Communication method and apparatus for broadcast frame, and device, medium and program product

Abstract

The present application belongs to the field of zero power consumption. Disclosed are a communication method and apparatus for a broadcast frame, and a device, a medium and a program product. The method is executed by a zero-power-consumption device, and the method comprises: receiving a first broadcast frame, wherein the first broadcast frame is a broadcast frame that is sent at a different time-domain position from a second broadcast frame, which is periodically sent. By means of the method, a first broadcast frame is received, wherein the first broadcast frame is a broadcast frame that is sent at a different time-domain position from a second broadcast frame, which is periodically sent, so as to facilitate a zero-power-consumption device in completing time-frequency synchronization and obtaining system information, thereby accelerating a communication process between a network device and the zero-power-consumption device, shortening the waiting time of the zero-power-consumption device to receive the broadcast frame, and thus reducing the power consumption of the zero-power-consumption device.

Description

Communication method, device, equipment, medium and program product for broadcast frame Technical Field

[0001] The present application relates to the field of zero power consumption, and in particular to a communication method, apparatus, device, medium and program product for broadcast frames. Background Art

[0002] In a Wireless Fidelity (WiFi) system or a cellular communication system, a network device sends a broadcast frame to a terminal device, and the terminal device performs time-frequency synchronization and system configuration according to the broadcast frame.

[0003] In a zero-power IoT, IoT devices synchronize their time and frequency, as well as configure their systems, by receiving broadcast frames from these network devices. Because IoT devices can sleep and these broadcast frames are sent periodically, if the interval between the device's wakeup time and the next broadcast frame is large, the device cannot synchronize quickly enough, increasing service latency and device power consumption.

[0004] Summary of the Invention

[0005] The present application provides a communication method, apparatus, device, medium, and program product for broadcast frames. The technical solution at least includes:

[0006] According to one aspect of an embodiment of the present application, a communication method for a broadcast frame is provided. The method is performed by a zero-power consumption device, and the method includes:

[0007] A first broadcast frame is received, where the first broadcast frame is sent at a time domain position different from a second broadcast frame that is periodically sent.

[0008] According to another aspect of an embodiment of the present application, a communication method for a broadcast frame is provided, the method being performed by a network device, the method comprising:

[0009] A first broadcast frame is sent, where the first broadcast frame is a broadcast frame sent at a time domain position different from a second broadcast frame that is periodically sent.

[0010] According to another aspect of an embodiment of the present application, a communication device for broadcasting a frame is provided, the device including:

[0011] The receiving module is configured to receive a first broadcast frame, where the first broadcast frame is sent at a time domain position different from a second broadcast frame sent periodically.

[0012] According to another aspect of an embodiment of the present application, a communication device for broadcasting a frame is provided, the device including:

[0013] The sending module is used to send a first broadcast frame, where the first broadcast frame is sent at a time domain position different from a second broadcast frame that is periodically sent.

[0014] According to another aspect of an embodiment of the present application, a zero-power consumption device is provided, the zero-power consumption device including:

[0015] processor;

[0016] a transceiver connected to the processor;

[0017] a memory for storing executable instructions for the processor;

[0018] The processor is configured to load and execute executable instructions to implement the communication method of broadcast frames as described in the above aspects.

[0019] According to another aspect of an embodiment of the present application, a network device is provided, the network device including:

[0020] processor;

[0021] a transceiver connected to the processor;

[0022] a memory for storing executable instructions for the processor;

[0023] The processor is configured to load and execute executable instructions to implement the communication method of broadcast frames as described in the above aspects.

[0024] According to another aspect of an embodiment of the present application, a computer-readable storage medium is provided, in which at least one program is stored. The at least one program is loaded and executed by a processor to implement the communication method of the broadcast frame as described in the above aspects.

[0025] According to another aspect of an embodiment of the present application, a computer program product or computer program is provided, which includes computer instructions, the computer instructions are stored in a computer-readable storage medium, a processor obtains the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to implement a communication method for broadcast frames as described in the above aspects.

[0026] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0027] By receiving the first broadcast frame, which is a broadcast frame sent at a time domain position different from the periodically sent second broadcast frame, even if the interval between the wake-up time of the IoT device and the next second broadcast frame is large, since the time position of the first broadcast frame is close to the wake-up time of the zero-power device, it is used to help the zero-power device quickly complete time and frequency synchronization and obtain system information, thereby speeding up the communication process between the network device and the zero-power device, and reducing the waiting time for the zero-power device to receive the second broadcast frame, thereby reducing the power consumption of the zero-power device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] FIG1 shows a schematic diagram of a zero-power communication system provided by an exemplary embodiment of the present application;

[0030] FIG2 shows a schematic diagram of radio frequency energy harvesting provided by related art;

[0031] FIG3 is a schematic diagram showing a backscatter communication process provided by the related art;

[0032] FIG4 shows a schematic diagram of resistive load modulation provided by the related art;

[0033] FIG5 is a schematic diagram showing an encoding method provided by related art;

[0034] FIG6 shows a schematic diagram of a zero-power device searching for a beacon frame according to an exemplary embodiment of the present application;

[0035] FIG7 shows a flow chart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0036] FIG8 shows a flow chart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0037] FIG9 shows a flow chart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0038] FIG10 shows a schematic diagram of sending a first broadcast frame and a second broadcast frame provided by an exemplary embodiment of the present application;

[0039] FIG11 shows a schematic diagram of sending a first broadcast frame and a second broadcast frame provided by an exemplary embodiment of the present application;

[0040] FIG12 is a schematic diagram showing sending a first broadcast frame and a second broadcast frame provided by an exemplary embodiment of the present application;

[0041] FIG13 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0042] FIG14 is a schematic diagram showing a structural format of a beacon frame provided by an exemplary embodiment of the present application;

[0043] FIG15 is a schematic diagram showing a structural format of a beacon frame provided by an exemplary embodiment of the present application;

[0044] FIG16 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0045] FIG17 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application;

[0046] FIG18 shows a block diagram of a communication device for broadcasting frames provided by an exemplary embodiment of the present application;

[0047] FIG19 shows a block diagram of a communication device for broadcasting frames provided by an exemplary embodiment of the present application;

[0048] FIG20 shows a schematic structural diagram of a zero-power consumption device or a network device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. Exemplary embodiments will be described in detail herein, with examples shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0050] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0051] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0052] The technical solutions described in some embodiments of the present application can be applicable to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Advanced long term evolution (LTE-A) system, New Radio (NR) system, NR system evolution system, LTE on unlicensed spectrum (LTE-U) system, NR on unlicensed spectrum (NR-U) system, Non-Terrestrial Networks (NTN) system, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), Wireless Fidelity (Wireless Fidelity) system. Fidelity, WiFi), fifth-generation communication (5th-Generation, 5G) system, cellular Internet of Things system, cellular passive Internet of Things system, and can also be applied to subsequent evolution systems of 5G NR system, and can also be applied to 6G and subsequent evolution systems.

[0053] It should be understood that in some embodiments of the present application, "5G" may also be referred to as "5G NR" or "NR".

[0054] It should be understood that in the description of the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and being indicated, configuration and being configured, etc.

[0055] In the embodiments of the present application, "predefined" can be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (for example, a terminal device and a network device). The present application does not limit the specific implementation method. For example, predefined can refer to information defined in a protocol.

[0056] In the embodiments of the present application, "protocol" may refer to a standard protocol in the field of communications, for example, it may include an LTE protocol, a NR protocol, and related protocols used in future communication systems, and this application does not limit this.

[0057] FIG1 shows a schematic diagram of a zero-power communication system 100 provided by an exemplary embodiment of the present application. The zero-power communication system 100 includes a network device 120 and a zero-power device 140 .

[0058] The network device 120 is used to send wireless power supply signals, downlink communication signals and receive backscatter signals from the zero-power device 140 to the zero-power device 140. The zero-power device 140 is also called an ambient power enabled Internet of Things (Ambient IoT) device, which includes an energy collection module 141, a backscatter communication module 142 and a low-power computing module 143. The energy collection module 141 can collect energy carried by radio waves in space, which is used to drive the low-power computing module 143 of the zero-power device 140 and realize backscatter communication. After the zero-power device 140 obtains energy, it can receive control signaling from the network device 120 and send data to the network device 120 based on the backscattering method according to the control signaling. The sent data can come from the data stored in the zero-power device 140 itself (such as an identity or pre-written information, such as the production date, brand, manufacturer, etc. of the product).

[0059] Zero-power device 140 may also include a sensor module 144 and a memory 145. Sensor module 144 may include various sensors, and zero-power device 140 may report data collected by these sensors based on a zero-power mechanism. Memory 145 is used to store basic information (such as item identification) or obtain sensor data such as ambient temperature and humidity.

[0060] The zero-power device 140 itself does not require a battery, and at the same time, the low-power computing module 143 can perform simple signal demodulation, decoding or encoding, modulation and other simple calculation tasks. Therefore, the zero-power module only requires a very simple hardware design, making the zero-power device 140 very low in cost and small in size.

[0061] The network device 120 includes but is not limited to: cellular network devices, such as 5G / 6G network devices, base station devices; WiFi / WLAN network devices, such as access points (APs), routers, mobile access points, etc., and the mobile access point is, for example, a mobile phone.

[0062] The zero-power device 140 includes but is not limited to: handheld devices, wearable devices, vehicle-mounted devices and Internet of Things devices, etc. The zero-power device 140 can be at least one of a mobile phone, a tablet computer, an e-book reader, a laptop computer, a desktop computer, a television, a game console, an augmented reality (AR) terminal, a virtual reality (VR) terminal and a mixed reality (MR) terminal, a wearable device, a handle, an electronic tag and a controller, etc.

[0063] Next, the key technologies of zero-power communication are introduced:

[0064] Radio Frequency Power Harvesting

[0065] Figure 2 shows a schematic diagram of RF energy harvesting provided by related technologies. RF energy harvesting is based on the principle of electromagnetic induction, using the RF module RF to conduct electromagnetic induction and maintain a parallel relationship with the capacitor C and the load resistor R L By connecting to the power supply, the energy required to operate zero-power devices can be collected from electromagnetic waves in space, such as for driving low-power demodulation modules, modulation modules, sensors, and memory reading. Therefore, zero-power devices do not require traditional batteries.

[0066] Back scattering communication

[0067] Figure 3 shows a schematic diagram of the backscatter communication process provided by related art. A zero-power device 140 receives a wireless signal carrier 131 transmitted by a transmitter (TX) module 121 of a network device 120 using an amplifier (AMP) 122. It modulates the wireless signal carrier 131, loads the information to be transmitted using a logic processing module 147, and harvests radio frequency energy using an energy harvesting module 141. Zero-power device 140 radiates the modulated reflected signal 132 using an antenna 146. This information transmission process is called backscatter communication. A receiver (RX) module 123 of the network device 120 receives the modulated reflected signal 132 using a low-noise amplifier (LNA) 124. Backscatter and load modulation are closely related. Load modulation achieves this by adjusting and controlling the circuit parameters of the oscillator circuit of the zero-power device 140 according to the data stream's rhythm, causing parameters such as the electronic tag's impedance to change accordingly.

[0068] Load modulation technology mainly includes resistance load modulation and capacitance load modulation. Figure 4 shows a schematic diagram of resistance load modulation provided by related technology. In resistance load modulation, the load resistor R L The third resistor R3 is connected in parallel, and the switch S based on the binary code control is turned on or off. The on and off of the third resistor R3 will cause the voltage on the circuit to change. The load resistor R L Maintaining a parallel connection relationship with the first capacitor C1, the load resistor R L The first inductor L1 is connected in series with the second resistor R2, and the second resistor R2 is connected in series with the first inductor L1. The first inductor L1 is coupled to the second inductor L2, and the second inductor L2 is connected in series with the second capacitor C2. Amplitude Shift Keying (ASK) can be implemented, that is, the modulation and transmission of the signal is achieved by adjusting the amplitude of the backscattered signal of the zero-power device. Similarly, in capacitive load modulation, the resonant frequency of the circuit can be changed by turning the capacitor on and off, and frequency shift keying (FSK) can be implemented, that is, the modulation and transmission of the signal is achieved by adjusting the operating frequency of the backscattered signal of the zero-power device.

[0069] Zero-power devices use load modulation to modulate incoming signals, enabling backscatter communication. These devices offer significant advantages: they don't actively transmit signals, eliminating the need for complex RF links like power amplifiers (PAs) and RF filters. They don't actively generate high-frequency signals, eliminating the need for high-frequency crystal oscillators. Furthermore, backscatter communication allows signal transmission without consuming the device's own energy.

[0070] Extremely low power active transmission technology;

[0071] Zero-power devices can also use ultra-low-power active transmission technology. Unlike backscattering, when using ultra-low-power active transmission technology for data transmission, the device uses a relatively simple and low-power oscillator to generate the RF carrier, and then modulates the information to be transmitted onto the RF carrier. Based on current research, the power consumption of ultra-low-power active transmitters can be as low as hundreds of microwatts, thus achieving ultra-low-power data transmission.

[0072] Next, the encoding method of zero-power communication is introduced:

[0073] FIG5 is a schematic diagram of an encoding method provided by related art. The data transmitted by the electronic tag can use different forms of codes to represent binary "1" and "0". Wireless radio frequency identification systems generally use one of the following encoding methods: Not Return to Zero (NRZ) encoding, Manchester encoding, Unipolar Return to Zero (URZ) encoding, Differential Binary Phase (DBP) encoding, Miller encoding, and differential encoding. That is, different pulse signals can be used to represent 0 and 1.

