Base station and control method

Abstract

To provide a base station, a terminal, and a control method capable of achieving proper channel allocation in consideration of schedule related to movement of terminals.SOLUTION: A base station comprises: a reception unit that receives schedule information on a timing when a terminal goes out of a communication range from each terminal in the communication range; and a control unit that allocates terminals to each channel on the basis of the schedule information.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In communication between a base station and a terminal, for example, the base station may assign a channel to be used for wireless communication to the terminal. In this case, the terminal transmits a signal to the base station and receives a signal from the base station on the assigned channel.

[0003] Depending on the environment of the communication range covered by a base station, multiple terminals may move collectively from inside to outside the communication range or from outside to inside the communication range on a specific schedule (e.g., at a specific timing or within a specific period of time). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-172407 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is room for improvement in terms of appropriate channel allocation that takes into account the schedules of terminal movements.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a base station, a terminal, and a control method capable of performing appropriate channel allocation taking into account a schedule related to the movement of the terminal. [Means for solving the problem]

[0007] A base station according to one embodiment of the present disclosure includes a receiving unit that receives, from each terminal within a communication range, schedule information regarding the timing of leaving the communication range, and a control unit that assigns the terminal to each channel based on the schedule information.

[0008] A terminal according to one embodiment of the present disclosure includes a transmitting unit that transmits schedule information regarding the timing of going outside the communication range of a base station to the base station, and a control unit that controls data transmission using the channel allocated based on the schedule information.

[0009] In a control method according to one embodiment of the present disclosure, a base station receives schedule information from each terminal within its communication range regarding the timing of leaving the communication range, and assigns the terminal to each channel based on the schedule information.

[0010] In addition, these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0011] According to an embodiment of the present disclosure, appropriate channel allocation can be performed taking into consideration the schedule regarding the movement of terminals.

[0012] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings, in which such advantages and / or benefits are provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of which are provided to obtain one or more identical features. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 shows an example of users and communication ranges on a station platform. [Diagram 2]FIG. 2 is a diagram showing an example of channel allocation in the example shown in FIG. 1; [Diagram 3] FIG. 3 is a diagram showing an example of a state after the wireless connection of the first terminal is disconnected in the channel allocation shown in FIG. [Figure 4] FIG. 1 is a block diagram showing a configuration example of a base station according to an embodiment; [Diagram 5] FIG. 1 is a block diagram showing a configuration example of a terminal according to an embodiment; [Figure 6] FIG. 1 is a diagram showing an example of a frame configuration of schedule information transmitted by a terminal according to an embodiment; [Figure 7] FIG. 1 shows an example of channel allocation in a first example. [Figure 8] FIG. 8 is a diagram showing an example of a state after the wireless connection of the first terminal is disconnected in the channel allocation shown in FIG. [Figure 9] A flowchart showing an example of a processing flow of a base station in a first example of the present embodiment. [Figure 10] FIG. 13 is a diagram showing an example of channel allocation in the second example. [Figure 11] FIG. 11 is a diagram showing an example of a state after the wireless connection of the third terminal is disconnected in the channel allocation shown in FIG. 10. [Figure 12] A flowchart showing an example of a processing flow of a base station in a second example of the present embodiment. [Figure 13] FIG. 2 is a diagram showing a second example of a frame configuration of schedule information transmitted by a terminal according to the present embodiment. [Figure 14] FIG. 11 is a diagram showing an example of channel allocation in the third example. [Figure 15] FIG. 15 is a diagram showing an example of a state after the wireless connection of a fifth terminal is disconnected in the channel allocation shown in FIG. 14. [Figure 16] A flowchart showing an example of a processing flow of a base station in a third example of the present embodiment. [Figure 17] FIG. 13 is a diagram showing an example of channel allocation in the fourth example. [Figure 18] FIG. 18 is a diagram showing an example of a state after some wireless connections of the fifth terminal and the seventh terminal are disconnected in the channel allocation shown in FIG. 17. [Figure 19] A flowchart showing an example of a processing flow of a base station in a fourth example of the present embodiment. [Figure 20] FIG. 1 is a block diagram showing a configuration example of a base station according to an embodiment of the present invention; [Figure 21] FIG. 13 is a diagram showing an example of channel allocation in the fifth example. [Figure 22] A flowchart showing an example of a processing flow of a base station in a fifth example of the present embodiment. [Figure 23] FIG. 13 is a diagram showing an example of channel allocation in the sixth example. [Figure 24] A flowchart showing an example of a processing flow of a base station in a sixth example of the present embodiment. [Diagram 25] FIG. 13 is a diagram showing an example of channel allocation in the seventh example. [Figure 26] A flowchart showing an example of a processing flow of a base station in a seventh example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functions are denoted by the same reference numerals, and redundant description will be omitted.

[0015] <Findings that led to this disclosure> For example, on a station platform (hereinafter sometimes abbreviated to "station"), many railroad passengers (hereinafter sometimes abbreviated to "users") wait for the arrival of a railroad car (hereinafter sometimes abbreviated to "train"). The terminals owned by the users wirelessly connect to a base station and perform wireless communication using a channel assigned by the base station.

[0016] Fig. 1 is a diagram showing an example of users and communication ranges in a station. Fig. 1 shows a communication range Ar of a base station covering two platforms and two user groups (user group #1 and user group #2).

[0017] User group #1 is a group of users who plan to board train #1 traveling in the direction of arrow A. User group #2 is a group of users who plan to board train #2 traveling in the direction of arrow B.

[0018] The base station wirelessly connects to terminals owned by users of two user groups included in the communication range Ar of the base station, assigns a channel to each of the terminals, and performs wireless communication with the terminals.

[0019] When a train arrives at a station, users who are using the arriving train board the arriving train. On the other hand, users who are not using the arriving train (for example, users who are heading to a destination different from the destination of the arriving train) and users who get off the arriving train remain on the station platform. Hereinafter, users who board a train may be referred to as boarding users, and users who do not board a train may be referred to as remaining users.

[0020] For example, in Fig. 1, users in user group #1 are users boarding train #1 when train #1 arrives at the station and are staying users when train #2 arrives at the station. Users in user group #2 are users staying at the station when train #1 arrives at the station and are users boarding train #2 when train #2 arrives at the station.

[0021] The train with the boarding user departs for the next station. In this case, the boarding user's terminal goes out of the communication range of the base station as the train moves. On the other hand, the terminal of the staying user remains within the communication range of the base station. As a result, the channel assigned to the boarding user's terminal by the base station has an increasing amount of free space as the train moves, and in some cases, the channel may become free. In this case, channel assignment becomes biased, and frequency utilization efficiency may decrease.

[0022] For example, in the example of FIG. 1, if train #1 arrives at the station and departs from the station while train #2 has not yet arrived at the station, the terminals of users riding on train #1 will fall out of the communication range Ar. Meanwhile, the terminals of users in user group #2 will remain on the platform. In this case, the channels to which the terminals of users in user group #1 are assigned will see an increase in available capacity as train #1 moves, while the channels to which the terminals of users in user group #2 are assigned will not see an increase in available capacity.

[0023] Next, an example of channel allocation to the terminals of users in user group #1 and the terminals of users in user group #2 will be described. Note that, below, the terminals of users in user group #1 may be described as "first terminals," and the terminals of users in user group #2 may be described as "second terminals."

[0024] Fig. 2 is a diagram showing an example of channel allocation in the example shown in Fig. 1. The horizontal axis of Fig. 2 indicates frequency, and the vertical axis indicates the number of allocated terminals. Fig. 2 shows four channels with center frequencies f1 to f4, and terminals allocated to each channel. Hereinafter, the four channels with center frequencies f1 to f4 may be referred to as channel f1 to channel f4, respectively.

[0025] 2, the first terminals #a-#b and #c-#d, and the second terminals #A-#B and #C-#D are different terminals. The first terminals #a-#b and #c-#d are terminals owned by users in user group #1 shown in FIG. 1, and the second terminals #A-#B and #C-#D are terminals owned by users in user group #2 shown in FIG. 1.

[0026] In the example of Fig. 2, first terminals #a to #b are assigned to channel f1, and first terminals #c to #d are assigned to channel f2. Also, in the example of Fig. 2, second terminals #A to #B are assigned to channel f3, and second terminals #C to #D are assigned to channel f4.

[0027] For example, when users in user group #1 shown in Fig. 1 board train #1 that arrives at a station, and then train #1 departs from the station and moves out of communication range Ar, the wireless connections between the first terminals #a to #b and #c to #d and the base station are disconnected. When the wireless connections are disconnected, the channel resources allocated to the first terminals #a to #b and #c to #d become available resources.

[0028] FIG. 3 is a diagram showing an example of a state after the wireless connection of the first terminal is disconnected in the channel allocation shown in FIG.

[0029] For example, in the channel allocation shown in Figure 2, if the resources of the channels assigned to the first terminals #a to #b and the first terminals #c to #d become available resources, as shown in Figure 3, channel f1 and channel f2 become available channels, while channel f3 assigned to the second terminals #A to #B and channel f4 assigned to the second terminals #C to #D become congested.

[0030] That is, in the example shown in FIG. 3, even though channels f1 and f2 are free channels, channels f3 and f4 are congested, resulting in a decrease in frequency utilization efficiency.

[0031] 1 to 3, as an example, a base station that covers the premises of a station including a platform has been described, but in various environments other than the premises of a station, such as places where buses, planes, and ships arrive and depart (for example, bus stops, airports, and ports), some of the terminals present within the communication range of the base station may move out of the communication range en masse. Even in such cases, there is a possibility that the frequency utilization efficiency may decrease, as in the examples shown in Figs. 2 and 3.

[0032] In a non-limiting embodiment of the present disclosure, information regarding the movement of a terminal is acquired from the terminal, and channel allocation is performed based on the acquired information, thereby suppressing a decrease in frequency utilization efficiency.

[0033] The wireless communication system according to this embodiment has base station 100 shown in FIG. 4 and terminal 200 shown in FIG.

[0034] <Base station configuration example> 4 is a block diagram showing an example of the configuration of base station 100 according to this embodiment. Base station 100 includes receiving section 101, demodulation / decoding section 102, schedule information extraction section 103, allocation control section 104, control information generation section 105, encoding / modulation section 106, and transmission section 107.

[0035] The receiving unit 101 receives a signal transmitted by the terminal 200, and performs a predetermined receiving process on the received signal. For example, the predetermined receiving process includes a frequency conversion process (down-conversion). For example, the receiving unit 101 performs a frequency conversion process on the received signal based on the frequency of the channel assigned to the terminal 200. Information on the frequency of the channel assigned to the terminal 200 may be acquired from, for example, the allocation control unit 104. Alternatively, the receiving unit 101 may perform a frequency conversion process on the received signal including the control information based on the frequency of the predetermined channel. The receiving unit 101 outputs the received signal that has been subjected to the predetermined receiving process to the demodulation / decoding unit 102.

