Method for random access procedure related to ambient IoT and device therefor

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving MSG1 related to a random access procedure from a device; and transmitting MSG2 to the device. A slot number related to the MSG1 is determined on the basis of a group ID related to CFRA. The group ID is related to a plurality of device IDs, and one of frequency division multiplexed resources is determined on the basis of the slot number.

Description

Method and device for random access procedure related to AMBIENT IOT

[0001] This specification relates to a method and device for transmitting and receiving signals related to Ambient IoT.

[0002] The 5G mobile communications system, the successor to LTE (long-term evolution), is a new, clean-slate mobile communications system characterized by high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to intermediate-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz. 6G mobile communications systems are being developed based on the underlying technologies of 5G mobile communications.

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

[0004] In Ambient IoT, a random access procedure based on slotted ALOHA is being considered.

[0005] Meanwhile, in the random access procedure of the slotted ALOHA scheme, frequency division multiplexing (FDM) can be considered.

[0006] The purpose of this specification is to propose a method to support Contention Free Random Access (CFRA) in slots where FDM is applied.

[0007] The technical problems to be achieved in this specification 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 this specification pertains from the description below.

[0008] According to one embodiment of the present disclosure for solving the above-described technical problem, a method includes the steps of receiving a message 1 (Message 1, MSG 1) related to a random access procedure from a device and transmitting a message 2 (MSG 2) to the device. A slot number related to the MSG 1 is determined based on a group ID related to contention-free based random access (CFRA). The group ID is characterized in that it is related to a plurality of device IDs, and one of frequency division multiplexed (FDMed) resources is determined based on the slot number. As described above, CFRA can be supported in units of slots to which FDM is applied by utilizing the group ID.

[0009] According to embodiments of the present disclosure, CFRA based on FDM resources can be supported in a slotted ALOHA random access procedure for Ambient IoT. Specifically, multiple grouped devices can perform CFRA using FDM resources. In other words, a random access operation (e.g., MSG1 transmission) by devices belonging to one group does not collide with a random access operation (e.g., MSG1 transmission) by devices belonging to another group. By minimizing retransmissions in the random access procedure performed by each device, the overall delay of Ambient IoT-based services can be reduced.

[0010] Additionally, CFRA is supported on a group basis, as described above, by allocating dedicated slots at the device ID group level. Therefore, compared to allocating CFRA resources without specific criteria, this technology minimizes radio resource waste while ensuring flexible resource utilization. Specifically, by operating resources at a level appropriate to CFRA demand, the unnecessary occupation of inactive CFRA resources (unused resources) can be reduced.

[0011] Additionally, devices within each group can be defined to perform CBRA. Compared to using all FDM resources within a slot for CFRA, overall system throughput can be expected to improve. Furthermore, the resource balance between CFRA and CBRA can be optimized to meet the Quality of Service (QoS) required for Ambient IoT use cases.

[0012] The effects that can be obtained from this specification are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the technical field to which this specification belongs from the description below.

[0013] Figure 1 illustrates topology 1 related to Ambient IoT.

[0014] Figure 2 illustrates topology 2 related to Ambient IoT.

[0015] Figure 3 is an example of topology 3 related to Ambient IoT.

[0016] Figure 4 is another example of topology 3 related to Ambient IoT.

[0017] Figure 5 illustrates topology 4 related to Ambient IoT.

[0018] Figure 6 illustrates the state according to the operating status of an energy harvesting-based device.

[0019] FIG. 7 is an example of a Slotted ALOHA-based random access operation according to an embodiment of the present specification.

[0020] FIG. 8 is an example of an Enhanced Slotted ALOHA-based random access operation according to an embodiment of the present specification.

[0021] FIG. 9 is another example of an Enhanced Slotted ALOHA-based random access operation according to an embodiment of the present specification.

[0022] FIG. 10 is a flowchart illustrating a method according to one embodiment of the present specification.

[0023] FIG. 11 is a flowchart illustrating a method according to another embodiment of the present specification.

[0024] FIG. 12 is a drawing showing the configuration of the first device and the second device according to an embodiment of the present specification.

[0025] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0026] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0027] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0028] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0029] Additionally, parentheses used herein may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0030] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0031] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0032] In this specification, a terminal (UE, User Equipment) may be a portable device and may be a second node that receives a signal from a base station / first node / IAB node.

[0033] In this specification, a base station (BS) may be a base station / first node / IAB node / Transmission-Reception Point.

[0034] In this specification, higher layer parameters may be parameters that are set for the terminal, preset, or predefined. For example, a base station or network may transmit higher layer parameters to the terminal. For example, higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0035] In this specification, "configured or defined" may be interpreted as being configured or preset to a device through predefined signaling (e.g., SIB, MAC, RRC) from a base station or network. In this specification, "configured or defined" may be interpreted as being preset to a device.

[0036] 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 system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0037] Ambient IoT communication (Rel-18)

[0038] Ambient IoT (A-IoT) may be a new device type / segment that operates solely on energy harvested from the surrounding environment. For example, A-IoT could refer to a new type of Internet of Things (IoT) device that is powered by various energy sources harvested from the surrounding environment, such as radio waves, light, motion, and heat. Examples of A-IoT use cases are shown in Table 1.

[0039]

[0040] Table 2 shows the IoT communication-related issues discussed in 3GPP RAN.

[0041]

[0042] For example, active signal generation and / or backscattering may be among the communication technologies considered to achieve low-power operation of A-IoT devices. For example, backscattering is a technique widely used in radio frequency identification (RFID), which allows devices to communicate with a network by reflecting incident waves after modulating them with information to be transmitted. For example, the device may be powered by the incident RF signal or by stored energy.

[0043] For example, IoT devices can be classified into various device types, such as passive, semi-passive, and active, depending on how they store energy and generate transmission signals. For example, a passive device does not have an energy storage device (e.g., a capacitor) and can communicate based on backscatter communication technology. For example, a semi-passive device has an energy storage device and can communicate using backscatter communication technology with the help of the energy storage device. For example, an active device has an energy storage device and can actively generate signals using active RF components and the stored energy to communicate. For example, in the present disclosure, the following three types of IoT devices can be considered. For example, device A can be a device without energy storage and without independent signal generation (e.g., a device that supports backscatter transmission). For example, device B can be a device with energy storage and without independent signal generation (e.g., a device that supports backscatter transmission). In this case, for example, the use of stored energy may involve amplification of the reflected signal. For example, device C may be a device with energy storage and independent signal generation (e.g., a device with an active RF component for transmission).

[0044] For example, the following basic topologies may be considered to support A-IoT devices in indoor and outdoor scenarios. For example, the basic topologies may include direct connections between base stations and A-IoT devices, connections between base stations and intermediate nodes and A-IoT devices, connection support by auxiliary nodes, and / or connections between terminals and A-IoT devices. The basic topologies proposed in this disclosure are merely examples, and the proposals in this disclosure may be extended / applied to other topologies.

[0045] Figure 1 illustrates topology 1 related to Ambient IoT.

[0046] Specifically, FIG. 1 illustrates a topology (e.g., Topology 1) in which a base station and an A-IoT device are directly connected, according to one embodiment of the present disclosure. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure.

[0047] Referring to FIG. 1, an Ambient IoT device (A-IoT device) can communicate directly and bidirectionally with a base station (BS). For example, communication between the BS and the A-IoT device may include A-IoT data and / or signals. For example, the A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 1, the BS transmitting to the A-IoT device and the BS receiving from the A-IoT device may be different. For example, in the topology 1, the BS and the A-IoT device in a micro-cell environment may communicate directly with each other. For example, the BS may be located at a co-site with a BS equipped with an existing 3GPP technology.

[0048] Figure 2 illustrates topology 2 related to Ambient IoT.

[0049] Specifically, FIG. 2 illustrates a topology (e.g., topology 2) in which a base station (BS) and an Ambient IoT device (A-IoT device) are connected via an intermediate node, according to one embodiment of the present disclosure. The embodiment of FIG. 2 can be combined with various embodiments of the present disclosure.

