Method and apparatus for performing random access procedure

Abstract

The present embodiments provide a method by which an ambient IoT terminal performs a random access procedure, the method comprising the steps of: receiving, from a reader apparatus, terminal ID information, paging opportunity information, and radio resource-related information; and determining a radio resource for performing random access on the basis of the terminal ID information, the paging opportunity information, and the radio resource-related information, and starting the random access procedure through the determined radio resource.

Description

Method and device for performing a random access procedure

[0001] The embodiments propose a method and apparatus for performing a random access procedure in a next-generation wireless access network (in this disclosure, "5G", "NR [New Radio]", "5G-Advanced", "6G" or subsequent 3GPP wireless access networks).

[0002] In recent years, the Internet of Things (IoT) has attracted significant attention in the field of wireless communication. It is expected that an increasing number of objects will become interconnected to improve productivity efficiency and enhance the comfort of daily life. Further reducing the size, complexity, and power consumption of IoT devices enables the deployment of tens or even hundreds of billions of IoT devices for various applications, thereby providing added value across the entire value chain. However, it is impossible to power all IoT devices with batteries, and since batteries must be manually replaced or recharged, this can lead to high maintenance costs, serious environmental issues, and even safety risks for some use cases.

[0003] In this regard, efficient power consumption of IoT devices is required, and accordingly, there is a need for specific designs regarding methods to manage the energy of IoT devices more efficiently.

[0004] Embodiments of the present disclosure may provide a method and apparatus for performing a random access procedure in an Ambient IoT (hereinafter also referred to as A-IoT) environment.

[0005] In one aspect, the present embodiments may provide a method for an Ambient IoT terminal to perform a random access procedure, comprising the steps of receiving terminal ID information, paging opportunity information, and wireless resource-related information from a reader device, determining a wireless resource for performing random access based on the terminal ID information, paging opportunity information, and wireless resource-related information, and starting a random access procedure through the determined wireless resource.

[0006] In another aspect, the present embodiments may provide a method for a reader device to perform a random access procedure, comprising the steps of transmitting terminal ID information, paging opportunity information, and wireless resource-related information to an Ambient IoT terminal, and performing a random access procedure through a wireless resource determined based on the terminal ID information, paging opportunity information, and wireless resource-related information.

[0007] In another aspect, the embodiments may provide an Ambient IoT terminal that performs a random access procedure, comprising a transmitter, a receiver, and a control unit that controls the operation of the transmitter and the receiver. The control unit receives terminal ID information, paging opportunity information, and wireless resource-related information from a reader device, determines a wireless resource for performing random access based on the terminal ID information, paging opportunity information, and wireless resource-related information, and can provide a terminal that starts a random access procedure through the determined wireless resource.

[0008] In another aspect, the embodiments may provide a reader device for performing a random access procedure, comprising a transmitter, a receiver, and a control unit for controlling the operation of the transmitter and the receiver, wherein the control unit transmits terminal ID information, paging opportunity information, and wireless resource-related information to an Ambient IoT terminal, and performs a random access procedure through a wireless resource determined based on the terminal ID information, paging opportunity information, and wireless resource-related information.

[0009] According to the embodiments, a method and apparatus for performing a random access procedure in an ambient IoT environment can be provided.

[0010] In addition, A-IoT terminals that failed to be allocated wireless resources can be provided with paging opportunity information or paging failure count information to grant them the opportunity to acquire more wireless resources.

[0011] FIG. 1 is a diagram briefly illustrating the structure of an NR wireless communication system to which the present embodiment can be applied.

[0012] FIG. 2 is a drawing illustrating the frame structure in an NR system to which the present embodiment can be applied.

[0013] FIG. 3 is a diagram illustrating a resource grid supported by wireless access technology to which the present embodiment can be applied.

[0014] FIG. 4 is a diagram illustrating the bandwidth part supported by the wireless access technology to which the present embodiment can be applied.

[0015] FIG. 5 is a diagram illustrating an exemplary synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0016] FIG. 6 is a diagram illustrating a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0017] Figure 7 is a diagram for explaining CORESET.

[0018] FIG. 8 is a diagram illustrating the Reader / Tag operations and tag state of RFID.

[0019] FIGS. 9 to 13 are drawings illustrating a connectivity topology for an Ambient IoT network and device to which the present embodiment can be applied.

[0020] FIG. 14 is a diagram illustrating the general operation between an Ambient IoT terminal and a reader according to one embodiment.

[0021] FIG. 15 is a diagram illustrating a procedure for an Ambient IoT terminal to perform random access according to one embodiment.

[0022] FIG. 16 is a diagram illustrating a procedure in which a reader performs random access according to one embodiment.

[0023] FIGS. 17 and FIGS. 18 are drawings for illustrating an Ambient IoT topology according to one embodiment.

[0024] FIGS. 19 to 21 are drawings for illustrating random access procedures according to one embodiment.

[0025] FIGS. 22 and FIGS. 23 are drawings for explaining the operation according to the reception of a paging message in each round according to one embodiment.

[0026] FIG. 24 is a diagram showing the configuration of a terminal according to another embodiment.

[0027] FIG. 25 is a drawing showing the configuration of a reader according to another embodiment.

[0028] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the exemplary drawings. In assigning reference numerals to the components of each drawing, the same components may have the same reference numeral as much as possible, even if they are shown in different drawings. Furthermore, in describing the embodiments, if it is determined that a detailed description of related known components or functions may obscure the essence of the technical concept, such detailed description may be omitted. Where terms such as "comprising," "having," or "consisting of" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it may include a plural unless otherwise specified.

[0029] Additionally, terms such as first, second, A, B, (a), (b), etc., may be used to describe the components of the present disclosure. These terms are used merely to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by such terms.

[0030] In describing the positional relationship of components, where it is stated that two or more components are "connected," "combined," or "joined," it should be understood that while the two or more components may be directly "connected," "combined," or "joined," they may also be "connected," "combined," or "joined" with other components "intervened." Here, the other components may be included in one or more of the two or more components that are "connected," "combined," or "joined" with one another.

[0031] In describing the temporal flow relationship regarding components, methods of operation, or methods of production, for example, when the temporal or sequential relationship is described using "after," "following," "next," or "before," it may include cases where the relationship is not continuous unless "immediately" or "directly" is used.

[0032] Meanwhile, where numerical values ​​or corresponding information regarding a component (e.g., levels, etc.) are mentioned, even without separate explicit notation, the numerical values ​​or corresponding information may be interpreted as including a range of error that may occur due to various factors (e.g., process factors, internal or external shocks, noise, etc.).

[0033] A wireless communication system in this specification refers to a system for providing various communication services, such as voice and data packets, using wireless resources, and may include a terminal, a base station, or a core network.

[0034] The embodiments disclosed below may be applied to wireless communication systems using various wireless access technologies. For example, the embodiments may be applied to various wireless access technologies such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), or NOMA (non-orthogonal multiple access). Furthermore, wireless access technology may refer not only to specific access technologies but also to communication technologies for each generation established by various telecommunication organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA may be implemented as a wireless technology such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA may be implemented as a wireless technology such as GSM (global system for mobile communications), GPRS (general packet radio service), or EDGE (enhanced datarates for GSM evolution). OFDMA can be implemented using wireless technologies such as IEEE (Institute of Electrical and Electronic Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e.UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink. As such, these embodiments can be applied to currently disclosed or commercialized radio access technologies, and can also be applied to radio access technologies currently under development or to be developed in the future.

[0035] Meanwhile, the term "terminal" in this specification is a comprehensive concept meaning a device including a wireless communication module that communicates with a base station in a wireless communication system. It should be interpreted as a concept that includes not only User Equipment (UE) in WCDMA, LTE, NR, HSPA, and IMT-2020 (5G or New Radio), but also Mobile Station (MS), User Terminal (UT), Subscriber Station (SS), and wireless device in GSM. Furthermore, depending on the usage type, the terminal may be a user portable device such as a smartphone, or in a V2X communication system, it may refer to a vehicle or a device including a wireless communication module inside a vehicle. Additionally, in the case of a Machine Type Communication (MMC) system, it may refer to an MTC terminal, M2M terminal, URLLC terminal, etc., equipped with a communication module to perform machine type communication.

[0036] In this specification, "base station" or "cell" refers to an end that communicates with a terminal in terms of a network, and encompasses various coverage areas such as Node-B, eNB (evolved Node-B), gNB (gNode-B), LPN (Low Power Node), Sector, Site, various types of antennas, BTS (Base Transceiver System), Access Point, Point (e.g., Transmitter Point, Receiver Point, Transceiver Point), Relay Node, Mega Cell, Macro Cell, Micro Cell, Pico Cell, Femto Cell, RRH (Remote Radio Head), RU (Radio Unit), and Small Cell. Additionally, "cell" may include a Bandwidth Part (BWP) in the frequency domain. For example, a serving cell may refer to the Activation BWP of a terminal.

[0037] Since there is a base station controlling one or more of the various cells listed above, the term "base station" can be interpreted in two senses. 1) It may refer to the device itself that provides a mega cell, macro cell, micro cell, pico cell, femto cell, or small cell in relation to a wireless area, or 2) it may refer to the wireless area itself. In 1), all devices that provide a specific wireless area are controlled by the same entity or interact to configure the wireless area collaboratively are referred to as base stations. Depending on the configuration method of the wireless area, a point, a transmitting / receiving point, a transmitting point, a receiving point, etc., are examples of a base station. In 2), the wireless area itself that receives or transmits a signal from the perspective of a user terminal or from the perspective of a neighboring base station may also be referred to as a base station.

[0038] In this specification, "Cell" may refer to a component carrier having coverage of a signal transmitted from a transmitting / receiving point or coverage of a signal transmitted from a transmitting / receiving point (transmission point or transmission / reception point), or the transmitting / receiving point itself.

[0039] Uplink (UL, or Uplink) refers to the method of transmitting and receiving data from a terminal to a base station, and Downlink (DL, or Downlink) refers to the method of transmitting and receiving data from a base station to a terminal. Downlink may refer to communication or a communication path from multiple transmission and reception points to a terminal, and uplink may refer to communication or a communication path from a terminal to multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of the multiple transmission and reception points, and the receiver may be part of the terminal. Additionally, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission and reception points.

[0040] The uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control Channel) and PUCCH (Physical Uplink Control Channel), and transmit and receive data by configuring data channels such as PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel). In the following description, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also referred to as "transmitting and receiving PUCCH, PUSCH, PDCCH, and PDSCH."

[0041] To clarify the explanation, the technical concept described below is based primarily on 3GPP LTE / LTE-A / NR (New RAT) communication systems, but the technical features are not limited to said communication systems.

[0042] Following research on 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of the ITU-R for next-generation radio access technology. Specifically, 3GPP develops LTE-A pro, which enhances LTE-Advanced technology to meet ITU-R requirements, and NR, a new communication technology distinct from 4G communication technology, as 5G communication technologies. Since both LTE-A pro and NR refer to 5G communication technology, the following description of 5G communication technology will focus on NR unless a specific technology is being identified.

[0043] The operational scenarios in NR define various operation scenarios by adding considerations for satellites, automobiles, and new verticals to the existing 4G LTE scenarios, and in terms of service, they support eMBB (Enhanced Mobile Broadband) scenarios, mMTC (Massive Machine Communication) scenarios which require low data rates and asynchronous access while having high terminal density and being deployed over a wide range, and URLLC (Ultra Reliability and Low Latency) scenarios which require high responsiveness and reliability and can support high-speed mobility.

