WO2025174126A1 - Method and device for device-to-device communication in wireless communication system - Google Patents

Abstract

Disclosed are a method and a device for device-to-device communication in a wireless communication system. The method according to one embodiment of the present disclosure may comprise the steps of: receiving, by a first device, information related to a time and/or frequency resource set from a base station; and transmitting, by the first device, a first transmission to a second device in a time and/or frequency resource selected from the time and/or frequency resource set.

Description

Method and device for device-to-device communication in a wireless communication system

The present disclosure relates to a wireless communication system, and more particularly, to a method and device for communication between devices in a wireless communication system.

Mobile communication systems were developed to provide voice services while ensuring user activity. However, they have expanded beyond voice to include data services. Currently, explosive growth in traffic is leading to resource shortages and users' demand for higher-speed services, necessitating a more advanced mobile communication system.

Next-generation mobile communication systems must support explosive data traffic growth, dramatically increasing data rates per user, a vastly increased number of connected devices, ultra-low end-to-end latency, and high energy efficiency. To achieve these goals, various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.

The technical problem of the present disclosure is to provide a method and device for communication between a device (e.g., a base station, a user equipment (UE), etc.) operating as a leader and a device operating as a tag in a wireless communication system supporting the ambient Internet of Things (A-IoT).

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

A method according to an aspect of the present disclosure may include: receiving, by a first device, information related to a set of time and/or frequency resources from a base station; and transmitting, by the first device, a first transmission to a second device on a time and/or frequency resource selected from the set of time and/or frequency resources. Based on receiving a particular transmission from the base station or the second device, the time and/or frequency resource may be selected by the first device from the set of time and/or frequency resources.

A method according to an additional aspect of the present disclosure may include: receiving, by a second device, a first transmission from a first device at a time and/or frequency resource selected from a set of time and/or frequency resources established by a base station; and transmitting, in response to the first transmission, a second transmission to the first device. The time and/or frequency resource may be selected by the first device from the set of time and/or frequency resources based on a particular transmission being transmitted from the base station or the second device.

According to an embodiment of the present disclosure, communication between a device operating as a leader and a device operating as a tag in a wireless communication system supporting A-IoT can be performed smoothly.

In addition, according to an embodiment of the present disclosure, it is possible to prevent a resource conflict problem for communication between a device operating as a leader and a device operating as a tag in a wireless communication system supporting A-IoT.

The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.

FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied.

FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.

FIG. 8 illustrates an overall procedure between an A-IoT device and a reader in a wireless communication system to which the present disclosure can be applied.

FIG. 9 illustrates a logical system architecture in a wireless communication system to which the present disclosure can be applied.

FIG. 10 illustrates four topologies for ambient IoT in a wireless communication system to which the present disclosure can be applied.

FIG. 11 is a flowchart illustrating a procedure for an ambient IoT device to access a reader device in a wireless communication system to which the present disclosure can be applied.

FIG. 12 is a diagram illustrating a symbol duration for ambient IoT communication in a wireless communication system to which the present disclosure can be applied.

FIG. 13 is a diagram illustrating ambient IoT communication in the time domain in a wireless communication system to which the present disclosure can be applied.

FIG. 14 is a flowchart illustrating signaling between a terminal (e.g., UE or ambient IoT device) and a base station in a wireless communication system to which the present disclosure can be applied.

FIG. 15 illustrates the operation of a device for device-to-device communication according to one embodiment of the present disclosure.

FIG. 16 illustrates the operation of a device for device-to-device communication according to one embodiment of the present disclosure.

FIG. 17 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and/or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and/or" as used herein may refer to any one of the associated enumerated items, or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the use of "/" between words in this disclosure has the same meaning as "and/or" unless otherwise stated.

The present disclosure describes a wireless communication network or a wireless communication system, and an operation performed in a wireless communication network may be performed in a process of controlling the network and transmitting or receiving a signal from a device (e.g., a base station) that manages the wireless communication network, or may be performed in a process of transmitting or receiving a signal to or between terminals connected to the wireless network.

In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI (Artificial Intelligence) system/module, RSU (road side unit), robot, drone (UAV: Unmanned Aerial Vehicle), 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, RSU (road side unit), robot, AI (Artificial Intelligence) module, UAV (Unmanned Aerial Vehicle), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

The following technologies can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. CDMA can be implemented using wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced)/LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE/LTE-A/LTE-A pro.

For clarity, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS (Technical Specification) 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE/NR may be referred to as a 3GPP system. "xxx" refers to a standard document detail number. LTE/NR may be collectively referred to as a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure. For example, reference may be made to the following documents.

For 3GPP LTE, see TS 36.211 (Physical channels and modulation), TS 36.212 (Multiplexing and channel coding), TS 36.213 (Physical layer procedures), TS 36.300 (General description), and TS 36.331 (Radio resource control).

For 3GPP NR, see TS 38.211 (Physical channels and modulation), TS 38.212 (Multiplexing and channel coding), TS 38.213 (Physical layer procedures for control), TS 38.214 (Physical layer procedures for data), TS 38.300 (Overall description of NR and New Generation-Radio Access Network (NG-RAN)), and TS 38.331 (Radio Resource Control Protocol Specification).

Abbreviations for terms that may be used in this disclosure are defined as follows.

- BM: beam management

- CQI: Channel Quality Indicator

- CRI: Channel state information - reference signal resource indicator

- CSI: Channel State Information

- CSI-IM: Channel State Information - Interference Measurement

- CSI-RS: Channel state information - reference signal

- DMRS: Demodulation Reference Signal

- FDM: frequency division multiplexing

- FFT: fast Fourier transform

- IFDMA: interleaved frequency division multiple access

- IFFT: inverse fast Fourier transform

- L1-RSRP: Layer 1 reference signal received power

- L1-RSRQ: Layer 1 reference signal received quality

- MAC: Medium Access Control

- NZP: non-zero power

- OFDM: orthogonal frequency division multiplexing

- PDCCH: Physical downlink control channel

- PDSCH: Physical downlink shared channel

- PMI: precoding matrix indicator

- RE: resource element

- RI: Rank indicator

- RRC: Radio Resource Control

- RSSI: Received signal strength indicator

- Rx: Reception

- QCL: quasi co-location

- SINR: signal to interference and noise ratio

- SSB (or SS/PBCH block): Synchronization signal block (including primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH))

- TDM: Time Division Multiplexing

- TRP: transmission and reception point

- TRS: Tracking Reference Signal

- Tx: transmission

- UE: user equipment

- ZP: Zero Power

System General

As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communications compared to existing radio access technologies (RATs) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide diverse services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services/terminals is being discussed. Accordingly, the introduction of next-generation RATs that consider enhanced mobile broadband communication (eMBB), massive MTC (MMTC), and Ultra-Reliable and Low Latency Communication (URLLC) is being discussed. For convenience, these technologies are referred to as NR in this disclosure. NR is an expression representing an example of 5G RAT.

A new RAT system, including NR, uses OFDM or a similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the existing LTE/LTE-A numerology but support a larger system bandwidth (e.g., 100 MHz). Alternatively, a single cell may support multiple numerologies. That is, terminals operating under different numerologies can coexist within a single cell.

A numerology corresponds to a single subcarrier spacing in the frequency domain. Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.

Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

Referring to Fig. 1, the NG-RAN consists of gNBs that provide NG-RA (NG-Radio Access) user plane (i.e., new AS (access stratum) sublayer/PDCP (Packet Data Convergence Protocol)/RLC (Radio Link Control)/MAC/PHY) and control plane (RRC) protocol termination for UE. The gNBs are interconnected via Xn interfaces. The gNBs are also connected to the NGC (New Generation Core) via the NG interface. More specifically, the gNBs are connected to the AMF (Access and Mobility Management Function) via the N2 interface and to the UPF (User Plane Function) via the N3 interface.

FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

NR systems can support multiple numerologies. Numerologies can be defined by subcarrier spacing and cyclic prefix (CP) overhead. Multiple subcarrier spacings can be derived by scaling the base (reference) subcarrier spacing by an integer N (or μ). Furthermore, even if it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band. Furthermore, NR systems can support various frame structures corresponding to multiple numerologies.

Below, we examine OFDM numerologies and frame structures that can be considered in NR systems. The various OFDM numerologies supported in NR systems can be defined as shown in Table 1 below.

μ Δf=2 ^μ ·15 [kHz] CP 0 15 Normal 1 30 common 2 60 General, Extended 3 120 common 4 240 common

NR supports multiple numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports wide areas in traditional cellular bands; an SCS of 30 kHz/60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

The NR frequency band is defined by two types of frequency ranges (FR1 and FR2). FR1 and FR2 can be configured as shown in Table 2 below. FR2 can also mean millimeter wave (mmW).

Frequency Range designation Corresponding frequency range Subcarrier Spacing FR1 410MHz - 7125MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

With respect to the frame structure in the NR system, the sizes of various fields in the time domain are expressed as multiples of the time unit T _c = 1/(Δf _max · N _f ). Here, Δf _max = 480 · 10 ³ Hz and N _f = 4096. Downlink and uplink transmissions are organized into radio frames with a duration of T _f = 1/(Δf _max N _f / 100) · T _c = 10 ms. Here, each radio frame has a duration of T _sf = (Δf _max N _f / 1000) · T _c = 1 ms. It consists of 10 subframes with an interval of . In this case, there can be one set of frames for uplink and one set of frames for downlink. In addition, transmission in uplink frame number i from a terminal must start T _TA =(N _TA +N _TA,offset )T _c before the start of the corresponding downlink frame from the terminal. For a subcarrier spacing configuration μ, slots are numbered in increasing order of n _s ^μ ∈{0,..., N _slot ^subframe,μ -1} within a subframe, and in increasing order of n _s,f ^μ ∈{0,..., N _slot ^frame,μ -1} within a radio frame. One slot consists of consecutive OFDM symbols of N _symb ^slot , where N _symb ^slot is determined according to a CP. The start of slot n _s ^μ in a subframe is temporally aligned with the start of OFDM symbol n _s ^μ N _symb ^slot in the same subframe. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or uplink slot can be utilized.

Table 3 shows the number of OFDM symbols per slot (N _symb ^slot ), the number of slots per radio frame (N _slot ^frame,μ ), and the number of slots per subframe (N _slot ^subframe,μ ) in the general CP, and Table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

μ N _symb ^slot N _slot ^frame,μ N _slot ^subframe,μ 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

μ N _symb ^slot N _slot ^frame,μ N _slot ^subframe,μ 2 12 40 4

FIG. 2 is an example when μ=2 (SCS is 60 kHz), and referring to Table 3, 1 subframe can include 4 slots. 1 subframe={1,2,4} slot illustrated in FIG. 2 is an example, and the number of slot(s) that can be included in 1 subframe is defined as in Table 3 or Table 4. In addition, a mini-slot can include 2, 4, or 7 symbols, or more or fewer symbols.

Regarding physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered. Below, the physical resources that can be considered in an NR system will be examined in detail.

First, with respect to antenna ports, antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. Two antenna ports are said to be in a QC/QCL (quasi co-located or quasi co-location) relationship if the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on another antenna port is carried. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.

Referring to FIG. 3, a resource grid is exemplarily described as consisting of N _RB ^μ N _sc ^RB subcarriers in the frequency domain, and one subframe consists of 14·2 ^μ OFDM symbols, but is not limited thereto. In an NR system, a transmitted signal is described by one or more resource grids consisting of N _RB ^μ N _sc ^RB subcarriers and 2 ^μ N _symb ^(μ) OFDM symbols. Here, N _RB ^{μ ≤} N _RB ^{max, μ} . The N _RB ^{max, μ} represents the maximum transmission bandwidth, which may vary not only between numerologies but also between uplink and downlink. In this case, one resource grid may be configured for μ and each antenna port p. Each element of the resource grid for μ and each antenna port p is referred to as a resource element and is uniquely identified by an index pair (k, l'). Here, k=0,...,N _RB ^μ N _sc ^RB -1 is an index in the frequency domain, and l'=0,...,2 ^μ N _symb ^(μ) -1 designates the position of a symbol within a subframe. When designating a resource element in a slot, an index pair (k,l) is used, where l=0,...,N _symb ^μ -1. The resource element (k,l') for μ and antenna port p corresponds to the complex value a _k,l' ^(p,μ) . If there is no risk of confusion or if a particular antenna port or numerology is not specified, the indices p and μ can be dropped, resulting in a complex value a _k,l' ^(p) or a _k,l' . Furthermore, a resource block (RB) is defined as N _sc ^RB =12 consecutive subcarriers in the frequency domain.

Point A serves as a common reference point of the resource block grid and is obtained as follows.

- offsetToPointA for the Primary Cell (PCell) downlink represents the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping the SS/PBCH block used by the UE for initial cell selection. It is expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2.

- absoluteFrequencyPointA represents the frequency-position of point A expressed as ARFCN (absolute radio-frequency channel number).

Common resource blocks (CRBs) are numbered from 0 upward in the frequency domain for a subcarrier spacing setting μ. The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting μ coincides with 'point A'. The relationship between the CRB number n _CRB ^μ in the frequency domain and the resource elements (k, l) for a subcarrier spacing setting μ is given by Equation 1 below.

In Equation 1, k is defined relative to point A such that k = 0 corresponds to the subcarrier centered at point A. Physical resource blocks are numbered from 0 to N _BWP,i ^size,μ -1 within a bandwidth part (BWP), where i is the BWP number. The relationship between physical resource block n _PRB and common resource block n _CRB in BWP i is given by Equation 2 below.

N _BWP,i ^start,μ is the common resource block where the BWP starts relative to common resource block 0.

FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied. FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

Referring to FIGS. 4 and 5, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot includes seven symbols, but in the case of an extended CP, one slot includes six symbols.

A carrier comprises multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined as multiple consecutive (physical) resource blocks in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can comprise up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

The NR system can support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the radio frequency (RF) chip for the entire CC turned on, the terminal battery consumption may increase. Alternatively, when considering multiple use cases operating within a single wideband CC (e.g., eMBB, URLLC, Mmtc, V2X, etc.), different numerologies (e.g., subcarrier spacing, etc.) may be supported for each frequency band within the CC. Alternatively, each terminal may have different maximum bandwidth capabilities. Considering this, the base station can instruct the terminal to operate only on a portion of the bandwidth rather than the entire bandwidth of the wideband CC, and this portion of bandwidth is conveniently defined as the bandwidth part (BWP). A BWP can be composed of consecutive RBs on the frequency axis and can correspond to a single numerology (e.g., subcarrier spacing, CP length, slot/mini-slot interval).

