Improved inventory procedures for radio tags

Abstract

A radio tag is discloses which is a member of at least one or more radio tag groups. The radio tag group includes a plurality of group members. The plurality of group members include at least the radio tag and a further radio tag. Each group member of the radio tag group has assigned a member ID. At a communication instance, the radio tag is to communicate with a reader device querying the radio tag group.

Description

[0001] IMPROVED INVENTORY PROCEDURES FOR RADIO TAGS

[0002] Description

[0003] The present invention relates to the field of radio tags and reader devices for wireless communication systems or networks, more specifically to low complexity radio tags employing low-power communication techniques. Embodiments of the present invention concern enhancements of inventory procedures for low complexity radio devices or radio tags.

[0004] Low complexity radio devices or radio tags using backscattered communication techniques for transmitting a signal are well-known, see, e.g., Jin-Ping Niu, Geoffrey Ye Li in “An Overview on Backscatter Communications”, Journal of Communications and Information Networks, Vol. 4, No. 2, June 2019. One example of low complexity radio devices using backscatter communication techniques are radio frequency identification, RFID, tags. An RFID tag identification is performed through a series of interactions between an RFID reader and an RFID tag. Radio frequency signals are used to communicate and exchange data between the RFID reader and the RFID tag. An RFID tag, which has a unique identification, ID, responds to a query of an RFID reader by transmitting information stored in the RFID tag. This process, also known as inventorying, uses anti-collision algorithms, like the slotted ALOHA protocol, to manage multiple tags within a RFID reader’s field or communication range and for avoiding signal interferences. The RFID tags are typically identified individually, with the RFID reader sequentially querying each RFID tag to compile a list of all RFID tags within the RFID reader’s communication range. The actual identification process varies dependent on the type of RFID tags in use, which may be passive, semi-passive or active. Passive RFID tags, which are most common due to their cost-effectiveness, rely entirely on the RFID reader’s signal for power. These RFID tags backscatter the received signal to transmit data stored in the RFID tag. Semi-passive RFID tags have an internal battery to power the circuits of the RFID tag thereby improving the read range and the data transmission reliability. Active RFID tags, which are equipped with an own power source, may communicate over greater distances and may store more data, making them suitable for applications requiring more coverage.

[0005] Another technology using low complexity devices using backscatter communication techniques for low power consumption involve Internet-of-Thing, loT, devices in accordance

[0006] HHI 2 - 2024P67419EP - final with the 3GPP standard. Such loT devices are currently further developed so as to provide ultra-low complexity devices with ultra-low power consumption, especially for very low end loT applications. Such further developed loT devices, like Ambient loT devices, are well- below the existing 3GPP technologies, e.g., narrowband loT (NB-loT) devices, enhanced Machine Type Communication (eMTC) devices, or devices with reduce capabilities (RedCap devices). The further development of loT devices towards ultra-low complexity devices with ultra-low power consumption is not driven by a desire to replace existing low- power wide area, LPWA, systems, rather, it is driven by the desire to provide a missing piece of ultra-low complexity and ultra-low power devices in the 3GPP system such that other 3GPP devices, like a user equipment or user device, UE, a base station, BS, or any New Generation Radio Access Network (NG-RAN) node may directly or indirectly connect with such devices or may be used for controlling or managing a whole system including thousands of low complexity devices like Ambient loT devices. The ultra-low complexity loT devices having ultra-low power consumption may be classified in the following power classes:

[0007] (1 ) The device has a peak power consumption of about 1 pW and includes an energy storage. The device has an initial sampling frequency offset, SFO, of up to 10xppm. The device provides neither a downlink, DL, amplification nor an uplink, LIL, amplification. An uplink transmission of the device is backscattered on a carrier wave provided by an external source.

[0008] (2) The device has a peak power consumption less than a few hundred pW and includes an energy storage. The device has an initial sampling frequency offset, SFO, of up to 10xppm. The device provides a downlink, DL, amplification and / or an uplink, UL, amplification. An UL transmission may be generated internally by the device or may be backscattered on a carrier wave provided by an external source.

[0009] A maximum communication distance of such devices, when being deployed indoors, is between 10 m and 50 m. Different topologies are supported, e.g., topology 1 and / or topology 2. In detail, topology 1 refers to a direct communication between the reader and the device, while topology 2 involves the use of an intermediate node. In the latter, a user equipment, UE, may be provided in such topologies as an intermediate note which is under control of the 3GPP network for supporting the loT devices with low complexity and low power consumption which may have no Radio Resource Control, RRC, states, provide for no mobility support, i.e., do not support any cell selection and / or cell reselection functions, and

[0010] HHI 2 - 2024P67419EP - final do not have any feedback capabilities, like hybrid acknowledge request, HHARQ, and / or acknowledge request, ARQ, capabilities.

[0011] Like in RFID systems, also in the above-described loT systems, each loT device is assigned with a unique identifier, ID, and / or a group-ID for allowing the identification and tracking of a single loT device or of a set of loT devices.

[0012] The above-described RFID systems and loT systems focus on an individual tag identification using, for example, a unique identifier or individual tag identification, which may be used for single devices or for a group of devices. However, such systems are not capable to handle scenarios in which the devices belong to different groups simultaneously.

[0013] For instance, a supply chain item may belong to multiple groups depending on different aspects, like product type (e.g., fragile, electronic, perishable), storage requirements (e.g., refrigerated, climate-controlled), and shipment details (e.g., batch number, shipping method). In such a context, conventional RFID / loT systems which support single tag / single group operations, lack mechanisms for managing overlapping group memberships. Such limitations hinder an efficient management and tracking across multiple functional categories leading to multiple constraints. For example, the rigid structure of single group- ID indications reduces the system flexibility and makes it difficult to adapt to changing environments where items or individuals frequently shift between different groups. Also the lacking capacity to manage overlapping groups makes resource allocation and tracking cumbersome and difficult and leads to undesired delays.

[0014] Further, conventional systems do not inherently support the requirements for a group reconfiguration responsive to changing operational needs which, in turn, restricts the ability of conventional systems to adapt to real-time conditions, such as fluctuating inventory levels, varying environment conditions or shifting operational properties. Also the lack of mechanisms for managing group-specific commands and responses increases a complexity in applications that require dynamic grouping.

[0015] In addition, conventional systems may lead to problems when managing multiple radio devices or radio tags due to collisions that occur during respective inventory rounds. When a plurality of radio devices or radio tags is queried by a reader device, also referred to as an inventory round or inventorying, despite the applied anti-collision algorithms, collisions may occur, especially in situations in which multiple devices attempt to communicate

[0016] HHI 2 - 2024P67419EP - final simultaneously which leads to an interference. Such an interference may, in turn, lead to a data loss or to the requirement of performing retransmissions. Thus, conventional approaches, due to the potential collisions during inventory rounds, may not be efficient for handling or managing multiple radio tags.

[0017] It is noted that the information in the above section is only for enhancing the understanding of the background of the present invention and, therefore, it may contain information that does not form prior art that is already known to a person of ordinary skill in the art.

[0018] Starting from the above, there may a need for enhancing inventory procedures for low complexity radio tags or devices, for example for RFID tags or for low complexity loT devices.

[0019] Embodiments of the present invention may be implemented in a wireless communication system including RAN entities, like base stations, reader devices, like UEs or mobile terminals, and radio tags, like A-loT devices or RFID tags. Fig. 1 is a schematic representation of a wireless communication system including a plurality of radio tags 100a, 100b and one or more reader devices 200, like a UE or a RAN entity, e.g., a base station. The radio tags 100a, 100b and the reader device 200 may communicate via respective wireless communication links or channels 300a, 300b. The radio tags 100a, 100b may include one or more antennas ANTTagor an antenna array having a plurality of antenna elements, a signal processor or chip 102a, 102b and a transceiver 104a, 1040b, coupled with each other. The reader device 200 includes one or more antennas ANTRor an antenna array having a plurality of antennas, a signal processor 202, and a transceiver 202 coupled with each other. The system or network of Fig. 1 , the one or more radio tags 100a, 100b of Fig. 1 , and the one or more reader devices 200 of Fig. 1 may operate in accordance with the inventive teachings described herein.

[0020] Aspect 1

[0021] In accordance with a first aspect of the present invention, an approach is provided which avoids collisions during inventory rounds by querying a group of radio tags, wherein each member of the radio tag group has assigned a member ID which defines for a respective radio tag within the group a communication instance at which the radio tag is to communicate with the reader device which queries the radio tag group. In accordance with embodiments of the first aspect of the present invention, at one communication instance only one of the radio tags but none of the other radio tags within the radio tag group is

[0022] HHI 2 - 2024P67419EP - final allowed to transmit, thereby avoiding collisions during the inventory round initiated by the reader device as the respective radio tags do not communicate simultaneously, rather they use the different communication instances, thereby avoiding interference and a possible data loss or a possible need for retransmissions.

[0023] Thus, embodiments of the first aspect of the present invention mitigate the problems encountered in the prior art by grouping radio tags and assigning each radio tag a member ID within the group which, in turn, identifies for the radio tag a communication instance at which this radio tag and none of the other radio tags in the group is to communicate with the reader device.

[0024] The present invention provides a radio tag, wherein the radio tag is a member of at least one or more radio tag groups, the radio tag group including a plurality of group members, the plurality of group members including at least the radio tag and a further radio tag, and each group member of the radio tag group having assigned a member ID, and at a communication instance, the radio tag is to communicate with a reader device querying the radio tag group.

[0025] In accordance with embodiments, the member ID is unique.

[0026] In accordance with embodiments, when communicating with the reader device, the radio tag is

[0027] - to only receive a signal from a reader device, e.g., is restricted to only receive or decode signals received from a reader device, and / or

[0028] - to only transmit a signal to a reader device.

[0029] In accordance with embodiments, the communication instance is defined by the member ID of the radio tag.

[0030] In accordance with embodiments, the radio tag is a wireless device capable to transmit and / or receive radio frequency signals with one or more reader devices.

[0031] In accordance with embodiments, the radio tag is a wireless device capable to receive radio frequency signals from one or more reader devices and to transmit using a backscatter communication.

[0032] HHI 2 - 2024P67419EP - final In accordance with embodiments, at the communication instance among the group members only, the radio tag is to communicate with the reader device but none of the other group members.

[0033] In accordance with embodiments, at the communication instance, the radio tag is to transmit at instances associated to the member ID.

[0034] In accordance with embodiments, at the communication instance, the radio tag is to process and / or respond to transmissions associated with the member ID.

[0035] In accordance with embodiments, at the communication instance none of the group members are to communicate with the reader device, except for the radio tag.

[0036] In accordance with embodiments, the respective member IDs of the group members define respective different communication instances for the respective radio tags of the radio tag group.

[0037] In accordance with embodiments, the member ID of the radio tag defines one or more of the following communication instances:

[0038] - a time at which the radio tag is to communicate with the reader device, e.g., a slot,

[0039] - a frequency on which the radio tag is to communicate with the reader device, e.g., a shift applied to a CW during the backscattered response,

[0040] - a code the radio tag is to use for a communication with the reader device,

[0041] - a beam, e.g., beam ID, on which the radio tag is to communicate with the reader device.

[0042] In accordance with embodiments, the member ID of the radio tag defines a time instance from a predefined sequence of time instances at which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command.

[0043] In accordance with embodiments, the member ID of the radio tag indicates a time offset with which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command, wherein the time offset is counted from a receipt of the control message.

[0044] HHI 2 - 2024P67419EP - final In accordance with embodiments, the time offset depends on one or more of the following:

[0045] - a number of transmission opportunities, e.g., slots, in addition to the time instance, e.g., defined by the member ID,

[0046] In accordance with embodiments, the time offset further depends on a clock signal, e.g., a general clock signal provided by one or more of the following:

[0047] - a base station,

[0048] - a reader device,

[0049] - another UE,

[0050] - another radio tag.

[0051] In accordance with embodiments, the time offset is a fixed value, which is configured and or pre-configured in the radio tag, e.g., a fixed time interval or a fixed time limit or a fixed number of one or more slots, within which a reader tag can respond or is allowed to respond to a reader device query.

[0052] In accordance with embodiments, the member ID of the radio tag defines a time slot from a predefined sequence of time slots in which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command.

[0053] In accordance with embodiments, the predefined sequence of time slots comprises a number of time slots that is equal to or greater than a number of group members of the radio tag group.

[0054] In accordance with embodiments, responsive to the reader device querying the radio tag group, the radio tag is to receive an initial control signal the reader device, wherein the reader device may be one of the following:

[0055] - a base station,

[0056] - a user equipment, another type of 3GPP RAN nodes, e.g., a non-terrestrial network, NTN,

[0057] - a non-3GPP node,

[0058] - a device, e.g., a transmitter, which can emit such a signal, and the initial control signal comprising one or more communication instances, e.g., slots.

[0059] HHI 2 - 2024P67419EP - final In accordance with embodiments, responsive to the reader device querying the radio tag group, the radio tag is to

[0060] - listen to the initial control signal, and responsive to determining the communication instance, e.g., time slot, defined by the member ID of the radio tag, communicate with the reader device.

[0061] In accordance with embodiments, a first slot indicator in the predefined sequence of time slots is the control message from the reader device.

[0062] In accordance with embodiments, responsive to the reader device querying the radio tag group, the radio tag is to reduce its power consumption, e.g., by staying in an energy saving mode, until determining the time slot defined by the member ID of the radio tag.

[0063] In accordance with embodiments, the energy saving mode comprises one or more of a Discontinuous Reception (DRX) mode, an eDRX mode,

[0064] - a mode where a WUS signal or a broadcast signal or a synchronization signal can still be received.

[0065] In accordance with embodiments, the radio tag is to terminate a communication with the reader device responsive to one or more of the following:

[0066] - receiving a next slot indicator from the reader device,

[0067] - receiving an end signal to terminate communication, e.g., a termination signal or an acknowledgement, ACK,

[0068] - a lapse of a configured or preconfigured timer, exceeding a maximum transmission duration, exceeding a maximum number of transmissions, exceeding a maximum number of transmissions within a configured or preconfigured time interval,

[0069] - detecting an energy level below a configured or preconfigured threshold, a mobility condition,

[0070] - detecting interference that exceeds a configured or preconfigured threshold.

[0071] In accordance with embodiments, the slot indicator is a signal having a configured or preconfigured pattern or a configured or preconfigured sequence, e.g., of high-low

[0072] HHI 2 - 2024P67419EP - final amplitude transitions or of a pulse width modulated signal, PWM, e.g., with a width of signal pulse being varied in proportion to an amplitude of an analog input signal.

[0073] In accordance with embodiments, a time slot is identified by two or more slot indicators, the slot indicators being different.

[0074] In accordance with embodiments, the two or more slot indicators are successive, e.g., following each other in time domain.

[0075] In accordance with embodiments, a time gap between a first and one or more second slot indicators is limited by a configured and / or preconfigured threshold.

[0076] In accordance with embodiments, the time slots are indicated with an alternating sequence of two or more slot indicators.

[0077] In accordance with embodiments, responsive to missing a slot indicator, the radio tag is to detect this and / or use a subsequent slot indicator for correcting a count of the time slots.

[0078] In accordance with embodiments, the slot indicators are followed by or contain a sequence.

[0079] In accordance with embodiments, the two or more slot indicators are identical or different slot indicators.

[0080] In accordance with embodiments, the two or more slot indicators identifying the time slot are obtained by including a truncated slot index, e.g., by using only a certain number of the least significant bits or by a modulo operation.

[0081] In accordance with embodiments, responsive to losing synchronization due to one or more missed slot indicators, the radio tag is to:

[0082] - stop transmitting any data,

[0083] - wait for a specific signal before further transmitting any data,

[0084] - wait for a slot indicator including a count indication,

[0085] - wait for a start slot indicator,

[0086] - wait for a stop slot indicator,

[0087] - wait for a specific sequence of one or more start and / or stop slot indicators.

[0088] HHI 2 - 2024P67419EP - final In accordance with embodiments, the radio tag is to receive from the reader device, in addition to querying the radio tag group, one or more additional signals for controlling a transmission process and / or for supporting one or more certain scenarios that may arise during the communication.

[0089] In accordance with embodiments, responsive to the reader device querying the radio tag group, the radio tag, while being in an energy saving mode, is to monitor transmissions from the reader device for the one or more additional signals.

[0090] In accordance with embodiments, the one or more additional signals comprise an adjust signal, the adjust signal indicating one or more of the following:

[0091] - skipping of one or more time slots,

[0092] - jumping to a different time slot,

[0093] - changing one or more transmission parameters, e.g., responsive to a certain channel characteristic between the radio tag and the reader device, a coding modulation or repetition factor may be adjusted for ensuring that the communication between the radio tag and the reader device remains robust and efficient.

