Communication method and communication apparatus

Abstract

Embodiments of the present application provide a communication method and a communication apparatus, capable of configuring a D2R signal. The method comprises: on the basis of a first configuration, a terminal device sends a D2R signal to a reader / writer. The D2R signal comprises a first random access message and / or a third random access message. The first configuration comprises one or more of the following: a level of the terminal device, the level including a coverage level and / or an access level; a configuration of a first time unit, wherein the terminal device sends or does not send a signal within the first time unit; a configuration of the type of the D2R signal; a configuration of a frame structure of the D2R signal for uplink synchronization; the number of repetitions of the D2R signal and a configuration of time-frequency resources for the repetitions; a configuration of a random offset corresponding to the D2R signal; a configuration of a retransmission time of the D2R signal; or a configuration of time extension for the terminal device to send the third random access message.

Description

Communication methods and communication devices Technical Field

[0001] This application relates to the field of communications, and more specifically, to communication methods and communication devices. 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. Ambient IoT (AIoT) technology has been widely discussed. AIoT devices primarily utilize the external environment (e.g., light, radio waves, motion, heat, etc.) to obtain energy, thus eliminating the need for battery devices or requiring only low energy storage capacity (e.g., capacitors), eliminating the need for manual battery replacement or charging.

[0003] The 3rd Generation Partnership Project (3GPP) Release 19 introduced the topic of AIoT. However, many issues regarding AIoT remain unresolved. Summary of the Invention

[0004] This application provides a communication method and a communication device that can be configured with D2R signals.

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

[0006] Firstly, a communication method is provided. This method can be executed by a terminal device, or by a component of the terminal device, such as a processor, chip, or chip system, or by a logic module or software capable of implementing all or part of the terminal device's functions. Taking the method being executed by a terminal device as an example, the method includes: based on a first configuration, the terminal device sends a D2R signal to a reader / writer, the D2R signal including a random access first message and / or a random access third message; wherein the first configuration includes one or more of the following: the level of the terminal device, the level including a coverage level and / or an access level; a configuration of a first time unit, wherein the terminal device sends or does not send a signal within the first time unit; a configuration of the D2R signal type; a configuration of the frame structure of the D2R signal for uplink synchronization; a configuration of the number of repetitions of the D2R signal and the time-frequency resources used for repetition; a configuration of the random offset corresponding to the D2R signal; a configuration of the retransmission time of the D2R signal; or, a configuration of the time extension line for the terminal device to send the random access third message.

[0007] Secondly, a communication method is provided, which can be executed by a reader or writer, or by a component of the reader or writer, such as the reader or writer's processor, chip, or chip system, or by a logic module or software that can implement all or part of the reader or writer's functions. Taking the method as an example of being executed by a reader / writer, the method includes: the reader / writer receiving a D2R signal from a terminal device, the D2R signal including a random access first message and / or a random access third message; wherein the D2R signal is determined by the terminal device based on a first configuration, the first configuration including one or more of the following: the level of the terminal device, the level including a coverage level and / or an access level; a configuration of a first time unit, wherein the terminal device sends or does not send a signal within the first time unit; a configuration of the D2R signal type; a configuration of the frame structure of the D2R signal for uplink synchronization; a configuration of the number of repetitions of the D2R signal and the time-frequency resources used for repetition; a configuration of the random offset corresponding to the D2R signal; a configuration of the retransmission time of the D2R signal; or, a configuration of the time extension line for the terminal device to send the random access third message; the reader / writer sending an R2D signal according to the D2R signal.

[0008] Thirdly, a communication device is provided for implementing the various methods described above. This communication device may be the terminal device described in the first aspect, or a device included in the terminal device, such as a chip; or, the communication device may be the reader / writer described in the second aspect, or a device included in the reader / writer, such as a chip.

[0009] The communication device includes modules, units, or means that implement the above methods. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0010] In some possible designs, the communication device may include a processing module and a communication module. The communication module may include an output module (or transmitting module) and an input module (or receiving module), respectively used to implement the output (or transmitting) and input (or receiving) functions in any of the above aspects and any possible designs. The processing module can be used to implement the processing functions in any of the above aspects and any possible designs.

[0011] Optionally, the communication device also includes a storage module for storing program instructions and data.

[0012] Fourthly, a communication device is provided, comprising: at least one processor configured to execute computer programs or instructions, or to cause the communication device to perform the method described in any of the preceding aspects via logic circuitry. The communication device may be a terminal device as described in the first aspect, or a device included in a terminal device, such as a chip; or, the communication device may be a reader / writer as described in the second aspect, or a device included in a reader / writer, such as a chip.

[0013] In some possible designs, the communication device also includes a memory for storing configuration files of computer instructions and / or logic circuits. Optionally, the memory is integrated with the processor, or the memory is independent of the processor.

[0014] In one possible design, the communication device also includes a communication interface for inputting and / or outputting signals.

[0015] In some possible designs, the communication interface is an interface circuit used to read and write computer instructions. For example, the interface circuit is used to receive computer execution instructions (which are stored in memory and may be read directly from memory or may be transmitted through other devices) and transmit them to the processor.

[0016] In some possible designs, this communication interface is used to communicate with modules outside the communication device.

[0017] In some possible designs, the communication device can be a chip system. When the communication device is a chip system, the chip system may include chips, or it may contain chips and other discrete components.

[0018] Fifthly, a communication device is provided, comprising: a logic circuit and an interface circuit; the interface circuit is used for inputting information and / or outputting information; the logic circuit is used to execute the method described in any of the preceding aspects, processing the input information and / or generating output information. The communication device may be a terminal device as described in the first aspect, or a device included in a terminal device, such as a chip; or, the communication device may be a reader / writer as described in the second aspect, or a device included in a reader / writer, such as a chip.

[0019] In a sixth aspect, a computer-readable storage medium is provided that stores a computer program or instructions that, when executed by a processor, cause the methods described in any of the preceding aspects to be performed.

[0020] In a seventh aspect, a computer program product is provided, which, when executed by a processor, causes the method described in any of the preceding aspects to be performed.

[0021] Eighthly, a communication system is provided, which includes the terminal device of the first aspect and the reader / writer of the second aspect.

[0022] It is understood that when the communication device provided by any of the third to fifth aspects is a chip, the aforementioned sending action / function can be understood as output information, and the aforementioned receiving action / function can be understood as input information.

[0023] The technical effects of any of the design methods in aspects three through five can be found in the technical effects of the different design methods in aspects one and two above, and will not be repeated here. Attached Figure Description

[0024] Figure 1 is a schematic diagram of four topologies of an AIoT system;

[0025] Figure 2A is a schematic diagram of the CW signal and the sideband signal generated by the CW signal provided in the embodiments of this application;

[0026] Figure 2B is a schematic diagram of a scenario based on topology 1 / 2 and whether the CW node is within the topology;

[0027] Figure 3 is a schematic diagram of the mapping relationship between bits and chips in Manchester encoding;

[0028] Figure 4 is a schematic diagram of PIE encoding;

[0029] Figure 5 is a schematic diagram of FM0 encoding;

[0030] Figure 6 is a schematic diagram of Miller coding;

[0031] Figure 7 is a schematic diagram of the R2D start indicator;

[0032] Figure 8 is a schematic diagram of the R2D intermediate guide code;

[0033] Figure 9 is a schematic diagram of the D2R intermediate guide code;

[0034] Figure 10 is a schematic diagram of the R2D postcode;

[0035] Figure 11 is a schematic diagram of the D2R postcode;

[0036] Figure 12 is a schematic diagram of the approximate time relationship between the D2R preamble, D2R intermediate preamble, and D2R postamble.

[0037] Figure 13 is a schematic diagram of the random access process between the reader and the terminal device;

[0038] Figure 14 is a schematic diagram of TDMA, FDMA, and TDMA+FDMA provided in the embodiments of this application;

[0039] Figure 15 is a schematic diagram of the reader / writer sending an MSG2 to the terminal device according to an embodiment of this application;

[0040] Figure 16 is a schematic diagram of the MSG2 response to the terminal device provided in an embodiment of this application;

[0041] Figure 17 is a schematic diagram of MSG2 in embodiment 2 of this application;

[0042] Figure 18 is a schematic diagram of MSG2 in embodiment 3 provided in this application;

[0043] Figure 19 is a schematic diagram with the end time unit of Step A as a reference point provided in the embodiment of this application;

[0044] Figure 20 is a schematic diagram of the communication system provided in an embodiment of this application;

[0045] Figure 21 is a schematic diagram of the structure of the communication device 2100 provided in an embodiment of this application;

[0046] Figure 22 is a schematic diagram of an example of the communication method provided in an embodiment of this application;

[0047] Figure 23 is a schematic diagram of the location of the first time unit;

[0048] Figure 24 is a schematic diagram of a reader receiving multiple D2R signals during a round of inventory counting;

[0049] Figure 25 is a schematic diagram of the first sequence being a sparse sequence;

[0050] Figure 26 is a schematic diagram of the Preamble insertion synchronization sequence provided in an embodiment of this application;

[0051] Figure 27 is a schematic diagram of the first sequence being a compact sequence;

[0052] Figure 28 is a schematic diagram of block-level repetition provided in an embodiment of this application;

[0053] Figure 29 is a schematic diagram of bit-level repetition provided in an embodiment of this application;

[0054] Figure 30 is a schematic diagram of the repeating granularity at the chip level provided in the embodiments of this application;

[0055] Figure 31 is a schematic diagram of the time domain offset of the first message of random access under the non-contention access mechanism provided in the embodiments of this application;

[0056] Figure 32 is a schematic diagram of the configuration of the random offset of the random access first message of the terminal device through the retransmitted AIoT paging message provided in an embodiment of this application;

[0057] Figure 33 is a schematic diagram of the listening window provided in an embodiment of this application before the retransmitted AIoT paging message;

[0058] Figure 34 is a schematic diagram of the time extension line provided in an embodiment of this application;

[0059] Figure 35 is a schematic diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0060] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0061] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following or similar expressions" refers to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b and / or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0062] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0063] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0064] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process 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.

[0065] It is understood that in this application, "...when" and "if" both refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed during implementation, nor do they imply any other limitations.

[0066] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0067] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, unless otherwise specified or there is a logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be mutually referenced. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. The following descriptions of the embodiments of this application do not constitute a limitation on the scope of protection of this application.

[0068] To facilitate the reader's understanding, the relevant technologies involved in the embodiments of this application are described.

[0069] I. Topology of AIoT System

[0070] Figure 1 shows a schematic diagram of four topologies for an AIoT system. As shown in Figure 1, the AIoT system mainly includes four topologies: Topology 1 to Topology 4, which will be introduced below.

[0071] Topology 1:

[0072] In topology 1, the access network devices and AIoT terminals are directly connected for uplink / downlink communication. That is, the AIoT terminal sends information to the access network devices, or the AIoT terminal receives information from the access network devices.

[0073] Topology 2:

[0074] In topology 2, AIoT terminals and intermediate nodes communicate uplink / downlink, while intermediate nodes communicate uplink / downlink with access network devices. That is, AIoT terminals send or receive information from intermediate nodes, and intermediate nodes send or receive information from access network devices. Intermediate nodes can be relays, integrated access backhaul (IAB) nodes, user equipment (UE), repeaters, etc.

[0075] Topology 3:

[0076] In topology 3, the AIoT terminal communicates unidirectionally with the access network device / auxiliary node. In the left diagram, the AIoT terminal directly sends signals to the access network device but receives signals through the auxiliary node. In the right diagram, the AIoT terminal can directly receive signals from the access network device but sends signals to the auxiliary node. The auxiliary node can be a relay, IAB node, UE, repeater, etc.

[0077] Topology 4:

[0078] In topology 4, the UE and AIoT terminal are directly connected for uplink / downlink communication. That is, the AIoT terminal sends information to the UE or receives information from the UE.

[0079] In the following embodiments of this application, unless otherwise stated, the AIoT terminal is referred to as a terminal device, the access network device, the intermediate node, and the UE are referred to as a 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).

[0080] II. Types of terminal equipment.

[0081] Terminal devices (AIoT terminals) can be broadly categorized into two types: those capable of generating their own signals and those unable to do so. The latter type receives backscattered signals from third-party signals (carrier waves, CW) and transmits them; therefore, they can also be called backscatter-based communication terminals. Because backscatter-based communication terminals cannot actively generate signals, their architecture is simpler and less expensive, resulting in lower power consumption compared to the former type. In the four topologies described in Related Technology 1, the signals sent by the terminal device to the access network device / intermediate node / UE can be either self-generated signals or backscattered signals.

[0082] The types of terminal devices can be shown in Table 1.

[0083] Table 1

[0084] It should be noted that the peak power values ​​in the embodiments of this application are merely examples, and the specific values ​​of peak power are not limited in the embodiments of this application.

[0085] III. Carrier wave (CW).

[0086] In an AIoT system, in addition to the nodes mentioned in the above-mentioned related technologies (access network devices, AIoT terminals, intermediate nodes / auxiliary nodes), there are also nodes that send CW (Content Written).

[0087] One function of CW (Cyber-Wave) is to provide energy to AIoT devices, meaning that AIoT devices receive energy from CW. All AIoT devices can obtain energy by receiving CW signals.

[0088] Another function of CW is for backscatter communication. For example, the uplink signals of device 1 and device 2a mentioned above are backscatter signals generated by the terminal device through receiving CW.

[0089] In this embodiment, the node providing the CW can be an access network device, an intermediate node, a UE, or a third-party node. Taking topology 1 as an example, the CW can be sent by the access network device, and the AIoT terminal receives other signals (e.g., control information) and the CW sent by the access network device; the CW can also be sent by a third-party node, and the AIoT terminal receives signals (e.g., control information) sent by the access network device and the CW sent by the third-party node.

[0090] Based on the topology described in the above-mentioned related technology 1, depending on the situation, the device that sends CW (denoted as CW node) may be inside or outside the topology.

[0091] In this embodiment, CW can be a single-tone signal or a multi-tone signal, with two-tone signals being the primary type. However, other multi-tone signals can also be used, and this embodiment does not limit the specific type. A single-tone CW signal generates two sideband signals, a two-tone CW signal generates four sideband signals, and so on. The sideband signals are the backscattered signals, i.e., the D2R signals of device 1 and device 2a. Figure 2A is a schematic diagram of the CW signal and the sideband signals generated by the CW signal provided in this embodiment. As shown in Figure 2A, f1 and f2 are two CW signals, f1-f' and f1+f' are the two sideband signals generated by f1, and f2-f' and f2+f' are the two sideband signals generated by f2.

[0092] IV. AIoT Scenarios.

[0093] Currently, 3GPP is mainly researching Topology 1 and Topology 2. Based on Topology 1 / 2 and whether the CW node is within the topology, the following scenarios are possible, as shown in Table 2 and Figure 2B. In Topology 1, the reader / writer is an access network device; in Topology 2, the reader / writer is an intermediate node, which can be a relay, IAB node, UE, repeater, etc.

[0094] Table 2

[0095] V. AIoT Modulation and Coding.

[0096] Due to the simple structure of AIoT terminals, their signal processing methods differ from traditional communication. R2D signals use Manchester encoding or pulse-interval encoding (PIE). D2R signals use Manchester encoding, FM0 encoding, Miller encoding, or forward error correction (FEC).

[0097] Figure 3 is a schematic diagram of the mapping relationship between Manchester encoding bits and chips. As shown in Figure 3, Manchester encoding is an encoding method that uses level transitions to represent bits 0 and 1. Based on Manchester encoding, the mapping relationship between bits and chips can be as follows: bit 0 is mapped to chip {10}, which can be understood as switching from a high level to a low level; bit 1 is mapped to chip {01}, which can be understood as switching from a low level to a high level. Of course, bit 0 can also be mapped to chip {01}, and bit 1 can be mapped to chip {10}. According to the mapping relationship in the figure, the encoding efficiency of Manchester encoding is 1 / 2.

[0098] In Figure 3, the length of chip 1 in each bit is the same as the length of chip 0. The lengths of chip 1 and chip 0 can also be different. The time relationship between chip 0 and chip 1 can be represented by the duty cycle, which refers to the proportion of the on-time (high level time) to the total time in one pulse cycle.

[0099] Figure 4 is a schematic diagram of PIE encoding. As shown in Figure 4, PIE encoding represents 0 and 1 by the time interval between the falling edges of a pulse. The time interval between the falling edges of "0" and "1" pulses is different. Based on PIE encoding, the high-level duration of data 0 and data 1 can be the same; this embodiment of the application does not limit this.

[0100] Figure 5 is a schematic diagram of FM0 encoding. As shown in Figure 5, FM0 encoding is also known as biphase space encoding. The FM0 encoding rule is that a level switch occurs at the boundary of each bit window. Specifically, bit 0 undergoes a level switch at both the boundary and the middle, while bit 1 undergoes a level switch only at the boundary. That is to say, bit 0 has 3 level switches, and bit 1 has 1 level switch.

[0101] Miller coding, also known as delay modulation coding, is illustrated in Figure 6. Its coding rules are shown in Table 3 below:

[0102] Table 3

[0103] Forward error correction (FEC) codes, by adding redundant error correction codes to the sequence, can automatically correct errors through decoding under certain conditions, thereby reducing the bit error rate of the received signal. FEC codes are divided into two types: block codes and convolutional codes.

[0104] VI. Channels and signals of AIoT systems.

[0105] 1. R2D synchronization signal.

[0106] The R2D synchronization signal can also be called an R2D preamble, or any other name, which is not limited in this application. The R2D synchronization signal can be used by the terminal device to obtain time synchronization and the start time of the R2D physical channel. Typically, the R2D synchronization signal is followed by the R2D physical channel. This application does not limit the other functions of the R2D synchronization signal.

[0107] The R2D synchronization signal consists of two parts: synchronization information and start indication information. The start indication information is used by the terminal device to determine the start time of the R2D physical channel, while the synchronization information is used by the terminal device to obtain time synchronization.

[0108] Figure 7 is a schematic diagram of the R2D synchronization signal. For the start indication pattern, in one possible implementation, the start indication pattern consists of high and low levels, or in other words, the sequence of start indication information consists of a first value and a second value, which are different. For example, the first value is 0 and the second value is 1. Or, for another example, the first value is 1 and the second value is 0. In another possible implementation, as shown in Figure 7, the start indication pattern consists of all low levels, or in other words, the sequence of start indication information consists entirely of either the first value or the second value, where either the first value or the second value is 0.

[0109] 2. R2D physical channel.

[0110] The R2D physical channel can be called PRDCH, or other names, which are not limited to 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 from higher layers.

[0111] 3. D2R synchronization signal.

[0112] The D2R synchronization signal can also be called the D2R preamble, or other names, which are not limited 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.

[0113] 4. D2R physical channel.

[0114] The D2R physical channel may be called PDRCH, or other names, which are not limited to in this application. The D2R 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 from higher layers.

[0115] 5. R2D intermediate guide code.

[0116] 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. The R2D intermediate preamble is used by the terminal device to obtain time synchronization. An example of the R2D intermediate preamble is shown in Figure 8. This application does not limit its name.

[0117] 6. D2R intermediate guide code.

[0118] 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. The D2R intermediate preamble is used by the reader for time synchronization. A D2R intermediate preamble can be shown in Figure 9. This application does not limit its name in its embodiments.

[0119] 7. R2D postcode.

[0120] The R2D postcode follows the R2D physical channel and is used to determine the end time position of the R2D physical channel. The R2D postcode can be as shown in Figure 10. The name of the postcode is not limited in the embodiments of this application.

[0121] 8. D2R postcode.

[0122] The D2R postcode follows the D2R physical channel and is used to determine the end time position of the D2R physical channel. The D2R postcode can be as shown in Figure 11. This application does not limit its name in its embodiments. It should be noted that the intermediate preamble and / or postcode are optional and may not necessarily exist.

[0123] Taking D2R as an example, the approximate time relationship between the D2R preamble, D2R intermediate preamble, and D2R postamble is shown in Figure 12.

[0124] 7. AIoT Transmission Process.

[0125] 1. 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. This means that the terminal device initiates a session only after receiving a signal from the reader / writer. Therefore, AIoT terminals do not actively initiate sessions like traditional terminals (e.g., NR BSR / SR). The process between the reader / writer and the terminal device is shown in Figure 13.

[0126] Step A: The reader sends a trigger message, triggering a response from one or more terminal devices. Step A can also be understood as AIoT paging. Step A may include device ID, device group ID, etc. Step A may also include resource information. Step A may also include the type of random access, which must include at least one of the following: 2-step random access, 3-step (or 4-step) random access, contention-based random access, and non-contention-based random access. Step A may also include other content, which is not limited in this embodiment. Optionally, Step A can be transmitted via PRDCH.

[0127] Step B: The terminal 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 non-contention-based random access.

