Method and device by which ambient IoT terminal receives r2d message

Abstract

Provided are a method and device by which an ambient Internet of things (IoT) terminal receives a reader-to-device (R2D) message. The terminal receives duration information for reception of an R2D message. In addition, the terminal corrects the duration for reception of the R2D message on the basis of the received duration information. The terminal then receives the R2D message on the basis of the corrected duration.

Description

Method and device for receiving R2D messages of an ambient IoT terminal

[0001] This specification relates to wireless communication applicable to 5G NR, 5G-Advanced, and 6G.

[0002] As the times change and more communication devices demand larger communication traffic, there is a demand for next-generation 5G systems, which are wireless broadband communication systems that are improved over existing LTE systems. In these next-generation 5G systems, referred to as NewRAT, communication scenarios are classified into Enhanced Mobile BroadBand (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

[0003] Here, eMBB is a next-generation mobile communication scenario characterized by High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario characterized by Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, Remote Control); and mMTC is a next-generation mobile communication scenario characterized by Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT).

[0004] One disclosure of the present specification aims to provide an efficient method and apparatus for receiving R2D messages of an ambient IoT device, i.e., a terminal, in a wireless communication system.

[0005] In one embodiment of the present specification, in a wireless communication system, a terminal receives duration information for receiving a Reader to Device (R2D) message. Additionally, the terminal corrects the duration for receiving the R2D message based on the received duration information. Subsequently, the terminal provides a method for receiving the R2D message based on the corrected duration.

[0006] Additionally, one embodiment of the present specification comprises, in a wireless communication system, at least one processor and at least one memory that stores instructions and is operablely electrically connected to at least one processor, and an operation performed based on the instruction being executed by at least one processor is: receiving duration information for receiving an R2D (Reader to Device) message. Additionally, based on the received duration information, the duration for receiving the R2D message is corrected. Subsequently, based on the corrected duration, a terminal that receives the R2D message is provided.

[0007] The interval for receiving the above R2D message may be at least one of an R2D reception expectation interval and an R2D monitoring interval. Additionally, the interval information for receiving the above R2D message may be received through a paging message or a message setting a D2R (Device to Reader) transmission resource.

[0008] The terminal transmits a first message, and the R2D message may be received as a second message in response to the first message.

[0009] Meanwhile, the interval information for receiving the above R2D message may be set differently depending on at least one of the random access (RA) step type, terminal type, and the size of the first message.

[0010] The first message may include at least one of random access (RA) step type information and size information of the first message. Here, the first message may be transmitted through a contention-based resource.

[0011] The above R2D message may be configured according to at least one of the same random access (RA) step type, the same terminal type, and the same size of the first message.

[0012] According to the disclosure of the present specification, when ambient IoT devices supporting CBRA (Contention-Based Random Access) in a wireless communication system transmit Message 1 (MSG1) through different frequency resources, if they have different Message 1 sizes depending on the RA step and / or device type (e.g., device 1, 2a, or 2b), the success rate of receiving Message 2 (MSG2) by the devices can be increased.

[0013] Figure 1 is a diagram illustrating a wireless communication system.

[0014] Figure 2 illustrates the structure of a wireless frame used in NR.

[0015] FIGS. 3a to 3c are exemplary diagrams illustrating exemplary architectures for wireless communication services.

[0016] Figure 4 illustrates the slot structure of an NR frame.

[0017] Figure 5 illustrates an example of a subframe type in NR.

[0018] Figure 6 illustrates the structure of a self-contained slot.

[0019] Figure 7 shows an example of a protocol between a reader and a tag.

[0020] FIGS. 8a through 8e show examples of connectivity topologies for ambient IoT networks and devices.

[0021] Figure 9 shows an example of an Access Stratum (AS) procedure between an ambient IoT device and a reader.

[0022] FIGS. 10a and 10b show examples of random access procedures.

[0023] FIGS. 11a to 11e show examples of R2D transmission corresponding to D2R.

[0024] FIGS. 12a and 12b are examples illustrating the successful reception of message 2 by an A-IoT device.

[0025] FIGS. 13a and 13b are examples for explaining the failure to receive message 2 of an A-IoT device.

[0026] FIGS. 14a and 14b are examples for explaining the R2D reception expectation interval correction according to one embodiment of the present specification.

[0027] FIG. 15 is an example for explaining R2D message transmission according to one embodiment of the present specification.

[0028] FIG. 16 is a flowchart illustrating a method of operation of a terminal according to one embodiment of the present specification.

[0029] FIG. 17 is a flowchart illustrating a method of operation between a reader and a terminal according to one embodiment of the present specification.

[0030] FIG. 18 illustrates a procedure between a reader and a terminal according to one embodiment of the present specification.

[0031] FIG. 19 illustrates a procedure between a reader and a terminal according to another embodiment of the present specification.

[0032] FIG. 20 shows an apparatus according to one embodiment of the present specification.

[0033] FIG. 21 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0034] FIG. 22 shows a block diagram of a processor in which the disclosure of the present specification is implemented.

[0035] FIG. 23 is a block diagram showing in detail the transceiver of the first device shown in FIG. 20 or the transceiver of the device shown in FIG. 21.

[0036] It should be noted that technical terms used in this specification are used merely to describe specific embodiments and are not intended to limit the content of this specification. Furthermore, unless specifically defined otherwise in this specification, technical terms used in this specification should be interpreted in the sense generally understood by those skilled in the art to which this disclosure pertains, and should not be interpreted in an overly broad or overly narrow sense. Additionally, if a technical term used in this specification is an incorrect technical term that fails to accurately express the content and concept of this specification, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. Moreover, general terms used in this specification should be interpreted according to their prior definitions or the context, and should not be interpreted in an overly narrow sense.

[0037] Additionally, singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "have" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0038] Additionally, terms including ordinal numbers, such as first, second, etc., used herein may be used to describe various components, but said components shall not be limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights, the first component may be named the second component, and similarly, the second component may be named the first component.

[0039] When it is stated that a component is connected to or coupled with another component, it may be directly connected to or coupled with that other component, or there may be other components in between. On the other hand, when it is stated that a component is directly connected to or directly coupled with another component, it should be understood that there are no other components in between.

[0040] Hereinafter, embodiments will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are assigned the same reference number, and redundant descriptions thereof will be omitted. Furthermore, in describing the contents of this specification, if it is determined that a detailed description of related prior art may obscure the gist of this specification, such detailed description will be omitted. Additionally, it should be noted that the attached drawings are intended only to facilitate understanding of the contents and concepts of this specification, and should not be interpreted as limiting the contents and concepts of this specification. The contents and concepts of this specification should be interpreted as extending to all modifications, equivalents, and substitutions in addition to the attached drawings.

[0041] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0042] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “A and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B or C.”

[0043] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0044] Additionally, in this specification, “at least one of A, B and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” may mean “at least one of A, B and C.”

[0045] Additionally, parentheses used in this specification may mean “for example.” Specifically, where indicated as “Control Information (PDCCH),” “PDCCH (Physical Downlink Control Channel)” may be proposed as an example of “Control Information.” In other words, “Control Information” in this specification is not limited to “PDCCH,” and “PDDCH” may be proposed as an example of “Control Information.” Furthermore, even when indicated as “Control Information (i.e., PDCCH),” “PDCCH” may be proposed as an example of “Control Information.”

[0046] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0047] In the attached drawings, User Equipment (UE) is illustrated as an example, but the illustrated UE may also be referred to by terms such as Terminal or Mobile Equipment (ME). Furthermore, the UE may be a portable device such as a laptop, mobile phone, PDA, smartphone, multimedia device, etc., or a non-portable device such as a PC or vehicle-mounted device.

[0048] In the following, UE is used as an example of a wireless communication-capable device (e.g., wireless communication device, wireless device, or wireless apparatus). The operations performed by the UE may be performed by any wireless communication-capable device. A wireless communication-capable device may also be referred to as a wireless communication device, wireless device, or wireless apparatus.

[0049] The term "base station" as used below generally refers to a fixed station that communicates with wireless devices, and can be used as a comprehensive term including eNodeB (evolved-NodeB), eNB (evolved-NodeB), BTS (Base Transceiver System), Access Point, gNB (Next generation NodeB), RRH (remote radio head), TP (transmission point), RP (reception point), relay, etc.

[0050] This specification describes embodiments using LTE systems, LTE-A systems and NR systems, but these embodiments may be applied to any communication system corresponding to the above definitions.

[0051] Wireless Communication System

[0052] Building on the success of LTE (long term evolution) / LTE-Advanced (LTE-A) for 4th generation mobile communication, commercialization and subsequent research for the next generation, namely 5th generation (so-called 5G) mobile communication, are also continuing.

[0053] Fifth-generation mobile communication, as defined by the International Telecommunication Union (ITU), refers to providing data transmission speeds of up to 20 Gbps and a perceived transmission speed of at least 100 Mbps anywhere. Its official name is 'IMT-2020'.

[0054] The ITU presents three major usage scenarios, such as eMBB (enhanced Mobile BroadBand), mMTC (massive Machine Type Communication), and URLLC (Ultra Reliable and Low Latency Communications).

[0055] URLLC concerns use scenarios requiring high reliability and low latency. For example, services such as autonomous driving, factory automation, and augmented reality require high reliability and low latency (e.g., latency of 1ms or less). Currently, the latency of 4G (LTE) is statistically 21-43ms (best 10%) and 33-75ms (median). This is insufficient to support services requiring latency of 1ms or less. Next, eMBB use scenarios concern use scenarios requiring mobile ultra-broadband.

