Communication method and related apparatus

Abstract

The present application belongs to the technical field of wireless communications. Provided are a communication method and a related apparatus. The communication method is applied to a reader side, and comprises: sending a first R2D signal to an AIoT device, wherein the first R2D signal is a signal having a transmission direction from a reader to the AIoT device, and the first R2D signal comprises a paging message and / or a second random access message, the paging message including a first paging message and / or a second paging message, the first paging message preceding the second paging message, and the second paging message including one or more paging messages, and the first R2D signal is used for indicating at least one of the following information: information of a fixed listening window for the reader to listen for a first D2R signal, the first D2R signal being a signal having a transmission direction from the AIoT device to the reader, and the first D2R signal comprising a first random access message and / or a third random access message; resources for indicating activation and / or deactivation of the first D2R signal; a superposition transmission mode for the first R2D signal; and data for indicating a D2R parameter or updating the AIoT device.

Description

Communication methods and related devices Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a communication method and related apparatus. Background Technology

[0002] In recent years, the Internet of Things (IoT) has received considerable attention in the field of wireless communication. With the continuous development of communication systems, IoT devices are being applied to various scenarios, including homes, industry, agriculture, and healthcare. To enable large-scale deployment of IoT terminals across diverse applications, reducing their size, complexity, and power consumption becomes crucial. Traditional IoT devices, such as NB-IoT, MTC, and RedCap terminals, require batteries that need regular replacement or charging. As the number of IoT terminals increases dramatically in the future, using existing IoT systems will significantly increase power supply and labor costs. Furthermore, traditional IoT terminals are not suitable for extreme environments, such as high temperatures and high pressures. Therefore, ambient IoT (AIoT) technology has been widely discussed. AIoT devices primarily utilize external environmental factors (e.g., light, radio waves, motion, heat) for energy, thus eliminating the need for batteries or requiring only low energy storage (e.g., capacitors). This eliminates the need for manual battery replacement or charging, effectively avoiding the problems of existing IoT systems. Compared to existing NB-IoT, MTC, and RedCap terminals, AIoT devices will be less complex, consume less power, and cost less. For example, NB-IoT consumes power in the milliwatt range, while AIoT devices consume power in the microwatt range. This invention is applicable to environmental IoT, passive IoT, or ultra-low power IoT.

[0003] However, there are still many issues that need to be explored and resolved regarding the transmission mechanism of AIoT to make it more perfect. Summary of the Invention

[0004] This application provides a communication method to reduce signaling overhead and improve inventory efficiency during AIoT inventory or control operations.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a communication method applied to a reader / writer side, which sends a first R2D signal to an AIoT device. The first R2D signal is a signal whose transmission direction is from the reader / writer to the AIoT device. The first R2D signal includes a paging message and / or a second random access message. The paging message includes a first paging message and / or a second paging message, wherein the first paging message precedes the second paging message, and the second paging message includes one or more paging messages. The first R2D signal is used to indicate at least one of the following: fixed listening window information for the reader / writer to listen to the first D2R signal; the first D2R signal is a signal whose transmission direction is from the AIoT device to the reader / writer; the first D2R signal includes a first random access message and / or a third random access message; resources indicating the activation and / or deactivation of the first D2R signal; the transmission mode of the first R2D signal superimposed on the first R2D signal; and D2R parameters or data updates of the AIoT device.

[0007] A second aspect of this application also provides a communication method applied to an AIoT device, comprising: sending a first D2R signal to a reader based on first configuration information, wherein the first D2R signal is a signal with a transmission direction from the AIoT device to the reader, and the first D2R signal includes a first random access message and / or a third random access message; the first configuration information includes, but is not limited to, one or more of the following configurations: a fixed listening window configuration for the reader to listen to the transmission of the first D2R signal; a resource configuration indicating the activation and / or deactivation of the first D2R signal; a transmission method for superimposed transmission of the first D2R signal; and indicating D2R parameters or updating data of the AIoT device.

[0008] A third aspect of this application also provides a wireless communication device, including: a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the method as described in any of the preceding embodiments.

[0009] A fourth aspect of this application also provides a computer-readable storage medium, the computer-readable storage medium including instructions that, when executed, cause the method described in any of the preceding claims to be implemented. Attached Figure Description

[0010] Figure 1a is a schematic diagram of a possible backscatter communication principle;

[0011] Figure 1b-1 is a topology diagram of the AIoT system;

[0012] Figure 1b-2 is a schematic diagram of a possible scenario for an AIoT system;

[0013] Figure 1c is a schematic diagram of a possible signal;

[0014] Figure 1d shows one possible signal generation diagram;

[0015] Figure 1e is a schematic diagram of another possible signal;

[0016] Figure 1f is a schematic diagram of another possible signal;

[0017] Figure 1g is a schematic diagram of another possible signal;

[0018] Figure 1h is a flowchart of a possible communication method;

[0019] Figure 1i is a schematic diagram of a possible signal transmission;

[0020] Figure 1j is a schematic diagram of a possible symbol transmission;

[0021] Figure 1k is a schematic diagram of a possible signal mode;

[0022] [Correction 30.05.2025 according to Article 91] Figure 2a is a diagram of a possible communication method provided by this application;

[0023] [Correction 30.05.2025 according to Article 91] Figure 2b is a schematic diagram of a possible signal transmission provided in this application;

[0024] [Correction 30.05.2025 according to Rule 91] Figure 2c is a possible channel schematic diagram provided by an embodiment of this application;

[0025] [Correction 30.05.2025 according to Rule 91] Figure 2d is a possible signal transmission schematic diagram provided by an embodiment of this application;

[0026] [Correction 30.05.2025 according to Rule 91] Figure 2e is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0027] [Correction 30.05.2025 according to Rule 91] Figure 2f is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0028] [Correction 30.05.2025 according to Rule 91] Figure 2g is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0029] [Correction 30.05.2025 according to Rule 91] Figure 2i is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0030] [Correction 30.05.2025 according to Rule 91] Figure 2j is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0031] [Correction 30.05.2025 according to Rule 91] Figure 2k is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0032] [Correction 30.05.2025 according to Rule 91] Figure 21 is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0033] [Correction 30.05.2025 according to Rule 91] Figure 2m is a schematic diagram of another possible signal transmission provided by an embodiment of this application;

[0034] [Correction 30.05.2025 according to Rule 91] Figure 2n is a flowchart of another possible communication method provided in the embodiments of this application;

[0035] Figure 3 is a schematic diagram of the storage of a possible wireless communication device provided in an embodiment of this application. Detailed Implementation

[0036] For ease of understanding, the relevant technologies involved in the embodiments of this application will be described below.

[0037] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] It should be understood that the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. It should be noted that the naming of the parameters in this document is for ease of description; other names may be used in practice, and this application does not impose any restrictions on their specific use.

[0039] The messages described in this article include frames, instructions, commands, etc., and the names of device or functional entities, process names, frames, fields, etc. are not unique and are only used to assist in the description of functions, methods, behaviors, information, etc.

[0040] Figure 1a illustrates the principle of backscatter communication. Unlike the signal modulation and transmission process in traditional communication, devices supporting backscatter communication do not have carrier generation capabilities and cannot "actively" transmit signals. Instead, they modulate the information bits they need to transmit onto a third-party signal. The backscatter device selects the corresponding load impedance based on the information bits to be transmitted, thereby changing the amplitude, phase, or frequency of the third-party signal, thus achieving "passive" communication. The aforementioned backscatter communication principle mainly involves the transmitting end. A typical backscatter device, besides including the channel coding and modulation module for the transmitting end, usually also includes an antenna, microcontroller, signal receiving module, and memory. The signal receiving module is responsible for receiving downlink signals sent to the backscatter device from the network side or card reader. Its architecture and technology can reuse the LP-WUR technology currently being developed by the 3rd Generation Partnership Project (3GPP). Because backscatter communication does not actively generate carrier signals, its power consumption is extremely low, typically between 1µW and 1mW.

[0041] 3GPP R19 RAN1 defines different types of AIoT devices, as shown in Table 1. AIoT devices can be divided into two main categories: devices that can generate signals themselves, and devices that cannot actively generate signals. These latter devices obtain backscattered signals by receiving signals from third parties and then transmit them. Therefore, these devices can also be called backscatter communication-based devices. Because backscatter communication does not actively generate carrier signals, backscatter communication-based devices consume less power than the former type of device.

[0042] Table 1

[0043] It should be noted that the types of AIoT devices in this application embodiment are only three examples. This application embodiment does not limit the types of AIoT devices. For example, it may also include Device 3, which is a device that includes the functions of Device 1 and Device 2b, or it may be a device that includes the functions of Device 2a and 2b.

[0044] 3GPP Release 19 focuses on researching various AIoT topologies, as shown in Figure 1b-1, which includes four topologies.

[0045] Topology 1: Access network devices and AIoT devices are directly connected for uplink / downlink communication. That is, AIoT devices send information to access network devices, or AIoT devices receive information from access network devices. Specifically, carrier signals and downlink control information are sent by the base station, or CW (carrier wave) is sent by a third-party node. Backscattered signals are received by the same BS (Base Station), and the BS must have full-duplex capability.

[0046] Topology 2: AIoT devices are directly connected to intermediate nodes, which communicate with access network devices via uplink / downlink. That is, AIoT devices send or receive information from intermediate nodes, and intermediate nodes send or receive information from access network devices. Specifically, carrier signals and downlink control information are sent by the intermediate nodes, or the carrier signals are sent by a third-party node. Backscattered signals are received by the same intermediate node. The BS and intermediate nodes are connected via a Uu port. Intermediate nodes can be relays, integrated access backhaul (IAB) nodes, user equipment (UE), repeaters, etc.

[0047] Topology 3: AIoT devices communicate unidirectionally with access network devices / auxiliary nodes. In the left diagram, the AIoT device directly sends signals to the access network device but receives signals through an auxiliary node. In the right diagram, the AIoT device can directly receive signals from the access network device but sends signals to an auxiliary node. The auxiliary node can be a relay, IAB node, UE, repeater, etc.

[0048] Topology 4: The UE and AIoT device are directly connected for uplink / downlink communication. That is, the AIoT device sends information to the UE or receives information from the UE.

[0049] It is worth noting that, in addition to the above-mentioned topology, the present invention is still applicable if other topologies exist.

[0050] Based on the four topologies described above, the AIoT system employs two communication methods: backscatter communication for device 1 and device 2a, and active communication for device 2b. Backscatter communication requires an ambient carrier wave as the carrier of the modulated information, while active communication only considers the AIoT device actively generating its own carrier signal. Unlike the carrier signal of new radio (NR), the carrier waves for devices 1 and 2a can be transmitted by the BS in Topology 1 or the UE in Topology 2, or by additional carrier nodes. Therefore, the waveform of the ambient carrier signal is one of the key factors determining the implementation difficulty and communication performance of AIoT technology.

[0051] In addition, the existing standard defines five scenarios, namely:

[0052] Scenario 1: Device indoors, BS indoors;

[0053] Scene 2: Device indoors, BS outdoors;

[0054] Scenario 3: Device indoors, UE reader;

[0055] Scenario 4: Device outdoors, BS outdoors;

[0056] Scene 5: Device outdoors, UE reader.

[0057] RAN1#116 further distinguishes between scenarios such as D1T1 and D2T2, as shown in Figure 1b-2, including scenarios A1, A2 and B, where R represents Reader, D represents Device, and CW represents CW node.

[0058] In the following embodiments of this application, unless otherwise stated, the AIoT device is referred to as the terminal device, or simply the device, the access network device, the intermediate node, and the UE are referred to as the reader, the transmission direction from the terminal device to the reader is referred to as (device to reader, D2R), and the transmission direction from the reader to the terminal device is referred to as (reader to device, R2D).

[0059] To facilitate a better understanding of this application, the prior art that may be involved in this application will be briefly described below.

[0060] In an AIoT system, besides the nodes mentioned above (base stations, AIoT devices, intermediate / auxiliary nodes), there are also nodes that transmit carrier waves (CW). One function of a CW node is to transmit energy storage signals to provide energy to AIoT devices, i.e., the AIoT devices collect energy by receiving energy storage signals. Another function of a CW node is for backscatter communication; for example, the uplink signals of device 1 and device 2a mentioned above are backscattered signals generated by the AIoT devices by receiving carrier signals. Nodes providing energy storage signals or CW can be base stations, intermediate nodes, UEs, or third-party nodes. Taking topology 1 as an example, energy storage signals or CW can be transmitted by the base station, and the AIoT devices receive other signals (e.g., control information) and CW transmitted by the base station; energy storage signals or carrier signals can also be transmitted by third-party nodes, and the AIoT devices receive signals (e.g., control information) transmitted by the base station and energy storage signals or carrier signals transmitted by the third-party nodes. That is, the device transmitting carrier signals, i.e., the CW node, may be inside or outside the topology, depending on the situation.

[0061] Unlike traditional communication systems, AIoT terminals have very low complexity. Some signals and channels in traditional communication systems are unsuitable for AIoT. For example, Demodulation Reference Signal (DMRS), Phase Tracking Reference Signal (PT-RS), CSI-RS / CSI-RS for Tracking (TRS), Sounding Reference Signal (SRS), CSI, Scheduling Request (SR), and dedicated broadcast channels are all unsuitable for AIoT. Based on the current discussion, the channels and signals involved in AIoT systems can be specifically categorized as follows:

[0062] The R2D synchronization signal, or R2D timing acquisition signal, can be included in the R2D preamble, or it can be a separate signal, or it can have other names; this application embodiment does not limit this. The R2D synchronization signal can be used by AIoT devices to acquire time synchronization / frequency synchronization and the start time of the R2D physical channel. Typically, the R2D synchronization signal is followed by the R2D physical channel, as shown in Figure 1c. This application embodiment does not limit other functions of the R2D synchronization signal. The R2D preamble signal comprises two parts: a start-indicator part and a clock-acquisition part. The start-indicator part can be used by the AIoT device to determine the start time of the R2D physical channel. The start-indicator part has two pattern options:

[0063] 1) Option 1: ON / OFF pattern, which consists of high and low levels. It can also be understood as the sequence of the start-indicator part containing a first value and a second value, which are different.

[0064] a) 1-1: A single ON-OFF pattern, such as ON+OFF where OFF follows ON, and ON and OFF have the same or different durations.

[0065] b) 1-2: Multiple ON-OFF patterns, where each ON and each OFF has the same or different durations.

[0066] 2) Option 2: Predefined sequences form ON-OFF sequences, which can be used for digital correlation on the device.

[0067] Synchronization information can be used by AIoT devices to obtain time synchronization / frequency synchronization, and it can also be used to determine chip duration. Specifically, the synchronization information is the first synchronization information in the following embodiments, and the start indication information is the first start indication in the following embodiments.

[0068] The R2D physical channel, also known as PRDCH, downlink physical channel, or other names, is not limited to any particular name in this application. The R2D physical channel can be used to carry data, payloads from higher layers, or control information from Layer 1 (L1). The payloads from higher layers include control information. The signal generation process of PRDCH is roughly as shown in Figure 1d (other processing steps are not excluded). The R2D information bits undergo CRC (CRC attachment), line coding, and OOK modulation (OOK-1 / OOK-4 generation with OFDM waveform). CRC attachment is optional; if the CRC length is 0, CRC attachment is not required.

