Uplink transmission control for environmental IoT devices

Abstract

The present document relates to a method of controlling an uplink transmission scheme considering characteristics of an environmental IoT device and an apparatus thereof. To this end, a method of a reader controlling an uplink transmission scheme of an environmental IoT device includes transmitting a downlink signal to the environmental IoT device, receiving a first uplink signal from the environmental IoT device, and controlling a transmission scheme of a second uplink signal after the first uplink signal of the environmental IoT device, wherein the downlink signal does not perform channel measurement, flow control, and FEC (forward error correction), wherein the first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC, and wherein controlling the transmission scheme of the second uplink signal includes considering a reception state of the first uplink signal in a unit of a group of the environmental IoT devices.

Description

Technical Field

[0001] The following description relates to a mobile communication system supporting environmental IoT (Internet of Things), and more specifically, to a method and apparatus for controlling uplink transmission schemes taking into account the characteristics of environmental IoT devices. Background Technology

[0002] Within 3GPP (3rd Generation Partnership Project), which leads the technical standards for mobile communication systems, various technologies have been introduced to support IoT devices in LTE and 5G.

[0003] Figure 1 This diagram is a brief summary of the requirements for IoT devices considered in 3GPP.

[0004] Figure 1 The figure is from material presented at the 19th GSMA 5G IoT Strategy Group meeting (January 2022), which shows a comparison of the performance of a passive IoT UE, discussed in Rel-18 and being discussed in Rel-19 as Ambient IoT (hereinafter referred to as A-IoT), with the transmission rates of general NR LTE UE, RedCap UE, LTE-M UE, and NB-IoT UE.

[0005] While all other IoT UEs are battery powered, A-IoT devices are discussed under the assumption of a large number of passive devices that are self-powered through energy harvesting, supporting low transmission rates of approximately 10 kbps, consuming extremely low power of 1 to 100 uW, and costing 10 to 100 times less than NB-IoT UEs. In other words, Figure 1 The pyramid structure can be interpreted as meaning that the A-IoT devices at the bottom can be attached to more objects than other IoT devices.

[0006] Although various use cases for A-IoT are being discussed, such as Figure 2 The inventory use cases shown are being studied in the most in-depth way.

[0007] Figure 2 This is a diagram used to describe use cases in an automated warehouse, serving as an example of the concept of inventory use cases in A-IoT use cases.

[0008] Figure 2The concept of an automated warehouse illustrated illustrates the use of A-IoT in the inbound inventory (2), inventory storage (3), and outbound inventory (4) steps during the goods inspection and unloading (1), inbound inventory (2), inventory storage (3), outbound inventory (4), and check and load (5) steps. That is, A-IoT can be used to obtain an inventory list during inbound / outbound operations, and if necessary, base station 220 or another reader can query a large number of A-IoT devices 210a-210n in the warehouse to obtain data for each product group and each manufacturer, and this data can be transmitted to A-IoT server 230 (S210).

[0009] However, as Figure 1 The conceptualization in this paper assumes that A-IoT devices 210a-210n are deployed in a situation where there are a large number of devices compared to other IoT devices, and since they are passive UEs, it is necessary to consider the different transmission methods of downlink signals received from base station 220 and uplink signals sent from IoT devices 210a-210n to base station 220.

[0010] Meanwhile, as mentioned above, A-IoT technology is based on RFID technology. However, in RFID, the frequency to be used is fixed, so the RFID terminal does not need to find the frequency to use. In A-IoT, the way to define the frequency to be used has not yet been standardized.

[0011] Even though the communication frequency of A-IoT devices can be used variably, unlike regular 5G terminals, they do not use UE capability messages. Therefore, it is necessary to consider the characteristic that the base station cannot know which functions the corresponding A-IoT device supports. Summary of the Invention

[0012] Technical issues

[0013] To address the aforementioned problems, one aspect of the present invention is to provide a method and apparatus for controlling uplink transmission schemes by taking into account the characteristics of environmental IoT devices.

[0014] Specifically, a method and apparatus are proposed, wherein downlink signals transmitted to an A-IoT device do not perform channel measurement, flow control, and FEC (forward error correction), while uplink signals transmitted by the A-IoT device selectively apply at least one of channel measurement, flow control, and FEC, taking into account the reception status of uplink signals in groups. In this case, flow control may include performing line coding on duplicate messages.

[0015] Furthermore, according to the embodiments, a specific method is proposed for configuring an MCS (modulation and coding scheme) applied to an uplink signal, which will be applied in one round or the next round, and is intended to specifically define the uplink transmission scheme based on line coding, status and the device type applied to the A-IoT device.

[0016] Furthermore, in order to solve the above problems, another aspect of the present invention proposes a method and apparatus for controlling the communication frequency by taking into account the characteristics of the A-IoT device, assuming that the A-IoT device operates at a non-fixed frequency.

[0017] Specifically, the aim is to propose a method for controlling frequency information by hard-coding an initial frequency (hereinafter “first frequency”) for each device, taking into account the characteristics of A-IoT devices, and using that initial frequency, while providing information about the frequency to be actually used for communication within a predetermined period T (hereinafter “second frequency”) through messages sent on that initial frequency.

[0018] Furthermore, according to the embodiments, a method is proposed to set the aforementioned first frequency as a guard band and efficiently provide the location of the second frequency, so as to efficiently utilize the A-IoT communication bandwidth.

[0019] Furthermore, according to the embodiments, it is intended to provide a method for variably controlling the frequency to be used to adapt to network conditions by defining a second frequency to be used within a predetermined period T.

[0020] The problems to be solved by the present invention are not limited to the above-mentioned technical problems, and those skilled in the art will clearly understand from the following description other technical problems not mentioned.

[0021] Technical solution

[0022] In one aspect of the invention for solving the above-mentioned problems, a method for controlling an uplink transmission scheme is proposed. This method is a method by which a reader controls an uplink transmission scheme of an environmental IoT device in a mobile communication system supporting environmental IoT (Internet of Things). The method includes: sending a downlink signal to the environmental IoT device; receiving a first uplink signal from the environmental IoT device; and controlling a transmission scheme of a second uplink signal of the environmental IoT device following the first uplink signal, wherein the downlink signal does not perform channel measurement, flow control, and FEC (forward error correction), wherein the first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC, and wherein controlling the transmission scheme of the second uplink signal includes control taking into account the reception status of the first uplink signal on a group basis of the environmental IoT devices.