[0056] In other words, 5th generation mobile communication systems support higher capacity than current 4G LTE, increase the density of mobile broadband users, and can support D2D (Device to Device), high stability, and MTC (Machine type communication). 5G research and development also aims for lower latency and lower battery consumption than 4G mobile communication systems to better implement the Internet of Things. New radio access technology (New RAT or NR) may be proposed for such 5G mobile communication.

[0057] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges may change; for example, the two types of frequency ranges (FR1, FR2) may be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 may mean the “sub 6GHz range” and FR2 may mean the “above 6GHz range” and may be referred to as millimeter wave (mmW).

[0058] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0059] The numerical values ​​of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 1. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0060] Meanwhile, 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from upper layers, and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from upper layers. For example, physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, refers to a signal of a specific waveform that is known to both the gNB and the UE. For example, cell-specific RS, UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements that carry information originating from upper layers, and uplink physical signals corresponding to resource elements used by the physical layer but that do not carry information originating from upper layers.For example, the physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and physical random access channel (PRACH) are defined as uplink physical channels, and the demodulation reference signal (DMRS) for uplink control / data signals and the sounding reference signal (SRS) used for uplink channel measurement are defined.

[0061] In this specification, PDCCH (Physical Downlink Control Channel) / PCFICH (Physical Control Format Indicator Channel) / PHICH (Physical Hybrid automatic retransmit request Indicator Channel) / PDSCH (Physical Downlink Shared Channel) each refers to a set of time-frequency resources or a set of resource elements carrying DCI (Downlink Control Information) / CFI (Control Format Indicator) / downlink ACK / NACK (ACKnowlegement / Negative ACK) / downlink data. Additionally, PUCCH (Physical Uplink Control Channel) / PUSCH (Physical Uplink Shared Channel) / PRACH (Physical Random Access Channel) each refers to a set of time-frequency resources or a set of resource elements carrying UCI (Uplink Control Information) / uplink data / random access signals.

[0062] Figure 1 is a diagram illustrating a wireless communication system.

[0063] As can be seen with reference to FIG. 1, the wireless communication system includes at least one base station (BS). The BS is divided into a gNodeB (or gNB) (20a) and an eNodeB (or eNB) (20b). The gNB (20a) supports 5th generation mobile communication. The eNB (20b) supports 4th generation mobile communication, i.e., LTE (Long Term Evolution).

[0064] Each base station (20a and 20b) provides communication services for a specific geographical area (generally called a cell) (20-1, 20-2, 20-3). A cell can be further divided into multiple areas (called sectors).

[0065] User Equipment (UE) typically belongs to a single cell, and the cell to which the UE belongs is called the serving cell. The base station that provides communication services to the serving cell is called the serving base station (serving BS). Since the wireless communication system is a cellular system, there exists another cell adjacent to the serving cell. The other cell adjacent to the serving cell is called the neighbor cell. The base station that provides communication services to the neighbor cell is called the neighbor base station (neighbor BS). The serving cell and neighbor cells are determined relatively to the UE.

[0066] In the following, the downlink refers to communication from the base station (20) to the UE (10), and the uplink refers to communication from the UE (10) to the base station (20). In the downlink, the transmitter may be part of the base station (20) and the receiver may be part of the UE (10). In the uplink, the transmitter may be part of the UE (10) and the receiver may be part of the base station (20).

[0067] Meanwhile, wireless communication systems can be broadly classified into Frequency Division Duplex (FDD) and Time Division Duplex (TDD) methods. In the FDD method, uplink and downlink transmissions occupy different frequency bands. In the TDD method, uplink and downlink transmissions occupy the same frequency band and occur at different times. The channel response in the TDD method is practically reciprocal. This means that the downlink channel response and the uplink channel response are nearly identical within a given frequency range. Therefore, in a wireless communication system based on TDD, there is an advantage in that the downlink channel response can be derived from the uplink channel response. In the TDD method, since the entire frequency band is time-divided for uplink and downlink transmissions, downlink transmission by the base station and uplink transmission by the UE cannot be performed simultaneously. In a TDD system where uplink and downlink transmissions are separated by subframes, uplink and downlink transmissions are performed in different subframes.

[0068] Figure 2 illustrates the structure of a wireless frame used in NR.

[0069] In NR, uplink and downlink transmissions consist of frames. A radio frame has a length of 10 ms and is defined as two 5 ms half-frames (HF). A half-frame is defined as five 1 ms subframes (SF). A subframe is divided into one or more slots, and the number of slots within a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols depending on the cyclic prefix (CP). When a standard CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) or SC-FDMA symbols (or DFT-s-OFDM symbols).

[0070] Support for various numerologies

[0071] In NR systems, as wireless communication technology develops, multiple numerologies may be provided to the terminal. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands; when the SCS is 30 kHz / 60 kHz, it supports dense-urban, lower latency, and wider carrier bandwidth; and when the SCS is 60 kHz or higher, it supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0072] The above numerology can be defined by the cycle prefix (CP) length and the subcarrier spacing (SCS). A single cell can provide multiple numerologies to the terminal. When the index of the numerology is denoted by μ, each subcarrier spacing and the corresponding CP length may be as shown in the table below.

[0073] μ△f=2 μ 15 [kHz]CP015General 130General 260General, Extended 3120General 4240General 5480General 6960General

[0074] For a standard CP, when the numerology index is denoted by μ, the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,μ slot ) And, the number of slots per subframe (N subframe,μ slot ) is as shown in the table below.

[0075] μ△f=2 μ 15 [kHz]N slot symb N frame,μ slot N subframe,μ slot 015141011301420226014404312014808424014160165480143203269601464064

[0076] For extended CP, when the numerology index is denoted by μ, the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,μ slot ) And, the number of slots per subframe (N subframe,μ slot ) is as shown in the table below.

[0077] μSCS (15*2 u )N slot symb N frame,μ slot N subframe,μslot 260KHz (u=2)12404

[0078] In an NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0079] FIGS. 3a to 3c are exemplary diagrams illustrating exemplary architectures for wireless communication services.

[0080] Referring to Fig. 3a, the UE is connected to an LTE / LTE-A based cell and an NR based cell in a DC (dual connectivity) manner.

[0081] The above NR-based cell is connected to the core network for existing 4th generation mobile communication, namely the EPC (Evolved Packet Core).

[0082] Referring to Fig. 3b, unlike Fig. 3a, the LTE / LTE-A based cell is connected to a core network for 5th generation mobile communication, that is, a 5G core network.

[0083] A service method based on the architecture as illustrated in Figures 3a and 3b above is called NSA (non-standalone).

[0084] Referring to Fig. 3c, the UE is connected only to NR-based cells. A service method based on this architecture is called SA (standalone).

[0085] Meanwhile, in the above NR, it may be considered that reception from the base station utilizes a downlink subframe, and transmission to the base station utilizes an uplink subframe. This method can be applied to paired spectra and unpaired spectra. A paired spectrum means that it includes two carrier spectra for downlink and uplink operations. For example, in a paired spectrum, one carrier may include a downlink band and an uplink band that are paired with each other.

[0086] Figure 4 illustrates the slot structure of an NR frame.

[0087] A slot contains multiple symbols in the time domain. For example, in the case of a standard CP, one slot contains 14 symbols, whereas in the case of an extended CP, one slot contains 12 symbols. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive (physical, P)RBs in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A terminal may be configured with up to N (e.g., 4) BWPs in both the downlink and uplink. Downlink or uplink transmission is performed through an active BWP, and at a given time, only one of the BWPs configured for the terminal may be active. In the resource grid, each element is referred to as a Resource Element (RE), and a single complex symbol may be mapped to it.

[0088] Figure 5 illustrates an example of a subframe type in NR.

[0089] The transmission time interval (TTI) illustrated in Fig. 5 can be referred to as a subframe or slot for NR (or new RAT). The subframe (or slot) of Fig. 5 can be used in the TDD system of NR (or new RAT) to minimize data transmission delay. As illustrated in Fig. 5, the subframe (or slot) contains 14 symbols. The symbols at the beginning of the subframe (or slot) can be used for the downlink (DL) control channel, and the symbols at the end of the subframe (or slot) can be used for the uplink (UL) control channel. The remaining symbols can be used for DL ​​data transmission or UL data transmission. According to this subframe (or slot) structure, downlink transmission and uplink transmission can proceed sequentially within a single subframe (or slot). Thus, downlink data can be received within the subframe (or slot), and uplink acknowledgments (ACK / NACK) can be transmitted within that subframe (or slot).

[0090] The structure of such a subframe (or slot) can be called a self-contained subframe (or slot).

[0091] Specifically, the first N symbols within the slot are used to transmit a DL control channel (hereinafter referred to as the DL control area), and the last M symbols within the slot may be used to transmit a UL control channel (hereinafter referred to as the UL control area). N and M are each integers greater than or equal to 0. A resource area (hereinafter referred to as the data area) located between the DL control area and the UL control area may be used for DL ​​data transmission or for UL data transmission. For example, a physical downlink control channel (PDCCH) may be transmitted in the DL control area, and a physical downlink shared channel (PDSCH) may be transmitted in the DL data area. A physical uplink control channel (PUCCH) may be transmitted in the UL control area, and a physical uplink shared channel (PUSCH) may be transmitted in the UL data area.

