Base station and control method

Abstract

To contribute to the provision of a base station and a control method that can improve communication characteristics.SOLUTION: A base station includes a receiving unit that receives a first signal transmitted by a first terminal using a spread spectrum method and a second signal transmitted by a second terminal using a method different from the spread spectrum method, and a control unit that determines a channel to be assigned to the first terminal on the basis of information on the communication quality of the first signal, and determines a channel to be assigned to the second terminal on the basis of information on the communication quality of the second signal. The control unit switches the transmission power control of the first terminal according to the assignment status of the second terminal in the channel assigned to the first terminal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a base station and a control method. [Background technology]

[0002] 2. Description of the Related Art Unlicensed bands are often used for communication between wireless communication devices (for example, between a base station and a terminal). Unlicensed bands are used by various wireless communication systems.

[0003] For example, Patent Document 1 describes a wireless communication system that determines channel allocation so as to minimize the amount of interference when allocating channels to be used for communication to a plurality of base stations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-81089 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is room for further study on methods for improving communication characteristics in an environment where various wireless communication systems are used.

[0006] Non-limiting examples of the present disclosure contribute to providing a base station and a control method that can improve communication characteristics. [Means for solving the problem]

[0007] A base station according to one embodiment of the present disclosure includes a receiving unit that receives a first signal transmitted by a first terminal using a spread spectrum method and a second signal transmitted by a second terminal using a method different from the spread spectrum method, and a control unit that determines a channel to be assigned to the first terminal based on information regarding the communication quality of the first signal and determines a channel to be assigned to the second terminal based on information regarding the communication quality of the second signal, and the control unit switches transmission power control of the first terminal depending on the allocation status of the second terminal in the channel assigned to the first terminal.

[0008] A control method according to one embodiment of the present disclosure receives a first signal transmitted by a first terminal using a spread spectrum method and a second signal transmitted by a second terminal using a method different from the spread spectrum method, determines a channel to be assigned to the first terminal based on information regarding the communication quality of the first signal, determines a channel to be assigned to the second terminal based on information regarding the communication quality of the second signal, and switches transmission power control of the first terminal depending on the allocation status of the second terminal in the channel assigned to the first terminal.

[0009] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0010] According to an embodiment of the present disclosure, communication characteristics can be improved.

[0011] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0012] [Figure 1] Diagram showing an overview of wireless systems including LPWA [Figure 2] FIG. 1 is a block diagram showing a configuration example of a base station according to an embodiment; [Figure 3] FIG. 10 is a diagram showing an example of a classification process for interference within management and interference outside management. [Figure 4] FIG. 1 shows a first example of channel allocation and transmission power control. [Figure 5] Flowchart of a first example of channel allocation and transmission power control [Figure 6] FIG. 2 shows a second example of channel allocation and transmission power control. [Figure 7] Flowchart of a second example of channel allocation and transmission power control [Figure 8] Flowchart executed in S202 of FIG. 7 [Figure 9] FIG. 10 shows a third example of channel allocation and transmission power control. [Figure 10] Flowchart of a third example of channel allocation and transmission power control [Figure 11] FIG. 4 shows a fourth example of channel allocation and transmission power control. [Figure 12] Flowchart of a fourth example of channel allocation and transmission power control [Figure 13] Flowchart executed in S401 of FIG. 12 [Figure 14] A diagram showing an example of variation 1-1 of channel allocation [Figure 15] Flowchart for Channel Allocation Variation 1-1 [Figure 16] A diagram showing an example of variation 1-2 of channel allocation [Figure 17] Flowchart for Channel Allocation Variation 1-2 [Figure 18] A diagram showing an example of variation 2 of channel allocation [Figure 19]Channel Allocation Variation 2 Flowchart [Figure 20] Flowchart executed in S601 of FIG. 19 [Figure 21] A diagram showing an example of variation 3 of channel allocation [Figure 22] Flowchart executed in S601 of FIG. 19 [Figure 23] A diagram showing an example of variation 4-1 of channel allocation [Figure 24] Flowchart for Channel Allocation Variation 4 [Figure 25] Flowchart corresponding to Variation 4-1, which is executed in S806 of FIG. 24 [Figure 26] A diagram showing an example of variation 4-2 of channel allocation [Figure 27] Flowchart corresponding to Variation 4-2, which is executed in S806 of FIG. 24 [Figure 28] A diagram showing an example of variation 4-3 of channel allocation [Figure 29] Flowchart corresponding to Variation 4-3, which is executed in S806 of FIG. 24 [Figure 30] A diagram showing an example of variation 5-1 of channel allocation [Figure 31] Example of a flowchart for channel allocation variation 5-1 [Figure 32] A diagram showing an example of variation 5-2 of channel allocation [Figure 33] An example of a flowchart corresponding to Variation 5-2, which is executed in S806 of FIG. 24. [Figure 34] A diagram showing an example of variation 5-3 of channel allocation [Figure 35] FIG. 31 shows an example of transmission power control for the channel allocation shown in FIG. 30. [Figure 36] An example of a flowchart relating to the transmission power control shown in FIG. 35 [Figure 37]FIG. 33 is a diagram showing an example of transmission power control for the channel allocation shown in FIG. 32. [Figure 38] An example of a flowchart relating to the transmission power control shown in FIG. 37 DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description will be omitted.

[0014] (One embodiment) In the Internet of Things (IoT) and / or Machine to Machine (M2M), the use of a wireless communication technology called Low Power Wide Area (LPWA), which enables communication over a wide area with low power consumption, is being considered.

[0015] LPWA is being considered for operation in unlicensed bands (for example, the 920 MHz band). There are multiple LPWA methods (standards). For example, LPWA communication methods include a first communication method that uses a spread spectrum method for communication and a second communication method that does not use a spread spectrum method. The first communication method includes, for example, a communication method called "LoRa." Furthermore, the second communication method includes, for example, a communication method called "Wi-SUN (Wireless Smart Utility Network)."

[0016] In the following, a communication method called "LoRa" (hereinafter referred to as "LoRa method") will be given as an example of the first communication method, and a communication method called "Wi-SUN" (hereinafter referred to as "Wi-SUN method") will be given as an example of the second communication method. However, the present disclosure is not limited to the LoRa method and the Wi-SUN method.

[0017] Furthermore, hereinafter, a terminal that operates based on the LoRa system (supports the LoRa system) will be referred to as a "LoRa terminal," and a terminal that operates based on the Wi-SUN system (supports the Wi-SUN system) will be referred to as a "Wi-SUN terminal." Furthermore, a "LoRa terminal" and a "Wi-SUN terminal" may be referred to as an LPWA terminal or terminal without distinction. Furthermore, hereinafter, a signal transmitted and received based on the LoRa system will be referred to as a "LoRa signal," and a signal transmitted and received based on the Wi-SUN system will be referred to as a "Wi-SUN signal."

[0018] LPWA terminals are not limited to terminals owned by users, but are installed in various devices. For example, LPWA terminals are installed in home appliances such as televisions, air conditioners, washing machines, and refrigerators, as well as in mobile transportation such as vehicles.

[0019] In addition to LPWA, unlicensed bands are used by various systems including Wi-fi (registered trademark) and RFID (Radio Frequency IDentifier).

[0020] FIG. 1 is a diagram showing an overview of a wireless system including LPWA.

[0021] 1 shows Group #1, Group #2, and Group #3. Each group includes multiple devices.

[0022] Both groups #1 and #2 are LPWA systems. However, network #1 (NW#1) to which each device in group #1 belongs is different from network #2 (NW#2) to which each device in group #2 belongs. For example, NW#1 and NW#2 are the same LPWA system, but are networks operated by different operators. The LPWA system in group #2 is a wireless system in a network (unmanaged network) not managed by group #1.

[0023] Group #1 includes devices that belong to NW #1 and are connected to NW #1 via wired or wireless connections. For example, group #1 includes base station #1, Wi-SUN terminal #1, LoRa terminal #1, and LoRa terminal #2. Group #1 also includes control device #1 that centrally controls gateways and the like via NW #1.

[0024] Base station #1 may have a gateway (GW) function and a radio wave monitoring function. For example, the GW function of base station #1 may support both the Wi-SUN system and the LoRa system. Wi-SUN terminal #1, LoRa terminal #1, and LoRa terminal #2 may be wirelessly connected to base station #1 to transmit and receive signals.

[0025] Group #2 includes devices that belong to NW #2 and are connected to NW #2 via wired or wireless connections. For example, group #2 includes base station #2, Wi-SUN terminal #2, LoRa terminal #3, and LoRa terminal #4. Group #2 also includes control device #2 that centrally controls GWs and the like via NW #2.

[0026] Base station #2 may have a gateway function and a radio wave monitoring function. For example, the gateway function of base station #2 may support both the Wi-SUN system and the LoRa system. Wi-SUN terminal #2, LoRa terminal #3, and LoRa terminal #4 may be wirelessly connected to base station #2 to transmit and receive signals.

[0027] Note that the number of devices in group #1 and group #2 in FIG. 1 is an example, and the present disclosure is not limited to this. For example, the number of base stations included in group #1 and group #2 in FIG. 1 may be two or more. The number of LPWA terminals included in group #1 and group #2 in FIG. 1 may be four or more, or two or less. Furthermore, other devices may be connected to the network of each group.

[0028] Group #1 may also include a relay station that relays wireless communication between base station #1 and any of the terminals, and group #2 may also include a similar relay station.

[0029] Group #3 is a wireless system different from the wireless system (LPWA system) of group #1. The wireless system of group #3 is a wireless system of an unmanaged network not managed by group #1. The wireless system of group #3 is, for example, RFID and Wi-Fi. Group #3 includes RFID readers / writers, RFID tags, and terminals that use Wi-Fi. The wireless system of group #3 may also include an LTE (Long Term Evolution) system, a radar system, etc.

[0030] Note that the network configuration and / or device configuration shown in FIG. 1 is an example, and the present disclosure is not limited to this.

[0031] For example, although FIG. 1 shows an example in which the LoRa terminal and the Wi-SUN terminal are separate terminals, the terminal may be capable of operating based on both the LoRa system and the Wi-SUN system.

[0032] In the above example, base station #1 and base station #2 have gateways that support both the Wi-SUN and LoRa systems, but the gateways that support the Wi-SUN system and the gateways that support the LoRa system may be separate devices. Also, the device that performs radio wave monitoring may be a device separate from the base stations.

[0033] Also, for example, two or more of the Wi-SUN gateway, the LoRa gateway, the radio wave monitoring device, and the control device may be integrated.

[0034] Furthermore, each network shown in FIG. 1 may include a device other than the device shown in FIG. 1. In that case, the other device may have some or all of the functions of the device shown in FIG. 1. For example, if a relay station is provided between a base station and a Wi-SUN terminal and / or a LoRa terminal, the relay station may have the function of a radio wave monitoring device. Furthermore, the relay station may have the function of a Wi-SUN gateway and / or a LoRa gateway and the function of a radio wave monitoring device. Alternatively, the relay station may have the function of a radio wave monitoring device, but not the function of a Wi-SUN gateway and / or a LoRa gateway.

[0035] The wireless devices in groups #1 to #3 use a common system band (e.g., an unlicensed band). Therefore, each of the wireless devices in groups #1 to #3 is subject to interference from the other wireless devices. The interference experienced by the wireless devices in group #1 will be described as an example.

[0036] For example, a signal transmitted or received by a wireless device included in group #1 (e.g., LoRa terminal #2) causes interference in another wireless device included in group #1 (e.g., LoRa terminal #1). Hereinafter, interference received by a wireless device belonging to NW #1 from another wireless device belonging to NW #1 may be referred to as "internal interference." For example, internal interference corresponds to interference received by a wireless device that supports LPWA system communications and belongs to NW #1 from another wireless device that supports LPWA system communications and belongs to NW #1.

[0037] Furthermore, a terminal (e.g., LoRa terminal #2) that belongs to the same network as a certain base station (e.g., base station #1) and a certain terminal (e.g., LoRa terminal #1) may be described as a "terminal within the management" of the certain base station and the certain terminal. A terminal within the management may be a terminal that may transmit a signal that causes interference within the management. Furthermore, a LoRa terminal and a Wi-SUN terminal that are terminals within the management may be described as a "LoRa terminal within the management" and a "Wi-SUN terminal within the management", respectively.

[0038] Furthermore, for example, signals transmitted or received by wireless devices (e.g., LoRa terminal #3 and / or RFID reader / writer) included in group #2 and / or group #3 cause interference in wireless devices (e.g., LoRa terminal #1) included in group #1. Hereinafter, interference received by a wireless device belonging to NW #1 from a wireless device not belonging to NW #1 may be referred to as "unmanaged interference." For example, unmanaged interference corresponds to interference received by a wireless device that supports communication in an LPWA system and belongs to NW #1 from a wireless device not belonging to NW #1.

[0039] Furthermore, a terminal (e.g., LoRa terminal #3) that belongs to a different network from a certain base station (e.g., base station #1) and a certain terminal (e.g., LoRa terminal #1) may be described as an "unmanaged terminal" with respect to the certain base station and the certain terminal. An unmanaged terminal may be a terminal that may transmit a signal that causes unmanaged interference. Furthermore, a LoRa terminal and a Wi-SUN terminal that are unmanaged terminals may be described as an "unmanaged LoRa terminal" and an "unmanaged Wi-SUN terminal," respectively.

[0040] Uncontrolled interference is further classified based on the cause of the interference.

[0041] For example, a signal transmitted or received by a wireless device included in group #2 (e.g., LoRa terminal #3) causes interference in a wireless device included in group #1 (e.g., LoRa terminal #1). Hereinafter, interference received by a wireless device included in NW #1 from a wireless device included in NW #2 may be referred to as "radio interference" within the category of "unmanaged interference." For example, "radio interference" corresponds to interference received by a wireless device included in NW #1 that supports LPWA system communications from a wireless device included in NW #2 that supports LPWA system communications and is different from NW #1.

[0042] Furthermore, for example, a signal transmitted or received by a wireless device (e.g., an RFID reader / writer) included in group #3 causes interference in a wireless device (e.g., LoRa terminal #1) included in group #1. Hereinafter, interference received by a wireless device that supports LPWA system communications and belongs to NW #1 from a wireless device that supports a wireless system different from the LPWA system may be referred to as "environmental noise" under the category of "uncontrolled interference."

[0043] As shown in Figure 1 as an example, an LPWA system uses a common system band with a different wireless system from the LPWA system and / or with the same LPWA system belonging to a different network. Therefore, it is desirable for the LPWA system to detect (monitor) interference and use the detected results to improve the efficiency (e.g., frequency utilization efficiency) and / or communication quality (communication characteristics) of the LPWA system.

[0044] For example, communication methods supported by LPWA systems include the above-mentioned Wi-SUN method and LoRa method.

[0045] The LoRa system defines a parameter called the Spreading Factor (hereinafter referred to as SF). SF indicates the ratio of the spreading code rate (chip rate) to the transmission data rate (bit rate) when performing wireless communication using the spread spectrum system. In the LoRa system, the value of SF is, for example, 2 7 ~2 12 It is set from six levels.

[0046] In the following, 2 7 ~2 12 The SF values ​​set to six levels are written as SF7 to SF12, respectively. For example, if the SF value is 2 7 A transmission signal transmitted using a spread spectrum method set to SF7 may be referred to as a transmission signal using SF7.

[0047] For example, in the LoRa system, the larger the SF value, the higher the resistance to noise and interference in communication and the longer the communication distance. On the other hand, the larger the SF value, the longer the time required to transmit the same amount of data (signal length). Therefore, the larger the SF value, the more frequently a terminal will cause interference to other terminals and be interfered with by other terminals.

[0048] Furthermore, in the LoRa system, the resistance to collisions between LoRa signals differs depending on the SF value. For example, two LoRa signals transmitted using different SF values ​​can easily obtain spreading gain in reception processing (e.g., despreading processing) even if they overlap partially or completely within the same time. On the other hand, if two LoRa signals transmitted using the same SF value overlap partially or completely within the same time, it is more difficult to obtain spreading gain in reception processing (e.g., despreading processing) than in the case of two LoRa signals transmitted using different SF values.

