Method for controlling random access procedure of ambient internet of things apparatus and device thereof

Abstract

A method by which an ambient IoT terminal performs a random access procedure and a device may be provided, the method comprising the steps of: receiving, from a reader device, an access occasion resource configuration message including one or more pieces of resource information and resource index information configured to correspond to the resource information; transmitting message 1 to the reader device through transmission resource information selected from among the one or more pieces of resource information; and monitoring message 2 including response information for message 1 in a monitoring window configured on the basis of the transmission resource index information configured to correspond to the transmission resource information.

Description

Method and apparatus for controlling a random access procedure of an ambient IoT device

[0001] The present disclosure describes a random access operation of an ambient Internet of Things device.

[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] In particular, considering the energy efficiency of IoT devices, specific optimization of the random access procedure capable of establishing communication with the reader device is also required.

[0005] The present disclosure proposes a method and apparatus for controlling random access operations of an ambient Internet of Things device.

[0006] 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 an access occasion resource setting message from a reader device that includes one or more resource information and resource index information set corresponding to the resource information; transmitting message 1 to the reader device through transmission resource information selected from one or more resource information; and monitoring message 2 that includes response information for message 1 in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

[0007] In another aspect, the present embodiments may provide a method for a reader device to control a random access procedure of an ambient IoT terminal, comprising the steps of: transmitting an access occasion resource setting message to the ambient IoT terminal, the message including one or more resource information and resource index information set corresponding to the resource information; receiving a message 1 from the ambient IoT terminal through a transmission resource information selected from one or more resource information; and transmitting a message 2 to the ambient IoT terminal, the message including response information for message 1, in a monitoring window set based on the transmission resource index information set corresponding to the transmission resource information.

[0008] In another aspect, the embodiments may provide an ambient IoT terminal device that performs a random access procedure, comprising: a receiving unit that receives an access occasion resource setting message from a reader device including one or more resource information and resource index information set corresponding to the resource information; a transmitting unit that transmits message 1 to the reader device through transmission resource information selected from one or more resource information; and a control unit that monitors message 2 including response information for message 1 in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

[0009] In another aspect, the embodiments may provide a reader device for controlling a random access procedure of an ambient IoT terminal, comprising: a transmitter that transmits an access occasion resource setting message to the ambient IoT terminal, the message including one or more resource information and resource index information set corresponding to the resource information; and a receiver that receives a message 1 from the ambient IoT terminal through a transmission resource information selected from one or more resource information, wherein the transmitter transmits a message 2 to the ambient IoT terminal, the message including response information for message 1, in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

[0010] The present disclosure may provide a method and apparatus for controlling and completing random access operations of an ambient Internet of Things device.

[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 operation of an ambient IoT terminal device according to one embodiment.

[0019] FIG. 9 is a diagram illustrating the operation of an ambient IoT terminal device according to another embodiment.

[0020] FIG. 10 is a drawing for explaining the operation of a reader device according to one embodiment.

[0021] FIG. 11 is a drawing for explaining the operation of a reader device according to another embodiment.

[0022] FIG. 12 is a diagram illustrating the operation of an ambient IoT terminal performing a random access procedure according to one embodiment.

[0023] FIG. 13 is a diagram illustrating the operation of monitoring message 2 in a monitoring window according to one embodiment.

[0024] FIG. 14 is a diagram illustrating the operation of monitoring message 2 in a monitoring window set in time units according to another embodiment.

[0025] FIG. 15 is a diagram illustrating the configuration of an ambient IoT terminal according to one embodiment.

[0026] FIG. 16 is a diagram illustrating a different reader device configuration in one embodiment.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.).

[0032]

[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, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also indicated in the form of "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 explanation 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 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 be used to refer to gNB or ng-eNB separately as needed.

[0050] <NR 웨이브 폼,뉴머롤러지 및 프레임 구조>

[0051] 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.

[0052] 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.

[0053] 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.

[0054] μsubcarrier intervalCyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0055] 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, 120, and 240 kHz. Additionally, extended CP is applied only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR defines a frame with a length of 10 ms, composed of 10 subframes of equal length of 1 ms. A single frame can be divided into 5 ms half-frames, and each half-frame contains 5 subframes. In the case of a 15 kHz subcarrier spacing, 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.

[0056] 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 spacing. For example, in the case of a numeral with a 15 kHz subcarrier spacing, 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 spacing, 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 spacing.

[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 primary synchronization signal (PSS) and a secondary synchronization signal (SSS) 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 when viewed from the perspective of 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 SSB's PBCH. 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] 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.

[0092]

[0093] The ambient IoT terminal described in this specification may refer to an Internet of Things device. In this disclosure, IoT devices that support battery-less or energy harvesting are described as IoT terminals, terminals, ambient IoT terminals, etc., for the convenience of explanation and should be understood as devices that communicate with other devices. Meanwhile, descriptions such as ambient IoT terminal, IoT terminal, IoT device, terminal, A-IoT, etc., may be understood as referring to the same device.

[0094] In addition, the device that communicates with the aforementioned ambient IoT terminal is described as a reader device or reader, etc.

[0095] Use cases and scenarios for IoT devices that support battery-less or energy harvesting are being studied. Technologies are also being researched to support IoT devices with higher requirements that cannot be met by existing IoT technologies.

[0096] Slotted Aloha can be considered as a data transmission method for A-IoT devices. Slotted Aloha attempts to transmit data from the starting point of a slot based on one or more slots; if one or more devices transmit data simultaneously in the same slot, a collision occurs. In this case, the device that detects the collision selects one of the next slots to retry data transmission.

[0097] To increase resource efficiency, one or more RO (RACH Occasion) or AO (Access Occasion) may be set within a single slot. That is, it provides multiple access methods in the frequency domain as well as resources in the time domain. This means that an A-IoT device can set i*j distinct access occasions using i time resources and j frequency resources in a single time slot resource area, and can select a competing resource based on time and frequency resources.

[0098] Accordingly, the reader device can receive multiple messages 1 (Msg1) from multiple A-IoT devices within a single slot and send message 2 (Msg2) in response.

[0099] For example, Msg 2 can be sent with the following two options. Additionally, a time interval for monitoring Msg 2 may be set according to each Msg 2 sending option.

[0100] For example, a PRDCH for transmitting Msg2 can be transmitted in response to an A-IoT Msg1 received on one device. As another example, a PRDCH for transmitting Msg2 can be transmitted in response to multiple A-IoT Msg1s received on multiple devices.

[0101] Meanwhile, in the case of an A-IoT terminal, there may be instances where Msg 3 is transmitted but the reader device fails to receive it. In such cases, the reader device may retransmit Msg 2 to trigger the retransmission of Msg 3. For example, if Msg 3 is not received by only some of the multiple A-IoT terminals, the reader device may control the retransmission of Msg 3 by retransmitting Msg 2 only to the corresponding terminals.

[0102] The present disclosure proposes an embodiment in which resources based on multiple access methods in the time and frequency domains are set for IoT device(s) transmitting data in a Slotted Aloha manner, and when an IoT device transmits a D2R (i.e., MSG1 or MSG3) message through a single resource, a monitoring interval for monitoring a response message is set based on the resource information that transmitted the D2R.

[0103]

[0104] FIG. 8 is a diagram illustrating the operation of an ambient IoT terminal device according to one embodiment.

[0105] Referring to FIG. 8, a method for an ambient IoT terminal to perform a random access procedure may include the step of receiving an access occasion resource setting message from a reader device, the message including one or more resource information and resource index information set in correspondence with the resource information (S810).

