Wireless communication terminal, wireless communication system, and wireless communication method

Abstract

To provide a wireless communication terminal that can partially select a wireless channel according to an interfered place.SOLUTION: A wireless communication system in which three or more nodes communicate via two or more wireless links between an upper-end node and a terminal node makes parameters of some wireless links different from parameters of the other wireless links. A wireless link is a wireless connection between a node and another node, and two or more wireless links are continuous.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless communication terminal, a wireless communication system, and a wireless communication method, and more particularly to a wireless communication terminal, a wireless communication system, and a wireless communication method for wirelessly communicating and transmitting / receiving information while being less susceptible to interference. [Background technology]

[0002] For example, Non-Patent Document 1 discloses a technique for changing a wireless channel used in a wireless network when interference exists in the wireless network. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE802.15.4g, “Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPNs), Amendment 3: Physical Layer (PHY) Specifications for Low-Data-Rate, Wireless, Smart Metering Utility Networks,” 2012. Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional method described in Non-Patent Document 1 changes the radio channel in the entire wireless network even in a situation where interference exists only in a part of the wireless network. As a result, the available wireless channel before the change cannot be effectively used in the places not affected by the interference, and the frequency utilization efficiency of the wireless communication system may decrease.

[0005] An object of one aspect of an embodiment of the present invention is to provide a wireless communication terminal capable of partially selecting parameters depending on an interfered portion. [Means for solving the problem]

[0006] A wireless communication system in which three or more nodes communicate with each other via two or more wireless links from an upper end node to an end node, where parameters of some wireless links are made different from parameters of other wireless links, and the wireless links are wireless connections between a certain node and another node, and the two or more wireless links are continuous. a node includes a wireless transmission unit that transmits information to another node via a first wireless link that is one of the two or more wireless links, a wireless reception unit that receives information from another node of the first wireless link via a second wireless link that is one of the two or more wireless links and detects interference with the second wireless link, and a control unit that considers changing parameters of the second wireless link when interference is detected, and when interference is detected, the control unit transmits parameters to the control unit of the other node of the second wireless link via the wireless transmission unit during a sleep period that is a period during which main control is not performed, and applies the parameters depending on the result of the consideration; The present invention provides a wireless communication system.

[0007] One of three or more wireless communication terminals in a wireless communication system in which three or more wireless communication terminals communicate with each other via wireless links between two or more respective wireless communication terminals comprises: a wireless transmission unit that transmits information to another wireless communication terminal via a first wireless link that is one of the two or more wireless links; a wireless reception unit that receives information from the other wireless communication terminal via a second wireless link that is one of the two or more wireless links and detects interference with the second wireless link; and a control unit that changes a parameter of the second wireless link when interference is detected, During the sleep period, when no main control is performed, To the control unit of another wireless communication terminal of the second wireless link And nothing Transmitting parameters via line transmitter and apply parameters according to the results of the study. The present invention provides a wireless communication terminal characterized by the above.

[0008] A wireless communication method by one of three or more wireless communication terminals in a wireless communication system in which three or more wireless communication terminals communicate with each other via wireless links between two or more respective wireless communication terminals, comprising a first step of transmitting information to another wireless communication terminal via a first wireless link that is one of the two or more wireless links, a second step of receiving information from the other wireless communication terminal via a second wireless link that is one of the two or more wireless links and detecting interference to the second wireless link, and a step of detecting a parameter of the second wireless link when interference is detected. of change Consider and a third step of: During the sleep period, which is the period when no main control is performed, To another wireless communication terminal of the second wireless link SendTo be believed and will be applied depending on the results of the above review. The present invention provides a wireless communication method comprising the steps of: Effect of the Invention