[0092] Using such a subframe (or slot) structure has the advantage of reducing the time required to retransmit data that has received errors, thereby minimizing the waiting time for final data transmission. In such a self-contained subframe (or slot) structure, a time gap may be required during the transition from transmit mode to receive mode or from receive mode to transmit mode. To this end, some OFDM symbols during the transition from DL to UL in the subframe structure may be set as a Guard Period (GP).

[0093] Figure 6 illustrates the structure of a self-contained slot.

[0094] In an NR system, a frame is characterized by a self-complete structure in which a DL control channel, DL or UL data, a UL control channel, etc., can all be included within a single slot. For example, the first N symbols within the slot are used to transmit a DL control channel (hereinafter referred to as the DL control area), and the last M symbols within the slot may be used to transmit a UL control channel (hereinafter referred to as the UL control area). N and M are each integers greater than or equal to 0. The resource area (hereinafter referred to as the data area) located between the DL control area and the UL control area may be used for transmitting DL data or for transmitting UL data. As an example, the following configuration can be considered. Each section is listed in chronological order.

[0095] 1. DL only configuration

[0096] 2. UL only configuration

[0097] 3. Mixed UL-DL Configuration

[0098] - DL Area + GP (Guard Period) + UL Control Area

[0099] - DL Control Area + GP + UL Area

[0100] DL Area: (i) DL Data Area, (ii) DL Control Area + DL Data Area

[0101] UL Area: (i) UL Data Area, (ii) UL Data Area + UL Control Area

[0102] PDCCH can be transmitted in the DL control area, and PDSCH can be transmitted in the DL data area. PUCCH can be transmitted in the UL control area, and PUSCH can be transmitted in the UL data area. In PDCCH, DCI (Downlink Control Information), such as DL data scheduling information and UL data scheduling information, can be transmitted. In PUCCH, UCI (Uplink Control Information), such as ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, and SR (Scheduling Request), can be transmitted. GP provides a time gap during the process in which the base station and the terminal switch from transmit mode to receive mode or from receive mode to transmit mode. Within a subframe, some symbols at the point of transition from DL to UL can be set as GP.

[0103] Meanwhile, IoT technology has garnered significant attention in wireless communication over the past few years. IoT technology has evolved to enable a greater number of interconnected objects, thereby improving industrial productivity and quality of life. Examples of this include NB-IoT (Narrowband Internet of Things) and eMTC (enhanced Machine-Type Communication) technologies defined by 3GPP. However, to build a more effective IoT ecosystem, improvements are needed in various aspects, such as the size, form factor, price, complexity, power consumption, and coverage of IoT devices.

[0104] Radio Frequency Identification (RFID) is a representative technology service of the IoT. The advantages of RFID include very low complexity and the fact that RFID tags have a very small form factor. However, RFID supports a very narrow coverage area with a reading distance of only a few meters, is labor-intensive due to handheld scanning, and requires high deployment costs due to the installation costs of RFID portals / gates. Therefore, RFID has limitations in supporting seamless service and coverage in large-scale networks.

[0105] To meet these requirements, 3GPP has been conducting studies on ambient IoT technology since Release 18. Ambient IoT devices have a lower form factor compared to conventional IoT devices and support energy harvesting based on battery-less or minimal energy storage capability, allowing them to operate without charging or with minimal power charging. In addition, research is being conducted to support wide coverage based on higher power efficiency and to enable the utilization of RF signals supported by existing networks.

[0106] In addition, 3GPP is conducting research on protocol stacks and signaling procedures that take into account the low form factor and battery capacity characteristics of ambient IoT devices, such as less than 1 μW or less than several hundred μW. In particular, definitions are being made for the paging message functionality, which is the first message transmitted by a reader or base station to an ambient IoT device for wireless access of the ambient IoT device, and the random access procedure of the ambient IoT device.

[0107] Figure 7 shows an example of a protocol between a reader and a tag.

[0108] RFID technology, which is the foundation of ambient IoT technology, is defined in the document "EPC Radio-Frequency Identity Protocols Generation-2 UHF RFID". This document defines the protocol between the reader and the tag and adopts a slotted-ALOHA-based random access procedure.

[0109] Referring to Fig. 7, the reader has three main actions: select, inventory, and access. The select action is an action in which the reader selects one or more tag populations, and it consists of 'select' and 'challenge' commands. At this time, the tags enter a ready state. The select command is a mandatory action, and the challenge command is an optional action. The select command allows the reader to select a tag population based on user-defined criteria. The inventory action involves the reader identifying / detecting each tag and generating a unique Random Number (RN) based on commands / responses with each tag to prepare for access. The access action involves the reader performing mutual communication with each tag to carry out procedures such as read / write / authenticate.

[0110] A tag can exist in various states during communication with a reader. First, the tag may enter a "ready" state, where it becomes operational upon receiving power from the reader, and subsequently an "arbitrate" state to prevent collisions when multiple tags exist simultaneously. Additionally, it may enter a "reply" state, where it transmits temporary identifiers or similar information in response to the reader's query commands, and an "acknowledge" state, where the reader recognizes and selects a specific tag. Furthermore, the tag may enter an "open" state, where a session with the reader is open allowing for the transmission and reception of additional commands, and a "secured" state, when authentication or encryption procedures are completed. Meanwhile, if the tag receives a kill command, it transitions to a "killed" state and may not respond to any subsequent reader commands.

[0111] FIGS. 8a through 8e show examples of connectivity topologies for ambient IoT networks and devices.

[0112] In recent years, IoT technology has garnered significant attention in wireless communication. IoT technology has evolved to enable a greater number of interconnected objects, thereby improving industrial productivity and quality of life. Examples of this include NB-IoT (Narrowband Internet of Things) and eMTC (enhanced Machine-Type Communication) technologies defined by 3GPP. However, to build a more effective IoT ecosystem, improvements are needed in various aspects, such as the size, form factor, price, complexity, power consumption, and coverage of IoT devices.

[0113] Radio Frequency Identification (RFID) is a representative technology service of the IoT. The advantages of RFID include very low complexity and the fact that RFID tags have a very small form factor. However, RFID supports a very narrow coverage area with a reading distance of only a few meters, is labor-intensive due to handheld scanning, and requires high deployment costs due to the installation costs of RFID portals / gates. Therefore, RFID has limitations in supporting seamless service and coverage in large-scale networks.

[0114] To meet these requirements, 3GPP has been conducting studies on ambient IoT technology since Release 18. Ambient IoT devices have a lower form factor compared to conventional IoT devices and support energy harvesting based on battery-less or minimal energy storage capability, allowing them to operate without charging or with minimal power charging. In addition, research is being conducted to support wide coverage based on higher power efficiency and to enable the utilization of RF signals supported by existing networks.

[0115] For convenience of explanation, in this specification, an ambient IoT device may be referred to as an ambient IoT terminal, an IoT device, an IoT terminal, a device, or a terminal.

[0116] Connectivity topologies such as those shown in FIGS. 7a to 7e can be defined for ambient IoT networks and devices.

[0117] Referring to FIG. 8a, the ambient IoT device communicates directly and bidirectionally with a base station (BS). Communication between the base station and the ambient IoT device includes ambient IoT data and / or signaling. In the topology of FIG. 7a, the BS transmitted to the ambient IoT device may be different from the BS received from the ambient IoT device.

[0118] Referring to FIG. 8b, the ambient IoT device communicates bidirectionally with an intermediate node between the device and the base station. In the topology of FIG. 8b, the intermediate node can be an ambient IoT-enabled relay, an IAB (Integrated Access Backhaul) node, a UE, a repeater, etc. The intermediate node transmits ambient IoT data and / or signaling between the BS and the ambient IoT device.

[0119] Referring to FIG. 8c, the ambient IoT device transmits data / signaling to a base station and receives data / signaling from an assisting node. Alternatively, as shown in FIG. 8d, the ambient IoT device receives data / signaling from a base station and transmits data / signaling to an assisting node. The assisting node in the topology of FIG. 8c to FIG. 8d can be an ambient IoT-enabled relay, IAB, UE, repeater, etc.

[0120] Referring to FIG. 8e, the ambient IoT device communicates bidirectionally with the UE. Communication between the UE and the ambient IoT device includes the transmission of ambient IoT data and / or signaling.

[0121] Figure 9 shows an example of an Access Stratum (AS) procedure between an ambient IoT device and a reader.

[0122] Referring to FIG. 9, the overall Access Stratum (AS) procedure between an ambient IoT (A-IoT) device and a reader is described below.

[0123] Step A: A-IoT Paging (S901)

[0124] The reader transmits an A-IoT paging message indicating the device requiring a response in response to the service request. Here, the A-IoT paging message can be used interchangeably with the initial trigger message.

[0125] Step B: D2R (Device-to-Reader) data transfer (S902~S903)

[0126] An A-IoT device triggered by paging can transmit a device identifier (ID) to the reader, either by performing an A-IoT random access procedure or without such procedure. Subsequently, D2R data is transmitted to the reader.

[0127] Step C1: R2D (Reader-to-Device) data transfer (S904)

[0128] Optionally, the reader can transmit data including commands, etc. to the device.

[0129] Step C2: D2R data transmission (S905)

[0130] Optionally, the device can transmit response data to the above command to the reader.

