Method and apparatus for communicating with a device having limited availability in a wireless communication system

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. methods and apparatuses for communicating with a device having limited availability in a wireless communication system. A method performed by an Ambient Internet of Things (A-IoT) device comprises, receiving, in a first interval, from a reader, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device, receiving, from the reader, a second R2D message, identifying whether to transmit to the reader a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the reception of the second R2D message. The method further includes, based on the identification, transmitting, to the reader, the first PDRCH, or receiving, from the reader, a third R2D message, the third R2D message including the same content as the second R2D message.

Description

METHOD AND APPARATUS FOR COMMUNICATING WITH A DEVICE HAVING LIMITED AVAILABILITY IN A WIRELESS COMMUNICATION SYSTEM

[0001] The present disclosure relates generally to wireless communication systems and, more specifically, the present disclosure is related to methods and apparatuses for communicating with a device having limited availability in a wireless communication system.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The present disclosure relates generally to wireless communication systems. More specifically, the present disclosure relates to method and apparatus for communicating with a device having limited availability in a wireless communication system

[0009] According to an embodiment of the present disclosure, a method performed by an Ambient Internet of Things (A-IoT) device comprises, receiving, in a first interval, from a reader, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device, receiving, from the reader, a second R2D message, identifying whether to transmit to the reader a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the reception of the second R2D message, and based on the identification, transmitting, to the reader, the first PDRCH, or receiving, from the reader, a third R2D message, the third R2D message including the same content as the second R2D message.

[0010] According to an embodiment of the present disclosure, an Ambient Internet of Things (A-IoT) device comprises, at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the A-IoT device to, receive, in a first interval, from a reader, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device, receive, from the reader, a second R2D message, identify whether to transmit to the reader a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the reception of the second R2D message, and based on the identification, transmit, to the reader, the first PDRCH, or receive, from the reader, a third R2D message, the third R2D message including the same content as the second R2D message.

[0011] According to an embodiment of the present disclosure, a method performed by a reader comprises, transmitting, in a first interval, to an Ambient Internet of Things (A-IoT) device, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device, transmitting, to the A-IoT device, a second R2D message, receiving, from the A-IoT device a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the transmission of the second R2D message, and transmitting, to the A-IoT device, a third R2D message, the third R2D message including the same content as the second R2D message.

[0012] According to an embodiment of the present disclosure, a reader comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the reader to, transmit, in a first interval, to an Ambient Internet of Things (A-IoT) device, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device, transmit, to the A-IoT device, a second R2D message, receive, from the A-IoT device a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the transmission of the second R2D message, and transmit, to the A-IoT device, a third R2D message, the third R2D message including the same content as the second R2D message.

[0013] Aspects of the present disclosure provide efficient communication methods in a wireless communication system.

[0014] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

[0015] FIG. 1 illustrates an example wireless network according to embodiments of the present disclosure;

[0016] FIG. 2 illustrates an example gNodeB (gNB) according to embodiments of the present disclosure;

[0017] FIG. 3 illustrates an example user equipment (UE) according to embodiments of the present disclosure;

[0018] FIGS. 4A and 4B illustrate an example of a wireless transmit and receive paths according to embodiments of the present disclosure;

[0019] FIG. 5 illustrates an example of a transmitter structure using orthogonal frequency division multiplexing (OFDM) according to embodiments of the present disclosure;

[0020] FIG. 6 illustrates an example of a receiver structure using OFDM according to embodiments of the present disclosure;

[0021] FIG. 7 illustrates an example encoding structure for a downlink control information (DCI) format according to embodiments of the present disclosure;

[0022] FIG. 8 illustrates an example decoding structure for a downlink control information (DCI) format according to embodiments of the present disclosure;

[0023] FIG. 9 illustrates a diagram of an example type-1 backscatter structure for IoT devices according to embodiments of the present disclosure;

[0024] FIG. 10 illustrates a diagram of an example impedance matching circuit according to embodiments of the present disclosure;

[0025] FIG. 11 illustrates a diagram of an example type-2a backscatter structure for IoT devices according to embodiments of the present disclosure;

[0026] FIG. 12 illustrates a diagram of an example type-2a backscatter structure for IoT devices according to embodiments of the present disclosure;

[0027] FIG. 13 illustrates a diagram of an example type-2a backscatter structure for IoT devices according to embodiments of the present disclosure;

[0028] FIG. 14 illustrates a diagram of an example type-2b active structure for IoT devices according to embodiments of the present disclosure;

[0029] FIG. 15 illustrates a diagram of an example type-2b active structure for IoT devices according to embodiments of the present disclosure;

[0030] FIG. 16 illustrates a diagram of an example type-2b active structure for IoT devices according to embodiments of the present disclosure;

[0031] FIG. 17 illustrates an example system for device to reader (D2R) / reader to device (R2D) transmission involving an intermediate node according to embodiments of the present disclosure;

[0032] FIG. 18 illustrates example signal structures for ambient IoT (A-IoT) systems according to embodiments of the present disclosure;

[0033] FIG. 19 illustrates a timeline for an example sequential identification process according to embodiments of the present disclosure;

[0034] FIG. 20 illustrates a flowchart of an example device procedure for performing random access according to embodiments of the present disclosure;

[0035] FIG. 21 illustrates a timeline of an example multiplexed identification process according to embodiments of the present disclosure;

[0036] FIG. 22 illustrates a flowchart of an example device procedure for monitoring R2D transmission(s) according to embodiments of the present disclosure;

[0037] FIG. 23 illustrates a flowchart of an example device procedure for performing random access with dormancy according to embodiments of the present disclosure;

[0038] FIG. 24 illustrates a timeline of an example D2R transmission following a R2D transmission according to embodiments of the present disclosure;

[0039] FIG. 25 illustrates a flowchart of an example device procedure for transmitting an energy status report according to embodiments of the present disclosure;

[0040] FIG. 26 illustrates a flowchart of an example device procedure for transmitting an energy status report according to embodiments of the present disclosure;

[0041] FIG. 27 illustrates a timeline of an example R2D transmission following a R2D transmission according to embodiments of the present disclosure;

[0042] FIG. 28 illustrates a flowchart of an example device procedure for transmitting an energy status report according to embodiments of the present disclosure;

[0043] FIG. 29 illustrates a timeline of an example D2R transmission following a D2R transmission according to embodiments of the present disclosure; and

[0044] FIG. 30 illustrates a flowchart of an example device procedure for transmitting an energy status report according to embodiments of the present disclosure.

[0045] FIG. 31 is a block diagram of a terminal or user equipment (UE) according to an embodiment of the disclosure;

[0046] FIG. 32 is a block diagram of a base station (BS) according to an embodiment of the disclosure; and

[0047] FIG. 33 is a block diagram of a network entity according to an embodiment of the disclosure.

[0048] The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 695,977 filed on September 18, 2024, and U.S. Non-Provisional Patent Application No. 63 / 695,977, which are hereby incorporated by reference in theirs entirety.

[0049] Wireless communication has been one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services exceeded five billion and continues to grow quickly. The demand of wireless data traffic is rapidly increasing due to the growing popularity among consumers and businesses of smart phones and other mobile data devices, such as tablets, “note pad” computers, net books, eBook readers, and machine type of devices. In order to meet the high growth in mobile data traffic and support new applications and deployments, improvements in radio interface efficiency and coverage are of paramount importance. To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, and to enable various vertical applications, 5G communication systems have been developed and are currently being deployed.

[0050] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0051] In describing the embodiments, descriptions related to technical contents well-known in the art and not associated directly with the disclosure will be omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.

[0052] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or schematically illustrated. Further, the size of each element does not completely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals or different reference numerals.

[0053] The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to completely disclose the disclosure and inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the appended claims. Throughout the specification, the same or like reference numerals designate the same or like elements. Furthermore, in describing the disclosure, a detailed description of known functions or constitution incorporated herein will be omitted in the case that it is determined that the description may make the subject matter of the disclosure unnecessarily unclear. The terms which will be described below are terms defined in consideration of the functions in the disclosure, and may be different according to users, intentions of the operators, or customs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

[0054] Herein, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, may be performed based on computer program instructions. These computer program instructions may be loaded collectively onto at least one processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which perform through any one of, or in any combination of, the at least one processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a non-transitory computer usable or computer-readable memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that perform the function specified in the flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to produce a computer executed process such that the instructions that perform on the computer or other programmable data processing apparatus provide steps for executing the functions specified in the flowchart block(s).

[0055] Further, each block may represent a module, segment, or portion of code, which includes one or more executable instructions for executing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks(or functions) shown in succession may in fact be performed substantially concurrently or the blocks may sometimes be performed in the reverse order, depending upon the functionality involved.

[0056] As used in embodiments of the disclosure, a “~unit” may refer to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs a predetermined function. However, the term including the word “~unit” does not always have a meaning limited to software or hardware. The “~unit” may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the “~unit” includes, for example, software elements, object-oriented software elements, components such as class elements and task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The components and functions provided by the “~unit” may be either combined into a smaller number of components and a “~unit,” or divided into additional components and a “~unit.” Moreover, the components and “~units” may be implemented to reproduce one or more central processing units (CPUs) within a device or a security multimedia card. Further, in the embodiments, the “~unit” may include one or more processors.

[0057] It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

[0058] Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g. a CPU), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display driver integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

[0059] It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

[0060] Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device individually or collectively, cause the electronic device to perform a method of the disclosure.

[0061] Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

[0062] Hereinafter, the determination of priority between A and B in the present disclosure may refer to various actions such as selecting the one having a higher priority based on a predefined priority rule and performing an operation corresponding thereto, or omitting or dropping an operation corresponding to the one having a lower priority.

[0063] Hereinafter, "A or B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0064] In addition, "at least one of A, B, and C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0065] In addition, "at least one of A, B, or C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0066] Furthermore, "A / B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0067] Furthermore, "A, B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0068] Furthermore, "A and B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0069] Furthermore, “if condition A and condition B are satisfied,” as described in the present disclosure, may not be limited to a case where both condition A and condition B are satisfied, but may be understood to include a case where either condition A or condition B is individually satisfied, both condition A and condition B are satisfied, or one or more additional conditions are satisfied in combination.

[0070] Furthermore, throughout this disclosure, ordinal terms such as "first," "second," "third," etc., (and similar qualifiers) are used merely to distinguish between different instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information as described herein. Unless the context clearly dictates otherwise, the use of such ordinal terms does not itself require that the elements, operations, or information distinguished by these terms be structurally different, numerically distinct, or substantively dissimilar. For example, a "first signal" and a "second signal" may refer to instances of the same signal transmitted at different times or containing the same core information despite minor variations, or they may refer to signals with different content or characteristics, depending on the specific context. Similarly, a "first value" and a "second value" may represent the same magnitude but measured or applied in different circumstances, or they may represent different magnitudes. The interpretation should be guided by the specific technical context, function, and relationship described in the relevant portion of the specification and claims.

[0071] Furthermore, the terms “first ~”, “second ~”, etc., as described in the present disclosure with respect to various elements (e.g., information, objects, operation, sequences, or the like), should not limit those elements. These terms may only be intended to distinguish one element from another, and may not be intended to indicate a specific order. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element.

[0072] Furthermore, even if “first ~” and “second ~” are described in the present disclosure, it may be understood that element(s) referred to by “first ~” and “second ~” may be the same or different. For example, in case of element(s) being information, first information and second information may both be same information and, in some cases, are separate and different information.

[0073] In addition, the terms “if ~” and “in case that ~” as used in the disclosure or claims may be interpreted to include the meanings of “when (or upon) ~,” “in response to ~,” “based on ~,” or “according to ~,” and may be used interchangeably with these expressions. In addition, expressions other than those exemplified herein may also be used, as long as they have substantially the same meaning and do not impair the technical features of the present disclosure.

[0074] For example, the physical layer signaling may be referred to as Layer 1 (L1) signaling and may include downlink control information (DCI). In addition, the higher layer signaling may include a medium access control (MAC) control message, a radio resource control (RRC) signaling message, a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling. It should be noted, however, that the higher layer signaling is not limited to the aforementioned examples.

[0075] In addition, the term "not perform" as used in the present disclosure or claims may, in context, be understood to mean that the corresponding step is omitted or skipped. Such a term may be replaced with other terms having the same or substantially equivalent meaning.

[0076] In addition, "transmitting a message including A and B" as described in the present disclosure, may be understood as encompassing both (i) transmitting A and B in a single message, and (ii) transmitting A and B separately via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply to messages that include two or more items (e.g., A, B, C), transmitted either together or separately.

[0077] In addition, "transmitting a message including A and transmitting a message including B" may also be interpreted as transmitting a message including A and B in a single message.

[0078] In the specific embodiments of the present disclosure described below, terms or components included in the disclosure may be expressed in singular or plural form depending on the specific embodiments presented. However, such singular or plural expressions are selected appropriately for convenience of description, and the present disclosure is not limited to a singular or plural number of components. A component expressed in the plural form may be implemented as a single component, and a component expressed in the singular form may be implemented as multiple components.

[0079] The drawings or flowcharts described below illustrate exemplary methods that may be implemented according to the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts of the present disclosure. For example, although illustrated as a series of steps, various steps in each drawing or flowchart may overlap, occur in parallel, occur in a different order, or be repeated. In other examples, any step may be omitted or replaced with another step.

[0080] The methods and apparatuses proposed in the embodiments of the present disclosure are not limited to each embodiment individually, but may also be applied in combination of all or some of the embodiments proposed in the disclosure. Therefore, the embodiments of the present disclosure may be modified and applied without significantly departing from the scope of the present disclosure, as would be understood by those skilled in the art.

[0081] In this case, even if certain wordings are described differently across embodiments, they may be used interchangeably or in substitution or in combination if their underlying concepts are equivalent. For example, for the same or equivalent concept, even if one embodiment uses the expression "A" and another embodiment uses the expression "B", such expressions may be understood interchangeably, in substitution, or in combination.

[0082] The terms used in the following description to refer to access nodes, network entities, messages, interfaces between network entities, various types of identification information, and the like, are provided merely for the convenience of explanation by way of example. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may also be used. Such terms may also be interchangeable with terms defined in any 3rd generation partnership project　(3GPP) technical specifications (TS) where appropriate.

[0083] Hereinafter, a base station is an entity that allocates resources to terminals, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a BS controller, or a node on a network.

[0084] Furthermore, the base station of the present disclosure may include a split architecture comprising a central unit (CU) and a distributed unit (DU). In this structure, the CU is configured to process the higher layers of the control and user planes, while the DU is configured to process lower-layer radio resource functions. The embodiments of the present disclosure may be equally applicable to 5G base station architectures in which such CU and DU functional splits are implemented.

[0085] A terminal may include a UE, a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions.

[0086] In the disclosure, a downlink (DL) refers to a radio link through which a BS transmits a signal to a UE, and an uplink (UL) refers to a radio link through which a UE transmits a signal to a BS.

[0087] Furthermore, hereinafter, 5th generation (5G) mobile communication technologies (e.g., 5G new radio (NR)), 6th generation (6G) mobile communication technologies may be described by way of example, but the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, newly evolved mobile communication systems developed after 5G and 6G may be included. Furthermore, based on determinations by those skilled in the art, the embodiments of the present disclosure may also be applied to other communication systems (e.g., Wi-Fi systems) through some modifications without significantly departing from the scope of the present disclosure

[0088] In the following description, the terms physical channel and signal may be used interchangeably with data or control signal. For example, the term physical downlink shared channel (PDSCH) refers to a physical channel through which data is transmitted, but the term PDSCH may also be used to refer to the data itself. That is, in the present disclosure, the expression "transmit a physical channel" may be interpreted as being equivalent to the expression "transmit data or a signal via a physical channel."