[0044] To satisfy these scenarios, NR introduces a wireless communication system equipped with new waveform and frame structure technologies, low latency technology, mmWave support technology, and forward compatibility technology. In particular, the NR system presents various technical changes in terms of flexibility to provide forward compatibility. The main technical features of NR are explained below with reference to the drawings.

[0045]

[0046] <NR 시스템 일반>

[0047] FIG. 1 is a simplified diagram illustrating the structure of an NR system to which the present embodiment can be applied.

[0048] Referring to FIG. 1, the NR system is divided into a 5G Core Network (5GC) and an NR-RAN part. The NG-RAN consists of gNBs and ng-eNBs that provide control plane (RRC) protocol endpoints for the user plane (SDAP / PDCP / RLC / MAC / PHY) and User Equipment (UE). gNBs are interconnected with each other, or gNBs and ng-eNBs are interconnected via Xn interfaces. Each gNB and ng-eNB is connected to the 5GC via an NG interface. The 5GC may be configured to include an Access and Mobility Management Function (AMF), which is responsible for control plane functions such as terminal access and mobility control, and a User Plane Function (UPF), which is responsible for control functions for user data. The NR system includes support for both frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands above 6 GHz (FR2, Frequency Range 2).

[0049] gNB refers to a base station that provides NR user plane and control plane protocol terminations to a terminal, and ng-eNB refers to a base station that provides E-UTRA user plane and control plane protocol terminations to a terminal. The base station described in this specification should be understood as encompassing both gNB and ng-eNB, and may also be used to refer to gNB or ng-eNB separately as necessary.

[0050] <NR 웨이브 폼, 뉴머롤러지 및 프레임 구조>

[0051]

[0052] In NR, CP-OFDM waveforms using a cyclic prefix are used for downlink transmission, and CP-OFDM or DFT-s-OFDM are used for uplink transmission. OFDM technology is easy to combine with MIMO (Multiple Input Multiple Output) and has the advantage of allowing the use of low-complexity receivers along with high frequency efficiency.

[0053] Meanwhile, in NR, since the requirements for data rate, latency, coverage, etc. differ for each of the three scenarios mentioned above, it is necessary to efficiently satisfy the requirements for each scenario through the frequency bands that constitute an arbitrary NR system. To this end, a technology has been proposed to efficiently multiplex wireless resources based on multiple different numerologies.

[0054] Specifically, the NR transmission numerator is determined based on sub-carrier spacing and CP (Cyclic prefix), and as shown in Table 1 below, the μ value is used as an exponential value of 2 based on 15 kHz and changes exponentially.

[0055] μ서브캐리어 간격Cyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0056] As shown in Table 1 above, the numerators of NR can be classified into five types based on the subcarrier spacing. This differs from LTE, one of the 4G communication technologies, where the subcarrier spacing is fixed at 15 kHz. Specifically, the subcarrier spacings used for data transmission in NR are 15, 30, 60, and 120 kHz, while the subcarrier spacings used for synchronization signal transmission are 15, 30, 12, and 240 kHz. Additionally, extended CP applies only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR defines a frame with a length of 10ms, composed of 10 subframes of equal length of 1ms. A single frame can be divided into 5ms half-frames, and each half-frame contains 5 subframes. In the case of a 15 kHz subcarrier interval, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. FIG. 2 is a diagram illustrating the frame structure in an NR system to which the present embodiment can be applied. Referring to FIG. 2, in the case of a normal CP, the slot is fixedly composed of 14 OFDM symbols, but the length of the slot in the time domain may vary depending on the subcarrier interval. For example, in the case of a numeral with a 15 kHz subcarrier interval, the slot is composed of a length of 1 ms, which is the same length as the subframe. In contrast, in the case of a numeral with a 30 kHz subcarrier interval, the slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined with a fixed time length, while the slot is defined by the number of symbols, and the time length may vary depending on the subcarrier interval.

[0057] Meanwhile, NR defines the basic unit of scheduling as a slot and introduced mini-slots (or sub-slots or non-slot based schedules) to reduce transmission delay in the wireless section. Using a wide subcarrier spacing reduces transmission delay in the wireless section because the length of a single slot becomes inversely shorter. Mini-slots (or sub-slots) are designed for efficient support of URLLC scenarios and allow scheduling in units of 2, 4, or 7 symbols.

[0058] Furthermore, unlike LTE, NR defines uplink and downlink resource allocation at the symbol level within a single slot. To reduce HARQ latency, a slot structure was defined that allows HARQ ACK / NACK to be transmitted directly within the transmission slot; this slot structure is described as a self-contained structure.

[0059] NR is designed to support a total of 256 slot formats, of which 62 are used in 3GPP Rel-15. Additionally, it supports common frame structures that form FDD or TDD frames through various slot combinations. For example, it supports slot structures where all slot symbols are set to downlink, slot structures where all symbols are set to uplink, and slot structures where downlink and uplink symbols are combined. Furthermore, NR supports data transmission being distributed and scheduled across one or more slots. Therefore, base stations can use a Slot Format Indicator (SFI) to inform a terminal whether a slot is a downlink slot, an uplink slot, or a flexible slot. Base stations can indicate the slot format by using the SFI to indicate an index of a table configured via UE-specific RRC signaling, or they can indicate it dynamically via Downlink Control Information (DCI) or statically or semi-statically via RRC.

[0060] <NR 물리 자원 >

[0061] Regarding physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered.

[0062] An antenna port is defined such that the channel carrying a symbol on the antenna port can be inferred from the channel carrying another symbol on the same antenna port. If the large-scale property of the channel carrying a symbol on one antenna port can be inferred from the channel carrying a symbol on another antenna port, the two antenna ports can be said to be in a QC / QCL (quasi co-located or quasi co-location) relationship. Here, the large-scale property includes one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0063] FIG. 3 is a diagram illustrating a resource grid supported by wireless access technology to which the present embodiment can be applied.

[0064] Referring to FIG. 3, a resource grid may exist for each numerator because NR supports multiple numerators on the same carrier. Additionally, a resource grid may exist depending on the antenna port, subcarrier spacing, and transmission direction.

[0065] A resource block consists of 12 subcarriers and is defined only in the frequency domain. Additionally, a resource element consists of one OFDM symbol and one subcarrier. Therefore, as shown in Fig. 3, the size of a single resource block can vary depending on the subcarrier spacing. Furthermore, NR defines "Point A," which serves as a common reference point for the resource block grid, as well as common resource blocks, virtual resource blocks, etc.

[0066] FIG. 4 is a diagram illustrating the bandwidth part supported by the wireless access technology to which the present embodiment can be applied.

[0067] In NR, unlike LTE where the carrier bandwidth is fixed at 20 MHz, the maximum carrier bandwidth is set from 50 MHz to 400 MHz depending on the subcarrier interval. Therefore, it is not assumed that all terminals use this entire carrier bandwidth. Accordingly, in NR, as shown in Fig. 4, a Bandwidth Part (BWP) can be designated within the carrier bandwidth for the terminal to use. Additionally, a Bandwidth Part is associated with a single numerator and consists of a subset of a continuous common resource block, and can be dynamically activated over time. Up to four Bandwidth Parts are configured for the uplink and downlink respectively, and data is transmitted and received using the Bandwidth Part activated at a given time.

[0068] In the case of paired spectrum, the uplink and downlink bandwidth parts are set independently, whereas in the case of unpaired spectrum, the downlink and uplink bandwidth parts are paired to share a center frequency in order to prevent unnecessary frequency re-tuning between downlink and uplink operations.

[0069] <NR 초기 접속>

[0070] In NR, the terminal performs cell search and random access procedures to connect to the base station and perform communication.

[0071] Cell search is a procedure in which a terminal uses a Synchronization Signal Block (SSB) transmitted by a base station to synchronize with the corresponding base station's cell, obtain a physical layer cell ID, and acquire system information.

[0072] FIG. 5 is a diagram illustrating an exemplary synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0073] Referring to FIG. 5, the SSB consists of a PSS (primary synchronization signal) and an SSS (secondary synchronization signal) each occupying 1 symbol and 127 subcarriers, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

[0074] The terminal monitors the SSB in the time and frequency domains and receives the SSB.

[0075] SSBs can be transmitted up to 64 times within 5ms. Multiple SSBs are transmitted via different transmission beams within the 5ms timeframe, and the terminal performs detection by assuming that an SSB is transmitted every 20ms based on a specific beam used for transmission. The number of beams available for SSB transmission within the 5ms timeframe can increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted at 3GHz or lower, up to 8 beams in the frequency band from 3GHz to 6GHz, and up to 64 different beams can be used to transmit SSBs in the frequency band above 6GHz.

[0076] Two SSBs are included in a single slot, and the starting symbol and number of repetitions within the slot are determined according to the subcarrier interval as follows.

[0077] Meanwhile, unlike the SS of conventional LTE, the SSB is not transmitted at the center frequency of the carrier bandwidth. That is, the SSB can be transmitted even at locations other than the center of the system band, and multiple SSBs can be transmitted across the frequency domain when broadband operation is supported. Accordingly, the terminal monitors the SSB using a synchronization raster, which is a candidate frequency location for monitoring the SSB. The carrier raster, which is information on the center frequency location of the channel for initial connection, and the synchronization raster were newly defined in NR, and the synchronization raster is set with a wider frequency interval compared to the carrier raster, thereby supporting fast SSB search by the terminal.

[0078] The terminal can obtain the MIB through the PBCH of the SSB. The Master Information Block (MIB) contains minimum information for the terminal to receive the Remaining Minimum System Information (RMSI) broadcast by the network. Additionally, the PBCH may include information regarding the location of the first DM-RS symbol in the time domain, information for the terminal to monitor SIB1 (e.g., SIB1 numeral information, information related to SIB1 CORESET, search space information, PDCCH related parameter information, etc.), and offset information between the Common Resource Block and the SSB (the absolute location of the SSB within the carrier is transmitted via SIB1). Here, the SIB1 numeral information is applied identically to some messages used in the random access procedure for the terminal to connect to the base station after completing the cell search procedure. For example, the SIB1 numeral information may be applied to at least one of messages 1 to 4 for the random access procedure.

[0079] The aforementioned RMSI may refer to SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., 160ms) from the cell. SIB1 contains information necessary for the terminal to perform the initial random access procedure and is transmitted periodically via PDSCH. To receive SIB1, the terminal must receive the numerology information used for transmitting SIB1 and the CORESET (Control Resource Set) information used for scheduling SIB1 via PBCH. The terminal checks the scheduling information for SIB1 using SI-RNTI within the CORESET and obtains SIB1 on the PDSCH according to the scheduling information. The remaining SIBs, excluding SIB1, may be transmitted periodically or upon the terminal's request.

[0080] FIG. 6 is a diagram illustrating a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0081] Referring to FIG. 6, when cell search is completed, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via PRACH. Specifically, the random access preamble is transmitted to the base station via PRACH, which consists of a series of radio resources in specific slots that are repeated periodically. Generally, when the terminal initially connects to a cell, a contention-based random access procedure is performed, and when performing random access for Beam Failure Recovery (BFR), a non-contention-based random access procedure is performed.