[0023] Meanwhile, in another aspect of the present invention, a communication method for an environmental IoT device is proposed. This method involves an environmental IoT (Internet of Things) device communicating with a reader in a mobile communication system supporting environmental IoT. The method includes: receiving a downlink signal from the reader; sending a first uplink signal to the reader; receiving a message from the reader regarding a transmission scheme for a second uplink signal following the first uplink signal; and sending the second uplink signal to the reader according to the message. The downlink signal does not perform channel measurement, flow control, or FEC (forward error correction). The first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC. The message controlling the transmission scheme for the second uplink signal is determined considering the reception status of a group including the environmental IoT device.

[0024] Furthermore, in another aspect of the invention, a reader for a mobile communication system supporting environmental IoT (Internet of Things) is proposed, the reader comprising: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: sending a downlink signal to an environmental IoT device; receiving a first uplink signal from the environmental IoT device; and controlling a transmission scheme for a second uplink signal of the environmental IoT device following the first uplink signal, wherein the downlink signal does not perform channel measurement, flow control, and FEC (forward error correction), wherein the first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC, and wherein controlling the transmission scheme for the second uplink signal includes controlling the reception state of the first uplink signal, on a group basis, of the environmental IoT devices.

[0025] Furthermore, in another aspect of the invention, an environmental IoT device supporting a mobile communication system for environmental IoT (Internet of Things) is proposed. This environmental IoT device includes: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: receiving a downlink signal from a reader; sending a first uplink signal to the reader; receiving from the reader a message controlling a transmission scheme for a second uplink signal following the first uplink signal; and sending the second uplink signal to the reader according to the message, wherein the downlink signal does not perform channel measurement, flow control, and FEC (forward error correction), wherein the first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC, and wherein the message controlling the transmission scheme for the second uplink signal is determined considering the reception state in groups including the environmental IoT device.

[0026] In this case, the control scheme for the transmission of the second uplink signal may include: taking into account at least one of the following: the proportion of devices that have a CRC (Cyclic Redundancy Check) error in the first uplink signal as a group of IoT devices in the environment, the average CRC error rate of each IoT device in the environment, or the SINR (Signal to Interference and Noise Ratio) of the first uplink signal.

[0027] Specifically, it may include: increasing the MCS (modulation and coding scheme) level to apply FEC to the second uplink signal when the proportion of devices experiencing CRC errors in the first uplink signal or the average CRC error rate of IoT devices in various environments is equal to or greater than a first threshold, or when the SINR is equal to or less than a second threshold.

[0028] The downlink signal may include information indicating whether FEC is applied to the uplink signal, and FEC may be selectively applied to the first uplink signal and the second uplink signal based on the information indicating whether FEC is applied. Simultaneously, depending on whether the line coding applied to the first uplink signal and the second uplink signal can ensure the required coverage, the first uplink signal and the second uplink signal may selectively perform at least one of channel measurement, flow control, and FEC.

[0029] In this case, the transmission scheme for controlling the second uplink signal may include: increasing the number of chips per symbol when applying the line coding when the proportion of devices experiencing CRC (Cyclic Redundancy Check) errors of the first uplink signal or the average CRC error rate of each IoT device in the group of IoT devices in the environment is equal to or greater than a first threshold, or when the SINR of the first uplink signal is equal to or less than a second threshold.

[0030] Furthermore, the method may also include sending a first query message to the environmental IoT device, and in this case, a first uplink signal may be received as a response within the response period of the first query message.

[0031] In this case, raising the MCS level may also include: sending a message to the environmental IoT device during the response cycle, the message including a command instructing the raising of the MCS level.

[0032] In this scenario, the second uplink signal may include: a signal sent by an environmental IoT device in a first state according to an MCS level elevation command, wherein the environmental IoT device in the first state failed to send the first uplink signal; and a signal retransmitted by an environmental IoT device in a second state according to an MCS level elevation command, wherein the environmental IoT device in the second state has sent the first uplink signal, but the sent signal was not successfully received by the reader.

[0033] Alternatively, or in combination with it, increasing the MCS level may include: sending a command indicating to increase the MCS level via the second query message when sending a second query message to the environmental IoT device after the end of the response cycle.

[0034] In this case, the second uplink signal can be received as a response within the response period of the second query message.

[0035] In one embodiment of the present invention, the environmental IoT device can operate in any of the following states: an initial state, a state in which a device ID has been sent to the reader, or a state in which a positive acknowledgment has been received from the reader.

[0036] In this case, the transmission scheme for controlling the second uplink signal may include sending a message that includes information specifying a response target based on the state of each of the environmental IoT devices.

[0037] The reader may correspond to a base station or an intermediate medium, and the intermediate medium may include a device that can be carried by a user.

[0038] In another aspect of the present invention for solving the above-mentioned problems, a method for acquiring frequency information is proposed. This method is a method for an environmental IoT (Internet of Things) device to acquire frequency information for communication in a mobile communication system supporting environmental IoT. The method includes: receiving a first message including a preamble and data from a reader via a first frequency; obtaining second frequency information via the preamble of the first message; and sending a second message to the reader via the second frequency, wherein the information about the first frequency is hard-coded in the environmental IoT device.

[0039] In another aspect of the invention for solving the above-mentioned problems, a method for providing frequency information is proposed. This method is a way for a reader to provide frequency information for communication with an environmental IoT (Internet of Things) device in a mobile communication system supporting environmental IoT. The method includes: sending a first message including a preamble and data to the environmental IoT device via a first frequency hard-coded in the environmental IoT device, wherein the preamble of the first message includes second frequency information; and receiving a second message from the environmental IoT device via the second frequency.

[0040] In another aspect of the invention, an environmental IoT device supporting a mobile communication system for environmental IoT (Internet of Things) is proposed. The environmental IoT device includes: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: receiving a first message including a preamble and data from a reader via a first frequency; obtaining second frequency information via the preamble of the first message; and sending a second message to the reader via the second frequency, wherein the information regarding the first frequency is hard-coded in the environmental IoT device.

[0041] In another aspect of the invention, a reader for a mobile communication system supporting environmental IoT (Internet of Things) is provided, the reader comprising: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform an operation, wherein the operation comprises: sending a first message including a preamble and data to the environmental IoT device via a first frequency hard-coded in the environmental IoT device, wherein the preamble of the first message includes second frequency information; and receiving a second message from the environmental IoT device via the second frequency.

[0042] The first frequency may be located within the protection band of the IoT environment bandwidth of the mobile communication system.

[0043] The preamble of the first message may include information about the difference between the first frequency and the second frequency.

