Data transmission control method and system for narrowband Internet of Things

Abstract

The invention belongs to the technical field of Internet of Things, and discloses a data transmission control method and system for a narrowband Internet of Things, and the method is applied to terminal equipment. Comprising the following steps: receiving a control link parameter of gateway equipment, and counting a confirmation success rate of uplink data; adjusting a coding rate, a spreading factor and a burst repetition number in the control link parameter according to the confirmation success rate to obtain an adjusted control link parameter; modulating and coding a physical burst frame in the uplink data based on the adjusted control link parameter; and sending the modulated and coded uplink data to gateway equipment. According to the invention, the transmission reliability of the narrowband Internet of Things under various channel conditions can be effectively improved, and meanwhile, the waste of power consumption caused by increasing excessive physical burst frames is avoided.

Description

Technical Field

[0001] This application relates to the technical field of narrowband Internet of Things (NB-IoT), and particularly to a data transmission control method and system for narrowband Internet of Things. Background Art

[0002] Different from mobile communication, due to the limitations of hardware complexity, power consumption requirements and cost, low-power narrowband Internet of Things usually adopts a bursty physical frame structure. And due to the processing capabilities of different devices, the processing delay for bursts is also different. Therefore, low-power narrowband Internet of Things usually adopts a single-burst frame structure for data transmission.

[0003] However, limited by system complexity, the synchronization threshold and data demodulation threshold of traditional narrowband Internet of Things radio frequency transceiver chips use the same threshold value. Therefore, the single-burst frame structure is limited by the demodulation ability of the synchronization header, and it is difficult to further improve the system stability and transmission reliability through technologies such as spread spectrum, making the communication system design less flexible. Summary of the Invention

[0004] This application provides a data transmission control method and system for narrowband Internet of Things, which can effectively improve the transmission reliability of narrowband Internet of Things in various channel conditions, and at the same time avoid power consumption waste caused by adding too many physical burst frames.

[0005] In a first aspect, this application provides a data transmission control method for narrowband Internet of Things, which is applied to a terminal device and includes:

[0006] Receiving control link parameters of a gateway device and statistically calculating the confirmation success rate of uplink data;

[0007] Adjusting the coding rate, spreading factor and burst repetition number in the control link parameters according to the confirmation success rate to obtain adjusted control link parameters;

[0008] Modulating and encoding the physical burst frames in the uplink data based on the adjusted control link parameters;

[0009] Sending the modulated and encoded uplink data to the gateway device.

[0010] Further, the method further includes:

[0011] Sending an access request signal to the gateway device at a preset semi-static power;

[0012] Receiving the expected power and expected link parameters of the gateway device;

[0013] Determining initial link parameters according to the difference between the preset maximum power and the expected power;

[0014] Obtaining registration link parameters according to the initial link parameters and the expected link parameters;

[0015] Generate registration data based on the registration link parameters and send it to the gateway device.

[0016] Furthermore, the method further includes:

[0017] If the information of the gateway device is not received within the preset retransmission duration after sending the network access request signal, then adjust the preset semi-static power according to the preset increment and re-send the network access request signal with the preset semi-static power.

[0018] Furthermore, the method further includes:

[0019] Calculate the path loss value according to the received control link parameters;

[0020] Add the path loss value and the preset semi-static power to obtain the open-loop operating power;

[0021] If the open-loop operating power is greater than the preset maximum power, then send the uplink data with the preset maximum power, otherwise send the uplink data with the open-loop operating power.

[0022] Furthermore, the method further includes:

[0023] Determine whether there is a control semi-static power in the control link parameters;

[0024] If there is, then update the preset semi-static power according to the control semi-static power.

[0025] Furthermore, the method further includes:

[0026] Calculate the signal strength of the downlink channel according to the received control link parameters;

[0027] Calculate the noise data of the downlink channel based on the erasure estimation algorithm;

[0028] If the signal strength is less than the preset downlink strength threshold, or the noise data is greater than the preset downlink noise threshold, then generate downlink status information according to the signal strength and the noise data and send it to the gateway device.

[0029] Furthermore, the method further includes:

[0030] Obtain the number of successful synchronizations of the control link parameters during the decoding process based on sliding window statistics;

[0031] If the number of successful synchronizations is less than the preset synchronization threshold, then determine that the downlink channel fails.

[0032] Furthermore, the method further includes:

[0033] Receive the frequency point change instruction from the gateway device;

[0034] Modify the uplink channel frequency of the transmitted uplink data according to the frequency point change instruction.

[0035] In a second aspect, the present application provides a data transmission control method for narrowband Internet of Things, which is applied to a gateway device and includes:

[0036] Receive the uplink data of the terminal device, and determine whether the number of repeated physical burst frames in the uplink data is greater than 1;

[0037] If so, merge the repeated physical burst frames and then perform demodulation and decoding, and count the demodulation success rate;

[0038] Generate control link parameters according to the demodulation success rate and send them to the terminal device.

[0039] Further, the method further includes:

[0040] Receive the network access request signal of the terminal device, and estimate the uplink channel state of the terminal device according to the network access request signal;

[0041] Generate the expected power and expected link parameters according to the uplink channel state and send them to the terminal device.

[0042] Further, the method further includes:

[0043] Receive the uplink data of each terminal device;

[0044] Based on each uplink data and the voice erasure detection algorithm, obtain the channel noise of each uplink channel;

[0045] According to each channel noise, count the average noise corresponding to each uplink channel within a preset time period;

[0046] Obtain the power margin of each terminal device and count the number of terminals with a power margin of 0;

[0047] Determine whether the number of terminals reaches a preset power adjustment threshold;

[0048] If so, determine the maximum semi-static power corresponding to the preset power adjustment threshold;

[0049] Obtain the control semi-static power according to the maximum average noise and the maximum semi-static power and send it to the terminal device.