[0074] ·NRZ encoding; Inverse non-return-to-zero encoding uses a high level to represent a binary "1" and a low level to represent a binary "0". Figure 5 shows a level diagram of encoding binary data: 101100101001011 using the NRZ method.

[0075] Manchester encoding: Manchester encoding is also known as split-phase coding. In Manchester encoding, a binary value is represented by a voltage level change (rising or falling) during half a bit period within the bit length. A negative transition during half a bit period represents a binary "1," and a positive transition during half a bit period represents a binary "0." Data transmission errors occur when multiple tags simultaneously transmit data bits with different values, causing the received rising and falling edges to cancel each other, resulting in an uninterrupted carrier signal throughout the entire bit length. Manchester encoding makes it impossible to have an unchanging state within the bit length. The reader can use this error to determine the specific location of the collision. Manchester encoding facilitates data transmission error detection and is commonly used for data transmission from tags to readers when using carrier load modulation or backscatter modulation. Figure 5 shows a schematic diagram of the voltage levels for binary data 101100101001011 encoded using the Manchester method.

[0076] ·URZ encoding; unipolar return-to-zero encoding: a high level in the first half of the bit period represents a binary "1", while a low level signal that lasts throughout the entire bit period represents a binary "1". Figure 5 shows a level diagram of encoding binary data: 101100101001011 using the URZ method.

[0077] DBP encoding: Differential biphase encoding uses any edge within half a bit period to represent a binary "0," while the absence of an edge represents a binary "1." Furthermore, the voltage level is inverted at the beginning of each bit period. This makes the bit beat easier for the receiver to reconstruct. Figure 5 shows the voltage levels of the binary data 101100101001011 encoded using the DBP method.

[0078] Miller coding: In Miller coding, any edge within half a bit period represents a binary "1," while a constant level throughout the next bit period represents a binary "0." The level transition at the beginning of a bit period makes it easier for the receiver to reconstruct the bit beat. Figure 5 shows the level diagram of the binary data 101100101001011 encoded using the Miller method.

[0079] Differential encoding: In differential encoding, each transmitted binary "1" causes a change in the signal level, while for a binary "0" the signal level remains unchanged.

[0080] Next, we will introduce the classification of zero-power devices:

[0081] Based on the energy source and usage of zero-power devices, zero-power devices can be divided into the following types:

[0082] Passive zero-power devices;

[0083] Zero-power devices do not require internal batteries. When they approach a network device, they are within the near field generated by the network device's antenna radiation. For example, the network device is a reader / writer in a radio frequency identification (RFID) system. Therefore, the zero-power device's antenna generates an induced current through electromagnetic induction, which drives the device's low-power chip circuitry. This enables tasks such as demodulating forward link signals and modulating reverse link signals. For backscatter links, the zero-power device can use backscatter or extremely low-power active transmission to transmit signals. Passive zero-power devices do not require internal batteries for either the forward or reverse link, making them truly zero-power devices. Passive zero-power devices do not require batteries, and their RF and baseband circuits are very simple. For example, they do not require components such as LNAs, PAs, crystal oscillators, and analog-to-digital converters (ADCs). They offer numerous advantages, including small size, light weight, very low price, and a long service life.

[0084] Semi-passive zero-power device;

[0085] Semi-passive zero-power devices lack conventional batteries. Instead, they use a radio frequency energy harvesting module to harvest radio wave energy and store it in an energy storage unit, typically a capacitor. This energy is then used to power the device's low-power chip circuitry, enabling tasks such as demodulating forward link signals and modulating backward link signals. For backscatter links, the device can transmit signals using either backscatter or extremely low-power active transmission.

[0086] Semi-passive zero-power devices require no internal batteries for either the forward or reverse link. Instead, the energy stored in the capacitors is harvested by the radio energy harvesting module, making them truly zero-power devices. They inherit many of the advantages of passive zero-power devices, including small size, light weight, very low price, and long service life.

[0087] Active zero-power devices;

[0088] Zero-power devices used in some scenarios can also be active zero-power devices, which can have built-in batteries. The battery is used to drive the low-power chip circuit of the zero-power device. This enables tasks such as demodulating forward link signals and modulating reverse link signals. However, for backscatter links, zero-power devices can use backscatter or extremely low-power active transmission to transmit signals. Therefore, the zero-power of active zero-power devices is mainly reflected in the fact that reverse link signal transmission does not consume the zero-power device's own power, but instead uses backscatter. In active zero-power devices, the built-in battery powers the RFID chip, increasing the tag's read and write distance and improving communication reliability. Therefore, they are used in scenarios with relatively high requirements for communication distance and read latency.

[0089] Next, we will introduce the classification of zero-power devices based on transmitter type:

[0090] (1) Zero-power devices based on backscattering;

[0091] These zero-power devices use backscattering, as described above, for uplink data transmission. They lack active transmitters, only backscattering transmitters. Therefore, when these zero-power devices transmit uplink data, they require network equipment to provide a carrier. These zero-power devices use backscattering based on the carrier to achieve uplink data transmission.

[0092] (2) Zero-power devices based on active transmitters;

[0093] These zero-power devices use active transmitters with active transmission capabilities for uplink data transmission. Therefore, when sending uplink data, these zero-power devices can use their own active transmitters to send uplink data without the need for network equipment to provide a carrier. Examples of active transmitters suitable for zero-power devices include ultra-low-power ASK transmitters and ultra-low-power FSK transmitters. Based on current implementations, these transmitters can reduce overall power consumption to 400-600 microwatts when transmitting a 100-microwatt signal.

[0094] (3) Zero-power devices with both backscatter and active transmitter capabilities;

[0095] These zero-power devices can support both backscatter and active transmitters. They can determine whether to use backscatter or active transmitters based on different situations (such as varying battery levels, available ambient energy), or based on network device scheduling.

[0096] Next, let’s introduce the cellular Internet of Things:

[0097] Cellular IoT is booming. The 3rd Generation Partnership Project (3GPP) has standardized IoT technologies such as NarrowBand-Internet of Things (NB-IoT), Machine-Type Communications (MTC), and RedCap. However, IoT communication needs in many scenarios remain unmet. For example:

[0098] Harsh communication environment;

[0099] Certain IoT scenarios may encounter extreme environments such as high temperature, extremely low temperature, high humidity, high voltage, high radiation, or high-speed movement. Examples include ultra-high voltage substations, high-speed train track monitoring, environmental monitoring in high-altitude cold regions, and industrial production lines. In these scenarios, existing IoT devices will not function due to the operating environment limitations of conventional power supplies. Furthermore, extreme operating environments are not conducive to IoT device maintenance, such as battery replacement.

[0100] ·Requirement for extremely small terminal form factor;

[0101] Certain IoT communication scenarios, such as food traceability, commodity distribution, and smart wearables, require terminals to be extremely small for ease of use. For example, IoT terminals used for commodity management in the distribution process often use electronic tags, which are embedded in the product packaging in a very compact form factor. Another example is lightweight wearable IoT terminals that can meet user needs while improving the user experience.

[0102] Extremely low-cost IoT communication requirements;

[0103] Many IoT communication scenarios require IoT terminal devices to be sufficiently low-cost to enhance their competitiveness compared to alternative technologies. For example, in logistics or warehousing scenarios, IoT terminal devices can be attached to each item to facilitate the management of large quantities of circulating items. Communication between the IoT terminal device and the logistics network enables precise management of the entire logistics process and lifecycle. These scenarios require IoT terminal devices to be sufficiently competitively priced.

[0104] Therefore, in order to cover these unmet IoT communication needs, cellular IoT also needs to develop ultra-low-cost, extremely small-size, battery-free / maintenance-free IoT, and zero-power IoT can just meet these needs.

[0105] Zero-power IoT, also known as Ambient IoT or passive IoT, refers to IoT devices that use various environmental energies, such as radio frequency energy, light energy, solar energy, thermal energy, and mechanical energy, to power themselves. These devices can have no energy storage capacity or very limited energy storage capacity (such as using capacitors with a capacity of tens of microfarads). Compared to existing IoT devices, Ambient IoT devices offer many advantages, including no conventional batteries, no maintenance, small size, low complexity, low cost, and a long lifespan.

[0106] Zero-power IoT can be used in at least four scenarios:

[0107] (1) Object recognition, such as logistics, production line product management, and supply chain management;

[0108] (2) Environmental monitoring, such as temperature, humidity, and harmful gas monitoring of the working environment and natural environment;

[0109] (3) Positioning, such as indoor positioning, intelligent object search, and production line item positioning;

[0110] (4) Intelligent control, such as intelligent control of various electrical appliances in smart homes (turning on and off air conditioners, adjusting temperature), and intelligent control of various facilities in agricultural greenhouses (automatic irrigation and fertilization).

[0111] In the future, cellular passive IoT, WLAN passive IoT, or Ambient IoT will support new Ambient IoT devices, thereby meeting the corresponding IoT communication needs in different application scenarios. Ambient IoT devices do not require batteries, and their RF and baseband circuits are very simple. For example, they do not require components such as LNAs, PAs, crystal oscillators, and ADCs. Therefore, they have many advantages, such as small size, light weight, very low price, long service life, and no maintenance.

[0112] Ambient IoT devices may be used in the following two scenarios:

[0113] (1) Searching for items;

[0114] Ambient IoT devices can be attached to personal items such as passports and ID cards. When people find that they cannot find these items, they can use a router or smartphone to send wireless signals to the Ambient IoT device attached to the personal items (for example, if a mobile phone has an item-finding app installed, the item-finding function can be turned on through the app). The Ambient IoT device will then start working after collecting enough energy.

[0115] In this case, the router or smartphone can deploy a WiFi network, and the Ambient IoT device can quickly connect to and communicate with the WiFi network, allowing the router or smartphone to obtain the identity and / or location information of the Ambient IoT device. This process can help realize the object search function.

[0116] (2) Rapid identification and inventory of items;

[0117] In logistics scenarios, Ambient IoT devices can be attached to item packaging or containers. When items arrive at a logistics station, they must be quickly counted. Similarly, a quick count is required when items leave the warehouse.

[0118] When items are entering or leaving the warehouse (the approach of a logistics vehicle can be detected using third-party technologies such as infrared or ultrasonic waves), a router or smartphone can send a wireless signal to the Ambient IoT device attached to the item. The Ambient IoT device then begins operating after collecting enough energy. At this point, the router or smartphone can deploy a WiFi network, which the Ambient IoT device quickly connects to and communicates with, allowing the router or smartphone to obtain the Ambient IoT device's identity information. This process enables rapid identification and inventory of items.

[0119] In the above-mentioned application cases of Ambient IoT devices, the Ambient IoT devices are all in a power-off state, and they receive wireless signals sent by the network, thereby switching to a working state. How to quickly synchronize with the network and quickly obtain network configuration information in such a process is an urgent problem to be solved. In the current WLAN system, network devices send beacon frames, and zero-power devices synchronize with the network based on the beacon frames and read the system information carried by them (such as network capabilities, system configuration parameters, etc.). As shown in Figure 6, beacon frames 610 are periodically sent according to a period T. At the wake-up time T0 of the zero-power device (Ambient IoT device), the zero-power device enters the working state and starts searching for the first beacon frame 610 received after being awakened.

[0120] However, in related technologies, beacon frames are generally sent periodically. If the beacon frame sending period is too long, it will take too long for the Ambient IoT device to synchronize with the network and obtain system information. This will increase service latency on the one hand and increase the time it takes the Ambient IoT device to search for beacon frames on the other hand, thereby increasing the power consumption of the Ambient IoT device. However, if the beacon frame sending period is too short, too many beacon frames will lead to greater system overhead.

[0121] To address the above issues, an embodiment of the present application proposes a communication method for broadcast frames. FIG7 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is performed by the zero-power device 140 and the network device 120. The method includes:

[0122] Step 710: The zero-power device 140 receives a first broadcast frame.

[0123] In some embodiments, the first broadcast frame is a broadcast frame sent at a different time domain position than the periodically transmitted second broadcast frame. It can also be understood that the first broadcast frame is a broadcast frame sent supplementally or additionally at a different time domain position than the periodically transmitted second broadcast frame.

[0124] In some embodiments, the first broadcast frame is sent between periodically sent second broadcast frames; and / or, the first broadcast frame is sent before the first second broadcast frame; and / or, the first broadcast frame is sent after the last second broadcast frame.

[0125] In some embodiments, the first broadcast frame is sent at a first time domain position, and the periodic second broadcast frame is sent at a second time domain position, and the first time domain position is different from the second time domain position.

[0126] In some embodiments, network device 120 transmits the first broadcast frame aperiodically or periodically. The first broadcast frame is used by zero-power device 140 to perform at least one of time-frequency synchronization with the wireless network, obtain system information, acquire power supply energy, and obtain scheduling information. Time-frequency synchronization includes at least one of time domain synchronization and frequency domain synchronization.

[0127] In some embodiments, the first broadcast frame is sent within a designated search space, which may be a dedicated search space for zero-power devices. The zero-power devices listen for the first broadcast frame within the designated search space. In some embodiments, the first broadcast frame is sent within a designated resource pool, which may be a dedicated resource pool for zero-power devices.

