Method and apparatus for configuring monitoring window for receiving downlink signal in low-power wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates, connections between more devices, and the like, such as ultra-high speed, ultra-low latency, and ultra-connectivity. The present disclosure also relates to a low-power communication system in which an apparatus having no battery or having only a capacitor-level energy storage capability is able to operate. The present disclosure relates to operations of a reader and a device in a wireless communication system. The present disclosure relates to a method and apparatus for configuring a monitoring window for receiving a downlink signal in a device for carrying out a random access procedure and detecting a downlink signal within the monitoring window.

Description

Method and device for setting a monitoring window for receiving downlink signals in a low-power wireless communication system

[0001] The present disclosure relates to a terminal, a base station, and a low-power communication device in a communication system. Specifically, the present disclosure relates to a method and apparatus for setting a monitoring window for receiving a downlink signal when the low-power communication device receives the signal to communicate with the terminal or the base station.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes to expand network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) to incorporate Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to the communication network. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms to guarantee coverage in the terahertz band of 6G mobile communication technology, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas; metamaterial-based lenses and antennas to improve terahertz band signal coverage; high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum); and Reconfigurable Intelligent Surface (RIS) technology; as well as Full Duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] As mentioned above, with the advancement of wireless communication systems, it has become possible to provide various services, and thus measures are required to provide these services smoothly.

[0009] The present disclosure may provide an apparatus and method capable of effectively providing services in a mobile communication (or wireless communication) system.

[0010] The technical problems to be solved in the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0011] In a mobile communication (or wireless communication) system according to one embodiment of the present disclosure, a low-power communication device (hereinafter referred to as "device") may report information regarding its energy status to a base station or a terminal (hereinafter referred to as "reader"). This energy status information may include various information that can infer the energy status of the device directly or indirectly. The device may be able to configure the energy status information according to a method of expressing the energy status information and transmit it to the reader. The reader may receive the energy status information reported by the device, determine the availability of the device, and perform appropriate scheduling based thereon. To support such energy status reporting by the device, the reader may transmit related configuration information to the device. The device may report to the reader device capabilities related to energy status reporting that it can perform. The reader may transmit configuration information related to energy status reporting or transmit an energy status reporting request to the device by referring to the device capabilities transmitted by the device.

[0012] A signal processing method by a device in a wireless communication system according to one embodiment of the present disclosure may include: receiving a first signal from a reader; processing the received first signal; generating information regarding the energy state information or energy state reporting capability of the device based on the processing; and transmitting a second signal including the generated information to the reader.

[0013] A signal processing method by a device in a wireless communication system according to one embodiment of the present disclosure may include: determining a transmission resource and transmission data for sending a first signal; determining a monitoring window for detecting a second signal; transmitting the first signal to a reader; and detecting the second signal within the determined monitoring window.

[0014] A method performed by a device in an A-IoT (ambient internet of things) system according to one embodiment of the present disclosure may include: identifying information on a random access occasion; identifying a plurality of random access occasions based on the random access occasion information; defining a mapping relationship between the plurality of random access occasions and a plurality of monitoring windows for monitoring a message 2 for the random access procedure; transmitting a message 1 for the random access procedure based on a random access occasion among the plurality of random access occasions; and monitoring the message 2 within a monitoring window mapped to the random access occasion to which the message 1 was transmitted among the plurality of monitoring windows.

[0015] According to one embodiment of the present disclosure, the plurality of random access opportunities correspond to a plurality of random access opportunity indices, and the plurality of monitoring windows correspond to a plurality of monitoring window indices, and the mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), i is a random access opportunity index among the plurality of random access opportunity indices, z is a monitoring window index among the plurality of monitoring window indices, and Z may be the maximum number of the plurality of monitoring windows.

[0016] According to one embodiment of the present disclosure, the plurality of random access opportunity indices may be assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

[0017] According to one embodiment of the present disclosure, the plurality of monitoring windows may be determined based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

[0018] A device of an A-IoT (ambient internet of things) system according to one embodiment of the present disclosure comprises: a transceiver; and a processor connected to the transceiver, wherein the processor: identifies information on a random access occasion; identifies a plurality of random access occasions based on the information on the random access occasion, and defines a mapping relationship between the plurality of random access occasions and a plurality of monitoring windows for monitoring a message 2 for the random access procedure; transmits a message 1 for the random access procedure based on a random access occasion among the plurality of random access occasions; and may be configured to monitor the message 2 within a monitoring window among the plurality of monitoring windows that is mapped to the random access occasion to which the message 1 was transmitted.

[0019] According to one embodiment of the present disclosure, the plurality of random access opportunities correspond to a plurality of random access opportunity indices, and the plurality of monitoring windows correspond to a plurality of monitoring window indices, and the mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), i is a random access opportunity index among the plurality of random access opportunity indices, z is a monitoring window index among the plurality of monitoring window indices, and Z may be the maximum number of the plurality of monitoring windows.

[0020] According to one embodiment of the present disclosure, the plurality of random access opportunity indices may be assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

[0021] According to one embodiment of the present disclosure, the plurality of monitoring windows may be determined based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

[0022] A method performed by a reader in an A-IoT (ambient internet of things) system according to one embodiment of the present disclosure may include: identifying a plurality of random access opportunities; defining a mapping relationship between the plurality of random access opportunities and a plurality of monitoring windows for a message 2 for the random access procedure; receiving a message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and transmitting the message 2 within a monitoring window mapped to the random access opportunity to which the message 1 was transmitted among the plurality of monitoring windows.

[0023] According to one embodiment of the present disclosure, the plurality of random access opportunities correspond to a plurality of random access opportunity indices, and the plurality of monitoring windows correspond to a plurality of monitoring window indices, and the mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), i is a random access opportunity index among the plurality of random access opportunity indices, z is a monitoring window index among the plurality of monitoring window indices, and Z may be the maximum number of the plurality of monitoring windows.

[0024] According to one embodiment of the present disclosure, the plurality of random access opportunity indices may be assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

[0025] According to one embodiment of the present disclosure, the plurality of monitoring windows may be based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

[0026] A leader of an A-IoT (ambient internet of things) system according to one embodiment of the present disclosure comprises: a transceiver; and a processor connected to the transceiver, wherein the processor: identifies a plurality of random access opportunities, and a mapping relationship is defined between the plurality of random access opportunities and a plurality of monitoring windows for a message 2 for the random access procedure; receives a message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and may be configured to transmit the message 2 within a monitoring window among the plurality of monitoring windows that is mapped to the random access opportunity to which the message 1 was transmitted.

[0027] According to one embodiment of the present disclosure, the plurality of random access opportunities correspond to a plurality of random access opportunity indices, and the plurality of monitoring windows correspond to a plurality of monitoring window indices, and the mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), i is a random access opportunity index among the plurality of random access opportunity indices, z is a monitoring window index among the plurality of monitoring window indices, and Z may be the maximum number of the plurality of monitoring windows.