[0050] Further, the above-mentioned obtaining the control semi-static power according to the maximum average noise and the maximum semi-static power and sending it to the terminal device includes:

[0051] Determine whether the maximum average noise is greater than the maximum semi-static power;

[0052] If not, add the maximum average noise to the demodulation threshold to obtain the minimum power threshold; calculate the control semi-static power of each terminal device based on the minimum power threshold.

[0053] If so, eliminate the uplink channels with average noise greater than the maximum semi-static power, and generate channel interference prompt information.

[0054] Determine whether the number of remaining uplink channels meets the preset available conditions.

[0055] If so, obtain the control semi-static power according to the average noise and demodulation threshold of the uplink channel; put the control semi-static power and the remaining channel information into the control link parameters of the terminal device.

[0056] Further, calculating the control semi-static power of each terminal device based on the minimum power threshold includes:

[0057] Obtain the preset semi-static power of the terminal device.

[0058] Determine whether the minimum power threshold is less than the preset semi-static power.

[0059] If not, use the minimum power threshold as the control semi-static power of the terminal device, and put the control semi-static power into the control link parameters of the terminal device.

[0060] Further, the method further includes:

[0061] If the minimum power threshold is less than the preset semi-static power, multiply the demodulation threshold by a preset factor, then add the maximum average noise, and update the minimum power threshold according to the obtained sum value.

[0062] Determine whether the minimum power threshold is less than the preset semi-static power; if so, use the minimum power threshold as the control semi-static power of the terminal device, and put the control semi-static power into the control link parameters of the terminal device.

[0063] Further, the method further includes:

[0064] Receive the downlink status information of the terminal device.

[0065] Obtain the average signal-to-noise ratio of the corresponding terminal device according to the downlink status information.

[0066] Count the proportion of terminal devices with an average signal-to-noise ratio lower than the demodulation threshold.

[0067] If the proportion exceeds the preset signal-to-noise ratio threshold, generate channel interference prompt information.

[0068] Further, the method further includes:

[0069] After receiving each piece of uplink data, count the proportion of the uplink data carrying error data;

[0070] If the proportion exceeds the preset reception success rate threshold, generate a channel interference prompt message.

[0071] Further, the method further includes:

[0072] When the number of generated channel interference prompt messages is greater than or equal to the preset frequency conversion threshold, initiate channel scanning to obtain the noise floor value of each current channel, and generate a frequency point change instruction according to the frequency point of the current channel with the minimum noise floor value;

[0073] Broadcast and send the frequency point change instruction to each terminal device.

[0074] In a third aspect, the present application provides a terminal device, including a module for executing the data transmission control method of narrowband Internet of Things in any one of the above embodiments.

[0075] In a fourth aspect, the present application provides a gateway device, including a module for executing the data transmission control method of narrowband Internet of Things in any one of the above embodiments.

[0076] In a fifth aspect, the present application provides a data transmission control system for narrowband Internet of Things, including at least one terminal device for executing the data transmission control method of narrowband Internet of Things in any one of the above embodiments; and, a gateway device for executing the data transmission control method of narrowband Internet of Things in any one of the above embodiments.

[0077] In summary, compared with the prior art, the beneficial effects brought by the technical solutions provided by the embodiments of the present application at least include:

[0078] A data transmission control method for narrowband Internet of Things provided by an embodiment of the present application. First, the present application proposes a multi-burst physical frame structure, and multiple physical burst frames in the transmitted data are repeatedly set to improve the transmission reliability of the data; secondly, the present application also designs an adaptive adjustment of the burst repetition number based on the confirmation success rate of the uplink data. The counted confirmation success rate represents the uplink channel state. Since the channel state changes in real time, the present application enables the gateway device to determine the control link parameters according to the demodulation success rate, and then enables the terminal device to adjust the control link parameters according to the confirmation success rate of the uplink data counted at the data reception moment, ensuring the real-time nature of the control link parameters. This not only effectively improves the transmission reliability of narrowband Internet of Things in different channel states, but also avoids power consumption waste caused by blindly increasing physical burst frames. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 It is a schematic diagram of the frame structure of a physical burst frame provided by an exemplary embodiment of the present application.

[0080] Figure 2 Schematic diagram of the frame structure of a multi-burst data frame provided for an exemplary embodiment of the present application.

[0081] Figure 3 Flowchart of a data transmission control method for narrowband Internet of Things provided for an exemplary embodiment of the present application.

[0082] Figure 4 Flowchart of a data transmission control method for narrowband Internet of Things provided for another exemplary embodiment of the present application.

[0083] Figure 5 Flowchart of the steps for a terminal device to register and access the network provided for an exemplary embodiment of the present application.

[0084] Figure 6 Flowchart of the steps for a terminal device to control the uplink transmission power provided for an exemplary embodiment of the present application.

[0085] Figure 7 Flowchart of a gateway device controlling the transmission power of a terminal device provided for an exemplary embodiment of the present application. Detailed implementation manners

[0086] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0087] All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0088] Before elaborating on the data transmission control method of the present application, first define the data / physical frame structure used in the present application, that is, the multi-burst physical frame structure adopted by the present application.

[0089] Please refer to Figure 1 , the physical burst frame of the present application is composed of a preamble, a physical burst header PHR, a header check CRC, a payload, and a payload CRC. Among them, the preamble is used for AGC adjustment and synchronization detection; the payload is used to carry protocol layer information.

[0090] The PHR is used to carry physical layer control information, such as coding mode, spreading factor, etc. In the present application, the control link parameters are set in the PHR of the data frame sent by the gateway device.

[0091] Please refer to Figure 2, a multi-burst physical frame with N physical bursts, where the payload information in each physical burst can be repeated or different information. When the payload information in each physical burst is repeated, burst demodulation signals can be combined to obtain a greater gain; if the information is different, each burst is demodulated independently.

[0092] Whether the payload information in each burst is repeated can be determined by the PHR of the first burst.