[0089] Hereinafter, in the context of the present disclosure, higher layer signaling may refer to signaling corresponding to at least one or any combination of the following: master information block (MIB), system information block (SIB) or SIB M (M = 1, 2, ...), radio resource control (RRC), or medium access control (MAC) control element (CE), or a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling.

[0090] In addition, L1 signaling may refer to signaling corresponding to at least one or any combination of signaling techniques using the at least one or any combination of the following physical layer channels or signaling: physical downlink control channel (PDCCH), downlink control information (DCI), user equipment (UE)-specific DCI, group-common DCI, common DCI, scheduling DCI (e.g., DCI used for scheduling downlink or uplink data), non-scheduling DCI (e.g., DCI not used for scheduling downlink or uplink data) physical uplink control channel (PUCCH), or uplink control information (UCI). The L1 signaling message may be referred to as a physical layer signaling.

[0091] Hereinafter, the expression that information is configured by the BS, as used in the present disclosure or claims, may, in context, be understood to mean that the terminal receives the corresponding information from the BS via a physical layer signaling or a higher layer signaling. Such an expression may be replaced with other terms having the same or substantially equivalent meaning.

[0092] Hereinafter, the operational principle of the present disclosure will be described in detail with reference to the accompanying drawings.

[0093] FIGS. 1-33, discussed below, and the various, non-limiting embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device.

[0094] To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. The 5G / NR communication system is implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60GHz bands, so as to accomplish higher data rates or in lower frequency bands, such as 6 GHz, to enable robust coverage and mobility support. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G / NR communication systems.

[0095] In addition, in 5G / NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancelation, radio access technology (RAT)-dependent positioning and the like.

[0096] The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems, or the frequency bands associated therewith, and embodiments of the present disclosure may be utilized in connection with any frequency band. For example, aspects of the present disclosure may also be applied to deployment of 5G communication systems, 6G or even later releases which may use terahertz (THz) bands.

[0097] The following documents and standards descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: [REF 1] 3GPP TS 38.211 v18.3.0, “NR; Physical channels and modulation;” [REF 2] 3GPP TS 38.212 v18.3.0, “NR; Multiplexing and channel coding;” [REF 3] 3GPP TS 38.213 v18.3.0, “NR; Physical layer procedures for control;” [REF 4] 3GPP TS 38.214 v18.3.0, “NR; Physical layer procedures for data;” [REF 5] 3GPP TS 38.331 v18.1.0, “NR; Radio Resource Control (RRC) protocol specification;” and [REF 6] 3GPP TS 38.321 v18.1.0, “NR; Medium Access Control (MAC) protocol specification.”

[0098] FIGS. 1-3 below describe various embodiments implemented in wireless communications systems and with the use of OFDM or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions of FIGS. 1-3 are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably arranged communications system.

[0099] FIG. 1 illustrates an example wireless network 100 according to embodiments of the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 could be used without departing from the scope of this disclosure.

[0100] As shown in FIG. 1, the wireless network 100 includes a gNB 101 (e.g., base station, BS), a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0101] The gNB 102 provides wireless broadband access to the network 130 for a first plurality of user equipments (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes a UE 111, which may be located in a small business; a UE 112, which may be located in an enterprise; a UE 113, which may be a WiFi hotspot; a UE 114, which may be located in a first residence; a UE 115, which may be located in a second residence; and a UE 116, which may be a mobile device, such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB 103 provides wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs includes the UE 115 and the UE 116. In some embodiments, one or more of the gNBs 101-103 may communicate with each other and with the UEs 111-116 using 5G / NR, long term evolution (LTE), long term evolution-advanced (LTE-A), WiMAX, WiFi, or other wireless communication techniques.

[0102] Depending on the network type, the term “base station” or “BS” can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G / NR 3rd generation partnership project (3GPP) NR, long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For the sake of convenience, the terms “BS” and “TRP” are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term “user equipment” or “UE” can refer to any component such as “mobile station,” “subscriber station,” “remote terminal,” “wireless terminal,” “receive point,” or “user device.” For the sake of convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

[0103] The dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions.

[0104] As described in more detail below, one or more of the UEs 111-116 include circuitry, programing, or a combination thereof for communicating as a device having limited availability. In certain embodiments, one or more of the gNBs 101-103 include circuitry, programing, or a combination thereof to provide for communicating with a device having limited availability.

[0105] Although FIG. 1 illustrates one example of a wireless network, various changes may be made to FIG. 1. For example, the wireless network 100 could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB 101 could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 could communicate directly with the network 130 and provide UEs with direct wireless broadband access to the network 130. Further, the gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0106] FIG. 2 illustrates an example gNB 102 according to embodiments of the present disclosure. The embodiment of the gNB 102 illustrated in FIG. 2 is for illustration only, and the gNBs 101 and 103 of FIG. 1 could have the same or similar configuration. However, gNBs come in a wide variety of configurations, and FIG. 2 does not limit the scope of this disclosure to any particular implementation of a gNB.

[0107] As shown in FIG. 2, the gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0108] The transceivers 210a-210n receive, from the antennas 205a-205n, incoming radio frequency (RF) signals, such as signals transmitted by UEs in the wireless network 100. The transceivers 210a-210n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0109] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225 receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. The transceivers 210a-210n up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 205a-205n.

[0110] The controller / processor 225 can include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 could control the reception of uplink (UL) channel signals and the transmission of downlink (DL) channel signals by the transceivers 210a-210n in accordance with well-known principles. The controller / processor 225 could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller / processor 225 could support beam forming or directional routing operations in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB 102 by the controller / processor 225.

[0111] The controller / processor 225 is also capable of executing programs and other processes resident in the memory 230, such as providing communication with a device having limited availability. The controller / processor 225 can move data into or out of the memory 230 as required by an executing process.

[0112] The controller / processor 225 is also coupled to the backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The backhaul or network interface 235 could support communications over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as one supporting 5G / NR, LTE, or LTE-A), the backhaul or network interface 235 could allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the backhaul or network interface 235 could allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The backhaul or network interface 235 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or transceiver.

[0113] The memory 230 is coupled to the controller / processor 225. Part of the memory 230 could include a RAM, and another part of the memory 230 could include a Flash memory or other ROM.

[0114] Although FIG. 2 illustrates one example of gNB 102, various changes may be made to FIG. 2. For example, the gNB 102 could include any number of each component shown in FIG. 2. Also, various components in FIG. 2 could be combined, further subdivided, or omitted and additional components could be added according to particular needs.

[0115] FIG. 3 illustrates an example UE 116 according to embodiments of the present disclosure. The embodiment of the UE 116 illustrated in FIG. 3 is for illustration only, and the UEs 111-115 of FIG. 1 could have the same or similar configuration. However, UEs come in a wide variety of configurations, and FIG. 3 does not limit the scope of this disclosure to any particular implementation of a UE.

[0116] As shown in FIG. 3, the UE　116 includes antenna(s) 305, a transceiver(s) 310, and a microphone 320. The UE　116 also includes a speaker 330, a processor 340, an input / output (I / O) interface 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0117] The transceiver(s) 310 receives from the antenna(s) 305, an incoming RF signal transmitted by a gNB of the wireless network 100. The transceiver(s) 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in the transceiver(s) 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry sends the processed baseband signal to the speaker 330 (such as for voice data) or is processed by the processor 340 (such as for web browsing data).

[0118] TX processing circuitry in the transceiver(s) 310 and / or processor 340 receives analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver(s) 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 305.

[0119] The processor 340 can include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the processor 340 could control the reception of DL channel signals and the transmission of UL channel signals by the transceiver(s) 310 in accordance with well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0120] The processor 340 is also capable of executing other processes and programs resident in the memory 360. For example, the processor 340 may execute processes to support communicating with a device having limited availability as described in embodiments of the present disclosure. The processor 340 can move data into or out of the memory 360 as required by an executing process. In some embodiments, the processor 340 is configured to execute the applications 362 based on the OS 361 or in response to signals received from gNBs or an operator. The processor 340 is also coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0121] The processor 340 is also coupled to the input 350, which includes, for example, a touchscreen, keypad, etc., and the display 355. The operator of the UE 116 can use the input 350 to enter data into the UE 116. The display 355 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0122] The memory 360 is coupled to the processor 340. Part of the memory 360 could include volatile memory such as a random-access memory (RAM), and another part of the memory 360 could include non-volatile memory a Flash memory or other read-only memory (ROM).

[0123] Although FIG. 3 illustrates one example of UE 116, various changes may be made to FIG. 3. For example, various components in FIG. 3 could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor 340 could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, the transceiver(s) 310 may include any number of transceivers and signal processing chains and may be connected to any number of antennas. Also, while FIG. 3 illustrates the UE 116 configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices.

[0124] FIG. 4A and FIG. 4B illustrate an example of wireless transmit and receive paths 400 and 450, respectively, according to embodiments of the present disclosure. For example, a transmit path 400 may be described as being implemented in a gNB (such as gNB 102), while a receive path 450 may be described as being implemented in a UE (such as UE 116). However, it will be understood that the receive path 450 can be implemented in a gNB and that the transmit path 400 can be implemented in a UE. In some embodiments, the transmit path 400 and / or the receive path 450 is configured for communicating with a device having limited availability as described in embodiments of the present disclosure.

[0125] As illustrated in FIG. 4A, the transmit path 400 includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, a size N Inverse Fast Fourier Transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, an add cyclic prefix block 425, and an up-converter (UC) 430. The receive path 450 includes a down-converter (DC) 455, a remove cyclic prefix block 460, a S-to-P block 465, a size N Fast Fourier Transform (FFT) block 470, a parallel-to-serial (P-to-S) block 475, and a channel decoding and demodulation block 480.

[0126] In the transmit path 400, the channel coding and modulation block 405 receives a set of information bits, applies coding (such as a low-density parity check (LDPC) coding), and modulates the input bits (such as with Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) to generate a sequence of frequency-domain modulation symbols. The serial-to-parallel block 410 converts (such as de-multiplexes) the serial modulated symbols to parallel data in order to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and the UE 116. The size N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 420 converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block 415 in order to generate a serial time-domain signal. The add cyclic prefix block 425 inserts a cyclic prefix to the time-domain signal. The up-converter 430 modulates (such as up-converts) the output of the add cyclic prefix block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at a baseband before conversion to the RF frequency.

[0127] As illustrated in FIG. 4B, the down-converter 455 down-converts the received signal to a baseband frequency, and the remove cyclic prefix block 460 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 465 converts the time-domain baseband signal to parallel time-domain signals. The size N FFT block 470 performs an FFT algorithm to generate N parallel frequency-domain signals. The (P-to-S) block 475 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates and decodes the modulated symbols to recover the original input data stream.

[0128] Each of the gNBs 101-103 may implement a transmit path 400 that is analogous to transmitting in the downlink to UEs 111-116 and may implement a receive path 450 that is analogous to receiving in the uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement a transmit path 400 for transmitting in the uplink to gNBs 101-103 and may implement a receive path 450 for receiving in the downlink from gNBs 101-103.

[0129] Each of the components in FIGS. 4A and 4B can be implemented using only hardware or using a combination of hardware and software / firmware. As a particular example, at least some of the components in FIGS. 4A and 4B may be implemented in software, while other components may be implemented by configurable hardware or a mixture of software and configurable hardware. For instance, the FFT block 470 and the IFFT block 415 may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation.

[0130] Furthermore, although described as using FFT and IFFT, this is by way of illustration only and should not be construed to limit the scope of this disclosure. Other types of transforms, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can be used. It will be appreciated that the value of the variable N may be any integer number (such as 1, 2, 3, 4, or the like) for DFT and IDFT functions, while the value of the variable N may be any integer number that is a power of two (such as 1, 2, 4, 8, 16, or the like) for FFT and IFFT functions.

[0131] Although FIGS. 4A and 4B illustrate examples of wireless transmit and receive paths 400 and 450, respectively, various changes may be made to FIGS. 4A and 4B. For example, various components in FIGS. 4A and 4B can be combined, further subdivided, or omitted and additional components can be added according to particular needs. Also, FIGS. 4A and 4B are meant to illustrate examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architectures can be used to support wireless communications in a wireless network.

[0132] Internet of things (IoT) devices include ambient-power-enabled IoT (A-IoT) devices, which are ultra-low-complexity devices with very small form factor and low-cost design that operate without a common battery that can be manually replaced or recharged. Instead, A-IoT devices can be battery-less or with a small battery (such as a small capacitor) that operate based on energy harvesting from RF waveforms or other ambient energy sources. Regarding the limited size and complexity required by practical applications for battery-less devices with no energy storage capability or devices with limited energy storage that do not need to be replaced or recharged manually, the output power of energy harvester is typically from 1μW to a few hundreds of μW.

[0133] In various embodiments throughout the disclosure, a UE (e.g., the UE 116) or a device may be referred to as an A-IoT device or an A-IoT UE based on energy harvesting with ultra-low complexity and power consumption and for low-end IoT applications. For example, the UE may have limited (or no) energy storage or battery capability (e.g., a capacitor), such as an energy storage unit for amplification of receptions at the UE or transmission by the UE, or for other UE operations, such as power-on, warm-up, memory, internal processing, and so on, or operating with backscattering communication.

[0134] An A-IoT device can be an IoT device that satisfies one or more of the following (or variations thereof):

[0135] - powered by energy harvesting, being either battery-less or with limited energy storage capability (e.g., using a capacitor) and the energy is provided through the harvesting of radio waves (including RF waveforms), light (including solar light or indoor light), motion, pressure, heat, or any other power source that could be seen suitable;

[0136] - with low complexity, small size and lower capabilities and lower power consumption than previously defined 3GPP IoT devices (e.g., NB-IoT / enhanced machine type communication (eMTC) devices);

[0137] - maintenance free and can have long life span (e.g., more than 10 years).

[0138] An A-IoT may directly communicate with a base station / gNB (e.g., the BS 102) (e.g., operating as a reader), or may indirectly communicate with a BS / gNB through an intermediate / assisting node, such as a handheld device / UE (for example, a “reader” UE that scans the A-IoT devices), a relay, integrated access and backhaul (IAB) node, a repeater for example a network-controlled repeater (NCR), and so on. The communication can be mono-static wherein the transmitter node to the A-IoT device is same as the receiving node from the A-IoT device, or can be bi-static (or multi-static) wherein the transmitter nodes to the A-IoT device can be different from the receiving nodes from the A-IoT device.

[0139] In various embodiments, the A-IoT device operates with energy storage and power management capability. These devices are characterized by ultra-low power consumption, and they employ energy harvesting mechanisms such as solar, RF energy and kinetic energy and thus don't require battery replacement or swapping frequently. In various embodiments, an A-IoT device operates with energy harvesting (EH) or with limited (or no) energy storage / battery capability (such as a capacitor), such as an energy storage unit for amplification of receptions at the UE (e.g., the UE 116) or transmission by the UE, or for other UE operations, such as power-on, warm-up, memory, internal processing, and so on, or operating with backscattering communication.

[0140] In various embodiments, the A-IoT device operates with RF envelope detection for receiving amplitude shift keying (ASK), e.g., OOK, modulated signal. RF envelope detection is a key function that enables the Ambient IoT devices to filter and analyze RF signals. This technique is applied in the reception of modulated RF signals with a view of acquiring information from the signals and hence enable communication between devices with efficiency and with minimum power consumption. RF envelope detection is one of the most important techniques that are used in many of the low power consumption wireless communication protocols that are employed in Ambient IoT systems.

[0141] In various embodiments, the A-IoT device may operate with impedance matching. Impedance matching may be utilized in passive Ambient IoT devices backscattering externally provisioned carrier wave (CW) signal.

[0142] The disclosure relates to defining functionalities and procedures for A-IoT device operations to communicate as a device having limited availability. DL and UL are also referred to as reader-to-device (R2D) and device-to-reader (D2R), respectively, and vice versa.

