Apparatuses, methods, and computer programs for a reader device and a low power device

Abstract

202407061 29 Abstract Provided are apparatuses, methods, and computer programs for a reader device and a low power device. The method (10) for a reader device (400; 500) and for controlling a low-power device (300) comprises providing (12) an indication to the low-power device (300) to indicate whether the low-power device (300) should continue monitoring signals transmitted by the reader device (400; 500). The method (10) further comprises transmitting (14) information about a duration to the low-power device (300), the information about the duration relating to a duration for which the low-power device (300) may go into sleep state within a monitoring cycle for the signals of the reader device (400; 500).

Description

[0001] 202407061 1

[0002] Apparatuses, Methods, and Computer Programs for a Reader Device and A Low Power Device

[0003] Description

[0004] The present disclosure relates to apparatuses, methods, and computer programs for a reader device and a low power device, and more particularly, but not exclusively, to a concept for controlling sleep and off cycles of a low power device using a reader device.

[0005] Ambient Internet of Things (A-loT) devices represent a new frontier in the loT landscape, characterized by their extremely low complexity, small form factor, and ability to operate with minimal power, often by harvesting energy from their surroundings. These devices are designed for specific, high-volume use cases where traditional powered devices are impractical or cost-prohibitive. Key applications include smart logistics and warehouse management, where A-loT devices can be attached to packages for real-time tracking and inventory control, replacing manual checks. Other use cases extend to medical inventory management in hospitals, intra-logistics in factories, and even visitor guidance in museums. The primary function in many of these scenarios is tag-based identification, which requires a very low data rate and allows for seamless interaction between the object and the network.

[0006] The implementation of A-loT devices often relies on technologies like multi-static backscattering, where the device communicates by reflecting and modulating ambient radio frequency (RF) signals. This method allows for a very low-power, passive form of communication. A crucial aspect of A-loT implementation is positioning, which serves two main purposes: locating the A-loT device itself for tracking purposes and using the A-loT device to locate other nearby devices. The positioning of these devices can be integrated into the existing 3GPP (3rd Generation Partnership Project) positioning architecture, using network nodes like gNBs to trigger and listen for positioning signals. Given the simple nature of A-loT devices, the conventional registration procedures used by more complex user equipment are not required, streamlining their deployment in various environments. 202407061 2

[0007] The 3GPP has been actively involved in the standardization of A-loT to ensure its integration into the broader cellular ecosystem. The work began with studies in the Service and System Aspects working group 1 (SA1 ), which resulted in Technical Report (TR) 22.840, outlining use cases, traffic scenarios, and service requirements for ambient power-enabled loT. Subsequently, the Radio Access Networks (RAN) plenary conducted feasibility studies, captured in TR 38.848, to assess the air interface design and coexistence with existing NR technologies. Following these studies, 3GPP has moved towards normative specification work in Release 19, focusing on specific scenarios and device types, with further enhancements and additional use cases planned for Release 20, starting in the latter half of 2025. This phased approach will help expand the 3GPP loT portfolio to include low-complexity, low-power devices, opening up new markets and applications for cellular technology.

[0008] Further details can be found in:

[0009] 1. Futurewei, “Discussion on Frame Structure and Timing Aspects for Ambient loT”, 3GPP TSG RANWG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2407611 ;

[0010] 2. Ericsson, “Frame structure and timing aspects for Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis Hefei, China, October 14-18, 2024, R1 -2407639;

[0011] 3. Huawei, HiSilicon, “On frame structure and timing aspects of Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2407670;

[0012] 4. Spreadtrum Communications, “Discussion on frame structure and timing aspects for Ambient loT” 2021 , 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2407708;

[0013] 5. Lenovo, “Discussion on frame structure and physical layer procedures for Ambient loT”, 2021 , 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2407818;

[0014] 6. Xiaomi, “Discussion on frame structure and timing aspects for Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2407971 ;

[0015] 7. HONOR, “Discussion on frame structure and timing aspects for Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2408234; 202407061 3

[0016] 8. Sharp, “Discussion on frame structure and timing aspects”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408251 ;

[0017] 9. Sony, “Frame structure and timing aspects for Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408411 ;

[0018] 10. InterDigital, Inc., “Frame structure and timing aspects of Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2408434;

[0019] 11 . Apple, “On remaining frame structure and timing aspects for AloT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408467;

[0020] 12. Samsung, “Considerations for frame structure and timing aspects”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408648;

[0021] 13. MediaTek Inc., “Frame structure and timing aspects”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408702;

[0022] 14. NTT DOCOMO, INC., “Study on frame structure and timing aspects for Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408788;

[0023] 15. Qualcomm Incorporated, “Frame structure and timing aspects”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408852;

[0024] 16. InterDigital, Inc., “Frame structure and timing aspects of Ambient loT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1- 2408434;

[0025] 17. Apple, “On remaining frame structure and timing aspects for AloT”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408467; and

[0026] 18. Samsung, “Considerations for frame structure and timing aspects”, 3GPP TSG RAN WG1 Meeting #118bis, Hefei, China, October 14-18, 2024, R1 -2408648.