[0009] According to the present invention, it is possible to realize a wireless communication terminal capable of partially selecting parameters depending on an interfered portion. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a configuration of a wireless communication system including a wireless communication terminal according to this embodiment. [Diagram 2] FIG. 2 is a timing chart for explaining functions provided in the wireless communication terminal according to this embodiment. [Diagram 3] FIG. 3 is a flowchart showing a processing procedure of the wireless communication processing according to the present embodiment. [Figure 4] FIG. 4 is a block diagram showing a configuration of a wireless communication system including a modified example of a wireless communication terminal according to this embodiment. [Diagram 5] FIG. 5 is a timing chart illustrating the function of a modified example of the wireless communication terminal according to the present embodiment. [Figure 6] FIG. 6 is a diagram for explaining the effects of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The embodiment of the present invention is applied to, for example, the IEEE 802.15.4 standard and is used in, for example, the Internet of Things (IoT).

[0012] Compared to wired communication systems, wireless communication systems have the advantage of reducing the space required for wiring and allowing mobile devices, such as mobile phones, smartphones, tablet devices, and wearable devices, to connect to a communication network without compromising portability.

[0013] In addition, wireless communication, which is communication by radio, is becoming faster and the equipment required for wireless communication is becoming cheaper, so the number of situations in which wireless communication is used is increasing. For this reason, the standardization of wireless communication is being promoted by the IEEE (Institute of Electrical and Electronics Engineering).

[0014] The IEEE802.15.4 standard is a standard for wireless communication networks that use small, inexpensive terminals and consume little power. A wireless communication network that complies with IEEE802.15.4 is configured to include, for example, a collection station (CS) and one or more nodes, as described in Non-Patent Document 1.

[0015] In such a configuration, the lower node transmits sensing information, which is information sensed by the lower node, to the upper node including the CS. The upper node including the CS also transmits control information, which is information for controlling the lower node. In such a configuration, the communication network is multi-hop, and the same communication method, such as the frequency band, may be used for communication between each node.

[0016] There is a possibility that information may collide in communications between the nodes, and if information does collide, there is a concern that, for example, interference may occur. There is also a concern that nodes in a wireless communication network that conforms to the IEEE802.15.4 standard may affect nodes in other wireless communication networks when transmitting information. The configuration for resolving such concerns is shown below.

[0017] (Present embodiment) 1 is a block diagram showing a configuration of a wireless communication system including a wireless communication terminal 1B according to the present embodiment. The wireless communication system according to the present embodiment includes wireless communication terminals 1 (1A to 1C). The wireless communication terminal 1 may be called a node in the sense of being a constituent element of the wireless communication system.

[0018] In a wireless communication system including a wireless communication terminal 1B according to this embodiment, three or more wireless communication terminals 1 communicate with each other via wireless links 5 and 6 between two or more wireless communication terminals 1 respectively.

[0019] The wireless communication terminal 1 is a terminal capable of wireless communication, such as a CS, a mobile phone, a smartphone, a tablet terminal, a wearable terminal, a personal computer, or an actuator.

[0020] For example, if the wireless communication terminal 1 is an actuator, it can control the opening and closing of a valve to stop gas flow, or control a robot. Note that wireless communication terminals 1 other than the CS may be called child terminals.

[0021] The wireless communication terminal 1 includes a wireless transmitting unit 2, which is an integrated circuit or the like, a wireless receiving unit 3, and a control unit 4. Here, the wireless communication terminal 1B will be described as an example. The wireless transmitting unit 2 of the wireless communication terminal 1B transmits information to another wireless communication terminal 1A via a first wireless link 5, which is one of two or more wireless links.

[0022] The wireless receiving unit 3 of the wireless communication terminal 1B receives information from another wireless communication terminal 1C via a second wireless link 6, which is one of two or more wireless links. In addition, for example, the wireless receiving unit 3 of the wireless communication terminal 1B senses interference 7 to the second wireless link 6.

[0023] For example, the interference 7 is generated by a magnetic field or radio waves generated by a work vehicle such as an electric forklift, etc., by a system unrelated to the wireless communication terminal 1 according to this embodiment. Also, for example, the wireless receiving unit 3 of the wireless communication terminal 1B detects the interference 7 to the second wireless link 6 when the bit error rate becomes equal to or exceeds a predetermined value.