[0028] According to one embodiment of the present disclosure, the plurality of random access opportunity indices may be assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

[0029] According to one embodiment of the present disclosure, the plurality of monitoring windows may be based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

[0030] The various embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by those skilled in the art based on the detailed description to be described below.

[0031] The disclosed embodiments can provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0032] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0033] FIG. 1 is a diagram illustrating the process of a low-power device and a reader transmitting and receiving signals in a wireless communication system according to one embodiment of the present disclosure.

[0034] FIG. 2 illustrates the structure of a transmission signal in an A-IoT system according to one embodiment of the present disclosure.

[0035] FIG. 3 is a flowchart illustrating an example of a random access (RA) procedure between a reader and a device in an Ambient IoT system according to one embodiment of the present disclosure.

[0036] FIG. 4 is T according to one embodiment of the present disclosure. reference This is a diagram illustrating an example of the start times (402, 403) of two A-IoT Msg2 monitoring windows #1 (405) and #2 (406) that can be represented based on (401).

[0037] FIG. 5 illustrates an example of an A-IoT Msg1 transmission resource grid that can be defined in accordance with one embodiment of the present disclosure, where a device has 5 connection opportunities (504, 509) for A-IoT Msg1 transmission and 2 frequency resources corresponding to M=2 (505, 507) and M=4 (506, 508).

[0038] FIG. 6 shows different reference times (T) for each device according to an embodiment of the present disclosure. reference When ) can be had, different A-IoT Msg2 window start times per device (T start Shows an example of setting ).

[0039] FIG. 7 is a diagram showing the structure of a device in a wireless communication system according to one embodiment of the present disclosure.

[0040] FIG. 8 is a diagram showing the structure of a reader in a wireless communication system according to one embodiment of the present disclosure.

[0041] Hereinafter, embodiments of the present disclosure may be described in detail with reference to the attached drawings.

[0042] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure may be omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0043] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0044] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals may refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration would unnecessarily obscure the essence of the present disclosure, such detailed description may be omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0045] In the present disclosure, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), radio access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In the present disclosure, a downlink (DL) may refer to a wireless transmission path for a signal transmitted by a base station to a terminal, and an uplink (UL) may refer to a wireless transmission path for a signal transmitted by a terminal to a base station. Furthermore, while LTE or LTE-A systems may be described below as examples, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technologies (5G, new radio, NR) developed after LTE-A may be included, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of the present disclosure.

[0046] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment may create means for performing the functions described in the flow diagram block(s). Since these computer program instructions may also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in such computer-available or computer-readable memory may also produce a manufactured item containing instruction means for performing the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0047] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specified logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0048] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" may perform certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" may include components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0049] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0050] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above-mentioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0051] As a future communication system following LTE, that is, a 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously may need to be supported. Services being considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0052] eMBB may aim to provide data transmission speeds that are superior to those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB may need to be able to provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing the peak data rates, the 5G communication system may also need to provide an increased user-perceived data rate. To satisfy these requirements, improvements in various transmission and / or reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology, may be required. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0053] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC may require support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, it may be necessary to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0054] Finally, URLLC is a mission-critical cellular-based wireless communication service. Examples include services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC may require very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and simultaneously meet the requirement of a packet error rate of 10^-5 or less. Consequently, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and design considerations may be required to allocate wide resources in the frequency band to ensure the reliability of the communication link.

[0055] The three 5G services, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted within a single system. In this case, different transmission and / or reception techniques and transmission and / or reception parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G may not be limited to the three aforementioned services.

[0056] [Low-power communication: Ambient-IoT]

[0057] The Internet of Things (IoT) is a technology in which various devices are interconnected via the internet to exchange data, and it is utilized in diverse fields such as smart homes, industrial automation, healthcare, and smart cities. Most existing IoT devices operate using batteries, requiring periodic replacement or charging. This increases maintenance costs and time consumption for IoT systems and can be a significant constraint, particularly when large-scale deployments are required or when used in hard-to-reach locations. Ambient IoT (AIoT) represents one of the next evolutionary stages for such IoT technology, a new type of IoT that is powered by collecting energy from the surrounding environment. AIoT devices can utilize energy harvesting technology to receive energy from light, radio waves, motion, heat, or other power sources deemed suitable, enabling them to operate for extended periods without battery replacement or charging. The output of energy harvesters typically ranges from 1 μW to several hundred μW, which is a very low level compared to the maximum power of 10 mW required for communication technology in current commercial systems. Accordingly, there is a growing need for new low-power communication technologies that can be used in various AIoT use cases.

[0058] In the present disclosure, the reader is an entity that transmits and receives data with a low-power device, and may include a base station or a terminal. Additionally, in the following disclosure, R2D (reader-to-device) transmission or AIoT downlink (hereinafter referred to as downlink in the present disclosure) may refer to a wireless transmission path for a signal transmitted by the reader to the low-power device, and D2R (device-to-reader) transmission or AIoT uplink (hereinafter referred to as uplink in the present disclosure) may refer to a wireless transmission path for a signal transmitted by the low-power device to the reader.

[0059] FIG. 1 is a diagram showing the process of a low-power device (101) and a reader (100) transmitting and receiving signals (103, 104) in a wireless communication system according to one embodiment of the present disclosure.

[0060] The reader (100) can instruct the device to transmit D2R (104) via R2D transmission (103) or transmit information necessary for the operation of the device (101) or for updating the state of the device (101). The device (101) can perform its own state information, report on the reader's instructions, etc. via D2R transmission (104).

[0061] FIG. 2 illustrates the structure of a transmission signal in an A-IoT system according to one embodiment of the present disclosure.

[0062] D2R transmission and R2D transmission may include physical channels for data transmission of each link, such as PDRCH (Physical device to reader channel) and PRDCH (Physical reader to device channel), and may be processed as data of the transmission signal (203, 205). According to one embodiment, the structure of the transmission signal when transmitting a physical layer channel in an A-IoT system may include a preamble (200) that is transmitted at the front of the signal and can be used to determine the signal's start point and clock. Specifically, the preamble (200) may include a start-indicator part (201) that can be used to indicate the signal's start point and a clock-acquisition part (202) that can be used to determine the clock to be used when receiving data. According to one embodiment, the structure transmitted prior to the A-IoT physical layer data (203) of the preamble (200) may be utilized for both R2D transmission and D2R transmission.

[0063] According to one embodiment, a midamble (204) or a postamble (206), etc., may be added in various ways to the signal when transmitting a physical layer channel to increase the accuracy of signal reception or to indicate the end time of the signal. These signals may be utilized for various purposes depending on the design and configuration of the signal, and the structure and use of the signal are not limited to the example illustrated in FIG. 2. According to one embodiment, the signals when transmitting a physical layer channel in an A-IoT system may be composed of binary signals represented by a specific pattern. For example, the signals may be composed of an ON (1)-OFF (0) pattern.