[0027] Examples of the present disclosure are based on the finding that a time, during which an A-loT device is unavailable, can be reduced or managed by duty cycle monitoring and / or using suitable indications from a reader to transition to a sleep / off state. It is a further finding that duty cycling operation depends on the accuracy of a clock at the device at the start of the duty cycle. Examples therefore provide a mechanism that considers different clock accuracies of devices. 202407061 4

[0028] The proposed concept relates to techniques for managing communication between a reader device and a low-power device, particularly in a mobile communication system. Various examples of the present disclosure are based on the finding that optimizing the sleep / wake cycles of the low-power device can significantly reduce energy consumption and improve system efficiency. This is achieved by providing the low-power device with information regarding its sleep duration, allowing it to intelligently manage its monitoring of signals transmitted by the reader device. The proposed concept addresses the need for efficient power management in applications such as wireless sensor networks, Internet of Things (loT) devices, and mobile accessories.

[0029] Some aspects of the present disclosure relate to a method for a reader device, comprising providing an indication to a low-power device to signal whether the low- power device should continue monitoring signals transmitted by the reader device and transmitting information about a duration to the low-power device. The information relates to a duration for which the low-power device may enter a sleep state within a monitoring cycle for the signals of the reader device. By providing this information, the low-power device can optimize its power consumption by entering a sleep state for a predetermined duration, reducing unnecessary monitoring, and extending battery life.

[0030] To further refine the duration control, the method may comprise transmitting information about the duration as an index to one or more tables, wherein the one or more tables comprise multiple durations to select from. This allows for a flexible and configurable approach to sleep duration, enabling the reader device to adapt to varying conditions and optimize power consumption based on specific requirements.

[0031] To account for variations in clock accuracy at the low-power device, the index may point to one of a plurality of tables for different clock accuracies. This ensures that the sleep duration is accurately calculated and applied, even if the low-power device has a different clock accuracy than the reader device.

[0032] To further optimize power management, the method may comprise receiving information from the low-power device about its energy state, and determining the duration based on this energy state. This enables the reader device to dynamically 202407061 5 adjust the sleep duration based on the remaining battery life or energy harvested of the low-power device, improving and maximizing its operating time.

[0033] For enhanced control and customization, the method may further comprise receiving an indication of a selected duration and / or clock accuracy from the low-power device. This allows the low-power device to actively participate in the power management process, tailoring the sleep duration to its specific needs and capabilities.

[0034] To improve the efficiency of communication, the provision of the indication may comprise signaling the indication on a physical layer, and / or the reader device and the low-power device may communicate using signals specified for a mobile communication system. This leverages existing communication infrastructure and protocols, reducing complexity and overhead.

[0035] To ensure timely communication, the method may comprise timing a next message transmission to the low-power device based on the information about the duration and / or the indication. This allows the reader device to coordinate communication with the low-power device, minimizing latency and maximizing efficiency.

[0036] In scenarios requiring reliable wake-up signaling, the method may further comprise timing a next transmission of a wake-up signal to the low-power device based on the information regarding the duration and / or the indication. This ensures that the low- power device is reliably awakened from its sleep state when needed.

[0037] To facilitate seamless integration with existing communication networks, the method may comprise relaying messages between the low-power device and an access node of a mobile communication system. This allows the low-power device to participate in the broader communication network without requiring direct communication with the access node.

[0038] Some aspects of the present disclosure relate to a method for a low-power device to be controlled by a reader device, comprising receiving an indication from the reader device indicating whether the low-power device should continue monitoring signals transmitted by the reader device, and receiving information about a duration for which the low- 202407061 6 power device may enter a sleep state from the reader device. The information relates to a duration for which the low-power device may enter a sleep state within a monitoring cycle for the signals of the reader device. This allows the low-power device to intelligently manage its power consumption by entering a sleep state for a predetermined duration, thereby extending its battery life.

[0039] To enable flexible power management, the method may further comprise selecting an actual duration based on the information regarding the duration. This allows the low- power device to adapt its sleep duration based on the information received from the reader device.

[0040] To provide a configurable sleep duration, the information about the duration may comprise an index to one or more tables, wherein the one or more tables comprise multiple actual durations to select from. This may allow fine-grained control over the sleep duration, enabling the low-power device to optimize its power consumption based on specific requirements.

[0041] To ensure accurate sleep duration, the method may further comprise selecting a table and a table entry based on the index. This allows the low-power device to retrieve the appropriate sleep duration from the table based on the index provided by the reader device.

[0042] To improve the precision of power management, the method may further comprise estimating a clock accuracy of a clock within the low-power device and selecting the actual duration based on the estimated clock accuracy. This ensures that the sleep duration is accurately calculated and applied, even if the low-power device has a different clock accuracy than the reader device.

[0043] To facilitate communication and optimization, the method may further comprise transmitting information about an energy state of the low-power device to the reader device, and / or transmitting information about the selected duration to the reader device. This allows the reader device to adjust the sleep duration based on the low-power device’s energy state and allows for feedback regarding the sleep duration selection. 202407061 7

[0044] To conserve energy, the method may comprise monitoring signals from the reader device based on the indication. This ensures that the low-power device only monitors signals when necessary, minimizing energy consumption.

[0045] To optimize communication efficiency, the receiving of the indication may comprise receiving the indication on a physical layer. This leverages existing communication infrastructure and protocols, reducing complexity and overhead.

[0046] To ensure timely communication, the method may further comprise timing a next message reception from the low-power device based on the selected duration. This allows the low-power device to coordinate communication with the reader device, minimizing latency and maximizing efficiency.

