Wireless terminal and wireless communication method

Abstract

The present invention achieves a wireless terminal that appropriately selects a communication path even when handover occurs. The wireless terminal comprises a path selection unit that selects a communication path for an application to communicate on from among a plurality of wireless communication paths on the basis of communication performance and communication requirements. If a handover management unit determines that there is a condition in which handover may occur in the wireless communication path, the path selection unit changes the communication path of the application using the wireless communication path which is in the condition in which handover may occur.

Description

Wireless terminal and wireless communication method

[0001] The present disclosure relates to a wireless terminal and a wireless communication method.

[0002] Conventionally, in order to improve communication performance, technological developments have been carried out in each RAT (Radio Access Technology) and standards have advanced, making it possible to maintain a certain level of communication quality even when large-volume communication is performed.

[0003] For example, in the case of mobile communications, communication capacity has improved with the advancement of technological developments such as 3G (third generation mobile communications system), 4G (fourth generation mobile communications system) / LTE (Long Term Evolution), and 5G (fifth generation mobile communications system). 5G has further expanded use cases with operating modes such as high reliability and low latency mode and multiple simultaneous connection mode.

[0004] Furthermore, in wireless LAN (Local Area Network) communications, advances in technological development, such as IEEE802.11n, IEEE802.11ac, and IEEE802.11ax, have led to improvements in communication capacity and simultaneous connectivity.

[0005] In addition to improving the performance of each RAT, methods are also being used to ensure service quality by implementing Quality of Service (QoS) in network equipment on the network infrastructure side and prioritizing specific communications. For example, since delays and packet loss have a significant impact on the quality of voice calls, the quality of voice calls is ensured by prioritizing and controlling voice traffic at points where multiple traffic flows coexist.

[0006] Network slicing is a technology that virtually divides a single network infrastructure to realize multiple network services tailored to specific applications, and its use in conjunction with 5G is being considered. For example, consider three applications: (1) video distribution, which requires high-capacity communication performance; (2) IoT and BEMS (Building and Energy Management System), which require communication with multiple devices simultaneously; and (3) remote control of robots, which requires low-latency communication performance. In this case, it is being considered to virtually separate one 5G infrastructure into three infrastructures using network slicing and provide services to each with parameters appropriate for the application: (1) eMBB (enhanced Mobile Broadband), (2) mMTC (massive Machine Type Communication), and (3) URLLC (Ultra-Reliable and Low Latency Communications).

[0007] The following Patent Document 1 discloses an information processing device having an acquisition means for acquiring information indicating the communication quality of a first wireless communication path and information indicating the communication quality of a second wireless communication path, and a control means for executing communication of the application on a communication path including the first wireless communication path and the second wireless communication path according to the application, the communication quality of the first wireless communication path, and the communication quality of the second wireless communication path.

[0008] International Publication No. 2023 / 084605

[0009] In the information processing device described in the above-mentioned Patent Document 1, for example, if the wireless communication path includes a wireless communication path of distributed control in which a terminal autonomously selects a connection destination, such as a wireless LAN, there is a possibility that an appropriate communication path cannot be selected when a handover occurs.

[0010] The present disclosure has been made in consideration of the above-mentioned problems, and an exemplary purpose thereof is to provide a technology that is capable of appropriately selecting a communication path even when a handover occurs.

[0011] A wireless terminal according to an exemplary aspect of the present disclosure comprises a performance estimation means for estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies, an information acquisition means for acquiring information regarding the communication requirements required for each of a plurality of applications, a handover management means for managing handover, and a route selection means for selecting a communication path through which the application will communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements, and when the handover management means determines that the wireless communication path is in a state in which the handover may occur, the route selection means changes the communication path of the application that is using the wireless communication path in a state in which the handover may occur.

[0012] A wireless communication method according to an exemplary aspect of the present disclosure includes estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies, acquiring information regarding the communication requirements required for each of a plurality of applications, managing handover, and selecting a communication path from among the plurality of wireless communication paths through which the application will communicate based on the communication performance and the communication requirements, and if, in managing the handover, it is determined that the wireless communication path is in a state in which the handover may occur, in selecting the communication path, changing the communication path of the application that is using the wireless communication path in a state in which the handover may occur.

[0013] According to an exemplary aspect of the present disclosure, an exemplary effect is achieved in that a communication path can be appropriately selected even when a handover occurs.

