Wireless communication system, controller, wireless base station, and data packet transfer method

Abstract

To reduce a processing load in a wireless communication system.SOLUTION: A wireless communication system 1 includes transfer means 61. When a destination of a data packet DP transmitted from a server 11A is a first wireless communication terminal 3A, the transfer means 61 converts the data packet DP into a predetermined data frame DF and transfers it to the first wireless communication terminal 3A. On the other hand, when a destination of a data packet DP transmitted from the server 11A is a second wireless communication terminal 3B, the transfer means 61 transfers it to the second wireless communication terminal 3B without converting the data packet DP into the data frame DF.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless communication system, and in particular to a system comprising a plurality of wireless communication terminals, a wireless base station wirelessly connected to the wireless communication terminals, and a controller that communicates with the wireless communication terminals via the wireless base station and is communicatively connected to other communication systems via a predetermined network. [Background technology]

[0002] In a typical wireless communication system, communication packets in a general-purpose communication protocol format transferred over Ethernet (registered trademark) are transmitted and received so that general-purpose wireless communication devices can communicate. Patent Document 1 describes a technology in which communication with a mobile IP terminal included in an external network is performed by setting only the destination and source addresses in the packet header, and communication with a counterpart node is performed by setting information necessary for Mobile IPv6 communication in the packet header. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-289659 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional inventions such as that described in Patent Document 1 convert data packets uniformly for all mobile IP terminals included in an external network, and the processing load for such conversion becomes a problem.

[0005] An object of the present invention is to reduce the processing load in a wireless communication system. [Means for solving the problem]

[0006] In the following, several aspects will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.

[0007] A wireless communication system according to one aspect of the present invention includes a plurality of wireless communication terminals, a wireless base station wirelessly connected to the wireless communication terminals, and a controller that communicates with the wireless communication terminals via the wireless base station and is communicatively connected to other communication systems via a predetermined network. The wireless communication system includes a transfer means. When the destination of the data packet transmitted from the other communication system is a specific wireless communication terminal among the multiple wireless communication terminals, the transfer means converts the data packet into a predetermined data frame and transfers it to the wireless communication terminal, whereas when the destination of the data packet transmitted from the other communication system is a wireless communication terminal other than the specific wireless communication terminal among the multiple wireless communication terminals, the transfer means transfers the data packet to the wireless communication terminal without converting it into the predetermined data frame. In this wireless communication system, when the destination of a data packet transmitted from another communication system is a wireless communication terminal other than the specific wireless communication terminal among the multiple wireless communication terminals, the data packet is not converted, so that the processing load for converting the data packet is reduced. Also, by reducing the capacity of the data packet for the specific wireless communication terminal by conversion, the communication load of the wireless communication system can be reduced.

[0008] When the destination of a predetermined data frame transmitted from a specific wireless communication terminal is another communication system, the transfer means may convert the predetermined data frame into a data packet and transfer it to the other communication system. In this wireless communication system, in upstream communication, the transfer means converts a predetermined data frame into a data packet, thereby realizing wireless communication according to a communication protocol that matches another communication system.

[0009] A wireless communication system may comprise a number of specific wireless communication terminals. When the destination of a specified data frame transmitted from a specific wireless communication terminal is another specific wireless communication terminal, the forwarding means may forward the specified data frame to the wireless communication terminal without converting it into a data packet. In this wireless communication system, the communication load relating to communication between specific wireless communication terminals can be reduced.

[0010] The transfer means may be provided in the controller. In this wireless communication system, the transfer means of the controller determines the destination of a given data packet, converts the data packet into a given data frame, and transfers it. Since the controller can centrally manage data conversion, it is easy to respond to various changes, such as when changing wireless communication settings.

[0011] The forwarding means may be provided in a wireless base station. In this wireless communication system, the forwarding means of the wireless base station determines the destination of the data packet, converts the data packet into a predetermined data frame, and forwards it. Since multiple wireless base stations can perform data conversion, the processing load can be distributed.

[0012] The data frame may be a data frame that includes at least a destination and a data portion to be transmitted. The data packets may be communication packets in a general-purpose communication protocol format transferred over Ethernet.