[0094] In accordance with embodiments, the one or more additional signals comprise an end signal, the end signal causing all radio tags of the radio tag group to enter an energy saving mode.

[0095] In accordance with embodiments, the end signal causes an active radio tag to stop its data transmission and to enter an energy saving mode.

[0096] In accordance with embodiments, the one or more additional signals comprise a repeat signal, the repeat signal causing the radio devices to repeat a

[0097] - last time slot, or the n last time slots, n > 1 , or

[0098] - a specific time slot.

[0099] In accordance with embodiments, the member ID of the radio tag defines a frequency from a predefined set of frequencies on which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory call.

[0100] HHI 2 - 2024P67419EP - final In accordance with embodiments, the member ID of the radio tag indicates a frequency offset with which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., like an inventory call, the frequency offset being from a frequency on which the control message is transmitted.

[0101] In accordance with embodiments, the frequency offset indicates either a positive or a negative offset with respect to a carrier frequency.

[0102] In accordance with embodiments, frequency offset defined by the member ID of the radio tag comprises:

[0103] - a zero offset so that the radio tag is to respond to the control message on o the same frequency on which the control message is transmitted, or o on a configured or preconfigured frequency, or

[0104] - a non-zero offset so that the radio tag is to respond to the control message on a frequency higher or lower by the offset than o the frequency on which the control message is transmitted, or o the configured or preconfigured frequency.

[0105] In accordance with embodiments, the radio tag is to code a response to a control message from the reader device querying the radio tag group, like an inventory call or command, by including or encoding into the response the member ID or a part of the member ID or a processed form of the member ID, or scrambling or interleaving the response with the member ID or a part of the member ID or a processed form of the member ID, or

[0106] - applying a configured or preconfigured coding scheme or sequence to respond to the control message that yield encoded signals having a certain property, like an orthogonality under correlation or a cross-correlation property or an autocorrelation property, e.g., having a peak value above or below a configured or pre-configured threshold and / or having certain symmetry constraints, the relationship between two distinct signals may have different characteristics or magnitudes.

[0107] In accordance with embodiments, the member ID of the radio tag defines the configured or preconfigured coding scheme from a set of coding schemes, e.g., using an index or code index.

[0108] HHI 2 - 2024P67419EP - final In accordance with embodiments, the member ID of the radio tag defines the configured or preconfigured sequence from a set of sequences being orthogonal to each other, such as Zadoff-Chu-sequences or Gold sequences.

[0109] In accordance with embodiments, the radio tag belongs to one of a plurality of radio tag groups, the radio tag having assigned a member ID for one or more of the groups, and the radio tag is to receive from the reader device, querying the radio tag group, a signaling indicating the queried radio tag group.

[0110] In accordance with embodiments, the radio tag belongs to a plurality of radio tag groups, the radio tag having assigned a joint member ID for more than one or all of the groups it belongs to.

[0111] In accordance with embodiments, the radio tag group includes radio tags within a certain range, e.g., a configured or preconfigured pathloss, received power, e.g., RSSI or SNR or SINR, or a distance from the reader device such as Euclidean distance, e.g., measured in meters, or a zone, e.g., having a certain measure and / or zone ID. A zone may have a certain size in height and width or a particular shape, e.g., rectangular or circular, defined by a center and radius.

[0112] In accordance with embodiments, the radio tag group includes a plurality of subgroups, and the radio tag is assigned to a subgroup using one or more criteria.

[0113] In accordance with embodiments, the radio tag is assigned to a subgroup and the subgroup is addressed by a subgroup ID.

[0114] In accordance with embodiments, the subgroups are in an ordered list.

[0115] In accordance with embodiments, a signal tells that a next subgroup of the list is to communicate in a subsequent communication instance.

[0116] In accordance with embodiments, the radio tag associates itself with a certain group or subgroup depending on one or more of the following:

[0117] - a signal quality,

[0118] - a received power,

[0119] HHI 2 - 2024P67419EP - final - a location,

[0120] - application requirements, such as latency and or reliability requirements,

[0121] - a range or distance to the reader,

[0122] - a power status,

[0123] - a bandwidth, e.g., a bandwidth defined in frequency domain, e.g., by a set of subcarriers,

[0124] - a type of data, e.g., transmission of inventory messages or transmission of a health status of a product, e.g., temperature or accelerometer values.

[0125] In accordance with embodiments, one of the plurality of subgroups has a channel access priority over the other subgroups.

[0126] In accordance with embodiments, the radio tag is to

[0127] - receive from the reader device a repetition signal, e.g., the reader device providing the repetition signal responsive to a collision of a transmission of the radio tag with a transmission of another radio tag not being a group member.

[0128] In accordance with embodiments, the radio tag is to respond to a control signal to perform one or more of the following: a retransmission of the transmission, a DRX or eDRX, e.g., in case a max. retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold.

[0129] In accordance with embodiments, the control signal indicates a plurality of retransmission instances, and the radio tag is to select one of the plurality of retransmission instances.

[0130] In accordance with embodiments, the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,

[0131] - a set of different codes for a retransmission that can be separated by the reader device,

[0132] - a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

[0133] HHI 2 - 2024P67419EP - final In accordance with embodiments, a retransmission instance comprises one or more of the following:

[0134] - transmission of an exact copy of the previously transmitted signal,

[0135] - transmission of a redundancy version of the previously transmitted signal,

[0136] - transmission of a different signal,

[0137] - a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.

[0138] In accordance with embodiments, the radio tag is to select the retransmission instance randomly.

[0139] In accordance with embodiments, the radio tag group is a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit, and responsive to having data to be transmitted to the reader device, the radio tag is to join the SR group and remain in the SR group until the SR group is queried by the reader device and the radio tag has successfully transmitted the data.

[0140] In accordance with embodiments, responsive to having data to be transmitted to the reader device, the radio tag is to initiate a communication with the reader device.

[0141] In accordance with embodiments, the radio tag is to initiate the communication with the reader device independent of the communication occurrence and / or independent of being queried by the reader device via the radio tag group.

[0142] In accordance with embodiments, the radio tag is to send a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

[0143] In accordance with embodiments, the radio tag is to send the request signal once, repeatedly, continuously, periodically or in certain RACH slots indicated by the reader device.

[0144] HHI 2 - 2024P67419EP - final In accordance with embodiments, the radio tag is to continue sending the request signal until receiving a response from the reader device.

[0145] In accordance with embodiments, the radio tag is to initiate the communication with the reader device independent of the communication occurrence when having data to send and to include the data or part of the data in the request signal.

[0146] In accordance with embodiments, for communicating with the reader device, e.g., if there is data to be transmitted, the radio tag is to:

[0147] - send a data message, the data message including control and / or payload data

[0148] In accordance with embodiments, the radio tag is to perform one or more of the following:

[0149] - send an access message including a random access preamble, sequence or ID to the reader device indicating that the radio tag wants to initiate a communication, receive from the reader device a response message including a random ID number corresponding to the access message, receive from the reader device one or more further messages, the one or more further messages including a feedback message indicating a successful or unsuccessful transmission of the data message, and a message including control and / or payload data for the radio tag.

[0150] In accordance with embodiments, responsive to the feedback message indicating an unsuccessful transmission of the data message, the radio tag is to:

[0151] - retransmit the data message.

[0152] In accordance with embodiments, the radio device is to

[0153] - transmit the access message and the data message in one message, and / or

[0154] - receive the response message and the feedback message in one message.

[0155] The present invention provides a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, and the reader device is to query a radio tag group, the radio tag group including a plurality of group members, the plurality of group members including at least a first radio tag and a second radio tag, and each group member of the radio tag group having assigned a

[0156] HHI 2 - 2024P67419EP - final member ID, the member ID of a radio tag defining a communication instance for a communication with the reader device.

[0157] In accordance with embodiments, the reader device is to configure the group members of the radio tag group with respective member IDs, the respective member IDs defining one or more of the following communication instances:

[0158] - a time at which the radio tag is to communicate with the reader device, e.g., a slot,

[0159] - a frequency on which the radio tag is to communicate with the reader device, e.g., a shift applied to the CW during the backscattered response,

[0160] - a code the radio tag is to use for a communication with the reader device,

[0161] - a beam, e.g., beam ID, on which the radio tag is to communicate with the reader device.

[0162] In accordance with embodiments, the respective member IDs define respective time slots from a predefined sequence of time slots in which a radio tag is to respond to the query from the reader device querying the radio tag group, and the reader device is to transmit, responsive to querying the radio tag group, an initial control signal, the initial control signal comprising a plurality of slots, each slot indicating a time slot from the predefined sequence of time slots.

[0163] In accordance with embodiments, the reader device is to send to one or more or all of the radio tags of the radio tag group, in addition to querying the radio tag group, one or more additional signals for controlling a transmission process and / or for supporting one or more certain scenarios that may arise during the communication.

[0164] In accordance with embodiments, the one or more additional signals comprise an adjust signal, the adjust signal indicating one or more of the following:

[0165] - skipping of one or more time slots,

[0166] - jumping to a different time slot,

[0167] - changing one or more transmission parameters, e.g., responsive to a certain channel characteristic between the radio tag and the reader device, a coding modulation or repetition factor may be adjusted for ensuring that the communication between the radio tag and the reader device remains robust and efficient.

[0168] HHI 2 - 2024P67419EP - final In accordance with embodiments, the one or more additional signals comprise an end signal, the end signal causing all radio tags of the radio tag group to enter an energy saving mode.

[0169] In accordance with embodiments, the one or more additional signals comprise a repeat signal, the repeat signal causing the radio devices to repeat

[0170] - last time slot, or the n last time slots, n > 1 , or

[0171] - a specific time slot.

[0172] In accordance with embodiments, the radio tag belongs to one of a plurality of radio tag groups, the radio tag having assigned a member ID for each of the groups, and the reader device is to send a signaling indicating the queried radio tag group.

[0173] In accordance with embodiments, the reader device is to

[0174] - send to one or more or all of the radio tags of the radio tag group a control signal, the reader device providing the control signal responsive to one or more of the following: o a collision of a transmission of the radio tag with a transmission of another radio tag not being a group member, o an external interference, from 3GPP or non-3GPP systems, o a degradation in the communication channel, o an decoding error at the radio device, o a failure on receiving an explicit or implicit acknowledgement signal

[0175] - responsive to providing the control signal, receive a retransmission of the transmission.

[0176] In accordance with embodiments, the control signal indicates a plurality of retransmission instances, and wherein the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,

[0177] - a set of different codes for a retransmission that can be separated by the reader device,

[0178] HHI 2 - 2024P67419EP - final - a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

[0179] In accordance with embodiments, the radio tag group is a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit.

[0180] In accordance with embodiments, the reader device is to receive a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that a radio tag has data to send and needs to be queried.

[0181] The present invention provides a method for operating a radio tag, wherein the radio tag is a member of at least one or more radio tag groups, the radio tag group including a plurality of group members, the plurality of group members including at least the radio tag and a further radio tag, and each group member of the radio tag group having assigned a member ID, the method comprising: at a communication instance, communicating with a reader device querying the radio tag group.

[0182] The present invention provides a method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: querying a radio tag group, the radio tag group including a plurality of group members, the plurality of group members including at least a first radio tag and a second radio tag, and each group member of the radio tag group having assigned a member ID, the member ID of a radio tag defining a communication instance for a communication with the reader device.

[0183] Aspect 2

[0184] In accordance with a second aspect of the present invention, the problems encountered in prior art approaches are addressed by monitoring a radio environment by a reader device for the radio tags so that the radio tag, responsive to querying one or more radio tags, either grouped or non-grouped, and determining that for one or more of the transmissions received from the queried radio tags, a collision occurs with a transmission from another radio tag, a repetition or control signal is provided to the radio tag so as to cause the radio tag to perform

[0185] HHI 2 - 2024P67419EP - final a retransmission of one or more previous transmissions to the reader device. The repetition signal indicates a plurality of retransmission instances from which the radio tag selects one retransmission instance for performing its retransmission to the radio device.

[0186] Thus, in accordance with embodiments of the second aspect of the present invention, despite the fact that collisions may occur during a communication between radio tags and reader device, a management of the multiple radio tags handled by a reader device is improved as necessary retransmissions, due to collisions experienced in the radio environment, are allowed on predefined retransmission instances. Thus, retransmissions occur within a well-defined radio environment thereby reducing the potential collisions when performing retransmissions which, in turn, increases the efficiency to handle or manage multiple radio tags by a reader device.

[0187] The present invention provides a radio tag, wherein the radio tag is to communicate with a reader device responsive to a query by the reader device, responsive to a control signal from the reader device, the radio tag is to perform a retransmission of one or more previous transmissions to the reader device, and the control signal indicates a plurality of retransmission instances, and the radio tag is to select one of the plurality of retransmission instances for the retransmission.

[0188] In accordance with embodiments, the radio tag is to receive the repetition signal responsive to one or more of the following:

[0189] - a collision of a transmission of the radio tag with a transmission of another radio tag, an external interference, from 3GPP or non-3GPP systems,

[0190] - a degradation in the communication channel,

[0191] - a decoding error at the radio device,

[0192] - a failure on receiving an explicit or implicit acknowledgement signal

[0193] In accordance with embodiments, the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,

[0194] - a set of different codes for a retransmission that can be separated by the reader device,

[0195] HHI 2 - 2024P67419EP - final - a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

[0196] In accordance with embodiments, the radio tag is to select the retransmission instance randomly.

[0197] In accordance with embodiments, the radio tag is to respond to a control signal to perform one or more of the following: a retransmission of the transmission, a DRX or eDRX, e.g., in case a max. retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold.

[0198] In accordance with embodiments, a retransmission instance comprises one or more of the following:

[0199] - transmission of an exact copy of the previously transmitted signal,

[0200] - transmission of a redundancy version of the previously transmitted signal,

[0201] - transmission of a different signal,

[0202] - a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.

[0203] The present invention provides a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, and responsive to a collision of a transmission of a radio tag with a transmission of another radio tag, the reader device is to send to the radio tag a control signal, the control signal causing the radio tag to perform a retransmission of one or more previsions transmissions to the reader device, and the control signal indicates a plurality of retransmission instances.

[0204] In accordance with embodiments, the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,

[0205] HHI 2 - 2024P67419EP - final - a set of different codes for a retransmission that can be separated by the reader device,

[0206] - a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

[0207] The present invention provides a method for operating a radio tag capable of communicating with a reader device responsive to a query by reader device, the method comprising: responsive to a control signal from the reader device, performing a retransmission of one or more previous transmissions to the reader device, wherein the control signal indicates a plurality of retransmission instances, and the radio tag selects one of the plurality of retransmission instances for the retransmission.

[0208] The present invention provides a method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: responsive to a collision of a transmission of a radio tag with a transmission of another radio tag, sending to the radio tag a control signal, the control signal causing the radio tag to perform a retransmission of one or more previsions transmissions to the reader device, wherein the control signal indicates a plurality of retransmission instances.

[0209] Aspect 3

[0210] In accordance with the third aspect of the present invention, improvements in the management of multiple radio tags is achieved. Conventionally, radio tags are allowed to transmit data they gathered only responsive to being queried by the reader device. However, radio tags may acquire data which needs to be transmitted to the reader device as soon as possible so that an undesired delay until the radio tag is actually queried by the reader device is undesired. Therefore, in accordance with embodiments of the third aspect of the present invention, a radio tag is allowed to initiate a communication with the reader device responsive to having data to be transmitted to the reader device.

[0211] Thus, in accordance with embodiments of the third aspect of the present invention, the problems encountered in prior art approaches, namely the delay between gathering data by

[0212] HHI 2 - 2024P67419EP - final a radio tag and actually forwarding it to the reader device, are overcome by allowing the radio tag to request an uplink transmission to the reader device as soon as it received or gathered certain data, for example, data having a high priority that need to be forwarded by the reader device to the wireless network as soon as possible, for example, in situations in which a radio tag determines a certain parameter of a monitored environment, like a temperature, to exceed a certain threshold which may require some counteraction, like in a manufacturing process or factory process. An increase in temperature at one location may require immediate counteraction so as to make sure that the temperature returns to the desired range. In such situations, embodiments of the third aspect of the present invention are advantageous as they allow the radio tag to immediately request uplink of the gathered data, for example, the mentioned critical or high priority data.

[0213] The present invention provides a radio tag, wherein the radio tag is to communicate with a reader device responsive to a query by reader device, and responsive to having data to be transmitted to the reader device, the radio tag is to initiate a communication with the reader device.