[0064] An AIoT device (hereinafter referred to as the device) is a device that receives energy through energy harvesting and can utilize the following two methods to generate a signal to be transmitted to a reader. First, the device can use backscattering communication to generate a signal by reflecting an incoming RF (radio frequency) signal to transmit data. In this case, the signal transmitted to the device from the outside for signal transmission from the device to the reader (i.e., the uplink of the AIoT system) can be referred to as a carrier wave (hereinafter referred to as CW). The CW can be transmitted to the device from an external node outside the device, and the device can generate an uplink signal to be transmitted to the reader by reflecting the corresponding signal. When based on backscattering communication, the device does not include a local oscillator (LO) in its internal structure, and thus can significantly reduce power consumption and device complexity. The device can encode information stored in memory while reflecting the signal, and the reflected signal can be delivered to the reader for decoding. Generating a signal directly within the device can be another method for generating a signal to be transmitted to a reader. In this case, since the device must generate the signal directly using an internal LO, greater power consumption and device complexity can be expected compared to when using backscattering communication. AIoT devices may also use amplifiers at the transmitting and receiving ends to improve communication performance.

[0065] While devices can generate signals for uplink transmission in various ways, to reduce the cost or complexity of system design, it may be appropriate to aim for a harmonized design that allows signals to be received at the base station reception side regardless of the uplink signal generation method. For example, by designing the device so that the signal generated by reflecting a CW and the signal generated internally share similar signal forms and transmission technologies, it may be possible to enable the receiver to receive and interpret these signals using the same algorithm. Therefore, although this document describes devices that generate signals by reflecting a CW, in cases where a signal is generated directly internally, the same reception technique can be applied when the reader receives the signal by designing the generated signal to have a form similar to the signal generated through CW reflection. As an example, when generating a signal through CW reflection, the CW signal is a sine wave with a single tone (frequency), and the device can reflect the signal by applying a frequency conversion of △f to the sine wave. When generating signals internally, a similar signal can be produced by directly generating a single-tone sine wave within the device and applying the same frequency shift. Alternatively, the signal can be generated by simulating a signal with applied frequency shift from the signal generation stage. This approach enables the receiver to receive and interpret signals using the same algorithm regardless of the signal generation method, which can help reduce system complexity and improve overall efficiency.

[0066] FIG. 3 is a flowchart illustrating an example of a random access (RA) procedure between a reader (300) and a device (301) in an Ambient IoT system according to one embodiment of the present disclosure.

[0067] In an Ambient IoT system, when at least one device attempts to connect to a network for data transmission, an Ambient IoT random access procedure may be performed. The above Ambient IoT RA procedure may be triggered by a leader (300), and a message transmitted from the leader (300) to a device (301) to trigger the RA procedure may be called an A-IoT paging message (302) or an R2D transmission triggering random access. The A-IoT paging message (302) may include information regarding an access occasion ((random) access occasion / resource, D2R occasion / resource) for at least one device, and the device (301) may perform the RA procedure by transmitting an A-IoT message1 (303) at at least one access occasion.

[0068] An A-IoT paging message (302) may include information about an identifier indicating one device, a device group consisting of one or more devices, and / or one or more devices. Such an identifier may be used to restrict that only the device indicated by the identifier among the devices receiving the A-IoT paging message (302) performs the RA procedure, but this use is not limited. In this case, the A-IoT paging message (302) may not include an identifier. In this case, all devices receiving the A-IoT paging message (302) may perform the RA procedure.

[0069] A device that has received an A-IoT paging message (302) may select one type of random access procedure, either contention-based or non-contention-based, by referring to the message. The reader (300) may directly or indirectly transmit information regarding the type of random access procedure and configuration information to the device (301) through the A-IoT paging message (301). If the device (301) performs a non-contention-based random access procedure, the device (301) may perform D2R transmission (e.g., A-IoT msg1 (303)) through a D2R occasion or resource directly or indirectly indicated in the A-IoT paging message (302). If the device (301) performs a contention-based random access procedure, the device (301) may select at least one access occasion from among at least one access occasion provided by the reader (300) through the A-IoT paging message (302) and perform A-IoT msg1 (303) transmission. In this case, the device can randomly select an access occasion. These access occasions can be multiplexed in the time axis or the frequency axis.

[0070] A reader (300) may send an A-IoT paging message (302) to a device (301) to trigger an RA procedure. If the A-IoT paging message (301) includes an identifier for a device or a device group, only the device or device group indicated by the identifier may perform the RA procedure. A device (301) performing the RA procedure may send an A-IoT Msg1 (303) to the reader (300). At this time, information regarding time and / or frequency resources for which the A-IoT Msg1 (303) can be sent may be included in the A-IoT paging message (302). For example, information regarding at least one time domain resource may be included in the A-IoT paging message (302). For example, information regarding at least one frequency domain resource may be included in the A-IoT paging message (302). In this case, information regarding the frequency domain resource may be the location of a specific frequency resource or an index representing the frequency transition capability of the device. For example, when the device multiplies a sub-carrier sequence in which the ON-OFF pattern is repeated 2*M times per unit time for frequency transition, or distinguishes the symbols of 1 and 0 using signal transitions from 0 to 1 or 1 to 0, it may repeat such signal transitions M times, such as 0->1->…->0->1 and 1->0->..->1->0. In this case, information regarding the available M value may be included in the A-IoT paging message (302). When performing a contention-based RA procedure, there may be at least one piece of information regarding the time resource and / or frequency resource that can be selected.When performing a non-contention-based RA procedure, information about selectable time resources and / or information about frequency resources is already set, and the resource indicated by the set information can be used for A-IoT Msg1 transmission (303).

[0071] A-IoT Msg1 (303) may contain at least one of the following information. A-IoT Msg1 (303) may contain a 16-bit random ID generated by the device (301). In this case, the 16-bit may be a random ID of a different length, for example. A-IoT Msg1 (303) may contain the ID of the device, rather than a random ID. A-IoT Msg1 (303) may contain part or all of the data coming down from the upper layer.

[0072] A reader (300) that receives Msg1 (303) transmitted by device (301) may attempt to resolve the contention by transmitting A-IoT Msg2 (304) to device (301). A-IoT Msg2 (304) may include at least one of the following information. A-IoT Msg2 (304) may include a random ID sent by device (301) in A-IoT Msg1 (303). A-IoT Msg2 (304) may include part or all of the data coming down from the upper layer.