[0128] In some embodiments, the wireless network is a WiFi / WLAN network, and the first broadcast frame is a first beacon frame, which is used for the zero-power device 140 to perform at least one of time and frequency synchronization with the wireless network, obtain system information, obtain power supply energy, and obtain scheduling information.

[0129] In some embodiments, the wireless network is a cellular communication network, and the first broadcast frame is a broadcast frame used to carry a synchronization signal and / or system information. Since cellular communication networks include evolving multi-generation networks, the broadcast frame used to carry a synchronization signal and / or system information may be called differently in different cellular communication networks, for example, a synchronization signal / physical broadcast channel block (SSB) in a 5G system and a physical broadcast channel (PBCH) in a fourth-generation (4G) system. The embodiments of the present application do not limit this term and will be described using the first broadcast frame as an example.

[0130] In some embodiments, the first broadcast frame is sent by network device 120 in response to a triggering event. The triggering event indicates that zero-power device 140 requires at least one of a synchronization signal and system information. Illustratively, the triggering event includes at least one of a logistics vehicle arrival event in a logistics scenario and a warehouse inventory event in a warehousing scenario.

[0131] In the logistics scenario, the network device 120 senses (for example, through sound wave sensing, motion sensing, etc.) the arrival of the logistics vehicle. When the logistics vehicle arrives, the network device 120 starts the inventory process of the items on the logistics vehicle (zero-power device 140). At this time, the zero-power device 140 has the need to obtain at least one of the synchronization signal and system information.

[0132] In a warehousing scenario, when it is necessary to take inventory of items in the warehouse, the items in the warehouse (zero-power consumption devices 140 ) have a need to obtain at least one of a synchronization signal and system information.

[0133] In some embodiments, zero-power device 140 receives a wireless signal sent by network device 120 and harvests energy from the wireless signal to switch to an operating state. In this case, zero-power device 140 needs to find a wireless network provided by network device 120, establish time and frequency synchronization with the wireless network, and then obtain system information. Illustratively, zero-power device 140 quickly completes time and frequency synchronization and obtains system information by receiving the first broadcast frame with a relatively close time position, thereby quickly entering an operating state.

[0134] In some embodiments, at least one first broadcast frame is transmitted within the first time window. The at least one first broadcast frame also carries information indicating the first time window. When there are multiple first broadcast frames within the first time window, all or some of the multiple first broadcast frames carry information indicating the first time window.

[0135] In some embodiments, the first time window is expressed in the form of: window start point + window length.

[0136] In some embodiments, the first time domain position and the remaining time occupied by the first broadcast frame represent the length of the first time window. That is, the remaining time of the first time window may be carried in all or part of the first broadcast frames. For example, the remaining time may be carried in each first broadcast frame except for the last first broadcast frame. A remaining time of 1000 milliseconds carried by a first broadcast frame indicates that, starting from the time domain position of the first broadcast frame, the remaining time of the first time window is 1000 milliseconds.

[0137] In some embodiments, the current first broadcast frame carries indication information of the time domain position of the next first broadcast frame. If the indication information exists, it indicates that the first time window has not yet ended and indicates the time domain position of the next first broadcast frame; if the indication information does not exist, it indicates that the first time window ends after the time domain position of the first broadcast frame.

[0138] To sum up, the method provided in this embodiment receives a first broadcast frame, which is a broadcast frame sent at a time domain position different from the periodically sent second broadcast frame, to help zero-power devices complete time and frequency synchronization and obtain system information, thereby increasing the transmission opportunities of broadcast frames, reducing the time to complete time and frequency synchronization, speeding up the communication process between network devices and zero-power devices, and reducing the waiting time for zero-power devices to receive broadcast frames, thereby reducing the power consumption of zero-power devices.

[0139] FIG8 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is performed by the zero-power device 140 and the network device 120. The method includes:

[0140] Step 810: The zero-power device 140 receives a second broadcast frame.

[0141] In some embodiments, network device 120 periodically transmits a second broadcast frame. Zero-power device 140 periodically receives the second broadcast frame. The second broadcast frame is used by zero-power device 140 to perform at least one of time-frequency synchronization with the wireless network, obtain system information, obtain energy supply, and obtain scheduling information. Time-frequency synchronization includes at least one of time domain synchronization and frequency domain synchronization.

[0142] In some embodiments, the wireless network is a WiFi / WLAN network, and the second broadcast frame is a second beacon frame, which is used for the zero-power device 140 to periodically perform at least one of time and frequency synchronization with the wireless network, obtain system information, obtain power supply energy, and obtain scheduling information.

[0143] In some embodiments, the wireless network includes a cellular communication network, and the second broadcast frame is a frame used to carry synchronization signals and system information. Because cellular communication networks include evolving multi-generation networks, the information structure used to carry synchronization signals and system information may be referred to differently in different cellular communication networks, and embodiments of the present application do not limit this terminology.

[0144] Step 820: The zero-power device 140 receives the first broadcast frame.

[0145] In some embodiments, the first broadcast frame is a broadcast frame sent at a different time domain position than the periodically transmitted second broadcast frame. It can also be understood that the first broadcast frame is a broadcast frame sent supplementally or additionally at a different time domain position than the periodically transmitted second broadcast frame.

[0146] In some embodiments, the network device 120 transmits the first broadcast frame aperiodically or periodically.

[0147] The execution order of step 820 and step 810 is not limited in this embodiment of the present application. For specific implementation details of step 820, please refer to step 710 of the embodiment of Figure 7 and will not be repeated here.

[0148] Step 830: Based on at least one of the first broadcast frame and the second broadcast frame, the zero-power device 140 completes at least one function of performing time and frequency synchronization with the wireless network, obtaining system information, obtaining power supply energy, and obtaining scheduling information.

[0149] The scheduling information includes scheduling information of random access resources.

[0150] In some embodiments, based only on the first broadcast frame, time and frequency synchronization is performed through the synchronization signal in the first broadcast frame, system information is obtained through the system information carried by the first broadcast frame, power supply energy is obtained through the wireless energy carried by the first broadcast frame, and scheduling information is obtained through the scheduling information carried by the first broadcast frame.

[0151] In some embodiments, based only on the second broadcast frame, time and frequency synchronization is performed through the synchronization signal in the second broadcast frame, system information is obtained through the system information carried by the second broadcast frame, power supply energy is obtained through the wireless energy carried by the second broadcast frame, and scheduling information is obtained through the scheduling information carried by the second broadcast frame.

[0152] In some embodiments, when a first broadcast frame is received before a second broadcast frame, some functions are completed based on the first broadcast frame, and the remaining functions are completed based on the second broadcast frame. For example, time and frequency synchronization is performed using the synchronization signal in the first broadcast frame, system information is obtained using the system information carried in the first broadcast frame, energy is obtained using the wireless energy carried in the first broadcast frame, and scheduling information is obtained using the scheduling information carried in the second broadcast frame.

[0153] In some embodiments, when a second broadcast frame is received before a first broadcast frame, some functions are performed based on the second broadcast frame, and the remaining functions are performed based on the first broadcast frame. For example, time and frequency synchronization is performed using the synchronization signal in the second broadcast frame, system information is obtained using the system information carried in the second broadcast frame, energy is obtained using the wireless energy carried in the second broadcast frame, and scheduling information is obtained using the scheduling information carried in the first broadcast frame.

[0154] Among them, some functions are part of the above-mentioned time-frequency synchronization, obtaining system information, obtaining power supply energy, and obtaining scheduling information, and the remaining functions are all or part of the functions remaining in the above-mentioned functions except some functions.

[0155] In some embodiments, the zero-power consumption device may also use at least three broadcast frames to complete the above functions, which is not limited. The number of first broadcast frames and / or second broadcast frames included in the at least three broadcast frames is not limited.

[0156] To sum up, the method provided in this embodiment receives a first broadcast frame, which is a broadcast frame sent at a time domain position different from the periodically sent second broadcast frame, to help zero-power devices complete time and frequency synchronization and obtain system information, thereby increasing the transmission opportunities of broadcast frames, reducing the time to complete time and frequency synchronization, speeding up the communication process between network devices and zero-power devices, and reducing the waiting time for zero-power devices to receive broadcast frames, thereby reducing the power consumption of zero-power devices.

[0157] The method provided in this embodiment also periodically completes time-frequency synchronization and updates system information by receiving a second broadcast frame sent periodically, thereby maintaining the stability of the zero-power device.

[0158] FIG9 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is performed by a zero-power device, and the method includes:

[0159] Step 910: Receive a first broadcast frame.

[0160] The first broadcast frame is sent between periodically sent second broadcast frames, and / or is sent before the first second broadcast frame, and / or is sent after the last second broadcast frame.

[0161] In some embodiments, the first broadcast frame is a broadcast frame sent at a different time domain position than the periodically transmitted second broadcast frame. It can also be understood that the first broadcast frame is a broadcast frame sent supplementally or additionally at a different time domain position than the periodically transmitted second broadcast frame.

[0162] In some embodiments, when the network device is a device in a WiFi system, the first broadcast frame is a first beacon frame, which is used for the zero-power device to quickly establish time and frequency synchronization with the network and obtain system information.

[0163] In some embodiments, when the network device is a device in a cellular communication system, the first broadcast frame is system broadcast information, which is used to broadcast synchronization signals and system information, such as SSB in a 5G system.

[0164] In some embodiments, the first broadcast frame is sent by a network device, and the network device is a device in a WiFi system and / or a device in a cellular communication system (or mobile communication system).

[0165] In some embodiments, a first broadcast frame is received, and a second broadcast frame is received.

[0166] The first broadcast frame is a broadcast frame supplementarily sent by the network device or an additional broadcast frame, and is sent aperiodically or periodically by the network device; the second broadcast frame is a broadcast frame periodically sent by the network device.

[0167] In some embodiments, the first broadcast frame is sent within a designated search space, which may be a dedicated search space for zero-power devices. The zero-power devices listen for the first broadcast frame within the designated search space. In some embodiments, the first broadcast frame is sent within a designated resource pool, which may be a dedicated resource pool for zero-power devices.

[0168] The second broadcast frame is a second beacon frame or system broadcast information. The second beacon frame is used for the zero-power device to periodically establish time and frequency synchronization with the network and obtain system information. Exemplarily, the period is 100 milliseconds.

[0169] The second beacon frame is a beacon frame sent periodically and may carry information such as capability information (Capability Information) and a service set identifier (Service Set IDentifier, SSID).

[0170] In some embodiments, the second beacon frame includes a preamble portion and a data portion. The preamble portion is used to indicate the start of data transmission and help the receiving device (zero-power device) determine the valid data portion. The preamble portion contains a set of specific signals used to synchronize the clocks between the receiving device (zero-power device) and the transmitting device (network device).

[0171] In some embodiments, the network device configures at least one of the sending position, number of transmissions, and time window length of the first broadcast frame, and the sending position of the next second broadcast frame. The zero-power device receives at least one of the sending position, number of transmissions, and time window length of the first broadcast frame, and the sending position of the next second broadcast frame. The sending position of the next second broadcast frame can be an absolute time position or an offset position relative to the current first broadcast frame.

[0172] In some embodiments, the network device sends at least one first broadcast frame.

[0173] When the signal strength is greater than a first threshold, the network device sends a first broadcast frame. For example, when the network device is near a router, a first broadcast frame can help the zero-power device complete time and frequency synchronization and obtain all system information. The first threshold is preset by those skilled in the art.

[0174] When the signal strength is less than the second threshold, the network device sends multiple first broadcast frames. For example, when it is far away from the router, multiple first broadcast frames are required to help the zero-power device complete time and frequency synchronization and obtain all system information. The second threshold is pre-set by a technician in this field.

[0175] The signal strength may be the signal strength when the zero-power device sends a signal and / or data to the network device. Exemplarily, the first threshold is greater than or equal to the second threshold.

[0176] In some embodiments, the first broadcast frame is sent periodically; or, the first broadcast frame is sent aperiodically.

[0177] In some embodiments, the aperiodic transmission method includes at least one of the following:

[0178] Continuous transmission mode; or,

[0179] Discontinuous transmission mode; or,

[0180] Burst sending mode;

[0181] Among them, the continuous sending mode indicates that the first broadcast frame is sent n times one after another, and there is no sending interval during the sending process, and n is an integer greater than 1; the discontinuous sending mode indicates a sending mode in which there is a sending interval during the sending process of the first broadcast frame, and the sending interval may be periodic or non-periodic; the burst sending mode indicates a sending mode in which the first broadcast frame is sent at any time. Compared with the discontinuous sending mode, the sending interval between two transmissions is usually longer and more random.

[0182] As shown in Figure 10, the first broadcast frame is the first beacon frame 1010, and the second broadcast frame is the second beacon frame 1020. The network device periodically sends the second beacon frame 1020 according to the period T, and non-periodically sends a total of 4 first beacon frames 1010 between the first second beacon frame 1020 and the second second beacon frame 1020, among which the first 3 first beacon frames 1010 are sent continuously, and the fourth first beacon frame 1010 is sent discontinuously.

[0183] As shown in Figure 11, the first broadcast frame is the first beacon frame 1110, and the second broadcast frame is the second beacon frame 1120. The network device periodically sends the second beacon frame 1120 and uses a burst sending method before the first second beacon frame 1120. A total of 4 first beacon frames 1110 are sent, among which the first 3 first beacon frames 1110 are sent continuously, and the fourth first beacon frame 1110 is sent discontinuously.

[0184] In some embodiments, the first broadcast frame and the second broadcast frame have the same structure.