[0047] To improve the reliability of wake-up signaling, the method may further comprise timing a wake-up cycle based on the indication. This ensures that the low-power device is reliably awakened from its sleep state when needed.

[0048] Some aspects of the present disclosure relate to a computer program having program code for performing one of the methods described herein when the computer program is executed on a computer, a processor, or a programmable hardware component. This allows the techniques described above to be implemented on a variety of hardware and software platforms.

[0049] Some aspects of the present disclosure relate to an apparatus for a reader device, comprising one or more interfaces configured to communicate within the communication system. The apparatus further comprises one or more processing devices configured to perform one of the methods described herein. This provides a hardware implementation of the techniques described above.

[0050] Some aspects of the present disclosure relate to an apparatus for a low-power device, comprising one or more interfaces configured to communicate within the communication system; and one or more processing devices configured to perform one of the methods described herein. This provides a hardware implementation of the techniques described 202407061 8 above for a low-power device. A mobile communication system is another example, including an example of the reader device and an example of the low-power device.

[0051] Some examples of apparatuses and / or methods will be described in the following by way of example only, and with reference to the accompanying figures, in which

[0052] Fig. 1 shows an example of a flowchart for a method for a reader device;

[0053] Fig. 2 depicts an example of a flowchart for a method for a low-power device;

[0054] Fig. 3 illustrates block diagrams of examples of apparatuses for a reader device, a low- power device, and a communication network;

[0055] Fig. 4 shows a reception cycle of an energy-harvesting low-power device;

[0056] Fig. 5 depicts another reception cycle of an energy-harvesting low-power device;

[0057] Fig. 6 illustrates an example of a discontinuous monitoring cycle;

[0058] Fig. 7 shows another example of a flowchart for a method for a reader device; and

[0059] Fig. 8 depicts an example of a flowchart for a method for a low-power device.

[0060] Some examples are now described in more detail with reference to the enclosed figures. However, other possible examples are not limited to the features of these embodiments described in detail. Other examples may include modifications of the features, as well as equivalents and alternatives to the features. Furthermore, the terminology used herein to describe certain examples should not be restrictive of further possible examples.

[0061] Throughout the description of the figures, same or similar reference numerals refer to same or similar elements and / or features, which may be identical or implemented in a modified form while providing the same or a similar function. The thickness of lines, layers, and / or areas in the figures may also be exaggerated for the sake of clarification. 202407061 9

[0062] When two elements A and B are combined using an “or”, this is to be understood as disclosing all possible combinations, i.e. , only A, only B, as well as A and B, unless expressly defined otherwise in the individual case. As an alternative wording for the same combinations, "at least one of A and B" or "A and / or B" may be used. This applies equivalently to combinations of more than two elements.

[0063] If a singular form, such as “a”, “an”, and “the” is used and the use of only a single element is not defined as mandatory either explicitly or implicitly, further examples may also use several elements to implement the same function. If a function is described below as implemented using multiple elements, further examples may implement the same function using a single element or a single processing entity. It is further understood that the terms "include", "including", "comprise", and / or "comprising", when used, describe the presence of the specified features, integers, steps, operations, processes, elements, components, and / or a group thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components, and / or a group thereof.

[0064] Fig. 1 shows an example of a flowchart for a method 10 for a reader device and for controlling a low-power device. The method 10 comprises providing 12 an indication to the low-power device to indicate whether the low-power device should continue monitoring signals transmitted by the reader device. The method 10 further comprises transmitting 14 information about a duration to the low-power device. The information about the duration relates to a duration for which the low-power device may enter a sleep state within a monitoring cycle for the signals of the reader device. As further indicated by the dashed line box (dashed lines indicate optional steps / actions) in Fig.1 , the method 10 may comprise an optional step of receiving 16 from the low-power device information about an energy state of the low-power device and determining the information about the duration based on the information about the energy state of the low-power device.

[0065] In examples, the information about the duration may comprise an index to one or more tables, and the one or more tables comprise multiple durations to select from. For example, the index points to one of a plurality of tables for different clock accuracies at 202407061 10 the low-power device, which may be selected based on the energy state of the low- power device.

[0066] Fig. 2 depicts an example of a flowchart for a method 20 for a low-power device to be controlled by a reader device. The method 20 comprises receiving 22 an indication from the reader device indicating whether the low-power device should continue monitoring signals transmitted by the reader device. The method further comprises receiving 24 information about a duration for which the low-power device may go into / enter a sleep state from the reader device. The information about the duration relates to a duration for which the low-power device may go into / enter a sleep state within a monitoring cycle for the signals of the reader device.

[0067] As further shown in Fig. 2, the method 20 may further comprise selecting 26 an actual duration based on the information about the duration. Another optional step is transmitting 28 information about an energy state of the low-power device to the reader device and / or transmitting information about the selected duration to the reader device.

[0068] The information about the duration may comprise an index to one or more tables, wherein the one or more tables comprise multiple actual durations to select from. The selecting 26 may comprise selecting a table and a table entry based on the index. As will be outlined in more detail subsequently, the method 20 may comprise estimating a clock accuracy of a clock of the low-power device and selecting the actual duration based on the estimated clock accuracy.

[0069] Fig. 3 illustrates block diagrams of examples of apparatuses 30, 40, and 50 for a reader device, a low-power device, and a communication network.