[0106] For example, a connection opportunity resource setting message may include one or more resource information for transmitting Message 1, which is necessary for an ambient IoT terminal to perform a random access procedure through a reader device. Additionally, the connection opportunity resource setting message may include resource index information configured in correspondence with each resource information to identify each resource information. Such a connection opportunity resource setting message may be received from a reader device via PRDCH.

[0107] Meanwhile, the connection opportunity resource setting message may further include at least one of the following: information on the number of resources distinguished on the time axis for one or more resource information, information on the number of resources distinguished on the frequency axis, information on the total number of resources for one or more resource information, minimum time information for setting a monitoring window, maximum time information for setting a monitoring window, and frequency shift information.

[0108] Information on the number of resources distinguished on the time axis can indicate how many resource information for the ambient IoT terminal to transmit Message 1 is composed of on the time axis. Similarly, information on the number of resources distinguished on the frequency axis can indicate how many resource information for the ambient IoT terminal to transmit Message 1 is composed of on the frequency axis. For example, if there are i resources on the time axis and j resources on the frequency axis, the total number of resources can be calculated as i*j. The connection opportunity resource setting message may include information on the total number of resources separately from the number of resources on the time axis and the frequency axis. For example, the total number of resources may be composed of n. As previously mentioned, n can be i*j. That is, the connection opportunity resource setting message may include information on the number of resources on the time axis and information on the number of resources on the frequency axis, or it may include only information on the total number of resources.

[0109] Additionally, the connection opportunity resource setting message may include minimum time information and maximum time information used for setting a monitoring window for an ambient IoT terminal to receive message 2. At least one of the minimum time information and maximum time information may be composed of offset information.

[0110] A method for performing a random access procedure may include the step of transmitting message 1 to a reader device through transmission resource information selected from one or more resource information (S820).

[0111] The ambient IoT terminal can select any connection resource among the connection resources and transmit Message 1 to the reader device. By transmitting Message 1, the random access procedure of the ambient IoT terminal can be performed.

[0112] Message 1 may include terminal identification information of an ambient IoT terminal. Terminal identification information may refer to arbitrary identification information to be used in a random access procedure. That is, terminal identification information may be used to distinguish the ambient IoT terminal from other terminals. For example, terminal identification information may be set to a 16-bit random value. Message 1 is transmitted over one selected access resource among one or more resource information configured on the time axis and the frequency axis. Resource information may be pre-configured for each ambient IoT terminal by a reader device, such as RACH Occasion (RO) or Access Occasion (AO). Message 1 may be transmitted via a PDRCH (Physical Device to Reader Channel).

[0113] A method for performing a random access procedure may include the step of monitoring message 2, which includes response information for message 1, in a monitoring window set based on transmission resource index information set corresponding to transmission resource information (S830).

[0114] For example, an ambient IoT terminal needs to receive message 2 containing response information to message 1. To do this, the ambient IoT terminal monitors message 2 in a monitoring window.

[0115] The monitoring window can have its start and end times set based on transmission resource index information, minimum time information, and maximum time information.

[0116] For example, an ambient IoT terminal can set a monitoring window for receiving message 2 using the transmission resource index information that transmitted message 1. The ambient IoT terminal can use minimum time information and maximum time information to set the start and end points of the monitoring window.

[0117] For example, the reference point for minimum time information and maximum time information may be set to the last time resource on the time axis where one or more resource information is set. Alternatively, the reference point for minimum time information and maximum time information may be set to the last time resource of the transmission resource where message 1 was transmitted.

[0118] For example, an ambient IoT terminal can check a monitoring window using a preset algorithm that takes transmission resource index information, minimum time information, and maximum time information as input parameters.

[0119] For example, a preset algorithm can be set as shown in Equation 1 below.

[0120] [Mathematical Formula 1]

[0121] MSG2 monitoring duration for AO i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0122] i is transmission resource index information, and the minimum time information is T D2R_min and the maximum time information is T D2R_max am.

[0123] For example, an ambient IoT terminal can set a monitoring window by setting the start time when the minimum time information from the reference point has elapsed as the start time, and the end time when the maximum time information from the reference point has elapsed as the end time. To prevent the monitoring window from being duplicated for each terminal, resource index information may be used.

[0124] Meanwhile, the monitoring window may be configured in conjunction with individual transmission resources, or it may be configured based on resource information on the time axis at which the transmission resources are configured.

[0125] In addition, the reference point may be the end point of the transmission resource where Message 1 was transmitted. Or, the reference point may be the end point where all of one or more resource information is terminated.

[0126] Through this, the ambient IoT terminal can perform random access operations by monitoring whether Message 2 is received in a specific monitoring window. In addition, when each ambient IoT terminal uses a different Message 1 transmission resource, energy efficiency can be maximized by monitoring only Message 2 corresponding to the transmitted Message 1 without monitoring every connection opportunity.

[0127] FIG. 9 is a diagram illustrating the operation of an ambient IoT terminal device according to another embodiment.

[0128] Referring to FIG. 9, the method by which an ambient IoT terminal performs a random access procedure may further include the step of sending message 3 to a reader device in response to message 2 when message 2 is received in a monitoring window (S940).

[0129] Step S940 may be performed after steps S810 to S830. Steps S810 to S830 are described with reference to FIG. 8, and a detailed description is omitted to avoid redundant explanation.

[0130] The ambient IoT terminal can receive message 2 in the monitoring window. The ambient IoT terminal can send message 3 to the reader device in response to message 2.

[0131] Message 2 may include terminal identification information included in Message 1. Through this, even when multiple ambient IoT terminals transmit Message 1 on the same connection resource and Message 2 is transmitted in response, each ambient IoT terminal can distinguish and verify them. That is, the correspondence between Message 1 and Message 2 can be confirmed through terminal identification information.

[0132] Message 2 may include information for scheduling Message 3, which the ambient IoT terminal will transmit to the reader device. For example, the scheduling information included in Message 2 may include time and frequency resource information for transmitting Message 3. Alternatively, the scheduling information for Message 3 may be determined based on the transmission resource transmitting Message 1.

[0133] For example, upon receiving Message 2, the ambient IoT terminal can transmit Message 3 to a reader device to complete the random access procedure. Message 3 can be transmitted through wireless resource information specified by the scheduling information included in Message 2.

[0134] Additionally, the method by which the ambient IoT terminal performs a random access procedure may further include the step of monitoring the reception of a retransmission message 2, which is transmitted when the message 3 transmission resource to which message 3 was transmitted is not normally received by the reader device, in a retransmission monitoring window (S950).

[0135] In the random access procedure of an ambient IoT terminal, when Message 3 is transmitted, it is necessary to check whether the reader device has successfully received it. To do this, the reader device does not transmit a separate message indicating ack or nack. However, if Message 3 is not successfully received, the reader device can control the transmission of Message 2 to ensure that Message 3 is transmitted again.

[0136] Therefore, the ambient IoT terminal must monitor whether message 2 is retransmitted even after sending message 3. However, since continuous monitoring can be inefficient in terms of battery consumption, monitoring should be performed within a configured retransmission monitoring window.

[0137] For example, the ambient IoT terminal checks whether message 2 is received in a retransmission monitoring window, which is a set time interval after sending message 3. If message 2 is received, message 3 is retransmitted. If message 2 is not received in the retransmission monitoring window, the ambient IoT terminal can determine that the random access procedure was successful and terminate.

[0138] The retransmission monitoring window can be configured based on message 3 transmission resources, retransmission minimum time information for retransmission monitoring window configuration, and retransmission maximum time information for retransmission monitoring window configuration.