[0128] Step C: Optionally, considering different application scenarios, in some scenarios, the terminal device will send data or control information to the reader, such as the terminal device ID or higher-level information; or the reader will send data or control information to the terminal device. Step C and Step B may not be distinguished, and part or all of the process in Step C may be included in Step B, that is, the random access process may include the transmission of data / control information. Step C may include one or more interaction processes, which is not limited in this embodiment.

[0129] 2. Random access procedures can be divided into contention-based random access and contention-free random access. Contention-based random access can include at least one of the following types: 2-step random access, 3-step (or 4-step) random access. These will be described in detail below.

[0130] 2.1, 3-step (or 4-step) contention-based random access.

[0131] The random access process is roughly as follows:

[0132] Msg1 (also known as the first random access message): The terminal device sends a random access sequence (also known as a random ID) to the reader. Msg1 can be transmitted via D2Rpreamble or PDRCH.

[0133] Msg2 (also known as the second random access message): After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the terminal device. This response message may contain the random access sequence or other types of acknowledgment information. Msg2 can be transmitted using R2Dpreamble or PRDCH.

[0134] Msg3 (also known as Random Access Third Message): After receiving Msg2, the terminal device can send data (e.g., device ID, higher-level information) or control information to the reader. Msg3 can be transmitted via D2Rpreamble or PDRCH.

[0135] Msg4 (also known as the Random Access Fourth Message) is an optional step where the reader sends information to the terminal device, such as an acknowledgment message. Msg4 can be transmitted using R2D preamble or PRDCH.

[0136] 2.2 Two-step contention-based random access.

[0137] Msg1 (also known as the first random access message): The terminal device sends data (e.g., device ID, higher-level information) or control information to the reader. Msg1 can be transmitted via D2Rpreamble or PDRCH.

[0138] Msg2 (also known as the second random access message): After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the terminal device. This response message may contain the random access sequence or other types of acknowledgment information. Msg2 can be transmitted using R2Dpreamble or PRDCH.

[0139] 2.3 The non-contention-based random access process is roughly as follows:

[0140] (Random Access) First Message (also known as MSG1 or MSG3): The terminal device sends data (e.g., device ID, higher-level information) or control information to the reader. The first message can be transmitted via D2Rpreamble or PDRCH.

[0141] (Random Access) Second Message (also known as MSG2 or MSG4): After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the terminal device. The second message can be transmitted using R2D preamble or PRDCH.

[0142] In contention-based random access methods, multiple terminal devices may transmit MSG1 on the same time-frequency resource, resulting in a collision and causing random access failure. In non-contention-based random access procedures, the reader pre-allocates MSG1 resources, preventing collisions between different terminal devices.

[0143] For AIoT terminals, random access can be implemented using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM). Msg1 and / or Msg3 can be transmitted using TDM, FDM, or CDM, and this application embodiment does not limit this. Specifically, TDM random access means that different terminal devices can initiate random access at different times; FDM random access means that different terminal devices can initiate random access on different frequency resources; and CDM random access means that different terminal devices can initiate random access using different sequences. Terminal devices can also initiate random access using two or three combinations of the above methods, for example, TDM + FDM, and this application embodiment does not limit this.

[0144] 3. For MSG1 of the AIoT system, the content carried by MSG1 shall include at least one of the following:

[0145] A terminal device identifier is used by the reader to distinguish different terminal devices. The terminal device identifier can be a random ID or other forms of ID; this application embodiment does not limit this. The terminal device identifier can be randomly generated by the terminal device, generated according to predefined rules, assigned to the terminal device by the reader, or obtained through other means; this application embodiment does not limit this. The length of the random ID can be 16 bits. If it is another form of ID, the ID length may be longer; this application embodiment does not limit this.

[0146] Energy status is used to indicate the energy status of terminal devices.

[0147] Other high-level information.

[0148] In this embodiment of the application, as described above, the MSG1 of multiple terminal devices can be transmitted using TDM and / or FDM. When the reader triggers X resources (where X is greater than or equal to 1) for MSG1 transmission, the X resources can be TDM, FDM, or a combination of TDM and FDM. The terminal device can randomly select one of the X resources to transmit MSG1, which can be considered as a contention-based random access method (CBRA). Alternatively, the reader allocates specific resources to the terminal device, and the terminal device uses those resources to transmit MSG1, which can be considered as a non-contention-based random access method (CFRA). Step A (also known as a trigger message or AIoT paging message) can indicate the resources for MSG1, including the number of time-domain resources X, the start time / offset of each MSG1 resource, and the length. The resources for MSG1 can also include the number of frequency-domain resources and the location of the frequency-domain resources. The frequency domain resource set of MSG1 can be obtained by the backscatter link frequency (BLF), and / or the line code repetition number or factor, and / or the frequency of the D2R signal, and / or the frequency offset of the D2R signal relative to the CW frequency.

[0149] Figure 14 is a schematic diagram of TDMA, FDMA, and TDMA+FDMA provided in the embodiments of this application. As shown in Figure 14, X is greater than or equal to 1, meaning the reader / writer can trigger one or more MSG1 resources. As shown in Figure 14, R2D is similar to Step A described above. For TDM, a time gap needs to be reserved between temporally adjacent MSG1 resources to address the impact of SFO. This time gap may or may not be included in each MSG1 resource. If it is included in the resource, then each MSG1 resource should include the actual MSG1 transmission resource plus a time gap, and no further time gap needs to be reserved between adjacent resources; if it is not included in the resource, then each MSG1 resource is the actual MSG1 transmission resource, and a time gap is reserved between adjacent resources. For FDM, a guard band also needs to be reserved between frequency-adjacent MSG1 resources.

[0150] In a contention-based random access method, different terminals can randomly select one MSG1 resource to send MSG1.

[0151] 4. For MSG2 in the AIoT system, MSG2 serves as a response message to MSG1, and the content carried by MSG2 must include at least one of the following:

[0152] Terminal device identifier. After receiving MSG2, if the identifier carried in MSG2 matches its own identifier, the terminal device indicates successful access; otherwise, access has failed. Depending on the implementation, MSG2 can carry one or more terminal device identifiers. When an MSG2 carries multiple terminal device identifiers, one of the following methods can be used: Other forms of acknowledgment information, such as ACK or NACK. The terminal device uses this acknowledgment information to determine whether access was successful. Depending on the implementation, MSG2 can carry acknowledgment information for one or more terminal devices.

[0153] MSG3 resource scheduling information. The terminal device sends MSG3 to the reader / writer based on this scheduling information.

[0154] When a reader needs to send MSG2 to multiple terminal devices, it can use one or more of the following methods:

[0155] Method 1: The reader sends an MSG2 to the terminal device to respond to multiple terminal devices. As shown in Figure 15, it is a schematic diagram of the reader sending an MSG2 to the terminal device according to the embodiment of this application.

[0156] When an MSG2 carries multiple terminal identifiers or confirmation information from multiple terminals, as shown in Figure 16, which is a schematic diagram of the MSG2 responding to a terminal device according to an embodiment of this application, it can be done in at least one of the following ways:

[0157] In one possible implementation, each part of MSG2 corresponds to a response from a terminal device.

[0158] In another possible implementation, one part of MSG2 corresponds to the responses of multiple terminal devices. MSG2 can also adopt a combination of the two methods described above, and this application embodiment does not limit this approach.

[0159] Method 2: TDM.

[0160] Figure 17 shows a schematic diagram of MSG2 mode 2 provided in this application embodiment. There are multiple MSG2 resources. The reader sends MSG2 on multiple resources. The multiple resources are in different time units. The terminal device receives its own MSG2 on the corresponding resource.

[0161] Method 3: FDM.

[0162] For some terminal devices, MSG2 can be transmitted using FDM. Figure 18 shows a schematic diagram of MSG2 transmission method 3 provided in this embodiment. There are multiple MSG2 resources; the reader transmits MSG2 on multiple resources, which are located in different frequency domain units. The terminal device receives its own MSG2 on the corresponding resource. This embodiment does not describe method 3 in detail.

[0163] It should be noted that the transmission timing of MSG2 should fall within the range of [TD2R_min, TD2R_max], where TD2R_min represents the minimum time interval between the R2D signal and the previous D2D signal, and TD2R_max represents the maximum time interval between the R2D signal and the previous D2D signal. For the above methods, the protocol needs to specify the resource location of MSG2, including the start time of the terminal device receiving MSG2 and the resource size of MSG2.

[0164] The start time of MSG2 shall be determined using at least one of the following methods:

[0165] For method 1, different terminal devices begin receiving MSG2 at the same time unit.

[0166] For method 2, one MSG2 corresponds to one terminal device. Different MSG2s have different start times, and different terminal devices start receiving MSG2s at different time units; or, different terminal devices start receiving MSG2s at the same time unit, for example, these MSG2s are within a time window, and the terminal device receives MSG2s within that time window.

[0167] The reference point for the start time of MSG2 can be determined in several ways:

[0168] This reference point is the end time unit of the terminal device's own MSG1;

[0169] In MSG1 TDM mode, the reference point is the end time unit of the last resource among X MSG1 resources;

[0170] This reference point is the end time unit of Step A;

[0171] This reference point is the end time unit of other MSG2 resources, such as the end time unit of the previous MSG2 resource.

[0172] For example, Figure 19 is a schematic diagram with the end time unit of Step A as a reference point provided in an embodiment of this application.

[0173] The duration of MSG2 resources shall be determined using at least one of the following methods:

[0174] Predefined rules, for example, determined by TD2R_min and / or TD2R_max;

[0175] Instructions are sent to the terminal device via Step A.

[0176] 5. MSG3 for AIoT systems.

[0177] MSG3 carries at least one of the following:

[0178] The terminal device identifier in MSG3 differs from that in MSG1. The terminal device identifier in MSG1 can be a temporary ID, while the terminal device identifier in MSG3 can be a permanent or long-term ID. The lengths of the terminal device identifiers in MSG1 and MSG3 also differ.

[0179] Energy status is used to indicate the energy status of terminal devices.

[0180] Other high-level information.

[0181] It should be noted that, similar to MSG1, MSG3 can also be transmitted using TDM and / or FDM. MSG3 resources can be obtained explicitly and / or implicitly, including:

[0182] MSG3 has the same resources or resource indexes as MSG1;

[0183] MSG3 has the same frequency domain resources or resource index as MSG1, while the time domain resources are indicated by MSG2.

[0184] The time-domain resources or resource index of MSG3 are the same as those of MSG1, while the frequency-domain resources are indicated by MSG2.

[0185] The time-domain and frequency-domain resources of MSG3 are indicated by MSG2.

[0186] The communication method provided in the embodiments of this application will be described below. First, Figure 20 is a schematic diagram of the communication system provided in the embodiments of this application.

[0187] As shown in Figure 20, the communication system includes a reader / writer and a terminal device.

[0188] In this embodiment of the application, the terminal device is used to send D2R signals based on a first configuration. The reader / writer is used to receive the D2R signals from the terminal device and send R2D signals.

[0189] The D2R signal includes a first random access message and / or a third random access message; the first configuration includes one or more of the following: the level of the terminal device, including coverage level and / or access level; the configuration of the first time unit, wherein the terminal device transmits or does not transmit a signal within the first time unit; the configuration of the D2R signal type; the configuration of the frame structure of the D2R signal for uplink synchronization; the configuration of the number of repetitions of the D2R signal and the time-frequency resources used for repetition; the configuration of the random offset corresponding to the D2R signal; the configuration of the retransmission time of the D2R signal; or, the configuration of the time extension line for the terminal device to transmit the third random access message.

[0190] The R2D signal includes a random access second message.

[0191] The functions of the reader and terminal device involved in the embodiments of this application can be implemented by the communication device 2100 in FIG21. FIG21 is a schematic diagram of the structure of the communication device 2100 provided in the embodiments of this application. The communication device 2100 includes one or more processors 2101, communication lines 2102, and at least one communication interface (FIG21 is only an example illustrating the inclusion of a communication interface 2104 and a processor 2101), and optionally may also include a memory 2103.

[0192] The processor 2101 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application.

[0193] The communication line 2102 may include a path for connecting different components.

[0194] The communication interface 2104 can be a transceiver module used to communicate with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (WLAN), etc. For example, the transceiver module can be a transceiver or a similar device. Optionally, the communication interface 2104 can also be a transceiver circuit located within the processor 2101, used to implement the processor's signal input and signal output.

[0195] The memory 2103 can be a device with storage function. For example, it can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions; random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions; it can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices; or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory can exist independently and be connected to the processor via communication line 2102. The memory can also be integrated with the processor.

[0196] The memory 2103 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 2101. The processor 2101 executes the computer execution instructions stored in the memory 2103, thereby implementing the communication method provided in the embodiments of this application.

[0197] Alternatively, in this embodiment, the processor 2101 may execute the processing-related functions of the communication method provided in the following embodiments of this application, and the communication interface 2104 may be responsible for communicating with other devices or communication networks. This embodiment does not specifically limit this.

[0198] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0199] In a specific implementation, as one example, processor 2101 may include one or more CPUs, such as CPU0 and CPU1 in FIG21.

[0200] In a specific implementation, as one embodiment, the communication device 2100 may include multiple processors, such as processors 2107 and 2101 in FIG. 21. Each of these processors may be a single-core processor or a multi-core processor. The processors here may include, but are not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, etc., and various computing devices that run software. Each computing device may include one or more cores for executing software instructions to perform calculations or processing.

[0201] In a specific implementation, as one embodiment, the communication device 2100 may further include an output device 2105 and an input device 2106. The output device 2105 communicates with the processor 2101 and can display information in various ways. For example, the output device 2105 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 2106 communicates with the processor 2101 and can receive user input in various ways. For example, the input device 2106 may be a mouse, keyboard, touchscreen device, or sensing device, etc.

[0202] The aforementioned communication device 2100 may sometimes be referred to as a communication device, which can be a general-purpose device or a special-purpose device. For example, the communication device 2100 may be a desktop computer, a portable computer, a web server, a handheld computer (personal digital assistant, PDA), a mobile phone, a tablet computer, a wireless AIoT device, an embedded device, or a device with a similar structure to that in Figure 21. The embodiments of this application do not limit the type of communication device 2100.

[0203] Furthermore, the composition shown in Figure 21 does not constitute a limitation on the communication device. In addition to the components shown in Figure 21, the communication device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0204] It should be noted that in the following embodiments of this application, the message names, parameter names, or information names between network elements are just examples. Other names may also be used in other embodiments. The communication method provided in this application does not specifically limit these names.

[0205] It is understood that in the embodiments of this application, each network element can execute some or all of the steps in the embodiments of this application. These steps or operations are merely examples, and the embodiments of this application can also perform other operations or variations of various operations. Furthermore, the steps can be executed in different orders as presented in the embodiments of this application, and it is not necessary to execute all the operations in the embodiments of this application.

[0206] The communication method provided in the embodiments of this application will be described below with reference to Figures 22 to 34.

[0207] It should be noted that the embodiments of this application can be applied not only to AIoT devices, but also to other similar low-power devices, which will be collectively referred to as terminal devices below.

[0208] Figure 22 is a schematic diagram of an example of the communication method provided in this application embodiment. This method can be applied to the communication system shown in Figure 20, and is illustrated using the interaction between a reader and a terminal device as an example. Of course, the entity executing the reader's actions in this method can also be a device / module within the reader, such as a chip, processor, or processing unit within the reader; similarly, the entity executing the terminal device's actions in this method can also be a device / module within the terminal device, such as a chip, processor, or processing unit within the terminal device. This application embodiment does not specifically limit this. In this application embodiment, a single executing entity (e.g., the processing performed by the reader or terminal device) can also be divided into multiple executing entities, which can be logically and / or physically separated. For example, as shown in Figure 22, method 2200 includes the following steps:

[0209] S2210, based on the first configuration, the terminal device sends a D2R signal to the reader / writer. Correspondingly, the reader / writer receives the D2R signal from the terminal device.

[0210] In this embodiment of the application, the D2R signal includes a first random access message and / or a third random access message.

[0211] In this embodiment of the application, the first random access message may also be MSG1 or MSGA as described in the above-mentioned related technologies, or it may be other names. This embodiment of the application does not limit this.

[0212] In this embodiment, the random access third message can also be MSG3 as described in the above-mentioned related technologies, or it can be other names. This embodiment does not limit this.

[0213] In this embodiment of the application, the first configuration includes one or more of the following:

[0214] The level of the terminal device, wherein the level includes coverage level and / or access level.

[0215] The configuration of the first time unit, wherein the terminal device may or may not send a signal within the first time unit.

[0216] Configuration of D2R signal type.

[0217] Configure the frame structure of the D2R signal for uplink synchronization.

[0218] Configuration of the random offset corresponding to the D2R signal.

[0219] Configuration of retransmission time for D2R signals.

[0220] Alternatively, the configuration of the time extension line for the terminal device to send random access third messages.

[0221] The following sections will provide a detailed introduction.

[0222] In this embodiment of the application, the coverage level of the terminal device includes:

[0223] 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.

[0224] Coverage level B is defined as an area where the D2R signal strength is less than or equal to a first threshold and greater than or equal to a second threshold. In this embodiment, coverage level B is lower than coverage level A. Coverage level B can be an area where the D2R signal is weak but still sufficient to ensure the normal completion of basic inventory, control, and positioning services (e.g., in an indoor scenario, the coverage range of coverage level B is 10-20m). Alternatively, coverage level B can be an area where the D2R signal strength is less than the first threshold and greater than the second threshold.

[0225] Coverage level C is defined as an area where the D2R signal strength is less than a second threshold. In this embodiment, coverage level C is lower than coverage level B, representing the area with the lowest coverage level. Coverage level C can be used in scenarios where the D2R signal is very weak, where only control services and / or inventory services are performed, and the data rate is the lowest (e.g., 1 Kbps). Alternatively, coverage level C can be defined as an area where the D2R signal strength is less than or equal to the second threshold.

[0226] It should be noted that the above-mentioned coverage level classification is not unique and may include more coverage levels. This application embodiment does not limit this.

[0227] In the embodiments of the present application, the access levels of the terminal device include:

[0228] Access level A, where access level A is an area where the access success rate is greater than the third threshold. For example, access level A can be a level where the reader can select and activate N% (N = 1 to 100) of the terminal devices within the coverage area when sending an AIoT paging message. At this access level, it is ensured that the terminal device can correctly send the D2R signal based on the R2D signal or external CW to complete operations such as inventory, positioning, and control. Or, access level A is an area where the access success rate is greater than or equal to the third threshold.

[0229] Access level B, where access level B is an 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, under access level B, there may be problems such as missed detections and misdetections due to insufficient power or weak signals of the terminal device. Access level B can be a level where the reader can select and activate M% (for example, M = 1 to 100, and M < N) of the terminal devices within the coverage area when sending an AIoT paging message. At this level, it is ensured that the terminal device can basically correctly send the D2R signal based on the R2D signal or external CW. Or, access level B is an area where the access success rate is less than the third threshold and greater than the fourth threshold.

[0230] Access level C, where access level C is an area where the access success rate is less than the fourth threshold. For example, under access level C, there are often problems such as missed detections and misdetections due to insufficient power or weak signals of the terminal device. Access level C can be a level where the reader can select and activate T% (for example, M = 1 to 100, and T < M) of the terminal devices within the coverage area when sending an AIoT paging message. At this level, the terminal device 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.

[0231] It should be noted that the above division of coverage levels is not unique and may include more coverage levels, which are not limited in the embodiments of the present application.

[0232] In the embodiments of the present application, for terminal devices of the same type with different capabilities, or for terminal devices of different types, their coverage levels, and / or, access levels can be different.

[0233] In the embodiments of the present application, different coverage levels, and / or, access levels can be configured for the same type of terminal device. The different coverage levels, and / or, access levels of the same type of terminal device are determined according to one or more of the following: the capabilities of the terminal device, the distance between the reader and the terminal device, the number of at least one terminal device to be inventoried, or the number of at least one terminal device successfully accessed in the previous inventory.

[0234] For example, for device 1: the capabilities of the terminal device include one or more of the following: frequency offset error range, time offset error range, ability to correct frequency deviation or time offset, energy storage capacity, or remaining power. For instance, the reader can determine the coverage level and / or access level of the terminal device based on its frequency offset error range, ability to correct frequency deviation or time offset, energy storage capacity, and remaining power. Alternatively, in one possible implementation, the reader can determine the coverage level and / or access level of the terminal 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 terminal device is determined by the total number of terminal devices to be inventoried and / or the number of terminal devices successfully accessed in the previous inventory round.

[0235] For example, for device 2a: the capabilities of the terminal 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. The signal amplification capability includes the amplification capability of R2D and D2R signals. For example, the reader can determine its coverage level and / or access level based on the terminal device's 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 terminal device's coverage level and / or access level based on the path loss measurement results of the D2R signal. Or, in another possible implementation, the terminal device's coverage level and / or access level is determined by the total number of terminal devices to be inventoried and / or the number of terminal devices successfully accessed in the previous inventory round.

