Method and apparatus for d2r transmission and reception

Abstract

A method according to one embodiment of the present specification comprises steps in which: an R2D message including information about D2R transmission is received; and a device performs D2R transmission for a reader. The D2R transmission is related to a PDRCH, a D2R preamble and one or more D2R midambles. The D2R transmission includes i) the PDRCH after block repetition, ii) the D2R preamble and iii) the one or more D2R midambles. In the D2R transmission, each of the D2R preamble and the one or more D2R midambles is arranged on the basis of an interval for D2R midamble insertion indicated on the basis of the information.

Description

Method and apparatus for D2R transmission and reception

[0001] This specification relates to a method and apparatus for D2R transmission and reception.

[0002] The 5G mobile communication system is a successor technology to LTE (Long Term Evolution) and is a new clean-slate type of mobile communication system characterized by high performance, low latency, and high availability. In the case of 5G NR, all available spectrum resources can be utilized, ranging from low-frequency bands below 1 GHz to intermediate frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz. Based on the underlying technology of 5G mobile communication, 6G mobile communication systems are being developed.

[0003] The 6G (wireless communication) system aims for (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of battery-free IoT (internet of things) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity.

[0004] Meanwhile, as of Release 19, in the procedure for D2R transmission of Ambient IoT, the device performs block repetition.

[0005] When the aforementioned block repetition is performed, reception sensitivity increases, but the packet / bit length (Time Duration) increases. In such cases, the following problems occur.

[0006] Due to the structure of A-IoT devices (e.g., low-cost oscillators or backscatter structures), timing / frequency errors (e.g., Carrier Frequency Offset (CFO), Sampling Frequency Offset (SFO), timing drift) are prone to accumulating during the transmission of long packets (bit sequences with long lengths). Consequently, the Bit Error Rate (BER) may worsen.

[0007] In addition, if the reader fails to reliably track repeated transmissions, failure to detect or incorrect determination of some repeated blocks may occur, which may lead to a decrease in the D2R reception success rate or an increase in retries / retransmissions.

[0008] The purpose of this specification is to propose a method for solving the aforementioned problems. More specifically, the purpose of this specification is to propose a method that supports synchronization maintenance and channel estimation updates throughout the transmission interval in D2R transmissions performing block repetition, and can alleviate the burden on the reader while securing iterative combination gain.

[0009] The technical problems to be solved in this specification are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this specification belongs from the description below.

[0010] A method according to an embodiment of the present specification for solving the aforementioned technical problem comprises the steps of receiving an R2D message containing information for D2R (Device to Reader) transmission from a reader by a device, and performing D2R transmission to the reader by the device based on the information. The D2R transmission involves a PDRCH (Physical Device to Reader Channel), a D2R preamble, and one or more D2R midambles. Based on the information, a repetition number is indicated, and a block repetition is performed based on the repetition number. The D2R transmission includes i) the PDRCH after the block repetition, ii) the D2R preamble, and iii) the one or more D2R midambles. In the D2R transmission, the D2R preamble is arranged at the very beginning. In the above D2R transmission, each of the D2R preamble and the one or more D2R midambles is positioned based on an interval for D2R midamble insertion indicated based on the information. In the above D2R transmission, the PDRCH is characterized by being positioned on all bits not occupied by the D2R preamble or the one or more D2R midambles.

[0011] Therefore, since D2R preambles and one or more midambles are arranged based on a fixed interval and PDRCH bits are distributed after block repetition at each position (bit) corresponding to that fixed interval, the D2R-related procedure can be improved in terms of maintaining synchronization, updating channel estimates, and iterative combination gain compared to the case where only block repetition is applied.

[0012] According to an embodiment of the present specification, a D2R preamble is placed at the beginning of a bit sequence, and subsequently, a D2R midamble is inserted based on a fixed interval. Accordingly, the reader can reliably acquire initial timing synchronization at the start of transmission by the device and can periodically correct timing drift even during transmission. Therefore, the accumulation of synchronization errors can be suppressed even when the transmission interval is extended due to block repetition.

[0013] In addition, since preambles and midambles are inserted at regular intervals, the reader can update the channel (or equivalent channel) estimate for each interval. As a result, demodulation performance, such as BER or BLER, can be improved even in channel environments that change over time or have high variability. Furthermore, by using the midambles inserted during transmission, the reader can periodically estimate and correct frequency / sampling-related errors, such as frequency error (CFO) and sampling error (SFO), thereby mitigating the accumulation of residual errors.

[0014] Even when block repetition is performed, increasing the length of the bit sequence or when there are multiple repetition intervals, synchronization and channel estimation accuracy for each repetition interval can be secured through preamble and midamble. Accordingly, the reader can combine the repetition blocks in a more aligned state and improve reception sensitivity and recovery success rate by securing combination gain.

[0015] The insertion intervals for D2R preambles and D2R midambles can be dynamically specified based on R2D messages. Accordingly, the trade-off between overhead and performance can be optimized on a situational basis. Specifically, when the channel is stable or the transmission length is short, increasing the midamble interval to lower the insertion frequency can reduce pilot overhead and improve pure data transmission efficiency or effective throughput. Conversely, when channel variability is high or CFO / SFO drift is significant, decreasing the midamble interval to increase the insertion frequency allows for more frequent tracking and correction, thereby improving demodulation performance (BER / BLER) and reception reliability.

[0016] In addition, according to the embodiments of this specification, an insertion interval may be indicated to correspond to heterogeneity of the device or environment (e.g., whether a low-cost oscillator is used, mobility, energy status, etc.). For example, when the types of devices differ or the harvesting / battery states differ, the reader may induce optimal operation for each device by indicating different intervals according to the device characteristics.

[0017] In addition, since the interval during which synchronization and channel estimation are maintained may vary depending on the number of iterations or frame length, if the reader adjusts the insertion interval according to the situation, it can maintain alignment quality between iteration blocks and mitigate the degradation of combination gain. In particular, if the fixed interval for inserting preambles / midambles is excessively wide, failures due to performance degradation may increase in the latter part of the transmission; conversely, if it is excessively dense, transmission efficiency may decrease due to increased overhead. Therefore, by dynamically controlling the insertion interval, the probability of failure can be lowered, thereby reducing retries and decreasing mean latency and worst-case latency.

[0018] Even in environments where multiple terminals operate simultaneously, uniformly applying conservative intervals to all devices can increase overall overhead. In contrast, if the reader applies differential instructions by increasing the insertion interval for devices with good link quality and decreasing it for devices with poor link quality, shared resource efficiency can be improved, and the number of accommodated devices or system capacity can be enhanced.

[0019] In addition, by dynamically instructing the device on the insertion interval, the reader can adaptively optimize the balance between midamble overhead and synchronization / channel tracking performance based on channel variation, oscillator error, transmission length, number of iterations, etc. As a result, improved reception reliability, securing iterative combining gain, reduced retransmissions, and enhanced resource efficiency and system capacity can be achieved.

[0020] The effects obtainable in this specification are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which this specification belongs from the description below.

[0021] Figure 1 illustrates a topology 1 related to Ambient IoT.

[0022] Figure 2 illustrates topology 2 related to Ambient IoT.

[0023] Figure 3 is an example of topology 3 related to Ambient IoT.

[0024] Figure 4 is another example of topology 3 related to Ambient IoT.

[0025] Figure 5 illustrates topology 4 related to Ambient IoT.

[0026] Figure 6 illustrates the state according to the operating state of an energy harvesting-based device.

[0027] Figure 7 is a diagram illustrating scenarios of topology 1.

[0028] Figure 8 is a diagram illustrating scenarios of topology 2.

[0029] FIG. 9 illustrates the structure of device type 1.

[0030] FIG. 10 illustrates the structure of device type 2a.

[0031] Figure 11 illustrates the structure of device type 2b.

[0032] Figure 12 illustrates the entire AS procedure between the device and the reader.

[0033] FIG. 13 illustrates resource allocation for messages of a random access procedure according to an embodiment of the present specification.

[0034] FIG. 14 illustrates resource allocation for Msg1 / Msg3 according to an embodiment of the present specification.

[0035] FIG. 15 illustrates a TDM iterative transmission according to an embodiment of the present specification.

[0036] FIG. 16 illustrates an FDM iterative transmission according to an embodiment of the present specification.

[0037] FIG. 17 illustrates a table for determining transmission resources according to an embodiment of the present specification.

[0038] FIG. 18 shows examples in which a midamble is inserted according to an embodiment of the present specification.

[0039] FIG. 19 illustrates the structure of Control information and PRDCH or PDRCH according to an embodiment of the present specification.

[0040] FIG. 20 illustrates a transmission including a preamble and a postamble according to an embodiment of the present specification.

[0041] FIG. 21 illustrates a MAC Payload structure according to an embodiment of the present specification.

[0042] FIG. 22 illustrates D2R transmission and midamble transmission according to an embodiment of the present specification.

[0043] FIG. 23 is a flowchart illustrating a method according to one embodiment of the present specification.

[0044] FIG. 24 is a flowchart illustrating a method according to another embodiment of the present specification.

[0045] FIG. 25 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0046] 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."

[0047] A slash ( / ) or a comma used in this specification 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."

[0048] 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."

[0049] 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." Also, "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."

[0050] Additionally, parentheses used in this specification may mean "for example." Specifically, when indicated as "control information (PDCCH)," "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" 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."

[0051] In the following explanation, 'when, if, in case of' can be replaced with 'based on'.

[0052] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0053] In this specification, the terminal (UE, User Equipment) may be a portable device and may be a second node that receives a signal from a base station / first node / IAB node.

[0054] In this specification, a base station (BS, Base Station) may be a base station / first node / IAB node / transmission-reception point.

[0055] In this specification, a higher layer parameter may be a parameter that is set for the terminal, pre-set, or pre-defined. For example, a base station or a network may transmit the higher layer parameter to the terminal. For example, the higher layer parameter may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0056] In this specification, "set or defined" may be interpreted as being set or pre-configured to the device through pre-defined signaling (e.g., SIB, MAC, RRC) from a base station or network. In this specification, "set or defined" may be interpreted as being pre-configured to the device.

[0057] In the following, the downlink (DL) refers to communication from a base station to a terminal, and the uplink (UL) refers to communication from a terminal to a base station. In the downlink, the transmitter may be part of the base station and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal and the receiver may be part of the base station. The base station may be referred to as the first communication device and the terminal as the second communication device. The base station (BS) may be replaced by terms such as fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), Access Point (AP), network (5G network), AI system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device.

[0058] Ambient IoT communication (Rel-18) >

[0059] Ambient IoT (A-IoT) can be a new type of device or segment that operates solely on energy harvested from the surrounding environment. For example, A-IoT can refer to a new type of Internet of Things device that operates by being powered by various energy sources harvestable from the surrounding environment, such as radio waves, light, motion, and thermal energy. Examples of A-IoT use cases are shown in Table 1 below.

[0060]

[0061] Table 2 shows matters related to IoT communication discussed in the 3GPP RAN.

[0062]

[0063] For example, active signal generation and / or backscattering may be one of the communication technologies considered to achieve low-power operation of A-IoT devices. For example, backscattering is a widely used technique in radio frequency identification (RFID) that can enable a device to communicate with a network by reflecting incident waves after modulating them with information to be transmitted. For example, the device may be powered by an incident RF signal or stored energy.

[0064] For example, A-IoT devices can be classified into various device types, such as passive, semi-passive, and active, depending on the energy storage and transmission signal generation methods. For example, a passive device does not have an energy storage device (e.g., a capacitor) and can communicate based on backscatter communication technology. For example, a semi-passive device has an energy storage device and can communicate using backscatter communication technology with the assistance of the energy storage device. For example, an active device has an energy storage device and can communicate by actively generating signals using active RF components and stored energy. For example, in the present disclosure, the following three types of IoT devices may be considered. For example, device A may be a device without energy storage and without independent signal generation (e.g., a device supporting backscatter transmission). For example, device B may be a device with energy storage and without independent signal generation (e.g., a device supporting backscatter transmission). In this case, for example, the use of the stored energy may include amplification of the reflected signal. For example, device C may be a device with energy storage and independent signal generation (e.g., a device with an active RF component for transmission).