[0014] FIG. 1 is a block diagram showing an example configuration of a wireless terminal according to the present disclosure. FIG. 2 is a flow diagram showing the flow of a wireless communication method according to the present disclosure. FIG. 3 is a block diagram showing an example configuration of a wireless communication system according to the present disclosure. FIG. 4 is a block diagram showing an example configuration of a wireless terminal according to the present disclosure. FIG. 5 is a block diagram showing an example configuration of a terminating device according to the present disclosure. FIG. 6 is a flow diagram showing the processing flow of an information acquisition unit of a wireless terminal according to the present disclosure. FIG. 7 is a flow diagram showing the processing flow of a route selection unit of a wireless terminal according to the present disclosure. FIG. 8 is a flow diagram showing the processing flow of a route control unit of a wireless terminal according to the present disclosure. FIG. 9 is a block diagram showing the configuration of a computer functioning as a wireless terminal according to the present disclosure.

[0015] The following are examples of embodiments of the present invention. However, the present invention is not limited to the exemplary embodiments shown below, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means employed in the exemplary embodiments shown below may also be included in the scope of the present invention. Furthermore, embodiments obtained by appropriately omitting some of the technical means employed in the exemplary embodiments shown below may also be included in the scope of the present invention. Furthermore, the effects mentioned in the exemplary embodiments shown below are examples of effects expected in the exemplary embodiments, and do not define the scope of the present invention. In other words, embodiments that do not exhibit the effects mentioned in the exemplary embodiments shown below may also be included in the scope of the present invention.

[0016] [First Exemplary Embodiment] A first exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. This exemplary embodiment is a basic form for each of the exemplary embodiments described below. Note that the scope of application of each technical means employed in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technical means employed in this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical obstacles arise. Furthermore, each technical means shown in the drawings referenced to explain this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical obstacles arise.

[0017] (Configuration of Wireless Terminal 1) The configuration of the wireless terminal 1 will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example configuration of the wireless terminal 1. As shown in Fig. 1, the wireless terminal 1 includes a performance estimation unit 11, an information acquisition unit 12, a handover management unit 13, and a route selection unit 14.

[0018] The performance estimation unit 11 estimates the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies (RATs), such as mobile communications such as 3G, 4G / LTE, 5G, and local 5G, wireless LANs such as IEEE802.11n, IEEE802.11ac, and IEEE802.11ax, and wireless communication technologies such as WiFi (Wide Fidelity) (registered trademark).

[0019] The performance estimation unit 11 periodically monitors the communication performance of the wireless communication path of each RAT, and notifies the acquired communication performance to the path selection unit 14. The communication performance is, for example, the communication rate, maximum delay time, average delay time, etc. of the wireless communication path of each RAT.

[0020] The information acquisition unit 12 acquires information about communication requirements required for each of a plurality of applications. For example, the information acquisition unit 12 acquires communication requirements for each application set by the user.

[0021] The communication requirements are, for example, information such as a communication rate, a maximum delay time, an average delay time, etc. required for each application. The information acquiring unit 12 may also acquire information such as a source IP address, a source port number, a destination IP address, a destination port number, and a protocol number set by the user as the communication requirements required for one application.

[0022] The handover management unit 13 manages handover. Among RATs, there are those that control the destination base station by centralized control from the base station side, such as mobile networks such as LTE and 5G, and those that use distributed control, such as wireless LAN, in which a wireless terminal autonomously selects a destination.

[0023] In centralized control such as LTE and 5G, methods are used to prevent disconnection times and packet loss when switching connections by synchronizing the timing of changes in connection destination and sharing data between the base stations at the source and destination.

[0024] On the other hand, in distributed control such as wireless LAN, the timing of connection switching and the selection of connection destination depend on the wireless terminal, so disconnection and packet loss are likely to occur during switching, which can often cause application disconnection.Even if it does not go as far as disconnection, searching for a base station with a frequency band different from the currently connected frequency in order to switch to the new base station makes communication impossible and causes degradation of delay performance.

[0025] The handover management unit 13 mainly manages handovers in distributed control such as wireless LAN, and determines that a handover may occur when, for example, the reception strength of radio waves in a wireless communication path is below a predetermined value.

[0026] The route selection unit 14 selects a communication route for the application to communicate from among a plurality of wireless communication routes based on the communication performance and communication requirements. For example, the route selection unit 14 selects a communication route for the application to communicate, the communication performance of which matches the communication requirements of the application.

[0027] If the handover management unit 13 determines that a handover may occur on the wireless communication path, the route selection unit 14 changes the communication path of the application that is using the wireless communication path in a state where a handover may occur.

[0028] For an application that is using a wireless communication path in a state where handover may occur, the route selection unit 14 again selects a communication path that matches the communication performance of another wireless communication path and the communication requirements required by the application, and sets this as the communication path through which the application will communicate.

[0029] (Effects of Wireless Terminal 1) As described above, in the wireless terminal 1, when the handover management unit 13 determines that a handover may occur on a wireless communication path, the path selection unit 14 changes the communication path of an application that uses the wireless communication path that is in a state where a handover may occur. Therefore, it is possible to prevent in advance a deterioration in communication performance due to scanning of other frequency bands, switching of connection destinations, etc., that accompanies a handover, and to select an optimal communication path.