[0069] The D2R synchronization signal, also known as the D2R preamble or other names, is not limited to any particular term in this application. The D2R synchronization signal can be used by the reader to obtain time synchronization and the start time of the D2R physical channel. As shown in Figure 1e, the D2R timing acquisition signal is followed by the D2R physical channel.

[0070] The D2R physical channel, also known as PDRCH, uplink physical channel, or other names, is not limited to any particular name in this application embodiment. The D2R physical channel can be used to carry data, load from higher layers, or control information from Layer 1 (L1). The load from higher layers includes control information from those layers.

[0071] The R2D intermediate preamble is the intermediate preamble between two adjacent R2D physical channels, or between two adjacent segments of a single R2D physical channel, as shown in Figure 1f. The R2D intermediate preamble is used for device time synchronization. This application does not limit its name in its embodiments.

[0072] The D2R intermediate preamble is the intermediate preamble between two adjacent D2R physical channels, or between two adjacent segments of a single D2R physical channel, as shown in Figure 1g. The D2R intermediate preamble is used by the reader / writer for time synchronization. This application does not limit its name in its embodiments.

[0073] The R2D postcode, located after the R2D physical channel, is used to determine the end time position of the R2D physical channel. The embodiments in this application do not limit its name.

[0074] The D2R post-prefix, located after the D2R physical channel, is used to determine the end time position of the D2R physical channel. The embodiments of this application do not limit its name. It should be noted that the intermediate prefix and / or post-prefix are optional and may not necessarily be present.

[0075] The R2D signal, generated by the reader, can be at least one of the following: R2D timing acquisition signal, R2D start-indicator part, R2D clock-acquisition part, PRDCH, R2D midamble, and R2D postamble. The R2D preamble consists of two parts: the R2D clock-acquisition part and the R2D start-indicator part. The start-indicator part is used by the AIoT device to determine the start time of the R2D physical channel, and the clock-acquisition part is used by the AIoT device to obtain time / frequency synchronization. The PRDCH carries data, payloads from higher layers, or L1 control information. The R2D midamble is the intermediate preamble between two adjacent PRDCHs or between two adjacent segments of a PRDCH, and can be used by the reader to obtain time synchronization. The R2D postamble follows the PRDCH and can be used to determine the end time of the PRDCH. Different R2D signals may have different signal generation processes, which include inserting a cyclic prefix (CP), i.e., CP processing.

[0076] AIoT Transmission Process: AIoT technology can be used indoors or outdoors, with main application scenarios including inventory, command, positioning, and sensing. The main research scenarios for the 3GPP Release 19 AIoT project are inventory and command; therefore, the DO-DTT (Device-originated–device-terminated triggered) service type is prioritized, meaning the device initiates a session only after receiving a signal from the reader. However, this solution is also applicable to DO-DOA service scenarios. Therefore, AIoT devices do not actively initiate sessions like traditional devices. The general process between the reader and the device is shown in Figure 1c.

[0077] Step A: The reader sends a trigger message, prompting one or more devices to respond. Step A can also be understood as AIoT paging. Step A may include device ID, device group ID, etc. It may also include resource information. Step A may contain other content; the specific content is yet to be determined and will be discussed further. Step A can be transmitted via PRDCH.

[0078] Step B: The device will initiate random access. Step B can include one or more interaction processes. The random process in AIoT can also include contention-based random access and contention-free random access.

[0079] Step C: This is an optional step. In some application scenarios, the device will send data or control information to the reader, such as device ID or higher-level information; or the reader will send data or control information to the device. Step C and Step B may not be distinguished, as some or all of the process in Step C may be included in Step B. Step C may contain one or more interaction processes.

[0080] The four-step random access process is roughly as follows, where Msg3 and / or Msg4 are optional.

[0081] Msg1: The device sends a random access sequence (also known as a random ID) to the reader. Msg1 can be transmitted via D2Rpreamble or PDRCH;

[0082] Msg2: After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the device. This response message may contain a random access sequence. Msg2 can be transmitted via an R2D preamble or a PRDCH, where the PRDCH is used to carry data, payload from higher layers, or control information from L1.

[0083] Msg3: After receiving Msg2, the device can send data (e.g., device ID, higher-level information) or control information to the reader. Msg3 can be transmitted via D2R preamble or PDRCH.

[0084] Msg4: The reader sends information to the device, such as an acknowledgment message. Msg4 can be transmitted using R2Dpreamble or PRDCH.

[0085] The two-step random access process is roughly as follows:

[0086] Msg1 or Msg A: The device sends its device ID or higher-level information to the reader. Msg1 or Msg A: This can be transmitted via D2R preamble or PDRCH.

[0087] Msg2 or Msg B: After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the device. Msg2 or Msg B: Can be transmitted via R2D preamble or PRDCH, carrying corresponding control or data information.

[0088] The prior art has discussed the use of R2D and D2R signals for purposes including timing acquisition / tracking, calibration / frequency synchronization between device and reader, channel or interference estimation of the reader, and indicating the end of R2D / D2R transmission.

[0089] Regarding the discussion of AIoT random access, TR version 38.769V2.0 summarizes the relevant content of Rel-19 SI random access. For MSG1, TR currently supports two access mechanisms: Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). When the reader triggers X resources (X greater than or equal to 1) for MSG1 transmission, the X resources can be Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or a combination of TDM and FDM. The device can randomly select one of these X resources to send MSG1; this method can be considered a contention-based random access (CBRA). Alternatively, the reader allocates specific resources to the device, and the device uses those resources to send MSG1; this method can be considered a non-contention-based random access (CFRA).

[0090] RAN 1 primarily discusses the transmission mechanism when the transmission of Msg 2 corresponds to one or more Msg 1s, including the following options:

[0091] Option 1: When Msg 2's PRDCH responds to a Msg 1 message,

[0092] Option 1-1: The start time for device monitoring Msg 2 is independent for each Msg 1 resource; different devices monitor Msg 2 within their respective time windows.

[0093] Option 1-2: The start time for device monitoring Msg 2 is common to multiple Msg 1 resources, and different devices listen to Msg 2 in the same time window.

[0094] Option 2: When Msg2's PRDCH responds to multiple AIoT Msg1s, different devices listen to Msg2 within the same time window.

[0095] To determine the duration of Msg2 corresponding to multiple Msg1 transmissions, the following options are determined (not mutually exclusive):

[0096] Option 1: Predefined, for example, determined by TD2R_min and / or TD2R_max, where TD2R_min is used to indicate the maximum time interval between the D2R signal and the corresponding R2D signal, and TD2R_max is used to indicate the maximum time interval between the D2R signal and the corresponding R2D signal;

[0097] Option 2: Indicate the triggering of random access in R2D transmission;

[0098] The reference time for the start time of device monitor Msg 2 corresponds to the following options:

[0099] Option 1: End position of time domain resources for device transmission of Msg1;

[0100] Option 2: The end position of the last time domain resource among the X time domain resources transmitted by Msg1;

[0101] Option 3: The end position of Step A;

[0102] Option 4: The end position of the R2D carrying Msg2.

[0103] It is important to note that the reference time is used to determine the start time of Msg2 monitoring, but this does not mean that the start time is always equal to the reference time. For Msg3 from multiple devices, in response to a given set of one or more Msg2 transmissions during the access process, the FDMA and / or TDMA of D2R transmissions were investigated, including how to allocate the frequency and time domain resources of Msg3.

[0104] For RAN 2, the main considerations are random access aspects related to the transmission process, including access triggering a single device, access of a group of devices, or access of all devices within the reader's coverage area. As shown in Figure 1h, Steps A / B are related to random access. A slotted-ALOHA-based access mechanism is used as a baseline study, as shown in Figure 1i.

[0105] Access occasion: A time-frequency resource opportunity for an AIoT device to perform access (e.g., when the device transmits AIoT Msg1). The Reader schedules a set of access occasions for different AIoT devices using R2D.

[0106] When an AIoT device responds, it performs the following steps:

[0107] Option 1: Random access type (i.e., contention-free or contention-based) and access timing / resource determination:

[0108] The AIoT device determines the random access type from the AIoT paging message. The Reader can be configured for contention-free or contention-based random access (and corresponding configurations). Whether this is explicit or implicit needs further discussion.

[0109] If random access is contention-free: select the indicated D2R timing / resource;

[0110] If random access is contention-based: Access timing / resource selection is performed: at least in the case of TDMA, the device can randomly select an access timing for AIoT Msg1 within the access timings provided / allocated by the Reader. Further discussion is needed if this applies to the FDMA case. Further enhancement options can be considered after TDMA and FDMA are discussed in more detail in RAN 1.

[0111] Option 2: Contention-based random access contention resolution:

[0112] Three candidate solutions are being investigated for contention resolution, as shown below (further discussion is needed in down-section and / or unified design):

[0113] Solution 1: AIoT Msg 1without data;

[0114] AIoT Msg1: When the AIoT device recognizes the start of its own access time, it sends a 16-bit Random ID generated by the AIoT device to the reader;

[0115] AIoT Msg2: The reader responds with a Random ID that was successfully received;

[0116] If the AIoT device receives AIoT Msg2 containing a random ID that is the same as the ID previously transmitted in AIoT Msg1, then the contention is considered resolved successfully.

[0117] Solution 2:AIoT Msg 1with data;

[0118] AIoT Msg1: When an AIoT device recognizes the start of its own access opportunity, it sends AIoT Msg 1 to the reader, which includes higher-level data, such as a 16-bit Random ID generated by the AIoT device, a device ID, and / or any other higher-level data.

[0119] AIoT Msg2: The Reader may respond with a successfully received Random ID;

[0120] If the AIoT device receives AIoT Msg 2 containing a Random ID, which is the same ID transmitted in AIoT Msg 1, the contention is considered resolved successfully. If the device does not receive AIoT Msg 2, Re-access will not be performed automatically; it is always controlled by the Reader.

[0121] Solution 3: AIoT Msg1 may optionally include data (supporting a unified solution for Solution 1 and Solution 2);

[0122] AIoT Msg1: When the AIoT device recognizes the start of its access opportunity, it sends a 16-bit Random ID generated by the AIoT device to the Reader. Additionally, the Reader controls whether it includes higher-level data, which can be the device ID and / or any other higher-level data. AIoT Msg2: The Reader responds with the successfully received Random ID.

[0123] If the AIoT device receives AIoT Msg2 containing a Random ID that is the same as the ID previously transmitted in AIoT Msg1, then the contention is considered resolved successfully.

[0124] Several points need to be noted: The Random ID is randomly generated by the AIoT device; it is assumed that the size of the Random ID in AIoT Msg1 should be sufficient to resolve contention, while AIoT Msg2 is used to resolve contention. Assuming a sufficient range of Random IDs, the probability of multiple AIoT devices choosing the same access timing and the same Random ID for AIoT Msg1 transmission will be sufficiently low; whether to send AIoT Msg2 in Random Access Solution 2 depends on the Reader implementation; AIoT Msg2 may contain more information; regarding the advantages and disadvantages of the above solutions, it is understood that Option 1 can support a relatively larger AIoT Msg1 coverage range than Option 2. Option 2 has higher transmission efficiency when the probability of AIoT Msg1 contention is low (e.g., it can reduce one step of data transmission interaction if successful).

[0125] If contention-based random access or contention-free access is used, the AIoT device can perform higher-level data transmission with the Reader after the contention is successfully resolved. This data can be the device ID and / or any other higher-level data (if it exists).

[0126] Furthermore, the potential unification between contention-free access and contention-based random access was investigated from a device perspective. In this solution, when an AIoT device identifies its own access opportunity, it sends at least one 16-bit random ID generated by the AIoT device (regardless of whether the access opportunity is contention-free or contention-based) to the reader. The motivation and drawbacks of including a random ID in contention-free access require further discussion. For example, one drawback is that the reader may not know whether the expected device will respond on a given resource.

[0127] In the event of D2R data transmission failure or contention-based random access contention resolution failure, AIoT devices are supported to re-access during an additional opportunity controlled / provided by the reader. Automatic re-transmission by the AIoT device is not expected; re-transmission is always controlled by the reader. The reader is supported in using an optional explicit R2D failure / success feedback indication to determine device re-transmission. This indication can be used at least to determine re-transmission in response to the failure of the first D2R message transmission, which contains the device ID and / or any other higher-level data (i.e., Msg3). Additionally, this indication can also be used for D2R data to determine re-transmission.

[0128] R2D messages are used by the reader to provide access opportunities for retransmission purposes. If additional information is needed in this R2D message to distinguish the retransmission purpose, further discussion is required. AIoT paging messages are one option for this R2D message. Another option is some R2D messages between AIoT paging messages.

[0129] Regarding energy storage for AIoT devices, the relevant conclusions summarized in the FL summary of RAN 1#118 are that the charging and discharging times of AIoT devices are related to factors such as capacitor size, receiving power, energy storage efficiency, and power consumption of AIoT devices in different states (ON / OFF / Sleep).

[0130] For different states of AIoT devices, there are two scenarios: 1) only ON and OFF states; 2) three states: ON / OFF / Sleep. The actions and rules for each state are as follows:

[0131] The ON state supports: communication signal transmission, signal and signaling reception, etc.

[0132] The OFF state does not support: communication signal transmission, signal and signaling reception, clock maintenance, etc.; the OFF state does support: energy storage, etc.

[0133] The Sleep state can support at least one of the following: maintaining memory from the ON state, including non-volatile memory (NVM) and volatile memory (VM), such as writing information or ID; maintaining a clock for timing to switch from Sleep to other states; energy storage; listening to certain signals such as preamble / wake-up (activation) signals; the Sleep state does not support: communication signal transmission, signal and signaling reception, etc.

[0134] It's also important to understand that in traditional Legacy Radio Resource Management (RRM) measurement mechanisms, if cells A and B have the same center frequency and subcarrier spacing in their Synchronization Signal and Physical Broadcast Channel Block (SSB), then the measurement between cells A and B is called an intra-frequency measurement; otherwise, it's called an inter-frequency measurement. Intra-frequency and inter-frequency measurements are logically symmetrical; that is, it's either an intra-frequency measurement or an inter-frequency measurement. For example, if the measurement between cells A and B is based on the Channel State Information Reference Signal (CSI-RS), where A is the serving cell and B is the neighboring cell, A and B have the same subcarrier spacing, and B's CSI-RS bandwidth is less than or equal to A's CSI-RS bandwidth, then the measurement between serving cell A and neighboring cell B is an intra-frequency measurement; all other measurements are inter-frequency measurements. Here, the two are not logically symmetrical. Conversely, if B is the serving cell, measuring neighboring cell A is an inter-frequency measurement.

[0135] The Serving Cell has the following functions: 1. To serve as a comparison object to define intra-frequency and inter-frequency measurements; 2. To serve as a comparison object to trigger certain measurement events, such as the A3 event.

[0136] In most cases, SSBs are not continuous in the time domain. When performing measurements, the UE does not need to continuously search and measure in the time domain; it only needs to lock onto the time window where these SSBs are located. Therefore, the concept of an SSB-based measurement timing configuration (SMTC) is introduced in the measurement configuration. An SMTC appears in the time domain at certain intervals and is a measurement window with a fixed duration. The interval ranges from 5 to 160 ms, and the window size is 1 to 5 ms. From a measurement perspective, the UE will consider that SSBs outside the SMTC do not exist. In terms of granularity, an SMTC is configured for each SSB measurement frequency point, and another SMTC with a shorter period can be set for individual cells within this SSB frequency point.