[0185] Exemplarily, the first broadcast frame is a first beacon frame, and the second broadcast frame is a second beacon frame. The first beacon frame and the second beacon frame have the same structure: the preamble portion is first, followed by the data portion. Both frames have the same preamble portion, the same key parameters as the data portion length and bit rate, and carry the same type of configuration information. Most parameters have the same values, but a few have different values. For example, the timestamp information changes depending on the time position of the two beacon frames.

[0186] The preamble part includes: Legacy Short Training Field (L-STF), Legacy Long Training Field (L-LTF), and Legacy Signal (L-SIG) field. Among them, L-STF contains a specified and unique waveform that is easily detected by the receiving device (zero-power device). The functions of L-STF include at least one of the following: packet detection, automatic gain control (AGC), initial frequency offset estimation, and initial time synchronization. L-LTF also contains a specified and unique waveform, but it is not exactly the same as L-STF. The functions of L-LTF include at least one of the following: channel estimation, more accurate frequency offset estimation, and more accurate time synchronization. The L-SIG field includes information such as the transmit rate, coding scheme, guard interval, and length, which are used to calculate the duration of the data packet.

[0187] In some embodiments, the structures of the first broadcast frame and the second broadcast frame are different.

[0188] In some embodiments, the first broadcast frame and the second broadcast frame have different structures, including at least one of the following:

[0189] (1) The preamble codes used in the first broadcast frame and the second broadcast frame are different;

[0190] (2) The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different;

[0191] (3) the information type of the data portion of the first broadcast frame is smaller than the information type of the data portion of the second broadcast frame, or the information type of the data portion of the first broadcast frame is larger than the information type of the data portion of the second broadcast frame;

[0192] (4) The code rate of the data portion of the first broadcast frame is lower than the code rate of the data portion of the second broadcast frame.

[0193] For example, the first broadcast frame is the first beacon frame, and the second broadcast frame is the second beacon frame:

[0194] The designs of (1) and (2) can provide different synchronization performances. For example, if the preamble sequence length of the first beacon frame is longer than that of the second beacon frame, it can contain more synchronization signals, thereby improving the probability and accuracy of the zero-power device identifying the data part, thereby providing better synchronization performance.

[0195] By adopting the design (3), when the information types of the data part of the first beacon frame are smaller than the information types of the data part of the second beacon frame, for example, only including the timestamp, the period of the second beacon frame and other information, key information can be quickly transmitted to the zero-power device, and the smaller data part can also increase the reception probability of the zero-power device. When the information types of the data part of the first beacon frame are greater than the information types of the data part of the second beacon frame, system information can be directly transmitted to the zero-power device to help the zero-power device establish time-frequency synchronization.

[0196] By adopting the design of (4), when the code rate of the data portion of the first beacon frame is lower than the code rate of the data portion of the second beacon frame, the probability of the zero-power device successfully receiving the beacon frame can be increased.

[0197] In some embodiments, in a WiFi / WLAN system, the period of the second broadcast frame is associated with a partial configuration. For example, the second beacon frame may carry a Traffic Indication Map (TIM) indication, which is used to send information to the zero-power device regarding whether there is downlink data to be transmitted. The period of the TIM is an integer multiple of the period of the second beacon frame. Each beacon frame contains a TIM, which includes a bitmap control field. Each bit maps to a zero-power device. When the bit is 1, it indicates that the zero-power device corresponding to the bit has downlink data cached in the network device.

[0198] For example, the configuration of a restricted access window (RAW) can be indicated in the second beacon frame. During the RAW period, the zero-power device transmits data with the network device. The RAW is configured after the second beacon frame. The key idea of ​​RAW is to limit the set of stations that can access the channel and spread their access attempts over a longer period of time, thereby reducing interference and improving communication reliability and efficiency.

[0199] In some embodiments, when the network device sends both the first broadcast frame and the second broadcast frame, the zero-power device needs to distinguish between the two because:

[0200] First, after completing time-frequency synchronization and obtaining system information based on either the first or second broadcast frame, the zero-power device needs to periodically maintain time-frequency synchronization based on the second broadcast frame. Therefore, the position of the second broadcast frame needs to be determined.

[0201] Second, the second broadcast frame can send new system information at any time, such as RAW configuration. Zero-power devices also need to obtain new system information based on the second broadcast frame.

[0202] In some embodiments, the first broadcast frame and the second broadcast frame are distinguished by at least one of the following methods:

[0203] Type indication in the information field;

[0204] Preamble;

[0205] Signal Information (SIG) field.

[0206] Exemplarily, the frame control field (FC) of the beacon media access control (MAC) header is used for type indication. The FC includes fields such as a frame type field and a subtype field. The frame type field specifies the type of the data frame, and the subtype field specifies a more specific subtype of the data frame.

[0207] Alternatively, the first broadcast frame and the second broadcast frame may be indicated by a preamble code, and different preamble code sequences may be used to distinguish the first broadcast frame from the second broadcast frame;

[0208] Alternatively, the SIG field (i.e., L-SIG field) in the preamble can be used for indication. The SIG field includes information about the channel state, such as signal-to-noise ratio, rate, and frequency. Zero-power devices can identify the channel state by decoding and analyzing the signal parameters in the SIG field, thereby adjusting the transmission rate. The first and second broadcast frames use different bit values ​​in the SIG field, which can also distinguish the first and second broadcast frames.

[0209] In some embodiments, after waking up, the zero-power device may first search for the first broadcast frame or the second broadcast frame. The zero-power device completes time-frequency synchronization and obtains system information based on either of the two.

[0210] In some embodiments, the first broadcast frame carries time domain position information of the next second broadcast frame. The time domain position information may be an absolute time position or an offset position relative to the current first broadcast frame.

[0211] As shown in Figure 12, the first broadcast frame is a first beacon frame 1210, and the second broadcast frame is a second beacon frame 1220. The network device periodically transmits the second beacon frame 1220 and aperiodically transmits a total of four first beacon frames 1210 between the first second beacon frame 1220 and the second second beacon frame 1220. Each first beacon frame 1210 carries the time domain position information of the next second beacon frame 1220. For example, the first first beacon frame 1210 carries the time domain position information of the next second beacon frame 1220 (i.e., the second second beacon frame 1220), which is located at a time domain position T2 after the first first beacon frame 1210; the fourth first beacon frame 1210 carries the time domain position information of the next second beacon frame 1220 (i.e., the second second beacon frame 1220), which is located at a time domain position T1 after the first first beacon frame 1210.

[0212] In some embodiments, the first broadcast frame is sent by the network device in the presence of a triggering event.

[0213] In some embodiments, the network device triggers the transmission of the first broadcast frame based on a trigger event. That is, when the zero-power device needs to complete time-frequency synchronization and obtain system information, such as in an item search event, the network device can transmit radio waves to power the zero-power device and transmit the first broadcast frame and the second broadcast frame to the zero-power device when the item search event is triggered. For example, the first broadcast frame is transmitted first, followed by the second broadcast frame; or the first broadcast frame is transmitted between periodically transmitted second broadcast frames.

[0214] In some embodiments, the triggering event includes at least one of the following:

[0215] Find item events;

[0216] Logistics vehicle arrival event;

[0217] Warehouse inventory events.

[0218] For example, in a logistics scenario, the network device senses (for example, through sound wave sensing, motion sensing, etc.) the arrival of a logistics vehicle. When the logistics vehicle arrives, the network device starts the inventory process of the items (zero-power devices) on the logistics vehicle. At this time, the network device can send radio waves to power the zero-power device, and send the first broadcast frame and the second broadcast frame to the zero-power device.

[0219] Similarly, in a warehousing scenario, when inventory of items (zero-power devices) in the warehouse needs to be taken, the network device can send radio waves to power the zero-power devices and send a first broadcast frame and a second broadcast frame to the zero-power devices.

[0220] In the above scenario, through such operations, a sufficient number of broadcast frames can be quickly sent to the zero-power device at the moment the item search and warehouse inventory process starts, so that the zero-power device can quickly complete time and frequency synchronization and obtain system information, thereby speeding up the above-mentioned item search and warehouse inventory.

[0221] In some embodiments, at least one first broadcast frame is transmitted within the first time window. The at least one first broadcast frame also carries information indicating the first time window. When there are multiple first broadcast frames within the first time window, all or some of the multiple first broadcast frames carry information indicating the first time window.

[0222] In some embodiments, the first time window is expressed in the form of: window start point + window length.

[0223] In some embodiments, the first time domain position and the remaining time occupied by the first broadcast frame represent the length of the first time window. That is, the remaining time of the first time window may be carried in all or part of the first broadcast frames. For example, the remaining time may be carried in each first broadcast frame except for the last first broadcast frame. A remaining time of 1000 milliseconds carried by a first broadcast frame indicates that, starting from the time domain position of the first broadcast frame, the remaining time of the first time window is 1000 milliseconds.

[0224] In some embodiments, the current first broadcast frame carries indication information of the time domain position of the next first broadcast frame. If the indication information exists, it indicates that the first time window has not yet ended and indicates the time domain position of the next first broadcast frame; if the indication information does not exist, it indicates that the first time window ends after the time domain position of the first broadcast frame.

[0225] To sum up, the method provided in this embodiment receives a first broadcast frame, which is a broadcast frame sent at a time domain position different from the periodically sent second broadcast frame, to help zero-power devices complete time and frequency synchronization and obtain system information, thereby increasing the transmission opportunities of broadcast frames, reducing the time to complete time and frequency synchronization, speeding up the communication process between network devices and zero-power devices, and reducing the waiting time for zero-power devices to receive broadcast frames, thereby reducing the power consumption of zero-power devices.

[0226] The method provided in this embodiment also periodically completes time-frequency synchronization and updates system information by receiving the second broadcast frame, thereby maintaining the stability of the zero-power consumption device.

[0227] The method provided in this embodiment also provides better synchronization performance by designing the first broadcast frame and the second broadcast frame into different structures, for example, the preamble code sequence length of the first beacon frame is longer than the preamble code sequence length of the second beacon frame, or the code rate of the data part of the first beacon frame is less than the code rate of the data part of the second beacon frame, thereby increasing the probability of zero-power consumption devices successfully receiving beacon frames.

[0228] The method provided in this embodiment also meets the demand for zero-power devices in different scenarios by triggering the sending of the first broadcast frame according to an actual event, thereby improving the versatility of the zero-power devices.

[0229] In some embodiments, for a WiFi system, the first broadcast frame is a first beacon frame, and the second broadcast frame is a second beacon frame; for a cellular communication system, the first broadcast frame is a first system information frame, and the second broadcast frame is a second system information frame.

[0230] Embodiment for WiFi system:

[0231] FIG13 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is performed by a zero-power device, and the method includes:

[0232] Step 1310: Receive a first beacon frame.

[0233] In some embodiments, the first beacon frame is used for the zero-power device to quickly establish time and frequency synchronization with the network and obtain system information.

[0234] The first beacon frame is a broadcast frame supplementarily sent by the network device or an additional broadcast frame, and is sent aperiodically or periodically by the network device.

[0235] In some embodiments, the first beacon frame is sent within a designated search space, which may be a dedicated search space for the zero-power device. The zero-power device listens for the first beacon frame within the designated search space. In some embodiments, the first beacon frame is sent within a designated resource pool, which may be a dedicated resource pool for the zero-power device.

[0236] In some embodiments, the first beacon frame is sent periodically; or

[0237] The first beacon frame is sent in an aperiodic manner.

[0238] In some embodiments, the non-periodic transmission mode includes at least one of the following: a continuous transmission mode; or

[0239] Discontinuous transmission mode; or,

[0240] Burst sending mode;

[0241] Among them, the continuous transmission mode indicates that the first beacon frame is sent n times one after another, and there is no transmission interval during the transmission process, and n is an integer greater than 1; the discontinuous transmission mode indicates that there is a transmission interval during the transmission of the first beacon frame, and the transmission interval may be periodic or non-periodic; the burst transmission mode indicates that the first beacon frame is sent at any time. Compared with the discontinuous transmission mode, the transmission interval between two transmissions is usually longer and more random.

[0242] In some embodiments, the structural format of the first beacon frame is shown in Figure 14. The first beacon frame includes a preamble part and a data part, including at least one of the following fields: preamble, frame control, destination address (DA), source address (SA), basic service set ID (BSSID), sequence number (Sequence Number), frame body (Frame Body), and frame check sequence (FCS).

[0243] Among them, the frame body field includes at least one of the following subfields (system information): timestamp (Timestamp), beacon interval (Beacon Interval, BI), performance information (Capability Info), service set identifier (SSID), data rate, maximum transmission power, channel information, traffic indication map (TIM), BSS load, Quality of Service (Quality of Service, QoS) function, robust security network (Robust Security Network, RSN) function, and vendor-specific information.

[0244] Among them, the preamble is used to locate the start of the first beacon frame and perform channel estimation; the timestamp indicates the system time; the BI is used to indicate the time interval for periodic transmission; the performance information is used to transmit performance-related information of the network device when sending the first beacon frame, including: performance information on whether radio measurement is supported, performance information on whether automatic power saving is supported, performance information on whether quality of service assurance is supported, performance information on whether spectrum management is supported, performance information on whether backscatter access to the network is supported, etc.; the SSID represents the logical name of the wireless local area network; the data rate represents the basic rate and supported rates (rates); the maximum transmission power represents the maximum power supported during transmission; the channel information represents the channel used by the network device; the TIM is a field used in the paging process; the BSS load is a field indicating channel utilization; the QoS function represents QoS and Enhanced Distributed Channel Access (EDCA) information; the RSN function represents the Temporal Key Integrity Protocol (TKIP) or the Counter mode with Cipher-block chaining Message authentication code protocol (CMCA) The embodiment of the present application does not limit the specific types and order of the fields and subfields included in the first beacon frame, and uses the above content as an example for illustration.