[0073] If the device (301) receives an ID identical to the random ID transmitted from the A-IoT Msg1 (303) through the A-IoT Msg2 (304), the device (301) may assume that the contention has been successfully resolved. After receiving the A-IoT Msg2 (304) and determining that the contention has been resolved, the device (301) may proceed with the procedure for transmitting upper-layer data. For example, some or all of the information of the upper layer, the ID of the device (301), etc., may be included in the upper-layer data. This upper-layer data may be transmitted through the A-IoT Msg3 (305). If the device is a device performing a non-contention-based RA, it may skip the transmission and reception procedure of the A-IoT Msg1 (303) or the A-IoT Msg2 (304) and proceed directly with the procedure for transmitting upper-layer data. The random connection procedure described in the above example is merely an example; in reality, additional procedures may exist or some of the above procedures may be omitted, and is not limited to this example.

[0074] In a 5G NR system, the random access procedure is a process for a terminal to synchronize with the network and be allocated resources, and it can be initiated via a Physical Random Access Channel (PRACH). In 5G NR, this procedure may consist of transmitting Msg1 (RA preamble), receiving Msg2 (RA response, RAR), and transmitting and receiving Msg3 and Msg4 used for contention resolution. Before initiating the random access procedure, the terminal receives configuration information for transmitting PRACH from the upper layer, which may include the PRACH preamble format, time resources, frequency resources, etc. Information related to the root sequence and cyclic shift (CS) for determining the PRACH preamble sequence may also be provided by the upper layer. In the random access procedure, the terminal transmits the random access preamble (Msg1) via PRACH, and in response, the base station generates and transmits a random access response (RAR, MSG2) to the terminal. RAR is transmitted via DL-SCH (downlink shared channel) (physical downlink shared channel, PDSCH). RAR is scheduled via DCI (downlink control information) Format 1_0, which is scrambled into RA-RATI (random access-radio network temporary identifier) ​​and transmitted. That is, the CRC (cyclic redundancy check) of DCI Format 1_0 is scrambled into RA-RNTI. In this case, RA-RATI is a value determined by the index of the first OFDM symbol of the PRACH occasion in which Msg1 was transmitted, the slot index, the position in the frequency domain, etc.A terminal that has transmitted Msg1 can detect DCI format 1_0 scrambled with the corresponding RA-RNTI within the Msg2 window by referring to the RA-RATI value calculated from the PRACH occasion it has transmitted, and information such as the start time of this window and the length of the window may be included in the upper layer configuration information. Terminals that have received the same upper layer configuration information from the same base station can receive Msg2(RAR) by detecting DCI format 1_0 scrambled with the RA-RNTI associated with themselves within the same Msg2 window.

[0075] If an Ambient IoT system is configured so that multiple devices performing random access procedures—similar to 5G NR systems—all share the same A-IoT Msg2 monitoring window, the window length may need to be increased as the number of devices in the network increases to ensure that all devices have sufficient random access opportunities. However, a long A-IoT Msg2 window can lead to unnecessary energy consumption during the monitoring process in environments where energy storage capacity is limited and energy efficiency is critical, such as with Ambient IoT devices. For example, if a device consumes excessive energy while observing a long window to detect an A-IoT Msg2, causing its stored energy to be completely depleted, it may fail to complete the RA procedure. This can result in unnecessary energy waste as additional energy is consumed during the process of retrying the RA procedure. Conversely, if the window is set too short, the number of devices capable of receiving an A-IoT Msg2 during a specific period may be limited.

[0076] Accordingly, the present embodiment provides various embodiments of a method and apparatus for setting a monitoring window for a device to receive an A-IoT Msg2 in an Ambient IoT system to solve the above problem. The A-IoT Msg2 window setting method and apparatus presented in this disclosure can help increase the energy efficiency of the device and enable more devices to perform random access procedures during the same period of time by adjusting the size of the window that the device must monitor to receive the A-IoT Msg2 and allowing different A-IoT Msg2 windows to be observed per device or per group of devices.

[0077] Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "less than" may be replaced with "less than," and "less than" may be replaced with "less than." Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "greater than" may be replaced with "greater than," and "greater than" may be replaced with "greater than."

[0078] In this disclosure, the examples are described through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0079] Example 1: Setting different start times based on random information transmitted from A-IoT Msg1

[0080] In this embodiment, a method is presented to determine the A-IoT Msg2 monitoring window of a device based on a random ID transmitted by the device to A-IoT Msg1 during a random access procedure. In this embodiment, the monitoring window for receiving A-IoT Msg2 is T, which is a reference time that can be commonly used among devices performing the random access procedure. reference It is assumed that it can be calculated based on .

[0081] FIG. 4 is T according to one embodiment of the present disclosure. reference This is a diagram illustrating an example of the start times (402, 403) of two A-IoT Msg2 monitoring windows #1 (405) and #2 (406) that can be represented based on (401).

[0082] Referring to FIG. 4, the start time T of window #1 (405) start,#1 (402) is T reference T based on (401) default (407) and T offset,#1 It can correspond to a time later by that amount (i.e., T start, #1 = T reference +T default +T offset,#1 ). Start time T of Windows #2 (406) start,#2 (403) is T reference T based on (401) default (407) and T offset,#2 It can correspond to a time later by that amount (i.e., T start, #2 = T reference +T default +T offset,#2 ).

[0083] At this time, T reference (401) may be a reference time that can be commonly referenced among devices that have received the same random access trigger R2D transmission, such as the time when the R2D transmission triggering random access ends or the end of the connection opportunity corresponding to the latest time among the available A-IoT Msg1 connection opportunities indicated by the R2D transmission triggering random access. However, the scope of the present disclosure is not limited thereto.

[0084] T default (407) may be the same or different for each device and may be a value for correcting a timing offset that may occur in an Ambient IoT system, which is an asynchronous system. The value may be sent to the device by the reader in advance, or may be pre-set within the device, and may be set to 0 as needed.

[0085] T offset is a value that may vary depending on the random ID transmitted by the device via A-IoT Msg1, for example, T offset =z*T window It can be calculated as follows. In this case, T window (404) is the length of the A-IoT Msg2 monitoring window, which may not require separate signaling, such as when the reader instructs the device via A-IoT paging or when the value is pre-agreed upon / defined between the device and the reader. However, the scope of application of this disclosure is not limited thereto, and other time lengths other than T, where no overlapping area between windows may occur, may also be used. windowIt may be applied in place of. z may be a value calculated from at least one of the random information transmitted by the device to the reader using A-IoT Msg1. For example, z may be a value obtained by applying modulo Z to some of the LSB (least significant bit) and MSB (most significant bit) of the random ID transmitted by the device via A-IoT Msg1. In this case, Z may be the maximum number of A-IoT Msg2 windows, a value pre-set by the reader to the device, or a value determined / defined in advance between the reader and the device that does not require separate signaling. Alternatively, z may be a specific value calculated and mapped based on the LSB and MSB of the random ID. For example, z may be calculated as mod(N-bit LSB XOR N-bit MSB, Z). As another example, z may be a value calculated based on at least one upper-layer information transmitted by the device via A-IoT Msg1. When a device transmits a preamble based on a sequence, etc. through an A-IoT Msg1, the z value may be calculated based on the configuration information of the sequence, etc. FIG. 4 illustrates an example where z is calculated as 1 for device #1 and z is calculated as 2 for device #2, where z=1 and z=2 may be calculated based on information included in the A-IoT Msg1, such as a random ID, sequence ID, or other upper layer information of the A-IoT Msg1 transmitted by each device, or a random value for setting the z value.