[0131] These procedures can support the following A-IoT use cases:

[0132] Inventory-only: Can be supported through a procedure consisting of Step A and Step B.

[0133] Inventory and command: This can be supported through a procedure including steps A, B, C1, and C2. Here, this does not mean that the A-IoT paging message includes both inventory and command simultaneously, nor does it mean that the reader receives both inventory and command simultaneously from the upper layer.

[0134] Command-only: Basically, this can be supported through a procedure consisting of steps A, B, C1, and C2, and the following alternative procedures may also be considered.

[0135] Step A: The reader can send an A-IoT paging message containing a command to a device to instruct the device to process the command and respond.

[0136] Step C2: The device transmits device ID or response data for the command; this process may be performed through an A-IoT random access procedure or without such procedure.

[0137] Meanwhile, 3GPP classifies ambient IoT terminals into three types as shown in Table 5 below.

[0138] DeviceTypeEnergyStoragePeak PowerConsumptionAmplificationUL Independent Signal GenerationUL Tx MethodPassiveDevice 1Yes≤ 1 μWNoNoBackscattering from external CWDevice 2aYes≤ a few hundred μWYes (DL and / or UL)NoBackscattering from external CWActiveDevice 2bYes≤ a few hundred μWYes (DL and / or UL)NoGenerated internally

[0139] In Table 5, the difference between passive and active is the presence or absence of independent signal generation functions and hardware within the ambient IoT device. It is defined as passive if there is no independent signal generation function for uplink (UL) signal transmission of the ambient IoT device, and active if there is an independent signal generation function. The maximum power consumption of Device 1 is 1 μW or less, and it lacks independent signal generation and amplification functions. Additionally, the uplink of the ambient IoT device is transmitted via backscattering of the external carrier wave signal. The maximum power consumption of Device 2a is several hundred μW or less, and it does not support independent signal generation but supports UL / DL amplification functions. Additionally, the UL is transmitted via backscattering of the external carrier wave signal. The maximum power consumption of device 2b is less than several hundred μW, and it supports independent signal generation and UL / DL amplification functions. Additionally, UL is transmitted through signal generation within the device.

[0140] Meanwhile, the common feature of Devices 1, 2a, and 2b discussed by 3GPP to date is that they are equipped with energy storage devices inside the ambient IoT devices. However, ambient IoT devices may have energy storage of limited capacity depending on the topology and deployment scenario. Here, limited energy storage may refer to a storage device composed of small-sized capacitors. In order to support seamless communication between the reader and the ambient IoT device, protocols and signaling to support energy harvesting need to be defined, but detailed operations have not yet been defined.

[0141] Meanwhile, discussions on ambient IoT topologies are underway at 3GPP, and the topologies of FIGS. 8a to 8d described above are applicable to the present invention, and in particular, it is preferable to apply the topologies of FIGS. 8a to 8b.

[0142] In addition, 3GPP decided to support paging messages at the Access Stratum (AS) layer between ambient IoT devices and readers (e.g., base stations), but since existing paging messages are difficult to support, it decided to define new A-IoT paging messages. The purpose of A-IoT paging is to have ambient IoT device(s) identify a radio resource, select / determine it, and then send a Device-to-Reader (D2R) response message to the reader.

[0143] To identify A-IoT device(s), types of identifier information in the form shown in Table 6 are being discussed for paging messages. (Table 6. Types of A-IoT device identifier information in paging messages)

[0144] Cases Information Type Recipient Case 1 Single A-IoT device ID A single A-IoT Device Case 2 Group ID Multiple A-IoT device(s) mapped to a Group ID Case 3 No ID-related information All A-IoT device(s) receiving A-IoT paging messages Case 4 Multiple A-IoT device IDs Multiple A-IoT device IDs

[0145] In addition, regarding the method of selecting / determining radio resources for D2R transmission (e.g., Message 1) of ambient IoT devices, how to perform D2R transmission (implicit / explicit / configured / preconfigured) or through which (dedicated / shared) resources will be discussed later.

[0146] FIGS. 10a and 10b show examples of random access procedures.

[0147] Discussions are underway at 3GPP regarding random access procedures for ambient IoT device(s). The Slotted-ALOHA random access procedure has been adopted as the standard, and Content-Based Random Access (CBRA) and Content-Free Random Access (CFRA) for a single device, a group of devices, or all devices are set to be defined. Additionally, CBRA-based 4-step, 3-step, and 2-step procedures, as well as CFRA procedures, are also under discussion.

[0148] FIGS. 10a and 10b respectively show examples of CBRA-based 2-step and 3-step (or 4-step) Random Access (RA) procedures. A-IoT devices must select one of a 2-step CBRA, a 3-step CBRA, or a CFRA, and the information for making the selection can be made explicitly through an A-IoT paging message or implicitly through specific information within the A-IoT paging message.

[0149] Referring to FIG. 10a, the reader transmits Message 0 (Message 0, MSG0) to the device (S1001a). Here, MSG0 may be an A-IoT paging message, which may include candidate radio resource information required for the device to perform D2R transmission (Message 1). Additionally, device ID (identity) information may be included in MSG0 and transmitted.

[0150] Subsequently, the device randomly selects a resource, i.e., an access occasion, from among candidate radio resources consisting of a time / frequency / code sequence (S1002a). The device transmits Message 1 (MSG1) to the reader (1003a), where MSG1 may include at least one of a device ID, upper layer data, and a random ID.

[0151] The reader transmits an R2D message, i.e., Message 2 (Message 2, MSG2), to the device, including some of the information received from MSG1 (S1004a). The random ID (information) included in MSG1 may be included in MSG2 and transmitted.

[0152] Referring to FIG. 10b, the reader transmits Message 0 (Message 0, MSG0) to the device (S1001b). Here, MSG0 may be an A-IoT paging message, which may include candidate radio resource information required for the device to perform D2R transmission (Message 1). Additionally, device ID (identity) information may be included in MSG0 and transmitted.

[0153] Subsequently, the device randomly selects a resource, i.e., an access occasion, from among candidate radio resources consisting of a time / frequency / code sequence (S1002b). The device transmits Message 1 (MSG1) to the reader (1003b), where MSG1 may include at least a random ID.

[0154] The reader transmits an R2D message, i.e., Message 2 (Message 2, MSG2), to the device, including some of the information received from MSG1 (S1004b). The random ID (information) included in MSG1 may be included in MSG2 and transmitted. Contention resolution may be performed by exchanging the random ID (information) through MSG1 and MSG2. This random ID information and dedicated resource information may be included in MSG2 and transmitted to the device. The dedicated resource information may be for transmitting Message 3 (Message 3, MSG3).

[0155] Subsequently, the terminal transmits MSG3 to the reader (S1005b), which may include at least one of a device ID and upper layer data. After transmitting MSG3, the terminal may receive Message 4 (MSG4) from the reader (S1006b). Here, MSG4 may be defined as a message for handling MSG3 transmission failure or the reader's MSG3 reception failure, and may not necessarily be a message that requires transmission and reception. If MSG4 transmission and reception are required, the reader (e.g., base station) may transmit MSG4 to the device(s), which can be assumed to be a 4-step RA procedure. In addition to MSG4, additional message transmission and reception may occur between the A-IoT device and the reader (e.g., base station) as needed. However, to date, it has not been determined what type of random access procedure the A-IoT device(s) will determine in the RA (random access) procedure, and what information is required in the paging and R2D messages transmitted by the reader (e.g., base station) for the RA determination.

[0156] FIGS. 11a to 11e show examples of R2D transmission corresponding to D2R.

[0157] 3GPP is also discussing communication methods based on FDM(A), TDM(A), and CDM(A) in A-IoT systems. In wireless resource allocation, they are discussing support measures for communication based on frequency / time / code sequence. Figures 11a to 11e illustrate various examples of D2R and R2D transmission methods based on FDM(A) and TDM(A).

[0158] FIGS. 11a through 11e assume a procedure in which A-IoT devices perform random access (RA) in different steps, such as 2-step or 3-step. Examples according to the corresponding R2D transmission method are shown when the A-IoT device transmits a D2R message using Frequency Division Multiple Access (FDMA) or Time Division Multiple Access (TDMA).

[0159] FIG. 11a illustrates the transmission of an FDMA-based D2R message (MSG1) and the transmission of an R2D message (MSG2) corresponding to the D2R message transmitted by multiple A-IoT devices. FIG. 11b illustrates the transmission of an FDMA-based D2R message (MSG1) and the sequential transmission of an R2D message (MSG2) corresponding to the D2R message transmitted by a single A-IoT device. That is, FIG. 11b represents a case where a reader that receives a D2R message transmitted by an A-IoT device transmits a corresponding R2D message individually and sequentially for each D2R message. FIG. 11c is similar to FIG. 11b, but differs in that, from the reader's perspective, the transmission of an R2D message (MSG2) is triggered for Device 2, which receives the D2R message first, and the D2R message (MSG3) transmitted by Device 2 is executed first. Subsequently, it represents a case where an R2D message corresponding to the D2R message transmitted by Device 1 is transmitted.

[0160] FIG. 11d illustrates the transmission of a TDMA-based D2R message (MSG1) and the transmission of an R2D message (MSG2) corresponding to the D2R message transmitted by multiple A-IoT devices. FIG. 11e illustrates a case where an A-IoT device transmits a D2R message (MSG1) based on TDMA, and a reader transmits an R2D message (MSG2) via a different frequency than that of the A-IoT device. In this case, the reader can transmit a corresponding R2D message for each D2R message transmitted by the A-IoT device.