[0044] Specifically, the difference information may include the frequency offset of the first PRB (Physical Resource Block) of the occupied bandwidth from the first frequency to the bandwidth of the IoT environment of the mobile communication system, and the PRB index corresponding to the second frequency.

[0045] Furthermore, for a predetermined period T starting from at least one of the time point when the first message is received or the time point when the second message is sent via the second frequency, the environmental IoT device may send a signal to the reader or receive a signal from the reader via the second frequency.

[0046] Meanwhile, after the predetermined period T ends, the environmental IoT device can monitor the first frequency and receive a third message including a preamble and data from the reader via the first frequency.

[0047] In this case, the third frequency information can be obtained through the preamble of the third message.

[0048] Furthermore, the mobile communication system supporting the environmental IoT defines a variety of environmental IoT device types, and the environmental IoT device can correspond to a specific type among the various types with a variable frequency to be used.

[0049] The various types can be distinguished by their peak power consumption level, whether an amplifier is included in at least one of the uplink or downlink, whether the uplink transmitted signal is backscattered or internally generated, and whether the frequency to be used is variable.

[0050] Furthermore, the reader corresponds to a base station or an intermediate medium, and the intermediate medium may include a device that can be carried by a user.

[0051] Beneficial effects

[0052] According to the embodiments of the present invention described above, the characteristics of the environmental IoT device can be taken into account to control the uplink transmission scheme, which is different from the downlink transmission.

[0053] Specifically, the downlink signals sent to A-IoT devices do not perform channel measurement, flow control, and FEC, while the uplink signals sent by A-IoT devices selectively apply at least one of channel measurement, flow control, and FEC by considering the reception status of uplink signals in groups. This allows for efficient assurance of A-IoT service coverage while minimizing the increase in device complexity.

[0054] Furthermore, according to an embodiment, a specific method is provided for configuring an MCS (modulation and coding scheme) applied to an uplink signal, which will be applied in one round or the next round, enabling efficient handling of various situations in A-IoT communication.

[0055] Furthermore, by specifically defining the uplink transmission scheme based on line coding, status, and the type of device applied to A-IoT devices, unnecessary signaling can be minimized.

[0056] Furthermore, according to the embodiments of the present invention described above, for A-IoT devices operating at non-fixed frequencies, the characteristics of the A-IoT devices can be taken into account to efficiently control the communication frequency.

[0057] Furthermore, according to the embodiments, by positioning the first frequency in the guard band, the A-IoT communication bandwidth can be used efficiently.

[0058] Furthermore, according to an embodiment, by defining the use of a second frequency within a predetermined period T, the frequency to be used can be variably controlled to adapt to network conditions.

[0059] The effects that can be obtained by the present invention are not limited to those described above. Other effects not mentioned will be clearly understood by those skilled in the art from the following description. Attached Figure Description

[0060] Figure 1 This diagram briefly summarizes the requirements for IoT devices considered in 3GPP.

[0061] Figure 2 This is a diagram used to describe use cases in an automated warehouse, serving as an example of the concept of an inventory use case within the A-IoT use cases.

[0062] Figure 3 and Figure 4 This is a diagram illustrating a method for an uplink transmission scheme of an IoT device in a reader control environment within a mobile communication system supporting A-IoT, according to an embodiment of the present invention.

[0063] Figure 5 This is a diagram illustrating an example of an uplink signal at the MCS level applicable to an A-IoT system according to an embodiment of the present invention.

[0064] Figure 6 This is a diagram used to describe the configuration of an A-IoT device according to an embodiment of the present invention.

[0065] Figure 7 This is a diagram illustrating a scheme for performing uplink signal control based on rounds according to an embodiment of the present invention.

[0066] Figure 8 This is a diagram illustrating a scheme for performing uplink signal control in one round according to an embodiment of the present invention.

[0067] Figure 9 This is a table used to define the state of an A-IoT device according to an embodiment of the present invention.

[0068] Figure 10 This is a diagram illustrating a method for an A-IoT device to obtain frequency information for communication according to an embodiment of the present invention.

[0069] Figure 11 This is a diagram used to specifically describe the frequencies to be used by the A-IoT device according to an embodiment of the present invention.

[0070] Figure 12 This is a diagram illustrating the time relationship between the receipt of a first message and the transmission of a second message in response to it, according to an embodiment of the present invention.

[0071] Figure 13 and Figure 14 This is a diagram illustrating a method for periodically managing the frequencies used by A-IoT devices according to an embodiment of the present invention.

[0072] Figure 15 The illustration shows a wireless device that can be applied to this technology. Detailed Implementation

[0073] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the invention. However, the invention can be implemented in various different forms and is not limited to the embodiments described herein. Furthermore, for clarity of description in the drawings, parts irrelevant to the description have been omitted, and the same reference numerals are assigned to the same parts throughout the specification.

[0074] Throughout the specification, when a section is referred to as "including" a component, it means that, unless otherwise explicitly stated, it may include other components rather than exclude them.

[0075] As described above, one aspect of the present invention is to provide a method and apparatus for controlling uplink transmission taking into account the characteristics of environmental IoT devices.

[0076] Figure 3 and Figure 4 This is a diagram illustrating a method for uplink transmission of an IoT device in a reader control environment within a mobile communication system supporting A-IoT, according to an embodiment of the present invention.

[0077] exist Figure 3In this context, the "reader" is a device used to acquire data from A-IoT devices 210a-210n and provide A-IoT services, and can be a base station 220 or an intermediate node 215 between the base station 220 and the A-IoT devices 210a-210n. This will refer to... Figure 4 Detailed description.

[0078] Figure 4 Reference numeral 410 shows the structure in which an A-IoT device 210a is directly connected to a base station 220 and sends data in response to a query from the base station 220.

[0079] at the same time, Figure 4 Reference numeral 420 shows the structure in which the A-IoT device 210b does not connect directly to the base station 220, but instead sends data to the base station 220 via an intermediate medium 215.

[0080] The intermediate medium 215 can be a general portable user equipment (UE) that performs 5G communication or subsequent 6G communication, such as a smartphone. Figure 4 Accordingly, the concept of a general UE 215 connecting to a base station 220 via a Uu interface is shown.

[0081] The UE, which serves as an intermediate medium 215, can connect to multiple A-IoT devices and transmit data from the A-IoT devices to the base station 220.

[0082] Combination Figure 4 As described above, base station 220 can generally be considered as a reader that performs the function of collecting data from A-IoT devices 210a and 210b. However, depending on the situation / use case, UE 215 may also perform the function of a reader that collects data from A-IoT devices 210a and 210b.