[0050] Referring to FIG. 2, an A-IoT device can bidirectionally communicate with an intermediate node between the device and a base station. Here, for example, the intermediate node may be an A-IoT-capable relay, an IAB node, a terminal, a repeater, etc. For example, the intermediate node may transmit A-IoT data and / or signals between the base station and the A-IoT device. For example, the A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 2, the intermediate node transmitting to the A-IoT device and the intermediate node receiving from the A-IoT device may be different. For example, in the topology 2, an intermediate node may exist between a base station and the A-IoT device in a macro-cell environment. For example, the base station may be located at a co-site with a base station equipped with an existing 3GPP technology. For example, intermediate nodes may be limited to terminals, and intermediate nodes may be located indoors.

[0051] Fig. 3 is an example of topology 3 related to Ambient IoT. Fig. 4 is another example of topology 3 related to Ambient IoT.

[0052] FIGS. 3 and 4 illustrate a topology (e.g., Topology 3) supported by an assisting node according to one embodiment of the present disclosure. The embodiments of FIGS. 3 and 4 may be combined with various embodiments of the present disclosure.

[0053] Referring to FIG. 3, an auxiliary node may be supported for downlink reception. For example, an A-IoT device may transmit data / signals to a base station, and the A-IoT device may receive data / signals from the auxiliary node. Referring to FIG. 4, an auxiliary node may be supported for uplink transmission. For example, an A-IoT device may receive data / signals from a base station, and the A-IoT device may transmit data / signals to an auxiliary node. Here, for example, the auxiliary node may be an A-IoT-capable relay, an IAB node, a terminal, a repeater, etc.

[0054] Figure 5 illustrates topology 4 related to Ambient IoT.

[0055] Specifically, FIG. 5 illustrates a topology (e.g., topology 4) in which a terminal (UE) and an Ambient IoT device (A-IoT device) are directly connected according to one embodiment of the present disclosure. The embodiment of FIG. 5 can be combined with various embodiments of the present disclosure.

[0056] Referring to FIG. 5, the A-IoT device can communicate bidirectionally with the terminal. For example, communication between the terminal and the A-IoT device may include A-IoT data and / or signals. For example, the A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel).

[0057] For example, transmission by an A-IoT device may be performed over a frequency division duplexing (FDD) spectrum (e.g., an FDD UL spectrum).

[0058] < Ambient IoT solutions SI (Rel-19) >

[0059] A study item titled “Study on solutions for Ambient IoT (Internet of Things) in NR” was approved in 3GPP NR Release 19. Specifically, the study item will be conducted in 3GPP NR Release 19 based on the following:

[0060] This study aims to further evaluate Ambient IoT, a new 3GPP IoT technology suitable for deployment in 3GPP systems, at the RAN WG level. It relies on ultra-low-power, ultra-low-complexity devices for very low-end IoT applications. This study must provide a clear differentiation: it must address use cases and scenarios that cannot be met by existing 3GPP LPWA IoT technologies (e.g., NB-IoT with reduced peak Tx power).

[0061] General range

[0062] The definitions given in TR 38.848 apply to this SI and are of an exclusive general scope.

[0063] A. The overall goal is to study a harmonized wireless interface design that minimizes the differences required to enable Ambient IoT to enable the following devices:

[0064] i. ~1μW peak power consumption, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, and no DL or UL amplification in the device. The device's UL transmission is backscattered from an externally supplied carrier wave.

[0065] ii. ≤hundreds of μW peak power consumption1, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, and DL and / or UL amplification within the device. The device's UL transmission may be generated internally or backscattered from an externally provided carrier wave.

[0066] -X is decided by WG.

[0067] - Coverage design goal: Up to 10-50 m distance with the device indoors according to TR 38.848: "...the range within which the WG can sub-select".

[0068] -No RRC state, no mobility (i.e. at least no functionality like cell selection / reselection), no HARQ, no ARQ for topologies 1 and 2 (UE as intermediate node under NW control) according to TR 38.848.

[0069] Note 1: It should be understood that the WG is not tasked with setting a specific value for "≤hundreds of μW", and it is a matter for the WG to discuss whether the proposed design and its power consumption meet the "≤hundreds of μW" requirement.

[0070] B. Deployment scenarios with the following characteristics, referring to the table in clause 4.2.2 of TR 38.848:

[0071] - Deployment Scenario 1 Using Topology 1

[0072] Base Station and Coexistence Characteristics: Microcells, Co-sites

[0073] - Deployment scenario 2 using UE as an intermediate node under topology 2 and network control.

[0074] Base Station and Coexistence Characteristics: Macro Cell, Co-site

[0075] The location of the intermediate node is indoors

[0076] C. FDD's FR1 licensed spectrum.

[0077] D. In-band spectrum distribution for NR, guard bands for LTE / NR, and standalone band(s).

[0078] E. Traffic types DO-DTT, DT focusing on rUC1 (indoor inventory) and rUC4 (indoor command).

[0079] - In RAN#104, this study evaluates whether the harmonized radio interface design (see bullet 'A' above) can address Device-Initiated Autonomous (DO-A) use cases and identifies which parts of the harmonized radio interface design (see bullet 'A' above) are insufficient for DO-A use cases.

[0080] Transmissions from surrounding IoT devices (including backscattering when used) can occur at least in the UL spectrum.

[0081] The following goals are set within the general range:

[0082] 1. Evaluation assumptions

[0083] a) Conclude at least the following aspects of the design objectives left to the WG in clause 5 (RAN design objectives) of TR 38.848 [RAN1]:

[0084] Article 5.3: Applicable Maximum Distance Target Value

[0085] Clause 5.6: Refines the definition of latency suitable for use in RAN WGs.

[0086] Article 5.8: 2D Distribution of Devices

[0087] b) Define additional assessment assumptions required for deployment scenarios for coverage and coexistence assessments [RAN1, RAN4].

[0088] c) Identify the basic blocks / components of a possible peripheral IoT device architecture, considering the latest implementations of low-power, low-complexity devices that meet RAN design goals for power consumption and complexity. [RAN1]

[0089] d) Define link budget calculations for coverage, including whether / how to model carrier waves at nodes inside or outside the connection topology.

[0090] Note: The evaluation performance of the design target falls within the scope of the feasibility and necessity study of the proposal, with the following objectives: For example, testing a reference implementation in the field, conducting simulations, and conducting analytical tests.

[0091] Note: RAN1 strives to minimize evaluation cases.

[0092] 2. Investigate necessary and feasible solutions for Ambient IoT, as defined in the general scope. This includes determining which functions, procedures, etc. are necessary and which are not, and ensures at least the essential functions specified in Section 6.2 of TR 38.848.

[0093] Positioning research for Rel-19 is led by RAN3 and is limited to features that have no or minimal impact on the specification (Note: This does not imply decisions regarding WI generation).

[0094] We study the feasibility and required features for proximity determination (coordination with SA3 is necessary for privacy reasons).

[0095] - RAN1 led:

[0096] For Ambient IoT DL and UL:

[0097] Frame structure, synchronization and timing, random access

[0098] Numerology, Bandwidth, and Multi-Access

[0099] Waveforms and modulation

[0100] Channel coding

[0101] Downlink channel / signal aspect

[0102] Uplink channel / signal aspect

[0103] Scheduling and Timing Relationships

[0104] We study the required characteristics of the carrier wave waveform provided to ambient IoT devices from outside, including interference handling at ambient IoT UL receivers and NR base stations.

[0105] For topology 2, there is no difference in the physical layer design from topology 1.

[0106] RAN2 led:

[0107] We study and determine the features required for an ambient IoT compact protocol stack and lightweight signaling procedures that enable DO-DTT and DT data transmission.

[0108] for example:

[0109] Paging

[0110] Random access

[0111] Data transmission including necessary radio resource control aspects that comply with general range limitations.

[0112] Interaction with higher layers

[0113] Features not listed above will only be studied if deemed essential.

[0114] RAN3 led:

[0115] Identify the necessary impacts on the signals and procedures of the CN-RAN interface to enable:

[0116] Paging

[0117] Device context management

[0118] Data transfer

[0119] Identify RAN architecture aspects, including whether split architecture support is required.

[0120] Identify potential solutions for finding Ambient IoT devices that don't impact the specifications. For example, reusing existing user location reports or transmitting location information to the core network with minimal impact on the specifications.

[0121] RAN4 led:

[0122] A study on the coexistence of Ambient IoT and NR / LTE.