[0161] Meanwhile, regarding the timing relationship between an A-IoT device and a reader (e.g., a base station) in terms of D2R and R2D message transmission, reception, and processing time, it can be defined as follows.

[0162] T R2D_min From the reader's perspective, this may refer to the minimum time required from the transmission of an R2D message to the transmission of the corresponding D2R message. (T R2D_min : Minimum time between a R2D transmission and the corresponding D2R transmission following it.)

[0163] T D2R_min From the device's perspective, this may refer to the minimum time required from the transmission of a D2R message to the transmission of the corresponding R2D message. (T D2R_min : Minimum time between a D2R transmission and the corresponding R2D transmission following it.)

[0164] T D2R_maxFrom the device's perspective, this may refer to the maximum time required from the transmission of the D2R message to the transmission of the corresponding R2D message. The transmission timing of the R2D message (MSG2) corresponding to the D2R message (MSG1) is [T D2R_min , T D2R_max It can be defined as needing to take place within a time interval. (T D2R_max : Maximum time between the D2R transmission and the corresponding R2D transmission following it, so that the R2D transmission timing is expected to be within [T D2R_min , T D2R_max ], when a R2D transmission in response to a D2R transmission is expected for A-IoT Msg2 response to A-IoT Msg1 for the A-IoT device.)

[0165] Additionally, the reader can continuously transmit two different R2D transmissions to a single device, in which case the minimum time between R2D transmissions is T R2D_R2D_min It can be defined as. (T R2D_R2D_min : Minimum time between two different consecutive R2D transmissions to the same A-IoT device.

[0166] In addition, the same device can perform two different D2R transmissions consecutively, and the minimum time between each D2R transmission is T D2R_D2R_min It can be defined as. (T D2R_D2R_min : Minimum time between two different consecutive D2R transmissions from the same A-IoT device.)

[0167] Meanwhile, 3GPP is considering two options for the transmission method of MSG2 that the reader transmits in response to MSG1 transmitted by the device.

[0168] - Option 1: A "MSG1 : MSG2 = 1 : 1" method in which a reader receiving MSG1 from one device transmits the corresponding MSG2. The previously described FIGS. 11b, 11c, and 11e may correspond to this. (Option 1: A PRDCH for Msg2 transmission corresponds to an A-IoT Msg1 received from one device)

[0169] - Option 2: This is a "MSG1 : MSG2 = N : 1" method in which a reader receiving multiple MSG1s from different devices transmits a corresponding MSG2. In other words, it is a method of including information corresponding to the MSG1s transmitted by multiple devices into a single MSG2 and transmitting it all at once. Figures 11a and 11d described earlier may correspond to this. (Option 2: A PRDCH for Msg2 transmission corresponds to multiple A-IoT Msg1 received from different devices)

[0170] In addition, 3GPP plans to discuss the monitoring start time and monitoring time interval for MSG2 reception by the device.

[0171] The CBRA procedure currently being considered by 3GPP is that a D2R message (MSG1) is triggered when a leader sends a paging message (MSG0) containing candidate resource information to the device(s). Upon receiving this, the device(s) select an access occasion from among the candidate resources and send a D2R message (MSG1) containing a random ID and / or device ID. If the D2R message (MSG1) contains a random ID, the leader sends a R2D message (MSG2) containing the random ID to the device. Upon successfully receiving the R2D message (MSG2) sent by the leader, the device determines that the D2R message (MSG1) transmission was successful and sends MSG3 or continues data transmission and reception according to the RA step.

[0172] The present invention provides a method for setting an MSG2 monitoring start time and a monitoring time interval for successful MSG2 (R2D) reception by A-IoT devices supporting CBRA, and a method for transmitting MSG2 by a reader.

[0173] To summarize the previously described details, the R2D message or A-IoT paging message transmitted by the reader to trigger RA (random access) to A-IoT devices contains X (X instances) of resource information to be used for the transmission of D2R (e.g., MSG1) by the A-IoT devices. n A-IoT devices can transmit a D2R message (MSG1) by occupying one or more of the X resources (e.g., access occasions). After transmitting MSG1, the A-IoT devices [T D2R_min , T D2R_maxDuring the interval, the reception of MSG2 as a corresponding response can be expected. If MSG2 is not received during that interval, A-IoT devices may determine that MSG2 reception has failed. A-IoT devices must perform MSG2 monitoring to receive MSG2, and 3GPP has decided to conduct a study on the monitoring starting time and the monitoring time duration. Regarding the method in which a reader transmits MSG2 in response to multiple MSG1s, options are being considered to transmit a single MSG2 corresponding to an MSG1 received from a single A-IoT device (via PRDCH (Physical Reader to Device Channel)) or to transmit a single MSG2 corresponding to multiple MSG1s received from different A-IoT devices (via PRDCH). In addition, 3GPP decided to study the starting time and time duration of MSG2 monitoring for A-IoT devices in order to successfully receive MSG2 transmitted by the reader.

[0174] FIGS. 12a and 12b are examples illustrating the successful reception of message 2 by an A-IoT device.

[0175] Referring to FIGS. 12a and 12b, A-IoT devices have a minimum time (T) between the transmission of MSG1 (D2R) and the corresponding transmission of MSG2 (R2D). D2R_min ) and maximum time (T D2R_max Reception of MSG2(R2D) can be expected within the ) interval. In other words, D2R and R2D transmission between the A-IoT device and the reader is [T D2R_mim , T D2R_max It must be performed within the ] section, and the A-IoT device is the corresponding [T D2R_mim , TD2R_max ] Within the time interval or within the monitoring duration of MSG2(R2D) set to an arbitrary value, reception of MSG2(R2D) corresponding to MSG1(D2R) can be expected.

[0176] FIG. 12a shows that different A-IoT devices transmit MSG1s having data of the same or similar size to a reader using an FDMA transmission method separated by different frequencies, and the reader receiving this responds to the MSG1s with [T D2R_mim , T D2R_max This represents the case where MSG2 is successfully transmitted via different frequency resources within the ] interval (or within the MSG2 monitoring interval of A-IoT devices), and A-IoT devices successfully receive it. Here, the monitoring time interval for MSG2 of the A-IoT devices is [T D2R_mim , T D2R_max ] or may be an arbitrary set time interval (e.g., in the form of a timer for monitoring or a monitoring starting / end point), which may be a pre-defined / configured value from the reader. The reader may also support the function of generating and transmitting one or more MSG2s through different time / frequency resources within the time interval.

[0177] Figure 12b above is an example of successfully receiving MSG2 in a case where the transmission method between the A-IoT device and the reader in Figure 12a is the same, but the sizes of the MSG1 transmitted by the A-IoT devices are different. Since the sizes of MSG1 are different, the interval [T] where each A-IoT device expects to receive MSG2 is D2R_mim , T D2R_max] may differ. The reason the sizes of MSG1s differ is that they may vary depending on the RA step type. For example, in the case of 2-step RA, random access must be completed with a simpler procedure compared to 3-step RA, so a relatively large amount of data may be included in MSG1. In Fig. 12b, we assume that devices 1 / 4 are of the 2-step RA type and devices 2 / 3 are of the 3-step RA type. After the A-IoT device finishes transmitting MSG1 (D2R), at least T D2R_min It starts waiting for MSG2(R2D) reception from and waits for MSG2(R2D) reception up to the maximum TD2R_max. In other words, the A-IoT device waits for T D2R_max If MSG2(R2D) is not received until [time], it can be determined that MSG2 reception has failed. However, in FIG. 12b, the reader monitors the MSG2 of the A-IoT devices during the MSG2 monitoring period and / or [T D2R_mim , T D2R_max This shows an example where MSG2 is successfully transmitted within the ] interval and A-IoT devices successfully receive MSG2.

[0178] FIGS. 13a and 13b are examples for explaining the failure to receive message 2 of an A-IoT device.

[0179] FIGS. 13a and 13b show different expected R2D (MSG2) reception intervals [T due to different MSG1 data sizes D2R_mim , T D2R_max These are examples of MSG2 reception failures according to ]. In FIGS. 13a and 13b, it is assumed that device 1 / 4 is of the 2-step RA type and device 2 / 3 is of the 3-step RA type. The data size of the MSG1 transmitted by device 1 / 4 may be relatively larger than that of device 2 / 3. Accordingly, T, which begins to expect MSG2 reception for each device having different MSG1 sizes D2R_minT terminating the expectation of receiving wa MSG2 D2R_max It may differ. That is, [T varies by device. D2R_mim , T D2R_max The start and end times of the interval may differ.

[0180] The reader [T] is set considering the processing time of the A-IoT device D2R_mim , T D2R_max MSG2 can be transmitted via different frequencies by considering the ] interval. (i.e., [T D2R_mim , T D2R_max The ] interval is the expected R2D transmission timing.) At this time, the reader considers T, taking into account the processing time of the device that transmitted the last received MSG1 (1 / 4 of the time). D2R_min From then on, you can generate MSG2 and start preparing for transmission.

[0181] However, as shown in FIG. 13a, when a reader that has received MSG1 distinguished by n different frequencies from n A-IoT devices transmits the corresponding MSG2, [T differs for each device D2R_mim , T D2R_max MSG2 may be transmitted without fully considering the ] interval. In this case, even though the reader has transmitted MSG2, the expected MSG2 reception interval [T D2R_mim , T D2R_max ] A problem may occur where 2 / 3 of the devices that were terminated first determine that they failed to receive MSG2.