[0049] In wireless systems including LPWA, a base station assigns channels to terminals (terminals under its control) and the terminals transmit signals on the assigned channels using the LoRa and / or Wi-SUN systems. Since other terminals under its control and / or terminals not under its control are transmitting signals on the channel assigned to the terminal under its control, interference may occur, resulting in degradation of communication characteristics.

[0050] Therefore, in LPWA systems, controlling the transmission power of LoRa terminals that use the spread spectrum method is being considered.

[0051] For example, in group #1, base station #1 receives a signal transmitted by a LoRa terminal under its management (e.g., LoRa terminal #1), measures the received power (e.g., Received Signal Strength Indicator (RSSI)), and outputs the measured received power to the network (e.g., control device #1). Control device #1 determines the transmission power of the LoRa terminal under its management based on the received power. The LoRa terminal under its management acquires information about the determined transmission power via base station #1 and transmits a signal.

[0052] However, in situations where multiple wireless devices, including managed LoRa terminals, use the same channel, the above-mentioned transmission power control may not be sufficient. Therefore, it is desirable to improve communication characteristics by performing appropriate transmission power control according to the channel allocation situation.

[0053] Therefore, non-limiting examples of the present disclosure contribute to providing a terminal, a base station, and a control method that can improve communication characteristics.

[0054] The wireless communication system according to the present embodiment includes a base station 100 shown in Fig. 2 and a terminal under the control of the base station 100. The base station 100 and the terminal are included in, for example, an LPWA wireless communication system. For example, the base station 100 supports both the LoRa system and the Wi-SUN system.

[0055] <Base station configuration> 2 is a block diagram showing an example configuration of base station 100 according to this embodiment. Base station 100 includes receiving section 101, despreading section 102, communication quality measurement section 103, preamble detection section 104, interference classification section 105, SF selection section 106, demodulation / decoding section 107, despreading section 108, SF extraction section 109, SF allocation section 110, allocation control section 111, control scheme selection section 112, transmission power setting section 113, control signal generation section 114, coding / modulation section 115, and transmission section 116. For example, some or all of the despreading unit 102, communication quality measurement unit 103, preamble detection unit 104, interference classification unit 105, SF selection unit 106, demodulation / decoding unit 107, despreading unit 108, SF extraction unit 109, SF allocation unit 110, allocation control unit 111, control method selection unit 112, transmission power setting unit 113, control signal generation unit 114, and encoding / modulation unit 115 may be collectively referred to as the "control unit."

[0056] The receiving unit 101 receives a signal transmitted by a terminal and performs predetermined receiving processing on the received signal. For example, the predetermined receiving processing includes frequency conversion processing (down-conversion) based on the frequency of a channel allocated to the terminal. Information on the frequency of the channel allocated to the terminal may be acquired from the allocation control unit 111, for example.

[0057] Furthermore, the receiver 101 receives signals on each available channel (e.g., each channel included in an unlicensed band) for interference measurement (radio wave monitoring). The receiver 101 then performs predetermined reception processing on the received signals. The predetermined reception processing includes, for example, frequency conversion processing based on the frequency of each channel.

[0058] The receiving unit 101 outputs the received signal that has undergone predetermined reception processing to the despreading unit 102, the communication quality measuring unit 103, the preamble detecting unit 104, and the despreading unit .

[0059] The despreading unit 102 performs despreading processing on the LoRa signal included in the received signal acquired from the receiving unit 101. The despreading unit 102 may perform despreading processing for each SF value that can be used between the base station 100 and the terminal. The despreading unit 102 outputs the result of the despreading processing to the SF selecting unit 106.

[0060] The SF selection unit 106 determines the SF value used for the LoRa signal based on the result of the despreading process. For example, the SF selection unit 106 determines the SF value corresponding to the result of the despreading process that produces a peak in the result of the despreading process of the LoRa signal for each available SF value as the SF value used for the LoRa signal. The SF selection unit 106 outputs the determined SF value and the result of the despreading process to the demodulation / decoding unit 107.

[0061] Note that the despreading process and the selection of the SF value do not need to be performed on the Wi-SUN signal included in the received signal.

[0062] The demodulation / decoding unit 107 demodulates and decodes the LoRa signal based on the SF value acquired from the SF selection unit 106 and the result of the despreading process, to generate received data. The demodulation / decoding unit 107 also demodulates and decodes the Wi-SUN signal included in the received signal to generate received data. The demodulation / decoding unit 107 outputs the received data to the allocation control unit 111. Note that the received data may include an identifier that identifies a terminal that belongs to the same NW (Network) as the base station 100.

[0063] The communication quality measurement unit 103 generates communication quality information based on the received signal acquired from the receiving unit 101. The communication quality information may be, for example, the quality of the received signal (for example, a Received Signal Strength Indicator (RSSI)). The communication quality measurement unit 103 outputs the communication quality information to the allocation control unit 111.

[0064] The preamble detection unit 104 detects whether or not a preamble is included in the received signal acquired from the receiving unit 101. If a preamble is included, the preamble detection unit 104 determines the type of preamble included in the received signal.

[0065] For example, the preamble detection unit 104 calculates the correlation between a preamble used in the LoRa system and the received signal. If the calculated correlation results in a peak equal to or greater than a predetermined value, the preamble detection unit 104 determines that the received signal contains a preamble used in the LoRa system. If the received signal contains a preamble used in the LoRa system, the received signal is determined to be a LoRa signal and its sender is a LoRa terminal.

[0066] As in the example of the LoRa system, the preamble detection unit 104 calculates the correlation between the preamble used in the Wi-SUN system and the received signal. If a peak equal to or greater than a predetermined value occurs in the calculated correlation, the preamble detection unit 104 determines that the received signal contains a preamble used in the Wi-SUN system. If the received signal contains a preamble used in the Wi-SUN system, it is determined that the received signal is a Wi-SUN signal and that the sender of the received signal is a Wi-SUN terminal.

[0067] The preamble detection unit 104 detects the preamble regardless of whether the source of the received signal is included in the network to which the base station 100 belongs. In other words, the preamble detection unit 104 may determine the type of preamble included in a signal transmitted by a LoRa terminal or a Wi-SUN terminal that is not included in the network to which the base station 100 belongs.

[0068] Furthermore, if neither the correlation result between the preamble used in the LoRa system and the received signal nor the correlation result between the preamble used in the Wi-SUN system and the received signal produces a peak equal to or greater than a predetermined value, the preamble detection unit 104 determines that the sender of the received signal is neither a LoRa terminal nor a Wi-SUN terminal.

[0069] The preamble detection unit 104 outputs information indicating whether or not a preamble is included in the received signal, and, if a preamble is included in the received signal, information indicating the type of the preamble, to the interference classification unit 105. In addition, the preamble detection unit 104 outputs the received signal acquired from the receiving unit 101 to the interference classification unit 105.

[0070] The interference classification unit 105 classifies, for example, interference in each channel. For example, the interference classification unit 105 performs classification by monitoring received signals for a predetermined time in one channel. For example, the interference classification unit 105 may distinguish between different transmission sources of received signals within the predetermined time. The interference classification unit 105 calculates the ratio of the time of received signals for each transmission source to the predetermined time, and classifies the interference in each channel. For example, the interference classification unit 105 may classify the transmission source of a signal that causes dominant interference in the interference in each channel. Here, dominant interference in each channel may correspond to, for example, a result of monitoring received signals for a predetermined time, where the proportion of the time taken up by the signal is equal to or greater than a predetermined percentage.

[0071] The interference classification unit 105 outputs the classification result of the interference in each channel to the allocation control unit 111 .

[0072] The despreading unit 108 performs despreading processing on the received signal obtained from the receiving unit 101. The despreading unit 108 may perform despreading processing for each SF value that can be used between the base station 100 and the terminal. The despreading unit 108 outputs the result of the despreading processing to the SF extraction unit 109.

[0073] The SF extraction unit 109 detects the SF value used for the LoRa signal from the result of the despreading process. For example, the SF extraction unit 109 determines an SF value, excluding the SF value used for the LoRa signal from among the available SF values, i.e., an unused SF value. Alternatively, the SF extraction unit 109 may determine the frequency with which the SF value is used for the LoRa signal. The frequency with which the SF value is used may be represented by the number of times the SF value is detected. For example, an unused SF value may be an SF value whose frequency of use (number of times detected) is 0. The SF extraction unit 109 outputs the determined unused SF value and / or information regarding the frequency with which the SF value is used to the SF allocation unit 110.

[0074] The SF allocation unit 110 allocates an SF value to the LoRa terminal under the control of the base station 100 based on the information acquired from the SF extraction unit 109. For example, the SF allocation unit 110 allocates one of the unused SF values ​​to the terminal. If there are multiple unused SF values, the SF allocation unit 110 may allocate the smallest SF value among the multiple unused SF values ​​to the terminal. Alternatively, in this case, the SF allocation unit 110 may allocate an SF value randomly selected from the multiple unused SF values ​​to the terminal. The SF allocation unit 110 outputs information indicating the SF value to be allocated to the allocation control unit 111.

[0075] The allocation control unit 111 determines a channel to be allocated to a terminal based on communication quality information (for example, information indicating received power such as RSSI) acquired from the communication quality measurement unit 103. The allocation control unit 111 may also determine a channel to be allocated to a terminal based on the communication quality information and the interference classification result acquired from the interference classification unit 105.

[0076] Allocation control unit 111 outputs information (channel allocation information) related to the channels allocated to the terminal to control method selection unit 112. Furthermore, allocation control unit 111 outputs information related to determining the transmission power of the terminal to control method selection unit 112. The information related to determining the transmission power of the terminal includes, for example, information indicating the received power of the signal transmitted from the terminal at base station 100. Furthermore, the information related to determining the transmission power of the terminal may include the classification result of interference in each channel.

[0077] The allocation control unit 111 also controls data communication with the terminal. For example, received data acquired from the demodulation / decoding unit 107 may be output to a higher-level station (not shown) or another device in the network (for example, a control device (see FIG. 1)). The allocation control unit 111 also outputs transmission data addressed to the terminal acquired from the higher-level station or another device in the network to the encoding / modulation unit 115. The transmission data addressed to the terminal may include an identifier indicating the destination.

[0078] The control method selection unit 112 selects a method for controlling the transmission power of the terminal (transmission power control method) based on the channel allocation information and information indicating the received power. The control method selection unit 112 outputs the selection result to the transmission power setting unit 113.

[0079] The transmission power setting unit 113 sets the transmission power of the terminal based on the selection result. The transmission power setting unit 113 stores the set transmission power of the terminal. The transmission power setting unit 113 outputs the set transmission power of the terminal and channel allocation information to the control signal generation unit 114.

[0080] The control signal generating unit 114 generates a control signal addressed to the terminal based on the information acquired from the transmission power setting unit 113. The control signal generating unit 114 outputs the control signal that has been subjected to predetermined signal processing (for example, encoding processing and modulation processing) to the transmitting unit 116.

[0081] The coding / modulation unit 115 performs coding and modulation on the transmission data acquired from the allocation control unit 111 to generate a transmission signal. The coding / modulation unit 115 outputs the transmission signal to the transmission unit 116. Note that if the destination terminal of the transmission signal is a LoRa terminal, the modulation process may include spectrum spread processing used in the LoRa system. Furthermore, the spectrum spread process may use an SF value assigned to the LoRa terminal.

[0082] The transmitter 116 performs predetermined transmission processing on the transmission signal acquired from the encoder / modulator 115. For example, the predetermined transmission processing includes frequency conversion processing (up-conversion) based on the frequency of the channel assigned to the terminal. Information on the frequency of the channel assigned to the terminal may be acquired from the allocation controller 111, for example.

[0083] Furthermore, the transmitter 116 performs a predetermined transmission process on the control signal acquired from the control signal generator 114. For example, the predetermined transmission process includes a frequency conversion process (up-conversion) based on the frequency of a channel for transmitting the control signal to the terminal. The channel for transmitting the control signal to the terminal may be, for example, a predetermined channel or a channel currently being used for communication with the terminal.

[0084] In the above description, an example has been described in which the configuration shown in Fig. 2 is included in one base station 100. However, the present disclosure is not limited to this. For example, any of two or more devices may include each of the configurations shown in Fig. 3.

[0085] <Classification processing example> Next, a description will be given of an example of classification processing in the interference classification unit 105. A description will be given of classification processing for classifying signals (interference) received by the receiving unit 101 into interference within management and interference outside management.

[0086] <Example of classification process for controlled and uncontrolled interference> Fig. 3 is a diagram showing an example of a process for classifying interference into in-management interference and interference outside of management. The horizontal axis in Fig. 3 represents the time axis. Fig. 3 shows the signal level of a received signal in a predetermined monitoring interval, the detection result of interference with the received signal, the detection result of the terminal identifier (terminal ID), and the judgment result.

[0087] The detection result of interference with the received signal corresponds to the detection result of preamble detection, for example, and determines the LoRa signal included in the received signal based on this result.

[0088] In the detection result of the terminal identifier (terminal ID), if an identifier can be obtained by demodulating / decoding the received signal, the terminal ID indicates "OK." If the terminal ID indicates "OK," it is determined that the network to which the sender of the received signal belongs is the same network as base station 100. In other words, as indicated by the determination result, it is determined that the received signal corresponds to intra-management interference.

[0089] In the detection result of the terminal identifier (terminal ID), if the identifier cannot be obtained by demodulation / decoding processing of the received signal, the terminal ID indicates "NG." If the terminal ID indicates "NG," it is determined that the NW to which the sender of the received signal belongs is a NW different from the base station 100. In other words, as indicated by the determination result, it is determined that the received signal corresponds to unmanaged interference.

[0090] Through the above classification process, the received signal is classified as to whether it corresponds to within-control interference or to outside-control interference.

[0091] Next, channel allocation and terminal transmission power control performed by base station 100 will be described using an example.

[0092] <First example of channel allocation and transmission power control> FIG. 4 is a diagram showing a first example of channel allocation and transmission power control.

[0093] The horizontal axis of Fig. 4 represents frequency, and the vertical axis represents the usage level of each channel. Fig. 4 shows the usage levels of managed terminals and unmanaged terminals on each of channels #24 to #60, which are assigned identification numbers. In Fig. 4, channels #24 to #32 are LoRa channels, channels #33 to #38 are shared channels, and channels #39 to #60 are Wi-SUN channels. The usage level in Fig. 4 is defined based on the number of assigned terminals and the transmission probability of the assigned terminals. For example, the greater the number of assigned terminals, the higher the usage level, and the higher the transmission probability of the assigned terminals.

[0094] The managed LoRa terminals are assigned to the LoRa channel and the shared channel. The managed Wi-SUN terminals are assigned to the Wi-SUN channel and the shared channel. In other words, the LoRa channel corresponds to a channel to which the managed LoRa terminals are assigned and the managed Wi-SUN terminals are not assigned. The Wi-SUN channel corresponds to a channel to which the managed Wi-SUN terminals are assigned and the managed LoRa terminals are not assigned. The shared channel corresponds to a channel to which the managed LoRa terminals and the managed Wi-SUN terminals are assigned. The LoRa channel and the Wi-SUN channel may also be referred to as non-shared channels.

[0095] In this embodiment, an example is shown in which an unmanaged LoRa terminal is assigned to a LoRa channel, but an unmanaged Wi-SUN terminal is not assigned to the LoRa channel. In this case, the LoRa channel may be referred to as a LoRa-dedicated channel, for example. However, in the present disclosure, the LoRa channel does not have to be a LoRa-dedicated channel. For example, an unmanaged Wi-SUN terminal may be assigned to the LoRa channel.

[0096] In this embodiment, an example is shown in which an unmanaged Wi-SUN terminal is assigned to a Wi-SUN channel, but an unmanaged LoRa terminal is not assigned to the Wi-SUN channel. In this case, the Wi-SUN channel may be referred to as a Wi-SUN dedicated channel, for example. However, in the present disclosure, the Wi-SUN channel does not have to be a Wi-SUN dedicated channel. For example, an unmanaged LoRa terminal may be assigned to the Wi-SUN channel.

[0097] The base station 100 receives signals transmitted from each terminal under its control, determines the received power, and performs channel allocation based on the received power of the signals transmitted from each terminal under its control.

[0098] In the following, the received power determined by the base station 100 may be referred to as "GW received power." For example, the received power determined by the base station 100 after receiving a signal transmitted by a certain terminal x may be referred to as "GW received power of terminal x." Furthermore, terminal x that is the sender of a signal indicating a certain GW received power may be referred to as "terminal x corresponding to GW received power."