[0070] The apparatus 30 for the low-power device 300 (shown in dashed lines as being optional from the perspective of the apparatus 30) comprises one or more interfaces 32 configured to communicate within the communication system. The one or more interfaces 32 are coupled to one or more processing devices 34, which are configured to perform one of the methods for the low power device as described herein. 202407061 11

[0071] The apparatus 40 for the reader device 400 comprises one or more interfaces 42 configured to communicate within the communication system 50 and coupled to one or more processing devices 44 configured to perform one of the methods for the reader device as described herein.

[0072] Fig. 3 further illustrates another apparatus 50 for a reader device 500, which also comprises one or more interfaces configured to communicate in the communication system and coupled to one or more processing devices 54 configured to perform one of the methods for the reader device as described herein. In the scenario depicted in Fig. 3 the apparatus 40 in the reader device 400 is configured as a relay between reader device 500 and the low power device 300. In examples, the method for the reader device may hence also comprise relaying messages between the low-power-device and an access node or another reader device of the communication system.

[0073] As illustrated in Fig. 3, the respective one or more signal processing devices 34, 44, 54 are coupled to the respective one or more interfaces 32, 42, 52. The one or more interfaces 32, 42, 52 may serve as an interface for communicating in the communication system 600. The one or more interfaces 32, 42, 52 may correspond to one or more inputs and / or outputs for receiving and / or transmitting information, which may be in digital (bit) values or analog according to a specified code or protocol, within a module, between modules, or between modules of different entities. For example, an interface may comprise interface circuitry configured to receive and / or transmit information. In examples, an interface may comprise any means for obtaining, receiving, transmitting, or providing analog or digital signals or information, e.g., any connector, contact, pin, register, input port, output port, conductor, lane, etc., which allows providing or obtaining a signal or information.

[0074] The one or more interfaces 32, 42, 52 may be configured to communicate (transmit, receive, or both) in a wireless and / or wired manner, and they may be configured to communicate, i.e., transmit and / or receive signals or information with further internal or external components. The one or more interfaces 32, 42, 52, or the apparatuses 30, 40, 50 may comprise further components to enable communication in a (mobile) communication system or network; such components may include transceiver (transmitter and / or receiver) components, such as one or more Low-Noise Amplifiers 202407061 12

[0075] (LNAs), one or more Power-Amplifiers (PAs), one or more duplexers, one or more diplexers, one or more filters or filter circuitry, one or more converters, one or more mixers, accordingly adapted radio frequency components, one or more antennas, etc. For example, the respective one or more interfaces 32, 42, 52 may enable radio communication with UEs and communication between base stations, which can be directly and / or indirectly, wired and / or wireless, respectively.

[0076] The one or more (signal) processing devices 34, 44, 54 may be implemented using one or more processing units, one or more circuitries, or any means for processing, such as a processor, a computer, or a programmable hardware component being operable with accordingly adapted software. In other words, the described function of the one or more processing devices 34, 44, 54 may as well be implemented in software, which is then executed on one or more programmable hardware components. Such hardware components may comprise a general-purpose processor, a Digital Signal Processor (DSP), a micro-controller, etc.

[0077] In examples, the reader device may be terrestrial or non-terrestrial, and it may also be referred to as a base station, network node, etc. In case the reader device works as a relay, it may also comprise a component of user equipment (UE) or a mobile device. It may belong to an access network or to a core network. A non-terrestrial base station may be implemented in an aircraft, a satellite, or a High-Altitude Platform System (HAPS). A network entity, e.g., a non-terrestrial base station (implemented at a satellite, platform, airplane, etc.) or a terrestrial base station, may generate cells of a cellular system. A network entity may correspond to a remote radio head, a transmission point, an access point, a macro cell, a small cell, a micro cell, a pico cell, a femto cell, or a metro cell. The term small cell may refer to any cell smaller than a macro cell, e.g., a micro cell, a pico cell, a femto cell, or a metro cell. A network entity / base station can be a wireless interface of a wired network, which enables transmission and reception of radio signals to a communication device. Such a radio signal may comply with radio signals as, for example, standardized by 3GPP or, generally, in line with one or more of the above-listed systems. Thus, a network entity may be a base station and may correspond to a NodeB, an eNodeB, an ngNB, a gNB, a BTS (Base Transceiver Station), or an access point, all of which may be implemented in a satellite, plane, HAPS, etc. In case of a moving implementation in a satellite, an airplane, etc., the link 202407061 13 towards a core network of the communication system may also be implemented in a wireless manner.

[0078] The mobile communication system 600 may hence be cellular. The term cell refers to a coverage area of radio services provided by a transmission point, a remote unit, a remote head, a remote radio head, communication device, network entity, or a NodeB, an eNodeB, an ngNB, a gNB, a beam, or a satellite, respectively. The terms cell and base station may be used synonymously; a base station may generate multiple cells and it may be implemented in a high-altitude platform, a plane, a drone, a satellite, etc. A wireless communication device, such as the low power device e.g., the UE, can be registered or associated with at least one cell (e.g., the network entity); e.g., it can be associated with a cell such that data can be exchanged between the network and the mobile in the coverage area of the associated cell using a dedicated channel, connection, or link.