[0065] For example, the following basic topologies may be considered to support A-IoT devices in indoor and outdoor scenarios. For example, basic topologies may include a direct connection between a base station and an A-IoT device, a connection between a base station, an intermediate node, and an A-IoT device, support for connection by an auxiliary node, and / or a connection between a terminal and an A-IoT device. The basic topologies proposed in this disclosure are merely examples, and the proposals of this disclosure may be extended and applied to other topologies.

[0066] Figure 1 illustrates a topology 1 related to Ambient IoT.

[0067] Specifically, FIG. 1 shows a topology (e.g., Topology 1) in which a base station and an A-IoT device are directly connected according to one embodiment of the present disclosure. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure.

[0068] Referring to FIG. 1, an A-IoT device (Ambient IoT device) can communicate directly and bidirectionally with a base station (BS). For example, communication between the base station and the A-IoT device may include A-IoT data and / or signals. For example, A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 1, the base station transmitting to the A-IoT device and the base station receiving from the A-IoT device may be different. For example, in the topology 1, the base station and the A-IoT device in a micro-cell environment may communicate directly with each other. For example, the base station may be located at a co-site with a base station equipped with existing 3GPP technology.

[0069] Figure 2 illustrates topology 2 related to Ambient IoT.

[0070] Specifically, FIG. 2 illustrates a topology (e.g., Topology 2) in which a base station (BS) and an A-IoT device (Ambient IoT device) are connected through an intermediate node, according to one embodiment of the present disclosure. The embodiment of FIG. 2 may be combined with various embodiments of the present disclosure.

[0071] Referring to FIG. 2, an A-IoT device can communicate bidirectionally with an intermediate node between the device and the base station. Here, for example, the intermediate node may be an A-IoT-enabled relay, IAB node, terminal, repeater, etc. For example, the intermediate node may transmit A-IoT data and / or signals between the base station and the A-IoT device. For example, A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 2, the intermediate node transmitting to the A-IoT device and the intermediate node receiving from the A-IoT device may be different. For example, in the topology 2, an intermediate node may exist between the base station in a macro-cell environment and the A-IoT device. For example, the base station may be located at a co-site with a base station equipped with existing 3GPP technology. For example, the intermediate node can be limited to a terminal, and the intermediate node can be located indoors.

[0072] Figure 3 is one example of topology 3 related to Ambient IoT. Figure 4 is another example of topology 3 related to Ambient IoT.

[0073] FIGS. 3 and 4 illustrate a topology (e.g., topology 3) supported by an assisting node according to one embodiment of the present disclosure. The embodiment of FIGS. 3 and 4 may be combined with various embodiments of the present disclosure.

[0074] Referring to FIG. 3, an auxiliary node may be supported for downlink reception. For example, an A-IoT device may transmit data / signals to a base station, and the A-IoT device may receive data / signals from an auxiliary node. Referring to FIG. 4, an auxiliary node may be supported for uplink transmission. For example, an A-IoT device may receive data / signals from a base station, and the A-IoT device may transmit data / signals to an auxiliary node. Here, for example, the auxiliary node may be an A-IoT-enabled relay, IAB node, terminal, repeater, etc.

[0075] Figure 5 illustrates topology 4 related to Ambient IoT.

[0076] Specifically, FIG. 5 illustrates a topology (e.g., topology 4) in which a terminal (UE) and an A-IoT device (Ambient IoT device) are directly connected according to one embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure.

[0077] Referring to FIG. 5, an A-IoT device can communicate bidirectionally with a terminal. For example, communication between the terminal and the A-IoT device may include A-IoT data and / or signals. For example, A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel).

[0078] For example, transmission by an A-IoT device can be performed in the frequency division duplexing (FDD) spectrum (e.g., FDD UL spectrum).

[0079] < Ambient IoT solutions SI (Rel-19) >

[0080] A study item titled “Study on solutions for Ambient IoT (Internet of Things) in NR” was approved in 3GPP NR release 19. Specifically, the study item is scheduled to proceed in 3GPP NR release 19 based on the following.

[0081] This study aims to further evaluate Ambient IoT at the RAN WG level, a new 3GPP IoT technology suitable for deployment in 3GPP systems, which relies on ultra-low complexity devices with ultra-low power consumption for very low-level IoT applications. This study must provide a clear differentiation; that is, it must address use cases and scenarios that cannot be met based on existing 3GPP LPWA IoT technologies (e.g., NB-IoT with reduced peak Tx power).

[0082] General range

[0083] The definitions provided in TR 38.848 apply to this SI, and the following are exclusive general scopes.

[0084] A. The overall objective is to research a harmonized wireless interface design that minimizes differences when Ambient IoT is required to enable the following devices.

[0085] i. ~1μW peak power consumption, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, no DL or UL amplification in the device. The device's UL transmission is backscattered from the externally provided carrier wave.

[0086] ii. Peak power consumption ≤ hundreds of μW1, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, and DL and / or UL amplification in the device. UL transmission in the device may be generated internally or backscattered from carrier waves provided externally.

[0087] -X is determined in WG.

[0088] -Coverage design target: Up to 10-50m distance with the device indoors according to TR 38.848: "...range where WG can sub-select".

[0089] - According to TR 38.848, for Topologies 1 and 2 (UEs acting as intermediate nodes under NW control), there is no RRC state, no mobility (i.e., no functions such as cell selection / reselection at least), no HARQ, and no ARQ.

[0090] Note 1: It should be understood that the WG has no duty to set a specific value for "≤ hundreds of μW", and that determining whether the proposed design and its power consumption meet the "≤ hundreds of μW" requirement is a matter for the WG to discuss.

[0091] B. Deployment scenarios with the following characteristics, referring to the table in Clause 4.2.2 of TR 38.848:

[0092] - Deployment Scenario 1 using Topology 1

[0093] Base Station and Coexistence Characteristics: Microcells, Co-sites

[0094] - Deployment Scenario 2 using a UE as an intermediate node under Topology 2 and network control

[0095] Base Station and Coexistence Characteristics: Macro Cells, Co-sites

[0096] The location of the intermediate node is indoors

[0097] C. FDD's FR1 License Spectrum.

[0098] D. In-band spectrum distribution for NR, guard band for LTE / NR, standalone band(s)

[0099] E. Traffic types DO-DTT, DT focused on rUC1 (Indoor Inventory) and rUC4 (Indoor Command).

[0100] - In RAN#104, this study evaluates whether a harmonized wireless interface design (see bullet point 'A' above) can handle DO-A (Device-Initiated Autonomous) use cases and identifies which parts of the harmonized wireless interface design (see bullet point 'A' above) are insufficient for DO-A use cases.

[0101] Transmission from surrounding IoT devices (including backscattering when in use) may occur at least within the UL spectrum.

[0102] The next goal is set within the general range.

[0103] 1. Evaluation Assumptions

[0104] a) Conclude at least the following aspects of the design objectives left to the WG in Clause 5 (RAN Design Objectives) of TR 38.848 [RAN1].

[0105] Clause 5.3: Applicable maximum distance target value

[0106] Clause 5.6: Refine the definition of latency suitable for use in the RAN WG.

[0107] Clause 5.8: 2D distribution of the device

[0108] b) Define the necessary additional evaluation assumptions for deployment scenarios for coverage and coexistence evaluation. [RAN1, RAN4]

[0109] c) Identify the basic blocks / components of possible peripheral IoT device architectures by considering modern implementations of low-power, low-complexity devices that meet RAN design goals regarding power consumption and complexity. [RAN1]

[0110] d) Define link budget calculations for coverage, including whether / how to model carrier waves at nodes inside or outside the connection topology.

[0111] Note: The evaluation performance of the design target falls within the scope of the feasibility and necessity study of the proposal in the following objectives. For example, it involves inspecting the reference implementation in the field, performing simulations, and conducting analytical analysis.

[0112] Note: We strive to minimize evaluation cases in RAN1.

[0113] 2. Investigate necessary and viable solutions for Ambient IoT as defined in the general scope. This includes determining which functions, procedures, etc. are necessary and which are not, and ensuring at least the essential functions specified in Section 6.2 of TR 38.848.

[0114] Rel-19 localization studies are led by RAN3 and are limited to features that have no or minimal impact on the specification (Note: This does not imply decisions related to WI generation).

[0115] We study the feasibility and necessary functions for proximity determination (coordination with SA3 is necessary for privacy reasons).

[0116] - RAN1-led:

[0117] For Ambient IoT DL and UL:

[0118] Frame structure, synchronization and timing, random access

[0119] Numerology, Bandwidth, and Multiple Access

[0120] Waveform and Modulation

[0121] Channel coding

[0122] Downlink Channel / Signal Aspect

[0123] Uplink Channel / Signal Side

[0124] Scheduling and Timing Relationships

[0125] We study the necessary characteristics of carrier wave waveforms provided externally to ambient IoT devices, including interference processing at ambient IoT UL receivers and NR base stations.

[0126] For Topology 2, there is no difference in the physical layer design compared to Topology 1.

[0127] RAN2 Lead:

[0128] We research and determine the functions required for the Ambient IoT Compact Protocol stack and lightweight signaling procedures that enable DO-DTT and DT data transmission, and study those functions.

[0129] for example:

[0130] Paging

[0131] Random access

[0132] Data transmission including necessary wireless resource control aspects that comply with general range limitations

[0133] Interaction with the upper class

[0134] Features not listed above are researched only if deemed essential.

[0135] RAN3 Leading:

[0136] Identify the necessary effects on the signals and procedures of the CN-RAN interface to enable the following.

[0137] Paging

[0138] Device Context Management

[0139] Data transmission

[0140] Identify RAN architecture aspects, including whether partitioned architecture support is required.

[0141] Identify potential solutions for finding Ambient IoT devices without impacting specifications. For example, reuse existing user location reports or transmit location information to the core network with minimal impact on specifications.

[0142] RAN4 Leading:

[0143] Research on the coexistence of Ambient IoT and NR / LTE.

[0144] Research on RF Requirements for Ambient IoT:

[0145] Ambient IoT BS Transmitter / Receiver

[0146] Ambient IoT devices and transmission / reception based on general range

[0147] Intermediate node (UE) and transmission / reception based on general range

[0148] RAN2 and RAN3 are expected to cooperate with SA2 to identify RAN-CN functional splits.

[0149] Note: This study targets IoT segments that are much lower than existing 3GPP IoT technologies (e.g., NB-IoT, eMTC, RedCap, etc.). This study does not aim to replace existing 3GPP LPWA technologies.

[0150] For example, as described above, the types of A-IoT devices can be classified into two as follows. For example, a Type 1 device has a maximum power consumption of approximately 1 uW, is capable of energy storage, has no amplification function, and can perform transmission by backscattering a carrier wave (CW) provided from an external source (e.g., a reader such as a base station or terminal, or a separate node). For example, a Type 2 device has a maximum power consumption of approximately several hundred uW, is capable of energy storage, has an amplification function, and can perform transmission by backscattering a carrier wave (CW) provided from an external source (e.g., a reader such as a base station or terminal, or a separate node) or by using a signal generated internally.

[0151] For example, in addition to the classification methods described above, the type / class of an A-IoT device may be distinguished based on parameters associated with device characteristics (e.g., presence / capacity of energy storage, degree of energy / power consumption, presence / capability of amplification, presence / capability of a band-pass filter (BPF), supported DL / UL transmission method(s), etc.) or combinations of parameters. Here, for example, the BPF capability may be distinguished by the 3-dB bandwidth of the supported BPF, sharpness, etc., and the UL transmission methods may be distinguished by, for example, backscattered UL transmission, UL transmission by internal signal generation, etc.