[0099] Furthermore, among the GW reception powers determined by receiving signals transmitted by each of a plurality of terminals, terminal x that is the sender of a signal showing a relatively large GW reception power may be described as "terminal x with a relatively large GW reception power."

[0100] The signal received by the base station 100 may be a signal that the terminal transmits on a channel after the base station 100 assigns the channel to the terminal. Alternatively, the signal received by the base station 100 may be a signal (e.g., a control signal, a synchronization signal, etc.) that the terminal transmits on a specific channel before the base station 100 assigns the channel to the terminal.

[0101] 4, the base station 100 allocates to the LoRa channel those LoRa terminals under its management that have relatively low GW reception power among the LoRa terminals under its management that are subject to allocation, and also allocates to the shared channel those LoRa terminals under its management that have relatively high GW reception power among the LoRa terminals under its management that are subject to allocation.

[0102] For example, the base station 100 may compare the GW received power with a threshold, and assign LoRa terminals under its management whose GW received power is equal to or less than the threshold to the LoRa channel, and assign LoRa terminals under its management whose GW received power is greater than the threshold to the shared channel. Note that the threshold may be fixed, or may be set according to the usage status of the LoRa channel and the shared channel (for example, the number of assigned terminals and / or the transmission probability of each terminal).

[0103] Alternatively, base station 100 may assign LoRa terminals under its management corresponding to the GW reception power to LoRa channels in ascending order of GW reception power. In this case, when the number of LoRa terminals under its management assigned to the LoRa channel reaches or exceeds a specified value, the remaining LoRa terminals under its management may be assigned to the shared channel. For example, the specified value may be fixed, or may be set according to the respective usage conditions of the LoRa channel and the shared channel (e.g., the number of assigned terminals and / or the transmission probability of each terminal).

[0104] Alternatively, base station 100 may assign LoRa terminals under its management corresponding to the GW reception power to the shared channel in descending order of GW reception power. In this case, when the number of LoRa terminals under its management assigned to the shared channel reaches or exceeds a specified value, the remaining LoRa terminals under its management may be assigned to the LoRa channel. For example, the specified value may be fixed, or may be set according to the respective usage conditions of the LoRa channel and the shared channel (e.g., the number of assigned terminals and / or the transmission probability of each terminal).

[0105] Furthermore, for example, base station 100 allocates, among the Wi-SUN terminals to be allocated within its management, those Wi-SUN terminals with relatively low GW received power to the Wi-SUN channel. Furthermore, base station 100 allocates, among the Wi-SUN terminals to be allocated within its management, those Wi-SUN terminals with relatively high GW received power to the shared channel.

[0106] The method of determining the managed Wi-SUN terminals to be assigned to the Wi-SUN channels and shared channels may be the same as that for the managed LoRa terminals described above. For example, the managed Wi-SUN terminals to be assigned to each channel may be determined by comparing the GW received power with a threshold, or the managed Wi-SUN terminals to be assigned to each channel may be determined in ascending order of GW received power, or the managed Wi-SUN terminals to be assigned to each channel may be determined in descending order of GW received power.

[0107] Base station 100 performs channel allocation based on the received power of signals transmitted by each managed terminal (GW received power of each managed terminal), and controls the transmission power of the managed LoRa terminals assigned to the shared channel. Here, in FIG. 4, the transmission power control for the managed LoRa terminals assigned to the shared channel is sometimes referred to as "first transmission power control." In other words, in FIG. 4, base station 100 performs first transmission power control for the managed LoRa terminals assigned to the shared channel (first transmission power control: ON), and does not perform first transmission power control for the managed LoRa terminals assigned to the LoRa channel (first transmission power control: OFF). Below, an example of first transmission power control for a certain terminal x assigned to a certain channel c will be described.

[0108] <First example of transmission power control> The first transmission power control is performed using, for example, equation (1).

number

[0109] The RSSI in equation (1) indicates the received power calculated by the base station 100 after receiving the signal transmitted from the terminal x before the first transmission power control.

[0110] In equation (1), α is a coefficient determined by the communication method. α may be a coefficient for correcting the SINR difference between the LoRa method and the Wi-SUN method. α is set to a value within the range of the required SINR for both the LoRa method and the Wi-SUN method. Note that, in channel c, if either the LoRa method or the Wi-SUN method is used and the other is not used, the SINR difference does not need to be corrected. If the SINR difference is not corrected, α may be 1.

[0111] Furthermore, target in equation (1) indicates a target value of GW received power. For example, the target value may be the GW received power of a signal transmitted at the maximum transmission power by a Wi-SUN terminal that is farthest from the base station 100. The target value may be set independently for each channel. The target value for a certain channel c may be set based on the GW received power of a Wi-SUN terminal within its management that is assigned to channel c. The target value for channel c may be the smallest GW received power among the GW received powers of the Wi-SUN terminals within its management that are assigned to channel c.

[0112] 4, the base station 100 allocates a Wi-SUN terminal within its management having a relatively high GW received power to the shared channel. Therefore, when performing the first transmission power control on the shared channel, the base station 100 may set the target value for the shared channel to a relatively high value. For example, the base station 100 may set the target value to a value higher than the smallest GW received power among the Wi-SUN terminals within its management that are the allocation targets.

[0113] In the first transmission power control, the base station 100 controls the transmission power Txpow of the terminal x using the formula (1). next The determined transmission power Txpow next The terminal x notifies the terminal x of the transmission power Txpow notified by the base station 100. next Signal transmission is performed at

[0114] As shown in Figure 4, by performing allocation based on GW received power and controlling the transmission power of managed LoRa terminals allocated to shared channels, it is possible to suppress, for example, deterioration of the communication characteristics of managed Wi-SUN terminals and improve the communication characteristics of managed LoRa terminals.

[0115] <Flow of the first example of channel allocation and transmission power control> 5 is a flowchart of a first example of channel allocation and transmission power control. For example, the flowchart shown in FIG. 5 may be started at predetermined time intervals.

[0116] The base station 100 measures interference (S101).

[0117] The base station 100 determines whether or not the allocation of channels to the terminals under its control has been completed (S102).

[0118] If the allocation is not complete (NO in S102), that is, if there is a terminal (hereinafter referred to as "terminal z") among the terminals to be allocated that has not yet completed the allocation process, base station 100 executes the allocation process from S103 onwards for terminal z. On the other hand, if the allocation process is complete (YES in S102), that is, if there is no terminal among the terminals to be allocated that has not yet completed the allocation process, base station 100 ends the flow shown in FIG.

[0119] The base station 100 determines whether the communication method used by the terminal z is the Wi-SUN method (S103).

[0120] If the communication method used by the terminal z is Wi-SUN (YES in S103), the base station 100 determines whether the GW reception power of the terminal z is greater than the first threshold value (S104).

[0121] If the GW reception power of terminal z is greater than the first threshold (YES in S104), the base station 100 assigns terminal z to the shared channel (S105), and then the process of S102 is executed.

[0122] If the GW reception power of terminal z is not greater than the first threshold (NO in S104), the base station 100 assigns terminal z to a Wi-SUN channel (S106), and then the process of S102 is executed.

[0123] If the communication method used by terminal z is not Wi-SUN (NO in S103), that is, if the communication method used by terminal z is LoRa, base station 100 determines whether the GW received power of terminal z is greater than the second threshold (S107).

[0124] If the GW received power of terminal z is greater than the second threshold (YES in S107), the base station 100 assigns terminal z to the shared channel (S108). Then, the base station 100 performs first transmission power control for terminal z (first transmission power control: ON) (S109). In this first transmission power control, as illustrated in FIG. 4, the target value (target in equation (1)) may be set to a relatively high value. Then, the process of S102 is executed.

[0125] If the GW received power of terminal z is not greater than the second threshold (NO in S107), the base station 100 assigns terminal z to a LoRa channel (S110). Then, the base station 100 does not perform the first transmission power control for terminal z (first transmission power control: OFF) (S111). Then, the process of S102 is executed.

[0126] As described above, in the first example, by performing allocation based on GW received power and transmission power control for managed LoRa terminals allocated to shared channels, it is possible to suppress, for example, deterioration of the communication characteristics of managed Wi-SUN terminals and improve the communication characteristics of managed LoRa terminals.

[0127] Note that, while FIG. 4 above shows an example in which the usage status of channels #33 to #38, which are shared channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #33 to #38 may be different from one another. In this case, the transmission power determined in the first transmission power control may be different for each channel. For example, if the GW reception power of managed Wi-SUN terminals differs for each channel, the target in equation (1) is determined for each channel.

[0128] <Second example of channel allocation and transmission power control> In the second example, transmission power control for managed LoRa terminals assigned to a LoRa channel will be described.

[0129] Fig. 6 is a diagram showing a second example of channel allocation and transmission power control. The horizontal and vertical axes in Fig. 6 are the same as those in Fig. 4. Furthermore, the allocation of managed terminals to each channel and the transmission power control in the shared channel are the same as those in the first example shown in Fig. 4, so a description thereof will be omitted.

[0130] In FIG. 6, two transmission power control methods, A and B, are selected for LoRa terminals within management assigned to a LoRa channel. A is an option for not performing the first transmission power control, and B is an option for performing the first transmission power control. Note that, since no Wi-SUN terminals within management are assigned to the LoRa channel, the first transmission power control of B does not require consideration of the SINR difference correction coefficient described above. In other words, when performing the first transmission power control of B, α may be set to 1 in equation (1).

[0131] For example, the base station 100 may adaptively select either A or B based on the results of environmental monitoring. If the results of environmental monitoring on the LoRa channel indicate that out-of-management interference is dominant, the base station 100 may select B, and if in-management interference is not dominant, the base station 100 may select A. For example, if the amount of out-of-management interference is greater than the amount of in-management interference, the base station 100 may determine that out-of-management interference is dominant. Also, if the amount of out-of-management interference is equal to or less than the amount of in-management interference, the base station 100 may determine that in-management interference is dominant. Alternatively, out of the amount of in-management interference and the amount of out-of-management interference, the interference that exhibits an amount of interference equal to or greater than a threshold may be determined to be dominant.

[0132] As shown in Figure 6, the communication characteristics of the managed LoRa terminals can be improved by controlling the transmission power of the managed LoRa terminals assigned to the LoRa channel based on the results of environmental monitoring. For example, when the managed interference is dominant, the managed interference can be reduced by performing the first transmission power control, thereby improving the communication characteristics of the managed LoRa terminals.

[0133] <Flow of the second example of channel allocation and transmission power control> Fig. 7 is a flowchart of a second example of channel allocation and transmission power control. In Fig. 7, the same processes as those in Fig. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0134] 7, after measuring interference (after S101), the base station 100 classifies the measured interference into non-management interference and management interference (S201), and then executes the processing from S102 onwards.

[0135] 7, the base station 100 assigns terminal z to a LoRa channel (S110), and selects transmission power control for terminal z assigned to the LoRa channel (transmission power control selection #1) (S202). Then, the process of S102 is executed.

[0136] The process in S202 will be described with reference to FIG.

[0137] FIG. 8 is a flowchart of the process executed in S202 of FIG.

[0138] The base station 100 determines whether or not unmanaged interference is dominant in the LoRa channel assigned to the terminal z (S203).

[0139] If the unmanaged interference is dominant (YES in S203), the base station 100 does not perform the first transmission power control for the terminal z (first transmission power control: OFF) (S204). Then, the flowchart shown in Fig. 8 ends, and the process of S102 in Fig. 7 is executed.

[0140] If the unmanaged interference is not dominant (NO in S203), the base station 100 performs the first transmission power control for the terminal z (first transmission power control: ON) (S205). Here, the base station 100 does not perform difference correction for each communication method in the first transmission power control of S205. Then, the flowchart shown in FIG. 8 ends, and the process of S102 in FIG. 7 is executed.

[0141] As described above, in the second example, the communication characteristics of the managed LoRa terminals can be improved by controlling the transmission power of the managed LoRa terminals assigned to the LoRa channel based on the results of environmental monitoring. For example, when the managed interference is dominant, the managed interference can be reduced by performing the first transmission power control, thereby improving the communication characteristics of the managed LoRa terminals.

[0142] While FIG. 6 above illustrates an example in which the usage status of channels #24 to #32, which are LoRa channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #24 to #32 may be different. In this case, the selection result of the transmission power control methods A and B described above may be different for each LoRa channel. Furthermore, the transmission power determined in the first transmission power control may be different for each channel. For example, if the GW reception power of managed Wi-SUN terminals differs for each channel, the target in equation (1) is determined for each channel.

[0143] Furthermore, in the present embodiment, the case where two methods are used as the transmission power control method has been described, but the present disclosure is not limited to this, and three or more transmission power control methods may be used. For example, base station 100 may adaptively select one or more from three or more transmission power control methods based on the results of environmental monitoring. For example, in the example of FIG. 8 described above, one from two different transmission power control methods ("first transmission power control: ON" and "first transmission power control: OFF") is selected depending on the case where unmanaged interference is dominant and the case where unmanaged interference is not dominant. However, one or more from three or more transmission power control methods may be adaptively selected depending on the magnitude of the unmanaged interference. Furthermore, for some of these different transmission power control methods, the same transmission power control method may be used, but the values ​​of some parameters may be changed.

[0144] <Third Example of Channel Allocation and Transmission Power Control> In the third example, in addition to the first transmission power control described above, transmission power control based on the spreading factor of the LoRa system is performed. The transmission power control based on the spreading factor of the LoRa system is referred to as second transmission power control.

[0145] Fig. 9 is a diagram showing a third example of channel allocation and transmission power control. The horizontal and vertical axes in Fig. 9 are the same as those in Fig. 4. Furthermore, the allocation of managed terminals to each channel is the same as that in the first example shown in Fig. 4, so a description thereof will be omitted.

[0146] In FIG. 9, a second transmission power control is added to the second example shown in FIG.

[0147] For example, in the third example, the base station 100 performs the first transmission power control (first transmission power control: ON) and the second transmission power control (second transmission power control: ON) for the LoRa terminals within its management that are assigned to the shared channel. Note that in the first transmission power control for the LoRa terminals within its management that are assigned to the shared channel, the target value may be set to a relatively high value, as in the first example.

[0148] Also, for example, in a third example, the base station 100 performs either transmission power control A or B on the LoRa terminals within its management assigned to the LoRa channel. A is an option in which the first transmission power control is not performed, but the second transmission power control is performed. B is an option in which the first transmission power control is performed and the second transmission power control is performed. Note that, as in the second example, the base station 100 may select either A or B based on the results of environmental monitoring. For example, the base station 100 may select B if the results of environmental monitoring on the LoRa channel show that non-managed interference is dominant, and may select A if in-management interference is not dominant.

[0149] <Example of second transmission power control> The second transmission power control for a certain LoRa terminal y will be explained below. The second transmission power control is performed using, for example, equation (2).

number

[0150] In addition, in equation (2), Txpow SFn indicates the transmission power of LoRa terminal y after the second transmission power control, and Txpow prev indicates the transmission power of LoRa terminal y before the second transmission power control.

[0151] Here, when both the first transmission power control and the second transmission power control are performed, for example, in the case of transmission power control for a managed LoRa terminal assigned to a shared channel, Txpow prev is the Txpow determined using equation (1). next In addition, when the first transmission power control is not performed and the second transmission power control is performed, for example, in the case of transmission power control of a managed LoRa terminal assigned to a LoRa channel where non-managed interference is dominant, Txpow prev is the current transmission power Txpow of the LoRa terminal y under management. now It may be.

[0152] As shown in Fig. 9, by controlling the transmission power of managed LoRa terminals, it is possible to suppress deterioration of the communication characteristics of managed Wi-SUN terminals and improve the communication characteristics of managed LoRa terminals. For example, in Fig. 9, transmission power control is performed based on the spreading factor of the LoRa system, which can further improve the communication characteristics of managed LoRa terminals.

[0153] <Flow of the third example of channel allocation and transmission power control> Fig. 10 is a flowchart of a third example of channel allocation and transmission power control. In Fig. 10, the same processes as those in Fig. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0154] In the flowchart of FIG. 10, the base station 100 determines whether or not to perform the first transmission power control (after S109 or S110), and then controls the spreading factor (assigns the spreading factor) for the terminal z (S301).