Meanwhile, the base station can configure multiple BWPs even within a single CC configured for a terminal. For example, in the PDCCH monitoring slot, a BWP occupying a relatively small frequency range can be configured, and the PDSCH indicated by the PDCCH can be scheduled on a larger BWP. Alternatively, if UEs are concentrated on a specific BWP, some terminals can be configured to a different BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, a portion of the spectrum in the middle of the entire bandwidth can be excluded and both BWPs can be configured within the same slot. In other words, the base station can configure at least one DL/UL BWP for a terminal associated with a wideband CC. The base station can activate at least one DL/UL BWP(s) among the configured DL/UL BWP(s) at a specific time (via L1 signaling, MAC CE (Control Element), RRC signaling, etc.). Additionally, the base station can instruct switching to another configured DL/UL BWP (e.g., via L1 signaling or MAC CE or RRC signaling). Alternatively, switching to a configured DL/UL BWP can be performed based on a timer when the timer value expires. In this case, the activated DL/UL BWP is defined as the active DL/UL BWP. However, in situations such as when the terminal is performing the initial access process or before the RRC connection is set up, the configuration for the DL/UL BWP may not be received. Therefore, in these situations, the DL/UL BWP assumed by the terminal is defined as the initially active DL/UL BWP.

FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.

In wireless communication systems, terminals receive information from a base station via the downlink and transmit it to the base station via the uplink. The information transmitted and received between the base station and terminals includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

When a terminal is powered on or enters a new cell, it performs an initial cell search operation, such as synchronizing with the base station (S601). To this end, the terminal receives a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell identifier (ID). Afterwards, the terminal can receive a physical broadcast channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a downlink reference signal (DL RS) during the initial cell search phase to check the downlink channel status.

A terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information included in the PDCCH (S602).

Meanwhile, when accessing a base station for the first time or when there are no radio resources for signal transmission, the terminal may perform a random access procedure (RACH) for the base station (steps S603 to S606). To this end, the terminal may transmit a specific sequence as a preamble via the Physical Random Access Channel (PRACH) (steps S603 and S605) and receive a response message to the preamble via the Physical Data Channel Control Channel (PDCCH) and the corresponding PDSCH (steps S604 and S606). In the case of a contention-based RACH, a contention resolution procedure (Contention Resolution Procedure) may additionally be performed.

The terminal that has performed the procedure described above can then perform PDCCH/PDSCH reception (S607) and physical uplink shared channel (PUSCH)/physical uplink control channel (PUCCH) transmission (S608) as general uplink/downlink signal transmission procedures. In particular, the terminal receives downlink control information (DCI) through the PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and its format varies depending on the purpose of use.

Meanwhile, the control information that the terminal transmits to the base station via the uplink or that the terminal receives from the base station includes downlink/uplink ACK/NACK (Acknowledgement/Non-Acknowledgement) signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), etc. In the case of the 3GPP LTE system, the terminal can transmit the above-described control information such as CQI/PMI/RI via PUSCH and/or PUCCH.

Table 5 shows an example of the DCI format in the NR system.

DCI format conjugation 0_0 Scheduling PUSCH within a cell 0_1 Scheduling of one or multiple PUSCHs within a cell, or indicating cell group (CG) downlink feedback information to the UE. 0_2 Scheduling PUSCH within a cell 1_0 Scheduling of PDSCH within a DL cell 1_1 Scheduling of PDSCH within a cell 1_2 Scheduling of PDSCH within a cell

Referring to Table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information related to scheduling of PUSCH (e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS (Modulation Coding and Scheme), NDI (New Data Indicator), RV (Redundancy Version), etc.), HARQ (Hybrid - Automatic Repeat and request) related information (e.g., process number, DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.

DCI format 0_0 is used for scheduling PUSCH in a cell. The information contained in DCI format 0_0 is transmitted after being scrambled with a CRC (cyclic redundancy check) by a C-RNTI (Cell RNTI: Cell Radio Network Temporary Identifier), a CS-RNTI (Configured Scheduling RNTI), or a MCS-C-RNTI (Modulation Coding Scheme Cell RNTI).

DCI format 0_1 is used to indicate scheduling of one or more PUSCHs in a single cell, or configure grant (CG: configure grant) downlink feedback information to the UE. The information contained in DCI format 0_1 is CRC-scrambled and transmitted using the C-RNTI, CS-RNTI, SP-CSI-RNTI (Semi-Persistent CSI RNTI), or MCS-C-RNTI.

DCI format 0_2 is used for scheduling PUSCH in a cell. The information contained in DCI format 0_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

Next, DCI formats 1_0, 1_1, and 1_2 may include resource information related to scheduling of PDSCH (e.g., frequency resource allocation, time resource allocation, virtual resource block (VRB)-physical resource block (PRB) mapping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., antenna port, transmission configuration indicator (TCI), sounding reference signal (SRS) request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.

DCI format 1_0 is used for scheduling PDSCH in a DL cell. The information contained in DCI format 1_0 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

DCI format 1_1 is used for scheduling PDSCH in a single cell. The information contained in DCI format 1_1 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

DCI format 1_2 is used for scheduling PDSCH in a single cell. The information contained in DCI format 1_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

Ambient Internet of Things (A-IoT)

IoT has recently attracted a lot of attention in the wireless communications field, and it is expected that more things will be interconnected to improve productivity efficiency.

Most existing wireless communication devices are powered by batteries that require manual replacement or recharging. Therefore, powering all IoT devices with these batteries is impossible, leading to high maintenance costs and serious environmental impacts.

To address these challenges, new IoT technologies are needed that support battery-less devices without energy storage capabilities, or devices with energy storage capabilities that do not require manual replacement or recharging. As one type of application, most industries currently rely primarily on barcodes and RFID (radio frequency identification). However, their limited read range (a few meters) and lack of interference management systems can lead to serious interference between RFID readers and capacity issues, making it difficult to support large-scale networks with seamless RFID coverage.

3GPP is discussing a new IoT technology called Ambient IoT. Ambient IoT technology can enable connections and/or device densities orders of magnitude higher than existing 3GPP IoT technologies, while offering complexity and power consumption orders of magnitude lower than existing 3GPP LPWA (low power wide area) technologies, such as narrow band (NB)-IoT and LTE-MTC (machine type communication).

FIG. 7 illustrates an ambient IoT device architecture in a wireless communication system to which the present disclosure can be applied.

- Antenna: The antenna may be shared or separate for the radio frequency (RF) energy harvester and receiver/transmitter.

- Matching network: The matching network matches the impedance between the antenna and other components (including RF energy harvester and receiver-related blocks).

- RF energy harvester: The RF energy harvester may include a rectifier that converts an RF signal (i.e., alternating current (AC)) into direct current (DC).

- Energy storage (e.g., capacitor): Stores energy harvested from RF energy harvesters.

- Power Management Unit (PMU): The PMU manages the storage of energy in the energy harvester and the supply of power to the active component blocks that require power supply.

- (Digital) BB (balanced-balanced) logic: BB logic includes functional blocks such as encoder, decoder, and controller.

- Memory: Memory can include two types of memory: i) non-volatile memory (NVM), such as electrically erasable programmable read-only memory (EEPROM), for permanently storing device IDs, etc., and 2) registers, for temporarily storing information necessary for operation only while energy is present in the energy storage.

- Clock generator: The clock generator provides the required clock signal(s). Here, the clock signal is a periodic signal used for timing and synchronization. In on-off-keying (OOK) modulation, the time for transmitting a bit (0 or 1) is determined by the chip duration, and this chip duration is precisely controlled by the clock signal and can be defined as a multiple of the clock period, for example. In other words, based on the clock signal, a TARI (Type A Reference Interval) for setting a time interval that serves as a reference for communication can be determined, and based on the TARI, the chip duration can be determined.

The receiving related blocks include:

- RF band pass filter (BPF) to improve selectivity: RF BPF may not exist depending on the implementation.

- RF envelope detector: The RF envelope detector converts the RF signal to baseband.

- BB low-pass filter (LPF): The BB LPF can improve the quality of the input signal to the comparator by filtering out harmonics and high-frequency components. The BB LPF may not be present depending on the implementation.

- Comparator: The comparator determines whether the input signal is high or low.

The receiving related blocks include:

- Backscatter modulator: The backscatter modulator modulates the backscatter signal into a signal transmitted from the BB logic by switching the impedance.

Figure 7 illustrates a device with a peak power consumption of ~1 μW, no reader-to-device (R2D) (i.e., receiving) or device-to-reader (D2R) (i.e., transmitting) amplification within the device, and where the device's D2R transmission backscatters (i.e., uses the energy of the received CW to transmit a signal) against an externally provided carrier wave (CW).

Although not shown in FIG. 7, for devices with peak power consumption of ~ hundreds of μW and R2D or D2R amplification within the device, a reflection amplifier and/or a low noise amplifier (LNA) may be further included to amplify at least one of the R2D/CW2D (Carrier-wave, or carrier-wave node, to device) and D2R.

Additionally, although not shown in FIG. 7, if the D2R transmission of the device is generated internally by the device, the transmission-related blocks of FIG. 7 may be replaced with blocks for generating and transmitting the following D2R signal.

- Transmission modulator: The transmission modulator modulates baseband bits according to a modulation method.

- Digital-to-analog converter (DAC): A DAC converts a digital signal into an analog signal.

- Low pass filter (LPF): LPF filters out unwanted signals.

- Mixer: The mixer upconverts the baseband signal to the RF range.

- Local oscillator (LO): LO generates the carrier frequency.

- Frequency locked loop (FLL)/phase-locked loop (PLL): Can be used for frequency synthesis, but may not be present depending on the implementation.

- Power amplifier (PA): The PA amplifies the transmission signal.

Below, we describe solutions for ambient IoT.

A-IoT processing time can be defined by the following timing relationship:

TR2D_min: Minimum time between an R2D transmission and the corresponding D2R transmission.

TD2R_min: Minimum time between a D2R transmission and its corresponding R2D transmission.

TD2R_max: Maximum time between a D2R transmission and its corresponding R2D transmission.

TR2D_R2D_min: Minimum time between two different consecutive R2D transmissions to the same A-IoT device.

TD2R_D2R_min: Minimum time between two different consecutive D2R transmissions from the same A-IoT device.

1. R2D (reader-to-device)

1) R2D waveform, modulation, and numerology

Dedicated physical broadcast channels (e.g., PBCH-like) and reference signals including DMRS, PTRS (phase tracking reference signal), and CSI-RS/TRS may not be considered for R2D.

An OFDM-based OOK waveform with a subcarrier spacing (SCS) of 15 kHz is considered. For this waveform, the start of the R2D transmission from the reader's perspective can be assumed to be aligned with the boundary of an NR OFDM symbol (including the CP) for in-band/guard-band operation. Both CP-OFDM and DFT-s-OFDM are possible to generate this waveform. Both CP-OFDM (cyclic prefix-OFDM) and DFT-s-OFDM (DFT-spread OFDM) are possible when M=1, i.e., using On-off keying (OOK)-1 or OOK-4 for single-chip transmission per OFDM symbol. DFT-s-OFDM is possible when M>1, i.e., using OOK-4 for M-chip transmission per OFDM symbol.

2) PRDCH (physical reader-to-device channel)

For R2D, the PRDCH can be defined as the sole physical channel. The PRDCH can carry all upper-layer payloads (including system information, if defined) and L1 R2D control information, if defined. For example, if no L1 R2D control information is transmitted via the PRDCH, a PRDCH transmission carrying only R2D data is also possible.

3) R2D timing

An R2D timing acquisition signal (R-TAS) preceding the PRDCH may be included at least for timing acquisition, and the R-TAS may indicate the start of an R2D transmission in the time domain. The structure of the R-TAS using a preamble is being discussed, and may include a start-indicator part that provides the start of an R2D transmission and a clock-acquisition part that is used to determine the OOK chip duration of a subsequent PRDCH transmission. Here, the preamble may not be part of the PRDCH.

The R-TAS start-indicator part is not included in TD2R_min, and an ON/OFF pattern (i.e., high/low voltage transmission) can be applied. An ON-OFF transmission based on energy/edge detection can be considered for the R-TAS start-indicator part. In this case, a single ON-OFF transmission or multiple ON-OFF transmissions can be included. Here, ON and OFF can have the same or different time intervals. Alternatively, an ON-OFF sequence-based design consisting of a predefined sequence for detecting the R-TAS start-indicator part based on digital correlation can be considered.

The clock-acquisition portion is based on OOK without line coding, and the device may include rising/falling edges including at least two rising or two falling edges to determine the OOK chip time interval.

To determine or induce the end of a PRDCH transmission, information may be transmitted via implicit/explicit L1 R2D control information or a postamble may be included at the end of the PRDCH.

4) R2D scheduling

For R2D reception, the device may explicitly/implicitly indicate to the device via the PRDCH the ID associated with the device(s) for R2D reception (potentially including all devices (if supported)).

2. D2R (device-to-reader)

1) Waveform and modulation

Reference signals, including DMRS, PTRS, and SRS, may not be considered for D2R. Additionally, CSI feedback and autonomous scheduling requests (SRs) may not be considered for L1 (layer-1) D2R control information.

For D2R by backscattering, the waveform can be provided by a CW (carrier wave). The D2R baseband signal (distinguished from the inner or outer carrier wave) can be non-OFDM.

The following D2R baseband modulations are discussed for all devices:

- OOK

- BPSK (binary phase shift keying)

- BFSK (binary frequency shift keying), MSK (minimum shift keying)

2) PDRCH (physical device-to-reader channel)

For D2R, the physical channel PDRCH can carry upper layer payload, responses sent from the device to the leader during contention-based access procedures, and L1 D2R control information (if defined).