[0079] In general, the UE implementing the low power device may be a communication device that is capable of communicating wirelessly. In particular, however, the communication device may be a mobile communication device, e.g., a communication device that is suitable for being carried around by a user. For example, the communication device may be a User Terminal (UT) or UE within the meaning of the respective communication standards being used for mobile communication. For example, the communication device may be a mobile phone, such as a smartphone, a network access device embedded in a vehicle, ship, or airplane, or another type of mobile communication device, such as a computer, a laptop computer, a tablet computer, and so on.

[0080] For example, the communication device and the network entity may be configured to communicate in a cellular mobile communication system. Accordingly, the communication device and the network entity may be configured to communicate in a cellular mobile communication system, for example in a Sub-6GHz-based cellular mobile communication system (covering frequency bands between 400 MHz and, in the meantime, 7 GHz), in a mmWave-based cellular mobile communication system (covering frequency bands between 24 GHz and 71 GHz), or in the so-called mid-bands (covering frequency bands between 7 GHz and 24 GHz). For example, the 202407061 14 communication device and the network entity may be configured to communicate in a mobile communication system / cellular mobile communication system.

[0081] In general, the mobile communication system may, for example, correspond to one of the 3GPP-standardized mobile communication networks, where the term mobile communication system is used synonymously with mobile communication network. The mobile communication system may correspond to, for example, a 6th Generation system (6G), a 5th Generation system (5G), a New Radio (NR) system, Long-Term Evolution (LTE), an LTE-Advanced (LTE-A) system, High Speed Packet Access (HSPA), a Universal Mobile Telecommunication System (UMTS), or a UMTS Terrestrial Radio Access Network (UTRAN), an evolved-UTRAN (e-UTRAN), a Global System for Mobile communication (GSM) or Enhanced Data rates for GSM Evolution (EDGE) network, a GSM / EDGE Radio Access Network (GERAN), or mobile communication networks with different standards, for example, generally an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Time Division Multiple Access (TDMA) network, a Code Division Multiple Access (CDMA) network, a Wideband-CDMA (WCDMA) network, a Frequency Division Multiple Access (FDMA) network, a Spatial Division Multiple Access (SDMA) network, etc.

[0082] Examples may provide a way to ensure that an ambient loT (A-loT) device is available for communication with a reader and does not become unavailable at random occasions due to insufficient energy storage. Examples may consider the varying clock accuracies at the devices. Examples may introduce certain time ranges for the device to sleep which are dependent on the device's clock accuracy. Further, the reader indicates an index to denote the time for which the device may go into a low energy consuming SLEEP state after replying to the current R2D transmission by the reader. If the device clock accuracy is not sufficient, it can decide to go to the OFF state without maintaining a timer, instead of going into a SLEEP state. Before going into the SLEEP / OFF state, the device informs the reader of the index of the table it has used, so that the reader will be aware of when the device would wake up next.

[0083] Conventional concepts may make use of wake-up signals, duty cycle configuration, sleep indications, etc., but these are independent of the clock accuracy of the device. When a device is not required to receive / transmit data, it can go into a low-energy 202407061 15 consuming state where it also harvests energy from RF or other sources. However, this might be at an arbitrary time, since a device may become unavailable once its energy storage runs out, which could lead to the device missing messages from the reader.

[0084] As outlined above, the reader may include an indication in (each) R2D (reader-to- device) transmission of whether the device needs to keep monitoring for signals beyond the current R2D transmission. The reader also indicates a sleep timer value / period (information about duration) in the R2D transmission. Upon receiving the indication, depending on its clock accuracy, the device may go into a low-energy consuming state (SLEEP) until the timer / time period expires or an OFF state until it has sufficient storage to turn on.

[0085] Thereby, examples may ensure that the device is available for information exchange with a reader. Depending on clock accuracy, the device can either wake up after a certain time, or else the reader may wake the device up when it is required.

[0086] With respect to 3GPP RAN WGs (Radio Access Network Working Groups), studies are directed to energy harvesting impacts. A first device is assumed to have two states: On and OFF. A second device is assumed to have three states: ON, OFF, SLEEP. 3GPP seeks to identify function(s) of the device that can be assumed supported and assumed not supported in each of the device states, subject to:

[0087] > ON state supports at least: transmission, reception for communication;

[0088] > OFF state does not support at least: transmission, reception for communication;

[0089] > OFF state supports at least: energy harvesting; and

[0090] > SLEEP state supports at least:

[0091] > maintaining a memory content from ON state;

[0092] > maintaining a timer (RAN1 to discuss purpose(s) of timer);

[0093] > SLEEP state does not support at least: transmission;

[0094] > No additional physical layer signals / channels specific to support of SLEEP are introduced.

[0095] 3GPP seeks to identify reader knowledge / control of the above states and to approximately identify durations of the above device states. 202407061 16

[0096] For the study of the potential impact of device unavailability due to charging by energy harvesting, the following directions are captured in TR 38.769 (3GPP TR 38.769 V19.0.0 (2024-12), Technical Report, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on solutions for Ambient loT (Internet of Things) in NR (Release 19)):

[0097] • Direction 1 : Reader does not provide information to a device regarding when the device may become available / unavailable, and

[0098] • Direction 2: Reader can provide information to a device based on which the device may become available / unavailable.