[0182] Additionally, as shown in FIG. 13b, if the reader that received MSG1 can transmit MSG2 via different frequencies within an arbitrary time interval, device 2 / 3 is the MSG2 reception expectation interval [T D2R_mim , T D2R_max A problem may occur where ] terminates first and determines that MSG2 reception failed.

[0183] Accordingly, the present invention proposes a solution to the problem of failure to receive an R2D message (e.g., MSG2) that may occur when each A-IoT device intending to transmit a D2R message (e.g., MSG1) of a different size has a different expected reception period or an R2D message monitoring period.

[0184] Plan 1. Expected interval for R2D message reception [T D2R_min , T D2R_max ] correction

[0185] Method 1 is the expected reception interval [T] for R2D messages (e.g., MSG2) from devices intending to transmit a D2R message (e.g., MSG1) consisting of a relatively small amount of data. D2R_mim , T D2R_max This is a method to enable stable reception of the MSG2 transmitted by the reader by correcting the ] or R2D monitoring interval.

[0186] FIGS. 14a and 14b are examples for explaining the R2D reception expectation interval correction according to one embodiment of the present specification.

[0187] Referring to FIGS. 14a and 14b, device 2 / 3 may attempt to connect to the reader using a 3-step or 4-step RA type, and device 1 / 4 may attempt to connect using a 2-step RA type. In this case, device 2 / 3 may transmit MSG1 consisting of a smaller amount of data compared to device 1 / 4, and T D2R_mim , T D2R_max As the value differs by a magnitude of 'α', the point in time when the reception of an R2D message is expected may end by a magnitude of 'α'. In other words, the time-shifted interval for the expected reception of an R2D message for device 2 / 3 is corrected to be identical to the expected interval for device 1 / 4. Alternatively, for device 2 / 3, T, which is the maximum expected value for R2D message reception, D2R_maxCorrecting only by the magnitude of α, T of device 1 / 4 D2R_max It is to correct it to be the same as the point in time.

[0188] Therefore, [T set based on the processing time of the A-IoT device D2R_mim , T D2R_max Correcting ] by a size of 'α', the R2D message reception interval of device 2 / 3 is [T D2R_min +α, T D2R_max +α] or [T D2R_min , T D2R_max We propose a method of setting it to [+α]. (i.e., [T D2R_min +α, T D2R_max +α] or [T D2R_min , T D2R_max The interval [+α] is the expected R2D transmission timing. Here, the value of 'α' may be the difference between the size of MSG1 that will consist of the largest amount of data and the size of MSG1 that will consist of a smaller amount of data. Or it may be the difference between the size of a D2R message (e.g., MSG1) operating as a 3-step / 4-step RA type and a 2-step type. Here, the value of 'α' may be used to correct the start timing or the MSG2 monitoring time interval for MSG2 monitoring by devices.

[0189] Option 2. Sending Message 2 to each device that sent Message 1 of the same size

[0190] Method 2 involves a reader transmitting an R2D message (e.g., MSG2) for each device transmitting a D2R message (e.g., MSG1) of the same size, thereby providing a separate R2D reception expectation interval [T D2R_mim , T D2R_max This is a method to enable devices to reliably receive MSG2 without correction.

[0191] FIG. 15 is an example for explaining R2D message transmission according to one embodiment of the present specification.

[0192] A reader that receives MSG1 from n devices can determine the size of MSG1 for each device. Additionally, the reader can determine RA type information for each device or device group, thereby determining the expected size of MSG1 for each device or device group. For example, if the reader explicitly informs a device or device group of a 2-step or 3-step RA type, the reader may know the RA type information for each device or device group in advance. Furthermore, if a device or device group implicitly selects its own RA type and transmits it including RA type information in the MSG1, the reader can determine the RA type information for each device or device group.

[0193] Therefore, by the reader transmitting MSG2 per device or device group operating with MSG1 of the same size or RA type of the same step, the expected interval for device-specific R2D reception [T resulting from MSG1 of different sizes D2R_mim , T D2R_max ] Without any problems, the devices can receive MSG2. In FIG. 15, it is assumed that device 2 / 3 operates in 3-step RA and device 1 / 4 operates in 2-step RA. Referring to FIG. 15, a reader that receives MSG1 from devices operating in different RA steps, [T of device 2 / 3 D2R_mim , T D2R_max Considering ], MSG2 for device 2 / 3 can be transmitted first, and then MSG2 for device 1 / 4 can be transmitted.

[0194] FIG. 16 is a flowchart illustrating a method of operation of a terminal according to one embodiment of the present specification.

[0195] Referring to FIG. 16, an A-IoT device (i.e., a terminal) obtains R2D reception interval correction information (S1601). The R2D reception interval correction information can be obtained through at least one of i) a paging message transmitted from a reader, ii) an R2D message that triggers RA (Random Access), iii) a message that explicitly transmits an x-step RA type, and iv) a message containing resource information for D2R transmission.

[0196] Subsequently, the terminal corrects at least one of the R2D reception expectation interval and the R2D monitoring interval based on the acquired correction information (S1602). The correction of R2D monitoring is [T D2R_mim , T D2R_max ] can be corrected by an amount of 'α'. For example, [T D2R_min , T D2R_max It can be corrected to ±α.

[0197] FIG. 17 is a flowchart illustrating a method of operation between a reader and a terminal according to one embodiment of the present specification.

[0198] Referring to FIG. 17, when an A-IoT device (i.e., a terminal) implicitly selects an RA type, the device transmits RA type information from the reader (S1701). Here, the RA type information may be 'x-step' RA type information. (x may be one of 2, 3, and 4.)

[0199] Meanwhile, the reader transmits an R2D message to i) devices (or device groups) that have transmitted message 1 of the same size, or ii) devices (device groups) that operate with the same RA type (S1702). Here, the transmission of the R2D message to devices (device groups) that operate with the same RA type can be performed based on 'x-step' RA type information received from the A-IoT device.

[0200] FIG. 18 illustrates a procedure between a reader and a terminal according to one embodiment of the present specification.

[0201] Hereinafter, with reference to FIG. 18, the operation of an A-IoT device (i.e., a terminal) will be described in detail.

[0202] 1. An A-IoT device receives an R2D message (e.g., an A-IoT paging message) from a reader (e.g., a base station) (S1801). The message may be a message containing resource information for D2R transmission (e.g., MSG1). That is, it may contain time and / or frequency resource information for CBRA-based D2R transmission (e.g., MSG1). Additionally, it may contain information for instructing a device or group of devices on an 'x-step' RA type. (x may be one of 2, 3, and 4.)

[0203] Additionally, the message contains the R2D reception expectation interval [T D2R_min , T D2R_max ] and / or α information (compensation information) for compensating the R2D message monitoring interval may be included. Here, the α information [T which can be set differently for each device corresponding to a 2-step, 3-step, or 4-step RA type, or for each device type (device 1 / 2a / 2b). D2R_min , T D2R_max It can be mapped to indicate the correction of the ] interval.

[0204] The above message may be a message from an upper layer, a MAC (Medium Access Control) layer, or a PHY (Physical) layer, and may be received via PDRCH. For example, a message from the MAC layer may be a MAC CE (Control Element).

[0205] If the reader knows the MSG1 size for a device or per device, it can transmit including α information that varies according to different MSG1 sizes. Here, the α value based on the α information may be the difference between the largest MSG1 size and a smaller MSG1 size, and in this case, the α value may be set differently for each device or device group. For example, X in order of largest MSG1 size device 1 , Y device 2 , Z device 3 If so, the α value of device 2 is XY or (T D2R_max device 1 - T D2R_max device 2 ), the α value of device 3 is (XZ) or (T D2R_max device 1 - T D2R_max device 3 It can be calculated in the form of ). Here, X, Y, and Z values ​​may represent transmission time based on the amount of data.

[0206] If the MSG1 transmission start time or MSG1 transmission end time differs by device or device group, it may be set based on the MSG1 transmission start time and / or MSG1 transmission end time along with the largest MSG1 size. For example, X in order of largest MSG1 size device 1 , Y device 2 , Z device 3 In this case, if the MSG1 transmission start time of Device 1 is set to start later by a time size β compared to Device 2 / 3, or if a delay of a time size β is expected, the α value of Device 2 is (X-Y+β) or (T D2R_max device 1 - T D2R_max device 2 It can be in the form of (+ β), and the α value of device 3 is (X-Z+β) or (T D2R_max device 1 - T D2R_max device 3 It can be in the form of + β).

[0207] 2. The A-IoT device, based on frequency resource information among the received CBRA-based resources, monitors the R2D time interval and / or expects the reception of an R2D message [T D2R_min , T D2R_max ] is corrected. The R2D monitoring time interval and / or R2D message reception expectation interval can be corrected as follows.

[0208] [T D2R_min +α, T D2R_max +α] or [T D2R_min , T D2R_max +α]

[0209] 3. The A-IoT device transmits MSG1 through an arbitrary frequency resource based on the received contention resource information (S1802, S1803).

[0210] 4. The A-IoT device monitors MSG2 reception during the corrected R2D monitoring time interval and / or the corrected R2D message reception expectation interval.