[0082] The terminal receives a random access response for the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), an UL Grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a TAC (Time Alignment Command). Since a single random access response may contain random access response information for one or more terminals, the random access preamble identifier may be included to indicate which terminal the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the terminal to coordinate uplink synchronization. The random access response may be indicated by the random access identifier on the PDCCH, namely the RA-RNTI (Random Access - Radio Network Temporary Identifier).

[0083] A terminal that receives a valid random access response processes the information contained in the random access response and performs a transmission scheduled to the base station. For example, the terminal applies a TAC and stores a temporary C-RNTI. Additionally, using a UL Grant, it transmits data stored in the terminal's buffer or newly generated data to the base station. In this case, information that can identify the terminal must be included.

[0084] Finally, the terminal receives a downlink message to resolve competition.

[0085] <NR CORESET>

[0086] The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) with a length of 1 to 3 symbols, and transmits uplink / downlink scheduling information, SFI (Slot format Index), TPC (Transmit Power Control) information, etc.

[0087] In this way, NR introduced the concept of CORESET to ensure system flexibility. CORESET (Control Resource Set) refers to time-frequency resources for downlink control signals. A terminal can decode control channel candidates by using one or more search spaces from the CORESET time-frequency resources. Quasi CoLocation (QCL) assumptions were established for each CORESET, and these are used to indicate characteristics regarding the analog beam direction in addition to the characteristics assumed by conventional QCL, such as delay spread, Doppler spread, Doppler shift, and mean delay.

[0088] Figure 7 is a diagram for explaining CORESET.

[0089] Referring to FIG. 7, CORESET can exist in various forms within a single slot and within the carrier bandwidth, and in the time domain, CORESET can be composed of up to 3 OFDM symbols. Additionally, CORESET is defined as a multiple of 6 resource blocks up to the carrier bandwidth in the frequency domain.

[0090] The first CORESET is specified via the MIB as part of the initial bandwidth part configuration to enable the reception of additional configuration and system information from the network. After establishing a connection with the base station, the terminal can be configured by receiving one or more CORESET information via RRC signaling.

[0091] Wider bandwidth operations

[0092] In the case of existing LTE systems, scalable bandwidth operation was supported for any LTC Component Carrier (CC). That is, depending on the frequency deployment scenario, any LTE operator could configure a bandwidth ranging from a minimum of 1.4 MHz to a maximum of 20 MHz when configuring a single LTE CC, and normal LTE terminals supported a transmit / receive capability of 20 MHz bandwidth for a single LTE CC.

[0093] However, in the case of NR, the design is made to enable support for NR terminals with different transmit / receive bandwidth capabilities through a single wideband NR CC. Accordingly, it is required to configure one or more bandwidth parts (BWPs) consisting of subdivided bandwidths for any NR CC, and to support flexible wider bandwidth operation through different bandwidth part configurations and activations for each terminal.

[0094] Specifically, in NR, one or more bandwidth parts can be configured through a single serving cell configured from the perspective of a terminal, and the terminal is defined to activate one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) in the serving cell to use for uplink / downlink data transmission and reception. In addition, for terminals where multiple serving cells are configured, i.e., terminals to which CA is applied, it is defined to activate one downlink bandwidth part and / or uplink bandwidth part for each serving cell to use the wireless resources of the serving cell for uplink / downlink data transmission and reception.

[0095] Specifically, an initial bandwidth part for the initial access procedure of a terminal is defined in any serving cell, and one or more terminal-specific (UE-specific) bandwidth parts are configured for each terminal through dedicated RRC signaling, and a default bandwidth part for a fallback operation can also be defined for each terminal.

[0096] However, depending on the capability and bandwidth part(s) configuration of the terminal in any serving cell, it may be defined to simultaneously activate and use multiple downlink and / or uplink bandwidth parts, but in NR rel-15, it is defined to activate and use only one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) at any time in any terminal.

[0097] In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, or various messages related to NR (New Radio) may be interpreted in the sense used in the past or present, or in various senses used in the future.

[0098]

[0099] Below, we will specifically explain how to perform a random access procedure in an Ambient IoT environment with reference to the relevant drawings.

[0100] The present disclosure proposes a method for determining a random access type by an Ambient IoT terminal (also referred to as an Ambient IoT device or Ambient IoT apparatus in the present disclosure) in an Ambient Internet of Things (Ambient IoT; referred to as Ambient IoT or A-IoT in the present disclosure) system of a 3GPP (3rd Generation Partnership Project) wireless access network (hereinafter referred to as "5G" or "NR [New Radio]" in the present disclosure) or a next-generation wireless access network (hereinafter referred to as "5G-Advanced or 6G" in the present disclosure), and a method for configuring and transmitting paging and R2D messages transmitted by a reader (also referred to as a reader device in the present disclosure) or a base station for the same.

[0101] In recent years, IoT technology has garnered significant attention in wireless communication. IoT technology has evolved to enable a greater number of interconnected objects, thereby improving industrial productivity and quality of life. NB-IoT and eMTC technologies are examples of this. However, to build a more effective IoT ecosystem, improvements are needed in various aspects, such as the size, form factor, price, complexity, power consumption, and coverage of IoT devices.

[0102] RFID is a representative technology service of the IoT. The advantages of RFID include very low complexity, and RFID tags have a very small form factor. However, RFID supports a very narrow coverage area with a reading distance of only a few meters, is labor-intensive due to handheld scanning, and requires high deployment costs due to the installation costs of RFID portals / gates. Therefore, RFID has limitations in supporting seamless service and coverage in large-scale networks.

[0103] To meet these demands, research on Ambient IoT technology has been conducted. Ambient IoT terminals feature a lower form factor compared to conventional IoT terminals and support energy harvesting based on battery-less operation and minimal energy storage capability, enabling them to operate without charging or with minimal power consumption. Furthermore, research is underway to support wider coverage based on higher power efficiency and to enable the utilization of RF signals supported by existing networks.

[0104] 3GPP is conducting research on protocol stacks and signaling procedures that take into account the low form factor and battery capacity characteristics of Ambient IoT terminals, such as less than 1 μW or less than several hundred μW. In particular, definitions are being made for the paging message functionality, which is the first message transmitted by a reader or base station to an Ambient IoT terminal for wireless access of the Ambient IoT terminal, and the random access procedure of the Ambient IoT terminal.

[0105] RFID technology, the foundation of Ambient IoT technology, is "EPC TM It is defined in the document "Radio-Frequency Identity Protocols Generation-2 UHF RFID". The document defines the protocol between the Reader and the Tag and adopts a slotted-ALOHA-based random access procedure. As shown in Fig. 8, there are three main "Select, Inventory, Access" operations.

[0106] The Select operation is an action in which the Reader selects one or more tag populations, and consists of "Select" and "Challenge" commands. At this time, the Tag enters the Ready state. The Select command is a mandatory operation, while the Challenge command is optional. The Select command allows the Reader to select a set of Tags based on user-defined criteria. The Inventory operation prepares for Access by having the Reader identify and detect each Tag, and generating a unique random number based on commands and responses with each Tag. The Access operation involves the Reader communicating with each Tag to perform procedures such as Read, Write, and Authenticate.

[0107] As mentioned above, IoT has attracted significant attention in the field of wireless communication in recent years. More 'things' are expected to become interconnected to improve productivity efficiency and increase comfort in daily life. Further reducing the size, complexity, and power consumption of IoT devices enables the deployment of tens or even hundreds of billions of IoT devices for various applications, providing added value across the entire value chain. However, it is impossible to power all IoT devices with batteries, and since batteries must be manually replaced or recharged, this can lead to high maintenance costs, serious environmental issues, and even safety risks for some use cases (e.g., wireless sensors in the power and oil industries).

[0108] Most existing wireless communication devices are powered by batteries that require manual replacement or recharging. Automation and digitalization across various industries are opening up new markets that demand new IoT technologies supporting energy storage devices that lack energy storage capabilities or do not require manual replacement or recharging. The form factor of these devices must be appropriately small to convey the effectiveness of the target use cases.

[0109] The goal is to capture use cases, traffic scenarios, and device constraints for ambient power-based IoT, and to identify new potential service requirements. Cases are considered where devices operate without batteries or have limited energy storage capabilities (e.g., using capacitors), and energy is supplied by collecting it from radio waves, light, motion, heat, or other suitable power sources.

[0110] Given the size and complexity required for practical applications that lack battery-free energy storage capabilities or have limited energy storage devices that do not require manual replacement or recharging, the output power of an energy harvester is typically between 1 μW and several hundred μW. Conventional cellular devices may not work well with energy harvesting because their peak power consumption is over 10 mW.

[0111] One example of an application type is asset identification, for which most industries currently rely primarily on barcodes and RFID. The main advantages of these two technologies are the ultra-low complexity and small form factor of the tags. However, the limited read range of only a few meters typically necessitates handheld scanning, resulting in labor-intensive and time-consuming tasks, or the need for RFID portals / gates, leading to costly deployments. Furthermore, the lack of interference management schemes causes serious interference and capacity issues between RFID readers, which are particularly problematic in dense deployments. RFID struggles to support large-scale networks that provide seamless coverage.

[0112] TSG RAN has completed the Rel-18 RAN-level SI on Ambient IoT, which provides a framework for terminology and scope setting for future discussions on Ambient IoT. This work defined representative use cases, deployment scenarios, connectivity topologies, Ambient IoT devices, design goals, and required functions, conducted an initial feasibility assessment, and presented recommendations for sub-selections in setting the scope of future WG-level research.

[0113] Because existing technologies cannot meet all the requirements of target use cases, it is recommended that new IoT technologies open up new markets within the 3GPP system. These new technologies can have tens of times higher connectivity and / or device densities than existing 3GPP IoT technologies. The new IoT technologies must have tens of times lower complexity and power consumption than existing 3GPP LPWA technologies (e.g., NB-IoT and eMTC) and must address use cases and scenarios that cannot be met by existing 3GPP LPWA IoT technologies.

[0114] This study aims to conduct further evaluations at the RAN WG level of Ambient IoT, a new 3GPP IoT technology suitable for deployment in 3GPP systems. This technology is suitable for ultra-low power IoT applications based on devices with ultra-low power consumption and ultra-low complexity. The study must provide clear differentiation and address use cases and scenarios that cannot be met by existing 3GPP LPWA IoT technologies (e.g., NB-IoT). This includes cases involving reduced peak Tx power.

[0115] In this regard, the overall goal is to research the design of a harmonized air interface for Ambient IoT to enable the following devices.

[0116] ~1 μW peak power consumption, energy storage device included, initial sampling frequency offset (SFO) up to 10X ppm, no DL or UL amplification within the device. The device's UL transmission is backscattered by an externally provided carrier.

[0117] Peak power consumption of a few hundred μW or less, possession of energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, presence of DL and / or UL amplification within the device. The device's UL transmission may be backscattered by carriers generated within the device or provided externally.

[0118] For Topologies 1 & 2 (where the UE acts as an intermediate node under NW control), there is no RRC state, no mobility (i.e., no functions such as cell selection / reselection), no HARQ, and no ARQ.

[0119] Deployment scenarios according to the table referenced in item 4.2.2 of TR 38.848

[0120] For deployment scenario 1 with topology 1, base station and coexistence characteristics are defined as microcells and co-sites.

[0121] For deployment scenario 2 with topology 2, where the UE is an intermediate node under network control, the base station and coexistence characteristics: the location of the macro cell, co-site, and intermediate node are defined as indoors.

[0122] FR1 License Spectrum (FDD).