[0024] The control unit 4 of the wireless communication terminal 1B changes parameters of the second wireless link 6 when the wireless receiving unit 3 of the wireless communication terminal 1B detects interference 7. The parameters include at least one of a frequency band such as a channel, a modulation method, a reception waiting period in the wireless link in which interference is detected, and a sleep period in the wireless link in which interference is detected.

[0025] For example, it is assumed that the wireless channel can be selected by changing the frequency band. The control unit 4 of the wireless communication terminal 1B may repeatedly change the parameters until the bit error rate is improved to an improvement threshold value that is a predetermined value.

[0026] When the wireless receiving unit 3 of the wireless communication terminal 1B detects interference 7, the control unit 4 of the wireless communication terminal 1B transmits parameters to the control unit 4 of the other wireless communication terminal 1C on the second wireless link 6 via the wireless transmitting unit 2 of the wireless communication terminal 1B, for example, by utilizing a sleep period during which no main control is performed. Changed parameters are also applied during the sleep period.

[0027] Next, a description will be given with reference to Fig. 2. Fig. 2 is a timing chart for explaining functions of the wireless communication terminal 1 according to this embodiment. For example, the wireless receiving unit 3 of the wireless communication terminal 1A waits for a predetermined period of time to receive information transmitted from the wireless transmitting unit 2 of the wireless communication terminal 1B via the first wireless link 5.

[0028] The wireless transmitting unit 2 of the wireless communication terminal 1B transmits information via the first wireless link 5 during a period when the wireless receiving unit 3 of the wireless communication terminal 1A is waiting to receive. The wireless receiving unit 3 of the wireless communication terminal 1B waits to receive for a predetermined period to receive information transmitted from the wireless transmitting unit 2 of the wireless communication terminal 1C via the second wireless link 6, including when the wireless transmitting unit 2 of the wireless communication terminal 1B transmits information via the first wireless link 5. In this manner, the period of transmission via the first wireless link 5 and the period of transmission via the second wireless link 6 may at least partially overlap.

[0029] Next, a description will be given with reference to Fig. 3. Fig. 3 is a flowchart showing a processing procedure of wireless communication processing according to this embodiment. For example, the control unit 4 of the wireless communication terminal 1B determines whether or not the wireless receiving unit 3 of the wireless communication terminal 1B has sensed interference 7 (S1).

[0030] If the control unit 4 of the wireless communication terminal 1B determines that the wireless receiving unit 3 of the wireless communication terminal 1B has not sensed interference 7 and the result of step S1 is negative, the control unit 4 of the wireless communication terminal 1B executes step S1 again.

[0031] If the control unit 4 of the wireless communication terminal 1B determines that the wireless receiving unit 3 of the wireless communication terminal 1B does not detect interference 7 and the result of step S1 is negative (S1: NO), the control unit 4 of the wireless communication terminal 1B executes step S1 again.

[0032] If the control unit 4 of the wireless communication terminal 1B determines that interference 7 is detected by the wireless receiving unit 3 of the wireless communication terminal 1B and step S1 returns a positive result (S1: YES), the control unit 4 of the wireless communication terminal 1B instructs the wireless transmitting unit 2 of the wireless communication terminal 1B to send a parameter change notification, which is a notification to change the parameters (S2).

[0033] The wireless transmitting unit 2 of the wireless communication terminal 1B transmits a parameter change notification to the wireless communication terminal 1C, for example, during a sleep period of the wireless communication terminal 1B. When the control unit 4 of the wireless communication terminal 1C receives the parameter change notification via the wireless receiving unit 3 of the wireless communication terminal 1C, the control unit 4 considers changing the parameters during the sleep period of the wireless communication terminal 1C, for example, according to the contents of the parameter change notification.

[0034] As a result of considering parameter change, the wireless communication terminal 1C may not change the parameters, or may change the parameters to parameters predicted by the wireless communication terminal 1C to be less susceptible to interference. Next, the control unit 4 of the wireless communication terminal 1B changes the parameters during a sleep period of the wireless communication terminal 1B (S3).