[0155] Then, the base station 100 performs the second transmission power control for the terminal z (second transmission power control: ON) (S302). In S302, the base station 100 weights the transmission power of the terminal z in accordance with the spreading factor of the terminal z. Then, the processing of S102 is executed.

[0156] As described above, in the third example, by controlling the transmission power of the managed LoRa terminals, it is possible to suppress deterioration of the communication characteristics of the managed Wi-SUN terminals, and improve the communication characteristics of the managed LoRa terminals. For example, in Fig. 9, transmission power control is performed based on the spreading factor of the LoRa system, which makes it possible to further improve the communication characteristics of the managed LoRa terminals.

[0157] While FIG. 9 above illustrates an example in which the usage status of channels #24 to #32, which are LoRa channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #24 to #32 may be different. In this case, the selection result of the transmission power control methods A and B described above may be different for each LoRa channel. Furthermore, although an example in which the usage status of channels #33 to #38, which are shared channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #33 to #38 may be different. Furthermore, the transmission power determined in the first transmission power control may be different for each channel. For example, if the GW reception power of managed Wi-SUN terminals is different for each channel, the target in equation (1) is determined for each channel.

[0158] <Fourth Example of Channel Allocation and Transmission Power Control> In the first to third examples, examples were shown in which a managed LoRa terminal and a managed Wi-SUN terminal were assigned to a shared channel, but in the fourth example, an example will be described in which a managed Wi-SUN terminal is not assigned to a shared channel. An example in which a managed Wi-SUN terminal is not assigned to a shared channel is an example in which the number of managed Wi-SUN terminals to be assigned is the number that can be assigned to a Wi-SUN channel.

[0159] Figure 11 is a diagram showing a fourth example of channel allocation and transmission power control. The horizontal and vertical axes in Figure 11 are the same as those in Figure 4. The allocation of managed LoRa terminals to each channel is the same as in the first example shown in Figure 4, so a description thereof will be omitted.

[0160] In the fourth example, as described above, no Wi-SUN terminals are assigned to the shared channel. In this case, the base station 100 may control the transmission power of the LoRa terminals assigned to the shared channel in the same way as it controls the transmission power of the LoRa terminals assigned to the LoRa channel.

[0161] For example, in Fig. 11, the transmission power control for managed LoRa terminals assigned to the LoRa channel is the same as the transmission power control for managed LoRa terminals assigned to the LoRa channel shown in Example 3. Also, in Fig. 11, the transmission power control for managed LoRa terminals assigned to the shared channel is the same as the transmission power control for managed LoRa terminals assigned to the LoRa channel.

[0162] 11 shows an example of transmission power control for managed LoRa terminals assigned to a shared channel when no managed Wi-SUN terminals are assigned to the shared channel, but the present disclosure is not limited to this.Even when the number of Wi-SUN terminals assigned to the shared channel is less than a predetermined value, transmission power control for managed LoRa terminals assigned to the shared channel may be the same as transmission power control for managed LoRa terminals assigned to a LoRa channel.

[0163] <Fourth Example Flow of Channel Allocation and Transmission Power Control> Fig. 12 is a flowchart of a fourth example of channel allocation and transmission power control. In Fig. 12, the same processes as those in Fig. 5 and Fig. 7 are denoted by the same reference numerals, and the description thereof will be omitted.

[0164] 12, the base station 100 allocates a shared channel to terminal z (S108), and selects transmission power control for terminal z allocated to the shared channel (transmission power control selection #2) (S401). Then, the process of S102 is executed.

[0165] The process in S401 will be described with reference to FIG.

[0166] FIG. 13 is a flowchart of the process executed in S401 of FIG.

[0167] The base station 100 determines whether or not a terminal using the Wi-SUN system exists (is assigned) in the shared channel assigned to the terminal z (S402).

[0168] If there is a terminal using the Wi-SUN system (YES in S402), the base station 100 performs the first transmission power control for the terminal z (first transmission power control: ON) (S403). In the first transmission power control here, the target value (target in equation (1)) may be set to a relatively high value, as illustrated in Figs. 4 and 11. Then, the flowchart shown in Fig. 13 ends, and the process of S102 in Fig. 12 is executed.

[0169] If there is no terminal using the Wi-SUN system (NO in S402), the base station 100 determines whether or not unmanaged interference is dominant in the shared channel allocated to the terminal z (S404).

[0170] If the unmanaged interference is dominant (YES in S404), the base station 100 does not perform the first transmission power control for the terminal z (first transmission power control: OFF) (S405). Then, the flowchart shown in Fig. 13 ends, and the process of S102 in Fig. 12 is executed.

[0171] If the unmanaged interference is not dominant (NO in S404), the base station 100 performs the first transmission power control for the terminal z (first transmission power control: ON) (S406). Here, the base station 100 does not perform difference correction for each communication method in the first transmission power control of S406. Then, the flowchart shown in FIG. 13 ends, and the process of S102 in FIG. 12 is executed.

[0172] As described above, in the fourth example, by controlling the transmission power of the shared channel for the managed LoRa terminals in accordance with the allocation status of the managed Wi-SUN terminals, it is possible to suppress, for example, deterioration of the communication characteristics of the managed Wi-SUN terminals and improve the communication characteristics of the managed LoRa terminals.

[0173] While FIG. 11 illustrates an example in which the usage status of channels #24 to #32, which are LoRa channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #24 to #32 may be different. In this case, the selection result of the transmission power control methods A and B described above may be different for each LoRa channel. Furthermore, although an example in which the usage status of channels #33 to #38, which are shared channels, is the same, the present disclosure is not limited to this. For example, the usage status of channels #33 to #38 may be different. In this case, the selection result of the transmission power control methods A and B described above may be different for each shared channel. Furthermore, the transmission power determined in the first transmission power control may be different for each channel.

[0174] <Channel Allocation Variation 1-1> In the first to fourth examples described above, the base station 100 assigns channels to managed terminals according to the magnitude of the GW received power, but the present disclosure is not limited to this. Below, variations in channel assignment will be described.

[0175] Fig. 14 is a diagram showing an example of variation 1-1 of channel allocation. The horizontal and vertical axes in Fig. 14 are the same as those in Fig. 4. The allocation of managed Wi-SUN terminals to each channel is the same as in the first example shown in Fig. 4, so a description thereof will be omitted. The transmission power control for managed LoRa terminals allocated to LoRa channels and shared channels is the same as in the first example, so a description thereof will be omitted.

[0176] In variation 1-1, the base station 100 determines the allocation of managed terminals based on the GW received power and the communication success rate. The GW received power and the communication success rate are examples of information related to communication quality. The communication success rate indicates, for example, whether communication is successful within a predetermined time Tk.

[0177] For example, base station 100 assigns to a shared channel those LoRa terminals under its management that have a relatively high GW received power and that communicate successfully within a predetermined time Tk. Base station 100 also assigns to a LoRa channel those LoRa terminals under its management that have a relatively low GW received power or that do not communicate successfully within the predetermined time Tk. In other words, even if the GW received power is relatively high, those LoRa terminals under its management that do not communicate successfully within the predetermined time Tk are assigned to the LoRa channel rather than the shared channel.

[0178] For example, base station 100 assigns to a LoRa channel those LoRa terminals under its management that do not successfully communicate within a predetermined time Tk. Then, of the LoRa terminals under its management that successfully communicate within the predetermined time Tk, base station 100 assigns to a LoRa channel those LoRa terminals under its management that have relatively low GW received power. Then, when the number of LoRa terminals under its management assigned to LoRa channels reaches the number of LoRa terminals under its management that can be assigned to LoRa channels, base station 100 assigns to a shared channel the remaining LoRa terminals under its management that successfully communicated within the predetermined time Tk.

[0179] <Channel allocation variation 1-1 flow> Fig. 15 is a flowchart of variation 1-1 of channel allocation. In Fig. 15, the same processes as those in Fig. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0180] In the flowchart shown in FIG. 15, if the GW reception power of terminal z is greater than the second threshold (YES in S107), the base station 100 determines whether or not communication with terminal z has been successful within a predetermined time Tk (S501).

[0181] If communication is successful within the predetermined time Tk (YES in S501), the base station 100 assigns the terminal z to the shared channel (S108). Then, the base station 100 performs the first transmission power control for the terminal z (first transmission power control: ON) (S109). Then, the process of S102 is executed.

[0182] If the GW received power of terminal z is not greater than the second threshold (NO in S107), or if communication is not successful within the predetermined time Tk (NO in S501), the base station 100 assigns terminal z to a LoRa channel (S110). Then, the base station 100 does not perform the first transmission power control for terminal z (first transmission power control: OFF) (S111). Then, the processing of S102 is executed.

[0183] Among the managed LoRa terminals assigned to the shared channel, those that do not successfully communicate within a predetermined time Tk may have their assignment changed (reassigned) from the shared channel to a LoRa channel.

[0184] <Channel Allocation Variations 1-2> Fig. 16 is a diagram showing an example of variation 1-2 of channel allocation. The horizontal and vertical axes in Fig. 16 are the same as those in Fig. 4. Compared to Fig. 14, Fig. 16 shows that a change in allocation from the LoRa channel to the shared channel is performed.

[0185] In this case, among the managed LoRa terminals that successfully communicate within the predetermined time Tk, those with relatively high GW reception power may be assigned to the shared channel, and those with relatively low GW reception power may not be assigned to the shared channel. For example, whether or not to perform reallocation may be determined based on the usage status of the LoRa channel. Furthermore, if reallocation is performed, the managed LoRa terminals to which the allocation should be changed to the shared channel may be determined based on the usage status of the LoRa channel. For example, if the usage status of the LoRa channel exceeds a predetermined level, reallocation from the LoRa channel to the shared channel may be performed.

[0186] In this type of allocation, the LoRa channel is allocated to the managed LoRa terminals that have a relatively large GW reception power but take a long time to communicate successfully, thereby reducing the time required for the managed LoRa terminals to communicate successfully.

[0187] <Channel allocation variation 1-2 flow> 17 is a flowchart of variation 1-2 of channel allocation. The flow shown in FIG. 17 is performed, for example, by using the LoRa terminal Z in the management area that is assigned to LoRa channel #m. L This is performed periodically.

[0188] The base station 100 determines whether the usage level of LoRa channel #m is greater than a third threshold (S503). For example, the usage level of LoRa channel #m may be the number of managed LoRa terminals assigned to LoRa channel #m. Alternatively, the usage level of LoRa channel #m may be a value based on the number of managed LoRa terminals assigned to LoRa channel #m and the transmission probability of each managed LoRa terminal.

[0189] If the level of usage of LoRa channel #m is greater than the third threshold (YES in S503), the base station 100 L It is determined whether the GW reception power is greater than a fourth threshold (S504).

[0190] Managed LoRa device Z L If the GW reception power is greater than the fourth threshold (YES in S504), the base station 100 L It is determined whether the communication is successful within a predetermined time Tk (S505).

[0191] If communication is successful within the predetermined time Tk (YES in S505), the base station 100 L 17 to the shared channel (S506). Then, the flow in FIG. 17 ends.

[0192] If the usage level of LoRa channel #m is not greater than the third threshold (NO in S503), L If the GW reception power is not greater than the fourth threshold (NO in S504), or if communication is not successful within the predetermined time Tk (NO in S505), the base station 100 assigns the LoRa terminal Z under its management to the LoRa channel #m. L The flow of FIG. 17 ends without changing the allocation.

[0193] In the variations described above, by performing allocation based on GW received power and transmission power control for managed LoRa terminals allocated to shared channels, it is possible to suppress degradation of the communication characteristics of managed Wi-SUN terminals and improve the communication characteristics of managed LoRa terminals, for example.

[0194] <Channel allocation variation 2> In channel allocation variation 2, the channel allocation is changed according to the results of environmental monitoring.

[0195] Fig. 18 is a diagram showing an example of channel allocation variation 2. Fig. 18 shows channel allocation for two cases with different levels of unmanaged interference. The vertical and horizontal axes for each of the two cases are the same as those in Fig. 4.

[0196] Of the two cases, Case 1, in which the amount of non-management interference (e.g., the usage status shown on the vertical axis in FIG. 18) is relatively low, is an example of a case in which in-management interference is dominant. In Case 1, the amount of non-management interference is relatively low, so base station 100 may allocate in-management LoRa terminals evenly between LoRa channels and shared channels. For example, in this case, base station 100 keeps the difference between the number of in-management LoRa terminals allocated to LoRa channels and the number of in-management LoRa terminals allocated to shared channels within a predetermined range (e.g., within a range of ±2).

[0197] In addition, in Case 1, base station 100 may allocate Wi-SUN terminals under its management equally between Wi-SUN channels and shared channels. For example, in this case, base station 100 keeps the difference between the number of Wi-SUN terminals under its management allocated to Wi-SUN channels and the number of Wi-SUN terminals under its management allocated to shared channels within a predetermined range (for example, within a range of ±2).

[0198] Of the two cases, Case 2, in which the amount of non-management interference is relatively high, is an example of a case in which non-management interference is dominant. In Case 2, because the amount of non-management interference is relatively high, base station 100 may allocate more in-management LoRa terminals to the LoRa channel than to the shared channel. In other words, in Case 2, base station 100 sets the difference between the number of LoRa channels allocated to the LoRa channel and the number of in-management LoRa terminals allocated to the shared channel to a predetermined value or greater.

[0199] In addition, in case 2, base station 100 may allocate more Wi-SUN terminals under its management to Wi-SUN channels than to shared channels. In other words, in case 2, base station 100 sets the difference obtained by subtracting the number of Wi-SUN terminals under its management allocated to shared channels from the number allocated to Wi-SUN channels to a predetermined value or more.

[0200] <Channel allocation variation 2 flow> Fig. 19 is a flowchart of channel allocation variation 2. In Fig. 19, the same processes as those in Fig. 5 and Fig. 7 are denoted by the same reference numerals, and the description thereof will be omitted.

[0201] 19, the base station 100 classifies interference (after S201), and then performs settings related to channels to be assigned to terminals (S601).Then, the processing from S102 onwards is executed.

[0202] The processing in S601 will be described with reference to FIG.

[0203] FIG. 20 is a flowchart of the process executed in S601 of FIG.

[0204] The base station 100 determines whether the average uncontrolled interference of each channel is dominant (S602).

[0205] If the non-management interference is not dominant (NO in S602), base station 100 sets the allocation ratio between the unshared channel and the shared channel to a (a is a number greater than 0) (S604). Here, the allocation ratio is expressed, for example, as the number of in-management terminals allocated to the shared channel / the number of in-management terminals allocated to the unshared channel. The higher the allocation ratio, the greater the number of in-management terminals allocated to the shared channel compared to the number of in-management terminals allocated to the unshared channel.

[0206] If the non-management interference is dominant (YES in S602), the base station 100 sets the allocation ratio between the unshared channel and the shared channel to b (b is a number greater than 0 and less than a) (S603). By setting b to a value smaller than a, if the non-management interference is dominant, the ratio of allocation to the unshared channel is higher than that to the shared channel.

[0207] Then, the base station 100 determines a first threshold (see S104 in FIG. 19) and a second threshold (see S107 in FIG. 19) based on the set ratio (S605). Then, the flow in FIG. 20 ends, and S102 in FIG. 19 is executed. For example, since the larger the first threshold and the second threshold are, the more in-management terminals are allocated to the unshared channel. Therefore, the first threshold and the second threshold when the allocation ratio is b (for example, when out-of-management interference is dominant) may be set to values ​​greater than the first threshold and the second threshold when the allocation ratio is a (for example, when in-management interference is dominant).

[0208] In this type of allocation, the ratio of the number of managed LoRa terminals allocated to the LoRa channel to the number of managed LoRa terminals allocated to the shared channel is changed depending on the amount of interference from unmanaged interference, thereby improving the communication characteristics of managed LoRa terminals regardless of the state of the radio wave environment (e.g., the amount of interference from unmanaged interference).

[0209] Furthermore, in such allocation, the ratio between the number of managed Wi-SUN terminals allocated to the Wi-SUN channel and the number of managed Wi-SUN terminals allocated to the shared channel is changed depending on the amount of interference from unmanaged interference, thereby improving the communication characteristics of managed Wi-SUN terminals regardless of the state of the radio wave environment (e.g., the amount of interference from unmanaged interference).