[0093] When the payload information in each burst is repeated, the PHR and its CRC of subsequent bursts can be omitted to save protocol overhead.

[0094] Figure 2 The GP in [[ ]] refers to the guard interval between burst frames, which is used to prevent signal overlap and interference.

[0095] Please refer to Figure 3 , this embodiment of the present application provides a data transmission control method for narrowband Internet of Things, which is applied to each terminal device in the narrowband Internet of Things; specifically, it may include the following steps:

[0096] Step S11, receive the control link parameters of the gateway device and count the confirmation success rate of the uplink data.

[0097] It should be noted that the control link parameters of the gateway device are set in the PHR data of the data frame sent by the gateway device, and the terminal device can obtain the control link parameters by decoding the PHR data in the received data frame.

[0098] Specifically, the confirmation success rate can be obtained by performing ACK (Acknowledgement) success rate sliding window statistics on the ACK signals of the uplink data sent before receiving the control link parameters. The principle of ACK success rate sliding window statistics is mainly based on the monitoring and analysis of the confirmation mechanism (ACK) in the communication protocol. During the communication process of Internet of Things devices, when the terminal device sends data, the receiving party will reply with an ACK signal to confirm that the data has been successfully received.

[0099] Therefore, if the gateway device successfully receives the uplink data sent by the terminal device, it will feedback an ACK signal to the corresponding terminal device, and the terminal device will record whether each uplink data has received an ACK signal.

[0100] The sliding window is a technique used to track data streams or event sequences. In the ACK success rate statistics of this application, the sliding window is used to record the uplink data sent in the recent period of time and the corresponding ACK responses. This "window" will slide over time, only retaining the latest uplink data packets and ACK signals, so as to dynamically reflect the current state of the uplink channel.

[0101] It can be understood that the confirmation success rate in the above step S11 is the ratio of the ACK signal responses obtained from the uplink data sent within a preset window duration forward from the moment when the terminal device receives the control link parameters to the end.

[0102] Among them, the preset window duration can be adjusted according to actual needs to adapt to different communication environments and requirements. A larger sliding window can provide smoother success rate statistics, while a smaller sliding window can respond more quickly to changes in the communication state.

[0103] Step S12, adjust the coding rate, spreading factor, and burst repetition number in the control link parameters according to the confirmation success rate to obtain the adjusted control link parameters.

[0104] Specifically, the gateway device generates the control link parameters based on the demodulation success rate of the uplink data sent by the terminal device. However, due to the relatively long feedback cycle in the Internet of Things application scenario, the time for the gateway device to decode the uplink data is different from the time when the terminal device receives the control link parameters, and even separated by a relatively long period. During this period, the uplink channel state is very likely to change, resulting in poor real-time performance of the control link parameters generated by the gateway device.

[0105] Therefore, in this application, after obtaining the control link parameters, the confirmation success rate of the sent uplink data is statistically calculated to quantify the current state of the uplink channel, and the control link parameters are adjusted accordingly.

[0106] In the specific implementation process, a preset confirmation gear table can be set in the terminal device. In the preset confirmation gear table, different confirmation success rates correspond to different theoretical link parameters; for example, when the confirmation success rate is between 90% and 100%, the theoretical link parameter is the first parameter, and when the confirmation success rate is between 80% and 90%, the theoretical link parameter is the second parameter.

[0107] Furthermore, since the preset confirmation gear table depends on historical experience values, the parameter settings in some gears may not be accurate enough due to insufficient data volume. Therefore, this application can further use a large model for analysis and prediction; that is, the historical data on which the preset confirmation gear table is based is input into a machine learning model for training to obtain a trained theoretical parameter prediction model.

[0108] In the official application, the statistically obtained confirmation success rate is input into the theoretical parameter prediction model to obtain the theoretical link parameters.

[0109] When adjusting the control link parameters, compare whether the coding code rate, spreading factor, and burst repetition number in the control link parameters and the theoretical link parameters are the same respectively; if they are not the same, the average value of the two can be taken, or they can be multiplied by the corresponding preset weights and then added together to obtain the adjusted control link parameters. Taking the burst repetition number as an example, assume that the burst repetition number in the received control link parameters is 10, and the burst repetition number of the theoretical link parameters obtained by looking up the preset confirmation gear table based on the confirmation success rate is 14. Then, the average value of the two, which is 12, can be taken as the adjusted burst repetition number; or multiply by the preset weights 0.3 and 0.7 and then sum to get 12.8, and round up to get 13, that is, the adjusted burst repetition number is 13.

[0110] Step S13, modulate and encode the physical burst frames in the uplink data based on the adjusted control link parameters.

[0111] Step S14, send the modulated and encoded uplink data to the gateway device.

[0112] Among them, the number of repeated physical burst frames in the uplink data is equal to the adjusted burst repetition number.

[0113] Specifically, if the number of the same physical burst frames in the uplink data is greater than 1, a mark needs to be made in the PHR data of the first physical burst frame among the repeated ones; the PHR data in each physical burst frame is encoded and spread using the coding code rate and spreading factor in the adjusted control link parameters.

[0114] Please refer to Figure 4 , the embodiment of the present application also correspondingly provides a data transmission control method for narrowband Internet of Things, which is applied to a gateway device communicatively connected to the above terminal device, including:

[0115] Step S21, receive the uplink data of the terminal device, and judge whether the number of repeated physical burst frames in the uplink data is greater than 1. Specifically, the gateway device can judge whether the subsequent frames are repeated frames of the first physical burst frame according to whether there is a corresponding mark in the PHR data of the first physical burst frame in the uplink data.

[0116] The gateway device will also feedback an ACK signal to the terminal device after receiving the uplink data.

[0117] Step S22, if so, merge the repeated physical burst frames and then perform demodulation and decoding, and count the demodulation success rate.

[0118] Specifically, if each subsequent physical burst frame is a repeated frame of the first physical burst frame, merge each physical burst frame to obtain a unique physical burst frame and then perform demodulation and decoding, and use a sliding window to count the demodulation success rate.