[0139] For example, retransmission minimum time information and retransmission maximum time information may be included in the connection opportunity resource setup message or Message 2. That is, the retransmission minimum time information and retransmission maximum time information for the ambient IoT terminal to monitor Retransmission Message 2 may be included in the connection opportunity resource setup message received initially. As an example, the retransmission minimum time information and retransmission maximum time information may be used with the same values ​​as the minimum time information and maximum time information, respectively. As another example, the retransmission minimum time information and retransmission maximum time information may be set to values ​​distinct from the minimum time information and maximum time information used for the initial transmission of Message 2. As yet another example, the retransmission minimum time information and retransmission maximum time information may be set to offset values ​​or multiple values ​​based on the minimum time information and maximum time information.

[0140] The retransmission monitoring window can be configured as a period starting after the minimum retransmission time has elapsed and extending before the maximum retransmission time, based on the point in time when the message 3 transmission resource that transmitted message 3 is terminated. Alternatively, the retransmission monitoring window may be configured by further utilizing the index information of the message 3 transmission resource. For example, the retransmission monitoring window may be configured as shown in Equation 2 below.

[0141] [Mathematical Formula 2]

[0142] MSG2 monitoring duration for AO i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0143] Here, i can be the transmission resource index of Message 3 or the transmission resource index information of Message 1. T D2R_min represents the minimum retransmission time information, and T D2R_maxcan mean maximum retransmission time information.

[0144] The retransmission monitoring window may be set using the same algorithm as the monitoring window for the initial reception of message 2, or it may be set using a different algorithm.

[0145] Through the above operations, the ambient IoT terminal can monitor and receive the initially transmitted message 2, and also efficiently monitor the retransmitted message 2 corresponding to the transmission of message 3.

[0146] Below, the aforementioned operation is explained with reference to the drawings regarding the reader device.

[0147] FIG. 10 is a drawing for explaining the operation of a reader device according to one embodiment.

[0148] Referring to FIG. 10, a method for a reader device to control a random access procedure of an ambient IoT terminal may include the step of transmitting an access occasion resource setting message to the ambient IoT terminal, the message including one or more resource information and resource index information set in correspondence with the resource information (S1010).

[0149] For example, a connection opportunity resource setting message may include one or more resource information for transmitting Message 1, which is necessary for an ambient IoT terminal to perform a random access procedure through a reader device. Additionally, the connection opportunity resource setting message may include resource index information configured in correspondence with each resource information to identify each resource information. Such a connection opportunity resource setting message may be transmitted via PRDCH.

[0150] Meanwhile, the connection opportunity resource setting message may further include at least one of the following: information on the number of resources distinguished on the time axis for one or more resource information, information on the number of resources distinguished on the frequency axis, information on the total number of resources for one or more resource information, minimum time information for setting a monitoring window, maximum time information for setting a monitoring window, and frequency shift information.

[0151] For example, the information on the total number of resources can consist of n. As previously mentioned, n can be i*j. That is, the connection opportunity resource setting message may include information on the number of resources on the time axis and information on the number of resources on the frequency axis, or it may include only information on the total number of resources.

[0152] Additionally, the connection opportunity resource setting message may include minimum time information and maximum time information used for setting a monitoring window for the ambient IoT terminal to transmit message 2. At least one of the minimum time information and maximum time information may be composed of offset information.

[0153] A method for controlling a random access procedure may include the step of receiving message 1 from an Amberant IoT terminal through transmission resource information selected from one or more resource information (S1020).

[0154] The reader device can receive Message 1 through any connection resource selected from among the connection resources configured in the ambient IoT terminal. By receiving Message 1, a random access procedure of the ambient IoT terminal can be performed.

[0155] Message 1 may include terminal identification information of an ambient IoT terminal. Terminal identification information may refer to arbitrary identification information to be used in a random access procedure. That is, terminal identification information may be used to distinguish the ambient IoT terminal from other terminals. For example, terminal identification information may be set to a 16-bit random value. Message 1 is received on one selected access resource among one or more resource information configured on the time axis and the frequency axis. Resource information may be pre-configured for each ambient IoT terminal by a reader device, such as RACH Occasion (RO) or Access Occasion (AO). Message 1 may be received via a PDRCH (Physical Device to Reader Channel).

[0156] A method for controlling a random access procedure may include the step of transmitting a message 2 containing response information for message 1 to an ambient IoT terminal in a monitoring window set based on transmission resource index information set corresponding to transmission resource information (S1030).

[0157] For example, the reader device must transmit message 2 containing response information for message 1. To do this, the reader device transmits message 2 in a monitoring window monitored by an ambient IoT terminal.

[0158] The monitoring window can have its start and end times set based on transmission resource index information, minimum time information, and maximum time information.

[0159] For example, the reader device can set a monitoring window for sending message 2 using the transmission resource index information from which the ambient IoT terminal sent message 1. The reader device and the ambient IoT terminal can use minimum time information and maximum time information to set the start and end points of the monitoring window.

[0160] For example, the reference point for minimum time information and maximum time information may be set to the last time resource on the time axis where one or more resource information is set. Alternatively, the reference point for minimum time information and maximum time information may be set to the last time resource of the transmission resource where message 1 was transmitted.

[0161] For example, the reader device can check the monitoring window monitored by the ambient IoT terminal using a preset algorithm that takes transmission resource index information, minimum time information, and maximum time information as input parameters.

[0162] The preset algorithm can be set as in the aforementioned mathematical formula 1.

[0163] For example, a reader device can set a monitoring window by setting the point in time when the minimum time information has elapsed from the reference point as the start point, and the point in time when the maximum time information has elapsed from the reference point as the end point. To prevent the monitoring window from being duplicated for each terminal, resource index information may be used.

[0164] Meanwhile, the monitoring window may be configured in conjunction with individual transmission resources, or it may be configured based on resource information on the time axis at which the transmission resources are configured.

[0165] In addition, the reference point may be the end point of the transmission resource where Message 1 was transmitted. Or, the reference point may be the end point where all of one or more resource information is terminated.

[0166] FIG. 11 is a drawing for explaining the operation of a reader device according to another embodiment.

[0167] Referring to FIG. 11, the method for controlling the random access procedure may further include the step of monitoring message 3 (S1140).

[0168] For example, the reader device expects a response to Message 3 following the transmission of Message 2. To this end, the reader device may monitor whether Message 3 has been received. Message 3 may be received through a wireless resource scheduled by Message 2. Alternatively, Message 3 may be received through a resource configured in conjunction with Message 1. To this end, the reader device may include scheduling information for the transmission of Message 3 in Message 2.

[0169] The reader device may determine that the random access procedure of the ambient IoT terminal has been successfully completed when Message 3 is received. If Message 3 is not received through a scheduled resource, the reader device must retransmit Message 2 for the random access procedure of the ambient IoT terminal. This is described as Retransmission Message 2.

[0170] A method for controlling a random access procedure may further include the step of transmitting a retransmission message 2 from a retransmission monitoring window to an ambient IoT terminal if message 3 is not received in response to message 2 (S1150).

[0171] For example, the reader device retransmits retransmission message 2 to the ambient IoT terminal. However, in order for the ambient IoT terminal to receive retransmission message 2, it must monitor whether message 2 has been received at a certain time interval after sending message 3. To do this, the reader device sends retransmission message 2 in the retransmission monitoring window.

[0172] For example, the retransmission monitoring window can be set based on the message 3 transmission resource set for the transmission of message 3, the retransmission minimum time information for setting the retransmission monitoring window, and the retransmission maximum time information for setting the retransmission monitoring window. The reader device can know the message 3 transmission resource set for the transmission of message 3 since message 3 has been scheduled. In addition, the reader device can set the retransmission monitoring window by using the retransmission maximum time information and retransmission minimum time information of the ambient IoT terminal through message 2 or the previous message.