[0137] In addition to Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ), NR also defines the Signal-to-Integer Plus Noise Ratio (SINR) as one of the metrics for RRM. These measurements are for the terminal and are shown in Table 2 below.

[0138] Table 2

[0139] The physical layer first measures the beam, obtains the beam quality after passing it through the physical layer filter, and then obtains the cell quality through the L3 filter. In addition to carrying the cell quality, the measurement report can also include the beam quality of the X best beams. The UE measurement behavior of the NR terminal (such as measurement configuration and measurement report configuration) is handled by the Radio Resource Control (RRC) layer.

[0140] For the network energy-saving RRM measurement relaxation mechanism, the terminal needs to perform RRM measurements in the Idle / Inactive state to achieve cell reselection and ensure terminal mobility. Relaxing the measurement cycle by four times (assuming one SSB set is used per measurement cycle) can result in some energy-saving gains. Further simulations show that at a terminal speed of 3 km / h, the handover failure probability is less than 0.26%. Therefore, if the terminal is stationary or has low mobility, the measurement can be appropriately relaxed without affecting terminal mobility performance, thus reducing terminal power consumption.

[0141] Additionally, when the terminal is in the cell center, it is permissible to refrain from performing intra-frequency and / or low-priority inter-frequency measurements under certain conditions, thereby reducing terminal power consumption. However, when the terminal is not in the cell center or cell edge, the need for the terminal to perform cell reselection is not urgent. In this case, the terminal can appropriately relax RRM measurements (e.g., increase the RRM measurement cycle) to reduce terminal power consumption.

[0142] The network side can configure only the low mobility criterion or the "not at the cell edge" criterion as the trigger condition for RRM measurement relaxation, or it can configure both the low mobility criterion and the "not at the cell edge" criterion simultaneously. When the network side configures both criteria, it will additionally configure whether the terminal needs to meet both criteria simultaneously or only one criterion to perform RRM measurement relaxation.

[0143] Regarding AIoT transmission, this application addresses several existing problems based on current technologies:

[0144] 1. Currently, R2D signal transmission only supports TDMA, but it is possible that high-capability devices can receive and demodulate R2D signals via FDMA. For OOK-4 modulation, an Orthogonal Frequency Division Multiplexing (OFDM) symbol may carry one or more chips. Considering that Msg 2 may correspond to Msg 1 transmitted by one or more devices, the mapping rule based on chips as time units needs to comprehensively consider the effects of encoding, CP insertion, etc. The number of chips in an OFDM is related to the number of SCS and RB. When the device does not use line code for encoding, TR specifies that the OOK and Binary Phase Shift Keying (BPSK) modulation square waves of the D2R signal are [0, 1, 0, 1...] or [1, 0, 1, 0...] and [1, -1, 1-1...] or [-1, 1, -1, 1...].

[0145] For line codes, existing technologies, when considering Manchester encoding, superimpose an OFDM 1-0 sequence onto the ON symbol of OOK-4, as shown in Figure 1j, thereby improving the transmission rate and reducing the detection power consumption of the terminal. Currently, the generation methods for OFDM 1-0 sequences are agreed upon, including predefined sequences and selection from candidate sequences. Further discussion includes the possibility that the superimposed OFDM sequence carries partial information, while the terminal obtains all information through the sequence and its position.

[0146] For Ambient IoT, when the value of M is small, it is also possible to improve transmission efficiency by superimposing sequences, which can reduce the power consumption of device monitoring. Specifically, since the ACK of RN 16 carrying Msg 1 is carried on the PRDCH channel, the following issues are raised regarding the two rules for Msg 2 mapping: (Subsequent) Setting a listening window before and after AIoT Paging facilitates the reader's monitoring of devices that have not successfully received Msg 1 and send monitoring information (e.g., the first message), allowing the reader to determine the configured Msg 1 resources based on the monitoring results. Therefore, how to configure the listening window needs to be considered; the activation issue when there are multiple PRDCHs; the format design and indication method of AIoT Paging need to be considered; if the number of devices being inventoried is too large, the segmentation design of AIoT Paging and the silent indication of inventoried devices; how to apply the LP-WUS-based ON-chip overlay transmission scheme to AIoT devices needs further consideration and design; when the PRDCH of Msg 2 responds to one or more Msg 1 messages, the impact of Msg 1 packets on the starting position, time window setting, transmission power, and mapping rules of Msg 2 transmission.

[0147] Given that TR 38.769 provides pattern design options for both the start-indicator and clock-acquisition (CAP) signals, and considering the impact of CAP insertion on CAP, including the length of CAP and the level of adjacent chips, the synchronization function of CAP for R2D signals is mainly reflected in the estimation and compensation of the sample clock frequency offset (SFO). CAP can also be used to implicitly indicate chip duration. CAP can also estimate and correct the CFO of D2R signals, similar to the function of the primary synchronization signal (PSS) and secondary synchronization signal (SSS) in SSB. However, this function is mainly considered for device2b.

[0148] The start-indicator pattern is as described above. The CAP pattern includes:

[0149] Option 1: The duration of CAP is variable for different values ​​of M. For example, as M increases, the duration of CAP decreases. The value of M can be understood as the number of chips in an OFDM symbol.

[0150] Option 2: For different values ​​of M, considering repetition, the duration of CAP is fixed. For example, as M increases, the repetition factor also increases, so the duration of CAP remains unchanged. As shown in Figure 1k, for option 1, the CAP duration when M=6 is greater than the CAP duration when M=12, or the CAP duration when M=6 is twice the CAP duration when M=12. For option 2, to ensure that the CAP duration when M=6 and M=12 are consistent, the repetition factor corresponding to M=12 is also set to 2.

[0151] Therefore, the following issues need to be further considered:

[0152] For the start-indicator, regardless of the scheme, its starting position may be at the beginning of the OFDM symbol or in the middle. If a CAP (Capacitor Component) needs to be added, the CAP is located at the beginning of the next OFDM symbol. A gap may exist after the start-indicator transmission is complete. Adaptive signal design is required for this situation. For example, for a single ON-OFF pattern, the ON duration can be lengthened, and the definition of the ON percentage can be considered.

[0153] If a CP needs to be added to the CAP, the CAP is located at the beginning of the next OFDM symbol. Some companies suggest that the start-indicator should have at least one OFF chip to distinguish the start level of the CAP. Since the start-indicator does not consider encoding, when the last level of the start-indicator is OFF, the duration of the OFF can extend forward or backward (to the next OFDM symbol) to compensate for the effect of SFO, i.e., a gap is set before the CP. Optionally, the length of the OFF at the end can also be designed to counteract the effect of SFO.

[0154] For CAP, the estimation of SFO and Carrier Frequency Offset (CFO) needs to be reconsidered for different sequence types and lengths to differentiate between different functions. For example, differentiation could be based on duty cycle or sequence pattern. For option 1, as M increases, the CAP duration decreases, and the CAP rate increases. However, the reduced duration lowers the reliability of CAP detection, further affecting time-frequency synchronization. When the R2D TBS is small and the indication information is limited, a small duration may be sufficient for CAP, requiring the maximum value of M (i.e., the minimum CAP duration) to be limited by the CP length. However, when the data volume is large, a midamble may be needed to perform periodic synchronization. Whether the midamble's pattern type, length, and rate are the same as CAP, as well as the midamble's period and position, need further discussion. For option 2, the handling of the CP issue during CAP cross-symbol transmission requires further resolution.

[0155] As mentioned above, R2D control information can be used to indicate the reception of R2D signals and the scheduling of D2R signals and resources, which can be scheduled through higher-layer signaling and L1 control signaling. For the scheduling of D2R signals and resources, the following can be indicated explicitly / implicitly via PRDCH: time-domain resources, frequency-domain resources, MCS-like information, chip duration, device-related ID information, repetition-related information, and midamble-related information (if supported). In the D2R scheduling information, some parameters need to be dynamically indicated, some are semi-statically configured (e.g., MCS-like and midamble configuration information, sequence type and length), and some are statically indicated (Device ID, etc.). The specific indication method needs to be discussed and protected according to different transmission scenarios.

[0156] Additionally, proximity can be used to determine whether a device is within the reader's coverage area and its distance from the reader. This includes two approaches:

[0157] Solution 1: The Reader successfully receives the corresponding R2D transmission for D2R, and the Reader can determine that the device is within the coverage area;

[0158] Solution 2: The Reader successfully receives the corresponding R2D transmission and measures the D2R signal. The Reader can then determine that the device is within its coverage area and the distance between the device and the Reader.

[0159] Since the NR protocol does not currently consider AIoT-Uu measurements, it is necessary to consider new measurement definitions based on the NR-defined measurements for AIoT-Uu port measurements (same-frequency and different-frequency measurements, related to small and large frequency offsets, and related to frequency / antenna hopping). Furthermore, based on the device (group) ID, a measurement relaxation mechanism and corresponding relaxation criteria should be considered. Based on the measurement results and the assigned device ID (understanding the device type, whether it has been moved, etc.), a period of no measurement (relaxed measurement) should be considered, and the relaxation criteria should be used for judgment.

[0160] [Correction based on Rule 91, 30.05.2025] In summary, this application provides a communication method to solve the aforementioned problems. Please refer to Figure 2a, which is a flowchart of a possible communication method, including at least one of the following steps:

[0161] 201. The reader sends the first R2D signal to the device;

[0162] The reader sends a first R2D signal, which is a signal transmitted from the reader to the AIoT device. The first R2D signal includes a paging message and / or a second random access message (Msg 2). The AIoT Paging message is used to paging one or more devices for random access or control services, and includes the first paging message and / or the second paging message. The first paging message precedes the second paging message, and the second paging message includes one or more paging messages. The first R2D signal is used to indicate at least one of the following:

[0163] Fixed listening window information for the reader to listen to the first D2R signal, the first D2R signal being a signal transmitted from the AIoT device to the reader, the first D2R signal including a first random access message and / or a third random access message; or, resource indication for activating and / or deactivating the first D2R signal; or, the transmission method of the first R2D signal superimposed; or, indication of D2R parameters or updating data of the AIoT device.

[0164] [Corrected according to Rule 91, 30.05.2025] When the first R2D signal includes an indication of fixed listening window information, the fixed listening window includes, but is not limited to, at least one of the following: a first listening window, a second listening window, and a third listening window; the reader can also configure, according to the configuration conditions of each listening window, at least one of the following: the position of each listening window, and / or, the listening length corresponding to each listening window. As shown in Figure 2b, the first listening window, the second listening window, and the third listening window are configured based on different configuration conditions for the reader to listen to the information sent by the device. The first paging message, i.e., AIoT Paging in Figure 2b, or the second paging message, i.e., Subsequent AIoT Paging in Figure 2b, indicates the period during which the device can send D2R signals, and the sending period of the D2R signals is earlier than the additional D2R signals sent by Msg 1.

[0165] For the first listening window, such as in a CFRA scenario, after the reader sends the AIoT Paging paging message, within the first listening window, it receives the first information sent by the device, such as an N-bit energy status. This allows it to determine if device N might not be sending Msg 1 or Msg A in the Nth Msg 1 or Msg A resource, enabling scheduling of energy storage signals and the Msg 1 or Msg A resource. The start time of the first listening window is later than the paging message sending time, and the end time is later than the device sending the first D2R signal. The listening length of the first listening window is related to at least one of the following parameters:

[0166] The number of Msg 1 or Msg A, for example, when the number of configured Msg 1 or Msg A resources is large (e.g., 200), the configured listening window duration is A; this parameter can be semi-statically configured or dynamically indicated, for example, indicated through AIoT Paging control information; or,

[0167] The listening window duration B is determined based on the common time offset (or empty window time interval) between the device receiving the start or end position of the AIoT Paging and the start position of the device sending the first Msg 1 or Msg A; or,

[0168] The listening window duration C is determined based on the common time offset from the end position of the AIoT Paging process (T_R_D_min or T_R_D_max) to the start position of the first Msg 1 or Msg A sent by the device. This common offset (or empty window time interval) is used to determine the listening window duration C, where C <= B. Alternatively,

[0169] The length of the first listening window is a predefined parameter, which is T_R2D_min, T_R2D_max, T_D2R_min, or T_D2R_max. T_R2D_max is defined as the maximum time interval between the R2D signal and the corresponding D2R signal; T_D2R_max is defined as the maximum time interval between the D2R signal and the corresponding R2D signal, for example, the maximum time interval between Msg 1 and Msg 2. Correspondingly, T_R2D_min is defined as the minimum time interval between the R2D signal and the corresponding D2R signal; T_D2R_min is defined as the minimum time interval between the D2R signal and the corresponding R2D signal.

[0170] In addition, in this application, when the PDRCH quality is lower than the preset value, the device is in a low power state, and / or a conflict occurs, a second listening window and / or a third listening window can also be configured. Specifically, the configuration conditions for the second listening window include: 1. The reader determines the number of devices that failed to successfully receive D2R messages based on the received D2R messages, such as Msg 1 / A or other messages, and configures the second listening window accordingly. The reasons for unsuccessful reception include: conflicts arising from different devices sending Msg 1 / Msg A messages on the same resource, leading to access failure; reader failure to receive Msg 1 / A messages due to changes in device battery level or channel conditions, leading to access failure; and reader failure to receive Msg 1 / A messages due to the influence of SFO / CFO on the device or reader side, leading to access failure. 2. The reader receives the first message sent by a device that failed to send Msg 3 during the listening window. Situations where the device actively sends information include: the resource for Msg 3 scheduled by AIoT Paging or R2D signals such as Msg 2 is less than the resource actually required for the device to send Msg 3. For example, if the scheduled Msg 3 TBS is 500 bits, but the device needs to report 800 bits of data via Msg 3, then the device will not send Msg 3 and will send Msg 2 within the listening window.

[0171] Optionally, the starting position of the second listening window depends on the mapping or sending method of Msg 2, specifically including: when Msg 2 is sent in response to a single Msg 1, the starting position of the second listening window is the position where the first Msg 2 is sent and ends, or the position where the device sending Msg 1 listens for Msg 2 and ends; when Msg 2 is sent in response to multiple Msg 1, the starting position of the second listening window is the position where the Msg 2 that responds to multiple Msg 1 is sent and ends, or the position where the device corresponding to multiple Msg 1 listens for Msg 2 and ends.

[0172] [Corrected according to Rule 91, May 30, 2025] The configuration conditions for the third listening window are similar to those for the second listening window, and will not be repeated here. As shown in Figure 2b, when the reader sends multiple paging messages, including the first paging message and the second paging message, the reader configures the listening length of the third listening window according to the resource size configured in the subsequent second paging message, Subsequent AIoT Paging.

[0173] It should be noted that, in this embodiment, the reader reports at least one of the D2R messages monitored in the first, second, and / or third monitoring windows to the CN, facilitating resource scheduling and reader handover management by the CN. As a special case, when the reader is a UE, the monitored data can also be reported to the base station.