[0083] In the following text, for ease of description, it is assumed that "reader" corresponds to base station 220, but the present invention is not limited thereto.

[0084] Refer again Figure 3 The reader (base station 220) can send downlink signals (S310a-S310n) to environmental IoT devices 210a-210n and receive first uplink signals (S320a-S320n) from environmental IoT devices 210a-210n.

[0085] It is proposed that channel measurement, flow control, and FEC are not performed on the downlink in such an A-IoT system. On the other hand, in one embodiment of the invention, it is proposed that at least one of channel measurement, flow control, and FEC be selectively performed on the uplink signal (S330).

[0086] In A-IoT systems using passive UEs, the downlink signal is strong enough that A-IoT services can be provided efficiently without increasing the complexity of A-IoT devices 210a-210n for separate channel measurements, flow control, and FEC. However, with uplink signals, especially those transmitted via a backscattering scheme as described later, it can be difficult to ensure a sufficiently strong signal, and may not be able to guarantee sufficient coverage for providing A-IoT services.

[0087] Therefore, in this embodiment, the aim is to propose a method for efficiently and selectively performing uplink control (e.g., the application of FEC) only for uplink signals sent by A-IoT devices 210a-210n.

[0088] This also distinguishes it from RFID solutions that also use passive UEs. In RFID solutions, no channel measurement, flow control, or FEC is performed on either the interrogator-to-tag or tag-to-interrogator bidirectional link. However, in the case of A-IoT systems, unlike RFID solutions, given... Figure 2 For use cases like these, sufficient coverage needs to be ensured. Therefore, in this embodiment, unlike RFID solutions, uplink control, such as FEC, is proposed to be selectively performed on uplink signals.

[0089] In LTE / NR, the transport block size is different for each MCS index during flow control based on measurement results, while in RFID / A-IoT, a fixed amount of data is typically transmitted at fixed intervals.

[0090] In addition, A-IoT devices include passive devices with weak uplink signal strength (device 1) and semi-passive devices with relatively strong uplink signal strength (device 2a), and depending on the type of device or the service to be provided, FEC may not be necessary as in RFID, or FEC may be necessary to ensure coverage.

[0091] Refer again Figure 3 In the A-IoT system, A-IoT devices 210a-210n do not perform measurements on the downlink signals received in S310a-S310n. However, a reader 220 is proposed to perform measurements on the uplink signals received from A-IoT devices 210a-210n via S320a-S320n.

[0092] In RFID / A-IoT, performing channel measurements and flow control for each individual device is extremely difficult. In RFID, when a collision is detected in response to a query command, the time slot counter can be changed via the queryAdjust command, and then the next round can begin, but the format of the data sent by individual devices (such as the application of FEC, changes in coding rate, etc.) cannot be changed.

[0093] Therefore, in one embodiment of the present invention, a scheme for controlling the transmission of subsequent second uplink signals is proposed, taking into account the reception status of the first uplink signal in groups of A-IoT devices 210a-210n, such as the application of FEC (S330).

[0094] Figure 5 This is a diagram illustrating an example of an uplink signal at the MCS level applicable to an A-IoT system according to an embodiment of the present invention.

[0095] In Figure 3 In related embodiments, the transmission scheme (S330) for controlling the second uplink signal can be implemented by considering at least one of the following: the proportion of devices that have CRC (Cyclic Redundancy Check) errors in the first uplink signal, the average CRC error rate of each environmental IoT device, or the SINR (Signal to Interference and Noise Ratio) of the first uplink signal, based on the group of environmental IoT devices 210a-210n.

[0096] For example, it may include: increasing the MCS (modulation and coding scheme) level to apply FEC to the second uplink signal when the proportion of devices with CRC errors in the first uplink signal or the average CRC error rate of IoT devices in the various environments is equal to or greater than a first threshold, or when SINR is equal to or less than a second threshold.

[0097] In other words, such as Figure 5 As shown, when the MCS level for uplink signal transmission applicable to A-IoT systems is defined as GCS (Group Coding Scheme) on a group basis, FEC is not applied at GCS level 0 during initial transmission. However, in cases of increased error rate / insufficient received strength as described above, control can be implemented to increase the GCS value. When FEC is applied in this way, the coding rate is reduced, and the number of repetitions can be increased.

[0098] At the same time, in this way, the GCS level corresponding to a specific A-IoT uplink MCS level can also be determined by further subdivision, taking into account the characteristics of the A-IoT device.

[0099] Figure 6 This is a diagram used to describe the configuration of an A-IoT device according to an embodiment of the present invention.

[0100] A-IoT devices can come in various types, and the types of A-IoT devices currently being discussed in the 3GPP standardization are as follows.

[0101] Device Type 1: 1 uW power consumption, supports energy storage and backscattering functions

[0102] Device type 2a: Hundreds of uW power consumption, supporting energy storage, backscattering, and DL and / or UL amplifiers.

[0103] Device type 2b: Hundreds of uW power consumption, supporting energy storage, active signal generation, and DL and / or UL amplifiers.

[0104] Figure 6 The example illustrates a Type 1 device from the aforementioned A-IoT device types.

[0105] To support energy storage capabilities Figure 6 The A-IoT device shown may include a matching network 510, an RF energy harvester 520, a PMU (Power Management Unit) 531, and an energy storage module 532. Indicatively, the RF energy harvester 520 extracts energy from received RF signals and stores that energy in the energy storage module 532, thereby enabling the operation of low-power A-IoT devices.

[0106] In addition, to process the signals received on the DL, the A-IoT device may include an RF BPF (bandpass filter) 541, an RF energy envelope detector 542, a BB LPF (baseband low-pass filter) 543, a comparator / 1-bit ADC 552, and a clock generator 551.

[0107] Whether the DL signal bandwidth of A-IoT devices should be used in a fixed or variable manner is currently under discussion, therefore the RF BPF 541 in... Figure 6 The structure is represented by dashed lines.

[0108] like Figure 6 As shown, the processing of the received DL signal and the generation of the UL signal can be performed by the BB logic 553, which includes a decoder, controller, and encoder. Necessary information is stored in the memory 560, and the stored information can be reused in the BB logic 553.

[0109] UL signal transmission for A-IoT devices can be performed using a backscatter modulator 570. Illustratively, an A-IoT device with low power consumption and a simple transmission structure transmits a UL signal by backscattering the signal, and can be transmitted via, for example... Figure 6 The impedance is adjusted to Z1 or Z2 to perform line coding.