[0086] Example 2: Setting different start times based on resource indices of A-IoT Msg1 and Msg2

[0087] In this embodiment, a method for determining an A-IoT Msg2 window is presented based on a resource index determined for the time and frequency resources available to a device for transmitting an A-IoT Msg1. In this embodiment, the monitoring window for receiving the A-IoT Msg2 is T, which is a reference time that can be commonly used among devices performing a random access procedure. reference It is assumed that it can be calculated based on .

[0088] FIG. 4 is T according to one embodiment of the present disclosure. reference This is a diagram illustrating an example of the start times (402, 403) of two A-IoT Msg2 monitoring windows #1 (405) and #2 (406) that can be represented based on (401).

[0089] Referring to FIG. 4, the start time T of window #1 (405) start,#1 (402) is T reference T based on (401) default (407) and T offset,#1 It can correspond to a time later by that amount (i.e., T start, #1 = T reference +T default +T offset,#1 ). Start time T of Windows #2 (406) start,#2 (403) is T reference T based on (401) default (407) and T offset,#2 It can correspond to a time later by that amount (i.e., T start, #2 = T reference +T default +T offset,#2 ).

[0090] At this time, T reference(401) may be a reference time that can be commonly referenced among devices that have received the same random access trigger R2D transmission, such as the time when the R2D transmission triggering random access ends or the end of the connection opportunity corresponding to the latest time among the available A-IoT Msg1 connection opportunities indicated by the R2D transmission triggering random access. However, the scope of the present disclosure is not limited thereto.

[0091] T default (407) may be the same or different for each device and may be a value for correcting a timing offset that may occur in an Ambient IoT system, which is an asynchronous system. The value may be sent to the device by the reader in advance, or may be pre-set within the device, and may be set to 0 as needed.

[0092] T offset is a value that may vary depending on the transmission resource index of the A-IoT Msg1 transmitted by the device via A-IoT Msg1, for example, T offset = z*T window It can be calculated as follows. In this case, T window (404) is the length of the A-IoT Msg2 monitoring window, which may not require separate signaling, such as when the reader instructs the device via A-IoT paging or when a value is pre-agreed upon between the device and the reader. However, the scope of application of this disclosure is not limited thereto, and other time lengths other than T, where no overlapping area between windows may occur, may also be used. windowIt can be applied in place of. z is a value determined by the transmission resource index i used by the device when transmitting A-IoT Msg1, and devices that have transmitted A-IoT Msg1 to different transmission resources can be configured to monitor different A-IoT Msg2 windows. In this case, regarding the transmission resources available to the device for transmitting A-IoT Msg1, if there is a number of resources I available in the time axis and a number of resources J available in the frequency axis, a total of I * J transmission resources may be available to the device for transmitting A-IoT Msg1. In this case, some of these transmission resources may be configured to be unavailable for separate purposes, but for the convenience of explanation, they are not described separately in this example. Information regarding available A-IoT Msg1 time resources may be instructed by the reader to the device via an A-IoT paging message or may be agreed upon in advance between the reader and the device. For example, time resources available for transmitting A-IoT Msg1 can be defined by increasing the time index by 1 by operating a timer for a certain period after a specific offset, starting from after the device receives A-IoT paging from the reader. Information regarding available A-IoT Msg1 frequency resources may be frequency resources determined based on the M value if the device is capable of frequency transition according to the above description. However, the present disclosure is not limited to these embodiments and may be equally applicable to time resources and frequency resources that can be defined in the device.

[0093] FIG. 5 illustrates an example of an A-IoT Msg1 transmission resource grid that can be defined according to one embodiment of the present disclosure, in which a device has 5 connection opportunities (504, 509) for A-IoT Msg1 transmission and 2 frequency resources corresponding to M=2 (505, 507) and M=4 (506, 508). It can be assumed that the device has 5 transmission resources for the time axis (500, 502) and 2 transmission resources for the frequency axis (501, 503).

[0094] FIG. 5(a) is an example of a resource index that can be set when the resource index is set with priority to the time axis. That is, the resource index can be set with priority to the time axis. In the example of FIG. 5(a), for the frequency resource of M=2 (505), it can be indexed as 0, 1, 2, 3, 4 for 5 access occasions (504) based on the time axis (500), and for the frequency resource of M=4 (506), which is the next frequency resource in the direction of the frequency axis (501), it can be indexed as 5, 6, 7, 8, 9 for 5 access occasions (504) based on the time axis (500).

[0095] Figure 5(b) is an example of a resource index that can be set when the resource index is set with priority to the frequency axis. That is, the resource index can be set with priority to the frequency axis. In the example of FIG. 5(b), for the first time resource among the five access occasions (509), two frequency resources (507, 508) are indexed as 0 and 1 with respect to the frequency axis (503); for the second time resource position among the five access occasions (509) that is the next time resource in the direction of the time axis (502), two frequency resources (507, 508) are indexed as 2 and 3 with respect to the frequency axis (503); for the third time resource position among the five access occasions (509) that is the next time resource in the direction of the time axis (502), two frequency resources (507, 508) are indexed as 4 and 5 with respect to the frequency axis (503); and for the fourth time resource position among the five access occasions (509) that is the next time resource in the direction of the time axis (502), the frequency axis Based on (503), two frequency resources (507, 508) can be indexed as 6 and 7, and for the fifth time resource position among the five access occasions (509) that are the next time resources in the direction of the time axis (502), two frequency resources (508, 509) can be indexed as 8 and 9 based on the frequency axis (503).

[0096] In the above embodiment, the resource group index can replace the resource index. For example, if resource indices from 0 to 7 can be set, resource group index 1 can be set for resource indices from 0 to 3, and resource group index 2 can be set for resource indices from 4 to 7. In this case, a Msg2 window corresponding to z=0 can be allocated for resource index group 1, and a Msg2 window corresponding to z=1 can be allocated for resource index group 2. If there are more Msg2 windows than the entire resource or the entire resource group, mapping between the Msg1 resource and the Msg2 window may be performed using only some of the windows among the entire Msg2 window according to rules agreed upon in advance between the reader and the device.