[0123] In-band spectrum placement for NR, guard band placement for LTE / NR, independent band placement.

[0124] Traffic types: Focus on DO-DTT, DT, rUC1 (Indoor Inventory) and rUC4 (Indoor Command).

[0125] We will evaluate whether DO-A (Device-originated autonomous) use cases can be addressed based on the harmonized wireless interface (air interface) design, and identify which parts of the harmonized wireless interface design are insufficient for DO-A use cases.

[0126] Transmission in ambient IoT devices (including backscattering when used) may occur at least in the UL spectrum.

[0127] For Ambient IoT DL and UL, frame structure, synchronization and timing, random access, numerical scheme, bandwidth, multiple access, waveform and modulation, channel coding, downlink channel / signal aspects, uplink channel / signal aspects, scheduling and timing relationships, and studies of essential characteristics regarding carrier waves provided externally to Ambient IoT devices are defined. Interference handling at Ambient IoT UL receivers and NR base stations is included. For Topology 2, there is no difference from Topology 1 in the physical layer design.

[0128] The necessary functions for the compact protocol stack and lightweight signaling procedures of Ambient IoT are studied and determined to enable DO-DTT and DT data transmission. For example, paging, random access, data transmission, and aspects of necessary wireless resource control, respect for limitations in general range, and interaction with upper layers are defined.

[0129] It identifies the impact on necessary signals and procedures at the CN-RAN interface to enable the following. For example, paging, device context management, and data transmission are defined. It identifies aspects of RAN architecture, including whether support for partitioned architectures is required. It identifies potential solutions for locating ambient IoT devices that do not affect specifications or have minimal specification impact, for example, by reusing existing user location reports or transmitting location information to the core network.

[0130] As a study on the coexistence of Ambient IoT and NR / LTE and the RF requirements for Ambient IoT, Ambient IoT BS transmission and reception, transmission and reception of Ambient IoT devices, and transmission and reception of intermediate nodes (UEs) are defined.

[0131] This disclosure reports on the feasibility of meeting design objectives for relevant use cases of a new 3GPP IoT technology based on suitable deployment scenarios in a 3GPP system based on ultra-low complexity devices for low-power IoT applications. This technology aims to address use cases and scenarios that cannot be achieved with existing 3GPP LPWA IoT technologies and seeks to provide a clear differentiation.

[0132] In terms of energy storage, the present disclosure considers the following device characteristics. A purely battery-free device having no energy storage function at all and relying entirely on the availability of an external energy source, and a device having a limited energy storage function that does not require manual replacement or charging are considered.

[0133] Connectivity topologies

[0134] FIGS. 9 to 13 are drawings illustrating a connectivity topology for an Ambient IoT network and device to which the present embodiment can be applied.

[0135] The following connection topologies are defined for Ambient IoT networks and devices. In all of these topologies, Ambient IoT devices can receive carrier waves from other nodes within or outside the topology. The links in each topology can be bidirectional or unidirectional.

[0136] A BS, UE, secondary node, or intermediate node can each be multiple BSs or UEs. The mixed indoor and outdoor placement of these nodes is considered a network implementation choice. It is necessary to consider the potential impact on device or node complexity. In the connection topology, the presence of multi-hop secondary nodes or intermediate nodes is not implied.

[0137] Referring to FIG. 9, in topology 1, the Ambient IoT device communicates directly with the base station in both directions. The communication between the base station and the Ambient IoT device includes Ambient IoT data and / or signals. This topology also includes the possibility that the base station transmitting to the Ambient IoT device may be different from the base station receiving from the Ambient IoT device.

[0138] Referring to FIG. 10, in topology 2, the Ambient IoT device communicates bidirectionally with an intermediate node between the device and the base station. In this topology, the intermediate node can be a device capable of supporting Ambient IoT, such as a relay, an IAB node, a UE, or a repeater. The intermediate node transmits Ambient IoT data and / or signals between the base station and the Ambient IoT device.

[0139] Referring to FIG. 11, in topology 3, the Ambient IoT device transmits data / signals to the base station and receives data / signals from the auxiliary node. Alternatively, referring to FIG. 12, in topology 3, the Ambient IoT device receives data / signals from the base station and transmits data / signals to the auxiliary node. In this topology, the auxiliary node can be a device capable of supporting Ambient IoT, such as a relay, IAB, UE, or repeater.

[0140] Referring to FIG. 13, in topology 4, the Ambient IoT device communicates bidirectionally with the UE. The communication between the UE and the Ambient IoT device includes Ambient IoT data and / or signals.

[0141] Deployment scenarios

[0142] Deployment scenarios are characterized, such as when the Ambient IoT device is indoors and the base station is indoors, when the Ambient IoT device is indoors and the base station is outdoors, when the Ambient IoT device is indoors and there is a UE-based reader, when the Ambient IoT device is outdoors and the base station is outdoors, and when the Ambient IoT device is outdoors and there is a UE-based reader.

[0143] Device classification (Device categorization)

[0144] In the present disclosure, an ambient IoT device is characterized according to its energy storage capacity and its ability to generate RF signals for transmission. It is assumed that the device may have no energy storage at all or may have a limited energy storage capability.

[0145] Based on this storage capacity, the present disclosure considers the following set of Ambient IoT devices.

[0146] Device A: No energy storage, no independent signal generation / amplification, i.e., backscattering transmission.

[0147] Device B: Energy storage present, no independent signal generation, i.e., backscattering transmission. Use of stored energy may involve amplification of the reflected signal.

[0148] Device C: Has energy storage, has independent signal generation, i.e., an active RF component for transmission.

[0149] Limited energy storage may vary between implementations within Device B or within Device C, and may also differ between Device B and Device C. This storage capacity is generally expected to be several times smaller than the storage capacity included in NB-IoT devices. Devices A, B, and C can demodulate control, data, etc. from relevant entities in the RAN depending on the connection topology.

[0150] Protocol stack and signaling procedures

[0151] FIG. 14 is a diagram illustrating the general operation between an Ambient IoT terminal and a reader according to one embodiment.

[0152] Step A: A-IoT Paging. Based on the service request, the reader sends an A-IoT paging message indicating the terminal requiring a response.

[0153] Step B: D2R data transmission. The triggered A-IoT terminal performs terminal ID transmission via or without the A-IoT random access procedure.

[0154] Step C1: Optional R2D data transmission (e.g., command transmission)

[0155] Step C2: Optional D2R data transmission (e.g., response to a command).

[0156] A-IoT Paging Function

[0157] At the AS layer, the A-IoT paging function is intended to indicate a terminal requiring a response. In relation to the A-IoT paging message, an identifier for identifying a terminal or a group of terminals may be included in this trigger message.

[0158] A-IoT paging message containing the identifier of a single A-IoT terminal

[0159] A-IoT paging message including a group ID mapped to multiple A-IoT terminals

[0160] An A-IoT paging message that does not contain any identifier, i.e., a case indicating that all A-IoT terminals capable of receiving said A-IoT paging message must respond.

[0161] An A-IoT paging message containing multiple A-IoT terminal identifiers.

[0162] Regarding A-IoT paging messages, additional information may be provided to determine the resources that the terminal can use for the D2R response message. Regarding A-IoT terminal paging functions, existing NR paging messages, existing paging occupations, and existing DRX may not be supported.

[0163] A-IoT Random Access Procedure

[0164] Defines the A-IoT random access procedure used by an A-IoT terminal to connect to a network for data transmission.

[0165] A-IoT random access is triggered by a reader and includes triggering access to a single A-IoT terminal, a group of A-IoT terminals, or all A-IoT terminals within the reader's coverage.

[0166] The basic method of the A-IoT random access procedure is slotted-ALOHA.

[0167] If the A-IoT terminal is selected to respond, the A-IoT terminal performs the following procedure.

[0168] Step 1: Determine Random Access Type and Access Occasion / Resource

[0169] If the random access is non-contention random access, select the designated D2R occupancy / resource. Skip the contention resolution of Step 2 and perform the data transfer of Step 3. If the random access is contention-based random access, perform access occupancy / resource determination and selection. Perform the contention resolution procedure of Step 2.

[0170] Step 2: Competition Resolution of Competition-Based Random Access

[0171] Solution 1: Data-free A-IoT Msg1

[0172] A-IoT Msg1: When the A-IoT terminal identifies the start of its access occupancy, it sends a random ID generated by the A-IoT terminal to the reader.

[0173] A-IoT Msg2: The reader responds with a successfully received random ID. If the A-IoT terminal receives an A-IoT Msg2 containing the same random ID it previously transmitted, it is considered that the contention has been resolved successfully.

[0174] Solution 2: A-IoT Msg1 including data

[0175] A-IoT Msg1: When an A-IoT terminal identifies the start of its access occupancy, it transmits an A-IoT Msg1 containing the terminal ID and / or other upper-layer data.

[0176] A-IoT Msg2: The reader may respond with information that was successfully received. If an A-IoT terminal receives an A-IoT Msg2 containing information received as a response to its transmission, it is considered that the contention has been resolved successfully.

[0177] Step 3: Data Transfer

[0178] When contention-based random access is used, after it is determined that the contention has been resolved successfully, or when contention-free access is used, the terminal may perform upper-layer data transmission with the reader, which may include the terminal ID and / or other upper-layer data.

[0179]

[0180] In the following, the method by which an ambient IoT terminal performs a random access procedure will be explained in detail with reference to the relevant drawings.

[0181] In the present disclosure, the ambient IoT device may be referred to by various terms such as terminal, ambient IoT terminal, A-IoT terminal, ambient IoT device, IoT device, and IoT terminal. Additionally, the reader may be referred to by various terms such as reader device, base station, intermediate node, and general terminal, and may include a base station of the aforementioned topology 1 or an intermediate node of topology 2, for example, a UE. Furthermore, the carrier wave node (CW node) is a device that transmits carrier waves for energy harvesting and may include a base station, a reader, or a CW node. Additionally, in describing the link between the reader and the ambient IoT device, transmission from the reader to the ambient IoT device is referred to as R2D transmission, and conversely, transmission from the ambient IoT device to the reader is referred to as D2R transmission. Additionally, the physical channel for R2D transmission is referred to as PRDCH (Physical Reader-to-Device Channel), and the physical channel for D2R transmission is referred to as PDRCH (Physical Device-to-Reader Channel). However, these terms are provided as examples and are not limited thereto; other terms may be used if the technical concept of the present disclosure can be applied substantially identically.

[0182] Ambient IoT terminals can be classified into three types as shown in Table 2 below.

[0183] DeviceTypeEnergyStoragePeak PowerConsumptionAmplificationUL Independentsignal generationUL Tx methodPassiveDevice 1Yes≤ 1 μWNoNoBackscatteringfrom external CWDevice 2aYes≤ a few hundred μWYes (DL and / or UL)NoBackscatteringfrom external CWActiveDevice 2bYes≤ a few hundred μWYes (DL and / or UL)YesGenerated internally

[0184] In Table 2, the difference between Passive and Active lies in the presence or absence of independent signal generation functions and hardware within the Ambient IoT terminal. It is defined as Passive if there is no independent signal generation function for uplink signal transmission, and Active if there is. Device 1 has a maximum power consumption of 1 μW or less and lacks independent signal generation and amplification functions. Additionally, the uplink of the Ambient IoT terminal is transmitted via backscattering of the external carrier wave signal. Device 2a has a maximum power consumption of several hundred μW or less, does not support independent signal generation, but supports UL / DL amplification functions. Furthermore, the UL is transmitted via backscattering of the external carrier wave signal. Device 2b has a maximum power consumption of several hundred μW or less and supports independent signal generation and UL / DL amplification functions. Additionally, the UL is transmitted through the device's internal signal generation.