[0236] For example, for device 2b: the capabilities of the terminal 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, the reader can determine its coverage level and / or access level based on the terminal device's 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 terminal device's coverage level and / or access level based on the path loss measurement results of the D2R signal. Or, in another possible implementation, the terminal device's coverage level and / or access level is determined by the total number of terminal devices to be inventoried and / or the number of terminal devices successfully accessed in the previous inventory round.

[0237] In one possible implementation of this application, the coverage level and / or access level of the terminal device are predefined.

[0238] In another possible implementation of this application embodiment, the coverage level and / or access level configuration of the terminal device is indicated by indication information.

[0239] For example, the coverage level and / or access level configuration of a terminal device can be indicated via AIoT paging messages or other signaling, which can be considered a display indication method. Optionally, the indication information indicating the coverage level and / or access level configuration of the terminal device can be carried in the control and / or data sections of the PRDCH. For example, this indication information can be 1-bit 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 situations may exist, which are not limited in this embodiment.

[0240] For example, indications can be given through predefined rules, which can be considered implicit indications. For instance, the terminal device ID / group ID can be carried in the AIoT paging message, where terminal device (group) ID 1 corresponds to coverage level A and / or access level A; terminal device (group) ID 2 corresponds to coverage level and / or access level B; and terminal device (group) ID 3 corresponds to coverage level and / or access level C. Alternatively, the terminal device can determine the coverage level and / or access level based on the indicated TBS size; or, the terminal device can determine 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 Xbit 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.

[0241] It should be noted that for terminal devices that have not yet been inventoried, when the terminal 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 to facilitate the reader configuration and ensure successful access to resources. For example, the default coverage level can be C, and / or access level can be C.

[0242] In this embodiment, different coverage levels and / or access levels can be configured for different types of terminal devices. The coverage level and / or access level of different types of terminal devices are determined based on one or more of the following: the capabilities of the terminal device, the distance between the reader and the terminal device, the number of at least one terminal device to be inventoried, or the number of at least one terminal device that successfully accessed the system in the previous inventory round.

[0243] In one possible implementation, the coverage level and / or access level ranges for different types of terminal 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.

[0244] Alternatively, in another possible implementation, a default level can be specified for different types of terminal 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 changes with the scenario. This is just one example, and the embodiments of this application do not limit it.

[0245] 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.

[0246] In this scheme, by configuring different levels, the efficiency of the resources indicated by the reader to the D2R signal can be improved, and the efficiency and reliability of inventory counting can be guaranteed while improving resource utilization.

[0247] In this embodiment of the application, the configuration of the first time unit includes one or more of the following: the position of the first time unit, the period of the first time unit, or the duration of the first time unit.

[0248] The first time unit is determined based on one or more of the following: coverage level, access level, type of terminal device, type of reader (e.g., the reader is an access network device, or the reader is a UE, etc.), type of signal corresponding to the period of the first time unit (e.g., random access first message, or random access third message, or other D2R signals, etc.), or random access type (e.g., three-step random access, or two-step random access).

[0249] In this embodiment, the first time unit may also be called a silent unit, or other names, and this embodiment does not limit this.

[0250] It should be noted that the first time unit means that the terminal device does not send D2R signals within this time unit. Correspondingly, the reader performs cross-link interference estimation, self-interference estimation, channel estimation, and non-ideal factor (SFO / CFO) estimation within this time unit.

[0251] It should be noted that since CW transmission can cause self-interference or cross-link interference, a first time unit needs to be configured. This first time unit is used to perform interference channel estimation before the reader receives the D2R signal, so that the estimation result can be used to eliminate self-interference or cross-link interference when receiving the D2R signal.

[0252] Optionally, the embodiments of this application can be applied to the following two scenarios: the CW node is not controlled by the network and always sends CW signals; after the R2D transmission is completed, CW is sent.

[0253] Figure 23 is a schematic diagram of the location of the first time unit. As shown in Figure 23, in one possible implementation, interference estimation or channel estimation can be performed before D2R signal reception. In another possible implementation, interference estimation or channel estimation can be performed during D2R signal reception.

[0254] For cases where interference estimation or channel estimation is performed before D2R signal reception:

[0255] In this embodiment, the first time unit is located after the reader sends a first signal, which includes a paging message and / or a randomly accessed second message. For example, the first time unit can be located at position 1 in Figure 23, i.e., during the window between the sending of the paging message and / or the randomly accessed second message and the reception of the D2R signal. Alternatively, in other words, the first time unit can be located after the terminal device receives the first signal and before it sends the D2R signal.

[0256] In this embodiment of the application, the duration of the first time unit begins with the first or last time unit in which the reader sends the first signal and ends when the terminal device receives the first D2R signal.

[0257] In this embodiment, the period of the first time unit is one inventory count or one control operation. That is, in one inventory count or one control operation, there is only one silence period after the first signal is sent.

[0258] It should be noted that before receiving D2R signals, the reader performs interference estimation or channel estimation between the CW node and the reader, which may be an implementation behavior of the reader.

[0259] For cases where interference estimation or channel estimation is performed during D2R signal reception:

[0260] In this embodiment of the application, the position of the first time unit is located at the beginning position of the preamble of the D2R signal (position 2 in Figure 23), and / or, the position of the first time unit is located at at least one intermediate preamble of the D2R signal (position 3 in Figure 23), and / or, the position of the first time unit is located at the first uplink channel PDRCH of the D2R signal. This embodiment of the application does not limit this.

[0261] It should be noted that, for different modulation methods, the position of the first time unit may vary as follows:

[0262] For example, in OOK modulation, the terminal device can transmit bit 0, encoded using a radio code. That is, a preamble of 0, or an intermolecular code, etc. It should be noted that, for OOK modulation, the terminal device transmits a D2R signal of bit 0, but no D2R signal is transmitted over the air interface.

[0263] For example, with BPSK modulation, the terminal device can remain silent within the first time unit. For instance, for a terminal device of type 1, it is only in the OFF state; for a terminal device of type 2a / 2b, it is in the OFF or Sleep state.

[0264] In one possible implementation of this application embodiment, the period of the first time unit is one inventory count, or it is statically configured in one control.

[0265] For example, during the same inventory / control process, the terminal device can send D2R signals in multiple time units. Specifically, at multiple preamble positions 2 during the first D2R signal transmission (e.g., random access to the first message, or random access to the third message), silence can be maintained, allowing the reader to perform interference estimation or channel estimation at these silenced positions. For instance, the terminal device can silence at all preamble positions 2 during the first D2R signal transmission. Alternatively, the terminal device can silence at the odd number of preamble positions 2 during the first D2R signal transmission. Furthermore, the terminal device can silence at the even number of preamble positions 2 during the first D2R signal transmission; this embodiment of the application does not limit this approach.

[0266] For example, during the same inventory / control process, the terminal device sends a D2R signal within one time unit. During this same inventory / control process, the start position of the first Preamble of the D2R signal is silent. For instance, the start position of the first Preamble of the first D2R signal can be silent; this embodiment of the application does not limit this.

[0267] In another possible implementation of this application embodiment, the period of the first time unit is one inventory count, or it is statically configured in one control.

[0268] For example, during the same inventory / control process, the terminal device can send D2R signals in multiple time units. For instance, positions 2 of multiple preambles may be silent during each D2R signal transmission in each inventory / control service (e.g., random access to the first message, and / or random access to the third message). Another example is that the first preamble and multiple midambles (position 3) may be silent in each transmitted D2R signal. Yet another example is that multiple midambles (position 3) may be silent in each transmitted D2R signal. It should be noted that the multiple midambles can be midambles of D2R signals transmitted by the same terminal device, or midambles of D2R signals transmitted by different terminal devices; this application embodiment does not limit this.

[0269] For example, during the same inventory / control process, the terminal device sends a D2R signal in one time unit. Specifically, during each D2R signal transmission in the inventory / control service (e.g., random access to the first message, and / or random access to the third message), Preamble position 2 and one or more Midamble positions 3 are silent.

[0270] It should be noted that, for the case of OOK modulation without encoding, a silent preamble and / or intermediate preamble can be implemented by defining a binary sequence / M sequence / 0-1 sequence in which the modulation bit is all 0 during the silent period.

[0271] In one possible implementation, the duration of the first time unit is predefined. For example, the duration of the first time unit is three consecutive time units. This time unit can be an OFDM symbol, a chip, or other time units. This application does not limit this.

[0272] In another possible implementation, the duration of the first time unit is indicated by the indication information.

[0273] For example, the indication information can be a D2RTBS indication. For example, the indication information can be an MCS-like indication. For example, the indication information can be an indication of the M value, where the M value can be calculated based on coverage level, access level, etc. For example, when TBS is 500 bits, the duration of the first time unit is 5 time units, and the period of the first time unit is semi-statically configured. For another example, when TBS is 100 bits, the duration of the first time unit is 3 time units, and the period of the first time unit is statically configured. For yet another example, when M is 32, the duration of the first time unit is 8 time units; when M is 6, the duration of the first time unit is 3 time units.

[0274] For example, the indication information can be an AIoT paging message or an R2D signal. If the duration of the first time unit is non-uniform (e.g., the first time unit has a duration of 5 time units, the second time unit has a duration of 3 time units, and the third time unit has a duration of 5 time units; or, for example, the duration of the first time unit of a randomly accessed first message is 5 time units, the duration of the first time unit of a randomly accessed third message is 3 time units, etc.), the duration of the first time unit can be indicated by an AIoT paging message, an R2D signal, or other indication information. This application embodiment does not limit this.

[0275] It should be noted that the length of the first time unit is less than or equal to the length of the intermediate preamble of the D2R signal, or the length of the first time unit is less than or equal to the length of the preamble of the D2R signal. If the duration of the first time unit is configured as a set, the length of the intermediate preamble or the preamble of the D2R signal must be greater than or equal to the maximum length of the first time unit.

[0276] It should be noted that, in the embodiments of this application, the configuration of the first time unit can be used for the reader to perform interference estimation, or it can be used to estimate the SFO or CFO between readers and terminal devices.

[0277] It should be noted that the first time unit described above can be a time unit in which the terminal device does not send D2R signals. In another implementation, the first time unit can also be configured as a time unit in which the terminal device sends D2R signals, i.e., the preamble and / or intermediate preamble of the D2R signal are not silent, used for interference estimation, channel estimation, or estimation of non-ideal factors. Its configuration duration and period are similar to those described above and will not be repeated here. The differences are: 1. The non-silent duration used for channel estimation and interference estimation can be continuous or non-continuous N time units (N is greater than or equal to 1) or a combination of sequences such as +1+1+1, +1-1+1, or -1-1-1. It should be noted that the length of the sequence is not limited in this application embodiment. 2. Position 1 is not applicable to non-silent methods for interference estimation, channel estimation, and measurement mechanisms. 3. For position 2, it is not necessarily located at the beginning of the preamble, but can also be located in the middle or end of the preamble.

[0278] In this embodiment, the D2R signal types include: Type 1: The D2R signal includes a first random access message; Type 2: The D2R signal includes a first random access message and a third random access message. Alternatively, in other words, the type of D2R signal is related to the random access method described in the aforementioned related technologies, the difference being whether or not a third random access message is sent.

[0279] In this embodiment of the application, the frame structure types of the D2R signal include:

[0280] Type 1: The frame structure of a D2R signal includes a D2R preamble; Type 2: The frame structure of a D2R signal includes a D2R preamble and at least one intermediate preamble; Type 3: The frame structure of a D2R signal includes a D2R preamble and a postamble; Type 4: The frame structure of a D2R signal includes a D2R preamble, at least one intermediate preamble, and a postamble.

[0281] For D2R signal type one:

[0282] In this embodiment of the application, the random access first message may include one or more of the following: a 16-bit random number RN16, data, a non-data signal, or energy state indication information. The size of the energy state indication information can be X bits, where X is a positive integer greater than or equal to 1.

[0283] Optionally, the data may include sensing data, or one or more of the terminal device IDs, which will be uniformly explained here and will not be repeated below.

[0284] In this embodiment, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information. This indication information can be an AIoT paging message, or it can be other R2D signaling; this embodiment does not limit the specific indication information.

[0285] In one possible implementation, the reader can instruct the terminal device to send a random access first message via an AIoT paging message or other R2D signaling. The random access first message carries only RN 16 / non-data signal / Xbit energy state information and indicates that the frame structure type of the D2R signal is type one or type three.

[0286] In another possible implementation, the reader can instruct the terminal device to send a random access first message via an AIoT paging message or other R2D signaling. The random access first message carries RN 16+ data and indicates that the frame structure type of the D2R signal is a frame structure carrying Midamble and / or Postamble (e.g., type two, type three, or type four). The value of the number of intermediate preambles is related to the size of TBS, the indication of MCS-like, the M value, etc., and this application embodiment does not limit this.

[0287] For example, when the size of TBS decreases and the rate of MCS-like operations decreases (the level decreases), the number of intermediate precodes also decreases accordingly.

[0288] For type two of D2R signals:

[0289] In this embodiment of the application, the correspondence between the information included in the random access first message and the frame structure type of the D2R signal can be indicated by the indication information. Optionally, the indication information can be an AIoT paging message or other R2D signaling. This embodiment of the application does not limit this.

[0290] In this embodiment of the application, the correspondence between the information included in the random access third message and the frame structure type of the D2R signal can be indicated by the indication information. Optionally, the indication information can be the random access second message, or other R2D signaling. This embodiment of the application does not limit this.

[0291] In one possible implementation, the first random access message includes RN16, and the third random access message includes data.

[0292] Optionally, the frame structure type of the first random access message is type one, and the frame structure type of the third random access message is type two, type three, or type four.

[0293] Optionally, the frame structure type of the first random access message is type two or type four, and the frame structure type of the third random access message is type one or type three. That is, the reader can obtain interference estimation, channel estimation, and SFO or CFO estimation by receiving the D2R preamble or intermediate preamble of the first random access message, without needing to perform further estimation based on the third random access message. The intermediate preamble or postamble of the third random access message can be omitted.

[0294] Optionally, the frame structure type of the first random access message is type one or type three, and the frame structure type of the third random access message is type two or type four. That is, the third random access message carries longer data, so it needs to carry intermediate preambles or post-preambles to obtain interference estimation, channel estimation, and SFO or CFO estimation.

[0295] In another possible implementation, the first random access message includes RN16 and data, and the third random access message includes data.

[0296] Optionally, the frame structure type of the first random access message is type two, type three, or type four, and the frame structure type of the third random access message is type two, type three, or type four.

[0297] Optionally, the frame structure type of the first random access message is type two or type four, and the frame structure type of the third random access message is type one or type three. The advantages of using this type can be found in the above description, and will not be repeated here.

[0298] Optionally, the frame structure type of the first random access message can be type one or type three, and the frame structure type of the third random access message can be type two or type four. That is, the third random access message carries longer data, so it needs to carry intermediate preambles or post-preambles to obtain interference estimation, channel estimation, and SFO or CFO estimation.

[0299] In this embodiment of the application, if multiple terminal devices in the AIoT system send a first random access message and / or a third random access message, the following situations may occur:

[0300] In one possible implementation, during the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is the same, and / or, the frame structure type of the third random access message sent by multiple terminal devices is the same.

[0301] In another possible implementation, during the same inventory count, the frame structure types of the first random access message sent by multiple terminal devices are different, and / or, the frame structure types of the third random access message sent by multiple terminal devices are different.

[0302] Optionally, during the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is determined according to predefined rules, and / or, the frame structure type of the third random access message sent by multiple terminal devices is determined according to predefined rules.

[0303] For example, the first random access message sent in the first time unit uses a frame structure with Midamble / Postamble, while the first random access messages sent in other time units do not have a Midamble / Postamble frame structure. Another example is multiple first random access messages during an inventory count: #1(Preamble+PDRCH+Midamble+PDRCH)+#2(PDRCH)+#3(Midamble+PDRCH)+#4(PDRCH+Postamble). Yet another example is that the first random access message sent in specific time units (e.g., the 1st, Nth, and Mth time units) uses a specific frame structure (e.g., with Midamble / Postamble), while the first random access messages sent in other time units use a frame structure (e.g., without Midamble / Postamble), where N and M are distinct positive integers.

[0304] Optionally, during the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is indicated by indication information, and / or, the frame structure type of the third random access message sent by multiple terminal devices is indicated by indication information.

[0305] One possible implementation is to use explicit indication. For example, this can be indicated through L1 control information (time-frequency resources, Midamble-related information) or higher-layer control information in the PRDCH. Alternatively, it can be indicated through additional indication information, such as: 3 bits of indication information, where the first bit indicates whether the random access first message carries data; the second bit indicates the frame structure type of the random access first message (if it does not carry data, it is limited to frame structure type one or frame structure type three; if it carries data, the frame structure type is any one of type one, type two, type three, or type four, depending on the implementation of the terminal device); and the third bit indicates the frame structure type of the random access third message (for example, 1 bit indicates whether it carries Midamble, and if it does, it selects frame structure type two or frame structure type four, depending on the implementation of the terminal device).

[0306] In another possible implementation, an implicit indication method can be used. For example, the indication can be made through the TBS of the AIoT paging message / random access second message. For instance, when the terminal device detects that the TBS of the PRDCH of the AIoT paging message / random access second message is N, the terminal device sends the frame structure type three of the random access first message to select the D2R signal and the frame structure type one of the random access third message to select the D2R signal.

[0307] It should be noted that a Cyclic Redundancy Check (CRC) can be added to the D2R signal according to the frame structure type of the D2R signal. The CRC length includes CRC-6 and CRC-16.

[0308] In one possible implementation, when the frame structure of the D2R signal does not contain a D2D Midamble and / or Postamble, a CRC is added to the control information and / or data information of the PDRCH, and its length is determined by the length of the control information or data information. Optionally, a CRC can be added to both the control information and the data information. Optionally, a CRC can be added to the data information but not to the control information; this application does not limit this approach.

[0309] In another possible implementation, the frame structure of the D2R signal includes a D2D Midamble and / or Postamble. However, when the length of the D2D Midamble and / or Postamble is short, a CRC is added to the control information and / or data information of the PDRCH, and its length is determined by the length of the control information or data information. Optionally, a CRC can be added to both the control information and the data information. Optionally, a CRC can be added to the data information but not to the control information; this application does not limit this approach.

[0310] In another possible implementation, when sending N bits of energy state, the energy state can be carried in the PDRCH as either control information or data information. A CRC is added to the control information and / or data information of the PDRCH, and its length is determined by the length of the control information or data information. Optionally, a CRC can be added to both the control information and the data information; alternatively, a CRC can be added to the data information but not the control information. This application does not limit this approach.

[0311] In this embodiment of the application, as shown in Figure 24, it is a schematic diagram of the reader receiving multiple D2R signals in one round of inventory counting. Considering that R2D may schedule resources from multiple random access first messages or random access third messages for random access during the same round of inventory counting, and these resources may be continuous time-domain or frequency-domain resources, or discrete time-domain or frequency-domain resources. During the same round of inventory counting, when the reader receives multiple random access first messages or random access third messages, optionally, the reader can perform autocorrelation on the Preamble / Midamble in some random access first messages or random access third messages, thereby achieving uplink synchronization or estimating the corresponding SFO / CFO.

[0312] In one possible implementation of this application, the configuration of the frame structure of the D2R signal for uplink synchronization can be indicated by indication information.

[0313] In one possible implementation, the indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a random access first message and / or a random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble, wherein the frame structure of all random access first messages includes the first preamble, and the frame structure of all random access third messages includes the first preamble.

[0314] For example, the reader instructs all random access first messages or random access third messages to transmit RN16 or data using frame structures such as Preamble and / or Midamble and / or Postamble. The reader performs correlation by receiving Preamble and / or Midamble and / or Postamble to achieve resource-level synchronization based on random access first messages or random access third messages.

[0315] It should be noted that this scheme can be used in scenarios where both the first random access message and the third random access message carry data information. In order to ensure transmission reliability, all first random access messages and third random access messages adopt frame structures such as Preamble and / or Midamble and / or Postamble.

[0316] For example, random access first message or random access third message #1 has a preamble, but other random access first messages or random access third messages may not have a preamble configured. If no preamble is configured, synchronization / correction is performed through midamble. If both preamble and midamble are configured, the autocorrelation sequence for synchronization / correction depends on the implementation of the access network equipment.

[0317] In another possible implementation, the indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a first random access first message and / or a first random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble, wherein the frame structure of N first random access first messages in all random access first messages includes the first preamble, and the frame structure of M first random access third messages in all random access third messages includes the first preamble, where N is less than or equal to the number of all random access first messages, and M is less than or equal to the number of all random access third messages.