[0035] Next, a description will be given with reference to Fig. 4. Fig. 4 is a block diagram showing a configuration of a wireless communication system including a wireless communication terminal 1D which is a modified example of the wireless communication terminal 1 according to the present embodiment. The wireless receiving unit 3 of the wireless communication terminal 1D receives information from the wireless transmitting unit 2 of the wireless communication terminal 1E and the wireless transmitting unit 2 of the wireless communication terminal 1F. The wireless communication terminal 1D differs from the wireless communication terminal 1B which receives information from one wireless communication terminal 1C in that the wireless communication terminal 1D receives information from two wireless communication terminals 1E and 1F.

[0036] By using the wireless communication terminal 1D, the system designer can build a tree-type wireless communication system in which information flows from the top to the bottom. In Fig. 4, the wireless communication terminal 1A is the root (hereinafter, this may be called the root node) and is at the top.

[0037] Next, a description will be given with reference to Fig. 5. Fig. 5 is a timing chart for explaining the function of a wireless communication terminal 1D which is a modified example of the wireless communication terminal according to the present embodiment. For example, the wireless receiving unit 3 of the wireless communication terminal 1A waits for a predetermined period of time to receive information transmitted from the wireless transmitting unit 2 of the wireless communication terminal 1D via a third wireless link 8 which is one of two or more wireless links.

[0038] The wireless transmitting unit 2 of the wireless communication terminal 1D transmits information via the third wireless link 8 during a period when the wireless receiving unit 3 of the wireless communication terminal 1A is waiting to receive information. The wireless receiving unit 3 of the wireless communication terminal 1D waits to receive information for a predetermined period to receive information transmitted from the wireless transmitting unit 2 of the wireless communication terminal 1E and the wireless transmitting unit 2 of the wireless communication terminal 1F via the fourth wireless link 9, which is one of the two or more wireless links, and the fifth wireless link 10, which is one of the two or more wireless links, including when the wireless transmitting unit 2 of the wireless communication terminal 1D transmits information via the third wireless link 8.

[0039] It is assumed that the period during which the wireless receiving unit 3 of the wireless communication terminal 1D waits for reception from the wireless transmitting unit 2 of the wireless communication terminal 1E is equal to the period during which the wireless receiving unit 3 of the wireless communication terminal 1F waits for reception from the wireless transmitting unit 2 of the wireless communication terminal 1E.

[0040] Next, a description will be given with reference to Fig. 6. Fig. 6 is a diagram for explaining the effects of this embodiment. For example, when the number of wireless links is two, this refers to the case shown in Fig. 1 where wireless link 5 and wireless link 6 exist.

[0041] For example, when the number of wireless links is 5, this refers to the case shown in Fig. 4 where wireless links 5, 6, 8, 9, and 10 exist. For example, when the number of wireless links is 3, this refers to the case where wireless links 5, 6, and 8 exist in Fig. 4, and when the number of wireless links is 4, this refers to the case where wireless links 5, 6, 8, and 9 exist in Fig. 4.

[0042] As shown in FIG. 6, by using the wireless communication terminal 1 according to this embodiment in a wireless communication system, the communication success rate becomes about 1.2 to 1.5 times higher than that of a wireless communication system according to the conventional technology.

[0043] When the number of wireless links is 2, the communication success rate is about 1.2 times, whereas when the number of wireless links is 5, the communication success rate is about 1.5 times. The effect becomes more pronounced as the number of wireless links increases.

[0044] As described above, according to the wireless communication terminal 1 of this embodiment, it is possible to detect interference 7 in some of the wireless links among the multiple wireless links 5, 6, 8, 9, and 10, and therefore possible to partially select wireless channels depending on the location of interference.