3) D2R timing

A D2R timing acquisition signal (D-TAS) preceding each PDRCH may be included at least for timing acquisition purposes and may indicate the start of a D2R transmission in the time domain. A D-TAS structure using a preamble is being discussed, and a binary signal may be considered. Here, the preamble may not be part of the PDRCH.

To ensure that the leader obtains the end of a PDRCH transmission, a D2R postamble may be included immediately after the PDRCH or may be based on control information.

4) D2R scheduling

For D2R scheduling, the following information can be explicitly/implicitly indicated to the device via the PRDCH:

- Time domain resources

- Frequency domain resources

- MCS-like information

- Chip duration

- ID associated with the device(s)

- Repeat

- Information about midamble (if supported)

3. Overall procedure

FIG. 8 illustrates an overall procedure between an A-IoT device and a reader in a wireless communication system to which the present disclosure can be applied.

- Step A: A-IoT Paging. Based on the service request, the leader transmits an A-IoT paging message indicating the device(s) that should respond.

Here, the A-IoT paging function can use A-IoT paging messages to indicate the device(s) that require a response.

An identifier may be included in this trigger message within the A-IoT paging message to identify the device/device group. Additionally, the A-IoT paging message may include additional information that allows the device to determine the resources to use in the D2R response message.

A leader can transmit multiple (subsequent) A-IoT paging messages related to the same service request in the core network (CN). Duplicate responses from devices to the same service request must be avoided. Information to avoid such duplicate responses from devices to the leader can be included in the A-IoT paging message. Based on this information, the device can decide whether to skip sending a response to the A-IoT paging message.

- Step B: D2R data (device ID) transmission. The triggered A-IoT device(s) perform device ID transmission with or without the A-IoT random access procedure.

The A-IoT random access procedure is used by A-IoT devices to access the network for data transmission. The A-IoT random access procedure is triggered by the leader and can trigger access for a single A-IoT device, a group of A-IoT devices, or all A-IoT devices within the leader's coverage area.

Slotted-ALOHA (slotted-additive links on-line Hawaii area) can be used as an A-IoT random access procedure.

After the A-IoT device considers contention resolution successful when contention-based random access is used, or when contention-free access is used, the A-IoT device may perform upper layer data transmission with the leader (e.g., device ID and/or other upper layer data, if any).

In the event of a D2R data transmission failure and contention-based random access contention resolution failure, the A-IoT device is supported to re-access at another opportunity (i.e., random access retry) controlled/provided by the leader. Note that the A-IoT device cannot autonomously re-access, and re-access is always controlled by the leader. The leader can use an optional explicit R2D failure/success feedback indication to determine whether the A-IoT device should re-access.

- Step C1: Possible R2D data transmission (e.g. command transmission).

- Step C2: Possible D2R data transmission (e.g., response to a command).

Subsequent R2D data transmissions following a D2R data transmission can be considered as not requiring retransmission of the D2R data. In the event of a D2R data transmission failure, the A-IoT device can follow the leader's subsequent R2D instructions. For example, the leader can repeat an R2D upper-layer "command" to trigger the A-IoT device to resend the same D2R upper-layer "response" (i.e., the A-IoT device can transmit a D2R following the received R2D).

The A-IoT MAC layer can only support simplified segmentation and can support a maximum TB size of approximately 1000 bits in both R2D and D2R directions.

Additionally, A-IoT devices can report their energy status to the leader. For example, an A-IoT device can report a 1-bit energy status indicator to the leader in a D2R message. The leader can consider this indicator in the remaining/follow-up procedures. For example, the leader may not transmit subsequent messages for a while, or the leader may not take any action.

From a higher-level perspective, an "AS (access stratum) ID" can be used for D2R scheduling and R2D reception purposes. Any ID used in the first D2R message can be reused as the "AS ID," or the leader can assign this "AS ID" to an A-IoT device.

4. RAN Architecture

FIG. 9 illustrates a logical system architecture in a wireless communication system to which the present disclosure can be applied.

The RAN architecture for supporting ambient IoT can support a logical system architecture for topology 1 as in Fig. 9(a) and a logical system architecture for topology 2 as in Fig. 9(b).

- A-IoT device: A device that supports ambient IoT.

- A-IoT RAN: Hosts specific functions for A-IoT as part of the RAN's functionality.

- A-IoT radio: Radio interface between A-IoT devices and A-IoT RAN nodes in topology 1, and between A-IoT devices and A-IoT enabled UEs in topology 2.

- A-IoT CN: Hosts specific functions for A-IoT in terms of CN's functional aspects.

- XX Interface: Interface between A-IoT RAN/A-IoT supporting gNB and A-IoT CN where specific A-IoT specific functions are performed.

- Common reader function: Ability to communicate with A-IoT devices via A-IoT wireless.

- A-IoT RAN node functions: Functions including, for example, control of A-IoT radio resources used for A-IoT devices.

FIG. 9(a) shows that both the common reader function and the A-IoT RAN node function can be supported by the A-IoT RAN node. Conversely, FIG. 9(b) shows that the common reader function is supported by the A-IoT-enabled UE, and the A-IoT RAN node function can be supported by the A-IoT-enabled gNB.

5. Information exchanged between the A-IoT CN (core network) and the A-IoT RAN (radio access network).

Information about A-IoT service types (e.g., inventory, commands) can be directed to the leader from the CN.

1) Inventory: This refers to the service that the network provides to discover and obtain identifiers of A-IoT devices.

A-IoT CN can transmit inventory for a single device, a group of devices, or all devices.

An inventory request transmitted from an A-IoT CN to an A-IoT RAN may include:

- A-IoT device identification (to find a single device, a group of devices, or all devices)

- The scope of the inventory request (e.g. the specific area where the inventory will be triggered)

Multiple individual A-IoT device IDs (one ID per device) can be provided to the A-IoT CN via a single inventory report.

2) Command: This refers to the service (e.g., read, write, etc.) that the network provides to send work instructions to A-IoT devices.

A-IoT CN can transmit commands to a single device.

A method for transmitting and receiving signals in a wireless communication system supporting the Ambient Internet of Things (A-IoT).

3GPP IoT can be applied to indoor/outdoor environments, base station characteristics (e.g., macro/micro/pico cell-based deployments), connection topology (e.g., nodes that can communicate with target devices such as base stations, terminals, relay terminals, repeaters, etc.), TDD/FDD and licensed/unlicensed spectrum frequency bands, coexistence of terminals and infrastructure in frequency bands of 3GPP technologies, and assumption of device-initiated/terminated traffic.

In one embodiment of the present disclosure, three types of IoT devices may be utilized.

- Device A: A device that does not store energy and does not generate independent signals (i.e., backscattering transmission).

- Device B: A device that stores energy and does not generate an independent signal (i.e., backscattering transmission), and use of the stored energy may include amplification of the reflected signal.

- Device C: A device that stores energy and generates an independent signal (i.e., includes an active RF component for transmission).

The present disclosure relates to a signal transmission and reception method of devices A and B that perform communication through backscattering transmission among three types of devices. However, this is only one embodiment, and various embodiments of the present disclosure can also be applied to device C.

Additionally, as an example of the present disclosure, at least one of the following four topologies may be applied, as illustrated in FIG. 7.

FIG. 10 illustrates four topologies for ambient IoT in a wireless communication system to which the present disclosure can be applied.

- Topology (1): BS <-> Ambient IoT Device

- Topology (2): BS <-> intermediate node <-> ambient IoT device

- Topology (3): BS <-> Assisting node <-> Ambient IoT device <-> BS

- Topology (4): UE <-> Ambient IoT Device

Here, the BS may be included in or replaced by the gNB, and may be a distribution unit (gNB-DU) of the gNB. Furthermore, the ambient IoT device may be replaced by a UE, a remote UE, a device, or a tag. An intermediate node (IN) may be at least one of a relay node, an integrated access backhaul (IAB) node, a relay UE, or a repeater of the network. In the present disclosure, the gNB and the IN may be collectively referred to as a reader.

For example, for topology (1), the possibility of BS Rx and BS Tx may be included in different BSs. For topologies (2) and (3), the intermediate nodes and auxiliary nodes may be relay terminals, IAB nodes, repeaters, etc. that enable ambient IoT.

The present disclosure describes a method for transmitting and receiving signals in topologies 1 and 2, in which direct communication (i.e., mono-static communication) is performed between a base station (or/and intermediate node) and an IoT device among four topologies. However, this is only one embodiment, and the present disclosure may also be applied to topologies 3 and/or 4.

Hereinafter, in the description of the present disclosure, the direction from base station to device in topology 1 is referred to as DL or R2D (reader-to-device) or R2T (reader-to-tag), and the direction from device to base station is referred to as UL or D2R (device-to-reader) or T2R (tag-to-reader). The base station transmits an R2D (or R2T) message or data/information to the device through R2D (or R2T) signaling, and the device transmits a D2R (or T2R) message or data/information to the base station through D2R (or T2R) signaling.

In addition, in the following description of the present disclosure, in topology 2, the direction from intermediate node (IN) to device is referred to as DL or R2D (reader-to-device) or R2T (reader-to-tag), and the direction from device to IN is referred to as UL or D2R (device-to-reader) or T2R (tag-to-reader). The IN transmits an R2D (or R2T) message or data/information to the device through R2D (or R2T) signaling, and the device transmits a D2R (or T2R) message or data/information to the IN through D2R (or T2R) signaling.

In addition, in the description of the present disclosure below, transmission of an R2D signal or R2D data/information may be transmission of a physical reader-to-device channel (PRDCH), and transmission of a D2R signal or D2R data/information may be transmission of a physical device-to-reader channel (PDRCH).

In describing the present disclosure, “/” means “and”, “or”, or “and/or”, depending on the context.

The present disclosure proposes a method for transmitting and receiving signals between a tag (e.g., an IoT device or device) and a reader (e.g., a BS, gNB, intermediate node, UE, etc.).

Example 1

Embodiment 1 relates to a process for an ambient IoT device to access a reader device. As an example of the present disclosure, FIG. 11 is a flowchart illustrating a process for an ambient IoT device to access a reader device. Specifically, the connection process may be comprised of an MSG0 transmission/reception process (Embodiment 1-1), an MSG1 transmission/reception process (Embodiment 1-2), an MSG2 transmission/reception process (Embodiment 1-3), an MSG3 transmission/reception process (Embodiment 1-4), an MSG4 transmission/reception process, and an MSG5 transmission/reception process (Embodiment 1-5). In addition, the DTX (discontinuous transmission) period and offset of the MSG may be set/defined (Embodiment 1-6).

Example 1-1

As an example of the present disclosure, a leader device may transmit MSG0 (e.g., a query signal or/and PDCCH order, etc.) to an ambient IoT device.

For example, if MSG0 is a query signal, the terminal can determine whether to transmit MSG1 based on MSG0. MSG0 can be used as a DL sync signal, such as PSS/SSS. For example, MSG0 can be reused as a DL sync signal, such as PSS/SSS, or defined as a new sync signal.

Ambient IoT devices can monitor MSG0 for carrier sensing-based connectivity. MSG0 may include information indicating whether the ambient IoT device can connect to the reader device (e.g., whether the ambient IoT device can transmit MSG1). For example, if MSG0 includes information indicating "busy" or/and "idle," the ambient IoT device may determine that it can transmit MSG1 within a certain period of time.

Additionally or alternatively, ambient IoT devices may use the carrier of another device to avoid collisions. For example, (ambient IoT) device 2 may detect the carrier transmitted by device 1 and avoid accessing it for a period of time after detecting the carrier.

At this time, MSG0 may include connection-related system information. For example, the connection-related system information may include a timer value for connection operations, information related to the time interval during which MSG1 transmission is possible (e.g., information related to the start time, length, window pattern, etc.). Additionally or alternatively, the connection-related system information may be transmitted via a separate MSG 0 for each specific device type, and the MSG 0 may indicate that the system information applies only to the specific device type.

Additionally or alternatively, MSG0 may include information for resolving conflicts. For example, MSG0 may include probability-based access information, UE ID-based access information, early indication-based access information, UE group/type-based access information, service/access type-based access information, etc.

Additionally or alternatively, an ambient IoT device that detects the transmission of a message (e.g., MSG0, MSG2, MSG4, etc.) to another device may not transmit MSG 1. However, if the ambient IoT device does not detect such a message for a certain period of time, the ambient IoT device may transmit MSG 1.

For example, an ambient IoT device can monitor MSG0 to determine whether access to the leader device is permitted. If MSG0 indicates "Busy" or "Idle," the ambient IoT device can access the leader device only after the "Idle" indication.

Example 1-2

The ambient IoT device can (re)transmit MSG1 to the reader device. For example, the ambient IoT device can (re)transmit MSG1 to the reader device using backscattering. The method described below can also be applied to transmitting and receiving messages subsequent to MSG1 (e.g., MSG 3/5).

As an example of the present disclosure, when MSG1 is transmitted in a slotted ALOHA manner, the ambient IoT device can transmit MSG1 at a time aligned with a specific time point (e.g., a transmission time of a DL sync signal or MSG0 transmitted by a reader device, a CW (carrier wave) transmission time, a backscattering transmission time (e.g., ambient IoT device A or B), etc.). The slotted ALOHA manner is a method of transmitting data by unit time (e.g., slot). As another example, the ambient IoT device can transmit MSG1 by selectively backscattering CW.

Additionally, MSG 1 may include a sequence for collision avoidance. The sequence for collision avoidance may be determined based on at least one of the options described below.

Option 1: Select a random sequence

Option 1A: Random sequence + early indication or UE group/type/service/connection type indication

When Option 1A is applied, the ambient IoT device may transmit MSG1 in the form of an early indication or UE group/type/service/connection type indication attached before or after a randomly selected sequence. In this case, the indication may correspond to a sequence according to Option 3, Option 4, or Option 5.

Option 1B: Select a random sequence from a cell-specific sequence pool.

When Option 1B is applied, the ambient IoT device may receive sequence-related information from the leader device or randomly select a sequence from a preset pool of sequences.

Option 2: Device-dedicated sequence

When Option 2 is applied, the ambient IoT device can receive sequence-related information from the leader device or transmit a preset device-specific sequence.

Option 3: Early Instruction-Based Sequence Selection

When Option 3 is applied, the ambient IoT device can transmit a sequence that maps to an early indication. Here, the early indication can be a general term for an indicator that indicates the type or capability of the device (or terminal).