[0245] In some embodiments, the first beacon frame includes some system information. As shown in FIG15 , the fields included in the first beacon frame are the same as those shown in FIG14 and are not further described here. The frame body field includes at least one of the following subfields (system information): timestamp, BI, capability information (Capability Info), data rate, maximum transmission power, and TIM. This embodiment of the application does not limit the specific types and field order of the subfields included in the first beacon frame, and the above content is used as an example for illustration.

[0246] Step 1320: Receive a second beacon frame.

[0247] The second beacon frame is a broadcast frame periodically sent by the network device.

[0248] In some embodiments, the second beacon frame is used for the zero-power device to periodically establish time and frequency synchronization with the network and obtain system information. For example, the period is 100 milliseconds. In some embodiments, the structure of the first beacon frame and the second beacon frame is the same, as shown in Figure 14, and will not be repeated here.

[0249] In some embodiments, the first beacon frame and the second beacon frame have different structures, including at least one of the following:

[0250] (1) The preamble codes used by the first beacon frame and the second beacon frame are different;

[0251] (2) The preamble sequence lengths of the first beacon frame and the second beacon frame are different;

[0252] (3) the information type of the data portion of the first beacon frame is smaller than the information type of the data portion of the second beacon frame, or the information type of the data portion of the first beacon frame is larger than the information type of the data portion of the second beacon frame;

[0253] (4) The code rate of the data portion of the first beacon frame is lower than the code rate of the data portion of the second beacon frame.

[0254] The designs of (1) and (2) can provide different synchronization performances. For example, if the preamble sequence length of the first beacon frame is longer than that of the second beacon frame, it can contain more synchronization signals, thereby improving the probability and accuracy of the zero-power device identifying the data part, thereby providing better synchronization performance.

[0255] By adopting the design (3), when the information types of the data part of the first beacon frame are smaller than the information types of the data part of the second beacon frame, for example, only including the timestamp, the period of the second beacon frame and other information, key information can be quickly transmitted to the zero-power device, and the smaller data part can also increase the reception probability of the zero-power device. When the information types of the data part of the first beacon frame are greater than the information types of the data part of the second beacon frame, system information can be directly transmitted to the zero-power device to help the zero-power device establish time-frequency synchronization.

[0256] By adopting the design of (4), when the code rate of the data portion of the first beacon frame is lower than the code rate of the data portion of the second beacon frame, the probability of the zero-power device successfully receiving the beacon frame can be increased.

[0257] In some embodiments, the structures of the first beacon frame and the second beacon frame are different. The structure of the second beacon frame is shown in Figure 14, and the structure of the first beacon frame is shown in Figure 15. The first beacon frame is a simplified version of the second beacon frame. For example, the first beacon frame does not include at least one field of SSID, channel information, BSS load, QoS function, RSN function, and vendor-specific information. The embodiments of the present application do not limit the simplified content and use the above content as an example for illustration.

[0258] In some embodiments, the zero-power device obtains part of the system information through a first beacon frame, and then obtains the remaining system information through a second beacon frame. For example, the first beacon frame includes a timestamp, BI, performance information on whether radio measurement is supported, performance information on whether automatic power saving is supported, performance information on whether backscatter access to the network is supported, data rate, maximum transmission power, and TIM. The second beacon frame includes all of the above system information. The embodiments of the present application do not limit the included partial system information, and the above content is used as an example for illustration.

[0259] Step 1330: Based on at least one of the first beacon frame and the second beacon frame, complete at least one function of performing time and frequency synchronization with the wireless network, obtaining system information, obtaining power supply energy, and obtaining scheduling information.

[0260] In some embodiments, based only on the first beacon frame, time and frequency synchronization is performed through the timestamp in the first beacon frame, system information is obtained through the system information carried by the first beacon frame, power supply energy is obtained through the wireless energy carried by the first beacon frame, and scheduling information is obtained through the scheduling information carried by the first beacon frame.

[0261] In some embodiments, based only on the second beacon frame, time and frequency synchronization is performed through the timestamp in the second beacon frame, system information is obtained through the system information carried by the second beacon frame, power supply energy is obtained through the wireless energy carried by the second beacon frame, and scheduling information is obtained through the scheduling information carried by the second beacon frame.

[0262] In some embodiments, when a second beacon frame is received before a first beacon frame, some functions are performed based on the second beacon frame, and the remaining functions are performed based on the first beacon frame. For example, time and frequency synchronization is performed using the timestamp in the second beacon frame, system information is obtained using the system information carried in the second beacon frame, energy is obtained using the wireless energy carried in the second beacon frame, and scheduling information is obtained using the scheduling information carried in the first beacon frame.

[0263] In some embodiments, when a first beacon frame is received before a second beacon frame, some functions are performed based on the first beacon frame, and the remaining functions are performed based on the second beacon frame. For example, time and frequency synchronization is performed using the timestamp in the first beacon frame, system information is obtained using the system information carried in the first beacon frame, energy is obtained using the wireless energy carried in the first beacon frame, and scheduling information is obtained using the scheduling information carried in the second beacon frame.

[0264] Or, time and frequency synchronization is performed through the timestamp in the first beacon frame, and part of the system information carried by the first beacon frame, such as BI, maximum transmission power, TIM, and the time domain position information of the next second beacon frame, is used to obtain part of the system information. Then, based on the time domain position information of the next second beacon frame, the remaining system information is obtained from the next second beacon frame, the power supply energy is obtained through the wireless energy carried by the first beacon frame, and the scheduling information is obtained through the scheduling information carried by the second beacon frame.

[0265] Or, time and frequency synchronization is performed through the timestamp in the first beacon frame, and part of the system information is obtained through part of the system information carried by the first beacon frame, such as BI, maximum transmission power, TIM, and the time domain position information of the next first beacon frame. Then, based on the time domain position information of the next first beacon frame, the remaining system information is obtained from the next first beacon frame, the power supply energy is obtained through the wireless energy carried by the first beacon frame, and the scheduling information is obtained through the scheduling information carried by the second beacon frame.

[0266] Among them, some functions are part of the above-mentioned time-frequency synchronization, obtaining system information, obtaining power supply energy, and obtaining scheduling information, and the remaining functions are all or part of the functions remaining in the above-mentioned functions except some functions.

[0267] In some embodiments, the zero-power device may also use at least three beacon frames to complete the above functions, which is not limited. The number of first beacon frames and / or second beacon frames included in the at least three beacon frames is not limited.

[0268] In this embodiment, step 1310 and step 1320 are optional. In different embodiments, one or more of these steps may be omitted or replaced, for example, step 1320 may be omitted and only the first beacon frame may be received.

[0269] Step 1310 and step 1330 may be implemented as independent embodiments; step 1320 and step 1330 may be implemented as independent embodiments; but are not limited thereto.

[0270] Step 1310 may be implemented as an independent embodiment, such as being implemented separately as a beacon frame receiving method;

[0271] Step 1320 may be implemented as an independent embodiment, such as being implemented separately as a beacon frame receiving method;

[0272] Step 1330 may be implemented as an independent embodiment, such as implementing the communication method of a beacon frame separately.

[0273] Embodiments for a cellular communication system:

[0274] FIG16 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is performed by a zero-power device, and the method includes:

[0275] Step 1610: Receive a first broadcast frame.

[0276] In some embodiments, the first broadcast frame is a broadcast frame used to carry a synchronization signal and / or system information.

[0277] The first broadcast frame is a broadcast frame supplementarily sent by the network device or an additional broadcast frame, and is sent aperiodically or periodically by the network device.

[0278] In some embodiments, the broadcast frame used to carry synchronization signals and / or system information may be called differently in different cellular communication networks, for example, SSB in 5G systems and PBCH in 4G systems. This embodiment of the present application does not limit this name and will be described using the first broadcast frame as an example.

[0279] In some embodiments, the first broadcast frame is sent within a designated search space, which may be a dedicated search space for zero-power devices. The zero-power devices listen for the first broadcast frame within the designated search space. In some embodiments, the first broadcast frame is sent within a designated resource pool, which may be a dedicated resource pool for zero-power devices.

[0280] In some embodiments, the first broadcast frame is sent periodically; or

[0281] The first broadcast frame is sent in an aperiodic manner.

[0282] In some embodiments, the non-periodic transmission mode includes at least one of the following: a continuous transmission mode; or

[0283] Discontinuous transmission mode; or,

[0284] Burst sending mode;

[0285] Among them, the continuous sending mode indicates that the first broadcast frame is sent n times one after another, and there is no sending interval during the sending process, and n is an integer greater than 1; the discontinuous sending mode indicates a sending mode in which there is a sending interval during the sending process of the first broadcast frame, and the sending interval may be periodic or non-periodic; the burst sending mode indicates a sending mode in which the first broadcast frame is sent at any time. Compared with the discontinuous sending mode, the sending interval between two transmissions is usually longer and more random.

[0286] In some embodiments, the system information carried by the first broadcast frame includes at least one of the following: channel number, channel bandwidth, timestamp, subcarrier spacing information, system frame number (SFN), and paging information.

[0287] The channel number indicates the channel selected by the network device for data transmission; the channel bandwidth indicates the frequency range of the channel for data transmission; the timestamp indicates the system time; the subcarrier spacing information indicates the spacing between subcarriers; the SFN identifies the order of system frames and is used for synchronization information; and the paging information is used to send resource allocation configuration or specified operation instructions to the zero-power device. The embodiments of the present application do not limit the specific type of system information carried by the first broadcast frame and use the above content as an example for illustration.

[0288] Step 1620: Receive a second broadcast frame.

[0289] The second broadcast frame is a broadcast frame periodically sent by the network device.

[0290] In some embodiments, the second broadcast frame is used for the zero-power device to periodically establish time and frequency synchronization with the network and obtain system information, and the period is exemplarily 100 milliseconds. In some embodiments, the first broadcast frame and the second broadcast frame have the same structure.

[0291] In some embodiments, the structures of the first broadcast frame and the second broadcast frame are different. The first broadcast frame is a simplified version of the second broadcast frame. For example, the first broadcast frame does not include subcarrier spacing information. The embodiments of the present application do not limit the simplified content and use the above content as an example for illustration.

[0292] In some embodiments, the zero-power device obtains partial system information through a first broadcast frame and obtains the remaining system information through a second broadcast frame. For example, the first broadcast frame includes a channel number, channel bandwidth, timestamp, SFN, and paging information, and the second broadcast frame includes all of the above system information. The embodiments of the present application do not limit the partial system information included and use the above content as an example for illustration.

[0293] Step 1630: Based on at least one of the first broadcast frame and the second broadcast frame, complete at least one function of performing time and frequency synchronization with the wireless network, obtaining system information, obtaining power supply energy, and obtaining scheduling information.

[0294] In some embodiments, based only on the first broadcast frame, time and frequency synchronization is performed through the timestamp in the first broadcast frame, system information is obtained through the system information carried by the first broadcast frame, power supply energy is obtained through the wireless energy carried by the first broadcast frame, and scheduling information is obtained through the scheduling information carried by the first broadcast frame.

[0295] In some embodiments, based only on the second broadcast frame, time and frequency synchronization is performed through the timestamp in the second broadcast frame, system information is obtained through the system information carried by the second broadcast frame, power supply energy is obtained through the wireless energy carried by the second broadcast frame, and scheduling information is obtained through the scheduling information carried by the second broadcast frame.

[0296] In some embodiments, when a second broadcast frame is received before a first broadcast frame, some functions are performed based on the second broadcast frame, and the remaining functions are performed based on the first broadcast frame. For example, time and frequency synchronization is performed using the timestamp in the second broadcast frame, system information is obtained using the system information carried in the second broadcast frame, energy is obtained using the wireless energy carried in the second broadcast frame, and scheduling information is obtained using the scheduling information carried in the first broadcast frame.

[0297] In some embodiments, when a first broadcast frame is received before a second broadcast frame, some functions are completed based on the first broadcast frame, and the remaining functions are completed based on the second broadcast frame. For example, time and frequency synchronization is performed using the timestamp in the first broadcast frame, system information is obtained using the system information carried in the first broadcast frame, energy is obtained using the wireless energy carried in the first broadcast frame, and scheduling information is obtained using the scheduling information carried in the second broadcast frame.

[0298] Or, time and frequency synchronization is performed through the timestamp in the first broadcast frame, and part of the system information carried by the first broadcast frame, such as the channel number, SFN, paging information, and the time domain position information of the next second broadcast frame, is obtained, and then based on the time domain position information of the next second broadcast frame, the remaining system information is obtained from the next second broadcast frame, the power supply energy is obtained through the wireless energy carried by the first broadcast frame, and the scheduling information is obtained through the scheduling information carried by the second broadcast frame.

[0299] Among them, some functions are part of the above-mentioned time-frequency synchronization, obtaining system information, obtaining power supply energy, and obtaining scheduling information, and the remaining functions are all or part of the functions remaining in the above-mentioned functions except some functions.

[0300] In some embodiments, the zero-power consumption device may also use at least three broadcast frames to complete the above functions, which is not limited. The number of first broadcast frames and / or second broadcast frames included in the at least three broadcast frames is not limited.