[0143] FIG. 5 illustrates an example of a transmitter structure 500 using OFDM according to embodiments of the present disclosure. For example, transmitter structure 500 using OFDM can be implemented in gNB 102 of FIG. 1. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0144] Information bits, such as DCI bits or data bits 510, are encoded by encoder 520, rate matched to assigned time / frequency resources by rate matcher 530, and modulated by modulator 540. Subsequently, modulated encoded symbols and demodulation reference signal (DM-RS) or channel state information reference signal (CSI-RS) 550 are mapped to REs 560, an inverse fast Fourier transform (IFFT) is performed by filter 570. A BW selector unit 565, a filter 580, a radio frequency (RF) amplifier 590, and transmitted signal 595 are also included.

[0145] FIG. 6 illustrates an example of a receiver structure 600 using OFDM according to embodiments of the present disclosure. For example, receiver structure 600 using OFDM can be implemented by any of the UEs 111-116 of FIG. 1. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0146] A received signal 610 is filtered by filter 620, a CP removal unit removes a CP 630, a filter 640 applies a fast Fourier transform (FFT), RE de-mapping unit 650 de-maps REs selected by BW selector unit 655, received symbols are demodulated by a channel estimator and a demodulator unit 660, a rate de-matcher 670 restores a rate matching, and a decoder 680 decodes the resulting bits to provide information bits 690.

[0147] With reference to FIG. 5, an example transmitter structure using OFDM according to this disclosure is shown.

[0148] With reference to FIG. 6, an example receiver structure using OFDM according to this disclosure is shown.

[0149] FIG. 7 illustrates an example encoding structure 700 for a downlink control information (DCI) format according to embodiments of the present disclosure. For example, encoding structure 700 can be implemented in gNB 102 of FIG. 1. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0150] A gNB separately encodes and transmits each DCI format in a respective physical downlink control channel (PDCCH). When applicable, a radio network temporary identifier (RNTI) for a UE (e.g., the UE 116) that a DCI format is intended for masks a cyclic redundancy check (CRC) of the DCI format codeword in order to enable the UE to identify the DCI format. For example, the CRC can include 24 bits and the RNTI can include 16 bits or 24 bits. The CRC of (non-coded) DCI format bits 710 is determined using a CRC computation unit 720, and the CRC is masked using an exclusive OR (XOR) operation unit 730 between CRC bits and RNTI bits 740. The XOR operation is defined as XOR(0,0) = 0, XOR(0,1) = 1, XOR(1,0) = 1, XOR(1,1) = 0. The masked CRC bits are appended to DCI format information bits using a CRC append unit 750. An encoder 760 performs channel coding, such as polar coding, followed by rate matching to allocated resources by rate matcher 770. Interleaving and modulation units 780 apply interleaving and modulation, such as QPSK, and the output control signal 790 is transmitted.

[0151] FIG. 8 illustrates an example decoding structure 800 for a DCI format according to embodiments of the present disclosure. For example, decoding structure 800 for a DCI format can be implemented by any of the UEs 111-116 of FIG. 1. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0152] A received control signal 810 is demodulated and de-interleaved by a demodulator and a de-interleaver 820. A rate matching applied at a gNB transmitter is restored by rate matcher 830, and resulting bits are decoded by decoder 840. After decoding, a CRC extractor 850 extracts CRC bits and provides DCI format information bits 860. The DCI format information bits are de-masked 870 by an XOR operation with a RNTI 880 (when applicable) and a CRC check is performed by unit 890. When the CRC check succeeds (check-sum is zero), the DCI format information bits are regarded to be valid. When the CRC check does not succeed, the DCI format information bits are regarded to be invalid.

[0153] With reference to FIG. 7, an example encoding process for a DCI format according to this disclosure is shown.

[0154] With reference to FIG. 8, an example decoding process for a DCI format for use with a UE according to this disclosure is shown.

[0155] It is envisaged that the number of connected devices will reach ~500 billion by 2030, which is about ~59 times larger than the expected world population (~8.5 billion) by that time. Mobile devices will take various form-factors, such as augmented reality (AR) glasses, virtual reality (VR) headsets, hologram devices, while a large portion of the devices will be Internet-of-Things (IoT) devices for improving productivity efficiency and increasing comforts of life. As the number of IoT devices grows exponentially, those IoT devices will become dominant in the next generation wireless communication systems such as fifth generation (5G) advanced, sixth generation (6G) systems, and so on.

[0156] With the explosive number of IoT devices, it may be challenging to power the IoT devices by battery that needs to be replaced or recharged manually, which leads to high maintenance cost. The automation and digitalization of various industries demand new IoT technologies of supporting batteryless devices with no energy storage capability or devices with energy storage that does not need to be replaced or recharged manually. Such types of devices are collectively termed as ambient IoT (A-IoT) in this disclosure, which is powered by various renewable energy sources such as radio waves, light, motion, or heat, etc. Use cases of A-IoT devices include asset inventory / tracking and remote environmental monitoring. The following list provides example use cases of A-IoT devices:

[0157] - Indoor inventory

[0158] -- Automated warehousing

[0159] -- Medical instruments inventory management and positioning

[0160] -- Non-Public Network for logistics

[0161] -- Automobile manufacturing

[0162] -- Airport terminal / shipping port

[0163] -- Smart laundry

[0164] -- Automated supply chain distribution

[0165] -- Fresh food supply chain

[0166] -- End-to-end logistics

[0167] -- Flower auction

[0168] -- Electronic shelf label

[0169] - Indoor sensor

[0170] -- Smart homes

[0171] -- Base station machine room environmental supervision

[0172] -- Smart laundry

[0173] -- Smart agriculture

[0174] -- Smart pig farm

[0175] -- Cow stable

[0176] - Indoor positioning

[0177] -- Finding Remote Lost Item

[0178] -- Location service

[0179] -- Ranging in a home

[0180] -- Personal belongings finding

[0181] -- Positioning in shopping center

[0182] -- Museum Guide

[0183] - Indoor command

[0184] -- Online modification of medical instruments status

[0185] -- Device activation and deactivation

[0186] -- Elderly Health Care

[0187] -- Device Permanent Deactivation

[0188] -- Electronic shelf label

[0189] - Outdoor inventory

[0190] -- Medical instruments inventory management and positioning

[0191] -- Non-public network for logistics

[0192] -- Airport terminal / shipping port

[0193] -- Automated supply chain distribution

[0194] - Outdoor sensor

[0195] -- Smart grids

[0196] -- Forest Fire Monitoring

[0197] -- Dairy farming

[0198] -- Smart manhole cover safety monitoring

[0199] -- Smart bridge health monitoring

[0200] - Outdoor positioning

[0201] -- Finding remote lost item

[0202] -- Location service

[0203] -- Personal belongings finding

[0204] - Outdoor command

[0205] -- Online modification of medical instruments status

[0206] -- Device activation and deactivation

[0207] -- Elderly Health Care

[0208] -- Controller in smart agriculture

[0209] Taking into account the limited size and low complexity required by practical applications of A-IoT devices, the output power of energy harvesting from ambient power sources is typically from 1μW to a few hundreds of μW, which is orders of magnitude lower than normal user equipment (UE) having peak power consumption higher than 10mW. This requires a new wireless access technology for A-IoT devices, which cannot be fulfilled by existing cellular systems including low-power IoT technologies such as NB-IoT and eMTC.

[0210] In the following, an italicized name for a parameter implies that the parameter is provided by higher layers.

[0211] DL (e.g., physical reader to device (R2D) channel (PRDCH)) transmissions or UL (e.g., PDRCH) transmissions can be based on an OFDM waveform including a variant using DFT precoding that is known as DFT-spread-OFDM that is typically applicable to UL transmissions.

[0212] In the following, subframe (SF) refers to a transmission time unit for the LTE RAT and slot refers to a transmission time unit for an NR RAT. For example, the slot duration can be a sub-multiple of the SF duration. NR can use a different DL or UL slot structure than an LTE SF structure. Differences can include a structure for transmitting physical downlink control channels (PDCCHs), locations and structure of demodulation reference signals (DM-RS), transmission duration, and so on. Further, eNB refers to a base station serving UEs operating with LTE RAT and gNB refers to a base station serving UEs operating with NR RAT. Exemplary embodiments provide a same numerology, that includes a sub-carrier spacing (SCS) configuration and a cyclic prefix (CP) length for an OFDM symbol, for transmission with LTE RAT and with NR RAT. In such case, OFDM symbols for the LTE RAT as same as for the NR RAT, a subframe is same as a slot and, for brevity, the term slot is subsequently used in the remaining of the disclosure.

[0213] A unit for DL signaling or for UL signaling on a cell is referred to as a slot and can include one or more symbols. A bandwidth (BW) unit is referred to as a resource block (RB). One RB includes a number of sub-carriers (SCs). For example, a slot can have duration of one millisecond and an RB can have a bandwidth of 180 kHz and include 12 SCs with inter-SC spacing of 15 kHz. A sub-carrier spacing (SCS) can be determined by a SCS configuration as kHz. A unit of one sub-carrier over one symbol is referred to as resource element (RE). A unit of one RB over one symbol is referred to as physical RB (PRB).

[0214] DL signaling include physical downlink shared channels (PDSCHs) conveying information content, PDCCHs conveying DL control information (DCI), and reference signals (RS). A PDCCH can be transmitted over a variable number of slot symbols including one slot symbol and over a number of control channel elements (CCEs) from a predetermined set of numbers of CCEs referred to as CCE aggregation level within a control resource set (CORESET) as described in v17.6.0 of [REF 1] and v17.6.0 of [REF 3].

[0215] DCI can serve several purposes. A DCI format includes a number of fields, or information elements (IEs), and is typically used for scheduling a PDSCH (DL DCI format) or a PUSCH (UL DCI format) transmission. A DCI format includes cyclic redundancy check (CRC) bits in order for a UE (e.g., the UE 116) to confirm a correct detection. A DCI format type is identified by a radio network temporary identifier (RNTI) that scrambles the CRC bits. For a DCI format scheduling a physical downlink shared channel (PDSCH) or a PUSCH for a single UE with RRC connection to a gNB (e.g., the BS 102), the RNTI is a cell RNTI (C-RNTI) or another RNTI type such as a modulation and coding scheme-cell RNTI (MCS-C-RNTI). For a DCI format scheduling a PDSCH conveying system information (SI) to a group of UEs, the RNTI is a system information RNTI (SI-RNTI). For a DCI format scheduling a PDSCH providing a response to a random access (RA) from a group of UEs, the RNTI is a random access (RA-RNTI). For a DCI format scheduling a PDSCH providing contention resolution in Msg4 of a RA process, the RNTI is a temporary C-RNTI (TC-RNTI). For a DCI format scheduling a PDSCH paging a group of UEs, the RNTI is a paging RNTI (P-RNTI). For a DCI format providing transmission power control (TPC) commands to a group of UEs, the RNTI is a transmit power control radio network temporary identifier (TPC-RNTI), and so on. Each RNTI type is configured to a UE through higher layer signaling. A UE typically decodes at multiple candidate locations for PDCCH receptions as determined by an associated search space set.

[0216] For each DL bandwidth part (BWP) indicated to a UE in a serving cell, the UE can be provided by higher layer signaling with control resource sets (CORESETs). For each CORESET, the UE is provided a CORESET index a DM-RS scrambling sequence initialization value, a precoder granularity for a number of resource element groups (REGs) in the frequency domain where the UE can expect use of a same DM-RS precoder, a number of consecutive symbols for the CORESET, a set of resource blocks (RBs) for the CORESET, control channel element to resource element group (CCE-to-REG) mapping parameters, an antenna port quasi co-location, from a set of antenna port quasi co-locations, indicating quasi co-location information of the DM-RS antenna port for PDCCH reception in a respective CORESET, and an indication for a presence or absence of a transmission configuration indication (TCI) field for DCI format 1_1 transmitted by a PDCCH in CORESET

[0217] For each DL BWP configured to a UE in a serving cell, the UE is provided by higher layers with search space sets. For each search space set from the search space sets, the UE is provided a search space set index an association between the search space set and a CORESET a PDCCH monitoring periodicity of slots and a PDCCH monitoring offset of slots, a PDCCH monitoring pattern within a slot, indicating first symbol(s) of the CORESET within a slot for PDCCH monitoring, a duration of slots indicating a number of slots that the search space set exists, a number of PDCCH candidates per CCE aggregation level and an indication that search space set is either a common search space (CSS) set or a UE-specific search space (USS) set. When search space set is a CSS set, the UE monitors PDCCH for detection of DCI format 2_x, where x ranges from 0 to 7 as described in v17.6.0 of [REF2] or for DCI formats associated with scheduling broadcast / multicast PDSCH receptions, and for DCI format 0_0 and DCI format 1_0.

[0218] A UE determines a PDCCH monitoring occasion on an active DL BWP from the PDCCH monitoring periodicity, the PDCCH monitoring offset, and the PDCCH monitoring pattern within a slot. For search space set the UE determines that a PDCCH monitoring occasion(s) exists in a slot with number in a frame with number if The UE monitors PDCCH candidates for search space set for consecutive slots, starting from slot and does not monitor PDCCH candidates for search space set for the next consecutive slots. The UE determines CCEs for monitoring PDCCH according to a search space set based on a search space equation as described in [REF3].

[0219] A UE expects to monitor PDCCH candidates for up to 4 sizes of DCI formats that include up to 3 sizes of DCI formats with CRC scrambled by C-RNTI per serving cell. The UE counts a number of sizes for DCI formats per serving / scheduled cell based on a number of PDCCH candidates in respective search space sets for the corresponding active DL BWP. In the following, for brevity, that constraint for the number of DCI format sizes will be referred to as DCI size limit. When the DCI size limit would be exceeded for a UE based on a configuration of DCI formats that the UE monitors PDCCH, the UE aligns the size of some DCI formats, as described in v17.6.0 of [REF2], so that the DCI size limit would not be exceeded.

[0220] For each scheduled cell, the UE is not required to monitor on the active DL BWP with SCS configuration of the scheduling cell more than PDCCH candidates or more than non-overlapped CCEs per slot, wherein and are respectively a maximum number of PDCCH candidates and non-overlapping CCEs for a scheduled cell and and are respectively a total number of PDCCH candidates and non-overlapping CCEs for a scheduling cell, as described in [REF3].

[0221] A UE does not expect to be configured CSS sets, other than CSS sets for multicast PDSCH scheduling, that result to corresponding total, or per scheduled cell, numbers of monitored PDCCH candidates and non-overlapped CCEs per slot on the primary cell that exceed the corresponding maximum numbers per slot. For USS sets or for CSS sets associated with multicast PDSCH scheduling, when a number of PDCCH candidates or non-overlapping CCEs in a slot would exceed the limits / maximum per slot for scheduling on the primary cell mentioned herein, the UE selects the USS sets or the CSS sets to monitor corresponding PDCCH in an ascending order of a corresponding search space set index until and an index of a search space set for which PDCCH monitoring would result to exceeding the maximum number of PDCCH candidates or non-overlapping CCEs per slot for scheduling on the PCell as described in [REF3].

[0222] For same cell scheduling or for cross-carrier scheduling where a scheduling cell and scheduled cells have DL BWPs with same SCS configuration a UE does not expect a number of PDCCH candidates, and a number of corresponding non-overlapped CCEs per slot on a secondary cell to be larger than the corresponding numbers that the UE is capable of monitoring on the secondary cell per slot. For cross-carrier scheduling, the number of PDCCH candidates for monitoring and the number of non-overlapped CCEs per slot are separately counted for each scheduled cell.