Option 4: UE Group/Type-Based Sequence Selection

When Option 4 applies, the ambient IoT device can transmit a sequence that is mapped to a UE group/type.

Option 5: Select a sequence based on service/connection type.

When Option 5 is applied, the ambient IoT device can transmit a sequence that maps to the service or connection type it is currently trying to access.

Option 6: Channel quality-based sequence

The ambient IoT device can measure the signal transmitted by the reader device and transmit MSG1 with a sequence mapped to the measured value. For example, if the measured value is less than or equal to threshold 1, the ambient IoT device can select a sequence from the first sequence pool. If the measured value is greater than threshold 1 but less than or equal to threshold 2, the ambient IoT device can select a sequence from the second sequence pool.

Based on the sequence, early indication, UE group/type, service/access type or channel quality level selected through at least one of the above-described options, the ambient IoT device can determine the (backscatter-based) transmission time and/or reception time of MSG1, MSG2, MSG3, MSG4 or/and MSG5. For example, based on the UE group/type or service/access type, a subsequent specific MSG transmission start time, a specific MSG reception start time, a specific MSG transmission interval or a specific MSG reception interval can be determined.

Additionally or alternatively, based on a sequence, early indication, UE group/type, service/access type, or channel quality level selected through at least one of the above-described options, the ambient IoT device may determine the transmission/reception resources/time/frequency of MSG1, MSG2, MSG3, MSG4, or/and MSG5. Accordingly, the ambient IoT device may transmit and receive MSG1, MSG2, MSG3, MSG4, or/and MSG5 based on the determined resources/time/frequency.

When an ambient IoT device transmits MSG 1, at least one of the methods described below may be applied to resolve a collision. That is, the ambient IoT device may distribute MSG1 transmissions using at least one of the methods described below.

Method 1: Distribution over multiple frequencies

Method 1 is a method in which an ambient IoT device selects one MSG1 frequency among multiple MSG1 frequencies and transmits MSG1 using the selected frequency. The ambient IoT device may configure multiple MSG1 frequencies (e.g., via MSG0), or multiple MSG1 frequencies may be preset/defined. Distribution methods via multiple frequencies may include a probability-based distribution method, a UE ID/sequence-based distribution method, a UE-only signaling method (based on preset configuration rather than for initial access), a channel quality-based distribution method, a beam/SSB index-based distribution method, and/or a UE group/type-based sequence selection method.

As an example of the present disclosure, when a probability-based distribution method is applied, the ambient IoT device may select the MSG1 frequency based on preset probability information and/or probability information received via MSG0. For example, the ambient IoT device may select a value between 0 and 1 immediately before transmitting MSG1. If the selected value exceeds a threshold value set by the reader device or a preset threshold value, the ambient IoT device may select a first frequency among the plurality of MSG1 frequencies. If the selected value is less than or equal to the threshold value set by the reader device or a preset threshold value, the ambient IoT device may select a second frequency among the plurality of MSG1 frequencies.

As an example of the present disclosure, when a UE ID/sequence based distribution scheme is applied, the ambient IoT device can select the MSG1 frequency according to the MSG1 sequence selected according to the above-described option or according to the pre-assigned UE ID.

As an example of the present disclosure, when a UE-only signaling scheme (based on pre-configuration rather than initial connection) is applied, the ambient IoT device can transmit MSG1 using a frequency determined according to the UE-only signal. The UE-only signal may be pre-stored configuration information or a message notified in advance by the reader device.

As an example of the present disclosure, when a channel quality-based distribution method is applied, an ambient IoT device can measure a signal transmitted by a reader device and transmit MSG1 using a frequency mapped to the measured value. Here, the measured signal can be a DL sync signal or MSG0. For example, if the measured value is less than or equal to a threshold value 1, the ambient IoT device can select a first frequency among a plurality of MSG1 frequencies. If the measured value is greater than or equal to a threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device can select a second frequency among a plurality of MSG1 frequencies.

As another example, when a channel quality-based distribution method is applied, the ambient IoT device can measure a signal transmitted by the leader device and transmit an MSG1 resource mapped to the measured value. Here, the measured signal can be a DL sync signal or MSG0. For example, if the measured value is less than or equal to a threshold value of 1, the ambient IoT device can select the first resource among multiple resources. If the measured value is greater than the threshold value of 1 and less than or equal to the threshold value of 2, the ambient IoT device can select the second resource among multiple resources. The multiple resources can be set by the leader device or can be predefined.

As an example of the present disclosure, when a beam/SSB index-based distribution method is applied, the ambient IoT device may measure a beam RS or SSB transmitted by a reader device, and transmit MSG1 using a frequency or resource mapped to a best RS index, a best SSB index, or an RS/SSB greater than or equal to a threshold value. For example, if an SSB having an SSB index value of 0 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device may select a first frequency/resource among the plurality of MSG1 frequencies/resources. For example, if an SSB having an SSB index value of 1 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device may select a second frequency/resource among the plurality of MSG1 frequencies/resources.

As an example of the present disclosure, when a UE group/type based sequence selection method is applied, an ambient IoT device can select a frequency mapped to a UE group/type (among multiple MSG1 frequencies) and transmit MSG1 using the selected frequency.

As an example of the present disclosure, when a service/connection type-based sequence selection method is applied, the ambient IoT device can select a frequency (among multiple MSG1 frequencies) mapped to a service or connection type to which it is currently trying to connect, and transmit MSG1 using the selected frequency.

Method 2: Time-based distribution method

The time-based distribution method is a method in which the ambient IoT device selects a specific point in time/slot within a time interval for MSG1 transmission and transmits MSG1 within the selected specific point in time/slot. The ambient IoT device may set the time interval for MSG1 transmission (via MSG0), or the time interval for MSG1 transmission may be determined according to a predefined rule. The ambient IoT device may select the MSG1 transmission point in time/slot using at least one of the methods described below. In this case, the MSG1 transmission interval/point in time/slot may be determined as a point in time that is offset by a positive/negative amount from the CW transmission/reception point in time.

As an example of the present disclosure, when a probability-based distribution method is applied, the ambient IoT device may select a MSG1 transmission time/slot within the MSG 1 time interval based on preset probability information or probability information received from MSG0. For example, the ambient IoT device may select a specific value between 0 and 1 immediately before transmitting MSG1. If the selected specific value is preset by the reader device or exceeds a preset threshold, the ambient IoT device may select a first transmission time interval/transmission time/slot (within the time interval for MSG1 transmission). If the selected specific value is preset by the reader device or is less than or equal to a preset threshold, the ambient IoT device may select a second transmission time interval/transmission time/slot (within the time interval for MSG1 transmission). Then, the ambient IoT device may transmit MSG 1 in the selected transmission time interval/transmission time/slot.

As an example of the present disclosure, when a UE ID/sequence based distribution scheme is applied, the ambient IoT device can select an MSG1 transmission time point/slot within the time interval for MSG 1 transmission according to the MSG1 sequence selected according to the above-described option or the pre-assigned UE ID. For example, when the result value of sequence mode N or UE ID mod N is 0, the ambient IoT device can select the first transmission time interval/transmission time point/slot (within the time interval for MSG 1 transmission). When the result value of sequence mode N or UE ID mod N is 1, the ambient IoT device can select the second transmission time interval/transmission time point/slot (within the time interval for MSG 1 transmission).

As an example of the present disclosure, when a UE-only signaling scheme (based on pre-configuration rather than initial connection) is applied, the ambient IoT device can transmit MSG1 through a MSG1 transmission time interval/point/slot determined according to the UE-only signal. The UE-only signal may be pre-stored configuration information or a message notified in advance by the reader device.

As an example of the present disclosure, when a channel quality-based distribution scheme is applied, the ambient IoT device can measure a signal transmitted by the leader device and transmit MSG1 using a transmission time interval/point in time/slot within a time interval mapped to the measured value. Here, the measured signal can be a DL sync signal or MSG0. For example, if the measured value is less than or equal to a threshold value 1, the ambient IoT device can select the first time interval/point in time/slot (within the time interval for transmitting MSG1). If the measured value is greater than or equal to a threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device can select the second time interval/point in time/slot (within the time interval for transmitting MSG1).

In another example of the present disclosure, when a channel quality-based distribution method is applied, the ambient IoT device can measure a signal transmitted by a leader device and transmit an MSG1 resource mapped to the measured value. Here, the measured signal can be a DL sync signal or MSG0. For example, if the measured value is less than or equal to a threshold value 1, the ambient IoT device can select a first resource among a plurality of resources. If the measured value is greater than the threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device can select a second resource among the plurality of resources. Here, the resource can be determined by frequency and/or time.

As an example of the present disclosure, when a beam/SSB index-based distribution scheme is applied, the ambient IoT device can measure the beam RS or SSB transmitted by the reader device, and transmit MSG1 using a transmission time interval/point in time/slot or resource within a time interval mapped to a best RS index, a best SSB index, or an RS/SSB greater than or equal to a threshold value. For example, if an SSB having an SSB index value of 0 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device can select a first transmission time interval/point in time/slot or resource (within a time interval for transmitting MSG1). For example, if an SSB having an SSB index value of 1 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device can select a second transmission time interval/point in time/slot or resource (within a time interval for transmitting MSG1).

As an example of the present disclosure, when an energy storage based distribution scheme is applied, the ambient IoT device may measure the remaining energy storage level of the device and transmit MSG1 using a specific time interval/transmission point/slot within a time interval mapped to the measured value. For example, if the measured value (i.e., the energy storage level of the ambient IoT device) is less than or equal to a threshold value 1, the ambient IoT device may select the first transmission time interval/point/slot or resource (within the time interval for transmitting MSG1). If the measured value is greater than the threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device may select the second transmission time interval/point/slot or resource (within the time interval for transmitting MSG1). In this case, the ambient IoT device may be configured to select a faster transmission time interval/point/slot as the remaining energy storage level decreases.

As an example of the present disclosure, when an energy storage-based distribution method is applied, an ambient IoT device can measure the remaining energy storage level of the device and transmit an MSG1 resource mapped to the measured value. For example, if the measured value (i.e., the energy storage level of the ambient IoT device) is less than or equal to a threshold value 1, the ambient IoT device can select a first resource among a plurality of resources. If the measured value is greater than the threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device can select a second resource among the plurality of resources. Here, the resource can be determined by frequency/time.

As an example of the present disclosure, when a UE group/type-based sequence selection method is applied, an ambient IoT device can select a transmission time interval/point/slot mapped to a UE group/type (within a time interval for MSG1 transmission) and transmit MSG1 using the selected transmission time interval/point/slot.

As an example of the present disclosure, when a service/connection type-based sequence selection method is applied, the ambient IoT device can select a transmission time interval/point/slot mapped to a service or connection type to which it is currently trying to access (within the time interval for MSG1 transmission), and transmit MSG1 using the selected transmission time interval/point/slot.

As an example of the present disclosure, when a priority-based distribution scheme is applied, the ambient IoT device may select a transmission time interval/slot/point in time (for transmitting MSG1) based on the device priority or the priority of the connection to which it is currently trying to connect, and transmit MSG1 at the selected transmission time interval/slot/point in time. For example, in an access procedure with a high priority, or the device may select a short first transmission time interval/point in time/slot (within the time interval for transmitting MSG1), and transmit MSG1 using the first selected transmission time interval/point in time/slot. In an access procedure with a low priority, or the device may select a long second transmission time interval/point in time/slot or resource (within the time interval for transmitting MSG1), and transmit MSG1 using the second selected transmission time interval/point in time/slot.

An ambient IoT device can transmit MSG1 to a reader device according to at least one of the above-described methods. At this time, the terminal can probabilistically determine whether to actually transmit MSG1. For example, if the predefined/set probability value is a specific value (e.g., 0.3), the ambient IoT device can select a random number. If the random number is less than or equal to the specific value, the ambient IoT device can transmit MSG1. If the random number exceeds the specific value, the ambient IoT device can start a timer for back-off without transmitting MSG1.

After back-off (i.e., after the timer for back-off expires), the ambient IoT device may perform MSG1 retransmission according to at least one of the above-described methods. Additionally or alternatively, if MSG2 or/and MSG4 are not received, if MSG 2 or/and MSG4 do not contain a sequence or UE ID of the ambient IoT device, if MSG 2 or/and MSG4 do not indicate ACK, or/and if MSG 2 or/and MSG4 indicate NACK, the ambient IoT device may perform back-off.

After back-off (i.e., after the timer for back-off expires), the ambient IoT device can perform MSG1 retransmission according to at least one of the methods described above. The ambient IoT device can retransmit MSG1 after selecting/determining a back-off time (i.e., a timer value) according to at least one of the methods described below. The ambient IoT device can obtain the selectable back-off time values from MSG 0, MSG 2, or/and MSG 4, or from pre-stored information/system information.

As an example of the present disclosure, when a probability-based back-off time scheme is applied, the ambient IoT device may select a back-off time based on preset probability information or probability information received from MSG0. For example, the ambient IoT device may select a specific value between 0 and 1 immediately before transmitting MSG1. If the selected specific value is preset by the reader device or exceeds a preset threshold, the ambient IoT device may select a first back-off time (from among the plurality of back-off times). If the selected specific value is preset by the reader device or is less than or equal to a preset threshold, the ambient IoT device may select a second back-off time (from among the plurality of back-off times). Then, the ambient IoT device may transmit MSG 1 based on the selected back-off time.

As an example of the present disclosure, when a UE ID/sequence based back-off time scheme is applied, the ambient IoT device may select a back-off time according to a selected MSG1 sequence or a pre-assigned UE ID according to the above-described options. For example, when the result value of sequence mode N or UE ID mod N is 0, the ambient IoT device may select a first back-off time (from among a plurality of back-off times). When the result value of sequence mode N or UE ID mod N is 1, the ambient IoT device may select a second back-off time (from among a plurality of back-off times). Here, N may be equal to the number of selectable back-off times.

As an example of the present disclosure, when a UE-only signaling scheme (based on pre-configuration rather than initial connection) is applied, the ambient IoT device may transmit MSG1 based on a back-off time determined according to the UE-only signal. The UE-only signal may be pre-stored configuration information or a message notified in advance by the leader device.