[0211] 5. If the A-IoT device succeeds in receiving MSG2 within the corrected time interval (S1804), the 3-step / 4-step RA devices proceed with subsequent procedures. If the A-IoT device fails to receive MSG2, it may perform a procedure for requesting MSG2 retransmission or retransmitting MSG1.

[0212] Hereinafter, with reference to FIG. 18, the operation of a reader (e.g., a base station) will be described in detail.

[0213] 1. The reader transmits an R2D message (e.g., an A-IoT paging message) to an A-IoT device (S1801). The message may be a message containing resource information for D2R transmission (e.g., MSG1). That is, it may contain time and / or frequency resource information for CBRA-based D2R transmission (e.g., MSG1). Additionally, it may contain information for indicating an 'x-step' RA type to a device or group of devices. (x may be one of 2, 3, and 4.)

[0214] Additionally, the message contains the device's expected R2D reception interval [T D2R_min , T D2R_max ] and / or α information for correcting the R2D message monitoring interval may be included. Here, the α information [T which can be set differently per device corresponding to a 2-step, 3-step, or 4-step RA type, or per device type (device 1 / 2a / 2b). D2R_min , T D2R_max It can be mapped to indicate the correction of the ] interval.

[0215] The above message may be a message from an upper layer, a MAC (Medium Access Control) layer, or a PHY (Physical) layer, and may be transmitted via PDRCH. For example, a message from the MAC layer may be a MAC CE (Control Element).

[0216] If the reader knows the MSG1 size for a device or per device, it can transmit including α information that varies according to different MSG1 sizes. Here, the α value based on the α information may be the difference between the largest MSG1 size and a smaller MSG1 size, and in this case, the α value may be set differently for each device or device group. For example, X in order of largest MSG1 size device 1 , Y device 2 , Zdevice 3 If so, the α value of device 2 is XY or (T D2R_max device 1 - T D2R_max device 2 ), the α value of device 3 is (XZ) or (T D2R_max device 1 - T D2R_max device 3 It can be calculated in the form of ). Here, X, Y, and Z values ​​may represent transmission time based on the amount of data.

[0217] If the MSG1 transmission start time or MSG1 transmission end time differs by device or device group, it may be set based on the MSG1 transmission start time and / or MSG1 transmission end time along with the largest MSG1 size. For example, X in order of largest MSG1 size device 1 , Y device 2 , Z device 3 In this case, if the MSG1 transmission start time of Device 1 is set to start later by a time size β compared to Device 2 / 3, or if a delay of a time size β is expected, the α value of Device 2 is (X-Y+β) or (T D2R_max device 1 - T D2R_max device 2 It can be in the form of (+ β), and the α value of device 3 is (X-Z+β) or (T D2R_max device 1 - T D2R_max device 3 It can be in the form of + β).

[0218] 2. The reader receives MSG1, which is distinguished by different frequency resources, from the A-IoT device (S1802, S1803).

[0219] 3. The reader uses T based on the last received MSG1. D2R_minConsidering this, preparation for transmitting MSG2 corresponding to MSG1 or starting transmission can be performed or transmission can be started through arbitrary time resources from that point in time or during the set MSG2 monitoring period (S1804).

[0220] FIG. 19 illustrates a procedure between a reader and a terminal according to another embodiment of the present specification.

[0221] Hereinafter, with reference to FIG. 19, the operation of an A-IoT device (i.e., a terminal) will be described in detail.

[0222] 1. An A-IoT device receives an R2D message (e.g., an A-IoT paging message) from a reader (e.g., a base station) (S1901). The message may be a message containing resource information for D2R transmission (e.g., MSG1). That is, it may contain time and / or frequency resource information for CBRA-based D2R transmission (e.g., MSG1). Additionally, it may contain information for instructing a device or group of devices on an 'x-step' RA type. (x may be one of 2, 3, and 4.)

[0223] 2. The A-IoT device transmits MSG1 through an arbitrary frequency resource based on the received contention resource information (S1902, S1904). If the device has implicitly determined its own RA step type, the 'x-step' RA type information selected by the device may be included in MSG1 and transmitted. And / or, the size information of the MSG1 that the device transmits may be included in MSG1 and transmitted.

[0224] 3. The A-IoT device has its R2D monitoring time interval or R2D message reception expectation interval [T D2R_min , T D2R_maxIf MSG2 is successfully received in ] (S1903, S1905), the 3-step / 4-step RA devices proceed with subsequent procedures. If the A-IoT device fails to receive MSG2, it may perform a procedure for requesting MSG2 retransmission or retransmitting MSG1.

[0225] Hereinafter, with reference to FIG. 19, the operation of a reader (e.g., a base station) will be described in detail.

[0226] 1. The reader transmits an R2D message (e.g., an A-IoT paging message) to an A-IoT device (S1901). The message may be a message containing resource information for D2R transmission (e.g., MSG1). That is, it may contain time and / or frequency resource information for CBRA-based D2R transmission (e.g., MSG1). Additionally, it may contain information for indicating an 'x-step' RA type to a device or group of devices. (x may be one of 2, 3, and 4.)

[0227] 2. The reader receives an MSG1 from an A-IoT device that is distinguished by different frequency resources (S1902, S1904). If the device implicitly determines its own RA step type, or if the RA type information is not included in the R2D message (e.g., an A-IoT paging message), information regarding the 'x-step' RA type selected by the device(s) may be received in the MSG1. And / or, size information of the MSG1 transmitted by the device may be received in the MSG1. Through this, the reader can obtain size information of the MSG1 corresponding to each device or device group.

[0228] 3. Based on the information contained in MSG1, the reader transmits MSG2 for each device and / or device group that operates at the same RA step or transmitted an MSG1 of the same size (S1903, S1905). That is, the reader transmits MSG2 by grouping devices or device groups that operate at the same RA step. For example, the reader may first transmit an MSG2 corresponding to an MSG1 transmitted by a device or device group operating at 3-step RA, and then transmit an MSG2 corresponding to an MSG1 transmitted by a device or device group operating at 2-step RA. If the reader receives multiple MSG1s distinguished by n frequencies, it may group them by devices or device groups that transmitted an MSG1 of the same size and transmit an MSG2 corresponding to that MSG1. Alternatively, the reader T D2R_min or T D2R_max Based on this, devices corresponding to the MSG1 received first in the time domain can be grouped together to transmit the MSG2 corresponding to the MSG1.

[0229] The disclosures of this specification described above may be implemented through various means. For example, the disclosures of this specification may be implemented by hardware, firmware, software, or a combination thereof. Specifically, they will be described below with reference to the drawings.

[0230] FIG. 20 shows an apparatus according to one embodiment of the present specification.

[0231] Referring to FIG. 20, the wireless communication system may include a first device (100a) and a second device (100b).

[0232] The first device (100a) may be a base station, network node, transmission terminal, receiving terminal, wireless device, wireless communication device, vehicle, vehicle equipped with autonomous driving function, connected car, drone (Unmanned Aerial Vehicle, UAV), AI (Artificial Intelligence) module, robot, AR (Augmented Reality) device, VR (Virtual Reality) device, MR (Mixed Reality) device, hologram device, public safety device, MTC device, IoT device, medical device, fintech device (or financial device), security device, climate / environment device, device related to 5G service, or other device related to the field of the Fourth Industrial Revolution.

[0233] The second device (100b) may be a base station, network node, transmission terminal, receiving terminal, wireless device, wireless communication device, vehicle, vehicle equipped with autonomous driving function, connected car, drone (Unmanned Aerial Vehicle, UAV), AI (Artificial Intelligence) module, robot, AR (Augmented Reality) device, VR (Virtual Reality) device, MR (Mixed Reality) device, hologram device, public safety device, MTC device, IoT device, medical device, fintech device (or financial device), security device, climate / environment device, device related to 5G service, or other device related to the field of the Fourth Industrial Revolution.

[0234] The first device (100a) may include at least one processor, such as a processor (1020a), at least one memory, such as a memory (1010a), and at least one transceiver, such as a transceiver (1031a). The processor (1020a) may perform the aforementioned functions, procedures, and / or methods. The processor (1020a) may perform one or more protocols. For example, the processor (1020a) may perform one or more layers of a wireless interface protocol. The memory (1010a) is connected to the processor (1020a) and may store various forms of information and / or commands. The transceiver (1031a) is connected to the processor (1020a) and may be controlled to transmit and receive wireless signals.

[0235] The second device (100b) may include at least one processor, such as a processor (1020b), at least one memory device, such as a memory (1010b), and at least one transceiver, such as a transceiver (1031b). The processor (1020b) may perform the aforementioned functions, procedures, and / or methods. The processor (1020b) may implement one or more protocols. For example, the processor (1020b) may implement one or more layers of a wireless interface protocol. The memory (1010b) is connected to the processor (1020b) and may store various forms of information and / or commands. The transceiver (1031b) is connected to the processor (1020b) and may be controlled to transmit and receive wireless signals.

[0236] The memory (1010a) and / or the memory (1010b) may be connected to the processor (1020a) and / or the processor (1020b) respectively, either internally or externally, and may also be connected to other processors through various technologies such as wired or wireless connections.

[0237] The first device (100a) and / or the second device (100b) may have one or more antennas. For example, the antenna (1036a) and / or antenna (1036b) may be configured to transmit and receive wireless signals.

[0238] FIG. 21 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0239] In particular, FIG. 21 is a drawing illustrating the device of FIG. 20 in more detail.