[0036] Demodulation / decoding section 102 performs demodulation processing and decoding processing on the received signal acquired from receiving section 101, and generates received data and / or control information. Note that the control information may include schedule information transmitted by terminal 200. Demodulation / decoding section 102 outputs the received data and / or control information to allocation control section 104. Demodulation / decoding section 102 also outputs the control information to schedule information extraction section 103.

[0037] The schedule information extraction unit 103 extracts the schedule information included in the control information, and outputs the extracted schedule information to the allocation control unit 104 .

[0038] The allocation control unit 104 performs control regarding data communication with the terminal 200. For example, the allocation control unit 104 may output received data acquired from the demodulation / decoding unit 102 to an external device (not shown). The allocation control unit 104 also outputs transmission data addressed to the terminal 200 acquired from an external device (not shown) to the encoding / modulation unit 106.

[0039] Allocation control section 104 allocates channels to terminal 200 based on control information (schedule information) received from terminal 200. Allocation control section 104 outputs allocation information indicating the channels allocated to terminal 200 to receiving section 101, transmitting section 107, and encoding / modulating section 106. An example of channel allocation will be described later.

[0040] Control information generating section 105 generates control information addressed to terminal 200 based on the allocation information acquired from allocation control section 104. Control information generating section 105 outputs the control information to encoding / modulating section .

[0041] The coding / modulation unit 106 performs coding and modulation processes on the transmission data acquired from the allocation control unit 104 to generate a transmission data signal. The coding / modulation unit 106 also performs coding and modulation processes on the control information acquired from the control information generation unit 105 to generate a transmission control signal. The coding / modulation unit 106 outputs the transmission signal (the transmission data signal and / or the transmission control signal) to the transmission unit 107.

[0042] The transmitting unit 107 performs a predetermined transmission process on the transmission signal acquired from the encoding / modulating unit 106, and transmits the transmission signal after the transmission process to the terminal 200. For example, the predetermined transmission process includes a frequency conversion process (up-conversion). For example, the transmitting unit 107 performs a frequency conversion process on the transmission data signal addressed to the terminal 200, based on the frequency of the channel assigned to the terminal 200. Allocation information on the frequency of the channel assigned to the terminal 200 may be acquired from the channel allocation unit 105, for example. Alternatively, the transmitting unit 107 may perform a frequency conversion process on the received signal including the control information, based on the frequency of the predetermined channel.

[0043] <Example of terminal configuration> 5 is a block diagram showing an example configuration of terminal 200 according to the present embodiment. Terminal 200 includes receiving section 201, demodulating / decoding section 202, schedule information generating section 203, allocation control section 204, encoding / modulating section 205, and transmitting section 206.

[0044] The receiving unit 201 receives a signal transmitted by the base station 100, and performs a predetermined receiving process on the received signal. For example, the predetermined receiving process includes a frequency conversion process (down-conversion) based on the frequency of the channel used for reception. Information on the frequency of the channel used for reception may be acquired from, for example, the allocation control unit 204. Alternatively, the receiving unit 201 may perform a frequency conversion process based on the frequency of the predetermined channel on the received signal including the control information. The receiving unit 201 outputs the received signal that has been subjected to the predetermined receiving process to the demodulation / decoding unit 202.

[0045] Demodulation / decoding section 202 performs demodulation processing and decoding processing on the received signal acquired from receiving section 201 to generate received data and / or control information. Demodulation / decoding section 202 outputs the received data or control information to allocation control section 204. Note that the control information includes information on the channel allocated to terminal 200.

[0046] The schedule information generating unit 203 acquires information about the user's schedule from the user who owns the terminal 200 via an operation unit (not shown). The schedule information generating unit 203 generates schedule information based on the information about the user's schedule. The schedule information in this embodiment may be information about the timing when the terminal 200 leaves (moves outside) the communication range of the base station 100 that is wirelessly connected to the terminal 200. The timing may indicate a time or a period (or a period). The time span indicated by the timing is not particularly limited, and may be, for example, a span between certain times. An example of the schedule information will be described later.

[0047] The allocation control unit 204 performs control regarding data communication with the base station 100. For example, the allocation control unit 204 may output received data acquired from the demodulation / decoding unit 202 to a processing unit of an upper layer (not shown). The allocation control unit 204 also outputs transmission data addressed to the base station 100 acquired from a processing unit of an upper layer (not shown) to the encoding / modulation unit 205.

[0048] Furthermore, the allocation control section 204 may generate control information including the schedule information acquired from the schedule information generating section 203. The allocation control section 204 outputs the control information to the encoding / modulating section 205.

[0049] Furthermore, the allocation control unit 204 sets a channel to be used for communication based on control information included in the received signal received from the base station 100 , and outputs information about the set channel to the transmitting unit 206 and the receiving unit 201 .

[0050] The coding / modulation unit 205 performs coding and modulation on the transmission data and / or control information acquired from the allocation control unit 204 to generate a transmission signal. The coding / modulation unit 205 outputs the transmission signal to the transmission unit 206.

[0051] The transmitting unit 206 performs a predetermined transmission process on the transmission signal obtained from the encoding / modulating unit 205, and transmits the transmission signal after the transmission process to the base station 100. For example, the predetermined transmission process includes a frequency conversion process (up-conversion) based on the frequency of the channel assigned to the terminal 200. Information on the frequency of the channel assigned to the terminal 200 may be obtained from, for example, the allocation control unit 204. Alternatively, the transmitting unit 206 may perform a frequency conversion process based on the frequency of the predetermined channel on the received signal including the control information.

[0052] <Information sent by the device> Next, an example of schedule information transmitted from terminal 200 to base station 100 will be described. In the following, information transmitted from terminal 200 present in the station illustrated in FIG. 1 to base station 100 covering the station in its communication range will be taken as an example.

[0053] For example, in an application installed in the terminal 200, a user who owns the terminal 200 inputs information, and schedule information is determined based on the input information. Information included in the schedule information may be information input in advance when registering a user in the application (for example, a user ID), or may be information input when using the application (for example, when using a station).

[0054] FIG. 6 is a diagram showing an example of a frame configuration of schedule information transmitted by a terminal according to the present embodiment.

[0055] The schedule information in the frame configuration shown in FIG. 6 includes a "user ID", "destination information", and "train attribute information".

[0056] The user ID is identification information for identifying a user who owns the terminal 200. Note that the user ID may be replaced with information for identifying the terminal (terminal ID).

[0057] The destination information is information indicating the destination of a user who owns the terminal 200. For example, the destination information may indicate the direction of a train the user will board (e.g., arrow A or arrow B (see FIG. 1)), may indicate the terminal station of the train the user will board, or may indicate the station where the user plans to get off.

[0058] The train attribute information is information indicating attributes of a train that a user boards. For example, the train attribute information may indicate the type of train. The type of train may be, for example, a local train, an express train, a rapid train, or a limited express train. The train attribute information may also be information about the train route (for example, the railway company).

[0059] The schedule information is not limited to the example in Fig. 6, and may be changed according to the communication range of the base station 100. For example, when the communication range of the base station 100 is a station where trains proceeding in one specific direction depart and arrive (for example, the starting station of a specific line), the destination information will be the same, and therefore the destination information may be omitted. Alternatively, when the communication range of the base station 100 is a station where one type of train departs and arrives (for example, a station where trains other than local trains do not stop), the train attribute information will be the same, and therefore the train attribute information may be omitted.

[0060] Furthermore, the schedule information may include identification information specific to the train that the user boards, or may include information on the departure time of the train that the user boards. Furthermore, even if the destination is the same, the transfer route of the train may be different. For example, among users departing from station S and heading to station T, there may be a user (hereinafter referred to as user #α) who travels from station S to station U by train #W, and transfers from train #W to train #X at station U to head to station T, and a user (hereinafter referred to as user #β) who travels from station S to station V by train #Y, and transfers from train #Z at station V to head to station T. In this way, when there is a difference in the transfer route, even if the destination is the same, the train to board at station S is different, so the schedule information may include transfer route information. Here, this transfer route information may be substituted with, for example, information on major stations along the way. In the above example of user #a and user #b, the schedule information of user #α may include transfer route information indicating that the intermediate station is U station, and the schedule information of user #β may include transfer route information indicating that the intermediate station is V station.

[0061] <First example> As a first example, as shown in FIG. 1, a case will be described in which base station 100 covers the platform of a station where train #1 traveling in the direction of arrow A and train #2 traveling in the direction of arrow B opposite to arrow A depart and arrive.

[0062] In this case, the destination information in the schedule information received from the terminal 200 of the user who is on train #1 differs from the destination information in the schedule information received from the terminal 200 of the user who is on train #2. The base station 100 assigns the terminal 200 to a channel based on the destination information, for example.

[0063] Fig. 7 is a diagram showing an example of channel allocation in the first example. The horizontal axis of Fig. 7 indicates frequency, and the vertical axis indicates the number of allocated terminals. Fig. 7 shows a first terminal and a second terminal allocated to each of channels f1 to f4.

[0064] In the example of Fig. 7, the number of first terminals assigned to each of channels f1 to f4 is the same. Also, the number of second terminals assigned to each of channels f1 to f4 is the same. That is, when the number of first terminals is 4N (N is an integer equal to or greater than 1), the number of first terminals #a to #b, first terminals #c to #d, first terminals #e to #f, and first terminals #g to #h is N. Similarly, when the number of second terminals is 4M (M is an integer equal to or greater than 1), the number of second terminals #A to #B, second terminals #C to #D, second terminals #E to #F, and second terminals #G to #H is M.

[0065] In the example of Fig. 7, the number of first terminals to be assigned is the same between channels, but the number of first terminals to be assigned may differ between channels. For example, when the numbers of first terminals to be assigned to channels f1 to f4 are defined as C1 to C4 (C1 to C4 are each an integer equal to or greater than 0), respectively, C1 to C4 may be the same number. Alternatively, in this case, the difference between the maximum and minimum values ​​among C1 to C4 may be equal to or less than a predetermined value. Alternatively, the standard deviation of C1 to C4 may be equal to or less than a predetermined value. Alternatively, the numerical range indicated by the values ​​of C1 to C4 may be equal to or less than a predetermined range.