[0173] For example, the retransmission minimum time information and the retransmission maximum time information may be included in the connection opportunity resource setting message or message 2. Alternatively, the retransmission minimum time information and the retransmission maximum time information may be pre-set and configured in the ambient IoT terminal.

[0174] The retransmission minimum time information and retransmission maximum time information for the ambient IoT terminal to monitor retransmission message 2 may be included in the connection opportunity resource setup message received initially. For example, the retransmission minimum time information and retransmission maximum time information may be used with the same values ​​as the minimum time information and maximum time information, respectively. As another example, the retransmission minimum time information and retransmission maximum time information may be set to values ​​distinct from the minimum time information and maximum time information used for the initial transmission of message 2. As yet another example, the retransmission minimum time information and retransmission maximum time information may be set to offset values ​​or multiple values ​​based on the minimum time information and maximum time information.

[0175] The retransmission monitoring window can be configured as a period starting after the minimum retransmission time has elapsed and before the maximum retransmission time, based on the point in time when the message 3 transmission resource that transmitted message 3 is terminated. Alternatively, the retransmission monitoring window may be configured by further utilizing index information of the message 3 transmission resource. For example, the retransmission monitoring window may be configured as in Equation 2 described above.

[0176] The retransmission monitoring window may be set using the same algorithm as the monitoring window for the initial reception of message 2, or it may be set using a different algorithm.

[0177] Through the above operations, the reader device can perform the monitoring window setup and message transmission through the monitoring window necessary to perform the random access procedure of the ambient IoT terminal.

[0178] Below, the operation of the ambient IoT terminal and reader device according to the present disclosure described above is explained in more detail with reference to various embodiments. The embodiments described below may be performed by the ambient IoT terminal and / or reader device through any combination.

[0179]

[0180] In an ambient IoT terminal (A-IoT device), contention resources for MSG1 transmission can be established by considering not only TDMA but also FDMA, and based on this, a data transmission and reception method for the A-IoT device can be performed. If a total of i*j access occasions are established within a single time slot through i time resources and j frequency resources, a reader device that receives two or more MSG1s distinguished by different time / frequency resources can transmit up to i*j different MSG2s in response. The A-IoT device sets an MSG2 monitoring period to receive an MSG2 corresponding to the MSG1 it transmitted, and if it receives an MSG2 that echoes the MSG1 it transmitted during this period, it is considered that contention resolution has been achieved.

[0181] A device that has undergone contention resolution can be allocated dedicated resources for MSG3 via MSG2 or transmit MSG3 using predetermined dedicated resources. An A-IoT device that transmits MSG3 using dedicated resources needs to additionally verify the successful transmission of the MSG3 it sent by checking for retransmission of MSG2 after the MSG3 transmission. Accordingly, there is a need to concretize a method for setting the MSG2 monitoring duration to monitor MSG2 messages that may be transmitted in response to MSG1 or MSG3.

[0182] In particular, a method needs to be defined for the device transmitting MSG1 or MSG3 and the reader receiving MSG1 or MSG3 to implicitly calculate the MSG2 monitoring duration based on each transmitted and received MSG1 / MSG3 without explicit signaling regarding the MSG2 monitoring duration.

[0183] Accordingly, the present disclosure provides various embodiments in which an A-IoT terminal performing a random access procedure through any slot receives a PRDCH that triggers an RA or sets a resource for an RA, and transmits an MSG1 through an arbitrarily selected Access Occasion (AO) based thereon, and sets a corresponding MSG2 monitoring duration based on resource information for the AO selected to transmit the MSG1. The MSG2 monitoring duration may refer to the aforementioned monitoring window or retransmission monitoring window.

[0184] FIG. 12 is a diagram illustrating the operation of an ambient IoT terminal performing a random access procedure according to one embodiment.

[0185] Referring to FIG. 12, an A-IoT terminal can receive a PRDCH from a reader device that includes resource index information for one or more AOs and corresponding resource setting information (S1210).

[0186] For example, resource information (resource configuration information) is index information for resources separated into at least time / frequency domains, and such information can be assigned to resources sequentially through implicit methods or through explicit signaling. Assuming that there are x time domain resources and y frequency domain resources, and that x*y, or a total of n resources, are assigned, resource indices from 0 to (n-1) can be assigned.

[0187] The A-IoT terminal transmits a D2R message from the selected or assigned AO (S1220). For example, the A-IoT terminal may transmit MSG1 from the AO to the reader device. For another example, the A-ToT terminal may transmit MSG3 to the reader device. MSG3 may be transmitted upon receipt of MSG 2.

[0188] An A-IoT terminal can set an MSG2 monitoring interval based on resource index information for a selected or assigned AO (S1230). For example, based on an explicitly / implicitly assigned resource index, the A-IoT device can set a resource index (AO) for the MSG1 it selected. i An MSG2 monitoring interval for receiving a response to MSG1 transmitted based on ) can be set using an arbitrary expression. Mathematical Equation 3 is an example of an expression for setting a monitoring interval.

[0189] [Mathematical Formula 3]

[0190] MSG2 monitoring duration for AO i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0191] Here, i is a resource index for the AO selected by the device to transmit D2R(MSG1), and can have an integer value between 0 and n-1. Here, n is the number of resources configured separately for time and frequency; in the case of x resources in the time domain and y resources in the frequency domain, it means x*y. T D2R_min represents the minimum time interval between the D2R(MSG1) transmission and the R2D(MSG2) transmission transmitted along with it, and T D2R_max represents the maximum time interval between the D2R(MSG1) transmission and the R2D(MSG2) transmission transmitted along with it. Here, T D2R_min and T D2R_max The start time of the MSG1 / MSG3 must be synchronized among the devices that transmitted the MSG1 / MSG3 through an arbitrary reference time.

[0192] To this end, various methods can be applied. For example, among the resource information for a PRDCH containing resource information or one or more AOs included in the PRDCH, T is set with the end of the time resource as the reference point. D2R_min and T D2R_max It is assumed that is calculated. In addition, based on the MSG1 transmitted by the devices, T D2R_min and T D2R_max If calculated, additional signaling may be required to synchronize the starting time of the first MSG2 monitoring between devices that have selected different time domain resources.

[0193] The A-IoT terminal may receive an MSG containing a response to MSG1 transmitted during the monitoring period (S1240). Alternatively, the A-IoT terminal may monitor MSG2 after transmitting MSG3. If a retransmitted MSG2 is received after transmitting MSG3, the A-IoT terminal must retransmit MSG3.

[0194]

[0195] Meanwhile, at least one of the following information may be included in a PRDCH message that triggers an RA or contains D2R resource information (for an RA). Some of the following information may use values ​​defined within the specification, or values ​​specified per device or service may be defined, but it is desirable to use the same values ​​for devices operating within the same round / slot.

[0196] - Number of resources distinguished by time domain (x);

[0197] - Number of resources distinguished by the frequency domain (y);

[0198] - Total number of resources distinguished by time / frequency domain (x*y = n);

[0199] - T D2R_max;

[0200] - T D2R_min ;

[0201] - Frequency shift information;

[0202] - Resource index information for resources classified as T / F resources.

[0203] In addition, the device receiving the information in the present disclosure may set the MSG2 monitoring section using index information for the resource that transmitted MSG3 as well as MSG1. That is, the device receiving MSG2 transmits MSG3 through the dedicated resource indicated / allocated / predefined through MSG2. That is, MSG3 is transmitted based on the resource information allocated in MSG2, and the device transmitting MSG3 sets the monitoring section for MSG2 based on Equation 1 based on the resource index information for MSG3.