[0123] RF Requirements Study for Ambient IoT:

[0124] Ambient IoT BS Transmission and Reception

[0125] Ambient IoT devices, transmitting and receiving, according to general scope

[0126] Intermediate nodes (UEs) according to general range, transmitting and receiving

[0127] RAN2 and RAN3 are expected to work with SA2 to identify the RAN-CN functional split.

[0128] Note: This study targets IoT segments that are significantly lower than existing 3GPP IoT technologies (e.g., NB-IoT, eMTC, RedCap, etc.). This study does not aim to replace existing 3GPP LPWA technologies.

[0129] For example, as mentioned above, the types of A-IoT devices can be divided into two as follows. For example, a Type 1 device has a maximum power consumption of approximately 1 uW, can store energy, has no amplification function, and can transmit by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or a terminal, or a separate node). For example, a Type 2 device has a maximum power consumption of approximately several hundred uW, can store energy, has an amplification function, and can transmit by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or a terminal, or a separate node) or by using a signal generated internally by itself.

[0130] For example, in addition to the above-described classification methods, the type / class of A-IoT devices can be distinguished based on parameters associated with device characteristics (e.g., presence / capacity of energy storage, energy / power consumption, presence / capacity of amplification, presence / capacity of BPF (band-pass filter), supported DL / UL transmission method(s), etc.) or a combination of parameters. Here, for example, BPF capability can be distinguished by 3-dB bandwidth of supported BPF, sharpness, etc., and UL transmission methods can be distinguished by, for example, backscatter UL transmission, UL transmission by internal signal generation, etc.

[0131] In addition, the type / class of A-IoT devices can be subdivided based on parameters associated with the device characteristics (e.g., presence / capacity of energy storage, level of energy / power consumption, presence / capacity of amplification, presence / capacity of band-pass filter (BPF), supported DL / UL transmission method(s), etc.) or a combination of parameters. For example, the above-described Type 2 device can be classified into Type 2a if it performs transmission by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or terminal or a separate node), and Type 2b if it performs transmission using a signal generated internally by itself. In this case, Type 2a and 2b can be the same in that they have a maximum power consumption of approximately several hundred microwatts, are capable of energy storage, and have an amplification function.

[0132] For example, some types / classes of A-IoT devices (e.g., Device B, Device C, Type 1 devices, and / or Type 2 devices) may have energy storage capabilities (e.g., capacitors or charging batteries) for the following purposes:

[0133] - Stable energy security at the time of reception / transmission

[0134] - Operation of low-power communication modules through energy storage in low RF energy states

[0135] For example, the minimum RF reception sensitivity for operation of a low-power communication module may be -20 dBm, and the minimum reception sensitivity for energy harvesting may be -20 dBm. In this case, if the reception power of the A-IoT device ranges between -30 and -20 dBm, communication may not be possible without a capacitor, but communication may be possible after a charging time with a capacitor.

[0136] - Energy harvested from different energy sources (e.g. solar, thermal, wind, kinetic, etc.) is accumulated in a single capacitor and used to operate a low-power communication module at a desired time.

[0137] Figure 6 illustrates the state according to the operating status of an energy harvesting-based device.

[0138] Specifically, FIG. 6 illustrates power consumption and device energy states according to the operating states of an energy harvesting-based device with energy storage capabilities, according to an embodiment of the present disclosure. The embodiment of FIG. 6 may be combined with various embodiments of the present disclosure.

[0139] Referring to (b) of Fig. 6, S1 may be a sleep state, S2 may be an active state, and P1 and P2 may be power consumption in S1 and S2, respectively. For example, the active state may mean a state in which the device consumes power to perform operations such as receiving / transmitting for communication and sensing, and the sleep state may be a state in which it is not an active state.

[0140] Figure 6 (a) may represent a device energy state corresponding to Figure 6 (b). Referring to Figure 6 (a), the E1 value and the E2 value may differ depending on the device (type / class), and the device may report information related to the E1 value and / or information related to the E2 value to R and / or the base station as capability parameters. For example, the E2 value may be defined as an energy value in a buffered state, and the E1 value may be defined as a minimum energy value required in an active state.

[0141] For example, a transition from S1 to S2 may be possible only when the device energy state value is E2 or has reached E2. For example, a transition from S1 to S2 may be possible when the device energy state value is greater than E1 (i.e., in the range between E1 and E2). The embodiment of FIG. 6 illustrates an example in which a transition from S1 to S2 is performed when the device energy state value is E2 or has reached E2.

[0142] For example, A-IoT devices may require externally provided CW for backscatter transmission. For example, CW may be used to power A-IoT devices or as CW for downlink transmission, regardless of the transmission mode (e.g., backscatter transmission or internally generated transmission).

[0143] For example, CW waveforms can be supported in various types. For example, the CW waveform type can be a single-tone CW waveform type or a more complex multi-tone CW waveform type. For example, single-tone CW can be advantageous over multi-tone CW in terms of the multiplexing capacity of tags or readers and in terms of interference because it uses fewer resources. On the other hand, multi-tone CW has advantages such as being able to transfer more energy when transmitting CW in DL, and also securing greater coverage from a single device.

[0144] Considering the advantages of these different CW waveform types, multiple CW waveform types can be supported in the A-IoT system, and the base station / IN / AN / UE can configure the CW waveform type. For example, one or more CW waveform types supported in the A-IoT communication system can be configured / defined in advance, and the base station / IN / AN / UE can select one of the one or more supported CW waveform types and transmit it to the A-IoT device. For example, the base station / IN / AN / UE can configure / instruct / indicate the selected CW waveform type to the A-IoT device in the form of a command / message transmitted as a preamble / frame-sync or payload.

[0145] For example, the present disclosure may propose at least one of the following for A-IoT communication: frame structure, synchronization and timing, random access, numerology, bandwidth, multiple access, waveforms, modulation, channel coding, channel / signal aspects, scheduling and timing relationships, and / or required characteristics of carrier waveforms for carriers provided external to the A-IoT device (including interference handling at the A-IoT device UL receiver and the NR base station). For example, the present disclosure may propose at least one of the following for A-IoT communication: paging, random access, data transmission including required radio resource control aspects to comply with general range limitations, interaction with upper layers (e.g., RRC layer, non-access stratum (NAS) layer, application layer, etc.), device context management, data transmission, coexistence of A-IoT and 6G / NR / LTE, and / or RF requirements for A-IoT.

[0146] For example, technical terms used in this specification may include:

[0147] - SSB: Synchronization Signal Block

[0148] - MIB: Master Information Block

[0149] - RMSI: Remaining Minimum System Information

[0150] - FR1: Frequency Range 1. Refers to the frequency range below 6 GHz (e.g., 450 MHz to 6000 MHz).

[0151] - FR2: Frequency Range 2. Refers to the millimeter wave (mmWave) range above 24 GHz (e.g., 24250 MHz to 52600 MHz).

[0152] - BW: Bandwidth

[0153] - BWP: Bandwidth Part

[0154] - RNTI: Radio Network Temporary Identifier

[0155] - CRC: Cyclic Redundancy Check

[0156] - SIB: System Information Block

[0157] - SIB1: SIB1 for NR devices = RMSI (Remaining Minimum System Information). Broadcasts information necessary for NR terminals to access cells.

[0158] - CORESET: CONTOL REsource SET. Time / frequency resource for the terminal to attempt candidate PDCCH decoding.

[0159] - CORESET#0: CORESET for Type0-PDCCH CSS set for NR devices (configured in MIB)

[0160] - Type0-PDCCH CSS set: a search space set in which an NR UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0161] - MO: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0162] - SIB1-R: (additional) SIB1 for reduced capability NR devices. May be limited to cases where it is generated as a separate TB from SIB1 and transmitted on a separate PDSCH.

[0163] - CORESET#0-R: CORESET#0 for reduced capability NR devices

[0164] - Type0-PDCCH-R CSS set: a search space set in which an redcap UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0165] - MO-R: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0166] - Cell defining SSB (CD-SSB): SSB containing RMSI scheduling information among NR SSBs

[0167] Non-cell defining SSB (non-CD-SSB): An SSB that is placed in the NR sync raster but does not contain RMSI scheduling information for the corresponding cell for measurement purposes. However, it may contain information indicating the location of the cell defining SSB.