[0066] For example, the base station 100 receives schedule information from each of the terminals 200, and divides the terminals 200 into groups based on the schedule information. For example, one group includes the terminals 200 (in the first example, the terminals 200 of users with the same destination) whose timing of going out of the communication range of the base station 100 is within a predetermined time. The base station 100 assigns the first terminals corresponding to the terminals 200 of users who board train #1 (for example, users with the same destination) to channels such that the number of terminals assigned to each channel is approximately uniform. The base station 100 also assigns the second terminals corresponding to the terminals of users who board train #2 (for example, users with the same destination) to channels such that the number of terminals assigned to each channel is approximately uniform. By such assignment control, the base station 100 performs channel assignment as shown in FIG. 7, for example.

[0067] Here, for example, if users of user group #1 shown in FIG. 1 board train #1 that has arrived at a station, and then train #1 departs from the station and moves outside the communication range Ar of base station 100, the wireless connections between first terminals #a-#b, first terminals #c-#d, first terminals #e-#f, and first terminals #g-#h and base station 100 are disconnected.

[0068] FIG. 8 is a diagram showing an example of a state after the wireless connection of the first terminal is disconnected in the channel allocation shown in FIG.

[0069] When the wireless connection of the first terminal is disconnected and the resource of the channel to which the first terminal is assigned becomes an available resource in the channel assignment shown in Fig. 7, the amount of available resources becomes uniform among the channels, and the amount of used resources becomes uniform among the channels, as shown in Fig. 8. In other words, by performing channel assignment as shown in Fig. 7, the degree of congestion of each channel (for example, the number of assigned terminals) can be made approximately uniform among the channels, and frequency utilization efficiency can be improved.

[0070] <Processing flow of the base station in the first example> Next, an example of the processing flow of base station 100 in the first example described above will be described. FIG. 9 is a flowchart showing an example of the processing flow of base station 100 in the first example of this embodiment. For example, the processing shown in the flowchart of FIG. 9 may be started periodically, or may be started in response to fluctuations in traffic (for example, when the number of terminals increases or decreases by more than a predetermined number). In addition, an example of allocating terminal 200 to allocatable channel #i will be shown below. Note that i represents a channel index and is an integer between 0 and K-1. K represents the number of allocatable channels and is an integer of 1 or more.

[0071] The base station 100 receives schedule information including destination information from the terminal 200 (S101).

[0072] The base station 100 determines the number of terminals that have transmitted the same destination information (S102). In the example of Fig. 7, the base station 100 determines the number of first terminals that have transmitted destination information indicating that they will use train #1, and the number of second terminals that have transmitted destination information indicating that they will use train #2. In other words, the base station 100 sets one group for the terminals 200 that have transmitted the same destination information, and determines the number of terminals in the group.

[0073] The base station 100 determines the number of terminals to be assigned to each channel based on the determined number of terminals and the number of allocatable channels (S103). For example, the base station 100 determines a first predetermined value related to the number of first terminals to be assigned to one channel and a second predetermined value related to the number of second terminals to be assigned to one channel. For example, as shown in the example of FIG. 7, when the number of first terminals is 4N, the number of second terminals is 4M, the number of channels is 4, and the first terminals and the second terminals are uniformly assigned to four channels, the first predetermined value may be 4N / 4 and the second predetermined value may be 4M / 4. However, when the number of terminals is not an integer multiple of the number of allocatable channels, the number of terminals assigned to each channel will not be completely uniform, but the difference in the number of terminals is considered to be sufficiently small, so that it is considered that there is no significant impact.

[0074] Alternatively, a predetermined value may be determined for each of the allocatable channels. For example, if the number of allocatable channels is K, the base station 100 may determine a first predetermined value and a second predetermined value for each of the K channels. That is, in this case, K first predetermined values ​​and K second predetermined values ​​are determined.

[0075] For example, when the number of first terminals is N, base station 100 may determine each of K first predetermined values ​​from among positive integers equal to or greater than ((N / K)-α) and equal to or less than ((N / K)+α). In this case, base station 100 may determine each of K first predetermined values ​​such that the sum of the K first predetermined values ​​is N.

[0076] Similarly, when the number of second terminals is M, base station 100 may determine each of K second predetermined values ​​from among any positive integer between ((M / K)-α) and ((M / K)+α). In this case, base station 100 may determine each of K second predetermined values ​​such that the sum of the K second predetermined values ​​is M.

[0077] For example, when N=8, M=13, K=4, and α=1, the base station 100 determines four first predetermined values ​​among positive integers between 1 and 3, such that the sum of the four first predetermined values ​​is 8. In this case, the base station 100 determines four second predetermined values ​​among positive integers between 9 / 4 and 17 / 4, such that the sum of the four second predetermined values ​​is 12. For example, the four second predetermined values ​​may take a combination of {3,3,3,4}. For example, the four first predetermined values ​​may take a combination of {3,3,3,3}, {1,2,2,3}, {1,1,3,3}, etc.

[0078] The above-mentioned method of setting the predetermined value is merely an example, and the present disclosure is not limited thereto. For example, the above-mentioned method of setting the predetermined value is implemented based on the number of terminals, but may be implemented based on the channel occupancy rate of each terminal instead of the number of terminals.

[0079] Alternatively, instead of determining a predetermined value representing the number of terminals to be assigned to each channel, a numerical range indicating an upper limit and a lower limit of the number of terminals to be assigned to each channel may be determined.

[0080] After S104, the base station 100 performs a process of allocating a channel to the first terminal and a process of allocating a channel to the second terminal.

[0081] The base station 100 sets the channel index i to 0 for the process of channel allocation to the first terminal (S104).

[0082] The base station 100 determines whether or not the channel allocation to the first terminal is complete (S105).

[0083] If channel allocation to the first terminal is not completed (NO in S105), that is, if there is a first terminal to which a channel has not been allocated (an unallocated first terminal), base station 100 judges whether the number of first terminals to which channel #i has been allocated is equal to or greater than a first predetermined value (S106). Note that, if the first predetermined value is determined for each channel, the first predetermined value in S106 may be the first predetermined value for channel #i.

[0084] If the number of first terminals already assigned to channel #i is equal to or greater than the first predetermined value (YES in S106), base station 100 adds 1 to the index i of the channel (S107), and the flow then proceeds to S105.

[0085] If the number of first terminals already assigned to channel #i is not equal to or greater than the first predetermined value (NO in S106), base station 100 assigns one of the unassigned first terminals to channel #i (S108). Then, the flow proceeds to S105.

[0086] When channel allocation to the first terminal is completed (YES in S105), that is, when there is no first terminal to which a channel has not been allocated (an unallocated first terminal), base station 100 sets (resets) the channel index i to 0 in order to process channel allocation to the second terminal (S109).

[0087] The base station 100 determines whether or not the channel allocation to the second terminal is complete (S110).

[0088] If channel allocation to the second terminal is not completed (NO in S110), that is, if there is a second terminal to which a channel has not been allocated (an unallocated second terminal), base station 100 judges whether the number of second terminals to which channel #i has been allocated is equal to or greater than a second predetermined value (S111). Note that, if the second predetermined value is determined for each channel, the second predetermined value in S111 may be the second predetermined value for channel #i.

[0089] If the number of second terminals already assigned to channel #i is equal to or greater than the second predetermined value (YES in S111), base station 100 adds 1 to the index i of the channel (S112), and the flow then proceeds to S110.

[0090] If the number of second terminals already assigned to channel #i is not equal to or greater than the second predetermined value (NO in S111), base station 100 assigns one of the unassigned second terminals to channel #i (S113). Then, the flow proceeds to S110.

[0091] When channel allocation to the second terminal is completed (YES in S110), that is, when there is no second terminal to which a channel has not been allocated (an unallocated second terminal), the flow ends.

[0092] Through the above-described flow, base station 100 assigns, to each channel, first terminals whose number is represented by the first predetermined value and second terminals whose number is represented by the second predetermined value.

[0093] As described above, in the first example described above, base station 100 groups terminals 200 according to the destinations of users who own terminals 200, and performs channel allocation for terminals 200 in each group so that the number of terminals assigned to each channel is uniform. With this type of allocation, even if terminals in a certain group simultaneously disconnect wireless connections, it is possible to suppress bias in the number of terminals in the channel allocation after disconnection, so that the degree of channel congestion can be made uniform between channels, and frequency utilization efficiency can be improved.

[0094] In the above-mentioned first example, two trains with opposite destinations are described as an example, but the present disclosure is not limited thereto. The present disclosure may be applied to trains with different destinations in three or more directions. In addition, in the above-mentioned first example, a terminal owned by a user who gets on the train is described as an example, but the present disclosure is not limited thereto. For example, the present disclosure may be applied to a terminal owned by a user who gets off the train. For example, in the example of FIG. 1, users who get off the train #1 may be grouped into user group #3. In this case, channels may be assigned to the terminals of users in user group #3 so that the channels are evenly distributed, similar to the first terminal and the second terminal.

[0095] <Second example> As a second example, a case will be described in which the base station 100 covers platforms at stations where two trains, which run in the same direction on the same line and stop at different stations, depart and arrive. For example, the two trains in this case correspond to a train that stops at each station on a line and a train that stops at some of the stations on the line. A train that stops at each station on a line is called, for example, a "local train." Also, a train that stops at some of the stations on a line is called an "express train" below.

[0096] In this case, the destination information in the schedule information received from the terminal 200 of the user who is riding on a local train may be the same as the destination information in the schedule information received from the terminal 200 of the user who is riding on an express train. However, as described above, the schedule information received by the base station 100 includes train attribute information. For example, the train attribute information indicates whether the user who owns the terminal 200 uses a local train or an express train. In the second example, the base station 100 assigns the terminal 200 to a channel based on the destination information and attribute information included in the information received from each terminal 200.

[0097] Hereinafter, the terminal 200 owned by a user who uses a local train will be referred to as a third terminal, and the terminal 200 owned by a user who uses an express train will be referred to as a fourth terminal.

[0098] Fig. 10 is a diagram showing an example of channel allocation in the second example. The horizontal axis of Fig. 10 indicates frequency, and the vertical axis indicates the number of allocated terminals. Fig. 10 shows a third terminal and a fourth terminal allocated to channels f1 to f4, respectively.

[0099] In the example of Fig. 10, the number of third terminals assigned to channels f1, f2, f3, and f4 is the same number. Also, the number of fourth terminals assigned to channels f1, f2, f3, and f4 is the same number. That is, when the number of third terminals is 4N (N is an integer of 1 or more), the number of third terminals #a to #b, third terminals #c to #d, third terminals #e to #f, and third terminals #g to #h is N. Similarly, when the number of fourth terminals is 4M (M is an integer of 1 or more), the number of fourth terminals #A to #B, fourth terminals #C to #D, fourth terminals #E to #F, and fourth terminals #G to #H is M.