[0223] A UE can be configured for operation with carrier aggregation (CA) for PDSCH receptions over multiple cells (DL CA) or for PUSCH transmissions over multiple cells (UL CA). The UE can also be configured multiple transmission-reception points (TRPs) per cell via indication (or absence of indication) of acoresetPoolIndexfor CORESETs where the UE receives PDCCH / PDSCH from a corresponding TRP as described in v17.6.0 of [REF3]and [REF4].

[0224] MIMO technologies have a key role in boosting system throughput both in NR and LTE and such a role will continue and further expand in the future generations of wireless technologies. For MIMO operation, an antenna port is defined such that a channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. There is not necessarily a one to one correspondence between an antenna port and an antenna element, and a plurality of antenna elements can be mapped onto one antenna port.

[0225] FIG. 9 illustrates a diagram of an example type-1 backscatter structure 900 for IoT devices according to embodiments of the present disclosure. For example, type-1 backscatter structure 900 can be implemented by any of the UEs 111-116 of FIG. 1, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0226] As shown in FIG. 9, the type-1 backscatter structure 900 for IoT devices includes an antenna 905, a matching network 910, a RF energy harvester 915, a power measurement unit (PMU) 920, an energy storage 925, a RF bandpass filter (BPF) 930, a RF envelope detector 935, a baseband (BB) lowpass filter (LPF) 940, a comparator 945, a clock generator 950, a BB logistics 955, a memory 960, backscatter (imp matching) 965, and processing circuitry 913.

[0227] In various embodiments, the processing circuitry 913, which may be a full-powered processor, such as included in UE 116, a lower-power microprocessor or microcontroller, an application specific integrated circuit (ASIC), or logic circuitry. The processing circuitry 913 can control the overall operation of the IoT device including determination of reception and / or transmission timing. The processing circuitry 913 may be powered via energy storage 925. The signal receiving and transmitting processing circuitry included in the IoT devices, such as RF BPF 930, a RF envelope detector 935, a BB LPF 940, a comparator 945, a clock generator 950, a BB logistics 955, a memory 960, and a backscatter (impedance matching) 965, may be referred to as a transceiver, which may use separate antennas for reception and transmission, respectively, or may use a common antenna, such as antenna 905 for transmission and reception. One or more implementations described herein further include other implementation variations such as separate Tx-Rx antennas vs common Tx-Rx antenna, use of a sensor, etc. The implementations should be understood as an example and not as a restriction.

[0228] FIG. 10 illustrates a diagram of an example impedance matching circuit according to embodiments of the present disclosure. For example, impedance matching circuit 1000 can be implemented in any of the IoT device described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0229] FIG. 11 illustrates a diagram of an example type-2a backscatter structure 1100 for IoT devices according to embodiments of the present disclosure. For example, backscatter structure 1100 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 111, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0230] As shown in FIG. 11, the type-2a backscatter structure 1100 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a low noise amplifier (LNA) 1132, a RF envelope detector 935, a BB amp 1137, a BB LPF 940, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a frequency shifter 1162, backscatter (imp matching) 965, a reflection amp 1167, and processing circuitry 913.

[0231] FIG. 12 illustrates a diagram of an example type-2a backscatter structure 1200 for IoT devices according to embodiments of the present disclosure. For example, backscatter structure 1200 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 112, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0232] As shown in FIG. 12, the type-2a backscatter structure 1200 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a LNA 1132, a mixer 1205, a LO 1225, an IF amp / BPF 1210, an IF ED 1215, a BB Amp / LPF 1220, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a frequency shifter 1162, a backscatter (impedance Matching) 965, reflection amp 1167, and processing circuitry 913.

[0233] FIG. 13 illustrates a diagram of an example type-2b active structure 1300 for IoT devices according to embodiments of the present disclosure. For example, structure 1300 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 113, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0234] As shown in FIG. 13, the type-2b active structure 1300 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a LNA 1132, a mixer 1205, an LO 1225, a BB amplifier 1137, a BB LPF 940, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a frequency shifter 1162, a backscatter (impedance matching) 965, a reflection amp 1167, and processing circuitry 913.

[0235] FIG. 14 illustrates a diagram of an example type-2b active structure 1400 for IoT devices according to embodiments of the present disclosure. For example, backscatter structure 1400 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 114, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0236] As shown in FIG. 14, the type-2b active structure 1400 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a LNA 1132, a RF envelope detector 935, a BB amp 1137, a BB LPF 940, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a modulator 1465, a digital to analog converter (DAC) 1470, a LO 1475, a mixer 1480, a PA 1485, and processing circuitry 913.

[0237] FIG. 15 illustrates a diagram of an example type-2b active structure 1500 for IoT devices according to embodiments of the present disclosure. For example, backscatter structure 1500 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 115, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0238] As shown in FIG. 15, the structure 1500 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a LNA 1132, a mixer 1534, an IF amp / BPF 1536, an IF ED 1538, a BB amp / LPF 1540, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a modulator 1465, a DAC 1470, a LO 1475, a mixer 1480, a PA 1485, and processing circuitry 913.

[0239] FIG. 16 illustrates a diagram of an example type-2b active structure 1600 for IoT devices according to embodiments of the present disclosure. For example, backscatter structure 1600 can be implemented by any of the UEs 111-116 of FIG. 1, such as the UE 116, or may be devices with fewer components and functionality than a UE. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0240] As shown in FIG. 16, the structure 1600 includes an antenna 905, a matching network 910, a RF energy harvester 915, a PMU 920, an energy storage 925, an energy harvester (other than RF) 1122, a RF BPF 930, a LNA 1132, a mixer 1534, a BB amp 1137, a BB LPF 940, a comparator / ADC 1142, a clock generator 950, a BB logistics 955, a memory 960, a modulator 1465, a DAC 1470, a LO 1475, a mixer 1480, a PA 1285, and processing circuitry 913.

[0241] Several different types of A-IoT devices can be regarded as following.

[0242] - Device 1: ~1 μW peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10X ppm, neither R2D nor D2R amplification in the device. The device's D2R transmission is backscattered on a carrier wave provided externally.

[0243] - Device 2a: ≤ a few hundred μW peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10X ppm, both R2D and / or D2R amplification in the device. The device's D2R transmission is backscattered on a carrier wave provided externally.

[0244] - Device 2b: ≤ a few hundred μW peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10X ppm, both R2D and / or D2R amplification in the device. The device's D2R transmission is generated internally by the device.

[0245] The devices may operate in frequency division duplexing (FDD) spectrum or time division duplexing (TDD) spectrum, which may be licensed or unlicensed.

[0246] In the following, reference architectures for the device types herein are provided, which should be understood as an example and not as a restriction.

[0247] With reference to FIG. 9, an example Type-1 backscatter device structure according to the disclosure is shown.

[0248] The RF energy harvester 915 converts RF signal to DC power and supplies the device. Either a R2D signal or an externally provisioned CW signal for backscattering can be utilized for RF energy harvesting. The CW is externally provided from a gNB or a dedicated source. The source of CW signal, e.g., either a gNB or a dedicated node, may or may not be agnostic to A-IoT devices. The harvested energy, e.g., using a rectifier, can be stored using a capacitor, super-capacitor, or, generally speaking, an energy storage. Antenna could be either shared or separate for RF energy harvester and receiver / transmitter. Matching network 910 is to match impedance between antenna and other components. Clock generator 950 provides required clock signal(s).

[0249] The PMU 920 manages storing energy to energy storage from energy harvester and supplying power to active component blocks which needs power supply. The PMU 920 can also transition the device operation state between at least ON state, the OFF state, and the power saving (PS) state. The PMU 920 includes or is implemented by power management circuitry. In some embodiments, the PMU 920 may be implemented by program code (e.g., software or firmware) executed by one or more processors such as the processing circuity 913, such that, in some embodiments, the power management circuitry of the PMU 920 is the same as or includes at least some of the processing circuity 913. In other embodiments, the power management circuitry of the PMU 920 may be a separate processor, controller, or circuit, such as a lower-power microprocessor or microcontroller, an ASIC, or logic circuitry that is programmed to implement the functions of the PMU 920 or configured to implement the functions of the PMU 920 in logic.

[0250] The R2D signal is demodulated using a low complexity envelope detector and comparator, whose output is provided as an input to the baseband circuit. Given the low-power and low-complexity requirements of the Type-1 backscatter device, an RF envelope detection can be a viable solution for a receiver architecture, compared to a heterodyne architecture with IF envelope detection or a homodyne architecture with baseband envelope detection, which require LO and frequency mixer for frequency down-conversion. The input RF signal passes through an RF band-pass filter (BPF) 930 for an adjacent channel interference suppression, and then the filtered RF signal is directly converted into a baseband using an RF envelope detector 935, followed by a baseband low-pass filter (LPF) 940 for filtering out harmonics and high frequency components, and an n-bit comparator, where n can be 1, 2, 4, 8, ... The use of filters, e.g., BPF 930 only, LPF 940 only, or both, can be an implementation choice.

[0251] For the D2R backscatter transmission, any of the following can be used:

[0252] - Case 1) CW is provisioned at DL spectrum and backscattered, i.e., CW @ DL spectrum, D2R backscattering @ DL spectrum.

[0253] - Case 2) CW is provisioned at UL spectrum and backscattered, i.e., CW @ UL spectrum, D2R backscattering @ UL spectrum.

[0254] - Case 3) CW is provisioned at DL spectrum, frequency shifted to UL spectrum, and then backscattered, i.e., CW @ DL spectrum, D2R backscattering @ UL spectrum.

[0255] In one example, Case 1) or Case 2) is evaluated for device 1, i.e., CW and D2R backscattering on the same frequency and, therefore, a frequency shifter (FS) is not required.

[0256] With reference to FIG. 10, an example impedance matching circuit for backscatter device D2R modulation according to the disclosure is shown.

[0257] The followings are simple examples of impedance matching operations:

[0258] - Open circuit: Full reflection of the received CW signal in the same phase. This can be used for OOK modulation with matching circuit.

[0259] - Short circuit: Full reflection of the received CW signal in the reversed phase. This can be used for phase-shift keying (PSK) modulation.

[0260] - Matching circuit: No reflection as the impedance is matched to a load, i.e., absorption. This can be utilized for energy harvesting, Rx mode, or modulation with other matching states.

[0261] - Multi-level matching circuit: As illustrated in FIG. 10. Multi-level impedance matching to Z1, Z2, ..., ZLfor log2(L) bits per symbol ASK modulation.

[0262] Depending on the matched load impedance, the matching circuit can backscatter the incoming CW signal with different reflection coefficients in both amplitude and phase. In general, amplitude shift keying (ASK) / phase shift keying (PSK) / frequency shift keying (FSK) may be supported using an impedance matching circuit. As a simplest modulation scheme, OOK may be evaluated. The device may indicate its modulation capability or impedance matching capability to the network (e.g., the network 130), or certain requirement may be predefined in the specification of system operation.

[0263] With reference to FIG. 11, an example device 2a backscatter architecture based on RF envelope detection according to the disclosure is shown.

[0264] The device 2a may share similar structure at large with device 1 as the D2R transmission is still based on backscattering of an externally provided CW, while the device 2a may differ from device 1 from the following aspects.

[0265] The device 2a has ≤ a few hundred μW peak power consumption and both R2D and / or D2R amplification in the device. In this case, alternative to the RF energy harvesting from a R2D signal or an externally provided CW signal, other renewable energy sources, e.g., solar, thermal, kinetic, etc., may be provided for energy harvesting. The presence of a certain energy harvesting capability from a certain renewable energy source may be expected for system design point of view. The use of energy harvesters, e.g., RF energy harvester 915 only, other energy harvester only, or both, can be an implementation choice.

[0266] The device 2a may be equipped with both R2D and / or D2R amplification in the device. Given the power consumption requirement, i.e., ≤ a few hundred μW, the R2D / D2R amplification for device 2a may be based on an architecture that is different from the typical power amplifier (PA) and low noise amplifier (LNA). In some example low-power / complexity architectures for forward amplifier for reader-to-device (R2D) reception and reflection amplifier for device-to-reader (D2R) transmission, a single bipolar transistor terminated with microstrips may be used. The receiver amplification can be either RF amplification prior to the envelope detector, baseband amplification after the envelope detector, or both, which is an implementation choice. In one example, a reflection amplifier is used for both R2D reception and D2R transmission, and LNA may or may not exist. In another example, a reflection amplifier is used for D2R transmission only and LNA is used for R2D reception amplification.

[0267] In one example, a reflection amplifier can be used only for backscattering, i.e., one-way amplification. In another example, a reflection amplifier can be used for both backscattering and receiving, i.e., two-way amplification. For a reflection amplifier, it can be expected that 10 ~ 25 dB gain is achievable, at a power consumption of a few tens to hundreds micro-Watts. It is noted that an exact power consumption value will be highly dependent on implementations. On the other hand, a stability of an amplifier is a function of an input impedance and operating frequency. Since A-IoT devices are expected to be deployed for a certain operating frequency and not expected to adapt to another frequency after deployment, the implementation can ensure a stable operation of the amplifier for the target frequency.

[0268] One additional difference of device 2a compared to device 1 may be a use of a FS. With a few hundred μW peak power consumption, some low-power LO architectures with a frequency mixer can be taken into account for Case 3). With FS, it can be expected that the CW is provided in a frequency different than the UL carrier frequency. Because the A-IoT devices are targeting for low complexity and low power consumption, the following options can be evaluated as an example method for frequency shift:

[0269] - Ultra-low power local oscillator (LO), whose output frequency is multiplied in one or more stages using a frequency multiplier to obtain a desired amount of frequency shift.

[0270] - Calibrated RC (resistor-capacitor) oscillator, which uses CW frequency as an input to the RC oscillator with phase locked loop (PLL) circuitry.

[0271] - CW signal provided at the UL carrier frequency; In this case, no frequency shifter is needed.

[0272] - Use of harmonic frequencies of CW signal or intermodulation frequencies of two-tone CW signals.

[0273] The device 2a receiver architecture may be based on RF envelope detector, intermediate frequency (IF) envelope detector (ED), i.e., heterodyne receiver, or homodyne receiver with zero IF, as exemplified for device 2b.

[0274] The device 2b shares similar structure at large with the device 2a other than the UL signal is internally generated using LO rather than backscattering the externally provided CW. The example architecture shown in FIGS. 12-14 is based on an active transmitter chain, wherein the UL data is modulated, converted to an analog signal using digital to analog converter (DAC) and, then up-converted to a UL carrier frequency using LO and frequency mixer, which is followed by an amplifier.

[0275] In FIG. 12, the DL receiver chain is still based on the RF envelope detector as in the previous architectures. In FIG. 13, the DL receiver chain is based on heterodyne receiver with IF envelope detector. In the heterodyne architecture, the RF signal is down converted into an intermediate frequency and then detected using an envelope detector. In FIG. 14, the DL receiver is based on homodyne receiver, i.e., zero-IF. In the homodyne / zero-IF architecture, the RF signal is directly down converted into baseband signal and then detected using a comparator / ADC.

[0276] FIGS. 9-14 should be understood for illustration purpose only. There can be other components not explicitly shown in the figure such as switch, duplexer, and filters, or some components may be replaced to different options. Also, the devices can operate both in TDD and FDD spectrum, either licensed or unlicensed, and, depending on the operating spectrum, the actual architectures can be different from the conceptual illustrations in the figures.

[0277] In deploying A-IoT devices, different topology options can be evaluated. The following provides examples of topology options:

[0278] - Topology 1: BS ↔ A-IoT device

[0279] -- An A-IoT device directly and bidirectionally communicates with a basestation. The communication between the basestation and the A-IoT device includes A-IoT data and / or signalling. This topology includes the BS transmitting to the A-IoT device is different from the BS receiving from the A-IoT device.

[0280] - Topology 2: BS ↔ intermediate node ↔ Ambient IoT device

[0281] -- An A-IoT device communicates bidirectionally with an intermediate node between the device and basestation. In this topology, the intermediate node can be a relay, IAB node, UE, repeater, etc. which is capable of A-IoT. The intermediate node transfers A-IoT data and / or signalling between BS and the A-IoT device. The intermediate node is referred to as I-node in this disclosure.