[0045] Therefore, by using the wireless communication terminal 1 according to this embodiment, it becomes possible to efficiently utilize the frequency resources of the wireless communication system, and wireless communication can be performed by a larger number of wireless communication terminals 1 compared to existing technologies.

[0046] For example, the wireless communication terminal 1A serves as a CS that is a master device in a tree-type wireless communication system and collects information from wireless communication terminals 1B to 1F that are mobile phones, smartphones, tablet terminals, wearable terminals, personal computers, actuators, and the like.

[0047] For example, the wireless communication terminal 1A controls each node such as the wireless communication terminals 1A to 1F of the wireless communication system, and transmits control information for controlling lower nodes such as the wireless communication terminals 1B to 1F.

[0048] The lower node communicates sensing information, which is information sensed by the lower node, to the higher node. For example, the wireless communication terminal 1A is a node in the first layer, the wireless communication terminals 1B and 1D are nodes in the second layer, and the wireless communication terminals 1C, 1E, and 1F are nodes in the third layer.

[0049] The order is from top to bottom: first layer, second layer, third layer. Nodes in the third layer transmit sensing information to nodes in the second layer and the first layer. Nodes in the second layer transmit sensing information to nodes in the first layer. In particular, priority information such as control information that must be transmitted with priority over sensing information is also less susceptible to interference.

[0050] As described above, in the wireless communication system of this embodiment, communication terminal 1A (which may hereinafter be referred to as a first wireless communication terminal), which is one of three or more wireless communication terminals, and wireless communication terminal 1B (which may hereinafter be referred to as a second wireless communication terminal), which is one of the three or more wireless communication terminals, communicate with each other via a first wireless link 5, which is one of two or more wireless links.

[0051] In the wireless communication system of this embodiment, wireless communication terminal 1B, which is one of the three or more wireless communication terminals, and wireless communication terminal 1C (which may hereinafter be referred to as a third wireless communication terminal), which is also one of the three or more wireless communication terminals, communicate with each other via a second wireless link 6, which is one of the two or more wireless links.

[0052] Furthermore, in the wireless communication system of this embodiment, when interference with the first wireless link 5 or the second wireless link 6 is detected, the parameters for the first wireless link 5 and the parameters for the second wireless link 6 are made different.

[0053] In other words, the wireless communication system in this embodiment has three or more nodes 1A to 1F communicating with each other via two or more wireless links 5, 6, 8, 9, and 10 between the upper end node 1A and the lower end nodes 1C, 1E, and 1F, and can make the parameters of some of the wireless links 5, 6, 8, and 9 different from the parameters of the other wireless links 5, 6, 8, 9, and 10.

[0054] It should be noted that the two or more wireless links 5, 6, 8, 9, and 10 are assumed to be continuous, and that the wireless links 5, 6, 8, 9, and 10 each indicate a wireless connection between a certain node and another node, as described above.

[0055] The wireless communication system in this embodiment is of a tree type with the collection control station as the root node, and a hierarchy is formed by the collection control station (e.g., wireless communication terminal 1A) and child terminals (e.g., wireless communication terminals 1B, 1C) that are nodes other than the root node, and information collected by the child terminals may be transmitted to the collection control station via wireless links (e.g., the first wireless link 5 and the second wireless link 6). As described above, the hierarchy refers to a node under which another node is placed, and this is repeated once or multiple times.

[0056] For example, the collection control station may instruct the communication between the wireless communication terminal 1A and the wireless communication terminal 1B and the communication between the wireless communication terminal 1B and the wireless communication terminal 1C. Also, for example, the collection control station may make the parameters in the first wireless link 5 and the parameters in the second wireless link 6 different.

[0057] It is sufficient that there is one or more lower-level nodes such as the wireless communication terminals 1B to 1F, and the type of branching is not limited, such as wireless communication terminal 1D communicating with wireless communication terminal 1E and wireless communication terminal 1F.

[0058] In addition to the tree-type wireless communication system, a bus-type wireless communication system can also be constructed by applying the wireless communication terminal 1D according to the modification of this embodiment. The wireless receiving unit 3 of the wireless communication terminal 1 may receive signals from the wireless transmitting units 2 of three or more wireless communication terminals 1 via three or more wireless links.