[0318] For example, the reader can instruct that, based on the frame structure of the configured random access first message or random access third message (e.g., all random access first messages or random access third messages adopt a type two Preamble+Midamble frame structure), other parts of the random access first message or random access third message #1 only transmit RN 16 or data, without sending the Preamble / Midamble sequence. This scheme can save resource overhead and power consumption on both the terminal device side and the reader side.

[0319] For example, as shown in Figure 24, the reader receives the signals of the first random access first message or the third random access third message from different BLFs (both carrying Preamble and Midamble sequences) and performs correlation. The remaining random access first messages or random access third messages are sparsely correlated (i.e., they do not carry Preamble and Midamble sequences and are not synchronized / corrected). Specifically, the second random access first message or random access third message is correlated with BLF1 and BLF3 for synchronization / correction; the third random access first message or random access third message is correlated with BLF2 and BLF3 for synchronization / correction; and the fourth random access first message or random access third message is correlated with BLF1 for synchronization / correction.

[0320] The time-frequency position of the first preamble is related to one or more of the following factors:

[0321] Does the first random access message include data? For example, all first random access messages carrying data are synchronized / corrected, but synchronization and correction are only performed between first random access messages with RN 16.

[0322] The number of resources configured for the first and / or third random access messages in the reader / writer configuration. For example, when the number of configured resources is small, such as <3 first random access messages, only the first random access message is considered for time-frequency synchronization / correction.

[0323] The size of the TBS for the first and / or third random access messages. For example, when the TBS for each first and / or third random access message is >500 bits, then each first and / or third random access message undergoes time-frequency synchronization / correction.

[0324] The frame structure type of the D2R signal. That is, whether it contains a Midamble. If it does not contain a Midamble, then Preamble synchronization / correction is considered, or the first random access message and / or the third random access message are not synchronized / corrected.

[0325] In another possible implementation, the density of the sequence corresponding to the frame structure of the D2R signal can be used for uplink synchronization. Or, in other words, the first sequence in the frame structure of the D2R signal can be used for uplink synchronization.

[0326] It should be noted that the first sequence can be a sequence in the same random access first message or random access third message, or it can be a sequence in different random access first messages or random access third messages. This application embodiment does not limit this.

[0327] It should be noted that a sparse sequence refers to a sequence used for channel estimation and SFO / CFO correction that is sparse within a preamble of fixed time length. In this scheme, the intervals between different sequence units are relatively large, which can reduce the complexity of correlation for the reader and the overhead of the terminal device sending synchronization sequences. For a midamble sparse sequence, it means that sparse synchronization sequences are inserted between PDRCH channels to maintain coarse synchronization during D2R signal transmission. Similarly, the definition of a compact sequence can be referenced from that of a sparse sequence. Compact sequences can maintain higher-precision synchronization and are suitable for data transmission scenarios.

[0328] Optionally, the first sequence can be a sparse sequence, which can be used for coarse synchronization or correction. Figure 25 is a schematic diagram of the first sequence being a sparse sequence. As shown in Figure 25, the Preamble sequence is a sparse sequence. When there is a Midamble (if any), the gap between Midambles is also relatively large, and the gap is related to the TBS size of the PDRCH.

[0329] It should be noted that the Preamble and Midamble in Figure 25 can be the same Msg 1 or Msg 3, or they can be different Msg 1 / 3. For example, the Preamble is Msg 1#1, and the Midamble is Msg 1#3.

[0330] In one possible implementation, when a synchronization sequence is inserted into the Preamble, the synchronization sequence is sent at a fixed time interval at any position in the Preamble. As shown in Figure 26, the PDRCH carries data, and the synchronization sequence is sent at the end of the Preamble, which facilitates the reader and device to maintain synchronization and correctly receive the data information carried by the PDRCH.

[0331] Optionally, the first sequence can be a compact sequence, which can be used for fine synchronization or correction. Figure 27 is a schematic diagram of the first sequence being a compact sequence. As shown in Figure 27, the Preamble sequence is a compact sequence, and when there is a Midamble (if any), the gap between Midambles is also relatively small, and the gap is related to the TBS size of the PDRCH.

[0332] Alternatively, the first sequence may be a sequence that is dense first and then sparse, or the first sequence may be a sequence that is sparse first and then dense. This application does not limit this.

[0333] In this embodiment, the position and / or interval of the first sequence are determined based on the number of resources of the D2R signal.

[0334] For example, during a round of inventory, when the number of resources for the first random access message is greater than 100, consider that the first random access message {1, 21, 41, 61, 81} adopts a compact sequence, with the compact sequence located at the Preamble and Midamble; consider that the first random access message {11, 31, 51, 71, 91} adopts a sparse sequence, with the sparse sequence located at the Midamble, or at the Preamble.

[0335] Optionally, sparse sequences are implemented through encoded values. For example, a sparse sequence can be a {1, 0, 1, 0, ...} sequence, where 0 represents the D2R signal without reflection, thus achieving the effect of a sparse sequence. Compact sequences are implemented through encoded values. For example, a compact sequence can be a {1, 1, 1, ...} or {1, -1, 1, -1, ...} sequence.

[0336] Alternatively, sparse sequences are achieved by reducing the number of bit-level or chip-level repetitions, while compact sequences are achieved by increasing the number of bit-level or chip-level repetitions.

[0337] In another possible implementation of this application, the configuration of the frame structure of the D2R signal used for uplink synchronization can be predefined, and this application does not limit this.

[0338] In this embodiment, the repetition granularity of the D2R signal includes: block-level repetition, bit-level repetition, or chip-level repetition. These will be described in detail below.

[0339] The repetition granularity for D2R signals is block-level repetition:

[0340] Figure 28 is a schematic diagram of block-level repetition provided in an embodiment of this application. As shown in Figure 28, for example, a block includes information on the Preamble, PDRCH, Midamble, DRCH, and Postamble of the random access first message.

[0341] In this embodiment, the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, the capability of the terminal device, or the amount of resources occupied by the D2R signal.

[0342] For example, the number of repetitions of the D2R signal is affected by coverage. For instance, the R value is 0 for the default coverage level and / or access level A, meaning no repetition occurs. When the coverage level and / or access level changes from A to B, the R value increases, for example, the number of repetitions becomes 3, or it becomes another value greater than 0. This application embodiment does not limit this.

[0343] For example, the number of repetitions of a D2R signal is affected by the capabilities of the terminal device. For instance, within the same coverage area, device 1 may have 2 repetitions, while device 2 may have 0. The capabilities of the terminal device include amplification and energy storage capabilities.

[0344] For example, the number of repetitions of the D2R signal is affected by the resource configuration size. For instance, when the reader configures resources for a random access first message based on CF or CB, a time-domain resource for a random access first message occupies 100 time units (this time unit includes symbols, chips, etc., which are not limited in this embodiment). When the TBS of the random access first message occupies more than 50 time units, the number of repetitions is 0, that is, no repetition occurs. When the TBS of the random access first message occupies 30 time units, in order to enhance transmission reliability, the number of repetitions is 2 or 3, or it can be any other number greater than 0, which is not limited in this embodiment.

[0345] In this embodiment of the application, the configuration of the time-domain resources used for repetition includes one or more of the following: the number of times the block-level repetition is performed, or the starting position of the block-level repetition.

[0346] It should be noted that, for example, this block can be Msg 1 / Msg 3 / MsgA signals sent by one or more terminal devices (or, randomly accessed first signal, or randomly accessed third signal), or it can be a portion of Msg 1 / Msg 3 / MsgA signals sent by a single terminal device (or, randomly accessed first signal, or randomly accessed third signal). It should also be noted that the block length is generally greater than one bit.

[0347] In one possible implementation, the starting position of block-level repetition is the offset value of each repetition block relative to the start or end position of the AIoT paging message or R2D signal received by the terminal device. For example, the offset value of the second repetition block is t1, and the offset value of the third repetition block is t2. The difference between t2 and t1 is greater than or equal to the length of one block. Optionally, t1 and t2 can be indicated by the reader / writer based on resources, repetition count, etc., of the scheduled random access first message or random access third message.

[0348] In another possible implementation, the starting position of block-level repetition is the offset value of each repeating block relative to the adjacent previous repeating block. Optionally, this offset value includes the effect of SFO (Side Forward Occurrence), and the offset value may be 0. For example, the offset value of the second repeating block relative to the first repeating block is Δt1, and the offset value of the third repeating block relative to the first repeating block is Δt2. Here, Δt1 and Δt2 can be a set selected by the terminal device based on the TBS (Tracking Base Size). For example, when Δt1 > Δt2, the TBS length of block 1 is greater than the TBS length of block 2. Alternatively, Δt1 and Δt2 can be indicated by the reader based on the resources, repetition count, etc., of the scheduled random access first message or random access third message.

[0349] In this embodiment of the application, the configuration of frequency domain resources for repetition includes: block-level repetition frequency hopping level. In other words, within the time domain resources of the configured random access first message or random access third message, frequency domain resources for repetition can be configured, and the configuration of frequency domain resources for repetition includes block-level repetition frequency hopping level.

[0350] The block-level repetitive frequency modulation levels include: Level 1, no frequency hopping; Level 2, frequency hopping once every one frequency domain unit. For example, hopping once every 1RB or one frequency domain unit (e.g., a subcarrier unit of 15kHz); Level 3, frequency hopping once every at least two frequency domain units. For example, hopping once every ARB or A frequency domain units, where A is a positive integer greater than 1, and A is related to the capabilities of the terminal equipment and the D2R transmission bandwidth.

[0351] In one possible implementation, the number of block-level repetitions and / or the time-frequency resources used for repetition are indicated via PRDCH control information. This approach can be considered an explicit indication method, where the control information can be L1 control information or higher-level indication information. The explicit indication can also indicate a set of resources, for example, configuring {△t1, △t2...}, {△f1, △f2...}, which the terminal device randomly selects based on information such as the MCS-like or TBS of the previous block (it should be noted that the selection by the terminal device is an implementation behavior of the terminal device).

[0352] In another possible implementation, the number of block-level repetitions and / or the time-frequency resources used for repetitions are determined by at least one of the following: the size of the D2R TBS, or MCS-like information. This approach can be considered an implicit indication. For example, when the TBS for the first random access message occupies more than 50 time units, the number of repetitions is 0, i.e., no repetition occurs; when the TBS for the first random access message occupies 30 time units, the number of repetitions is 2 or 3 to enhance transmission reliability.

[0353] For D2R signals, the repetition granularity is bit-level repetition:

[0354] Figure 29 is a schematic diagram of bit-level repetition provided in an embodiment of this application. One bit includes one or more chips, which can be a D2R premble, a D2R imidamble, or a D2R postamble. When the D2R signal is linearly encoded, 1 bit of information represents 1 chip; when the D2R signal is linearly encoded, 1 bit of information represents at least 2 chips.

[0355] In this embodiment, the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, or the capability of the terminal device. For a description of the influencing factors of bit-level repetition, please refer to the description of the influencing factors of block-level repetition described above; this embodiment will not repeat them here.

[0356] In this embodiment, the number of bit-level repetitions can be predefined. Optionally, the number of repetitions is related to factors such as the maximum TBS (the protocol defines the maximum TBS before repetition as 1000 bits, and the maximum TBS after repetition is not limited) and the frame structure type of the D2R signal.

[0357] For example, the number of repetitions can be N = {N1, N2, N3...} (e.g., {1, 2, 4, 8, 16, 32, 64, 128, 256, 512...}).

[0358] For example, the number of repetitions may be related to the level, which includes coverage level and / or access level. For instance, coverage level / access level A has the lowest number of repetitions, while coverage level / access level C has the highest number of repetitions.

[0359] For example, when D2R only considers preamble transmission, the number of repetitions ranges from 1 to D1; when considering preamble + midamble transmission, the number of repetitions ranges from 1 to D2, and D2 is less than D1. That is, when the frame structure of the D2R signal contains midamble or multiple PDRCHs, the number of repetitions will be reduced.

[0360] For example, as the number of repetitions increases, the frame structure of the D2R signal considers midamble and / or postamble. For instance, when the number of repetitions is 2, a frame structure of type one is considered; when the number of repetitions is 16, a frame structure of type four is considered.

[0361] In this embodiment of the application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of bit-level repetitions, or the starting position of the bit-level repetitions. Alternatively, in other words, within the time-domain resources of the configured random access first message or random access third message, time-domain resources for repetition can be configured, and the configuration of the time-domain resources for repetition includes at least one of the following: the number of bit-level repetitions, or the starting position of the bit-level repetitions.

[0362] In this embodiment, the number of repetitions is related to one or more of the following factors: coverage level and / or access level, terminal device capability, maximum TBS, and frame structure type of D2R signal. For details, please refer to the relevant description of block-level repetitions. This embodiment will not repeat them here.

[0363] In this embodiment, the starting position of bit-level repetition includes the offset value of each repeated bit relative to the adjacent previous bit. Optionally, the offset value includes the effect of SFO (Side Forward Error). It should be noted that, considering the short time domain length occupied by bit-level repetition, the effect of SFO in the first few repetitions can be ignored, so the offset value may be 0. For example, as shown in Figure 29, the offset value of the second repeated bit relative to the first repeated bit is 0, and the offset value of the third repeated bit relative to the first repeated bit is Δt. Here, Δt can be a set, and the terminal device can select the offset at a fixed number of repetitions, for example, the repetition bits {4th, 8th, 12th, 16th...} are offset (the offset values ​​can be the same or different), and the remaining repeated bits are not offset. Alternatively, Δt can be indicated by the reader / writer based on the resources, repetition count, etc. of the scheduled random access first message or random access third message. Alternatively, Δt can also be filled by Midamble, which is not limited in this embodiment.

[0364] In this embodiment, the configuration of frequency domain resources for repetition includes: bit-level repetition frequency hopping levels. Frequency hopping is frequency hopping relative to the previous one or several bit frequencies (e.g., Δf1 and Δf2 in Figure 29) or frequency hopping relative to CW frequency points. Frequency hopping is implemented through BLF or the number of repetitions. The frequency hopping rules include at least one of the following: 1) When the coverage level / access level increases (e.g., from A to B, or from B to C), frequency hopping is required, and the magnitude of the frequency hopping and the number of bits hopping are related to the time-frequency resources corresponding to the coverage level / access level. For example, 32 chips represent one bit; when the coverage level changes, each bit hops, and the frequency hopping value is randomly selected from a BLF set or hops according to the indicated frequency hopping level.

[0365] In this embodiment, the frequency hopping levels for bit-level repetition include: a first level, no frequency hopping; a second level, frequency hopping once every one frequency domain unit; and a third level, frequency hopping once every at least two frequency domain units. For a description of the frequency hopping levels for bit-level repetition, please refer to the description of the frequency hopping levels for block-level repetition; this will not be repeated here.

[0366] In one possible implementation, the number of bit-level repetitions and / or the time-frequency resources used for repetition are indicated via PRDCH control information. This method can be called an explicit indication method, where the control information can be L1 control information or higher-level indication information. The explicit indication can also indicate a set of resources, for example, configuring {△t1, △t2...}, {△t}, {△f1, △f2...}, which the terminal device randomly selects based on the repetition count of the previous / first few bits (it should be noted that the selection by the terminal device is an implementation behavior of the terminal device).

[0367] In another possible implementation, the number of bit-level repetitions and / or the time-frequency resources used for repetition are determined via MCS-like information. This approach can be referred to as an implicit indication method. For example, the offset value and frequency hopping value (BLF or number of repetitions) for each repetition bit are determined based on the coding type of the D2R signal (e.g., line code multiplication).

[0368] For repetition at the chip level:

[0369] Figure 30 is a schematic diagram of chip-level repetition provided in an embodiment of this application. As shown in Figure 30, chip-level repetition refers to a repetition of one ON or one OFF signal, which is the repetition of the smallest time unit in an AIoT system. According to the description of TR, chip repetition is performed after online coding or modulation. Therefore, chip-level repetition can improve transmission reliability, but it will reduce the transmission rate of D2R signals, which is equivalent to stretching or doubling the level of each chip in the time domain (the number of doubling depends on the number of repetitions).

[0370] In this embodiment, the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, or the capability of the terminal device. For a description of the influencing factors of chip-level repetition, please refer to the description of the influencing factors of block-level repetition; this embodiment will not repeat it here.

[0371] In this embodiment, the number of chip-level repetitions can be predefined. Optionally, the number of repetitions is related to factors such as whether line codes are used and the number of repetitions of the line codes (it should be noted that the number of repetitions of the line codes affects the data rate, which is different from the number of repetitions mentioned above).

[0372] For example, the number of repetitions can be determined based on whether line codes are used in D2R. For instance, when line codes are not used, 1 bit represents 1 chip, and the number of repetitions can refer to the rules for bit-level repetitions, which will not be elaborated further in this embodiment. As another example, when line codes are used, the rules for the next bullet can be referenced.

[0373] For example, the number of repetitions can be determined based on the MCS-likeness, data rate, or line code repetitions of the D2R. For instance, as the MCS-likeness level or data rate decreases, the number of repetitions can increase, for example, from 4 to 8. This application embodiment does not limit this.

[0374] In this embodiment of the application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of times chip-level repetition occurs, or the starting position of chip-level repetition. Alternatively, in other words, within the time-domain resources configured for the first or third random access message, one or more of the following can be configured: the number of times chip-level repetition occurs, or the starting position of chip-level repetition occurs.

[0375] In this embodiment, the starting position of chip-level repetition includes the offset value of each repeated bit relative to the adjacent previous chip. Optionally, this offset value includes the effect of SFO (Side Forward Error). It should be noted that, considering the short time domain length occupied by chip-level repetition, the effect of SFO in the first few repetitions can be ignored, so the offset value may be 0. For example, as shown in the figure, the offset values ​​of the second and third repeated chips relative to the first repeated chip are 0. Another example is that the repeated chip has a time domain offset (Δt) compared to the previous chip. Δt can be a set, and the terminal device can select the offset at a fixed number of repetitions, for example, offsetting the {4th, 8th, 12th, 16th...} repeated bits (where the offset values ​​can be the same or different), and offsetting the remaining repeated bits. Alternatively, Δt can also be indicated by the reader based on the resources, repetition count, etc., of the scheduled random access first message or random access third message; this embodiment does not limit this.

[0376] In this embodiment of the application, the configuration of frequency domain resources for repetition includes: no frequency hopping for chips within the same bit, and frequency hopping levels that are repeated at the chip level within different bits.

[0377] For example, chips within the same bit do not hop frequencies, as shown in Figure 30. For instance, the first chip group represents at least one bit, and frequency hopping is performed within the chip group. The second chip group represents at least one bit, and the frequency hopping is Δf1 compared to the first chip group.

[0378] For example, for different chip groups belonging to different bits, repeating frequency hopping levels can be set. This frequency hopping is a frequency hopping relative to the frequency of the previous one or several bits (or a chip group representing at least one bit) (e.g., Δf1 and Δf2 in the figure) or a frequency hopping relative to the CW frequency point, which is implemented by BLF.

[0379] In this embodiment, the frequency hopping levels for chip-level repetition include: a first level, no frequency hopping; a second level, frequency hopping once every one frequency domain unit; and a third level, frequency hopping once every at least two frequency domain units. For a description of the frequency hopping levels for chip-level repetition, please refer to the description of the frequency hopping levels for block-level repetition described above; this embodiment will not repeat it here.

[0380] In one possible implementation, the number of chip-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information. This method can be called an explicit indication method, where the control information can be L1 control information or higher-level indication information. The explicit indication can also indicate a set of resources, for example, configuring {△t1, △t2...}, {△t}, {△f1, △f2...}, which the terminal device randomly selects based on the number of repetitions of the previous / previous few chips (it should be noted that the selection by the terminal device is an implementation behavior of the terminal device).

[0381] In another possible implementation, the number of chip-level repetitions and / or the time-frequency resources used for repetition are determined using MCS-like information. This approach can be called an implicit indication method. For example, the number of chip-level repetitions and the time-frequency resources can be determined based on the number of line code repetitions or the data rate level of the D2R signal. For instance, when the rate level decreases, the number of chip-level repetitions increases, and time-domain offsets can be performed on the 4th, 8th, 16th, etc., repetitions; or, frequency hopping can be performed between chip groups corresponding to different bits.

[0382] In this embodiment of the application, the configuration of the random offset of the D2R signal includes a common offset, and the random offset of the D2R signal is determined based on the common offset.

[0383] The common offset is the time-domain interval between the AIoT paging message and the first random access message, or the common offset is the time-domain interval between the second random access message and the first random access message. The time-domain interval between the AIoT paging message and the first random access message includes the time-domain interval between the start position of the AIoT paging message and the start position of the first random access message, or the time-domain interval between the end position of the AIoT paging message and the start position of the first random access message.