[0210] <Channel allocation variation 3> In the third variation of channel allocation, an example of channel allocation independent for each communication method will be described.

[0211] 21 is a diagram showing an example of channel allocation variation 3. The horizontal and vertical axes in FIG. 21 are the same as those in FIG.

[0212] In Figure 21, the ratio R of LoRa terminals allocated to the managed LoRa channel to those allocated to the shared channel is L and a second ratio R of the managed Wi-SUN terminals assigned to the Wi-SUN channel and the managed Wi-SUN terminals assigned to the shared channel. W and are set independently.

[0213] For example, the ratio R L is the ratio R W In other words, the ratio of allocation to shared channels for managed LoRa terminals may be set higher than that for managed Wi-SUN terminals.

[0214] <Channel allocation variation 3 flow> The flowchart of channel allocation variation 3 is similar to the flowchart of channel allocation variation 2 shown in Fig. 19, but the processing of S601 differs from that of Fig. 20. The processing of S601 in the flowchart of channel allocation variation 3 will be described below with reference to Fig. 22.

[0215] FIG. 22 is a flowchart of the process executed in S601 of FIG.

[0216] The base station 100 determines whether the average uncontrolled interference of each channel is dominant or not (S701).

[0217] If the unmanaged interference is not dominant (NO in S701), the base station 100 sets the allocation ratio between the shared channel and the LoRa channel to a (a is a number greater than 0) (S702). Also, the base station 100 sets the allocation ratio between the shared channel and the Wi-SUN channel to c (c is a number greater than 0) (S703).

[0218] If the unmanaged interference is dominant (YES in S701), the base station 100 sets the allocation ratio between the shared channel and the LoRa channel to b (b is a number greater than 0 and less than a) (S704). Also, the base station 100 sets the allocation ratio between the shared channel and the Wi-SUN channel to d (d is a number greater than 0 and less than c) (S705).

[0219] Here, by setting b to a value smaller than a, when non-managed interference is dominant, a higher proportion of in-management LoRa terminals are assigned to LoRa channels than to shared channels. Also, by setting d to a value smaller than c, when non-managed interference is dominant, a higher proportion of in-management Wi-SUN terminals are assigned to Wi-SUN channels than to shared channels. Also, by setting a to a value larger than c and b to a value larger than d, a higher proportion of in-management LoRa terminals are assigned to shared channels than a higher proportion of in-management Wi-SUN terminals are assigned to shared channels.

[0220] Then, the base station 100 determines the first threshold (see S104 in FIG. 19) and the second threshold (see S107 in FIG. 19) based on the set ratio (S706). Then, the flow in FIG. 20 ends, and S102 in FIG. 19 is executed. For example, the first threshold when the allocation ratio is b is set to be larger than the first threshold when the allocation ratio is a. Furthermore, the second threshold when the allocation ratio is d is set to be larger than the second threshold when the allocation ratio is c.

[0221] Furthermore, in such allocation, the ratio between the number of managed Wi-SUN terminals allocated to the Wi-SUN channel and the number of managed Wi-SUN terminals allocated to the shared channel is changed depending on the amount of interference from unmanaged interference, thereby improving the communication characteristics of managed Wi-SUN terminals regardless of the state of the radio wave environment (e.g., the amount of interference from unmanaged interference).

[0222] In the above-described embodiment, interference classification into managed interference and unmanaged interference has been described, but the present disclosure is not limited to this. For example, unmanaged interference may be classified into radio interference and environmental noise. In this case, a control method for transmission power control may be selected based on the usage status of radio interference in each channel (channel occupancy rate information). Furthermore, a level of priority may be specified for environmental noise. For example, a control method for transmission power control may be selected based on the usage status (channel occupancy rate information) of radio interference and environmental noise with a high priority.

[0223] For example, radio interference and environmental noise may be classified based on preamble information. Furthermore, for environmental noise, information about the wireless system that causes the environmental noise (e.g., the level of priority) may be estimated based on band information.

[0224] Furthermore, in the above-described embodiment, an example was shown in which the LoRa channel is a channel to which LoRa terminals are assigned and Wi-SUN terminals are not assigned, but the present disclosure is not limited to this. For example, a channel to which the number of Wi-SUN terminals assigned (or the usage status) is less than a threshold may be considered an example of a "LoRa channel." For example, in the above-described fourth example, an example was shown in which no managed Wi-SUN terminals are assigned to a shared channel, but managed Wi-SUN terminals less than the threshold may be assigned to a shared channel.

[0225] In the above embodiment, an example has been shown in which channel allocation to terminals and transmission power control for terminals are performed sequentially for each terminal, but the present disclosure is not limited to this. For example, base station 100 may perform transmission power control for each terminal after allocating a channel to each of the terminals to which the channel is to be allocated. In this case, base station 100 may also perform transmission power control according to the allocation status of each channel to the terminal.

[0226] Furthermore, the examples of channel allocation and transmission power control and the variations of channel allocation shown in the above embodiments may be applied in combination. For example, the transmission power control shown in the first example may be applied to the shared channel, and the transmission power control shown in the third example may be applied to the LoRa channel. Furthermore, for example, the transmission power control of each channel in the channel allocation variation 1-1 shown in FIG. 14 may be changed to the transmission power control shown in the second or third example. Furthermore, transmission power control may be set independently for each of multiple LoRa channels and / or multiple shared channels. For example, the transmission power control shown in the first example may be applied to a certain LoRa channel, and the transmission power control shown in the third example may be applied to another LoRa channel.

[0227] <Channel allocation variation 4> The above-mentioned channel allocation shows an example in which a channel to be allocated to a managed terminal is determined from among LoRa channels, Wi-SUN channels, and shared channels. There may be multiple LoRa channels, Wi-SUN channels, and shared channels. For example, in the example of FIG. 4, channels #24 to #32 are LoRa channels, channels #33 to #38 are shared channels, and channels #39 to #60 are Wi-SUN channels.

[0228] Hereinafter, one or more LoRa channels may be referred to as a "LoRa channel group (CG)", one or more Wi-SUN channels may be referred to as a "Wi-SUNCG", and one or more shared channels may be referred to as a "shared CG". In other words, in the above example, "assigning to a LoRa channel" may be equivalent to "assigning to a channel in the LoRaCG". Also, "assigning to a Wi-SUN channel" may be equivalent to "assigning to a channel in the Wi-SUNCG", and "assigning to a shared channel" may be equivalent to "assigning to a channel in the shared CG".

[0229] For example, after determining which terminals are to be assigned to the shared channel, the base station 100 may randomly determine the channel to be assigned to each of the determined terminals from among a plurality of channels included in the shared CG (e.g., channels #33 to #38). The same may be true for the LoRaCG and Wi-SUNCG.

[0230] Alternatively, after determining which terminals are to be assigned shared channels, the base station 100 may determine which channels to assign to each of the determined terminals from among multiple channels included in the shared CG using the following method. The same may be true for LoRaCG and Wi-SUNCG.

[0231] In the following, an example will be described in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the shared CG.

[0232] <Variation 4-1> Fig. 23 is a diagram showing an example of channel allocation variation 4-1. The horizontal axis of Fig. 23 indicates frequency, and the vertical axis indicates the level of usage of each channel. Fig. 23 shows the levels of usage of in-management terminals and out-of-management terminals for each of four channels (channels #C1 to #C4) assigned with identification numbers. Fig. 23 also shows n in-management terminals to be assigned to any of channels #C1, #C2, #C3, and #C4.

[0233] For example, channels #C1 to #C4 indicate four channels included in the common CG. Also, for example, when channels #C1 to #C4 are channels of the common CG, the n under-management terminals are under-management LoRa terminals or under-management Wi-SUN terminals that have been determined to be assigned to the common CG.

[0234] Channels #C1 to #C4 may be classified according to the usage status of non-managed terminals. For example, channels #C1 and #C2 have a lower level of usage status compared to channel #C3. Therefore, channels #C1 and #C2 are classified as "channels with low non-managed interference," and channel #C3 is classified as "channels with high non-managed interference." Furthermore, channel #C4 is close to the upper limit value α of the usage status level, so it may correspond to "a channel to which non-managed terminals are not assigned."

[0235] A "channel with little non-management interference" may be referred to as a "channel with a low occupancy rate of non-management interference" or a "channel with a lot of free space." Furthermore, a "channel with a lot of non-management interference" may correspond to a "channel with a high occupancy rate of non-management interference" or a "channel with little free space." Furthermore, a "channel to which no in-management terminal is assigned" may correspond to a "channel with no free space." For example, a "channel with little non-management interference" and a "channel with a lot of non-management interference" may be classified by comparing a threshold value with the amount of non-management interference, or a predetermined number of channels with the most non-management interference may be classified as "channels with a lot of non-management interference" and the remaining channels may be classified as "channels with little non-management interference." This classification may be performed by base station 100.

[0236] The base station 100 determines which in-management terminals are to be assigned to channels with low out-of-management interference and which in-management terminals are to be assigned to channels with high in-management interference based on the received power (e.g., RSSI) of signals received by the base station 100 from each in-management terminal. Hereinafter, the RSSI determined by the base station 100 after receiving a signal transmitted by a certain in-management terminal x may be referred to as "RSSI of terminal x." Furthermore, the terminal x that is the sender of a signal indicating a certain RSSI may be referred to as "terminal x corresponding to the RSSI."

[0237] In the example of Fig. 23, n terminals under management are arranged in order of RSSI. Of the RSSIs of the n terminals under management, terminal under management #1 has the smallest RSSI, and terminal under management #n has the largest RSSI. In the example of Fig. 23, the n terminals under management are divided into a group of m terminals consisting of terminals under management #1 to #m corresponding to relatively small RSSIs, and a group of n-m terminals consisting of terminals under management #m+1 to #n corresponding to relatively large RSSIs. Here, m is an integer between 1 and n. For example, m may be determined based on the ratio between the availability of channels #C1 and #C2 and the availability of channel #C3.

[0238] Base station 100 decides to assign in-management terminals #1 to #m corresponding to relatively small RSSI to channels #C1 and #C2 with small out-of-management interference, and decides to assign in-management terminals #m+1 to #n corresponding to relatively large RSSI to channel #C3 with large out-of-management interference.

[0239] 23 shows an example in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the common CG, but this may also be applied to the Wi-SUNCG and the LoRaCG. For example, if channels #C1, #C2, #C3, and #C4 are Wi-SUNCG channels, the n managed terminals are Wi-SUN terminals determined to be allocated to the Wi-SUNCG. Also, for example, if channels #C1 to #C4 are LoRaCG channels, the n managed terminals are LoRa terminals determined to be allocated to the LoRaCG.

[0240] Fig. 24 is a flowchart of channel allocation variation 4. Note that in Fig. 24, the same processes as in Fig. 5 are denoted by the same reference numerals, and descriptions thereof will be omitted. In the flow of Fig. 24, the processes of S102, S105, S106, S108, and S110 in the flow of Fig. 5 are replaced with processes of S801, S802, S803, S804, and S805, respectively. Furthermore, in the flow of Fig. 24, the process of S806 is added to the flow of Fig. 5.

[0241] The base station 100 determines whether the allocation of the group of channels to the terminals under its control has been completed (S801).

[0242] If the allocation is not complete (NO in S801), that is, if there is a terminal (hereinafter referred to as "terminal z") among the terminals to be allocated that has not yet completed the allocation process, base station 100 executes the allocation process from S103 onwards for terminal z.

[0243] If the GW reception power of terminal z is greater than the first threshold (YES in S104), the base station 100 determines to allocate terminal z to the shared CG (S802), and then the process of S801 is executed.

[0244] If the GW received power of the terminal z is not greater than the first threshold (NO in S104), the base station 100 determines to allocate the terminal z to the Wi-SUNCG (S803). Then, the process of S801 is executed.

[0245] If the GW reception power of the terminal z is greater than the second threshold (YES in S107), the base station 100 determines to allocate the terminal z to the shared CG (S804).

[0246] If the GW reception power of terminal z is not greater than the second threshold (NO in S107), the base station 100 determines to assign terminal z to the LoRaCG (S805).

[0247] On the other hand, if the channel group allocation process is completed (YES in S801), that is, if there are no terminals among the allocation target terminals for which the allocation process has not been completed, an allocation channel for each allocation target is determined from the channel group based on the RSSI (S806).

[0248] The process of S806 may be executed independently for each channel group. In other words, the process of determining a channel to which each of the terminals determined to be assigned to the LoRaCG becomes an assignment target, and the process of determining a channel to which each of the terminals determined to be assigned to the Wi-SUNCG becomes an assignment target, and the process of determining a shared channel to which each of the terminals determined to be assigned to the shared CG becomes an assignment target, and the process of determining a shared channel to which each of the terminals determined to be assigned to the shared CG becomes an assignment target, may be executed independently.

[0249] Then, the flow of FIG. 24 ends.

[0250] Fig. 25 is a flowchart corresponding to variation 4-1, which is executed in S806 of Fig. 24. The flow shown in Fig. 25 is executed independently for each of the managed terminals assigned to the LoRaCG, the managed terminals assigned to the shared CG, and the managed terminals assigned to the Wi-SUNCG.

[0251] In the following, an example will be shown in which the managed terminals to be assigned to one group are the terminals to be assigned.

[0252] The base station 100 sorts the terminals under its management in ascending order of RSSI (S901).

[0253] The base station 100 determines whether or not the allocation of the channel to the terminal to which the channel is to be allocated has been completed (S902).

[0254] If the allocation is not complete (NO in S902), that is, if there is a terminal (hereinafter referred to as "terminal z") among the terminals to be allocated that has not yet completed the allocation process, base station 100 executes the allocation process from S903 onwards for terminal z. On the other hand, if the allocation process is complete (YES in S902), that is, if there is no terminal among the terminals to be allocated that has not yet completed the allocation process, the flow shown in Fig. 25 ends.

[0255] The base station 100 determines whether the terminal z can be assigned to a channel with small unmanaged interference (S903). For example, the base station 100 may determine that the terminal z can be assigned to a channel with small unmanaged interference if the RSSI of the terminal z corresponds to an RSSI that allows the terminal z to be assigned to a channel with small unmanaged interference.

[0256] If terminal z can be assigned to a channel with small non-management interference (YES in S903), base station 100 assigns terminal z to a channel with small non-management interference (S904), and then the process of S902 is executed.

[0257] If terminal z cannot be assigned to a channel with small out-of-control interference (NO in S903), the base station assigns terminal z to a channel with large out-of-control interference (S905), and then the process of S902 is executed.

[0258] As explained above, in variation 4-1, by assigning in-management terminals with smaller RSSI to channels with less out-of-management interference (in other words, channels with more available channels), it is possible to reduce interference caused by in-management terminals to other terminals (e.g., out-of-management terminals). For example, even if the range of control of transmission power (e.g., dynamic range) is not sufficient for in-management terminals, it is possible to reduce interference caused by in-management terminals. Furthermore, since in-management terminals with a relatively small difference in RSSI are assigned to the same channel, it is possible to reduce the effects of causing and receiving interference.

[0259] <Variation 4-2> In the example of Variation 4-1 (e.g., FIG. 23), the base station 100 determines the channel to be assigned to the terminal under management based on the RSSI, but in Variation 4-2, the base station 100 determines the channel to be assigned to the terminal under management based on the RSSI and a condition determination of whether a certain condition is met. Illustratively, in the following description, the certain condition is a condition relating to the time interval (hereinafter referred to as the communication success interval) from the most recent timing at which communication was successful (the timing at which communication was last successful) to the present time at the terminal under management.

[0260] In the following, an example will be described in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the shared CG.

[0261] Figure 26 is a diagram showing an example of channel allocation variation 4-2. The horizontal and vertical axes in Figure 26 are the same as those in Figure 23. The usage levels of non-managed terminals in each of the four channels (channels #C1 to #C4) are also the same as those in Figure 23. Figure 26 also shows n+v in-management terminals to be assigned to any of channels #C1, #C2, #C3, and #C4.

[0262] 26, similarly to FIG. 23, channels #C1 and #C2 are classified as "channels with low non-management interference," and channel #C3 is classified as "channels with high non-management interference." Furthermore, channel #C4 is close to the upper limit value α of the usage level, and therefore may correspond to "a channel to which no non-management terminals are assigned."