[0152] In addition, the type / class of an A-IoT device may be subdivided based on parameters associated with the above device characteristics (e.g., presence / capacity of energy storage, degree of energy / power consumption, presence / capability of amplification, presence / capability of a band-pass filter (BPF), supported DL / UL transmission method(s), etc.) or combinations of such parameters. For example, the above-described Type 2 device may be classified into Type 2a when it performs transmission by backscattering a carrier wave (CW) provided from an external source (e.g., a reader such as a base station or terminal, or a separate node), and Type 2b when it performs transmission using a signal generated internally. In this case, Types 2a and 2b may be identical in that they have a maximum power consumption of approximately several hundred uW, are capable of energy storage, and have amplification capabilities.

[0153] For example, some types / classes of A-IoT devices (e.g., device B, device C, type 1 device, and / or type 2 device) may be equipped with energy storage capabilities (e.g., capacitors or charging batteries) for the following purposes.

[0154] - Securing stable energy at the time of reception / transmission

[0155] - Operation of low-power communication modules through energy storage in low RF energy states

[0156] For example, the minimum RF reception sensitivity for operating a low-power communication module may be -20dBm, and the minimum reception sensitivity for energy harvesting may be -20dBm. In this case, if the received power of the A-IoT device is distributed between -30 and -20dBm, communication may be impossible without a capacitor, and communication may be possible after a charging time with a capacitor.

[0157] - Store energy harvested from different energy sources (e.g., solar, thermal, wind, kinetic, etc.) in a single capacitor to operate a low-power communication module at a desired time.

[0158] Figure 6 illustrates the state according to the operating state of an energy harvesting-based device.

[0159] Specifically, FIG. 6 illustrates examples of power consumption and device energy status according to the operating state of an energy harvesting-based device having energy storage capacity, according to one embodiment of the present disclosure. The embodiment of FIG. 6 may be combined with various embodiments of the present disclosure.

[0160] Referring to FIG. 6(b), S1 may be a sleep state, S2 may be an active state, and P1 and P2 may be power consumption in S1 and S2, respectively. For example, the active state may refer to a state in which the device consumes power to perform operations such as receiving / transmitting for communication or sensing, and the sleep state may be a state that is not an active state.

[0161] FIG. 6(a) may represent the device energy state corresponding to FIG. 6(b). Referring to FIG. 6(a), the E1 and E2 values ​​may vary by device (type / class), and the device may report information related to the E1 value and / or information related to the E2 value to R and / or the base station as capability parameters. For example, the E2 value may be defined as the energy value in the buffered state, and the E1 value as the minimum energy value required in the active state.

[0162] For example, the transition from S1 to S2 may be possible only when the device energy state value is E2 or when E2 is reached. For example, the transition from S1 to S2 may be possible when the device energy state value is greater than E1 (i.e., within the range between E1 and E2). An embodiment of FIG. 6 illustrates an example in which the transition from S1 to S2 is performed when the device energy state value is E2 or when E2 is reached.

[0163] For example, an A-IoT device may require an externally provided CW for backscatter transmission. For example, the CW can be used to supply energy to A-IoT devices or as a CW for DL ​​transmission, regardless of the transmission mode (e.g., backscatter transmission or internally generated transmission).

[0164] For example, CW waveforms can be supported in various types. For instance, the type of CW waveform can be a single-tone CW waveform or a somewhat complex multi-tone CW waveform. For instance, single-tone CW may be advantageous over multi-tone CW in terms of the multiplexing capacity of tags or readers and in terms of interference, as it uses fewer resources. On the other hand, multi-tone CW has advantages, such as the ability to deliver more energy when transmitting CW over DL and to secure greater coverage on a single device.

[0165] Considering the advantages of these different CW waveform types, multiple CW waveform types may be supported in an A-IoT system, and the base station / IN / AN / UE may configure the CW waveform type. For example, one or more CW waveform types supported in the A-IoT communication system may be pre-configured / defined, and the base station / IN / AN / UE may select one of the one or more supported CW waveform types and transmit it to an A-IoT device. For example, the base station / IN / AN / UE may configure / instruct / display the selected CW waveform type to the A-IoT device in the form of a command / message transmitted as a preamble / frame-sync or payload.

[0166] For example, in the present disclosure, for A-IoT communication, at least one of the necessary characteristics of a carrier waveform for a carrier provided outside the A-IoT device (including interference handling at the A-IoT device UL receiver and NR base station) may be proposed. For example, in the present disclosure, for A-IoT communication, at least one of paging, random access, data transmission including necessary radio resource control aspects complying with general range limitations, interaction with upper layers (e.g., RRC layer, NAS (non-access stratum) layer, application layer, etc.), device context management, data transmission, coexistence of A-IoT and 6G / NR / LTE, and / or RF requirements for A-IoT may be proposed.

[0167] For example, technical terms used in this specification may be as follows.

[0168] - SSB: Synchronization Signal Block

[0169] - MIB: Master Information Block

[0170] - RMSI: Remaining Minimum System Information

[0171] - FR1: Frequency Range 1. Refers to the frequency range of 6 GHz or lower (e.g., 450 MHz ~ 6000 MHz).

[0172] - FR2: Frequency Range 2. Refers to the millimeter wave (mmWave) region of 24 GHz or higher (e.g., 24250 MHz ~ 52600 MHz).

[0173] - BW: Bandwidth

[0174] - BWP: Bandwidth Part

[0175] - RNTI: Radio Network Temporary Identifier

[0176] - CRC: Cyclic Redundancy Check

[0177] - SIB: System Information Block

[0178] - SIB1: SIB1 for NR devices = RMSI (Remaining Minimum System Information). Broadcasts information necessary for cell connection of NR terminals.

[0179] - CORESET: Control REsource SET. The time / frequency resource at which the terminal attempts candidate PDCCH decoding.

[0180] - CORESET#0: CORESET for Type0-PDCCH CSS set for NR devices (configured in MIB)

[0181] - Type0-PDCCH CSS set: a search space set in which an NR UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0182] - MO: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0183] - SIB1-R: (additional) SIB1 for reduced capability NR devices. This may be limited to cases where it is created as a separate TB from SIB1 and transmitted via a separate PDSCH.

[0184] - CORESET#0-R: CORESET#0 for reduced capability NR devices

[0185] - Type0-PDCCH-R CSS set: a search space set in which an redcap UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0186] - MO-R: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0187] - Cell defining SSB (CD-SSB): An NR SSB that includes RMSI scheduling information

[0188] - Non-cell defining SSB (non-CD-SSB): Refers to an SSB deployed in an NR sync raster that does not include the corresponding cell's RMSI scheduling information for measurement purposes. However, it may include information indicating the location of the cell defining SSB.

[0189] - SCS: subcarrier spacing

[0190] - SI-RNTI: System Information Radio-Network Temporary Identifier

[0191] - Camp on: "Camp on" is the UE state in which the UE stays on a cell and is ready to initiate a potential dedicated service or to receive an ongoing broadcast service.

[0192] - TB: Transport Block

[0193] - RSA (Redcap standalone): Redcap device 또는 service만 지원하는 cell.

[0194] - SIB1(-R)-PDSCH: SIB1(-R)을 전송하는 PDSCH

[0195] - SIB1(-R)-DCI: SIB1(-R)-PDSCH를 scheduling하는 DCI. DCI format 1_0 with CRC scrambled by SI-RNTI.

[0196] - SIB1(-R)-PDCCH: SIB1(-R)-DCI를 전송하는 PDCCH

[0197] - FDRA: Frequency Domain Resource Allocation

[0198] - TDRA: Time Domain Resource Allocation

[0199] - RA: Random Access

[0200] - MSGA: preamble and payload transmissions of the random access procedure for 2-step RA type.

[0201] - MSGB: response to MSGA in the 2-step random access procedure. MSGB may consist of response(s) for contention resolution, fallback indication(s), and backoff indication.

[0202] - RO-N: normal UE 4-step RACH and 2-step RACH(if configured)를 위한 RO(RACH Occasion)

[0203] - RO-N1, RO-N2: When separate ROs are configured for normal UE 2-step RACH, they are distinguished as RO-N1 (4-step) and RO-N2 (2-step).

[0204] - RO-R: RO (RACH Occasion) configured separately from RO-N for RedCap UE 4-step RACH and 2-step RACH (if configured)

[0205] - RO-R1, RO-R2: When separate ROs are configured for Redcap UE 2-step RACH, they are distinguished as RO-R1 (4-step) and RO-R2 (2-step).

[0206] - PG-R: MsgA-Preambles Group for redcap UEs

[0207] - RAR: Random Access Response

[0208] - RAR window: the time window to monitor RA response(s)

[0209] - FH: Frequency Hopping

[0210] - iBWP: initial BWP

[0211] - iBWP-DL(-UL): initial DL(UL) BWP

[0212] - iBWP-DL(-UL)-R: (separate) initial DL(UL) BWP for RedCap

[0213] - CS: Cyclic shift

[0214] - NB: Narrowband

[0215] - TO: Traffic Offloading

[0216] -mMTC; Massive Machine Type Communications

[0217] - eMBB: enhanced Mobile Broadband Communication

[0218] - URLLC: Ultra-Reliable and Low Latency Communication

[0219] - RedCap: Reduced Capability

[0220] - eRedCap: enhanced RedCap

[0221] - FDD: Frequency Division Duplex

[0222] - HD-FDD: Half-Duplex-FDD

[0223] - DRX: Discontinuous Reception

[0224] - RRC: Radio Resource Control

[0225] - RRM: Radio Resource Management

[0226] - MM: Mobility Management

[0227] - IWSN: Industrial Wireless Sensor Network

[0228] - LPWA: Low Power Wide Area

[0229] - RB: Resource Block

[0230] - CCE: Control Channel Element

[0231] - AL: Aggregation Level

[0232] - PRG: Physical Resource-block Group

[0233] - DFT-s-OFDM: DFT-spread OFDM

[0234] - PBCH: Physical Broadcast Channel

[0235] - A-PBCH: Additional PBCH

[0236] - BD: blind detection

[0237] - EPRE: Energy Per RE

[0238] - SNR: Signal-to-Noise Ratio

[0239] - TDM: Time Division Multiplexing

[0240] - FDM: Frequency Division Multiplexing

[0241] - DMRS: DeModulation Reference Signal

[0242] - TDD: Time Division Duplex

[0243] - PCI: Physical layer Cell ID

[0244] - EH: Energy Harvesting

[0245] - EH device: A device that operates based on EH. It may include all of Device A / B / C currently under discussion by 3GPP. Additionally, while this specification primarily considers RF EH, the EH device does not necessarily have to be RF EH-based.

[0246] - ES: Energizing Signal. A signal / channel transmitted by a base station / IN / AN / UE for the purpose of supplying RF energy to a device operating on an RF-based energy harvesting basis. (Modulated) CW, NR / LTE DL / UL signals, etc. can be ES, and a dedicated signal / channel for ES can be designed to support it.

[0247] - ET: Energy Transfer

[0248] - CW: Carrier wave. Ambient IoT devices supporting backscattering-based UL transmission transmit information by modulating and backscattering the “externally provided” CW. Ambient IoT devices supporting independent signal generation-based UL transmission transmit information by modulating the “internally generated” CW. Unless otherwise noted, it is assumed to refer to the “externally provided” CW for backscattering. The CW can be used as an ES (Energizing Signal) for RF energy transfer.

[0249] - CWN: Carrier Wave Node. A node that provides the above CW. It may be a base station, IN, AN, or UE, and a separate CWN may exist for the purpose of providing CW.