[0174] [Correction 30.05.2025 based on Rule 91] Optionally, the first R2D signal may further include an indication of the activation and / or deactivation of the first D2R signal. The first R2D signal, such as AIoT Paging, Msg 1, or other R2D signals, may include multiple PRDCHs carrying different scheduling information. For example, as shown in Figure 2c, the first part of the PRDCH carries scheduling and data information for Group 1 device; the second part carries scheduling and data information for Group 2 device; the third part carries scheduling and data information for Group 3 device; and the fourth part carries scheduling and data information for Group 4 device. Only the activation and / or deactivation of the first R2D signal for four groups of devices is listed here; the number of device groups is not limited. Other forms are similar and will not be elaborated further.

[0175] [Correction based on Rule 91, May 2025] Considering that a single inventory may involve hundreds or thousands of devices, and that the first D2R signal (including Msg 1, Msg A, or Msg 3) only supports TDMA and FDMA, AIoT Paging needs to configure a large number of time-frequency resources for the first D2R signal (including Msg 1, Msg A, or Msg 3) for random device access during the same inventory round. However, for device 1, its energy storage capacity is limited, and there is a possibility that even if resources are configured, it may not be able to transmit the first D2R signal on specific resources due to insufficient power. Therefore, according to the configuration information of AIoT Paging or additional R2D signals, as shown in Figure 2d, resource indications can be provided to indicate the activation and / or deactivation of the device's first D2R signal, wherein the indication method includes, but is not limited to, one of the following:

[0176] [Corrected according to Rule 91 30.05.2025] 1. The control information of the previous PRDCH indicates that the resources of the corresponding Group device configured by the adjacent PRDCH are in a waiting activation state. If activation information is received again, the first D2R signal can be sent according to the indicated resources; otherwise, the first D2R signal is not sent. The activation information received again can be the second paging message, i.e., the Subsequent AIoT Paging in Figure 2d, or it can be an R2D message.

[0177] [Corrected according to Rule 91, May 2025] 2. The first paging message, i.e., the AIoT Paging in Figure 2d, configures the activation / waiting-for-activation information for each group. For a device waiting to be activated, if the activation information is received again, the first D2R signal can be sent according to the indicated resource; otherwise, the first D2R signal is not sent. The received activation information can be a Subsequent AIoT Paging or an R2D message.

[0178] 3. AIoT Paging configures the device's transmission resources and configuration information, such as Modulation and Coding Scheme (MCS)-like settings, Transport Block Size (TBS), Backscatter Link Frequency (BLF) set, or D2R signal frequency, or D2R signal frequency offset relative to CW frequency, or D2R line code repetition factor, but does not activate them. Subsequent AIoT Paging or other R2D messages activate these transmission resources and configuration information. It is important to note that in this application, MCS-like settings are related to D2R modulation, linear coding, and channel coding. D2R modulation includes OOK and BPSK modulation, whether line codes are used, convolutional codes, and the use of repetition factors. Line codes include, but are not limited to, Miller codes or Manchester codes. The constraint length of the convolutional codes is K = 4, 6, 7, 8, and the code rate is 1 / 6, 1 / 4, 1 / 3, 1 / 2. In addition, different levels of MCS can be defined for D2R signal transmission. Specifically, different levels of MCS can be defined in the following ways:

[0179] Method 1: Define different levels of MCS based on the modulation method, where the modulation method includes, but is not limited to, OOK modulation or BPSK modulation;

[0180] Method 2: Define different MCS levels based on line code usage. When line codes are used, the MCS level is determined by the line code's repetition factor; for example, a low repetition factor corresponds to a low MCS level, and a high repetition factor corresponds to a high MCS level. When line codes are not used, for example, a low MCS level is used.

[0181] Method 3: Determine the MCS level based on the constraint length and code rate of the convolutional code;

[0182] Method 4: Determine the MCS level based on the number of repetitions. If the number of repetitions increases, the corresponding MCS level is lower, such as Block-level repetition, Bit-level repetition, or Chip-level repetition.

[0183] For example, in this application, the MCS level can be divided into the following levels:

[0184] The first MCS level, corresponding to the low MCS, is suitable for weak signal environments and scenarios with low access rates, and is used to determine the reliability of Msg 1 or Msg 3 transmission.

[0185] The second MCS level corresponds to the medium MCS level, which is used in scenarios with moderately good channel conditions, and has the next level of coverage and access rate.

[0186] The third MCS level, corresponding to high MCS, is suitable for scenarios with excellent signal conditions, and has a relatively high coverage level and access rate.

[0187] Furthermore, in the prior art, when the device does not use line code for encoding, TR specifies that the OOK and BPSK modulation square waves of the D2R signal are [0,1,0,1...] or [1,0,1,0...] and [1,-1,1-1...] or [-1,1,-1,1...]. In this application, it is also designed that when the D2R signal does not consider the use of line code or considers the use of line code, the sequence of D2R OOK modulation can also be: [1111...1111] and / or [000111...] and / or [111000...]; the sequence of D2R BPSK modulation can also be: [+1,+1,+1..+1,+1] and / or [+1,+1,+1,-1,-1,-1...] and / or [-1,-1,-1,+1,+1,+1,...]; optionally, D2R BPSK modulation satisfies the constraint that the absolute value of the difference between the phase corresponding to the +1 modulation symbol and the phase corresponding to the -1 modulation symbol is greater than or equal to a specific value, for example, 90°.

[0188] In this embodiment, regarding the AIoT Paging format, the reader requests resources from the core network based on device capability information, power status, etc., and requests the AIoT Paging format. The reader receives the AIoT Paging format and corresponding resources sent by the core network. When the reader sends AIoT Paging to the device, it indicates the AIoT Paging format to the device. The indication method includes, but is not limited to, any of the following: determined by the number of repetitions in CAP or the M value within the OFDM symbol. For example, when M is less than 6, it is low-rate AIoT Paging; when M is greater than 6, it is high-rate AIoT Paging; or, indicated by the control part of the PRDCH. For example, the type of AIoT Paging is indicated by 2-bit indication information. In this embodiment, the AIoT Paging format includes the following information:

[0189] 1. Different rate levels of AIoT Paging: a. Low-rate AIoT Paging, used for devices with the lowest capabilities such as device 1, or for devices with good coverage performance and high access success rate, can be indicated by the M value (e.g., M=1 or M=2), encoding rate, etc.; b. High-rate AIoT Paging, used for high-capability devices such as device 2a or 2b, or for devices with average coverage performance and average access success rate, can be indicated by the M value (e.g., M=16 or M=32), encoding rate, etc.

[0190] 2. Different transmission block lengths for AIoT Paging: a. Short AIoT Paging: This includes AIoT Paging where the number of devices to be inventoried is less than a preset value, such as less than 20 devices. Specifically, when Subsequent AIoT Paging only inventories a small number of devices, its length is short; or when AIoT Paging is transmitted in segments, with each segment paging a small number of devices, its length is short. It can also be when the R2D signal transmission rate is higher than a preset rate, for example, when M=32, one OFDM symbol carries multiple R2D bit information, and its AIoT Paging length is short. b. Long AIoT Paging: This includes AIoT Paging where the number of devices to be inventoried is greater than a preset value, such as more than 50 devices. Specifically, when the number of devices inventoried in Subsequent AIoT Paging exceeds a specific value, its length is long. The length of the paging is also long; it can also be when the transmission rate of the R2D signal is lower than the preset rate, for example, when M=2, an OFDM symbol carries 1 bit of R2D information, and its AIoT paging length is long.

[0191] 3. Different types of AIoT Paging: a. Differentiated AIoT Paging by different groups, that is, each AIoT Paging only needs to inventory the devices of the current group, which are devices with the same characteristics, such as device 1. a) AIoT Paging carries the identifier of the current group (e.g., Group ID) during paging, which can be predefined or configured by higher layers; b) AIoT Paging is distinguished by different resource types, i.e., by whether the control information in the PRDCH is L1 control information or higher-layer control information. For example, AIoT Paging 1 only carries L1 control information; AIoT Paging 2 only carries higher-layer control information; c) AIoT Paging is distinguished by different TBS. For example, the TBS of AIoT Paging 1 is 900 bits; the TBS of AIoT Paging is 500 bits; d) AIoT Paging is divided into different functional zones, such as: AIoT Paging without control information versus AIoT Paging with control information; AIoT Paging used for the first paging and subsequent subsequent paging in the same round of inventory; AIoT Paging used for inventory or for control; AIoT Paging used for Device-to-Device Direct Transmission (DO-DTT) or AIoT Paging used for DOA. Paging, a combination of the above functions, for example, AIoT Paging 1 can be used for DO-DTT inventory and carrying control information; AIoT Paging 2 can be used for control, scenarios without carrying control information, and DOA scenarios.

[0192] In addition, in this embodiment of the application, when the first D2R information (e.g., Msg 1 or Msg A) is sent using the TDMA+FDMA mechanism, the reader needs to send AIoT Paging information multiple times due to the limited resources, for example, sending a shorter AIoT Paging information each time.

[0193] [Corrected according to Rule 91, 30.05.2025] As shown in Figure 2e, assume there are 50 devices to be inventoried in this round of inventory. Due to the limited resources configured on the network side, one AIoT Paging is insufficient to indicate the transmission resources of Msg 1 or Msg A for 50 devices. Therefore, the AIoT Paging and the corresponding Msg 1 or Msg A need to be transmitted in segments. Optionally, AIoT Paging and the corresponding Msg 1 or Msg A can be transmitted in segments as follows: The reader sends AIoT Paging 1 to inventory 25 devices (out of 50); Step 1: AIoT Paging indicates the time-domain and frequency-domain access resources of these 25 devices, where the frequency-domain resources are indicated by the frequency of the BLF or D2R signal, or the frequency offset of the D2R signal relative to the CW frequency, or the D2R line code repetition factor; Step 2: The reader receives Msg 1 / A information from the 25 devices (in scenarios where there may be conflicts or transmission failures, the actual number of received Msg 1 or Msg A is less than 25, which is not limited here), and sends Msg 2 / B information; Step 3: The reader sends AIoT Paging 2 or Subsequent AIoT Paging to inventory the remaining 25 devices; AIoT Paging indicates the time-domain and frequency-domain access resources of these 25 devices, where the frequency-domain resources are indicated by the BLF; AIoT Paging 2 / Subsequent AIoT Paging and Msg 2 can be sent simultaneously in a frequency-division relationship, or Msg 2 can be sent after it has been sent. Step 4: The reader receives the remaining Msg 1 or Msg A information from the devices, and based on the received Msg 1 or Msg A information from the remaining devices, sends Msg 2 or Msg B. It should be noted that in steps 1 to 4 above, when the reader sends the first round of Msg 2 or Msg B from the devices, there is a certain timing relationship with AIoT Paging 2 or Subsequent AIoT Paging, including: 1) simultaneous but not frequency-division sent; or 2) sending Msg 2 or Msg B first, and then sending AIoT Paging 2 or Subsequent AIoT Paging; or 3) sending AIoT Paging 2 or Subsequent AIoT Paging first, and then sending Msg 2 or Msg B. When sending AIoT Paging 2 or Subsequent AIoT Paging first, it should not be sent earlier than AIoT Paging 1. This application does not limit the specific timing relationship.

[0194] [Corrected according to Rule 91, 30.05.2025] Optionally, as shown in Figure 2f, the reader can also receive both Msg 1 and Msg A together, and then send Msg 2 or Msg B signals to the device to be inventoried. The AIoT Paging segmentation can complete device inventory in resource-constrained scenarios, and each AIoT Paging transmission can be used for timing the devices to be inventoried. For ease of understanding, this application uses the two-round inventory shown in Figure 2f as an example. Multiple rounds of inventory can use a similar method, which will not be elaborated here. Assuming the number of devices to be inventoried is 100, in the first round of inventory, the reader sends AIoT Paging 1 to inventory 50 devices. AIoT Paging indicates the time-domain and frequency-domain access resources of these 50 devices. The frequency-domain resources can be indicated by the frequency of the BLF or D2R signal, the frequency offset of the D2R signal relative to the CW frequency, or the D2R line code repetition factor. The reader then receives Msg 1 or Msg A information from the 50 devices and sends R2DMessage to these 50 devices. Due to potential conflicts and transmission failures in practical applications, the actual number of received Msg 1 or Msg A messages may be less than 50, which is not limited here. The R2DMessage indicates that the device is silent. The device silence can be an indication that the device switches to OFF or Sleep state, or energy storage state, or when in ON state, the transmitted bit 0 is adjusted by OOK and no linear encoding is performed. During the silence period, the device no longer sends D2R signals; the silence duration can be indicated by R2D Message or predefined. After the silence period ends, the device switches to the ON state to continue listening for Msg 2 or Msg B signals; in the second round of inventory, the reader sends AIoT Paging 2 or Subsequent AIoT Paging to inventory the remaining 50 devices. AIoT Paging 2 or Subsequent AIoT Paging indicates the time-domain and frequency-domain access resources of these 50 devices, where frequency-domain resources are indicated by BLF; the reader receives Msg 1 or Msg A signals from the remaining devices; optionally, if a third round of inventory is performed, the reader sends an R2D signal again to instruct the devices just inventoried to remain silent; based on the received Msg 1 or Msg A information from all devices, the reader sends Msg 2 or Msg B. In this scheme, by sending an additional R2D Message to indicate that the device is silent, the likelihood of the reader receiving the corresponding Msg 1 is increased, and the probability of missed detection is reduced.

[0195] [Corrected according to Rule 91, 30.05.2025] Optionally, based on Figure 2f, assuming the number of devices to be inventoried this time is 100, in the first round of inventory, the reader sends AIoT Paging 1 to inventory 50 devices. AIoT Paging indicates the time-domain and frequency-domain access resources of these 50 devices, wherein the frequency-domain resources are indicated by BLF; the reader receives Msg 1 or Msg A information from the 50 devices. After the 50 devices have sent Msg 1, they remain silent. The silence duration is indicated by AIoT Paging that schedules Msg 1 resources. After the quiet period ends, the device switches to the ON state to listen for Msg 2 or Msg B messages. In the second round of inventory, the reader sends AIoT Paging 2 or Subsequent AIoT Paging to inventory the remaining 50 devices. AIoT Paging 2 or Subsequent AIoT Paging indicates the time-domain and frequency-domain access resources for these 50 devices, with frequency-domain resources indicated via BLF. The reader receives Msg 1 or Msg A messages from the remaining devices and, based on all received Msg 1 or Msg A messages, sends Msg 2 or Msg B. In this scheme, devices that send Msg 1 become silent, eliminating the need to send additional R2D messages to notify devices that have sent Msg 1 / Msg A to remain silent, thus saving signaling overhead.