[0030] (Flow of Wireless Communication Method) The flow of the wireless communication method S1 will be described with reference to Fig. 2. Fig. 2 is a flow diagram showing the flow of the wireless communication method S1. As shown in Fig. 2, the wireless communication method S1 includes processes S11 to S15.

[0031] First, the performance estimation unit 11 estimates the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies (S11). The performance estimation unit 11 periodically monitors the communication performance of the wireless communication path of each RAT, and notifies the acquired communication performance to the path selection unit 14. The communication performance includes, for example, the communication rate, maximum delay time, and average delay time of the wireless communication path of each RAT.

[0032] Next, the information acquisition unit 12 acquires information on communication requirements required for each of the plurality of applications (S12). For example, the information acquisition unit 12 acquires communication requirements for each application set by the user.

[0033] Next, the route selection unit 14 selects a communication route through which the application will communicate from among the plurality of wireless communication routes based on the communication performance and communication requirements (S13). For example, the route selection unit 14 selects a communication route through which the application will communicate, the communication performance of which matches the communication requirements of the application.

[0034] Next, the handover management unit 13 determines whether or not the wireless communication path is in a state where a handover can occur (S14). If the handover management unit 13 determines that the wireless communication path is not in a state where a handover can occur (S14, No), the handover management unit 13 repeats the process of step S14.

[0035] Furthermore, if the handover management unit 13 determines that a handover may occur on the wireless communication path (Yes in S14), the path selection unit 14 changes the communication path of the application that is using the wireless communication path in the state where a handover may occur (S15).

[0036] (Effects of the Wireless Communication Method) As described above, in the wireless communication method S1, when the handover management unit 13 determines that a wireless communication path is in a state where a handover may occur, the path selection unit 14 changes the communication path of the application that is using the wireless communication path in the state where a handover may occur. Therefore, it is possible to prevent in advance a deterioration in communication performance due to scanning of other frequency bands, switching of connection destinations, etc., that accompanies a handover, and it is possible to select an optimal communication path.

[0037] Second Exemplary Embodiment A second exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. Components having the same functions as those described in the above exemplary embodiment will be denoted by the same reference numerals, and their description will be omitted as appropriate. The scope of application of each technical means employed in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technical means employed in this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical hindrance occurs. Furthermore, each technical means shown in each drawing referenced to describe this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical hindrance occurs.

[0038] (Configuration of wireless communication system 100) The configuration of the wireless communication system 100 will be described with reference to FIG. 3. FIG. 3 is a block diagram showing the configuration of the wireless communication system 100. As an example of the wireless communication system 100, a system will be described that automates and unmanned logistics operations within a factory by attaching and detaching a workpiece (hereinafter referred to as a workpiece) such as metal to and from a machine tool in a factory environment and transporting the removed workpiece to the next processing machine or stocker by autonomous travel. It is assumed that this factory has a local 5G infrastructure and a wireless LAN infrastructure.

[0039] The wireless communication system 100 includes an autonomous mobile robot 20, a 5G (local 5G) base station 31, a wireless LAN access point (AP) 32, a production control controller 33, a mobile control controller 34, an analysis server 35, and a terminal device 36.

[0040] The autonomous traveling robot 20 includes a wireless terminal 1A, an arm robot 21, a traveling robot 22, and a camera 23. The wireless terminal 1A performs wireless communication with a 5G base station 31, which is a plurality of RATs, and a wireless LAN access point 32. Details of the wireless terminal 1A will be described later.

[0041] The arm robot 21 operates according to instructions received from the production control controller 33 via the wireless terminal 1A, and periodically transmits the operating status and operating results to the production control controller 33 via the wireless terminal 1A.

[0042] The traveling robot 22 travels according to travel instructions received from the travel controller 34 via the wireless terminal 1A. The camera 23 captures images of the traveling direction of the autonomous traveling robot 20 and transmits the camera images to the analysis server 35 via the wireless terminal 1A.

[0043] The production control controller 33 manages the entire wireless communication system 100 and instructs each section on the next task for the autonomous mobile robot 20. For example, the production control controller 33 transmits the next task instruction to the mobile controller 34 and the arm robot 21 of the autonomous mobile robot 20 according to the production status.

[0044] The analysis server 35 receives the video from the camera 23 via the 5G base station 31 or the wireless LAN access point 32 and analyzes the received video. The analysis server 35 then compares the analysis results with map information learned in advance to estimate the current position of the autonomous mobile robot 20 and notifies the travel control controller 34 of the position information of the autonomous mobile robot 20.

[0045] The traveling controller 34 creates traveling instructions based on the position information of the autonomous traveling robot 20 received from the analysis server 35 and the next work information received from the production control controller 33. Then, the traveling controller 34 transmits the traveling instructions to the traveling robot 22 of the autonomous traveling robot 20 via the 5G base station 31 or the wireless LAN access point 32.