[0250] - R: Reader / Interrogator. This is an RFID standard term. In the 3GPP Ambient IoT context, depending on the topology, gNBs / eNBs, intermediate / assisting nodes, UEs, etc., can act as readers. Furthermore, since Ambient IoT is not limited to 4G / 5G communication systems, it can include base stations, intermediate / assisting nodes, and UEs of next-generation communication systems. It may also refer to an Ambient IoT reader.

[0251] - T: Tag / ambient IoT device. An RFID standard term. It may be interchangeable with EH device in this specification, and in the 3GPP Ambient IoT context, it primarily refers to Ambient IoT device, Device A / B / C. The abbreviation 'T' above may be interpreted / replaced with 'D', which signifies Ambient IoT Device.

[0252] - D: Ambient IoT device (may have the same meaning as T above)

[0253] - R=>T: Reader-to-Tag or Reader-to-Tag communication link. If the base station or intermediate / assisting node is the reader, it may have the same meaning as DL or forward link. 'R=>T' can be interpreted / replaced with 'R=>D' (Reader-to-Device).

[0254] - R2D: R-to-D link (Can be synonymous with R=>T. Can be denoted as R=>D.)

[0255] - CW2D: CWN-to-D link (CW node to Ambient IoT device link)

[0256] - T=>R: Tag-to-Reader or Tag-to-Reader communication link. If the base station or intermediate / assisting node is a reader, it may have the same meaning as a UL or reverse / backward link. 'T=>R' can be interpreted / substituted as 'D=>R' (Device-to-Reader).

[0257] - D2R: May have the same meaning as T=>R. Can be written as D=>R.

[0258] - R<=>T: Includes cases of R=>T and T=>R, or R=>T or T=>R. May apply to both R=>T and T=>R.

[0259] - R<=>D: Includes cases of R2D and D2R, or R2D or D2R. May apply to both R2D and D2R. (May have the same meaning as R<=>T)

[0260] - RF-EH: RF energy harvesting

[0261] - PRDCH: Physical R2D CHannel (may be denoted as PR2DCH). Physical channel for R2D communication.

[0262] - PDRCH: Physical D2R CHannel (may be denoted as PD2RCH). Physical channel for D2R communication.

[0263] - BS: Base Station

[0264] - IN: Intermediate node. In Topology 2 (BS ↔ IN ↔ Ambient IoT device), IN acts as a reader. Relays, IABs, UEs, repeaters, etc., can be INs.

[0265] - AN: Assisting node. It can assist with DL transmission in Topology 3-1 (BS -> AN -> Ambient IoT device -> BS) or assist with UL transmission in Topology 3-2 (BS -> Ambient IoT device -> AN -> BS). Relays, IABs, UEs, repeaters, etc. can be ANs.

[0266] - UE: User Equipment. In the case of LTE, NR, or next-generation communication systems, it refers to the LTE, NR, or next-generation communication system UE / terminal, respectively. It is a general wireless communication terminal form distinct from Ambient IoT devices or Devices A / B / C. In Topology 4 (UE ↔ Ambient IoT device), the UE acts as a reader.

[0267] - Device: Unless otherwise noted, and when used alone, it refers to the EH device, Ambient IoT device, or Device A / B / C without distinction.

[0268] - AmIoT: Ambient IoT (=A-IoT)

[0269] - F-gap: Frequency gap

[0270] - T-gap: Time gap

[0271] - TD: Time Domain

[0272] - FD: Frequency Domain

[0273] - PEI: Paging Early Indication

[0274] - LP-WUS: Low-Power Wake-Up Signal

[0275] - LP-SS: Low-Power Synchronization Signal

[0276] - RSRP: Reference Signal Received Power

[0277] - ESRP: ES Received Power. May refer to RSRP measured using ES. May have the same meaning as ES-RSRP.

[0278] - PRB: Physical Resource Block

[0279] - EH circuit: A circuit that performs EH operation. An EH device can be viewed as including the EH circuit as a component.

[0280] - PHR: Power Headroom Report

[0281] - EHR: Energy Headroom Report

[0282] - BPF: Band-Pass Filter

[0283] - SM: Subcarrier Modulation

[0284] The methods proposed in this specification can be applied commonly to topology 1 and topology 2, and UE1 as gNB and IN is referred to as reader for convenience. Additionally, the embodiments of this specification can be extended to cases where the reader receiving the BSS may directly generate and transmit the CW, or where the node transmitting the CW is a separate node from the reader.

[0285] As used herein, an Ambient IoT BS (base station) (e.g., reader) may be a gNB in ​​topology 1 and a specific UE in topology 2. Additionally, an Ambient IoT device (e.g., tag) as used herein may be interpreted as an Ambient IoT device in both topology 1 and / or topology 2. This will be explained below with reference to Table 3, FIG. 7, and FIG. 8.

[0286] Table 3 illustrates Ambient IoT scenarios. In Table 3, R is the leader, D is the device, and CW is the CW node. In Table 3, the D1T1 series scenarios are topology 1 scenarios. Figure 7 is a diagram illustrating topology 1 scenarios. In Table 3, the D2T2 series scenarios are topology 2 scenarios. Figure 8 is a diagram illustrating topology 2 scenarios.

[0287] In this case, depending on the scenario, the leader for R2D transmission and the leader for D2R reception may be the same or a different node. Additionally, depending on the scenario, the CW node performing CW2D transmission may be the same or a different node as the leader.

[0288]

[0289] The structure of device type 1 / 2a / 2b will be explained below with reference to FIGS. 9 to 11.

[0290] FIG. 9 illustrates the structure of device type 1. FIG. 10 illustrates the structure of device type 2a. Devices 1 and 2a perform D2R transmission by backscattering CW.

[0291] FIG. 11 illustrates the structure of device type 2b. Device 2b is equipped with a local oscillator at the transmitting end so that it can perform D2R transmission without the assistance of CW.

[0292] Device 1 is a simple structure that does not have amplifiers for R2D reception and D2R transmission at the receiving end and transmitting end, respectively. In contrast, devices 2a and 2b are structures that have a reflection amplifier and a power amplifier at the transmitting end, respectively, for D2R transmission.

[0293] Meanwhile, this specification proposes preamble, midamble, and postamble design methods that can be used for Ambient IoT transmission and reception. In this specification, the term "x-amble" is used to refer collectively to preamble, midamble, and postamble. Characteristically, a preamble refers to a transmission that occurs at the very beginning of a specific D2R or R2D transmission, a midamble in the middle, and a postamble at the very end.

[0294] Meanwhile, the preamble, midamble, and postamble mentioned in this specification may be transmitted together with D2R, R2D transmissions (e.g., PDRCH, PRDCH), etc., or may be transmitted included in said D2R, R2D transmissions.

[0295] The device ID mentioned in this specification may refer to a unique ID embedded within each device. However, instead of the device ID used in this specification, a method of using an ID such as a C-RNTI that can be exchanged between devices / readers during the inventory round phase may also be considered.

[0296] The state mentioned in this specification refers to states such as ON / SLEEP / OFF to increase the available time of a device in an Ambient IoT system. In this case, the ON state is defined as a state in which the device can perform TX / RX while consuming energy. The SLEEP state is defined as a state in which the device can perform energy harvesting without performing TX / RX, while maintaining memory content or timer / clock, etc., from the ON state. The OFF state is defined as a state in which the device can perform energy harvesting without maintaining memory content or timer / clock, etc., from the ON state, and without performing TX / RX.

[0297] In this document, ' / ' means 'and', 'or', or 'and / or' depending on the context.

[0298] Figure 12 illustrates the entire AS procedure between the device and the reader.

[0299] The entire Access Stratum (AS) procedure can be summarized as follows.

[0300] Step A: A-IoT paging. Upon a service request, the reader sends an A-IoT paging message specifying the device(s) requiring a response.

[0301] Step B: Transmission of D2R data (Device ID). The triggered A-IoT device(s) perform device ID transmission via the A-IoT random access procedure or without using the procedure.

[0302] Step C1: (If necessary) R2D data transmission (e.g., Reader -> Device data transmission for command transmission)

[0303] Step C2: (If necessary) D2R data transmission (e.g., device -> reader data transmission for response to command)

[0304] In step A of FIG. 12, paging (i.e., Msg0) may include one or more device IDs, a device group ID, or all devices, so that one or more or all devices that receive it may trigger the random access procedure of Step B.

[0305] In Step B of FIG. 12, Msg1 / Msg2 / Msg3 / (Msg4) are each considered for a random access (RA) procedure to be performed by multiple devices in an Ambient IoT system. Among these, Msg1 / Msg3 are D2R signals / channels transmitted by the device, and Msg2 / (Msg4) are R2D signals / channels transmitted by the reader. In this specification, 'Msg1' can be interpreted / replaced as an Access Random ID message, 'Msg2' can be interpreted / replaced as a Random ID Response message, and 'Msg3' can be interpreted / replaced as a D2R message (Device to Reader, D2R, message). At this time, if the Reader sets / instructs multiple devices to a time gap index / frequency gap index for D2R transmission, the Msg1 / Msg3 of the multiple devices can be transmitted via TDM / FDM. In this specification, 'time gap index' may be interpreted as a value related to a time domain resource, a value related to a time resource, or a value based on a time resource indication field. Additionally, in this specification, 'frequency gap index' may be interpreted as a value related to a frequency domain resource, a value related to a frequency resource, or a value based on a frequency resource indication field. On the other hand, Msg2 is primarily considered to use TDM. This is based on the following technical considerations. Since the presence or absence of bandpass filtering capability varies by device (or device type), it may be difficult for each device to appropriately filter and receive multiple FDMed R2D signals / channels transmitted via FDM from the reader. Considering this, TDM is considered for the transmission of Msg2.

[0306] This specification proposes a method for configuring TDMed / FDMed resources for Msg1 / Msg2 / Msg3 / (Msg4) in a contention-based access procedure (or random access procedure) in an ambient IoT system.

[0307] As used in this specification, the term "slot" may refer to a slot considered in slotted ALOHA operation. Such a slot may have a variable length in the time domain depending on the reader's settings or instructions. Alternatively, in A-IoT, a slot in slotted ALOHA may be defined as an access occasion.

[0308] TDM / FDM transmission of Msg1 and Msg3

[0309] In this specification, a case where the Msg1 resource undergoes TDM & FDM can be considered, and a case where the Msg3 resource also undergoes TDM & FDM can be considered. For example, a case can be considered where the Msg1 resource undergoes TDM n times within a specific slot in an inventory round to generate n sub-slots, and each sub-slot undergoes FDM m times to generate m frequency domain resources. In such a case where Msg1 undergoes TDM & FDM, Msg3 can also be considered to undergo TDM & FDM in a similar manner.

[0310] Specifically, after receiving Msg2 within the aforementioned specific slot, the Msg3 resource is TDMed n times to create n sub-slots, and each sub-slot is FDMed m times to create m frequency domain resources. Meanwhile, when the Msg1 resource is configured by TDMing and FDMing as described above, the corresponding Msg2 resource can be TDMed and transmitted. At this time, the Msg2 resource can be configured / defined to be TDMed and transmitted in the order of time first - frequency second (or frequency first - time second) relative to the Msg1 resource. This can be illustrated as shown in Fig. 13.

[0311] FIG. 13 illustrates resource allocation for messages of a random access procedure according to an embodiment of the present specification.

[0312] Specifically, in Fig. 13, we considered the case where n=3 and m=2, and the Msg2 resource is arranged in a frequency first - time second manner based on the Msg1 resource. Specifically, based on the Msg1 resource, the Msg2 resource can be arranged first in an increasing order of frequency index within the same time index, and then the time index can be increased, and the Msg2 resource can be arranged consecutively in an increasing order of frequency index within that time index.

