JP7191478B2 - wireless communication device - Google Patents

Description

The present invention relates to a wireless communication device that switches wireless LAN channels in consideration of channel interference.

Conventionally, the channel used when the power is turned off is stored as the last channel, and if this channel is a DFS (Dynamic Frequency Selection) channel, another channel that does not cause channel interference is searched and stored as an alternative channel. Then, when the power is turned on next time, the wireless communication device starts communication using the alternative channel, and after confirming that no channel interference occurs with respect to the DFS channel as the last channel, switches to this DFS channel. (See Patent Document 1, for example).

JP 2018-121253 A

By the way, in the wireless communication device disclosed in the above-mentioned Patent Document 1, when the power is next turned on, after starting communication with an alternative channel in which radio wave interference does not occur, another DFS channel in which channel interference does not occur is searched. Since switching is performed, two systems of wireless communication units are required in order to avoid channel interference when power is turned on and perform communication, which complicates the configuration and increases the product cost. .

SUMMARY OF THE INVENTION The present invention has been created in view of such points, and its object is to provide a wireless communication device capable of avoiding channel interference at the time of power-on while simplifying the configuration and reducing the product cost. to provide.

In order to solve the above-described problems, the radio communication apparatus of the present invention includes activation channel setting means for setting a first channel that does not cause channel interference as a channel to be used when the power is turned on, and , a channel changing means for changing a used channel to a second channel in which channel interference may occur, and a wireless communication means for performing communication using the used channel. In particular, it is desirable to further include a switching determination means for determining whether or not a predetermined timing has come after the power is turned on and when the first channel is set as the channel to be used.

By setting the first channel, which does not cause channel interference, as a channel to be used when the power is turned on, it is possible to reliably avoid channel interference when the power is turned on. Further, after that, by setting the second channel, which may cause channel interference, as the used channel at a predetermined timing, it is possible to perform efficient communication. In addition, since the channel setting that is set when the power is turned on is simply switched at a predetermined timing thereafter, it is sufficient to prepare only one system of wireless communication means, and it is possible to simplify the configuration and reduce the product cost. .

Further, the above-described predetermined timing is the point in time when the communication operation performed via the first channel in response to the user's instruction is completed immediately after the start-up of the own device . This makes it possible to avoid channel interference and reliably perform communication operations corresponding to some operations performed by the user immediately after startup.

Alternatively , the above-described predetermined timing is the point in time when the vehicle in which the device is mounted shifts from a stopped state to a running state. This makes it possible to avoid channel interference and reliably carry out communication operations that are performed immediately after activation and before the vehicle on which the device is mounted starts running.

In addition, it is desirable that the communication speed of communication through the second channel is faster than the communication speed of communication through the first channel. Moreover, it is desirable that the above-mentioned first channel is a channel included in the 2.4 GHz band communication band, and the second channel is a channel included in the 5 GHz band communication band. As a result, it is possible to perform communication while avoiding channel interference immediately after power-on, and to increase the communication speed after a predetermined timing.

It is a figure which shows the whole structure of the vehicle-mounted apparatus of one Embodiment. 1 is a diagram showing a configuration of a wireless communication device; FIG. FIG. 10 is a flow chart showing operation procedures of a wireless communication device that sets and updates a channel to be used; FIG.

An in-vehicle device according to an embodiment to which the wireless communication device of the present invention is applied will be described below with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of an in-vehicle device according to one embodiment. As shown in FIG. 1, the in-vehicle device 100 of this embodiment includes a navigation processing unit 10, an operation unit 20, an input processing unit 22, a display processing unit 30, a display device 32, a digital-analog converter (D/A) 40 , a speaker 42 , a CPU 50 , a memory 60 and a wireless communication device 80 . This in-vehicle device 100 is, for example, a head unit mounted in a vehicle, and operates as a navigation device or the like, and also has a function as a wireless LAN access point.

The navigation processing unit 10 uses the map data stored in the memory 60 to perform a navigation operation of guiding the vehicle in which the in-vehicle device 100 is mounted. This navigation operation includes detection of the position of the vehicle using the GPS device 12, display of a map around the position of the vehicle, route search for calculating the driving route to the destination, and driving to the destination along the calculated driving route. Each operation such as route guidance that guides is included. The map data necessary for the navigation operation is stored in the memory 60, but may be stored in other storage devices such as a hard disk device, or may be sent from an external map distribution server (not shown) or the like by wireless communication. It may be acquired.

The operation unit 20 is for accepting user's operations on the in-vehicle device 100 , and includes various operation keys, operation switches, operation knobs, etc. arranged around the display device 32 . Also, when various operation screens and input screens are displayed on the display device 32, the user can directly point to a part of these operation screens and input screens with a finger or the like to change the display items of the operation screens and input screens. can be selected, and in order to enable operations using such operation screens and input screens, a touch panel that detects the position of a pointed finger is part of the operation unit 20 It is provided as The input processing section 22 monitors the operation section 20 and determines the content of the user's operation.