[0110] As line coding that can be applied to UL signals sent by A-IoT devices, Manchester, FMO, and Miller coding are being discussed, and performance verification is being discussed for each line coding scheme.

[0111] If sufficient coverage can be ensured by line coding of the uplink signal in an A-IoT system, then separate FEC (Functional Estimation and Control) may not be necessary. Therefore, in one embodiment of the invention, it is proposed to selectively perform at least one of channel measurement, flow control, and FEC based on whether the line coding applied to the uplink signal can ensure the required coverage. Here, flow control may include line coding of repeating messages and sending those messages.

[0112] As an example of the present invention, the reader can determine whether to apply FEC to the D2R signal sent by the A-IoT device to the reader and notify the A-IoT device accordingly. That is, when the inventory process begins, the reader can predetermine whether to apply FEC and notify the A-IoT device accordingly, so the A-IoT device can operate to apply or not apply FEC from the first message (msg1).

[0113] Therefore, according to this embodiment, when the reader sends an inventory / query message, it is proposed to notify the A-IoT device whether to apply D2R FEC in a manner similar to notifying about MCS information. Upon receiving this, the A-IoT device, when sending a D2R signal to the reader, can selectively apply FEC based on the received information regarding whether to apply D2R FEC.

[0114] As another example, besides combining Figure 5 Beyond the proposed GCS level definition, when the proportion of A-IoT devices experiencing CRC errors in the first uplink signal, or the average CRC error rate of all A-IoT devices, is equal to or greater than a first threshold, or when the SINR of the first uplink signal is equal to or less than a second threshold, the number of chips per symbol in applied line coding can be increased. Therefore, an item for adjusting the number of chips per symbol in line coding can also be added to... Figure 5 GCS value table.

[0115] Meanwhile, as mentioned above, the transmission scheme of the second uplink signal can be controlled based on the uplink signal transmission rounds, according to the reception status of the first uplink signal, or the transmission scheme of the second uplink signal can be controlled in the middle of the rounds, according to the reception status of the first uplink signal.

[0116] Round-based control

[0117] Figure 7This is a diagram illustrating a scheme for performing uplink signal control based on rounds according to an embodiment of the present invention.

[0118] When a reader (e.g., base station 220) sends an initial query message 610 to A-IoT device 210, it may pass a value representing the number of time resources (e.g., time slots) that each A-IoT device 210 can access. Hereinafter, the number of such time resources is referred to as Q.

[0119] A-IoT devices can set a random function of 2^Q - 1 based on the corresponding Q value, and can send data as a query response 620 in the time resources (time slots) corresponding to that value.

[0120] The Q value can be changed by the base station 220 itself by taking into account the number of A-IoT devices 210 and / or the impact of interference.

[0121] In one embodiment of the present invention, in conjunction with Figure 3 In related embodiments, the transmission scheme for controlling the second uplink signal may correspond to: using the uplink signal received within one cycle (T: 630) from the downlink transmission of query message 610 until the query response 620 is received as described above as the first uplink signal to determine the CRC error rate, SINR, etc., and based on this, determining the MCS (GCS) level of the second uplink signal to be received in the next cycle (T), including whether to apply FEC.

[0122] For this purpose, after the period (T: 630) for receiving query response 620 ends, reader 220 can send a command to A-IoT device 210 to improve MCS (GCS) level via SelectCommand selection command message 640, etc.

[0123] In-round control

[0124] Figure 8 This is a diagram illustrating a scheme for performing uplink signal control in one round according to an embodiment of the present invention.

[0125] like Figure 7 As shown, when a reader (e.g., base station 220) sends an initial query message 610 to an A-IoT device 210, it can pass a value representing the number of time resources (e.g., time slots) that each A-IoT device 210 can access, and thus a response period (T: 630) can be defined.

[0126] However, in this embodiment, with Figure 7In a different case, it is proposed that even before the end of the response period (T), when it is determined that there is a problem with the CRC error rate / SINR performance of the first uplink signal received from the A-IoT device 210, the uplink transmission scheme of the A-IoT device 210 is controlled by a message such as QueryAdjust message 710, even before the end of the response period (T: 630).

[0127] In this case, Figure 3 In this embodiment, both the first uplink signal and the second uplink signal are signals received within the response period 630 of the query message 610 of the base station 220, but the second uplink signal may correspond to the uplink signal after the MCS (GCS) level has been improved through the QueryAdjust query adjustment message 710.

[0128] Response based on device status

[0129] Meanwhile, in one embodiment of the present invention, a scheme is proposed to individually control subsequent uplink signal transmission (e.g., retransmission) based on the uplink signal transmission status of multiple A-IoT devices 210a-210n.

[0130] Specifically, in Figure 8 In one embodiment, the "second uplink signal" may include: a signal sent by an A-IoT device in a first state based on an MCS (GCS) level upgrade command of a QueryAdjust message 710, the first state being a state in which the first uplink signal was not sent; and a signal retransmitted by an A-IoT device in a second state based on an MCS (GCS) level upgrade command, the second state being a state in which the first uplink signal was sent but the sent signal was not successfully received by the base station 220.

[0131] Furthermore, depending on the circumstances, base station 220 can selectively indicate retransmissions based on the status of A-IoT devices, which can be efficient.

[0132] Figure 9 This is a table used to define the state of an A-IoT device according to an embodiment of the present invention.

[0133] like Figure 9 As shown, the A-IoT device can operate in any of the following states: initial state (A), state that has sent the device ID to the reader (B), or state that has received a positive acknowledgment (ACK or QueryRep) from the reader (C).

[0134] When the state of an A-IoT device is defined in this way, the transmission scheme for controlling the second uplink signal may include sending a message that includes information specifying a response target based on the state of the A-IoT device.

[0135] In other words, in this embodiment, when performing flow control based on a group of devices, if retransmission is performed without distinguishing between devices that have successfully transmitted uplink signals and those that have failed, it may lead to increased traffic and delays due to unnecessary retransmissions. Therefore, it is preferable to perform uplink signal control while distinguishing between them. However, since ARQ and similar mechanisms are not used in A-IoT, it may be difficult to perform control while distinguishing whether signal transmission has been successful on a single device basis.

[0136] Therefore, in one embodiment of the present invention, it is proposed that... Figure 9 The diagram illustrates how to distinguish the status of A-IoT devices, and to differentiate the uplink signal transmission success status of each device, it will be as follows: Figure 9 The status value shown is stored in the device's status flags and changes between three states depending on the transmission conditions.