[0046] Similar to the wireless terminal 1A, the terminating device 36 selects a communication path corresponding to an application from among a plurality of wireless communication paths of each RAT (5G, wireless LAN), and performs wireless communication. Details of this terminating device 36 will be described later.

[0047] 4 is a block diagram showing an example of the configuration of the wireless terminal 1 A. The wireless terminal 1 A includes a performance estimation unit 11 A, an information acquisition unit 12 A, a handover management unit 13 A, a route selection unit 14 A, a route storage unit 15, a route control unit 16, a tunnel IF unit (RAT1) 17, a tunnel IF unit (RAT2) 18, and a bridge IF unit 19.

[0048] The tunnel IF unit 17 is a communication IF corresponding to RAT1 (5G) and performs wireless communication with the 5G base station 31. The tunnel IF unit 18 is a communication IF corresponding to RAT2 (wireless LAN) and performs wireless communication with the wireless LAN access point 32.

[0049] The bridge IF unit 19 is connected to the arm robot 21 , the traveling robot 22 and the camera 23 , and inputs and outputs various data between the route control unit 16 and the arm robot 21 , the traveling robot 22 and the camera 23 .

[0050] The performance estimation unit 11A estimates the communication performance of each of a plurality of wireless communication paths using a plurality of RATs (5G, wireless LAN). The performance estimation unit 11A periodically monitors the communication performance of the wireless communication path of each RAT and notifies the path selection unit 14A of the acquired communication performance. The communication performance may be, for example, the communication rate, maximum delay time, average delay time, etc. of the wireless communication path of each RAT.

[0051] The information acquisition unit 12A acquires information about communication requirements required for each of a plurality of applications. For example, the information acquisition unit 12A acquires communication requirements for each application set by the user.

[0052] The communication requirements are, for example, information such as the communication rate, maximum delay time, average delay time, etc. required for each application. In addition, the information acquisition unit 12 acquires information such as a source IP address, a source port number, a destination IP address, a destination port number, and a protocol number set by the user as the communication requirements required for one application.

[0053] For example, if the application is video data, the source IP address is set to the IP address of the camera 23, the source port number is set to any, the destination IP address is set to the IP address of the analysis server 35, the destination port number is set to 5004, the protocol number is set to 17, etc. Furthermore, the communication requirements are set to a communication rate of 20 Mbps, a delay of 2000 ms, a jitter of 2000 ms, etc. Since the user often cannot grasp the communication requirements, a certain number of parameter sets may be prepared on the wireless terminal 1A side, and the user may be allowed to select from bandwidth priority, maximum delay priority, average delay priority, jitter priority, best effort, background, etc.

[0054] The handover management unit 13A manages handovers. Delay performance, which is one of the communication performances, tends to have a low correlation with reception strength, which is generally used as a judgment index for switching connection destinations. Specifically, delay performance remains almost unchanged from a state where reception strength is high to a state where reception strength is very low, and a deterioration in delay performance can be observed at a level just before connection is impaired.

[0055] As described above, distributed control wireless terminals often change the connection destination at a certain reception strength before disconnecting, or change the connection destination based on information such as a communication rate that is highly correlated with reception strength. Therefore, while an application is communicating on a wireless LAN communication path where reception strength is somewhat low but delay performance is not yet poor, the wireless terminal may decide to scan other frequency bands or switch the connection destination, which may result in the communication by the application being disconnected.

[0056] For example, the handover management unit 13A determines that a handover may occur when the radio wave reception strength on the wireless communication path is equal to or less than a predetermined value. As a result, the path selection unit 14A can change the communication path of an application that uses the wireless communication path in the state where a handover may occur before scanning other frequency bands or switching the connection destination.

[0057] 3, there are three types of communications that pass through the wireless section: upstream video data from the camera 23 to the analysis server 35, downstream travel control data from the travel controller 34 to the autonomous traveling robot 20, and bidirectional arm control data between the production controller 33 and the arm robot 21.

[0058] The communication requirements for video data vary depending on the resolution, frame rate, compression method, compression ratio, etc. The higher the resolution, the more accurate the position estimation, and the higher the frame rate, the higher the sampling rate for position estimation. However, there is a trade-off with the communication rate and the performance of the analysis server 35, and video data generally requires large-volume communication.

[0059] Furthermore, in order to ensure a fail-safe during disconnection, if the autonomous mobile robot 20 does not receive travel control data for a certain period of time, it will make a safety stop on the spot or return to the base to wait. Therefore, it is important that the travel control data has a delay performance that does not exceed a certain timeout period. In other words, the travel control data is required to have a maximum delay that is shorter than the certain period of time.