[0282] - Topology 3: BS ↔ assisting node ↔ Ambient IoT device ↔ BS

[0283] -- An A-IoT device transmits data / signalling to a basestation, and receives data / signalling from the assisting node; or the A-IoT device receives data / signalling from a basestation and transmits data / signalling to the assisting node. In this topology, the assisting node can be a relay, IAB, UE, repeater, etc. which is capable of A-IoT.

[0284] - Topology 4: UE ↔ Ambient IoT device

[0285] -- An A-IoT device communicates bidirectionally with a UE. The communication between UE and the A-IoT device includes A-IoT data and / or signalling.

[0286] This disclosure is applicable at least to the following deployment scenarios:

[0287] - Scenario 1: Device indoors, BS indoors

[0288] - Scenario 2: Device indoors, BS outdoors

[0289] - Scenario 3: Device indoors, UE-based reader

[0290] - Scenario 4: Device outdoors, BS outdoors

[0291] - Scenario 5: Device outdoors, UE-based reader

[0292] The deployment of A-IoT can be on the same sites as an existing 3GPP deployment corresponding to the BS type, e.g., macro-cell, micro-cell, pic-cell, etc. In some embodiments, it may be expected that the deployment of A-IoT can be on new sites without an expectation of an existing 3GPP deployment. The deployment can be based on licensed or unlicensed TDD or FDD spectrum, which may be in-band to an existing deployment, in guard-band of an existing deployment, or in a standalone band. Different traffic types can be supported including device-terminated (DT) and device-originated (DO), wherein DO traffic can be further divided into DO autonomous (DO-A), and DO device-terminated triggered (DO-DTT) types.

[0293] A-IoT device is one type of a UE. Embodiments in this disclosure can be generally applicable to other types of UEs, e.g., smartphones, AR / VR devices, or any other types of IoT devices.

[0294] FIG. 17 illustrates an example system 1700 for D2R / R2D transmission including an intermediate UE according to embodiments of the present disclosure. For example, system 1700 can be implemented in the wireless network 100 of FIG. 1. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0295] With reference to FIG. 17, a topology involving an intermediate node is shown, wherein the intermediate node (I-node) can be any of a UE, relay, repeater, a dedicated node, or a gNB (e.g., the BS 102). Any operations performed by a BS can be also performed by the I-node instead of the BS, and all or part of interfaces are transparent to the A-IoT devices.

[0296] An entity directly communicating with a device, or tag, is collectively termed as a reader, which can be an intermediate node as illustrated in FIG. 17, an assisting node, a UE, or a BS directly communicating with a device.

[0297] This disclosure is applicable to any of the following spectrum options, wherein a reader can be any of a BS, an intermediate node, an assisting node, or a UE in any of the topologies or scenarios disclosed herein:

[0298] - CW is transmitted on DL spectrum and D2R is transmitted on the DL spectrum or shifted to UL spectrum.

[0299] - CW is transmitted on UL spectrum and D2R is transmitted on the UL spectrum or shifted to DL spectrum.

[0300] - R2D transmission by a reader is on DL spectrum or UL spectrum.

[0301] - A node transmitting the CW can be a node inside the topology, e.g., a BS, an intermediate node, an assisting node, or a UE (e.g., the UE 116), or a node outside the topology, e.g., a dedicated CW source.

[0302] - A reader receiving D2R transmission and a reader transmitting R2D may be the same or different.

[0303] - As an example, CW is transmitted on DL spectrum and D2R transmission is shifted to UL spectrum, wherein the node transmitting the CW is a node inside topology or outside topology, and a reader transmitting R2D and a reader receiving D2R may be the same or different.

[0304] - As another example, CW is transmitted on DL or UL spectrum and D2R transmission is on the same spectrum for which the CW is transmitted, wherein the node transmitting the CW is a node inside topology or outside topology, and a reader transmitting R2D and a reader receiving D2R may be the same or different.

[0305] A physical channel for reader to device transmission is referred to as a physical reader to device (R2D) channel (PRDCH), and a physical channel for device to reader transmission is referred to as a physical device to reader (D2R) channel (PDRCH) in this disclosure.

[0306] For PRDCH and PDRCH transmission, a timing acquisition signal, e.g., a preamble, is included at least for timing acquisition and for indicating the start of the transmission in time domain, respectively.

[0307] There may be a timing relationship between transmissions as herein:

[0308] - TR2D_min, TR2D_max: Minimum / maximum time between a R2D transmission and the corresponding D2R transmission following it.

[0309] - TD2R_min, TD2R_max: Minimum / maximum time between a D2R transmission and the corresponding R2D transmission following it.

[0310] - TR2D_R2D_min, TR2D_R2D_max: Minimum / maximum time between two different consecutive R2D transmissions to the same A-IoT device.

[0311] - TD2R_D2R_min, TD2R_D2R_max: Minimum / maximum time between two different consecutive D2R transmissions from the same A-IoT device.

[0312] FIG. 18 illustrates example signal structures 1800 for A-IoT systems according to embodiments of the present disclosure. For example, signal architectures 1800 can be received by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0313] With reference to FIG. 18, an example signal structure used for A-IoT system for R2D or D2R transmission according to the disclosure is shown. The dotted block indicates that it may or may not exist.

[0314] The first figure in FIG. 18 illustrates a general signal structure comprised of one or more of the following elements:

[0315] - Start / End-indicator, i.e., delimiter: Start-of-signal and end-of-signal indication. It may be a short duration of low voltage signal or a sequence with low detection complexity prior to detecting preamble. The start-indicator is a part of the preamble. The end-indicator may be also termed as postamble. The delimiters may or may not be exist.

[0316] - Clock acquisition: A sequence that provides OOK chip rate acquisition, which is used to detect OOK chips for the rest of the signal, and the chip synchronization. The clock acquisition part is a part of preamble.

[0317] - Header: The header field carries necessary information for R2D or D2R signal reception, providing L1 or L2 control information

[0318] - Payload: The field provides data including any of L1, L2, or higher layer control information, system information, etc.

[0319] The second figure in FIG. 18 illustrates a signal structure with midamble. When a transmission is longer than a certain threshold, which may be predefined in a specification of system operations or indicated to the device for reception or transmission from the device, the payload may be divided into multiple segments with midamble. A single header for the entire payload, or one or more headers for each segments of the payload may be provided. A single CRC for the entire payload (either inclusive or non-inclusive of the header) or one or more CRCs for each segments of the payload may be provided.

[0320] One main use case of A-IoT is inventory, e.g., asset identification and tracking, while the reader may not have a prior knowledge of devices in its proximity. Therefore, there is a need to define procedures and methods for device identification via random access.

[0321] A device may be unavailable or time to time for a certain time duration due to the lack of energy and for charging by harvesting energy. This may impact the inventory process, if a device's remaining energy level cannot sustain the current inventory process. This may also impact a transmission or a reception if a device's remaining energy level cannot sustain the current transmission or reception duration.

[0322] Therefore, embodiments of the present disclosure recognize that there is a need to define procedures and methods for a device switching between an active monitoring of a potential R2D transmission and a dormancy during which the device is not require to monitor a potential R2D transmission.

[0323] Embodiments of the present disclosure further recognize that there is another need to define procedures and methods for a device to perform random access involving a switching to a dormancy during which the device is not require to monitor a potential R2D transmission.

[0324] Embodiments of the present disclosure further recognize that there is yet another need to define procedures and methods for a device to transmit an energy status report.

[0325] The disclosure relates to a communication system. The disclosure relates to defining functionalities and procedures for communication with A-IoT devices which may be lacking a precise timing capability and have a limited operation time due to energy harvesting.

[0326] The disclosure also relates to defining functionalities and procedures for a device to perform random access for inventory and defining timing parameters for exchanging messages during random access.

[0327] The disclosure further relates to defining functionalities and procedures for a device switching between an active monitoring of a potential R2D transmission and a dormancy during which the device is not require to monitor a potential R2D transmission.

[0328] The disclosure also relates to defining functionalities and procedures for a device to perform random access involving a switching to a dormancy during which the device is not require to monitor a potential R2D transmission.

[0329] The disclosure further relates to defining functionalities and procedures for a device to transmit an energy status report.

[0330] Embodiments of the disclosure for communication with A-IoT devices, which may be lacking a precise timing capability and have a limited operation time due to energy harvesting, are summarized in the following and are fully elaborated further herein.

[0331] - Method and apparatus for a device to perform random access for inventory and defining timing parameters for exchanging messages during random access.

[0332] - Method and apparatus for a device switching between an active monitoring of a potential R2D transmission and a dormancy during which the device is not require to monitor a potential R2D transmission.

[0333] - Method and apparatus for a device to perform random access involving a switching to a dormancy during which the device is not require to monitor a potential R2D transmission.

[0334] - Method and apparatus for a device to transmit an energy status report.

[0335] FIG. 19 illustrates a timeline 1900 for an example sequential identification process according to embodiments of the present disclosure. For example, timeline 1900 can be followed by any of the readers described herein and any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0336] With reference to FIG. 19, an example sequential device identification process via random access according to the disclosure is shown.

[0337] FIG. 20 illustrates a flowchart of an example device procedure 2000 for performing random access according to embodiments of the present disclosure. For example, procedure 2000 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0338] The procedure begins in 2010, a device receives paging message from a reader providing information related to perform random access. In 2020, the device draws a random number, which corresponds to a random access slot for message 1 transmission. In 2030, the device transmits message 1 upon receiving a triggering message from the reader announcing the current random access round index corresponding to the drawn random number. In 2040, the device receives message 2 from the reader after transmitting the message 1. In 2050, the device exchanges additional messages with the reader, if any.

[0339] With reference to FIG. 20, an example flowchart is shown for a device to perform random access according to the disclosure.

[0340] Random access for inventory is initiated by a reader transmitting a page in message and a device receiving the page in message.

[0341] The paging message includes device ID for target device identification and information related to determine the resources to be used for the following message 1 transmission. As an example, the paging message can include one or more of:

[0342] - Inventory procedure type, e.g., whether it is a full-step procedure or a reduced procedure such as four-step or two-step.

[0343] -- For the 4-step random access, whether the message 4 is expected or not.

[0344] - Reader ID which can be uniquely identify the reader, e.g., a reader device ID, a random number, or a Cell ID.

[0345] - Reader device type, whether it is a gNB based reader or a UE based reader.

[0346] - An ID for identifying the legitimate paging message such as an operator ID, e.g., to distinguish a reader from an operator from another reader from another operator.

[0347] - Parameters related to power control: transmission power of a message 1 preamble or any pathloss reference signal, target reception power, pathloss scaling factor, a power ramping step in dB for re-attempts.

[0348] - Parameters related to random access resource configuration

[0349] -- A number of time slots for random access, whose duration is predefined in the specifications of system operation or indicated in the triggering message.

[0350] -- A frequency domain resources. In one example, it can be a number of frequency domain resources, wherein the resource can be a sub-carrier, a PRB, a unit frequency amount, or frequency ranges. As an example, a device may randomly select a frequency resource from the number of resources. In another example, it can be a number of frequency shifts, wherein the shifts can be indicated by ±Δ Hz, ± integer multiples of a unit amount of a frequency, or a parameter of a line code, such as a number of subcarrier cycles per symbol.

[0351] -- There may be an indication of available or prohibited time slots / frequency resources / shifts for random access, e.g., using a mask or a bitmap of a size equal to the number of time slots. The mask / bitmap may be provided separately for each frequency resource / shift, or commonly.

[0352] - Preamble sequence: If more than one preamble pattern is supported, it can indicate information related to preamble sequence that can be used for PDRCH for the message 1 transmission. The indication may include a dedicated root sequence index for the preamble. The indication may include one or more dedicated preamble index(es). In one example, preamble indexes are indicated for respective devices addressed by the paging message.

[0353] - Parameters related to random access

[0354] -- Medium access probability, which may be applied for the given time slots, or per time slot in an individual manner. In one example, the access probability may be 1.

[0355] - Parameters related to identifier to include in PDRCH transmission. In one example, parameters are related to random number generation such as an interval to draw a random number, e.g., [0, 2N-1], wherein N is indicated. In another example, indication is provided for a type of identifier, such as device product code, e.g., product code (PC), extended product code (XPC), electronic product code (EPC), or a random number, and such as full format or a shortened format. In one example, more than one N values are indicated, one for a certain device group and another one for another device group. In this manner, a prioritized device identification can be performed by a device group indicated a smaller value of N.

[0356] - Parameters related to PDRCH

[0357] -- Transmission duration, e.g., in number of symbols or chips, payload size

[0358] -- Frequency resources such as a particular sub-carrier, PRB, or frequency range for transmission. In another example, a particular frequency shift amount for UL transmission such as by ±Δ Hz, ± integer multiples of a unit amount of a frequency, or a parameter of a line code, such as a number of subcarrier cycles per symbol.

[0359] -- MCS or a parameter of a line code, such as a number of subcarrier cycles per symbol.

[0360] -- Attachment of preamble, midamble, postamble, and their format, e.g., long or short format, if more than one formats are supported.

[0361] -- Attachment of CRC, and / or CRC size.

[0362] -- Modulation type such as OOK-1, OOK-4, BPSK, QPSK, FSK, ASK with orders.

[0363] -- Coding type such as indicator for Manchester coding, FM0, or Miller coding.

[0364] - Parameters related to device selection

[0365] -- A particular device ID, or a list of device IDs.

[0366] -- A particular device group ID

[0367] --- A device may be assigned with a unique device group ID, apart from a device ID.

[0368] --- A device ID may be comprised of two parts; first part a device group ID and second part a device ID within the group. In this case, the first part of the device ID is indicated.

[0369] --- mod (device ID, K) = L. In this case, K and L are indicated. In one example, L is fixed, e.g., zero, and only K is indicated.

[0370] -- All devices, e.g., by indicating NULL or some predefined codepoint for addressing the target device or device groups in the PRDCH transmission. Indicating NULL implies that the message does not contain an ID.

[0371] - Other parameters

[0372] -- Maximum number of allowed random access transmissions

[0373] -- Response monitoring window after transmitting the random access

[0374] -- Prohibit timer after a failed random access attempt

[0375] -- Allowance of UL power amplification

[0376] -- System / channel / occupied BW

[0377] -- Sub-carrier spacing

[0378] -- Parameters related to the carrier wave (CW), e.g., CW bandwidth, frequency, single-tone or multi-tone. PRDCH to CW power offset.

[0379] 4-step random access is comprised of the following steps:

[0380] - A-IoT Msg1: the device sends an ID to the reader. Fixed random ID size of 16 bit is used. The ID is randomly generated.

[0381] - A-IoT Msg2: the reader echoes the ID received in Msg1. Msg3 transmission resource can explicitly be indicated in Msg2.

[0382] - A-IoT Msg3: device sends Device ID and / or any other upper layer data (depending on upper layer request)

[0383] - A-IoT Msg4: the subsequent R2D transmission after D2R transmission, which does not need to be sent in random access. “Msg4” can be taken into account to handle the Msg3 transmission failure (due to various reasons).

[0384] In one example, the reader assigns an ID to the device, different from the random ID used in the previous steps, in message 2 or message 4 for the purpose of addressing the identified device for subsequent communication with the reader. In another example, when the device receives message 2 confirming its random ID in message 1, the device assumes that the random ID is automatically promoted to an assigned ID, which can be used for subsequent communication with the reader.

[0385] The Msg4 may or may not be present; therefore the random access may be compromised of three steps. However, in this disclosure, it is also referred to as 4-step random access.