[0214] In accordance with embodiments, for initiating a communication with the reader device, the radio tag is to

[0215] - join a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit, and

[0216] - remain in the SR group until the SR group is queried by the reader device and the radio tag has successfully transmitted the data.

[0217] In accordance with embodiments, the radio tag is to initiate the communication with the reader device independent of being queried by the reader device.

[0218] In accordance with embodiments, the radio tag is to send a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

[0219] In accordance with embodiments, the radio tag is to send the request signal once, repeatedly, continuously, periodically or in certain RACH slots indicated by the reader device.

[0220] HHI 2 - 2024P67419EP - final In accordance with embodiments, the radio tag is to continue sending the request signal until receiving a response from the reader device.

[0221] The present invention provides a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, and the reader device is to query a radio tag responsive to receiving an uplink transmission request from the radio tag.

[0222] In accordance with embodiments, the reader device is to query a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit.

[0223] In accordance with embodiments, the reader device is to query the radio tag responsive to a request signal from the radio tag, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

[0224] The present invention provides a method for operating a radio tag capable of communicating with a reader device responsive to a query by reader device, the method comprising: responsive to having data to be transmitted to the reader device, initiating a communication with the reader device.

[0225] The present invention provides a method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: querying a radio tag responsive to receiving an uplink transmission request from the radio tag.

[0226] In accordance with embodiments of all aspects of the present invention, the radio tag is connectable to the reader device, the reader device being an entity of a wireless communication system and capable of querying one or more radio tags or one or more radio tag groups or sub-groups.

[0227] In accordance with embodiments of all aspects of the present invention, the radio tag is to communicate with the reader device using a first communication protocol, and the reader

[0228] HHI 2 - 2024P67419EP - final device is to communicate with a core network of the wireless communication system using a second communication protocol.

[0229] In accordance with embodiments of all aspects of the present invention, the wireless communication system comprises one of the following: a 3GPP network or a WiFi network or an Radio-frequency identification, RFID, network, the first communication protocol is the same as of different from the second communication protocol, and may be one of the following: a 3GPP communication protocol, e.g., A-loT or NB-loT or eMTC or LTE-M, a non-3GPP radio, e.g., WiFi communication protocol or an RFID communication protocol or a lower power wide area protocol, LPWA, e.g., mioty®, or a satellite radio protocol, e.g., Iridium®.

[0230] In accordance with embodiments of all aspects of the present invention, the radio tag comprises a backscatter transmitter for transmitting a signal using a backscattered signal, wherein the radio tag is to receive an incident signal for querying the data tag group from the reader device and transmit the signal using the backscattered signal responsive to the incident signal.

[0231] In accordance with embodiments of all aspects of the present invention, the radio tag comprises one the following: an loT Internet-of-Things, loT, device, an NB-loT or eMTC device, a low power wide area device, LPWA, an Ambient loT device,

[0232] - a sensor device,

[0233] - an actuator device,

[0234] - a passive device,

[0235] - a device without active transmitter, using backscatter communication, e.g. of a carrier wave, CW, signal, an Radio-frequency identification, RFID, device, like an RFID tag.

[0236] In accordance with embodiments of all aspects of the present invention, the radio tag is to communicate with the reader device using a first communication protocol, and the reader device is to communicate with a core network of the wireless communication system using a second communication protocol.

[0237] HHI 2 - 2024P67419EP - final In accordance with embodiments of all aspects of the present invention, the wireless communication system comprises one of the following: a 3GPP network or a WiFi network or an Radio-frequency identification, RFID, network, the first communication protocol is the same as of different from the second communication protocol, and the second communication protocol is one of the following: a 3GPP communication protocol or a WiFi communication protocol or an RFID communication protocol.

[0238] In accordance with embodiments of all aspects of the present invention, the reader device comprises one the following: a mobile terminal of a wireless communication network, e.g., a user equipment, LIE, of a 3GPP network or of a WiFi network, an Radio-frequency identification, RFID, device, like an RFID reader.

[0239] In accordance with embodiments of all aspects of the present invention, the radio tag comprises one the following: an loT Internet-of-Things, loT, device, an NB-loT or eMTC device, a low power wide area device, LPWA, an Ambient loT device,

[0240] - a sensor device,

[0241] - an actuator device,

[0242] - a passive device,

[0243] - a device without active transmitter, using backscatter communication, e.g. of a carrier wave, CW, signal, an Radio-frequency identification, RFID, device, like an RFID tag.

[0244] Further present invention provides a wireless communication network, comprising: one or more reader devices in accordance with embodiments all aspects of the present invention, and. one or more radio tags in accordance with embodiments of all aspects of the present invention.

[0245] HHI 2 - 2024P67419EP - final Further present invention provides a computer program product comprising instructions which, when the program is executed by a computer, causes the computer to carry out one or more methods in accordance with the present invention.

[0246] Embodiments of the present invention are now described in further detail with reference to the accompanying drawings:

[0247] Fig. 1 illustrates a schematic representation of a wireless communication system for implementing a radio tag and an reader device in accordance with embodiments of the present invention,

[0248] Fig. 2 illustrates a radio tag in accordance with embodiments of a first aspect of the present invention,

[0249] Fig. 3 illustrates a reader device in accordance with embodiments of a first aspect of the present invention,

[0250] Fig. 4 illustrates a wireless communication system in accordance with embodiments of a first aspect of the present invention,

[0251] Fig. 5 illustrates an embodiment of a radio tag group including four radio tags,

[0252] Fig. 6 illustrates a frequency offset used by the radio tags for the group of Fig. 5 group for transmitting to the reader device in accordance with embodiments of the present invention,

[0253] Fig. 7 illustrates a code offset used by the radio tags for the group of

[0254] Fig. 5 group for transmitting to the reader device in accordance with embodiments of the present invention,

[0255] Fig. 8(A) and Fig. 8(B) illustrate a time offset used by the radio tags for the group of

[0256] Fig. 5 group for transmitting to the reader device in accordance with embodiments of the present invention,

[0257] Fig. 9 illustrates the use of a slot indicator as a synchronization signal for radio tags according to embodiments of the present invention,

[0258] Fig. 10(A) and Fig.10(B) illustrates the use of multiple slot indicators as a synchronization signal for radio tags according to embodiments of the present invention,

[0259] Fig. 1 1 (A) to Fig. 1 1 (G) illustrate a communication of a radio tag of a radio tag group with a reader device according to embodiments of the present invention,

[0260] HHI 2 - 2024P67419EP - final Fig. 12 illustrates a radio tag in accordance with embodiments of a second aspect of the present invention,

[0261] Fig. 13 illustrates a reader device in accordance with embodiments of a second aspect of the present invention,

[0262] Fig. 14 illustrates a radio tag in accordance with embodiments of a third aspect of the present invention,

[0263] Fig. 15 illustrates a reader device in accordance with embodiments of a third aspect of the present invention,

[0264] Fig. 16A and Fig. 16B are schematic representations of an example of a terrestrial wireless communication network in which embodiments of the present invention may be implemented, and

[0265] Fig. 17 illustrates an example of a computer system on which units or modules as well as the steps of the methods described in accordance with the inventive approach may execute.

[0266] In the following description of embodiments of the present invention, in the accompanying drawings the same or similar elements have assigned the same reference signs.

[0267] First Aspect

[0268] Fig. 2 illustrates a radio tag or radio device 100 in accordance with embodiments of the first aspect of the present invention. The radio tag, like an Ambient loT device or an RFID device, is a member of a radio tag group and communicates with a reader device, like a user equipment, UE, or a base station, BS, or a WiFi device, or a RFID reader, at an instance, like a certain time or frequency or code, that is defined by a member ID assigned to the radio tag 100. Stated differently, the radio tag 100 is a member of a radio tag group. The radio tag group includes a plurality of group members. The plurality of group members includes at least the radio tag and a further radio tag. Each group member of the radio tag group has assigned a member ID 102. At a communication instance defined by the member ID 102 of the radio tag 100, only the radio tag 100 communicates 104 with a reader device querying the radio tag group. In accordance with embodiments, the radio tag 100 may be an ultra-low complexity loT device having an ultra-low power consumption in accordance with the 3GPP standards. In accordance with other embodiments, the radio device 100 may be a device operating in accordance with the WiFi standard. In accordance with yet other embodiments, the radio device 100 may be an RFID device, like an RFID tag.

[0269] HHI 2 - 2024P67419EP - final Fig. 3 illustrates a reader device 200 in accordance in accordance with embodiments of the first aspect of the present invention. The reader device 200, like a user equipment, UE, or a base station, BS, or a WiFi, or a RFID reader, communicates with a radio tag, like the radio tag 100. Stated differently, the reader device 200 is a radio access network, RAN, entity of a wireless communication system or is connectable to a RAN entity of the wireless communication system. Further, the reader device 200 is connectable to a plurality of radio tags. The reader device 200 queries 202 a radio tag group. The radio tag group includes a plurality of group members. The plurality of group members includes at least a first radio tag and a second radio tag. Each group member of the radio tag group has assigned a member ID. The member ID of a radio tag defines a communication instance for a communication 240 with the reader device 200. In accordance with embodiments, the reader device 200 may be a network entity of a 3GPP wireless communication network, for example a user equipment, UE, or a base station, BS, or any other radio access network, RAN, entity of the network. In accordance with other embodiments, the radio device may be a station, STA, or access point, AP, of a WiFi network. In accordance with yet other embodiments, the radio device 200 may be an RFID-reader.

[0270] Fig. 4 illustrates a wireless communication system in accordance with embodiments of the first aspect of the present invention. Within the wireless communication system illustrated in Fig. 4, one or more radio tags and one or more reader devices in accordance with embodiments of the first aspect of the present invention may be implemented. The wireless communication system includes a plurality of radio devices 100a to 10Od. Some or all of the radio devices of Fig. 4 may be radio devices as described above with reference to Fig. 2, e.g., may be an loT device, an Ambient loT device, a Wi-Fi device or an RFID device. Each of the radio tags 100a to 100d may have a structure as illustrated with reference to RFID tag 100a. RFID tag 100a includes, in accordance with embodiments, a transceiver 106, a microchip or signal processor 108 and one or more antennas 1 10a or an antenna array having one or more antenna elements. The signal processor 108 may include a memory 112 storing the member ID 1 12 of radio tag 100a. In accordance with certain embodiments, the member ID 112 may be a unique member ID. The member ID or the unique member ID may be assigned given different conditions, e.g., a priority, position, type of device, at random, etc. In accordance with other embodiments, the radio tag 100a may further include a memory separate from the signal processor 108 which stores the member ID 112. The radio tag 100a collects data which is stored by the radio tag and, responsive to being queried by the reader device 200, transmits the collected data by transmitting a data signal 114a. In accordance with embodiments, the transceiver 106 is controlled by the radio tag

[0271] HHI 2 - 2024P67419EP - final 100a so as to generate the data signal 1 14a for transmission via the antenna 1 10a. In accordance with other embodiments, the transceiver 106 may be a backscatter transmitter for transmitting the data signal 1 14a as a reflected or backscattered signal responsive to a signal transmitted by the reader device 200 for querying the radio tag 100a.

[0272] As is schematically illustrated in Fig. 4, the radio tag 100a is a member of a radio tag group 300 which, in the depicted embodiment, includes radio tag 100a, radio tag 100b and radio tag 100c. Radio tags 100b and 100c may have a similar structure as radio tag 100a. Each of the radio tags 100a to 100c has assigned a member ID. In accordance with embodiments, also a group ID may be assigned by identifying the radio tag group to which the radio tags 100a to 100c belong. Fig. 4 further illustrates a radio tag 100d that is not a member of the group 300. Radio tag 100d may belong to another group or may not belong to any group. Radio tag 100d may also be queried by the reader device 200. In accordance with embodiments, a radio tag, e.g., radio tag 100a, may be a member a plurality of radio tag groups.

[0273] The wireless communication system includes the reader device 200, like a reader device of Fig. 3, e.g., a 3GPP device, like a UE or a base station, BS, , a Wi-Fi device, like a STA or an AP, or an RFID reader. The reader device 200 includes a transceiver 206 and one or more antennas 208 or an antenna array having one or more antenna elements for transmitting a signal 210 initiating an inventory round for querying the radio tags being within range of the reader device 200. The signal 210 may identify the group 300 using a group ID so that, responsive to receiving the signal 210, the radio tags 100a to 100c transmit the data signals 1 14a to 114c via the respective antennas 1 10a to 100c to the reader device 200 at the communication occurrences identified for each of the radio tags 100a to 100c by their respective member IDs.

[0274] In accordance with embodiments of the first aspect of the present invention, a radio tag, like radio tag 100a, of a radio tag group 300 is to communicate with the reader device 200 at a communication instance that is defined in accordance with the member ID 112 of the radio tag 100a. In accordance with embodiments, when communicating with the reader device 200, the radio tag 100a may only receive a signal from a reader device, e.g., is restricted to only receive or decode signals received from a reader device, and / or may only transmit a signal to a reader device.

[0275] HHI 2 - 2024P67419EP - final In accordance with embodiments, at the communication instance, among the group members 100a-100c, only the radio tag 100a is to communicate with the reader device 200 but none of the other group members 100b and 100c. Stated differently, at the communication instance, none of the group members 100b, 100d communicates with the reader device 200, except for the radio tag 100a. Thus, the respective IDs for the group members 100a-100c define respective different communication instances for the respective radio tags 100a-100c of the radio tag group 300. In other words, at the communication instance, the radio tag may transmit at instances associated to the member ID. Further, at the communication instance, the radio tag may process and / or respond to transmissions associated with the member ID.

[0276] In accordance with embodiments, the member ID 1 12 of the radio tag 100a may define as a communication instance a frequency on which the radio tag 100a is to communicate with the reader device. Considering Fig. 5 which illustrates an embodiment of a radio tag group 300 including four radio tags A1 -A4, the respective member IDs ID1 to ID4 define the frequency to be used by the respective radio tags for a communication to the reader device 200. As is illustrated in Fig. 6, the respective frequencies may be such that radio tag A1 has assigned a frequency f2, radio tag A2 has assigned a frequency f4, radio tag A3 has assigned a frequency f3 and radio tag A4 has assigned a frequency f1 . As is illustrated, all radio tags, when transmitting to the reader device 200, use a different frequency or frequency band for their transmission thereby avoiding collisions despite the fact that they transmit the data signals 114 simultaneously.

[0277] In accordance with further embodiments, rather than specifying the respective frequencies to be used by the radio tags via the member IDs, in accordance with other embodiments, the member IDs may be used for identifying a frequency offset with which a radio tag is to respond to a control message, like the message 210. For example, a shift applied to the CW during a backscattered response may be defined via the member ID. The frequency offset may indicate either a positive or a negative offset with respect to a carrier frequency. In accordance with embodiments, the offset may be an offset from a frequency at which the signal 210 is transmitted by the reader device 200 or it may be an offset from a configured or preconfigured frequency. Thus, the radio tag may respond on a frequency that is shifted in accordance with the member ID with regard to the inventory call. For example, the response frequency may be determined based on the member ID so that a radio tag having the member ID ID1 may respond on the same frequency as the inventory call or at the mentioned configured or preconfigured frequency. Assuming, in the embodiment of Fig. 6,

[0278] HHI 2 - 2024P67419EP - final the frequency at which the reader device 200 transmitted the inventory call or command 210 to be frequency f2, the member ID ID1 of radio tag A1 indicates that this radio tag is to use the same frequency f2 as the inventory call 210. All other radio tags respond at a different frequency. For example, a radio tag having the member ID ID2 may respond at a next higher or lower frequency with respect to the inventory call or with respect to the configured or preconfigured frequency. In other words, the next radio tag may respond with an offset from the frequency at which the inventory call was performed leading either to the next higher or next lower frequency. For the other radio tags, also an offset higher or lower with regard to the frequency of the inventory call is defined which is different from the offset of the radio tag having the ID ID2.

[0279] Thus, in accordance with embodiments of the present invention, the frequency offset defined by the member ID 1 12 may define for a radio tag a zero offset so that the radio tag responds to the control message on the same frequency on which the control message 210 has been transmitted or on a predefined frequency. The member ID may also define a nonzero offset so that the response to the control message 210 is on a frequency higher or lower by the offset than the frequency on which the control message has been transmitted or than the predefined frequency.