As an example of the present disclosure, when a channel quality-based distribution method is applied, an ambient IoT device can measure a signal transmitted by a leader device and transmit MSG1 using a back-off time mapped to the measured value. Here, the measured signal can be a DL sync signal or MSG0. For example, if the measured value is less than or equal to a threshold value 1, the ambient IoT device can select a first back-off time (from among a plurality of back-off times). If the measured value is greater than or equal to a threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device can select a second back-off time (from among a plurality of back-off times).

As an example of the present disclosure, when a beam/SSB index-based distribution scheme is applied, the ambient IoT device may measure the beam RS or SSB transmitted by the reader device, and transmit MSG1 using a back-off time mapped to a best RS index, a best SSB index, or an RS/SSB greater than or equal to a threshold value. For example, if an SSB having an SSB index value of 0 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device may select a first back-off time (from among a plurality of back-off times). For example, if an SSB having an SSB index value of 1 is the best SSB or a measurement value of the SSB is greater than or equal to a threshold value, the ambient IoT device may select a second back-off time (from among a plurality of back-off times).

As an example of the present disclosure, when an energy storage-based distribution method is applied, an ambient IoT device may measure the remaining energy storage level of the device and transmit MSG1 using a back-off time mapped to the measured value. For example, if the measured value (i.e., the energy storage level of the ambient IoT device) is less than or equal to a threshold value 1, the ambient IoT device may select a first back-off time (from among a plurality of back-off times). If the measured value is greater than the threshold value 1 and less than or equal to a threshold value 2, the ambient IoT device may select a second back-off time (from among a plurality of back-off times). In this case, the ambient IoT device may be configured to select a shorter back-off time as the remaining energy storage level decreases.

As an example of the present disclosure, when a UE group/type-based sequence selection method is applied, an ambient IoT device can select a back-off time mapped to a UE group/type (among multiple back-off times) and transmit MSG1 using the selected back-off time.

As an example of the present disclosure, when a service/connection type-based sequence selection method is applied, the ambient IoT device can select a back-off time (among multiple back-off times) that is mapped to a service or connection type to which it is currently trying to connect, and transmit MSG1 using the selected back-off time.

As an example of the present disclosure, when a priority-based distribution scheme is applied, the ambient IoT device may select a back-off time based on the device priority or the priority of the connection to which it is currently trying to connect, and transmit MSG1 using the selected back-off time. For example, in an access procedure with a high priority, or the device may select a short first back-off time (from among a plurality of back-off times) that is mapped to the service or connection type to which it is currently trying to connect, and transmit MSG1 using the selected first back-off time. In an access procedure with a low priority, or the device may select a long second back-off time (from among a plurality of back-off times) that is mapped to the service or connection type to which it is currently trying to connect, and transmit MSG1 using the selected second back-off time.

Example 1-3

The ambient IoT device may receive MSG2 (from the reader device) after performing (re)transmission of MSG1. In one example of the present disclosure, MSG2 may include/indicate ACK and/or NACK information. For example, if the reader device successfully receives MSG1 and allows connection, MSG2 may include/indicate ACK. If the reader device does not successfully receive MSG1 or/and does not allow connection, MSG2 may include/indicate NACK.

For example, if MSG2 includes/indicates ACK, MSG2 may include at least one of information included in MSG1 (e.g., sequence information), transmission/reception resources of MSG1 (e.g., time/frequency resources), time/frequency for transmitting/receiving MSGs (e.g., MSG0, MSG1, MSG2, MSG3, MSG4, and/or MSG5, etc.), or CW time/frequency information for backscattering. If MSG2 includes/indicates NACK, MSG2 may include a back-off time.

Example 1-4

In one embodiment of the present disclosure, when an ACK including/indicating an ACK is received, the ambient IoT device may transmit MSG3 (to the reader device). For example, the ambient IoT device may transmit MSG3 in a backscattering manner. The selection of a time interval/point in time/frequency/resource for transmitting MSG3 may be determined/selected based on at least one of the transmission/reception time interval/point in time/frequency/resource selection methods of MSG2.

MSG3 may contain at least one of UE ID, sequence, early indication, UE group/type, connection type, RRC connection/resume request message for initial connection, and C-RNTI MAC CE for UE within RRC_CONNECTED.

Here, the UE ID (e.g., C-RNTI) may be scrambled, masked, or attached to all UL messages. The sequence may be part or all of the sequence selected for MSG1. In another example, the sequence may be part or all of a newly selected sequence using at least one of the MSG1 sequence selection methods described above. The early indication may include the device type (e.g., device A, device B, or device C) and/or other processing times. The RRC connection/resume request message may include the UE ID (e.g., s-TMSI or resumption ID), etc.

Example 1-5

An ambient IoT device that transmitted MSG 3 may receive MSG4 (from a reader device). MSG4 may include a UE ID (or/and contention resolution MAC CE) and/or sequence information. Here, the sequence may be selected/determined based on at least one of the MSG1 sequence selection methods described above.

If MSG4 contains the UE ID (or device ID) or sequence of the ambient IoT device, the ambient IoT device may transmit MSG5 (to the reader device).

For example, MSG5 may include terminal capability information. For example, the terminal capability information may include capability information related to device type (e.g., device type A, B, C), other processing times, early indication (e.g., device type, other processing times), terminal group/type, connection type, etc. Additionally or alternatively, MSG5 may include at least one of a UE ID, a sequence, and user data.

Example 2

Example 2 relates to a method for setting/defining a symbol duration for ambient IoT (AmIoT) terminal/device communication.

Considering the numerology of the NR system and the target data rate of the AmIoT system, the symbol interval for AmIoT communication can be determined according to at least one of the embodiments described below.

In describing the present disclosure, the NR system can be replaced with a (5G and/or 6G) wireless communication system (or a parent system/coexisting communication system). The (CP-)OFDM symbol can be replaced with an existing transmission time unit of the (5G and/or 6G) wireless communication system (or a parent system/coexisting communication system).

Example 2-1

N CF-OFDM symbol intervals of an NR system can be defined as a symbol interval for one AmIoT communication. The N value can be predefined or set/instructed to an AmIoT device.

Example 2-2

A CP-OFDM symbol interval of an NR system can be divided into M equal parts, and one of the M equally divided CP-OFDM symbol intervals can be defined as a symbol interval for AmIoT communication. Here, the value of M can be predefined or set/indicated by an AmIoT device. In this case, a CP interval can be included in a CF-OFDM symbol interval, but is not limited thereto. A CF-OFDM symbol interval may include only a part of a CP interval or may not include a CP interval.

Example 2-3

One or more OFDM symbols (e.g., predefined OFDM symbol sample values (e.g., TC or TS) can be defined as a sample group, and K sample group(s) can be defined as a symbol interval for one AmIoT communication. Here, the K value and the sample group determination method can be predefined or set/instructed to the AmIoT device.

One of Examples 2-1, 2-2 and 2-3 may be set/applied differently or set/applied commonly depending on the following elements.

- Use cases of AmIoT terminals (e.g., sensors, commands, inventory, positioning, etc.)

- Device type of AmIoT terminal, tag ID or/and topology of AMIoT communication

Example 3

It relates to a method for configuring a symbol interval for ambient IoT (AmIoT) terminal communication.

For communication between AmIoT terminals corresponding to device type A or B, both an energy transfer signal (ETS) for energy harvesting purposes and a backscattering signal (BSS) exchanged for backscattering communication after the AmIoT terminals receive the ETS may be required.

In order for the BSS signal transmitted by the base station or intermediate node (or, a separate UE device) to be efficiently received as a backscattered signal by the AmIoT device, it may be advantageous for the BSS signal to be configured as CW.

However, in order to be robust against inter-symbol interference (ISI) after generating a single OFDM symbol in an NR system, a CP may be attached to the front of the generated OFDM symbol, thereby configuring the final OFDM symbol. Due to the above-described characteristics, it may be difficult to construct a CW structure that maintains the same frequency component across multiple OFDM symbols, as illustrated in (a) of Fig. 12.

To overcome this, as shown in (b) of Fig. 12, by adjusting the phase for each OFDM symbol, the waveform can be configured so that the CW condition is satisfied across multiple OFDM symbols even if a CP is attached to the front of the OFDM symbol.

As described above, the pi/2-BPSK (binary phase-shift keying) modulation method can be applied to control the phase for each CP. However, even when the Pi/2-BPSK modulation method is applied, a problem may arise where the phase exceeds Pi/2 or Pi/4 due to the CP inserted in the middle. Therefore, a method that controls the phase for each CP while applying the Pi/2-BPSK modulation method can be applied at the same time.

Pi/2-BPSK modulation (and phase control per CP) makes sense in situations where data is transmitted by modulating it on a symbol-by-symbol basis, but Pi/2-BPSK modulation (and phase control per CP) can only be applied to BSS (not ETS).

Additionally, when the above-described CW transmission method is applied, the unit and/or period in which CW is maintained can be set/instructed by the base station to the AmIoT device. For example, as illustrated in (b) of FIG. 12, when CW is maintained for every 2 OFDM symbols, 2 OFDM symbol interval information and/or the starting point of the interval (e.g., SFN#0 or every sub-frame) can be set/defined/instructed. Here, the interval information can be configured in units of OFDM symbols (or slots, subframes, or absolute time). For example, when the interval is set/instructed as 1 slot, the AmIoT device can assume that CW is maintained for at least a plurality of OFDM symbols within the same slot.

As another example of the present disclosure, a signal for an AmIoT terminal can be configured by repeating OFDM symbols without a CP (similar to the NR PRACH signal configuration). In this case, the base station can either abandon FDM with NR signals or perform FDM with existing NR signals after setting a guard band along the frequency axis.

Since the CW properties may not be maintained due to CP insertion, the CP interval may be used for other purposes. For example, during the CP interval (or during the symbol interval (or part of the symbol interval) for AmIoT terminal communication that includes the CP interval), the base station may transmit a known sequence, rather than data, to the AmIoT device, which may then use the sequence for time and/or frequency axis synchronization.

As described above, the CP interval (or the symbol interval for AmIoT terminal communication including the CP interval (or a part of the symbol interval)) for each symbol may not be utilized for other purposes. Therefore, the AmIoT device can set/receive specific time interval information. The interval information may be configured in units of OFDM symbols (or slots, sub-frames, absolute time) (e.g., X mesc, Y usec). For example, if information such as 1 slot is set, the AmIoT device can recognize that the CP interval (or the symbol interval for AmIoT terminal communication including the CP interval (or a part of the symbol interval)) for each slot is configured in a known sequence.

As described above, the method of maintaining CW across multiple OFDM symbols can be applied to Embodiment 2-1 (i.e., an embodiment of a method of defining N CP-OFDM symbol intervals as a symbol interval for one AmIoT communication).

As described above, the CW transmission method can be applied to both ETS and BSS without distinction. As another example, since a higher PAPR can increase energy transfer efficiency, the CW transmission method can be applied only to BSS (and not to ETS).

Example 4

Implementation 5 relates to a frequency modulation method of a backscattering signal considering frequency diversity and/or (inter-cell) interference randomization.

As an example of the present disclosure, as illustrated in FIG. 13 (a), an AmIoT device that receives a CW (i.e., BSS signal) of frequency F_c transmitted by a base station or intermediate node (or a separate terminal device) can modulate the frequency by applying F_gap. Then, the AmIoT device can transmit the backscattered signal/data to the base station or intermediate node (or a separate terminal device) via the frequency F_t.

It may be advantageous to increase the efficiency of IoT communications by reducing interference when signals are received from multiple base stations or intermediate nodes (or separate UE devices) that may be present in the vicinity from the receiving perspective of a single AmIoT device. Similarly, it may be advantageous to increase the efficiency of IoT communications by reducing interference when signals are received from multiple AmIoT devices from the receiving perspective of a base station or intermediate node (or separate UE device).

Additionally, fading on specific frequencies (e.g., F_c or F_t) in wireless channel environments can significantly degrade communication efficiency. Therefore, pursuing frequency diversification can help maximize the efficiency of IoT communications to overcome this issue. Below, we describe a method for determining F_c and/or F_t.

In consideration of the effect of reducing interference when signals are received from multiple base stations or intermediate nodes (or separate terminal devices) from the perspective of receiving a single AmIoT terminal, the position of F_c may be varied by considering all or some of a plurality of factors (e.g., (physical) cell index, sub-frame index, slot index, CP-OFDM symbol index of NR system, symbol index for AmIoT terminal communication, AmIoT device type).

Similarly, in consideration of the effect of reducing interference when signals are received from multiple AmIoT devices from a base station or intermediate node (or separate terminal device) receiving perspective, the position of F_t (relative to F_c) (or the size of F_gap) may be varied by taking into account all or some of a plurality of factors (e.g., AmIoT device index, sub-frame index, slot index, CP-OFDM symbol index of NR system, symbol index for AmIoT terminal communication, AmIoT device type, capability for (maximum) F_gap size of AmIoT, etc.).

As an example of F_t size variability considering the AmIoT device type, for a terminal of device type A, an F_t (or F_gap size) value within a maximum of X may be set/indicated, but for a terminal of device type B, an F_t (or F_gap size) value within a maximum of Y (>X) (or within a maximum of Y but equal to or greater than a minimum of X) may be set/indicated. Here, the values of X and Y may be preset or defined.

Additionally or alternatively, taking into account the frequency diversification effect, CWs utilizing more than one F_c value at a time may be transmitted by the BSS (or/and ETS), even if the signal is from one base station or intermediate node (or separate terminal device).

Additionally or alternatively, a frequency hopping scheme may be applied to the position of F_c and/or the position of F_t (relative to F_c) (or the size of F_gap) considering both the frequency diversification effect and the interference randomization effect. For example, individual hopping offsets of F_hop 1 and F_hop 2 may be applied, and the change period and the size of the approximate value between the two offsets may be set/applied differently. For example, the F_c value at the {t+1}-th time may be determined from the F_c value at the t-th time by the formula "F_c(t+1) = F_c(t) + F_hop1 + F_hop2".