[0196] In addition, it should be noted that the AIoT Paging and the corresponding Msg 1 or Msg A need to be transmitted in segments, and the influencing factors of the number of segments include but are not limited to the following factors: the number of devices to be accessed, the TBS of Msg 1, the TBS of AIoT Paging, and / or the device capabilities. Specifically, when the number of segments is two segments, the resources scheduled by AIoT Paging 1 are M, and the resources scheduled by AIoT Paging 2 are N, where M = N, or M < N, or M > N, and M and N correspond to the same or different TBS sizes; AIoT Paging 1 schedules all the Msg 1 or Msg A and Msg 3 resources to be sent, and activates some resources for the device to send D2R signals in this round, and AIoT Paging 2 only sends the signaling for activating the remaining resources; according to the capabilities of the devices, for example, AIoT Paging 1 is used to inventory devices with relatively weak capabilities (such as device 1), and AIoT Paging 2 is used to inventory devices with slightly stronger capabilities (such as device 2a). When the number of segments is multiple segments, for example, taking three segments as an example, the others are similar, the resources scheduled by AIoT Paging 1 are M, the resources scheduled by AIoT Paging 2 are N, and the resources scheduled by AIoT Paging 3 are T. Among them, M = N = T, or M < N < T, or M > N > T, and the specific size relationship of M, N, and T is not limited in this application, and M, N, and T correspond to the same or different TBS sizes; AIoT Paging 1 schedules all the Msg 1 or Msg A and Msg 3 resources to be sent, and activates some resources for the device to send D2R signals in this round; AIoT Paging 2 and AIoT Paging 3 only send the signaling for activating the remaining resources; AIoT Paging 1 schedules some of the Msg 1 or Msg A and Msg 3 resources to be sent, and activates some resources for the device to send D2R signals in this round, AIoT Paging 2 schedules the remaining part of the Msg 1 or Msg A and Msg 3 resources to be sent, and activates some resources for the device to send D2R signals in this round, and AIoT Paging 3 only sends the signaling for activating the remaining resources; according to the capabilities of the devices, for example, AIoT Paging 1 is used to inventory devices with relatively weak capabilities (such as device 1), AIoT Paging 2 is used to inventory devices with slightly stronger capabilities (such as device 2a), and AIoT Paging 3 is used to inventory devices with stronger capabilities (such as device 2b).

[0197] In addition, in this embodiment of the application, in order to improve the transmission rate of the first R2D signal including AIoT Paging, when considering Manchester encoding, an OFDM 1-0 sequence is superimposed on the ON symbol of OOK-4. This method can also reduce the detection power consumption of the terminal. It should be noted that the superposition scheme proposed in this application is applicable to all frame structure types of R2D signals, and is not particularly limited here. A detailed description will follow.

[0198] For OOK-4 waveforms, one OFDM symbol may carry multiple time units, for example, 32 chips. This embodiment uses bit 0 → chips{10}, bit 1 → chips{01} as an example for scheme protection. The case of bit 0 → chips{01}, bit 1 → chips{10} is similar and will not be repeated. It should be noted that in this application, the time unit can be a chip, a bit, or other unit; this application is not limited. For ease of description, this application uses a chip as an example. Furthermore, for high-capacity devices, such as device 2b, the Manchester encoding method combined with the method of this embodiment can be used to transmit D2R signals, thereby improving the D2R transmission rate, which will not be elaborated here. When the D2R signal is not encoded using line codes, it can be superimposed using symbols, with the same principle. Specifically, this includes the following methods:

[0199] [Corrected according to Rule 91, May 2025] Method 1: If the AIoT Paging or Msg 2 signal to be transmitted has a total of M bits, then the first N bits of the ON chip carry (N+1) to M bits of information. Assuming each chip carries Q bits of information, then N chips carry a total of N*Q bits of information. The relationship between M, N, and Q is that N is equal to the integer part of M divided by (Q+1). For example, as shown in Figure 2g, there are 6 bits to be transmitted, and each chip carries 2 bits. Therefore, the first 2 bits of the ON chip in AIoT Paging or Msg 2 are needed to carry the subsequent bit information. As another example, if there are 111 bits to be transmitted, and each chip carries 3 bits, then the first 28 bits of the ON chip in AIoT Paging or Msg 2 are needed to carry the subsequent bit information (rounded up).

[0200] In practical applications, overlay processing can be considered in the following situations: For example, in a segmented transmission method for AIoT Paging or Msg 2, segmented data is transmitted via overlay, with OFDM symbols used for segmentation to avoid the impact of overlay on CP insertion; or, for CAP signals, after detecting CP within an OFDM symbol, the overlay of subsequent data is considered, where the segmented data range is the range of the OFDM symbols containing the two CPs; or, when one Msg 2 corresponds to one Msg 1 for transmission, segmentation is not required, and transmission is done via overlay; or, when one Msg 2 corresponds to multiple Msg 1s for TDMA transmission, segmentation is performed on each Msg 2 carrying RN 16, and then overlay transmission is performed. Alternatively, in AIoT Paging or Msg 2 preamble, overlay processing is only performed on CAP. Overlay processing is considered when the TBS is long (e.g., greater than 500 bits), the MCS-like level is high, and the transmission rate is high; or, when the M value is less than a certain threshold, for example, less than 8, overlay processing is considered.

[0201] [Corrected according to Rule 91, 30.05.2025] Method 2: The AIoT Paging or Msg 2 signal to be transmitted consists of M bits. The ON chip of the first bit carries multiple bits of information. Assuming each chip carries Q bits of information, the first (N-1) chips carry a total of (N-1)*Q bits of information, and the Nth chip carries T bits of information. The relationship between M, N, Q, and T is that N is equal to the difference between M and T divided by Q: N = (MT) / Q. For example, please refer to Figure 2i. There are a total of 6 bits to be transmitted, and each chip carries 2 bits. Therefore, the ON chips of the first 3 bits of AIoT Paging or Msg 2 need to carry the subsequent bits of information, where the first ON chip carries the 1st-2nd bits of information, the second ON chip carries the 3rd-4th bits of information, and the third ON chip carries the 5th-6th bits of information. For example, if there are 111 bits to be transmitted, and each chip carries 3 bits, then the first 37 bits of the ON chip of AIoT Paging or Msg 2 are needed to carry the subsequent bit information.

[0202] Compared to method one, method two can detect the information of adjacent bits faster, which is beneficial for Msg 2 to send multiple ACK / NACK signals corresponding to Msg 1 via TDMA, but the resource overhead is also greater.

[0203] Considering the demodulation complexity of the device, the sequence type for superposition in the superposition process can be a binary sequence, an M-sequence, or a Gold sequence. The device can obtain the bit information carried by the sequence through digital correlation. When the sequence type for superposition is a binary sequence, the original bit information can be copied as the superposition sequence.

[0204] The first R2D signal, including AIoT Paging or Subsequent AIoT Paging or Msg 2, is also used to indicate the overlay transmission method, which includes, but is not limited to, any of the following methods:

[0205] Display indication, that is, instructing the device through N bit control information, for example, 1 bit control information, bit 1 indicating mode one, bit 2 indicating mode two; 1 bit ON chip carries information about the number of bits, the superposition method of subsequent transmitted information, or the superposition method of indicating Msg 1 or Msg 2 transmission;

[0206] Implicit indications can be provided through the size of the TBS, MCS-like values, or the value of M. For example, when the TBS exceeds 500 bits, method one is used; when it exceeds 800 bits, method two is used. Optionally, it can also be determined by the M value of CAP. For example, if M is less than 6, method one is considered; if M is greater than 6, method two is considered. It should be noted that the number of bits carried by each ON chip can be predefined (e.g., 2 bits) or implicitly indicated, such as by the M value of CAP; or...

[0207] The reader can also indicate the M value or the minimum duration of ON after the device is overlaid with a sequence of bits based on the number of bits carried by a chip. For example, one OFDM symbol may include 8 chips, which can carry 4 bits of data after Manchester encoding. If each ON chip carries 2 bits of data, then each ON chip is further subdivided into 2 smaller chips. Thus, the original 2 chips corresponding to 1 bit become 4 smaller chips, where the OFF chip includes 2 smaller OFF chips. The ON chip becomes 2 smaller chips, which can be either ON or OFF, with the ON duration halved.

[0208] Furthermore, as mentioned above, the R2D timing acquisition signal of the first R2D signal comprises two parts: a start-indicator part and a CAP. The start-indicator part is used by the device to determine the start time of the R2D physical channel, and the CAP is used by the device to acquire time synchronization / frequency synchronization. In this application, the start-indicator part and the CAP will be configured separately.

[0209] The start-indicator pattern has two possibilities: option 1: an ON / OFF pattern, either a single ON-OFF pattern or multiple ON-OFF patterns; option 2: a predefined sequence forming an ON-OFF sequence, which can be used for digital correlation on the device. In this application, the lengths of the ON and OFF sequences in the start-indicator will be designed separately.

[0210] Because within an OFDM symbol, the first chip is ON, and different ON-OFF patterns can affect the length of the ON.

[0211] For a single ON-OFF pattern, the length of ON can be configured such that the length of ON occupies N chips, and N is greater than 50% of the value of M (the number of chips in an OFDM symbol). For example, if M = 16, then ON occupies 12 chips in the OFDM symbol, and the rest are OFF or empty; or, when the starting position of ON is not at the beginning of the OFDM symbol, for example, in the middle of the OFDM symbol, then the number of chips occupied by ON is greater than 50% (e.g., 70%) of the remaining chips. For example, if there are 12 remaining chips, then the number of chips for ON is 8; or, if the start-indicator is transmitted across symbols, then in the first OFDM symbol, all chips are ON; in the second OFDM symbol, at least the first 50% of the chips correspond to the level of ON; or, for scenarios involving transmission across symbols, the length of ON is greater than the length of OFF.

[0212] For multiple ON-OFF patterns, the length of ON can be configured as follows: the length of the first ON is greater than the length of the ONs after the first one, that is, the number of chips occupied by the first ON is greater than the number of chips occupied by the ONs after the first one, so that the device can complete the switching from OFF / Sleep state to ON state; or, at least the length of the first ON is greater than the length of OFF, including all ONs having a length greater than the length of OFF; or, when the start-indicator is transmitted across symbols, all chips are ON in the first OFDM symbol; or, the first OFDM symbol contains at least one ON-OFF, where the length of ON is equal to or greater than the length of OFF; and the second OFDM symbol contains at least one ON-OFF, where the length of ON is equal to or greater than the length of OFF.

[0213] The above configuration of the ON length satisfies the device's activation threshold and energy storage requirements, thus improving configuration flexibility.

[0214] Regarding the length of OFF, when OFF extends to the next OFDM symbol, the reader is unaware that the device's SFO might cause OFF to extend to the next OFDM symbol. If CP is ON, the device can process CP by identifying its position, for example, by the number of sampling points of CP, or by the rising / falling edges before and after CP. If CP is OFF, the length of OFF extending from the start-indicator to the next OFDM symbol plus the length of CP must satisfy the following condition: it must be greater than the number of sampling points of CP. For example, if the number of sampling points across OFF is 10 and the number of sampling points of CP is 50, then as long as there are 40 OFF sampling points within the first 50 sampling points, the device will determine it as CP.

[0215] When there is a gap between the end of OFF and the end of the OFDM symbol, the gap is introduced by the device's SFO. In this case, the reader is unaware that the device's SFO might introduce a gap. If CP is ON, the extension value of OFF is specified, and the specific operation is as follows: If the device does not obtain an ON sample value for M1 consecutive sampling points, where the M1 sampling points include the OFF of the actual start-indicator plus the existing gap, then by default, the sampled value for this time period is OFF. The number of sampling points for CP is only counted after Q consecutive ON values ​​are sampled. Here, M1 and Q are a range, and M1 may be greater than or less than Q to facilitate the device's identification of CP; or, the extension length of OFF is randomly specified as [0, T1] time units, where T1 is a number greater than or equal to 1, and the time unit includes the chip; if CP is OF If F, then the length of the OFF of the start-indicator plus the length of the CP satisfy the following conditions: greater than the number of sampling points of the OFF of the start-indicator plus the number of sampling points of the CP, or greater than N1 chips, where N1 is greater than or equal to 2; if the OFF ends prematurely and no gap is added, the rules for the device to identify the CP position include at least one of the following: the number of sampling points of the OFF at the end of the start-indicator is (N2-M2, N2), where N2 is the number of OFF sampling points when there is no SFO offset, and M2 is a dynamic range related to the number of chips configured for OFF, the duration, and the size of the device's SFO; or, the number of chips of the OFF at the end of the start-indicator is (N3-M3, N3), where N3 is the number of OFF chips when there is no SFO offset, and M3 is a dynamic range related to the size of the device's SFO.

[0216] By configuring the length of OFF as described above, the time offset effect of SFO is offset, ensuring the accuracy of CP identification in CAP.

[0217] In this embodiment of the application, different CAP functions are distinguished by designing a CAP pattern. Specifically, this includes, but is not limited to, the following methods:

[0218] Method 1: Differentiate based on whether CAP is repetition / linear encoding: When repetition / linear encoding is not considered, it is function 1, which includes chip duration indication, SFO estimation, CFO estimation, etc.; when repetition / linear encoding is considered, it is function 2, which includes chip duration indication, SFO estimation, CFO estimation, etc., where function 1 and function 2 have different functions.

[0219] Method 2: Differentiate by the number of repetitions: When the number of repetitions is N1, it is function 1, which includes chip duration indication, SFO estimation, CFO estimation, etc.; when the number of repetitions is N2, it is function 2, which includes chip duration indication, SFO estimation, CFO estimation, etc., where N1 is not equal to N2, and the functions of function 1 and function 2 are also different.

[0220] Method 3: Differentiate by sequence type: A single ON-OFF, i.e., the sequence before encoding is 10 or 01, represents function 1, which includes chip duration indication, SFO estimation, CFO estimation, etc.; multiple ON-OFF, i.e., the sequence before encoding is 10101010, or 01010101, or 111000, etc., sequence types >2 bits. Further, a sequence of all 1s represents a specific function, for example, used for SFO estimation; a 101010... sequence represents a specific function, for example, used for chip duration determination; a 11110000... sequence represents a specific function, for example, used for CFO estimation. The above are only examples, and the specific sequences can be set according to the actual situation. This application does not limit them.

[0221] Method 4: Differentiate by the size or rate of M. For example, when M is less than 8, it is used for SFO estimation; when M is greater than 16, it is used for CFO estimation.

[0222] Method 5: Determined by the number of sampling points or length of the first bit. For example, if the first bit (non-CP) is ON and occupies 4 chips, then the subsequent CAP can be used for chip duration estimation + SFO estimation.

[0223] This application also discusses solutions for the insertion of the same OFDM symbol and cross-OFDM symbol classes in CAP. As described above, the possible patterns of CAP include the following:

[0224] Option 1: The duration of CAP is variable for different values ​​of M. For example, as M increases, the duration of CAP decreases.

[0225] Option 2: For different values ​​of M, considering repetition, the duration of CAP is fixed. For example, as M increases, the repetition factor also increases, so the duration of CAP remains unchanged.

[0226] For option 2, to ensure the CAP length remains constant, when M decreases, consider the following repetition cases:

[0227] When within the same OFDM symbol, the first CAP carries the CP, while the CAPs of the remaining repetitions do not carry the CP, which has no particular impact on the protocol.

[0228] [Corrected according to Rule 91, May 2025] For CAPs spanning OFDM symbols, in addition to the first CAP requiring the addition of a CP, the first CAP of the adjacent second OFDM symbol can carry a CP. Specifically, if the starting position of the repetition CAP is aligned with the second OFDM symbol, a CP can be added directly; if the starting position of the repetition CAP is not aligned with the second OFDM symbol, as shown in Figure 2j, and the repetition count is 3, then the following schemes are considered: the second OFDM symbol does not consider CP insertion, or the second OFDM symbol considers CP insertion, with the CP length and level consistent with the CP inserted in the first OFDM symbol.