[0280] In accordance with other embodiments of the first aspect of the present invention, rather than defining the frequency, the member ID of the radio tag may define an code to be used by the radio tag for responding to the inventory call 210 of the reader device 200. The member ID of the radio tag may define a coding scheme from a set of coding schemes, e.g., using an index or code index. Assuming again a radio tag group 300 as depicted in Fig. 5, each of the radio tags A1 -A4 may have assigned a different code which is identified by the respective member IDs ID1 to ID4. Fig. 7 illustrates an embodiment of radio tags A1 - A4 of the radio tag group 300 responding to the inventory call 210 by the reader device 200 using transmissions being coded by different codes C1 -C4. The transmissions or responses may be transmitted by the radio tags of the radio tag group 300 on the same frequency or at the same time or on shared time / frequency resources, however, despite the simultaneous transmission of the responses, the problems encountered in conventional approaches are avoided as the reader device is capable to distinguish the different transmissions from the different radio tags given the different codes used for coding the data signal 114.

[0281] In accordance with embodiments, a radio tag may code the response to the control message 210 by including or encoding into the response the member ID or a part of the

[0282] HHI 2 - 2024P67419EP - final member ID or a processed form of the member ID. In one embodiment, this can be achieved by performing an operation or function, e.g., an XOR operation, of the member ID with a sequence known to the receiver. Thus, the receiver decoding the response message of the radio tag can perform the same XOR operation or the inverse function and retrieve the said member ID.

[0283] In accordance with other embodiments, the different member IDs may indicate different coding schemes, different scrambling or interleaving schemes or different sequences to be used by the radio tag when responding to the inventory call 210 of the reader device 200. The respective coding schemes, scrambling schemes or sequences may be selected such that resulting encoded signals 1 14 have certain properties, like an orthogonality under correlation or a cross-correlation property or an autocorrelation property, e.g., having a peak value above or below a configured or pre-configured threshold and / or having certain symmetry constraints, the relationship between two distinct signals may have different characteristics or magnitudes. For example, a first radio tag A1 may scramble its data using its member ID ID1 , and a second radio tag may scramble its data with its member ID ID2, and so on. In accordance with other embodiments, the first radio tag may respond using a first response sequence, such as a first Zadoff-Chu-sequence or Gold sequence, and a second radio tag may respond using a second response sequence, such as a second Zadoff-Chu-sequence or a Gold sequence, with the first and second sequence being orthogonal with respect to each other under correlation operation.

[0284] In accordance with further embodiments, the member ID of the radio tag defines as the one or more of the communication instances a beam, e.g., beam ID, on which the radio tag is to communicate with the reader device.

[0285] In accordance with further embodiments of the first aspect of the present invention, the member ID of the radio tag may define a time, e.g., a time slot, at which the radio tag is to communicate with the reader device. Fig. 8 illustrates an embodiment in accordance with which a time at which a radio tag is transmitted to the reader device is determined using the member ID of the radio tag. Fig. 8(A) illustrates the radio tag group 300 as also depicted in Fig. 5 including the four radio tags A1 -A4 each having a different member ID ID1 to ID4. As is illustrated in Fig. 8(B), by means of the respective member IDs the respective times t1 -t4 at which the respective radio tags A1 -A4 transmit the data signals is determined. Thus, the problems encountered in conventional approaches due to the collisions of the data transmissions 1 14 by the respective radio tags A1 -A4 are avoided as each of the radio tags

[0286] HHI 2 - 2024P67419EP - final has its own time at which it performs the data transmission thereby avoiding any collision with a transmission from another radio tag of the radio tag group 300.

[0287] In accordance with embodiments, rather than specifying specific times at which the respective radio tags communicate with the reader device 200, also a time offset may be defined using the respective member IDs. For example, the member ID of the radio tag may indicate a time offset with which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command, and the time offset may be counted from a receipt of the control message. The time offset may depend a number of transmission opportunities, e.g., slots, and / or on a clock signal, e.g., a general clock signal provided by one or more of the following: a base station, a reader device, another UE, another radio tag. The time offset may be a fixed value, which is configured and or pre-configured in the radio tag, e.g., a fixed time interval or a fixed time limit or a fixed number of one or more slots, within which a reader tag can respond or is allowed to respond to a reader device query. By means of the times or time offsets defined via the member IDs, in accordance with embodiments, different time slots to be used by the respective radio tags may be defined.

[0288] Thus, when a control message 210, like the inventory call, is sent to the group 300 at a time tO, each radio tag A1 -A4 knows its specific time t1 -t4 to respond based on its member ID ID1 to ID4. For example, when considering the devices A1 -A4 forming the radio tag group 300, they will respond in the predefined sequence depicted in Fig. 8(B), i.e., radio tag A1 will respond first, followed by radio tag A2, then radio tag A3 and finally radio tag A4. Stated differently, in accordance with the described embodiment, an approach similar to a roll call is implemented in accordance with which each tag or device waits for its turn to communicate with the reader device. By organizing the radio tags into the radio tag group 300 and assigning the member IDs, a communication between the radio tags and the reader device can be efficiently managed in a way ensuring that each radio tag has a collision free window for transmitting its data 1 14.

[0289] In accordance with embodiments in which the member IDs of the radio tags identify the respective time slots during which the respective tag IDs communicate with the reader device 200, the reader device 200, in addition to providing the inventory call signal 210, may also provide an initial control signal including the one or more communication instances, e.g., time slots. The time slots may be indicated by respective slot indicators. Each of the slot indicators indicates a time slot from a predefined sequence of time slots. The slot

[0290] HHI 2 - 2024P67419EP - final indicator is also referred to herein as a slot command or as a start indicator and may serve for synchronizing the radio tags. Fig. 9 illustrates an embodiment using a plurality of slot indicators as a synchronization signal for radio tags. Fig. 9 assumes a radio tag group 300 as depicted in Fig. 8(A) including the radio tags A1 to A4 for which, by means of the respective number IDs ID1 to ID4, the time slots #1 to #4 depicted in Fig. 9 are defined in which the respective radio tags A1 to A4 communicate with the reader device. As is illustrated in Fig. 9, following the inventory call 210, the reader device 200 transmits, prior to the first time slot #1 the slot indicator signal 400a. Also between the time slots #1 and #2, between the time slots #2 and #3 and between the time slots #3 and #4 the reader device 200 transmits a slot indicator signal, namely slot indicator signals 400b, 400c and 400d. In accordance with embodiments, the initial slot indicator signal 400a may be omitted and the transmission of the inventory call 210 may serve also as the slot indicator signal for the first time slot #1 . The radio tags may be devices having internal clocks which are not very accurate, and, especially for such devices, the synchronization using the slot indicator signals 400a to 400d is advantageous as the respective radio tags A1 to A4 may rely on the slot indicators 400a to 400d to stay synchronized with the network. In addition, using the slot indicators 400a to 400d allows the radio tags to reduce its power consumption, e.g., by staying in an energy saving mode, until determining the time slot defined by the member ID of the radio tag. The energy saving mode comprises one or more of the following:

[0291] A Discontinuous Reception (DRX) mode which is a power-saving mechanism used in 5G New Radio (NR) networks to improve the energy efficiency of user equipment (LIE) by reducing the frequency of monitoring the network for incoming data. In DRX mode, the LIE periodically turns off its radio receiver for certain periods, known as DRX cycles, and wakes up only at specific times to check for incoming data or signals. This intermittent reception mechanism helps reduce power consumption without compromising the UE's ability to receive data in a timely manner.

[0292] An eDRX mode which allows devices to remain in a deep sleep state for extended periods of time, ranging from hours to days, depending on the configuration set by the network. This enables devices to conserve power by reducing the frequency of network monitoring and signaling exchanges.

[0293] - A mode where a WUS signal or broadcast signal or synchronization signal can still be received by the radio tag.

[0294] Thus, by using the above described slot indicator mechanism, radio tags may achieve significant power savings while maintaining an accurate synchronization with the network.

[0295] HHI 2 - 2024P67419EP - final The radio tag may terminate a communication with the reader device responsive to one or more of the following:

[0296] - receiving a next slot indicator from the reader device,

[0297] - receiving an end signal to terminate communication, e.g., a termination signal or an acknowledgement, ACK,

[0298] - a lapse of a configured or preconfigured timer, exceeding a maximum transmission duration, exceeding a maximum number of transmissions, exceeding a maximum number of transmissions within a configured or preconfigured time interval,

[0299] - detecting an energy level below a configured or preconfigured threshold, a mobility condition,

[0300] - detecting interference that exceeds a configured or preconfigured threshold.

[0301] In accordance with embodiments, the above described slot indicator mechanism may be implemented as follows. The radio tags of the radio tag group 300 stay in a low power mode, thereby conserving time by minimizing their active time. For example, in the context of an ambient loT device, a low power mode refers to a state in which the device does not perform any transmission or reception but maintains a minimum timing requirement, for example keeps a clock running or maintains a timer. Under this low power mode, the radio tag may also retain the memory and keep a full or partial energy storage. In this way, the radio tag can reduce its energy consumption. Furthermore, by maintaining at least a partial energy storage, a radio tag can store certain slot indicator values received or store a state machine keeping track of its current state, which may depend on one or more slot indicators received and / or decoded. The radio tags listen for the slot indicator signal 400a to 400d which, in accordance with embodiments, may have a predefined pattern or a predefined sequence of, e.g., high-low amplitude transitions or of a pulse width modulated signal, PWM, e.g., the width of the signal pulse being varied in proportion to the amplitude of the analog input signal. Once a radio tag received a slot indicator, the radio tag starts counting down the slot indicator until it is its turn to transmit the data signal to the reader device. For example, in the embodiment of Fig. 9, the radio tag A4 receives the initial slot indicator 400a and all other slot indicators 400b to 400d. Upon receiving the first slot indicator 400a, the radio tag A4 starts the countdown and when receiving the fourth slot indicator 400d it determines that the next slot is the fourth time slot #4 which, in accordance with the number ID ID4 of radio tag A4 is the time slot to be used by radio tag A4 for transmitting its data to the reader device 200.

[0302] HHI 2 - 2024P67419EP - final Using the slot indicators and the above described countdown ensures that each radio tag knows exactly when to wake up and transmit its data, thereby avoiding collisions and ensuring an ordered communication with the reader device.

[0303] In accordance with further embodiments, for further improving the synchronization of the radio tags with the network, a plurality of slot indicators may be signaled by the reader device for each of the time slots. For example, the respective slot indicators may be sent multiple times or a series of different slot indicators, i.e., slot indicators having different distinguishable patterns, may be transmitted. For example, in radio tag systems, like ambient loT systems, the use of multiple slot indicators may be advantageous as it allows for maintaining an accurate synchronization also during long chains of transmissions. In such scenarios, keeping synchronization is important for avoiding collisions between the transmissions from the respective radio tags. For example, collisions may occur when one of the radio tags misses a slot indicator signal thereby causing the above described count to be off and leading to an interference with transmissions by other radio tags of the group. To mitigate this risk, for example in scenarios as described above in which long chains of transmissions occur, the system may use two or more slot indicators which allows for the detection and correction of missed signals. Fig. 10(A) and Fig. 10(B) illustrate embodiments of the use of two or more slot indicators for a group of radio tags A1 to A4 as depicted in Fig. 8(A) having assigned the respective time slots #1 to #4 for communicating with the reader device 200 in accordance with the member ID A1 . The process is similar to the one described above with reference to Fig. 9, except that the reader device 200, in the embodiment of Fig. 10(A), for each time slot transmits two slot indicator signals, namely slot indicators 400a1 , 400a2 ahead of time slot #1 , slot indicators 400b1 , 400b2 ahead of time slot #2, slot indicators 400c1 , 400c2 ahead of time slot #3 and slot indicators 400d1 , 400d2 ahead of time slot #4. The use of the two alternating slot indicators ahead of each time slot allows a radio tag to detect and correct a missed slot indicator.

[0304] Fig. 10(B) illustrates an embodiment in accordance with which the reader device 200 transmits ahead of each time slot #1 to #4 three slot indicator signals 400a1 to 400a3, 400b1 to 400b3, 400c1 to 400c3 and 400d1 to 400d3. The use of three alternating slot indicators allows a radio tag to detect and correct more than one missed indicator.

[0305] In accordance with embodiments, the two or more slot indicators are successive, e.g., follow each other in time domain. A time gap between a first and one or more second slot

[0306] HHI 2 - 2024P67419EP - final indicators may be limited by a configured and / or preconfigured threshold. The time slots may be indicated with an alternating sequence of two or more slot indicators. Responsive to missing a slot indicator, the radio tag may detect this miss and / or use a subsequent slot indicator for correcting a count of the time slots. The slot indicators may be followed by or contain a sequence. In one embodiment, this sequence may indicate a continuous sequence number, such that a radio tag would notice after decoding, if it has missed the reception of a previous slot indicator. In another embodiment, this sequence can encode a state, e.g., 1 or more states, such that a radio tag would also detect a missed slot indicator, e.g., in case a radio tag expects to decode state 4, and it decodes state 5. Thus, it would be aware of a missed slot indicator. This state could be toggled by a modulo operation.

[0307] The respective multiple slot indicators described with reference to Fig. 10(A) and Fig. 10(B) may be identical or may be different. If slot indicators are identical, the radio tag interprets the first received slot indicator as a start slot indication, the second received slot indicator as the end or stop slot indication. This may be erroneous in case the radio tag misses a slot indicator. Thus, in another embodiment, the slot indicators for start and end may be different, e.g., using a different type of slot indicator, e.g., a different sequence, such that a radio tag can identify, whether a slot indicator is indicating a start, or whether it is indicating an end. For example, two or more of the slot indicator signals may have two or more predefined patterns or sequences which may be achieved by including a truncated slot index, and the truncation may be achieved by using only a number of the least significant bits. In accordance with other embodiments, the truncation may be achieved by a modular operation. Instead of using a complete slot indicator index, which may get long if lots of start indicators are transmitted, the index can be derived from different operations to make it shorter. For truncation, only a specified number of the least significant bits of the original index is used to indicate the current one. For instance, the 2 least significant bits of the slot indicator index can be used to map further slots in a repeating sequence, e.g., from 0 to 3. Alternatively, the slot index can be generated by the modulo operation, where the full slot index is divided by a given value, and then the remainder is used as the slot index.

[0308] As mentioned above, this embodiment is particularly useful in scenarios where long chains of transmissions are common so that the risk of a missed signal is high. By implementing the alternating or multiple slot indicators 400a1 to 400d3 in a way as described above with reference to Fig. 10(A) and Fig. 10(B), a more robust and more reliable communication is achieved ensuring that all radio tags remain accurately synchronized with the network.

[0309] HHI 2 - 2024P67419EP - final In accordance with embodiments, the multiple slot indicator mechanism as described above with reference to Fig. 10(A) and Fig. 10(B) may be implemented as follows. By using alternating slot indicators or a series of a same or different slot indicators, the overall system provides for a certain degree of redundancy so that, in case a radio tag misses one slot indicator signal, for example slot indicator signal 400b1 a radio tag A2 may still synchronize using the next of the multiple slot indicators, for example slot indicator 400b2. This is advantageous as the radio tag A2, despite missing a slot indicator, remain synchronized and correctly detects the time slot #2 for its transmission thereby reducing the likelihood of collisions of transmissions from radio tags within the radio tag group 300. When the radio tag detects a missed slot indicator signal the radio tag, like radio tag A2 which has missed slot indicator 400b1 , may use the subsequent slot indicator 400b2 or the subsequent slot indicators 400b2 and 400b3 to correct its count thereby remaining synchronized with a system and being able to transmit its data at the correct time, namely at time slot #2. A missed slot indicator can be detected in case of an erroneous sequence number is detected, e.g., in case the slot indicator includes such a value, or in case a radio tag detects an unexpected slot indicator, e.g., according to a state machine stored within the radio tag. E.g., a radio tag expects to receive a start and a stop indicator, but it received two start or two stop indicators, or a single stop indicator without reception of a start indicator.

[0310] In case a radio tag detects one or more missed slot indicators and cannot reliably correct its count the radio tag may go, in accordance with embodiments, into an out-of-sync state. This may occur in case a radio tag does not have enough memory or has stored previous slot indicators, and may have no possibility to be aware of the value of a previously received slot indicator. Furthermore, a radio tag may try to decode a sequence number or value of a slot indicator by performing an operation, e.g., XOR operation, but in case of too many errors caused by the transmission, e.g., one or more bit-flips, the resulting value cannot be corrected by the radio tag. Brute force correction of such errors may result in power drainage at the radio tag, thus a radio tag may not reliable correct its count.