[0013] The wireless communication terminal may be mounted on a mobile object. In this wireless communication system, the communication load on a moving wireless communication terminal is reduced.

[0014] A controller according to another aspect of the present invention is used in a wireless communication system including a plurality of wireless communication terminals and a wireless base station wirelessly connected to the wireless communication terminals. The controller communicates with the wireless communication terminal via the wireless base station, and is communicatively connected to other communication systems via a predetermined network. The controller includes a transfer means. When the destination of the data packet transmitted from the other communication system is a specific wireless communication terminal among the multiple wireless communication terminals, the forwarding means converts the data packet into a predetermined data frame and forwards it to a wireless base station wirelessly connected to the wireless communication terminal, whereas when the destination of the data packet transmitted from the other communication system is a wireless communication terminal other than the specific wireless communication terminal among the multiple wireless communication terminals, the forwarding means forwards the data packet to the wireless base station wirelessly connected to the wireless communication terminal without converting it into the predetermined data frame.

[0015] A wireless base station according to yet another aspect of the present invention is used in a wireless communication system including a plurality of wireless communication terminals and a controller communicatively connected to another communication system via a predetermined network. The wireless base station is wirelessly connected to the wireless communication terminal and is connected to the controller. The radio base station includes a forwarding means. When the destination of a data packet transmitted from another communication system via the controller is a specific wireless communication terminal among the plurality of wireless communication terminals, the transfer means converts the data packet into a predetermined data frame and transfers it to the wireless communication terminal. On the other hand, when the destination of a data packet transmitted from another communication system via the controller is a wireless communication terminal other than the specific wireless communication terminal among the plurality of wireless communication terminals, the transfer means transfers the data packet to the wireless communication terminal without converting it into the predetermined data frame.

[0016] A data packet transfer method according to another aspect of the present invention is used in a wireless communication system including a plurality of wireless communication terminals, a wireless base station wirelessly connected to the wireless communication terminals, and a controller that communicates with the wireless communication terminals via the wireless base station and is communicatively connected to other communication systems via a predetermined network. The data packet forwarding method includes the following steps. A step of determining whether or not the destination of a data packet transmitted from another communication system is a specific wireless communication terminal among a plurality of wireless communication terminals. A step of converting the data packet into a predetermined data frame if the wireless communication terminal is a specific wireless communication terminal, and not converting the data packet if the wireless communication terminal is a wireless communication terminal other than the specific wireless communication terminal. Transferring a predetermined data frame or data packet to the wireless communication terminal. Effect of the Invention

[0017] In the wireless communication system according to the present invention, the processing load is reduced. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing an overall configuration of a wireless communication system according to a first embodiment (uplink communication and downlink communication). [Diagram 2] 1 is a schematic diagram showing an overall configuration of a wireless communication system according to a first embodiment (communication between wireless communication terminals); [Diagram 3] FIG. 2 is a block diagram showing the control configuration of a wireless base station and a controller. [Figure 4] A conversion table between IP addresses and wireless communication terminal identifiers. [Diagram 5] FIG. 13 is a schematic diagram showing data conversion in a controller (downstream communication). [Figure 6] FIG. 13 is a schematic diagram showing data conversion in a controller (downstream communication). [Figure 7] FIG. 13 is a schematic diagram showing data conversion in a controller (upstream communication). [Figure 8] 4 is a flowchart showing a data conversion control operation by a controller. [Figure 9] FIG. 11 is a schematic diagram showing the overall configuration of a wireless communication system according to a second embodiment (uplink communication and downlink communication). [Figure 10] FIG. 2 is a block diagram showing the control configuration of a wireless base station and a controller. [Figure 11]FIG. 1 is a schematic diagram showing data conversion in a wireless base station (downstream communication). [Figure 12] FIG. 1 is a schematic diagram showing data conversion in a wireless base station (downstream communication). [Figure 13] FIG. 1 is a schematic diagram showing data conversion in a wireless base station (uplink communication). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1. First embodiment (1) Basic configuration of a wireless communication system A wireless communication system 1 according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figures 1 and 2 are schematic diagrams showing the overall configuration of the wireless communication system according to the first embodiment of the present invention. The wireless communication system 1 includes a plurality of first wireless communication terminals 3A, a plurality of second wireless communication terminals 3B, a plurality of wireless base stations 5, and a controller .