[0313] In the case where multiple responses to multiple Msg1s are transmitted to Msg2 as described above, the device sets a Msg2 transmission window after a certain period of time following the transmission of Msg1 and begins monitoring the transmission of Msg2 during the window. At this time, the start time and length of the window can be indicated / set by the reader through the L1 control info, L2 control info, MAC CE, or preamble of Msg0 that triggered the Msg1. If Msg0 does not indicate / set / include the start time and length of the window, or if Msg0's L1 control info, L2 control info, MAC CE, or preamble indicates / sets the exclusion of the start time and length of the window, the device monitors Msg2 by determining the start time and length of the window using a stored pre-defined value. Alternatively, if Msg0's L1 control info, L2 control info, MAC CE, or preamble indicates the use of a pre-defined value, the device monitors Msg2 by determining the start time and length of the window using a stored pre-defined value.

[0314] More specifically, a specific 1 bit of L1 or L2 control information or MAC CE indicates whether to use a pre-defined value or to set the window start time and length using a value specified or set thereafter. If the specific 1 bit indicates a value to be specified or set, the device obtains the value from the bits following that specific 1 bit and uses the obtained value to set the window start time and length. However, if the specific 1 bit indicates the use of a pre-defined value, the device determines that there are no bits specifying a value to be specified or set following that specific 1 bit. That is, in this case, the reader does not include bits specifying a value to be specified or set in the L1 or L2 control information or MAC CE following the specific 1 bit.

[0315] In this specification, a single R2D or D2R transmission / repeated transmission may be transmitted by filling all resources within the sub-slot or by filling only a portion thereof. In the case of partial transmission, the device may transmit such that the start and end of each R2D or D2R transmission / repeated transmission fall within the allocated sub-slot, or transmit such that only the start of each R2D or D2R transmission / repeated transmission falls within the allocated sub-slot, or transmit such that only the end of each R2D or D2R transmission / repeated transmission falls within the allocated sub-slot.

[0316] [Method #1] How to set up the resource for repeated transmission of Msg1 or Msg3

[0317] When MSG0 transmitted by the reader to R2D triggers RA, the D2R repeat transmission resource of Msg1 or Msg3 may be configured as in one of the following embodiments based on the Msg0 R2D transmission (e.g., Msg0 or R2D message). Alternatively, the D2R repeat transmission resource of Msg3 may be configured as in one of the following embodiments based on the Msg2 R2D transmission (e.g., Msg2 or R2D message). Or, the repeat transmission resource of the corresponding D2R transmission may be configured as in one of the following embodiments based on the R2D transmission (R2D message) that triggers the D2R transmission.

[0318] - A method in which D2R transmission is repeated with TDM resources

[0319] Repeated transmission of Msg1 transmitted by the same device is performed as follows. First, the device selects one Msg1 resource within a specific slot. The device selects k-1 sub-slot(s) on the same frequency that are either contiguous or non-contiguous with the sub-slot of the selected Msg1 resource. The device transmits Msg1 repeatedly k times based on the selected k sub-slot(s). At this time, all of the selected k-1 sub-slots may belong to the specific slot or to the slot(s) following the specific slot.

[0320] For example, the above repeated transmissions may all be performed based on the same slot. For example, the above repeated transmissions may be performed based on different slots.

[0321] For example, the first of the k iteration transmission groups may be performed based on a specific slot, while the second of the k iteration transmission groups may be performed based on the next slot. In this manner, g iteration transmission groups may be performed based on g slots. In this case, one iteration transmission group may be transmitted based on multiple sub-slots within a single slot.

[0322] - A method in which D2R transmission is repeated with FDM resources

[0323] Repeated transmission of Msg1 by the same device is performed as follows. First, the device selects one Msg1 resource within a specific slot. The device selects k-1 frequency resource(s) that are different from the frequency position of the selected Msg1 resource. The device repeatedly transmits Msg1 k times based on the selected k frequency resource(s). At this time, all of the selected k-1 frequency resources may belong to the specific slot or to the slot(s) following the specific slot.

[0324] For example, the above k frequency resources can all be based on different frequency resources within the same sub-slot.

[0325] For example, the k frequency resources mentioned above may be based on different frequency resources of different sub-slots.

[0326] For example, m frequency resources can be divided into g repeating transmission groups. A repeating transmission group for a single Msg 1 repeating transmission may consist of consecutive or non-consecutive frequency resources in the same sub-slot. Different repeating transmission groups may consist of resources that repeat in different sub-slots.

[0327] For example, m frequency resources can be divided into g repetitive transmission groups. A single repetitive transmission group can consist of resources of different sub-slots that are either consecutive or non-consecutive. Different repetitive transmission groups can be configured to repeat with different frequency resources.

[0328] In an embodiment of the present specification, when Msg1 and / or Msg3 are TDM & FDM, the resources of one slot may be n=4 and m=2, and the Msg1 / 3 resources may be indexed as follows. FIG. 14 illustrates resource allocation for Msg1 / Msg3 according to an embodiment of the present specification.

[0329] In FIG. 14, the same column signifies the same sub-slot (e.g., R00 and R01 belong to the same sub-slot), and the same row signifies the same frequency position (e.g., R00, R10, R20, and R30 have the same frequency position F1). Meanwhile, one cell in FIG. 14 signifies one sub-slot in terms of time, and adjacent sub-slots of adjacent cells in FIG. 14 may be assigned to be physically adjacent or separated by a certain time interval. Additionally, one cell in FIG. 14 signifies one frequency resource for one D2R transmission in terms of frequency, and adjacent frequency resources of adjacent cells in FIG. 14 may be assigned to be physically adjacent or separated by a certain frequency interval. When a device performs repeated D2R transmissions according to the resource setting / allocation of the reader, the settings / allocations may be configured to be adjacent in terms of time or frequency, or separated by a certain interval between repeated transmissions.

[0330] At this time, the device sets / determines the resource allocation of Msg1 and / or Msg3 according to the transmission or instruction of Msg0. Alternatively, the device sets / determines the resource allocation of Msg3 according to the transmission or instruction of Msg2. For example, Msg 1 / 3 resources may be set as shown in FIG. 14, and in this case, D2R transmissions for Msg1 or Msg3 may be repeatedly transmitted in the following manner according to the TDM / FDM options. At this time, the device performing the Msg1 or Msg 3 D2R transmission upon R2D reception must have the ability to maintain an operable level of time / frequency synchronization for all possible sub-slots (for example, all sub-slots in FIG. 14) for the corresponding D2R transmission, and the reader sets all sub-slots by considering the ability of the responding devices to maintain such synchronization. The repeated transmission will be explained below with reference to FIGs. 15 and 16.

[0331] FIG. 15 illustrates a TDM iterative transmission according to an embodiment of the present specification.

[0332] - Example 1 of TDM iterative transmission (Fig. 15(a))

[0333] For example, a resource group consists of resources of consecutive sub-slots of the same frequency (e.g., the first / second sub-slot of F1 (D2R1)). In this case, the same D2R transmission is repeated based on a single resource group.

[0334] - Example 2 of TDM iterative transmission (Fig. 15(b))

[0335] For example, a resource group consists of resources of discontinuous sub-slots of the same frequency (e.g., the first / third sub-slot of F1 (D2R1)). In this case, the same D2R transmission is repeated based on a single resource group. Additionally, different sub-slots within the same group can be arranged at equal intervals.

[0336] FIG. 16 illustrates an FDM iterative transmission according to an embodiment of the present specification.

[0337] - Example 1 of FDM iterative transmission (Fig. 16a))

[0338] For example, a resource group consists of different frequency resources in the same sub-slots (e.g., the first sub-slot of F0 / F1 (D2R1)). In this case, the same D2R transmission is repeated based on a single resource group.

[0339] - Example 2 of FDM iterative transmission (Fig. 16(b))

[0340] For example, a resource group consists of resources of consecutive sub-slots of different frequencies (e.g., the first sub-slot of F1 (D2R1), the second sub-slot of F0 (D2R1)). In this case, the same D2R transmission is repeated based on a single resource group.

[0341] - Example 3 of FDM iterative transmission (Fig. 16 (c))

[0342] For example, a resource group consists of resources of discontinuous sub-slots at different frequency positions (e.g., the first sub-slot of F1 (D2R1), the third sub-slot of F0 (D2R1)). In this case, the same D2R transmission is repeated based on a single resource group. Additionally, different sub-slots within the same group may be arranged at equal intervals.

[0343] Meanwhile, when transmitting a D2R message such as Msg 1 or Msg 3, the device may transmit the D2R message with a length of one sub-slot or more. If the reader instructs the number of repetitions or repetitions based on the R2D transmission (R2D message), the device may determine D2R repeat transmission resources for each of a plurality of consecutive or non-consecutive sub-slots according to the above method, and perform repeated transmission of the same D2R transmission through the determined repeat transmission resources. At this time, the device may perform such D2R transmissions as many times as the maximum number of times or repetitions instructed by the reader based on the R2D transmission (R2D message).

[0344] If the reader does not indicate the number of repetitions or repetitions based on the above R2D transmission (R2D message), the device may perform repeated transmissions of the same D2R transmission or perform different D2R transmissions according to the determined D2R repeated transmission resources. In this case, the device may continue / perform these D2R transmissions for the maximum number of times. At this time, through the L1 control information or L2 control information or x-amble of the D2R transmission, the device may indicate / report to the reader whether to perform different D2R transmissions or repeat transmissions.

[0345] For example, when different D2R transmissions occur, different TBs may be transmitted based on each D2R transmission.

[0346] For example, when different D2R transmissions occur, a segment of one TB can be transmitted based on each D2R transmission. Specifically, one TB can be divided into multiple segments. The device can transmit each segment to the reader via a separate D2R transmission. The segments received by the reader can be restored into one TB through assembly.

[0347] In the case of repetitive transmission, if a single D2R transmission is the length of one sub-slot, the device can perform repetitive transmission for every sub-slot. In the case of repetitive transmission, if a single D2R transmission is the length of N sub-slots, the device can perform repetitive transmission for every N sub-slots.

[0348] Meanwhile, if the above D2R transmission is Msg3 or a device-only transmission, the device repeatedly transmits a D2R transmission such as Msg3 in the following cases.

[0349] - If an R2D transmission such as Msg0 or Msg2 instructs the repeated transmission of a D2R transmission such as Msg3, instructs the number of repetitions, instructs time / frequency resources for repetition, or sets the repetition method, the device repeatedly transmits Msg3 or subsequent D2R transmissions.

[0350] - If Msg1 is transmitted repeatedly, the device repeatedly transmits Msg3 or subsequent D2R.

[0351] - If NACK information regarding Msg3 is received via R2D transmission after transmitting or repeating Msg3, the device repeats Msg3 or subsequent D2R transmission.

[0352] - At this time, the NACK may indicate the number of repeated transmissions, whether to repeat transmissions, or the time / frequency resources for repeated transmissions, and accordingly, the device repeatedly transmits the corresponding Msg3 or D2R transmission.

[0353] Alternatively, if a NACK is received or an ACK is not received within a certain period of time, the device may increase the number of repetitions of the Msg3 or D2R transmission or increase the transmission power as the number of NACK transmissions and ACK reception failures for the Msg3 or D2R transmission increases. In particular, based on an R2D transmission (R2D message) such as Msg0 or Msg2, if i) the number of repetitions of a D2R transmission such as Msg3 is indicated, ii) time / frequency resources for repetition are indicated, or iii) a repetition method is set, the device performs the above increase operation.

[0354] If the frequency resource allocated / determined for Msg3 or D2R transmission is a specific frequency resource, the device repeatedly transmits Msg3 or subsequent D2R transmissions based on that frequency resource. In particular, if repeated transmission or the number of repetitions at the specific frequency resource is indicated based on an R2D transmission (R2D message) such as Msg0 or Msg2, the device performs the repeated transmission. For example, the number of repetitions / repeated transmissions may be indicated per frequency resource / frequency location based on an R2D transmission (R2D message) such as Msg0 or Msg2. As a specific example, no repeated transmission may be indicated at frequency F0, N1 repeated transmissions at frequency F1, and N2 repeated transmissions at F2. Accordingly, the device repeats and transmits D2R transmissions N1 or N2 times at F1 or F2.