[0311] In accordance with embodiments, a radio tag falling out of synchronization may perform certain predefined actions. A radio tag may fall out of synchronization for example due to missing one or more slot indicators, as described above, or due to other issues, for example due to an excessive drift of the internal clock. In such situations, the involved radio tag may not perform any transmission. Stated differently, when a radio tag detects that it is out of synchronization it does not transmit any data, i.e., any data transmission is omitted. This approach is advantageous as it prevents collisions and interference with other devices that

[0312] HHI 2 - 2024P67419EP - final are still synchronized, and by not transmitting, the radio tag avoids contributing to potential communication errors while waiting for an opportunity to resynchronize with the network.

[0313] In accordance with other embodiments, the out-of-sync state may be resolved by transmitting again only after receiving a certain signal. The radio tag involved may wait for a specific signal before transmitting its data 114. The signal may act as a backup point, allowing the radio tag to send the data responsive to having missed a slot count or having lost the count. This specific signal may be a carrier wave, CW, signal, or a synchronization signal, e.g., PSS or SSS, or another control signal or data signal carrying a specific sequence, being different compared to a slot indicator signal. Furthermore, the specific signal may be a broadcast, groupcast or unicast signal. Furthermore, the specific signal may also one or more of the following signals:

[0314] 1 . Barker Sequence: A Barker sequence is a specific type of pseudo-random sequence that is commonly used as a preamble in wireless communication systems. It has good autocorrelation properties, making it suitable for synchronization and detection purposes. Barker sequences are used in various loT communication protocols for wake-up signaling.

[0315] 2. Gold Sequence: Gold sequences are another type of pseudo-random sequence that exhibits good autocorrelation properties and are commonly used in spread spectrum communication systems. Gold sequences are used as preamble sequences in loT devices for wake-up signal detection.

[0316] 3. M-Sequence: M-sequences, also known as maximal-length sequences, are pseudorandom binary sequences with a maximum length of 2An - 1 , where n is an integer. M-sequences have desirable properties such as good autocorrelation and crosscorrelation properties, making them suitable for synchronization and wake-up signaling in loT devices.

[0317] 4. Sync Word: A sync word is a predefined bit sequence that is inserted at the beginning of a packet to assist the receiver in synchronization and frame detection. Sync words are commonly used as preamble sequences in loT devices to trigger wake-up and synchronization processes.

[0318] 5. Manchester Encoding: Manchester encoding is a line code in which the data and clock signals are combined to create a self-synchronizing signal. Manchester- encoded sequences can be used as preamble sequences in loT devices to facilitate wake-up and synchronization of the receiver.

[0319] HHI 2 - 2024P67419EP - final In accordance with yet further embodiments, when determining an out-of-sync state, the radio tag involved may:

[0320] - Stop transmitting any data.

[0321] - Wait for a specific signal before further transmitting any data. The specific signal can be again an initial signal, or a start or restart signal or a synchronization signal, e.g., being different than the start or stop slot indicator. Or it may be a signal containing the current slot number. In case start and stop indication are different types of signals, and in case the radio tag receives more than one stop slot indicator without receiving a start indicator, the radio tag may interpret this as a loss of synchronization and may also enter this mode.

[0322] - Wait for a slot indicator including a count indication. For example, the radio tag is to restart its transmission after receiving and counting n slot indicators, where 1 < n < count.

[0323] - Wait for a start slot indicator.

[0324] - Wait for a stop slot indicator.

[0325] - Wait for a specific sequence of one or more start and / or stop slot indicators.

[0326] The signal including the count indication may provide the radio tag with the necessary information to resynchronize accurately. The radio tag may listen for the slot signal which includes a count indication that supports the radio tag to determine the correct timing for its transmissions. For example, by counting down the slot indicators, the device may realign itself with a networks schedule and resume normal communication without causing any collisions. In this case, the radio tag may be counting up towards its transmission slot.

[0327] In accordance with further embodiments of the present invention, the reader device 200 in addition to the inventory call signal 210 querying the radio tags or radio tag group 300 may transmit additional signals, like additional short signals, for enhancing a functionality of the radio tag and / or for improving the communication efficiency. Using the additional short signals allows for more control over the transmission process and supports managing various scenarios that may arise during the communication. The additional short signals, in accordance with embodiments, comprise an adjust signal, an end signal and a repeat signal. The adjust signal allows the system to skip one or more slot numbers or to jump to a different slot number than a slot number in the sequence of time slots. For example, if interference is detected, a radio tag will not respond to a control message from the reader device during the time slot defined by the radio tag's member ID and will bypass a communication with the reader device in the inventory round. By jumping to a different time

[0328] HHI 2 - 2024P67419EP - final slot, the radio tag may update its slot indicator counter by receiving a direct indication of the radio device to jump to a specified slot number.

[0329] In accordance with further embodiments, the adjust signal may also change one or more transmission parameters. Using the adjust signal may be useful in situations where the current slot is experiencing an interference or when there is a need to modify the transmission setting for optimizing a transmission performance. For example, the adjust signal may change the coding modulation or repetition factor of a transmission, thereby ensuring that the communication remains robust and efficient. In a further embodiment, the adjust signal may also configure a radio tag to skip a certain number of slots, e.g., the radio tag performs a fast forward operation. Here, the radio tag may remove old states in its memory or buffer, which may already be outdated, such that a radio tag starts processing at the correct time instance. In a further embodiment, the adjust signal can also configure a radio tag to ignore states received until a future time instance, such that a radio tag can perform energy saving and continue processing data at a future time instance. In another embodiment, the radio tag can be configured to skip to past slots, e.g., a rewind operation, which configures a radio tag to process slots received in the past, which may be stored in the memory of a radio tag. Here, a radio tag can be configured to collect certain data in the past, store the date, and the rewind adjust signal triggers the radio tag to perform a processing on the stored data. Furthermore, the memory could be flushed after successful processing by the radio tag, e.g., dependent on a signal transmitted by the radio tag. In another embodiment, skipping to a certain different slot number may be useful in order to receive a retransmission from the radio tag, e.g., in case a device which triggered the radio tag could not decode the received signal, but may still be aware of the time slot that a radio tag should use to process and perform the said retransmission.

[0330] In accordance with embodiments, the end signal is provided to stop a round of transmission, for example when a current round of transmissions has been completed or needs to be terminated prematurely. This may be required in case the reader device could already decode the transmission from the radio tag, and / or in case the radio tag should perform energy saving. In another embodiment, in case the radio tag had tried to perform a transmission for a certain time duration or for a certain number of attempts, it may be required for the radio tag to perform energy saving and refrain from performing too many transmissions. Furthermore, another reason for terminating prematurely would be in case the scenario changes, e.g., the interference situation worsens, or in case of mobility, e.g., radio tags or reader devices start moving and it would be a waste of time and / or frequency

[0331] HHI 2 - 2024P67419EP - final and / or energy and / or memory resources to continue a transmission or continue any transmissions attempts. By sending an end signal, either at the end of the round, i.e., following time slot #4 or at any time during the round, for example between any of the time slots #1 to #3, the reader device can ensure that all radio tags stop transmitting and return to a power saving or energy saving mode. In accordance with other embodiments, the end signal causes an active radio tag to stop its data transmission and to enter an energy saving mode.

[0332] In accordance with embodiments, the repeat signal may be provided for instructing one or more radio tags to repeat the last slot, i.e., to transmit the data which has been transmitted in the last time slot again. The signal may be used in scenarios when a previous transmission was not successfully received at the reader device. The repeat signal may cause the radio devices to repeat a last time slot, or the n last time slots, n > 1 , or a specific time slot.

[0333] In the embodiments described above, the radio tags 100a to 100d and A1 to A4 are members of the radio tag group 300. In accordance with these embodiments, the grouping of the radio tags may be in accordance with a dynamic signaling defining the radio tags participating in a particular way round.

[0334] In accordance with embodiments, a dynamic grouping may be applied which allows for a flexible and efficient management of tags. For example, radio tags may be grouped dynamically based on various criteria. Grouping criteria may be that radio tags belong to the same product, e.g., car parts, or radio tags experience a similar condition, e.g., temperature or shock, or in case radio tags experience a similar mobility state, e.g., acceleration in a car or train. For example, radio tags 5, 7 and 10 may be grouped dynamically based on various criteria a stated above. For example, radio tags 5, 7 and 10 may be grouped together and another group may consist of radio tags 15, 7 and 5. Such a dynamic grouping enable the overall system to adapt to a change in conditions and requirements, thereby improving the performance.

[0335] In accordance with other embodiments, the radio tags may belong to multiple groups, i.e., there may be a joint group membership. For example, radio tag A1 may belong to groups A and B and stores a member ID of the joint group. This capability allows for a more complex and flexible group configuration, facilitating better management and tracking of tags that need to be part of multiple functional categories.

[0336] HHI 2 - 2024P67419EP - final In accordance with other embodiments, the control signaling may be used to dynamically indicate or group respective tags that are within a certain range. For example, only tags within a range of 1000m to 1300m, e.g., range measured in meters, m, may be addressed which simplifies the management of a large number of radio tags. In another embodiment, the range could also addressed with respect to a radio tag ID or group ID, e.g., only tags having a similar address range may communicate or may be grouped together.

[0337] For example, a configured or preconfigured pathloss, received power, e.g., RSSI or SNR or SINR, or a distance from the reader device such as an Euclidean distance, e.g., measured in meters, or a zone, e.g., having a certain measure and / or zone ID may be used for the range based grouping. A zone may have a certain size in height and width or a particular shape, e.g., rectangular or circular, defined by a center and radius.

[0338] In accordance with yet other embodiments, radio tags may also be organized into subgroups within the group they belong to. The organization into the subgroup may be based on various criteria, such as a power status, a bandwidth and a type of data. This subgrouping allows to manage the radio tags more efficiently. For example, if a battery status of one of the radio tags falls below a configured or preconfigured threshold, the radio tag may be assigned to a subgroup including radio tags having battery status below the threshold. This subgroup is also referred to as a low power subgroup and may be given channel access priority during an inventory round. For example, members of the low power subgroup may transmit their data first, for example, at the beginning of the inventory round and then go or enter the other mode. This allows the radio tags in the low power subgroup which already have a reduced power status to conserve energy as they do not need to monitor the entire round, for example, for the slot indicators. In accordance with embodiments, the low power subgroup may use specific time slots for further reducing collisions. For example, out of 100 available time slots, the radio tags of the low power subgroup may select one of the first 10 slots while other radio tags not being member of the low power subgroup, for example, high power tags having a battery status above the threshold, avoid the first 10 slots and utilize only the remaining slots 10 to 100.

[0339] In accordance with embodiments the radio tag is assigned to a subgroup and the subgroup is addressed by a subgroup ID. The subgroups may be in an ordered list, and a signal may tell that a next subgroup of the list is to communicate in a subsequent communication instance. The radio tag may associate itself with a certain group or subgroup depending on one or more of the following:

[0340] HHI 2 - 2024P67419EP - final - a signal quality,

[0341] - a received power,

[0342] - a location,

[0343] - application requirements, such as latency and or reliability requirements,

[0344] - a range or distance to the reader,

[0345] - a power status,

[0346] - a bandwidth, e.g., a bandwidth defined in frequency domain, e.g., by a set of subcarriers,

[0347] - a type of data, e.g., transmission of inventory messages or transmission of a health status of a product, e.g., temperature or accelerometer values.

[0348] Further embodiments of the first aspect of the present invention address the situation in which the reader device 200 detects a collision between data transmissions from radio tags within the radio tag group 300 and / or collision between data transmissions from a radio tag within the radio tag group 300 and a radio tag, like the radio tag 100d of Fig. 4, outside the radio tag group 300. Such collisions may occur when the multiple radio tags attempt to transmit data simultaneously leading to an interference and to a potential data loss. For addressing this issue, in accordance with embodiments of the first aspect of the present invention, a signaling, like a repetition signal, may be provided responsive to a collision of a transmission of the radio tag with a transmission of another radio tag not being a group member. In an another embodiment, a signaling, like a short indication signal also referred to herein as a control signal, may be provided responsive to a collision of transmissions of any radio tags. The radio tag responds to the control signal to perform a retransmission of the transmission, or enter a DRX or eDRX mode, e.g., in case a maximum retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold. The reader device 200 may signal the short indication signal to the radio tags of the radio tag group 300, and the short indication signal serves as a prompt for all radio tags within the group 300 to repeat their transmissions from a last time slot, from a preconfigured or configured time slot or from a previous time slot indicated by the short indication signal. This signaling is advantageous as it supports organizing the retransmission process in a way that ensures that the radio tags, when performing the retransmission, do not interfere with each other.

[0349] In accordance with embodiments, a random slot selection may be enabled. The short indication signal may provide two or more slots for radio tags to randomly choose from for performing their retransmission. By selecting different slots randomly, the likelihood of

[0350] HHI 2 - 2024P67419EP - final collisions is reduced, as devices are less likely to choose the same slot for the retransmission.

[0351] In accordance with other embodiments, a certain code may be chosen for the retransmission. The retransmission may happen with a choice of different codes that can be separated by the reader device. Each radio tag may select a code for its retransmission, thereby allowing the reader device to distinguish between the different transmissions and reducing the likelihood of collisions.

[0352] In accordance with further embodiments, a set of different frequency offsets, which can be separated by the reader device, is provided for a retransmission.

[0353] In accordance with yet another embodiment, the slot indication signal may provide for a spare slot selection. One or more time slots within the inventory round, for example, at or towards the end of each inventory round, may serve as the spare slots for the radio tags. These spare slots may be used by the radio tags for their retransmissions responsive to the short indication signal. For example, the reader device may send, together with a short indication signal, an indicator of the specific spare slot a device or radio tag has to use. In accordance with other embodiments, the radio tag may implement a backoff mechanism for accessing the spare slots. In one embodiment, the backoff mechanism would randomly draw a number, e.g., using a uniform distribution between a minimum and maximum value, and the resulting number would indicate when to utilize a backoff slot, e.g., similar to a backoff counter used in radio standards using unlicensed access, e.g., NR-U, SL-U or WiFi systems. In another embodiment, the backoff value could indicate how many backoff slots can be utilized or have to be skipped. In accordance with yet further embodiments, the radio tag may randomly select a spare slot for its retransmission.

[0354] A retransmission instance may include one or more of

[0355] - transmission of an exact copy of the previously transmitted signal,

[0356] - transmission of a redundancy version of the previously transmitted signal,

[0357] - transmission of a different signal,

[0358] - a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.

[0359] HHI 2 - 2024P67419EP - final Further embodiments of the first aspect of the present invention address a situation in which a radio tag of a radio tag group has acquired data that needs to be transmitted via the reader device without waiting for an inventory round being initiated by the reader device. For example, some high priority data may be required to be transmitted immediately after gathering the data by the radio tag. For example, in a certain scenario, like a factory, a radio tag monitoring certain parameters, like a temperature or the like, of a machine may require an immediate signaling of an increase of the temperature above a threshold so as to allow taking suitable countermeasures in the factory control for avoiding damages due to an overheated machine or the like. In accordance with such embodiments, an uplink triggered traffic may be implemented. Uplink triggered traffic refers to a process where a radio tag initiates a communication with the network when the radio tag has data to transmit. In other words, the uplink triggered traffic is independent of any communication occurrence of the radio tag in accordance with its member ID and is also independent of a query by the reader device. Stated differently, the radio tag may initiate the communication with the reader device independent of the communication occurrence when having data to send and to include the data or part of the data in the request signal. Thus, the radio tag of the radio tag group 300 may initiate the uplink transmission at any time, i.e., outside the inventory round initiated or at any time during the inventory round, i.e., the radio tag is not bound by the communication occurrence as defined by the member ID.

[0360] In accordance with embodiments, a radio tag which has data to be transmitted may join a scheduling request, SR, group which is a dynamic group of radio tags that have data to be transmitted. Thus, when a radio tag has data to be transmitted, it becomes a member of this dynamic group and remains in this group until the network queries the group and the device successfully transmits the data. For example, the reader device may be configured to query SR groups during times between regular inventory rounds thereby ensuring that radio tags having data to be transmitted being queried more often. In accordance with embodiments, the radio tag may have a dynamic group membership meaning that the radio tag, when having data to transmit, joins the SR group. The SR group is dynamic meaning that the radio devices may join or leave the group based on their transmission needs. The network, as mentioned above, may periodically query the SR group to check for devices that have data to transmit. When a radio tag in the SR group is queried, the data is transmitted and, responsive to a successful transmission of the data, the radio tag may leave the SR group.