[0060] Furthermore, arm control data is sent and received via cyclic communication, which is common in production control systems, and the shorter the delay, the more precise the control and the shorter the work time. Therefore, arm control data is required to have a short average delay time.

[0061] The path selection unit 14A selects a communication path for an application to communicate from among multiple wireless communication paths based on communication performance and communication requirements. For example, assume that the communication performance estimated by the performance estimation unit 11A is 10 Mbps for local 5G upload throughput and 50 Mbps for wireless LAN upload throughput. If the communication requirement for the video data communication rate acquired by the information acquisition unit 12A is 20 Mbps, the path selection unit 14A selects the wireless LAN communication path as the wireless communication path for the video data.

[0062] Furthermore, the communication performance estimated by the performance estimation unit 11A is assumed to be a maximum delay of 30 ms, an average delay of 20 ms, and a minimum delay of 10 ms for local 5G, and a maximum delay of 150 ms, an average delay of 5 ms, and a minimum delay of 2 ms for wireless LAN. If the communication requirement for the maximum delay of the driving control data acquired by the information acquisition unit 12A is 100 ms or less, the route selection unit 14A selects the local 5G communication route as the wireless communication route for the driving control data.

[0063] Furthermore, if the communication requirement for the average delay of the arm control data acquired by the information acquisition unit 12A is 10 ms, the path selection unit 14A selects the wireless LAN communication path as the wireless communication path for the arm control data.

[0064] The communication performance and requirements shown here are indices such as throughput, delay performance, and transmission efficiency, taking into account each communication direction and statistical information such as maximum, average, minimum, and variance values.

[0065] Furthermore, the information acquisition unit 12A may acquire priority information such as QoS information for each application. For example, if there are two applications that require throughput performance and the requirements of each application can be met, but sending both applications simultaneously over the same path would result in the requirements not being met, the application with the lower priority may be sent over another path based on the priority information. Additionally, a path for sending the aforementioned low-priority communications may be acquired from the user.

[0066] The route storage unit 15 stores the correspondence between the communication route selected by the route selection unit 14A and the application.

[0067] If the contents of the packet correspond to an application stored in the route storage unit 15, the route control unit 16 transmits the packet via a communication route corresponding to the application. For example, when video data is transmitted from the camera 23 to the analysis server 35, the route control unit 16 receives the video data via the bridge IF 19. The route control unit 16 searches for a match with an application stored in the route storage unit 15. If the video data matches the application registered, the route control unit 16 identifies the wireless LAN that is the communication route used by the video data, and forwards the packet from the tunnel IF unit 18 used as the communication route to the tunnel IF unit of the termination device 36 opposite the tunnel IF unit 18. The forwarded packet is forwarded via the wireless LAN access point 32 to the corresponding tunnel IF unit of the termination device 36, and then forwarded to the analysis server 35 via the bridge IF unit 363 described below.

[0068] Furthermore, if an application corresponding to the contents of a packet is not stored in the route storage unit 15, the route control unit 16 transfers the packet via a specified route. The specified route may be, for example, a route preset by a user, or may be determined based on communication performance, such as a route with a large communication capacity being set as the specified route.

[0069] 5 is a block diagram showing an example configuration of the termination device 36 according to the present disclosure. The termination device 36 includes tunnel IF units 361 and 362, a bridge IF unit 363, a route control unit 364, and a route storage unit 365.

[0070] The tunnel IF unit 361 is a communication IF compatible with RAT1 (5G) and performs wireless communication with the tunnel IF unit 17 of the opposing wireless terminal 1A. The tunnel IF unit 362 is a communication IF compatible with RAT2 (wireless LAN) and performs wireless communication with the tunnel IF unit 18 of the opposing wireless terminal 1A.

[0071] The bridge IF unit 363 is connected to the 5G base station 31, the wireless LAN access point 32, the production control controller 33, the driving control controller 34, and the analysis server 35, and performs input and output of various data between the route control unit 364 and the 5G base station 31, the wireless LAN access point 32, the production control controller 33, the driving control controller 34, and the analysis server 35.

[0072] The route control unit 364 receives information about the communication routes used by each application selected by the route selection unit 14A of the wireless terminal 1A from the wireless terminal 1A and stores the information in the route storage unit 365. If the contents of a packet correspond to an application stored in the route storage unit 365, the route control unit 364 transmits the packet via the communication route corresponding to the application. If the route storage unit 365 does not store an application corresponding to the contents of the packet, the route control unit 364 forwards the packet via a specified route.

[0073] 6 is a flow diagram showing the flow of processing by the information acquisition unit 12A of the wireless terminal 1A according to the present disclosure. As shown in FIG. 6, the processing method S2 of the information acquisition unit 12A includes steps S21 to S23.

[0074] First, the information acquisition unit 12A acquires a plurality of pieces of application information (S21). The application information is, for example, information about what type of data each application handles.