[0168] - SCS: subcarrier spacing

[0169] - SI-RNTI: System Information Radio-Network Temporary Identifier

[0170] - Camp on: "Camp on" is the UE state in which the UE stays on a cell and is ready to initiate a potential dedicated service or to receive an ongoing broadcast service.

[0171] - TB: Transport Block

[0172] - RSA (Redcap standalone): Redcap device 또는 service만 지원하는 cell.

[0173] - SIB1(-R)-PDSCH: SIB1(-R)을 전송하는 PDSCH

[0174] - SIB1(-R)-DCI: SIB1(-R)-PDSCH를 scheduling하는 DCI. DCI format 1_0 with CRC scrambled by SI-RNTI.

[0175] - SIB1(-R)-PDCCH: SIB1(-R)-DCI를 전송하는 PDCCH

[0176] - FDRA: Frequency Domain Resource Allocation

[0177] - TDRA: Time Domain Resource Allocation

[0178] - RA: Random Access

[0179] - MSGA: preamble and payload transmissions of the random access procedure for 2-step RA type.

[0180] - MSGB: response to MSGA in the 2-step random access procedure. MSGB may consist of response(s) for contention resolution, fallback indication(s), and backoff indication.

[0181] - RO-N: normal UE 4-step RACH and 2-step RACH(if configured)를 위한 RO(RACH Occasion)

[0182] - RO-N1, RO-N2: When a separate RO is set for normal UE 2-step RACH, it is divided into RO-N1 (4-step) and RO-N2 (2-step).

[0183] - RO-R: RO (RACH Occasion) set separately from RO-N for redcap UE 4-step RACH and 2-step RACH (if configured)

[0184] - RO-R1, RO-R2: When separate ROs are set for redcap UE 2-step RACH, they are distinguished as RO-R1 (4-step) and RO-R2 (2-step).

[0185] - PG-R: MsgA-Preambles Group for redcap UEs

[0186] - RAR: Random Access Response

[0187] - RAR window: the time window to monitor RA response(s)

[0188] - FH: Frequency Hopping

[0189] - iBWP: initial BWP

[0190] - iBWP-DL(-UL): initial DL(UL) BWP

[0191] - iBWP-DL(-UL)-R: (separate) initial DL(UL) BWP for RedCap

[0192] - CS: Cyclic shift

[0193] - NB: Narrowband

[0194] - TO: Traffic Offloading

[0195] -mMTC; Massive Machine Type Communications

[0196] - eMBB: enhanced Mobile Broadband Communication

[0197] - URLLC: Ultra-Reliable and Low Latency Communication

[0198] - RedCap: Reduced Capability

[0199] - eRedCap: enhanced RedCap

[0200] - FDD: Frequency Division Duplex

[0201] - HD-FDD: Half-Duplex-FDD

[0202] - DRX: Discontinuous Reception

[0203] - RRC: Radio Resource Control

[0204] - RRM: Radio Resource Management

[0205] - MM: Mobility Management

[0206] - IWSN: Industrial Wireless Sensor Network

[0207] - LPWA: Low Power Wide Area

[0208] - RB: Resource Block

[0209] - CCE: Control Channel Element

[0210] - AL: Aggregation Level

[0211] - PRG: Physical Resource-block Group

[0212] - DFT-s-OFDM: DFT-spread OFDM

[0213] - PBCH: Physical Broadcast Channel

[0214] - A-PBCH: Additional PBCH

[0215] - BD: blind detection

[0216] - EPRE: Energy Per RE

[0217] - SNR: Signal-to-Noise Ratio

[0218] - TDM: Time Division Multiplexing

[0219] - FDM: Frequency Division Multiplexing

[0220] - DMRS: DeModulation Reference Signal

[0221] - TDD: Time Division Duplex

[0222] - PCI: Physical layer Cell ID

[0223] - EH: Energy Harvesting

[0224] - EH device: A device that operates based on EH. It can include all of Device A / B / C being discussed in 3GPP. In addition, although this specification primarily considers RF EH, an EH device does not necessarily have to be RF EH-based.

[0225] - ES: Energizing Signal. A signal / channel transmitted by a base station / IN / AN / UE for the purpose of supplying RF energy to a device operating on RF-based energy harvesting. (Modulated) CW, NR / LTE DL / UL signals, etc. can be ES, and a dedicated signal / channel for ES can also be designed and supported.

[0226] - ET: Energy Transfer

[0227] CW: Carrier wave. Ambient IoT devices supporting backscattering-based UL transmission transmit information by modulating and backscattering "externally provided" CW. Ambient IoT devices supporting independent signal generation-based UL transmission transmit information by modulating "internally generated" CW. Unless otherwise specified, "externally provided" CW for backscattering is assumed. CW can be used as an energizing signal (ES) for RF energy transfer.

[0228] - CWN: Carrier Wave Node. A node that provides the CW. It may be a base station / IN / AN / UE, and there may be a separate CWN for CW provision purposes.

[0229] - R: Reader / interrogator. This is a standard RFID term. In the 3GPP Ambient IoT context, readers can include gNB / eNB, intermediate / assisting nodes, and UEs, depending on the topology. Furthermore, Ambient IoT is not limited to 4G / 5G communication systems, and can include base stations, intermediate / assisting nodes, and UEs in next-generation communication systems. This can also refer to Ambient IoT readers.

[0230] - T: Tag / ambient IoT device. This is a standard RFID term. In this specification, it can be interchanged with EH device, and in the 3GPP Ambient IoT context, it mainly refers to Ambient IoT device, Device A / B / C. The abbreviation 'T' can be interpreted / replaced with 'D', which stands for Ambient IoT Device.

[0231] - D: Ambient IoT device (may have the same meaning as T above)

[0232] - R=>T: Reader-to-Tag or Reader-to-Tag communication link. When the base station or intermediate / assisting node is the reader, it can have the same meaning as DL or forward link. 'R=>T' can be interpreted / replaced with 'R=>D' (Reader-to-Device).

[0233] - R2D: R-to-D link (can mean the same thing as R=>T. Can also be written as R=>D.)

[0234] - CW2D: CWN-to-D link (CW node to Ambient IoT device link)

[0235] - T=>R: Tag-to-Reader or Tag-to-Reader communication link. When the base station or intermediate / assisting node is the reader, it may have the same meaning as UL or reverse / backward link. 'T=>R' can be interpreted / replaced with 'D=>R' (Device-to-Reader).

[0236] - D2R: It can have the same meaning as T=>R. It can be written as D=>R.

[0237] - R<=>T: Includes cases where R=>T and T=>R, or R=>T or T=>R. It may be the case that both R=>T and T=>R apply.

[0238] - R<=>D: Includes R2D and D2R, or either R2D or D2R. This may apply to both R2D and D2R. (This may have the same meaning as R<=>T.)

[0239] - RF-EH: RF energy harvesting

[0240] - PRDCH: Physical R2D CHannel (may be written as PR2DCH). A physical channel for R2D communication.

[0241] - PDRCH: Physical D2R CHannel (may be denoted as PD2RCH). Physical channel for D2R communication.

[0242] - BS: Base Station

[0243] - IN: Intermediate node. In Topology 2 (BS ↔ IN ↔ Ambient IoT device), IN acts as the reader. Relay, IAB, UE, repeater, etc. can be IN.

[0244] - AN: Assisting node. It can assist DL transmission in Topology 3-1 (BS -> AN -> Ambient IoT device -> BS), or assist UL transmission in Topology 3-2 (BS -> Ambient IoT device -> AN -> BS). Relay, IAB, UE, repeater, etc. can be AN.

[0245] - UE: User Equipment. In the case of LTE, NR, or next-generation communication systems, it refers to the LTE, NR, or next-generation communication system UE / terminal, respectively. It is a general wireless communication terminal type that is distinct from Ambient IoT devices or Device A / B / C. In Topology 4 (UE ↔ Ambient IoT device), the UE acts as the reader.

[0246] - Device: Unless otherwise stated, and when used alone, refers to EH device, Ambient IoT device, or Device A / B / C indiscriminately.