[0301] In this embodiment, step 1610 and step 1620 are optional. In different embodiments, one or more of these steps may be omitted or replaced, for example, step 1620 may be omitted and only the first broadcast frame may be received.

[0302] Step 1610 and step 1630 may be implemented as independent embodiments; step 1620 and step 1630 may be implemented as independent embodiments; but are not limited thereto.

[0303] Step 1610 may be implemented as an independent embodiment, for example, implemented separately as a method for receiving a broadcast frame;

[0304] Step 1620 may be implemented as an independent embodiment, such as being implemented separately as a method for receiving a broadcast frame;

[0305] Step 1630 may be implemented as an independent embodiment, such as being implemented separately as a communication method for broadcasting frames.

[0306] To sum up, the method provided in this embodiment receives a first beacon frame, which is a beacon frame sent at a time domain position different from the periodically sent second beacon frame, to help the zero-power device complete time and frequency synchronization and obtain system information, thereby increasing the transmission opportunities of beacon frames, reducing the time to complete time and frequency synchronization, speeding up the communication process between the network device and the zero-power device, and reducing the waiting time for the zero-power device to receive the beacon frame, thereby reducing the power consumption of the zero-power device.

[0307] The method provided in this embodiment also receives a first broadcast frame, which is a broadcast frame sent at a time domain position different from the periodically sent second broadcast frame, to help the zero-power device quickly complete time and frequency synchronization and obtain system information, thereby increasing the transmission opportunities of the broadcast frame, reducing the time to complete time and frequency synchronization, speeding up the communication process between the network device and the zero-power device, and reducing the waiting time for the zero-power device to receive the broadcast frame, thereby reducing the power consumption of the zero-power device.

[0308] The method provided in this embodiment also periodically completes time-frequency synchronization and updates system information by receiving a second beacon frame or a second broadcast frame, thereby maintaining the stability of the zero-power consumption device.

[0309] The method provided in this embodiment also designs the first beacon frame and the second beacon frame into different structures, so that the zero-power device can first obtain part of the system information through the first beacon frame, and then obtain the remaining system information through the second beacon frame, so that the zero-power device can quickly complete time and frequency synchronization and obtain system information.

[0310] The method provided in this embodiment also designs the first broadcast frame and the second broadcast frame into different structures, so that the zero-power device can first obtain part of the system information through the first broadcast frame, and then obtain the remaining system information through the second broadcast frame, so that the zero-power device can quickly complete time and frequency synchronization and obtain system information.

[0311] FIG17 shows a flowchart of a communication method for broadcast frames provided by an exemplary embodiment of the present application. The method is executed by a network device and includes:

[0312] Step 1710: Send a first broadcast frame.

[0313] The first broadcast frame is sent between periodically sent second broadcast frames, and / or is sent before the first second broadcast frame, and / or is sent after the last second broadcast frame.

[0314] In some embodiments, the first broadcast frame is a broadcast frame sent at a different time domain position than the periodically transmitted second broadcast frame. It can also be understood that the first broadcast frame is a broadcast frame sent supplementally or additionally at a different time domain position than the periodically transmitted second broadcast frame.

[0315] In some embodiments, the first broadcast frame is sent within a designated search space, which may be a dedicated search space for zero-power devices. The zero-power devices listen for the first broadcast frame within the designated search space. In some embodiments, the first broadcast frame is sent within a designated resource pool, which may be a dedicated resource pool for zero-power devices.

[0316] In some embodiments, the first broadcast frame is sent periodically; or

[0317] The first broadcast frame is sent in an aperiodic manner.

[0318] In some embodiments, the aperiodic transmission method includes at least one of the following:

[0319] Continuous transmission mode; or,

[0320] Discontinuous transmission mode; or,

[0321] Burst sending mode.

[0322] In some embodiments, the first broadcast frame and the second broadcast frame have the same structure.

[0323] In some embodiments, the structures of the first broadcast frame and the second broadcast frame are different.

[0324] In some embodiments, the first broadcast frame and the second broadcast frame have different structures, including at least one of the following:

[0325] The first broadcast frame and the second broadcast frame use different preamble codes;

[0326] The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different;

[0327] The information type of the data portion of the first broadcast frame is smaller than the information type of the data portion of the second broadcast frame, or the information type of the data portion of the first broadcast frame is larger than the information type of the data portion of the second broadcast frame;

[0328] A code rate of the data portion of the first broadcast frame is lower than a code rate of the data portion of the second broadcast frame.

[0329] In some embodiments, the first broadcast frame and the second broadcast frame are distinguished by at least one of the following methods:

[0330] Type indication located in the information field;

[0331] Preamble;

[0332] SIG domain.

[0333] In some embodiments, the first broadcast frame carries time domain location information of the next second broadcast frame.

[0334] In some embodiments, the first broadcast frame is sent by the network device in the presence of a triggering event.

[0335] In some embodiments, the triggering event includes at least one of the following:

[0336] Find item events;

[0337] Logistics vehicle arrival event;

[0338] Warehouse inventory event.

[0339] In some embodiments, the first broadcast frame is sent by a network device, and the network device is a device in a WiFi system and / or a device in a cellular communication system.

[0340] The specific implementation details of the communication method of the above broadcast frame refer to the zero-power device side and will not be repeated here.

[0341] To sum up, the method provided in this embodiment sends a first broadcast frame, and the time position of the first broadcast frame is close to the wake-up time of the zero-power device, which is used to help the zero-power device complete time and frequency synchronization and obtain system information, thereby speeding up the communication process between the network device and the zero-power device, and reducing the waiting time for the zero-power device to receive the broadcast frame, thereby reducing the power consumption of the zero-power device.

[0342] The method provided in this embodiment also periodically completes time-frequency synchronization and updates system information by sending a second broadcast frame, thereby maintaining the stability of the zero-power consumption device.

[0343] In the above embodiments, steps with the same sequence number can be considered to be the same step. Among them, the embodiment corresponding to Figure 7, the embodiment corresponding to Figure 8, the embodiment corresponding to Figure 9, the embodiment corresponding to Figure 13, the embodiment corresponding to Figure 16, and the embodiment corresponding to Figure 17 can be implemented separately or in combination, and this application does not limit this.

[0344] FIG18 shows a block diagram of a communication device for broadcasting frames according to an exemplary embodiment of the present application. The device can be implemented as a zero-power device, or as part of a zero-power device, through software or hardware, or a combination of both. The device includes a receiving module 1810, wherein the functions of the receiving module 1810 are implemented by a receiver in the zero-power device.

[0345] The receiving module 1810 is configured to receive a first broadcast frame.

[0346] The first broadcast frame is sent between periodically sent second broadcast frames, and / or is sent before the first second broadcast frame, and / or is sent after the last second broadcast frame.

[0347] In one possible design of this embodiment, the first broadcast frame is transmitted at a different time domain location than the periodically transmitted second broadcast frame. Alternatively, the first broadcast frame may be supplementally or additionally transmitted at a different time domain location than the periodically transmitted second broadcast frame.

[0348] In a possible design of this embodiment, when the network device is a device in a WiFi system, the first broadcast frame is a first beacon frame, which is used for the device to quickly establish time and frequency synchronization with the network and obtain system information.

[0349] In a possible design of this embodiment, when the network device is a device in a cellular communication system, the first broadcast frame is system broadcast information, which is used to broadcast synchronization signals and system information, such as SSB in a 5G system.

[0350] In a possible design of this embodiment, the first broadcast frame is sent by a network device, and the network device is a device in a WiFi system and / or a device in a cellular communication system (or mobile communication system).

[0351] In a possible design of this embodiment, the receiving module 1810 is used to receive the first broadcast frame and the second broadcast frame.

[0352] The first broadcast frame is a broadcast frame supplementarily sent by the network device or an additional broadcast frame, and is sent aperiodically or periodically by the network device; the second broadcast frame is a broadcast frame periodically sent by the network device.

[0353] In a possible design of this embodiment, the first broadcast frame is sent in a specified search space, which may be set specifically for the device. The device monitors the first broadcast frame in the specified search space.

[0354] In a possible design of this embodiment, the first broadcast frame is sent in a designated resource pool, which may be a resource pool specifically set for the device.

[0355] The second broadcast frame is a second beacon frame or system broadcast information. The second beacon frame is used by the device to periodically establish time and frequency synchronization with the network and obtain system information. Exemplarily, the period is 100 milliseconds.

[0356] The second beacon frame is a beacon frame sent periodically and can carry information such as performance information and SSID.

[0357] In one possible design of this embodiment, the second beacon frame includes a preamble portion and a data portion. The preamble portion is used to indicate the start of data transmission and help the device determine the valid data portion. The preamble portion includes a set of specific signals used to synchronize the clocks between the device and the transmitting device (network device).

[0358] In one possible design of this embodiment, a network device configures at least one of a sending position, a number of transmissions, a time window length for sending a first broadcast frame, and a sending position of a next second broadcast frame. The apparatus receives at least one of the sending position, a number of transmissions, a time window length for sending a first broadcast frame, and a sending position of a next second broadcast frame. The sending position of the next second broadcast frame can be an absolute time position or an offset position relative to the current first broadcast frame.

[0359] In a possible design of this embodiment, the network device sends at least one first broadcast frame.

[0360] When the signal strength is greater than a first threshold, the network device sends a first broadcast frame. For example, when the device is near a router, a first broadcast frame can help the device complete time and frequency synchronization and obtain all system information. The first threshold is preset by those skilled in the art.

[0361] When the signal strength is less than the second threshold, the network device sends multiple first broadcast frames. For example, when it is far away from the router, multiple first broadcast frames are required to help the device complete time and frequency synchronization and obtain all system information. The second threshold is pre-set by a technician in this field.

[0362] The signal strength may be the signal strength when the apparatus sends a signal and / or data to a network device. Exemplarily, the first threshold is greater than or equal to the second threshold.

[0363] In a possible design of this embodiment, the first broadcast frame is sent periodically; or, the first broadcast frame is sent non-periodically.

[0364] In a possible design of this embodiment, the aperiodic sending manner includes at least one of the following:

[0365] Continuous transmission mode; or,

[0366] Discontinuous transmission mode; or,

[0367] Burst sending mode;

[0368] Among them, the continuous sending mode indicates that the first broadcast frame is sent n times one after another, and there is no sending interval during the sending process, and n is an integer greater than 1; the discontinuous sending mode indicates a sending mode in which there is a sending interval during the sending process of the first broadcast frame, and the sending interval may be periodic or non-periodic; the burst sending mode indicates a sending mode in which the first broadcast frame is sent at any time. Compared with the discontinuous sending mode, the sending interval between two transmissions is usually longer and more random.

[0369] In a possible design of this embodiment, the first broadcast frame and the second broadcast frame have the same structure.

[0370] Exemplarily, the first broadcast frame is a first beacon frame, and the second broadcast frame is a second beacon frame. The first beacon frame and the second beacon frame have the same structure: the preamble portion is first, followed by the data portion. Both frames have the same preamble portion, the same key parameters as the data portion length and bit rate, and carry the same type of configuration information. Most parameters have the same values, but a few have different values. For example, the timestamp information changes depending on the time position of the two beacon frames.

[0371] The preamble part includes: L-STF, L-LTF, and L-SIG fields. Among them, L-STF contains a specified and unique waveform that is easily detected by the device. The functions of L-STF include at least one of the following: packet detection, AGC, initial frequency offset estimation, and initial time synchronization. L-LTF also contains a specified and unique waveform, but it is not exactly the same as L-STF. The functions of L-LTF include at least one of the following: channel estimation, more accurate frequency offset estimation, and more accurate time synchronization. The L-SIG field includes information such as the transmit rate, coding scheme, guard interval, and length, which are used to calculate the duration of the data packet.

[0372] In a possible design of this embodiment, the structures of the first broadcast frame and the second broadcast frame are different.

[0373] In one possible design of this embodiment, the first broadcast frame and the second broadcast frame have different structures, including at least one of the following:

[0374] (1) The preamble codes used in the first broadcast frame and the second broadcast frame are different;

[0375] (2) The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different;

[0376] (3) the information type of the data portion of the first broadcast frame is smaller than the information type of the data portion of the second broadcast frame, or the information type of the data portion of the first broadcast frame is larger than the information type of the data portion of the second broadcast frame;

[0377] (4) The code rate of the data portion of the first broadcast frame is lower than the code rate of the data portion of the second broadcast frame.

[0378] For example, the first broadcast frame is the first beacon frame, and the second broadcast frame is the second beacon frame:

[0379] The designs of (1) and (2) can provide different synchronization performances. For example, if the preamble sequence length of the first beacon frame is longer than that of the second beacon frame, it can contain more synchronization signals, thereby improving the probability and accuracy of the device identifying the data part, thereby providing better synchronization performance.

[0380] By adopting the design (3), when the information types in the data portion of the first beacon frame are smaller than those in the data portion of the second beacon frame, for example, only information such as the timestamp and the period of the second beacon frame is included, key information can be quickly transmitted to the device, and the smaller data portion can also increase the reception probability of the device. When the information types in the data portion of the first beacon frame are larger than those in the data portion of the second beacon frame, system information can be directly transmitted to the device to help the device establish time-frequency synchronization.

[0381] By adopting the design of (4), when the code rate of the data portion of the first beacon frame is lower than the code rate of the data portion of the second beacon frame, the probability of the device successfully receiving the beacon frame can be increased.