Here, the time t value can be determined by a combination of a sub-frame index, a slot index, a symbol index, etc. The range of the period and the size of the changed value of F_hop 1 and F_hop 2 can be set separately. For example, the period and size of one of F_hop 1 and F_hop 2 (e.g., F_hop 2) can be set to always be greater than the other (e.g., F_hop 1).

Additionally, the same hopping rules may apply depending on whether the signal is an ETS or a BSS. Alternatively, different hopping rules may apply (e.g., in BSS, both F_hop 1 and F_hop 2 are applied, whereas in ETS, only one offset is applied (e.g., F_hop2 is applied, but F_hop1 is not applied).

The positions/sizes of F_c, F_gap, F_t, F_hop1, and F_hop2 can be defined to have a multiple relationship with the SCS defined in the NR system by considering the numerology of NR. For example, the position of F_c can be set by recycling NR-ARFCN. The sizes of F_gap, F_hop1, and F_hop2 can be determined as multiples of a specific SCS (e.g., a separately set SCS, an SCS set in the activated/initial/default BWP, the largest or smallest SCS among multiple SCSs set in the associated carrier, etc.), or as multiples of 1 RB (e.g., 12 sub-carriers) based on the specific SCS.

Example 5

Example 5 relates to a time-domain modulation method of a backscattering signal considering frequency diversification and/or (inter-cell) interference randomization.

As an example of the present disclosure, as illustrated in (b) of FIG. 13, an AmIoT device that receives a signal (i.e., a BSS signal) from a base station or an intermediate node (or a separate terminal device) at time T_c can perform delayed transmission after time T_gap by applying T_gap. Accordingly, the AmIoT device can transmit the backscattered signal/data to the base station or an intermediate node (or a separate terminal device) at time T_t.

From the perspective of a single AmIoT terminal receiving, it may be beneficial to increase the efficiency of IoT communication by reducing interference when signals are received from multiple base stations or intermediate nodes (or separate terminal devices) that may be present in the vicinity.

Similarly, from the perspective of a base station or intermediate node (or separate terminal device), it may be beneficial to increase the efficiency of IoT communications by reducing interference when signals can be received from multiple AmIoT terminals. Furthermore, pursuing a time-diversification effect, similar to that in Example 4, in a wireless channel environment may help maximize the efficiency of IoT communications.

Below, a method for determining F_c, F_t, T_c and/or T_t is described taking into account the above-described advantages.

In consideration of the effect of reducing interference when signals are received from multiple base stations or intermediate nodes (or separate terminal devices) from the perspective of receiving a single AmIoT terminal, the position of T_c may be varied by considering all or some of a plurality of factors (e.g., (physical) cell index, sub-frame index, slot index, CP-OFDM symbol index of NR system, symbol index for AmIoT terminal communication, AmIoT device type).

Similarly, considering the effect of reducing interference when signals can be received from multiple AmIoT terminals from the perspective of receiving from a base station or intermediate node (or separate terminal device), the position of T_t (relative to T_c) (or the size of T_gap) may be varied by considering all or some of a plurality of factors (e.g., AmIoT device index, sub-frame index, slot index, CP-OFDM symbol index of NR system, symbol index for AmIoT terminal communication, AmIoT device type, capability for (maximum) T_gap size of AmIoT, etc.).

As an example of T_t size variability considering the AmIoT device type, for a terminal of device type A, a T_t (or T_gap size) value within a maximum of X can be set/indicated. And, for a terminal of device type B, a T_t (or T_gap size) value within a maximum of Y (>X) (or within a maximum of Y but greater than/exceeding a minimum of X) can be set/indicated. The X and Y values can be separately set or predefined in advance.

Meanwhile, considering the time diversification effect, CWs utilizing multiple time points (i.e., multiple T_c values) can be transmitted as BSS (and/or ETS) even if it is the same signal (or modulated data) from one base station or intermediate node (or separate terminal device).

In addition, in the backscattered data transmission of the AmIoT terminal, the positions of one or more T_t (or the size of T_gap) corresponding to one T_c can be defined, and the AmIoT terminal can transmit a backscattered signal at the positions of multiple T_t for the same signal (or modulated signal).

Additionally or alternatively, time-varying values may be applied to the position of T_c and/or the position of T_t (relative to T_c) (or the size of T_gap) to account for time-varying and/or interference randomization effects.

For example, the T_gap value at the {t+1}th time can be determined from the T_gap value at the tth time by the formula "T_gap(t+1) = T_gap(t) + T_hop".

Here, the time t value can be determined by a combination of sub-frame index, slot index, symbol index, etc. The period in which T_hop changes and the range of the size of the changed value can be separately set. As another example, the period in which T_hop changes and the size of the changed value can be defined as a value that changes randomly (within a specific set range).

Additionally or alternatively, the value of T_gap(t+1) at a particular time {t+1} may be defined as a value that changes randomly (within a certain defined range) without any relation to T_gap(t) at a previous time t.

Considering that a larger T_gap may lead to greater power consumption of AmIoT terminals, it may be beneficial in terms of fairness for the T_gap value to change randomly. Furthermore, the same rules may apply depending on whether the signal is ETS or BSS, but different rules (e.g., a rule that applies the T_hop change cycle/value for BSS and a rule that applies the T_hop change cycle/value for ETS) may apply.

The timing/size of the above-described T_c, T_gap, T_t, and T_hop can be defined to have a multiple relationship with one or more OFDM samples (e.g., predefined T_c or T_s) defined in the NR system, taking into account the numerology of NR.

FIG. 14 is a flowchart illustrating signaling between a terminal (e.g., a UE or an ambient IoT device) and a base station according to one embodiment of the present disclosure.

The base station can transmit a CW (i.e., a BSS signal) of frequency F_c to the terminal (S1310).

A terminal receiving a CW of frequency F_c can modulate (or/and backscatter) the frequency by applying F_gap determined according to various factors (e.g., UE ID, time index, device type, etc.) (S1320). Then, the terminal can transmit the backscattered data/signal to the base station via frequency F_t (i.e., F_c + F_gap) (S1330).

As described in the above-described embodiments (e.g., embodiment 4, etc.), taking into account frequency diversification and/or interference randomization effects, the terminal may vary F_c and/or F_gap depending on the cell/UE ID, time index (e.g., subframe, slot, symbol, etc.), and device type.

By various embodiments described above, in a mixed situation where communication between multiple base stations and AmIot terminals is performed, backscattering-based communication can be efficiently performed by varying the time/frequency time using cell/UE ID, time index (e.g., subframe, slot, symbol, etc.), device type, etc. Accordingly, communication efficiency can be increased due to frequency diversification and/or interference randomization effects.

Example 6: Frequency Resource Allocation

Hereinafter, the term frequency channel is mainly used in this embodiment, but the present disclosure is not limited thereto, and frequency channel can be interpreted as frequency resource, and also in the frequency domain, frequency resource can be replaced with another term meaning a unit.

A base station or cell may configure one or more frequency channels for communication with devices. When multiple frequency channels are configured, the different frequency channels may be allocated adjacent or non-adjacent.

In addition, when there are multiple INs belonging to one cell, the same or different frequency channels can be set to different INs. For example, different frequency channels can be set to all INs belonging to one cell, and the same frequency channel can be set to each group of some INs among all INs. Here, one or more frequency channels can be set to one IN (or one IN group). Here, different frequency channels can be allocated to adjacent or non-adjacent locations. In addition, one or more frequency channels allocated to an IN can be set to belong to the UL BWP of the corresponding IN or not.

The base station or IN may be configured to enable R2D signal transmission and reception and/or D2R signal transmission and reception on all frequency channels when a device initially connects to the reader (i.e., the base station or IN). Alternatively, the initial connection frequency channel may be designated as a specific channel so that R2D signal transmission and reception and/or D2R signal transmission and reception for initial connection are only enabled on a specific frequency channel when the device initially connects to the reader (i.e., the base station or IN). Here, the initial connection frequency channel may be set to the same channel for all devices, or a specific channel may be set for a specific device or device group. In this case, the initial connection frequency channel may be indicated through system information or paging transmitted by the base station or IN.

The base station can configure one or more frequency channels for the IN via a higher layer message (e.g., an RRC message or a MAC control element (CE)) or a lower layer message (e.g., a DCI).

Additionally, the base station can activate or deactivate specific frequency channel(s) among one or more frequency channels configured for a specific IN via upper/lower layer messages (e.g., DCI or MAC CE).

When multiple frequency channels are allocated to a specific IN, the base station or the IN may be allocated different services, different sessions, different device groups, or different device types for each frequency channel.

When multiple frequency channels are allocated to multiple base stations/INs, a specific base station/IN may be configured to have the same or different frequency channels for R2D signaling and R2D signaling.

Example 7: Time Resource Allocation

A base station or cell sets a time offset for each device to establish time resources for communication with other devices, and different devices can have different offsets. In other words, a single time period can be divided into N time resources, and each time resource can be identified by N offsets from the start of the period. Here, since different time offsets are set for each device, different time resources can be allocated.

For example, the device may receive and respond to an R2D signal transmitted in a time resource according to the k+1th offset when 'UE ID mod N = k' or 'device ID mod N = k' or 'device group ID mod N = k'. Here, the device may also respond to a D2R signal in a time resource according to the k+1th offset, and may also respond to a D2R signal at a timing according to a predetermined interval between the R2D signal and the D2R signal.

As another example, device 1 may respond to an R2T signal (e.g., paging or query) aligned to the first time offset every 80 ms. Additionally, device 2 may respond to an R2T signal (e.g., paging or query) aligned to the second time offset every 80 ms.

Additionally, different base stations, different cells, or different inputs (INs) can have different offsets set for configuring time resources. In other words, a single time period can be divided into N time resources, and each time resource can be identified by N offsets from the start of the period. Here, different time resources can be allocated as different time offsets are set for each base station, each cell, or each input.

For example, the device can obtain a reader identifier (ID) through upper layer signaling (e.g., system information, etc.). If 'Reader ID mod N = k', the device can receive and respond to an R2D signal transmitted in a time resource according to the k+1th offset. Here, the device can also respond to a D2R signal in a time resource according to the k+1th offset, and can also respond to a D2R signal at a timing according to a predetermined interval between the R2D signal and the D2R signal.

As another example, device 1 may respond to an R2T signal (e.g., a paging or query) from base station 1 (or IN 1) aligned to the first time offset every 80 ms. Additionally, device 2 may respond to an R2T signal (e.g., a paging or query) from base station 2 (or IN 2) aligned to the second time offset every 80 ms.

Example 8: Parameter-Based Resource Allocation

Multiple base stations or INs can use the same time resource or the same frequency channel (resource) or the same time/frequency resource or the same resource pool (i.e., time resource pool or frequency resource pool or time/frequency resource pool). In this case, different R2D signals transmitted by different base stations/INs can include at least one of the base station ID or cell ID or the corresponding IN ID or leader ID (e.g., an identifier for all devices acting as leaders that is distinct from the base station/IN ID) or session ID or flag value. Accordingly, the device can recognize that the R2D signals are from different leaders based on the information included in the R2D signals. Accordingly, the device can receive the R2D signal from a specific leader or transmit the D2R signal only to a specific leader.

Example 9: Time/Frequency Resource Pooling Method

A base station may set a time/frequency resource pool (or resource set or resource region) for A-IoT communication for one or more base stations or one or more INs acting as a leader. Here, the time/frequency resource pool may be set to at least one of the following:

- Pool for R2D signal transmission resources

- Resource pool for D2R signal reception resources

- Resource pool for R2D signal transmission and D2R signal reception resources

- Resource pool for CW transmission resources

- Resource pool for R2D signals and CW transmission resources

- Resource pool for CW transmission resources and D2R signal reception resources

- Resource pool for R2D signal transmission and CW transmission resources, and D2R signal reception resources.

The base station can configure one or more time/frequency resource pools for IN via upper layer messages (e.g., RRC messages or MAC CE) or lower layer messages (e.g., DCI).

Additionally, the base station can activate or deactivate specific time/frequency resource pool(s) from among one or more time/frequency resource pools configured for a specific IN via upper/lower layer messages (e.g., DCI or MAC CE).

Example 10: How to categorize resources

A base station can categorize time/frequency resources for transmitting and receiving R2D/D2R signals into the following categories. This categorization of time/frequency resources can apply to dynamic resources, semi-static resources, or configured resources.

- TX dedicated resources of base station/IN (i.e. R2D signal transmission resources)

For example, these resource types may be configured for system information or paging transmission for initial connection of a device.

- TX and CW resources of the base station/IN (i.e., R2D signal transmission resources and CW transmission resources)

For example, these resource types may be set up for paging transmissions for the initial connection of a device, or together with RX-only resources for devices that have already completed the connection.

- TX, CW and RX resources of the base station/IN (i.e. R2D signal transmission resources, CW transmission resources and D2R signal reception resources)

For example, these resource types could be set up for device-specific message exchange after the devices have completed their initial connection.

- CW and RX resources of the base station/IN (i.e., CW transmission resources and D2R signal reception resources)

For example, such a resource type may be configured to cause the device to transmit a delay response to a leader (e.g., a base station or IN).

- CW transmission-only resources

For example, these resource types may be configured for CW transmission by a leader (e.g., a base station or IN) or by a separate CW transmitting node (i.e., a non-leader device).

- Dedicated RX resources for base station/IN

For example, this resource type could be configured to allow a device to receive CW from a separate CW transmitting node (i.e., a non-leader device) and transmit a delay response to the leader (e.g., a base station or IN).

When one or more resource pools are configured, the base station or IN can configure/indicate a specific resource pool to belong to one of the resource categories. For example, when configuring a resource pool with a higher layer message (e.g., an RRC message), the base station can configure a specific resource pool to belong to one of the above categories, and can configure/reconfigure/indicate the configured resource pool to be used for the specific category with a higher/lower layer message (e.g., MAC CE or DCI) transmitted to the IN.

A base station can configure a specific logical channel to be dedicated to D2R, dedicated to R2D, or available for both D2R and R2D.

If the logical channel is dedicated to D2R, the base station or IN can receive data for the logical channel by selecting a resource from a resource pool of a category that supports D2R transmission resources.

If the logical channel is dedicated to R2D, the base station or IN can select a resource from a resource pool of a category that supports R2D transmission resources to transmit data for the logical channel.