[0099] According to the 3GPP presumptions, RF (Radio Frequency) sensitivity of UHF (Ultra High Frequency) RFID (Radio Frequency Identification) may be -20 dBm or higher. To achieve better coverage, A-loT should be operable with much lower Rx power. RAN1 agreed that device 1 (RF-ED, RF envelop detector) RF sensitivity is {-30 dBm, -36 dBm, -40 dBm, etc.} and device 2 (RF-ED) RF sensitivity is {-40 dBm, -45 dBm, etc.} for coverage / link budget study. A device has to rely on energy in energy storage for A-loT activities. Due to the limited amount of energy in the energy storage, the device cannot sustain its activity all the time. For example, with RF power level of -30 dBm and RF energy harvesting conversion efficiency of 10%, the device cannot keep active unless its power consumption is not more than 0.1 uW.

[0100] An A-loT device that relies on energy storage becomes inoperative (i.e. , the device is unavailable) when the energy level of the storage falls below a certain threshold (‘Turnoff’ threshold). Below this threshold, there is not sufficient voltage to power the device’s circuit.

[0101] Once a device becomes unavailable, the device is not able to communicate with a reader until its energy level of the storage reaches another threshold where the voltage is high enough to turn on the device’s circuit, e.g., 100%. The device becomes operative (i.e., the device is available) after the energy level reaches a certain threshold (‘Turn-on’ threshold), and until it falls below the ‘Turn-off’ threshold again.

[0102] Fig. 4 shows a reception cycle of an energy harvesting low-power device. Fig. 4 shows the amount of energy stored in a low power device over time. Furthermore, Fig. 4 shows 202407061 17 a ‘Turn-on’-threshold 402 and a ‘Turn-Off’ -threshold 404. In the diagram, it can be seen that the charging process proceeds until threshold 402 is reached, and the device is turned on. The device is then available and consumes more energy than it can charge. Consequently, the energy level drops until the device is switched off at threshold 404.

[0103] If there is a continuous RF transmission with a power level for energy harvesting as shown at the top of Fig. 4, the device availabi lity / unavailabil ity follows the time line in Fig. 4. The device can receive / transmit only during the time when the device is available. During the time when the device is unavailable, it charges the energy in the storage (e.g. capacitor / battery) using RF energy harvesting.

[0104] The reader continues to try reaching an A-loT device until it becomes available. A simple solution for a reader to communicate with an unavailable A-loT device is to wait until the device is available after charging. Without knowledge of the device’s availability or controllability of its unavailability, the reader has to repeat or retry the communications over time.

[0105] Fig. 5 depicts another reception cycle of an energy harvesting low-power device. Fig. 5 shows a timeline from left to right. At the top there are the reader transmissions, which is a long RF transmission for RF-EH (RF-energy harvesting). At time t1 the reader device starts repetitions / retries for an inventory query. In the middle, Fig. 5 shows the timeline for device #1 with its ’Turn-on’- and ‘Turn-Off’ thresholds and periods of unavailability. Shortly after t1 , device #1 is able to join. At the bottom, Fig. 5 shows the timeline for another device #2 with its ’Turn-on’- and ‘Turn-Off’ thresholds and periods of unavailability. As can be seen, shortly before t1 device #2 enters a long unavailability period due to charging. Therefore, device #2 cannot join until a much later point in time.

[0106] For example, suppose the case where a reader wants to do inventory for A-loT devices. The reader should repeat msg-0 over time so that whenever the target device is available, it can receive the msg-0. If there is no msg-0 received during an available time duration, the device is not aware of the inventory procedure from the reader. Therefore, the reader should send msg-0 at least once per device available time duration. Taking the examples of available energy in the table below; the available energy could be 0.25uJ for a 1 uF capacitor and 2.5uJ for a 10uF capacitor. If a device 202407061 18 consumes 1 uWfor monitoring the msg-0 during an available time duration, the available time durations for available energies of 0.25uJ and 2.5uJ are 0.25sec and 2.5sec, respectively. The reader should send msg-0 at least once per time duration.

[0107] An example for direction 1 to improve energy harvesting efficiency by deployment / implementation may use energizers. A network can deploy energizers densely such that all the devices are always fully energized and available. Devices can implement energy harvesting sources such as solar, vibration, etc., which increases the form factor of the A-loT devices. Using a large capacitor size cannot be a solution for direction 1 , as in direction 1 the reader cannot ensure all the devices are fully charged when the reader starts the overall inventory procedure.

[0108] Examples of device unavailable time durations (Turn-on with 1V, Turn-off with 0.7V) are given in the following table:

[0109] Examples may use device duty-cycle monitoring (DCM). In an example, for all A-loT devices DCM may be carried out. A device shortens or controls the available time duration. Outside the available time duration, the device is unavailable and harvests energy from RF without communication activities. For example, if a device reduces its available time duration to 10ms, the unavailable time duration is shortened to the period that is necessary to harvest energy of {10ms x power consumption}. 202407061 19

[0110] This is illustrated in Fig. 6. Fig. 6 shows similar timelines as Fig. 5. However, the two devices #1 and #2 are operated in DCM. Hence, their availability periods and unavailability periods are shorter and controlled. Assuming a device power consumption during the available time duration is 1 pW, the corresponding unavailable time duration for charging is summarized in the following table.