[0020] The first wireless communication terminal 3A and the second wireless communication terminal 3B are, for example, communication units of local 5G or WI-FI (registered trademark). The IP addresses of the first wireless communication terminal 3A and the second wireless communication terminal 3B are fixed addresses. However, information for identifying the first wireless communication terminal 3A and the second wireless communication terminal 3B is not limited to IP addresses. The first wireless communication terminal 3A is a group of wireless communication terminals provided in a factory, and is mounted, for example, on a plurality of transport vehicles 9 (an example of a mobile body) in the factory. When the transport vehicle 9 moves, the first wireless communication terminal 3A may leave the communication range of the wireless base station 5, in which case it enters the communication range of another wireless base station 5 to continue communication. The second wireless communication terminals 3B are a group of wireless communication terminals provided in the factory, different from the first wireless communication terminals 3A, and are mounted on work computers (desktop computers, tablet computers, mobile phones, etc.) other than the transport vehicle 9. In this embodiment, the number of the first wireless communication terminals 3A is greater than the number of the second wireless communication terminals 3B. In this embodiment, the first wireless communication terminal 3A is an example of a "specific wireless communication terminal", and the second wireless communication terminal 3B is an example of a "wireless communication terminal other than the specific wireless communication terminal".

[0021] The wireless communication system 1 constitutes a part of a transport system having a plurality of transport vehicles 9. In the transport system, external servers 11A, 11B are higher-level systems and have information on all of the transport vehicles 9. Through the wireless communication system 1, for example, server 11A, 11B transmits package transport instructions to the plurality of transport vehicles 9, and the transport vehicles 9 transmit status, change, and position information of the transport vehicles 9 to the servers 11A, 11B. In the following description, server 11A will be used as a representative example.

[0022] As described later, data packets DP and data frames DF are transmitted and received between devices in the wireless communication system 1. The data packets DP are, for example, communication packets in a general-purpose communication protocol format transferred over Ethernet (registered trademark).

[0023] (2) Control configuration of wireless base station and controller The control configuration of the wireless base station 5 and the controller 7 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the control configuration of the wireless base station and the controller. The wireless base station 5 has a communication unit 41 and a destination determination unit 42. The destination determination unit 42 is a function of a CPU that operates according to a program. The CPU may be composed of a single processor, or may be composed of multiple processors independent for each control. Some or all of the functions of each element of the CPU may be realized as a program executable by a computer system that constitutes the control unit. In addition, some of the functions of each element of the control unit may be configured by a custom IC. The above explanation also applies to other CPUs.

[0024] The wireless base station 5 is wirelessly connected to a plurality of first wireless communication terminals 3A and second wireless communication terminals 3B. The wireless base station 5 notifies the controller 7 that the first wireless communication terminal 3A or the second wireless communication terminal 3B has entered or left the communication range of the wireless base station 5.

[0025] The controller 7 is a computer system including a CPU, RAM, ROM, etc., and performs overall control of the wireless communication system 1. The controller 7 communicates with the first wireless communication terminal 3A or the second wireless communication terminal 3B via the wireless base station 5. A router 13 is provided between the controller 7 and the multiple wireless base stations 5. In this embodiment, the controller 7 and the wireless base stations 5 are connected by wire. The controller 7 is communicably connected to servers 11A and 11B (examples of other communication systems) via a wired or wireless network 15 (an example of a predetermined network). As shown in FIG. 3, the controller 7 includes a communication unit 44, a destination determination unit 45, and a data conversion unit 46 (described later).

[0026] The controller 7 grasps the IP addresses of the first wireless communication terminal 3A and the second wireless communication terminal 3B, and grasps to which wireless base station 5 the first wireless communication terminal 3A and the second wireless communication terminal 3B are connected. Specifically, as shown in Fig. 4, the controller 7 has a table that associates IP addresses with wireless communication terminal identifiers, and determines the wireless communication terminal identifier from the IP address. Fig. 4 is an example of a table that associates IP addresses with wireless communication terminal identifiers.