[0100] For example, the base station 100 receives schedule information from each of the terminals 200, and divides the terminals 200 into groups based on the schedule information. For example, one group includes the terminals 200 (terminals 200 of users with the same attribute in the second example) whose timing of going out of the communication range of the base station 100 is within a predetermined time. The base station 100 assigns channels to a third terminal corresponding to the terminals 200 of users (for example, users with the same attribute) who board a local train, so that the number of channels assigned to each channel is uniform. The base station 100 also assigns channels to a fourth terminal corresponding to the terminals 200 of users (for example, users with the same attribute) who board an express train, so that the number of channels assigned to each channel is uniform. By such assignment control, the base station 100 performs channel assignment as shown in FIG. 10, for example.

[0101] Here, for example, if a user boards a local train that arrives at a station and then the local train departs from the station and moves outside the communication range of base station 100, the wireless connection between third terminals #a to #b, third terminals #c to #d, third terminals #e to #f, and third terminals #g to #h and base station 100 is disconnected.

[0102] FIG. 11 is a diagram showing an example of a state after the wireless connection of the third terminal is disconnected in the channel allocation shown in FIG.

[0103] When the wireless connection of the third terminal is disconnected and the resource of the channel to which the third terminal is assigned becomes an available resource in the channel assignment shown in Fig. 10, the amount of available resources becomes uniform among the channels, and the amount of used resources becomes uniform among the channels, as shown in Fig. 11. In other words, by performing channel assignment as shown in Fig. 10, the degree of congestion of each channel (for example, the number of assigned terminals) can be made approximately uniform among the channels, and frequency utilization efficiency can be improved.

[0104] <Processing flow of base station in second example> Next, an example of the processing flow of the base station 100 in the above-mentioned second example will be described. Fig. 12 is a flowchart showing an example of the processing flow of the base station 100 in the second example of the present embodiment. In Fig. 12, the same processes as those in Fig. 9 are denoted by the same reference numerals, and the description thereof may be omitted. For example, the processing shown in the flowchart in Fig. 12 may be started periodically.

[0105] The base station 100 receives schedule information including train attribute information from the terminal 200 (S201).

[0106] The base station 100 determines the number of terminals that have transmitted the same train attribute information (S202). In the example of Fig. 10, the base station 100 determines the number of third terminals that have transmitted train attribute information indicating that they will use a local train, and the number of fourth terminals that have transmitted train attribute information indicating that they will use an express train. In other words, the base station 100 sets one group for the terminals 200 that have transmitted the same train attribute information, and determines the number of terminals in the group.

[0107] The base station 100 determines the number of terminals to be assigned to each channel based on the determined number of terminals and the number of allocatable channels (S203). Here, the predetermined value regarding the number of third terminals to be assigned to one channel is described as a third predetermined value, and the predetermined value regarding the number of fourth terminals to be assigned to one channel is described as a fourth predetermined value. The method of determining the predetermined value may be the same as the example shown in S103 of FIG. 9.

[0108] After S204, the base station 100 performs channel allocation processing for the third terminal and channel allocation processing for the fourth terminal. Note that the channel allocation processing for the third terminal and the channel allocation processing for the fourth terminal are similar to the channel allocation processing for the first terminal and the channel allocation processing for the second terminal in Fig. 9, respectively, and therefore description thereof will be omitted.

[0109] Through the above-described flow, base station 100 assigns, to each channel, third terminals whose number is represented by the third predetermined value and fourth terminals whose number is represented by the fourth predetermined value.

[0110] As described above, in the second example described above, the base station 100 groups the terminals 200 according to the attributes (types) of the trains used by the users who own the terminals 200, and performs channel allocation for the terminals 200 in each group so that the number of terminals assigned to each channel is uniform. With this type of allocation, even if the terminals in a certain group simultaneously disconnect wireless connections, it is possible to suppress bias in the number of terminals in the channel allocation after disconnection, so that the degree of channel congestion can be made uniform among the channels, and frequency utilization efficiency can be improved.

[0111] In the above-mentioned second example, two types of train attributes are described as an example, but the present disclosure is not limited thereto. The present disclosure may be applied to a case where there are three or more types of train attributes (for example, a local train, an express train, and a limited express train, etc.). In addition, in the above-mentioned second example, a user who gets on a train is described as an example, but the present disclosure is not limited thereto. For example, the present disclosure may be applied to a terminal owned by a user who gets off a train. For example, in the example of FIG. 1, a user who gets off train #1 may be grouped into user group #3. In this case, a channel may be assigned to the terminal of a user in user group #3 so that the channels are evenly distributed, similar to the first terminal and the second terminal.

[0112] <Third Example> For example, among users using a train, a user who desires to sit in a seat may not board a crowded train, but may board a later train that is not crowded. In the third example, an example is described in which a channel is assigned to the terminal 200 based on the contents of a user's desire. In the following, an example is described in which a user desires to use a seat when boarding a train.

[0113] Fig. 13 is a diagram showing a second example of a frame configuration of schedule information transmitted by a terminal according to the present embodiment. Note that in Fig. 13, description of the same configuration as in Fig. 6 may be omitted.

[0114] The schedule information in the frame configuration shown in Fig. 13 includes a "user ID", a "destination information", a "train attribute information", and a "request information". Note that the "user ID", the "destination information", and the "train attribute information" are the same as those in the example of the frame configuration shown in Fig. 6, and therefore the explanation thereof will be omitted.

[0115] The request information indicates, for example, whether or not the user requests to sit in a seat on the train that the user is boarding, which is indicated by the destination information and the train attribute information. For example, the request information may indicate, in one bit, whether or not the user requests to sit in a seat. Alternatively, if the user requests to sit in a seat, the request information may be included in the schedule information, and if the user does not request to sit in a seat, the request information may not be included in the schedule information.

[0116] The user inputs information indicating whether or not he / she desires a seat, in addition to information on the destination and the train to be used, via the terminal 200. The terminal 200 generates schedule information based on the input information and transmits it to the base station 100.

[0117] For example, the base station 100 divides (groups) the terminals 200 into a group of terminals 200 of users who desire to sit in seats and a group of terminals 200 of users who do not desire to sit in seats, based on the desire information included in the schedule information received from each terminal. Hereinafter, the terminals 200 of users who do not desire to sit in seats are described as the fifth terminals, and the terminals of users who desire to sit in seats are described as the sixth terminals.

[0118] Fig. 14 is a diagram showing an example of channel allocation in the third example. The horizontal axis of Fig. 14 indicates frequency, and the vertical axis indicates the number of allocated terminals. Fig. 14 shows a fifth terminal and a sixth terminal that are allocated to channels f1 to f4, respectively.

[0119] In the example of Fig. 14, the number of fifth terminals assigned to channels f1, f2, f3, and f4 is the same number. Also, the number of sixth terminals assigned to channels f1, f2, f3, and f4 is the same number. That is, when the number of fifth terminals is 4N (N is an integer of 1 or more), the number of fifth terminals #a to #b, fifth terminals #c to #d, fifth terminals #e to #f, and fifth terminals #g to #h is N. Similarly, when the number of sixth terminals is 4M (M is an integer of 1 or more), the number of sixth terminals #A to #B, sixth terminals #C to #D, sixth terminals #E to #F, and sixth terminals #G to #H is M.

[0120] For example, the base station 100 receives schedule information from each of the terminals 200, and divides the terminals 200 into groups based on the schedule information. For example, one group includes the terminals 200 that will go out of the communication range of the base station 100 within a predetermined time (in the third example, the terminals 200 of users with the same desire). The base station 100 then assigns channels to the fifth terminal corresponding to the terminal 200 of the user who does not desire to sit in a seat, so that the number of channels assigned to each channel is uniform. The base station 100 also assigns channels to the sixth terminal corresponding to the terminal 200 of the user who desires to sit in a seat, so that the number of channels assigned to each channel is uniform. By such assignment control, the base station 100 performs channel assignment as shown in FIG. 14, for example.

[0121] Here, for example, if a user who does not wish to sit in a seat boards a train that has arrived at a station, and then the train departs from the station and moves outside the communication range of base station 100, the wireless connections between fifth terminals #a-#b, fifth terminals #c-#d, fifth terminals #e-#f, and fifth terminals #g-#h and base station 100 are disconnected.

[0122] FIG. 15 is a diagram showing an example of a state after the wireless connection of the fifth terminal is disconnected in the channel allocation shown in FIG.

[0123] When the wireless connection of the fifth terminal is disconnected and the resource of the channel to which the fifth terminal is assigned becomes an available resource in the channel assignment shown in Fig. 14, the amount of available resources becomes uniform among the channels, and the amount of used resources becomes uniform among the channels, as shown in Fig. 15. In other words, by performing channel assignment as shown in Fig. 14, the degree of congestion of each channel (for example, the number of assigned terminals) can be made almost uniform among the channels, and frequency utilization efficiency can be improved.

[0124] <Processing flow of base station in the third example> Next, an example of the processing flow of the base station 100 in the above-mentioned third example will be described. Fig. 16 is a flowchart showing an example of the processing flow of the base station 100 in the third example of the present embodiment. In Fig. 16, the same processes as those in Figs. 9 and 12 are given the same reference numerals, and the description thereof may be omitted. For example, the processing shown in the flowchart in Fig. 16 may be started periodically.

[0125] The base station 100 receives schedule information including request information from the terminal 200 (S301).

[0126] The base station 100 divides the terminals into groups based on the request information and determines the number of terminals in each group (S302). In the example of Fig. 14, the base station 100 determines the number of fifth terminals that have transmitted request information indicating that they do not request to sit in a seat, and the number of sixth terminals that have transmitted request information indicating that they request to sit in a seat.

[0127] The base station 100 determines the number of terminals to be assigned to each channel based on the determined number of terminals and the number of allocatable channels (S303). Here, the predetermined value for the number of fifth terminals to be assigned to one channel is described as a fifth predetermined value, and the predetermined value for the number of sixth terminals to be assigned to one channel is described as a sixth predetermined value. The method of determining the predetermined value may be the same as the example shown in S103 of FIG. 9.

[0128] After S304, the base station 100 performs channel allocation processing for the fifth terminal and channel allocation processing for the sixth terminal. Note that the channel allocation processing for the fifth terminal and the channel allocation processing for the sixth terminal are similar to the channel allocation processing for the first terminal and the channel allocation processing for the second terminal in FIG. 9, respectively, and therefore description thereof will be omitted.

[0129] Through the above-described flow, base station 100 assigns, to each channel, fifth terminals whose number is represented by the fifth predetermined value and sixth terminals whose number is represented by the sixth predetermined value.