[0229] Considering that when M is greater than a certain value, for example, M>8, the chip duration becomes smaller, and may even be less than the length of the CP, one possible embodiment of this application is to set M to be less than a first set value, or to set the length of the CP within the same OFDM symbol to always be greater than the length of the chip duration. It should be noted that this setting applies not only to the CP design of CAP in this application, but also to the CP design in all R2D signals, without any specific limitation.

[0230] It should be noted that this solution is applicable not only to option 2 in the CAP pattern, but also to option 1 in the CAP pattern, and can also be extended to scenarios where other non-CAP R2D signals are added with CP. This application does not limit the specific application.

[0231] In addition, in this application, the synchronization function design of CAP and Midamble can be adopted in the following ways: 1) the pattern and rate of Midamble are consistent with those of CAP, or 2) the pattern and rate of Midamble are inconsistent with those of CAP. Specifically, Midamble uses a sequence of all 1s, and its rate is N4 times that of CAP, where N4 is a positive number, such as 1 / 2, 1 / 3, or 2, 3; Midamble uses a non-all 1 sequence, such as 1010, and its rate is N5 times that of CAP, where N5 is a positive number, such as 1 / 2, 1 / 3, or 2, 3.

[0232] Optionally, the first R2D signal can also be used to indicate D2R parameters or update device data. When the first R2D signal is AIoT Paging or Msg 2, the parameters that can be dynamically indicated include, but are not limited to, at least one of the following:

[0233] TBS, including TBS indications for R2D and D2R signals, for example, each AIoT paging indicates the TBS for each Msg1 or Msg3; or,

[0234] Repetition includes the number of times the D2R signal passes through the block-level, bit-level, and chip-level, as well as the time offset, frequency offset, or set of time offsets and frequency offsets for each repetition relative to the previous block, bit, or chip; or,

[0235] The starting position of Msg 1 or Msg 3, for example, relative to the starting position of AIoT Paging, or the common offset, i.e., the interval between the ending position of AIoT paging and the first Msg 1, or the resource size of each Msg 1 or Msg 3; or,

[0236] The device remains silent or transmits bit 0 using OOK modulated radio code encoding; or the time interval between Msg 2 and Msg 3; or the D2R frame structure type.

[0237] When the first R2D signal is AIoT Paging, the statically or semi-statically configurable parameters can be understood as follows: when the inventory points are the same device or device group, the statically or semi-statically configurable parameters are sent periodically, or the configured parameters are periodic, or the parameters of the current inventory point are fixed. In this application, the statically or semi-statically configurable parameters include, but are not limited to, at least one of the following information: device status configuration, MCS-like, sequence type or sequence length, device (group) ID, periodic synchronization sequence, D2R frame structure type, wherein: the device status includes ON, OFF or Sleep.

[0238] When the first R2D signal is an R2D message, parameters that can be configured statically or semi-statically include a device silence indicator, which means that the device enters an OFF or Sleep state for a period of time.

[0239] In addition, in this application, the reader can also measure the D2R signal from the AIoT Uu and set the measurement window. The measurement window is used to measure the D2R signal to determine whether the device is within the reader's coverage area, or to determine the distance between the device and the reader, or for reader selection, reader reselection, power control, etc. It should be noted that the configuration position, configuration length, and other information of this measurement window can be similar to the information of the fixed listening window mentioned above, or it can be configured separately. When the measurement window is configured separately, it can be configured after sending AIoT Paging and during the reception of Msg 1, MsgA, or Msg3, and the measurement length is greater than the resource length of Msg 1, MsgA, or Msg3 configured by the reader.

[0240] Specifically, when the reader is a UE, the UE can also report the AIoT-RSRP measurement results to the base station via the Uu interface. The AIoT-RSRP is the average power received by the reader from a single resource element or resource unit (e.g., a resource element (RE)) based on the configured D2R signal. This average power can be calculated using linear units of milliwatts (mW), dBm, or other units, which are not limited in this application. It should be noted that the power is calculated by measuring the energy received during the useful portion of a time unit, which includes, but is not limited to, NR time slots, symbols, bit units, or chip units.

[0241] When the reader is a UE, in addition to reporting AIoT-RSRP, it can also report AIoT-RSRQ and / or AIoT-SINR to the base station. The unit of AIoT-RSRQ is dB or dBm, etc. Taking dB as an example, its precision can be any value from 0.1 to 1 dB. Different precisions or precision values ​​map to different corresponding index values. The UE can report the index value or specific AIoT-RSRQ value to the base station. AIoT-SINR is defined as the ratio of the required D2R signal strength to the interference plus noise. The interference includes, but is not limited to, intermodulation interference, harmonic interference, self-interference, and cross-link interference. Similar to AIoT-RSRQ, the unit of AIoT-SINR can be defined as dB or dBm, etc. Taking dB as an example, its precision can be any value from 0.1 to 1 dB. Different precisions or precision values ​​are mapped to different corresponding index values. When the Reader is a UE value, it can report the index value or specific AIoT-RSRQ value to the base station.

[0242] In this application, when Msg1 is based on Frequency Division Multiplexing (FDM), the resource mapping rules for Msg2 sent by the reader include, but are not limited to, any one of the following:

[0243] Sequential mapping is performed based on the size of the subcarrier numbers, such as from largest to smallest or from smallest to largest.

[0244] The order is mapped based on the size of the BLF indication information, such as from largest to smallest or from smallest to largest. The BLF indication information includes, but is not limited to, at least one of the following: backscatter link frequency, or D2R signal frequency, or line code rate.

[0245] Mapping is performed based on specific parameters, including but not limited to one of the following: coverage level or coverage performance, or the measured AIoT-RSRP of the first D2R signal;

[0246] Based on the frequency-selective fading points predicted by the first D2R signal, for example, for PRBs or subcarriers with larger frequency-selective fading, no Msg 2 mapping is performed.

[0247] When Msg1 is based on Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM), different start listening times for R2D signals are defined for different device groups. For example, when the reader groups by paging, it knows the number of devices in a group and the number of time-frequency resources based on BLF.

[0248] [Corrected according to Rule 91, 30.05.2025] As shown in Figure 2k, when Msg2 is used to respond to Msg1 from multiple different groups, different devices listen to Msg2 within the same time window. The reader can also determine the device group that listens to Msg2 first. Specifically, based on Msg1 and / or the corresponding device information, the device group that listens to Msg2 first is determined. The device information includes, but is not limited to, at least one of the following: capability information, energy status, coverage level, or access level. For example, Figure 2k first sends Msg2 corresponding to Group N, where N is not equal to 1, to reduce the likelihood that group devices with weaker capabilities, lower energy, or poorer coverage will listen to and obtain Msg2 first, thereby reducing the device's listening power consumption and improving the reliability of the device's access to the network. It should be noted that the start time of Msg2 is the same for all devices.

[0249] [Corrected according to Rule 91, 30.05.2025] As shown in Figure 21, when Msg2 is used to respond to one or a group of Msg1, the reader receives Msg1 from group 1, group 2...group T. After receiving Msg1 from Group 1, the reader sends a corresponding Msg2. Msg2 corresponds to the received Msg1, that is, Msg2 includes the RN16, Group ID, and other information of Msg1. The start time of Msg2 for each group is the same for the devices in that group, that is, the devices in Group 1 start listening for Msg2 at the same start time.

[0250] [Corrected according to Rule 91, 30.05.2025] In addition, in this application, before sending the first R2D signal to the device, the reader can also adjust the corresponding Msg 2 transmission information based on the coverage level or access level of each AIoT device, i.e., the device. Specifically, the reader obtains the coverage level or access level of different devices based on the measurement value of Msg 1, the energy information reported by the device, or the prior information at the time of network access, or adjusts the transmission power of Msg 2 as shown in Figure 2m, or increases the receiving power of the device, including but not limited to any of the following methods:

[0251] 1. Adjust the power factor of different Msg 2 time domain units, wherein the power factor is an increment or decrement compared to a fixed transmit power. For example, for a device with good coverage, the reader reduces its transmit power when transmitting Msg 2; for a device with good coverage, the reader increases its transmit power when transmitting Msg 2.

[0252] 2. Msg 2 indicates the amplification capability of the device. This amplification capability refers to the power received by a device equipped with a low-noise amplifier (LNA) when receiving Msg 2, amplified by the LNA. For example, the Msg 2 control information instructs the device to use an LNA to receive the Msg 2 signal with a gain of X dB, where X is a positive number greater than 1.

[0253] 3. Reader switching: When reader 1 receives Msg 1 and finds that its access rate is less than the preset value, for example, if AIoT Paging is configured with 50 Msg 1 resources but only receives 15 Msg 1s, then reader 1 requests the CN to switch to another reader to send Msg 2 or to re-inventory based on the measured Msg 1 results. The switched reader is reader 2, which may be closer to the 50 devices to be inventoried or have less path loss.

[0254] 202. The device sends the first D2R signal to the reader.

[0255] After receiving the first R2D signal, the device sends a first D2R signal to the reader based on the first R2D signal. The first D2R signal includes a first random access message Msg 1 and / or a third random access message Msg 3.

[0256] Additionally, it should be noted that the coverage levels of the AIoT devices involved in the embodiments of this application include the following:

[0257] Coverage level A is defined as an area where the D2R signal strength is greater than a first threshold. In this embodiment, coverage level A can be an area with good D2R signal strength (e.g., in an indoor scenario, the coverage range of coverage level A is 15–30 m). Alternatively, coverage level A can be an area where the D2R signal strength is greater than or equal to the first threshold.

[0258] Coverage level B, where coverage level B is the area where the D2R signal strength is less than or equal to the first threshold and greater than or equal to the second threshold. In the embodiments of the present application, coverage level B is less than coverage level A, and coverage level B can be an area where the D2R signal is weak but still can ensure the normal completion of basic inventory, control, positioning and other services (for example, in an indoor scenario, the coverage range of coverage level B is 10 - 20m). Or, coverage level B is the area where the D2R signal strength is less than the first threshold and greater than the second threshold.

[0259] Coverage level C, where coverage level C is the area where the D2R signal strength is less than the second threshold. In the embodiments of the present application, coverage level C is less than coverage level B and is the area with the lowest coverage level. Coverage level C can be a scenario where the D2R signal is very weak, only completing control services, and / or inventory services, with the lowest data rate (for example, 1Kbps). Or, coverage level C is the area where the D2R signal strength is less than or equal to the second threshold.

[0260] It should be noted that in the embodiments of the present application, the access levels of the above-mentioned AIoT devices include:

[0261] Access level A, where access level A is the area where the access success rate is greater than the third threshold. For example, access level A can be the level where the reader sends an AIoT paging message and can select and activate N% (N = 1 - 100) of the AIoT devices in the coverage area. At this access level, it is ensured that the AIoT devices can complete inventory, positioning, control and other services based on the RTD signal or the correctly sent D2R signal of external CW. Or, access level A is the area where the access success rate is greater than or equal to the third threshold.

[0262] Access level B, where access level B is the area where the access success rate is less than or equal to the third threshold and greater than or equal to the fourth threshold. For example, at access level B, there may be problems such as missed detections and misdetections due to insufficient power or weak signals of AIoT devices. Access level B can be the level where the reader sends an AIoT paging message and can select and activate M% (for example, M = 1 - 100, and M < N) of the AIoT devices in the coverage area. At this level, it is ensured that the AIoT devices can basically correctly send DTD signals based on the RTD signal or external CW. Or, access level B is the area where the access success rate is less than the third threshold and greater than the fourth threshold.

[0263] Access level C is an area where the access success rate is less than the fourth threshold. For example, under access level C, problems such as missed detection and misdetection often occur due to insufficient power or weak signals of AIoT devices. Access level C can be a level at which the reader can send an AIoT paging message to select and activate T% (for example, M = 1 to 100, and T < M) of the AIoT devices within the coverage area. Under this level, the AIoT devices may experience communication interruptions during inventory and control operations due to very weak power or signals. Or, access level C is an area where the access success rate is less than or equal to the fourth threshold.

[0264] It should be noted that in the embodiments of this application, for AIoT devices of the same type with different capabilities, or for different types of AIoT devices, their coverage levels and / or access levels can be different.

[0265] In the embodiments of this application, different coverage levels and / or access levels can be configured for the same type of AIoT devices. The different coverage levels and / or access levels of the same type of AIoT devices are determined according to one or more of the following: the capabilities of the AIoT devices, the distance between the reader and the AIoT devices, the number of at least one AIoT device to be inventoried, or the number of at least one AIoT device successfully accessed in the previous inventory.

[0266] Exemplarily, for device 1: The capabilities of the AIoT device include one or more of the following: frequency offset error range, the ability to correct frequency deviation or time offset, energy storage capacity, or remaining power. For example, the reader can determine its coverage level and / or access level based on the frequency offset error range, the ability to correct frequency deviation or time offset, energy storage capacity, and remaining power of the AIoT device. Or, in one possible implementation, the reader can determine the coverage level and / or access level of the AIoT device based on the path loss measurement result of the D2R signal. Or, in another possible implementation, the coverage level and / or access level of the AIoT device are determined by the total number of AIoT devices to be inventoried and / or the number of AIoT devices successfully accessed in the previous inventory.

[0267] For example, for device 2a: the capabilities of the AIoT device include one or more of the following: signal amplification capability, energy storage capability, remaining power, frequency offset error range, or the ability to correct frequency deviation or time offset. For instance, the reader can determine the coverage level and / or access level of the AIoT device based on its signal amplification capability, energy storage capability, remaining power, frequency offset error range, and ability to correct frequency deviation or time offset. Alternatively, in one possible implementation, the reader can determine the coverage level and / or access level of the AIoT device based on the path loss measurement results of the D2R signal. Or, in another possible implementation, the coverage level and / or access level of the AIoT device is determined by the total number of AIoT devices to be inventoried, and / or the number of AIoT devices successfully connected in the previous inventory round.

[0268] For example, for device 2b: the capabilities of an AIoT device include one or more of the following: carrier generation capability, signal amplification capability, energy storage capability, remaining power, frequency offset error range, or the ability to correct frequency deviation or time offset. For instance, a reader can determine the coverage level and / or access level of an AIoT device based on its carrier generation capability, signal amplification capability, energy storage capability, remaining power, frequency offset error range, and ability to correct frequency deviation or time offset. Alternatively, in one possible implementation, the reader can determine the coverage level and / or access level of an AIoT device based on path loss measurements of the D2R signal. Or, in another possible implementation, the coverage level and / or access level of an AIoT device is determined by the total number of AIoT devices to be inventoried, and / or the number of AIoT devices successfully accessed in the previous inventory round.

[0269] In one possible implementation of this application embodiment, the coverage level and / or access level of the AIoT device are configured as predefined.

[0270] In another possible implementation of this application embodiment, the coverage level and / or access level configuration of the AIoT device is indicated by indication information.