[0027] (3) Means of transfer 3, the communication unit 44, the destination determination unit 45, and the data conversion unit 46 realize a transfer means 61 as functions executed by the CPU according to a program. The destination determination unit 45 determines the destination of the data packet DP. Based on the result of the determination by the destination determination unit 45, the communication unit 44 transfers the data packet DP as is, or converts the data packet DP into a predetermined data frame DF (converted packet) by the data conversion unit 46 and then transfers it (described later). Since the controller 7 can centrally manage the transfer and conversion in this way, it is easy to respond to various changes.

[0028] The data frame DF is, for example, a data frame including at least a destination and a data section. Specifically, the data section is composed of control data for controlling the transport vehicle 9, such as a transport command including information on the origin and destination of the article to be transported by the transport vehicle 9, and a movement command including information on the destination to which the transport vehicle 9 should move. The data frame DF may or may not include information on the sender. More specifically, the data frame DF has RU (wireless header), SRC (IP / PORT) (source IP address (4 bytes)·port number), and DATA. That is, the data frame DF has MAC / IP / UDP deleted from the data packet DP. The DATA is, for example, about 64 bytes, and the deleted communication header is several tens of bytes in a communication packet of a general-purpose communication protocol format, so the reduction effect is high.

[0029] (3-1) Downstream communication (Figure 1) The data conversion in the controller 7 will be described with reference to Figures 5 and 6. Figures 5 and 6 are schematic diagrams showing the data conversion in the controller. In the downstream communication, conventionally, a data packet DP transmitted from the server 11A is transmitted to the first wireless communication terminal 3A and the second wireless communication terminal 3B via the controller 7, the router 13, and the wireless base station 5. In this embodiment, as described below, the data packet DP may or may not be converted into a data frame DF.

[0030] As an explanation of the case of conversion, when the destination of the data packet DP transmitted from the server 11A is one of the multiple first wireless communication terminals 3A, the data conversion unit 46 of the controller 7 converts the data packet DP into a predetermined data frame DF and transfers it to the destination first wireless communication terminal 3A. Specifically, the predetermined data frame DF is transmitted to the first wireless communication terminal 3A via the router 13 and the wireless base station 5.

[0031] 5, the data conversion unit 46 converts the data packet DP into a data frame DF. Specifically, the data packet DP (MAC / IP / UDP / DATA) is converted into a data frame DF (MAC / SRC(IP / PORT) / DATA). Furthermore, after processing in the controller 7, in the wireless base station 5, the MAC header of the data frame DF is replaced with an RU header.

[0032] As an explanation of the case where no conversion is performed, when the destination of the data packet DP transmitted from the server 11A is any one of the multiple second wireless communication terminals 3B, the data conversion unit 46 of the controller 7 does not convert the data packet DP as shown in Fig. 6. As a result, the data packet DP is transmitted to the destination second wireless communication terminal 3B via the router 13 and the wireless base station 5. After the processing by the controller 7, the wireless base station 5 replaces the MAC header of the data packet DP with an RU header.

[0033] As shown in Fig. 6, in this embodiment, if the destination of the data packet DP transmitted from the server 11A is the second wireless communication terminal 3B, the data packet DP is not converted. Therefore, the overall processing load for converting the data packet DP does not become extremely large. In other words, data conversion is not performed uniformly, but is performed as necessary. As shown in Fig. 5, by configuring the data packet DP destined for the first wireless communication terminal 3A to be converted into a data frame DF with a relatively small capacity and transferred to the first wireless communication terminal 3A, the communication load of the wireless communication system 1 can be reduced.

[0034] In general, real-time performance is required for control communication of industrial equipment and the like, and small amounts of data are required to be frequently transmitted and received with low latency. In particular, since there are hundreds to thousands of first wireless communication terminals 3A in a factory, even a slight increase in data per terminal increases the overall communication volume. In this embodiment, the above conversion allows the overall data volume to be significantly reduced by only slightly reducing the data volume per terminal related to communication with the first wireless communication terminal 3A.

[0035] (3-2) Upstream communication (Figure 1) In the upstream communication, the data frame DF transmitted from the first wireless communication terminal 3A is converted into a data packet DP by the wireless base station 5 and transmitted to the server 11A via the router 13 and the controller .