[0075] Next, the information acquisition unit 12A acquires communication requirements for each application (S22), and then determines whether or not to end the setting of communication requirements for the applications (S23).

[0076] If a communication requirement for another application is set (S23, No), the information acquisition unit 12A returns to step S21 and repeats the subsequent processes. If a communication requirement for another application is not set (S23, Yes), the information acquisition unit 12A ends the process.

[0077] 7 is a flow diagram showing the flow of processing by the route selection unit 14A of the wireless terminal 1A according to the present disclosure. As shown in FIG. 7, the processing method S3 of the route selection unit 14A includes steps S31 to S37.

[0078] First, the route selection unit 14A acquires the communication performance of each wireless communication route estimated by the performance estimation unit 11A (S31), and then acquires application information and communication requirements from the information acquisition unit 12A (S32).

[0079] Next, the path selection unit 14A selects a wireless communication path based on the communication performance of each wireless communication path and the communication requirements for each application (S33). For example, the path selection unit 14A acquires from the performance estimation unit 11A the communication performance of 10 Mbps for local 5G upload and 50 Mbps for wireless LAN upload. If the path selection unit 14A acquires from the information acquisition unit 12A the communication requirement of 20 Mbps for video data, the path selection unit 14A selects the wireless LAN as the communication path for video data.

[0080] Furthermore, suppose that the route selection unit 14A acquires from the performance estimation unit 11A communication performance information that the maximum delay of local 5G is 30 ms, the average delay is 20 ms, and the minimum delay is 10 ms, and that the maximum delay of wireless LAN is 150 ms, the average delay is 5 ms, and the minimum delay is 2 ms. If the route selection unit 14A acquires from the information acquisition unit 12A a communication requirement that the maximum delay of driving control data is 100 ms or less, then the route selection unit 14A selects local 5G as the communication path for driving control data.

[0081] Furthermore, if the path selection unit 14A acquires from the information acquisition unit 12A a communication requirement that the average delay of the arm control data be 10 ms or less, the path selection unit 14A selects the wireless LAN as the communication path for the arm control data. Then, the path selection unit 14A stores the application information and the corresponding communication path (path information) in the path storage unit 15A (S34).

[0082] Next, the route selection unit 14A determines whether there is an application for which a route has not been selected (S35). If there is an application for which a route has not been selected (Yes in S35), the route selection unit 14A returns to step S33 and repeats the subsequent processes.

[0083] If there is no application that has not selected a route (S35, No), the handover management unit 13A determines whether or not a handover can occur on the wireless communication route (S36). If the handover management unit 13A determines that a handover cannot occur on the wireless communication route (S36, No), the route selection unit 14A ends the process.

[0084] Furthermore, if the handover management unit 13A determines that a handover may occur on the wireless communication path (Yes in S36), the path selection unit 14A changes the communication path of the application that uses the wireless communication path in the state where a handover may occur (S37). For example, the path selection unit 14A changes the communication path to a communication path that best matches the communication performance estimated by the performance estimation unit 11A and the communication requirements of the application, from among communication paths other than the communication path where a handover may occur.

[0085] 8 is a flow diagram showing the flow of processing by the route control unit 16 of the wireless terminal 1A according to the present disclosure. As shown in FIG. 8, the processing method S4 of the route control unit 16 includes steps S41 to S45.

[0086] First, the route control unit 16 receives a packet via the bridge IF unit 19 (S41). Then, the route control unit 16 compares the received packet with the information stored in the route storage unit 15 (S42), and determines whether or not the route storage unit 15 contains corresponding application information (S43).

[0087] If the route storage unit 15 has the corresponding application information (Yes at S43), the route control unit 16 transfers the packet from the communication route corresponding to the application registered in the route storage unit 15 (S44).

[0088] If the route storage unit 15 does not have the corresponding application information (S43, No), the route control unit 16 transfers the packet via a specified route (S45). The specified route may be, for example, a route preset by the user, or may be determined based on communication performance, such as a route with a large communication capacity.

[0089] In the second exemplary embodiment, two RATs, local 5G and wireless LAN, have been described as an example, but the present invention can be expected to be effective if there are multiple communication paths with different characteristics. Therefore, the present invention can be expected to be effective even if it is combined with a wireless LAN that can cover long distances, such as IEEE 802.11ah, a conventional wireless LAN using 2.4 GHz or 5 GHz, or a wireless LAN using 6 GHz, which has been approved for use in recent years. Various other configurations, such as carrier 5G and wireless LAN, local 5G and carrier 5G, or local 5G, carrier 5G, and wireless LAN, can also be realized. By properly setting the application requirements, it becomes possible to autonomously use each RAT while taking advantage of its characteristics.