[0097] Alternatively, a resource index can be set for only one of the frequency or time axes. For example, a resource index can be set for time resources only, without considering frequency resources. In this case, it can be assumed that even if A-IoT Msg1 is transmitted using different M values ​​during the same connection opportunity, they have the same resource index. As another example, a resource index can be set for frequency resources only, without considering time resources.

[0098] Based on resource index i, z can be calculated as z=mod(i, Z). Alternatively, by adding an interleaving operation to mod(i, Z), the value of z based on i can be calculated as z=interleaver(mod(i, Z)). The present disclosure is not limited to such calculation methods, and various mapping methods that can be performed between a resource index or resource group index and a Msg2 window index may be applied. Here, Z may be the maximum number of A-IoT Msg2 windows, a value pre-configured by the reader to the device, or a value pre-determined / defined between the reader and the device that does not require separate signaling.

[0099] The rules for determining these resource indices can follow common rules between the device and the reader. Therefore, when a device sends an A-IoT Msg1 to a resource corresponding to a specific resource index, the reader can check the resource index based on the location of the resource to which the message was sent and send Msg2 to the device within the A-IoT Msg2 window mapped to it.

[0100] The present disclosure may consider a 1:n mapping between an A-IoT Msg1 resource or resource group and a Msg2 window. For example, two or more Msg2 windows may be mapped to a specific resource or resource group index, and such rules may be common between a reader and a device. When allocating a Msg2 window per resource group using a resource group index, at least one of the random ID sent by the device to the reader via the A-IoT Msg1 or the information instructed by the device to the reader via the A-IoT Msg1 may be additionally referenced in allocating the Msg2 window. For example, for resource group I, Msg2 detection in the Msg2 window may be attempted only when at least one of the random ID sent by the device to the reader via A-IoT Msg1 or the information instructed by the device to the reader via A-IoT Msg1 satisfies a predetermined condition, or when two or more Msg2 windows are mapped, one of the Msg2 windows may be selected according to a predetermined condition regarding at least one of the random ID sent by the device to the reader via A-IoT Msg1 or the information instructed by the device to the reader via A-IoT Msg1.

[0101] Example 3: Preset for priority transmission

[0102] If the reader wants to receive information from a specific device more quickly or has not received information from a specific device for a long time, the reader may set a priority for that device. In such cases, the reader may want to allocate an A-IoT Msg2 window to that device that has good channel conditions or is transmitted the fastest so that the device can successfully receive Msg2 and complete the random access procedure.

[0103] For example, if the device and the reader can set the A-IoT Msg2 window according to Example 1, the reader may set a priority for the device in advance, and the device may send the A-IoT Msg1 to the reader by setting information indicating priority transmission regarding the ID, upper layer information, or preamble sequence transmitted to the A-IoT Msg1. At this time, the reader may instruct the device regarding information on priority setting through an A-IoT paging message. For example, by transmitting the IDs of devices with priority in the A-IoT paging message, the device with the corresponding ID may determine that it has priority. For example, by instructing a threshold value for specific conditions for having priority in the A-IoT paging message, such as the number of transmissions and receptions of Msg1 / 2 / 3, energy reserves, or the time elapsed since the most recent transmission, the device may determine that it has priority if it satisfies certain conditions based on the threshold. Alternatively, even if the reader does not instruct the device regarding information on priority transmission, the device may periodically perform priority transmission or attempt to detect Msg2 in a priority A-IoT Msg2 window by setting specific information in A-IoT Msg1 and transmitting it to the reader to request priority reception. For example, if a specific ID is selected from A-IoT Msg1 and transmitted as a random ID for A-IoT Msg1, the reader may assign priority to the device and transmit the A-IoT Msg2 for that device to the fastest A-IoT Msg2 window.

[0104] For example, if the device and the reader can set an A-IoT Msg2 window according to Example 2, the reader may set a priority for the device in advance, and the device may transmit Msg1 to the reader through an A-IoT Msg1 transmission resource corresponding to a specific index. In this case, the resource index having the priority may be one agreed upon in advance between the device and the reader, or one instructed by the reader to the device via A-IoT paging. Alternatively, even if the reader does not directly instruct the device to prioritize transmission, the device may periodically perform priority transmission or transmit A-IoT Msg1 through a resource having a specific index to request priority reception from the reader. Subsequently, the device may attempt to detect Msg2 in the A-IoT Msg2 window mapped to the corresponding A-IoT Msg1.

[0105] Regarding resource information of A-IoT Msg1 that may have priority or specific information that may be transmitted to A-IoT Msg1, the reader and the device may agree on it in advance, it may be predefined, or the reader may instruct the device through A-IoT paging.

[0106] Example 4: A-IoT Msg2 Window Delay

[0107] When the device and the reader follow a rule for determining an A-IoT Msg2 window according to at least one of the above Examples 1 to 3, the device may be configured to attempt to detect Msg2 within a specific A-IoT Msg2 window after transmitting an A-IoT Msg1.

[0108] In the following cases, the device may attempt to detect Msg2 within a delayed A-IoT Msg2 window, rather than within the A-IoT Msg2 window configured according to the rules. For example, the device may determine that it does not possess sufficient energy to receive Msg2 within the configured A-IoT Msg2 window before or during the transmission of Msg1. Alternatively, even if it possesses sufficient energy to receive Msg2, it may determine that receiving Msg2 within the configured window is difficult due to energy management issues. In such cases, the device may request an A-IoT Msg2 window delay via A-IoT Msg1. For example, the device may request an A-IoT Msg2 window delay by transmitting its energy status information, such as an energy status report. For example, the device may request an A-IoT Msg2 window delay by transmitting at least one piece of information within A-IoT Msg1 as specific information, such as a specific ID, upper-layer information, or a preamble sequence. For example, if a specific ID is set as a random ID transmitted via A-IoT Msg1 and sent to the reader, the reader can set the A-IoT Msg2 window delay for the device with that ID. Alternatively, the reader can determine whether to perform the corresponding operation through an indicator transmitted via D2R data.

[0109] A-IoT Msg2 If window delay is not performed T start = T reference + T default + z*T window T calculated as follows start From T window Assuming the A-IoT Msg2 window is set for a duration, if the A-IoT Msg2 window delay is performed, T start = T refernce + T default + (z+z')Twindow T calculated as follows start From T window An A-IoT Msg2 window can be set for a specified duration. In this case, z' can be configured such that it includes information about the corresponding value when the device sends an A-IoT Msg1 to the reader, or when the reader sends an A-IoT paging message to the device. Alternatively, separate signaling may be avoided by using a pre-fixed / defined value. If the device first requests an A-IoT Msg2 window delay, the A-IoT Msg2 window delay may be performed according to the above method, and the specific circumstances (conditions) under which the operation occurs are not limited to this example. window In addition, T is another value that can reduce overlap between different windows. window It may be used instead, and this is not limited to these examples. Even if the device does not request an A-IoT Msg2 window delay, if the device detects Msg2 within the initially configured A-IoT Msg2 window but fails to receive Msg2 data due to reasons such as a CRC error, the device may attempt to detect Msg2 again in a delayed A-IoT Msg2 window. In this case, z' may be transmitted by the reader to the device via an A-IoT paging message or may use a pre-fixed / defined value, and the A-IoT paging message may also indicate whether the device attempts to re-detect the A-IoT Msg2 in a delayed window when Msg2 detection was successful but decoding failed. The A-IoT paging message may include an instruction regarding whether the device attempts to re-detect the A-IoT Msg2 in a delayed window when Msg2 detection was successful but decoding failed.