[0036] The upstream communication from the first wireless communication terminal 3A will be described with reference to Fig. 7. Fig. 7 is a schematic diagram showing data conversion in the controller. When the destination of the data frame DF transmitted from the first wireless communication terminal 3A is the server 11A, the data conversion unit 46 converts the data frame DF into a data packet DP and transfers it to the server 11A. In this way, in upstream communication originating from the first wireless communication terminal 3A, the transfer means 61 converts a predetermined data frame DF into a data packet DP. Specifically, the data conversion unit 46 converts the data frame DF (MAC / DST(IP / PORT) / DATA) into a data packet DP (MAC / IP / UDP / DATA). That is, the data packet DP has MAC / IP / UDP added to the data frame DF. Note that, before processing by the controller 7, the wireless base station 5 replaces the RU header of the data frame DF with a MAC header.

[0037] (3-3) Communication between wireless communication terminals (Fig. 2) When the destination of the data frame DF transmitted from the first wireless communication terminal 3A is another first wireless communication terminal 3A, the forwarding means 61 forwards the data frame DF to the first wireless communication terminal 3A without converting it. Specifically, the data frame DF is transmitted to the other first wireless communication terminal 3A via the router 13, the controller 7, the router 13, and the wireless base station 5. As described above, when the destination of the data frame DF received from the first wireless communication terminal 3A is another first wireless communication terminal 3A, the controller 7 transfers the data frame DF without converting it. This reduces the processing load on the controller 7.

[0038] (4) Data conversion control operation of the controller The data conversion control operation by the controller 7 will be described with reference to Fig. 8. Fig. 8 is a flow chart showing the data conversion control operation by the controller. The control flow charts described below are merely examples, and each step may be omitted or replaced as necessary. In addition, a plurality of steps may be executed simultaneously, or some or all of the steps may be executed in an overlapping manner. Furthermore, each block in the control flowchart is not limited to a single control operation, but can be replaced with a plurality of control operations represented by a plurality of blocks. The operation of each device is the result of commands from the control unit to each device, and these are represented by each step of the software application.

[0039] In step S1, the communication unit 44 of the controller 7 waits for reception of a data packet DP. In step S2, it is determined whether data conversion is necessary. Specifically, the destination determination unit 45 makes the determination. If data conversion is necessary, the process proceeds to step S3, and if data conversion is not necessary, the process skips step S3 and proceeds to step S4. Data conversion is necessary when the destination is the first wireless communication terminal 3A or the server 11A. Data conversion is not necessary when the destination is the second wireless communication terminal 3B.

[0040] In step S3, the data packet DP is converted into a predetermined data frame DF. Specifically, the data conversion unit 46 executes the above operation. In step S4, the destination of the data packet DP or the data frame DF is determined. Specifically, the destination determination unit 45 performs the determination. If the destination is the server 11A, the process proceeds to step S5, and if the destination is the first wireless communication terminal 3A or the second wireless communication terminal 3B, the process proceeds to step S6.

[0041] In step S5, the data packet DP is transmitted to the server 11 A. Specifically, the communication unit 44 executes the above operations. In step S6, the data frame DF or the data packet DP is transmitted to the first wireless communication terminal 3A or the second wireless communication terminal 3B, respectively. Specifically, the communication unit 44 executes the above-mentioned operations.

[0042] 2. Second embodiment In the first embodiment, the forwarding means 61 is provided in the controller 7 , but the forwarding means 61 may be provided in the wireless base station 5 . Such an example will be described as a second embodiment with reference to Figures 9 and 10. Figure 9 is a schematic diagram showing the overall configuration of a wireless communication system according to the second embodiment. Figure 10 is a block diagram showing the control configuration of a wireless base station and a controller. The basic configuration and operation of the wireless communication system 1A according to the second embodiment are the same as those of the first embodiment.

[0043] The wireless communication system 1A includes a plurality of first wireless communication terminals 3A, a plurality of second wireless communication terminals 3B, a plurality of wireless base stations 5, and a controller .