[0361] HHI 2 - 2024P67419EP - final In accordance with other embodiments, when the radio tag has data to be transmitted, a scheduling request signal, like a random access signal, may be transmitted by the radio tag. This signal is a request to the reader device indicating that the radio tag has to send data and needs to be queried or addressed. The radio tag may continue to send the scheduling request signal until it receives a response from the reader device or network. In accordance with embodiments, the signal may be sent once, repeatedly, continuously, periodically or in a certain RACH slot indicated by the reader device.

[0362] In accordance with embodiments of the present invention, the communication of the radio tag of a radio tag group with a reader device may include four messages, namely an access message (Msg1 ) and access response (Msg 2), a data transmission (Msg3) and a feedback message (Msg4). The radio tag sends a random success preamble, sequence or ID to the reader using the access message thereby indicating that the radio tag wants to initiate a communication. The access message may include a random identifier. The reader device may respond with the response message which includes the random identifier corresponding to the one of the access messages. The UE sends as a data transmission a data message including control and / or payload data. The reader device responds to the data message with a feedback message that may indicate a successful or unsuccessful transmission. The feedback message may also be used for sending further control and / or payload data to the radio tag. Fig. 11 illustrates embodiments of a communication of a radio tag K of a radio tag group with the reader device 200. Fig. 11 illustrates an inventory round for querying a radio tag group having at least K+1 members. As illustrated in Fig. 1 1 , initially, the reader device 200 sends the command RoundCmd for initiating the inventory round. RoundCmd is followed by the respective slot commands SlotCmd(1 ) to SlotCmd (K+1 ) which provide for the necessary synchronization of the radio tags 1 to K+1. The slot commands may use the slot indicators described above with reference to Figs. 8 and 9.

[0363] Fig. 1 1 (A) illustrates a four-step random access procedure used by the radio tag K for communicating with the reader device 200 during slot #K.. Responsive to determining the slot commands, the radio tag K, due to its number ID, knows that its transmission slot is reached when detecting SlotCmd(K). The radio tag K starts the transmission by sending, according to Fig. 11 (A) the message Msg1 to which the reader responds with the message Msg2 and followed by the data transmission using the message Msg3. The reader device responds to with a feedback message Msg4.

[0364] HHI 2 - 2024P67419EP - final Fig. 1 1 (B) illustrates a two-step random access procedure in which the messages Msg1 and Msg3 as well as the messages Msg2 and Msg4 are combined into respective common messages Msg1 +3 and Msg2+4.

[0365] Fig. 1 1 (C) illustrates a two-step non-random access procedure in which the radio tag K, when determining its time slot K only sends the data transmission Msg3 and receives the feedback Msg4. In other words, in this embodiment, the radio tag waits for its slot #K and then sends the data.

[0366] Fig. 1 1 (D) illustrates a one-step non-random access procedure in which the radio tag K only sends the data transmission Msg1 without receiving a feedback from the reader. In this one step, non-random access procedure the radio tag waits for its slot #K and then sends the data.

[0367] Fig. 1 1 (E) illustrates a one-step non-random access procedure in which the radio tag K initially sends the data Msg3 but receives a feedback Msg4 indicating a non-successful transmission of the data and, therefore performs the retransmission Msg3. The radio tag K waits for its slot #K and then sends. In case of an unsuccessful transmission, the retransmission command is sent using Msg4 so that a retransmission Msg3 may be performed.

[0368] Fig. 1 1 (F) illustrates a one-step non-random access procedure in which only messages Msg1 and Msg3 are transmitted in a combined message Msg 1 +3. The radio tag K waits for its slot #K and then sends the data including a random identifier.

[0369] Fig. 1 1 (G) illustrates a one-step non-random access procedure in which the radio tag K sends the messages Msg1 and Msg 3 in combined a message Msg1 +3, receives an access response Msg2, transmits data again in Msg3 and receives, optionally, a feedback message Msg4. The radio tag K waits for its slot #K and then sends the data including a random identifier which may be used to resolve any collisions by falling back to a RA procedure. In case of a collision, the reader could then use the previously received random identifier from radio tag K in a future random access, RA, procedure, such that a reader device setup the connection between reader device and radio tag again, e.g., by using the random identifier to provide a new slot command, e.g., a new SlotCmd (K).

[0370] Second

[0371] HHI 2 - 2024P67419EP - final Fig. 12 illustrates a radio tag or radio device 100’ in accordance with embodiments of the second aspect of the present invention. The radio tag, like an Ambient loT device or an RFID device, communicates with a reader device, like a user equipment, UE, or a base station, BS, or a WiFi device, or a RFID reader, and performs a retransmission responsive to a signal from the reader device. Stated differently, the radio tag 100’ communicates with a reader device responsive to a query by reader device. Responsive to a repetition or control signal 212 from the reader device, the radio tag 100’ performs a retransmission 104’ of one or more previous transmissions to the reader device. The control signal 212 indicates a plurality of retransmission instances. The radio tag 100’ selects one of the plurality of retransmission instances for the retransmission 104’. In accordance with embodiments, the radio tag 100 may be an ultra-low complexity loT device having an ultra-low power consumption in accordance with the 3GPP standards. In accordance with other embodiments, the radio device 100 may be a device operating in accordance with the WiFi standard. In accordance with yet other embodiments, the radio device 100 may be an RFID device, like an RFID tag.

[0372] Fig. 13 illustrates a reader device 200’ in accordance in accordance with embodiments of the second aspect of the present invention. The reader device 200, like a user equipment, UE, or a base station, BS, or a WiFi, or a RFID reader, communicates with a radio tag, like the radio tag 100’. The reader device is a radio access network, RAN, entity of a wireless communication system or is connectable to a RAN entity of the wireless communication system. The reader device 200’ is also connectable 202’ to a plurality of radio tags. Responsive to a collision of a transmission of a radio tag with a transmission of another radio tag, the reader device 200’ sends to the radio tag a repetition or control signal 212. The control signal 212 causes the radio tag to perform a retransmission of one or more previsions transmissions to the reader device 200’. In accordance with embodiments, the reader device 200 may be a network entity of a 3GPP wireless communication network, for example a user equipment, UE, or a base station, BS, or any other radio access network, RAN, entity of the network. In accordance with other embodiments, the radio device may be a station, STA, or access point, AP, of a WiFi network. In accordance with yet other embodiments, the radio device 200 may be an RFID-reader.

[0373] Thus, embodiments of the second aspect of the present invention resolve collisions that may occur when multiple radio tags attempt to transmit data simultaneously leading to interference and potential data loss. For addressing such situations, in accordance with embodiments of the second aspect of the present invention, the control signal, also referred

[0374] HHI 2 - 2024P67419EP - final to as a short indication signal or a repetition signal, is provided for effectively managing the retransmissions that are needed in response to detecting the collision and the potential data loss. The short indication signal serves as prompt for all radio tags to repeat their transmissions from a last time or from a preconfigured or configured time slot or from a previous time slot indicated by the repetition signal. This supports organizing the retransmission process in a way that interferences among the radio tags perform the retransmissions are reduced.

[0375] In accordance with further embodiments, the control or repetition signal responsive to one or more of the following:

[0376] - A collision of a transmission of the radio tag with a transmission of another radio tag. An external interference, from 3GPP or non-3GPP systems.

[0377] A degradation in the communication channel.

[0378] - A decoding error at the radio device.

[0379] A failure on receiving an explicit or implicit acknowledgement signal. An implicit acknowledgement signal can be a further transmission, which can be interpreted as acknowledgement of a previous frame.

[0380] In accordance with embodiments, the repetition signal may allow for a random slot selection or may provide two or more slots for the radio tags from which they may randomly choose a time slot for performing a retransmission. By selecting the time slots randomly, a likelihood of collision of the retransmissions is reduced as radio tags are less likely to choose the same timeslot for a retransmission.

[0381] In accordance with further embodiments, a set of different frequency offsets, which can be separated by the reader device, is provided for a retransmission.

[0382] In accordance with other embodiments, the retransmission may use different codes. Responsive to receiving the repetition or short indicator signal, the retransmission may be performed with the choice of different codes that can be separated by the reader device 200. For example, each radio tag may select a code for its retransmission thereby allowing the reader device or receiver to distinguish between the different transmission thereby reducing the chances of a data loss despite potential collisions.

[0383] Yet another embodiment provides for a spare slot selection. More specifically, one or more slots within inventory round may be configured or preconfigured as sparse slots, for

[0384] HHI 2 - 2024P67419EP - final example one or more time slots at the end of the inventory round. These slots serve as spare slots for the radio tags which utilize these spare time slots for their retransmission. For example, the reader device may send an indicator in the repetition signal or in the short indication signal allowing a radio tag to select a specific spare time slot. In accordance with other embodiments, a radio tag may implement a backoff mechanism, to access the spare slots in accordance with yet other embodiments, a radio tag may randomly select one of the available spare time slots. In one embodiment, the backoff mechanism would randomly draw a number, e.g., using a uniform distribution between a minimum and maximum value, and the resulting number would indicate when to utilize a backoff slot, e.g., similar to a backoff counter used in radio standards using unlicensed access, e.g., NR-U, SL-U or WiFi systems. In another embodiment, the backoff value could indicate how many backoff slots can be utilized or have to be skipped.

[0385] The radio tag may respond to the control signal to perform the retransmission of the transmission, or enter a DRX or eDRX mode, e.g., in case a maximum retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold. A retransmission instance may include one or more of

[0386] - transmission of an exact copy of the previously transmitted signal,

[0387] - transmission of a redundancy version of the previously transmitted signal,

[0388] - transmission of a different signal,

[0389] - a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.

[0390] Third Aspect

[0391] Fig. 14 illustrates a radio tag or radio device 100” in accordance with embodiments of the third aspect of the present invention. The radio tag, like an Ambient loT device or an RFID device independently initiates an uplink transmission when data is to be transmitted. Stated differently, the radio tag 100” communicates with a reader device responsive to a query by reader device. Responsive to having data to be transmitted to the reader device, the radio tag 100” initiates a communication with the reader device. In accordance with embodiments, the radio tag 100 may be an ultra-low complexity loT device having an ultra-low power consumption in accordance with the 3GPP standards. In accordance with other embodiments, the radio device 100 may be a device operating in accordance with the WiFi standard. In accordance with yet other embodiments, the radio device 100 may be an RFID device, like an RFID tag.

[0392] HHI 2 - 2024P67419EP - final Fig. 15 illustrates a reader device 200” in accordance in accordance with embodiments of the third aspect of the present invention. The reader device 200”, like a user equipment, UE, or a base station, BS, or a WiFi, or a RFID reader, communicates with a radio tag, like the radio tag 100”. Stated differently, the reader device 200” is connectable to a radio access network, RAN, entity of a wireless communication system or is a RAN entity of the wireless communication system. Further, the reader device 200” is connectable to a plurality of radio tags. The reader device 200” is to query 202” a radio tag responsive to receiving an uplink transmission request 104” from the radio tag. In accordance with embodiments, the reader device 200 may be a network entity of a 3GPP wireless communication network, for example a user equipment, UE, or a base station, BS, or any other radio access network, RAN, entity of the network. In accordance with other embodiments, the radio device may be a station, STA, or access point, AP, of a WiFi network. In accordance with yet other embodiments, the radio device 200 may be an RFID-reader.

[0393] Thus, embodiments of the third aspect of the present invention address a situation in which a radio tag of a radio tag group has acquired data that needs to be transmitted via the reader device without waiting for an inventory round being initiated by the reader device. For example, some high priority data may be required to be transmitted immediately after gathering the data by the radio tag. For example, in a certain scenario, like a factory, a radio tag monitoring certain parameters, like a temperature or the like, of a machine may require an immediate signaling of an increase of the temperature above a threshold so as to allow taking suitable countermeasures in the factory control for avoiding damages due to an overheated machine or the like. In accordance with such embodiments, an uplink triggered traffic may be implemented. Uplink triggered traffic refers to a process where a radio tag initiates a communication with the network when the radio tag has data to transmit. In other words, the uplink triggered traffic is independent of any communication occurrence of the radio tag in accordance with its member ID and is also independent of a query by the reader device. Stated differently, the radio tag may initiate the communication with the reader device independent of the communication occurrence when having data to send and to include the data or part of the data in the request signal. Thus, the radio tag of the radio tag group 300 may initiate the uplink transmission at any time, i.e., outside the inventory round initiated or at any time during the inventory round, i.e., the radio tag is not bound by the communication occurrence as defined by the member ID.

[0394] HHI 2 - 2024P67419EP - final In accordance with embodiments, a radio tag which has data to be transmitted may join a scheduling request, SR, group which is a dynamic group of radio tags that have data to be transmitted. Thus, when a radio tag has data to be transmitted, it becomes a member of this dynamic group and remains in this group until the network queries the group and the device successfully transmits the data. For example, the reader device may be configured to query SR groups during times between regular inventory rounds thereby ensuring that radio tags having data to be transmitted being queried more often. In accordance with embodiments, the radio tag may have a dynamic group membership meaning that the radio tag, when having data to transmit, joins the SR group. The SR group is dynamic meaning that the radio devices may join or leave the group based on their transmission needs. The network, as mentioned above, may periodically query the SR group to check for devices that have data to transmit. When a radio tag in the SR group is queried, the data is transmitted and, responsive to a successful transmission of the data, the radio tag may leave the SR group.

[0395] In accordance with other embodiments, when the radio tag has data to be transmitted, a scheduling request signal, like a random access signal, may be transmitted by the radio tag. This signal is a request to the reader device indicating that the radio tag has to send data and needs to be queried or addressed. The radio tag may continue to send the scheduling request signal until it receives a response from the reader device or network. In accordance with embodiments, the signal may be sent once, repeatedly, continuously, periodically or in a certain RACH slot indicated by the reader device.

[0396] General

[0397] In the embodiments described above, reference has been made to a wireless communication system including, as illustrated in Fig. 4, the radio tags 100a to 100d and the reader device 200. In accordance with further embodiments, the wireless communication network may include a plurality of reader devices for addressing respective radio tags within their communication range.

[0398] In accordance with embodiments, the reader devices 200 may be network entities of a certain wireless communication system, for example a network entity of a 3GPP system or a WiFi system, like a user equipment, base station or relay node in the 3GPP system or a WiFi station or access point in a WiFi system. In such embodiments, the radio devices may be addressed in accordance with the respective transmission protocol used by the wireless communication system, i.e., the radio devices may be directly addressed by the network

[0399] HHI 2 - 2024P67419EP - final entities of the respective wireless network. For example, the communication protocols used the communications between the reader device and the network and for the communication between the reader device and the radio tag may be the same or different and may be one of the following: a 3GPP communication protocol, e.g., A-loT or NB-loT or eMTC or LTE-M, or a non-3GPP radio, e.g., WiFi communication protocol or an RFID communication protocol or a lower power wide area protocol, LPWA, e.g., mioty®, or a satellite radio protocol, e.g., Iridium®.

[0400] In accordance with other embodiments, the reader tags, for example the above mentioned ultra-low complexity / ultra-low power consumption devices may not operate in accordance with the communication protocols as defined by a standard of the wireless communication network to which, for example, the reader device belongs, for example they may not operate fully in accordance with the 3GPP standard or the WiFi standard. Such radio devices, like ultra-low complexity / power ambient loT devices, may only be addressable by appropriately adapted reader devices 200, like Ambient loT readers or scanners. In accordance with such embodiments, the reader device 200 communicates with the respective radio devices using, for example, the ALOHA protocol, and acts as an intermediate or relay node or as a gateway node to the wireless communication system. For example the IDs of the radio devices may be translated into the International mobile subscriber identity, IMSI, and / or temporary mobile subscriber identity, TMSI. The IMSI is a unique identifier associated with a SIM card of a subscriber, while the TMSI is a temporary identifier that is used to provide a level of privacy and security by avoiding transmissions of the IMSI over the air interface. In a cellular network, these identifiers are used in the identification and communication with the UEs, and the reader device 200, as an intermediate node, translates the device-IDs of the radio devices 100 to 100c to respective identifiers being in conformity with the communication standard of the wireless communication system. Thus, the respective radio devices may also be addressed by network entities of the wireless communication network to which the reader device is connected, thereby integrating low complexity, low power radio devices into an existing wireless communication network, like the 3GPP network or the WiFi network.

[0401] In accordance with embodiments, the one or more reader devices 200 may be configured or preconfigured with a large number of virtual addresses, for example by using ESIM so that messages may be directly forwarded from and / or to an NG-RAN node or a core network, like 5GC.