[0271] For example, the coverage level and / or access level configuration of an AIoT device can be indicated via AIoT paging messages or other signaling, which can be considered a visible indication method. Optionally, the indication information indicating the coverage level and / or access level configuration of the AIoT device can be carried in the control and / or data sections of the PRDCH. For example, this indication information can be 1 bit of indication information, where bit 1 represents coverage level B and / or access level B, bit 0 represents coverage level C and / or access level C; no indication indicates that the default level is coverage level A and / or access level A. Alternatively, it can be bit 1 representing coverage level A and / or access level A, bit 0 representing coverage level B and / or access level B; no indication indicates that the default level is coverage level C and / or access level C. Alternatively, other cases may exist, which are not limited in this embodiment.

[0272] For example, indications can be given through predefined rules, which can be considered implicit indications. For instance, the AIoT device ID / group ID can be carried in the AIoT paging message, where AIoT device (group) ID 1 corresponds to coverage level A and / or access level A; AIoT device (group) ID 2 corresponds to coverage level and / or access level B; and AIoT device (group) ID 3 corresponds to coverage level and / or access level C. Another example is that the AIoT device determines the coverage level and / or access level based on the indicated TBS size; or, the AIoT device determines the coverage level and / or access level based on the remaining battery power (the reader can also determine the corresponding coverage level and / or access level through information reported by the X-bit energy status); or, the coverage level and / or access level can be determined based on the indicated MCS-like level. This application embodiment does not limit this approach.

[0273] It should be noted that for AIoT devices that have not yet been inventoried, when an AIoT device first enters the cell coverage area of ​​the reader, the default coverage level and / or access level can be set to the worst level. This allows the reader to configure resources to ensure successful access. For example, the default coverage level can be C, and / or access level can be C.

[0274] In this embodiment, different coverage levels and / or access levels can be configured for different types of AIoT devices. The coverage level and / or access level of different types of AIoT devices are determined based on one or more of the following: the capabilities of the AIoT device, the distance between the reader and the AIoT device, the number of at least one AIoT device to be inventoried, or the number of at least one AIoT device that was successfully connected in the previous round of inventory.

[0275] In one possible implementation, the coverage level and / or access level ranges for different types of AIoT devices can be predefined. For example, the coverage level and / or access level of device 1 may be A, B, and C (depending on path loss and the capabilities of device 1, please refer to the description of the above embodiments, which will not be repeated here); the coverage level and / or access level of device 2a may be A and B; and the coverage level and / or access level of device 2b may be A.

[0276] Alternatively, in another possible implementation, a default level can be specified for different types of AIoT devices. For example, the default level for device 1 is C; the default level for device 2a is B; and the default level for device 2b is C. It should be noted that the default level is not unique and varies with the scenario. This is just one example, and the embodiments of this application do not limit it.

[0277] It should be noted that the level may also include frequency modulation level, or other levels, etc. The embodiments of this application will not be described in detail here, but the frequency modulation level is also within the protection scope of the embodiments of this application.

[0278] In this application, by configuring different levels, the efficiency of the resources of the reader indicating D2R signals can be improved, and the efficiency and reliability of inventory counting can be guaranteed while improving resource utilization.

[0279] In summary, this application's embodiments improve the success rate of device network access and reduce R2D resource overhead by configuring the listening window of the first D2R signal before and after the second paging message; and improve inventory reliability by using AIoT paging segmented transmission to facilitate the configuration of Msg 1 and Msg 3 resources within limited resources; by designing a bit superposition transmission method for the first D2R signal such as AIoT Paging / Msg 2, R2D resource overhead and device detection power consumption are reduced; and by designing the Start-indicator and CAP frame structure, greater flexibility is provided, improving the reliability of device R2D signal detection. In other words, this application effectively reduces signaling overhead and improves inventory efficiency during AIoT inventory or control services through AIoT R2D frame structure design and transmission design, including AIoT Paging transmission enhancement, segmented transmission and signaling bearer methods; Msg 2 mapping mechanism; Start-indicator and CAP frame structure design and CP processing; R2D control information design; and AIoT Uu measurement mechanism.

[0280] [Corrected according to Rule 91, 30.05.2025] Optionally, in this embodiment, the reader can send multiple paging messages, i.e., a first paging message, a second paging message, or a third paging message, to paging one or more devices multiple times for random access or control services. To better understand the process of this solution, the example of sending two paging messages to paging at least one device or a group of devices for contention-based or non-contention-based random access will be used for detailed explanation. Please refer to Figure 2n for a flowchart of another possible communication method provided in this embodiment, which includes at least one of the following steps:

[0281] 201a. The reader sends the first paging message to the device;

[0282] 202a. The device sends the first Msg 1 to the reader;

[0283] 203a. The reader sends the first Msg 2 to the device;

[0284] 204a. The device sends the first Msg 3 to the reader;

[0285] 205a. The reader sends a second paging message to the device;

[0286] 206a. The device sends a second Msg 1 to the reader;

[0287] 207a. The reader sends a second Msg 2 to the device;

[0288] 208a. The device sends the second Msg 3 to the reader.

[0289] The reader sends a first paging message and, optionally, a second R2D signal. The first paging message or the second R2D signal is used to page one or more devices for random access or control services. The first paging message or the second R2D signal indicates at least one of the following:

[0290] 1. The device sends a D2R signal within a fixed listening window. The D2R signal includes the device's capabilities, N-bit energy status, and level information. The reader listens for the D2R signal within the fixed listening window to determine the transmission resources for Msg 1, Msg A, or Msg 3. The fixed listening window includes either a first paging message or a second paging message. Optionally, the reader reports the detected D2R signal to the CN.

[0291] 2. A first paging message, a second paging message, or other R2D signals indicate the activation or deactivation of device D2R signals. The device D2R signals include Msg 1 / A / 3;

[0292] 3. The reader sends AIoT Paging multiple times, including the first paging message and the second paging message. After receiving Msg 1 or Msg A together, it sends Msg 2 or Msg B signal to the device to be inventoried. The second R2D information indicates the silence period of the inventoried device; or it sends Msg 2 or Msg B according to each received Msg 1 or Msg A.

[0293] 4. If the AIoT Paging or the first / second R2D signal to be transmitted has a total of M bits, then the ON chip of the first N bits carries (N+1) to M bits of information. Alternatively, each chip carries Q bits of information, then the first (N-1) chips carry a total of (N-1)*Q bits of information, and the Nth chip carries T bits of information.

[0294] [Correction 30.05.2025 according to Rule 91] The indication information carried in the first paging message or the second R2D signal is similar to the relevant description in step 201 of Figure 2a above, and will not be repeated here;

[0295] In addition, the lengths of the ON and OFF of the start-indicator can be designed, as well as the relationship between OFF and CP insertion, including: the number of sampling points for OFF, the constraints of the length of OFF + the length of CP, etc.

[0296] [Corrected according to Rule 91 30.05.2025] In the embodiments of this application, the CAP pattern can also be designed to distinguish different CAP functions, the same OFDM symbol in CAP and cross OFDM symbol CP insertion, etc., which are similar to the relevant description in step 201 in Figure 2a, and will not be repeated here;

[0297] [Correction 30.05.2025 according to Rule 91] Optionally, the reader may send the first paging information or the second paging information or other R2D signals in segments. The specific segmented sending method is similar to the relevant description in step 201 of Figure 2a, and will not be repeated here.

[0298] [Correction 30.05.2025 according to Rule 91] The reader receives a first Msg 1 or first Msg A signal sent by the reader, wherein the first Msg 1 or first Msg A signal includes RN 16 or device data information. Optionally, the reader measures the first Msg 1 signal and defines AIoT-RSRP and measurement window, which is similar to the relevant description in step 201 of Figure 2a, and will not be repeated here;

[0299] [Corrected according to Rule 91, 30.05.2025] The reader sends the first Msg 2, the first Msg 2 responds to one or more first Msg 1 groups, and configures the transmission power of the first Msg 2, which is similar to the relevant description in step 201 in Figure 2a, and will not be repeated here.

[0300] The reader receives the first Msg 3 signal sent by the device.

[0301] Optionally, the reader can also perform a second paging, i.e., send a second paging message, such as a Subsequent AIoT Paging signal. The subsequent steps, including the signal transmission method or the signal frame structure, can be similar to the steps of the first paging, and will not be elaborated here.

[0302] In addition, when the reader sends multiple paging messages, including the first paging message, the second paging message, etc., since the length of multiple paging messages is relatively short, R2D Midamble may not be added. Alternatively, shorter paging messages may not have R2D Midamble added, while longer paging messages may have R2D Midamble added.

[0303] [Correction based on Rule 91, 30.05.2025] As shown in Figure 2f, for R2D messages, when the message length is short, for example, when it is only used to activate / deactivate PRDCH transmission, an R2D Midamble may not be added; when the message length is long, an R2D Midamble may be added.

[0304] When Msg 2 responds to multiple Msg 1 or multiple PDRCH, an R2D Midamble can be added to distinguish the Msg 2 resources corresponding to different Msg 1 or PDRCH, making it easier for the device to identify and receive them.

[0305] The figures above illustrate in detail the communication method provided in the embodiments of this application. Please refer to Figure 3, which is a storage diagram of the wireless communication device in the embodiments of this application. The storage medium 20 of the wireless communication device in the embodiments of this application stores instruction / program data 21. When the instruction / program data 21 is executed, it implements the method provided by any embodiment of the communication method of this application and any non-conflicting combination thereof. The instruction / program data 21 can be formed into a program file and stored in the storage medium 20 in the form of a software product, so that a computer device (which may be a personal computer, server, or network device, etc.) or processor can execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium 20 includes various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or terminals such as computers, servers, mobile phones, and tablets.

[0306] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0307] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0308] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

[0309] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0310] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0311] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0312] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0313] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0314] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0315] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0316] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0317] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0318] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0319] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