[0384] In one possible implementation, for a non-contention-based access mechanism, the random offset of the D2R signal is determined based on a common offset and the offset value of the D2R signal corresponding to the terminal device. The offset value of the D2R signal corresponding to the terminal device is indicated by indication information. For the offset value of the first random access message, this indication information can be an AIoT paging message; that is, the reader / writer indicates the offset value of the first random access message to the terminal device via a paging message. For the offset value of the third random access message, this indication information can be a second random access message; that is, the reader / writer indicates the offset value of the third random access message to the terminal device via the second random access message.

[0385] Figure 31 is a schematic diagram of the time-domain offset of the first random access message under the non-contention access mechanism provided in this application embodiment. As shown in Figure 31, after receiving the AIoT paging message, the terminal device obtains the transmission resources for the first random access message (described as Msg1) corresponding to the device ID. The transmission timing of Msg1#1 is separated from the AIoT paging message by a common offset. Other terminal devices that send Msg1 but not #1 can use the transmission timing of Msg1 as a reference point to perform time-domain offset (i.e., timing via a clock). Each time-domain offset is known to the corresponding terminal device by demodulating the AIoT paging message. Therefore, the transmission timing of Msg1 can be defined as follows:

[0386] T_#1=0

[0387] T_#2 = offset 1

[0388] T_#3 = offset 2 = offset 1 + Msg 1#2 resource length

[0389] ...

[0390] If the resource length of each Msg 1 is equal, the actual position of Msg 1 of #N is T_#N=(N-1)*offset 1.

[0391] In this scenario, the common offset is broadcast via AIoT paging messages to multiple terminal devices to be inventoried, with each terminal device's counting start time being the initial transmission time of #1. If a terminal device determines that the current time is more than M offset 1s away from the time Msg 1 was sent, it can enter an OFF or Sleep state. The value of M is configured by a higher layer or can be a behavior implemented by the terminal device itself; this embodiment does not limit this.

[0392] It should be noted that when the above AIoT paging message is a random access second message, a similar mechanism can be used to define the transmission reference time of the random access third message, which will not be elaborated here.

[0393] In one possible implementation, for a contention-based access mechanism, the random offset of the D2R signal is determined based on a common offset and the offset value of the D2R signal preempted by the terminal device. The offset value of the D2R signal preempted by the terminal device is predefined from a set of offset values.

[0394] For example, a set can be predefined and broadcast to multiple terminal devices via AIoT paging messages. This set is {Offset 1, offset 2, offset 3...}. Terminal devices can preempt the time domain offset value of the set and send a random access first message based on the broadcast common offset and the preempted offset value.

[0395] It should be noted that when the above AIoT paging message is a random access second message, a similar mechanism can be used to define the transmission reference time of the random access third message, which will not be elaborated here.

[0396] In this embodiment of the application, during a new round of inventory checks, the configuration of the random offset of the D2R signal is indicated by retransmission indication information. Specifically, the D2R signal is a first random access message, and the retransmission indication information can be an AIoT paging message; the D2R signal is a third random access message, and the retransmission indication information is a second random access message.

[0397] Figure 32 is a schematic diagram of the configuration of the random offset of the first random access message of the terminal device indicated by the retransmitted AIoT paging message according to an embodiment of this application. As shown in Figure 32, during the first round of inventory, the Msg 1 of some terminal devices is not received by the reader or a conflict occurs. These terminal devices will wait for the second round of inventory. The time-frequency resources of the Msg 1 in the second round of inventory will be sent through the second AIoT paging message. The second AIoT paging message refers to the paging message used for subsequent device inventory in the same round of inventory or different inventory processes, and does not conflict with the AIoT paging message described above. The first round of inventory and the second round of inventory can belong to different stages of the same round of inventory process or to different inventory processes.

[0398] In this embodiment, when the reader detects a conflict or fails to correctly receive the first random access message from some terminal devices, a listening window can be set. This listening window is used to listen for the reported information from terminal devices that failed to correctly receive the first random access message. Optionally, this listening window can be located before the retransmitted AIoT paging message; or, optionally, it can be located after the retransmitted AIoT paging message. Figure 33 shows a schematic diagram of the listening window provided in this embodiment before the retransmitted AIoT paging message.

[0399] For time-domain resources, the time-domain resources of the first random access message of the terminal device in the new round of inventory are predefined. The time-domain resources include two parts: common offset and offset value corresponding to the terminal device.

[0400] The common offset includes the time domain length when the end position of the terminal device's reported information in the listening window is taken as the starting reference point and the transmission timing of #1Msg 1 is taken as the ending reference point, which is common offset 1; and the time domain length when the start / end position of the device receiving the second AIoT paging message is taken as the starting reference point and the transmission timing of #1Msg 1 is taken as the ending reference point, which is common offset 2.

[0401] It should be noted that the transmission resource for each Msg 1 is Offset#N, where Offset#N includes the impact of SFO / CFO on the time offset.

[0402] For scenarios based on non-contention-based random access, the transmission timing of each Msg 1 can be expressed by the following formula:

[0403] T_#1=0

[0404] T_#2 = offset 1

[0405] T_#3 = offset 2 = offset 1 + Msg 2 resources

[0406] ...

[0407] If the resource length of each Msg 1 is equal, the actual position of Msg 1 of #N is T_#N=(N-1)*offset 1.

[0408] In this scenario, common offset 1 or common offset 2 is broadcast as an AIoT paging message to the terminal devices to be inventoried, and the counting start time for each terminal device is the initial transmission time of #1. If a terminal device determines that the current time is more than M offset 1s away from the time Msg 1 was sent, it can enter the OFF or Sleep state. The value of M is configured by the higher layer or can be a custom behavior of the terminal device itself.

[0409] For scenarios based on contention-based access, a set can be predefined and broadcast to the device via AIoT paging messages. The set is {Offset 1, offset 2, offset 3...}. The terminal device preempts the time-domain offset value of the set and sends Msg 1 based on the broadcast common offset and the preempted offset value.

[0410] For frequency domain resources, a BLF relative to CW can be configured for each random access first message, or when using line codes, the number of line code repetitions can be configured for each random access first message.

[0411] Alternatively, a set of BLFs relative to the CW can be configured for each Msg 1, or when using line codes, a set of line code repetitions can be configured for each random access first message, and the terminal device selects the corresponding BLF or repetition number through a competition mechanism.

[0412] It should be noted that the frequency domain resources of the terminal equipment in the new round of inventory may be the same as or different from those of the terminal equipment in the first round of inventory, depending on harmonic interference, intermodulation interference, etc. This application embodiment does not limit this.

[0413] In this embodiment of the application, the configuration of the retransmission time of the D2R signal includes one or more of the following: minimum retransmission time, maximum retransmission time, or update of retransmitted data or frame structure.

[0414] In this embodiment, the minimum retransmission time is related to the minimum time interval between two consecutive transmissions of the D2R signal by the terminal device.

[0415] For example, assuming the number of retransmissions is N, the minimum retransmission time-domain resource configured on the access network device side is:

[0416] T_min=(N-1)*T_D2R_D2R_min+offset

[0417] Where N represents the number of retransmissions, which is related to the type of terminal device and its power. For example, when the terminal device has insufficient power or weak capabilities (such as a terminal device of type device 1), the number of retransmissions will be 1 or 2.

[0418] Wherein, T_D2R_D2R_min represents the minimum time interval between two consecutive D2R signal transmissions by the same terminal device, and Offset represents the time offset introduced by non-ideal factors (SFO / CFO) on the terminal device or access network device side.

[0419] In this embodiment, the maximum retransmission time is related to the minimum and / or maximum time interval between two consecutive R2D signal transmissions by the terminal device.

[0420] For example, when the reader fails to receive / does not receive the D2R signal, the reader configures a maximum retransmission time. The maximum retransmission time is determined by either T_R2D_R2D_min or T_R2D_R2D_max.

[0421] T_max=T_R2D_R2D_min+offset=T_R2D_R2D_max

[0422] Wherein, T_R2D_R2D_min represents the minimum time interval between two consecutive R2D signals sent by the reader to the same terminal device, and T_R2D_R2D_max represents the maximum time interval between two consecutive R2D signals sent by the reader to the same terminal device; Offset represents the time offset introduced by non-ideal factors (SFO / CFO) on the terminal device or access network device side. Optionally, the maximum time interval may include the minimum time interval and the time offset introduced by the terminal device or access network device side.

[0423] In this embodiment, the retransmission time configuration may also include a general retransmission time. The general retransmission time ranges from {T_min, T_max}, or it may be a dedicated retransmission resource allocated by the access network device. For example, 5 retransmissions correspond to 5 time resources. These 5 time resources can be the same or different; this embodiment does not limit this. The starting reference point for the 5 time resources can be the end time or start time of the retransmission instruction, or it can be a random offset from the start time of the first retransmission resource; this embodiment does not limit this either.

[0424] In this embodiment, the retransmission count can also be updated. In one possible implementation, for DOA scenarios, or for DO-DTT / DT scenarios where retransmission is triggered by the terminal device, the terminal device listens for the information of the random access second message according to the listening window configured on the access network device side. When the listening window is exceeded, the terminal device upgrades to a new level and retransmits the random access first message. For example, coverage level and / or access level A corresponds to the coverage capability of a terminal device's transmitted and received signals, and its retransmission count is 0. When the terminal device does not receive the random access second message within the fixed listening window, the coverage level and / or access level changes from A to B, the default coverage capability deteriorates, and the random access first message is retransmitted 2 times.

[0425] For retransmitted frequency domain resources, the configuration of frequency domain resources for the first random access message can be referenced, and will not be elaborated here. For example, BLF / repetition count / MCK-like configuration. One method for configuring retransmitted frequency domain resources is to define different frequency domain resource ranges, such as BLF 1 = {64KHz, 128KHz, 256KHz}, BLF 2 = {1MHz, 1.5MHz, 2MHz}... The retransmitted frequency domain resources can be configured with different BLF sets according to the capabilities of the terminal device, and will not be elaborated here.

[0426] In this embodiment of the application, retransmission of data or frame structure updates are indicated by indication information.

[0427] In one possible implementation, the reader instructs the terminal device to update the retransmitted random number or data via 1-bit or N-bit information. The retransmitted data is different from the random number or data sent in the first round. For example, when the terminal device needs to update certain states, only a portion of the data needs updating (e.g., the last 10 bits). In this case, the 1-bit or N-bit information instructs the terminal device to update the data before retransmitting. This 1-bit or N-bit information is carried via AIoT Paging / Subsequent AIoT Paging / other R2D signals.

[0428] In another possible implementation, the reader instructs the terminal device to send the data that needs to be updated separately using 1 bit or N bits of information. After receiving the new data, the reader merges the original data with the new data to obtain the new transmission information. For example, when the terminal device writes content to update, it only retransmits the updated part.

[0429] In another possible implementation, the reader instructs the terminal device to update the retransmitted frame structure using 1-bit or N-bit information. This retransmitted frame structure is different from the frame structure of the D2R signal sent in the first round. For example, if the frame structure of the D2R signal sent by the terminal device in the first round is D2RPreamble+Midamble+PDRCH+Postamble, then the reader can instruct the terminal device not to retransmit the Midamble information during retransmission.

[0430] In this embodiment of the application, the configuration of the time extension line for the terminal device to send the random access third message includes the extended time interval, which includes multiple time units.

[0431] In this embodiment, to address the needs of terminal devices with different capabilities or varying remaining energy levels among the same type of terminal devices, the reader relaxes the timeline requirement between the random access second message and the random access third message, based on the general gap between the second and third random access messages. This provides more flexible terminal device inventory requirements, optimizes terminal device power consumption, and improves the access success rate of terminal devices. The general gap is configured at a higher level or predefined; this embodiment does not limit its specific configuration.

[0432] Figure 34 is a schematic diagram of the time extension line provided in an embodiment of this application. As shown in Figure 34, the general gap predefined by the higher-layer configuration or protocol is from the first time unit to the Mth time unit. The terminal device can send the random access third message in any one of the #1 to #M time units. Here, the time unit includes a frame, half-frame, time slot, symbol, or chip; this embodiment of the application does not limit this. After widening the time line, the gap between the random access second message and the random access third message increases by 1 to (N-M+1) time units, and the terminal device can send the random access third message in any one of the #1 to #N time units. Here, the time unit includes a frame, half-frame, time slot, symbol, or chip; this embodiment of the application does not limit this.

[0433] In this embodiment of the application, the conditions for extending the time interval include one or more of the following: the energy status reported by the terminal device, or the signal quality of the D2R signal.

[0434] For example, the terminal device reports 1 bit or N bits of energy status information in the first random access message or other D2R information. The reader configures an additional time unit based on its energy status information to extend the transmission gap between the second and third random access messages. For instance, if the terminal device reports that its battery is low, the reader determines that the remaining battery power of the terminal device is insufficient to send the third random access message, and therefore configures an additional time unit to ensure the energy storage and transmission of the terminal device.

[0435] For example, the reader determines the path loss between the terminal device and the reader based on the measured AIoT-RSRP of the D2R signal, and decides on the additional time unit to configure the terminal device based on whether to switch to a new reader. For instance, after the reader obtains AIoT-RSRP information by measuring AIoT Uu, the network decides to switch readers. The new reader may determine the time interval between the terminal device sending the second random access message and the third random access message based on the switching delay, new information such as AIoT-RSRP, etc.

[0436] In one possible implementation, the time extension line configuration is determined based on the remaining battery power of the terminal device. The reader dynamically configures the length of the time line for the random access second message to the random access third message based on the remaining battery power of the terminal device. This information can be carried via R2D PRDCH, for example, an AIoT paging message or a SubsequentAIoT paging message, or other new R2D control information.

[0437] In another possible implementation, the time extension configuration is included in the second random access message. If the general gap between the second and third random access messages is information included in the AIoT paging message, the reader / writer includes extended timeline information when scheduling the second random access message, notifying the terminal device that it can send the third random access message over a longer period.

[0438] In another possible implementation, the time extension line configuration is determined based on the access level and / or coverage level. During the same inventory cycle, the reader schedules multiple random access second-third-random access message timelines based on the coverage level or access level via AIoT paging messages or random access second-third-random access messages. For example, the timeline for random access second-third-random access messages at coverage level / access level A is M; the timeline for random access second-third-random access messages at coverage level / access level B is N (N>M); and the timeline for random access second-third-random access messages at coverage level / access level C is T (T>N).

[0439] S2220, the reader sends an R2D signal to the terminal device. Correspondingly, the terminal device receives the R2D signal from the reader.

[0440] In this embodiment, the R2D signal may include a random access second message. Optionally, the R2D signal may also include data, etc., which is not limited in this embodiment.

[0441] The following is a brief introduction to the MCS-like related content involved in the embodiments of this application.

[0442] In the embodiments of this application, MCS-like is associated with one or more of D2R modulation, linear coding, and channel coding.

[0443] D2R modulation includes OOK and BPSK modulation, the use of line codes, convolutional codes, and repetition correlation. Line codes include Miller codes, Manchester codes, and convolutional codes. The constraint lengths of the convolutional codes are K = 4, 6, 7, and 8, and the code rates are 1 / 6, 1 / 4, 1 / 3, and 1 / 2.

[0444] In one possible implementation of this application, different levels of MCS can be determined based on different modulation methods. Modulation methods include OOK modulation and BPSK modulation.

[0445] In another possible implementation, different levels of MCS can be determined based on the usage of the line code.

[0446] For example, using line code, the MCS level can be determined based on the repetition factor of the line code. For instance, a smaller repetition factor corresponds to a lower MCS level, and a larger repetition factor corresponds to a higher MCS level.

[0447] For example, without using line code, it could correspond to a low MCS level.

[0448] In another possible implementation, the MCS level can be determined based on the constraint length and code rate of the convolutional code.

[0449] In another possible implementation, different levels of MCS can be determined based on the number of repetitions. For example, a higher number of repetitions corresponds to a lower MCS level.

[0450] Optionally, for block-level repetition, bit-level repetition, and chip-level repetition, the MCS level can be divided into:

[0451] The first MCS level, corresponding to the lower MCS, is suitable for weak signal environments and scenarios with low access rates, in order to determine the reliability of the transmission of the first random access message or the third random access message.

[0452] The second MCS level corresponds to a medium MCS level, which is used in scenarios with moderately good channel conditions, and has a lower coverage level and access rate.

[0453] 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.

[0454] It should be noted that the BLF set, line code repetition factor, and spectrum of the D2R signal frequency involved in the embodiments of this application are consistent with the spectrum of CW, for example, both are uplink spectrum; of course, they can also be inconsistent, for example, the D2R signal is the downlink spectrum and the CW signal is the uplink spectrum.

[0455] 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.

[0456] For R2D signals, when the message length is short, for example, when it is only used to activate / deactivate PRDCH transmission, R2D Midamble is not required; when the message length is long, R2D Midamble is required.

[0457] When a second random access message responds to multiple first random access messages or multiple PDRCHs, an R2D Midamble can be added to distinguish the second random access message resources corresponding to different first random access messages or PDRCHs, making it easier for terminal devices to identify and receive them.

[0458] The above mainly describes the solutions provided by the embodiments of this application from the perspective of the interaction between the reader / writer and the terminal device. Correspondingly, the embodiments of this application also provide a communication device for implementing the various methods described above. This communication device can be the reader / writer in the above method embodiments, or a device containing the reader / writer, or a component usable in the reader / writer; or, the communication device can be the terminal device in the above method embodiments, or a device containing the terminal device, or a component usable in the terminal device. It is understood that, in order to achieve the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware 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.

[0459] For example, Figure 35 is a schematic diagram of a communication device provided in an embodiment of this application, wherein the communication device includes a transceiver module 3510 and a processing module 3520. The transceiver module 3510, also known as a transceiver unit, is used to implement the transceiver function, and may be a transceiver circuit, transceiver, transceiver device, or communication interface.

[0460] Taking the communication device as an example, which is the terminal device in the above method embodiment (which may be a chip of the terminal device, a module of the terminal device, or an internal device of the terminal device):

[0461] In this embodiment of the application, the processing module 3520 is used to determine the D2R signal.

[0462] In this embodiment of the application, the transceiver module 3510 is used to send a D2R signal to the reader / writer based on a first configuration.

[0463] In this embodiment of the application, the D2R signal includes a random access first message and / or a random access third message; wherein, the first configuration includes one or more of the following: the level of the communication device, the level including a coverage level and / or an access level; the configuration of a first time unit, wherein the communication device transmits or does not transmit a signal within the first time unit; the configuration of the D2R signal type; the configuration of the frame structure of the D2R signal for uplink synchronization; the configuration of the number of repetitions of the D2R signal and the time-frequency resources used for repetition; the configuration of the random offset corresponding to the D2R signal; the configuration of the retransmission time of the D2R signal; or, the configuration of the time extension line for the communication device to transmit the random access third message.

[0464] In one possible implementation of this application, the coverage level of the communication device includes: coverage level A, where the coverage level A is the area where the D2R signal strength is greater than a first threshold; coverage level B, where the 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 a second threshold; and coverage level C, where the coverage level C is the area where the D2R signal strength is less than the second threshold.

[0465] In one possible implementation of this application, the access level of the communication device includes: access level A, which is a region where the access success rate is greater than a third threshold; access level B, which is a region where the access success rate is less than or equal to the third threshold and greater than or equal to a fourth threshold; and access level C, which is a region where the access success rate is less than the fourth threshold.

[0466] In one possible implementation of this application embodiment, the coverage level and / or access level of the communication device are determined based on one or more of the following: the capability of the communication device, the distance between the reader / writer and the communication device, the number of at least one communication device to be inventoried, or the number of at least one communication device that was successfully accessed in the previous round of inventory.

[0467] In one possible implementation of this application embodiment, the capabilities of the communication device include one or more of the following: frequency offset error range, ability to correct frequency deviation or time offset, energy storage capacity, or remaining power.

[0468] In one possible implementation of this application embodiment, the capabilities of the communication 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.

[0469] In one possible implementation of this application embodiment, the communication device has the following capabilities: 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.

[0470] In one possible implementation of this application embodiment, the coverage level and / or access level of the communication device are configured as predefined.

[0471] In one possible implementation of this application embodiment, the coverage level and / or access level configuration of the communication device is indicated by indication information.

[0472] In one possible implementation of this application embodiment, the configuration of the first time unit includes one or more of the following: the position of the first time unit, the period of the first time unit, or the duration of the first time unit.

[0473] In one possible implementation of this application embodiment, the first time unit is determined according to one or more of the following: the coverage level, the access level, the type of the communication device, the type of the reader / writer, the type of signal corresponding to the period of the first time unit, or, random access type.

[0474] In one possible implementation of this application embodiment, the first time unit is located after the reader sends a first signal, the first signal including a paging message and / or a randomly accessed second message.