[0355] [Method #2] Frequency hopping method for Msg1 or Msg3

[0356] When MSG0 transmitted by the reader to R2D triggers RA, the D2R transmission resources and frequency hopping of Msg1 or Msg3 may be set / instructed based on the Msg0 R2D transmission (e.g., Msg0 or R2D message). Alternatively, the D2R transmission resources and frequency hopping of Msg3 may be set / instructed based on the Msg2 R2D transmission (e.g., Msg2 or R2D message). Alternatively, the transmission resources and frequency hopping of the corresponding D2R transmission may be set / instructed based on the R2D transmission that triggers the D2R transmission (e.g., R2D message). For example, the D2R transmission resources and frequency hopping may be set / instructed based on L1 or L2 control information of the R2D transmission.

[0357] For example, D2R transmission resources considering hopping may be indicated / configured according to the indication / configuration of an R2D transmission (e.g., Msg0 or 2) that directly or indirectly triggers a D2R transmission (e.g., Msg1 or Msg3). Such indication / configuration may include information on at least one of: i) the location of frequencies to be targeted for frequency hopping or frequency hopping intervals; ii) the device ID, device type, or device group to perform frequency hopping; iii) whether to sustain D2R transmission through frequency hopping for a certain number of sub-slots and the maximum number of D2R transmissions; and / or iv) whether to repeatedly transmit the same D2R message for each transmission resource or to transmit different D2R messages each time a D2R resource is hopping.

[0358] According to these instructions / settings, the device determines D2R resources for each of multiple consecutive or discontinuous sub-slots, and can perform different D2R transmissions or repeat the same D2R transmission through the determined resources. The device can continue / perform such transmissions for the maximum number of times / repetitions mentioned above.

[0359] For example, when different D2R transmissions occur, different TBs may be transmitted based on each D2R transmission.

[0360] For example, when different D2R transmissions occur, a segment of one TB can be transmitted based on each D2R transmission. Specifically, one TB can be divided into multiple segments. The device can transmit each segment to the reader via a separate D2R transmission. The segments received by the reader can be restored into one TB through assembly.

[0361] In the case of repetitive transmission, if a single D2R transmission is the length of one sub-slot, the device can perform repetitive transmission for every sub-slot. In the case of repetitive transmission, if a single D2R transmission is the length of N sub-slots, the device can perform repetitive transmission for every N sub-slots.

[0362] In this manner, the D2R transmission transmitted via frequency hopping may correspond to a feedback message for Msg1 or Msg2 or a device-only transmission or R2D transmission, and frequency hopping may be performed in the following manner.

[0363] Method 1: Frequency hopping based on frequency interval delta

[0364] Based on the R2D transmission (R2D message), eight frequency resource locations (F0 to F7) are indicated / set / determined. The device selects the first frequency resource in the first sub-slot allocated for the D2R transmission. For example, the first sub-slot and the first frequency may be indicated to the device by the reader based on the R2D transmission (R2D message). For example, the first sub-slot and the first frequency may be selected randomly by the device. For example, the first sub-slot and the first frequency may be selected by the device according to a predefined rule.

[0365] Subsequently, the device selects a frequency resource in the second sub-slot based on the frequency interval delta of the instructed / set / determined frequency hopping. For example, the delta value may be instructed to the device by the reader based on an R2D transmission (R2D message). For example, the delta value may be randomly selected / determined by the device. For example, the delta value may be selected / determined by the device according to a predefined rule. Accordingly, if the frequency resource of the first sub-slot is F1 and delta = 4, the frequency resource of the second sub-slot is F5.

[0366] Method 1A: F1 and F5 are paired. Subsequently, for D2R transmission or repetitive transmission in sub-slots, the device performs D2R transmission or repetitive transmission by switching frequency resources from F5 to F1 and back from F1 to F5.

[0367] Method 1B: When delta is indicated / set / determined as 4, the frequency resource of the third sub-slot after F5 is F9. However, since only resource locations from F0 to F7 are set, the frequency resource of the third sub-slot is determined as F2 as a result of 9 mod 7 = 2. Subsequently, D2R transmission is transmitted or repeated by hopping from the sub-slot to F6, F3, etc., up to the final sub-slot.

[0368] Method 2: Frequency pairing-based frequency hopping

[0369] Based on R2D transmission (R2D message), eight frequency resource locations (F0 to F7) can be indicated / set / determined as follows. For example, F0 can be paired with F4, and F1 and F5, F2 and F6, and F3 and F7 can be paired together. Specifically, the reader can set / instruct the terminal to frequency pairs of (F0, F4), (F1, F5), (F2, F6), and (F3, F7).

[0370] In this manner, the device selects the first frequency resource or frequency pair in the first sub-slot allocated for D2R transmission. For example, if the first frequency resource is selected, the frequency pair to which the first frequency belongs is selected. For example, the first sub-slot and the first frequency may be instructed to the device by the reader based on an R2D transmission (R2D message). For example, the first sub-slot and the first frequency may be selected randomly by the device. For example, the first sub-slot and the first frequency may be selected by the device according to a predefined rule.

[0371] Method 2A: Subsequently, for D2R transmission or repeat transmission in each sub-slot, the device performs D2R transmission or repeat transmission for a maximum number of transmissions / repeat transmissions while alternating between frequency positions belonging to the selected frequency pair. For example, if F0 of (F0, F4) is the first frequency resource, hopping can be performed in the order of F0 -> F4 -> F0 -> F4 -> F0 -> F4 -> F0 -> F4..

[0372] Method 2B: Subsequently, for D2R transmission or repeat transmission in each sub-slot, the device re-selects a different frequency pair and performs D2R transmission or repeat transmission once at the frequency positions belonging to the second re-selected pair. Then, it re-selects the next frequency pair again and performs D2R transmission or repeat transmission in the re-selected pair, and performs D2R transmission or repeat transmission while re-selecting pairs for the maximum number of transmissions / repeats. For example, hopping can be performed in the order of (F0 -> F4) --> (F1 -> F5) --> (F2 -> F6) --> (F3 -> F7). As a specific example, if frequency pairs are indicated / set / determined as (F0, F4), (F1, F5), (F2, F6), and (F3, F7), the device first selects (F0, F4) and transmits at F0 and F4 respectively. Subsequently, the device transmits from F2 and F6 of (F2, F6) respectively through frequency pair reselection. Then, the device reselects / changes the frequency pair to (F1, F5) and (F3, F7) through frequency pair reselection, and transmits from F1, F5, F3, and F7 respectively. Afterward, the device reselects / changes the frequency pair to (F0, F4) and repeats the above process to transmit or repeat D2R transmissions for the maximum number of transmissions / repeats.

[0373] Method 3: Transmission resource table configuration method

[0374] FIG. 17 illustrates a table for determining transmission resources according to an embodiment of the present specification.

[0375] For example, all transmission resources may be configured as shown in the table of FIG. 17 according to the instruction / setting / decision of the R2D transmission above. In this case, empty frequency / time resources in the table refer to resources that are used for another R2D / D2R transmission or resources that are not allocated for R2D / D2R transmission for NR / LTE transmission. Another D2R transmission resource may be another D2R transmission resource triggered by the same R2D transmission or another R2D transmission, or it may be a device transmission for a specific device or device group, or a D2R transmission resource dedicated to a device group.

[0376] In this manner, the device sets / determines D2R transmission or repetitive transmission resources according to the table of FIG. 17 and selects resources for D2R transmissions or D2R repetitive transmissions. For example, if the device selects resource F0 (D2R1) in sub-slot 1, it determines resources for the same D2R1 as follows. Specifically, the device selects resource F5 in sub-slot 2, resource F1 in sub-slot 3, and resource F6 in sub-slot 4 to continue D2R transmissions or repetitively transmit D2R transmissions. Subsequently, the table is repeated to perform D2R transmissions / repetitive transmissions by repeating F0, F5, F1, and F6.

[0377] For example, the device can select D2R3 resources (resources F1, F6, F2, and F7) to perform D2R transmission / repeating transmission. Specifically, the device can switch from D2R1 resources to D2R3 resources to transmit / repeate, and then switch from D2R2 resources to D2R4 resources to transmit / repeate.

[0378] Meanwhile, the frequency hopping method of this specification may be similarly applied to R2D transmissions or R2D repeated transmissions. In this case, frequency hopping instruction / setting information for the R2D transmission may be provided based on L1 or L2 control information of a previously transmitted R2D transmission. In this case, the R2D transmission to which frequency hopping is applied may be related to feedback for i) Msg0, ii) Msg2 and / or iii) Msg3. In other words, the device may receive i) Msg0, ii) Msg2 and / or iii) Msg3 from the reader based on frequency hopping.

[0379] [Method #3] How to set up x-amble during repetitive transmission or frequency hopping

[0380] For example, when D2R transmission is repeated, the first D2R transmission may consist of an x-amble and a PDRCH. The x-amble may include at least one of i) a D2R preamble, ii) D2R midamble(s) and / or iii) a D2R postamble.

[0381] For example, when D2R is repeated, only PDRCH may be repeatedly transmitted, or both x-amble and PDRCH may be repeatedly transmitted.

[0382] For example, if PDRCH is repeatedly transmitted, only PDRCH can be repeatedly transmitted without x-amble.

[0383] For example, when PDRCH is repeatedly transmitted, only the MAC PDU (TB) may be repeatedly transmitted without x-amble and L1 control info.

[0384] For example, when PDRCH is repeatedly transmitted, only x-amble and TB may be repeatedly transmitted without L1 control info.

[0385] For example, a PDRCH containing L1 control information and TB, or only TB, is repeatedly transmitted, and another x-amble may be included before, in the middle, during, or after each repeated transmission. In this case, the other x-amble may be repeated and contain an x-amble different from the x-amble of the first D2R transmission. For example, if the first D2R transmission includes a preamble and a PDRCH, subsequent transmissions may repeat only a midamble (or postamble) and a PDRCH without a preamble. In this manner, a postamble may be transmitted at the end of the last repeated PRDCH.

[0386] The above repeated transmission methods can be applied identically even when repeating R2D transmissions. That is, if D2R is changed to R2D and PDRCH is changed to PRDCH in the above method, R2D transmissions can be repeated according to the above method.

[0387] This repeated transmission may be repeated while changing the frequency by frequency hopping, or it may be repeated while fixing the frequency.

[0388] Meanwhile, detailed embodiments of D2R and R2D are as follows.

[0389] D2R or R2D transmission may be performed according to block level repetition or TB level repetition. For example, transmission may be performed based on bits (e.g., assembly of bits) including bits after block repetition (e.g., PDRCH bits or PRDCH bits). The bits after block repetition may refer to bits after block repetition based on a Transport Block (TB) associated with data. More specifically, the bits after block repetition may be expressed as R times the bits of the Transport Block (including CRC bits). Here, R may refer to the number of repetitions indicated based on R2D transmission (R2D message). R may be greater than or equal to 1.

[0390] Referring to FIG. 18(a), the bits after the block repetition may include bits from the first TB part 1 / TB part 2 bits to the third TB part 1 / TB part 2. The bits (e.g., assembly of bits) may refer to a total of bits including bits based on three TB part 1 / TB part 2 bits and bits based on three midambles. Referring to FIG. 18(b), the bits after the block repetition may include bits based on 80 chips, 20 chips, 60 chips, 40 chips, 20 chips, and 80 chips. The bits (e.g., assembly of bits) may refer to a total of bits including bits based on 80 chips, 20 chips, 60 chips, 40 chips, 20 chips, and 80 chips, and bits based on three midambles.