[0402] HHI 2 - 2024P67419EP - final Fig. 16A and Fig. 16B schematically represent an example of a terrestrial 3GPP wireless network 400 including, as is shown in Fig. 16A, the core network, CN, 402 and one or more radio access networks, RANi, RAN2, ... , RANN. Fig. 16B is a schematic representation of an example of a radio access network RANnincluding one or more base stations gNB1 to gNB5 each serving a specific area surrounding the base station as is schematically represented by the cells 406i to 406s. The base stations are provided to serve users within a cell, for example, in the licenced and / or unlicensed bands. The term base station, BS, may refer to a gNB in 5G networks, an eNB in UMTS / LTE / LTE-A / LTE-APO or just a base station in other mobile communication standards, for example a base station in a 6G network. The BS may also comprise integrated access and backhaul, IAB, modes, e.g., an IAB donor and / or an IAB node consisting of a central unit, CU, as well as distributed units, DU. Fig. 16B further illustrates the loT devices 100i, I OO2 operating in accordance with the teachings of the present invention. In accordance with first embodiments, the inventive loT device 100i is addressed directly by gNB4 acting as reader device 200 described above with reference to Fig. 4. On the other hand, loT device 10O2 may be a radio device which is not addressable using the communication protocol of the wireless communication network depicted in Fig. 16(A) and Fig. 16(B). In such embodiments, UE3 acts as the reader device 200 used for addressing loT device I OO2. UE3 may act as the above described intermediate or relay node for a communication via the base station gNB4.

[0403] In accordance with other embodiments, the wireless communication network may be a WiFi network and the illustrated elements may be WiFi elements, for example the base stations illustrated may refer to an access point, AP, in any one of the WiFi standards belonging, for example, to the IEEE 802.1 1 -family.

[0404] Although the respective aspects and embodiments of the inventive approach have been described separately, it is noted that each of the aspects / embodiments may be implemented independent from the other, or some or all of the aspects / embodiments may be combined.

[0405] In accordance with embodiments of the present invention, a user device comprises one or more of the following: a power-limited UE, or a hand-held UE, like a UE used by a pedestrian, and referred to as a Vulnerable Road User, VRU, or a Pedestrian UE, P-UE, or an on-body or hand-held UE used by public safety personnel and first responders, and referred to as Public safety UE, PS-UE, or an loT UE, e.g., a sensor, an actuator or a UE

[0406] HHI 2 - 2024P67419EP - final provided in a campus network to carry out repetitive tasks and requiring input from a gateway node at periodic intervals, a mobile terminal, or a stationary terminal, or a cellular loT-UE, or a vehicular UE, or a vehicular group leader (GL) UE, or a sidelink relay, or an loT or narrowband loT, NB-loT, device, or wearable device, like a smartwatch, or a fitness tracker, or smart glasses, or a ground based vehicle, or an aerial vehicle, or a drone, or a moving base station, or road side unit (RSU), or a building, or any other item or device provided with network connectivity enabling the item / device to communicate using the wireless communication network, e.g., a sensor or actuator, or any other item or device provided with network connectivity enabling the item / device to communicate using a sidelink the wireless communication network, e.g., a sensor or actuator, or any sidelink capable network entity.

[0407] In accordance with embodiments of the present invention, a RAN network entity, like the base station or gNB, comprises one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a road side unit (RSU), or a remote radio head, or an AMF, or an MME, or an SMF, or a core network entity, or mobile edge computing (MEC) entity, or a network slice as in the NR or 5G core context, or any transmission / reception point, TRP, enabling an item or a device to communicate using the wireless communication network, the item or device being provided with network connectivity to communicate using the wireless communication network.

[0408] Although some aspects of the described concept have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or a device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

[0409] Various elements and features of the present invention may be implemented in hardware using analog and / or digital circuits, in software, through the execution of instructions by one or more general purpose or special-purpose processors, or as a combination of hardware and software. For example, embodiments of the present invention may be implemented in the environment of a computer system or another processing system. Fig. 17 illustrates an example of a computer system 600. The units or modules as well as the steps of the methods performed by these units may execute on one or more computer systems 600. The computer system 600 includes one or more processors 602, like a special purpose or

[0410] HHI 2 - 2024P67419EP - final a general-purpose digital signal processor. The processor 602 is connected to a communication infrastructure 604, like a bus or a network. The computer system 600 includes a main memory 606, e.g., a random-access memory, RAM, and a secondary memory 608, e.g., a hard disk drive and / or a removable storage drive. The secondary memory 608 may allow computer programs or other instructions to be loaded into the computer system 600. The computer system 600 may further include a communications interface 610 to allow software and data to be transferred between computer system 600 and external devices. The communication may be in the from electronic, electromagnetic, optical, or other signals capable of being handled by a communications interface. The communication may use a wire or a cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels 612.

[0411] The terms “computer program medium” and “computer readable medium” are used to generally refer to tangible storage media such as removable storage units or a hard disk installed in a hard disk drive. These computer program products are means for providing software to the computer system 600. The computer programs, also referred to as computer control logic, are stored in main memory 606 and / or secondary memory 608. Computer programs may also be received via the communications interface 610. The computer program, when executed, enables the computer system 600 to implement the present invention. In particular, the computer program, when executed, enables processor 602 to implement the processes of the present invention, such as any of the methods described herein. Accordingly, such a computer program may represent a controller of the computer system 600. Where the disclosure is implemented using software, the software may be stored in a computer program product and loaded into computer system 600 using a removable storage drive, an interface, like communications interface 610.

[0412] The implementation in hardware or in software may be performed using a digital storage medium, for example cloud storage, a floppy disk, a DVD, a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate or are capable of cooperating with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.

[0413] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0414] HHI 2 - 2024P67419EP - final Generally, embodiments of the present invention may be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier.

[0415] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0416] A further embodiment of the inventive methods is, therefore, a data carrier or a digital storage medium, or a computer-readable medium comprising, recorded thereon, the computer program for performing one of the methods described herein. A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0417] In some embodiments, a programmable logic device, for example a field programmable gate array, may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus.

[0418] The above described embodiments are merely illustrative for the principles of the present invention. It is understood that modifications and variations of the arrangements and the details described herein are apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the impending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein.

[0419] HHI 2 - 2024P67419EP - final

Claims

CLAIMS1. A radio tag, wherein the radio tag is a member of at least one or more radio tag groups, the radio tag group including a plurality of group members, the plurality of group members including at least the radio tag and a further radio tag, and each group member of the radio tag group having assigned a member ID, and at a communication instance, the radio tag is to communicate with a reader device querying the radio tag group.

2. The radio tag of claim 1 , wherein the member ID is unique.

3. The radio tag of claim 1 or 2, wherein, when communicating with the reader device, the radio tag is- to only receive a signal from a reader device, e.g., is restricted to only receive or decode signals received from a reader device, and / or- to only transmit a signal to a reader device.

4. The radio tag of any one of the preceding claims, wherein the communication instance is defined by the member ID of the radio tag.

5. The radio tag of any one of the preceding claims, wherein the radio tag is a wireless device capable to transmit and / or receive radio frequency signals with one or more reader devices.

6. The radio tag of any one of the preceding claims, wherein the radio tag is a wireless device capable to receive radio frequency signals from one or more reader devices and to transmit using a backscatter communication.

7. The radio tag of any one of the preceding claims, wherein at the communication instance among the group members only, the radio tag is to communicate with the reader device but none of the other group members.HHI 2 - 2024P67419EP - final8. The radio tag of any one of the preceding claims, wherein at the communication instance, the radio tag is to transmit at instances associated to the member ID.

9. The radio tag of any one of the preceding claims, wherein at the communication instance, the radio tag is to process and / or respond to transmissions associated with the member ID.

10. The radio tag of any one of the preceding claims, wherein at the communication instance none of the group members are to communicate with the reader device, except for the radio tag.11 . The radio tag of any one of the preceding claims, wherein the respective member IDs of the group members define respective different communication instances for the respective radio tags of the radio tag group.

12. The radio tag of any one of the preceding claims, wherein the member ID of the radio tag defines one or more of the following communication instances:- a time at which the radio tag is to communicate with the reader device, e.g., a slot,- a frequency on which the radio tag is to communicate with the reader device, e.g., a shift applied to a CW during the backscattered response,- a code the radio tag is to use for a communication with the reader device,- a beam, e.g., beam ID, on which the radio tag is to communicate with the reader device.

13. The radio tag of claim 12, wherein the member ID of the radio tag defines a time instance from a predefined sequence of time instances at which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command.

14. The radio tag of claim 12 or 13, wherein the member ID of the radio tag indicates a time offset with which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command, wherein the time offset is counted from a receipt of the control message.

15. The radio tag of claim 14, wherein the time offset depends on one or more of the following:HHI 2 - 2024P67419EP - finala number of transmission opportunities, e.g., slots, in addition to the time instance, e.g., defined by the member ID,16. The radio tag of claim 14 or 15, wherein the time offset further depends on a clock signal, e.g., a general clock signal provided by one or more of the following:- a base station,- a reader device,- another UE,- another radio tag.

17. The radio tag of any one of claims 14 to 16, wherein the time offset is a fixed value, which is configured and or pre-configured in the radio tag, e.g., a fixed time interval or a fixed time limit or a fixed number of one or more slots, within which a reader tag can respond or is allowed to respond to a reader device query.

18. The radio tag of any one of claims 12 to 18, wherein the member ID of the radio tag defines a time slot from a predefined sequence of time slots in which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory command.

19. The radio tag of claim 18, wherein the predefined sequence of time slots comprises a number of time slots that is equal to or greater than a number of group members of the radio tag group.

20. The radio tag of claim 18 or 19, wherein responsive to the reader device querying the radio tag group, the radio tag is to receive an initial control signal the reader device, wherein the reader device may be one of the following:- a base station,- a user equipment, another type of 3GPP RAN nodes, e.g., a non-terrestrial network, NTN,- a non-3GPP node,- a device, e.g., a transmitter, which can emit such a signal, andHHI 2 - 2024P67419EP - finalthe initial control signal comprising one or more communication instances, e.g., slots.

21. The radio tag of claim 20, wherein, responsive to the reader device querying the radio tag group, the radio tag is to- listen to the initial control signal, and responsive to determining the communication instance, e.g., time slot, defined by the member ID of the radio tag, communicate with the reader device.

22. The radio tag of claim 21 , wherein a first slot indicator in the predefined sequence of time slots is the control message from the reader device.

23. The radio tag of any one of claims 20 to 22, wherein, responsive to the reader device querying the radio tag group, the radio tag is to reduce its power consumption, e.g., by staying in an energy saving mode, until determining the time slot defined by the member ID of the radio tag.

24. The radio tag of claim 23, wherein the energy saving mode comprises one or more of a Discontinuous Reception (DRX) mode, an eDRX mode,- a mode where a WUS signal or a broadcast signal or a synchronization signal can still be received.

25. The radio tag of any one of claims 20 to 24, wherein the radio tag is to terminate a communication with the reader device responsive to one or more of the following:- receiving a next slot indicator from the reader device,- receiving an end signal to terminate communication, e.g., a termination signal or an acknowledgement, ACK,- a lapse of a configured or preconfigured timer, exceeding a maximum transmission duration, exceeding a maximum number of transmissions, exceeding a maximum number of transmissions within a configured or preconfigured time interval,- detecting an energy level below a configured or preconfigured threshold, a mobility condition,- detecting interference that exceeds a configured or preconfigured threshold.HHI 2 - 2024P67419EP - final26. The radio tag of any one of claims 26 to 25, wherein the slot indicator is a signal having a configured or preconfigured pattern or a configured or preconfigured sequence, e.g., of high-low amplitude transitions or of a pulse width modulated signal, PWM, e.g., with a width of signal pulse being varied in proportion to an amplitude of an analog input signal.

27. The radio tag of any one of claims 20 to 26, wherein a time slot is identified by two or more slot indicators, the slot indicators being different.

28. The radio tag of claim 27, wherein the two or more slot indicators are successive, e.g., following each other in time domain.

29. The radio tag of claim 28, wherein a time gap between a first and one or more second slot indicators is limited by a configured and / or preconfigured threshold.

30. The radio tag of any one of claims 27 to 29, wherein the time slots are indicated with an alternating sequence of two or more slot indicators.31 . The radio tag of any one of claims 20 to 30, wherein responsive to missing a slot indicator, the radio tag is to detect this and / or use a subsequent slot indicator for correcting a count of the time slots.

32. The radio tag of any one of claims 20 to 31 , wherein the slot indicators are followed by or contain a sequence.

33. The radio tag of any one of claims 27 to 32, wherein the two or more slot indicators are identical or different slot indicators.

34. The radio tag of any one of claims 27 to 33, wherein the two or more slot indicators identifying the time slot are obtained by including a truncated slot index, e.g., by using only a certain number of the least significant bits or by a modulo operation.

35. The radio tag of any one of claims 20 to 34, wherein, responsive to losing synchronization due to one or more missed slot indicators, the radio tag is to:- stop transmitting any data,- wait for a specific signal before further transmitting any data,HHI 2 - 2024P67419EP - final- wait for a slot indicator including a count indication,- wait for a start slot indicator,- wait for a stop slot indicator,- wait for a specific sequence of one or more start and / or stop slot indicators.

36. The radio tag of any one of claims 20 to 35, wherein the radio tag is to receive from the reader device, in addition to querying the radio tag group, one or more additional signals for controlling a transmission process and / or for supporting one or more certain scenarios that may arise during the communication.

37. The radio tag of claim 36, wherein, responsive to the reader device querying the radio tag group, the radio tag, while being in an energy saving mode, is to monitor transmissions from the reader device for the one or more additional signals.

38. The radio tag of claims 36 or 37, wherein the one or more additional signals comprise an adjust signal, the adjust signal indicating one or more of the following:- skipping of one or more time slots,- jumping to a different time slot,- changing one or more transmission parameters, e.g., responsive to a certain channel characteristic between the radio tag and the reader device, a coding modulation or repetition factor may be adjusted for ensuring that the communication between the radio tag and the reader device remains robust and efficient.

39. The radio tag of any one of claims 36 to 38, wherein the one or more additional signals comprise an end signal, the end signal causing all radio tags of the radio tag group to enter an energy saving mode.

40. The radio tag of claim 39, wherein the end signal causes an active radio tag to stop its data transmission and to enter an energy saving mode.41 . The radio tag of any one of claims 36 to or 38, wherein the one or more additional signals comprise a repeat signal, the repeat signal causing the radio devices to repeat a- last time slot, or the n last time slots, n > 1 , or- a specific time slot.HHI 2 - 2024P67419EP - final42. The radio tag of claim 12, wherein the member ID of the radio tag defines a frequency from a predefined set of frequencies on which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., an inventory call.

43. The radio tag of claim 12 or 42, wherein the member ID of the radio tag indicates a frequency offset with which the radio tag is to respond to a control message from the reader device querying the radio tag group, e.g., like an inventory call, the frequency offset being from a frequency on which the control message is transmitted.

44. The radio tag of claim 12 or 43, wherein the frequency offset indicates either a positive or a negative offset with respect to a carrier frequency.

45. The radio tag of claim 43 or 44, wherein frequency offset defined by the member ID of the radio tag comprises:- a zero offset so that the radio tag is to respond to the control message on o the same frequency on which the control message is transmitted, or o on a configured or preconfigured frequency, or- a non-zero offset so that the radio tag is to respond to the control message on a frequency higher or lower by the offset than o the frequency on which the control message is transmitted, or o the configured or preconfigured frequency.

46. The radio tag of claim 5, wherein the radio tag is to code a response to a control message from the reader device querying the radio tag group, like an inventory call or command, by including or encoding into the response the member ID or a part of the member ID or a processed form of the member ID, or scrambling or interleaving the response with the member ID or a part of the member ID or a processed form of the member ID, or- applying a configured or preconfigured coding scheme or sequence to respond to the control message that yield encoded signals having a certain property, like an orthogonality under correlation or a cross-correlation property or an autocorrelation property, e.g., having a peak value above or below a configured or pre-configured threshold and / or having certain symmetry constraints, the relationship between two distinct signals may have different characteristics or magnitudes.HHI 2 - 2024P67419EP - final47. The radio tag of claim 46, wherein the member ID of the radio tag defines the configured or preconfigured coding scheme from a set of coding schemes, e.g., using an index or code index.

48. The radio tag of claim 46, wherein the member ID of the radio tag defines the configured or preconfigured sequence from a set of sequences being orthogonal to each other, such as Zadoff-Chu-sequences or Gold sequences.

49. The radio tag of any one of the preceding claims, wherein the radio tag belongs to one of a plurality of radio tag groups, the radio tag having assigned a member ID for one or more of the groups, and the radio tag is to receive from the reader device, querying the radio tag group, a signaling indicating the queried radio tag group.