[0044] The control configuration of the wireless base station 5 and the controller 7 will be described with reference to Fig. 10. Fig. 10 is a block diagram showing the control configuration of the wireless base station and the controller. The wireless base station 5 has a communication unit 41, a destination determination unit 42, and a data conversion unit 43. The communication unit 41, the destination determination unit 42, and the data conversion unit 43 realize a transfer means 61A as functions executed by the CPU according to a program. The destination determination unit 42 determines the destination of the data packet DP. Based on the determination result of the destination determination unit 42, the communication unit 41 transfers the data packet DP as is, or converts the data packet DP into a predetermined data frame DF by the data conversion unit 43 and then transfers it (described later). Since a plurality of wireless base stations 5 can perform data conversion in this way, the processing load can be distributed.

[0045] The data conversion in the wireless base station 5 will be described with reference to Figures 11 and 12. Figures 11 and 12 are schematic diagrams showing the data conversion in the wireless base station. In the downstream communication, conventionally, the data packet DP transmitted from the server 11A is transmitted to the first wireless communication terminal 3A or the second wireless communication terminal 3B via the controller 7, the router 13, and the wireless base station 5. In this embodiment, as described below, the data packet DP may or may not be converted into a data frame DF.

[0046] The controller 7 determines which wireless base station 5 the first wireless communication terminal 3A or the second wireless communication terminal 3B, which is the destination of the data packet DP sent from the server 11A, is in the communication range of, and sends the data packet DP to that wireless base station 5.

[0047] As an explanation of the case of conversion, the data converter 43 of the wireless base station 5 converts the data packet DP into a data frame DF when the destination of the data packet DP is any one of the multiple first wireless communication terminals 3A, as shown in Fig. 11. Specifically, the wireless base station 5 converts the data packet DP (MAC / IP / UDP / DATA) into a data frame DF (RU / SRC(IP / PORT) / DATA). As an explanation of the case where no conversion is performed, when the destination of the data packet DP is one of the multiple second wireless communication terminals 3B, the data conversion unit 43 of the wireless base station 5 transfers the data packet DP to the second wireless communication terminal 3B without performing the above conversion, as shown in Fig. 12. Note that in the wireless base station 5, the MAC header of the data packet DP is replaced with an RU header.

[0048] Upstream communication from the first wireless communication terminal 3A will be described with reference to Fig. 13. Fig. 13 is a schematic diagram showing data conversion in a wireless base station. The data conversion unit 43 of the wireless base station 5 converts the data frame DF into a data packet DP. Specifically, the data frame DF (RU / DST(IP / PORT) / DATA) is converted into a data packet DP (MAC / IP / UDP / DATA).

[0049] As shown in Fig. 13, in this embodiment, if the destination of the data packet DP transmitted from the server 11A is the second wireless communication terminal 3B, the data packet DP is not converted. Therefore, the processing load for converting the data packet DP is reduced overall. In other words, data conversion is not performed uniformly, but is performed as needed. Since the data packet DP is converted into a data frame DF with a relatively small capacity, the communication load of the wireless communication system 1A can be reduced.

[0050] 3. Other embodiments Although several embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications are possible without departing from the gist of the invention. In particular, several embodiments and modifications described in this specification can be arbitrarily combined as necessary. The present invention is most suitable for industrial equipment such as a transport system, but can also be applied to other devices and systems. In order to reduce the size of data packets, in addition to or in place of removing the headers described above, the amount of data contained in a single packet may be reduced. [Industrial Applicability]

[0051] The present invention can be broadly applied to a wireless network comprising a plurality of wireless communication terminals, a wireless base station wirelessly connected to the wireless communication terminals, and a controller that communicates with the wireless communication terminals via the wireless base station and is communicatively connected to other communication systems via a specified network. [Explanation of symbols]

[0052] 1: Wireless communication system 3A: Wireless communication terminal 3B: Wireless communication terminal 5: Wireless base station 7: Controller 9: Transport cart 11A: Server 11B: Server 13: Router 15: Network 41: Communications Department 42: Destination decision unit 43: Data conversion section 44: Communications Department 45: Destination decision unit 46: Data conversion section 61:Transfer means DF : Data frame DP: Data packet

Claims

1. A plurality of wireless communication terminals; a wireless base station wirelessly connected to the wireless communication terminal; a controller that communicates with the wireless communication terminal via the wireless base station and is communicatively connected to another communication system via a predetermined network, a transfer means for converting the data packet transmitted from the other communication system to a specific wireless communication terminal among the plurality of wireless communication terminals and transferring the data packet to the specific wireless communication terminal, and for transferring the data packet to the wireless communication terminal without converting the data packet to the specific data frame if the destination of the data packet transmitted from the other communication system is a wireless communication terminal other than the specific wireless communication terminal among the plurality of wireless communication terminals; There are a plurality of the specific wireless communication terminals, when a destination of a predetermined data frame transmitted from the specific wireless communication terminal is another specific wireless communication terminal, the forwarding means forwards the predetermined data frame to the other wireless communication terminal without converting it into the data packet. Wireless communication system.