[0263] Base station 100 assigns channels with small non-management interference to in-management terminals whose communication success interval is greater than a predetermined value (in FIG. 26, "in-management terminals that satisfy the conditions") among in-management terminals. In FIG. 26, in-management terminals #1 to #v that satisfy the conditions are assigned to channels with small non-management interference.

[0264] Then, base station 100 sorts n in-management terminals whose interval of successful communication is not greater than a predetermined value (in other words, "in-management terminals that do not satisfy the conditions") in order of RSSI. Then, as in FIG. 23, base station 100 decides to assign channels #C1 and #C2 with small non-management interference to in-management terminals #1 to #m corresponding to relatively small RSSI, and decides to assign channel #C3 with large non-management interference to in-management terminals #m+1 to #n corresponding to relatively large RSSI. Note that here, m may be determined based on, for example, the ratio of availability of channels #C1 and #C2 to availability of channel #C3 after allocation of v in-management terminals that satisfy the conditions.

[0265] 26 shows an example in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the common CG, as in FIG. 23, but this may also be applied to the Wi-SUNCG and the LoRaCG. For example, if channels #C1, #C2, #C3, and #C4 are Wi-SUNCG channels, the n+v managed terminals are Wi-SUN managed terminals that have been determined to be allocated to the Wi-SUNCG. Also, for example, if channels #C1 to #C4 are LoRaCG channels, the n+v managed terminals are LoRa managed terminals that have been determined to be allocated to the LoRaCG.

[0266] Next, the processing flow of variation 4-2 will be described. The processing flow of variation 4-2 is similar to that of variation 4-1 shown in Fig. 24, but the processing of S806 in Fig. 24 differs from that of variation 4-1.

[0267] Figure 27 is a flowchart corresponding to variation 4-2, which is executed in S806 of Figure 24. In Figure 27, the same processes as those in Figure 25 are given the same reference numerals, and their explanations will be omitted. In the flow of Figure 27, the process of S901 in Figure 25 is replaced with the processes of S1001 to S1004.

[0268] The base station 100 determines whether or not confirmation of the successful communication interval of the terminal to which the allocation is to be made has been completed (S1001).

[0269] If the confirmation is not completed (NO in S1001), that is, if there is a terminal (hereinafter referred to as "terminal y") among the terminals to be allocated that has not completed confirmation regarding the communication success interval, base station 100 executes confirmation processing of S1002 for terminal y.

[0270] The base station 100 determines whether the communication success interval of the terminal y is greater than a predetermined value (S1002).

[0271] If the communication success interval of terminal y is not greater than the predetermined value (NO in S1002), the process of S1001 is executed.

[0272] If the communication success interval of terminal y is greater than the predetermined value (YES in S1002), base station 100 assigns terminal y to a channel with less non-management interference (S1003), and then the process of S1001 is executed.

[0273] If the confirmation is completed (YES in S1001), that is, if there is no terminal among the terminals to be allocated that has not yet completed confirmation regarding the communication success interval, base station 100 sets the terminals to be allocated except for the terminals to which the channel allocation has been completed in S1003 as the terminals to be allocated, and sorts the terminals in ascending order of RSSI of each of the terminals to be allocated (S1004). Then, the processing from S902 onwards is executed.

[0274] Here, the number of in-management terminals to which channels with many available channels are preferentially assigned (in the above example, in-management terminals whose communication success interval is greater than a predetermined value) may be varied depending on the channel resources. For example, when channel resources are relatively scarce, the number of in-management terminals to which channels with many available channels are preferentially assigned may be increased, and when channel resources are relatively abundant, the number of in-management terminals to which channels with many available channels are preferentially assigned may be decreased. For example, the number of in-management terminals to which channels with many available channels are preferentially assigned may be determined based on the result of comparing the channel resources with one or more thresholds.

[0275] As described above, in variation 4-2, the channel to be assigned to a managed terminal is determined based on conditions related to the interval between successful communications in addition to the RSSI. This determination allows channels with more available channels to be preferentially assigned to managed terminals with long intervals between successful communications, thereby suppressing an increase in the interval between successful communications even when channel resources are insufficient. For example, when channel resources are insufficient, some terminals may not be assigned a channel despite having a large RSSI, and may therefore not be able to obtain a transmission opportunity. In variation 4-2, transmission opportunities can be given preferentially to such terminals. Furthermore, since managed terminals with a relatively small difference in RSSI are assigned the same channel, the effects of causing and receiving interference can be reduced.

[0276] <Variation 4-3> In the example of Variation 4-1 (e.g., FIG. 23), the base station determines the channel to be assigned to the managed terminal based on the RSSI, but in Variation 4-3, the base station determines the channel to be assigned to the managed terminal based on the RSSI and the type of the managed terminal. Note that Variation 4-3 is applied to a shared channel to which both LoRa terminals and Wi-SUN terminals are assigned.

[0277] Figure 28 is a diagram showing an example of channel allocation variation 4-3. The horizontal and vertical axes in Figure 28 are the same as those in Figure 23. The usage levels of unmanaged terminals on each of the four channels (channels #C1 to #C4) are also the same as those in Figure 23. However, since variation 4-3 is applied to shared channels, each of the four channels is a shared channel.

[0278] 28 also shows n+p managed terminals assigned to any of channels #C1, #C2, #C3, and #C4, where each of the n+p managed terminals is a managed Wi-SUN terminal or a managed LoRa terminal.

[0279] 28, similarly to FIG. 23, channels #C1 and #C2 are classified as "channels with low non-management interference," and channel #C3 is classified as "channels with high non-management interference." Furthermore, channel #C4 is close to the upper limit value α of the usage level, and therefore may correspond to "a channel to which no non-management terminals are assigned."

[0280] Base station 100 assigns within-management Wi-SUN terminals (abbreviated as "within-management Wi-SUN" in FIG. 28) among within-management terminals to channels with small outside-management interference. In FIG. 28, within-management Wi-SUN terminals #1 to #p are assigned to channels with small outside-management interference.

[0281] Then, base station 100 sorts the LoRa terminals under management (abbreviated as "LoRa under management" in FIG. 28) in order of RSSI. As in FIG. 23, base station 100 determines to assign channels #C1 and #C2 with low non-management interference to LoRa terminals under management #1 to #m corresponding to relatively low RSSI, and to assign channel #C3 with low non-management interference to LoRa terminals under management #m+1 to #n corresponding to relatively high RSSI. Note that here, m may be determined based on, for example, the ratio of availability of channels #C1 and #C2 to availability of channel #C3 after allocation of p Wi-SUN terminals under management.

[0282] Next, the processing flow of variation 4-3 will be described. The processing flow of variation 4-3 is similar to that of variation 4-1 shown in Fig. 24, but the processing of S806 in Fig. 24 differs from that of variation 4-1.

[0283] Figure 29 is a flowchart corresponding to variation 4-3, which is executed in S806 of Figure 24. In Figure 29, the same processes as those in Figure 25 are given the same reference numerals, and their explanations will be omitted. In the flow of Figure 29, the process of S901 in Figure 25 is replaced with the processes of S1101 to S1104.

[0284] The base station 100 determines whether confirmation of the communication method of the terminal to which the allocation is to be performed has been completed (S1101).

[0285] If the confirmation of the communication method has not been completed (NO in S1101), that is, if there is a terminal (hereinafter referred to as "terminal y") among the terminals to be allocated that has not yet completed confirmation of the communication method, base station 100 executes confirmation processing of S1102 for terminal y.

[0286] The base station 100 determines whether the communication system of the terminal y is the Wi-SUN system (S1102).

[0287] If the communication method of terminal y is not the Wi-SUN method (NO in S1102), the process of S1101 is executed.

[0288] If the communication system of terminal y is the Wi-SUN system (YES in S1102), base station 100 assigns terminal y to a channel with small out-of-control interference (S1103), and then the process of S1101 is executed.

[0289] If the confirmation of the communication method is completed (YES in S1101), that is, if there is no terminal among the terminals to be allocated that has not yet completed confirmation of the communication method, the base station 100 sets the terminals to be allocated except for the terminals to which the channel allocation has been completed in S1103 (managed Wi-SUN terminals), and sorts the terminals in ascending order of RSSI of each of the terminals to be allocated (S1104). Then, the processing from S902 onwards is executed.

[0290] Here, depending on the number of Wi-SUN terminals within management and the channel resources, the number of Wi-SUN terminals within management that are preferentially assigned to channels with low non-management interference may be limited. For example, if the number of Wi-SUN terminals within management is relatively small compared to the channel resources, the number of Wi-SUN terminals within management that are preferentially assigned to channels with low non-management interference may be increased. In other words, in this case, it is not necessary to limit the number of Wi-SUN terminals within management that are preferentially assigned to channels with low non-management interference. Also, if the number of Wi-SUN terminals within management is relatively large compared to the channel resources, the number of Wi-SUN terminals within management that are preferentially assigned to channels with low non-management interference may be reduced. In other words, in this case, the number of Wi-SUN terminals within management that are preferentially assigned to channels with low non-management interference may be limited. Note that the number to be limited (the number to be reduced) may be determined according to the channel resources.

[0291] As explained above, in variation 4-3, the channel to be assigned to the managed terminal is determined based on the communication method in addition to the RSSI. This determination can improve the communication quality of the Wi-SUN method, which has weaker error tolerance than the LoRa method. In addition, since managed terminals with a relatively small difference in RSSI are assigned to the same channel, the effects of causing and receiving interference can be reduced.

[0292] In the above-described variations 4-1 to 4-3, examples have been shown in which channels are classified into "channels with large non-management interference" and "channels with small non-management interference" based on the difference in the relative magnitude of non-management interference, but the present disclosure is not limited to this. For example, variations 4-1 to 4-3 may be applied when the relative difference in non-management interference is small and the non-management interference is almost uniform. For example, terminals corresponding to a relatively small RSSI may be assigned to a specific channel, and terminals corresponding to a relatively large RSSI may be assigned to a channel other than the specific channel. With this method, non-management terminals with a relatively small difference in RSSI are assigned to the same channel, thereby reducing the effects of causing and receiving interference.

[0293] The above-described variations 4-1 to 4-3 may be used for dedicated channels such as LoRa channels and Wi-SUN channels when they are available, or for shared channels when there is no available dedicated channel and there is available shared channel.

[0294] The above-described variations 4-1 to 4-3 may be used in combination, or may be applied independently to each channel group. For example, variation 4-1 may be applied to LoRaCG, variation 4-2 may be applied to Wi-SUNCG, and variation 4-3 may be applied to the common CG. For example, variations 4-2 and 4-3 may be combined and applied to the common CG.

[0295] Furthermore, for example, one channel group may be divided into a plurality of subgroups, and the above-described variations 4-1 to 4-3 may be applied independently to each subgroup.

[0296] In the examples of variations 4-1 to 4-3 described above, the channels are classified into three categories, "channels with low non-managed interference," "channels with high non-managed interference," and "channels to which in-management terminals are not assigned," depending on the level of usage of non-managed terminals, but the present disclosure is not limited to this. Depending on the level of usage of non-managed terminals, the channels may be classified into four or more categories, or into two categories. Also, there may not be any "channels to which in-management terminals are not assigned."

[0297] Furthermore, in the examples of variations 4-1 to 4-3, examples have been shown in which in-management terminals are classified into two groups that are assigned to two types of channels, "channels with low out-of-management interference" and "channels with high out-of-management interference," according to the magnitude of RSSI, but the present disclosure is not limited to this. For example, if channels are classified into four or more types according to the magnitude of the usage status of in-management terminals, in-management terminals may be classified into three or more groups corresponding to the number of channel classifications according to the magnitude of RSSI. Also, for example, in-management terminals may be classified into a number of groups excluding "channels not assigned to in-management terminals."

[0298] Furthermore, in the above-described variations 4-1 to 4-3, examples have been shown in which the base station determines channel allocation based on RSSI, but the present disclosure is not limited to this. For example, other information related to communication quality, such as a signal-to-interference power ratio, may be used instead of or in combination with RSSI. Note that the above-described RSSI and "GW received power" may be the same information, or may be different from each other.

[0299] Note that, although the processing flow of Variations 4-1 to 4-3 has been described above as being the flowchart exemplified in Fig. 25, the present disclosure is not limited to this. For example, in the flowchart exemplified in Fig. 25, the processing for turning on / off the first transmission power control (S109 and S111 in Fig. 25) may be skipped. In other words, Variation 4 may be applied when there is no transmission power control.

[0300] Although the above describes an example in which the processing flow of variations 4-1 to 4-3 is combined with the first example of transmission power control illustrated in Fig. 5, the present disclosure is not limited to this. For example, the processing flow may be combined with other examples of transmission power control.

[0301] <Channel Allocation Variation 5> Among the managed terminals, there may be managed terminals that require different communication qualities. These differences in communication quality requirements may be expressed by channel allocation priorities. That is, there may be managed terminals that have different priorities for channel allocation. For example, a managed terminal with a relatively high priority may be assigned to a channel that allows higher quality communication than a managed terminal with a relatively low priority. A channel that allows high quality communication is, for example, a channel that does not use a mixture of multiple communication methods, or a channel with relatively little non-managed interference and / or non-managed interference.

[0302] For example, a terminal with a relatively high priority is a terminal owned by a specific user. A specific user may be, for example, an elderly person with a chronic illness, a person with a guide dog (a guide dog user), an elderly person who has a special request from people around them such as family members, or a child with a history of risky behavior. A specific user may be a person who should be monitored closely.

[0303] Furthermore, the specific user may be a person who is unable to return home and evacuates to an evacuation shelter during a disaster. For example, if the specific user is a person who is unable to return home, local residents (people who can return home) are assigned a relatively low priority. Furthermore, if there are many people who are unable to return home, for example, people who live farther away may be assigned a higher priority. Furthermore, priorities may be set based on the attributes of the person. For example, a user whose home is relatively far from an evacuation shelter or the like but who is physically fit (and may be able to walk home in some cases) may be assigned a lower priority than a user who has difficulty walking home. The user's physical fitness (e.g., whether or not the user can walk home) may be determined based on user information such as the user's age, gender, whether or not the user has an injury, or whether or not the user has an illness. Alternatively, the user's physical fitness may be determined by the user's self-report.

[0304] Furthermore, the specific user may be a person who waits at a specific location for a predetermined period of time or more. For example, a person who waits for a long time at a commercial facility, a theme park, a restaurant, a stadium, or the like may be set to have a higher priority.

[0305] Furthermore, the specific user may be a person in a specific location. For example, the specific user may be a person in the mountains or on the sea. Furthermore, the terminal owned by the specific user is not limited to a terminal owned by a person, but may be, for example, a terminal mounted on a machine, robot, drone, or ship in the mountains or on the sea. There may be a large number of terminals around the coast, at the foot of a mountain, or the like, which may cause communication traffic congestion. In such cases, to prioritize communication, a higher priority is set for terminals located in dangerous areas in the mountains or on the sea. Furthermore, when there are many people in the mountains or on the sea, for example, a higher priority may be set for people located in more dangerous areas. For example, in the mountains, the priority of people located in areas other than general hiking trails, such as rocky areas, may be set higher than the priority of people located on general hiking trails.

[0306] Note that the specific user is not limited to these examples. Whether a terminal has a relatively high priority may be determined based on information about a user associated with the terminal. For example, the base station 100 may refer to information about a user registered in the terminal via the terminal. Furthermore, the base station 100 may obtain location information, etc., of the terminal to determine whether the terminal is a terminal of a specific user.

[0307] Furthermore, for example, a terminal with a relatively high priority is a terminal that provides a specific service to the owner of the terminal. The specific service may be, for example, a monitoring service for the user who owns the terminal. Alternatively, the specific service may be an information notification service regarding life-threatening illnesses and / or infectious diseases. Alternatively, the specific service may be a service related to life-threatening situations such as traffic accident prevention and / or disaster countermeasures. A terminal that provides a specific service may be a terminal dedicated to the service, or may be a terminal that has launched an application that provides the service among applications executed by the terminal.