[0130] As described above, in the above-mentioned third example, base station 100 groups terminals 200 based on whether or not users who own terminals 200 request seats, and performs channel allocation for terminals 200 in each group so that the number of terminals assigned to each channel is uniform. With this kind of allocation, even if terminals in a certain group simultaneously disconnect wireless connections, it is possible to suppress bias in the number of terminals in the channel allocation after disconnection, so that the degree of channel congestion can be made uniform between channels, and frequency utilization efficiency can be improved.

[0131] In the above-mentioned third example, the request information indicating whether or not to sit in a seat is used as an example, but the present disclosure is not limited thereto. The request information may be used to notify a request other than to sit in a seat. In this case, the base station 100 may group the terminals based on the notified request, and assign a channel to each group.

[0132] Here, the present disclosure is applicable not only to whether or not a user desires to sit in a seat, but also to a case where the user desires that the seat next to the seat where the user plans to sit be vacant. In this case, additional information for requesting that the seat next to the seat be vacant may be added to the seat desire information. For example, the additional information is represented by 1 bit. For example, if the user desires that the seat next to the user be vacant, the 1 bit of additional information is set to "1", and if not, the 1 bit of additional information is set to "0".

[0133] The present disclosure is also applicable to cases where multiple passengers wish to reserve seats together. In this case, seat number information indicating the number of seats that are desired to be reserved together may be added to the seat request information. For example, the seat number information is represented by multiple bits (e.g., 2 bits). For example, the seat number information is set to "1" if the user wishes to sit together with one other person or two other people, set to "2" if the user wishes to sit together with three people, and set to "3" if the user wishes to sit together with four people.

[0134] Furthermore, the present disclosure is also applicable to cases where a user wishes to specify a vehicle in which a seat is to be reserved. In this case, vehicle information indicating the vehicle in which a seat is to be reserved may be added to the seat request information. For example, the vehicle information is represented by multiple bits (e.g., 3 bits). For example, the vehicle information is set to "0" if the user wishes to reserve a seat in the first vehicle, set to "3" if the user wishes to reserve a seat in the fourth vehicle from the front, and set to "7" if the user wishes to reserve a seat in the eighth vehicle from the front.

[0135] <Fourth Example> In each of the above examples, each of terminals 200 transmits schedule information to base station 100, and base station 100 performs channel allocation based on the schedule information of each of terminals 200. On the other hand, there may be terminals 200 that do not transmit schedule information.

[0136] For example, a user can input a destination or the like via an application installed in terminal 200, and terminal 200 can transmit schedule information to base station 100 based on the information input by the user. On the other hand, if the application is not installed in terminal 200, terminal 200 cannot transmit schedule information to base station 100. Also, there are cases where a user does not transmit schedule information via terminal 200, taking into consideration the time spent at a station, etc.

[0137] In the fourth example, a channel allocation will be described in the case where there is a terminal 200 that does not transmit schedule information. Hereinafter, the terminal 200 that does not transmit schedule information will be referred to as the seventh terminal.

[0138] As a fourth example, channel allocation will be described for the case where there exists a terminal 200 that does not transmit schedule information in the above third example. That is, an example will be described in which there exists a fifth terminal corresponding to the terminal 200 of a user who does not wish to sit in a seat, a sixth terminal corresponding to the terminal 200 of a user who wishes to sit in a seat, and a seventh terminal corresponding to the terminal 200 that does not transmit schedule information.

[0139] Fig. 17 is a diagram showing an example of channel allocation in the fourth example. The horizontal axis of Fig. 17 indicates frequency, and the vertical axis indicates the number of allocated terminals. Fig. 17 shows a fifth terminal, a sixth terminal, and a seventh terminal that are allocated to channels f1 to f4, respectively.

[0140] In the example of FIG. 17, the number of fifth terminals assigned to channels f1, f2, f3, and f4 is almost the same number. The number of sixth terminals assigned to channels f1, f2, f3, and f4 is almost the same number. The number of seventh terminals assigned to channels f1, f2, f3, and f4 is almost the same number. That is, when the number of fifth terminals is 4N (N is an integer of 1 or more), the number of fifth terminals #a to #b, fifth terminals #c to #d, fifth terminals #e to #f, and fifth terminals #g to #h is N. Similarly, when the number of sixth terminals is 4M (M is an integer of 1 or more), the number of sixth terminals #A to #B, sixth terminals #C to #D, sixth terminals #E to #F, and sixth terminals #G to #H is M. Similarly, when the number of seventh terminals is 4L (L is an integer equal to or greater than 1), the number of seventh terminals #p to #q, seventh terminals #r to #s, seventh terminals #t to #u, and seventh terminals #v to #w is L, respectively.

[0141] For example, the base station 100 receives schedule information from each of the terminals 200, and divides the terminals 200 into groups based on the schedule information. Here, in the fourth example, the base station 100 divides the terminals 200 that are wirelessly connected to the base station 100 (for example, that have established a wireless link) and that do not transmit schedule information into a group separate from the terminals 200 that have transmitted the schedule information. For example, the group of the terminals 200 that do not transmit schedule information may be described as a group of unreported users.

[0142] Then, base station 100 assigns channels to a fifth terminal corresponding to terminal 200 of a user who does not wish to sit in a seat, so that the number of channels assigned to each channel is uniform. Also, base station 100 assigns channels to a sixth terminal corresponding to terminal 200 of a user who wishes to sit in a seat, so that the number of channels assigned to each channel is uniform. Also, base station 100 assigns channels to a seventh terminal corresponding to terminal 200 that does not transmit schedule information, so that the number of channels assigned to each channel is uniform. By such assignment control, base station 100 performs channel assignment as shown in FIG. 17, for example.

[0143] Here, for example, if a user who does not wish to sit in a seat gets on a train that has arrived at a station, and then the train departs from the station and moves out of the communication range of base station 100, the wireless connections between fifth terminals #a-#b, fifth terminals #c-#d, fifth terminals #e-#f, and fifth terminals #g-#h and base station 100 are disconnected. Also, there is a possibility that some of the users who own terminals 200 that do not transmit schedule information will get on this train.

[0144] FIG. 18 is a diagram showing an example of a state after some wireless connections of the fifth terminal and the seventh terminal are disconnected in the channel allocation shown in FIG.

[0145] When the wireless connection of the fifth terminal is disconnected, and in the channel allocation shown in Fig. 17, the resources of the channel allocated to the fifth terminal become free resources and some of the resources of the channel allocated to the seventh terminal become free resources, it is possible to reduce the probability that the amount of free resources becomes uneven in each channel, as shown in Fig. 18. In other words, by performing channel allocation as shown in Fig. 17, it is possible to reduce the probability that the degree of congestion in each channel (for example, the number of allocated terminals) becomes uneven, and it is possible to improve frequency utilization efficiency.

[0146] <Processing flow of the base station in the fourth example> Next, an example of the processing flow of the base station 100 in the above-mentioned fourth example will be described. Fig. 19 is a flowchart showing an example of the processing flow of the base station 100 in the fourth example of the present embodiment. In Fig. 19, the same processes as those in Figs. 9, 12, and 16 are given the same reference numerals, and the description may be omitted. For example, the processing shown in the flowchart in Fig. 19 may be started periodically.

[0147] The base station 100 receives schedule information including request information from the terminal 200 (S401). Note that here, the base station 100 does not receive schedule information from some of the terminals 200 under the control of the base station 100.

[0148] The base station 100 divides the terminals into groups based on the request information, and determines the number of terminals in each group (S402). In the example of Fig. 19, the base station 100 determines the number of fifth terminals that have transmitted request information indicating that they do not request to sit in a seat, and the number of sixth terminals that have transmitted request information indicating that they request to sit in a seat. The base station 100 also determines the number of seventh terminals that do not receive schedule information among the terminals 200 that are wirelessly connected.

[0149] The base station 100 determines the number of terminals to be assigned to each channel based on the determined number of terminals and the number of allocatable channels (S403). Here, the predetermined value for the number of fifth terminals to be assigned to one channel is written as the fifth predetermined value, the predetermined value for the number of sixth terminals to be assigned to one channel is written as the sixth predetermined value, and the predetermined value for the number of seventh terminals to be assigned to one channel is written as the seventh predetermined value. Note that the method of determining the predetermined values ​​may be the same as the example shown in S103 of FIG. 9.

[0150] In S304 to S313, similarly to the example shown in FIG. 16, base station 100 performs the process of channel allocation to the fifth terminal and the process of channel allocation to the sixth terminal.

[0151] Next, when channel allocation to the sixth terminal is completed (YES in S310), that is, when there is no sixth terminal to which a channel has not been assigned (an unassigned sixth terminal), base station 100 sets (resets) the channel index i to 0 in order to process channel allocation to the seventh terminal (S404).

[0152] In S405 to S408, base station 100 performs a process of channel allocation to a seventh terminal. Note that the process of channel allocation to a seventh terminal is similar to the process of channel allocation to a first terminal and the process of channel allocation to a second terminal in FIG. 9, and therefore a description thereof will be omitted.

[0153] When the channel allocation to the seventh terminal is completed (YES in S405), that is, when there is no seventh terminal to which a channel has not been allocated (an unallocated seventh terminal), the flow ends.

[0154] Through the flow described above, base station 100 assigns to each channel a number of fifth terminals represented by a fifth predetermined value, a number of sixth terminals represented by a sixth predetermined value, and a number of seventh terminals represented by a seventh predetermined value.

[0155] As described above, in the fourth example, the base station 100 groups the terminals 200 based on whether the users who own the terminals 200 request seats, and performs channel allocation for the terminals 200 in each group so that the number of terminals assigned to each channel is uniform. The base station 100 further groups the terminals 200 that do not transmit schedule information into another group, and performs channel allocation for the terminals 200 that do not transmit schedule information so that the number of terminals assigned to each channel is uniform. With this kind of allocation, even if there is a terminal 200 that does not transmit schedule information, it is possible to reduce the probability that the amount of free resources becomes uneven in each channel, and improve frequency utilization efficiency.

[0156] In the above-mentioned fourth example, channel allocation in the case where terminal 200 that does not transmit schedule information exists in the third example has been described, but the present disclosure is not limited thereto. For example, even if terminal 200 that does not transmit schedule information exists in the first or second example, channel allocation similar to that in the above-mentioned fourth example may be performed.

[0157] In addition, the channel allocations shown in the first to fourth examples may be appropriately combined. For example, in a combination of the first, second, and fourth examples, the directions are different from each other, and terminals 200 that do not transmit schedule information are considered on the platform of a station where an express train and a local train stop. In this case, for example, the terminals 100 may be divided into five groups: terminals of users who board an express train moving in direction A, terminals of users who board a local train moving in direction A, terminals of users who board an express train moving in direction B, terminals of users who board a local train moving in direction B, and terminals that do not transmit schedule information. Then, the base station 100 may allocate the number of terminals to each channel for each group equally among the channels.