[0247] - AmIoT: Ambient IoT (=A-IoT)

[0248] - F-gap: Frequency gap

[0249] - T-gap: Time gap

[0250] - TD: Time Domain

[0251] - FD: Frequency Domain

[0252] - PEI: Paging Early Indication

[0253] - LP-WUS: Low-Power Wake-Up Signal

[0254] - LP-SS: Low-Power Synchronization Signal

[0255] - RSRP: Reference Signal Received Power

[0256] - ESRP: ES Received Power. This may refer to RSRP measured using ES. It may have the same meaning as ES-RSRP.

[0257] - PRB: Physical Resource Block

[0258] - EH circuit: A circuit that performs EH operations. An EH device can be viewed as containing an EH circuit in component form.

[0259] - PHR: Power Headroom Report

[0260] - EHR: Energy Headroom Report

[0261] - BPF: Band-Pass Filter

[0262] - SM: Subcarrier Modulation

[0263] The methods proposed in this specification can be commonly applied to topology 1 and topology 2, and the gNB and UE1 as IN are conveniently referred to as readers. In addition, the embodiments of this specification can be extended to cases where a reader receiving a BSS (beam search signal) can directly generate and transmit a CW, or where a node transmitting a CW is a separate node from the reader. The BSS may refer to a signal that is transmitted spatially separated from an existing signal / channel (e.g., a downlink signal / channel) for beam search. The BSS may be transmitted based on a dedicated port for beam search. For example, the dedicated port may be a different port from a port for transmitting an existing signal / channel (e.g., SSB, PDSCH, etc.).

[0264] The Ambient IoT BS (base station) (e.g., reader) used in this specification can be a gNB in ​​topology 1 and a specific UE in topology 2. Additionally, the Ambient IoT device (e.g., tag) used in this specification can be interpreted as an Ambient IoT device in both topology 1 and / or topology 2.

[0265] Meanwhile, this specification proposes preamble, midamble, and postamble design methods that can be used for Ambient IoT transmission and reception. In this specification, the term "x-amble" is used to refer to all three: preamble, midamble, and postamble. Specifically, the preamble is transmitted at the very beginning of a specific D2R or R2D transmission, the midamble is transmitted in the middle, and the postamble is transmitted at the very end.

[0266] Meanwhile, the preamble, midamble, and postamble mentioned in this specification may be transmitted together with D2R, R2D transmission (e.g., PDRCH, PRDCH), or may be transmitted by being included in the corresponding D2R, R2D transmission.

[0267] The device ID mentioned in this specification may refer to a unique ID embedded within each device. However, instead of the device ID used in this specification, an ID such as the C-RNTI, which can be exchanged between devices and readers during the inventory round, may also be considered.

[0268] In this document, ' / ' means 'and', 'or', or 'and / or' depending on the context.

[0269] This specification proposes methods for implementing contention-free random access (CFRA) between multiple devices when applying slotted ALOHA operation to an A-IoT system. The term "slot" as used herein refers to a slot considered in slotted ALOHA operation. A slot can have a variable length in the time domain depending on the reader's settings / instructions. An example of a device performing random access using slotted ALOHA is illustrated in Figure 7.

[0270] FIG. 7 is an example of a Slotted ALOHA-based random access operation according to an embodiment of the present specification.

[0271] Referring to Figure 7, the Reader instructs each Device with a slot number through a Query. Specifically, slot number X is instructed to Device 1, and slot number Y is instructed to Device 2. In Figure 7, it is assumed that X=3 and Y=1.

[0272] Since the slot number counter of each device (e.g. X=3, Y=1) is not 0, Device 1 and Device 2 do not transmit msg1 in the first slot.

[0273] The Reader sends a 'QueryRep' to each Device, which triggers transmission for the second slot. Since the slot number counter of Device 2 is 0 (e.g., Y-1=0), Device 2 transmits msg1 to the Reader in the second slot. After that, the remaining operations of the CBRA 4-step procedure are performed. Specifically, Device 2 receives msg2 from the Reader. Device 2 transmits msg3 (e.g., PDRCH scheduled based on msg2) to the Reader. Device 2 receives msg4 from the Reader. Since Device 2 has completed the random access procedure, it may not respond to subsequent 'QueryReps'.

[0274] The Reader sends a 'QueryRep' to each Device, which triggers transmission for the third slot. Since the slot number counter of Device 1 is not 0 (e.g., X-2=1), Device 1 does not transmit msg1 in the third slot.

[0275] The Reader sends a 'QueryRep' to each Device, which triggers transmission for the fourth slot. Since the slot number counter of Device 1 is 0 (e.g., X-3=0), Device 1 transmits msg1 to the Reader in the fourth slot. The subsequent operations are the same as those for Device 2, so duplicate descriptions are omitted.

[0276] The 'Query' described in this specification can be interpreted / replaced with an A-IoT paging message or paging message, and 'QueryRep' can be interpreted / replaced with an Access Trigger message or Trigger message. The Query (A-IoT paging message) is a message that starts an inventory round and also triggers transmission for the first slot. Transmission for the first slot is triggered through the Query (A-IoT paging message), and when transmission and reception for the first slot is terminated, the reader can trigger transmission for the next slot by transmitting the QueryRep (Access trigger message).

[0277] [Method #1]

[0278] Below, we will look at how the Reader instructs the slot number and device ID to pair 1:1 through a command for an inventory round.

[0279] In one embodiment, a method may be considered in which the reader instructs the device ID by pairing the slot number 1:1 with the command for inventory round. For example, the reader may provide / set / instruct the device with a Q value for inventory round, and accordingly, slot numbers may be generated up to M=2Q (i.e., 0 to 2Q-1). The reader may set / instruct each device performing CFRA by pairing one of the M slot numbers.

[0280] In this specification, an inventory round refers to a periodic query and response procedure performed by the reader to scan devices and confirm their presence or identify them (collect their IDs). For example, the following operations are performed:

[0281] 1) The reader initiates an inventory round at specific time intervals. Specifically, the reader broadcasts a query message over a frequency channel / slot. Surrounding devices perform either i) or ii) of the following actions:

[0282] i) Transmit your ID or sensor data

[0283] ii) Non-responsive behavior in specific slots to avoid collisions.

[0284] 2) The reader that receives a response from the device can record the device's identification, location, status, sensor information, etc.

[0285] 3) If necessary, the reader can perform another inventory round for the remaining devices in the next round (e.g., an additional round to resolve collisions).

[0286] In one embodiment, since this is an inventory round for CFRA, a method of utilizing a device ID instead of a Q value may be considered. Specifically, instead of providing a Q value, the reader can provide / set / instruct the device by pairing the device ID and slot number. In this way, the total number of slot numbers can be set to be the same as the number of devices performing CFRA. Afterwards, devices receiving the information can set their own device ID and the paired slot number as a slot number counter. A device with a slot number counter of 0 can immediately transmit msg1. Devices with a slot number counter other than 0 can be configured to operate as follows. The devices can receive commands such as Query rep. The devices can decrease the slot number counter based on the command (e.g., Query rep). Among the devices, a device with a slot number counter of 0 can transmit msg1. Since a device is independently assigned to each slot number, CFRA can be performed.

[0287] [Method #2]

[0288] Below we will look at how the Reader performs CFRA based on the ascending (or descending) order of the device IDs provided via the command for inventory round.

[0289] One could consider a method in which the reader performs CFRA in ascending (or descending) order of the device IDs provided via the inventory round command. For example, the reader could provide / set / instruct each device to perform an inventory round by providing / setting / instructing a Q value, which could result in M=2Q slot numbers (i.e., 0 to 2Q-1). The reader could then assign / set slot numbers for the devices performing CFRA in ascending (or descending) order of their device IDs.

[0290] For example, slot numbers 0, 1, 2, ..., 2Q-1 can be assigned to devices in ascending (or descending) order of device ID. As a specific example, slot number 0 can be assigned / set to the device with the lowest device ID (or the device with the highest device ID).

[0291] For example, slot numbers 2Q-1, 2Q-2, 2Q-3, ..., 0 may be assigned to devices in ascending (or descending) order of device ID. As a specific example, slot number 2Q-1 may be assigned / set to the device with the highest device ID (or the device with the highest device ID).