50. The radio tag of any one of the preceding claims, wherein the radio tag belongs to a plurality of radio tag groups, the radio tag having assigned a joint member ID for more than one or all of the groups it belongs to.51 . The radio tag of any one of the preceding claims, wherein the radio tag group includes radio tags within a certain range, e.g., a configured or preconfigured pathloss, received power, e.g., RSSI or SNR or SINR, or a distance from the reader device such as Euclidean distance, e.g., measured in meters, or a zone, e.g., having a certain measure and / or zone ID. A zone may have a certain size in height and width or a particular shape, e.g., rectangular or circular, defined by a center and radius.

52. The radio tag of any one of the preceding claims, wherein the radio tag group includes a plurality of subgroups, and the radio tag is assigned to a subgroup using one or more criteria.

53. The radio tag of any of the preceding claims, wherein the radio tag is assigned to a subgroup and the subgroup is addressed by a subgroup ID.

54. The radio tag of claim 53, wherein the subgroups are in an ordered list.HHI 2 - 2024P67419EP - final55. The radio tag of claim 54, wherein a signal tells that a next subgroup of the list is to communicate in a subsequent communication instance.

56. The radio tag of any one of the preceding claims, wherein the radio tag associates itself with a certain group or subgroup depending on one or more of the following:- a signal quality,- a received power,- a location,- application requirements, such as latency and or reliability requirements,- a range or distance to the reader,- a power status,- a bandwidth, e.g., a bandwidth defined in frequency domain, e.g., by a set of subcarriers,- a type of data, e.g., transmission of inventory messages or transmission of a health status of a product, e.g., temperature or accelerometer values.

57. The radio tag of any one of claims 52 to 56, wherein one of the plurality of subgroups has a channel access priority over the other subgroups.

58. The radio tag of any one of the preceding claims, wherein the radio tag is to- receive from the reader device a repetition signal, e.g., the reader device providing the repetition signal responsive to a collision of a transmission of the radio tag with a transmission of another radio tag not being a group member.

59. The radio tag of any one of the preceding claims, wherein the radio tag is to respond to a control signal to perform one or more of the following: a retransmission of the transmission, a DRX or eDRX, e.g., in case a max. retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold.

60. The radio tag of claim 58 or 59, wherein the control signal indicates a plurality of retransmission instances, and the radio tag is to select one of the plurality of retransmission instances.HHI 2 - 2024P67419EP - final61 . The radio tag of claim 60, wherein the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,- a set of different codes for a retransmission that can be separated by the reader device,- a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

62. The radio tag of any of claims 58 to 61 , wherein a retransmission instance comprises one or more of the following:- transmission of an exact copy of the previously transmitted signal,- transmission of a redundancy version of the previously transmitted signal,- transmission of a different signal,- a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.

63. The radio tag of any of claims 58 to 62, wherein the radio tag is to select the retransmission instance randomly.

64. The radio tag of any one of the preceding claims, wherein the radio tag group is a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit, and responsive to having data to be transmitted to the reader device, the radio tag is to join the SR group and remain in the SR group until the SR group is queried by the reader device and the radio tag has successfully transmitted the data.

65. The radio tag of any one of the preceding claims, wherein, responsive to having data to be transmitted to the reader device, the radio tag is to initiate a communication with the reader device.HHI 2 - 2024P67419EP - final66. The radio tag of claim 65, wherein the radio tag is to initiate the communication with the reader device independent of the communication occurrence and / or independent of being queried by the reader device via the radio tag group.

67. The radio tag of claim 65 or 66, wherein the radio tag is to send a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

68. The radio tag of claim 67, wherein the radio tag is to send the request signal once, repeatedly, continuously, periodically or in certain RACH slots indicated by the reader device.

69. The radio tag of claim 67 or 68, wherein the radio tag is to continue sending the request signal until receiving a response from the reader device.

70. The radio tag of any one of the preceding claims, wherein the radio tag is to initiate the communication with the reader device independent of the communication occurrence when having data to send and to include the data or part of the data in the request signal.71 . The radio tag of any one of the preceding claims, wherein, for communicating with the reader device, e.g., if there is data to be transmitted, the radio tag is to:- send a data message, the data message including control and / or payload data72. The radio tag of claim 71 , wherein the radio tag is to perform one or more of the following:- send an access message including a random access preamble, sequence or ID to the reader device indicating that the radio tag wants to initiate a communication, receive from the reader device a response message including a random ID number corresponding to the access message, receive from the reader device one or more further messages, the one or more further messages including a feedback message indicating a successful or unsuccessful transmission of the data message, and a message including control and / or payload data for the radio tag.

73. The radio tag of claim 72, wherein, responsive to the feedback message indicating an unsuccessful transmission of the data message, the radio tag is to:HHI 2 - 2024P67419EP - finalretransmit the data message.

74. The radio tag of claim 71 or 72, wherein the radio device is to- transmit the access message and the data message in one message, and / or- receive the response message and the feedback message in one message.

75. A radio tag, wherein the radio tag is to communicate with a reader device responsive to a query by the reader device, responsive to a control signal from the reader device, the radio tag is to perform a retransmission of one or more previous transmissions to the reader device, and the control signal indicates a plurality of retransmission instances, and the radio tag is to select one of the plurality of retransmission instances for the retransmission.

76. The radio tag of claim 75, wherein the radio tag is to receive the repetition signal responsive to one or more of the following:- a collision of a transmission of the radio tag with a transmission of another radio tag, an external interference, from 3GPP or non-3GPP systems,- a degradation in the communication channel,- a decoding error at the radio device,- a failure on receiving an explicit or implicit acknowledgement signal77. The radio tag of claim 75 or 76, wherein the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,- a set of different codes for a retransmission that can be separated by the reader device,- a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.HHI 2 - 2024P67419EP - final78. The radio tag of any one of claims 75 to 77, wherein the radio tag is to select the retransmission instance randomly.

79. The radio tag of any one of claims 75 to 78, wherein the radio tag is to respond to a control signal to perform one or more of the following: a retransmission of the transmission, a DRX or eDRX, e.g., in case a max. retransmission counter is reached or in case the power budget of the radio tag is below a configured or preconfigured threshold.

80. The radio tag of claim 79, wherein a retransmission instance comprises one or more of the following:- transmission of an exact copy of the previously transmitted signal,- transmission of a redundancy version of the previously transmitted signal,- transmission of a different signal,- a change of target within the retransmission, e.g., the retransmission modifies the target of its transmission to a different value, e.g., changing the group and / or subgroup identifier.81 . A radio tag, wherein the radio tag is to communicate with a reader device responsive to a query by reader device, and responsive to having data to be transmitted to the reader device, the radio tag is to initiate a communication with the reader device.

82. The radio tag of claim 81 , wherein, for initiating a communication with the reader device, the radio tag is to- join a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit, and- remain in the SR group until the SR group is queried by the reader device and the radio tag has successfully transmitted the data.

83. The radio tag of claim 81 , wherein the radio tag is to initiate the communication with the reader device independent of being queried by the reader device.HHI 2 - 2024P67419EP - final84. The radio tag of claim 83, wherein the radio tag is to send a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

85. The radio tag of claim 84, wherein the radio tag is to send the request signal once, repeatedly, continuously, periodically or in certain RACH slots indicated by the reader device.

86. The radio tag of claim 84 or 85, wherein the radio tag is to continue sending the request signal until receiving a response from the reader device.

87. The radio tag of any one of the preceding claims, wherein the radio tag is connectable to the reader device, the reader device being an entity of a wireless communication system and capable of querying one or more radio tags or one or more radio tag groups or sub-groups.

88. The radio tag of claim 87, wherein the radio tag is to communicate with the reader device using a first communication protocol, and the reader device is to communicate with a core network of the wireless communication system using a second communication protocol.

89. The radio tag of claim 88, wherein the wireless communication system comprises one of the following: a 3GPP network or a WiFi network or an Radio-frequency identification, RFID, network, the first communication protocol is the same as of different from the second communication protocol, and may be one of the following: a 3GPP communication protocol, e.g., A-loT or NB-loT or eMTC or LTE-M, a non-3GPP radio, e.g., WiFi communication protocol or an RFID communication protocol or a lower power wide area protocol, LPWA, e.g., mioty®, or a satellite radio protocol, e.g., Iridium®.

90. The radio tag of any one of the preceding claims, comprising: a backscatter transmitter for transmitting a signal using a backscattered signal,HHI 2 - 2024P67419EP - finalwherein the radio tag is to receive an incident signal for querying the data tag group from the reader device and transmit the signal using the backscattered signal responsive to the incident signal.91 . The radio tag of any one of the preceding claims, wherein the radio tag comprises one the following: an loT Internet-of-Things, loT, device, an NB-loT or eMTC device, a low power wide area device, LPWA, an Ambient loT device,- a sensor device,- an actuator device,- a passive device,- a device without active transmitter, using backscatter communication, e.g. of a carrier wave, CW, signal, an Radio-frequency identification, RFID, device, like an RFID tag.

92. A reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, and the reader device is to query a radio tag group, the radio tag group including a plurality of group members, the plurality of group members including at least a first radio tag and a second radio tag, and each group member of the radio tag group having assigned a member ID, the member ID of a radio tag defining a communication instance for a communication with the reader device.

93. The reader device of claim 92, wherein the reader device is to configure the group members of the radio tag group with respective member IDs, the respective member IDs defining one or more of the following communication instances:- a time at which the radio tag is to communicate with the reader device, e.g., a slot,- a frequency on which the radio tag is to communicate with the reader device, e.g., a shift applied to the CW during the backscattered response,- a code the radio tag is to use for a communication with the reader device,HHI 2 - 2024P67419EP - finala beam, e.g., beam ID, on which the radio tag is to communicate with the reader device.

94. The reader device of claim 93, wherein the respective member IDs define respective time slots from a predefined sequence of time slots in which a radio tag is to respond to the query from the reader device querying the radio tag group, and the reader device is to transmit, responsive to querying the radio tag group, an initial control signal, the initial control signal comprising a plurality of slots, each slot indicating a time slot from the predefined sequence of time slots.

95. The reader device of any one of claims 92 to 94, wherein the reader device is to send to one or more or all of the radio tags of the radio tag group, in addition to querying the radio tag group, one or more additional signals for controlling a transmission process and / or for supporting one or more certain scenarios that may arise during the communication.

96. The reader device claim 95, wherein the one or more additional signals comprise an adjust signal, the adjust signal indicating one or more of the following:- skipping of one or more time slots,- jumping to a different time slot,- changing one or more transmission parameters, e.g., responsive to a certain channel characteristic between the radio tag and the reader device, a coding modulation or repetition factor may be adjusted for ensuring that the communication between the radio tag and the reader device remains robust and efficient.

97. The reader device of claim 96, wherein the one or more additional signals comprise an end signal, the end signal causing all radio tags of the radio tag group to enter an energy saving mode.

98. The reader device of claim 97, wherein the one or more additional signals comprise a repeat signal, the repeat signal causing the radio devices to repeat- last time slot, or the n last time slots, n > 1 , orHHI 2 - 2024P67419EP - finala specific time slot.

99. The reader device of any one of claims 92 to 98, wherein the radio tag belongs to one of a plurality of radio tag groups, the radio tag having assigned a member ID for each of the groups, and the reader device is to send a signaling indicating the queried radio tag group.

100. The reader device of any one of claims 92 to 99, wherein the reader device is to- send to one or more or all of the radio tags of the radio tag group a control signal, the reader device providing the control signal responsive to one or more of the following: o a collision of a transmission of the radio tag with a transmission of another radio tag not being a group member, o an external interference, from 3GPP or non-3GPP systems, o a degradation in the communication channel, o an decoding error at the radio device, o a failure on receiving an explicit or implicit acknowledgement signal- responsive to providing the control signal, receive a retransmission of the transmission.

101. The reader device of claim 100, wherein the control signal indicates a plurality of retransmission instances, and wherein the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,- a set of different codes for a retransmission that can be separated by the reader device,- a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.HHI 2 - 2024P67419EP - final102. The radio tag of any one of claims 92 to 101 , wherein the radio tag group is a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit.

103. The reader device of any one of claims 92 to 102, wherein the reader device is to receive a request signal, like a random access signal or a scheduling request signal, indicating to the reader device that a radio tag has data to send and needs to be queried.

104. A reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, and responsive to a collision of a transmission of a radio tag with a transmission of another radio tag, the reader device is to send to the radio tag a control signal, the control signal causing the radio tag to perform a retransmission of one or more previsions transmissions to the reader device, and the control signal indicates a plurality of retransmission instances.

105. The reader device of claim 104, wherein the plurality of retransmission instances indicates one or more of the following: two or more time slots for the radio tag to randomly choose from for the retransmission,- a set of different codes for a retransmission that can be separated by the reader device,- a set of different frequency offsets for a retransmission that can be separated by the reader device, one or more time slots within an inventory round to be used for a retransmission, e.g., one or more time slots at the end of the inventory round.

106. A reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, andHHI 2 - 2024P67419EP - finalthe reader device is to query a radio tag responsive to receiving an uplink transmission request from the radio tag.

107. The reader device of claim 106, wherein the reader device is to query a scheduling request, SR, group, the SR group being a group of radio tags that have data to transmit.

108. The reader device of claim 107, wherein the reader device is to query the radio tag responsive to a request signal from the radio tag, like a random access signal or a scheduling request signal, indicating to the reader device that the radio tag has data to send and needs to be queried.

109. The reader device of any one of claims 92 to 108, wherein the radio tag is to communicate with the reader device using a first communication protocol, and the reader device is to communicate with a core network of the wireless communication system using a second communication protocol.

110. The reader device of claim 108, wherein the wireless communication system comprises one of the following: a 3GPP network or a WiFi network or an Radio-frequency identification, RFID, network, the first communication protocol is the same as of different from the second communication protocol, and the second communication protocol is one of the following: a 3GPP communication protocol or a WiFi communication protocol or an RFID communication protocol.11 1. The reader device of any one of claims 92 to 1 10, wherein the reader device comprises one the following: a mobile terminal of a wireless communication network, e.g., a user equipment, LIE, of a 3GPP network or of a WiFi network, an Radio-frequency identification, RFID, device, like an RFID reader.

112. The reader device of any one of claims 92 to 11 1 , wherein the radio tag comprises one the following: an loT Internet-of-Things, loT, device,HHI 2 - 2024P67419EP - finalan NB-loT or eMTC device, a low power wide area device, LPWA, an Ambient loT device,- a sensor device,- an actuator device,- a passive device,- a device without active transmitter, using backscatter communication, e.g. of a carrier wave, CW, signal, an Radio-frequency identification, RFID, device, like an RFID tag.

113. A wireless communication network, comprising: one or more reader devices of any one of claims 92 to 112, and. one or more radio tags of any one of claims 1 to 91 .

114. A method for operating a radio tag, wherein the radio tag is a member of at least one or more radio tag groups, the radio tag group including a plurality of group members, the plurality of group members including at least the radio tag and a further radio tag, and each group member of the radio tag group having assigned a member ID, the method comprising: at a communication instance, communicating with a reader device querying the radio tag group.

115. A method for operating a radio tag capable of communicating with a reader device responsive to a query by the reader device, the method comprising: responsive to a control signal from the reader device, performing a retransmission of one or more previous transmissions to the reader device, wherein the control signal indicates a plurality of retransmission instances, and the radio tag selects one of the plurality of retransmission instances for the retransmission.

116. A method for operating a radio tag capable of communicating with a reader device responsive to a query by reader device, the method comprising:HHI 2 - 2024P67419EP - finalresponsive to having data to be transmitted to the reader device, initiating a communication with the reader device.

117. A method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: querying a radio tag group, the radio tag group including a plurality of group members, the plurality of group members including at least a first radio tag and a second radio tag, and each group member of the radio tag group having assigned a member ID, the member ID of a radio tag defining a communication instance for a communication with the reader device.

118. A method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: responsive to a collision of a transmission of a radio tag with a transmission of another radio tag, sending to the radio tag a control signal, the control signal causing the radio tag to perform a retransmission of one or more previsions transmissions to the reader device, wherein the control signal indicates a plurality of retransmission instances.

119. A method for operating a reader device, wherein the reader device is connectable to a radio access network, RAN, entity of a wireless communication system and to a plurality of radio tags, the method comprising: querying a radio tag responsive to receiving an uplink transmission request from the radio tag.

120. A non-transitory computer program product comprising a computer readable medium storing instructions which, when executed on a computer, perform the method of any one of claims 114 to 1 19.HHI 2 - 2024P67419EP - final

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