2. 2. The wireless communication system according to claim 1, wherein, when a destination of a specific data frame transmitted from a specific wireless communication terminal is another communication system, the forwarding means converts the specific data frame into the data packet and forwards it to the other communication system.

3. The wireless communication system according to claim 1 , wherein the forwarding means is provided in the controller.

4. The wireless communication system according to claim 1 , wherein the forwarding means is provided in the wireless base station.

5. The data frame includes at least a destination and a data portion to be transmitted, 5. The wireless communication system according to claim 1, wherein the data packet is a communication packet in a general-purpose communication protocol format transferred over Ethernet.

6. 6. The wireless communication system according to claim 1, wherein the wireless communication terminal is mounted on a moving object.

7. A controller for use in a wireless communication system including a plurality of wireless communication terminals and a wireless base station wirelessly connected to the wireless communication terminals, a wireless communication system that communicates with the wireless communication terminal via the wireless base station and is communicatively connected to another communication system via a predetermined network; a transfer means for converting a data packet transmitted from the other communication system to a predetermined data frame and transferring the data packet to a wireless base station wirelessly connected to the wireless communication terminal when the destination of the data packet transmitted from the other communication system is a wireless communication terminal other than the specific wireless communication terminal among the multiple wireless communication terminals, and for transferring the data packet to the wireless base station wirelessly connected to the wireless communication terminal without converting the data packet to the predetermined data frame when the destination of the data packet transmitted from the other communication system is a wireless communication terminal other than the specific wireless communication terminal among the multiple wireless communication terminals, There are a plurality of the specific wireless communication terminals, when a destination of a predetermined data frame transmitted from the specific wireless communication terminal is another specific wireless communication terminal, the forwarding means forwards the predetermined data frame to the other wireless communication terminal without converting it into the data packet. controller.

8. A wireless base station used in a wireless communication system including a plurality of wireless communication terminals and a controller communicatively connected to another communication system via a predetermined network, a wireless communication terminal connected to the controller; a transfer means for converting a data packet transmitted from the other communication system via the controller to a specific wireless communication terminal among the plurality of wireless communication terminals, converting the data packet into a specific data frame and transferring the data packet to the specific wireless communication terminal, and for transferring a data packet transmitted from the other communication system via the controller to a wireless communication terminal other than the specific wireless communication terminal among the plurality of wireless communication terminals, without converting the data packet into the specific data frame, There are a plurality of the specific wireless communication terminals, when a destination of a predetermined data frame transmitted from the specific wireless communication terminal is another specific wireless communication terminal, the forwarding means forwards the predetermined data frame to the other wireless communication terminal without converting it into the data packet. Radio base station.

9. A data packet transfer method in a wireless communication system including a plurality of wireless communication terminals, a wireless base station wirelessly connected to the wireless communication terminals, and a controller that communicates with the wireless communication terminals via the wireless base station and is communicatively connected to another communication system via a predetermined network, comprising: determining whether a destination of a data packet transmitted from the other communication system is a specific wireless communication terminal among the plurality of wireless communication terminals; converting the data packet into a predetermined data frame if the wireless communication terminal is the specific wireless communication terminal, and not converting the data packet if the wireless communication terminal is a wireless communication terminal other than the specific wireless communication terminal; transferring the predetermined data frame or the data packet to the wireless communication terminal; Including, There are a plurality of the specific wireless communication terminals, when a destination of a predetermined data frame transmitted from the specific wireless communication terminal is another specific wireless communication terminal, transferring the predetermined data frame to the other wireless communication terminal without converting it into the data packet. Data packet transfer method.

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