[0119] Step S23: Generate control link parameters according to the demodulation success rate and send them to the terminal device.

[0120] Specifically, in the gateway device, a corresponding preset demodulation gear table can also be set. In the preset demodulation gear table, each gear is stepped by 10%, and different gears where different demodulation success rates are located correspond to different control link parameters.

[0121] Furthermore, this application can also use a large model to predict control link parameters; that is, input the historical data on which the preset demodulation gear table is based into a machine learning model for training to obtain a trained control parameter prediction model. In the formal application, the statistically obtained demodulation success rate can be input into the control parameter prediction model to obtain the control link parameters.

[0122] For the data transmission control method of narrowband Internet of Things provided in the above embodiments, first, this application proposes a multi-burst physical frame structure, and multiple physical burst frames in the transmitted data are repeatedly set to improve the transmission reliability of the data; secondly, this application also designs an adaptive adjustment of the burst repetition number based on the confirmation success rate of the uplink data. The statistically obtained confirmation success rate represents the uplink channel state. Since the channel state changes in real time, this application makes the gateway device determine the control link parameters according to the demodulation success rate, and then makes the terminal device adjust the control link parameters according to the confirmation success rate of the uplink data statistically at the data reception moment, ensuring the real-time nature of the control link parameters, not only effectively improving the transmission reliability of narrowband Internet of Things under different channel states, but also avoiding power consumption waste caused by blindly increasing physical burst frames.

[0123] Please refer to Figure 5 , in some embodiments, the control method of the terminal device further includes:

[0124] Step S001: Send an access request signal to the gateway device at a preset semi-static power.

[0125] Among them, the access request signal of the terminal device is generally sent in the form of a broadcast.

[0126] The preset semi-static power is a general power value preset inside each terminal device, applicable to all terminal devices within a local area network, and reflects the noise level of the gateway device to a certain extent. Correspondingly, the control method in the gateway device further includes:

[0127] Step S011: Receive the access request signal of the terminal device and estimate the uplink channel state of the terminal device according to the access request signal. Specifically, here, the demodulation success rate of the access request signal is used as the estimated uplink channel state.

[0128] Step S012: Generate the expected power and expected link parameters according to the uplink channel state, and send them to the terminal device.

[0129] Specifically, in the gateway device, the expected link parameters are also obtained by looking up a preset demodulation gear table or inputting into a control parameter prediction model based on the demodulation success rate of the network access request information; while the expected power is generally a value preset in the gateway device.

[0130] After the gateway device sends the expected power and expected link parameters, the following steps are correspondingly executed in the terminal device:

[0131] Step S002: Receive the expected power and expected link parameters from the gateway device.

[0132] Step S003: Determine the initial link parameters according to the difference between the preset maximum power and the expected power.

[0133] Among them, the preset maximum power is the maximum power that the terminal device can send, which is a fixed value of the device.

[0134] The difference is obtained by subtracting the expected power from the preset maximum power.

[0135] Specifically, here the initial link parameters can also be obtained through a preset power gear table, that is, different initial link parameters corresponding to the gears where different differences are located are set in the preset power gear table based on historical experience values. For example, it is stipulated in the preset power gear table that when the difference is within 1 mW to 10 mW, the corresponding initial link parameter is the first initial parameter, and when the difference is within 10 mW to 20 mW, the corresponding initial link parameter is the second initial parameter.

[0136] Furthermore, since the preset power gear table depends on historical experience values, the parameter settings in some gears may not be accurate enough due to insufficient data volume. Therefore, this application can further use a large model for analysis and prediction; that is, the historical data on which the preset power gear table is based is input into a machine learning model for training to obtain a trained initial parameter prediction model. In the formal application, the difference between the two powers is input into the initial parameter prediction model to obtain the initial link parameters.

[0137] Step S004: Obtain the registration link parameters according to the initial link parameters and the expected link parameters.

[0138] Among them, the registration link parameters also include three parameters: coding code rate, spreading factor, and burst repetition number.

[0139] Specifically, the combination of the initial link parameters and the expected link parameters is the same as the combination method of the theoretical link parameters and the control link parameters in the above embodiments, that is, the coding code rate, spreading factor, and burst repetition number in the initial link parameters and the expected link parameters are compared respectively; if they are inconsistent, the average value of the two can be taken or they can be multiplied by the corresponding preset weights and then added together.

[0140] Step S005: Generate registration data according to the registration link parameters and send it to the gateway device.

[0141] Among them, the number of the same physical burst frames in the registration data is equal to the burst repetition number in the registration link parameters. If the number of the same physical burst frames is greater than 1, corresponding marks need to be made in the PHR data of the first physical burst frame to inform the gateway device that the subsequent physical burst frames are all repeated frames, and the PHR data in each physical burst frame is obtained by using the coding code rate and spreading factor in the registration link parameters.

[0142] The specific pairing process is a conventional Internet of Things operation process. This application only limits the coding code rate, spreading factor, and burst repetition number of the registration data, and does not elaborate too much on the specific content of the registration data here.

[0143] The above embodiments give the registration process of the terminal device and the gateway device in the Internet of Things. By determining the registration link parameters through the preset maximum power, expected power, expected link parameters, and initial link parameters, it can ensure that the gateway device can successfully receive the registration data without exceeding its own preset maximum power, thereby improving the registration efficiency.

[0144] In some embodiments, the control method of the terminal device further includes:

[0145] If the information of the gateway device is not received within the preset retransmission duration after sending the network access request signal, the preset semi-static power is adjusted according to the preset increment, and the network access request signal is re-sent with the preset semi-static power.

[0146] Specifically, if the terminal device does not receive the reply from the gateway device, it may be that the preset semi-static power is too low. Therefore, the preset semi-static power can be gradually increased according to the preset increment until the information of the gateway device is received.