[0137] Specifically, the reader can use the select command message to select a group of devices, and at this time, it can notify the initial time slot size and encoding rate. During the execution of the inventory round, A-IoT devices that have sent uplink signals (data) to the reader change their state from A to B, and subsequently, upon receiving an ACK from the reader, they can change their state from B to C.

[0138] If a conflict is detected during a counting round, the reader can use the queryAdjust command to increment the slot count.

[0139] Furthermore, during the inventory rounds, the reader performs uplink measurements. If the SINR is low or the error rate is high, it can change the encoding rate using the select command. The select flag in the select command can then be used to distinguish which A-IoT device is responding to the query command.

[0140] For example, the select flag can indicate "all devices", "devices other than those in state A", or "devices in state B that need to perform retransmission", etc.

[0141] Communication frequency control

[0142] As described above, based on the assumption that A-IoT devices operate at non-fixed frequencies, another aspect of the present invention is to propose a method and apparatus for controlling communication frequencies taking into account the characteristics of A-IoT devices.

[0143] Figure 10 This is a diagram illustrating a method for an A-IoT device to obtain frequency information for communication according to an embodiment of the present invention.

[0144] Reference Figure 10 The A-IoT device 210 can receive a first message including a preamble and data from the readers 220 and 215 on a first frequency (S1010). At this time, it is preferable to hard-code information about the first frequency in the corresponding A-IoT device 210.

[0145] In A-IoT, A-IoT devices can be of various types, but as mentioned above, it is assumed that A-IoT does not support a process for checking UE capabilities as is done in general 5G UEs.

[0146] Therefore, it is anticipated that the standard will be defined based on the A-IoT device type with the lowest performance among various types of A-IoT devices. Since ultra-low-cost A-IoT devices are expected not to have the frequency switching and frequency-based communication operations found in general 5G UEs, this embodiment proposes an A-IoT device 210 capable of variably using frequencies. This device stores a first frequency hard-coded as an initial frequency and obtains a second frequency information as the actual frequency of use via a first message received from readers 220 and 215, and then performs communication.

[0147] At this point, "hard coding" can refer to a scheme in which the frequency information (e.g., PRB (Physical Resource Block) information) to be used is written into and fixed in the storage device of the corresponding device 210 when manufacturing the A-IoT device 210.

[0148] An A-IoT device 210 that receives the first message in this manner obtains the second frequency information through the preamble of the first message (S1020).

[0149] Although the standardization of message transmission schemes in A-IoT is still underway, this embodiment proposes the following message transmission scheme.

[0150] - The channel bandwidth is 180 kHz, using one PRB.

[0151] - The PRB index to be used for communication is not fixed.

[0152] - In DL / UL transmission, control signals are not sent separately; control signals are sent together with data.

[0153] - Use a subcarrier spacing of 15 kHz.

[0154] As a scheme for sending control signals and data, this embodiment assumes that the control signal is sent in the form of a preamble before the data is sent, and proposes to send the control signal for the second frequency mentioned above (as a specific example, the PRB index to be used for communication) via the preamble.

[0155] The A-IoT device 210 can send a second message to the readers 220 and 215 on a second frequency obtained through the preamble of the first message (S1030) in this way, and can then communicate with the readers 220 and 215 on the second frequency.

[0156] Figure 11 This is a diagram used to specifically describe the frequencies to be used by the A-IoT device according to an embodiment of the present invention.

[0157] like Figure 11 As shown, the bandwidth 1110 for environmental IoT may include an occupied bandwidth 1120 and a guard band surrounding the occupied bandwidth. In one embodiment of the invention, it is proposed to improve bandwidth efficiency by positioning an initial frequency 1130 corresponding to the aforementioned first frequency within the guard band. Of course, the first frequency may also be located within the occupied bandwidth 1120 if necessary, and the invention is not limited thereto.

[0158] Under this assumption, the preamble of the first message sent by readers 220 and 215 to A-IoT device 210 may include information about the difference between the first frequency 1130 and the second frequency 1140 corresponding to the PRB actually to be used for communication.

[0159] Specifically, this difference information may include a frequency offset 1150 of a first PRB from a first frequency 1130 to an occupied bandwidth 1120, and a PRB index (PRB i) 1140 corresponding to a second frequency.

[0160] Figure 12 This is a diagram illustrating the time relationship between the receipt of a first message and the transmission of a second message in response to it, according to an embodiment of the present invention.

[0161] like Figure 12 As shown, the first message may include a preamble and a data field, where the preamble may include a control signal indicating the second frequency information as described above. Furthermore, the data may correspond to information indicating a query to the A-IoT device. This first message may be transmitted on an initial frequency (first frequency).

[0162] At the same time, Figure 12In the illustrated embodiment, the preamble of the first message includes, in addition to a control signal indicating the second frequency information, a time offset (T offset) 1210 for transmitting the second message. An A-IoT device that has received this information can send the second message to the reader after the time offset 1210, and this second message can be transmitted on the second frequency (PRB i).

[0163] at the same time, Figure 6 The Type 1 device shown does not use an uplink / downlink amplifier, but as mentioned above, Type 2a and Type 2b devices may also include an uplink / downlink amplifier.

[0164] In addition, with Figure 6 Similar to the Type 1 device shown, the Type 2a device also transmits UL signals via a backscattering scheme, while the Type 2b device differs in that it can be configured to transmit internally generated signals for UL signal transmission.

[0165] Furthermore, in one embodiment of the invention, in addition to the device type distinction as described above, a type is also defined to distinguish based on whether the frequency of use is variable.

[0166] For example, in one embodiment of the present invention, the type of A-IoT device can be defined as follows.

[0167] [Table 1]

[0168]

[0169] In the examples in [Table 1] above, considering that the frequency to be used in Type 1 and Type 2a may be limited due to the use of backscattering for UL signal transmission, an additional type has been defined in which the frequency to be used in devices using active signal generation (such as Type 2b) can be changed; however, this is merely an exemplary distinction and the invention is not necessarily limited thereto.

[0170] In other words, in this embodiment, it is proposed to distinguish A-IoT device types by (1) peak power consumption level, (2) whether an amplifier is included in at least one of the uplink or downlink, (3) whether the uplink transmitted signal is backscattered or internally generated, and (4) whether the frequency to be used is variable, and various combinations of device types can be defined as long as such criteria are met.

[0171] The following [Table 2] is an example of another type definition.