[0308] Hereinafter, a terminal with a relatively high priority may be referred to as a terminal for a specific user / service. A terminal for a specific user / service may be a terminal that satisfies specific conditions. Furthermore, a terminal with a relatively low priority (a terminal other than a terminal for a specific user / service) may be referred to as a normal terminal. A normal terminal may be a terminal that does not satisfy specific conditions. Furthermore, these descriptions may be written together with descriptions indicating examples of terminal types, such as a managed terminal or a LoRa terminal. Note that, although an example of channel allocation for two types of terminals, a terminal for a specific user / service and a normal terminal, is shown below, the present disclosure is not limited to this. For example, three or more priorities may be set, and different channel allocations may be performed for three or more types of terminals.

[0309] For example, different priorities may be set for a terminal owned by a specific user and providing a specific service, a terminal owned by the specific user and providing a service other than the specific service, and a terminal owned by a user other than the specific user and providing the specific service.

[0310] Furthermore, for example, when the number of terminals that provide a specific service is equal to or greater than a predetermined number, a terminal owned by a specific user may be a terminal with a relatively high priority among the terminals that provide the specific service. In this case, when the number of terminals that provide the specific service is less than the predetermined number, each of the terminals that provide the specific service may be a terminal with a relatively high priority, regardless of the owner of the terminal.

[0311] <Channel Allocation Variation 5-1> 30 is a diagram showing an example of variation 5-1 of channel allocation. The horizontal and vertical axes in FIG. 30 are the same as those in FIG.

[0312] In channel allocation variation 5-1, base station 100 allocates LoRa channels to terminals of a specific user / service among the LoRa terminals under its management that are subject to allocation, and also allocates Wi-SUN channels to terminals of a specific user / service among the Wi-SUN terminals under its management that are subject to allocation.

[0313] In channel allocation variation 5-1, base station 100 allocates, among the LoRa terminals under its management that are allocation targets (excluding terminals of a specific user / service), those with relatively low GW received power to the LoRa channel, and allocates those with relatively high GW received power to the shared channel. Note that the method of determining the LoRa terminals under its management to be allocated to the LoRa channel and the shared channel may be the same as the method shown in FIG. 4.

[0314] In channel allocation variation 5-1, base station 100 allocates, among the Wi-SUN terminals to be allocated within its management, excluding terminals of a specific user / service, those Wi-SUN terminals with relatively low GW received power to the Wi-SUN channel, and allocates, among the Wi-SUN terminals to be allocated within its management, those Wi-SUN terminals with relatively high GW received power to the shared channel. Note that the method of determining the Wi-SUN terminals to be allocated to the Wi-SUN channel and the shared channel may be the same as the method shown in FIG. 4.

[0315] <Channel allocation variation 5-1 flow> Fig. 31 is an example of a flowchart of variation 5-1 of channel allocation. In Fig. 31, the same processes as those in Fig. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0316] In the flowchart shown in FIG. 31, when the communication method used by terminal z is Wi-SUN (YES in S103), the base station 100 determines whether terminal z is a terminal for a specific user / service (S1201).

[0317] If the terminal z is a terminal of a specific user / service (YES in S1201), the base station 100 assigns the terminal z to a Wi-SUN channel (S106), and then the process of S102 is executed.

[0318] If the terminal z is not a terminal for a specific user / service (NO in S1201), the process of S104 is executed.

[0319] Also, in the flowchart shown in FIG. 31, if the communication method used by terminal z is not Wi-SUN (NO in S103), the base station 100 determines whether terminal z is a terminal for a specific user / service (S1202).

[0320] If terminal z is a terminal for a specific user / service (YES in S1202), the base station 100 assigns terminal z to a LoRa channel (S110), and then the process of S111 is executed.

[0321] If the terminal z is not a terminal for a specific user / service (NO in S1202), the process of S107 is executed.

[0322] It should be noted that the transmission power control processing (S109 and S111) in the flowchart shown in FIG. 31 is an example, and the present disclosure is not limited thereto. For example, S111 in FIG. 31 may be replaced with S202 in FIG. 7. Alternatively, the processing of S109 and S111 in FIG. 31 may be followed by the processing of S301 and S302, as in FIG. 10. This is not a limitation, and may be combined with other examples of transmission power control described above, or may be replaced by other examples of transmission power control described above. Alternatively, the processing of S109 and S111 may not be executed. Alternatively, transmission power control different from that performed on normal terminals may be performed on terminals of specific users / services. This example of transmission power control will be described later.

[0323] The above-described channel allocation variation 5-1 can improve the communication quality for user terminals and / or services for which better communication quality is desired. This allows, for example, terminals of elderly people and children to communicate with better communication quality, thereby avoiding temporary suspension of terminal functions due to communication disconnections and enhancing monitoring of elderly people, children, etc.

[0324] Note that, in the example of FIG. 30 , terminals of a specific user / service are assigned to a LoRa channel or a Wi-SUN channel regardless of the magnitude of the received power for each GW, but the present disclosure is not limited to this. LoRa terminals under the management of a specific user / service with relatively high GW received power may be assigned to a shared channel, and LoRa terminals under the management of a specific user / service with relatively low GW received power may be assigned to a LoRa channel. In this case, the conditions for LoRa terminals under the management of a specific user / service to be assigned to a shared channel may be stricter than the conditions for LoRa terminals under normal management to be assigned to a shared channel. For example, if the decision as to whether to assign a terminal to a shared channel or a LoRa channel is made by comparing the GW received power with a threshold, the threshold compared with the GW received power of LoRa terminals under the management of a specific user / service may be higher than the threshold compared with the GW received power of normal LoRa terminals under management.

[0325] <Channel Allocation Variation 5-2> Variation 5-1 above shows an example of determining a channel to be assigned to a terminal of a specific user / service from among LoRa channels, Wi-SUN channels, and shared channels. Variation 5-2, like Variation 4 above, shows an example of determining a channel to be assigned to a terminal of a specific user / service in each of "LoRaCG" including one or more LoRa channels, "Wi-SUNCG" including one or more Wi-SUN channels, and "Shared CG" including one or more shared channels.

[0326] In the following, an example will be described in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the shared CG.

[0327] Figure 32 is a diagram showing an example of channel allocation variation 5-2. The horizontal and vertical axes in Figure 32 are the same as those in Figure 23. The usage levels of non-managed terminals in each of the four channels (channels #C1 to #C4) are also the same as those in Figure 23. Figure 32 also shows n+z in-management terminals to be assigned to any of channels #C1, #C2, #C3, and #C4.

[0328] 32, similarly to FIG. 23, channels #C1 and #C2 are classified as "channels with low non-management interference," and channel #C3 is classified as "channels with high non-management interference." Furthermore, channel #C4 is close to the upper limit value α of the usage level, and therefore may correspond to "a channel to which no non-management terminals are assigned."

[0329] Base station 100 assigns channels with small non-management interference to terminals of a specific user / service among the terminals within its management. In Fig. 32, terminals #1 to #z of a specific user / service are assigned to channels #C1 and #C2 with small non-management interference.

[0330] Then, base station 100 sorts n in-management terminals that are not terminals of a specific user / service (in other words, "normal in-management terminals") in order of RSSI. Then, as in Fig. 23, base station 100 decides to assign channels #C1 and #C2 with small out-of-management interference to in-management terminals #1 to #m corresponding to relatively small RSSI, and decides to assign channel #C3 with large out-of-management interference to in-management terminals #m+1 to #n corresponding to relatively large RSSI. Note that here, m may be determined based on, for example, the ratio of the availability of channels #C1 and #C2 to the availability of channel #C3 after the in-management terminals of z specific users / services are assigned.

[0331] 32 shows an example in which a channel to be allocated to each of the managed terminals is determined from among a plurality of channels included in the common CG, as in FIG. 23, but this may also be applied to the Wi-SUNCG and the LoRaCG. For example, if channels #C1, #C2, #C3, and #C4 are Wi-SUNCG channels, the n+z managed terminals are Wi-SUN terminals determined to be allocated to the Wi-SUNCG. Also, for example, if channels #C1 to #C4 are LoRaCG channels, the n managed terminals are LoRa terminals determined to be allocated to the LoRaCG.

[0332] <Channel allocation variation 5-2 flow> Next, the processing flow of variation 5-2 will be described. The processing flow of variation 5-2 is similar to that of variation 4-1 shown in Fig. 24, but the processing of S806 in Fig. 24 differs from that of variation 4-1.

[0333] Fig. 33 is an example of a flowchart corresponding to Variation 5-2, which is executed in S806 of Fig. 24. In Fig. 33, the same processes as those in Fig. 25 are given the same reference numerals, and their explanations will be omitted. In the flow of Fig. 33, the process of S901 in Fig. 25 is replaced with the processes of S1301 to S1304.

[0334] The base station 100 determines whether confirmation regarding a specific user / service has been completed for the terminals to which the allocation is to be made (S1301).

[0335] If the confirmation is not completed (NO in S1301), that is, if there is a terminal (hereinafter referred to as "terminal y") among the terminals to be allocated that has not completed confirmation regarding a specific user / service, base station 100 performs confirmation processing from S1302 onwards for terminal y.

[0336] The base station 100 determines whether the terminal y is a specific user / service (S1302).

[0337] If the terminal y is not a specific user / service (NO in S1302), the confirmation of the terminal y ends, and the process of S1301 is executed.

[0338] If terminal y is a specific user / service (YES in S1302), base station 100 assigns terminal y to a channel with small out-of-control interference (S1303), and then the process of S1301 is executed.

[0339] If the confirmation is complete (YES in S1301), base station 100 selects terminals as allocation targets excluding terminals for which channel allocation has been completed in S1303, and sorts the terminals in ascending order of RSSI for each allocation target (S1304). Then, the processing from S902 onwards is executed. Note that if the confirmation is complete (YES in S1301), it corresponds to the case where there are no terminals among the allocation target terminals for which confirmation regarding a specific user / service has not been completed.

[0340] Although the processing flow of Variation 5-2 has been described as being similar to Variation 4-1 shown in FIG. 24 except that the processing of S806 in FIG. 24 is changed to the flowchart shown in FIG. 33, the present disclosure is not limited to this. For example, the transmission power control processing (S109 and S111) in the flowchart shown in FIG. 24 is an example, and the transmission power control processing in the processing flow of Variation 5-2 is not limited to the example of FIG. 24. For example, S111 in FIG. 24 in the processing flow of Variation 5-2 may be replaced with S202 in FIG. 7. Alternatively, the processing of S109 and S111 in FIG. 24 may be followed by the processing of S301 and S302, as in FIG. 10. This is not a limitation, and other examples of transmission power control described above may be combined or replaced with other examples of transmission power control described above. Alternatively, the processing of S109 and S111 may not be executed. Alternatively, transmission power control different from that performed on normal terminals may be performed on terminals for specific users / services. This example of transmission power control will be described later.

[0341] Variation 5-2 described above can improve the communication quality for user terminals and / or services for which better communication quality is desired, even when a terminal for a specific user / service is assigned to a shared channel. This allows, for example, terminals of elderly people and children to communicate with better communication quality, thereby avoiding temporary suspension of terminal functions due to communication disconnections and enabling stronger monitoring of elderly people, children, and the like.

[0342] <Channel Allocation Variation 5-3> Note that, in Variation 5-2, an example was shown in which no distinction was made between types of managed terminals, but the present disclosure is not limited to this. Variation 5-3 shows an example in which managed terminals include managed LoRa terminals and managed Wi-SUN terminals. Note that Variation 5-3 is applied to a shared channel to which both LoRa terminals and Wi-SUN terminals are assigned.

[0343] Figure 34 is a diagram showing an example of channel allocation variation 5-3. The horizontal and vertical axes in Figure 34 are the same as those in Figure 23. The usage levels of unmanaged terminals on each of the four channels (channels #C1 to #C4) are also the same as those in Figure 23. However, since variation 5-3 is applied to shared channels, each of the four channels is a shared channel.

[0344] 34 also shows z+x+n managed terminals that are assigned to any of channels #C1, #C2, #C3, and #C4. Here, the z+x+n managed terminals are each a managed Wi-SUN terminal or a managed LoRa terminal.

[0345] 34, similarly to FIG. 23, channels #C1 and #C2 are classified as "channels with low non-management interference," and channel #C3 is classified as "channels with high non-management interference." Furthermore, channel #C4 is close to the upper limit value α of the usage level, and therefore may correspond to "a channel to which no non-management terminals are assigned."

[0346] Base station 100 assigns channels with small non-management interference to terminals of a specific user / service among the terminals under its management. In Fig. 34, terminals #1 to #z of a specific user / service are assigned to channels #C1 and #C2 with small non-management interference. Note that the terminals of a specific user / service may include LoRa terminals under its management and Wi-SUN terminals under its management.

[0347] Base station 100 assigns within-management Wi-SUN terminals (abbreviated as "within-management Wi-SUN" in FIG. 34) among within-management terminals to channels with small outside-management interference. In FIG. 34, within-management Wi-SUN terminals #1 to #x are assigned to channels with small outside-management interference.

[0348] Then, base station 100 sorts the LoRa terminals under management (abbreviated as "LoRa under management" in FIG. 34) in order of RSSI. As in FIG. 23, base station 100 determines to assign channels #C1 and #C2 with low non-management interference to LoRa terminals #1 to #m corresponding to relatively low RSSI, and to assign channels #C3 and #C4 with high non-management interference to LoRa terminals #m+1 to #n corresponding to relatively high RSSI. Note that here, m may be determined based on, for example, the ratio of availability of channels #C1 and #C2 to availability of channel #C3 after allocation of z terminals of a specific user / service and x Wi-SUN terminals under management.

[0349] In the above example, a terminal for a specific user / service has the highest priority, followed by a Wi-SUN terminal within management, and then a normal LoRa terminal within management has the lowest priority, but the present disclosure is not limited to this.

[0350] Variation 5-3 described above can improve the communication quality for user terminals and / or services for which better communication quality is desired, even when a terminal for a specific user / service is assigned to a shared channel. This allows, for example, terminals of elderly people and children to communicate with better communication quality, thereby avoiding temporary suspension of terminal functions due to communication interruptions and enhancing monitoring of elderly people, children, etc. Variation 5-3 can also improve the communication quality of the Wi-SUN system, which has weaker error tolerance than the LoRa system.

[0351] <Example of transmission power control for variation 5-1> Next, another example of transmission power control in the channel allocation of variation 5-1 described above will be explained. Figure 35 is a diagram showing an example of transmission power control for the channel allocation shown in Figure 30. The horizontal and vertical axes in Figure 35 are the same as those in Figure 4. Furthermore, the allocation of managed terminals to each channel is the same as the example shown in Figure 30, so explanation will be omitted.

[0352] Transmission power control for normal managed LoRa terminals (managed LoRa terminals that are not terminals of a specific user / service) assigned to shared channels and LoRa channels is similar to the third example shown in FIG.

[0353] The base station 100 performs either (i) or (ii) of transmission power control for LoRa terminals managed by a specific user / service assigned to a LoRa channel. (i) is an option of not performing first transmission power control or second transmission power control. In other words, (i) is an option of performing communication at maximum transmission power. (ii) is an option of performing second transmission power control. The base station 100 may select either (i) or (ii) based on the results of environmental monitoring. For example, the base station 100 may select (i) if the results of environmental monitoring on the LoRa channel show that non-managed interference is dominant, and may select (ii) if in-management interference is not dominant.

[0354] Next, the process flow related to the transmission power control shown in Fig. 35 will be described. Fig. 36 is an example of a flowchart related to the transmission power control shown in Fig. 35. The process flow shown in Fig. 36 is a process flow for determining transmission power control for managed LoRa terminals assigned to LoRa channels. For example, the process flow shown in Fig. 36 may be a process that replaces S111 in Fig. 31. Hereinafter, the terminal that is the target of transmission power control will be referred to as terminal z, as in the example of Fig. 31.

[0355] The base station 100 determines whether or not the terminal z is a terminal for a specific user / service (S1401).

[0356] If the terminal z is not a terminal of a specific user / service (NO in S1401), the base station 100 determines whether or not unmanaged interference is dominant in the LoRa channel allocated to the terminal z (S1402).

[0357] If the unmanaged interference is dominant (YES in S1402), the base station 100 does not perform the first transmission power control for the terminal z (first transmission power control: OFF) (S1403).

[0358] If the unmanaged interference is not dominant (NO in S1402), the base station 100 performs the first transmission power control for the terminal z (first transmission power control: ON) (S1404). Here, the base station 100 does not need to perform difference correction for each communication method in the first transmission power control in S1404.