[0158] <Fifth Example> In the fifth example, an example will be described in which interference occurring in a channel to be allocated is measured and the measurement results are classified to more appropriately allocate channels to terminal 200. First, the configuration of a base station in the fifth example will be described.

[0159] <Base station configuration> Fig. 20 is a block diagram showing a configuration example of base station 300 according to this embodiment. In Fig. 20, the same components as those in Fig. 4 are given the same reference numerals, and the description thereof will be omitted. In base station 300 shown in Fig. 20, communication quality measurement unit 301, preamble detection unit 302, and interference classification unit 303 are added to base station 100 shown in Fig. 4, and allocation control unit 104 is changed to allocation control unit 304.

[0160] The communication quality measurement unit 301 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, Received Signal Strength Indicator (RSSI)). The communication quality measurement unit 301 outputs the communication quality information to the allocation control unit 304.

[0161] The preamble detection unit 302 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 302 determines the type of preamble included in the received signal.

[0162] For example, the preamble detection unit 302 calculates the correlation between the received signal and a preamble used in the communication method used by the terminal 200. When a peak equal to or greater than a predetermined value occurs in the calculated correlation, the preamble detection unit 302 determines that the received signal contains a preamble used in the communication method used by the terminal 200.

[0163] The preamble detection unit 302 detects the preamble regardless of whether the source of the received signal is included in the network (NW) to which the base station 300 belongs. In other words, the preamble detection unit 302 may determine the type of preamble included in a signal transmitted by a wireless device that is not included in the NW to which the base station 300 belongs.

[0164] In addition, if the correlation between the preamble used in the communication method used by terminal 200 and the received signal does not result in a peak equal to or greater than a predetermined value, preamble detection unit 302 determines that the sender of the received signal is not using the communication method used by terminal 200.

[0165] The preamble detection unit 302 outputs information indicating whether or not the received signal includes a preamble to the interference classification unit 303. In addition, the preamble detection unit 302 outputs the received signal acquired from the receiving unit 101 to the interference classification unit 303.

[0166] The interference classification unit 303 classifies, for example, the interference in each channel. For example, the interference classification unit 303 performs classification by monitoring a received signal in one channel for a predetermined time. For example, the interference classification unit 303 may determine differences in the transmission sources of the received signals within the predetermined time. The interference classification unit 303 calculates the ratio of the time of the received signal for each transmission source to the predetermined time, and classifies the interference in each channel.

[0167] For example, the interference classification unit 303 acquires a signal transmitted by the terminal 200 under the control of the base station 300 and a signal transmitted by a wireless device not under the control of the base station 300 via the receiver 101. Then, the interference classification unit 303 classifies the interference caused by the received signal based on the length of the acquired received signal, the power of the received signal, information on the preamble of the received signal, and information on the transmission source included in the received signal.

[0168] In the following, a wireless device that belongs to a network other than the network to which base station 300 belongs is described as an "unmanaged terminal", and interference caused by a signal transmitted by an "unmanaged terminal" is described as "unmanaged interference". In the following, a terminal 200 that belongs to the network to which base station 300 belongs and is subordinate to base station 300 is described as an "in-management terminal", and interference caused by a signal transmitted by an "in-management terminal" may be described as "in-management interference".

[0169] For example, when the preamble of the received signal is not detected as a result of preamble detection, the interference classification unit 303 determines that the received signal is a signal transmitted by a non-managed terminal. Then, the interference classification unit 303 determines that the signal transmitted by the non-managed terminal corresponds to non-managed interference.

[0170] Furthermore, when the received signal contains identification information of the terminal 200 under the control of the base station 300 as a result of demodulating and decoding the received signal, the interference classification unit 303 determines that the received signal is a signal transmitted by an in-management terminal. Then, the base station 300 determines that the signal transmitted by the in-management terminal corresponds to in-management interference.

[0171] The interference classification unit 303 performs the above-mentioned classification of interference in each of the channels that the base station 300 can allocate to the terminal 200, and outputs information indicating the classification result to the allocation control unit 304. The classification result includes at least the amount of unmanaged interference in each channel. Note that the amount of interference may be represented, for example, by the number of unmanaged terminals, by the channel occupancy rate, by the transmission probability, or by the transmission power.

[0172] The allocation control unit 304 performs control regarding data communication with the terminal 200. For example, the allocation control unit 304 may output received data acquired from the demodulation / decoding unit 102 to an external device (not shown). The allocation control unit 304 also outputs transmission data addressed to the terminal 200 acquired from an external device (not shown) to the encoding / modulation unit 106.

[0173] Allocation control unit 304 allocates channels to terminal 200 based on control information (schedule information) received from terminal 200 and classification results acquired from interference classification unit 303. Allocation control unit 304 outputs allocation information indicating the channels allocated to terminal 200 to receiving unit 101, transmitting unit 107, and encoding / modulating unit 106. An example of channel allocation will be described later.

[0174] As described above, the base station 300 classifies the interference in each of the channels and assigns channels based on the classification results and the scheduling information.

[0175] Hereinafter, as a fifth example, an example of channel allocation based on the magnitude of non-management interference and the station stay time of a user who owns terminal 200 will be described. In the fifth example, base station 300 assigns terminal 200 whose station stay time is relatively short to a channel with relatively large non-management interference, and assigns terminal 200 whose station stay time is relatively long to a channel with relatively small non-management interference. In other words, base station 300 sets a priority order to terminal 200 based on the station stay time, and assigns a channel with relatively many free resources (e.g., small non-management interference) to terminal 200 with high priority (e.g., relatively long station stay time).

[0176] There is no limitation on the method of acquiring information on the station stay time of the user who owns the terminal 200. For example, the user who owns the terminal 200 may input the station stay time into the terminal 200, and the terminal 200 may transmit the input information to the base station 300. For example, the input information on the stay time may be included in the schedule information.

[0177] Also, for example, the user base station 300 identifies a train that the user who owns the terminal will board based on schedule information received from each of the terminals 200, and identifies the arrival time (or departure time) of the identified train based on station timetable information. Then, the base station 300 may estimate the user's stay time at the station based on the identified arrival time (or departure time).

[0178] Fig. 21 is a diagram showing an example of channel allocation in the fifth example. The horizontal axis of Fig. 21 indicates frequency, and the vertical axis indicates the transmission probability of the assigned within-management terminal. Fig. 21 shows within-management terminals assigned to each of channels f1 to f4. Fig. 21 also shows n within-management terminals assigned to any of channels f1 to f4. The transmission probability shown on the vertical axis is defined based on, for example, the number of terminals. For example, the greater the number of assigned terminals, the higher the transmission probability.

[0179] In FIG. 21, there is no non-management interference (or it is extremely small) in channels f1 and f2. In addition, non-management interference exists in channel f3, and non-management interference exists in channel f4 that is larger than that of channel f3. Note that channels f1 and f2 are classified as "channels with small non-management interference", and channel f3 is classified as "channels with large non-management interference". In addition, since channel f4 is close to the upper limit value α of the transmission probability, it may correspond to "a channel to which an in-management terminal is not assigned".

[0180] The "channel with small 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 vacancy". The "channel with large non-management interference" may correspond to a "channel with a high occupancy rate of non-management interference" or a "channel with a little vacancy". The "channel to which the in-management terminal is not assigned" may correspond to a "channel with no vacancy". For example, the "channel with small non-management interference" and the "channel with large 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 large non-management interference may be classified as "channels with large non-management interference" and the remaining channels may be classified as "channels with small non-management interference". This classification may be performed by the base station 300.

[0181] In the example of FIG. 21, n managed terminals are arranged in order of the length of stay time at the station (time until the train to be boarded arrives). Among the n managed terminals, the user of managed terminal #1 has the longest stay time at the station, and the user of managed terminal #n has the shortest stay time at the station. In the example of FIG. 21, the n managed terminals are divided into a group of m terminals consisting of managed terminals #1 to #m of users with relatively long stay times, and a group of n-m terminals consisting of managed terminals #m+1 to #n of users with relatively short stay times. Here, m is an integer between 1 and n. For example, m may be determined based on the ratio of the availability of channels f1 and f2 to the availability of channel f3.

[0182] Base station 300 decides to assign in-management terminals #1 to #m of users with relatively long stay times to channels f1 and f2 with little non-management interference, and decides to assign in-management terminals #m+1 to #n of users with relatively short stay times to channel f3 with strong non-management interference.

[0183] The base station 300 further groups the managed terminals determined to be assigned to channels f1 and f2, and assigns a channel to each group. For example, the base station 300 groups the managed terminals of users who board trains moving in direction A (hereinafter, first managed terminals) and the managed terminals of users who board trains moving in direction B opposite to direction A (hereinafter, second managed terminals) based on the schedule information transmitted by each managed terminal. Then, the base station 300 assigns the first managed terminals to channels such that the number of the first managed terminals assigned to channel f1 is the same as the number of the first managed terminals assigned to channel f2 (or the difference is within a certain range). The base station 300 also assigns the second managed terminals to channels such that the number of the second managed terminals assigned to channel f1 is the same as the number of the second managed terminals assigned to channel f2 (or the difference is within a certain range).

[0184] <Processing flow of the base station in the fifth example> Next, an example of the processing flow of the base station 300 in the above-mentioned fifth example will be described. Fig. 22 is a flowchart showing an example of the processing flow of the base station 300 in the fifth example of the present embodiment. For example, the processing shown in the flowchart of Fig. 22 may be started periodically.

[0185] The base station 300 receives schedule information including destination information from the terminal 200 (S501).

[0186] Base station 300 measures interference on channels that can be assigned to terminal 200, and classifies the measured interference (S502).

[0187] Based on the magnitude of the unmanaged interference, the base station 300 classifies the allocatable channels into channels with large unmanaged interference and channels with small unmanaged interference (S503).

[0188] The base station 300 determines whether or not the decision of the channels to be assigned to each of the terminals 200 has been completed (S504).

[0189] If the channel determination has not been completed (NO at S504), that is, if there is a terminal 200 (hereinafter referred to as "terminal z") for which the assigned channel has not been determined, base station 300 executes the determination process from S505 onwards for terminal z.

[0190] The base station 300 determines whether the stay time of the user who owns the terminal z at the station (for example, the difference between the arrival time of the train that the user is taking and the current time) is less than a predetermined time (S505).

[0191] If the residence time is less than the predetermined time (YES in S505), the base station 300 determines to assign the terminal z to a channel with large unmanaged interference (S506), and the flow proceeds to S504.