[0386] If the paging message is addressed to one or more targeted devices with dedicated resources, the message 1 / 2 is skipped and the device directly transmits message 3 upon receiving the paging message. The device ID included in the message 3 can be a random ID that the device already exchanged with and confirmed from a reader or the ID is associated with the device itself, such as EPC, XPC and PC.

[0387] FIG. 21 illustrates a timeline 2100 of an example multiplexed identification process according to embodiments of the present disclosure. For example, timeline 2100 can be followed by any of the readers described herein and any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0388] 2-step random access is comprised of the following steps:

[0389] - A-IoT Msg1: The device sends Device ID and / or any other upper layer data (depending on upper layer request). Fixed random ID size of 16 bit is used. The ID is randomly generated.

[0390] - A-IoT Msg2: the reader may echo some information from Msg1.

[0391] A device randomly decides to transmit the message 1, and potentially transmit the message 1 following a triggering message reception. The first trigger message follows the paging message transmission in a time interval [TR2D_R2D_min, TR2D_R2D_max]. In one example, for the very first random access round, the triggering message transmission is skipped, and the paging message serves the purpose of the first triggering message. In one example, the time interval between two adjacent triggering messages are fixed, which is denoted by Ttrigger. In another example, the next triggering message can follow the previous triggering message in a certain time interval denoted by [Ttrigger _min, Ttrigger_max]. In yet another example, a triggering message indicates the transmission timing of the one or more next subsequent triggering messages. In one example, the message 4 transmission can serve the purpose of the next triggering message. Therefore, there is no separate triggering message transmission and devices can transmit message 1 following the message 4 in the time interval [TR2D_min, TR2D_max]. Similarly, for the 4-step random access, the message 2 can serve the purpose of the next triggering message.

[0392] The triggering message, including any other signal that can serve the purpose of triggering message such as paging, message 2 or message 4, can provide one or more of the followings:

[0393] - Any information from the list of information disclosed for the paging message.

[0394] - Any information provided in the paging message, which is repeated or an update to the previously indication in the paging.

[0395] - Remaining or the current triggering message count, e.g., N, N-1, N-2, ....

[0396] - Transmission timing of the one or more next subsequent triggering messages

[0397] - List of identified device IDs in the previous round. This serves as an acknowledgement (ACK), as well as the identified devices can skip the subsequent random access rounds of the inventory process.

[0398] - Remaining time until the end of the current inventory process or the start of next new inventory / command process. A device, which has successfully finished the random access, is not required to monitor R2D signal or expected to transmit D2R signal during the indicated remaining time.

[0399] - Parameters for facilitating the sleep state, e.g., the maximum and the minimum time between the triggering messages, and the sleep timer for devices already checked in. The sleep timer may be broadcasted, which applies to the devices which already have checked in. Alternatively, the timer may be specifically indicated to a specific device ID.

[0400] In the sequential device identification process via random access, device identification is performed for at most one device in one random access round. The figure is illustrated for time domain operation. It can be understood that the operation can be both in time and frequency domain, i.e., the message 1 transmission may involve a random time / frequency resource selection.

[0401] Furthermore, the message 1 transmission may further involve a selection for the preamble signal from the set of allowed preamble signals.

[0402] The message 1 transmission may follow the preceding trigger message in time interval [TR2D_min, TR2D_max]. Alternatively, the message 1 transmission timing is indicated in the trigger message. The message 2 may follow the preceding message 1 transmission in time interval [TD2R_min, TD2R_max]. The subsequent message 3 transmission may follow the preceding message 2 transmission in time interval [TR2D_min, TR2D_max]. Alternatively, the message 3 transmission timing is indicate in the message 2. The subsequent message 4 transmission may follow the preceding message 3 transmission in time interval [TD2R_min, TD2R_max]. The message 4 may or may not be transmitted.

[0403] The 2-step random access can be understood from FIG. 19 which only involves message 1 and message 2 transmission in each round.

[0404] With reference to FIG. 21, an example multiplexed device identification process via random access according to the disclosure is shown. Any details disclosed for the sequential identification process can be also applicable for the multiplexed device identification process as well.

[0405] The random access from multiple devices occurs in a burst manner over a number of consecutive time slots. In one example, the length of each time slot includes D2R transmission duration for random access and guard time. In another example, the length of each time slot is equal to D2R transmission duration for random access, and there is a separate guard time provided between time slots. In yet another example, the reader transmits a certain timing reference signal, e.g., preamble, synchronization signal, etc., in the beginning of each time slot, and the D2R transmission for random access follows after a certain time interval, e.g., [TR2D_min, TR2D_max].

[0406] In one example, one or multiple time instances are indicated in the paging message or in the trigger message. The interval between two consecutive time instances may be fixed. In this example, a number of time instances are indicated to the devices. The start of the first time instance may be indicated or predefined in the specifications of the system operation, e.g., TR2D_minor TR2D_maxfrom the triggering or paging message reception. In another example, the interval between two consecutive time instances are not fixed. For instance, the time interval increases for time instances later in time. This increased interval is to accommodate a timing drift of a device from the reception of a paging or a trigger message.

[0407] For the one or multiple indicated time instances, a device attempts to transmit at the indicated time instances according to the random decision for accessing. In another example, for the one or multiple indicated time instances, a device attempts to transmit within a certain margin, e.g., [-Δ1, Δ2] wherein Δ1and Δ2can be the same or different, at the indicated time instances according to the random decision for accessing. In yet another example, for the one or multiple indicated time instances, a device attempts to transmit within a certain time interval, e.g., [Δx, Δy] wherein Δxand Δycan be TR2D_minand TR2D_maxas an example, from the indicated time instances according to the random decision for accessing.

[0408] In one example, the message 2 is provided individually for each successfully received message 1 in a burst manner. When one or more message 2 are transmitted in a burst manner, there may be a time gap, e.g., TR2D_R2D, between the transmissions. Alternatively, there may be no time gap between the consecutive ACK transmissions. In another example, a group message is provided for a number of successfully received message 1 from the preceding one or more random access slots. The group message includes a number of message 2s in one transmission for one or multiple devices who message 1 transmission is successfully received at the reader.

[0409] FIG. 22 illustrates a flowchart of an example device procedure 2200 for monitoring R2D transmission(s) according to embodiments of the present disclosure. For example, procedure 2200 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0410] The procedure begins in 2210, a device monitors a potential R2D transmission for at least a certain time duration, TON_min.In 2220, after at least the time duration, TON_min, the device may transition into a dormancy during which the device is not required to monitor a R2D transmission . In 2230, the device periodically or aperiodically transitions and monitors a potential R2D transmission for at least TON_mintime duration.

[0411] The methods described herein is applicable for the sequential identification process, the multiplexed identification process or any inventory process.

[0412] With reference to FIG. 22, an example flowchart is shown for a device to monitor R2D transmission according to the disclosure.

[0413] When currently no inventory process ongoing, a device may be turned on and monitor potential R2D transmission based on its energy level. In another example, there is a minimum time duration TON_minfor a device to monitor potential R2D transmission, when the device is turned on. The device's transition may be periodic or aperiodic depending on the energy level of the device. For instance, a device transitions into ON state for activity monitoring the potential transmission when its energy level exceeds a certain threshold. In yet another example, there is a periodicity Tperiodin addition to TON_minfor a device to turn on with the given periodicity Tperiodand monitor potential R2D transmission for TON_min. In the examples herein, the parameters, such as TON_min, Tperiod, can be predefined in a specification of system operations or indicated to the device from the reader in an R2D transmission. In another example these parameters can be reported by the device to the reader.

[0414] FIG. 23 illustrates a flowchart of an example device procedure 2300 for performing random access with dormancy according to embodiments of the present disclosure. For example, procedure 2300 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0415] The procedure begins in 2310, a device receives a paging message from a reader providing information related to perform random access. In 2320, the device draws a random number, which corresponds to a random access slot for message 1 transmission. In 2330, the device may transition into a dormancy during which the device is not required to monitor a R2D transmission based on parameters such as the drawn random number, a time duration defined between two consecutive triggering messages, etc.. In 2340, the device transitions and monitors and receives a potential triggering message corresponding to the drawn random number. In 2350, the device transmits message 1 and subsequent message exchanges with the reader. In 2360, after a successful completion of the random access, the device may transition into a dormancy based on parameters such as the current random access slot index, a time duration defined between two consecutive triggering messages, etc.

[0416] With reference to FIG. 23, an example flowchart is shown for a device to perform random access with dormancy according to the disclosure.

[0417] When currently an inventory process ongoing, in one embodiment, there is a minimum time between any two trigger messages denoted by Ttrigger_min. Similarly, there is a maximum time between two consecutive trigger messages of an inventory process, denoted by Ttrigger_max. In one example, Ttrigger_minand Ttrigger_maxare the same. For a given random access round initiated by a trigger message, a device may or may not perform random access based on random determination. If the device decides to not to perform random access for the given random access round, the device is not required to monitor any new triggering message within Ttrigger_minfrom the reception of the current triggering message. During this time interval a device may transition into a dormant state turning off active components, perform energy harvesting, or continue to monitor potential R2D transmission, including paging and triggering, from the reader. If the device stays in a dormant state or performs energy harvesting during the time interval, the device may need to maintain a timer to keep the time for transitioning back to the normal operation mode for monitoring a potential R2D transmission, including paging and triggering, from the reader.

[0418] After the expiration of the Ttrigger_mintimer, the device is required to monitor a possible R2D transmission, including paging and triggering, from the reader at least for [0, Ttrigger_max- Ttrigger_min]. In another example, the device is required to monitor a possible R2D transmission, including paging and triggering, from the reader at least for [0, Ttrigger_max]. If no trigger is detected, the device may go back to a normal mode of operation, i.e., operation assuming currently no inventory process ongoing.

[0419] In one example a device draws a random number from [1, 2N], which corresponds to the time slot index, assuming that the indexing starts from 1, for the device to perform the message 1 transmission. If the times slot index starts from 0, then the range for drawing a random number will be [0, 2N-1] without loss of a generality.

[0420] For a given random number drawn by a device, denoted by n, the device is not required to monitor a R2D transmission or stay active until the time slot n for the message 1 transmission. Therefore, for N - n times lots, the device is not required to monitor a potential R2D transmission, including paging and triggering messages. If the time interval between two consecutive triggering messages is fixed, denoted by Ttrigger, the device can stay dormancy for (N - n)·Ttriggertime. If the time interval between two consecutive triggers is valuable in the range of [Ttrigger_min, Ttrigger_max], the device can stay dormancy for (N - n)·Ttrigger_mintime. After the device transitions into an active state for monitoring a potential R2D transmission, the device receive a new triggering message announcing the current random access round. In one example, the device is required to monitor a possible triggering message from the reader at least for [0, Ttrigger_max- Ttrigger_min]. In another example, the device is required to monitor a possible triggering message from the reader at least for [0, Ttrigger_max].

[0421] Based on the acquired current random access round index, denoted by M, the device can transition into a dormancy for additional (M - n)·Ttrigger_mintime. The device behavior repeats until the device finally receives a trigger message announcing the current random access round index as n.

[0422] If a device is successfully inventoried, the device does not need to participate in the remaining random access rounds of the current inventory process. Therefore, in one embodiment, the device is not required to monitor a potential R2D transmission, including paging and triggering, during a timer denoted by Tinventoried, after a successful completion of random access, i.e., by receiving message 2 / 4 of 4-step or message 2 of 2-step random access confirming its ID transmitted in the message 1. Tinventoriedmay be predefined in a specification of system operations, indicated to the device, or calculated by a device. During this time interval a device may transition into a dormant state turning off active components, perform energy harvesting, or continue to monitor potential R2D transmission, including paging and triggering, from the reader. The device may set a flag to memorize that the device itself has successfully finished the current inventory process. The device may additionally memorize the corresponding reader ID and / or the inventory process ID.

[0423] In one embodiment, the timer Tinventoriedis indicated to a device. The timer value may be provided device-specifically in message 2 / 4 of 4-step, message 2 of 2-step random access, or any R2D transmission, including paging and triggering. The timer value may be provided commonly to any device who successfully completed the random access. In this example, the timer can be provided in a paging message, a triggering message, or any R2D transmission, e.g., message 2 / 4 of 4-step, message 2 of 2-step random access, which includes a unicast R2D message addressed to a particular device but its header / control field can be decoded by any devices. The timer value may be repeated in one or more subsequent paging / triggering messages. The timer value can be updated in a subsequent paging / triggering messages. In one example, a device transitions from a dormancy and starts monitoring the R2D transmission earlier than or later than the indicated Tinventoriedtimer due to the possible timing drift. After the device transitions from a dormancy and stars monitoring the R2D transmission, the device is required to monitor a possible R2D transmission at least for a certain time duration. In one example, the certain time duration is TON_min, Ttrigger_max, Ttrigger_min, or any other minimum or maximum time defined in the specifications of a system operation. In yet another example, the time duration is also indicated in the in an R2D transmission including paging or triggering messages along with Tinventoriedtimer.

[0424] In another embodiment, the timer Tinventoriedis calculated by the device. The determination can be based on the remaining inventory rounds indicated in the trigger messages, as disclosed herein, and / or the minimum time between the rounds, i.e., Ttrigger_min. As an example, if the remaining inventory rounds is K, then the timer is calculated as Tinventoried= K· Ttrigger_min. After the device transitions after the expiration of the timer, Tinventoried, the current inventory process may still be on-going as the calculated timer is based on the minimum time between the trigger messages. After the device transitions from a dormancy and stars monitoring the R2D transmission, the device is required to monitor a possible R2D transmission at least for a certain time duration. Based on the received trigger message after waking up, and the remaining inventory rounds provided in the trigger message, the device recalculates the remaining inventory process as disclosed herein and the device goes back to the dormancy with the newly calculated timer value. This may be repeated until the current inventory process actually finishes. In one example, the calculated timer value by the device may be reported to the reader.

[0425] A device may be unavailable or time to time for a certain time duration due to the lack of energy and for charging by harvesting energy. This may impact the inventory process, if a device's remaining energy level cannot sustain the current inventory process. In another example, this may impact a transmission or a reception if a device's remaining energy level cannot sustain the current transmission or reception duration.

[0426] FIG. 24 illustrates a timeline 2400 of an example D2R transmission following a R2D transmission according to embodiments of the present disclosure. For example, timeline 2400 can be followed by any of the readers described herein and any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0427] With reference to FIG. 24, an example D2R transmission following R2D transmission according to the disclosure is shown. The R2D message can be any of a paging message, a triggering message, message 2 / 4 of the 4-step random access or message 2 of the 2-step random access, or any R2D message providing a command. The D2R message can be any of the message 1 / 3 of the 4-step random access or message 1 of the 2-step random access, or any message in response to the R2D command. The D2R message may be expected by the device to be performed within the time interval [TR2D_min, TR2D_max] from the reception of the preceding R2D message. In another example, the D2R transmission timing may be indicated in the preceding R2D message. For the indicated timing, the device attempts to transmit within a certain margin, e.g., [-Δ1, Δ2] wherein Δ1and Δ2can be the same or different.

[0428] FIG. 25 illustrates a flowchart of an example device procedure 2500 for transmitting an energy status report according to embodiments of the present disclosure. For example, procedure 2500 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0429] The procedure begins in 2510, a device receives an R2D message from a reader requesting an energy status report in the following D2R transmission. In 2520, the device performs D2R transmission including energy status report to the reader.

[0430] With reference to FIG. 25, an example flowchart is shown for a device to transmit an energy status report according to the disclosure.