[0090] Furthermore, in exemplary embodiment 2, the wireless terminal 1A selects the route, but by also providing the termination device 36 with a performance estimation unit 11A, an information acquisition unit 12A, and a route selection unit 14A and having it perform similar operations, it may be possible to select the optimal communication route depending on the communication direction when the communication quality differs between uplink and downlink communications, as in mobile communications, and further improve service quality.

[0091] Furthermore, as described above, in the case of including a RAT that has a long disconnection time during handover due to movement or obstruction, such as a wireless LAN, the handover management unit 13A is provided to determine whether or not to execute handover based on the communication performance estimated by the performance estimation unit 11 A. Then, if there is an application that uses a wireless route that executes handover when handover is executed, the handover management unit 13A overwrites the information in the route storage unit 15 so that the next route that satisfies the requirements is used, and after the handover is completed, overwrites the information in the route storage unit 15 so that the original route is used, thereby reducing the effects of communication interruption and degradation due to handover.

[0092] (Effects of Wireless Terminal 1A) As described above, in wireless terminal 1A, when the content of a packet corresponds to an application stored in route storage unit 15, route control unit 16 transmits the packet via a communication route corresponding to the application. Therefore, an effect is obtained in which the packet can be transmitted via an appropriate communication route.

[0093] In addition, in the wireless terminal 1A, the handover management unit 13A determines that a handover may occur when the received signal strength of the radio wave on the wireless communication path is equal to or less than a predetermined value, thereby preventing disconnection and packet loss during switching associated with the handover process.

[0094] Furthermore, in the wireless terminal 1A, the communication performance includes at least the communication rate, the maximum delay time, and the average delay time. Therefore, it is possible to obtain an effect that a communication path that meets the communication requirements of an application can be appropriately selected.

[0095] [Example of Software Implementation] Some or all of the functions of the wireless terminals 1 and 1A (hereinafter also referred to as "each of the wireless terminals") may be implemented by hardware such as an integrated circuit (IC chip), or by software.

[0096] In the latter case, each of the wireless terminals is realized by, for example, a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in Fig. 9. Fig. 9 is a block diagram showing the hardware configuration of computer C that functions as each of the wireless terminals.

[0097] The computer C includes at least one processor C1 and at least one memory C2. The memory C2 stores a program P for causing the computer C to function as each of the above systems. In the computer C, the processor C1 reads and executes the program P from the memory C2, thereby realizing the functions of each of the above wireless terminals.

[0098] The processor C1 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a tensor processing unit (TPU), a quantum processor, a microcontroller, or a combination thereof. The memory C2 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof.

[0099] The computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and for temporarily storing various data. The computer C may also include a communication interface for transmitting and receiving data to and from other devices. The computer C may also include an input / output interface for connecting input / output devices such as a keyboard, a mouse, a display, and a printer.

[0100] The program P can also be recorded on a non-transitory, tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can acquire the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communication network or broadcast waves. The computer C can also acquire the program P via such a transmission medium.

[0101] [Appendix 1] This disclosure includes the techniques described in the following appendices. However, the present invention is not limited to the techniques described in the following appendices, and various modifications are possible within the scope of the claims.

[0102] (Supplementary Note 1) A wireless terminal comprising: a performance estimation means for estimating communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; an information acquisition means for acquiring information relating to communication requirements required for each of a plurality of applications; a handover management means for managing handover; and a route selection means for selecting a communication path for the application to communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements, wherein when the handover management means determines that the wireless communication path is in a state where the handover may occur, the route selection means changes the communication path of the application that is using the wireless communication path in a state where the handover may occur.

[0103] (Supplementary Note 2) The wireless terminal according to Supplementary Note 1 further comprises: a route storage means for storing a correspondence between the communication route selected by the route selection means and the application; and a route control means for transmitting the packet via the communication route corresponding to the application when the content of the packet corresponds to the application stored in the route storage means.

[0104] (Supplementary Note 3) The wireless terminal according to Supplementary Note 1 or 2, wherein the handover management means determines that the handover is likely to occur when a reception strength of radio waves on the wireless communication path is equal to or less than a predetermined value.

[0105] (Supplementary Note 4) The wireless terminal according to any one of Supplementary Notes 1 to 3, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

[0106] (Supplementary Note 5) A wireless communication method comprising: estimating communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; acquiring information on communication requirements required for each of a plurality of applications; managing handover; and selecting a communication path through which the application will communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements, wherein, when it is determined in managing the handover that the wireless communication path is in a state in which the handover may occur, in selecting the communication path, changing the communication path of the application that is using the wireless communication path in a state in which the handover may occur.

[0107] (Supplementary Note 6) The wireless communication method according to Supplementary Note 5, further comprising: storing a correspondence between the selected communication path and the application; and, if the content of a packet corresponds to the stored application, transmitting the packet via the communication path corresponding to the application.