A communication method, applied to the reader / writer side, characterized in that, include: Send a first R2D signal to an AIoT device, wherein the first R2D signal is a signal transmitted from the reader to the AIoT device, the first R2D signal includes a paging message and / or a second random access message, the paging message includes a first paging message and / or a second paging message, the first paging message is earlier than the second paging message, and the second paging message includes one or more paging messages; The first R2D signal is used to indicate at least one of the following: Fixed listening window information for the reader to listen to the first D2R signal, wherein the first D2R signal is a signal whose transmission direction is from the AIoT device to the reader, and the first D2R signal includes a first random access message and / or a third random access message; Resources used to indicate the activation and / or deactivation of the first D2R signal; The method of superimposed transmission of the first R2D signal; Indicate D2R parameters or update the data of the AIoT device. The method according to claim 1, characterized in that, The fixed listening window includes, but is not limited to, at least one of the following: a first listening window, a second listening window, and a third listening window; the method further includes: Configure at least one of the following information according to the configuration conditions corresponding to each listening window: the position of each listening window, and / or the listening length corresponding to each listening window. The method according to claim 2, characterized in that, The start time of the first listening window is later than the sending time of the paging message, and the end time of the first listening window is later than the start time of the AIoT device sending the first D2R signal. The listening length of the first listening window is related to at least one of the following parameters: the number of resources for the first random access message, the common time offset from the start or end position of the AIoT device receiving the paging message to the start position of the AIoT device sending the first first random access message, the common time offset from the end position of the AIoT device processing the paging message to the start position of the AIoT device sending the first first random access message, or a predefined parameter. The method according to claim 3, characterized in that, The number of the first random access messages can be indicated by either a semi-static configuration indication or a dynamic indication. The method according to claim 4, characterized in that, The number of the first random access messages is indicated by the control information in the paging message. The method according to any one of claims 3 to 5, characterized in that, The configuration conditions for the second and third listening windows include, but are not limited to, at least one of the following conditions: the quality of the first uplink channel PDRCH is lower than a preset value, the device is in a low power state, and / or a collision occurs. The method according to claim 6, characterized in that, The start time of the second listening window is the end time of the first second random access message, or the end time of the second random access message being listened to by the reader / writer. The method according to claim 6 or 7, characterized in that, The listening length of the third listening window is related to the resource size of the first random access message configured in the second paging message. The method according to any one of claims 2 to 8, characterized in that, After sending the first R2D signal to the AIoT device, the method further includes: At least one of the first D2R signals received in the fixed listening window is sent to other control devices, including a base station. The method according to claim 1, characterized in that, The activation and / or deactivation indication methods of the first D2R signal include, but are not limited to, at least one of the following: The control information of the preceding first downlink channel (PRDCH) indicates whether the resources of the corresponding group device configured in the subsequent PRDCH are in a waiting-to-activate state; or, Instructions are given by configuring activation / awaiting activation information for each device group in the paging message; or... The transmission resources and configuration information of each AIoT device are configured in the paging message, and the transmission resources and configuration information are activated by sending the second paging message or other second R2D signal. The method according to claim 10, characterized in that, The method further includes: Send a first request message to the core network. The first request message is used to request the configuration of the paging message format and / or the resources for sending the paging message. The first request message carries the device information of the AIoT device, including capability information and / or power status. Sending the first R2D signal to the AIoT device includes: The paging message is sent to the AIoT device based on the resources of the paging message, and the format of the paging message is indicated. The method according to claim 11, characterized in that, The format of the paging message can be indicated in ways including, but not limited to, at least one of the following: indicated by the number of repetitions of the clock signal in the first R2D signal or the M value in the OFDM symbol, or indicated by the control section of the PRDCH. The method according to claim 11 or 12 is characterized in that, The format of the paging message includes, but is not limited to, at least one of the following: rate level, transport block length, and type information. The rate level includes high rate or low rate. The transport block length is positively correlated with the number of devices to be inventoried, or negatively correlated with the transmission rate of the R2D signal. The type information is based on at least one of the following: the group identifier of the devices to be inventoried, the type of resource carried, the transport block length, and the corresponding function. The method according to any one of claims 1 to 13, characterized in that, Sending the first R2D signal to the AIoT device includes: The paging message is sent to the AIoT device multiple times. The method according to claim 14, characterized in that, Sending the paging message to the AIoT device multiple times includes: The first paging message is sent to some of the devices in the AIoT device, and the first paging message indicates that the some devices access resources in the time domain and / or frequency domain; The second paging message is sent to other devices in the AIoT device, the second paging message indicating that the other devices access resources in the time domain and / or frequency domain. The method according to claim 15, characterized in that, The indication method for the frequency domain access resource includes indication via the frequency offset value of the first D2R signal. The method according to claim 15 or 16 is characterized in that, The method further includes: Receive the first random access message sent by the aforementioned devices in response to the first paging message; Receive the first random access message sent by the other device in response to the second paging message. The method according to claim 17, characterized in that, The method further includes: Based on the first random access message sent by the aforementioned devices, a corresponding second random access message is sent to the aforementioned devices. Based on the first random access message sent by the other devices, a corresponding second random access message is sent to the other devices. The method according to claim 17, characterized in that, After receiving the first random access message sent by the partial devices corresponding to the first paging message, the method further includes: An R2D instruction is sent to the aforementioned devices. The R2D instruction is used to instruct the aforementioned devices to switch to a silent state. The R2D instruction includes a silent duration. The silent state includes an OFF state, a Sleep state, or an energy storage state. Alternatively, in the ON state, the transmitted bit 0 is adjusted by OOK and no linear encoding is performed. The method according to claim 19, characterized in that, After receiving the first random access message sent by the partial devices corresponding to the first paging message, the method further includes: Based on the first random access message received from all AIoT devices, a second random access message is sent to all AIoT devices. The method according to any one of claims 14 to 20, characterized in that, The number of times the paging message is sent is related to at least one of the following parameters: the number of AIoT devices to be accessed, the TBS of the first random access message, the TBS of the paging message, and / or the capability information of the AIoT devices to be accessed. The method according to claim 1, characterized in that, Sending the first R2D signal to the AIoT device includes: By superimposing with a superimposed sequence, the superimposed sequence includes a first R2D signal to be transmitted, and the first R2D signal is carried on N time units to be transmitted to the AIoT device, wherein the time units include, but are not limited to, chips or bits. The method according to claim 22, characterized in that, The first R2D signal of M bits is carried on N time units, each time unit carrying Q bit information. The relationship between M, N and Q is that N is equal to the integer part of M divided by (Q+1). The method according to claim 22, characterized in that, The first R2D signal of M bits is carried on N time units, each time unit carries Q bit information, and the Nth time unit carries T bit information. The relationship between M, N, Q and T is that N is equal to the difference between M and T divided by the value of Q. The method according to any one of claims 22 to 24, characterized in that, The sequence types of the superimposed sequences include, but are not limited to: binary sequences, M sequences, or Gold sequences. The method according to any one of claims 1 to 25, characterized in that, The indication method for the overlay transmission method includes implicit indication or explicit indication. The method according to claim 26, characterized in that, The display indication includes indicating the overlay transmission method via control information in the first R2D signal. The method according to claim 26, characterized in that, The implicit indication includes indication through a mapping relationship between specific parameters and the superimposed transmission method. The specific parameters include, but are not limited to, one of the following: the size of TBS, MCS-like, the size of the M value, and the number of bits carried in a single time unit. The method according to any one of claims 1 to 28, characterized in that, The first R2D signal includes an R2D timing acquisition signal, which includes a first part and a second part. The first part is used to determine the start time of the second part and / or PRDCH. The second part is used by the AIoT device to acquire time and / or frequency synchronization and / or determine the duration of the time unit. The time and / or frequency synchronization includes the time and / or frequency synchronization of the first R2D signal reception and the time and / or frequency synchronization of the first D2R signal transmission. The method according to claim 29, characterized in that, The unit sequence of the first part includes a first value and a second value. The first value is different from the second value. The first value is an ON value, a high level, or a positive level, and the second value is an OFF value, a low level, a negative level, or a zero level. Within the OFDM symbol in which the first part is located, at least the first time unit is the first value. The method according to claim 30, characterized in that, When the first portion comprises a single sequence of said units and the first portion is transmitted on a single OFDM symbol, the time units occupied by the first value are greater than half of the total time units of the OFDM symbol. The method according to claim 30, characterized in that, When the first part comprises a single unit sequence and the first part is transmitted on a single OFDM symbol, if the starting position of the first value is not at the starting position of the OFDM symbol, the time unit occupied by the first value is greater than half of the remaining time units in the OFDM symbol. The method according to claim 30, characterized in that, When the first portion comprises a single sequence of said units and the first portion is transmitted across symbols, all time units within the first OFDM symbol are the first value, and at least the first 50% of time units within the second OFDM symbol are the first value. The method according to claim 30, characterized in that, When the first portion comprises a single sequence of said units, and the first portion is transmitted across symbols, the length of the first value is greater than the length of the second value. The method according to claim 30, characterized in that, When the first part includes multiple unit sequences, the time unit occupied by the first first value is greater than the time unit occupied by subsequent first values. The method according to claim 30, characterized in that, When the first part comprises a plurality of the unit sequences and the first part is transmitted on a single OFDM symbol, at least the time unit occupied by the first first value is greater than the time unit occupied by the second value. The method according to claim 30, characterized in that, When the first part includes multiple unit sequences and the first part is transmitted across symbols, all time units within the first OFDM symbol are the first value. The method according to claim 30, characterized in that, When the first part includes multiple unit sequences, and the first part is transmitted across symbols, at least one unit sequence is included in both the first OFDM symbol and the second OFDM symbol, and the time unit occupied by the first value in the unit sequence is not less than the time unit occupied by the second value. The method according to claim 30, characterized in that, When the time unit occupied by the second value extends to the next OFDM symbol of the OFDM symbol in which the first part is located, and the inserted cyclic prefix CP is off, the sum of the length of the second value extending to the next OFDM symbol and the length of the CP is greater than the number of sampling points of the CP, which is predefined or determined according to the type of AIoT device. The method according to claim 30, characterized in that, When the end position of the time unit occupied by the second value in the current OFDM symbol is less than the end position of the OFDM symbol in which the first part is located, and the CP of the next OFDM symbol is on, the extension length of the time unit occupied by the second value is [0,T] time units. The method according to claim 30, characterized in that, When there is a gap between the end position of the time unit occupied by the second value and the end position of the OFDM symbol where the first part is located, and CP is off, the sum of the length of the second value and the length of the CP is greater than the sum of the number of sampling points of the second value and the number of sampling points of the CP; or greater than N time units, where N is an integer greater than or equal to 2. The method according to claim 30, characterized in that, The second value ends earlier than the end of the OFDM symbol containing the first part, and no gap is added. The method according to claim 29, characterized in that, The second part includes a first function and a second function, both of which include, but are not limited to, at least one of the following functions: chip duration indication, SFO estimation, CFO estimation, and time and / or frequency synchronization for the AIoT device to acquire and / or determine chip duration. The first function is different from the second function. The method according to claim 43, characterized in that, The functional differentiation indication of the second part includes, but is not limited to, at least one of the following: indicating whether the second part is repetition / linearly encoded, indicating the number of repetitions, indicating the sequence type, indicating the size or rate of M, and indicating the number of sampling points or length of the first bit. The method according to claim 44, characterized in that, When the second part is a repetition / linear encoding, the function of the second part is the same as the first function; or... When the second part is not a repetition / linear encoding, the function of the second part is the second function. The method according to claim 44, characterized in that, When the number of repetitions is included in the first set, the function of the second part is the same as the first function; or... When the number of repetitions is included in the second set, the function of the second part is the second function; The first set and the second set do not overlap. The method according to claim 44, characterized in that, When the second part comprises a single unit sequence, the function of the second part is the same as the first function. The method according to claim 44, characterized in that, When the second part includes multiple unit sequences, different arrangements of the multiple unit sequences indicate corresponding specific functions, including but not limited to one of the following functions: chip duration indication, SFO estimation, CFO estimation, for the AIoT device to acquire time and / or frequency synchronization and / or determine chip duration. The method according to any one of claims 29 to 48, characterized in that, When the second part is transmitted on a single OFDM symbol, the first second part carries the CP, while the second parts of the remaining repetitions do not carry the CP. The method according to any one of claims 29 to 48, characterized in that, When the second part is transmitted across OFDM symbols, the first second part carries the first CP within the first OFDM symbol. If the starting position of the repetition second part is aligned with the subsequent second OFDM symbol, the first second part carries the second CP within the subsequent second OFDM symbol. The method according to any one of claims 29 to 48, characterized in that, When the second part is transmitted across OFDM symbols, the first second part carries the CP within the first OFDM symbol. If the starting position of the repetition second part is not aligned with the subsequent second OFDM symbol, the subsequent second OFDM symbol does not carry the CP. The method according to any one of claims 29 to 48, characterized in that, When the second part is transmitted across OFDM symbols, within the first OFDM symbol, the first second part carries the first CP. If the starting position of the repetition second part is not aligned with the subsequent second OFDM symbol, the length and level of the second CP carried by the subsequent second OFDM symbol are consistent with the length and level of the first CP. The method according to any one of claims 29 to 48, characterized in that, The value of M in the second part is less than the first set value, or the length of the CP within the same OFDM symbol is greater than the length of the chip duration, and the value of M is the number of time units of an OFDM symbol. The method according to any one of claims 29 to 53 is characterized in that, The frame structure of the first D2R signal includes an intermediate preamble. The method according to claim 54, characterized in that, The information related to the intermediate preamble is consistent with the second part of the R2D timing acquisition signal, and the information related includes, but is not limited to, the following: pattern and rate. The method according to claim 54, characterized in that, The intermediate precode can be either an all-1 sequence or a non-all-1 sequence. The method according to any one of claims 1 to 56, characterized in that, The first D2R signal indicates the D2R parameters or updates the data of the AIoT device in a manner including dynamic indication and / or, static / semi-static indication. The method according to claim 57, characterized in that, The parameters indicated by the dynamic indication include, but are not limited to, at least one of the following parameters: TBS, Repetition, the starting position of the first random access message or the third random access message, the position when the AIoT device remains silent or transmits bit 0 in the OOK modulation radio code encoding, the time interval between the second random access message and the third random access message, the frame structure type of the first D2R signal, the identification information ID or group ID of the AIoT device, the access layer ID, or a specific bit random number. The method according to claim 58, characterized in that, In the paging message, the parameters indicated by the static / semi-static method include, but are not limited to, at least one of the following parameters: the status configuration of the AIoT device, MCS-like, sequence type or sequence length, the identification information ID or group ID of the AIoT device, access layer ID, specific bit random number, periodic synchronization sequence, and the frame structure type of the first D2R signal. The method according to claim 57, characterized in that, The second R2D signal includes a silence indication, but does not include the paging message. The silence indication is used to indicate that the AIoT device enters a silence state within a specific duration. The silence state includes an off state or a sleep state, or an ON state where bit 0 is adjusted by OOK and no linear encoding is performed. The method according to any one of claims 1 to 60, characterized in that, The method further includes: Receive the first D2R signal; The first D2R signal is measured, and the measurement result is obtained. The method according to claim 61, characterized in that, The measurement results include, but are not limited to, at least one of the following: AIoT-RSRP, AIoT-RSRQ, and AIoT-SINR, wherein AIoT-RSRP is the average power received by the reader / writer based on a single resource element or resource unit of the configured first D2R signal, and AIoT-SINR is used to represent the ratio of the required D2R signal strength to interference plus noise. The method according to claim 62, characterized in that, The different values ​​of AIoT-RSRQ are respectively mapped to different first index values, and / or the different values ​​of AIoT-SINR are respectively mapped to different second index values. The method according to claim 63, characterized in that, When the reader / writer is a user equipment (UE), the method further includes: Report the value of the AIoT-RSRQ or the corresponding first index value; And / or, Report the value of the AIoT-SINR or the corresponding second index value. The method according to any one of claims 1 to 64, characterized in that, When the first random access message is based on Frequency Division Multiplexing (FDM), the resource mapping rules of the second random access message include, but are not limited to, any one of the following: sequential mapping based on the size of the subcarrier, sequential mapping based on the size of the backscatter link frequency (BLF) indication, the size of the D2R signal frequency, or the size of the line code frequency, or mapping based on specific parameters, wherein the specific parameters include, but are not limited to, one of the following: coverage level or coverage performance, or the measured AIoT-RSRP of the first D2R signal, or the frequency-selective fading point predicted based on the first D2R signal. The method according to any one of claims 1 to 64, characterized in that, The first random access message is based on FDM and Time Division Multiplexing (TDM). The method according to claim 66, characterized in that, When the second random access message is used in response to multiple different groups of the first random access messages, the method further includes: Determine the device group that will prioritize listening to the second random access message. The method according to claim 67, characterized in that, The device group that is given priority in listening to the second random access message includes: Based on the first random access message and / or the corresponding device information, a device group that prioritizes listening to the second random access message is determined. The device information includes, but is not limited to, at least one of the following: capability information, energy status, coverage level, or access level. The method according to claim 66, characterized in that, When the second random message is used to respond to the first random access message of the first group, the devices corresponding to the first group listen for the second random message at the same start time. The method according to any one of claims 1 to 69, characterized in that, Before sending the first R2D signal to the AIoT device, the method further includes: Based on the coverage level or access level of each AIoT device, adjust the sending information of the corresponding second random access message. The method according to claim 70, characterized in that, Adjust the power factor of the time-domain unit of the corresponding second random access message. The method according to claim 70, characterized in that, The second random access message carries an amplification capability indication, which is used to indicate the amplification power of receiving the second random access message. The method according to claim 70, characterized in that, The adjustment of the sending information of the second random access message includes: When the preset conditions are met, a request is sent to CN to switch to another reader / writer to resend the second random access message or to re-inventory the system. A communication method applied to AIoT devices, characterized in that, include: Based on the first configuration information, a first D2R signal is sent to the reader / writer. The first D2R signal is a signal with a transmission direction from the AIoT device to the reader / writer. The first D2R signal includes a first random access message and / or a third random access message. The first configuration information includes, but is not limited to, one or more of the following configurations: A fixed listening window configuration for the reader to listen to the transmission of the first D2R signal; Resources used to indicate the activation and / or deactivation of the first D2R signal; The method of superimposed transmission of the first R2D signal; Indicate D2R parameters or update the data of the AIoT device. The method according to claim 74, characterized in that, Before sending the first D2R signal to the reader, the method further includes: The system receives a first R2D signal sent by the reader, the first R2D signal being a signal with a transmission direction from the reader to the AIoT device, the first R2D signal including a paging message, and / or a second random access message. The method according to claim 75, characterized in that, The paging message includes a first paging message and / or a second paging message, wherein the first paging message precedes the second paging message, and the second paging message includes one or more paging messages. The method according to claim 75 or 76 is characterized in that, The first R2D signal also indicates the format of the paging message. The method according to any one of claims 75 to 77, characterized in that, Sending the first D2R signal to the reader includes: Based on the first random access message sent by the reader, a corresponding second random access message is sent to the reader. The method according to claim 78, characterized in that, The method further includes: The reader receives an R2D indication sent by the reader. The R2D indication is used to indicate switching to a silent state. The R2D indication includes a silent duration. The silent state includes an OFF state, a Sleep state, or an energy storage state. In the ON state, the transmitted bit 0 is adjusted by OOK and no linear encoding is performed. The method according to any one of claims 1 to 79 is characterized in that, The first R2D signal includes an R2D timing acquisition signal, which includes a first part and a second part. The first part is used to determine the start time of the second part and / or PRDCH. The second part is used by the AIoT device to acquire time and / or frequency synchronization and / or determine the duration of the time unit. The time and / or frequency synchronization includes the time and / or frequency synchronization of the first R2D signal reception and the time and / or frequency synchronization of the first D2R signal transmission. The method according to claim 80, characterized in that, The unit sequence of the first part includes a first value and a second value. The first value is different from the second value. The first value is an ON value, a high level, or a positive level, and the second value is an OFF value, a low level, a negative level, or a zero level. Within the OFDM symbol in which the first part is located, at least the first time unit is the first value. The method according to claim 81, characterized in that, When there is a gap between the end position of the time unit occupied by the second value and the end position of the OFDM symbol where the first part is located, and CP is on, the method further includes: If the AIoT device fails to obtain the first value for M1 consecutive sampling points, then it continuously samples Q first values ​​and counts the number of sampling points of the CP again, where M1 is greater than Q or M1 is less than Q. A communication device, characterized in that, The communication device includes a module for performing the method according to any one of claims 1 to 82. A wireless communication device, comprising: A processor and a memory, the memory being used to store a computer program, the processor being used to invoke and run the computer program stored in the memory to perform the method as described in any one of claims 1 to 82.

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