[0431] In one embodiment, the R2D message can indicate a device to provide an energy status report in the following D2R transmission. The R2D message can indicate one or more particular device ID or device group ID for the reporting. In one example, the energy status report can be a simple one bit indication on whether the device has a sufficient energy or not. The level of sufficiency, i.e., a threshold, can be predefined in a specification of a system operation or indicated to the device, for instance, in the R2D message triggering the energy status report. In another example, the energy status reporting can include the device's available energy level or the device's expected remaining operation time. In yet another example, the energy status report can include a maximum transmission time duration or a maximum reception time duration that the device can support. In yet another example, the energy status report includes N-bit indication indicating one state out of 2Nenergy states of the device. The energy states can be defined in terms of the energy level, remaining operation time, maximum transmission time duration, or a maximum reception time duration. In yet another example, the R2D message indicating a device to provide the energy status report can indicate a particular command, including inventory, and the energy status report from the device is expected to provide whether the device can sustain to complete the indicated command or not.

[0432] FIG. 26 illustrates a flowchart of an example device procedure 2600 for transmitting an energy status report according to embodiments of the present disclosure. For example, procedure 2600 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0433] The procedure begins in 2610, a device receives an R2D message from a reader triggering a subsequent D2R transmission. In 2625, the device transmits energy status report to the reader instead of the intended D2R transmission, when the device is unable to perform the intended D2R transmission.

[0434] With reference to FIG. 26, an example flowchart is shown for a device to transmit an energy status report instead of an intended D2R transmission according to the disclosure.

[0435] There are cases that a D2R transmission from a device is expected by a reader following an R2D transmission. For instance, a R2D transmission can indicate a particular command to execute by a device, and a device is expected to provide an execution result or data involved with the execution of the indicated command. In another example, following the message 2, it may be expected for a device to transmit message 3 to the reader in the 4-step random access. In yet another example, it can be a targeted device identification process for a particular device and the particular device is expected to transmit message 1 following the random access triggering or paging message from the reader. When a D2R transmission is expected by the device, but the device is unable to perform the intended D2R transmission, the device may instead transmit an energy status report. The energy status report may be 1-bit indication indicating that it cannot perform the intended D2R transmission. In another example, the energy status report may indicate how long it is expected that the device will become available again. This may be the situation that the device is running out of energy and will become unavailable soon for charging by harvesting energy. If the device is based on the RF energy harvesting, the energy status report can also indicate a request to provide carrier wave transmission for energy harvesting. In another example, the energy status report serves as a request to provide a carrier wave transmission and a reader or a carrier wave node transmits the carrier wave upon receiving the energy status report from one or more devices.

[0436] The energy status report is expected to be transmitted by a device within time interval [TR2D_min, TR2D_max] from the reception of the preceding R2D message, or according to the indicated D2R transmission timing, with or without a certain margin, e.g., [-Δ1, Δ2] wherein Δ1and Δ2can be the same or different.

[0437] For the case when an energy status report indicates how long it is expected that the device will become available again, the device is expected to be able to transmit or receive an R2D message from a reader. In one example, after the indicated unavailable time, the device is allowed to transmit a message indicating that the device is available for a certain time duration. The allowed certain time duration for the availability indication by the device may be defined in a specification of a system operation, indicated by a device, indicated by a reader, or indicated by the device and confirmed by the reader. In another example, after the indicated unavailable time, the device is required to monitor a potential R2D message for a certain time duration. The R2D message can be any message or, in particular, it may indicate that the previously paused communication will be resumed such that the device can perform the pending D2R transmission. The time duration for monitoring R2D transmission after unavailable time may be defined in a specification of a system operation or indicated by a reader.

[0438] FIG. 27 illustrates a timeline 2700 of an example R2D transmission following a R2D transmission according to embodiments of the present disclosure. For example, timeline 2700 can be followed by any of the readers described herein and any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0439] With reference to FIG. 27, an example R2D transmission following R2D transmission according to the disclosure is shown. The R2D message can be any of a paging message, a triggering message, message 2 / 4 of the 4-step random access or message 2 of the 2-step random access, any R2D message providing a command, or any transport block segmented into two R2D transmissions. In this case, the first R2D transmission provides the presence of the second subsequent R2D transmission. The indication in the first R2D transmission may also provide control information to receive the second R2D transmission such as time / frequency domain resources, MCS-like information (such as modulation scheme, modulation order, code rate, i.e., a ratio of information bits to total transmitted bits including redundancies), chip duration / rate, recipient device ID(s), repetitions, etc. If a part of control information is not provided, the device assumes that the same parameters provided for receiving the first R2D transmission apply for receiving the second R2D transmission. In another example, an R2D message is segmented into two R2D transmissions, one for the control (or header) part and the other one for the payload. In this case, the first R2D transmission provides an indication that a corresponding payload will be transmitted in the second subsequent R2D transmission. In yet another example, an R2D message is repeated N times and the first R2D transmission includes N1repetitions and the second R2D transmission includes N2repetitions, wherein N1+N2can be the same as N. In this case, the first R2D transmission provides the presence of the second subsequent R2D transmission. The indication in the first R2D transmission may also provide control information to receive the second R2D transmission including a number of repetitions N2to be received in the second R2D transmission. If a part of control information is not provided, the device assumes that the same parameters provided for receiving the first R2D transmission apply for receiving the second R2D transmission.

[0440] In one example, a subsequent R2D transmission cannot be earlier than a minimum time from the previous R2D reception time, denoted by TR2D_R2D_min, i.e., [TR2D_R2D_min, ∞]. In another example, there is a maximum time defined such that a subsequent R2D transmission is expected to follow the previous R2D transmission in time interval [TR2D_R2D_min, TR2D_R2D_max]. A maximum time limit may or may not be applicable for any two independent R2D transmissions; it may be applicable for two R2D transmissions related to each other, as described herein.

[0441] In one example, the preceding R2D transmission can indicate the presence of the following R2D transmission. The presence indication may be a 1-bit indication that there will be a following R2D transmission, wherein the R2D transmission is expected to occur in a predefined time later, in time interval [TR2D_R2D_min, ∞], or [TR2D_R2D_min, TR2D_R2D_max]. In another example, the preceding R2D transmission can indicate the presence and the timing of the following R2D transmission.

[0442] FIG. 28 illustrates a flowchart of an example device procedure 2800 for transmitting an energy status report according to embodiments of the present disclosure. For example, procedure 2800 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0443] The procedure begins in 2810, a device receives a first R2D message from a reader indicating a subsequent second R2D message. In 2820, the device transmits energy status report to the reader if the device is unable to receive the second R2D message.

[0444] With reference to FIG. 28, an example flowchart is shown for a device to transmit an energy status report between two consecutive R2D receptions according to the disclosure.

[0445] When a subsequent R2D transmission is expected following the previous R2D transmission, there may be a time duration allowed for a device to transmit an energy status report prior to the subsequent R2D transmission. The allowed time duration may be predefined in a specification of a system operation, or indicated to the device in the preceding R2D transmission. The indication may provide a presence of such a time duration for energy status report for a predefined time interval or the indication may provide both a presence of such time interval, and parameters related to indicate the time interval such as the start and the duration. During the allowed time interval, a device may transmit its energy status report to the reader including information disclosed herein for the energy status report contents. The energy status report can also indicate its unavailability to receive the subsequent R2D transmission or when it is expected to be available again.

[0446] FIG. 29 illustrates a timeline 2900 of an example D2R transmission following a D2R transmission according to embodiments of the present disclosure. For example, timeline 2900 can be followed by any of the readers described herein and any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0447] With reference to FIG. 29, an example D2R transmission following a preceding D2R transmission according to the disclosure is shown. The details disclosed for a D2R transmission following R2D described in FIG. 24 are applicable for the first D2R transmission following the preceding R2D transmission in FIG. 29.

[0448] The D2R message can be any transmission by a device, e.g., a transport block segmented into two D2R transmissions. In this case, the preceding R2D transmission indicates the segmentation, i.e., the presence of the first and the second D2R transmissions. The indication in the preceding R2D transmission provide control information to transmit the first and the second D2R transmissions such as time / frequency domain resources, MCS-like information (such as modulation scheme, modulation order, code rate, i.e., a ratio of information bits to total transmitted bits including redundancies), chip duration / rate, recipient device ID(s), repetitions, etc. If a part of control information is provided for the first D2R transmission but not for the second D2R transmission, the device assumes that the same parameters provided for transmitting the first D2R transmission apply for transmitting the second D2R transmission. In another example, a D2R message is segmented into two D2R transmissions, one for the control (or header) part and the other one for the payload. In this case, the preceding R2D transmission provides an indication that a D2R control and payload are transmitted in separate D2R transmissions. In yet another example, a D2R message is repeated N times and the first D2R transmission includes N1repetitions and the second D2R transmission includes N2repetitions, wherein N1+N2can be the same as N. In this case, the preceding R2D transmission provides an indication to split a D2R message into two D2R transmissions, and the indication may further include control information to transmit the first and the second D2R transmissions including a number of repetitions N1and N2to be transmitted in the first and the second D2R transmissions. If a part of control information is provided for the first D2R transmission but not provided for the second D2R transmission, the device assumes that the same parameters provided for transmitting the first D2R transmission apply for transmitting the second D2R transmission.

[0449] In one example, a subsequent D2R transmission cannot be earlier than a minimum time from the previous D2R transmission time, denoted by TD2R_D2R_min, i.e., [TD2R_D2R_min,∞]. In another example, there is a maximum time defined such that a subsequent D2R transmission is expected to follow the previous D2R transmission in time interval [TD2R_D2R_min, TD2R_D2R_max]. A maximum time limit may or may not be applicable for any two independent D2R transmissions; it may be applicable for two D2R transmissions related to each other, as exemplified herein.

[0450] In one embodiment, a device may determine the transmission timing of the second D2R transmission by itself such that the second transmission occurs in a predefined time later, in time interval [TD2R_D2R_min, ∞], or [TD2R_D2R_min, TD2R_D2R_max]. In another embodiment, the preceding R2D transmission indicates the second D2R transmission timing.

[0451] FIG. 30 illustrates a flowchart of an example device procedure 3000 for transmitting an energy status report according to embodiments of the present disclosure. For example, procedure 3000 can be performed by any of the devices described herein. This example is for illustration only and other embodiments can be used without departing from the scope of the present disclosure.

[0452] The procedure begins in 3010, a device receives a R2D message from a reader triggering a first D2R transmission and a second D2R transmission. In 3020, the device transmits energy status report in the first D2R transmission indicating its inability to perform the second D2R transmission or both the intended first and the second D2R transmission.

[0453] With reference to FIG. 30, an example flowchart is shown for a device to transmit an energy status report when the device is triggered for two consecutive D2R transmissions according to the disclosure.

[0454] When two consecutive D2R transmissions from a device are expected, the device may be unable to perform the second D2R transmission or both the first and the second D2R transmissions. In this case, the device may transmit its energy status report in the first D2R transmission, which may or may not include the first D2R payload depending on its ability to perform the transmission, indicating information disclosed earlier for the energy status report contents. The energy status report can also indicate its unavailability to transmit the second D2R transmission or both the first and the second D2R transmissions, or when it is expected to be available again.

[0455] FIG. 31 is a block diagram of a terminal or user equipment (UE) 3100 according to an embodiment of the disclosure. The UE of FIG. 31 corresponds to the UE of FIGS. 1 and 3.

[0456] The terminal is an electronic device capable of wireless communication, may include a User Equipment (UE), a portable phone, a smartphone, a tablet, an Internet of things (IoT) device, etc., having various form factors, and may perform wireless communication with a base station (BS) through a wireless channel.

[0457] Referring to FIG. 31, the UE 3100 may include at least one transceiver (hereinafter, referred to as simply “transceiver”) 3101, at least one processor (hereinafter, referred to as simply “processor”) 3102, and at least one memory (hereinafter, referred to as simply “memory”) 3103. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 3101, the processor 3102, and the memory 3103 of the UE 3100 may operate. However, components of the UE 3100 are not limited to the exemplary components illustrated in FIG. 31. In another embodiment, the UE 3100 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 3101, the processor 3102, or the memory 3103 may be integrated in the form of one component.

[0458] The transceiver 3101 may be a communication circuit or communication circuitry that enables the UE 3100 to perform wireless communication with a node or an entity of a network. For example, the transceiver 3101 may enable the UE 3100 to transmit or receive a signal to or from a BS through cellular communication, or to transmit or receive a signal to or from another UE through cellular communication. For example, the transceiver 3101 may support at least one of various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (3101) may include all subsequent generations of evolved wireless communications.

[0459] According to an embodiment, the UE 3100 may include a plurality of transceivers. For example, in the case of supporting evolved-universal terrestrial radio access-new radio (E-UTRA-NR) sual connectivity (EN-DC), the UE 3100 may include a first transceiver supporting the 4G LTE wireless communication and a second transceiver supporting the 5G NR wireless communication. According to another embodiment, in the case of supporting NR-dual connectivity (NR-DC), the UE 3100 may include a plurality of transceivers supporting the 5G NR wireless communication. According to still another embodiment, in the case of supporting near field wireless communication, the UE 3100 may separately include a transceiver supporting at least one standard in the group of wireless communication protocol standards as defined in the protocol standards for Bluetooth®, wireless local area network (WLAN) network (including institute of electrical and electronics engineers (IEEE) 802.11-2016 standard or its amendments, e.g., 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, without being limited thereto).

[0460] According to an embodiment, the transceiver 3101 may include various circuit structures used to transmit or receive signals to or from a BS through a wireless channel. The signals may include control information and data. For example, the transceiver 3101 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 3101 may output a signal received through a wireless channel to the processor 3102 and may transmit, through a wireless channel, a signal output from the processor 3102.

[0461] The processor 3102 may control general operations of the UE 3100 according to embodiments of the disclosure. The processor 3102 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 3102 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 3103, individually, collectively or in any combination thereof. Further, the processor 3102 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0462] The processor 3102 may be electrically, operatively, or communicatively coupled to the transceiver 3101 to control the transceiver 3101.

[0463] The processor 3102 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. For example, the processor 3102 may include a communication processor (CP) configured to control communication operations and an application processor (AP) configured to control execution of an upper layer (for example, an application layer) . In a specific embodiment, at least a part of the processor 3102 may be included in one chip and the other part of the processor 3102 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 3101 or the memory 3103.

[0464] The processor 3102 may perform or control or cause an operation of the UE 3100 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 3102 may control operations of the UE 3100 for processing a downlink signal received from a BS or generating and transmitting an uplink signal to a BS. To this end, the processor 3102 may execute a computer program, codes, or instructions stored in the memory 3103, so as to control other components of the UE 3100 to enable execution of various operations.

[0465] The memory 3103 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 3103 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0466] The memory 3103 may be electrically, operatively, or communicatively coupled to the processor 3102 and may be accessed by the processor 3102.

[0467] The memory 3103 may store a computer program, codes, or instructions executable by the processor 3102. According to an embodiment, a computer program, codes, or instructions executable by the processor 3102 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 3103, the processor 3102 may perform various functions according to an embodiment of the disclosure.

[0468] According to an embodiment of the disclosure, operations of the UE 3100 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 3103 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0469] FIG. 32 is a block diagram of a base station (BS) 3200 according to an embodiment of the disclosure. The BS of FIG. 32 corresponds to the UE of FIGS. 1 and 2.

[0470] The BS 3200 may perform wireless communication with at least one user equipment (UE) located within the area of the BS 3200 through a wireless channel.

[0471] Referring to FIG. 32, the BS 3200 may include at least one transceiver (hereinafter, referred to as simply “transceiver”) 3201, at least one processor (hereinafter, referred to as simply “processor”) 3202, and at least one memory (hereinafter, referred to as simply “memory”) 3203. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 3201, the processor 3202, and the memory 3203 of the BS 3200 may operate. However, components of the BS 3200 are not limited to the exemplary components illustrated in FIG. 32. In another embodiment, the BS 3200 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 3201, the processor 3202, or the memory 3203 may be integrated in the form of one component.