If a logical channel is available for both D2R/R2D, the base station or IN can transmit R2D data by selecting a resource from a resource pool in a category that supports R2D transmission resources, and can receive D2R data by selecting a resource from a resource pool in a category that supports D2R transmission resources. In addition, the base station or IN can transmit R2D data or receive D2R data by selecting a resource from a resource pool in a category that supports both D2R/R2D.

Meanwhile, in Topology 2, the IN can receive an R2D message generated by a base station or core network (CN) and transmit it to a device, or forward a D2R message received from a device to the base station or CN. Alternatively, the IN can transmit an R2D message generated by the IN to a device, or directly process a T2D message received by the IN. Embodiments related to such IN operations are described below.

Example 10: Autonomy-based resource allocation method of intermediate nodes (INs)

The base station can transmit the following information to the IN for IN autonomous resource allocation.

- Setting of R2D/CW/D2R resource pool/set/area through system information, e.g. IN for RRC_IDLE/INACTIVE

- Configuration of R2D/CW/D2R resource pool/set/area via dedicated messages, e.g. IN for RRC_CONNECTED

The payload (e.g., data, content, information) transmitted via the R2D transmission/message/signal by the IN can be delivered from the base station to the IN. That is, when the IN receives a signal/channel/message carrying the payload (e.g., data, content, information) of the R2D transmission associated with the R2D transmission/message/signal to be transmitted by the IN from the base station, the IN can (arbitrarily) determine resources for the R2D transmission as follows. In addition, when receiving a request (e.g., a request for R2D transmission) by the base station, the IN can (arbitrarily) determine resources for the R2D transmission as follows.

And/or, the IN may receive a D2R transmission/message/signal from the device and, based on or in response thereto, transmit an R2D transmission/message/signal to the device. For example, the D2R transmission/message/signal may correspond to a random access signal of the device. In this case, the IN may (arbitrarily) determine resources for the R2D transmission as follows.

(Method 1) IN's autonomous resource allocation method

First, we describe IN's autonomous frequency resource allocation method.

When multiple channels are set by a base station, IN can select frequency resources based on one or more of the following selection options. In this embodiment, a channel can be interpreted as a frequency resource.

- Priority-based selection: The base station can set channel priorities (or resource pool/set/area priorities). If channel priorities (or resource pool/set/area priorities) are set, the IN can select the resource pool/set/area for the channel with the highest priority.

- Random selection: If channel priority (or resource pool/set/area priority) is not set, IN can randomly select a channel from among multiple channels.

- Measurement-based selection: If the measured UL interference or block error rate (BLER) on a specific channel (e.g., a specific R2D channel) exceeds a threshold, the channel may be given a lower priority for selection. Conversely, if the measured RSRP on a specific channel exceeds a threshold, the channel may be given a higher priority for selection.

- NR UL resource-based selection: If a channel is allocated semi-static PUCCH/SRS/CG (configured grant) frequency resources, the channel may be given a lower priority in selection.

- QoS (quality of service) based selection: If the frequency resources on the channel satisfy the delay requirement, the channel can be given higher priority in selection.

- If frequency hopping is used, frequency hopping can be performed among frequencies whose priority has not been lowered. Furthermore, frequency hopping can be performed among frequencies whose priority has not been raised or lowered by the above-described options.

Next, we describe IN's autonomous-based time resource allocation method.

IN can select a time resource after a frequency channel is selected or, in the case of a single channel, based on one or more of the following selection options:

- Random Selection: IN can randomly select a time resource within a time interval from one or more resource pools/sets/areas of the selected channel.

Here, the time interval may start after receiving a signal/message carrying a payload for an R2D request or R2D transmission from a base station.

Additionally, the size of the above time interval, etc., can be set by the base station. Additionally, whether or not to set the above time interval, or the size, etc., can be determined according to delay requirements.

Additionally, the time interval can be set per IN, per device, or per device group.

- Measurement-based selection: Time resources with measured UL interference above a threshold (either predefined or set by the base station) may be given lower priority for selection.

- NR UL resource-based selection: Time resources that overlap with semi-static PUCCH/SRS/CG (configured grant) time resources may have lower priority in selection.

Additionally, time resources that overlap with dynamically allocated NR UL resources may have lower priority in selection.

- QoS-based selection: Time resources that meet delay requirements may be given higher priority for selection. Conversely, time resources that do not meet delay requirements may be given lower priority for selection.

(Method 2) Assistance information reporting for R2D/CW/D2R transmissions

IN can report the following information about the device to the base station each time the device connects, fails to connect, or releases after connecting:

Additionally, the IN may report a list of inventoried devices. For example, the list of inventoried devices may refer to devices participating in an inventory performed by the IN to identify the devices.

- Device identifier (ID) and/or device group ID

- D2R and/or R2D message buffer size

- CW resource request

- Request D2R and/or R2D resources

- Channel ID or frequency resource index per device or device group

- Successful connection, connection failure or disconnection

- List of handles/C-RNTI (cell-radio network temporary identifier)/EPC (electronic product code)

Here, handle/C-RNTI/EPC can all be used as identifiers to identify A-IoT devices.

When an IN in RRC_IDLE/INACTIVE receives system information requesting initial connection to the IN, the IN performs initial connection to the base station via a RACH procedure (i.e., random access procedure) and transitions to RRC_CONNECTED. The IN can then inform the base station of its capabilities, indicating whether the UE supports IN functions. In other words, after connecting to the base station, the UE can inform the base station of its ability to operate as an IN.

The gNB can find a better IN for the device and contact (e.g., re-inventory) the device with the same handle/C-RNTI as the target IN. Here, the target IN can contact or re-inventory the device by transmitting an R2D signal with the handle/C-RNTI. The source IN can remove the device without notifying the device.

Example 11: Method for setting up configuration resources for R2D/CW/D2R transmission and reception

1) R2D configured resource

When an IN transmits an R2D message to a device, the base station can configure one or more R2D configured resource (RCR) settings for one or more INs. Here, the RCR settings can be configured as unicast RCR settings per device, and/or the RCR settings can be configured as multicast (or broadcast) RCR settings per group of devices belonging to (connected to) the same IN or per IN. Here, the RCR settings can be activated/deactivated by upper/lower layer signaling (e.g., RRC message or MAC CE or DCI) transmitted by the base station.

For example, the base station can set RCR configuration index = 1 to unicast for IN#3 and RCR configuration index = 2 to multicast. Through the periodic RCR resource for RCR configuration index = 1, IN#3 can send R2D transmissions only to specific devices. Additionally, through the periodic RCR resource for RCR configuration index = 2, IN#3 can send R2D transmissions that are received simultaneously by multiple devices.

When transmitting the payload of an R2D transmission received from a base station to a device, the IN can select an RCR setting that enables transmission within the delay requirements of the R2D transmission (e.g., Packet Data Budget (PDB)) and an RCR resource within the RCR setting to transmit the R2D transmission (i.e., including the payload of the R2D transmission) to the device.

To this end, when the base station transmits an R2D transmission to the device via an IN (i.e., when the base station instructs the IN to transmit an R2D transmission), the PDB of the R2D transmission may be indicated in the DCI that schedules the payload of the R2D transmission. Alternatively, the base station may set a specific PDB value for a downlink logical channel or a semi-persistent scheduling (SPS) configuration or PDSCH transmission resource associated with the payload of the R2D transmission. Alternatively, the DCI that activates the SPS configuration may indicate a PDB value for the payload of the R2D transmission transmitted via the SPS configuration.

A base station can map one or more SPS configurations to one or more RCR configurations. In this case, the IN can transmit an R2D transmission to the device via an RCR configuration that is mapped to the payload of the R2D transmission received from a specific SPS configuration.

For R2D transmissions that need to be transmitted quickly, IN can send the R2D transmission to the device through the RCR setting with a short PDB.

When transmitting an R2D message that can be transmitted slowly, IN can send that R2D transmission to the device via an RCR setting with a long PDB.

The base station can configure/activate a separate RCR configuration for CW transmission of IN, or configure/activate a single RCR configuration to include both (periodic) R2D signal transmission resources and (periodic) CW transmission resources. Additionally, a single RCR configuration can configure/activate a single RCR configuration to include both (periodic) R2T signal transmission resources and (periodic) CW transmission resources, as well as D2R signal reception resources.

For example, if the RCR configuration index = 6 is set to include periodic R2D signal transmission resources and periodic CW transmission resources, and the RCR configuration index = 6 is activated by DCI, the IN can periodically perform R2D signal transmission and CW transmission based on the RCR configuration.

As another example, if the RCR configuration index = 7 is set to include periodic R2D signal transmission resources, periodic CW transmission resources, and periodic D2R signal reception resources, and the RCR configuration index = 7 is activated by DCI, the IN can schedule to periodically perform R2D signal transmission and CW transmission based on the RCR configuration, and to receive a D2R signal, which is a response to the R2D signal, through the D2R reception resources.

2) D2R configured resource

When an IN receives a D2R message from a device, the base station can configure one or more D2R configured resource (DCR) settings for one or more INs. Here, the DCR settings can be configured as unicast DCR settings per device, and/or the DCR settings can be configured as multicast (or broadcast) DCR settings per IN or per group of devices belonging to (connected to) the same IN. Here, the DCR settings can be activated/deactivated by upper/lower layer signaling (e.g., RRC message or MAC CE or DCI) transmitted by the base station.

For example, the base station can set DCR configuration index = 1 to unicast for IN#3 and set DCR configuration index = 2 to multicast or broadcast. Through the periodic DCR resource for DCR configuration index = 1, IN#3 can receive D2R messages from a specific device. Furthermore, through the periodic DCR resource for DCR configuration index = 2, IN#3 can receive D2R messages from multiple devices simultaneously.

When transmitting the payload of a D2R transmission received from a device to a base station, the IN can select a UL CG configuration and a CG PUSCH resource of the configuration that can be transmitted within the delay requirements of the D2R message (e.g., Packet Data Budget (PDB)) to transmit the payload of the D2R transmission to the base station.

In a DCR resource with an activated DCR configuration, an IN may skip UL transmissions to receive D2R transmissions. Here, depending on the priority of UL transmissions, reception of D2R transmissions may be skipped or UL transmissions may be skipped. For example, low-priority CSI reports, PUCCH transmissions, PUSCH transmissions, etc. may be skipped. However, high-priority PUCCH transmissions or PUSCH transmissions may be performed, in which case D2R reception may be skipped.

The base station can configure/enable both (periodic) CW transmission resources and (periodic) D2R signal reception resources within one DCR configuration for CW transmission of IN.

For example, if DCR configuration index = 7 is set to include periodic CW transmission resources and periodic D2R signal reception resources, and DCR configuration index = 7 is activated by DCI, IN can schedule to periodically perform CW transmission based on the DCR configuration and receive backscattered D2R signals for CW through D2R reception resources.

3) Unified configured resource

A base station can manage one or more RCR settings and one or more DCR settings as a single configured resource (CR) setting or as a single CR index. For example, an RCR setting and a DCR setting can be linked to a CR setting, and when the CR setting is set/activated, the linked RCR setting and DCR setting can be set/activated (in which case, the RCR setting and DCR setting can be set/activated individually). As another example, both an RCR and a DCR can be included in a single CR setting (in which case, the RCR and DCR included in the CR setting cannot be set/activated individually).

In this case, when the activation or deactivation of CR index = 5 is indicated by DCI, IN can simultaneously activate/deactivate the RCR setting and DCR setting corresponding to CR index = 5, or the integrated CR setting corresponding to CR index = 5 can be activated or deactivated.

4) CW specific configured resource

A base station can configure one or more CW configurations consisting of (periodic) CW resources for CW transmissions of an IN or a separate node (i.e., a separate node/device transmitting CW). Here, the CW configuration can be activated/deactivated by upper/lower layer signaling (e.g., RRC message or MAC CE or DCI) transmitted by the base station.

The base station can manage one or more CW configurations and one or more RCR configurations and/or one or more DCR configurations as a single CR configuration or as a single CR index. For example, a CW configuration, an RCR configuration and/or a DCR configuration can be linked to a CR configuration, and as the CR configuration is set/activated, the linked CW configuration, RCR configuration and/or DCR configuration can be set/activated (in which case, the CW configuration, RCR configuration and/or DCR configuration can be individually set/activated). As another example, a single CR configuration can include all of a CW resource, an RCR and/or a DCR (in which case, the CW resource, an RCR and/or a DCR included in the CR configuration cannot be individually set/activated).

In this case, when activation or deactivation of CR index = 5 is indicated by DCI, IN can simultaneously activate or deactivate the CW setting and the RCR setting and/or the DCR setting corresponding to CR index = 5.

The base station can distinguish between INs that will transmit CW and INs that will not. For example, an IN may request the base station to suspend CW transmission to reduce battery consumption or collisions or interference with other transmissions. Furthermore, if the IN has sufficient battery power or collisions/interference are minimal, it may request the base station to start/resume CW transmission. Alternatively, an IN may report to the base station its battery (i.e., energy storage capacity) level or the level of collisions or interference from R2D/D2R resources during transmission.

Based on these requests/reports, the base station can command the IN to stop or start/resume CW transmission. When commanding to stop CW transmission, the IN can cancel or deactivate the CW configuration or the RCR/DCR/CR configuration including CW resources. When commanding to start/resume CW transmission, the IN can set or activate the CW configuration or the RCR/DCR/CR configuration including CW resources. Or, according to the DCI or RRC message transmitted by the base station, the IN can set/activate or cancel/deactivate the CW configuration or the RCR/DCR/CR configuration including CW resources.

Meanwhile, based on whether there is a separate CW transmission node around a specific IN, whether other INs are transmitting CW, the channel quality of the serving cell measured by the IN, whether the UE capability of the IN is high, etc., the IN can set or activate the CW configuration or the RCR/DCR/CR configuration including CW resources at the command of the base station or at the decision of the IN itself.