[0204] Here, the resource configuration information for MSG3 may be included within MSG2 that triggers MSG3, or it may be configured to use the resource configuration information for MSG1 as is. Alternatively, the resource configuration information for MSG3 may be configured by a PRDCH that includes other resource configuration information. It is evident that operation is possible based on various other D2R resource configurations. At a minimum, a device that receives D2R resource configuration information transmitted by a reader may allocate a dedicated resource for MSG3 through MSG2 that triggers MSG3 based on this information.

[0205] This embodiment sets a separate MSG2 monitoring duration for a device based on index information regarding time and / or frequency for the allocated resources. If there is more than one allocated index, the duration may be set based on the lowest or highest index value among the allocated indices.

[0206] In other words, AO through MSG2 i The device allocated resources for is AO i MSG3 is transmitted through, and the MSG2 monitoring duration for this can also be calculated using the following mathematical formula 4.

[0207] [Mathematical Formula 4]

[0208] MSG2 monitoring duration for AO i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0209] Here, i is a resource index for the AO allocated to the device for transmitting D2R(MSG3), and can have an integer value between 0 and n-1. Here, n is the number of resources configured separately for time and frequency; in the case of x resources in the time domain and y resources in the frequency domain, it means x*y. T D2R_min represents the minimum time interval between the D2R(MSG3) transmission and the R2D(MSG2) transmission transmitted along with it, and T D2R_max represents the maximum time interval between the D2R(MSG3) transmission and the R2D(MSG2) transmission that follows it.

[0210]

[0211] FIG. 13 is a diagram illustrating the operation of monitoring message 2 in a monitoring window according to one embodiment.

[0212] Referring to FIG. 13, it can be assumed that 6r AOs are configured according to PRDCH. In each AO, MSG1 can be transmitted by different A-IoTs. Each A-IoT terminal can monitor MSG2 in the aforementioned monitoring window.

[0213] For example, T for setting the MSG2 monitoring duration D2R_min and T D2R_max It can start based on the end of the last time resource of the configured AO resources. Each duration is set based on the configured AO resource information. This example assumes that the configured AO resources are set once via MSG0 PRDCH, and that six resources from AO#0 to AO#5 are also configured for MSG3. However, if the resource configuration information for MSG3 is transmitted individually or configured dynamically, it is obvious that the reference time for the MSG2 monitoring interval may be set differently based on the configured resource information, the transmitted MSG3, the previously received MSG2, or the previously configured monitoring interval.

[0214] Unlike MSG1, where devices randomly select AOs, resource allocation for MSG3 can be scheduled by the reader; therefore, the reader can perform MSG3 resource scheduling to efficiently manage the wireless resources allocated for the monitoring section. When MSG2 is transmitted for AOs #0~#2, MSG3 can be transmitted by scheduling for three AOs. After MSG3 is transmitted, the A-IoT device monitors MSG2 again.

[0215] That is, if the MSG2 monitoring interval setting after MSG3 transmission is set based on the resource index proposed in this embodiment, it means that by sequentially allocating resources for MSG3 to the AO resource index, the resource setting for the MSG2 monitoring interval can also be set to use the minimum time resources.

[0216] In Fig. 13, MSG2 is transmitted from AO #0, and the corresponding MSG3 is retransmitted. Since MSG2 is not received in the subsequent monitoring section, it can be confirmed that random access to the three A-IoT devices from #0 to #2 was successfully completed.

[0217] Below, the operation of an A-IoT terminal and a reader device according to one embodiment of the present disclosure is described.

[0218] [A-IoT device operation]

[0219] 1. Receive a PRDCH containing D2R resource configuration information. This may be a message that triggers an RA. The received D2R resource information includes at least one of the following.

[0220] A. Total number of resources distinguished by time / frequency domain (x*y = n);

[0221] i. Number of resources distinguished by time domain (x);

[0222] ii. Number of resources distinguished by the frequency domain (y).

[0223] B. Resource index information for resources classified as T / F resources and corresponding time / frequency information.

[0224] i. T D2R_max , T D2R_min Time domain resource information separated by;

[0225] ii. Frequency domain resource information distinguished by frequency shift.

[0226] 2. Randomly select one resource based on the received resource information above.

[0227] 3. Transmit MSG1 through the selected resource above.

[0228] 4. Based on the resource index (i) information for the resource that transmitted MSG1, set the MSG2 monitoring interval using the following formula.

[0229] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0230] 5. Within the time interval set above, receive MSG2 that echoes MSG1 transmitted by the device. The MSG2 contains resource allocation information for MSG3.

[0231] 6. Transmit MSG3 based on the resource allocation information for the received MSG3.

[0232] 7. Set the MSG2 monitoring interval using the following formula based on the resource index (i) for the resource that transmitted MSG3.

[0233] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0234] 8. If the device receives MSG2 that echoes MSG1 transmitted by the device within the time interval set above, it retransmits MSG3 through the resources allocated by MSG2, and if MSG2 is not transmitted, the corresponding RA is considered to have been successfully completed.

[0235] [Reader Action]

[0236] 1. Transmit a PRDCH containing D2R resource configuration information. This may be a message that triggers an RA. The received D2R resource information includes at least one of the following.

[0237] A. Total number of resources distinguished by time / frequency domain (x*y = n);

[0238] i. Number of resources distinguished by time domain (x);

[0239] ii. Number of resources distinguished by the frequency domain (y).

[0240] B. Resource index information for resources classified as T / F resources and corresponding time / frequency information.

[0241] i. T D2R_max , T D2R_min Time domain resource information separated by;

[0242] ii. Frequency domain resource information distinguished by frequency shift.

[0243] 2. Receive MSG1 through one of the resources set above.

[0244] 3. Based on the resource index (i) information for the resource that received MSG1, set the MSG2 monitoring interval using the following formula.

[0245] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0246] 4. Within the time interval set above, transmit MSG2 that echoes MSG1 transmitted by the device. The MSG2 contains resource allocation information for MSG3.

[0247] 5. When MSG3 is successfully received using the resources allocated for the above MSG3,

[0248] A. The relevant RA is considered to have been successfully completed.

[0249] 6. If MSG3 is not successfully received using the resources allocated for the above MSG3,

[0250] A. Set the MSG2 monitoring interval using the following expression based on the resource index (i) for the resource allocated for MSG3.

[0251] i. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0252] B. Within the time interval set above, transmit MSG2 that echoes MSG1 transmitted by the device. The said MSG2 includes resources for retransmitting MSG3.

[0253] Meanwhile, in another embodiment, the same time region (T i You can also set the same monitoring interval for MSG1 or MSG3 transmitted from ).

[0254] FIG. 14 is a diagram illustrating the operation of monitoring message 2 in a monitoring window set in time units according to another embodiment.

[0255] Referring to FIG. 14, the MSG2 monitoring interval can be defined in association with the time resource area that transmitted the MSG1 or MSG3 that triggers it. This can be applied when a response message (MSG2) to MSG1 or MSG3 transmitted in a different frequency area of ​​the same time resource area is responded to through a single PRDCH.

[0256] That is, the monitoring window for the transmission resources set at time T0 from AO #0 to AO #2 is set as a single time interval. Similarly, the monitoring window for the transmission resources set at time T1 is also set as another time interval. In this case, i may be an index for the time interval containing the individual resource, rather than an individual index of the transmission resource.

[0257] Similarly, the monitoring window of the retransmission MSG2 can also be set based on time intervals, as explained above.

[0258] In this regard, the operation of the A-IoT terminal and reader device is explained below.