[0185] Meanwhile, the common feature of Device 1, 2a, and 2b discussed by 3GPP to date is that they are equipped with energy storage inside the Ambient IoT terminal. However, Ambient IoT terminals may have energy storage of limited capacity depending on the topology and deployment scenario. In this case, limited energy storage refers to a storage device composed of small-sized capacitors. To support seamless communication between the Reader and the Ambient IoT device, protocols and signaling to support energy harvesting need to be defined.

[0186] It was decided to support paging messages at the Access Stratum (AS) layer between Ambient IoT terminals and readers / base stations, but since existing paging messages are difficult to support, A-IoT paging messages are newly defined. The purpose of A-IoT paging messages is to identify Ambient IoT terminal(s), select / determine a radio resource, and send a Device-to-Reader (D2R) response message to the reader.

[0187] To identify A-IoT device(s), the paging message may include identifier information types in the form of Table 3.

[0188] Cases Information Type Recipient Case 1 Single A-IoT device ID A single A-IoT Device Case 2 Group ID Multiple A-IoT device(s) mapped to a Group ID Case 3 No ID-related information All A-IoT device(s) receiving A-IoT paging messages Case 4 Multiple A-IoT device IDs Multiple A-IoT device IDs

[0189] Regarding the radio resource selection / determination method for D2R transmission of the Ambient IoT terminal described above, how (implicit / explicit / configured / preconfigured) or through which resource (dedicated / shared) D2R transmission is performed can also be defined. Meanwhile, regarding the random access procedure of the Ambient IoT terminal(s), the Slotted-ALOHA random access procedure is adopted as the default. Contention-based (CBRA) and contention-free (CFRA) access procedures for a single terminal, a group of terminals, and all terminals can be defined. Additionally, "4-step", "3-step", and "2-step" random access type procedures based on CBRA and CFRA can also be defined.

[0190] Furthermore, it can be defined what type of random access procedure Ambient IoT terminal(s) will select / determine during the random access process, and what information is required in the paging and R2D messages transmitted by the reader / base station for the random access decision. Additionally, communication methods based on FDM(A), TDM(A), and CDM(A) can be defined in the A-IoT system. Regarding wireless resource allocation, communication support schemes based on frequency, time, or code sequence can be defined.

[0191] Regarding the transmission of A-IoT paging messages, specifications may be defined for the transmission of multiple or subsequent A-IoT paging messages from the same A-IoT service request (e.g., inventory and / or command) received by a reader from a core network. That is, the number of paging message transmissions and / or what information to include within the paging message may be defined. Additionally, what information to include in Msg2 as a response to multiple Msg1s triggered by a single paging message may also be defined.

[0192]

[0193] FIG. 15 is a diagram illustrating a procedure (1500) in which an Ambient IoT terminal performs random access according to one embodiment.

[0194] Referring to FIG. 15, the Ambient IoT terminal can receive terminal ID information, paging opportunity information, and wireless resource-related information from a reader device (S1510).

[0195] An Ambient IoT terminal can receive information necessary to perform a random access procedure from a reader corresponding to a base station or an intermediate node. In one example, terminal ID information, paging opportunities, and wireless resource-related information may be received via paging messages or PRDCH (Physical Reader-to-Device Channel) messages. For example, in addition to paging messages, such information may be received by the Ambient IoT terminal via at least RCI (R2D Control Information), the High (upper) layer, the PHY layer, MAC CE, etc. Furthermore, in another example, some of the terminal ID information, paging opportunity information, and wireless resource-related information may be received via paging messages, while the remaining information may be received via PRDCH messages.

[0196] For example, terminal ID information including terminal IDs for multiple Ambient IoT terminals may be received through a paging message. For example, assuming an 8-bit terminal ID, it may be received in a paging message in the form of {0000 0000, 0000 0001, 0000 0010, 0000 0100, 1010 0000, ...}.

[0197] Wireless resource information may include information regarding wireless resources used to transmit Msg1 for the Ambient IoT terminal to perform a random access procedure. Wireless resource information may include multiple wireless resource information configured to correspond to each of the multiple terminal IDs included in the terminal ID information. In this case, wireless resource information for each terminal may be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information may be configured to be mapped to the terminal ID for each terminal ID.

[0198] It may include the total number of Ambient IoT terminals or terminal IDs. Radio resource info may be information about available candidate / available radio resources. Depending on the communication method, radio resources may be time and / or frequency and / or code information. Total number of radio resource info may be the total number of radio resources or slots.

[0199] Wireless resource-related information may include information regarding the priority order in which multiple wireless resources are assigned to each of the multiple terminal IDs included in the terminal ID information. Resource allocation priority is information indicating the priority when occupying / allocating wireless resources, and may consist of time axis priority and / or frequency axis priority and / or code sequence priority.

[0200] Additionally, wireless resource-related information may include information on a method for determining the wireless resource allocation order of multiple terminal IDs included in the terminal ID information. The resource allocation method is a criterion and method for listing terminal IDs, and may include criteria such as sequential, increasing, decreasing, modulo, and bit size.

[0201] Paging opportunity information may include a value obtained by subtracting the number of paging messages already transmitted from the reader device during a predetermined time interval from the total number of transmissions of paging messages set for a predetermined time interval, or a value obtained by subtracting the number of msg1 received by the reader device during a predetermined time interval from the total number of transmissions. A predetermined time interval is a time interval in which paging messages are transmitted, and may be referred to as a "round" in this disclosure, provided that it is not limited to a specific name.

[0202] That is, the paging opportunity information may include and transmit information regarding the number of paging transmissions remaining per round and information regarding the wireless resources currently being allocated. The information on the number of paging transmissions per round may be the value obtained by subtracting the number of paging transmissions transmitted so far from the total number of paging transmissions reserved.

[0203] For example, the total number of paging messages to be transmitted can be pre-configured by the reader, the A-IoT RAN (Radio Access Network), or the core network. For example, the total number of paging messages to be transmitted can be set based on the number of terminal IDs to be included in the paging messages. Additionally, the reader can count the number of successful paging when receiving a Msg1 transmitted by an A-IoT terminal that has successfully configured the resource.

[0204] For example, if the number of terminal IDs to be included in the paging message is 10, the total number of paging message transmissions per round can be set to 10. Here, if the reader device has transmitted 2 paging messages so far, the remaining number of paging messages in the 3rd paging message to be transmitted can be set to 8.

[0205] Alternatively, the remaining paging count value per round can be set based on the number of times Msg1 has been received, rather than the number of paging messages transmitted so far. For example, if the total number of paging transmissions per round is 10, and the reader receives Msg1 from 4 A-IoT terminals after transmitting a paging message, the remaining paging count value per round is set to 6 and can be received by including it in the next paging message.

[0206] Referring again to FIG. 15, the Ambient IoT terminal determines a wireless resource for performing random access based on terminal ID information, paging opportunity information and wireless resource-related information (S1520), and can start a random access procedure through the determined wireless resource (S1530).

[0207] An Ambient IoT terminal can select time / frequency / code-based wireless resources based on its terminal ID, terminal ID information, resource allocation priority and allocation method, and paging opportunity information. For example, wireless resource information for each terminal can be configured to be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information can be configured to be mapped to the terminal ID for each terminal ID. In this case, the Ambient IoT terminal can explicitly select the wireless resource mapped to its terminal ID.

[0208] The paging opportunity information may further include information regarding wireless resources occupied by other Ambient IoT terminals. In this case, the determined wireless resources may be determined by excluding occupied wireless resources from among the available wireless resources. That is, among the Ambient IoT terminals constituting the paging message, the Ambient IoT terminal IDs that received Msg1 may be excluded, and the terminal ID information may be reconstructed using the Ambient IoT terminal IDs that did not receive Msg1 and included in the paging message for transmission.

[0209] Therefore, only Ambient IoT terminals that failed to acquire wireless resources via paging messages can obtain information on currently remaining paging opportunities. Ambient IoT terminals can attempt to acquire wireless resources in resource areas other than those currently occupied by time, frequency, or code resources. Additionally, they can attempt to acquire a larger amount of wireless resources compared to the size previously attempted. In this case, Ambient IoT terminals that failed to acquire wireless resources in the previous round may attempt to acquire wireless resources in the next round.

[0210] Additionally, the Ambient IoT terminal may increase the amount of wireless resources for performing random access if the number of failed attempts to occupy wireless resources for random access exceeds a predetermined threshold. That is, the Ambient IoT terminal may record / store the failure to occupy wireless resources via paging through count information (allocation_trial_failure). If the count information is higher than the predetermined threshold, the Ambient IoT terminal may determine a larger amount of wireless resources for transmitting Msg1 in order to attempt to occupy a larger amount of wireless resources.

[0211] After selecting a wireless resource, the Ambient IoT terminal can trigger a random access procedure and transmit a D2R(Msg1) message to a reader device. Subsequently, the Ambient IoT terminal can continue to perform a predetermined random access procedure.

[0212] According to this, a method and device for performing a random access procedure in an Ambient IoT environment can be provided. Additionally, A-IoT terminals that failed to be allocated wireless resources can be provided with paging opportunity information or paging failure count information to grant them more opportunities to acquire wireless resources.

[0213] FIG. 16 is a diagram illustrating a procedure (1600) in which a reader performs random access according to one embodiment. The description in FIG. 15 above may be omitted to avoid redundant descriptions, and in this case, the omitted content may be applied substantially the same to the reader as long as it does not contradict the technical concept of the invention.

[0214] Referring to FIG. 16, the reader device can transmit terminal ID information, paging opportunity information, and wireless resource-related information to an Ambient IoT terminal (S1610).

[0215] Reader devices corresponding to base stations or intermediate nodes can transmit information necessary to perform random access procedures to Ambient IoT terminals. In one example, terminal ID information, paging opportunities, and wireless resource-related information may be transmitted via paging messages or PRDCH (Physical Reader-to-Device Channel) messages. For example, in addition to paging messages, such information may be transmitted to Ambient IoT terminals via at least RCI (R2D Control Information), the upper layer, the PHY layer, MAC CE, etc. Furthermore, in another example, some of the terminal ID information, paging opportunity information, and wireless resource-related information may be transmitted via paging messages, while the remaining information may be transmitted via PRDCH messages.

[0216] According to one example, terminal ID information including terminal IDs for multiple Ambient IoT terminals may be transmitted via a paging message. For example, assuming an 8-bit terminal ID, it may be transmitted in a paging message in the form of {0000 0000, 0000 0001, 0000 0010, 0000 0100, 1010 0000, ...}.

[0217] Wireless resource information may include information regarding wireless resources used to transmit Msg1 for the Ambient IoT terminal to perform a random access procedure. Wireless resource information may include multiple wireless resource information configured to correspond to each of the multiple terminal IDs included in the terminal ID information. In this case, wireless resource information for each terminal may be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information may be configured to be mapped to the terminal ID for each terminal ID.

[0218] It may include the total number of Ambient IoT terminals or terminal IDs. Radio resource info may be information about available candidate / available radio resources. Depending on the communication method, radio resources may be time and / or frequency and / or code information. Total number of radio resource info may be the total number of radio resources or slots.