[0475] In one possible implementation of this application embodiment, the duration of the first time unit begins with the first or last time unit when the reader sends the first signal and ends when the communication device receives the first D2R signal.

[0476] In one possible implementation of this application embodiment, the period of the first time unit includes one or more of the following: an inventory count, or a control operation.

[0477] In one possible implementation of this application embodiment, the position of the first time unit is located during the period when the reader receives the D2R signal.

[0478] In one possible implementation of this application embodiment, the position of the first time unit is located at the beginning position of the preamble of the D2R signal, and / or, the position of the first time unit is located at at least one intermediate preamble of the D2R signal, and / or, the position of the first time unit is located at the first uplink channel PDRCH of the D2R signal.

[0479] In one possible implementation of this application embodiment, the period of the first time unit is one inventory count, or it is statically configured in one control.

[0480] In one possible implementation of this application embodiment, the communication device transmits the D2R signal in multiple time units, and the position of the first time unit is: the starting position of at least one preamble of the first transmitted D2R signal.

[0481] In one possible implementation of this application embodiment, the communication device transmits the D2R signal in a time unit, where the position of the first time unit is the starting position of the first preamble of the D2R signal.

[0482] In one possible implementation of this application embodiment, the period of the first time unit is one inventory count, or a semi-static configuration in one control.

[0483] In one possible implementation of this application embodiment, the communication device transmits the D2R signal in multiple time units, wherein the position of the first time unit is: the starting position of at least one preamble of the D2R signal transmitted each time, and / or the position of at least one intermediate preamble of the D2R signal.

[0484] In one possible implementation of this application embodiment, the communication device transmits the D2R signal in a time unit, wherein the position of the first time unit is: the starting position of the preamble of the D2R signal and the position of at least one intermediate preamble of the D2R signal.

[0485] In one possible implementation of this application embodiment, the duration of the first time unit is predefined.

[0486] In one possible implementation of this application embodiment, the duration of the first time unit is indicated by indication information.

[0487] In one possible implementation of this application, the length of the first time unit is less than or equal to the length of the intermediate preamble of the D2R signal, or the length of the first time unit is less than or equal to the length of the preamble of the D2R signal.

[0488] In one possible implementation of this application embodiment, the D2R signal type includes: the D2R signal includes the first random access message, or the D2R signal includes the first random access message and the third random access message.

[0489] In one possible implementation of this application, the frame structure type of the D2R signal includes: including a D2R preamble, including a D2R preamble and at least one intermediate preamble, including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0490] In one possible implementation of this application, the D2R signal type includes the random access first message, which includes one or more of the following information: a 16-bit random number RN16, data, a non-data signal, or energy state indication information.

[0491] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information.

[0492] In one possible implementation of this application embodiment, the random access first message includes the RN16, or the non-data signal, or the energy state indication information, and the frame structure type of the D2R signal is either including a D2R preamble, or including both a D2R preamble and a postamble.

[0493] In one possible implementation of this application embodiment, the random access first message includes RN16 and data, and the frame structure type of the D2R signal is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0494] In one possible implementation of this application, the D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and the third random access message includes data.

[0495] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information.

[0496] In one possible implementation of this application embodiment, the frame structure type of the first random access message is the inclusion of a D2R preamble, and the frame structure type of the third random access message is the inclusion of a D2R preamble and at least one intermediate preamble, or the inclusion of a D2R preamble and a postamble, or the inclusion of a D2R preamble, at least one intermediate preamble, and a postamble.

[0497] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including only a D2R preamble, or including a D2R preamble and a postamble.

[0498] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble or including both a D2R preamble and a postamble; the frame structure type of the third random access message is either including only a D2R preamble or including both a D2R preamble and a postamble.

[0499] In one possible implementation of this application, the D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and data, and the third random access message includes data.

[0500] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information.

[0501] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0502] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including a D2R preamble, or including a D2R preamble and a postamble.

[0503] In one possible implementation of this application embodiment, the message includes a D2R preamble, or the message includes both a D2R preamble and a postamble. The frame structure type of the random access third message is either only a D2R preamble or both a D2R preamble and a postamble.

[0504] In one possible implementation of this application embodiment, the data includes one or more of the following: sensing data, or the ID of the communication device.

[0505] In one possible implementation of this application embodiment, during the same inventory count, the frame structure type of the random access first message sent by multiple communication devices is the same, and / or, the frame structure type of the random access third message sent by multiple communication devices is the same.

[0506] In one possible implementation of this application embodiment, during the same inventory count, the frame structure type of the first random access message sent by multiple communication devices is determined according to a predefined rule, and / or, the frame structure type of the third random access message sent by multiple communication devices is determined according to a predefined rule.

[0507] In one possible implementation of this application embodiment, during the same inventory count, the frame structure type of the random access first message sent by multiple communication devices is indicated by indication information, and / or, the frame structure type of the random access third message sent by multiple communication devices is indicated by indication information.

[0508] In one possible implementation of this application, the configuration of the frame structure of the D2R signal for uplink synchronization is indicated by indication information, or the configuration of the frame structure of the D2R signal for uplink synchronization is predefined.

[0509] In one possible implementation of this application, the indication information is used to indicate uplink synchronization using the first preamble in the frame structure of the first random access message and / or the third random access message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. The frame structure of all the first random access messages includes the first preamble, and the frame structure of all the third random access messages includes the first preamble.

[0510] In one possible implementation of this application embodiment, the indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a first random access first message and / or a first random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. Specifically, the frame structures of N first random access first messages in all the first random access messages include the first preamble, and the frame structures of M first random access third messages in all the third random access messages include the first preamble. The N is less than or equal to the number of all first random access messages, and the M is less than or equal to the number of all third random access messages.

[0511] In one possible implementation of this application, the time-frequency position of the first preamble is related to one or more of the following factors: whether the random access first message includes data, the random access first message configured by the reader / writer, and / or the number of random access third message resources, the random access first message, and / or the size of the TBS of the random access third message, and the frame structure type of the D2R signal.

[0512] In one possible implementation of this application, the first sequence in the frame structure of the D2R signal is used for uplink synchronization.

[0513] In one possible implementation of this application, the type of the first sequence includes: a sparse sequence, a compact sequence, a sequence that is sparse first and then dense, or a sequence that is dense first and then sparse.

[0514] In one possible implementation of this application embodiment, the position and / or interval of the first sequence are determined based on the number of resources of the D2R signal.

[0515] In one possible implementation of this application, the sparse sequence is implemented using encoded values, and the compact sequence is implemented using encoded values.

[0516] In one possible implementation of this application, the sparse sequence is achieved by reducing the number of repetitions, and the compact sequence is achieved by increasing the number of repetitions.

[0517] In one possible implementation of this application, the sparse sequence is achieved by reducing the MCS-like level, and the compact sequence is achieved by increasing the MCS-like level.

[0518] In one possible implementation of this application, the first sequence is indicated by PRDCH control information, or the first sequence is determined by MCS-like information, or the number of repetitions of the D2R signal.

[0519] In one possible implementation of this application, the repetition granularity of the D2R signal includes: block-level repetition, bit-level repetition, or chip-level repetition.

[0520] In one possible implementation of this application embodiment, the repetition granularity of the D2R signal is block-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the communication device, the capability of the communication device, or the size of the resources occupied by the D2R signal.

[0521] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of times the block-level repetition occurs, or the starting position of the block-level repetition.

[0522] In one possible implementation of this application, the starting position of the block-level repetition includes one or more of the following: the offset value of each repetition block relative to the starting or ending position of the paging message received by the communication device, or the offset value of each repetition block relative to the adjacent previous repetition block.

[0523] In one possible implementation of this application, the configuration of the repetitive frequency domain resources includes: block-level repetitive frequency hopping levels; the block-level repetitive frequency hopping levels include: a first level, which is no frequency hopping; a second level, which is frequency hopping once every 1 frequency domain unit; and a third level, which is frequency hopping once every at least 2 frequency domain units.

[0524] In one possible implementation of this application, the number of block-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0525] In one possible implementation of this application, the number of block-level repetitions and / or the time-frequency resources used for repetitions are determined by at least one of the following: the size of the D2R TBS, or adjusting the coding level MCS-like information.

[0526] In one possible implementation of this application embodiment, the repetition granularity of the D2R signal is bit-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the communication device, or the capability of the communication device.

[0527] In one possible implementation of this application, the number of bit-level repetitions is predefined.

[0528] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of bit-level repetitions, or the starting position of the bit-level repetitions.

[0529] In one possible implementation of this application, the starting position of the bit-level repetition includes the offset value of each repeated bit relative to the adjacent previous bit.

[0530] In one possible implementation of this application embodiment, the configuration of frequency domain resources for repetition includes: bit-level repetition frequency hopping levels;

[0531] The bit-level repetition frequency hopping levels include: a first level, which is no frequency hopping; a second level, which is frequency hopping once every 1 frequency domain unit; and a third level, which is frequency hopping once every at least 2 frequency domain units.

[0532] In one possible implementation of this application, the number of bit-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0533] In one possible implementation of this application, the number of bit-level repetitions and / or the time-frequency resources used for repetition are determined by MCS-like information.

[0534] In one possible implementation of this application, the repetition granularity of the D2R signal is chip-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the communication device, or the capability of the communication device. In another possible implementation of this application, the number of chip-level repetitions is predefined.

[0535] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of times the chip-level repetition occurs, or the starting position of the chip-level repetition.

[0536] In one possible implementation of this application, the starting position of the chip-level repetition includes the offset value of each repeated bit relative to the adjacent previous chip.

[0537] In one possible implementation of this application, the configuration of repeated frequency domain resources includes: no frequency hopping for chips within the same bit, and repeated frequency hopping levels for chips within different bits; the repeated frequency hopping levels for chips include: a first level, where no frequency hopping; a second level, where frequency hopping occurs once every one frequency domain unit; and a third level, where frequency hopping occurs once every at least two frequency domain units.

[0538] In one possible implementation of this application, the number of chip-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0539] In one possible implementation of this application, the number of chip-level repetitions and / or the time-frequency resources used for repetition are determined by MCS-like information.

[0540] In one possible implementation of this application, the configuration of the random offset of the D2R signal includes a common offset, and the random offset of the D2R signal is determined according to the common offset; wherein, the common offset is the time domain interval between the AIoT paging message and the first random access first message, or, the common offset is the time domain interval between the random access second message and the first random access third message.

[0541] In one possible implementation of this application embodiment, under a non-contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal corresponding to the communication device.

[0542] In one possible implementation of this application embodiment, the offset value of the D2R signal corresponding to the communication device is indicated by indication information.

[0543] In one possible implementation of this application embodiment, under a contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal preempted by the communication device.

[0544] In one possible implementation of this application, the offset value is predefined in the offset value set.

[0545] In one possible implementation of this application embodiment, during a new round of inventory checks, the configuration of the random offset of the D2R signal is indicated by retransmission indication information.

[0546] In one possible implementation of this application, the configuration of the retransmission time of the D2R signal includes one or more of the following: minimum retransmission time, maximum retransmission time, or retransmission data or frame structure update.

[0547] In one possible implementation of this application embodiment, the minimum retransmission time is related to the minimum time interval between two consecutive transmissions of the D2R signal by the communication device.

[0548] In one possible implementation of this application, the maximum retransmission time is related to the minimum and / or maximum time interval between two consecutive R2D signal transmissions by the communication device.

[0549] In one possible implementation of this application, the retransmission of data or frame structure update is indicated by indication information.

[0550] In one possible implementation of this application, the configuration of the time extension line for the communication device to send the random access third message includes an extended time interval, which includes multiple time units.

[0551] In one possible implementation of this application embodiment, the conditions for extending the time interval include one or more of the following: the energy status reported by the communication device, or the signal quality of the D2R signal.

[0552] In one possible implementation of this application embodiment, the configuration of the time extension line is determined based on the remaining battery power of the communication device.

[0553] In one possible implementation of this application, the configuration of the time extension line is included in the random access second message.

[0554] In one possible implementation of this application embodiment, the configuration of the time extension line is determined according to the access level and / or the coverage level.

[0555] Optionally, the communication device may further include a storage module 3530, which can be used to store instructions and / or data, and the processing module 3520 can read the instructions and / or data in the storage module 3530.

[0556] In this embodiment, the terminal device is presented in an integrated manner, divided into various functional modules. Here, "module" can refer to a specific ASIC, circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices that can provide the aforementioned functions. In a simplified embodiment, those skilled in the art will recognize that the communication device can take the form of the communication device 2100 shown in FIG. 21.

[0557] For example, the processor 2101 in the communication device 2100 shown in FIG21 can call the computer execution instructions stored in the memory 2103 to make the communication device 2100 execute the communication method in the above method embodiment.

[0558] Specifically, the functions / implementation processes of the transceiver module 3510 and processing module 3520 in Figure 35 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103. Alternatively, the functions / implementation processes of the processing module 3520 in Figure 35 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103, and the functions / implementation processes of the transceiver module 3510 in Figure 35 can be implemented by the communication interface 2104 in the communication device 2100 shown in Figure 21.

[0559] Alternatively, taking the communication device as an example, which is the reader / writer in the above method embodiment (which may be the reader / writer chip, the reader / writer module, or an internal device of the reader / writer):

[0560] In this embodiment of the application, the processing module 3520 is used to determine the D2R signal.

[0561] In this embodiment of the application, the transceiver module 3510 is used to receive D2R signals from the terminal device.

[0562] In this embodiment of the application, the transceiver module 3510 is also used to send an R2D signal to the terminal device based on the D2R signal.

[0563] In this embodiment of the application, the D2R signal includes a random access first message and / or a random access third message; wherein, the first configuration includes one or more of the following: the level of the terminal device, the level including a coverage level and / or an access level; the configuration of a first time unit, wherein the terminal device transmits or does not transmit a signal within the first time unit; the configuration of the D2R signal type; the configuration of the frame structure of the D2R signal for uplink synchronization; the configuration of the number of repetitions of the D2R signal and the time-frequency resources used for repetition; the configuration of the random offset corresponding to the D2R signal; the configuration of the retransmission time of the D2R signal; or, the configuration of the time extension line for the terminal device to transmit the random access third message.

[0564] In one possible implementation of this application, the coverage level of the terminal device includes: coverage level A, where the coverage level A is the area where the D2R signal strength is greater than a first threshold; coverage level B, where the 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 a second threshold; and coverage level C, where the coverage level C is the area where the D2R signal strength is less than the second threshold.

[0565] In one possible implementation of this application, the access level of the terminal device includes: access level A, which is a region where the access success rate is greater than a third threshold; access level B, which is a region where the access success rate is less than or equal to the third threshold and greater than or equal to a fourth threshold; and access level C, which is a region where the access success rate is less than the fourth threshold.

[0566] In one possible implementation of this application embodiment, the coverage level and / or access level of the terminal device are determined based on one or more of the following: the capability of the terminal device, the distance between the reader / writer and the terminal device, the number of at least one terminal device to be inventoried, or the number of at least one terminal device that successfully accessed the system in the previous round of inventory.

[0567] In one possible implementation of this application embodiment, the capabilities of the terminal device include one or more of the following: frequency offset error range, ability to correct frequency deviation or time offset, energy storage capacity, or remaining power.

[0568] In one possible implementation of this application embodiment, the capabilities of the terminal 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.

[0569] In one possible implementation of this application embodiment, the capabilities of the terminal 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.

[0570] In one possible implementation of this application embodiment, the coverage level and / or access level of the terminal device are predefined.

[0571] In one possible implementation of this application embodiment, the coverage level and / or access level configuration of the terminal device is indicated by indication information.

[0572] In one possible implementation of this application embodiment, the configuration of the first time unit includes one or more of the following: the position of the first time unit, the period of the first time unit, or the duration of the first time unit.

[0573] In one possible implementation of this application embodiment, the first time unit is determined according to one or more of the following: the coverage level, the access level, the type of the terminal device, the type of the reader / writer, the type of signal corresponding to the period of the first time unit, or, random access type.

[0574] In one possible implementation of this application embodiment, the first time unit is located after the reader sends a first signal, the first signal including a paging message and / or a randomly accessed second message.

[0575] In one possible implementation of this application, the duration of the first time unit begins with the first or last time unit when the reader sends the first signal and ends when the terminal device receives the first D2R signal.

[0576] In one possible implementation of this application embodiment, the period of the first time unit includes one or more of the following: an inventory count, or a control operation.

[0577] In one possible implementation of this application embodiment, the position of the first time unit is located during the period when the reader receives the D2R signal.

[0578] In one possible implementation of this application embodiment, the position of the first time unit is located at the beginning position of the preamble of the D2R signal, and / or, the position of the first time unit is located at at least one intermediate preamble of the D2R signal, and / or, the position of the first time unit is located at the first uplink channel PDRCH of the D2R signal.

[0579] In one possible implementation of this application embodiment, the period of the first time unit is one inventory count, or it is statically configured in one control.

[0580] In one possible implementation of this application embodiment, the terminal device transmits the D2R signal in multiple time units, and the position of the first time unit is: the starting position of at least one preamble of the first transmitted D2R signal.

[0581] In one possible implementation of this application embodiment, the terminal device transmits the D2R signal in a time unit, where the position of the first time unit is the starting position of the first preamble of the D2R signal.

[0582] In one possible implementation of this application embodiment, the period of the first time unit is one inventory count, or a semi-static configuration in one control.

[0583] In one possible implementation of this application embodiment, the terminal device transmits the D2R signal in multiple time units, wherein the position of the first time unit is: the starting position of at least one preamble of the D2R signal transmitted each time, and / or the position of at least one intermediate preamble of the D2R signal.

[0584] In one possible implementation of this application embodiment, the terminal device transmits the D2R signal in a time unit, wherein the position of the first time unit is: the starting position of the preamble of the D2R signal and the position of at least one intermediate preamble of the D2R signal.

[0585] In one possible implementation of this application embodiment, the duration of the first time unit is predefined.

[0586] In one possible implementation of this application embodiment, the duration of the first time unit is indicated by indication information.

[0587] In one possible implementation of this application, the length of the first time unit is less than or equal to the length of the intermediate preamble of the D2R signal, or the length of the first time unit is less than or equal to the length of the preamble of the D2R signal.

[0588] In one possible implementation of this application embodiment, the D2R signal type includes: the D2R signal includes the first random access message, or the D2R signal includes the first random access message and the third random access message.

[0589] In one possible implementation of this application, the frame structure type of the D2R signal includes: including a D2R preamble, including a D2R preamble and at least one intermediate preamble, including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0590] In one possible implementation of this application, the D2R signal type includes the random access first message, which includes one or more of the following information: a 16-bit random number RN16, data, a non-data signal, or energy state indication information.

[0591] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information.

[0592] In one possible implementation of this application embodiment, the random access first message includes the RN16, or the non-data signal, or the energy state indication information, and the frame structure type of the D2R signal is either including a D2R preamble, or including both a D2R preamble and a postamble.

[0593] In one possible implementation of this application embodiment, the random access first message includes RN16 and data, and the frame structure type of the D2R signal is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0594] In one possible implementation of this application, the D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and the third random access message includes data.

[0595] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information.

[0596] In one possible implementation of this application embodiment, the frame structure type of the first random access message is the inclusion of a D2R preamble, and the frame structure type of the third random access message is the inclusion of a D2R preamble and at least one intermediate preamble, or the inclusion of a D2R preamble and a postamble, or the inclusion of a D2R preamble, at least one intermediate preamble, and a postamble.

[0597] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including only a D2R preamble, or including a D2R preamble and a postamble.

[0598] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble or including both a D2R preamble and a postamble; the frame structure type of the third random access message is either including only a D2R preamble or including both a D2R preamble and a postamble.

[0599] In one possible implementation of this application, the D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and data, and the third random access message includes data.

[0600] In one possible implementation of this application, the correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information.

[0601] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble.

[0602] In one possible implementation of this application embodiment, the frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble; the frame structure type of the third random access message is either including a D2R preamble, or including a D2R preamble and a postamble.

[0603] In one possible implementation of this application embodiment, the message includes a D2R preamble, or the message includes both a D2R preamble and a postamble. The frame structure type of the random access third message is either only a D2R preamble or both a D2R preamble and a postamble.

[0604] In one possible implementation of this application embodiment, the data includes one or more of the following: sensing data, or the ID of the terminal device.

[0605] In one possible implementation of this application embodiment, during the same inventory count, the frame structure type of the random access first message sent by multiple terminal devices is the same, and / or, the frame structure type of the random access third message sent by multiple terminal devices is the same.

[0606] In one possible implementation of this application embodiment, during the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is determined according to a predefined rule, and / or, the frame structure type of the third random access message sent by multiple terminal devices is determined according to a predefined rule.

[0607] In one possible implementation of this application, during the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is indicated by indication information, and / or, the frame structure type of the third random access message sent by multiple terminal devices is indicated by indication information.