[0259] [A-IoT device operation]

[0260] 1. Receive a PRDCH containing D2R resource configuration information. This may be a message that triggers an RA. The received D2R resource information includes at least one of the following.

[0261] A. Total number of resources distinguished by time / frequency domain (x*y = n);

[0262] i. Number of resources distinguished by time domain (x);

[0263] ii. Number of resources distinguished by the frequency domain (y).

[0264] B. Resource information classified as T / F resources.

[0265] i. T D2R_max , T D2R_min Time domain resource information separated by and the corresponding time resource index;

[0266] ii. Frequency domain resource information distinguished by frequency shift and corresponding frequency resource index.

[0267] 2. Randomly select one resource based on the received resource information above.

[0268] 3. Transmit MSG1 through the selected resource above.

[0269] 4. Based on the time resource index (i) information for the resource that transmitted MSG1, set the MSG2 monitoring interval using the following formula.

[0270] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0271] 5. Within the time interval set above, receive MSG2 that echoes MSG1 transmitted by the device. The MSG2 contains resource allocation information for MSG3.

[0272] 6. Transmit MSG3 based on the resource allocation information for the received MSG3.

[0273] 7. Based on the time resource index (i) for the resource that transmitted MSG3, set the MSG2 monitoring interval using the following formula.

[0274] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0275] 8. If the device receives MSG2 that echoes MSG1 transmitted by the device within the time interval set above, it retransmits MSG3 through the resources allocated by MSG2, and if MSG2 is not transmitted, the corresponding RA is considered to have been successfully completed.

[0276] [Reader Action]

[0277] 1. Transmit a PRDCH containing D2R resource configuration information. This may be a message that triggers an RA. The received D2R resource information includes at least one of the following.

[0278] A. Total number of resources distinguished by time / frequency domain (x*y = n);

[0279] i. Number of resources distinguished by time domain (x);

[0280] ii. Number of resources distinguished by the frequency domain (y).

[0281] B. Resource information classified as T / F resources.

[0282] i. T D2R_max , T D2R_min Time domain resource information separated by and the corresponding time resource index;

[0283] ii. Frequency domain resource information distinguished by frequency shift and corresponding frequency resource index.

[0284] 2. Receive MSG1 through one of the resources set above.

[0285] 3. Based on the time resource index (i) information for the resource that received MSG1, set the MSG2 monitoring interval using the following formula.

[0286] A. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0287] 4. Within the time interval set above, transmit MSG2 that echoes MSG1 transmitted by the device. The MSG2 contains resource allocation information for MSG3.

[0288] 5. When MSG3 is successfully received using the resources allocated for the above MSG3,

[0289] A. The relevant RA is considered to have been successfully completed.

[0290] 6. If MSG3 is not successfully received using the resources allocated for the above MSG3,

[0291] A. Based on the time resource index (i) for the resources allocated for MSG3, set the MSG2 monitoring interval using the following formula.

[0292] i. M i = [i*T D2R_max - (i-1)*T D2R_min , (i+1)*T D2R_max - i*T D2R_min ]

[0293] B. Within the time interval set above, transmit MSG2 that echoes MSG1 transmitted by the device. The said MSG2 includes resources for retransmitting MSG3.

[0294]

[0295] As explained above, the present disclosure presents various embodiments for setting the MSG2 monitoring interval. In addition, a random access procedure including this is presented. In particular, the total signaling overhead can be minimized by having the reader and the device each calculate a separate MSG2 monitoring duration using index information corresponding to the resources for MSG1 or MSG3 transmitted and received by the A-IoT device and the reader. Furthermore, when resources for MSG3 are allocated sequentially by the reader, the effect of maximizing overall system resource efficiency is achieved by enabling the monitoring interval to be set continuously.

[0296] The following describes an A-IoT terminal and a reader device capable of performing any operation regarding the aforementioned operation. Redundant parts of the above description are omitted, and even if omitted, the aforementioned operation can be performed by the devices below.

[0297] FIG. 15 is a diagram illustrating the configuration of an ambient IoT terminal according to one embodiment.

[0298] Referring to FIG. 15, an ambient IoT terminal (1500) performing a random access procedure may include a receiving unit (1530) that receives an access occasion resource setting message from a reader device, the message including one or more resource information and resource index information set corresponding to the resource information; a transmitting unit (1520) that transmits a message 1 to a reader device through a transmission resource information selected from one or more resource information; and a control unit (1510) that monitors a message 2 including response information for message 1 in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

[0299] For example, a connection opportunity resource setting message may include one or more resource information for transmitting Message 1, which is necessary for an ambient IoT terminal to perform a random access procedure through a reader device. Additionally, the connection opportunity resource setting message may include resource index information configured in correspondence with each resource information to identify each resource information. Such a connection opportunity resource setting message may be received from a reader device via PRDCH.

[0300] Meanwhile, the connection opportunity resource setting message may further include at least one of the following: information on the number of resources distinguished on the time axis for one or more resource information, information on the number of resources distinguished on the frequency axis, information on the total number of resources for one or more resource information, minimum time information for setting a monitoring window, maximum time information for setting a monitoring window, and frequency shift information.

[0301] The connection opportunity resource setting message may include information on the number of resources on the time axis and information on the number of resources on the frequency axis, or it may include only information on the total number of resources. Additionally, the connection opportunity resource setting message may include minimum time information and maximum time information used to set a monitoring window for the ambient IoT terminal to receive Message 2. At least one of the minimum time information and maximum time information may be composed of offset information.

[0302] The transmitting unit (1520) can select any connection resource among the connection resources and transmit message 1 to the reader device. By transmitting message 1, a random access procedure of the ambient IoT terminal can be performed.

[0303] Message 1 may include terminal identification information of an ambient IoT terminal. Terminal identification information may refer to arbitrary identification information to be used in a random access procedure. That is, terminal identification information may be used to distinguish the ambient IoT terminal from other terminals. For example, terminal identification information may be set to a 16-bit random value. Message 1 is transmitted over one selected access resource among one or more resource information configured on the time axis and the frequency axis. Resource information may be pre-configured for each ambient IoT terminal by a reader device, such as RACH Occasion (RO) or Access Occasion (AO). Message 1 may be transmitted via a PDRCH (Physical Device to Reader Channel).

[0304] Meanwhile, the receiver (1530) must receive message 2 containing response information for message 1. To do this, the control unit (1510) monitors message 2 in a monitoring window.

[0305] The monitoring window can have its start and end times set based on transmission resource index information, minimum time information, and maximum time information.

[0306] For example, the control unit (1510) can set a monitoring window for receiving message 2 using transmission resource index information that transmitted message 1. The control unit (1510) can use minimum time information and maximum time information to set the start and end points of the monitoring window.

[0307] For example, the reference point for minimum time information and maximum time information may be set to the last time resource on the time axis where one or more resource information is set. Alternatively, the reference point for minimum time information and maximum time information may be set to the last time resource of the transmission resource where message 1 was transmitted.

[0308] For example, the control unit (1510) can check the monitoring window using a preset algorithm that takes transmission resource index information, minimum time information, and maximum time information as input parameters.

[0309] Additionally, the control unit (1510) can set a monitoring window by setting the point in time when the minimum time information has elapsed from the reference point as the start point and the point in time when the maximum time information has elapsed from the reference point as the end point. In order to prevent the monitoring window from being duplicated for each terminal, resource index information may be used.

[0310] Meanwhile, the monitoring window may be configured in conjunction with individual transmission resources, or it may be configured based on resource information on the time axis at which the transmission resources are configured.

[0311] In addition, the reference point may be the end point of the transmission resource where Message 1 was transmitted. Or, the reference point may be the end point where all of one or more resource information is terminated.