[0110] Example 5: Method for setting Windows start time when having different reference times

[0111] FIG. 6 shows different reference times (T) for each device according to an embodiment of the present disclosure. reference When ) can be had, different A-IoT Msg2 window start times per device (T start This illustrates an example of setting ). In this embodiment, the monitoring window for receiving A-IoT Msg2 is T, which is a reference time that can be used individually between devices performing a random access procedure. reference It is assumed that it can be calculated based on .

[0112] Referring to FIG. 6, the start time T of window #1 (610) start,#1 (603) is T reference,#1 T based on (601) default (607) and T offset (605) may correspond to a later time (i.e., T start, #1 = T reference, #1 +T default +T offset ). Start time T of Windows #2 (611) start,#2 (604) is T reference, #2 T based on (602) default (607) and T offset (606) may correspond to a later time (i.e., T start, #2 = T reference, #2 +T default +T offset ).

[0113] At this time, T reference,#1 (601) and T reference, #2 (602) may be a reference time that can be set differently among devices that have received the same random access trigger R2D transmission, such as the time when the transmission of the A-IoT Msg1 transmitted by the device has ended. However, the scope of application of the present disclosure is not limited thereto.

[0114] T default(607, 608) may be the same or different for each device and may be a value for correcting a timing offset that may occur in an Ambient IoT system, which is an asynchronous system. The value may be transmitted to the device by the reader in advance, or pre-set within the device, and may be set to 0 as needed.

[0115] T offset (605, 606) is a value that can be determined identically for each device, for example, T offset =L*T window It can be calculated as follows (L is an integer greater than or equal to 1). In this case, T window is the length of the A-IoT Msg2 monitoring window, which may not require separate signaling as it is a value instructed by the reader to the device via A-IoT paging or pre-agreed upon between the device and the reader. However, the scope of application of the present disclosure is not limited thereto, and other time lengths other than those where overlapping areas between windows may not occur are also T window It can be applied in place of. For example, a multiple of the length of the shortest signal segment used in a D2R or R2D signal may be used. For example, in an R2D transmission, it may be a multiple of the chip length of a signal such as a preamble or a signal used in the subsequent data part. Here, the chip (chip length) may be the minimum time length constituting the modulated signal. For example, it may be a multiple of the sample length used in the device. For example, it may be a multiple of the length of the timer used in the device. Such T offsetThe value may be a value instructed by the reader to the device via A-IoT paging or a value agreed upon in advance. In this case, the L value may be a value agreed upon in advance between the device and the reader, or a value instructed by the reader to the device via A-IoT paging. The L value may be considered to be sufficiently large so that no overlap issues between windows occur during the process of distinguishing different windows.

[0116] Example 6: Method for setting window length

[0117] T according to at least one of the above embodiments start ul T window When calculating by referencing a fixed time unit such as, this time unit can be set in the following ways. This may be a value directly instructed by the reader to the device via A-IoT paging. It may also be set by instructing an index (e.g., a row / column index of the table) for that value based on a value pre-set in a table (a predefined / configured table; a table pre-defined to contain values ​​for the corresponding time unit). Alternatively, this value may be T instructed by the reader to the device via A-IoT paging window Indicates one or more of various transmission parameters that can determine, for example, the Msg2 message length, the chip length used for Msg2 transmission, the CRC length used for Msg2 transmission, and the length of the guard interval, and the reader and device refer to these transmission parameters to T window Calculate T startThese values ​​can be referenced in calculations. Alternatively, these values ​​may be multiples of the shortest or longest signal length within the signal used in the R2D or D2R parts. For example, various values ​​or multiples thereof may be considered, such as the chip length used in the start indicator or clock-acquisition part within R2D, the sample length used in D2R transmission, and the time length of a timer that can operate within the device, and are not limited to these examples. Alternatively, the window length may be determined by setting a default value between the device and the reader and additionally specifying an offset value. The default value may not require separate signaling, either by the reader jointly indicating it to the device via A-IoT paging or by using a pre-fixed value.

[0118] In the above embodiment, there may be one or multiple occasions for attempting actual detection within the A-IoT Msg2 window, and this may vary depending on the implementation method. The device may attempt detection only once within the window, or it may attempt detection repeatedly at multiple occasions. Additionally, after detecting the start-indicator within the window, the device may initiate signal reception based on this. Although the above embodiment describes a method for setting different A-IoT Msg2 windows between different devices, if different devices generate the same random ID and transmit it to the reader, or if different devices transmit it to the reader through the same A-IoT Msg1 transmission resource, the same A-IoT Msg2 window may be set between different devices. In this case, to distinguish between different devices, upper-layer information additionally transmitted in the A-IoT Msg1 or at least one piece of information included in the A-IoT Msg1 may be referenced. In the above embodiment, different devices can be described as different device groups.

[0119] In the above embodiment, a separate time interval between different A-IoT Msg2 windows was not described, but in actual implementation, a time interval to distinguish the windows may be considered.

[0120] For more specific details regarding the operation of the reader / device according to one embodiment of the present disclosure described above, refer to the description of one embodiment of the present disclosure described above.

[0121] FIG. 7 is a diagram showing the structure of a device in a wireless communication system according to one embodiment of the present disclosure.

[0122] Referring to FIG. 7, the device may include a transceiver (700, 706) referring to a device receiver (700) and a device transmitter (706), a memory (704), and a device processing unit (703, or a device control unit or processor). Additionally, in the case of a low-power device, it may include an energy collection unit (701) and an energy storage unit (702) to support energy harvesting. When the device receives a CW transmitted from the outside and generates a D2R signal by reflecting it, a backscattering unit (705) required for backscattering may be included in the device. If the device directly generates a signal internally and generates a D2R signal through it, the corresponding unit may not be included in the device. Depending on the communication method of the device described above, the device transmitter (706), receiver (700), energy collection unit (701), energy storage unit (702), backscattering unit (705), memory (704), and device processing unit (703) may operate. The above device processing unit (703, or processor) can control the operation of the device according to each of the above embodiments as well as a combination of at least one embodiment.