[0608] In one possible implementation of this application, the configuration of the frame structure of the D2R signal for uplink synchronization is indicated by indication information, or the configuration of the frame structure of the D2R signal for uplink synchronization is predefined.

[0609] In one possible implementation of this application, the indication information is used to indicate uplink synchronization using the first preamble in the frame structure of the first random access message and / or the third random access message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. The frame structure of all the first random access messages includes the first preamble, and the frame structure of all the third random access messages includes the first preamble.

[0610] In one possible implementation of this application embodiment, the indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a first random access first message and / or a first random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. Specifically, the frame structures of N first random access first messages in all the first random access messages include the first preamble, and the frame structures of M first random access third messages in all the third random access messages include the first preamble. The N is less than or equal to the number of all first random access messages, and the M is less than or equal to the number of all third random access messages.

[0611] In one possible implementation of this application, the time-frequency position of the first preamble is related to one or more of the following factors: whether the random access first message includes data, the random access first message configured by the reader / writer, and / or the number of random access third message resources, the random access first message, and / or the size of the TBS of the random access third message, and the frame structure type of the D2R signal.

[0612] In one possible implementation of this application, the first sequence in the frame structure of the D2R signal is used for uplink synchronization.

[0613] In one possible implementation of this application, the type of the first sequence includes: a sparse sequence, a compact sequence, a sequence that is sparse first and then dense, or a sequence that is dense first and then sparse.

[0614] In one possible implementation of this application embodiment, the position and / or interval of the first sequence are determined based on the number of resources of the D2R signal.

[0615] In one possible implementation of this application, the sparse sequence is implemented using encoded values, and the compact sequence is implemented using encoded values.

[0616] In one possible implementation of this application, the sparse sequence is achieved by reducing the number of repetitions, and the compact sequence is achieved by increasing the number of repetitions.

[0617] In one possible implementation of this application, the sparse sequence is achieved by reducing the MCS-like level, and the compact sequence is achieved by increasing the MCS-like level.

[0618] In one possible implementation of this application, the first sequence is indicated by PRDCH control information, or the first sequence is determined by MCS-like information, or the number of repetitions of the D2R signal.

[0619] In one possible implementation of this application, the repetition granularity of the D2R signal includes: block-level repetition, bit-level repetition, or chip-level repetition.

[0620] In one possible implementation of this application, the repetition granularity of the D2R signal is block-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, the capability of the terminal device, or the size of the resources occupied by the D2R signal.

[0621] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of times the block-level repetition occurs, or the starting position of the block-level repetition.

[0622] In one possible implementation of this application, the starting position of the block-level repetition includes one or more of the following: the offset value of each repetition block relative to the starting or ending position of the paging message received by the terminal device, or the offset value of each repetition block relative to the adjacent previous repetition block.

[0623] In one possible implementation of this application, the configuration of the repetitive frequency domain resources includes: block-level repetitive frequency hopping levels; the block-level repetitive frequency hopping levels include: a first level, which is no frequency hopping; a second level, which is frequency hopping once every 1 frequency domain unit; and a third level, which is frequency hopping once every at least 2 frequency domain units.

[0624] In one possible implementation of this application, the number of block-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0625] In one possible implementation of this application, the number of block-level repetitions and / or the time-frequency resources used for repetitions are determined by at least one of the following: the size of the D2R TBS, or adjusting the coding level MCS-like information.

[0626] In one possible implementation of this application embodiment, the repetition granularity of the D2R signal is bit-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, or the capability of the terminal device.

[0627] In one possible implementation of this application, the number of bit-level repetitions is predefined.

[0628] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of bit-level repetitions, or the starting position of the bit-level repetitions.

[0629] In one possible implementation of this application, the starting position of the bit-level repetition includes the offset value of each repeated bit relative to the adjacent previous bit.

[0630] In one possible implementation of this application embodiment, the configuration of frequency domain resources for repetition includes: bit-level repetition frequency hopping levels;

[0631] The bit-level repetition frequency hopping levels include: a first level, which is no frequency hopping; a second level, which is frequency hopping once every 1 frequency domain unit; and a third level, which is frequency hopping once every at least 2 frequency domain units.

[0632] In one possible implementation of this application, the number of bit-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0633] In one possible implementation of this application, the number of bit-level repetitions and / or the time-frequency resources used for repetition are determined by MCS-like information.

[0634] In one possible implementation of this application, the repetition granularity of the D2R signal is chip-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors: the coverage level or access level of the terminal device, or the capability of the terminal device. In another possible implementation of this application, the number of chip-level repetitions is predefined.

[0635] In one possible implementation of this application, the configuration of the time-domain resources for repetition includes one or more of the following: the number of times the chip-level repetition occurs, or the starting position of the chip-level repetition.

[0636] In one possible implementation of this application, the starting position of the chip-level repetition includes the offset value of each repeated bit relative to the adjacent previous chip.

[0637] In one possible implementation of this application, the configuration of repeated frequency domain resources includes: no frequency hopping for chips within the same bit, and repeated frequency hopping levels for chips within different bits; the repeated frequency hopping levels for chips include: a first level, where no frequency hopping; a second level, where frequency hopping occurs once every one frequency domain unit; and a third level, where frequency hopping occurs once every at least two frequency domain units.

[0638] In one possible implementation of this application, the number of chip-level repetitions and / or the time-frequency resources used for repetition are indicated by PRDCH control information.

[0639] In one possible implementation of this application, the number of chip-level repetitions and / or the time-frequency resources used for repetition are determined by MCS-like information.

[0640] In one possible implementation of this application, the configuration of the random offset of the D2R signal includes a common offset, and the random offset of the D2R signal is determined according to the common offset; wherein, the common offset is the time domain interval between the AIoT paging message and the first random access first message, or, the common offset is the time domain interval between the random access second message and the first random access third message.

[0641] In one possible implementation of this application embodiment, under a non-contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal corresponding to the terminal device.

[0642] In one possible implementation of this application embodiment, the offset value of the D2R signal corresponding to the terminal device is indicated by indication information.

[0643] In one possible implementation of this application embodiment, under a contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal preempted by the terminal device.

[0644] In one possible implementation of this application, the offset value is predefined in the offset value set.

[0645] In one possible implementation of this application embodiment, during a new round of inventory checks, the configuration of the random offset of the D2R signal is indicated by retransmission indication information.

[0646] In one possible implementation of this application, the configuration of the retransmission time of the D2R signal includes one or more of the following: minimum retransmission time, maximum retransmission time, or retransmission data or frame structure update.

[0647] In one possible implementation of this application embodiment, the minimum retransmission time is related to the minimum time interval between two consecutive transmissions of the D2R signal by the terminal device.

[0648] In one possible implementation of this application, the maximum retransmission time is related to the minimum and / or maximum time interval between two consecutive R2D signal transmissions by the terminal device.

[0649] In one possible implementation of this application, the retransmission of data or frame structure update is indicated by indication information.

[0650] In one possible implementation of this application, the configuration of the time extension line for the terminal device to send the random access third message includes an extended time interval, which includes multiple time units.

[0651] In one possible implementation of this application embodiment, the conditions for extending the time interval include one or more of the following: the energy status reported by the terminal device, or the signal quality of the D2R signal.

[0652] In one possible implementation of this application, the configuration of the time extension line is determined based on the remaining battery power of the terminal device.

[0653] In one possible implementation of this application, the configuration of the time extension line is included in the random access second message.

[0654] In one possible implementation of this application embodiment, the configuration of the time extension line is determined according to the access level and / or the coverage level.

[0655] Optionally, the communication device may further include a storage module 3530, which can be used to store instructions and / or data, and the processing module 3520 can read the instructions and / or data in the storage module 3530.

[0656] In this embodiment, the communication device is presented as an integrated unit divided into functional modules. Here, "module" can refer to a specific ASIC, circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices that can provide the aforementioned functions. In a simplified embodiment, those skilled in the art will recognize that the terminal device can take the form of the communication device 2100 shown in FIG. 21.

[0657] For example, the processor 2101 in the communication device 2100 shown in FIG21 can call the computer execution instructions stored in the memory 2103 to make the communication device 2100 execute the communication method in the above method embodiment.

[0658] Specifically, the functions / implementation processes of the transceiver module 3510 and processing module 3520 in Figure 35 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103. Alternatively, the functions / implementation processes of the processing module 3520 in Figure 35 can be implemented by the processor 2101 in the reader / writer 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103, and the functions / implementation processes of the transceiver module 3510 in Figure 35 can be implemented by the communication interface 2104 in the communication device 2100 shown in Figure 21.

[0659] It should be understood that one or more of the above modules or units can be implemented by software, hardware, or a combination of both. When any of the above modules or units are implemented by software, the software exists as computer program instructions and is stored in memory. The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into a SoC (System-on-a-Chip) or ASIC, or it can be a separate semiconductor chip. In addition to the core that executes software instructions for computation or processing, the processor may further include necessary hardware accelerators, such as field-programmable gate arrays (FPGAs), PLDs (Programmable Logic Devices), or logic circuits that implement dedicated logic operations.

[0660] When the above modules or units are implemented in hardware, the hardware can be any one or any combination of a CPU, microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, application-specific digital circuit, hardware accelerator, or non-integrated discrete device, which can run the necessary software or perform the above method flow independently of software.

[0661] Optionally, embodiments of this application also provide a communication device (e.g., the communication device may be a chip or a chip system), which includes a processor for implementing the methods in any of the above method embodiments. In one possible design, the communication device further includes a memory. The memory is used to store necessary program instructions and data, and the processor can call the program code stored in the memory to instruct the communication device to execute the methods in any of the above method embodiments. Of course, the memory may not be included in the communication device. When the communication device is a chip system, it may be composed of chips or may include chips and other discrete devices; embodiments of this application do not specifically limit this.

[0662] Optionally, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions that, when run on a communication device, enable the communication device to execute the methods described in any of the above method embodiments or any implementation thereof.

[0663] Optionally, embodiments of this application also provide a communication system, which includes the communication device described in the above method embodiments.

[0664] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is 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, computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0665] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0666] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