[0172] [Table 2]

[0173]

[0174] Figure 13 and Figure 14 This is a diagram illustrating a method for periodically managing the frequency of use of A-IoT devices according to an embodiment of the present invention.

[0175] First, refer to Figure 13 The operation corresponding to reference numerals S1010 to S1030 in the attached drawings is as follows: Figure 10 The same as in the previous embodiment. However, in this embodiment, it is proposed that when a predetermined period T2 has elapsed since the time point from which the first message was received, or when a predetermined period T1 has elapsed since the time point from which the second message was sent on the second frequency, the A-IoT device 210 monitors the first frequency again (S1310) and obtains information about the frequency to be used thereafter (hereinafter referred to as the "third frequency") through the message received from the readers 220, 215 (hereinafter referred to as the "third message") (S1320).

[0176] In other words, due to changes in the number / deployment of A-IoT devices providing services in A-IoT-supporting mobile communication systems, it may be necessary to change the frequency to be used. For this purpose, this embodiment proposes a configuration in which, after a predetermined period T (e.g., ...) is elapsed... Figure 13 After T1 or T2, the initial frequency (first frequency) is monitored again to monitor for changes in the frequency to be used. In this regard, the "first frequency" refers to the frequency at which the frequency to be used is repeatedly checked at predetermined intervals, and it may also be referred to by another term such as "fundamental frequency" rather than "initial frequency".

[0177] exist Figure 13 In the example, cycle T1 may have advantages in checking for changes in the frequency to be used based on the cycle in which the A-IoT device has used the second frequency, but it may also have disadvantages such as: managing the different second frequency usage cycles of all A-IoT devices is complex for reader 220.

[0178] In contrast, since period T2 is based on the transmission of the first message by reader 220, it has the advantage that the operation can be easily defined by the reader 220 periodically defining the transmission of the first message (or the subsequent third message). For this purpose, the first message (or the subsequent third message) can also include information about the T2 period.

[0179] Figure 14 In the case where the base station operates as a reader, the above references are organized in the form of a flowchart. Figure 13 A diagram illustrating the operation of the described embodiment.

[0180] First, base station 220 can send a first message (S910) including a preamble and a query message every specific period T in the first frequency band corresponding to the initial frequency.

[0181] A-IoT device 210 can check the first frequency and receive the preamble and query message of the first message (S920). Therefore, A-IoT device 210 can obtain the second frequency information, i.e., the information of the PRB location (PRB i) to be used for communication, through the preamble of the first message (S930). Thereafter, A-IoT device 210 can send a second message in response to the query message on the second frequency (PRB i) (S940).

[0182] According to this embodiment, the A-IoT device 210 determines whether a predetermined period T has expired after changing the communication frequency to PRBi (S950). Referring to the above... Figure 13 The determination of whether the predetermined period T has expired can also be replaced by the determination of whether the predetermined period T has expired after the first message is received.

[0183] If the predetermined period T has not yet elapsed, the A-IoT device 210 can continue to communicate on the second frequency (PRB i) (S960). However, if the predetermined period T has elapsed, the A-IoT device 210 can monitor the first frequency again and repeat the process of obtaining information about frequencies that can be used thereafter.

[0184] Figure 15 A wireless device applicable to this technology is shown.

[0185] Reference Figure 15 The first wireless device 100 and the second wireless device 200 can transmit and receive radio signals through various radio access technologies (e.g., LTE, NR). Here, the first wireless device 100 and the second wireless device 200 can respectively correspond to Figure 3 A-IoT devices 210a-210n and readers 215, 220.

[0186] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and / or one or more antennas 108. The processors 102 control the memories 104 and / or the transceivers 106, and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memories 104 to generate a first information / signal, and then transmit a radio signal including the first information / signal via the transceivers 106. Furthermore, the processor 102 may receive a radio signal including a second information / signal via the transceivers 106, and then store information obtained from the signal processing of the second information / signal in the memories 104. The memories 104 may be connected to the processor 102 and may store various types of information related to the operation of the processor 102. For example, memory 104 may store software code including instructions for executing some or all of the processes controlled by processor 102, or instructions for executing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technologies (e.g., LTE E-UTRA, 5G NR). Transceiver 106 may be connected to processor 102 and may transmit and / or receive radio signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or a receiver. Transceiver 106 may be used interchangeably with an RF (radio frequency) unit. In this document, wireless device may refer to a communication modem / circuit / chip.

[0187] The second wireless device 200 includes one or more processors 202 and one or more memories 204, and may also include one or more transceivers 206 and / or one or more antennas 208. The processors 202 control the memories 204 and / or the transceivers 206, and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processors 202 may process information in the memories 204 to generate a third message / signal, and then transmit a radio signal including the third message / signal via the transceivers 206. Furthermore, the processors 202 may receive a radio signal including a fourth message / signal via the transceivers 206, and then store information obtained from the signal processing of the fourth message / signal in the memories 204. The memories 204 may be connected to the processors 202 and may store various types of information related to the operation of the processors 202. For example, memory 204 may store software code including instructions for executing some or all of the processes controlled by processor 202, or instructions for executing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technologies (e.g., LTE E-UTRA, 5G NR). Transceiver 206 may be connected to processor 202 and may transmit and / or receive radio signals via one or more antennas 208. Transceiver 206 may include a transmitter and / or a receiver. Transceiver 206 may be used interchangeably with an RF unit. In this document, wireless device may refer to a communication modem / circuit / chip.

[0188] The hardware components of wireless devices 100 and 200 will be described in more detail below. While not limited thereto, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102, 202 may generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information, according to the functions, processes, proposals, and / or methods disclosed in this document, and may provide said signals to one or more transceivers 106, 206. One or more processors 102, 202 may receive signals (e.g., baseband signals) from one or more transceivers 106, 206, and may obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document.

[0189] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more ASICs (Application-Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field-Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document can be implemented using firmware or software in the form of code, instructions, and / or instruction sets.

[0190] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard disk drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located internally and / or externally to one or more processors 102, 202. Furthermore, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0191] One or more transceivers 106, 206 can transmit user data, control information, radio signals / channels, etc., mentioned in the methods and / or operation flowcharts of this document to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc., mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document from one or more other devices. For example, one or more transceivers 106, 206 can be connected to one or more processors 102, 202 and can transmit and receive radio signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or radio signals to one or more other devices. Furthermore, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or radio signals from one or more other devices. Furthermore, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, radio signals / channels, etc., mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document via one or more antennas 108, 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received radio signals / channels, etc., from RF band signals to baseband signals for processing by one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, radio signals / channels, etc., processed by one or more processors 102, 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0192] The detailed description of preferred embodiments of the invention disclosed above has been provided to enable those skilled in the art to make and practice the invention. Although the invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from its scope. For example, those skilled in the art can use each component described in the above embodiments in combination with each other.