[0472] The transceiver 3201 may be a communication circuit or communication circuitry that enables the BS 3200 to perform wireless communication with a node or an entity of a network. For example, the transceiver 3201 may enable the BS 3200 to transmit or receive a signal to or from the UE X00 through cellular communication, or to transmit or receive a signal to or from another network entity through wireless communication. For example, the transceiver 3201 may support various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (3201) may include all subsequent generations of evolved wireless communications.. According to an embodiment, the transceiver 3201 may include various circuit structures used to transmit or receive signals to or from a UE through a wireless channel. The signals may include control information and data. For example, the transceiver 3201 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 3201 may output a signal received through a wireless channel to the processor 3202 and may transmit, through a wireless channel, a signal output from the processor 3202.

[0473] Meanwhile, according to an embodiment of the present disclosure, the BS 3200 may perform communication with a node or an entity of a network through wired or wireless communication. For example, the BS 3200 may perform wired or wireless communication with an adjacent BS, or a node or an entity of a core network through a backhaul network. Although not illustrated in FIG. 32, when the BS 3200 performs wired communication, the BS 3200 may further include a separate network interface for wired communication in addition to the transceiver 3201. The network interface may be referred to as network interface circuitry or communication interface circuitry.

[0474] The processor 3202 may control general operations of the BS 3200 according to embodiments of the disclosure. The processor 3202 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 3202 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 3203, individually, collectively or in any combination thereof. Further, the processor 3202 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0475] The processor 3202 may be electrically, operatively, or communicatively coupled to the transceiver 3201 to control the transceiver 3201.

[0476] The processor 3202 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 3202 may be included in one chip and the other part of the processor 3202 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 3201 or the memory 3203.

[0477] The processor 3202 may perform or control or cause an operation of the BS 3200 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 3202 may control operations of the BS 3200 for generating and transmitting a downlink signal to a UE or processing an uplink signal received from a UE. Otherwise, the BS 3200 may transmit or receive a signal to or from a neighboring BS, transfer a signal received from a UE to an upper node of the network, or transmit a signal transferred from an upper node of the network to a UE. To this end, the processor 3202 may execute a computer program, codes, or instructions stored in the memory 3203, so as to control other components of the BS 3200 to enable execution of various operations.

[0478] The memory 3203 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 3203 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0479] The memory 3203 may be electrically, operatively, or communicatively coupled to the processor 3202 and may be accessed by the processor 3202.

[0480] The memory 3203 may store a computer program, codes, or instructions executable by the processor 3202. According to an embodiment, a computer program, codes, or instructions executable by the processor 3202 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 3203, the processor 3202 may perform various functions according to an embodiment of the disclosure.

[0481] According to an embodiment of the disclosure, operations of the BS 3200 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 3203 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0482] The UE or the base station may perform various communication procedures related to the control plane or the user plane by cooperating with one or more network entities based on wireless communication. For example, the UE may communicate with network entity such as an Access and Mobility Management Function (AMF) or a Session Management Function (SMF) via the base station, or the base station may perform at least one communication procedure by directly transmitting and receiving signals to / from, or relaying signals between, the network entities.

[0483] The structure of the above-described network entity will be described in more detail with reference to the drawings.

[0484] FIG. 33 is a block diagram of a network entity 3300 according to an embodiment of the disclosure. The network entity of FIG. 33 corresponds to a network entity in the network of FIG. 1.

[0485] The network entity 3300 may include an entity (apparatus, device, or server, etc.) that performs one or more network functions (NFs) or a part of a network function constituting a core network (e.g., a 5th generation (5G) core (5GC)) in a communication system. In this case, multiple NFs may be implemented within a single network entity, or a single NF may be distributed and implemented across a plurality of network entities. In addition, when an NF is implemented within the network entity, the NF may be implemented in the form of software, and in such a case, a program for operating the NF may be stored in memory of the network entity 3300.

[0486] A single NF may be implemented by one or more instances, which may be deployed on the same network entity or distributed across multiple network entities to operate. The instance may be a software unit that logically executes a specific network function, and may be implemented in a form that is decoupled from physical hardware resources. Further, one or more NFs may be implemented in the form of one network slice to operate to satisfy specifications required by a particular service.

[0487] The NF may include at least one of an access and mobility management function (AMF), a session management function (SMF), a local session management function (L-SMF), a user plane function (UPF), a local user plane function (L-UPF), a policy control function (PCF), a unified data management (UDM), a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), an application function (AF), a network slice selection function (NSSF), a network data analytics function (NWDAF), a network slice admission control function (NSACF), an authentication server function (AUSF), or a data network (DN).

[0488] Referring to FIG. 33, the network entity 3300 may include at least one network interface 3301, at least one processor 3302 (hereinafter, “processor”), and at least one memory 3303 (hereinafter, “memory”). As described above, a NF may be implemented in the form of a physical device such as the network entity 3300, or may be virtualized and executed in the form of an instance. When implemented as an instance, the NF need not necessarily include physical components as illustrated in FIG. 33. In such a case, the instance may be logically represented as comprising one or more logical functional elements.

[0489] According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the network interface 3301, the processor 3302, and the memory 3303 of the network entity 3300 may operate. However, components of the network entity 3300 are not limited to the exemplary components illustrated in FIG. 33. In another embodiment, the network entity 3300 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in an embodiment, the network interface 3301, the processor 3302, or the memory 3303 may be integrated in the form of one component.

[0490] The network interface 3301 is a collective term for a transmitter part of the network entity 3300 and a receiver part of the network entity 3300, and may be a communication circuit for transmitting or receiving a signal to or from a user equipment (UE), a base station (BS), or another network entity. Here, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for a wired communication. For example, the network interface 3301 may include a circuit, logic, hardware, etc., configured to exchange a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless communication or wired communication. The network interface 3301 may operate using various protocols (e.g., non-access stratum (NAS) protocol). The network interface 3301 may also be referred to, for convenience of description or depending on implementation, as communication circuitry, network interface circuitry, or a communication interface circuitry.

[0491] The processor 3302 may control general operations of the network entity 3300 according to embodiments of the disclosure. The processor 3302 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 3302 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 3303, individually, collectively or in any combination thereof. Further, the processor 3302 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme. Further, it should be noted that, according to another embodiment, in a case where NF is implemented in the form of an instance, the network function may be not necessarily configured by physical hardware.

[0492] According to an embodiment, the processor 3302 may be electrically, operatively, or communicatively coupled to the network interface 3301 to control the network interface 3301.

[0493] The processor 3302 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 3302 may be included in one chip and the other part of the processor 3302 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the network interface 3301 or the memory 3303.

[0494] The processor 3302 may perform or control or cause an operation of the network entity 3300 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 3302 may control operations of the network entity 3300 for exchanging a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless or wired communication, using various protocols (e.g., NAS protocol). To this end, the processor 3302 may execute a computer program, codes, or instructions stored in the memory 3303, so as to control other components of the network entity 3300 to enable execution of various operations.

[0495] The memory 3303 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 3303 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0496] The memory 3303 may be electrically, operatively, or communicatively coupled to the processor 3302 and may be accessed by the processor 3302.

[0497] The memory 3303 may store a computer program, codes, or instructions executable by the processor 3302. According to an embodiment, a computer program, codes, or instructions executable by the processor 3302 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 3303, the processor 3302 may perform various functions according to an embodiment of the disclosure.

[0498] According to an embodiment of the disclosure, operations of the network entity 3300 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 3303 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0499] In one embodiment, a method for an Ambient Internet of Things (A-IoT) device to communicate with a reader is provided. The method includes receiving, in a first interval, a first reader-to-device (R2D) message and receiving a second R2D message. The first interval is based on a periodicity or an energy level of the A-IoT device. The method further includes determining whether to transmit a first physical device-to-reader channel (PDRCH) providing a first device-to-reader (D2R) message in response to reception of the second R2D message and, based on the determination, one of transmitting the first PDRCH or receiving a third R2D message that includes the same content as the second R2D message.

[0500] In another embodiment, an Ambient Internet of Things (A-IoT) device is provided. The A-IoT device includes a transceiver configured to receive, in a first interval, a first R2D message and receive a second R2D message. The first interval is based on a periodicity or an energy level of the A-IoT device. The A-IoT device further includes processing circuitry operably coupled with the transceiver. The processing circuitry configured to determine whether to transmit a first PDRCH providing a first D2R message in response to reception of the second R2D message. The transceiver is further configured to, based on the determination, one of transmit the first PDRCH or receive a third R2D message that includes the same content as the second R2D message.

[0501] In yet another embodiment, a reader is provided. The reader includes a processor and a transceiver operably coupled with the processor. The transceiver is configured to transmit, in a first interval, a first R2D message to an A-IoT device, receive a second R2D message, receive a first PDRCH providing a first D2R message in response to transmission of the second R2D message, and transmit a third R2D message that includes the same content as the second R2D message. The first interval is based on a periodicity or an energy level of the A-IoT device.

[0502] Meanwhile, although specific embodiments of the present disclosure have been described in detail, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims and equivalents thereof.

[0503] Any of the above variation embodiments can be utilized independently or in combination with at least one other variation embodiment. The above flowchart(s) illustrate example methods that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps.

[0504] Although the figures illustrate different examples of user equipment, various changes may be made to the figures. For example, the user equipment can include any number of each component in any suitable arrangement. In general, the figures do not limit the scope of the present disclosure to any particular configuration(s). Moreover, while figures illustrate operational environments in which various user equipment features disclosed in this patent document can be used, these features can be used in any other suitable system.

[0505] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the descriptions in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.

Claims

1.A method performed by an Ambient Internet of Things (A-IoT) device, the method comprising:receiving, in a first interval, from a reader, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device;receiving, from the reader, a second R2D message;identifying whether to transmit to the reader a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the reception of the second R2D message; andbased on the identification:transmitting, to the reader, the first PDRCH, orreceiving, from the reader, a third R2D message, the third R2D message including the same content as the second R2D message.2.The method of claim 1,wherein the first R2D message is an A-IoT paging message for initiating device identification via random access, andwherein the A-IoT paging message indicates one or more parameters related to performing random access.3.The method of claim 1,wherein the first R2D message is an A-IoT paging message initiating device identification via random access,wherein the second and third R2D messages are access trigger messages for triggering a number of access occasions,wherein a minimum time gap exists between a first physical reader-to-device channel (PRDCH) including the second R2D message and a second PRDCH including the third R2D message, andwherein the third R2D message is received based on a monitoring for the second PRDCH after the minimum time gap.4.The method of claim 1,wherein the first R2D message is an A-IoT paging message initiating device identification via random access,wherein the second and third R2D messages are access trigger messages triggering a number of access occasions,wherein a minimum time gap and a maximum time gap exist between a first physical reader-to-device channel (PRDCH) including the second R2D message and a second PRDCH including the third R2D message,wherein the third R2D message is received after the minimum time gap, for at least a second interval, andwherein the second interval is the maximum time gap minus the minimum time gap.5.The method of claim 1, further comprising:receiving, from the reader, a physical reader-to-device channel (PRDCH) with a fourth R2D message in response to transmission of the first PDRCH;transmitting, to the reader, a second PDRCH with a second D2R message, wherein:the first R2D message is an A-IoT paging message for initiating device identification via random access and indicating a total number of access occasions,the second and third R2D messages are access trigger messages for triggering a number of access occasions from the total number of access occasions,the first D2R message provides a 16-bit random number as an identifier,the fourth R2D message is a response to the first D2R message confirming the 16-bit random number, andthe second D2R message provides additional data based on reception of the fourth R2D message; andmonitoring a PRDCH after a time gap from transmission of the second PDRCH, wherein the time gap is based on a number of remaining untriggered access occasions from the total number of access occasions.6.The method of claim 1, further comprising:identifying, based on an energy level of the A-IoT device, to transmit a second PDRCH providing an energy status report (ESR) to the reader; andtransmitting, to the reader, the second PDRCH,wherein the ESR provides at least one of:information related to the energy level of the A-IoT device,an indication of an inability to communicate with the reader, oran expected time for the A-IoT device to become available for communication with the reader.7.The method of claim 1, further comprising:receiving, from the reader, a physical reader-to-device channel (PRDCH) providing information related to transmission of a second PDRCH providing an energy status report (ESR), wherein the ESR provides information related to an energy level of the A-IoT device;identifying, based on the energy level of the A-IoT device, to transmit the second PDRCH providing the ESR; andtransmitting, to the reader, the second PDRCH, based on reception of the information related to transmission of the second PDRCH.8.An Ambient Internet of Things (A-IoT) device comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the A-IoT device to:receive, in a first interval, from a reader, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device;receive, from the reader, a second R2D message;identify whether to transmit to the reader a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the reception of the second R2D message; andbased on the identification:transmit, to the reader, the first PDRCH, orreceive, from the reader, a third R2D message, the third R2D message including the same content as the second R2D message.9.The A-IoT device of claim 8,wherein the first R2D message is an A-IoT paging message for initiating device identification via random access, andwherein the A-IoT paging message indicates one or more parameters related to performing random access.10.The A-IoT device of claim 8,wherein the first R2D message is an A-IoT paging message initiating device identification via random access,wherein the second and third R2D messages are access trigger messages for triggering a number of access occasions,wherein a minimum time gap exists between a first physical reader-to-device channel (PRDCH) including the second R2D message and a second PRDCH including the third R2D message, andwherein the third R2D message is received based on a monitoring for the second PRDCH after the minimum time gap.11.The A-IoT device of claim 8,wherein the first R2D message is an A-IoT paging message initiating device identification via random access,wherein the second and third R2D messages are access trigger messages triggering a number of access occasions,wherein a minimum time gap and a maximum time gap exist between a first physical reader-to-device channel (PRDCH) including the second R2D message and a second PRDCH including the third R2D message,wherein the third R2D message is received after the minimum time gap, for at least a second interval, andwherein the second interval is the maximum time gap minus the minimum time gap.12.The A-IoT device of claim 8, wherein the instructions further cause the A-IoT device to:receive, from the reader, a physical reader-to-device channel (PRDCH) with a fourth R2D message in response to transmission of the first PDRCH;transmit, to the reader, a second PDRCH with a second D2R message, wherein:the first R2D message is an A-IoT paging message for initiating device identification via random access and indicating a total number of access occasions,the second and third R2D messages are access trigger messages for triggering a number of access occasions from the total number of access occasions,the first D2R message provides a 16-bit random number as an identifier,the fourth R2D message is a response to the first D2R message confirming the 16-bit random number, andthe second D2R message provides additional data based on reception of the fourth R2D message; andmonitor a PRDCH after a time gap from transmission of the second PDRCH, wherein the time gap is based on a number of remaining untriggered access occasions from the total number of access occasions.13.The A-IoT device of claim 8, wherein the instructions further cause the A-IoT device to:identify, based on an energy level of the A-IoT device, to transmit a second PDRCH providing an energy status report (ESR) to the reader; andtransmit, to the reader, the second PDRCH,wherein the ESR provides at least one of:information related to the energy level of the A-IoT device,an indication of an inability to communicate with the reader, oran expected time for the A-IoT device to become available for communication with the reader.14.A method performed by a reader, the method comprising:transmitting, in a first interval, to an Ambient Internet of Things (A-IoT) device, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device;transmitting, to the A-IoT device, a second R2D message;receiving, from the A-IoT device a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the transmission of the second R2D message; andtransmitting, to the A-IoT device, a third R2D message, the third R2D message including the same content as the second R2D message.15.A reader comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the reader to:transmit, in a first interval, to an Ambient Internet of Things (A-IoT) device, a first reader-to-device (R2D) message, wherein the first interval is based on a periodicity or an energy level of the A-IoT device;transmit, to the A-IoT device, a second R2D message;receive, from the A-IoT device a first physical device-to-reader channel (PDRCH) with a first device-to-reader (D2R) message in response to the transmission of the second R2D message; andtransmit, to the A-IoT device, a third R2D message, the third R2D message including the same content as the second R2D message.

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