[0382] In one possible design of this embodiment, in a WiFi / WLAN system, the period of the second broadcast frame is associated with a partial configuration. For example, the second beacon frame may carry a TIM indication, which is used to inform the device whether there is downlink data to be transmitted. The TIM period is an integer multiple of the period of the second beacon frame. Each beacon frame contains a TIM, which includes a bitmap control field. Each bit in the TIM field maps to a communication device in the broadcast frame. When the bit is 1, it indicates that the communication device in the broadcast frame corresponding to the bit has downlink data cached in the network device.

[0383] For another example, the RAW configuration can be indicated in the second beacon frame. During the RAW period, the device transmits data with the network device, and the RAW configuration is after the second beacon frame. The key concept of RAW is to limit the set of stations that can access the channel and spread their access attempts over a longer period of time, thereby reducing interference and improving communication reliability and efficiency.

[0384] In a possible design of this embodiment, when the network device sends both the first broadcast frame and the second broadcast frame, the apparatus needs to distinguish between the two. This is because:

[0385] First, after completing time-frequency synchronization and obtaining system information based on either the first or second broadcast frame, the device needs to periodically maintain time-frequency synchronization based on the second broadcast frame. Therefore, the position of the second broadcast frame needs to be determined.

[0386] Second, the second broadcast frame can send new system information at any time, such as RAW configuration. The device also needs to obtain new system information based on the second broadcast frame.

[0387] In one possible design of this embodiment, the first broadcast frame and the second broadcast frame are distinguished by using at least one of the following methods:

[0388] Type indication located in the information field;

[0389] Preamble;

[0390] SIG domain.

[0391] Exemplarily, the FC of the beacon MAC header is used for type indication, and the FC includes fields such as a frame type field and a subtype field, wherein the frame type field specifies the type of the data frame, and the subtype field specifies a more specific subtype of the data frame;

[0392] Alternatively, the first broadcast frame and the second broadcast frame may be indicated by a preamble code, and different preamble code sequences may be used to distinguish the first broadcast frame from the second broadcast frame;

[0393] Alternatively, the SIG field (i.e., L-SIG field) in the preamble may be used for indication. The SIG field includes information about the channel state, such as signal-to-noise ratio, rate, frequency, etc. The device can identify the channel state by decoding and analyzing the signal parameters in the SIG field, thereby adjusting the transmission rate. The first broadcast frame and the second broadcast frame use different bit values ​​in the SIG field, which can also distinguish the first broadcast frame from the second broadcast frame.

[0394] In a possible design of this embodiment, after waking up, the device may first search for the first broadcast frame or the second broadcast frame, and the device completes time-frequency synchronization and obtains system information based on either of the two.

[0395] In a possible design of this embodiment, the first broadcast frame carries the time domain position information of the next second broadcast frame. The time domain position information can be an absolute time position or an offset position relative to the current first broadcast frame.

[0396] In a possible design of this embodiment, the first broadcast frame is sent by the network device when a triggering event occurs.

[0397] In one possible design of this embodiment, the network device triggers the transmission of the first broadcast frame based on a trigger event. That is, when a device needs to complete time-frequency synchronization and obtain system information, such as in an item search event, the network device can transmit radio waves to power the device and transmit the first and second broadcast frames to the device when the item search event is triggered. For example, the first broadcast frame may be transmitted first, followed by the second broadcast frame, or the first broadcast frame may be transmitted between periodically transmitted second broadcast frames.

[0398] In one possible design of this embodiment, the triggering event includes at least one of the following:

[0399] Find item events;

[0400] Logistics vehicle arrival event;

[0401] Warehouse inventory events.

[0402] For example, in a logistics scenario, the network device senses (for example, through sound wave sensing, motion sensing, etc.) the arrival of a logistics vehicle. When the logistics vehicle arrives, the network device starts the inventory process of the items on the logistics vehicle. At this time, the network device can send radio waves to power the device and send a first broadcast frame and a second broadcast frame to the device.

[0403] Similarly, in a warehousing scenario, when an inventory of items in the warehouse needs to be taken, the network device may send radio waves to power the device, and send a first broadcast frame and a second broadcast frame to the device.

[0404] In the above scenario, through such an operation, a sufficient number of broadcast frames can be quickly sent to the device at the moment the process of searching for items and warehouse inventory is started, so that the device can quickly complete time and frequency synchronization and obtain system information, thereby speeding up the above-mentioned search for items and warehouse inventory.

[0405] In a possible design of this embodiment, the first broadcast frame is sent by a network device, and the network device is a device in a WiFi system and / or a device in a cellular communication system.

[0406] In some embodiments, at least one first broadcast frame is transmitted within the first time window. The at least one first broadcast frame also carries information indicating the first time window. When there are multiple first broadcast frames within the first time window, all or some of the multiple first broadcast frames carry information indicating the first time window.

[0407] In some embodiments, the first time window is expressed in the form of: window start point + window length.

[0408] In some embodiments, the first time domain position and the remaining time occupied by the first broadcast frame represent the length of the first time window. That is, the remaining time of the first time window may be carried in all or part of the first broadcast frames. For example, the remaining time may be carried in each first broadcast frame except for the last first broadcast frame. A remaining time of 1000 milliseconds carried by a first broadcast frame indicates that, starting from the time domain position of the first broadcast frame, the remaining time of the first time window is 1000 milliseconds.

[0409] In some embodiments, the current first broadcast frame carries indication information of the time domain position of the next first broadcast frame. If the indication information exists, it indicates that the first time window has not yet ended and indicates the time domain position of the next first broadcast frame; if the indication information does not exist, it indicates that the first time window ends after the time domain position of the first broadcast frame.

[0410] In this embodiment, the receiving module 1810 can be divided into multiple receiving modules, such as a first receiving module and a second receiving module. The first receiving module is configured to receive the first broadcast frame, and the second receiving module is configured to receive the second broadcast frame; or the first receiving module is configured to receive the second broadcast frame, and the second receiving module is configured to receive the first broadcast frame. This embodiment does not limit the functions of the different receiving modules.

[0411] This embodiment is described by taking one receiving module 1810 as an example, and the number of receiving modules 1810 is not limited.

[0412] For an introduction to the functions of the receiving module 1810 , please refer to the contents of step 910 in the embodiment of FIG. 9 .

[0413] FIG19 shows a block diagram of a communication device for broadcasting frames provided by an exemplary embodiment of the present application. The device can be implemented as a network device, or as part of a network device, through software or hardware, or a combination of both. The device includes a sending module 1910. The functions of the sending module 1910 are implemented by a transmitter in the network device.

[0414] The sending module 1910 is configured to send a first broadcast frame.

[0415] The first broadcast frame is sent between periodically sent second broadcast frames, and / or is sent before the first second broadcast frame, and / or is sent after the last second broadcast frame.

[0416] In one possible design of this embodiment, the first broadcast frame is transmitted at a different time domain location than the periodically transmitted second broadcast frame. Alternatively, the first broadcast frame may be supplementally or additionally transmitted at a different time domain location than the periodically transmitted second broadcast frame.

[0417] In a possible design of this embodiment, when the apparatus is a device in a WiFi system, the first broadcast frame is a first beacon frame, which is used for the zero-power device to quickly establish time and frequency synchronization with the network and obtain system information.

[0418] In a possible design of this embodiment, when the apparatus is a device in a cellular communication system, the first broadcast frame is system broadcast information, which is used to broadcast synchronization signals and system information, such as SSB in a 5G system.

[0419] In a possible design of this embodiment, the first broadcast frame is sent by the apparatus, which is a device in a WiFi system and / or a device in a cellular communication system (or mobile communication system).

[0420] In a possible design of this embodiment, the sending module 1910 is used to send a first broadcast frame and a second broadcast frame.

[0421] The first broadcast frame is a broadcast frame supplementarily sent by the device or an additional broadcast frame, which is sent aperiodically or periodically by the device; and the second broadcast frame is a broadcast frame periodically sent by the device.

[0422] In a possible design of this embodiment, the first broadcast frame is sent in a specified search space, which may be set exclusively for zero-power devices. The zero-power devices listen to the first broadcast frame in the specified search space.

[0423] In a possible design of this embodiment, the first broadcast frame is sent in a designated resource pool, which may be a resource pool specifically set for zero-power devices.

[0424] The second broadcast frame is a second beacon frame or system broadcast information. The second beacon frame is used for the zero-power device to periodically establish time and frequency synchronization with the network and obtain system information. Exemplarily, the period is 100 milliseconds.

[0425] The second beacon frame is a beacon frame sent periodically and can carry information such as performance information and SSID.

[0426] In one possible design of this embodiment, the second beacon frame includes a preamble portion and a data portion. The preamble portion is used to indicate the start of data transmission and help the receiving device (zero-power device) determine the valid data portion. The preamble portion includes a set of specific signals used to synchronize the clocks between the receiving device (zero-power device) and the apparatus.

[0427] In one possible design of this embodiment, the apparatus configures at least one of the sending position, number of transmissions, and time window length of the first broadcast frame, and the sending position of the next second broadcast frame. The zero-power device receives at least one of the sending position, number of transmissions, and time window length of the first broadcast frame, and the sending position of the next second broadcast frame. The sending position of the next second broadcast frame can be an absolute time position or an offset position relative to the current first broadcast frame.

[0428] In a possible design of this embodiment, the sending module 1910 is used to send at least one first broadcast frame.

[0429] When the signal strength is greater than a first threshold, the device sends a first broadcast frame. For example, when the device is near a router, a first broadcast frame can help the zero-power device complete time and frequency synchronization and obtain all system information. The first threshold is preset by those skilled in the art.

[0430] When the signal strength is less than the second threshold, the device sends multiple first broadcast frames. For example, when it is far away from the router, multiple first broadcast frames are needed to help the zero-power device complete time and frequency synchronization and obtain all system information. The second threshold is pre-set by a technician in this field.

[0431] The signal strength may be the signal strength when the zero-power device sends a signal and / or data to the apparatus. Exemplarily, the first threshold is greater than or equal to the second threshold.

[0432] In a possible design of this embodiment, the first broadcast frame is sent periodically; or, the first broadcast frame is sent non-periodically.

[0433] In a possible design of this embodiment, the aperiodic sending manner includes at least one of the following:

[0434] Continuous transmission mode; or,

[0435] Discontinuous transmission mode; or,

[0436] Burst sending mode;

[0437] Among them, the continuous sending mode indicates that the first broadcast frame is sent n times one after another, and there is no sending interval during the sending process, and n is an integer greater than 1; the discontinuous sending mode indicates a sending mode in which there is a sending interval during the sending process of the first broadcast frame, and the sending interval may be periodic or non-periodic; the burst sending mode indicates a sending mode in which the first broadcast frame is sent at any time. Compared with the discontinuous sending mode, the sending interval between two transmissions is usually longer and more random.

[0438] In a possible design of this embodiment, the first broadcast frame and the second broadcast frame have the same structure.

[0439] Exemplarily, the first broadcast frame is a first beacon frame, and the second broadcast frame is a second beacon frame. The first beacon frame and the second beacon frame have the same structure: the preamble portion is first, followed by the data portion. Both frames have the same preamble portion, the same key parameters as the data portion length and bit rate, and carry the same type of configuration information. Most parameters have the same values, but a few have different values. For example, the timestamp information changes depending on the time position of the two beacon frames.

[0440] The preamble part includes: L-STF, L-LTF, and L-SIG fields. Among them, L-STF contains a specified and unique waveform, which is easily detected by the receiving device (zero-power device). The functions of L-STF include at least one of the following: packet detection, AGC, initial frequency offset estimation, and initial time synchronization. L-LTF also contains a specified and unique waveform, but it is not exactly the same as L-STF. The functions of L-LTF include at least one of the following: channel estimation, more accurate frequency offset estimation, and more accurate time synchronization. The L-SIG field includes information such as the transmit rate, coding scheme, guard interval, and length, which are used to calculate the duration of the data packet.

[0441] In a possible design of this embodiment, the structures of the first broadcast frame and the second broadcast frame are different.

[0442] In one possible design of this embodiment, the first broadcast frame and the second broadcast frame have different structures, including at least one of the following:

[0443] (1) The preamble codes used in the first broadcast frame and the second broadcast frame are different;

[0444] (2) The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different;

[0445] (3) the information type of the data portion of the first broadcast frame is smaller than the information type of the data portion of the second broadcast frame, or the information type of the data portion of the first broadcast frame is larger than the information type of the data portion of the second broadcast frame;

[0446] (4) The code rate of the data portion of the first broadcast frame is lower than the code rate of the data portion of the second broadcast frame.

[0447] For example, the first broadcast frame is the first beacon frame, and the second broadcast frame is the second beacon frame:

[0448] The designs of (1) and (2) can provide different synchronization performances. For example, if the preamble sequence length of the first beacon frame is longer than that of the second beacon frame, it can contain more synchronization signals, thereby improving the probability and accuracy of the zero-power device identifying the data part, thereby providing better synchronization performance.

[0449] By adopting the design (3), when the information types of the data part of the first beacon frame are smaller than the information types of the data part of the second beacon frame, for example, only including the timestamp, the period of the second beacon frame and other information, key information can be quickly transmitted to the zero-power device, and the smaller data part can also increase the reception probability of the zero-power device. When the information types of the data part of the first beacon frame are greater than the information types of the data part of the second beacon frame, system information can be directly transmitted to the zero-power device to help the zero-power device establish time-frequency synchronization.