[0292] In one embodiment, since this is an inventory round for CFRA, a method of utilizing the device ID instead of the Q value may be considered. Specifically, the reader may provide only the device ID instead of the Q value. In this case, the total number of slot numbers may be set to be the same as the number of devices performing CFRA. Afterwards, devices receiving the information may check the number of their device IDs and set the slot number counter accordingly. For example, a device with the first device ID may set the slot number counter to 0 (= device ID-1). Specifically, when the device receives a query (A-IoT paging message), it may transmit msg1 in the first slot.

[0293] As a concrete example, if the number of devices performing CFRA is D, the slot number counters can be set to 0, 1, 2, .., D-1 (or D-1, D-2, D-3, .., 0) in ascending (or descending) order of device ID. More specifically, the device with the lowest device ID (or the highest device ID) can set the slot number counter to 0 (or D-1).

[0294] If a device has a slot number counter of 0, it can immediately transmit msg1. Devices whose slot number counter is not 0 can be configured to operate as follows. The devices can receive commands such as Query rep. The devices can decrease the slot number counter based on the command (e.g., Query rep). Among the devices, the device whose slot number counter becomes 0 can transmit msg1. Since devices are independently allocated for each slot number, CFRA can be performed.

[0295] [Method #2-A]

[0296] Below, we will look at how to perform CFRA in the order of device IDs that the Reader lists up through a command for inventory round.

[0297] One could consider performing CFRA in the order of the device IDs that the reader lists up through a command for inventory round.

[0298] For example, a reader may provide / set / instruct a device to perform an inventory round by providing / setting / instructing a Q value, which may result in M=2Q slot numbers (i.e., 0 to 2Q-1). The slot numbers 0, 1, 2, .., 2Q-1 may be allocated in the order in which the reader lists up the device IDs of the devices performing CFRA (or conversely, slot numbers 2Q-1, 2Q-2, 2Q-3, .., 0).

[0299] In one embodiment, since this is an inventory round for CFRA, a method of utilizing device IDs instead of Q values ​​may be considered. Specifically, the reader could provide only device IDs instead of Q values. This would allow the total number of slots to be set equal to the number of devices performing CFRA. Devices receiving this information can then determine the position of their device ID and set their slot number counters accordingly.

[0300] As a concrete example, if the number of devices performing CFRA is D, the slot number counter for each device can be set to 0, 1, 2, .., D-1 (or D-1, D-2, D-3, .., 0) according to the order of the device IDs provided by the reader in the list-up. In more detail, the device with the device ID that is the first in the list configured by the reader can set the slot number counter to 0 (or D-1).

[0301] If a device has a slot number counter of 0, it can immediately transmit msg1. Devices whose slot number counter is not 0 can be configured to operate as follows. The devices can receive commands such as Query rep. The devices can decrease the slot number counter based on the command (e.g., Query rep). Among the devices, the device whose slot number counter becomes 0 can transmit msg1. Since devices are independently allocated for each slot number, CFRA can be performed.

[0302] [Method #3]

[0303] Below, we will look at how to set up CFRA using Device group ID.

[0304] One method for implementing CFRA by introducing a device group ID can be considered. For example, a reader can group multiple device IDs based on specific rules and / or values. In other words, the reader can classify multiple device IDs into multiple groups. The reader can set / indicate slot numbers for each device group ID. Subsequently, CBRA can be configured / defined between multiple devices within a specific device group.

[0305] For example, multiple sub-slot numbers can be defined within a slot number for a device group ID. Devices belonging to the device group ID assigned to the slot number can randomly select one of the multiple sub-slot numbers. When the sub-slot number counter of the corresponding device reaches 0, msg1 can be configured to be transmitted.

[0306] For example, assuming that K devices are grouped into a device group, K slot numbers can be assigned to each device group ID. Devices belonging to a specific device group ID can randomly select one of the K slot numbers. When the slot number counter of the corresponding device reaches 0, msg1 can be configured to be transmitted.

[0307] A method that can be commonly applied to the above-mentioned methods is described in detail below.

[0308] In one embodiment, the Reader can send a command (or message) to each device that specifies N consecutive slot numbers. Specifically, instead of the Reader sending a command to reduce each slot number, the N slot numbers can be sequentially set / specified through a single Query (or Query Rep, Query Adjust, etc.) command.

[0309] For example, the N value may be defined in advance. For example, the N value may be a value separately set / indicated by the reader. For example, the time occupied by the N slots may be indicated by the reader through a Query (or Query Rep, Query Adjust, etc.) command. For example, the time occupied by the N slots may be defined in advance. In this case, for the time occupied by the N slots, the time for each slot may be independently indicated / defined, or the time for each slot may be indicated / defined as the same value for all slots.

[0310] The above proposed method is represented in a diagram as in Fig. 8.

[0311] FIG. 8 is an example of an Enhanced Slotted ALOHA-based random access operation according to an embodiment of the present specification. Referring to FIG. 8, a Reader indicates a slot number to each Device through a Query. Specifically, slot number X is indicated to Device 1, and slot number Y is indicated to Device 2. In FIG. 8, it is assumed that X=5, Y=2, and N=2. At this time, transmission for two consecutive slots (1st slot, 2nd slot) is triggered based on the Query. Since the slot number counter of each Device is not 0 (e.g., X(5), Y(2), & X-1, Y-1), Device 1 and Device 2 do not transmit msg1 in the first slot and the second slot from the Query.

[0312] The Reader sends a QueryRep (the first QueryRep) to each Device, which triggers transmission for two consecutive slots (1st slot, 2nd slot). Since the slot number counter of Device 2 is 0 (e.g., Y-2=0), Device 2 sends msg1 to the reader in the first slot from the Query. Since the slot number counter of Device 1 is not 0 (e.g., X-2(=3) & X-3(=2)), Device 1 does not send msg1 in the first slot and the second slot from the QueryRep.

[0313] The Reader sends a QueryRep (2nd QueryRep) to each Device, which triggers transmission for two consecutive slots (1st slot, 2nd slot). Since the slot number counter of Device 1 is 0 (e.g. X-5(=0)), Device 1 sends msg1 to the reader in the second slot from the QueryRep.

[0314] In one embodiment, devices performing CFRA can sequentially transmit msg1 by TDM based on a previously set / indicated slot number counter value. For example, device 1 can transmit msg1 to the reader, and then device 2 can sequentially transmit msg1 to the reader. The reader can then sequentially transmit msg2 by TDM based on the corresponding slot number counter value. For example, the reader can transmit msg2 to device 1, and then sequentially transmit msg2 to device 2.

[0315] When set to operate as above, the following operations / settings can be considered. For example, the size of msg1 transmitted by each device can be set / instructed by the reader. For example, the size of msg1 transmitted by each device can be defined identically in advance. In this case, a specific device can know when to transmit msg1. Therefore, msg1s can be transmitted in TDM format without a separate command. When transmission up to msg1 of the last device is completed, the reader TDMs msg2 for each device and transmits it continuously. At this time, msg2 can be set to be transmitted in TDM format in the order of the initially selected slot number value. Therefore, each device can receive msg2 according to the slot number counter value. The proposed method is illustrated in FIG. 9.

[0316] FIG. 9 is another example of an Enhanced Slotted ALOHA-based random access operation according to an embodiment of the present specification.

[0317] Referring to Fig. 9, it is assumed that device 1 selected 3 as the slot number counter, and device 2 selected 2 as the slot number counter. In addition, it is assumed that X=3, Y=2, and N=2. Accordingly, msg1 of device 2 and msg1 of device 1 are transmitted in TDM.

[0318] Specifically, device 2 first transmits msg1 to the reader, and then device 1 subsequently transmits msg1 to the reader. In the same way as for msg1, msg2 for device 2 and msg2 for device 1 are transmitted in TDM. Specifically, the reader first transmits msg2 to device 2, and then transmits msg2 to device 1 subsequently.

[0319] Although the above proposed methods are basically proposed for TDM, similar operations can be applied to FDM, etc.

[0320] For example, a reader can be instructed by pairing a device ID and a frequency (or channel, sub-channel) index.

[0321] For example, it can be set / defined that resources based on the lowest frequency index to the highest frequency index (or resources based on the highest frequency index to the lowest frequency index) are used in ascending (or descending) order of device ID.