[0359] Base station 100 performs second transmission power control on terminal z (second transmission power control: ON) (S1405). Then, the flow shown in FIG. 36 ends. As a result, base station 100 performs second transmission power control without performing first transmission power control on within-management LoRa terminals that are not a specific user / service and that are assigned to LoRa channels where unmanaged interference is dominant. Furthermore, base station 100 performs first transmission power control and second transmission power control without difference correction on within-management LoRa terminals that are not a specific user / service and that are assigned to LoRa channels where unmanaged interference is not dominant.

[0360] If the terminal z is a terminal for a specific user / service (YES in S1401), the base station 100 does not perform the first transmission power control for the terminal z (first transmission power control: OFF) (S1406).

[0361] The base station 100 does not perform the second transmission power control for the terminal z (second transmission power control: OFF) (S1407). Alternatively, the base station 100 performs the second transmission power control for the terminal z (second transmission power control: ON). Then, the flow shown in FIG. 36 ends.

[0362] In the processes of S1406 and S1407, two examples of transmission power control are shown: one in which the first transmission power control and the second transmission power control are not performed, and one in which the first transmission power control is not performed but the second transmission power control is performed. Of the two types of transmission power control, the transmission power control that base station 100 performs for terminal z may be fixed to one of them. Alternatively, these two types of transmission power control may be selected randomly. For example, the transmission power control may be determined randomly for each terminal, or a transmission power control common to terminals may be determined randomly. Alternatively, the transmission power control may be determined depending on unmanaged interference in the LoRa channel assigned to the terminal.

[0363] In the example of transmission power control in variation 5-1 described above, transmission power control is performed on terminals of a specific user / service assigned to a LoRa channel. This allows, for example, the transmission power of a terminal of a specific user / service assigned to a LoRa channel to be set higher than the transmission power of a normal terminal assigned to a LoRa channel, thereby improving the communication characteristics of LoRa terminals managed by the specific user / service. Furthermore, for example, transmission power control based on the spreading factor of the LoRa system is performed on terminals of the specific user / service, thereby further improving the communication characteristics of LoRa terminals managed by the specific user / service.

[0364] <Example of transmission power control for variation 5-2> Next, another example of transmission power control in the channel allocation of variation 5-2 described above will be described. Figure 37 is a diagram showing an example of transmission power control for the channel allocation shown in Figure 32. The horizontal and vertical axes in Figure 37 are the same as those in Figure 23. Furthermore, the allocation of managed terminals to each channel is the same as the example shown in Figure 32, so a description thereof will be omitted. Furthermore, Figure 37 shows an example in which channels #C1, #C2, #C3, and #C4 are shared channels.

[0365] 37, for example, base station 100 performs first transmission power control (first transmission power control: ON) and second transmission power control (second transmission power control: ON) for normal LoRa terminals under its management that are not LoRa terminals under its management for a specific user / service. Note that in the first transmission power control for LoRa terminals under its management that are assigned to a shared channel, the target value may be set to a relatively high value, as in the first example.

[0366] The base station 100 then performs either (i) or (ii) transmission power control for LoRa terminals managed by a specific user / service. (i) is an option of not performing first transmission power control or second transmission power control. In other words, (i) is an option of performing communication at maximum transmission power. (ii) is an option of not performing first transmission power control but performing second transmission power control. The base station 100 may select either (i) or (ii) based on the results of environmental monitoring. For example, the base station 100 may select (i) if the results of environmental monitoring on the LoRa channel indicate that unmanaged interference is dominant, and may select (ii) if unmanaged interference is not dominant.

[0367] Next, the process flow related to the transmission power control shown in Fig. 37 will be described. Fig. 38 is an example of a flowchart related to the transmission power control shown in Fig. 37. The process flow shown in Fig. 38 is a process flow for determining transmission power control for managed LoRa terminals assigned to a shared channel. For example, the process flow shown in Fig. 38 may be executed after Fig. 33. Hereinafter, the terminal that is the target of transmission power control will be referred to as terminal y, as in the example of Fig. 33.

[0368] The base station 100 determines whether or not the terminal y is a terminal for a specific user / service (S1501).

[0369] If the terminal y is not a terminal of a specific user / service (NO in S1501), the base station 100 performs the first transmission power control on the terminal y (first transmission power control: ON) (S1502).

[0370] The base station 100 performs the second transmission power control on terminal y (second transmission power control: ON) (S1503). Then, the flow shown in Fig. 38 ends. As a result, the base station 100 performs the first transmission power control and the second transmission power control on LoRa terminals under its management that are not a specific user / service.

[0371] If the terminal y is a terminal for a specific user / service (YES in S1501), the base station 100 does not perform the first transmission power control on the terminal y (first transmission power control: OFF) (S1504).

[0372] The base station 100 does not perform the second transmission power control for the terminal y (second transmission power control: OFF) (S1505). Alternatively, the base station 100 performs the second transmission power control for the terminal y (second transmission power control: ON). Then, the flow shown in FIG. 38 ends.

[0373] In the processes of S1504 and S1505, two examples of transmission power control are shown: one in which the first transmission power control and the second transmission power control are not performed, and one in which the first transmission power control is not performed but the second transmission power control is performed. Of the two types of transmission power control, the transmission power control that base station 100 performs for terminal y may be fixed to one of them. Alternatively, these two types of transmission power control may be selected randomly. For example, the transmission power control may be determined randomly for each terminal, or a transmission power control common to terminals may be determined randomly. Alternatively, the transmission power control may be determined depending on unmanaged interference of the shared channel assigned to the terminal.

[0374] According to the transmission power control example of variation 5-2 described above, transmission power control is performed on terminals of a specific user / service assigned to a shared channel. This allows, for example, the transmission power of terminals of a specific user / service assigned to a shared channel to be set higher than the transmission power of normal terminals assigned to a shared channel, thereby improving the communication characteristics of LoRa terminals managed by the specific user / service. Furthermore, for example, transmission power control based on the spreading factor of the LoRa system is performed on terminals of the specific user / service, thereby further improving the communication characteristics of LoRa terminals managed by the specific user / service.

[0375] In each of the above examples, downlink signals (e.g., feedback information) transmitted to managed LoRa terminals assigned to LoRa channels may be transmitted on the LoRa channels, and downlink signals (e.g., feedback information) transmitted to managed Wi-SUN terminals assigned to Wi-SUN channels may be transmitted on the Wi-SUN channels.

[0376] In each of the above examples, a downlink signal (for example, feedback information) to be transmitted to an in-control terminal assigned to a channel with relatively small out-of-control interference may be transmitted on that channel.

[0377] Note that a terminal of a specific user / service may always be assigned a channel that allows higher quality communication than a normal terminal. Alternatively, whether or not a terminal of a specific user / service is assigned a channel that allows higher quality communication than a normal terminal may be variably determined. For example, a terminal of a specific user / service owned by a child with a history of risky behavior may be assigned a channel that allows higher quality communication while the child is in an area where accidents are likely to occur (e.g., near a road). In this case, a channel that allows high quality communication may not be assigned to the terminal of the specific user / service while the child is in an area where accidents are unlikely to occur (e.g., inside the child's home). In other words, in this case, the terminal may be treated the same as a normal terminal. Furthermore, a terminal of a person in the mountains or at sea may be assigned a channel that allows high quality communication if the number of people in the area is less than a predetermined number. In this case, a channel that allows high quality communication may not be assigned to the terminal of a person in the area if the number of people in the area is equal to or greater than a predetermined number and / or if a rescue team or the like is present in the area.

[0378] For example, when there are many terminals of a specific user / service (e.g., a predetermined number or more), a terminal with a higher priority may be set from among the terminals of the specific user / service. For example, among the terminals of a specific user / service owned by elderly people, a terminal owned by an elderly person who is in poor health may be set as a terminal with a higher priority than the other terminals. In this case, a channel that enables high-quality communication may be preferentially assigned to a terminal with a higher priority than the other terminals. Also, in this case, a channel with relatively little unmanaged interference may be assigned to a terminal with a lower priority from among the remaining available channels.

[0379] A terminal requesting preferential allocation of a LoRa channel or a Wi-SUN channel may notify the base station (or the server via the base station) of information indicating the request (allocation request) before starting communication (for example, when the terminal is started up, when a connection is established, etc.). For example, this notification may be performed by an upper layer message. In this case, the terminal may notify detailed user information of the owner. The detailed user information may include, for example, at least one of age, family composition, and medical condition. The notification of the detailed user information may be performed only the first time, or may be performed periodically. If the notification of the detailed user information is performed only the first time, the allocation request and user ID may be notified from the second time onwards. Such notification makes it possible to prevent a terminal of a user who is not actually given priority from unfairly receiving preferential allocation, thereby preventing fraudulent use.

[0380] In the spreading factor allocation control, a relatively large spreading factor may be allocated to a terminal of a specific user / service. Here, if the number of terminals of a specific user / service is equal to or greater than a predetermined number, a relatively large spreading factor may be allocated to a terminal with a higher priority among the terminals of the specific user / service. Furthermore, whether or not to allocate a relatively large spreading factor to a terminal of a specific user / service may be variably determined. Furthermore, two or more of spreading factor allocation, channel allocation, and transmission power control may be used in combination. Furthermore, whether or not to regard a certain terminal as a terminal of a specific user / service may be selected independently in each of spreading factor allocation, channel allocation, and transmission power control. For example, a certain terminal may be regarded as a terminal of a specific user / service in channel allocation, but not in spreading factor allocation and transmission power control.

[0381] Furthermore, a terminal moving at a relatively high speed may have difficulty in tracking control compared to a terminal moving at a slower speed, resulting in a higher-than-expected RSSI. In such a case, a managed LoRa terminal moving at a relatively high speed may be assigned to a shared channel with a relatively high level of non-managed interference. In this case, a small spreading factor (e.g., SF7) may be assigned to the managed LoRa terminal moving at a relatively high speed, and a transmission power below a predetermined value may be set regardless of the RSSI.

[0382] It should be noted that the notation "··· part" in the above embodiments may be replaced with other notations such as "··· circuitry," "··· device," "··· unit," or "··· module."

[0383] Furthermore, the term "channel" in the above embodiments may be replaced with other terms such as "frequency," "frequency channel," "band," "carrier," "subcarrier," or "(frequency) resource."

[0384] The present disclosure can be realized in software, hardware, or software in conjunction with hardware.

[0385] Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0386] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0387] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

[0388] The present disclosure may be implemented in any type of apparatus, device, or system with communications capabilities (collectively referred to as communications apparatus), including, but not limited to, telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communications-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above.

[0389] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0390] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0391] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0392] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0393] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the disclosure.

[0394] Although specific examples of the present disclosure have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. [Industrial Applicability]

[0395] The present disclosure is suitable for wireless communication systems. [Explanation of symbols]

[0396] 100 base stations 101 Receiving unit 102, 108 Despreading section 103 Communication Quality Measurement Unit 104 Preamble detector 105 Interference Classification Unit 106 SF Selection Section 107 Demodulation / Decoding Unit 109 SF extraction part 110 SF allocation department 111 Allocation control unit 112 Control method selection section 113 Transmission power setting unit 114 Control signal generation unit 115 Encoding / Modulation Section 116 Transmitter

Claims

1. a receiving unit that receives a first signal transmitted by a first terminal using a spread spectrum method and a second signal transmitted by a second terminal using a method different from the spread spectrum method; a control unit that determines a channel to be assigned to the first terminal based on information on a communication quality of the first signal, and determines a channel to be assigned to the second terminal based on information on a communication quality of the second signal; Equipped with the control unit switches a transmission power control of the first terminal depending on whether the second terminal is assigned to the channel assigned to the first terminal. Base station.

2. The control unit is assigning a first channel to the first terminal when a communication quality of the first signal is equal to or higher than a first threshold, and assigning the first channel to the second terminal when a communication quality of the second signal is equal to or higher than a second threshold; The control unit determines a transmission power of the first terminal in the first channel based on a communication quality of the second signal in the first channel. The base station according to claim 1 .

3. The control unit is assigning, to the first terminal, a second channel to which the second terminal is not assigned, when a communication quality of the first signal is less than a third threshold; the control unit determines a transmission power of the first terminal according to a usage status of the second channel of a wireless device that belongs to a network different from a network to which the base station belongs. The base station according to claim 1 .

4. the control unit reduces a transmission power of the first terminal by a specified amount when an amount of interference from the wireless device in the second channel is less than a fourth threshold. The base station according to claim 3.

5. The control unit adjusts a transmission power of the first terminal in accordance with a spreading factor of the spectrum spreading method used by the first terminal. A base station according to any one of claims 2 to 4.

6. The control unit is assigning the first terminal with which communication is not successful within a certain time Tk to a third channel to which the second terminal is not assigned; A base station according to any one of claims 1 to 5.

7. The control unit is the control unit, when the first terminal assigned to the third channel succeeds in communication within the time Tk, assigns the first terminal to a fourth channel assigned to the second terminal. The base station according to claim 6.

8. The control unit adjusts a first ratio of the first terminals to be assigned to a fifth channel that is assigned to the first terminals and a specified number or more of the second terminals, and a sixth channel that is assigned to the first terminals and a specified number or less of the second terminals; The control unit adjusts a second ratio of the second terminals to be assigned to the fifth channel and a seventh channel to which the second terminals are assigned and to which the first terminals are not assigned; the control unit adjusts the first ratio and the second ratio according to usage statuses of the fifth channel, the sixth channel, and the seventh channel of a wireless device that belongs to a network different from a network to which the base station belongs. The base station according to claim 1 .

9. The control unit sets the first ratio and the second ratio independently. The base station according to claim 8.

10. When the control unit determines that a plurality of terminals including the third terminal are to be assigned to a group of channels to be assigned to a third terminal corresponding to either the first terminal or the second terminal, the control unit determines a channel to be assigned to each of the plurality of terminals from the group based on information regarding communication quality of a signal transmitted by each of the plurality of terminals. The base station according to claim 1 .

11. the control unit assigns, to a terminal transmitting a signal whose reception power at the base station is smaller than a predetermined power, a channel in which interference caused by a signal transmitted by a wireless device not under the control of the base station is smaller than a predetermined value, among the channels included in the group; The base station according to claim 10.

12. the control unit assigns a terminal for which an elapsed time from the timing of the last successful communication is greater than a predetermined value to a channel, among the channels included in the group, in which interference caused by a signal transmitted by a wireless device not under the control of the base station is less than a predetermined value. The base station according to claim 10.

13. When the plurality of terminals includes the first terminal and the second terminal, the control unit assigns the second terminal to a channel included in the group, the channel having interference caused by a signal transmitted by a wireless device not under the control of the base station that is smaller than a predetermined value. The base station according to claim 10.

14. the control unit assigns a fourth terminal, among the plurality of terminals, which is determined to have a higher priority in channel assignment than terminals not satisfying a specific condition by satisfying the specific condition, to a channel among the channels included in the group, in which interference caused by a signal transmitted by a wireless device not under the control of the base station is smaller than a predetermined value; The base station according to claim 10.

15. When the fourth terminal is included in the first terminal, the control unit assigns a transmission power of the fourth terminal to the same channel as the fourth terminal and sets the transmission power of the first terminal excluding the fourth terminal to be higher than the transmission power of the first terminal. The base station of claim 14.

16. the control unit assigns a fourth terminal, which is determined to have a higher priority in channel allocation than terminals not satisfying a specific condition by satisfying a specific condition among the first terminals, to a channel to which the second terminal is not assigned, and assigns a fifth terminal, which is determined to have a higher priority in channel allocation than terminals not satisfying the specific condition by satisfying a specific condition among the second terminals, to a channel to which the first terminal is not assigned. The base station according to claim 1 .

17. the control unit sets a transmission power of the fourth terminal higher than a transmission power of the first terminal that is assigned to the same channel as the fourth terminal and that is excluding the fourth terminal; 17. The base station of claim 16.

18. A base station comprising: receiving a first signal transmitted by a first terminal using a spread spectrum method and a second signal transmitted by a second terminal using a method different from the spread spectrum method; determining a channel to be assigned to the first terminal based on information regarding a communication quality of the first signal; determining a channel to be assigned to the second terminal based on information regarding a communication quality of the second signal; switching a transmission power control of the first terminal depending on whether the second terminal is assigned to the channel assigned to the first terminal; Control methods.

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