[0240] The device includes a memory (1010), a processor (1020), a transceiver (1031), a power management module (1091), a battery (1092), a display (1041), an input unit (1053), a speaker (1042) and a microphone (1052), a SIM (subscriber identification module) card, and one or more antennas.

[0241] The processor (1020) may be configured to implement the proposed functions, procedures, and / or methods described herein. Layers of a radio interface protocol may be implemented in the processor (1020). The processor (1020) may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The processor (1020) may be an application processor (AP). The processor (1020) may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of processors (1020) may be SNAPDRAGON™ series processors manufactured by Qualcomm®, EXYNOSTM series processors manufactured by Samsung®, A series processors manufactured by Apple®, HELIO™ series processors manufactured by MediaTek®, ATOM™ series processors manufactured by INTEL®, KIRINTM series processors manufactured by HiSilicon®, or corresponding next-generation processors.

[0242] The power management module (1091) manages power for the processor (1020) and / or the transceiver (1031). The battery (1092) supplies power to the power management module (1091). The display (1041) outputs the results processed by the processor (1020). The input unit (1053) receives input to be used by the processor (1020). The input unit (1053) may be displayed on the display (1041). A SIM card is an integrated circuit used to securely store the International Mobile Subscriber Identity (IMSI) and associated keys used to identify and authenticate a subscriber in mobile devices such as mobile phones and computers. Contact information may also be stored on many SIM cards.

[0243] Memory (1010) is operably coupled with the processor (1020) and stores various information for operating the processor (610). Memory (1010) may include ROM (read-only memory), RAM (random access memory), flash memory, memory card, storage medium and / or other storage device. Where the embodiment is implemented in software, the techniques described herein may be implemented as modules (e.g., procedures, functions, etc.) that perform the functions described herein. Modules may be stored in memory (1010) and executed by the processor (1020). Memory (1010) may be implemented inside the processor (1020). Alternatively, memory (1010) may be implemented outside the processor (1020) and may be communically connected to the processor (1020) through various means known in the art.

[0244] The transceiver (1031) is operably coupled with the processor (1020) and transmits and / or receives a wireless signal. The transceiver (1031) includes a transmitter and a receiver. The transceiver (1031) may include a baseband circuit for processing a wireless frequency signal. The transceiver controls one or more antennas to transmit and / or receive a wireless signal. The processor (1020) transmits command information to the transceiver (1031) to transmit a wireless signal, for example, constituting voice communication data, in order to initiate communication. The antennas function to transmit and receive wireless signals. When receiving a wireless signal, the transceiver (1031) may transmit the signal to the processor (1020) for processing and convert the signal to baseband. The processed signal may be converted into audible or readable information output through a speaker (1042).

[0245] The speaker (1042) outputs sound-related results processed by the processor (1020). The microphone (1052) receives sound-related input to be used by the processor (1020).

[0246] The user inputs command information, such as a phone number, by, for example, pressing (or touching) a button on the input unit (1053) or by voice activation using the microphone (1052). The processor (1020) receives this command information and processes it to perform appropriate functions, such as making a call to the phone number. Operational data can be extracted from a SIM card or memory (1010). Additionally, the processor (1020) can display the command information or operation information on the display (1041) for the user's awareness and convenience.

[0247] FIG. 22 shows a block diagram of a processor in which the disclosure of the present specification is implemented.

[0248] As can be seen with reference to FIG. 22, a processor (1020) in which the disclosure of this specification is implemented may include a plurality of circuits to implement the proposed functions, procedures and / or methods described in this specification. For example, the processor (1020) may include a first circuit (1020-1), a second circuit (1020-2), and a third circuit (1020-3). Additionally, although not illustrated, the processor (1020) may include more circuits. Each circuit may include a plurality of transistors.

[0249] The above processor (1020) may be called an ASIC (application-specific integrated circuit) or an AP (application processor), and may include at least one of a DSP (digital signal processor), a CPU (central processing unit), and a GPU (graphics processing unit).

[0250] FIG. 23 is a block diagram showing in detail the transceiver of the first device shown in FIG. 20 or the transceiver of the device shown in FIG. 21.

[0251] Referring to FIG. 23, the transceiver unit (1031) includes a transmitter (1031-1) and a receiver (1031-2). The transmitter (1031-1) includes a Discrete Fourier Transform (DFT) unit (1031-11), a subcarrier mapper (1031-12), an IFFT unit (1031-13), a CP insertion unit (1031-14), and a wireless transmitter (1031-15). The transmitter (1031-1) may further include a modulator. Additionally, it may further include, for example, a scramble unit (not shown), a modulation mapper (not shown), a layer mapper (not shown), and a layer permutator (not shown), which may be positioned prior to the DFT unit (1031-11). That is, to prevent an increase in the PAPR (peak-to-average power ratio), the transmitter (1031-1) first passes the information through the DFT (1031-11) before mapping the signal to the subcarrier. After the signal spread (or precoded in the same sense) by the DFT section (1031-11) is mapped to the subcarrier through the subcarrier mapper (1031-12), it is then passed through the IFFT (Inverse Fast Fourier Transform) section (1031-13) to form a signal on the time axis.

[0252] The DFT unit (1031-11) performs a DFT on the input symbols to output complex-valued symbols. For example, if Ntx symbols are input (where Ntx is a natural number), the DFT size is Ntx. The DFT unit (1031-11) may be called a transform precoder. The subcarrier mapper (1031-12) maps the complex-valued symbols to each subcarrier in the frequency domain. The complex-valued symbols may be mapped to resource elements corresponding to resource blocks allocated for data transmission. The subcarrier mapper (1031-12) may be called a resource element mapper. The IFFT unit (1031-13) performs an IFFT on the input symbols to output a baseband signal for the data, which is a time-domain signal. The CP insertion section (1031-14) copies a portion of the latter part of the base band signal for data and inserts it into the front part of the base band signal for data. Through CP insertion, Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) are prevented, so that orthogonality can be maintained even in a multipath channel.

[0253] On the other hand, the receiver (1031-2) includes a wireless receiver (1031-21), a CP removal unit (1031-22), an FFT unit (1031-23), and an equalization unit (1031-24), etc. The wireless receiver (1031-21), CP removal unit (1031-22), and FFT unit (1031-23) of the receiver (1031-2) perform the inverse functions of the wireless transmitter (1031-15), CP insertion unit (1031-14), and IFF unit (1031-13) of the transmitter (1031-1). The receiver (1031-2) may further include a demodulator.

[0254] Although preferred embodiments have been described by way of example above, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope of the spirit and claims of this specification.

[0255] In the exemplary system described above, methods are described based on a flowchart as a series of steps or blocks, but are not limited to the order of the described steps, and some steps may occur in a different order or simultaneously with other steps as described above. Furthermore, a person skilled in the art will understand that the steps shown in the flowchart are not exclusive, and that other steps may be included, or that one or more steps of the flowchart may be omitted without affecting the scope of rights.

[0256] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

1. In a method of operation of a terminal in a wireless communication system, A step of receiving duration information for receiving an R2D (Reader to Device) message; A step of correcting the interval for receiving the R2D message based on the received interval information; and A method comprising the step of receiving the R2D message based on the above-mentioned corrected interval.

2. In Paragraph 1, A method in which the interval for receiving the above R2D message is at least one of an R2D reception expectation interval and an R2D monitoring interval.

3. In Paragraph 1, A method in which the above interval information is received through a paging message or a message setting a D2R (Device to Reader) transmission resource.

4. In Paragraph 1, It further includes the step of transmitting a first message, and A method in which the R2D message is received as a second message in response to the first message.

5. In Paragraph 4, A method in which the above interval information is set differently according to at least one of a random access (RA) step type, a terminal type, and the size of the first message.

6. In Paragraph 4, A method wherein the first message comprises at least one of random access (RA) step type information and size information of the first message.

7. In Paragraph 6, The above first message is a method transmitted through a competition-based resource.

8. In Paragraph 4, A method in which the above R2D message is configured according to at least one of the same random access (RA) step type, the same terminal type, and the same size of the first message.

9. As a terminal in a wireless communication system, At least one processor; and The operation performed based on the instruction being executed by the at least one processor includes at least one memory that stores instructions and is operablely electrically connected to the at least one processor: A step of receiving duration information for receiving an R2D (Reader to Device) message, and A step of correcting the interval for receiving the R2D message based on the received interval information, and, A terminal comprising the step of receiving the R2D message based on the above-mentioned corrected interval.

10. In Paragraph 9, A terminal for receiving the above R2D message, wherein the interval for receiving the above R2D message is at least one of an R2D reception expectation interval and an R2D monitoring interval.

11. In Paragraph 9, A terminal that receives the above section information through a paging message or a message setting a D2R (Device to Reader) transmission resource.

12. In Paragraph 9, Based on the execution of the above instruction by the at least one processor, the operation performed is: It further includes the step of transmitting a first message, and A terminal receiving the R2D message as a second message in response to the first message.

13. In Paragraph 12, A terminal, wherein the above interval information is set differently according to at least one of a random access (RA) step type, a terminal type, and the size of the first message.

14. In Paragraph 12, A terminal comprising at least one of random access (RA) step type information and size information of the first message, wherein the first message comprises at least one of the above.

15. In Paragraph 14, The above first message is a terminal transmitted through a contention-based resource.

16. In Paragraph 12, The above R2D message is configured according to at least one of the same random access (RA) step type, the same terminal type, and the same size of the first message.

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