[0312] Meanwhile, when the transmitting unit (1520) receives message 2 in the monitoring window, it can transmit message 3 to the reader device in response to message 2.

[0313] Message 2 may include terminal identification information included in Message 1. Through this, even when multiple ambient IoT terminals transmit Message 1 on the same connection resource and Message 2 is transmitted in response, each ambient IoT terminal can distinguish and verify them. That is, the correspondence between Message 1 and Message 2 can be confirmed through terminal identification information.

[0314] Message 2 may include information for scheduling Message 3, which the ambient IoT terminal will transmit to the reader device. For example, the scheduling information included in Message 2 may include time and frequency resource information for transmitting Message 3. Alternatively, the scheduling information for Message 3 may be determined based on the transmission resource transmitting Message 1.

[0315] For example, upon receiving message 2, the transmitting unit (1520) can transmit message 3 to a reader device to complete the random access procedure. Message 3 can be transmitted through wireless resource information specified by the scheduling information included in message 2.

[0316] Additionally, the control unit (1510) monitors the reception of a retransmission message 2, which is transmitted when the message 3 transmission resource in which message 3 was transmitted is not properly received by the reader device, in a retransmission monitoring window.

[0317] For example, the control unit (1510) checks whether message 2 is received in a retransmission monitoring window, which is a set time interval after message 3 is transmitted. If message 2 is received, the transmission unit (1520) retransmits message 3. If message 2 is not received in the retransmission monitoring window, the control unit (1510) can determine that the random access procedure was successful and terminate it.

[0318] The retransmission monitoring window can be configured based on message 3 transmission resources, retransmission minimum time information for retransmission monitoring window configuration, and retransmission maximum time information for retransmission monitoring window configuration.

[0319] For example, retransmission minimum time information and retransmission maximum time information may be included in the connection opportunity resource setup message or Message 2. That is, the retransmission minimum time information and retransmission maximum time information for the ambient IoT terminal to monitor Retransmission Message 2 may be included in the connection opportunity resource setup message received initially. As an example, the retransmission minimum time information and retransmission maximum time information may be used with the same values ​​as the minimum time information and maximum time information, respectively. As another example, the retransmission minimum time information and retransmission maximum time information may be set to values ​​distinct from the minimum time information and maximum time information used for the initial transmission of Message 2. As yet another example, the retransmission minimum time information and retransmission maximum time information may be set to offset values ​​or multiple values ​​based on the minimum time information and maximum time information.

[0320] The retransmission monitoring window can be configured as a period starting after the minimum retransmission time has elapsed and before the maximum retransmission time, based on the point in time when the message 3 transmission resource that transmitted message 3 is terminated. Alternatively, the retransmission monitoring window may be configured by further utilizing the index information of the message 3 transmission resource.

[0321] In addition to this, the control unit (1510) controls the overall operation of the ambient IoT terminal (1500) according to the MSG2 monitoring operation required to perform the above-described embodiment.

[0322] The transmitting unit (1520) and the receiving unit (1530) are used to transmit and receive signals, messages, and data necessary to perform the above-described embodiment with the reader device.

[0323]

[0324] FIG. 16 is a diagram illustrating a different reader device configuration in one embodiment.

[0325] Referring to FIG. 16, a reader device (1600) controlling a random access procedure of an ambient IoT terminal may include a transmitter (1620) that transmits an access occasion resource setting message to the ambient IoT terminal, the message including one or more resource information and resource index information set in correspondence with the resource information, and a receiver (1630) that receives a message 1 from the ambient IoT terminal through a transmission resource information selected from one or more resource information.

[0326] The transmitting unit (1620) can transmit message 2, which includes response information for message 1, to the ambient IoT terminal in a monitoring window that is set based on transmission resource index information set in correspondence with transmission resource information.

[0327] For example, a connection opportunity resource setting message may include one or more resource information for transmitting Message 1, which is necessary for an ambient IoT terminal to perform a random access procedure through a reader device. Additionally, the connection opportunity resource setting message may include resource index information configured in correspondence with each resource information to identify each resource information. Such a connection opportunity resource setting message may be transmitted via PRDCH.

[0328] Meanwhile, the connection opportunity resource setting message may further include at least one of the following: information on the number of resources distinguished on the time axis for one or more resource information, information on the number of resources distinguished on the frequency axis, information on the total number of resources for one or more resource information, minimum time information for setting a monitoring window, maximum time information for setting a monitoring window, and frequency shift information.

[0329] The connection opportunity resource setting message may include minimum time information and maximum time information used for setting a monitoring window for the ambient IoT terminal to transmit message 2. At least one of the minimum time information and maximum time information may be composed of offset information.

[0330] The receiver (1630) can receive Message 1 through any connection resource selected from among the connection resources configured in the ambient IoT terminal. By receiving Message 1, a random access procedure of the ambient IoT terminal can be performed.

[0331] Message 1 may include terminal identification information of an ambient IoT terminal. Terminal identification information may refer to arbitrary identification information to be used in a random access procedure. That is, terminal identification information may be used to distinguish the ambient IoT terminal from other terminals. For example, terminal identification information may be set to a 16-bit random value. Message 1 is received on one selected access resource among one or more resource information configured on the time axis and the frequency axis. Resource information may be pre-configured for each ambient IoT terminal by a reader device, such as RACH Occasion (RO) or Access Occasion (AO). Message 1 may be received via a PDRCH (Physical Device to Reader Channel).

[0332] For example, the transmitter (1620) must transmit message 2 containing response information for message 1. To do this, the transmitter (1620) transmits message 2 in a monitoring window monitored by an ambient IoT terminal.

[0333] The monitoring window can have its start and end times set based on transmission resource index information, minimum time information, and maximum time information.

[0334] For example, the control unit (1610) can set a monitoring window for transmitting message 2 using the transmission resource index information from which the ambient IoT terminal transmitted message 1. The reader device and the ambient IoT terminal can use minimum time information and maximum time information to set the start and end points of the monitoring window.

[0335] For example, the reference point for minimum time information and maximum time information may be set to the last time resource on the time axis where one or more resource information is set. Alternatively, the reference point for minimum time information and maximum time information may be set to the last time resource of the transmission resource where message 1 was transmitted.

[0336] For example, the control unit (1610) can check the monitoring window monitored by the ambient IoT terminal using a preset algorithm that has transmission resource index information, minimum time information, and maximum time information as input parameters.

[0337] The control unit (1610) can set a monitoring window by setting the point in time when the minimum time information has elapsed from the reference point as the start point and the point in time when the maximum time information has elapsed from the reference point as the end point. In order to prevent the monitoring window from being duplicated for each terminal, resource index information may be used.

[0338] Meanwhile, the monitoring window may be configured in conjunction with individual transmission resources, or it may be configured based on resource information on the time axis at which the transmission resources are configured.

[0339] In addition, the reference point may be the end point of the transmission resource where Message 1 was transmitted. Or, the reference point may be the end point where all of one or more resource information is terminated.

[0340] Meanwhile, the control unit (1610) expects a response to message 3 following the transmission of message 2. To this end, the reader device can monitor whether message 3 is received. Message 3 may be received through a wireless resource scheduled by message 2. Alternatively, message 3 may be received through a resource configured in conjunction with message 1. To this end, the control unit (1610) may include scheduling information for the transmission of message 3 in message 2.

[0341] If message 3 is not received in response to message 2, the transmitting unit (1620) can transmit the retransmission message 2 to the ambient IoT terminal in the retransmission monitoring window.