A communication method, characterized in that, Applied to terminal devices, including: Based on the first configuration, the terminal device sends a D2R signal to the reader, the D2R signal including a random access first message and / or a random access third message; The first configuration includes one or more of the following: The level of the terminal device includes coverage level and / or access level; The configuration of the first time unit, wherein the terminal device may or may not send a signal within the first time unit; Configuration of the D2R signal type; Configuration of the frame structure of the D2R signal used for uplink synchronization; The number of repetitions of the D2R signal and the configuration of time-frequency resources used for repetition; The configuration of the random offset corresponding to the D2R signal; Configuration of the retransmission time of the D2R signal; Alternatively, the configuration of the time extension line for the terminal device to send the random access third message. The method according to claim 1, characterized in that, The coverage level of the terminal device includes: Coverage level A, wherein coverage level A is the region where the D2R signal strength is greater than a first threshold; Coverage level B, wherein the coverage level B is the region where the D2R signal strength is less than or equal to the first threshold and greater than or equal to the second threshold; Coverage level C, where coverage level C is the region where the D2R signal strength is less than the second threshold. The method according to claim 1 or 2, characterized in that, The access level of the terminal device includes: Access level A, where access level A is a region with an access success rate greater than a third threshold; Access level B, where the access success rate is less than or equal to the third threshold and greater than or equal to the fourth threshold in the region. Access level C, where access level C is a region where the access success rate is less than the fourth threshold. The method according to any one of claims 1 to 3 is characterized in that, The coverage level and / or access level of the terminal device are determined according to one or more of the following: The capabilities of the terminal device, the distance between the reader and the terminal device, the number of at least one terminal device to be inventoried, or the number of at least one terminal device that was successfully connected in the previous round of inventory. The method according to claim 4, characterized in that, The capabilities of the terminal 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. The method according to claim 4, characterized in that, The capabilities of the terminal device include one or more of the following: Signal amplification capability, energy storage capability, remaining power, frequency deviation error range, or the ability to correct frequency deviation or time offset. The method according to claim 4, characterized in that, The capabilities of the terminal 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. The method according to any one of claims 1 to 7, characterized in that, The coverage level and / or access level of the terminal device are configured as predefined. The method according to any one of claims 1 to 7, characterized in that, The coverage level and / or access level configuration of the terminal device is indicated by indication information. The method according to any one of claims 1 to 9, characterized in that, The configuration of the first time unit includes one or more of the following: The position of the first time unit, the period of the first time unit, or the duration of the first time unit. The method according to claim 10, characterized in that, The first time unit is determined according to one or more of the following: The coverage level, the access level, the type of the terminal device, the type of the reader / writer, the type of signal corresponding to the period of the first time unit, or the random access type. The method according to claim 10 or 11 is characterized in that, The first time unit is located after the reader sends a first signal, which includes a paging message and / or a randomly accessed second message. The method according to claim 12, characterized in that, The duration of the first time unit begins with the first or last time unit in which the reader sends the first signal and ends when the terminal device receives the first D2R signal. The method according to claim 12 or 13 is characterized in that, The period of the first time unit includes one or more of the following: An inventory check, or a control measure. The method according to claim 10 or 11 is characterized in that, The first time unit is located during the period when the reader receives the D2R signal. The method according to claim 15, characterized in that, The first time unit is located at the beginning of the preamble of the D2R signal, and / or the first time unit is located at at least one intermediate preamble of the D2R signal, and / or the first time unit is located at the first uplink channel PDRCH of the D2R signal. The method according to claim 14 or 15 is characterized in that, The period of the first time unit is one inventory count, or a statically configured control cycle. The method according to claim 17, characterized in that, The terminal device transmits the D2R signal in multiple time units, and the position of the first time unit is: the starting position of at least one preamble of the first transmitted D2R signal. The method according to claim 17, characterized in that, The terminal device transmits the D2R signal in a time unit, where the position of the first time unit is the starting position of the first preamble of the D2R signal. The method according to claim 14 or 15 is characterized in that, The period of the first time unit is one inventory count, or a semi-static configuration in one control cycle. The method according to claim 20, characterized in that, The terminal device transmits the D2R signal in multiple time units, wherein the position of the first time unit is: the starting position of at least one preamble of the D2R signal transmitted each time, and / or the position of at least one intermediate preamble of the D2R signal. The method according to claim 20, characterized in that, The terminal device transmits the D2R signal in a time unit, the first time unit being the starting position of the preamble of the D2R signal and the position of at least one intermediate preamble of the D2R signal. The method according to any one of claims 14 to 22 is characterized in that, The duration of the first time unit is predefined. The method according to any one of claims 14 to 22 is characterized in that, The duration of the first time unit is indicated by an indication message. The method according to any one of claims 14 to 24 is characterized in that, The length of the first time unit is less than or equal to the length of the intermediate preamble of the D2R signal, or the length of the first time unit is less than or equal to the length of the preamble of the D2R signal. The method according to any one of claims 1 to 25, characterized in that, The D2R signal type includes: the D2R signal includes the first random access message, or the D2R signal includes the first random access message and the third random access message. The method according to claim 26, characterized in that, The frame structure types of the D2R signal include: It includes a D2R preamble, a D2R preamble and at least one intermediate preamble, a D2R preamble and a postamble, or a D2R preamble, at least one intermediate preamble and a postamble. The method according to claim 26 or 27 is characterized in that, The D2R signal type includes the first random access message, which includes one or more of the following information: A 16-bit random number RN16, representing data, non-data signals, or energy state indication information. The method according to claim 27 or 28 is characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by the indication information. The method according to claim 29 is characterized in that the first random access message includes the RN16, or the non-data signal, or the energy state indication information, and the frame structure type of the D2R signal is the inclusion of a D2R preamble, or the inclusion of a D2R preamble and a postamble. The method according to claim 29, characterized in that, The first random access message includes RN16 and data. The frame structure type of the D2R signal is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 26 or 27 is characterized in that, The D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and the third random access message includes data. The method according to claim 32, characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information. The method according to claim 33 is characterized in that, The frame structure type of the first random access message is the one that includes a D2R preamble, and the frame structure type of the third random access message is the one that includes a D2R preamble and at least one intermediate preamble, or the one that includes a D2R preamble and a postamble, or the one that includes a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 33 is characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including only a D2R preamble, or including a D2R preamble and a postamble. The method according to claim 33 is characterized in that, The frame structure type of the first random access message is either including a D2R preamble or including both a D2R preamble and a postamble. The frame structure type of the third random access message is either including only a D2R preamble or including both a D2R preamble and a postamble. The method according to claim 26 or 27 is characterized in that, The D2R signal type includes the first random access message and the third random access message. The first random access message includes RN16 and data, and the third random access message includes data. The method according to claim 37, characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information. The method according to claim 38, characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 38, characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including a D2R preamble, or including a D2R preamble and a postamble. The method according to claim 38, characterized in that, The frame structure type of the random access third message is either D2R preamble or D2R preamble and postamble. The method according to any one of claims 28 to 41, characterized in that, The data includes one or more of the following: sensor data, or the ID of the terminal device. The method according to any one of claims 27 to 42, characterized in that, In the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is the same, and / or the frame structure type of the third random access message sent by multiple terminal devices is the same. The method according to any one of claims 27 to 43, characterized in that, During the same inventory check, the frame structure type of the first random access message sent by multiple terminal devices is determined according to predefined rules, and / or, the frame structure type of the third random access message sent by multiple terminal devices is determined according to predefined rules. The method according to any one of claims 27 to 43, characterized in that, During the same inventory check, the frame structure type of the first random access message sent by multiple terminal devices is indicated by indication information, and / or, the frame structure type of the third random access message sent by multiple terminal devices is indicated by indication information. The method according to any one of claims 1 to 45, characterized in that, The configuration of the frame structure of the D2R signal for uplink synchronization is indicated by indication information, or the configuration of the frame structure of the D2R signal for uplink synchronization is predefined. The method according to claim 46, characterized in that, The indication information is used to indicate uplink synchronization using the first preamble in the frame structure of the first random access message and / or the third random access message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble, wherein the frame structure of all the first random access messages includes the first preamble, and the frame structure of all the third random access messages includes the first preamble. The method according to claim 46, characterized in that, The indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a first random access first message and / or a first random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. Specifically, the frame structures of N first random access first messages in all of the first random access messages include the first preamble, and the frame structures of M first random access third messages in all of the third random access messages include the first preamble. The N is less than or equal to the number of all first random access messages, and the M is less than or equal to the number of all third random access messages. The method according to claim 48, characterized in that, The time-frequency position of the first preamble is related to one or more of the following factors: whether the random access first message includes data, the random access first message configured by the reader / writer, and / or the number of random access third message resources, the size of the TBS of the random access first message, and / or the random access third message, and the frame structure type of the D2R signal. The method according to claim 46, characterized in that, The first sequence in the frame structure of the D2R signal is used for uplink synchronization. The method according to claim 50, characterized in that, The first sequence can be of the following types: sparse sequence, compact sequence, sparse-to-dense sequence, or dense-to-sparse sequence. The method according to claim 50 or 51 is characterized in that, The position and / or interval of the first sequence are determined based on the number of resources of the D2R signal. The method according to claim 51 or 52 is characterized in that, The sparse sequence is implemented using encoded values, and the compact sequence is implemented using encoded values. The method according to claim 51 or 52 is characterized in that, The sparse sequence is achieved by reducing the number of repetitions, while the compact sequence is achieved by increasing the number of repetitions. The method according to claim 51 or 52 is characterized in that, The sparse sequence is achieved by reducing the MCS-like level, and the compact sequence is achieved by increasing the MCS-like level. The method according to any one of claims 50 to 55, characterized in that, The first sequence is indicated by PRDCH control information, or the first sequence is determined by MCS-like information, or the number of repetitions of the D2R signal. The method according to any one of claims 1 to 55, characterized in that, The repetition granularity of the D2R signal includes: block-level repetition, bit-level repetition, or chip-level repetition. The method according to claim 57, characterized in that, The repetition granularity of the D2R signal is block-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, the capabilities of the terminal device, or the amount of resources occupied by the D2R signal. The method according to claim 58, characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of times the block repeats, or the starting position of the block repeat. The method according to claim 59, characterized in that, The starting position of the block-level repetition includes one or more of the following: the offset value of each repetition block relative to the start or end position of the paging message received by the terminal device, or the offset value of each repetition block relative to the adjacent previous repetition block. The method according to any one of claims 58 to 60, characterized in that, The configuration for repetitive frequency domain resources includes: Block-level repeating frequency hopping levels; The block-level repetitive frequency hopping levels include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 58 to 61, characterized in that, The number of times the block-level repetitions are specified, and / or the time-frequency resources used for repetitions are indicated by PRDCH control information. The method according to any one of claims 58 to 61, characterized in that, The number of times the block-level repetitions are determined, and / or the time-frequency resources used for repetitions are determined by at least one of the following: the size of the D2R TBS, or, adjusting the coding level MCS-like information. The method according to claim 57, characterized in that, The repetition granularity of the D2R signal is bit-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, or the capabilities of the terminal device. The method according to claim 64, characterized in that, The number of bit-level repetitions is predefined. The method according to claim 64 or 65 is characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of bit-level repetitions, or the starting position of the bit-level repetitions. The method according to claim 66, characterized in that, The starting position of the bit-level repetition includes the offset value of each repeated bit relative to the adjacent previous bit. The method according to any one of claims 64 to 67, characterized in that, The configuration for repetitive frequency domain resources includes: Frequency hopping levels with bit-level repetition; The frequency hopping levels with bit-level repetition include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 64 to 68, characterized in that, The number of bit-level repetitions, and / or the time-frequency resources used for repetition, are indicated by PRDCH control information. The method according to any one of claims 64 to 68, characterized in that, The number of bit-level repetitions, and / or the time-frequency resources used for repetition, are determined by MCS-like information. The method according to claim 57, characterized in that, The repetition granularity of the D2R signal is chip-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, or the capabilities of the terminal device. The method according to claim 71, characterized in that, The number of times the chip-level repetitions are predefined. The method according to claim 71 or 72 is characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of times the chip-level repeats, or the starting position of the chip-level repeats. The method according to claim 73, characterized in that, The starting position of the chip-level repetition includes the offset of each repeated bit relative to the adjacent previous chip. The method according to any one of claims 71 to 74 is characterized in that, The configuration for repetitive frequency domain resources includes: Chips within the same bit do not hop frequencies, while chip-level frequency hopping levels are repeated across different bits; The chip-level repetition frequency hopping levels include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 71 to 75, characterized in that, The number of chip-level repetitions, and / or the time-frequency resources used for repetitions, are indicated by PRDCH control information. The method according to any one of claims 71 to 75, characterized in that, The number of chip-level repetitions, and / or the time-frequency resources used for repetitions, are determined by MCS-like information. The method according to any one of claims 1 to 66, characterized in that, The configuration of the random offset of the D2R signal includes a common offset, and the random offset of the D2R signal is determined based on the common offset; Wherein, the common offset is the time-domain interval between the AIoT paging message and the first random access first message, or the common offset is the time-domain interval between the random access second message and the first random access third message. The method according to claim 78, characterized in that, Under a non-contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal corresponding to the terminal device. The method according to claim 79, characterized in that, The offset value of the D2R signal corresponding to the terminal device is indicated by the indication information. The method according to claim 78, characterized in that, Under a contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal preempted by the terminal device. The method according to claim 81, characterized in that, The offset value is predefined in the offset value set. The method according to any one of claims 1 to 66, characterized in that, In the new round of inventory checks, the configuration of the random offset of the D2R signal is indicated by the retransmission indication information. The method according to any one of claims 1 to 83, characterized in that, The retransmission time configuration of the D2R signal includes one or more of the following: minimum retransmission time, maximum retransmission time, or retransmission data or frame structure update. The method according to claim 84, characterized in that, The minimum retransmission time is related to the minimum time interval between two consecutive transmissions of the D2R signal by the terminal device. The method according to claim 84 or 85 is characterized in that, The maximum retransmission time is related to the minimum and / or maximum time interval between two consecutive R2D signal transmissions by the terminal device. The method according to any one of claims 84 to 86, characterized in that, The retransmitted data or frame structure update is indicated by the indication information. The method according to any one of claims 1 to 87, characterized in that, The configuration of the time extension line for the terminal device to send the random access third message includes the extended time interval, which includes multiple time units. The method according to claim 88, characterized in that, The conditions for extending the time interval include one or more of the following: The energy status reported by the terminal device, or the signal quality of the D2R signal. The method according to claim 88 or 89 is characterized in that, The configuration of the time extension line is determined based on the remaining battery power of the terminal device. The method according to claim 88 or 89 is characterized in that, The configuration of the time extension line is included in the random access second message. The method according to claim 88 or 89 is characterized in that, The configuration of the time extension line is determined based on the access level and / or the coverage level. A communication method, characterized in that, Applications in readers and writers include: The reader receives a D2R signal from the terminal device, the D2R signal including a first random access message and / or a third random access message; The D2R signal is determined by the terminal device based on a first configuration, which includes one or more of the following: The level of the terminal device includes coverage level and / or access level; The configuration of the first time unit, wherein the terminal device may or may not send a signal within the first time unit; Configuration of the D2R signal type; Configuration of the frame structure of the D2R signal used for uplink synchronization; The number of repetitions of the D2R signal and the configuration of time-frequency resources used for repetition; The configuration of the random offset corresponding to the D2R signal; Configuration of the retransmission time of the D2R signal; Alternatively, the configuration of the time extension line for the terminal device to send the random access third message; The reader sends an R2D signal based on the D2R signal. The method according to claim 93, characterized in that, The coverage level of the terminal device includes: Coverage level A, wherein coverage level A is the region where the D2R signal strength is greater than a first threshold; Coverage level B, wherein the coverage level B is the region where the D2R signal strength is less than or equal to the first threshold and greater than or equal to the second threshold; Coverage level C, where coverage level C is the region where the D2R signal strength is less than the second threshold. The method according to claim 93 or 94 is characterized in that, The access level of the terminal device includes: Access level A, where access level A is a region with an access success rate greater than a third threshold; Access level B, where the access success rate is less than or equal to the third threshold and greater than or equal to the fourth threshold in the region. Access level C, where access level C is a region where the access success rate is less than the fourth threshold. The method according to any one of claims 93 to 95, characterized in that, The coverage level and / or access level of the terminal device are determined according to one or more of the following: The capabilities of the terminal device, the distance between the reader and the terminal device, the number of at least one terminal device to be inventoried, or the number of at least one terminal device that was successfully connected in the previous round of inventory. The method according to claim 96, characterized in that, The capabilities of the terminal 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. The method according to claim 96, characterized in that, The capabilities of the terminal device include one or more of the following: Signal amplification capability, energy storage capability, remaining power, frequency deviation error range, or the ability to correct frequency deviation or time offset. The method according to claim 96, characterized in that, The capabilities of the terminal 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. The method according to any one of claims 93 to 99, characterized in that, The coverage level and / or access level of the terminal device are configured as predefined. The method according to any one of claims 93 to 99, characterized in that, The coverage level and / or access level configuration of the terminal device is indicated by indication information. The method according to any one of claims 93 to 101, characterized in that, The configuration of the first time unit includes one or more of the following: The position of the first time unit, the period of the first time unit, or the duration of the first time unit. The method according to claim 102, characterized in that, The first time unit is determined according to one or more of the following: The coverage level, the access level, the type of the terminal device, the type of the reader / writer, the type of signal corresponding to the period of the first time unit, or the random access type. The method according to claim 102 or 103 is characterized in that, The first time unit is located after the reader sends a first signal, which includes a paging message and / or a randomly accessed second message. The method according to claim 104, characterized in that, The duration of the first time unit begins with the first or last time unit in which the reader sends the first signal and ends when the terminal device receives the first D2R signal. The method according to claim 104 or 105 is characterized in that, The period of the first time unit includes one or more of the following: An inventory check, or a control measure. The method according to claim 102 or 103 is characterized in that, The first time unit is located during the period when the reader receives the D2R signal. The method according to claim 107, characterized in that, The first time unit is located at the beginning of the preamble of the D2R signal, and / or the first time unit is located at at least one intermediate preamble of the D2R signal, and / or the first time unit is located at the first uplink channel PDRCH of the D2R signal. The method according to claim 106 or 107 is characterized in that, The period of the first time unit is one inventory count, or a statically configured control cycle. The method according to claim 109, characterized in that, The terminal device transmits the D2R signal in multiple time units, and the position of the first time unit is: the starting position of at least one preamble of the first transmitted D2R signal. The method according to claim 109, characterized in that, The terminal device transmits the D2R signal in a time unit, where the position of the first time unit is the starting position of the first preamble of the D2R signal. The method according to claim 106 or 107 is characterized in that, The period of the first time unit is one inventory count, or a semi-static configuration in one control cycle. The method according to claim 112, characterized in that, The terminal device transmits the D2R signal in multiple time units, wherein the position of the first time unit is: the starting position of at least one preamble of the D2R signal transmitted each time, and / or the position of at least one intermediate preamble of the D2R signal. The method according to claim 112, characterized in that, The terminal device transmits the D2R signal in a time unit, the first time unit being the starting position of the preamble of the D2R signal and the position of at least one intermediate preamble of the D2R signal. The method according to any one of claims 106 to 114 is characterized in that, The duration of the first time unit is predefined. The method according to any one of claims 106 to 114 is characterized in that, The duration of the first time unit is indicated by an indication message. The method according to any one of claims 106 to 116 is characterized in that, The length of the first time unit is less than or equal to the length of the intermediate preamble of the D2R signal, or the length of the first time unit is less than or equal to the length of the preamble of the D2R signal. The method according to any one of claims 93 to 117 is characterized in that, The D2R signal type includes: the D2R signal includes the first random access message, or the D2R signal includes the first random access message and the third random access message. The method according to claim 118, characterized in that, The frame structure types of the D2R signal include: It includes a D2R preamble, a D2R preamble and at least one intermediate preamble, a D2R preamble and a postamble, or a D2R preamble, at least one intermediate preamble and a postamble. The method according to claim 118 or 119, characterized in that, The D2R signal type includes the first random access message, which includes one or more of the following information: A 16-bit random number RN16, representing data, non-data signals, or energy state indication information. The method according to claim 119 or 120 is characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by the indication information. The method according to claim 121 is characterized in that the random access first message includes the RN16, or the non-data signal, or the energy state indication information, and the frame structure type of the D2R signal is the inclusion of a D2R preamble, or the inclusion of a D2R preamble and a postamble. The method according to claim 121, characterized in that, The first random access message includes RN16 and data. The frame structure type of the D2R signal is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 118 or 119, characterized in that, The D2R signal type includes the first random access message and the third random access message, wherein the first random access message includes RN16 and the third random access message includes data. The method according to claim 124, characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information. The method according to claim 125, characterized in that, The frame structure type of the first random access message is the one that includes a D2R preamble, and the frame structure type of the third random access message is the one that includes a D2R preamble and at least one intermediate preamble, or the one that includes a D2R preamble and a postamble, or the one that includes a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 125, characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including only a D2R preamble, or including a D2R preamble and a postamble. The method according to claim 125, characterized in that, The frame structure type of the first random access message is either including a D2R preamble or including both a D2R preamble and a postamble. The frame structure type of the third random access message is either including only a D2R preamble or including both a D2R preamble and a postamble. The method according to claim 118 or 119, characterized in that, The D2R signal type includes the first random access message and the third random access message. The first random access message includes RN16 and data, and the third random access message includes data. The method according to claim 129, characterized in that, The correspondence between the information included in the first random access message and the frame structure type of the D2R signal is indicated by indication information, and the correspondence between the information included in the third random access message and the frame structure type of the D2R signal is indicated by indication information. The method according to claim 130, characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble and a postamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The method according to claim 131, characterized in that, The frame structure type of the first random access message is either including a D2R preamble and at least one intermediate preamble, or including a D2R preamble, at least one intermediate preamble, and a postamble. The frame structure type of the third random access message is either including a D2R preamble, or including a D2R preamble and a postamble. The method according to claim 130, characterized in that, The frame structure type of the random access third message is either D2R preamble or D2R preamble and postamble. The method according to any one of claims 120 to 133 is characterized in that, The data includes one or more of the following: sensor data, or the ID of the terminal device. The method according to any one of claims 119 to 134 is characterized in that, In the same inventory count, the frame structure type of the first random access message sent by multiple terminal devices is the same, and / or the frame structure type of the third random access message sent by multiple terminal devices is the same. The method according to any one of claims 119 to 135 is characterized in that, During the same inventory check, the frame structure type of the first random access message sent by multiple terminal devices is determined according to predefined rules, and / or, the frame structure type of the third random access message sent by multiple terminal devices is determined according to predefined rules. The method according to any one of claims 119 to 135 is characterized in that, During the same inventory check, the frame structure type of the first random access message sent by multiple terminal devices is indicated by indication information, and / or, the frame structure type of the third random access message sent by multiple terminal devices is indicated by indication information. The method according to any one of claims 93 to 137, characterized in that, The configuration of the frame structure of the D2R signal for uplink synchronization is indicated by indication information, or the configuration of the frame structure of the D2R signal for uplink synchronization is predefined. The method according to claim 138, characterized in that, The indication information is used to indicate uplink synchronization using the first preamble in the frame structure of the first random access message and / or the third random access message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble, wherein the frame structure of all the first random access messages includes the first preamble, and the frame structure of all the third random access messages includes the first preamble. The method according to claim 138, characterized in that, The indication information is used to indicate uplink synchronization using a first preamble in the frame structure of a first random access first message and / or a first random access third message. The first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble. Specifically, the frame structures of N first random access first messages in all of the first random access messages include the first preamble, and the frame structures of M first random access third messages in all of the third random access messages include the first preamble. The N is less than or equal to the number of all first random access messages, and the M is less than or equal to the number of all third random access messages. The method according to claim 140, characterized in that, The time-frequency position of the first preamble is related to one or more of the following factors: whether the random access first message includes data, the random access first message configured by the reader / writer, and / or the number of random access third message resources, the size of the TBS of the random access first message, and / or the random access third message, and the frame structure type of the D2R signal. The method according to claim 138, characterized in that, The first sequence in the frame structure of the D2R signal is used for uplink synchronization. The method according to claim 142, characterized in that, The first sequence can be of the following types: sparse sequence, compact sequence, sparse-to-dense sequence, or dense-to-sparse sequence. The method according to claim 142 or 143 is characterized in that, The position and / or interval of the first sequence are determined based on the number of resources of the D2R signal. The method according to claim 142 or 143 is characterized in that, The sparse sequence is implemented using encoded values, and the compact sequence is implemented using encoded values. The method according to claim 142 or 143 is characterized in that, The sparse sequence is achieved by reducing the number of repetitions, while the compact sequence is achieved by increasing the number of repetitions. The method according to claim 142 or 143 is characterized in that, The sparse sequence is achieved by reducing the MCS-like level, and the compact sequence is achieved by increasing the MCS-like level. The method according to any one of claims 141 to 147 is characterized in that, The first sequence is indicated by PRDCH control information, or the first sequence is determined by MCS-like information, or the number of repetitions of the D2R signal. The method according to any one of claims 93 to 148, characterized in that, The repetition granularity of the D2R signal includes: block-level repetition, bit-level repetition, or chip-level repetition. The method according to claim 149, characterized in that, The repetition granularity of the D2R signal is block-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, the capabilities of the terminal device, or the amount of resources occupied by the D2R signal. The method according to claim 150, characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of times the block repeats, or the starting position of the block repeat. The method according to claim 151, characterized in that, The starting position of the block-level repetition includes one or more of the following: the offset value of each repetition block relative to the start or end position of the paging message received by the terminal device, or the offset value of each repetition block relative to the adjacent previous repetition block. The method according to any one of claims 150 to 152, characterized in that, The configuration for repetitive frequency domain resources includes: Block-level repeating frequency hopping levels; The block-level repetitive frequency hopping levels include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 150 to 153 is characterized in that, The number of times the block-level repetitions are specified, and / or the time-frequency resources used for repetitions are indicated by PRDCH control information. The method according to any one of claims 150 to 153 is characterized in that, The number of times the block-level repetitions are determined, and / or the time-frequency resources used for repetitions are determined by at least one of the following: the size of the D2R TBS, or, adjusting the coding level MCS-like information. The method according to claim 149, characterized in that, The repetition granularity of the D2R signal is bit-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, or the capabilities of the terminal device. The method according to claim 156 is characterized in that, The number of bit-level repetitions is predefined. The method according to claim 156 or 157 is characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of bit-level repetitions, or the starting position of the bit-level repetitions. The method according to claim 158, characterized in that, The starting position of the bit-level repetition includes the offset value of each repeated bit relative to the adjacent previous bit. The method according to any one of claims 156 to 159 is characterized in that, The configuration for repetitive frequency domain resources includes: Frequency hopping levels with bit-level repetition; The frequency hopping levels with bit-level repetition include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 156 to 160, characterized in that, The number of bit-level repetitions, and / or the time-frequency resources used for repetition, are indicated by PRDCH control information. The method according to any one of claims 156 to 160, characterized in that, The number of bit-level repetitions, and / or the time-frequency resources used for repetition, are determined by MCS-like information. The method according to claim 159, characterized in that, The repetition granularity of the D2R signal is chip-level repetition, and the number of repetitions of the D2R signal is related to one or more of the following factors; The coverage level or access level of the terminal device, or the capabilities of the terminal device. The method according to claim 163 is characterized in that, The number of times the chip-level repetitions are predefined. The method according to claim 163 or 164 is characterized in that, The configuration for repeated time-domain resources includes one or more of the following: The number of times the chip-level repeats, or the starting position of the chip-level repeats. The method according to claim 165, characterized in that, The starting position of the chip-level repetition includes the offset of each repeated bit relative to the adjacent previous chip. The method according to any one of claims 162 to 165, characterized in that, The configuration for repetitive frequency domain resources includes: Chips within the same bit do not hop frequencies, while chip-level frequency hopping levels are repeated across different bits; The chip-level repetition frequency hopping levels include: The first level is non-frequency hopping; The second level involves hopping frequency once every one frequency domain unit; The third level is defined as hopping frequency once every at least two frequency domain units. The method according to any one of claims 163 to 167, characterized in that, The number of chip-level repetitions, and / or the time-frequency resources used for repetitions, are indicated by PRDCH control information. The method according to any one of claims 163 to 168, characterized in that, The number of chip-level repetitions, and / or the time-frequency resources used for repetitions, are determined by MCS-like information. The method according to any one of claims 93 to 148, characterized in that, The configuration of the random offset of the D2R signal includes a common offset, and the random offset of the D2R signal is determined based on the common offset; Wherein, the common offset is the time-domain interval between the AIoT paging message and the first random access first message, or the common offset is the time-domain interval between the random access second message and the first random access third message. The method according to claim 170, characterized in that, Under a non-contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal corresponding to the terminal device. The method according to claim 171, characterized in that, The offset value of the D2R signal corresponding to the terminal device is indicated by the indication information. The method according to claim 170, characterized in that, Under a contention-based access mechanism, the random offset of the D2R signal is determined based on the common offset and the offset value of the D2R signal preempted by the terminal device. The method according to claim 173 is characterized in that, The offset value is predefined in the offset value set. The method according to any one of claims 93 to 148, characterized in that, In the new round of inventory checks, the configuration of the random offset of the D2R signal is indicated by the retransmission indication information. The method according to any one of claims 93 to 175 is characterized in that, The retransmission time configuration of the D2R signal includes one or more of the following: minimum retransmission time, maximum retransmission time, or retransmission data or frame structure update. The method according to claim 176, characterized in that, The minimum retransmission time is related to the minimum time interval between two consecutive transmissions of the D2R signal by the terminal device. The method according to claim 176 or 177 is characterized in that, The maximum retransmission time is related to the minimum and / or maximum time interval between two consecutive R2D signal transmissions by the terminal device. The method according to any one of claims 176 to 178 is characterized in that, The retransmitted data or frame structure update is indicated by the indication information. The method according to any one of claims 93 to 179 is characterized in that, The configuration of the time extension line for the terminal device to send the random access third message includes the extended time interval, which includes multiple time units. The method according to claim 180, characterized in that, The conditions for extending the time interval include one or more of the following: The energy status reported by the terminal device, or the signal quality of the D2R signal. The method according to claim 180 or 181, characterized in that, The configuration of the time extension line is determined based on the remaining battery power of the terminal device. The method according to claim 180 or 181, characterized in that, The configuration of the time extension line is included in the random access second message. The method according to claim 180 or 181, characterized in that, The configuration of the time extension line is determined based on the access level and / or the coverage level. A communication device, characterized in that, The communication device includes a module for performing the method according to any one of claims 1 to 92, or the communication device includes a module for performing the method according to any one of claims 93 to 184. A communication device, characterized in that, The communication device includes a processor; the processor is configured to perform the method according to any one of claims 1 to 92, or to cause the communication device to perform the method according to any one of claims 93 to 184. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes instructions that, when executed, cause the method according to any one of claims 1 to 92 to be implemented, or cause the method according to any one of claims 93 to 184 to be implemented. A computer program product, characterized in that, The computer program product includes instructions that, when executed, cause the method according to any one of claims 1 to 92 to be implemented, or cause the method according to any one of claims 93 to 184 to be implemented. A communication system, characterized in that, The communication system includes the communication device as described in claims 185 and 186.

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