[0147] It should be noted that due to the limitation of the preset maximum power of the terminal device, when the preset semi-static power is gradually increased according to the preset increment here, it is also necessary to note that it cannot exceed the preset maximum power. If the preset semi-static power is greater than the preset maximum power after increasing the preset increment, the network access request signal is sent with the preset maximum power. If the response from the gateway device still cannot be obtained, it means that the hardware capability of this terminal device does not support it to join this Internet of Things, and then a device mismatch prompt message is generated.

[0148] Please refer to Figure 6 , in some embodiments, the control method of the terminal device further includes:

[0149] Step S31, calculate the path loss value according to the received control link parameters.

[0150] Specifically, uplink power control needs to balance two aspects of requirements, that is, the transmission power of the terminal device is large enough to meet the requirements of QoS (Quality of Service), and small enough to save the battery of the terminal device and reduce interference to other terminals. In addition, since the present application adopts a multi-burst frame data structure, the repeated burst frames can ensure transmission reliability, but inevitably increase the data transmission power consumption. Therefore, more stringent low-power requirements are imposed on uplink power control.

[0151] Considering that the narrowband Internet of Things has limited bandwidth and is sensitive to the power consumption of terminal devices, the present application selects an open-loop power control algorithm in uplink power control. That is, when each terminal device receives control link parameters, it measures the path loss value according to the received signal strength to determine how much transmission power is required to compensate for the path loss, and then obtains an open-loop operating power based on this.

[0152] Step S32, add the path loss value and the preset semi-static power to obtain the open-loop operating power.

[0153] Open-loop operating power = P 0 +P L , where P 0 is the preset semi-static power, and P L is the path loss value.

[0154] Step S33, if the open-loop operating power is greater than the preset maximum power, send uplink data with the preset maximum power, otherwise send uplink data with the open-loop operating power. Specifically, the uplink transmission power P of the terminal device = min{P MAX , P 0 +P L}dBm, where P MAX is the preset maximum power of the terminal device.

[0155] It can be considered that the open-loop operating power is the transmission power that can ensure the gateway device receives uplink data without loss, but the premise is that the terminal device can achieve this open-loop operating power. If the open-loop operating power is greater than the preset maximum power of the terminal device, then the terminal device cannot achieve it. Therefore, it is necessary to determine the final uplink transmission power with the preset maximum power as the limit.

[0156] In the registration phase, the transmission power of the registration data can also be determined based on the path loss value for calculating the expected link parameters.

[0157] The uplink transmission power control method provided by the above embodiments can control the uplink transmission power to the lowest level on the premise of being compatible with the hardware performance of the terminal device and ensuring the transmission quality of the uplink data.

[0158] Please refer to Figure 7 , in some embodiments, the control method of the gateway device further includes:

[0159] Step S401: Receive the uplink data of each terminal device.

[0160] Step S402: Obtain the channel noise of each uplink channel based on each uplink data and the voice erasure detection algorithm.

[0161] Step S403: Statistically calculate the average noise corresponding to each uplink channel within a preset time period according to the channel noise of each channel.

[0162] Step S404: Obtain the power margin of each terminal device and count the number of terminals with a power margin of 0.

[0163] Among them, the terminal device can put the power margin into each uplink data for the gateway device to read.

[0164] Step S405: Determine whether the number of terminals reaches a preset power adjustment threshold.

[0165] Specifically, if the number of terminal devices with a power margin of 0 reaches the preset power adjustment threshold, it means that many terminal devices in the Internet of Things have already been in the maximum power transmission state. At this time, it is necessary to adjust the preset semi-static power of each terminal device to avoid network congestion and excessive consumption of the terminal device's power while ensuring the communication quality.

[0166] Step S406: If so, determine the maximum semi-static power corresponding to the preset power adjustment threshold.

[0167] Specifically, the maximum semi-static power is the maximum preset semi-static power among the terminal devices with a power margin of 0.

[0168] Step S407: Obtain the control semi-static power according to the maximum average noise and the maximum semi-static power, and send it to the terminal device. Among them, the maximum average noise is the maximum value among the average noises of each uplink channel.

[0169] Specifically, obtaining the control semi-static power according to the maximum average noise and the maximum semi-static power includes:

[0170] Step S4071: Determine whether the maximum average noise is greater than the maximum semi-static power.

[0171] Step S4072: If the answer is no, then add the maximum average noise to the demodulation threshold to obtain the minimum power threshold.

[0172] It is expressed by the formula as: P 0 ′ = P avr_phr + P d .

[0173] Among them, P 0 ′ is the minimum power threshold, P avr_phr is the maximum average noise, and P d is the demodulation threshold.

[0174] Specifically, the maximum average noise represents the worst noise level in each uplink channel. The demodulation threshold is a benchmark for the signal strength. Signals below this threshold may not be correctly demodulated by the gateway device. Therefore, in this application, the worst average noise level in the channel is added to the demodulation threshold, and a signal strength benchmark considering the influence of noise can be obtained, ensuring that even in an environment with large noise, the uplink data sent by the terminal device can be correctly received and demodulated by the gateway device.

[0175] Step S4073: Calculate the control semi-static power of each terminal device based on the minimum power threshold, specifically including:

[0176] Step S40731: Obtain the preset semi-static power of the terminal device.

[0177] Specifically, the gateway device can obtain the control link parameters sent to the terminal device last time and use the control semi-static power therein as the preset semi-static power of the terminal device.

[0178] Step S40732: Determine whether the minimum power threshold is less than the preset semi-static power.

[0179] Step S40733: If the answer is no, then use the minimum power threshold as the control semi-static power of the terminal device and put the control semi-static power into the control link parameters of the terminal device.

[0180] Step S40734: If the answer is yes, then multiply the demodulation threshold by the preset factor, then add the maximum average noise, and update the minimum power threshold according to the obtained sum value; determine whether the minimum power threshold is less than the preset semi-static power.