Meanwhile, the base station sets the CW/RCR/DCR settings that enable the IN to transmit and receive CW/R2D/D2R, and only when the base station activates the corresponding CW/RCR/DCR settings, the IN may transmit and receive CW/R2D/D2R using the corresponding resources, and may not transmit and receive CW/R2D/D2R if it deactivates the settings. Alternatively, when the base station sets the CW/RCR/DCR settings, if the IN determines that CW/R2D/D2R transmission and reception are necessary, the IN may request the base station to activate the CW/RCR/DCR settings. Here, if the base station confirms this, the CW/RCR/DCR settings are activated so that CW/R2T/T2R can be transmitted and received, or the CW/RCR/DCR settings may be activated only at the request of the IN so that the IN can transmit and receive CW/R2T/T2R.

Meanwhile, even if the CW/RCR/DCR setting is enabled, the IN can actually transmit or receive CW or R2D transmission or D2R transmission only if the base station activates the transmission and reception of CW or R2D transmission or D2R transmission by a separate command (e.g., by DCI, MAC CE, or RRC message). After that, the base station may disable CW or R2D transmission or DCR transmission. Meanwhile, if the CW/RCR/DCR setting is disabled, the transmission and reception of the corresponding CW/R2D/D2R transmission may also be disabled.

Meanwhile, when CW transmission is enabled, the IN may skip UL PUSCH resources that overlap with CW transmission. In this case, the IN may report the skipped PUSCH resources to the base station as unused PUSCH resources. Alternatively, if the UL PUSCH resources have a high priority, the IN may skip the CW transmission if the UL PUSCH resources overlap with the CW transmission.

Meanwhile, the above CW/CR/DCR/RCR settings can be set within the same or different resource pools/sets/areas.

Additionally, the IN can set/activate the CW/CR/DCR/RCR settings on its own without being set by the base station. In this case, the IN can report information about the CW/CR/DCR/RCR settings it has set/activated on its own (or resource information about the settings) to the base station.

Base station 1 can share resource information of CW/CR/DCR/RCR configuration(s) configured for a specific base station or a specific IN with base station 2 or another IN. Here, base station 1 may share only the activated CW/CR/DCR/RCR configuration(s) with base station 2 or another IN, and may also share the deactivation of the corresponding configuration(s) with base station 2 or another IN. Alternatively, base station 1 may share resource information of all configured CW/CR/DCR/RCR configuration(s) with base station 2 or another IN, regardless of whether they are activated.

FIG. 15 illustrates the operation of a device for device-to-device communication according to one embodiment of the present disclosure.

FIG. 15 illustrates the operation of a device (i.e., an intermediate node (e.g., UE) or a leader) based on the proposed methods in the embodiments described above. The example in FIG. 15 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 15 may be omitted depending on the situation and/or setting. In addition, the device in FIG. 15 is only an example and may be implemented as the device illustrated in FIG. 17 below. For example, the processor (102/202) in FIG. 17 may control the transceiver (106/206) to transmit and receive channels/signals/data/information, etc., and may also control the processor (102/202) in FIG. 17 to store the channels/signals/data/information to be transmitted or received in the memory (104/204).

Additionally, the operation of FIG. 15 may be processed by one or more processors (102, 202) of FIG. 17. Additionally, the operation of FIG. 15 may be stored in a memory (e.g., one or more memories (104, 204) of FIG. 17) in the form of a command/program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 102, 202) of FIG. 17.

In FIG. 15, a device transmitting a first transmission (e.g., a leader, an intermediate node (e.g., a UE)) is referred to as a first device, and a device receiving the first transmission (e.g., a tag, an A-IoT device) is referred to as a second device. For example, the first device may be a device transmitting a carrier wave for energy harvesting or backscattering, and the second device may be a device transmitting a backscattered signal (referred to as a second transmission) based on the carrier wave in response to the first transmission. Furthermore, the carrier wave may be transmitted from an external device, in which case the second device may respond with a backscattered signal (i.e., a second transmission) based on the carrier wave transmitted from the external device in response to the first transmission.

Referring to FIG. 15, the first device receives information related to a set of time and/or frequency resources from a base station (S1501).

The first device transmits a first transmission to the second device on a time and/or frequency resource selected from a set of time and/or frequency resources (S1502).

Here, based on receiving a specific transmission from the base station or the second device, the time and/or frequency resource may be selected from the set of time and/or frequency resources by the first device.

For example, the particular transmission may be any one of a transmission of a payload for the first transmission from the base station, a transmission for a connection from the second device, or a request for the first transmission from the base station or the second device.

Additionally, the time and/or frequency resources may be selected within a predetermined time interval after receiving the specific transmission.

For example, the time interval may be i) set by the base station, or ii) determined by a delay requirement for the first transmission, or iii) set per the first device or per group for the first device, or iv) set per the second device or per group for the second device.

Additionally, the resource set may include at least one of a first time and/or frequency resource set for the first transmission from the first device to the second device, a second time and/or frequency resource set for the second transmission from the second device to the first device, and/or a third time and/or frequency resource set for carrier wave transmission to the second device.

Here, the time and/or frequency resource may be randomly selected by the first device from the time and/or frequency resource set. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on interference intensity or signal reception intensity. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on whether it overlaps with an uplink transmission. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on a delay requirement for the first transmission.

Although not shown in FIG. 15, the first device may receive a second transmission from the second device in response to the first transmission. Here, the second transmission may be a backscattered signal transmitted based on the carrier wave. Here, as described above, the carrier wave may be transmitted from the first device or transmitted by an external device.

Additionally, the second transmission may be transmitted at a time and/or frequency resource determined from the second time and/or frequency resource set, and the carrier wave may be transmitted at a time and/or frequency resource determined from the third time and/or frequency resource set.

Additionally, the first transmission may be a physical reader-to-device channel (PRDCH), and the second transmission may be a physical device-to-reader channel (PDRCH).

FIG. 16 illustrates the operation of a device for device-to-device communication according to one embodiment of the present disclosure.

FIG. 16 illustrates the operation of a device (i.e., an A-IoT device, e.g., a tag) based on the proposed methods in the embodiments described above. The example in FIG. 16 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some step(s) illustrated in FIG. 16 may be omitted depending on circumstances and/or settings. In addition, the device in FIG. 16 is only an example and may be implemented as the device illustrated in FIG. 17 below. For example, the processor (102/202) in FIG. 17 may control the transceiver (106/206) to transmit and receive channels/signals/data/information, etc., and may also control the processor (102/202) in FIG. 17 to store the channels/signals/data/information, etc. to be transmitted or received, in the memory (104/204).

Additionally, the operation of FIG. 16 may be processed by one or more processors (102, 202) of FIG. 17. Additionally, the operation of FIG. 16 may be stored in a memory (e.g., one or more memories (104, 204) of FIG. 17) in the form of a command/program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 102, 202) of FIG. 17.

In FIG. 16, a device transmitting a first transmission (e.g., a leader, an intermediate node (e.g., a UE)) is referred to as a first device, and a device receiving the first transmission (e.g., a tag, an A-IoT device) is referred to as a second device. For example, the first device may be a device transmitting a carrier wave for energy harvesting or backscattering, and the second device may be a device transmitting a backscattered signal (referred to as a second transmission) based on the carrier wave in response to the first transmission. Furthermore, the carrier wave may be transmitted from an external device, in which case the second device may respond with a backscattered signal (i.e., a second transmission) based on the carrier wave transmitted from the external device in response to the first transmission.

Referring to FIG. 16, the second device receives a first transmission from the first device at a time and/or frequency resource selected from a set of time and/or frequency resources set by the base station (S1601).

The second device transmits a second transmission to the first device in response to the first transmission (S1602).

Here, based on a specific transmission being transmitted from the base station or the second device, the time and/or frequency resource may be selected from the set of time and/or frequency resources by the first device.

For example, the particular transmission may be any one of a transmission of a payload for the first transmission from the base station, a transmission for a connection from the second device, or a request for the first transmission from the base station or the second device.

Additionally, the time and/or frequency resources may be selected within a predetermined time interval after receiving the specific transmission.

For example, the time interval may be i) set by the base station, or ii) determined by a delay requirement for the first transmission, or iii) set per the first device or per group for the first device, or iv) set per the second device or per group for the second device.

Additionally, the resource set may include at least one of a first time and/or frequency resource set for the first transmission from the first device to the second device, a second time and/or frequency resource set for the second transmission from the second device to the first device, and/or a third time and/or frequency resource set for carrier wave transmission to the second device.

Here, the time and/or frequency resource may be randomly selected by the first device from the time and/or frequency resource set. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on interference intensity or signal reception intensity. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on whether it overlaps with an uplink transmission. Alternatively, the time and/or frequency resource may be selected by the first device from the time and/or frequency resource set based on a delay requirement for the first transmission.

Additionally, the second transmission may be a backscattered signal transmitted based on the carrier wave. Here, as described above, the carrier wave may be transmitted from the first device or transmitted by an external device.

Additionally, the second transmission may be transmitted at a time and/or frequency resource determined from the second time and/or frequency resource set, and the carrier wave may be transmitted at a time and/or frequency resource determined from the third time and/or frequency resource set.

Additionally, the first transmission may be a physical reader-to-device channel (PRDCH), and the second transmission may be a physical device-to-reader channel (PDRCH).

General devices to which the present disclosure may be applied

FIG. 17 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

Referring to FIG. 17, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).

A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and/or one or more antennas (108). The processor (102) controls the memories (104) and/or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. For example, the processor (102) may process information in the memory (104) to generate first information/signal, and then transmit a wireless signal including the first information/signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information/signal via the transceiver (106), and then store information obtained from signal processing of the second information/signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operation flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and/or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and/or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may also mean a communication modem/circuit/chip.

A second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and/or one or more antennas (208). The processor (202) controls the memories (204) and/or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. For example, the processor (202) may process information in the memory (204) to generate third information/signals, and then transmit a wireless signal including the third information/signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information/signals via the transceivers (206), and then store information obtained from signal processing of the fourth information/signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and/or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and/or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a wireless device may also mean a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed in the present disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in the present disclosure.

One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods and/or operation flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods and/or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and/or sets of instructions.

One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and/or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and/or combinations thereof. The one or more memories (104, 204) may be located internally and/or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

One or more transceivers (106, 206) can transmit user data, control information, wireless signals/channels, etc., as mentioned in the methods and/or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and/or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals/channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) may convert received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals/channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or a filter.

The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and/or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on/in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and/or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

Here, the wireless communication technology implemented in the wireless device (100, 200) of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present disclosure may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by 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 above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present disclosure can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

The method proposed in this disclosure is explained with a focus on examples applied to 3GPP LTE/LTE-A and 5G systems, but can be applied to various wireless communication systems in addition to 3GPP LTE/LTE-A and 5G systems.

Claims (18)

A step of receiving information related to a set of time and/or frequency resources from a base station by a first device; and A step of transmitting a first transmission to a second device at a time and/or frequency resource selected from the set of time and/or frequency resources by the first device, A method wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on receiving a specific transmission from the base station or the second device. In the first paragraph, A method wherein said specific transmission is any one of a transmission of a payload for said first transmission from said base station, a transmission for a connection from said second device, or a request for said first transmission from said base station or said second device. In the first paragraph, A method wherein the time and/or frequency resources are selected within a predetermined time interval after receiving the specific transmission. In the third paragraph, A method wherein the time interval is i) set by the base station, or ii) determined by a delay requirement for the first transmission, or iii) set per group for the first device or the first device, or iv) set per group for the second device or the second device. In the first paragraph, A method according to claim 1, wherein the resource set comprises at least one of a first time and/or frequency resource set for the first transmission from the first device to the second device, a second time and/or frequency resource set for the second transmission from the second device to the first device, and/or a third time and/or frequency resource set for carrier wave transmission to the second device. In paragraph 5, Further comprising the step of receiving, by the first device, the second transmission in response to the first transmission from the second device, A method wherein the second transmission is a backscattered signal transmitted based on the carrier wave. In Article 6 The second transmission is transmitted at a time and/or frequency resource determined from the second time and/or frequency resource set, A method wherein the carrier wave is transmitted in a time and/or frequency resource determined from the third time and/or frequency resource set. In paragraph 6, A method wherein the first transmission is a physical reader-to-device channel (PRDCH) and the second transmission is a physical device-to-reader channel (PDRCH). In Article 6, A method wherein the carrier wave is transmitted from the first device or transmitted by an external device. In the first paragraph, A method wherein the time and/or frequency resource is randomly selected from the set of time and/or frequency resources. In the first paragraph, A method wherein the time and/or frequency resources are selected based on interference intensity or signal reception intensity from the set of time and/or frequency resources. In the first paragraph, A method wherein the time and/or frequency resources are selected based on whether they overlap with uplink transmissions in the set of time and/or frequency resources. In the first paragraph, A method wherein the time and/or frequency resource is selected from the set of time and/or frequency resources based on a delay requirement for the first transmission. The first device is: One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Receive information related to a set of time and/or frequency resources from a base station; and is configured to transmit a first transmission to a second device at a time and/or frequency resource selected from the set of time and/or frequency resources; A first device, wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on receiving a specific transmission from the base station or the second device. One or more non-transitory computer-readable media storing one or more instructions, The one or more instructions are executed by one or more processors, so that the first device: Receive information related to a set of time and/or frequency resources from a base station; and Controlling to transmit a first transmission to a second device at a time and/or frequency resource selected from the set of time and/or frequency resources; A computer-readable medium, wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on receiving a specific transmission from the base station or the second device. In a processing device configured to control a first device, the processing device: one or more processors; and One or more computer memories operatively connected to said one or more processors and storing instructions that perform operations based on being executed by said one or more processors, The above actions are: A step of receiving information related to a set of time and/or frequency resources from a base station; and comprising the step of transmitting a first transmission to a second device at a time and/or frequency resource selected from the set of time and/or frequency resources; A processing device, wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on receiving a specific transmission from the base station or the second device. A step of receiving, by a second device, a first transmission from a first device at a time and/or frequency resource selected from a set of time and/or frequency resources set by a base station; and comprising the step of transmitting a second transmission to the first device in response to the first transmission; A method wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on a specific transmission being transmitted from the base station or the second device. The second device is: One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Receiving a first transmission from a first device at a time and/or frequency resource selected from a set of time and/or frequency resources set by a base station; and and is configured to transmit a second transmission to the first device in response to the first transmission; A second device, wherein the time and/or frequency resource is selected from the set of time and/or frequency resources by the first device based on a specific transmission being transmitted from the base station or the second device.