[0192] If the residence time is not less than the predetermined time (NO in S505), the base station 300 determines to assign the terminal z to a channel with small unmanaged interference (S507), and the flow proceeds to S504.

[0193] When the channel determination is completed (YES in S504), that is, when there is no terminal for which the assigned channel has not been determined, channel allocation based on schedule information is executed for the terminal determined to be assigned to the channel with small unmanaged interference (S508). Then, the flow ends.

[0194] The processing flow in S508 is similar to the processing flow shown in, for example, S102 to S113 in Fig. 9, and therefore description thereof will be omitted. However, the processing flow in Fig. 9 determines terminals 200 to which each of the allocatable channels is assigned, whereas Fig. 22 differs in that terminals to which each of the allocatable channels is assigned are determined for channels with small unmanaged interference.

[0195] As described above, in the fifth example, the base station 300 classifies interference and determines a channel to be assigned to the terminal 200 according to the magnitude of the non-management interference. Then, for example, the base station 300 assigns a channel with relatively large non-management interference to the terminal 200 owned by a user who stays at the station for a relatively short time. With such an assignment, a channel with small non-management interference and good communication quality can be assigned to the terminal 200 who stays at the station for a relatively long time and is assumed to communicate frequently. Also, as in the first example, even if the terminals of a certain group simultaneously disconnect wireless connections, the bias in the number of terminals can be suppressed in the channel assignment after disconnection, so that the degree of channel congestion can be made uniform among the channels, and the frequency utilization efficiency can be improved.

[0196] In the fifth example, the assignable channels are classified into channels with large non-management interference and channels with small non-management interference, but the present disclosure is not limited to this. For example, the assignable channels may be classified into three or more levels based on the magnitude of non-management interference of each channel. In this case, for example, the terminals 200 may be divided into three or more groups based on the staying time of the user, and the terminals of each group may be assigned to each of the channels classified into three or more levels.

[0197] In the fifth example, the terminals 200 determined to be assigned to a channel with small non-management interference are grouped based on schedule information, and the terminals of each group are assigned to a channel, but the present disclosure is not limited to this. For example, the terminals 200 determined to be assigned to a channel with large non-management interference may be grouped based on schedule information, and the terminals of each group may be assigned to a channel. This allows the channel congestion level to be equalized between channels even in channels with large non-management interference, and improves frequency utilization efficiency.

[0198] In the fifth example, for example, when terminal 200 uses a communication method called "LoRa" (hereinafter referred to as "LoRa method"), which is one of the wireless communication technologies called LPWA (Low Power Wide Area) and performs communication using a spread spectrum method, the transmission power may be set higher for terminal 200 of a user who stays in a station for a longer period of time. When terminal 200 uses the LPWA LoRa method, a larger spreading factor may be assigned to terminal 200 of a user who stays in a station for a longer period of time. In this case, the transmission power of terminal 200 of a user who stays in a station for a longer period of time may be set higher and a larger spreading factor may be assigned.

[0199] <Example 6> In the sixth example, as in the fifth example, a case is described in which base station 300 classifies interference and determines a channel to be assigned to terminal 200 according to the magnitude of unmanaged interference, and a terminal 200 exists that does not transmit schedule information.

[0200] In the sixth example, the base station 300 assigns the terminal 200 that does not transmit schedule information to a channel with relatively large non-management interference. As in the fifth example, the base station 300 assigns the terminal 200 that stays at the station relatively short to a channel with relatively large non-management interference, and assigns the terminal 200 that stays at the station relatively long to a channel with relatively small non-management interference. In other words, the base station 300 sets the priority of the terminal 200 that does not transmit schedule information lower than the terminal 200 that transmits schedule information. Then, the base station 300 sets the priority of the terminal 200 based on the station stay time among the terminals 200 that transmit schedule information, and assigns the terminal 200 with a high priority (for example, a relatively long station stay time) to a channel with relatively many vacancies (for example, a channel with small non-management interference).

[0201] Fig. 23 is a diagram showing an example of channel allocation in the sixth example. The horizontal axis of Fig. 23 indicates frequency, and the vertical axis indicates the transmission probability of the allocated within-management terminal. Fig. 23 shows within-management terminals allocated to each of channels f1 to f4. Fig. 23 also shows within-management terminals allocated to any of channels f1 to f4.

[0202] In Fig. 23, similarly to Fig. 21, there is no (or very little) non-management interference in channels f1 and f2, and non-management interference exists in channel f3, and non-management interference exists in channel f4 that is greater than that in channel f3.

[0203] In the example of Fig. 23, managed terminals #1 to #n are terminals 200 that have transmitted schedule information, and unreported managed terminals #n+1 to #s are terminals 200 that have not transmitted schedule information. Also, in the example of Fig. 23, managed terminals #1 to #n are arranged in order of the length of time they stayed at the station, similar to Fig. 21.

[0204] Here, m is an integer between 1 and n. For example, m may be determined based on the ratio of the availability of channels f1 and f2 to the availability of channel f3. However, in the sixth example, since an in-management terminal that does not transmit schedule information is assigned to channel f3, the availability of channel f3 for determining m is the availability after the in-management terminal that does not transmit schedule information is assigned.

[0205] Base station 300 decides to assign in-management terminals #n+1 to #s that do not transmit schedule information to channel f3 with large non-management interference. Then, base station 300 decides to assign in-management terminals #1 to #m of users who have a relatively long stay time among the in-management terminals that have transmitted schedule information to channels f1 and f2 with small non-management interference, and to assign in-management terminals #m+1 to #n of users who have a relatively short stay time to channel f3 with large non-management interference.

[0206] The base station 300 further groups the managed terminals that are to be assigned to the channels f1 and f2, and assigns a channel to each group. This assignment may be the same as in the fifth example.

[0207] <Processing flow of the base station in the sixth example> Fig. 24 is a flowchart showing an example of a processing flow of the base station 300 in the sixth example of the present embodiment. In Fig. 24, the same processes as those in Fig. 22 are denoted by the same numbers, and the description thereof may be omitted.

[0208] If the channel determination has not been completed (NO at S504), that is, if there is a terminal (hereinafter referred to as "terminal z") for which the assigned channel has not been determined, base station 300 determines whether terminal z has not transmitted schedule information (determines whether it has not been transmitted) (S601).

[0209] If terminal z transmits schedule information (NO at S601), base station 300 determines whether the stay time of the user who owns terminal z at the station (e.g., the difference between the arrival time of the train that the user is taking and the current time) is less than a predetermined time (S505).

[0210] If the residence time is not less than the predetermined time (NO in S505), the base station 300 determines to assign the terminal z to a channel with small unmanaged interference (S507), and the flow proceeds to S504.

[0211] If terminal z has not transmitted schedule information (YES in S601) or if the stay time is less than the predetermined time (YES in S505), base station 300 determines to assign terminal z to a channel with large non-management interference (S506). Then, the flow proceeds to S504.

[0212] As described above, in the sixth example, the base station 300 classifies interference and determines a channel to be assigned to the terminal 200 according to the magnitude of the non-management interference. Then, for example, the base station 300 assigns a channel with relatively large non-management interference to the terminal 200 that does not transmit schedule information and the terminal 200 owned by a user who stays at the station for a relatively short time. By such an assignment, a channel with small non-management interference and good communication quality can be assigned to the terminal 200 that stays at the station for a relatively long time and is assumed to communicate frequently. Also, as in the first example, even if the terminals 200 of a certain group simultaneously disconnect wireless connections, the bias in the number of terminals can be suppressed in the channel assignment after disconnection, so that the probability that the degree of congestion of the channel becomes uneven between the channels can be reduced, and the frequency utilization efficiency can be improved.

[0213] In addition, when the terminal 200 that does not transmit schedule information and the terminal 200 that transmits schedule information use the LoRa system, the transmission power of the terminal 200 that does not transmit schedule information may be set lower than that of the terminal 200 that transmits schedule information. For example, the transmission power of the terminal 200 that does not transmit schedule information may be set to the minimum of the settable transmission power. Alternatively, when the terminal 200 that does not transmit schedule information and the terminal 200 that transmits schedule information use the LoRa system, a spreading factor smaller than that of the terminal 200 that transmits schedule information may be assigned to the terminal 200 that does not transmit schedule information. For example, SF7 may be assigned to the terminal that does not report.

[0214] <7th Example> In the seventh example, similar to the fifth and sixth examples, the base station 300 classifies interference and assigns channels to the terminal 200 according to the magnitude of unmanaged interference. The seventh example explains channel assignment in the case where an emergency occurs due to an accident or disaster, making it difficult for trains to depart or arrive.

[0215] In the event of an emergency that makes it difficult for a train to depart or arrive at a station, the base station 300 assigns the user's terminal 200 to a channel based on the distance (or time) from the station to the user's destination (e.g., home). Alternatively, the base station 300 may assign the user's terminal 200 to a channel based on whether or not an alternative means other than the train (e.g., at least one of bus, taxi, walking, and bicycle) is available to reach the destination. Here, a user who can use an alternative means other than the train to reach the destination may be notified of information such as a stop and / or timetable of the alternative means (e.g., bus, taxi). In addition, a user who agrees to return home by an alternative means may notify the base station 300 to that effect, and some kind of special benefit may be added to the user. Alternatively, the base station 300 may notify the terminal 200 of candidates for alternative means for moving from the station where the user is staying, and the user may determine whether or not there is an alternative means available from among the candidates. In this case, the determination result may be notified from the terminal 200 to the base station 300.

[0216] For example, the base station 300 assigns the terminal 200 of a user who can use alternative means to a channel with relatively large non-management interference. The base station 300 assigns the terminal 200 of a user who is a short distance to a destination to a channel with relatively large non-management interference, and assigns the terminal 200 of a user who is a long distance to a destination to a channel with relatively small non-management interference. In other words, the terminal 200 owned by a user who can use alternative means other than trains (e.g., at least one of bus, taxi, walking, and bicycle) to reach the destination may be set to a lower priority than the terminal 200 owned by a user who cannot use alternative means. The longer the distance to the user's destination, the higher the priority of the terminal 200 owned by the user may be set. The base station 300 assigns the terminal 200 with a high priority to a channel with relatively large vacancies (e.g., a channel with small non-management interference).

[0217] The method of acquiring information on the distance to the destination of the user who owns the terminal 200 is not limited. The base station 300 may estimate the distance to the destination based on information on the train that the user will board, which is indicated by the schedule information. Alternatively, the user who owns the terminal 200 may input information on the distance to the destination, the address of the user's home, or the like, into the terminal 200, and the terminal 200 may transmit the input information to the base station 300. The input information may be included in the schedule information.