[0181] Among them, the preset factor can be set to 1.5.

[0182] Step S40735: If the answer is yes, then use the minimum power threshold as the control semi-static power of the terminal device and put the control semi-static power into the control link parameters of the terminal device.

[0183] Specifically, if P 0 ′≥P 0 , then P 0 ′ is used as the new P 0 . If P 0 ′<P 0 , then P 0 ′ is updated as P avr_phr + 1.5×P d . If the updated P 0 ′≥P 0 , then P 0 ′ is used as the new P 0 , otherwise the preset semi-static power is not updated.

[0184] The reason for the above judgment process is that the minimum power threshold is the lowest benchmark that can ensure the successful demodulation of uplink data by the gateway device. If the preset semi-static power of the terminal device is less than this lowest benchmark, it means that there is a risk that the uplink power of the terminal device cannot be demodulated when the noise is severe. Therefore, it needs to be updated to the minimum power threshold. If the preset semi-static power of the terminal device is greater than this lowest benchmark, the uplink data of the terminal device can definitely be successfully demodulated. If the preset semi-static power is still greater than the adjusted minimum power threshold, it means that the preset semi-static power is set too large and can be adjusted down to the minimum power threshold for operation, so as to reduce the power consumption of the terminal device on the basis of ensuring successful demodulation.

[0185] It can be understood that this application reduces the power consumption of the terminal device on the premise of ensuring transmission reliability and stability.

[0186] Step S4074, if so, then eliminate the uplink channels with an average noise greater than the maximum semi-static power, and generate a channel interference prompt message; specifically, if the maximum average noise is greater than the maximum semi-static power, it means that the noise level of individual uplink channels will cause the signal-to-noise ratio of the signal transmitted on the uplink channel to be too high, so that the signal cannot be correctly demodulated. Therefore, the corresponding uplink channels are directly eliminated to improve the spectral utilization efficiency and avoid the terminal device wasting power on high-noise channels.

[0187] Step S4075, determine whether the number of remaining uplink channels meets the preset available conditions.

[0188] Among them, the preset available condition is a channel number threshold; in the specific implementation process, after eliminating the uplink channels, it is necessary to broadcast the number of remaining uplink channels after eliminating the channels to each terminal device.

[0189] Step S4076, if so, then obtain the control semi-static power according to the average noise and demodulation threshold of the uplink channel; put the control semi-static power and the remaining channel information into the control link parameters of the terminal device.

[0190] Specifically, directly add the average noise of the uplink channel and the demodulation threshold to obtain the control semi-static power of the uplink channel, and send the obtained control semi-static power to each terminal device using the uplink channel.

[0191] If the remaining number of uplink channels does not meet the preset available conditions, the maximum semi-static power is used as the control semi-static power. Broadcast it to each terminal device together with the remaining number of uplink channels, and generate channel interference prompt information. The channel interference prompt information generated at this time includes the original number of channels and the remaining number of channels after elimination.

[0192] The control semi-static power calculated by the gateway device can be put into the control link parameters and encoded into the PHR data of the data frame, and obtained by the terminal device after receiving the data frame sent by the gateway device and decoding the PHR data.

[0193] Correspondingly, in the control method of the terminal device, it further includes:

[0194] Step S411, determine whether there is control semi-static power in the control link parameters.

[0195] Step S412, if there is, update the preset semi-static power according to the control semi-static power.

[0196] It can be considered that the preset semi-static power is a preset value before registration and network access, and will be regulated and controlled by the gateway device after network access. That is, the gateway device judges the channel noise state of the uplink channel according to the reception situation of the uplink data of each terminal device, so as to set the preset semi-static power of the terminal device in the corresponding channel state.

[0197] In the above embodiment, the gateway device performs open-loop control on the preset semi-static power in the uplink transmission power of the terminal device. Different from the closed-loop control algorithm in traditional mobile communication, this application does not require frequent interaction between the terminal device and the gateway device. The gateway device only needs to analyze the noise of the uplink data to obtain the control semi-static power; and when the gateway device calculates the control semi-static power, it is based on parameters such as the channel noise and background noise of the uplink channel, which reduces the power consumption of the terminal device on the premise of ensuring that the generated control semi-static control can correctly demodulate the uplink data sent by the terminal device.

[0198] In practical applications, electromagnetic interference is a key factor affecting the channel state. Severe interference may even cause the channel noise to be extremely large, and it cannot be solved simply by increasing the data transmission power.

[0199] Therefore, in some embodiments, the control method of the terminal device further includes:

[0200] Step S501: Calculate the signal strength of the downlink channel according to the received control link parameters.

[0201] Specifically, the signal strength can be determined by detecting the preamble sequence of the data frame where the control link parameters are located.

[0202] Step S502: Calculate the noise data of the downlink channel based on the erasure estimation algorithm.

[0203] Step S503: If the signal strength is less than the preset downlink strength threshold or the noise data is greater than the preset downlink noise threshold, generate downlink status information according to the signal strength and the noise data, and send it to the gateway device.

[0204] In this application, when the strength or noise of the received signal exceeds the corresponding threshold for the terminal device, it is determined that there is interference in the downlink channel, and the received signal strength and noise data are used as the downlink status information of the downlink channel and fed back to the gateway device.

[0205] Correspondingly, the control method of the gateway device further includes:

[0206] Step S511: Receive the downlink status information of the terminal device.

[0207] Step S512: Obtain the average signal-to-noise ratio of the corresponding terminal device according to the downlink status information.

[0208] Specifically, since it is known that the downlink status information is generated by the terminal device from the signal strength and the noise data, that is, the downlink status information includes the signal strength and the noise data, the gateway device here can calculate the average signal-to-noise ratio according to the downlink status information.

[0209] Step S513: Count the proportion of terminal devices with an average signal-to-noise ratio lower than the demodulation threshold.

[0210] Step S514: If the proportion exceeds the preset signal-to-noise ratio threshold, generate a channel interference prompt message.