[0342] For example, the transmitting unit (1620) retransmits the retransmission message 2 to the ambient IoT terminal. However, in order for the ambient IoT terminal to receive the retransmission message 2, it must monitor whether message 2 has been received at a certain time interval after sending message 3. To do this, the transmitting unit (1620) sends the retransmission message 2 in the retransmission monitoring window.

[0343] For example, the retransmission monitoring window can be configured based on the message 3 transmission resource configured for the transmission of message 3, the minimum retransmission time information for the retransmission monitoring window configuration, and the maximum retransmission time information for the retransmission monitoring window configuration.

[0344] For example, the retransmission minimum time information and the retransmission maximum time information may be included in the connection opportunity resource setting message or message 2. Alternatively, the retransmission minimum time information and the retransmission maximum time information may be pre-set and configured in the ambient IoT terminal.

[0345] Meanwhile, the retransmission minimum time information and retransmission maximum time information for the ambient IoT terminal to monitor retransmission message 2 may be included in the connection opportunity resource setup message received initially. For example, the retransmission minimum time information and retransmission maximum time information may be used with the same values ​​as the minimum time information and maximum time information, respectively. As another example, the retransmission minimum time information and retransmission maximum time information may be set to values ​​distinct from the minimum time information and maximum time information used for the initial transmission of message 2. As yet another example, the retransmission minimum time information and retransmission maximum time information may be set to offset values ​​or multiple values ​​based on the minimum time information and maximum time information.

[0346] The retransmission monitoring window can be configured as a period starting after the minimum retransmission time has elapsed and before the maximum retransmission time, based on the point in time when the message 3 transmission resource that transmitted message 3 is terminated. Alternatively, the retransmission monitoring window may be configured by further utilizing the index information of the message 3 transmission resource.

[0347] The retransmission monitoring window may be set using the same algorithm as the monitoring window for the initial reception of message 2, or it may be set using a different algorithm.

[0348] In addition to this, the control unit (1610) controls the overall operation of the reader device (1600) for controlling the random access procedure according to the MSG2 monitoring operation required to perform the above-described embodiment.

[0349] The transmitting unit (1620) and the receiving unit (1630) are used to transmit and receive signals, messages, and data necessary to perform the above-described embodiment with the ambient IoT terminal.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356]

[0357] CROSS-REFERENCE TO RELATED APPLICATION

[0358] This patent application claims priority pursuant to Section 119(a) of the U.S. Patent Act (35 USC § 119(a)) to Korean Patent Application No. 10-2024-0191008 filed on December 19, 2024, 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 an Access Occasion resource setting message from a reader device, the message including one or more resource information and resource index information set corresponding to the resource information; A step of transmitting Message 1 to the reader device through transmission resource information selected from one or more of the above resource information; and A method comprising the step of monitoring a message 2 containing response information for the message 1 in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

2. In Paragraph 1, The above connection opportunity resource configuration message is, A method further comprising at least one of the following: information on the number of resources distinguished on a time axis for the above one or more resource information, information on the number of resources distinguished on a frequency axis, information on the total number of resources for the above one or more resource information, minimum time information for setting the monitoring window, maximum time information for setting the monitoring window, and frequency shift information.

3. In Paragraph 2, The above monitoring window is, A method for setting a start time and an end time based on the above transmission resource index information, the above minimum time information, and the above maximum time information.

4. In Paragraph 2, The reference point for the above minimum time information and the above maximum time information is, A method in which one or more of the above resource information is set as the last time resource on the time axis.

5. In Paragraph 1, When message 2 is received in the monitoring window, the step of transmitting message 3 to the reader device in response to message 2; and A method further comprising the step of monitoring the reception of a retransmission message 2, which is transmitted when the message 3 transmission resource to which the above message 3 was transmitted is not normally received by the reader device, in a retransmission monitoring window.

6. In Paragraph 5, The above retransmission monitoring window is, A method configured based on the above message 3 transmission resource, the above retransmission minimum time information for the above retransmission monitoring window setting, and the above retransmission maximum time information for the above retransmission monitoring window setting.

7. In Paragraph 6, The above retransmission minimum time information and the above retransmission maximum time information are, A method included in the above connection opportunity resource setting message or the above message 2.

8. A method for a reader device to control a random access procedure of an ambient IoT terminal, A step of transmitting an Access Occasion resource setting message to an Amberant IoT terminal, the message including one or more resource information and resource index information set corresponding to the resource information; A step of receiving Message 1 from the Amberant IoT terminal through transmission resource information selected from one or more of the above resource information; and A method comprising the step of transmitting a message 2, which includes response information for message 1, to the ambient IoT terminal in a monitoring window configured based on transmission resource index information configured in correspondence with the transmission resource information.

9. In Paragraph 8, The above connection opportunity resource configuration message is, A method further comprising at least one of the following: information on the number of resources distinguished on a time axis for the above one or more resource information, information on the number of resources distinguished on a frequency axis, information on the total number of resources for the above one or more resource information, minimum time information for setting the monitoring window, maximum time information for setting the monitoring window, and frequency shift information.

10. In Paragraph 9, The above monitoring window is, A method for setting a start time and an end time based on the above transmission resource index information, the above minimum time information, and the above maximum time information.

11. In Paragraph 8, A method further comprising the step of transmitting a retransmission message 2 from a retransmission monitoring window to an ambient IoT terminal if message 3 is not received in response to message 2.

12. In Paragraph 11, The above retransmission monitoring window is, A method configured based on a message 3 transmission resource configured for the transmission of the above message 3, retransmission minimum time information for the retransmission monitoring window configuration, and retransmission maximum time information for the retransmission monitoring window configuration.

13. In Paragraph 12, The above retransmission minimum time information and the above retransmission maximum time information are, A method included in the above connection opportunity resource setting message or the above message 2.

14. In an ambient IoT terminal performing a random access procedure, A receiving unit that receives an Access Occasion resource setting message from a reader device, the message including one or more resource information and resource index information set corresponding to the resource information; A transmitter that transmits Message 1 to the reader device through transmission resource information selected from one or more of the above resource information; and An ambient IoT terminal comprising a control unit that monitors a message 2 including response information for the message 1 in a monitoring window set based on transmission resource index information set corresponding to the transmission resource information.

15. In Paragraph 14, The above connection opportunity resource configuration message is, An ambient IoT terminal further comprising at least one of the following: information on the number of resources distinguished on a time axis for the one or more resource information, information on the number of resources distinguished on a frequency axis, information on the total number of resources for the one or more resource information, minimum time information for setting the monitoring window, maximum time information for setting the monitoring window, and frequency shift information.

16. In Paragraph 15, The above monitoring window is, An ambient IoT terminal in which a start time and an end time are set based on the transmission resource index information, the minimum time information, and the maximum time information.

17. In Paragraph 15, The reference point for the above minimum time information and the above maximum time information is, An ambient IoT terminal set as the last time resource on the time axis where the above one or more resource information is set.

18. In Paragraph 14, The above transmitting unit is, When message 2 is received in the monitoring window, message 3 is transmitted to the reader device in response to message 2, and The above control unit is, An ambient IoT terminal that monitors the reception of a retransmission message 2, which is transmitted when the message 3 transmission resource to which the above message 3 was transmitted is not normally received by the reader device, in a retransmission monitoring window.

19. In Paragraph 18, The above retransmission monitoring window is, An ambient IoT terminal configured based on the above message 3 transmission resource, the above retransmission minimum time information for the above retransmission monitoring window setting, and the above retransmission maximum time information for the above retransmission monitoring window setting.

20. In Paragraph 19, The above retransmission minimum time information and the above retransmission maximum time information are, An ambient IoT terminal included in the above connection opportunity resource setting message or the above message 2.

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