[0111] Examples of device unavailable time durations (Turn-on with 1V, Turn-off with 0.7V)

[0112] As outlined above, the reader transmits an indication as part of every R2D message which indicates whether the device should continue monitoring R2D signals or not. This indication may be transmitted as L1 or higher layer control information. Hence, in the method 10 for the reader device, the providing 12 of the indication may comprise signaling the indication on a physical layer and / or wherein the reader device and the low-power-device communicate using signals specified for a mobile communication system. The method 20 for the low power device may comprise receiving the indication on a physical layer and / or using signals specified for a mobile communication system.

[0113] This indication may be provided by the reader based on information about the energy status of the device, obtained using other signaling.

[0114] The reader also indicates an index to one or more tables to denote a duration for which the device may enter a sleep state. The duration of the sleep state may be chosen by 202407061 20 the reader based on the current energy status of the device. The table(s) may be provided in the specification, and the durations may be dependent on the clock accuracy of the device; i.e. , there are separate tables or values for different clock accuracy ranges.

[0115] An example set of tables comprises

[0116] Table 0:

[0117] For clock accuracy range 0; go to OFF state irrespective of index in R2D message.

[0118] Table 1 :

[0119] For clock accuracy range 1

[0120] Table 2:

[0121] For clock accuracy range 2

[0122] Based on the last clock correction / synchronization instance (e.g., using a start indicator / preamble transmitted by the reader), the device estimates its current clock accuracy. It then chooses the appropriate table based on the clock accuracy estimate and the index indicated by the reader. Based on this choice, the device either goes into sleep state for the appropriate period or goes into off state until (if table 0) the next on- state cycle. It sends the index of the table which it chose in a D2R message to the reader. Hence, the method 10 for the reader then comprises receiving an indication of a selected duration and / or clock accuracy from the low-power device. 202407061 21

[0123] The reader then knows when to transmit the next R2D message or wake-up signal to the device, as it can infer whether the device has gone to the OFF state or if it has gone to the SLEEP state, and how long it will be in that state. The method 10 for the reader then further comprises timing a next message transmission to the low-power device based on the information about the duration and / or the indication. Furthermore, method 10 may further comprise timing a next transmission of a wake-up signal to the low- power device based on the information about the duration and / or the indication.

[0124] On the side of the low power device, the method 20 may comprise monitoring signals of the reader device based on the indication received from the reader device. The method 20 can further include timing a next message reception from the low-power device based on the selected duration and / or timing a wake-up cycle based on the indication.

[0125] Fig. 7 shows another example of a flowchart for a method for a reader device. The method comprises sending 702 an indication to the device in an R2D message regarding the index of time to sleep. The method also comprises receiving 704 an indication on a chosen table from the device in reply to the D2R message. The method further includes sending 706 a next R2D message / wake-up signal according to the action taken by the device.

[0126] Fig. 8 depicts an example of a flowchart for a method for a low-power device. The method for the device comprises receiving 802 an indication in an R2D message and estimating 804 a clock accuracy and deciding to apply a suitable timer value or to go into the OFF state. The method further comprises sending an indication of the decision to the reader in a D2R (device-to-reader) message. The method further includes going into the OFF state or SLEEP state for the indicated time.

[0127] The aspects and features described in relation to a particular one of the previous examples may also be combined with one or more of the further examples to replace an identical or similar feature of that further example or to additionally introduce the features into the further example.

[0128] Examples may further be or relate to a (computer) program including a program code to execute one or more of the above methods when the program is executed on a 202407061 22 computer, processor or other programmable hardware component. Thus, steps, operations or processes of different ones of the methods described above may also be executed by programmed computers, processors or other programmable hardware components. Examples may also cover program storage devices, such as digital data storage media, which are machine-, processor- or computer-readable and encode and / or contain machine-executable, processor-executable or computer-executable programs and instructions. Program storage devices may include or be digital storage devices, magnetic storage media such as magnetic disks and magnetic tapes, hard disk drives, or optically readable digital data storage media, for example. Other examples may also include computers, processors, control units, (field) programmable logic arrays ((F)PLAs), (field) programmable gate arrays ((F)PGAs), graphics processor units (GPU), application-specific integrated circuits (ASICs), integrated circuits (ICs) or system-on-a-chip (SoCs) systems programmed to execute the steps of the methods described above.

[0129] It is further understood that the disclosure of several steps, processes, operations or functions disclosed in the description or claims shall not be construed to imply that these operations are necessarily dependent on the order described, unless explicitly stated in the individual case or necessary for technical reasons. Therefore, the previous description does not limit the execution of several steps or functions to a certain order. Furthermore, in further examples, a single step, function, process or operation may include and / or be broken up into several sub-steps, -functions, -processes or - operations.

[0130] If some aspects have been described in relation to a device or system, these aspects should also be understood as a description of the corresponding method. For example, a block, device or functional aspect of the device or system may correspond to a feature, such as a method step, of the corresponding method. Accordingly, aspects described in relation to a method shall also be understood as a description of a corresponding block, a corresponding element, a property or a functional feature of a corresponding device or a corresponding system.

[0131] The following claims are hereby incorporated in the detailed description, wherein each claim may stand on its own as a separate example. It should also be noted that 202407061 23 although in the claims a dependent claim refers to a particular combination with one or more other claims, other examples may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are hereby explicitly proposed, unless it is stated in the individual case that a particular combination is not intended. Furthermore, features of a claim should also be included for any other independent claim, even if that claim is not directly defined as dependent on that other independent claim.