[0219] Wireless resource-related information may include information regarding the priority order in which multiple wireless resources are assigned to each of the multiple terminal IDs included in the terminal ID information. Resource allocation priority is information indicating the priority when occupying / allocating wireless resources, and may consist of time axis priority and / or frequency axis priority and / or code sequence priority.

[0220] Additionally, wireless resource-related information may include information on a method for determining the wireless resource allocation order of multiple terminal IDs included in the terminal ID information. The resource allocation method is a criterion and method for listing terminal IDs, and may include criteria such as sequential, increasing, decreasing, modulo, and bit size.

[0221] Paging opportunity information may include a value obtained by subtracting the number of paging messages already transmitted from the reader device during a predetermined time interval from the total number of transmissions of paging messages set for a predetermined time interval, or a value obtained by subtracting the number of msg1 received by the reader device during a predetermined time interval from the total number of transmissions. A predetermined time interval is a time interval in which paging messages are transmitted, and may be referred to as a "round" in this disclosure, provided that it is not limited to a specific name.

[0222] That is, the paging opportunity information may include and transmit information regarding the number of paging transmissions remaining per round and information regarding the wireless resources currently being allocated. The information on the number of paging transmissions per round may be the value obtained by subtracting the number of paging transmissions transmitted so far from the total number of paging transmissions reserved.

[0223] For example, the total number of paging messages to be transmitted can be pre-configured by the reader, the A-IoT RAN (Radio Access Network), or the core network. For example, the total number of paging messages to be transmitted can be set based on the number of terminal IDs to be included in the paging messages. Additionally, the reader can count the number of successful paging when receiving a Msg1 transmitted by an A-IoT terminal that has successfully configured the resource.

[0224] For example, if the number of terminal IDs to be included in the paging message is 10, the total number of paging message transmissions per round can be set to 10. Here, if the reader device has transmitted 2 paging messages so far, the remaining number of paging messages in the 3rd paging message to be transmitted can be set to 8.

[0225] Alternatively, the remaining paging count value per round can be set based on the number of times Msg1 has been received, rather than the number of paging messages transmitted so far. For example, if the total number of paging transmissions per round is 10, and the reader receives Msg1 from 4 A-IoT terminals after transmitting a paging message, the remaining paging count value per round can be set to 6 and included in the next paging message and transmitted.

[0226] Referring again to FIG. 16, the reader device can perform a random access procedure through a wireless resource determined based on terminal ID information, paging opportunity information and wireless resource-related information (S1620).

[0227] An Ambient IoT terminal can determine time / frequency / code-based wireless resources based on its terminal ID, terminal ID information, resource allocation priority and allocation method, and paging opportunity information. For example, wireless resource information for each terminal can be configured to be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information can be configured to be mapped to the terminal ID for each terminal ID. In this case, the Ambient IoT terminal can explicitly select the wireless resource mapped to its terminal ID.

[0228] The paging opportunity information may further include information regarding wireless resources occupied by other Ambient IoT terminals. In this case, the determined wireless resources may be determined by excluding the occupied wireless resources from the available wireless resources. That is, among the Ambient IoT terminals constituting the paging message, the reader device may exclude the Ambient IoT terminal ID that received Msg1, reconstruct terminal ID information using the Ambient IoT terminal IDs that did not receive Msg1, and include and transmit it in the paging message.

[0229] Therefore, only Ambient IoT terminals that failed to acquire wireless resources via paging messages can obtain information on currently remaining paging opportunities. Ambient IoT terminals can attempt to acquire wireless resources in resource areas other than those currently occupied by time, frequency, or code resources. Additionally, they can attempt to acquire a larger amount of wireless resources compared to the size previously attempted. In this case, Ambient IoT terminals that failed to acquire wireless resources in the previous round may attempt to acquire wireless resources in the next round.

[0230] Additionally, the Ambient IoT terminal may increase the amount of wireless resources for performing random access if the number of failed attempts to occupy wireless resources for random access exceeds a predetermined threshold. That is, the Ambient IoT terminal may record / store the failure to occupy wireless resources via paging through count information (allocation_trial_failure). If the count information is higher than the predetermined threshold, the Ambient IoT terminal may determine a larger amount of wireless resources for transmitting Msg1 in order to attempt to occupy a larger amount of wireless resources.

[0231] After determining a wireless resource, the Ambient IoT terminal can trigger a random access procedure and transmit a D2R (Msg1) message. The reader device can transmit an R2D (Msg2) message in response to the D2R message received from the Ambient IoT terminal. Subsequently, the reader device can continue to perform a predetermined random access procedure with the Ambient IoT terminal.

[0232] According to this, a method and device for performing a random access procedure in an Ambient IoT environment can be provided. Additionally, A-IoT terminals that failed to be allocated wireless resources can be provided with paging opportunity information or paging failure count information to grant them more opportunities to acquire wireless resources.

[0233]

[0234] Hereinafter, each embodiment related to a method for performing a random access procedure in an Ambient IoT environment will be described in detail with reference to the relevant drawings.

[0235] The purpose of the present disclosure is to propose a method for the active acquisition and allocation of wireless resources by A-IoT device(s) in an Ambient IoT environment that supports FDM(A), TDM(A), or CDM(A)-based wireless communication between a base station / reader and an Ambient IoT device or between a reader / intermediate node and an Ambient IoT device. Specifically, for wireless access, an A-IoT device must transmit Msg1 (D2R, Device-to-Reader) to a reader, base station, or intermediate node, and at this time, the A-IoT device must select a wireless resource. In this case, in the CBRA procedure, access can only be obtained by successfully acquiring the resource in competition, but resource allocation may inevitably fail. In the CFRA procedure as well, A-IoT devices may fail to select a wireless resource due to coverage and other environmental issues. Accordingly, the present disclosure provides a method for providing A-IoT devices that have failed to be allocated wireless resources with paging opportunity information to give them more opportunities to acquire wireless resources. Additionally, the reader proposes a method for allocating more paging occasions and / or access occasions to A-IoT device(s) that have failed to paging, based on paging failure count information.

[0236] The present disclosure provides a method for active wireless resource occupation / allocation by A-IoT device(s) based on a reader's paging opportunity and paging occasion counters. By including paging opportunity information in an A-IoT paging message and / or R2D message transmitted by a Reader, base station, or intermediate node [hereinafter, Reader] to an A-IoT device(s), the A-IoT device(s) that receives the message may attempt to occupy / allocate more wireless resources than before among available resources for active resource occupation / allocation and transmit Msg1.

[0237] In the present disclosure, by providing paging opportunity information remaining in an A-IoT paging (R2D) message transmitted by a reader to an A-IoT device(s), an A-IoT device(s) that failed to occupy / allocate wireless resources can attempt to occupy and allocate a larger amount of wireless resources than before and can transmit Msg1 through said resources.

[0238] To this end, the reader can count the number of remaining paging occasions in the current round based on the total number of paging messages to be transmitted per round, and transmit them to the A-IoT device via a paging message. For example, if the total number of paging messages transmitted per round is n and 2 paging messages have been transmitted so far, the 3rd paging message can be transmitted including n-2 paging opportunity values.

[0239] Alternatively, based on the total number of paging transmissions (m) independent of the round, if the reader has sent 5 paging messages in the current round, it may send the 3rd paging message containing n-5 paging opportunity values. That is, by counting the remaining paging occasions and delivering them to the A-IoT device(s) via paging messages, the A-IoT device(s) that failed to acquire / allocate resources may attempt to acquire and allocate resources more actively than before.

[0240] In addition, the paging opportunity may include information regarding time, frequency, and code resources currently occupied by other A-IoT device(s), in addition to the number of opportunities. Therefore, an A-IoT device(s) that has successfully secured / allocated a wireless resource via paging messages can transmit Msg1 (D2R) to a reader that includes the time, frequency, and code resource information it has allocated. Upon receiving this information, the reader transmits the information to an A-IoT device(s) that failed to secure / allocate a wireless resource via paging. Consequently, the receiving A-IoT device(s) attempt to secure / allocate a resource while avoiding the relevant wireless resource, thereby enabling them to transmit Msg1.

[0241] FIGS. 17 and 18 are drawings illustrating an Ambient IoT topology according to one embodiment. In addition, the aforementioned topologies 3 and 4 are also applicable.

[0242] FIGS. 19 to 21 are drawings for illustrating random access procedures according to one embodiment. FIGS. 19, 20, and 21 are examples of 3-step (or 4-step) RA and 2-step RA procedures.

[0243] FIG. 19 illustrates an example of a 3-step RA procedure in A-IoT. Here, Msg 4 is a message for handling failure of reception of Msg3 by the Reader, and it may not necessarily be a message that requires transmission or reception. If transmission or reception of Msg 4 is required, the Reader / base station transmits Msg 4 to the A-IoT device(s), and this can be assumed to be a 4-step RA procedure. FIG. 20 illustrates a 2-step RA procedure, and FIG. 21 illustrates a contention-free RA example. The present disclosure is applicable to any procedure in which A-IoT device ID(s) information and / or radio resource information is included in the paging message.

[0244] In the present disclosure, as shown in FIGS. 19, 20, and 21, new paging opportunity information may be included and transmitted in a paging message. The paging opportunity information may be configured as follows.

[0245] Paging opportunity {# of remaining paging per round {n-1}, allocation resource info {...}, ...}

[0246] The paging opportunity information within the paging message received by the A-IoT device(s) from the Reader may include "remaining paging transmission count per round" information and "currently allocated wireless resource information." The "remaining paging transmission count per round" information may be the value obtained by subtracting the number of paging transmissions made so far from the total number of paging transmissions reserved.

[0247] The total number of paging messages to be transmitted can be pre-configured by the reader, A-IoT RAN, or Core network. For example, the total number of paging messages to be transmitted can be set based on the number of A-IoT device IDs to be included in the paging messages. Additionally, the reader can count the number of successful paging when receiving a Msg1 transmitted by an A-IoT device(s) that has successfully configured the resource.

[0248] Therefore, if the number of A-IoT Device IDs to be included in the paging message is 10, the total number of paging transmissions per round can be set to 10. Here, if 2 paging messages have been transmitted so far, the number of remaining paging attempts in the 3rd paging message, i.e., the number of remaining paging per round in the paging opportunity, can be set to 8 and transmitted.

[0249] In addition, the # of remaining paging per round value can be set based on the number of times Msg1 has been received, rather than the number of paging messages transmitted so far. For example, if the total number of paging transmissions per round is 10 and the reader receives Msg1 from 4 A-IoT device(s) after transmitting a paging message, the # of remaining paging per round value can be set to 6 and included in the next paging message. In this case, the A-IoT device ID info constituting the paging message can exclude the A-IoT device IDs that received Msg1, and the A-IoT device ID info can be reconstructed using the A-IoT device ID(s) that did not receive Msg1, and included in the paging message for transmission.

[0250] Therefore, only A-IoT device(s) that failed to acquire / allocate wireless resources via paging messages can obtain the currently remaining paging opportunity information. The A-IoT device(s) that have acquired the above information can attempt to acquire / allocate wireless resources in resource areas other than the currently occupied / allocated time / frequency / code resource information. Additionally, they can attempt to acquire / allocate a larger amount of wireless resources compared to the size of wireless resources previously attempted. In this case, A-IoT device(s) that failed to acquire wireless resources in the previous round can attempt to acquire / allocate wireless resources in the next round. Such A-IoT device(s) can record / store that they failed to acquire / allocate wireless resources via paging through new count information (allocation_trial_failure). If the above new count information is higher than a threshold, the A-IoT device(s) can attempt to acquire / allocate a larger amount of wireless resources using that information.