[0322] In addition, a method may be considered in which transmission and reception of msg1 / 3 are configured with FDM (or TDM), and transmission and reception of msg2 / 4 are performed based on TDM (or FDM). For example, transmission of msg1 / 3, which is a transmission of the device (D2R transmission), may be performed based on FDM according to the configuration / instruction information of the reader. The reader that receives msg1 / 3 may transmit msg2 / 4 based on TDM.

[0323] The above suggested methods can be set / applied independently (depending on the Q value set / indicated by the reader), but it is also possible to set / apply multiple suggested methods in combination.

[0324] In the above proposed methods, the timing values ​​defined in advance and / or set / indicated by the reader may be set in units of chip(s) / codeword(s) / NR OFDM(s) symbol / NR slot. Alternatively, a time unit may be defined for Ambient IoT (e.g., Tc). The reader may set / indicate the timing value in units of the corresponding time unit. The reader may set / indicate the timing value in multiples of the corresponding time unit, etc.

[0325] In terms of implementation, the operations of the first device (e.g., Ambient IoT Device or Reader, BS, IN, AN, UE) / second device (e.g., Reader, BS, IN, AN, UE or Ambient IoT Device) according to the above-described embodiments can be processed by the device of FIG. 12 (e.g., the processor (110, 210) of FIG. 12).

[0326] In addition, the operations of the first device (e.g., Ambient IoT Device or Reader, BS, IN, AN, UE) / second device (e.g., Reader, BS, IN, AN, UE or Ambient IoT Device) according to the above-described embodiment may be stored in a memory (e.g., 140, 240 of FIG. 12) in the form of a command / program (e.g., instruction, executable code) for driving at least one processor (e.g., 110, 210 of FIG. 12).

[0327] The embodiments described below are specifically described with reference to FIGS. 10 and 11 in terms of the operation of a first device (e.g., Ambient IoT Device or Reader, base station, intermediate node, auxiliary node, terminal) and a second device (e.g., Reader, base station, intermediate node, auxiliary node, terminal or Ambient IoT Device). The methods described below are distinguished only for convenience of explanation, and it goes without saying that some components of one method may be substituted for some components of another method or may be applied in combination with each other.

[0328] FIG. 10 is a flowchart illustrating a method according to one embodiment of the present specification.

[0329] Referring to FIG. 10, a method according to one embodiment of the present specification includes a MSG1 receiving step (S1010) and a MSG2 transmitting step (S1020).

[0330] In S1010, the first device receives Message 1 (MSG1) related to a random access procedure from the second device. For example, the MSG1 may be received based on at least one of the embodiments based on Method #1 to Method #3 described above.

[0331] In S1020, the first device transmits message 2 (MSG2) to the second device. For example, the MSG2 may be transmitted based on at least one of the embodiments based on method #1 to method #3 described above.

[0332] In one embodiment, the slot number associated with MSG1 may be determined based on a group ID associated with contention-free based random access (CFRA). This embodiment may be based on method #3.

[0333] For example, the group ID may be associated with a plurality of device IDs. The group ID may be predefined / set. As a specific example, the first device may classify a plurality of second devices into a plurality of groups. Each group may include two or more second devices. In other words, the group ID of each group may be associated with two or more device IDs. The first device may set a group ID for each of the plurality of second devices. For example, the first device may transmit information (e.g., group ID, slot number, K slot numbers) related to group IDs based on the plurality of groups to each of the plurality of second devices.

[0334] For example, one of the frequency division multiplexed (FDMed) resources may be determined based on the slot number. As a specific example, the MSG1 may be received based on the determined resource (frequency resource).

[0335] In one embodiment, the MSG1 may be received based on counting of a sub-slot number. The counting based on the sub-slot number may be based on decrementing a slot number counter according to one of FIGS. 7 to 9. For example, the sub-slot number may be randomly selected from among sub-slot numbers based on the slot number. More specifically, the second device may randomly select one of the sub-slot numbers based on the slot number. The selected sub-slot number may be decremented based on a message described below. Based on the selected sub-slot number being 0, the first device may receive the MSG1 from the second device.

[0336] In one embodiment, the MSG1 may be received based on counting of the slot number. The counting based on the slot number may be based on decrementing a slot number counter according to one of FIGS. 7 to 9. For example, the slot number may be randomly selected from among slot numbers associated with the group ID. More specifically, the second device may randomly select one of the slot numbers (e.g., the K slot numbers described above) associated with the group ID. Here, K may be the number of second devices belonging to each group. The selected slot number may be decremented based on a message described below. Based on the selected slot number being 0, the first device may receive the MSG1 from the second device.

[0337] In one embodiment, the FDMed resources may be frequency resources within a slot determined based on the slot number.

[0338] For example, the frequency resources may be associated with the plurality of device IDs. Specifically, frequency resource indices based on the frequency resources may be associated with the plurality of device IDs based on pairing or order.

[0339] For example, based on the pairing, each frequency resource index and each device ID may be associated one-to-one. In other words, based on the pairing, the frequency resource indices and the plurality of device IDs may be mapped one-to-one. In other words, one of the frequency resource indices may be paired with one of the plurality of device IDs.

[0340] For example, the order may be ascending or descending order of the plurality of device IDs.

[0341] As a specific example of the ascending order of the above multiple device IDs, the lowest device ID may be associated with the lowest frequency resource index (or the highest frequency resource index), and the highest device ID may be associated with the highest frequency resource index (or the lowest frequency resource index).

[0342] As a specific example of the descending order of the above multiple device IDs, the highest device ID may be associated with the lowest frequency resource index (or the highest frequency resource index), and the lowest device ID may be associated with the highest frequency resource index (or the lowest frequency resource index).

[0343] For example, based on the device ID of the second device among the plurality of device IDs, the frequency resource related to the MSG1 among the frequency resources can be determined.

[0344] In one embodiment, the method may further include a message transmission step. Specifically, the first device may transmit a message related to the trigger of MSG1 to the second device. The message may be a paging message or an access trigger message. The message transmission step may be performed prior to S1010.

[0345] For example, counting based on the slot number (or the sub-slot number) can be performed based on the message.

[0346] Specifically, based on the above message, i) MSG1 transmission for one or more slots may be triggered, and ii) the slot number (or the sub-slot number) may be decreased by the number of the one or more slots.

[0347] Referring to FIG. 7, based on the message, MSG1 transmission for one slot is triggered, and the slot number (or the sub-slot number) can be decreased by 1.

[0348] Referring to FIGS. 8 and 9, based on the message, MSG1 transmission for two consecutive slots is triggered, and the slot number (or the sub-slot number) may be decreased by 2. More specifically, the slot number (or the sub-slot number) is decreased by 1 based on the second device (e.g., Device 1 or Device 2 of FIGS. 8 / 9) receiving the message (e.g., Query or Queryrep). Thereafter, when a time based on one slot elapses from the time at which the second device (e.g., Device 1 or Device 2 of FIG. 8) receives the message (e.g., Query or Queryrep), the slot number (or the sub-slot number) is decreased by 1.

[0349] For example, the transmission by the first device may be an R2D (Reader to Device) transmission, and the transmission by the second device may be a D2R (Device to Reader) transmission.

[0350] As an example of R2D (Reader to Device), a signal transmitted from a first device (Reader) to a second device (Ambient IoT Device) may be based on a physical channel. The physical channel may be referred to as an R2D channel or a Physical Reader-to-Device CHannel (PRDCH). As a specific example, the PRDCH may carry i) all higher-layer payloads (e.g., higher-layer payload including system information, higher-layer payload including settings / information other than system information) and / or ii) R2D control information.

[0351] As an example of D2R (Device to Reader), the signal transmitted from a second device (Ambient IoT Device) to a first device (Reader) may be based on a physical channel. The physical channel may be referred to as a D2R channel or a Physical Device-to-Reader Channel (PDRCH). As a specific example, the PDRCH may carry i) any higher-layer payload, ii) a response transmitted from the Ambient IoT Device to the Reader during a contention-based access procedure, and / or iii) D2R control information.

[0352] In one embodiment, the first device and the second device may be based on devices that operate based on one of four topologies related to Ambient IoT (see FIGS. 1 to 5 ). Specifically, the first device (or the second device) may be i) a base station, ii) a user equipment (UE), iii) an intermediate node, or iv) an assisting node. The second device (or the first device) may be an Ambient IoT (Internet of Things) device.