[0132] 202407061 24

[0133] Reference numerals

[0134] 10 method for reader device

[0135] 12 providing an indication

[0136] 14 transmitting information about a duration

[0137] 16 receiving from the low-power device

[0138] 20 method for low-power device

[0139] 22 receiving an indication

[0140] 24 receiving information about a duration

[0141] 26 selecting an actual duration

[0142] 28 transmitting information

[0143] 30 apparatus for low-power device

[0144] 32 one or more interface

[0145] 34 one or more processing devices

[0146] 40 apparatus for reader device

[0147] 42 one or more interface

[0148] 44 one or more processing devices

[0149] 50 apparatus for reader device

[0150] 52 one or more interface

[0151] 54 one or more processing devices

[0152] 300 low power device

[0153] 400 reader device

[0154] 402 ‘Turn-Off’ threshold

[0155] 404 ‘Turn-On’ threshold

[0156] 500 reader device

[0157] 600 communication network

[0158] 702 send indication

[0159] 704 receive indication

[0160] 706 send next R2D message

[0161] 802 receive indication

[0162] 804 estimate clock accuracy

[0163] 806 indicate decision

[0164] 808 go into OFF or SLEEP state

Claims

202407061 25ClaimsWhat is claimed is:1 . A method (10) for a reader device (400; 500) and for controlling a low-power device (300), the method (10) comprising providing (12) an indication to the low-power device (300) to indicate whether the low-power device (300) should continue monitoring signals transmitted by the reader device (400; 500); and transmitting (14) information about a duration to the low-power device (300), the information about the duration relating to a duration for which the low-power device (300) may go into sleep state within a monitoring cycle for the signals of the reader device (400; 500).

2. The method (10) of claim 1 , wherein the information about the duration comprises an index to one or more tables, wherein the one or more tables comprise multiple durations to select from.

3. The method (10) of claim 2, wherein the index points to one of a plurality of tables for different clock accuracies at the low-power device (300).

4. The method (10) of one of the claims 2 or 3, further comprising receiving (16) from the low-power device (300) information about an energy state of the low-power device (300) and determining the information about the duration based on the information about the energy state of the low-power device (300).

5. The method (10) of one of the claims 1 to 4, further comprising receiving an indication on a selected duration and / or clock accuracy from the low-power device (300).

6. The method (10) of one of the claims 1 to 5, wherein the providing of the indication comprises signaling the indication on a physical layer and / or wherein the202407061 26 reader device (400; 500) and the low-power-device (300) communicate using signals specified for a communication system (600).

7. The method (10) of one of the claims 1 to 6, further comprising timing a next message transmission to the low-power device (300) based on the information about the duration and / or the indication.

8. The method (10) of one of the claims 1 to 7, further comprising timing a next transmission of a wake-up signal to the low-power device (300) based on the information about the duration and / or the indication.

9. The method (10) of one of the claims 1 to 8, further comprising relaying messages between the low-power-device (300) and an access node of a mobile communication system (600).

10. A method (20) for a low-power device (300) to be controlled by a reader device (400; 500), the method (20) comprising receiving (22) an indication from the reader device (400; 500) indicating whether the low-power device (300) should continue monitoring signals transmitted by the reader device (400; 500); and receiving (24) information about a duration for which the low-power device (300) may go into sleep state from the reader device (400; 500), the information about the duration relating to a duration for which the low-power device (300) may go into sleep state within a monitoring cycle for the signals of the reader device (400; 500).

11. The method (20) of claim 10, further comprising selecting (16) an actual duration based on the information about the duration.

12. The method (20) of one of the claims 10 or 11 , wherein the information about the duration comprises an index to one or more tables, wherein the one or more tables comprise multiple actual durations to select from.202407061 2713. The method (20) of claim 12, further comprising selecting a table and a table entry based on the index.

14. The method of one of the claims 11 to 13, further comprising estimating a clock accuracy of a clock of the low-power device and selecting the actual duration based on the estimated clock accuracy.

15. The method (20) of one of the claims 11 to 14, further comprising transmitting (28) information about an energy state of the low-power device to the reader device, and / or transmitting (28) information about the selected duration to the reader device.

16. The method (20) of one of the claims 10 to 15, monitoring signals of the reader device (400; 500) based on the indication.

17. The method (20) of one of the claims 10 to 16, wherein the receiving of the indication comprises receiving the indication on a physical layer.

18. The method (20) of one of the claims 10 to 17, further comprising timing a next message reception from the low-power device (300) based on the selected duration.

19. The method (20) of one of the claims 10 to 18, further comprising timing a wake-up cycle based on the indication.

20. A computer program having a program code for performing one of the methods (10; 20) of claims 1 to 19, when the computer program is executed on a computer, a processor, or a programmable hardware component.21 . An apparatus (30) for a low-power device (300), the apparatus (30) comprising one or more interfaces (32) configured to communicate in the communication system (600); and202407061 28 one or more processing devices (34) configured to perform one of the methods (10) of claims 10 to 19.

22. A low-power device (300) comprising the apparatus (30) of claim 21 .

23. An apparatus (40; 50) for a reader device (400; 500), the apparatus (40; 50) comprising one or more interfaces (42; 52) configured to communicate in the communication system (600); and one or more processing devices (44; 54) configured to perform one of the methods (20) of claims 1 to 9.

24. A reader device (400, 500) comprising the apparatus (40, 50) of claim 23.

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