[0251] FIGS. 22 and 23 are diagrams illustrating the operation following the reception of a paging message in each round according to one embodiment. FIGS. 22 and 23 are embodiments of A-IoT paging and Msg1 and Msg2 flows considering the CBRA procedure between [A-IoT device] and [Reader] discussed so far. FIG. 22 illustrates the operation in the event of a transmission failure of Msg1, based on the premise that a paging message is transmitted per terminal, and FIG. 23 illustrates the operation in the event of a transmission failure of Msg1, based on the premise that one paging message is transmitted for one round. However, the technical concept of the present disclosure is substantially applicable to other embodiments defined in 3gpp in addition to the aforementioned embodiments. The operation described below can be substantially applied in the case of FIGS. 22 and 23.

[0252] [A-IoT Device Operation]

[0253] - 1. An A-IoT device obtains information by receiving and decoding at least the following messages in addition to paging messages from a base station / Reader or an intermediate node / Reader.

[0254] The A-IoT device ID within an A-IoT paging message contains one or more A-IoT device ID information and can be configured in the form of bits.

[0255] Only the Device ID itself may be transmitted, or time / frequency / code-based resource information may be configured by mapping it to each Device ID. Upon receiving this, A-IoT device(s) can explicitly select the resources.

[0256] In addition, the total number of A-IoT Devices or Device IDs may also be included.

[0257] As mentioned above, the paging opportunity may include the number of paging transmissions remaining to date and information on wireless resources currently occupied by other devices.

[0258] As described above, the # of remaining paging opportunity in the message may be a value obtained by subtracting the number of paging attempts sent so far from the total number of paging attempts reserved, or by subtracting the count of Msg1 reception attempts sent by A-IoT device(s) that received the paging attempt.

[0259] As mentioned above, the message may include information about wireless resources currently occupied by other A-IoT device(s).

[0260] In addition to the paging message, the above information can be delivered to the A-IoT device(s) by newly defining at least the RCI (R2D Control Information), High (upper) layer, PHY layer, MAC CE, preamble, midamble, and postamble in the message.

[0261] - 2. A-IoT device(s) occupy / allocate wireless resources based on the information in the paging message above.

[0262] As described above, based on the wireless resource occupation / allocation attempt count information, the A-IoT device(s) can attempt to occupy / allocate a larger amount of wireless resources than before if the count is higher than the threshold.

[0263] - 3. After wireless resource allocation, the A-IoT device(s) trigger a random access procedure and transmit a D2R (msg1) message.

[0264] [Reader / Base Station or Reader / Intermediate Node Operation]

[0265] - 1. The Reader transmits to the A-IoT device(s) information necessary for the allocation of wireless resources to A-IoT devices, including paging opportunities and at least the following messages in addition to the paging message.

[0266] As mentioned above, the message may include paging opportunity information.

[0267] Examples of message and information region candidates that may include the above information:

[0268] Paging message, RCI (R2D Control Information), High (upper) layer, PHY layer, MAC CE, preamble, midamble, postamble

[0269] - 2. The Reader sends R2D(msg2) in response to the D2R message received from the A-IoT device(s).

[0270] The present disclosure provides a method for providing A-IoT devices that have failed to be allocated wireless resources with paging opportunity information to give them more opportunities to acquire wireless resources. Additionally, the reader proposes a method for allocating more paging occasions and / or access occasions to A-IoT device(s) that have failed to paging, based on paging failure count information.

[0271] With respect to the aforementioned embodiments, each embodiment is included within the scope of the invention according to the present disclosure not only in independent cases but also in all cases comprising combinations of embodiments.

[0272]

[0273] Hereinafter, the configuration of an Ambient IoT terminal and a reader device capable of performing some or all of the embodiments described with reference to FIGS. 1 to 23 will be described with reference to the drawings. The foregoing description may be omitted to avoid redundant descriptions, and in such cases, the omitted content may be applied substantially identically to the following description, provided that it does not contradict the technical concept of the invention.

[0274] FIG. 24 is a diagram showing the configuration of an Ambient IoT terminal (2400) according to another embodiment.

[0275] Referring to FIG. 24, an Ambient IoT terminal (2400) according to another embodiment includes a transmitter (2420), a receiver (2430), and a control unit (2410) that controls the operation of the transmitter and the receiver.

[0276] The control unit (2410) controls the overall operation of the terminal (2400) according to the method of performing a random access procedure necessary to perform the above-described invention.

[0277] The control unit (2410) can receive terminal ID information, paging opportunity information, and wireless resource-related information from a reader device. The control unit (2410) can receive information necessary to perform a random access procedure from a reader corresponding to a base station or an intermediate node. According to one example, the terminal ID information, paging opportunity, and wireless resource-related information may be received via a paging message or a PRDCH (Physical Reader-to-Device Channel) message. For example, in addition to the paging message, the information may be received at an Ambient IoT terminal via at least RCI (R2D Control Information), a High (upper) layer, a PHY layer, MAC CE, etc. Also, according to another example, some of the terminal ID information, paging opportunity information, and wireless resource-related information may be received via a paging message, and the remaining information may be received via a PRDCH message.

[0278] According to one example, terminal ID information including terminal IDs for multiple Ambient IoT terminals can be received through a paging message.

[0279] Wireless resource information may include information regarding wireless resources used to transmit Msg1 for the Ambient IoT terminal to perform a random access procedure. Wireless resource information may include multiple wireless resource information configured to correspond to each of the multiple terminal IDs included in the terminal ID information. In this case, wireless resource information for each terminal may be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information may be configured to be mapped to the terminal ID for each terminal ID.

[0280] It may include the total number of Ambient IoT terminals or terminal IDs. Radio resource info may be information about available candidate / available radio resources. Depending on the communication method, radio resources may be time and / or frequency and / or code information. Total number of radio resource info may be the total number of radio resources or slots.

[0281] Wireless resource-related information may include information regarding the priority order in which multiple wireless resources are assigned to each of the multiple terminal IDs included in the terminal ID information. Resource allocation priority is information indicating the priority when occupying / allocating wireless resources, and may consist of time axis priority and / or frequency axis priority and / or code sequence priority.

[0282] Additionally, wireless resource-related information may include information on a method for determining the wireless resource allocation order of multiple terminal IDs included in the terminal ID information. The resource allocation method is a criterion and method for listing terminal IDs, and may include criteria such as sequential, increasing, decreasing, modulo, and bit size.

[0283] Paging opportunity information may include a value obtained by subtracting the number of paging messages already transmitted from the reader device during a predetermined time interval from the total number of transmissions of paging messages set for a predetermined time interval, or a value obtained by subtracting the number of msg1 received by the reader device during a predetermined time interval from the total number of transmissions. A predetermined time interval is a time interval in which paging messages are transmitted, and may be referred to as a "round" in this disclosure, provided that it is not limited to a specific name.

[0284] That is, the paging opportunity information may include and transmit information regarding the number of paging transmissions remaining per round and information regarding the wireless resources currently being allocated. The information on the number of paging transmissions per round may be the value obtained by subtracting the number of paging transmissions transmitted so far from the total number of paging transmissions reserved.

[0285] For example, the total number of paging messages to be transmitted can be pre-configured by the reader, the A-IoT RAN (Radio Access Network), or the core network. For example, the total number of paging messages to be transmitted can be set based on the number of terminal IDs to be included in the paging messages. Additionally, the reader can count the number of successful paging when receiving a Msg1 transmitted by an A-IoT terminal that has successfully configured the resource.

[0286] Alternatively, the remaining paging count per round can be set based on the number of times Msg1 has been received, rather than the number of paging messages sent so far.

[0287] The control unit (2410) can determine a wireless resource for performing random access based on terminal ID information, paging opportunity information, and wireless resource-related information, and can start a random access procedure through the determined wireless resource. The control unit (2410) can determine a time / frequency / code-based wireless resource based on its own terminal ID, terminal ID information, resource allocation priority and allocation method, etc., and paging opportunity information. According to one example, wireless resource information for each terminal can be configured to be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information can be configured to be mapped to the terminal ID for each terminal ID. In this case, the control unit (2410) can explicitly select the wireless resource mapped to its own terminal ID.

[0288] The paging opportunity information may further include information regarding wireless resources occupied by other Ambient IoT terminals. In this case, the determined wireless resources may be determined by excluding occupied wireless resources from among the available wireless resources. That is, among the Ambient IoT terminals constituting the paging message, the Ambient IoT terminal IDs that received Msg1 may be excluded, and the terminal ID information may be reconstructed using the Ambient IoT terminal IDs that did not receive Msg1 and included in the paging message for transmission.

[0289] Therefore, only the Ambient IoT terminal that failed to occupy wireless resources via the paging message can obtain the currently remaining paging opportunity information. The control unit (2410) may attempt to occupy wireless resources in resource areas other than the currently occupied time / frequency / code resource information. Additionally, it may attempt to occupy a larger amount of wireless resources compared to the size of the wireless resources previously attempted. In this case, the Ambient IoT terminal that failed to occupy wireless resources in the previous round may attempt to occupy wireless resources in the next round.

[0290] Additionally, the control unit (2410) may increase the amount of wireless resources for performing random access when the number of failed attempts to occupy wireless resources for performing random access exceeds a predetermined threshold. That is, the Ambient IoT terminal may record / store that it failed to occupy wireless resources through paging via count information (allocation_trial_failure). If the count information is higher than a predetermined threshold, the Ambient IoT terminal may determine a larger amount of wireless resources for transmitting Msg1 in order to attempt to occupy a larger amount of wireless resources.

[0291] After selecting a wireless resource, the control unit (2410) can trigger a random access procedure and transmit a D2R (Msg1) message to a reader device. Subsequently, the Ambient IoT terminal can continue to perform a predetermined random access procedure.

[0292] According to this, a method and device for performing a random access procedure in an Ambient IoT environment can be provided. Additionally, A-IoT terminals that failed to be allocated wireless resources can be provided with paging opportunity information or paging failure count information to grant them more opportunities to acquire wireless resources.

[0293] FIG. 25 is a drawing showing the configuration of a reader device (2500) according to another embodiment.

[0294] Referring to FIG. 25, a reader device (2500) according to another embodiment includes a transmitter (2520), a receiver (2530), and a control unit (2510) that controls the operation of the transmitter and the receiver.

[0295] The control unit (2510) controls the operation of the overall reader device (2500) according to the method of performing a random access procedure necessary to perform the above-described invention. The transmitting unit (2520) transmits R2D messages, etc. to an Ambient IoT terminal through a predetermined channel. The receiving unit (2530) receives D2R messages, etc. from the Ambient IoT terminal through a predetermined channel.

[0296] The control unit (2510) can transmit terminal ID information, paging opportunity information, and wireless resource-related information to the Ambient IoT terminal. The control unit (2510) can transmit information necessary to perform a random access procedure to the Ambient IoT terminal. According to one example, the terminal ID information, paging opportunity, and wireless resource-related information may be transmitted via a paging message or a PRDCH (Physical Reader-to-Device Channel) message. For example, in addition to the paging message, such information may be transmitted to the Ambient IoT terminal via at least RCI (R2D Control Information), a High (upper) layer, a PHY layer, MAC CE, etc. Additionally, according to another example, some of the terminal ID information, paging opportunity information, and wireless resource-related information may be transmitted via the paging message, and the remaining information may be transmitted via the PRDCH message.