[0391] A single transmission or a single repeated transmission may include an x-amble (e.g., a midamble). In this case, subsequent repeated transmissions may also include an x-amble such as the midamble. FIG. 18 illustrates examples of midamble insertion according to embodiments of the present specification. FIG. 18(a) illustrates the insertion of a midamble according to Embodiment 1. In Embodiment 1, a midamble may be included at the same point for every TB repeated transmission. In this case, the position of the midamble may be determined such that TB part1 and TB part2 have the same or different lengths. Information regarding the position of the midamble may be indicated / set based on an R2D transmission (e.g., an R2D message). Specifically, information regarding the position of the midamble may be indicated / set based on L1 / L2 control info, MAC CE, MAC SDU, or system information of the R2D transmission.

[0392] FIG. 18(b) illustrates the insertion of a midamble according to Example 2. In Example 2, the interval between midambles included during repeated transmission can be defined / set / instructed by a fixed rule. For example, it may be assumed that one TB is transmitted based on 100 symbols or 100 chips. According to Example 2, x-ambles such as midambles can be repeatedly inserted at fixed intervals (e.g., 80 symbols interval). At this time, the interval between x-ambles / the interval for inserting x-ambles (e.g., the interval between a preamble and a midamble, the interval between a midamble and the next midamble, etc.) can be indicated / set based on R2D transmission (R2D message). As a specific example, the interval between x-ambles / the interval for inserting x-ambles can be indicated / set based on L1 / L2 control info, MAC CE, MAC SDU, and system information of the R2D transmission. In other words, in the entire set of bits (e.g., assembly of bits) including the bits based on the block repetition (PDRCH bits or PRDCH bits) and the bits of the x-amble(s), each bit of the x-amble(s) can be arranged based on the interval indicated by the R2D message.

[0393] In addition, depending on the interval setting, multiple x-ambles may be included in a single iteration transmission.

[0394] Meanwhile, in the above embodiments, an x-amble, such as a midamble or preamble, may or may not be additionally included between the R2D or D2R repeated transmissions.

[0395] Whether to include an x-amble, such as a midamble or preamble, between repeated transmissions can be indicated / set based on an R2D transmission (R2D message). Specifically, the inclusion of the x-amble can be indicated / set based on L1 / L2 control info, MAC CE, MAC SDU, or system information of the R2D transmission.

[0396] Additionally, in the above embodiments, the first transmission of the repeat transmission may begin with a preamble, and the last repeat transmission may end with a postamble. In other words, in the entire set of bits (e.g., assembly of bits) including the bits based on the block repetition (PDRCH bits or PRDCH bits) and the bits of the x-amble(s), the bits of the preamble may be arranged at the very beginning. As a specific example, the bits of the postamble may be arranged at the very end of the entire set of bits.

[0397] In the above embodiments, the R2D or D2R repeated transmissions may be immediately followed by an x-amble. Alternatively, a gap may be set between the repeated transmissions. Frequency hopping may occur with each repeated transmission. For example, the 1st transmission and the 2nd transmission may be repeated at the F0 frequency position, and the 3rd transmission and the 4th transmission may be repeated at the F1 frequency position. Alternatively, frequency hopping may occur each time so that different repeated transmissions are transmitted at different frequency positions.

[0398] Control information and PRDCH or PDRCH transmission structure

[0399] FIG. 19 illustrates the Control information and PRDCH or PDRCH transmission structure options of the present specification. In FIG. 19, each transmission option is transmitted immediately after the preamble. Additionally, a postamble may be transmitted immediately after the transmission of each transmission option. For example, if the PRDCH or PDRCH transmission of option a or option b of FIG. 19 includes a preamble and a postamble, it may be transmitted as in FIG. 20.

[0400] FIG. 20 illustrates a transmission including a preamble and a postamble according to an embodiment of the present specification. The method illustrated in FIG. 20 is an example, and D2R transmission may be performed differently depending on the implementation method. It will be described in detail below.

[0401] For example, D2R transmission may be performed in a manner other than the Manchester code. For example, the D2R preamble may be transmitted only as a clock acquisition part for D2R timing acquisition without a start indicator. For example, the postamble may also be transmitted for a different length by maintaining a high voltage as in FIG. 20, or as a specific sequence consisting of high and low voltages.

[0402] For example, only the preamble and PRDCH / PDRCH can be transmitted without the postamble of Fig. 20.

[0403] As shown in Fig. 19, R2D L1 control information can be transmitted in one of the following ways.

[0404] Alt 1

[0405] L1 control information is included at the end of the preamble as part of the R2D preamble. In Alt 1, the chip duration of the L1 control information may be the same as the preamble chip duration.

[0406] For example, L1 control info may be added immediately after the clock acquisition part of FIG. 20, and then PRDCH may be transmitted. In this case, the structure of PRDCH transmission may be the same as option a or b of FIG. 19. In the case of option b, PRDCH starts with L2 control info.

[0407] Alt 2

[0408] L1 control information is located between the R2D preamble and the PRDCH. At this time, the structure of the PRDCH transmission may be the same as option c, d, or e of FIG. 19.

[0409] In the case of Option d, L1 control information is transmitted through a separate R2D control channel.

[0410] In the case of Option c or e, L1 control information is transmitted as a separate part without a separate channel.

[0411] Alt 3

[0412] L1 control information is included in the beginning of the PRDCH as part of the PRDCH. The chip duration of the L1 control information can be the same as the PRDCH chip duration.

[0413] At this time, the structure of the PRDCH transmission may be the same as option b in Fig. 19, and the PRDCH starts with L1 control info.

[0414] FIG. 21 illustrates an example of the structure of the MAC payload of FIG. 19 according to the present specification. In this case, the MAC payload may correspond to a single transport block. In Options a, c, and d, the L2 control info may or may not be located at the beginning of the MAC payload. In this case, the clock acquisition part of the L1 control info or preamble of FIG. 19 may indicate that the L2 control info is included. Alternatively, without a separate indication, the MAC payload may always include or not include the L2 control info. Alternatively, the first bit / field of the L2 control info or the bit / field immediately preceding the L2 control info may indicate whether or not the L2 control info is included. Alternatively, the MAC CE (Control Element) following the MAC subheader of FIG. 21 may include the L2 control info. Additionally, padding may be added to the last part of the payload of FIG. 21. When a payload (i.e., TB) is configured at the MAC layer of a device / reader as shown in FIG. 21, the MAC layer of the device / reader transmits the payload to the physical layer of the device / reader. The physical layer can configure PRDCH or PDRCH transmission by adding a CRC to the TB. At this time, L1 control info, L2 control info, or MAC CE can indicate whether a CRC is added to the TB. In FIG. 21, L2 control information can also be classified as a specific MAC CE that is always located before the payload or as a MAC header.

[0415] FIG. 22 illustrates D2R transmission and midamble transmission according to an embodiment of the present specification.

[0416] A reader transmitting the PRDCH may or may not include L1 control information (L1CI) within the PRDCH. In this case, the R2D L1CI transmitted to the R2D may include control information for PRDCH transmission and / or control information for PDRCH transmission. Additionally, the reader may or may not include L2 control information (L2CI) within the PRDCH. In this case, the R2D L2CI transmitted to the R2D may include control information for PRDCH transmission and / or control information for PDRCH transmission.

[0417] Additionally, the device transmitting the PDRCH may or may not include L1 control information (L1CI) within the PDRCH. In this case, the D2R L1CI transmitted to the D2R may include i) control information for the PDRCH transmission, ii) control information for subsequent PRDCH transmission, and / or iii) reporting information. Additionally, the device may or may not include L2 control information (L2CI) within the PDRCH. In this case, the D2R L2CI transmitted to the D2R may include i) control information for the PDRCH transmission, ii) control information for PRDCH transmission, and / or iii) reporting information. The reporting information may include buffer status, remining D2R data size, device energy status / level, etc.

[0418] In this case, L2CI can be a MAC CE included in the MAC PDU, a MAC header / sub-header, or a part of these.

[0419] Various embodiments of the present disclosure may be combined with one another.

[0420] In terms of implementation, the operations of the first device (e.g., Ambient IoT Device or Reader, BS, IN, AN, UE) / second device (e.g., Reader, BS, IN, AN, UE or Ambient IoT Device) according to the embodiments described above can be processed by the device of FIG. 25 (e.g., the processor (110, 210) of FIG. 25).

[0421] In addition, the operations of the first device (e.g., Ambient IoT Device or Reader, BS, IN, AN, UE) / second device (e.g., Reader, BS, IN, AN, UE or Ambient IoT Device) according to the above-described embodiment may be stored in memory (e.g., 140, 240 of FIG. 25) in the form of instructions / programs (e.g., instruction, executable code) for driving at least one processor (e.g., 110, 210 of FIG. 25).

[0422] The embodiments described above will be explained in detail below with reference to FIGS. 23 and 24 in terms of the operation of a first device (e.g., Ambient IoT Device) and a second device (e.g., Reader, base station, intermediate node, auxiliary node). The methods described below are distinguished only for convenience of explanation, and it is understood that a part of one method may be substituted with a part of another method or combined with one another and applied.

[0423] FIG. 23 is a flowchart illustrating a method according to one embodiment of the present specification.

[0424] Referring to FIG. 23, a method according to one embodiment of the present specification includes a step of receiving an R2D message (S2310) containing information for D2R transmission and a step of transmitting D2R to a reader (S2320).

[0425] In S2310, the device receives an R2D message from the reader containing information for a Device to Reader (D2R) transmission. For example, a D2R transmission is generated based on the information. For example, the R2D message may be msg0 (e.g., A-IoT Paging message), msg2 (e.g., Random ID Response message), or msg3 (e.g., R2D Upper Layer Data Transfer message).

[0426] In S2320, the device performs a D2R transmission to the reader based on the information above. For example, the D2R transmission may be associated with a D2R message. Specifically, the D2R transmission may be associated with msg1 (e.g., Access Random ID message) or a D2R Upper Layer Data Transfer message.

[0427] According to one embodiment, the D2R transmission may refer to all bits (e.g., assembly of bits) based on the above-described method #3. For example, the D2R transmission may be generated based on i) bits of a D2R preamble, ii) bits of a D2R midamble(s), and iii) an arrangement of bits after a block repetition. This will be explained in detail below.

[0428] For example, the above D2R transmission may be associated with a PDRCH (Physical Device to Reader Channel), a D2R preamble, and one or more D2R midambles.

[0429] For example, a repetition number may be indicated based on the above information. Block repetition may be performed based on the repetition number.

[0430] For example, the D2R transmission may include i) the PDRCH after the block repetition (e.g., PDRCH bits), ii) the D2R preamble (e.g., bits of the D2R preamble), and iii) one or more D2R midambles (e.g., bits of the one or more D2R midambles). In the D2R transmission, the above-described i) to iii) may be arranged as follows.

[0431] As a specific example, the D2R preamble may be arranged at the very beginning of the D2R transmission. In the D2R transmission, each of the D2R preamble and the one or more D2R midambles may be arranged based on an interval for D2R midamble insertion indicated by the R2D message (e.g., the information for the D2R transmission). In the D2R transmission, the PDRCH may be placed on all bits not occupied by the D2R preamble or the one or more D2R midambles.

[0432] According to one embodiment, the D2R transmission can be performed based on backscattering of the carrier wave.

[0433] According to one embodiment, the PDRCH may be based on bits after the block repetition of the transmission block and the CRC bits (Cyclic redundancy check, CRC, bits) attached to the transmission block. More specifically, the PDRCH may be based on R repetitions of the transmission block and the CRC bits. In other words, the number of bits of the PDRCH may be based on R times the number of bits based on the transmission block and the CRC bits. R may be based on the number of repetitions.