[0108] (Supplementary Note 7) The wireless communication method according to Supplementary Note 5 or 6, wherein in managing the handover, it is determined that the handover may occur when a reception strength of radio waves in the wireless communication path is equal to or less than a predetermined value.

[0109] (Supplementary Note 8) The wireless communication method according to any one of Supplementary Notes 5 to 7, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

[0110] (Supplementary Note 9) A non-transitory recording medium having recorded thereon a control program for causing a computer to execute the following processes: a process of estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; a process of acquiring information on the communication requirements required for each of a plurality of applications; a process of managing handover; and a process of selecting a communication path through which the application will communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements; and when it is determined in the process of managing handover that the wireless communication path is in a state where the handover may occur, in the process of selecting the communication path, changing the communication path of the application that is using the wireless communication path in a state where the handover may occur.

[0111] (Supplementary Note 10) The recording medium according to Supplementary Note 9, further causing the computer to execute the following processes: storing a correspondence between the selected communication path and the application; and, if the contents of a packet correspond to the stored application, transmitting the packet via the communication path corresponding to the application.

[0112] (Supplementary Note 11) The recording medium according to Supplementary Note 9 or 10, wherein in the process of managing the handover, it is determined that the handover is likely to occur when the reception strength of the radio wave in the wireless communication path is equal to or less than a predetermined value.

[0113] (Supplementary Note 12) The recording medium according to Supplementary Note 9 or 10, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

[0114] 1, 1A Wireless terminal 11, 11A Performance estimation unit 12, 12A Information acquisition unit 13, 13A Handover management unit 14, 14A Route selection unit 15, 365 Route storage unit 16, 364 Route control unit 17, 18, 361, 362 Tunnel IF unit 19, 363 Bridge IF unit 20 Autonomous traveling robot 21 Arm robot 22 Traveling robot 23 Camera 31 5G base station 32 Wireless LAN access point 33 Production control controller 34 Travel control controller 35 Analysis server 36 End device 100 Wireless communication system

Claims

1. A wireless terminal comprising: a performance estimation means for estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; an information acquisition means for acquiring information relating to the communication requirements required for each of a plurality of applications; a handover management means for managing handovers; and a route selection means for selecting a communication path for the application to communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements, wherein when the handover management means determines that the wireless communication path is in a state where the handover may occur, the route selection means changes the communication path of the application that is using the wireless communication path in a state where the handover may occur.

2. The wireless terminal according to claim 1, further comprising: a route storage means for storing the correspondence between the communication route selected by the route selection means and the application; and a route control means for transmitting the packet via the communication route corresponding to the application when the contents of the packet correspond to the application stored in the route storage means.

3. The wireless terminal according to claim 1 or 2, wherein the handover management means determines that the handover is likely to occur when the received strength of radio waves on the wireless communication path is equal to or less than a predetermined value.

4. The wireless terminal according to claim 1 or 2, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

5. A wireless communication method comprising: estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; acquiring information regarding the communication requirements required for each of a plurality of applications; managing handover; and selecting a communication path from among the plurality of wireless communication paths through which the application will communicate based on the communication performance and the communication requirements; wherein, when it is determined in managing the handover that the wireless communication path is in a state in which the handover may occur, in selecting the communication path, the method changes the communication path of the application that is using the wireless communication path in a state in which the handover may occur.

6. The wireless communication method according to claim 5, further comprising: storing a correspondence between the selected communication path and the application; and, if the content of a packet corresponds to the stored application, transmitting the packet over the communication path corresponding to the application.

7. The wireless communication method according to claim 5 or 6, wherein, in managing the handover, it is determined that the handover may occur when the received strength of radio waves on the wireless communication path is equal to or less than a predetermined value.

8. The wireless communication method according to claim 5 or 6, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

9. A non-transitory recording medium having recorded thereon a control program for causing a computer to execute the following processes: a process for estimating the communication performance of each of a plurality of wireless communication paths using a plurality of wireless access technologies; a process for acquiring information regarding the communication requirements required for each of a plurality of applications; a process for managing handover; and a process for selecting a communication path for the application to communicate from among the plurality of wireless communication paths based on the communication performance and the communication requirements; and, if it is determined in the process for managing handover that the wireless communication path is in a state where the handover may occur, in the process for selecting the communication path, changing the communication path of the application that is using the wireless communication path in a state where the handover may occur.

10. The recording medium according to claim 9, further causing the computer to execute the following processes: storing the correspondence between the selected communication path and the application; and, if the contents of the packet correspond to the stored application, transmitting the packet via the communication path corresponding to the application.

11. The recording medium according to claim 9 or 10, wherein in the process of managing the handover, it is determined that the handover may occur if the received strength of the radio wave on the wireless communication path is equal to or less than a predetermined value.

12. The recording medium according to claim 9 or 10, wherein the communication performance includes at least a communication rate, a maximum delay time, and an average delay time.

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