[0297] For example, terminal ID information including terminal IDs for multiple Ambient IoT terminals can be transmitted via a paging message.

[0298] Wireless resource information may include information regarding wireless resources used to transmit Msg1 for the Ambient IoT terminal to perform a random access procedure. Wireless resource information may include multiple wireless resource information configured to correspond to each of the multiple terminal IDs included in the terminal ID information. In this case, wireless resource information for each terminal may be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information may be configured to be mapped to the terminal ID for each terminal ID.

[0299] It may include the total number of Ambient IoT terminals or terminal IDs. Radio resource info may be information about available candidate / available radio resources. Depending on the communication method, radio resources may be time and / or frequency and / or code information. Total number of radio resource info may be the total number of radio resources or slots.

[0300] Wireless resource-related information may include information regarding the priority order in which multiple wireless resources are assigned to each of the multiple terminal IDs included in the terminal ID information. Resource allocation priority is information indicating the priority when occupying / allocating wireless resources, and may consist of time axis priority and / or frequency axis priority and / or code sequence priority.

[0301] Additionally, wireless resource-related information may include information on a method for determining the wireless resource allocation order of multiple terminal IDs included in the terminal ID information. The resource allocation method is a criterion and method for listing terminal IDs, and may include criteria such as sequential, increasing, decreasing, modulo, and bit size.

[0302] Paging opportunity information may include a value obtained by subtracting the number of paging messages already transmitted from the reader device during a predetermined time interval from the total number of transmissions of paging messages set for a predetermined time interval, or a value obtained by subtracting the number of msg1 received by the reader device during a predetermined time interval from the total number of transmissions. A predetermined time interval is a time interval in which paging messages are transmitted, and may be referred to as a "round" in this disclosure, provided that it is not limited to a specific name.

[0303] That is, the paging opportunity information may include and transmit information regarding the number of paging transmissions remaining per round and information regarding the wireless resources currently being allocated. The information on the number of paging transmissions per round may be the value obtained by subtracting the number of paging transmissions transmitted so far from the total number of paging transmissions reserved.

[0304] For example, the total number of paging messages to be transmitted can be pre-configured by the reader, the A-IoT RAN (Radio Access Network), or the core network. For example, the total number of paging messages to be transmitted can be set based on the number of terminal IDs to be included in the paging messages. Additionally, the reader can count the number of successful paging when receiving a Msg1 transmitted by an A-IoT terminal that has successfully configured the resource.

[0305] Alternatively, the remaining paging count per round can be set based on the number of times Msg1 has been received, rather than the number of paging messages sent so far.

[0306] The control unit (2510) can perform a random access procedure through a wireless resource determined based on terminal ID information, paging opportunity information, and wireless resource-related information. An Ambient IoT terminal can determine a time / frequency / code-based wireless resource based on its own terminal ID, terminal ID information, resource allocation priority and allocation method, etc., and paging opportunity information. According to one example, wireless resource information for each terminal can be configured to be mapped to the terminal ID of each terminal. That is, time / frequency / code-based resource information can be configured to be mapped to the terminal ID for each terminal ID. In this case, the Ambient IoT terminal can explicitly select the wireless resource mapped to its own terminal ID.

[0307] The paging opportunity information may further include information regarding wireless resources occupied by other Ambient IoT terminals. In this case, the determined wireless resources may be determined by excluding the occupied wireless resources from the available wireless resources. That is, the control unit (2510) may exclude the Ambient IoT terminal ID that received Msg1 among the Ambient IoT terminals constituting the paging message, reconstruct terminal ID information using the Ambient IoT terminal ID that did not receive Msg1, and include it in the paging message for transmission.

[0308] Therefore, only Ambient IoT terminals that failed to acquire wireless resources via paging messages can obtain information on currently remaining paging opportunities. Ambient IoT terminals can attempt to acquire wireless resources in resource areas other than those currently occupied by time, frequency, or code resources. Additionally, they can attempt to acquire a larger amount of wireless resources compared to the size previously attempted. In this case, Ambient IoT terminals that failed to acquire wireless resources in the previous round may attempt to acquire wireless resources in the next round.

[0309] Additionally, the Ambient IoT terminal may increase the amount of wireless resources for performing random access if the number of failed attempts to occupy wireless resources for random access exceeds a predetermined threshold. That is, the Ambient IoT terminal may record / store the failure to occupy wireless resources via paging through count information (allocation_trial_failure). If the count information is higher than the predetermined threshold, the Ambient IoT terminal may determine a larger amount of wireless resources for transmitting Msg1 in order to attempt to occupy a larger amount of wireless resources.

[0310] After determining a wireless resource, the Ambient IoT terminal can trigger a random access procedure to transmit a D2R (Msg1) message. The control unit (2510) can transmit an R2D (Msg2) message in response to the D2R message received from the Ambient IoT terminal. Subsequently, the control unit (2510) can continue to perform a predetermined random access procedure with the Ambient IoT terminal.

[0311] According to this, a method and device for performing a random access procedure in an Ambient IoT environment can be provided. Additionally, A-IoT terminals that failed to be allocated wireless resources can be provided with paging opportunity information or paging failure count information to grant them more opportunities to acquire wireless resources.

[0312] The aforementioned embodiments may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP, and 3GPP2. That is, steps, configurations, and parts in the embodiments that are not described to clearly reveal the technical concept may be supported by the aforementioned standard documents. Furthermore, all terms disclosed in this specification may be explained by the standard documents disclosed above.

[0313] The embodiments described above may be implemented through various means. For example, the embodiments may be implemented by hardware, firmware, software, or a combination thereof.

[0314] In the case of implementation by hardware, the method according to the embodiments may be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, or microprocessors.

[0315] In the case of implementation by firmware or software, the method according to the embodiments may be implemented in the form of a device, procedure, or function that performs the functions or operations described above. Software code may be stored in a memory unit and executed by a processor. The memory unit may be located inside or outside the processor and may exchange data with the processor by various means already known.

[0316] Additionally, terms such as "system," "processor," "controller," "component," "module," "interface," "model," or "unit" described above may generally refer to computer-related entities, hardware, combinations of hardware and software, software, or running software. For example, the aforementioned components may be, but are not limited to, processes driven by a processor, processors, controllers, control processors, objects, execution threads, programs, and / or computers. For example, both the application running on the controller or processor and the controller or processor may be components. One or more components may reside within a process and / or execution thread, and the components may be located on a single device (e.g., a system, a computing device, etc.) or distributed across two or more devices.

[0317] The foregoing description is merely an illustrative explanation of the technical concept of the present disclosure, and those skilled in the art to which the present disclosure pertains may make various modifications and variations within the scope of the essential characteristics of the technical concept. Furthermore, since these embodiments are intended to explain, not limit, the scope of the technical concept is not limited by these embodiments. The scope of protection of the present disclosure shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present disclosure.

[0318]

[0319] CROSS-REFERENCE TO RELATED APPLICATION

[0320] This patent application claims priority pursuant to Section 119(a) of the U.S. Patent Act (35 USC § 119(a)) to Patent Application No. 10-2024-0133890 filed in Korea on October 2, 2024 and Patent Application No. 10-2025-0143891 filed in Korea on October 1, 2025, all of which are incorporated by reference into this patent application. Furthermore, this patent application claims priority in countries other than the United States for the same reasons as above, all of which are incorporated by reference into this patent application.

Claims

1. A method for an ambient IoT terminal to perform a random access procedure, A step of receiving terminal ID information, paging opportunity information, and wireless resource-related information from a reader device; A step of determining a wireless resource for performing random access based on the terminal ID information, the paging opportunity information, and the wireless resource-related information; and A method comprising the step of initiating a random access procedure through the wireless resources determined above.

2. In Paragraph 1, The above paging opportunity information is, A method comprising a value obtained by subtracting the number of paging messages already transmitted from the reader device in the predetermined time interval from the total number of transmissions of paging messages set for the predetermined time interval, or a value obtained by subtracting the number of Msg1 received by the reader device in the predetermined time interval from the total number of transmissions.

3. In Paragraph 1, The above paging opportunity information is, Includes information about wireless resources occupied by other Ambient IoT terminals, and The wireless resources determined above are, A method for determining the above-mentioned occupied wireless resources among available wireless resources.

4. In Paragraph 1, The step of determining a wireless resource for performing the above random access is, A method for increasing the amount of wireless resources for performing the random access when the number of failed attempts to occupy the wireless resources for performing the random access exceeds a predetermined threshold.

5. In Paragraph 1, The above terminal ID information, the above paging opportunity information, and the above wireless resource-related information are, A method of receiving via paging messages or PRDCH (Physical Reader-to-Device Channel) messages.

6. A method in which a reader device performs a random access procedure, A step of transmitting terminal ID information, paging opportunity information, and wireless resource-related information to an Ambient IoT terminal; and A method comprising the step of performing a random access procedure through a wireless resource determined based on the terminal ID information, the paging opportunity information, and the wireless resource-related information.

7. In Paragraph 6, The above paging opportunity information is, A method comprising a value obtained by subtracting the number of paging messages already transmitted from the reader device in the predetermined time interval from the total number of transmissions of paging messages set for the predetermined time interval, or a value obtained by subtracting the number of Msg1 received by the reader device in the predetermined time interval from the total number of transmissions.

8. In Paragraph 6, The above paging opportunity information is, Includes information about wireless resources occupied by other Ambient IoT terminals, and The wireless resources determined above are, A method for determining the available wireless resources excluding the occupied wireless resources.

9. In Paragraph 6, The wireless resources determined above are, A method for determining an increased amount when the number of failed attempts to occupy the wireless resource determined above exceeds a predetermined threshold.

10. In Paragraph 6, The above terminal ID information, the above paging opportunity information, and the above wireless resource-related information are, A method transmitted via paging messages or PRDCH (Physical Reader-to-Device Channel) messages.

11. In an Ambient IoT terminal performing a random access procedure, Transmitter; Receiver; and It includes a control unit that controls the operation of the transmitting unit and the receiving unit, and The above control unit is, A terminal that receives terminal ID information, paging opportunity information, and wireless resource-related information from a reader device, determines a wireless resource for performing random access based on the terminal ID information, paging opportunity information, and wireless resource-related information, and starts a random access procedure through the determined wireless resource.

12. In Paragraph 11, The above paging opportunity information is, A terminal comprising a value obtained by subtracting the number of paging messages already transmitted from the reader device in the predetermined time interval from the total number of transmissions of paging messages set for the predetermined time interval, or a value obtained by subtracting the number of Msg1 received by the reader device in the predetermined time interval from the total number of transmissions.

13. In Paragraph 11, The above paging opportunity information is, Includes information about wireless resources occupied by other Ambient IoT terminals, and The wireless resources determined above are, A terminal determined from available wireless resources, excluding the occupied wireless resources mentioned above.

14. In Paragraph 11, The above control unit is, A terminal that increases the amount of wireless resources for performing the random access when the number of failed attempts to occupy the wireless resources for performing the random access exceeds a predetermined threshold.

15. In Paragraph 11, The above terminal ID information, the above paging opportunity information, and the above wireless resource-related information are, A terminal that receives via paging messages or PRDCH (Physical Reader-to-Device Channel) messages.

Images