output from the processor to a terminal, another base station, or another entity through a wired or wireless network.

[0251] The storage unit (1i-30) can store programs and data necessary for the operation of the base station. Additionally, the storage unit (1i-30) can store control information or data included in signals acquired from the base station. The storage unit (1i-30) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, the storage unit (1i-30) can store at least one of information transmitted and received through the transceiver unit (1i-10) and information generated through the control unit (1i-20).

[0252] In the present disclosure, the control unit (1i-20) may be defined as a circuit or an application-specific integrated circuit or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications. The control unit (1i-20) may control the overall operation of a base station according to an embodiment proposed in the present disclosure. For example, the control unit (1i-20) may control the signal flow between each block to perform operations according to the flowchart described above.

[0253] FIG. 1j illustrates the structure of a terminal according to various embodiments of the present disclosure.

[0254] Referring to FIG. 1j, the terminal may include a transceiver (1j-10), a control unit (1j-20), and a storage unit (1j-30). The transceiver (1j-10), the control unit (1j-20), and the storage unit (1j-30) may operate according to the communication method of the terminal described above. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. For example, the terminal may include a transceiver (1j-10) and a control unit (1j-20). In addition, the transceiver (1j-10), the control unit (1j-20), and the storage unit (1j-30) may be implemented in the form of a single chip.

[0255] The transceiver unit (1j-10) is a collective term for the receiving unit and the transmitting unit of a terminal, and can transmit and receive signals with a base station, another terminal, or a network entity. The signals transmitted and received with the base station may include control information and data. For example, the transceiver unit (1j-10) can receive system information from the base station and can receive synchronization signals or reference signals. To this end, the transceiver unit (1j-10) may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver unit (1j-10), and the components of the transceiver unit (1j-10) are not limited to the RF transmitter and the RF receiver. Additionally, the transceiver unit (1j-10) may include a wired / wireless transceiver unit and may include various configurations for transmitting and receiving signals. Additionally, the transceiver (1j-10) can receive a signal through a wireless channel and output it to a control unit (1j-20), and transmit the signal output from the control unit (1j-20) through a wireless channel. Additionally, the transceiver (1j-10) can receive a communication signal and output it to a processor, and transmit the signal output from the processor to a network entity through a wired or wireless network.

[0256] The storage unit (1j-30) can store programs and data necessary for the operation of the terminal. Additionally, the memory (1j-30) can store control information or data included in signals obtained from the terminal. The storage unit (1j-30) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD.

[0257] In the present disclosure, the control unit (1j-20) may be defined as a circuit or an application-specific integrated circuit or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications. The control unit (1j-20) may control the overall operation of the terminal according to the embodiment proposed in the present disclosure. For example, the control unit (1j-20) may control the signal flow between each block to perform operations according to the flowchart described above.

[0258] Methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0259] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present invention.

[0260] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disc storage devices, CD-ROM (Compact Disc-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0261] In addition, the above program may be stored on an attachable storage device that can be accessed via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present invention through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present invention.

[0262] In the specific embodiments of the present invention described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present invention is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed in the singular form, or even if a component is expressed in the singular form, it may be composed in the plural form.

[0263] Meanwhile, although specific embodiments have been described in the detailed description of the present invention, it is understood that various modifications are possible within the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof. In other words, it is obvious to those skilled in the art that other modifications based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, parts of the methods proposed in the present disclosure may be combined to operate a base station and a terminal. Additionally, while the above embodiments have been presented based on 5G and NR systems, other modifications based on the technical concept of the above embodiments may be implemented in other systems such as LTE, LTE-A, and LTE-A-Pro systems.

Claims

1. A method performed by an A-IoT (Ambient Internet of Things) device in a wireless communication system, A step of transmitting a first message for CBRA (Contention-Based Random Access) to a reader; A step of receiving a second message from the reader in response to the first message; A step of storing an AS (Access Stratum) ID based on the second message above; A step of transmitting a D2R (Device to Reader) message to the above reader; and The method includes the step of receiving a NACK (Negative Acknowledgment) message containing the stored AS ID from the reader, A method wherein the above NACK message comprises information indicating that the message type is NACK, size information of the above NACK message, and one or more reserved bits.

2. In Paragraph 1, A method further comprising the step of releasing the stored AS ID based on the above NACK message.

3. In Paragraph 1, The stored AS ID is an assigned AS ID included in the second message or a random number included in the second message, and A method in which the random number included in the second message is the same value as the 16-bit random number included in the first message.

4. In Paragraph 1, The above NACK message includes at least one AS ID including the stored AS ID, and A method in which at least one AS ID corresponds to at least one A-IoT device.

5. In Paragraph 1, A method in which the above NACK message is an R2D (Reader to Device) message indicating a failure to transmit the above D2R message.

6. In Paragraph 5, A method in which the stored AS ID included in the above NACK message indicates a transmission failure of the above D2R message.

7. In Paragraph 5, A method in which the above NACK message is received within a predetermined time after transmitting the above D2R message.

8. A method performed by a reader in a wireless communication system, A step of receiving a first message for CBRA (Contention-Based Random Access) from an A-IoT (Ambient Internet of Things) device; A step of transmitting a second message to the A-IoT device in response to the first message; A step of receiving a D2R (Device to Reader) message from the above A-IoT device; and The method includes the step of transmitting a NACK (Negative Acknowledgment) message containing an AS (Access Stratum) ID to the above A-IoT device. The above AS ID is stored in the A-IoT device based on the above second message, and A method wherein the above NACK message comprises information indicating that the message type is NACK, size information of the above NACK message, and one or more reserved bits.

9. In Paragraph 8, A method in which the above AS ID is released by the A-IoT device based on the above NACK message.

10. In Paragraph 8, The above AS ID is an assigned AS ID included in the second message or a random number included in the second message, and A method in which the random number included in the second message is the same value as the 16-bit random number included in the first message.

11. In Paragraph 8, The above NACK message includes at least one AS ID including the above AS ID, and A method in which at least one AS ID corresponds to at least one A-IoT device.

12. In Paragraph 8, A method in which the above NACK message is an R2D (Reader to Device) message indicating a failure to transmit the above D2R message.

13. In Paragraph 12, A method in which the AS ID included in the above NACK message indicates a failure to transmit the above D2R message.

14. In an A-IoT (Ambient Internet of Things) device in a wireless communication system, At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the A-IoT device: Send a first message for CBRA (Contention-Based Random Access) to the reader, and From the above reader, a second message is received in response to the first message, and Based on the second message above, store the AS (Access Stratum) ID, and Send a D2R (Device to Reader) message to the above reader, and To receive a NACK (Negative Acknowledgment) message containing the stored AS ID from the above reader, and An A-IoT device in which the above NACK message includes information indicating that the message type is NACK, size information of the above NACK message, and one or more reserved bits.

15. In a reader in a wireless communication system, At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, and the reader: Receive a first message for CBRA (Contention-Based Random Access) from an A-IoT (Ambient Internet of Things) device, and A second message is transmitted to the above A-IoT device in response to the first message, and A D2R (Device to Reader) message is received from the above A-IoT device, and The above A-IoT device is instructed to send a NACK (Negative Acknowledgment) message containing an AS (Access Stratum) ID, and The above AS ID is stored in the A-IoT device based on the above second message, and A reader in which the above NACK message includes information indicating that the message type is NACK, size information of the above NACK message, and one or more reserved bits.

Images