[0218] Furthermore, the method by which the user who owns the terminal 200 obtains information regarding whether or not an alternative means is available is not limited. For example, the base station 300 may estimate whether or not an alternative means is available based on information on the train that the user will board, which is indicated by the schedule information. Alternatively, the user who owns the terminal 200 may input to the terminal 200 whether or not an alternative means is available, and the terminal 200 may transmit the input information to the base station 300. For example, the input information may be included in the schedule information.

[0219] Fig. 25 is a diagram showing an example of channel allocation in the seventh example. The horizontal axis of Fig. 25 indicates frequency, and the vertical axis indicates the transmission probability of the allocated within-management terminal. Fig. 25 shows within-management terminals allocated to each of channels f1 to f4. Fig. 25 also shows within-management terminals allocated to any of channels f1 to f4.

[0220] 25, similarly to FIG. 21 and FIG. 23, there is no (or very little) non-management interference in channel f1 and channel f2. In addition, non-management interference exists in channel f3, and non-management interference exists in channel f4 that is greater than that in channel f3.

[0221] In the example of FIG. 25, the managed terminals #1 to #n are terminals 200 of users who cannot use alternative means, and the mobile managed terminals #n+1 to #s are terminals 200 of users who can use alternative means. In the example of FIG. 25, the managed terminals #1 to #n are arranged in order of the distance to the destination. Among the n managed terminals, the managed terminal #1 has the longest distance to the destination of the user, and the managed terminal #n has the shortest distance to the destination of the user. In the example of FIG. 25, the managed terminals #1 to #n are divided into a group of m terminals consisting of the managed terminals #1 to #m of users who have a relatively long distance to the destination, and a group of n-m terminals consisting of the managed terminals #m+1 to #n of users who have a relatively short distance to the destination.

[0222] Here, m is an integer between 1 and n. For example, m may be determined based on the ratio between the availability of channels f1 and f2 and the availability of channel f3. However, in the seventh example, since an in-management terminal of a user who can use an alternative means is assigned to channel f3, the availability of channel f3 for determining m is the availability after the in-management terminal of a user who can use an alternative means is assigned.

[0223] The base station 300 decides to assign the in-management terminals #n+1 to #s of users for whom alternative means are available to the channel f3 with large non-management interference.Then, the base station 300 decides to assign, among the in-management terminals of users for whom alternative means are not available, the in-management terminals #1 to #m of users who are relatively far from their destinations to the channels f1 and f2 with small non-management interference, and to assign the in-management terminals #m+1 to #n of users who are relatively short from their destinations to the channel f3 with large non-management interference.

[0224] The base station 300 further groups the managed terminals that are to be assigned to the channels f1 and f2, and assigns a channel to each group. This assignment may be the same as in the fifth example.

[0225] <Processing flow of the base station in the seventh example> Fig. 26 is a flowchart showing an example of a processing flow of the base station 300 in the seventh example of the present embodiment. In Fig. 26, the same processes as those in Fig. 22 are denoted by the same numbers, and the description thereof may be omitted.

[0226] If the channel determination has not been completed (NO at S504), that is, if there is a terminal (hereinafter referred to as "terminal z") for which the assigned channel has not been determined, base station 300 determines whether the user of terminal z can travel by alternative means (S701).

[0227] If the user of terminal z is not able to travel by alternative means (NO in S701), base station 300 determines whether the distance to the destination of the user who owns terminal z is less than a threshold (S702).

[0228] If the distance to the destination is not less than the threshold (NO in S702), base station 300 determines to assign terminal z to a channel with small unmanaged interference (S704), and the flow proceeds to S504.

[0229] If the user of terminal z can move by alternative means (YES in S701), or if the distance to the destination is less than the threshold (YES in S702), base station 300 determines to assign terminal z to a channel with large unmanaged interference (S703). Then, the flow proceeds to S504.

[0230] As described above, in the seventh example, the base station 300 classifies interference and assigns channels to terminals according to the magnitude of non-management interference. Then, for example, the base station 300 assigns channels with relatively large non-management interference to the terminals 200 of users who can use alternative means and the terminals 200 owned by users who are relatively short distances to their destinations. With this assignment, it is possible to assign channels with small non-management interference and good communication quality to terminals 200 that are relatively long distances to their destinations, spend a long time at stations, and are assumed to communicate frequently. Also, as in the first example, even if the terminals 200 of a certain group simultaneously disconnect wireless connections, it is possible to suppress bias in the number of terminals in the channel assignment after disconnection, so that the degree of channel congestion can be made uniform among the channels, and frequency utilization efficiency can be improved.

[0231] When the terminal 200 uses the LPWA LoRa system, the transmission power may be set higher for the terminal 200 of a user whose distance to the destination is relatively longer. Alternatively, when the terminal 200 uses the LPWA LoRa system, the transmission power may be set higher for the terminal 200 of a user whose distance to the destination is relatively longer. In this case, the transmission power of the terminal 200 of the user whose distance to the destination is relatively longer may be set higher and a large spreading factor may be assigned.

[0232] Furthermore, when the terminal 200 uses the LoRa system of LPWA, the transmission power of the terminal 200 of the user who can use the alternative means may be set lower than that of the terminal 200 of the user who cannot use the alternative means. For example, the transmission power of the terminal 200 of the user who can use the alternative means may be set to the minimum of the settable transmission power. Alternatively, when the terminal 200 uses the LoRa system, the terminal 200 of the user who can use the alternative means may be assigned a smaller spreading factor than that of the terminal 200 of the user who cannot use the alternative means. For example, SF7 may be assigned to the terminal 200 of the user who can use the alternative means. Alternatively, when the terminal 200 uses the LoRa system, the terminal 200 of the user who can use the alternative means may be assigned a smaller spreading factor than that of the terminal of the user who cannot use the alternative means, and the transmission power may be set lower than that of the terminal 200 of the user who cannot use the alternative means.

[0233] In addition, the expression "··· part" in the above embodiments may be replaced with other expressions such as "··· circuit", "··· device", "··· unit", or "··· module".

[0234] In addition, the term "channel" in the above embodiments may be replaced with other terms such as "frequency," "frequency channel," "band," "carrier," "subcarrier," or "(frequency) resource."

[0235] The present disclosure can be realized in software, hardware, or software in conjunction with hardware.

[0236] 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 one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one 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, a system LSI, a super LSI, or an ultra LSI.

[0237] The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, after LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0238] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0239] The present disclosure may be implemented in any type of apparatus, device, or system with communications capabilities (collectively, communications apparatus), including, but not limited to, telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, communications-enabled vehicles or mobile conveyances (e.g., cars, planes, ships, etc.), and combinations of the above-mentioned devices.

[0240] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0241] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0242] 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.

[0243] 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.

[0244] 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 come up with various modified or amended examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. In addition, the components in the above-mentioned embodiments may be arbitrarily combined within the scope of the disclosure.

[0245] 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]

[0246] The present disclosure is suitable for a wireless communication system. [Explanation of symbols]

[0247] 100, 300 base stations 200 terminals 101, 201 Receiver 102, 202 Demodulation / Decoding Unit 103 Schedule information extraction unit 104, 204, 304 Allocation control unit 105 Control information generation unit 106, 205 Encoding / modulation section 107, 206 Transmitter 203 Schedule information generation unit 301 Communication Quality Measurement Unit 302 Preamble detector 303 Interference Classification Division

Claims

1. A receiving unit that receives schedule information regarding timing for each terminal that is within a communication range to go outside the communication range, A control unit that assigns the terminals to each channel based on the schedule information; Equipped with The control unit sets a group of the terminals based on the schedule information; The control unit determines the number of terminals to be assigned to each of the channels based on the number of terminals included in the group and the number of channels. Base station.

2. The group includes terminals whose timing is within a first predetermined time. The base station according to claim 1 .

3. the schedule information includes information indicating attributes of a means of transportation used by a user who owns the terminal; The group includes terminals having the same attribute. The base station according to claim 1 .

4. the schedule information includes information indicating whether the user who owns the terminal desires to use a seat provided in the means of transportation used by the user, the control unit sets a first group including a terminal owned by a user who desires to use the seat, and a second group including a terminal owned by a user who does not desire to use the seat; The base station according to claim 1 .

5. The control unit sets the terminal that has transmitted the schedule information and the terminal that has not transmitted the schedule information to different groups. The base station according to claim 1 .

6. A base station, A receiving unit that receives schedule information regarding timing for each terminal that is within a communication range to go outside the communication range, A control unit that assigns the terminals to each channel based on the schedule information; an interference classification unit that measures interference on each channel and detects an amount of interference from a wireless device that belongs to a network different from a network to which the base station belongs; Equipped with The control unit assigns the terminal to the channel based on the schedule information and the magnitude of the interference amount; The control unit classifies channels into a first channel having an amount of interference less than a predetermined level and a second channel having an amount of interference equal to or greater than the predetermined level, the control unit assigns a terminal that exists within the communication range for a time equal to or longer than a second predetermined time to the first channel, and assigns a terminal that exists within the communication range for a time shorter than the second predetermined time to the second channel. Base station.

7. The control unit assigns a terminal that does not transmit the schedule information to the second channel. The base station according to claim 6.

8. A base station, A receiving unit that receives schedule information regarding timing for each terminal that is within a communication range to go outside the communication range, A control unit that assigns the terminals to each channel based on the schedule information; an interference classification unit that measures interference on each channel and detects an amount of interference from a wireless device that belongs to a network different from a network to which the base station belongs; Equipped with The control unit assigns the terminal to the channel based on the schedule information and the magnitude of the interference amount; when the means of transportation of the user who owns the terminal indicated by the schedule information is unavailable, the control unit assigns the terminal to a channel with a smaller amount of interference as the distance to the destination of the user increases. Base station.

9. A base station, A receiving unit that receives schedule information regarding timing for each terminal that is within a communication range to go outside the communication range, A control unit that assigns the terminals to each channel based on the schedule information; an interference classification unit that measures interference on each channel and detects an amount of interference from a wireless device that belongs to a network different from a network to which the base station belongs; Equipped with The control unit assigns the terminal to the channel based on the schedule information and the magnitude of the interference amount; When the transportation means of the user who owns the terminal indicated by the schedule information is unavailable, the control unit assigns the terminal of the user who is not capable of traveling to the destination of the user by a method other than the transportation means to a channel having a smaller amount of interference than a channel to which the terminal of the user who is capable of traveling to the destination of the user by a method other than the transportation means is assigned. Base station.

10. The base station receiving schedule information from each terminal within a communication range regarding the timing of going outside the communication range; Setting a group of the terminals based on the schedule information; determining the number of terminals to be assigned to each of the channels based on the number of terminals included in the group and the number of channels; Control methods.

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