[0434] According to one embodiment, one of a plurality of values ​​related to the interval may be indicated based on the R2D message. The plurality of values ​​may refer to values ​​predefined for the interval for inserting the x-amble of the above-described method #3.

[0435] According to one embodiment, whether to insert an additional D2R midamble may be indicated based on the R2D message. This embodiment may be based on Method #3. The additional D2R midamble may refer to an x-amble associated with the last iteration transmission. For example, based on the indication that the insertion of the additional D2R midamble is indicated, the additional D2R midamble may be placed at the very end of the D2R transmission.

[0436] According to one embodiment, the R2D message may include i) a Time Resource Indication field related to time domain resources, and ii) a Frequency Resource Indication field related to frequency domain resources. One or more of the time domain resources or one or more of the frequency domain resources may be associated with repeated transmissions of the D2R transmission. This embodiment may be based on Method #1 and / or Method #2.

[0437] For example, based on the above R2D message, i) the one or more time domain resources or the one or more frequency domain resources and / or ii) a first number of repetitions for the one or more time domain resources or the one or more frequency domain resources may be indicated.

[0438] For example, i) the remaining time domain resources excluding one or more of the time domain resources among the time domain resources, or ii) the remaining frequency domain resources excluding one or more of the frequency domain resources among the frequency domain resources, may be associated with a second number of repetitions. As a specific example, the second number of repetitions may be greater than or equal to 1.

[0439] For example, the one or more frequency domain resources may include frequency domain resources based on intervals related to frequency hopping. This embodiment may be based on Method 1 of Method #3.

[0440] For example, the one or more frequency domain resources may include frequency domain resources based on pairing related to frequency hopping. This embodiment may be based on Method 2 of Method #3.

[0441] For example, the one or more frequency domain resources mentioned above may include frequency domain resources selected for frequency hopping based on a table. This embodiment may be based on Method 3 of Method #3.

[0442] For example, transmission by a reader may be R2D (Reader to Device) transmission, and transmission by a device may be D2R (Device to Reader) transmission.

[0443] According to one embodiment, the device and the reader may be based on devices operating based on one of four topologies related to Ambient IoT (see FIG. 1 to 5). Specifically, the reader may be i) a base station, ii) user equipment, iii) an intermediate node, or iv) an assisting node. The device may be an Ambient IoT (Internet of Things) device.

[0444] Operations based on the above-described S2310 to S2320 can be implemented by the device of FIG. 25. For example, referring to FIG. 25, the device (100) can control one or more transceivers (130) and / or one or more memories (140) to perform operations based on S2310 to S2320.

[0445] The embodiments described above will be explained in detail below in terms of the operation of the second device.

[0446] S2410 to S2420 described below correspond to S2310 to S2320 described in FIG. 23. Considering the above correspondence, redundant descriptions are omitted. That is, the specific description of the operation of the second device described below may be replaced by the description / embodiment of FIG. 23 corresponding to the operation.

[0447] FIG. 24 is a flowchart illustrating a method according to another embodiment of the present specification.

[0448] Referring to FIG. 24, a method according to another embodiment of the present specification includes a step of transmitting an R2D message (S2410) that includes information for D2R transmission and a step of receiving a D2R transmission from a device (S2420).

[0449] In S2410, the reader transmits an R2D message containing information for D2R (Device to Reader) transmission to the device. Based on this information, the device generates the D2R transmission.

[0450] In S2420, the reader receives a D2R transmission based on the above information from the device.

[0451] According to one embodiment, the D2R transmission may refer to all bits (e.g., assembly of bits) based on the above-described method #3. For example, the D2R transmission may be generated based on i) bits of a D2R preamble, ii) bits of a D2R midamble(s), and iii) an arrangement of bits after a block repetition. This will be explained in detail below.

[0452] For example, the above D2R transmission may be associated with a PDRCH (Physical Device to Reader Channel), a D2R preamble, and one or more D2R midambles.

[0453] For example, a repetition number may be indicated based on the above information. Block repetition may be performed based on the repetition number.

[0454] For example, the D2R transmission may include i) the PDRCH after the block repetition (e.g., PDRCH bits), ii) the D2R preamble (e.g., bits of the D2R preamble), and iii) one or more D2R midambles (e.g., bits of the one or more D2R midambles). In the D2R transmission, the above-described i) to iii) may be arranged as follows.

[0455] As a specific example, the D2R preamble may be arranged at the very beginning of the D2R transmission. In the D2R transmission, each of the D2R preamble and the one or more D2R midambles may be arranged based on an interval for D2R midamble insertion indicated by the R2D message (e.g., the information for the D2R transmission). In the D2R transmission, the PDRCH may be placed on all bits not occupied by the D2R preamble or the one or more D2R midambles.

[0456] Operations based on the above-described S2410 to S2420 can be implemented by the device of FIG. 25. For example, referring to FIG. 25, a reader (200) can control one or more transceivers (230) and / or one or more memories (240) to perform operations based on S2410 to S2420.

[0457] Hereinafter, an apparatus to which the embodiments of the present specification can be applied (an apparatus implementing the method / operation according to the embodiments of the present specification) will be described with reference to FIG. 25.

[0458] FIG. 25 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0459] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0460] The processor (110) performs baseband-related signal processing and may include an upper layer processing unit (111) and a physical layer processing unit (115). The upper layer processing unit (111) may process operations of the MAC layer, RRC layer, or higher upper layers. The physical layer processing unit (115) may process operations of the PHY layer. For example, if the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, if the first device (100) is a first terminal device in terminal-terminal communication, the physical layer processing unit (115) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (110) may also control the overall operation of the first device (100).

[0461] The antenna section (120) may include one or more physical antennas, and if it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110) and software, operating systems, applications, etc. related to the operation of the first device (100), and may include components such as a buffer.

[0462] The processor (110) of the first device (100) may be configured to implement the operation of the base station in base station-terminal communication (or the operation of the first terminal device in terminal-terminal communication) in the embodiments described in this disclosure.

[0463] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0464] The processor (210) performs baseband-related signal processing and may include an upper layer processing unit (211) and a physical layer processing unit (215). The upper layer processing unit (211) may process operations of the MAC layer, RRC layer, or higher upper layers. The physical layer processing unit (215) may process operations of the PHY layer. For example, if the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, if the second device (200) is a second terminal device in terminal-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (210) may also control the overall operation of the second device (210).

[0465] The antenna section (220) may include one or more physical antennas, and if it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210) and software, operating systems, applications, etc. related to the operation of the second device (200), and may include components such as a buffer.

[0466] The processor (210) of the second device (200) may be configured to implement the operation of the terminal in base station-terminal communication (or the operation of the second terminal device in terminal-terminal communication) in the embodiments described in this disclosure.

[0467] In the operation of the first device (100) and the second device (200), the details described in the examples of the present disclosure regarding the base station and terminal (or the first terminal and the second terminal in terminal-to-terminal communication) in base station-to-terminal communication may be applied in the same way, and redundant descriptions are omitted.

[0468] Here, the wireless communication technology implemented in the device of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above.

[0469] Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above.

[0470] Additionally or generally, the wireless communication technology implemented in the device of the present disclosure may include at least one of ZigBee, Bluetooth, and a Low Power Wide Area Network (LPWAN) for low-power communication, but is not limited to the names mentioned above. For example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4 and may be referred to by various names.

Claims

1. Regarding the method, A step of receiving an R2D message containing information for D2R (Device to Reader) transmission from a reader by a device; and The method includes the step of performing D2R transmission to the reader based on the information by the device; The above D2R transmission is associated with a PDRCH (Physical Device to Reader Channel), a D2R preamble, and one or more D2R midambles, and Based on the above information, a repetition number is indicated, and a block repetition is performed based on the above repetition number, and The above D2R transmission includes i) the PDRCH after the block repetition, ii) the D2R preamble, and iii) one or more D2R midambles, and In the above D2R transmission, the D2R preamble is arranged at the very front, and In the above D2R transmission, each of the D2R preamble and the one or more D2R midambles is positioned based on an interval for D2R midamble insertion indicated based on the information, and A method characterized in that, in the above D2R transmission, the PDRCH is placed on all bits not occupied by the D2R preamble or the one or more D2R midambles.

2. In Paragraph 1, A method characterized in that the above D2R transmission is performed based on backscattering of the carrier wave.

3. In Paragraph 1, A method characterized in that the above PDRCH is based on bits after the block repetition of the transmission block and the CRC bits (Cyclic redundancy check, CRC, bits) attached to the transmission block.

4. In Paragraph 1, A method characterized by indicating one of a plurality of values ​​related to the interval based on the above R2D message.

5. In Paragraph 1, A method characterized by indicating whether to insert an additional D2R midamble based on the above R2D message.

6. In Paragraph 5, A method characterized in that, based on the instruction to insert the additional D2R midamble, the additional D2R midamble in the D2R transmission is placed at the very end.

7. In Paragraph 1, The above R2D message includes i) a Time Resource Indication field related to time domain resources, and ii) a Frequency Resource Indication field related to frequency domain resources, and A method characterized in that one or more of the time domain resources or one or more of the frequency domain resources are related to the repeated transmission of the D2R transmission.

8. In Paragraph 7, A method characterized by indicating, based on the above R2D message, i) the one or more time domain resources or the one or more frequency domain resources and / or ii) the first number of repetitions for the one or more time domain resources or the one or more frequency domain resources.

9. In Paragraph 7, A method characterized in that i) the remaining time domain resources excluding one or more of the time domain resources among the above time domain resources, or ii) the remaining frequency domain resources excluding one or more of the above frequency domain resources, are related to the second number of repetitions.

10. In Paragraph 8, A method characterized in that the above one or more frequency domain resources include frequency domain resources based on intervals related to frequency hopping.

11. In Paragraph 8, A method characterized in that the above one or more frequency domain resources include frequency domain resources based on pairing related to frequency hopping.

12. In Paragraph 8, A method characterized in that the above one or more frequency domain resources include frequency domain resources selected for frequency hopping based on a table.

13. Regarding the device, One or more transmitters / receivers; One or more processors; and It includes one or more memories connected to the above one or more processors and storing instructions, A device characterized by the above instructions enabling the device to perform all steps of the method according to any one of claims 1 to 12, based on execution by the one or more processors.

14. An electronic device comprising one or more memories and one or more processors connected to the one or more memories, An electronic device characterized in that the one or more of the above memories store instructions that cause the electronic device to perform all steps of the method according to any one of claims 1 to 12, based on execution by the one or more processors.

15. In a non-transitory computer-readable storage medium for storing instructions, A non-transitory computer-readable storage medium characterized by instructions executable by one or more processors such that the device performs all steps of the method according to any one of claims 1 to 12.

16. Regarding the method, A step of transmitting an R2D message containing information for D2R (Device to Reader) transmission to a device by a reader; and The method includes the step of receiving a D2R transmission based on the information from the device by the reader; The above D2R transmission is associated with a PDRCH (Physical Device to Reader Channel), a D2R preamble, and one or more D2R midambles, and Based on the above information, a repetition number is indicated, and a block repetition is performed based on the above repetition number, and The above D2R transmission includes i) the PDRCH after the block repetition, ii) the D2R preamble, and iii) one or more D2R midambles, and In the above D2R transmission, the D2R preamble is arranged at the very front, and In the above D2R transmission, each of the D2R preamble and the one or more D2R midambles is positioned based on an interval for D2R midamble insertion indicated based on the information, and A method characterized in that, in the above D2R transmission, the PDRCH is placed on all bits not occupied by the D2R preamble or the one or more D2R midambles.

17. Regarding Reader, One or more transmitters / receivers; One or more processors; and It includes one or more memories connected to the above one or more processors and storing instructions, A reader characterized by the above instructions, based on execution by the one or more processors, causing the reader to perform all steps of the method according to claim 16.

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