[0211] It can be understood that when a single or a small number of terminal devices feedback the downlink status information, it may be due to local electromagnetic interference or hardware failures of the terminal devices. Therefore, a channel interference prompt message for promoting frequency conversion will not be generated at this time; while if most terminal devices have fed back the downlink status information, it indicates that the interference situation is reliable, and corresponding frequency conversion measures can be taken, etc.

[0212] In addition to judging the channel interference status according to the downlink status information fed back by the terminal device, the control method of the gateway device further includes:

[0213] Step S521: After receiving each uplink data, count the proportion of the uplink data carrying error data.

[0214] Step S522: If the ratio exceeds the preset reception success rate threshold, generate a channel interference prompt message.

[0215] Specifically, in addition to the downlink channel, the uplink channel will also face electromagnetic interference. Therefore, in this application, after the gateway device demodulates and decodes the uplink data, it determines whether it is interfered according to the obtained data content.

[0216] The above embodiments enable both the terminal device and the gateway device to analyze the received data to determine whether there is interference in the channel used by the data, thereby generating a channel interference prompt message, providing data support for subsequent frequency point replacement.

[0217] In some embodiments, the control method of the terminal device further includes:

[0218] Step S61: Based on sliding window statistics, obtain the number of successful synchronizations of the control link parameters during the decoding process.

[0219] Step S62: If the number of successful synchronizations is less than the preset synchronization threshold, determine that the downlink channel fails.

[0220] Specifically, if the terminal device determines that the downlink channel fails, it will re-search for the network and re-enter the network, that is, re-execute the process of sending the network access request signal with the preset semi-static power in the above embodiments.

[0221] In some embodiments, the control method of the gateway device further includes:

[0222] Step S701: When the number of generated channel interference prompt messages is greater than or equal to the preset frequency conversion threshold, initiate channel scanning to obtain the background noise value of each current channel, and generate a frequency point change instruction according to the frequency point of the current channel with the smallest background noise value.

[0223] Among them, the preset frequency conversion threshold is 1 or 2. As can be seen from the above embodiments, the scenarios corresponding to generating channel interference prompt messages include that the number of available channels does not meet the preset available conditions, severe downlink channel interference, and severe uplink channel interference.

[0224] When any one or two of the above three situations occur, the frequency point will be replaced; it can be understood that since in the network formation, frequent frequency point replacement has a wide impact, when there is noise in the channel, this application first adjusts the power through the open-loop control of the gateway device, and when the channel interference situation reaches the conditions for generating channel interference information in this application, it will determine whether to perform the frequency point change operation according to the number of generated channel interference information.

[0225] Step S702: Broadcast the frequency point change instruction to each terminal device.

[0226] Correspondingly, the control method in the terminal device further includes:

[0227] Step S711: Receive the frequency point change instruction from the gateway device.

[0228] Step S712: Modify the uplink channel frequency point for sending uplink data according to the frequency point change instruction.

[0229] The above embodiments perform frequency point change operations based on channel interference prompt information, realizing the adaptive frequency selection of the Internet of Things and improving the stability and robustness of the narrowband Internet of Things.

[0230] Each of the embodiments described in this application can be an independent solution or can be combined according to internal logic, and these solutions all fall within the protection scope of this application. It can be understood that in the above method embodiments, the methods and operations implemented by the terminal device can also be implemented by components (such as chips or circuits) available for the terminal device, and the methods and operations implemented by the gateway device can also be implemented by components (such as chips or circuits) available for the gateway device.

[0231] In the above embodiments provided in this application, the methods provided in the embodiments of this application are introduced from the perspective of the interaction between various devices. To implement each function in the methods provided in the above embodiments of this application, the terminal device and the gateway device may include a hardware structure and / or software module, and implement the above functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether a certain function among the above functions is executed in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the specific application and design constraint conditions of the technical solution.

[0232] The division of modules in the embodiments of this application is illustrative, only a logical function division, and there may be other division methods in actual implementation. In addition, each functional module in the embodiments of this application can be integrated in one processor, can also exist independently physically, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0233] Based on the above content and the same concept, this application provides a data transmission control system for a narrowband Internet of Things. The communication system includes, such as Figure 3 , such as Figure 5 or such as Figure 6 the terminal device in Figure 4 or such as Figure 7 the gateway device in

[0234] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) containing computer-usable program code.

[0235] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0236] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A data transmission control method for narrowband Internet of Things, characterized in that: Applied to terminal equipment, including: Receive the control link parameters of the gateway device and count the confirmation success rate of the uplink data; Adjusting the coding rate, spreading factor and burst repetition number in the control link parameters according to the confirmation success rate to obtain adjusted control link parameters; Modulating and encoding the physical burst frame in the uplink data based on the adjusted control link parameters; The modulated and encoded uplink data is sent to the gateway device.

2. The data transmission control method of narrowband Internet of Things according to claim 1, characterized in that: Also includes: Sending a network access request signal to the gateway device at a preset semi-static power; Receiving expected power and expected link parameters of the gateway device; Determining initial link parameters according to a difference between a preset maximum power and the expected power; Obtaining registration link parameters according to the initial link parameters and the expected link parameters; Generate registration data according to the registration link parameters and send it to the gateway device.

3. The data transmission control method of narrowband Internet of Things according to claim 2, characterized in that: Also includes: If the information of the gateway device is not received within the preset retransmission time after sending the network access request signal, the preset semi-static power is adjusted according to a preset increment, and the network access request signal is resent at the preset semi-static power.

4. The data transmission control method of narrowband Internet of Things according to claim 2, characterized in that: Also includes: Calculating a path loss value according to the received control link parameter; Adding the path loss value and the preset semi-static power to obtain an open-loop operation power; If the open-loop operation power is greater than the preset maximum power, the uplink data is sent with the preset maximum power; otherwise, the uplink data is sent with the open-loop operation power.