[0353] In one embodiment, the method may further include a configuration transmission step. Specifically, the first device (e.g., Reader) may transmit the configuration to the second device (e.g., Ambient IoT device). As an example, the configuration may include information based on at least one of Method #1 to Method #3. As an example, the configuration may include information on at least one of i) a device ID, ii) a group ID, iii) a slot number associated with the group ID, iv) K slot numbers associated with the group ID, v) sub-slot numbers based on the slot number associated with the group ID, vi) a frequency resource index associated with the device ID, vii) a Q value associated with the total number of slot numbers, and / or viii) a time based on one slot (e.g., a time occupied by one of the N slots described above).

[0354] For example, the above settings may be transmitted based on the paging message (Query) described above. Specifically, the first device may transmit the paging message including the settings to the second device. In this case, in the message transmission step described above, the message may be an access trigger message (Queryrep).

[0355] For example, the above settings may be transmitted based on the access trigger message described above. Specifically, the first device may transmit the access trigger message including the settings to the second device. In this case, in the message transmission step described above, the message may mean an additional access trigger message (e.g., a second access trigger message).

[0356] For example, the above setting transmission step may be performed before S1010.

[0357] The operations based on the above-described S1010 to S1020, message transmission step and setting transmission step can be implemented by the device of FIG. 12. For example, referring to FIG. 12, the first device (100) can control one or more transceivers (130) and / or one or more memories (140) to perform operations based on S1010 to S1020, message transmission step and setting transmission step.

[0358] The embodiments described below are specifically described in terms of the operation of the second device.

[0359] The message receiving step and the setting receiving step described below, S1110 to S1120, correspond to the message transmitting step and the setting transmitting step described above, S1010 to S1020, in FIG. 10. Considering the above correspondence, redundant descriptions are omitted. That is, the specific description of the second device operation described below may be replaced with the description / example of FIG. 10 corresponding to the operation.

[0360] FIG. 11 is a flowchart illustrating a method according to another embodiment of the present specification.

[0361] Referring to FIG. 11, a method according to another embodiment of the present specification includes a MSG1 transmission step (S1110) and a MSG2 reception step (S1120).

[0362] In S1110, the second device transmits a message 1 (Message1, MSG1) related to a random access procedure to the first device.

[0363] In S1120, the second device receives message 2 (MSG2) from the first device.

[0364] In one embodiment, a slot number associated with the MSG1 may be determined based on a group ID associated with contention-free based random access (CFRA). The group ID may be associated with multiple device IDs. Based on the slot number, one of the frequency division multiplexed (FDMed) resources may be determined. As a specific example, the MSG1 may be transmitted based on the determined resource (frequency resource).

[0365] In one embodiment, the method may further include a message receiving step. Specifically, the second device may receive a message related to the trigger of MSG1 from the first device. The message may be a paging message or an access trigger message. The message receiving step may be performed prior to S1110.

[0366] In one embodiment, the method may further include a configuration receiving step. Specifically, the second device (e.g., an Ambient IoT device) may receive configurations from the first device (e.g., a Reader). The configuration receiving step may be performed prior to S1110.

[0367] The operations based on the above-described S1110 to S1120, the message receiving step and the setting receiving step can be implemented by the device of FIG. 12. For example, referring to FIG. 12, the second device (200) can control one or more transceivers (230) and / or one or more memories (240) to perform operations based on S1110 to S1120, the message receiving step and the setting receiving step.

[0368] Hereinafter, a device to which an embodiment of the present specification can be applied (a device that implements a method / operation according to an embodiment of the present specification) is described with reference to FIG. 12.

[0369] FIG. 12 is a drawing showing the configuration of the first device and the second device according to an embodiment of the present specification.

[0370] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0371] The processor (110) performs baseband-related signal processing and may include a higher layer processing unit (111) and a physical layer processing unit (115). The higher layer processing unit (111) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (115) may process operations of a PHY layer. For example, when the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (100) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (115) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (110) may also control the overall operation of the first device (100).

[0372] The antenna unit (120) may include one or more physical antennas, and when including multiple antennas, may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110), software, an operating system, applications, etc. related to the operation of the first device (100), and may also include components such as a buffer.

[0373] The processor (110) of the first device (100) may be configured to implement the operation of the base station in the base station-to-terminal communication (or the operation of the first terminal device in the terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0374] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0375] The processor (210) performs baseband-related signal processing and may include a higher layer processing unit (211) and a physical layer processing unit (215). The higher layer processing unit (211) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (215) may process operations of a PHY layer. For example, when the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (200) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (210) may also control the overall operation of the second device (210).

[0376] The antenna unit (220) may include one or more physical antennas, and when including multiple antennas, may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210), software, an operating system, applications, etc. related to the operation of the second device (200), and may also include components such as a buffer.

[0377] The processor (210) of the second device (200) may be configured to implement operations of the terminal in base station-to-terminal communication (or operations of the second terminal device in terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0378] In the operation of the first device (100) and the second device (200), the same explanations given for the base station and the terminal (or the first terminal and the second terminal in the terminal-to-terminal communication) in the examples of the present disclosure may be applied, and redundant explanations are omitted.

[0379] Here, the wireless communication technology implemented in the device of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names.

[0380] Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may 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.

[0381] Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN), which take low-power communication into account, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

Claims

In terms of method, A step of receiving a message 1 (Message 1, MSG 1) related to a random access procedure from a second device; and A step of transmitting message 2 (MSG2) to the second device; including: The slot number associated with the MSG1 is determined based on the group ID associated with the contention-free based random access (CFRA). The above group ID is related to multiple device IDs, A method characterized in that one of the frequency division multiplexed (FDMed) resources is determined based on the slot number. In the first paragraph, The above MSG1 is received based on counting of the sub-slot number, A method characterized in that the sub-slot number is randomly selected from among sub-slot numbers based on the slot number. In the first paragraph, The above MSG1 is received based on counting of the slot number, A method characterized in that the above slot number is randomly selected from among slot numbers associated with the above group ID. In the first paragraph, A method characterized in that the above FDMed resources are frequency resources within a slot determined based on the slot number. In paragraph 4, A method characterized in that the above frequency resources are related to the plurality of device IDs. In paragraph 5, A method characterized in that frequency resource indices based on the above frequency resources are associated with the plurality of device IDs based on pairing or order. In paragraph 6, A method characterized in that the frequency resource indices and the plurality of device IDs are mapped one to one based on the pairing. In paragraph 6, A method characterized in that the above order is an ascending or descending order of the plurality of device IDs. In paragraph 6, A method characterized in that a frequency resource related to the MSG1 among the frequency resources is determined based on the device ID of the second device among the plurality of device IDs. In the first paragraph, Further comprising a step of transmitting a message related to the trigger of the MSG1 to the second device; A method characterized in that the above message is a paging message or an access trigger message. In Article 10, A method characterized in that counting based on the above slot number is performed based on the above message. In Article 11, A method characterized in that, based on the above message, i) MSG1 transmission for one or more slots is triggered, and ii) the slot number is decreased by the number of the one or more slots. In the first device, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A first device characterized in that the instructions, based on being executed by the one or more processors, cause the first device to perform all steps of the method according to any one of claims 1 to 12. In an electronic device comprising one or more memories and one or more processors connected to the one or more memories, An electronic device characterized in that said one or more memories store instructions that cause said electronic device to perform all steps of a method according to any one of claims 1 to 12, based on being executed by said one or more processors. In a non-transitory computer-readable storage medium storing instructions, A non-transitory computer-readable storage medium having instructions executable by one or more processors, characterized in that the instructions cause a first device to perform all steps of a method according to any one of claims 1 to 12. In terms of method, A step of transmitting a message 1 (Message1, MSG1) related to a random access procedure to a first device; and A step of receiving message 2 (MSG2) from the first device; including: The slot number associated with the MSG1 is determined based on the group ID associated with the contention-free based random access (CFRA). The above group ID is related to multiple device IDs, A method characterized in that one of the frequency division multiplexed (FDMed) resources is determined based on the slot number. In the second device, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, The second device characterized in that the instructions, based on being executed by the one or more processors, cause the second device to perform all steps of the method according to claim 16.

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