[0450] By adopting the design of (4), when the code rate of the data portion of the first beacon frame is lower than the code rate of the data portion of the second beacon frame, the probability of the zero-power device successfully receiving the beacon frame can be increased.

[0451] In one possible design of this embodiment, in a WiFi / WLAN system, the period of the second broadcast frame is associated with a partial configuration. For example, the second beacon frame may carry a TIM indication, which is used to send information to the zero-power device regarding whether there is downlink data to be transmitted. The TIM period is an integer multiple of the period of the second beacon frame. Each beacon frame includes a TIM, which includes a bitmap control field. Each bit of the TIM field maps to a zero-power device. When the bit is 1, it indicates that the zero-power device corresponding to the bit has downlink data cached in the device.

[0452] For another example, the RAW configuration can be indicated in the second beacon frame. During the RAW period, the zero-power device transmits data with the device. The RAW configuration follows the second beacon frame. The key idea of ​​RAW is to limit the set of stations that can access the channel and spread their access attempts over a longer period of time, thereby reducing interference and improving communication reliability and efficiency.

[0453] In a possible design of this embodiment, when the apparatus sends both the first broadcast frame and the second broadcast frame, the zero-power device needs to distinguish between the two. This is because:

[0454] First, after completing time-frequency synchronization and obtaining system information based on either the first or second broadcast frame, the zero-power device needs to periodically maintain time-frequency synchronization based on the second broadcast frame. Therefore, the position of the second broadcast frame needs to be determined.

[0455] Second, the second broadcast frame can send new system information at any time, such as RAW configuration. Zero-power devices also need to obtain new system information based on the second broadcast frame.

[0456] In one possible design of this embodiment, the first broadcast frame and the second broadcast frame are distinguished by using at least one of the following methods:

[0457] Type indication located in the information field;

[0458] Preamble;

[0459] SIG domain.

[0460] Exemplarily, the FC of the beacon MAC header is used for type indication, and the FC includes fields such as a frame type field and a subtype field, wherein the frame type field specifies the type of the data frame, and the subtype field specifies a more specific subtype of the data frame;

[0461] Alternatively, the first broadcast frame and the second broadcast frame may be indicated by a preamble code, and different preamble code sequences may be used to distinguish the first broadcast frame from the second broadcast frame;

[0462] Alternatively, the SIG field (i.e., L-SIG field) in the preamble can be used for indication. The SIG field includes information about the channel state, such as signal-to-noise ratio, rate, and frequency. Zero-power devices can identify the channel state by decoding and analyzing the signal parameters in the SIG field, thereby adjusting the transmission rate. The first and second broadcast frames use different bit values ​​in the SIG field, which can also distinguish the first and second broadcast frames.

[0463] In a possible design of this embodiment, after waking up, the zero-power device may first search for the first broadcast frame or the second broadcast frame. The zero-power device completes time-frequency synchronization and obtains system information based on either of the two.

[0464] In a possible design of this embodiment, the first broadcast frame carries the time domain position information of the next second broadcast frame. The time domain position information can be an absolute time position or an offset position relative to the current first broadcast frame.

[0465] In a possible design of this embodiment, the first broadcast frame is sent by the device when a trigger event occurs.

[0466] In one possible design of this embodiment, the apparatus triggers the transmission of the first broadcast frame based on a triggering event. That is, when the zero-power device needs to complete time-frequency synchronization and obtain system information, such as in an item search event, the apparatus may transmit radio waves to power the zero-power device and transmit the first and second broadcast frames to the zero-power device when the item search event is triggered. For example, the first broadcast frame may be transmitted first, followed by the second broadcast frame; or the first broadcast frame may be transmitted between periodically transmitted second broadcast frames.

[0467] In one possible design of this embodiment, the triggering event includes at least one of the following:

[0468] Find item events;

[0469] Logistics vehicle arrival event;

[0470] Warehouse inventory events.

[0471] For example, in a logistics scenario, the device senses (for example, through sound wave sensing, motion sensing, etc.) the arrival of a logistics vehicle. When the logistics vehicle arrives, the device starts the inventory process of the items (zero-power devices) on the logistics vehicle. At this time, the device can send radio waves to power the zero-power device, and send a first broadcast frame and a second broadcast frame to the zero-power device.

[0472] Similarly, in a warehousing scenario, when inventory of items (zero-power devices) in the warehouse needs to be taken, the device can send radio waves to power the zero-power devices, and send a first broadcast frame and a second broadcast frame to the zero-power devices.

[0473] In the above scenario, through such operations, a sufficient number of broadcast frames can be quickly sent to the zero-power device at the moment the item search and warehouse inventory process starts, so that the zero-power device can quickly complete time and frequency synchronization and obtain system information, thereby speeding up the above-mentioned item search and warehouse inventory.

[0474] In some embodiments, at least one first broadcast frame is transmitted within the first time window. The at least one first broadcast frame also carries information indicating the first time window. When there are multiple first broadcast frames within the first time window, all or some of the multiple first broadcast frames carry information indicating the first time window.

[0475] In some embodiments, the first time window is expressed in the form of: window start point + window length.

[0476] In some embodiments, the first time domain position and the remaining time occupied by the first broadcast frame represent the length of the first time window. That is, the remaining time of the first time window may be carried in all or part of the first broadcast frames. For example, the remaining time may be carried in each first broadcast frame except for the last first broadcast frame. A remaining time of 1000 milliseconds carried by a first broadcast frame indicates that, starting from the time domain position of the first broadcast frame, the remaining time of the first time window is 1000 milliseconds.

[0477] In some embodiments, the current first broadcast frame carries indication information of the time domain position of the next first broadcast frame. If the indication information exists, it indicates that the first time window has not yet ended and indicates the time domain position of the next first broadcast frame; if the indication information does not exist, it indicates that the first time window ends after the time domain position of the first broadcast frame.

[0478] In a possible design of this embodiment, the first broadcast frame is sent by the apparatus, which is a device in a WiFi system and / or a device in a cellular communication system.

[0479] In this embodiment, the sending module 1910 can be divided into multiple sending modules, such as a first sending module and a second sending module. The first sending module is used to send the first broadcast frame, and the second sending module is used to send the second broadcast frame; or the first sending module is used to send the second broadcast frame, and the second sending module is used to send the first broadcast frame. This embodiment does not limit the functions of the different sending modules.

[0480] This embodiment is described by taking one sending module 1910 as an example, and the number of sending modules 1910 is not limited.

[0481] For an introduction to the functions of the sending module 1910, please refer to the contents of step 1710 in the embodiment of FIG17 .

[0482] Figure 20 shows a structural diagram of a terminal device or network device 2000 provided by an exemplary embodiment of the present application, including: a processor 2001, a receiver 2002, a transmitter 2003, a memory 2004 and a bus 2005.

[0483] The processor 2001 includes one or more processing cores. The processor 2001 executes various functional applications and information processing by running software programs and modules.

[0484] Receiver 2002 and transmitter 2003 can be implemented as a communication component, which can be a communication chip, and can be called a transceiver. In some embodiments, receiver 2002 can be used to implement the functions and steps of the above-mentioned receiving module 1810, and transmitter 2003 can be used to implement the functions and steps of the above-mentioned sending module 1910.

[0485] The memory 2004 is connected to the processor 2001 via a bus 2005 .

[0486] The memory 2004 may be used to store at least one instruction, and the processor 2001 may be used to execute the at least one instruction to implement each step in the above method embodiment.

[0487] In addition, the memory 2004 can be implemented by any type of volatile or non-volatile storage device or a combination thereof. The volatile or non-volatile storage devices include but are not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), read-only memory (ROM), magnetic memory, flash memory, and programmable read-only memory (PROM).

[0488] In some embodiments, the receiver 2002 receives signals / data independently, or the processor 2001 controls the receiver 2002 to receive signals / data, or the processor 2001 requests the receiver 2002 to receive signals / data, or the processor 2001 cooperates with the receiver 2002 to receive signals / data.

[0489] In some embodiments, the transmitter 2003 independently sends signals / data, or the processor 2001 controls the transmitter 2003 to send signals / data, or the processor 2001 requests the transmitter 2003 to send signals / data, or the processor 2001 cooperates with the transmitter 2003 to send signals / data.

[0490] In an exemplary embodiment, a computer-readable storage medium is further provided, in which at least one program is stored. The at least one program is loaded and executed by a processor to implement the communication method of the broadcast frame provided by each of the above method embodiments.

[0491] In an exemplary embodiment, a computer program product or computer program is also provided. When the computer program product or computer program runs on a processor, it enables the zero-power device or network device 2000 to execute the communication method of the broadcast frame provided by the above-mentioned various method embodiments.

[0492] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by a program instructing the relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk, or an optical disk, etc.

[0493] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A communication method for broadcasting frames, characterized in that: The method is performed by a zero-power consumption device, and the method includes: A first broadcast frame is received, where the first broadcast frame is a broadcast frame sent at a time domain position different from a second broadcast frame that is periodically sent.

2. The method according to claim 1, characterized in that The first broadcast frame is sent periodically; or, The first broadcast frame is sent in a non-periodic manner.

3. The method according to claim 2, characterized in that The non-periodic transmission mode includes at least one of the following: Continuous transmission mode; or, Discontinuous transmission mode; or, Burst sending mode.

4. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame and the second broadcast frame have the same structure.

5. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame and the second broadcast frame have different structures.

6. The method according to claim 5, characterized in that The structures of the first broadcast frame and the second broadcast frame are different, including at least one of the following: The first broadcast frame and the second broadcast frame use different preamble codes; The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different; The information type of the data part of the first broadcast frame is smaller than the information type of the data part of the second broadcast frame, or the information type of the data part of the first broadcast frame is larger than the information type of the data part of the second broadcast frame; A code rate of the data portion of the first broadcast frame is lower than a code rate of the data portion of the second broadcast frame.

7. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame and the second broadcast frame are distinguished by at least one of the following methods: The type indicator located in the information field; Preamble; Signal information SIG field.

8. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame carries the time domain location information of the next second broadcast frame.

9. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame is sent by the network device when a trigger event occurs.

10. The method according to claim 9, characterized in that The triggering event includes at least one of the following: Find item events; Logistics vehicle arrival event; Warehouse inventory event.

11. The method according to any one of claims 1 to 3, characterized in that: The first broadcast frame is sent by a network device, and the network device is a device in a Wireless Fidelity WiFi system and / or a device in a cellular communication system.

12. A communication method for broadcast frames, characterized in that: The method is performed by a network device, and the method includes: A first broadcast frame is sent, where the first broadcast frame is a broadcast frame sent at a time domain position different from a second broadcast frame that is periodically sent.

13. The method according to claim 12, characterized in that The first broadcast frame is sent periodically; or, The first broadcast frame is sent in a non-periodic manner.

14. The method according to claim 13, characterized in that The non-periodic transmission mode includes at least one of the following: Continuous transmission mode; or, Discontinuous transmission mode; or, Burst sending mode.

15. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame and the second broadcast frame have the same structure.

16. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame and the second broadcast frame have different structures.

17. The method according to claim 16, characterized in that The structures of the first broadcast frame and the second broadcast frame are different, including at least one of the following: The first broadcast frame and the second broadcast frame use different preamble codes; The preamble sequence lengths of the first broadcast frame and the second broadcast frame are different; The information type of the data part of the first broadcast frame is smaller than the information type of the data part of the second broadcast frame, or the information type of the data part of the first broadcast frame is larger than the information type of the data part of the second broadcast frame; A code rate of the data portion of the first broadcast frame is lower than a code rate of the data portion of the second broadcast frame.

18. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame and the second broadcast frame are distinguished by at least one of the following methods: The type indicator located in the information field; Preamble; Signal information SIG field.

19. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame carries the time domain location information of the next second broadcast frame.

20. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame is sent by the network device when a trigger event occurs.

21. The method according to claim 20, characterized in that The triggering event includes at least one of the following: Find item events; Logistics vehicle arrival event; Warehouse inventory event.

22. The method according to any one of claims 12 to 14, characterized in that: The first broadcast frame is sent by a network device, and the network device is a device in a Wireless Fidelity WiFi system and / or a device in a cellular communication system.

23. A communication device for broadcasting frames, characterized in that: The device comprises: The receiving module is used to receive a first broadcast frame, where the first broadcast frame is a broadcast frame sent at a time domain position different from a second broadcast frame sent periodically.

24. A communication device for broadcasting frames, characterized in that: The device comprises: The sending module is used to send a first broadcast frame, where the first broadcast frame is a broadcast frame sent at a time domain position different from a second broadcast frame that is periodically sent.

25. A zero-power consumption device, characterized in that: The zero-power consumption device comprises: processor; a transceiver connected to the processor; a memory for storing executable instructions for the processor; The processor is configured to load and execute the executable instructions to implement the communication method of the broadcast frame as described in any one of claims 1 to 11.

26. A network device, characterized in that: The network equipment includes: processor; a transceiver connected to the processor; a memory for storing executable instructions for the processor; The processor is configured to load and execute the executable instructions to implement the communication method of the broadcast frame as described in any one of claims 12 to 22.

27. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one program, and the at least one program is loaded and executed by a processor to implement the communication method of the broadcast frame as described in any one of claims 1 to 22.

28. A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium. The processor obtains the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to implement the communication method of the broadcast frame as described in any one of claims 1 to 22.

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