5. The data transmission control method of narrowband Internet of Things according to claim 4, characterized in that: Also includes: Determining whether there is a control semi-static power in the control link parameters; If yes, the preset semi-static power is updated according to the controlled semi-static power.

6. The data transmission control method of narrowband Internet of Things according to claim 1, characterized in that: Also includes: Calculating the signal strength of the downlink channel according to the received control link parameter; Calculating noise data of the downlink channel based on an erasure estimation algorithm; If the signal strength is less than a preset downlink strength threshold, or the noise data is greater than a preset downlink noise threshold, downlink status information is generated according to the signal strength and the noise data, and sent to the gateway device.

7. The data transmission control method of narrowband Internet of Things according to claim 6, characterized in that: Also includes: Obtaining the number of successful synchronization of the control link parameters during the decoding process based on sliding window statistics; If the number of successful synchronizations is less than a preset synchronization threshold, it is determined that the downlink channel is faulty.

8. The data transmission control method of narrowband Internet of Things according to claim 1, characterized in that: Also includes: Receiving a frequency change instruction of the gateway device; The uplink channel frequency for sending the uplink data is modified according to the frequency change instruction.

9. A data transmission control method for narrowband Internet of Things, characterized in that: Applicable to gateway devices, including: Receiving uplink data of a terminal device, and determining whether the number of repeated physical burst frames in the uplink data is greater than 1; If yes, then the repeated physical burst frames are combined and then demodulated and decoded, and the demodulation success rate is counted; A control link parameter is generated according to the demodulation success rate and sent to the terminal device.

10. The data transmission control method of narrowband Internet of Things according to claim 9, characterized in that: Also includes: receiving a network access request signal from a terminal device, and estimating an uplink channel state of the terminal device according to the network access request signal; Generate expected power and expected link parameters according to the uplink channel state and send them to the terminal device.

11. The data transmission control method of narrowband Internet of Things according to claim 9, characterized in that: Also includes: Receiving the uplink data of each of the terminal devices; Obtaining channel noise of each uplink channel based on each of the uplink data and the erasure detection algorithm; Calculating average noise corresponding to each uplink channel within a preset time period according to noise statistics of each channel; Obtaining the power headroom of each of the terminal devices, and counting the number of terminals whose power headroom is 0; Determining whether the number of terminals reaches a preset power adjustment threshold; If yes, determining the maximum semi-static power corresponding to the preset power adjustment threshold; The controlled semi-static power is obtained according to the maximum average noise and the maximum semi-static power, and is sent to the terminal device.

12. The data transmission control method of narrowband Internet of Things according to claim 11, characterized in that: The controlling semi-static power according to the maximum average noise and the maximum semi-static power and sending the controlling semi-static power to the terminal device comprises: Determining whether the maximum average noise is greater than the maximum semi-static power; If not, add the maximum average noise and the demodulation threshold to obtain a minimum power threshold; calculate the controlled semi-static power of each terminal device based on the minimum power threshold; If yes, then remove the uplink channels whose average noise is greater than the maximum semi-static power, and generate channel interference prompt information; Determining whether the number of the remaining uplink channels meets a preset availability condition; If so, the control semi-static power is obtained according to the average noise and demodulation threshold of the uplink channel; the control semi-static power and the remaining channel information are put into the control link parameters of the terminal device.

13. The data transmission control method of narrowband Internet of Things according to claim 12, characterized in that: The calculating the controlling semi-static power of each of the terminal devices based on the minimum power threshold comprises: Obtaining a preset semi-static power of the terminal device; Determining whether the minimum power threshold is less than the preset semi-static power; If not, the minimum power threshold is used as the control semi-static power of the terminal device, and the control semi-static power is put into the control link parameters of the terminal device.

14. The data transmission control method of narrowband Internet of Things according to claim 13, characterized in that: Also includes: If the minimum power threshold is less than the preset semi-static power, multiply the demodulation threshold by a preset factor, add the factor to the maximum average noise, and update the minimum power threshold according to the obtained sum; Determining whether the minimum power threshold is less than the preset semi-static power; If so, the minimum power threshold is used as the control semi-static power of the terminal device, and the control semi-static power is put into the control link parameters of the terminal device.

15. The data transmission control method of narrowband Internet of Things according to claim 12, characterized in that: Also includes: Receiving downlink status information of the terminal device; Obtaining an average signal-to-noise ratio of a corresponding terminal device according to the downlink status information; Counting the proportion of terminal devices whose average signal-to-noise ratio is lower than the demodulation threshold; If the proportion exceeds a preset signal-to-noise ratio threshold, the channel interference prompt information is generated.

16. The data transmission control method of narrowband Internet of Things according to claim 15, characterized in that: Also includes: After receiving each of the uplink data, counting the proportion of erroneous data carried by each of the uplink data; If the ratio exceeds a preset reception success rate threshold, the channel interference prompt information is generated.

17. The data transmission control method of narrowband Internet of Things according to claim 16, characterized in that: Also includes: When the number of the generated channel interference prompt information is greater than or equal to the preset frequency change threshold, a channel frequency scan is initiated to obtain the noise floor value of each current channel, and a frequency change instruction is generated according to the frequency point of the current channel with the smallest noise floor value; The frequency change instruction is broadcasted to each of the terminal devices.

18. A terminal device, characterized in that: It comprises a module for executing the data transmission control method of the narrowband Internet of Things as claimed in any one of claims 1 to 8.

19. A gateway device, characterized in that: It comprises a module for executing the data transmission control method of the narrowband Internet of Things as claimed in any one of claims 9 to 17.

20. A data transmission control system for narrowband Internet of Things, characterized in that: It includes at least one terminal device that executes the data transmission control method of the narrowband Internet of Things as described in any one of claims 1 to 8; and a gateway device that executes the data transmission control method of the narrowband Internet of Things as described in any one of claims 9 to 17.

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