[0059] In the above embodiment, the wireless transmitting unit 2, the wireless receiving unit 3, and the control unit 4 are integrated circuits, but the present embodiment is not limited to this. For example, the wireless transmitting unit 2, the wireless receiving unit 3, and the control unit 4 may be programs stored in a RAM (Random Access Memory) (not shown) provided in the wireless communication terminal 1. For example, the programs are executed by being called by a CPU (Central Processing Unit) (not shown) provided in the wireless communication terminal 1. [Explanation of symbols]

[0060] 1, 1A, 1B, 1C... wireless communication terminal, 2... wireless transmitting unit, 3... wireless receiving unit, 4... control unit, 5... first wireless link, 6... second wireless link, 7... interference.

Claims

1. A wireless communication system in which three or more nodes communicate with each other via two or more wireless links from a top node to a bottom node, A parameter of some of the wireless links is made different from a parameter of other wireless links, the wireless links being wireless connections between a certain node and another node, and the two or more wireless links are continuous; One of the nodes is a wireless transmission unit configured to transmit information to another node via a first wireless link that is one of the two or more wireless links; a wireless receiver that receives information from another node of the first wireless link via a second wireless link that is one of the two or more wireless links, and detects interference with the second wireless link; a control unit that considers modifying a parameter of the second wireless link when the interference is detected; Equipped with When the control unit detects the interference, the control unit transmits the parameter to the control unit of the other node of the second wireless link via the wireless transmission unit during a sleep period during which no main control is performed, and applies the parameter according to a result of the examination.

1. A wireless communication system comprising:

2. a tree type in which a collection control station is a root node, a hierarchy is formed by the collection control station and child terminals which are the nodes other than the root node, and information collected by the child terminals is transmitted to the collection control station via the wireless link; The hierarchy is formed by repeating one or more times the arrangement of a node under another node.

2. The wireless communication system according to claim 1 .

3. The parameters include at least one of a frequency band, a modulation method, a waiting period for reception in the wireless link in which interference is detected, and a sleep period in the wireless link in which interference is detected.

2. The wireless communication system according to claim 1 .

4. One of three or more wireless communication terminals in a wireless communication system in which three or more wireless communication terminals communicate with each other via wireless links between two or more of the wireless communication terminals, a wireless transmission unit that transmits information to another of the wireless communication terminals via a first wireless link that is one of the two or more wireless links; a wireless receiving unit that receives information from another wireless communication terminal of the first wireless link via a second wireless link that is one of the two or more wireless links, and detects interference with the second wireless link; a control unit that considers modifying a parameter of the second wireless link when the interference is detected; Equipped with When the control unit detects the interference, during a sleep period during which no main control is performed, the control unit transmits the parameter to the control unit of the other wireless communication terminal of the second wireless link via the wireless transmission unit, and applies the parameter according to a result of the examination.

1. A wireless communication terminal comprising:

5. the control unit, as a result of the examination, does not change the parameters of the second wireless link, or changes the parameters to parameters predicted by the wireless communication terminal to be less affected by the interference.

5. The wireless communication terminal according to claim 4.

6. A wireless communication method by one of three or more wireless communication terminals in a wireless communication system in which three or more wireless communication terminals communicate with each other via wireless links between two or more of the wireless communication terminals, comprising: a first step of transmitting information to another of the wireless communication terminals via a first wireless link that is one of the two or more wireless links; a second step of receiving information from another of the wireless communication terminals via a second wireless link that is one of the two or more wireless links, and detecting interference to the second wireless link; a third step of considering modifying parameters of the second wireless link when the interference is detected; Equipped with the parameters are transmitted to the other wireless communication terminals of the second wireless link during a sleep period, which is a period during which no main control is performed, when the interference is detected, and are applied depending on the result of the consideration.

23. A wireless communication method comprising:

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