[0193] Therefore, the present invention is not intended to be limited to the embodiments shown herein, but should be given the widest scope consistent with the principles and novel features disclosed herein.

[0194] Industrial applicability

[0195] The method and apparatus for controlling uplink transmission based on the characteristics of environmental IoT devices according to the embodiments of the present invention described above are applicable to 3GPP-based mobile communication environments. However, as described above, they can also be widely used in communication schemes outside of 3GPP in order to efficiently ensure coverage performance in environmental IoT environments.

Claims

1. A method for controlling an environmental IoT device via a reader in a mobile communication system supporting environmental IoT (Internet of Things), the method comprising: Send downlink signals to the IoT devices in the environment; Receive a first uplink signal from the IoT device in the environment; as well as The transmission scheme of the second uplink signal after the first uplink signal for the control environment IoT device. The downlink signal does not perform channel measurement, flow control, or FEC (forward error correction). The first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC. The transmission scheme for controlling the second uplink signal includes controlling the reception status of the first uplink signal by considering the group of IoT devices in the environment.

2. The method according to claim 1, wherein, The control scheme for the transmission of the second uplink signal includes: taking into account at least one of the following: the proportion of devices that have a CRC (Cyclic Redundancy Check) error in the first uplink signal as a group of IoT devices in the environment, the average CRC error rate of each IoT device in the environment, and the SINR (Signal to Interference and Noise Ratio) of the first uplink signal.

3. The method according to claim 2, comprising: When the proportion of devices experiencing CRC errors in the first uplink signal or the average CRC error rate of IoT devices in various environments is equal to or greater than a first threshold, or when the SINR is equal to or less than a second threshold, the MCS (modulation and coding scheme) level is increased to apply FEC to the second uplink signal.

4. The method according to claim 1, wherein, The downlink signal includes information indicating whether FEC is applied to the uplink signal, and based on the information indicating whether FEC is applied, FEC is selectively applied to the first uplink signal and the second uplink signal.

5. The method according to claim 1, wherein, Depending on whether the line coding applied to the first uplink signal and the second uplink signal can ensure the required coverage, the first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC.

6. The method according to claim 5, wherein, The transmission scheme for controlling the second uplink signal includes: when the proportion of devices experiencing CRC (Cyclic Redundancy Check) errors in the first uplink signal, or the average CRC error rate of each IoT device in the environment, is equal to or greater than a first threshold, or when the SINR of the first uplink signal is equal to or less than a second threshold, increasing the number of chips per symbol when applying the line coding.

7. The method according to claim 3, further comprising sending a first query message to the environmental IoT device, wherein, The first uplink signal is received as a response within the response period of the first query message.

8. The method according to claim 7, wherein, The step of raising the MCS level further includes: sending a message to the environmental IoT device within the response cycle, the message including a command instructing the raising of the MCS level.

9. The method according to claim 8, wherein, The second uplink signal includes: a signal sent by an environmental IoT device in a first state according to a command instructing to increase the MCS level, wherein the environmental IoT device in the first state failed to send the first uplink signal; and a retransmission signal sent by an environmental IoT device in a second state according to a command instructing to increase the MCS level, wherein the environmental IoT device in the second state has sent the first uplink signal but sent a signal that was not successfully received by the reader.

10. The method according to claim 7, wherein, Improving the MCS level includes: when sending a second query message to the environmental IoT device after the response cycle ends, sending a command indicating to improve the MCS level through the second query message.

11. The method according to claim 10, wherein, The second uplink signal is received as a response within the response period of the second query message.

12. The method according to claim 1, wherein, The environmental IoT device operates in any of the following states: initial state, state in which the device ID has been sent to the reader, and state in which an acknowledgment has been received from the reader.

13. The method according to claim 12, wherein, The transmission scheme for controlling the second uplink signal includes sending a message that includes information specifying a response target based on the state of each of the environmental IoT devices.

14. The method according to claim 1, comprising: A first message, comprising a preamble and data, is sent to the environmental IoT device via a first frequency hard-coded in the device, wherein the preamble of the first message includes second frequency information; and a second message is received from the environmental IoT device via the second frequency.

15. The method according to claim 14, wherein, The first frequency is located in the protection band of the mobile communication system for the environmental IoT.

16. The method of claim 14, wherein, The preamble of the first message includes difference information from the first frequency to the second frequency.

17. The method according to claim 16, wherein, The difference information includes the frequency offset of the first PRB (Physical Resource Block) of the occupied bandwidth from the first frequency to the bandwidth of the IoT environment of the mobile communication system, and the PRB index corresponding to the second frequency.

18. A method for communication with a reader performed by an environmental IoT device in a mobile communication system supporting environmental IoT (Internet of Things), the method comprising: Receive downlink signals from the reader; Send a first uplink signal to the reader; The reader receives a message controlling the transmission scheme of the second uplink signal following the first uplink signal; as well as The second uplink signal is sent to the reader according to the message. The downlink signal does not perform channel measurement, flow control, or FEC (forward error correction). The first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC. The message controlling the transmission scheme of the second uplink signal is determined by considering the reception status of a group including the IoT devices in the environment.

19. A reader for a mobile communication system supporting environmental IoT (Internet of Things), the reader comprising: At least one processor; as well as At least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: Send downlink signals to environmental IoT devices; Receive a first uplink signal from the IoT device in the environment; and The transmission scheme of the second uplink signal after the first uplink signal for the control environment IoT device. The downlink signal does not perform channel measurement, flow control, or FEC (forward error correction). The first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC. The transmission scheme for controlling the second uplink signal includes controlling the reception status of the first uplink signal by considering the group of IoT devices in the environment.

20. An environmental IoT device for a mobile communication system supporting environmental IoT (Internet of Things), the device comprising: At least one processor; as well as At least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: Receive downlink signals from the reader; Send a first uplink signal to the reader; Receives from the reader a message controlling the transmission scheme of the second uplink signal following the first uplink signal; and The second uplink signal is sent to the reader according to the message. The downlink signal does not perform channel measurement, flow control, or FEC (forward error correction). The first uplink signal and the second uplink signal selectively perform at least one of channel measurement, flow control, and FEC. The message controlling the transmission scheme of the second uplink signal is determined taking into account the reception status of a group including the IoT devices in the environment.

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