[0123] However, the components of the device are not limited to the examples described above. For instance, the device may include more or fewer components than those described above. Furthermore, the transceiver, memory, and processor may be implemented as a single chip.

[0124] The transceiver can transmit and receive signals with a reader. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts its frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0125] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0126] Memory can store programs and data necessary for the operation of the device. Additionally, memory can store control information or data included in signals transmitted and received by the device. Memory can be composed of storage media or combinations of storage media, such as ROM, RAM, hard disks, CD-ROMs, and DVDs. Additionally, there may be multiple memory units.

[0127] In addition, the processor can control a series of processes to enable the device to operate according to the aforementioned embodiment. For example, there may be multiple processors, and the processors can perform component control operations of the device by executing a program stored in memory.

[0128] FIG. 8 is a diagram showing the structure of a reader in a wireless communication system according to one embodiment of the present disclosure. The reader may be a device designed exclusively for a base station, terminal, or low-power communication device in a wireless communication system.

[0129] Referring to FIG. 8, the reader may include a transceiver unit referring to a reader receiver (800) and a reader transmitter (802), a memory (not shown), and a reader processing unit (801, or reader control unit or processor). According to the communication method of the reader described above, the transceiver unit (800, 802), memory, and reader processing unit (801) of the reader may operate. The reader processing unit (801, or processor) may control the operation of the reader according to each of the embodiments described above, as well as a combination of at least one embodiment. However, the components of the reader are not limited to the examples described above. For example, the reader may include more components or fewer components than the components described above. Furthermore, the transceiver unit, memory, and processor may be implemented in the form of a single chip.

[0130] The transceiver can transmit and receive signals with a device. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts its frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0131] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0132] The memory can store programs and data necessary for the operation of the reader. Additionally, the memory can store control information or data included in signals transmitted and received by the reader. The memory may be composed of storage media or combinations of storage media, such as ROM, RAM, hard disks, CD-ROMs, and DVDs. Additionally, there may be multiple memories.

[0133] The processor can control a series of processes to enable the reader to operate according to the embodiments of the present disclosure described above. There may be multiple processors, and the processors can perform component control operations of the reader by executing a program stored in memory.

[0134] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0135] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.

[0136] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0137] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0138] In the specific embodiments of the present disclosure described above, the components included in the embodiments are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0139] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated together as needed.

Claims

1. A method performed by a device in an A-IoT (ambient internet of things) system, Step of identifying information on random access occasions; A step of identifying a plurality of random access opportunities based on the above random access opportunity information, and defining a mapping relationship between the plurality of random access opportunities and a plurality of monitoring windows for monitoring message 2 for the random access procedure; A step of transmitting a message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and A method comprising the step of monitoring message 2 within a monitoring window mapped to a random access opportunity where message 1 was transmitted, among the plurality of monitoring windows.

2. In Paragraph 1, The above plurality of random access opportunities correspond to a plurality of random access opportunity indices, and The above plurality of monitoring windows correspond to a plurality of monitoring window indices, and The above mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), and i is a random access opportunity index among the plurality of random access opportunity indices mentioned above, and z is a monitoring window index among the plurality of monitoring window indices mentioned above, and Z is the maximum number of the plurality of monitoring windows, method.

3. In Paragraph 2, A method wherein the plurality of random access opportunity indices are assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

4. In Paragraph 1, A method in which the plurality of monitoring windows are determined based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

5. In a device of an A-IoT (ambient internet of things) system, Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: Identify random access occasion information; Based on the above random access opportunity information, a plurality of random access opportunities are identified, and a mapping relationship is defined between the plurality of random access opportunities and a plurality of monitoring windows for monitoring message 2 for the random access procedure; Transmitting message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and A device configured to monitor Message 2 within a monitoring window mapped to a random access opportunity in which Message 1 was transmitted, among the plurality of monitoring windows.

6. In Paragraph 5, The above plurality of random access opportunities correspond to a plurality of random access opportunity indices, and The above plurality of monitoring windows correspond to a plurality of monitoring window indices, and The above mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), and i is a random access opportunity index among the plurality of random access opportunity indices mentioned above, and z is a monitoring window index among the plurality of monitoring window indices mentioned above, and Z is a device, which is the maximum number of the plurality of monitoring windows mentioned above.

7. In Paragraph 2, A device wherein the plurality of random access opportunity indices are assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

8. In Paragraph 5, A device in which the plurality of monitoring windows are determined based on a predefined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

9. In a method performed by a leader in an A-IoT (ambient internet of things) system, A step of identifying a plurality of random access opportunities, defining a mapping relationship between the plurality of random access opportunities and a plurality of monitoring windows for message 2 for the random access procedure; A step of receiving a message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and A method comprising the step of transmitting the message 2 within a monitoring window mapped to a random access opportunity in which the message 1 was transmitted, among the plurality of monitoring windows.

10. In Paragraph 9, The above plurality of random access opportunities correspond to a plurality of random access opportunity indices, and The above plurality of monitoring windows correspond to a plurality of monitoring window indices, and The above mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), and i is a random access opportunity index among the plurality of random access opportunity indices mentioned above, and z is a monitoring window index among the plurality of monitoring window indices mentioned above, and Z is the maximum number of the above-mentioned multiple monitoring windows, and A method wherein the plurality of random access opportunity indices are assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

11. In Paragraph 9, A method in which the plurality of monitoring windows are based on a predetermined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time.

12. As a leader in A-IoT (ambient internet of things) systems, Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: A plurality of random access opportunities are identified, and a mapping relationship is defined between the plurality of random access opportunities and a plurality of monitoring windows for message 2 for the random access procedure; Receiving message 1 for the random access procedure based on a random access opportunity among the plurality of random access opportunities; and A reader configured to transmit the message 2 within a monitoring window mapped to a random access opportunity in which the message 1 was transmitted, among the plurality of monitoring windows.

13. In Paragraph 12, The above plurality of random access opportunities correspond to a plurality of random access opportunity indices, and The above plurality of monitoring windows correspond to a plurality of monitoring window indices, and The above mapping relationship is defined based on z=mod (i, Z) or based on z=interleaver(mod(i, Z)), and i is a random access opportunity index among the plurality of random access opportunity indices mentioned above, and z is a monitoring window index among the plurality of monitoring window indices mentioned above, and Z is the maximum number of the aforementioned multiple monitoring windows, a reader.

14. In Paragraph 13, A reader in which the plurality of random access opportunity indices are assigned based on a time-first manner for the plurality of random access opportunities, assigned based on a frequency-first manner for the plurality of random access opportunities, assigned based on a time domain for the plurality of random access opportunities, or assigned based on a frequency domain for the plurality of random access opportunities.

15. In Paragraph 12, The above-mentioned plurality of monitoring windows are based on a predefined or set reference time, a default offset based on the reference time, and a plurality of offsets based on a time after the default offset from the reference time, a reader.

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