The display processing unit 30 outputs video signals for displaying various operation screens, input screens, etc., and displays these screens on the display device 32, and also displays map screens, intersection guidance screens, etc. created by the navigation processing unit 10. These screens are displayed on the display device 32 by outputting video signals to be displayed. The display device 32 is installed in front of the center between the driver's seat and the front passenger seat, and is configured using, for example, a liquid crystal display (LCD).

The digital-analog converter 40 converts the guidance voice or the like generated by the navigation processing unit 10 into an analog voice signal and outputs it from the speaker 42 .

By executing a predetermined program stored in the memory 60, the CPU 50 controls the entire in-vehicle device 100, and performs operations such as setting an activation channel and changing a use channel in the wireless communication device 80. FIG.

The memory 60 stores an operating program for the CPU 50 and is used as a work area for storing various data necessary for the operation of the CPU 50 . The operation program executed by the CPU 50 includes programs for setting the activation channel and changing the channel to be used as described above. The memory 60 is composed of, for example, a semiconductor memory such as a ROM or a RAM, and may include a hard disk device or the like.

The wireless communication device 80 designates a channel to be used from among a plurality of channels included in the 2.4 GHz band and the 5 GHz band, and performs wireless LAN communication. It functions as an access point that relays communications. In this embodiment, the 5 GHz radio band, which has a higher throughput than the 2.4 GHz communication band, is preferentially used. In addition, when outdoor use is considered, channel interference may occur between the channel of the 5 GHz radio band and the channel used by weather radar or the like. Further, in the configuration shown in FIG. 1, the case where the wireless communication device 80 is built in the in-vehicle device 100 has been described, but it may be externally attached to the in-vehicle device 100 .

FIG. 2 is a diagram showing the configuration of the wireless communication device 80. As shown in FIG. As shown in FIG. 2, the wireless communication device 80 includes a wireless communication unit 81, an activation channel (channel) setting unit 82, a channel switching determination unit 83, a switching channel setting unit 84, and a DFS processing unit 85. .

The wireless communication unit 81 controls Wi-Fi wireless communication using any one of the channels included in the 2.4 GHz band and the 5 GHz band based on standards such as IEEE802.11.

The activation channel setting unit 82 sets a channel (activation channel, first channel) to be used for wireless communication by the wireless communication unit 81 when the power of the wireless communication device 80 (in-vehicle device 100) is turned on.

The channel switching determination unit 83 determines whether or not to change the used channel after the power is turned on. Specifically, when a predetermined switching timing arrives, a decision is made to change the channel to be used. The predetermined switching timing may include, for example, one or all of Cases 1 to 3 shown below. Note that specific cases other than these may be included.

(Case 1) Immediately after the power is turned on, some operation involving communication via the wireless communication unit 81 is performed in accordance with an instruction from the user. (Case 3) Time when a process involving a communication operation with a data volume equal to or greater than a predetermined value is started.

When the channel switching determining unit 83 determines that the channel to be used is to be changed, the switching channel setting unit 84 switches the channel to be used by the wireless communication unit 81 to the 2.4 GHz band that has been used since the power was turned on. The channel (activation channel) included in the communication band is changed to a channel (second channel) included in the 5 GHz band communication band, which has a high communication speed but may cause channel interference.

The DFS processing unit 85 detects radio waves used by weather radar or the like (detection of channel interference) for channels used for wireless communication by the wireless communication unit 81, and searches for other channels in which channel interference does not occur. and set it as a new channel to be used.

The activation channel setting unit 82 described above corresponds to activation channel setting means, the switching channel setting unit 84 corresponds to channel changing means, the radio communication unit 81 corresponds to radio communication means, and the channel switching determination unit 83 corresponds to switching determination means.

The in-vehicle device 100 of this embodiment has such a configuration. Next, the operation of setting and changing the channel used by the wireless communication device 80 will be described.

FIG. 3 is a flow chart showing the operating procedure of the wireless communication device 80 that sets and updates the channel to be used. When the vehicle-mounted device 100 is activated by turning on the power, the activation channel setting unit 82 selects a channel included in the communication band of the 2.4 GHz band and designated in advance as the activation channel as a channel to be used by the wireless communication unit 81 . (step 100). The wireless communication unit 81 performs wireless communication operation using the set use channel (step 102).

Next, the channel switching determination unit 83 determines whether or not it is time to switch the channel that was set when the power was turned on (step 104). For example, it is determined whether any of the three cases 1 to 3 described above has come. If none of the cases apply, a negative determination is made and the process returns to step 102 to continue the communication operation using the channel set when the power is turned on.

Also, if any of the three cases 1 to 3 described above applies, a positive determination is made in the determination of step 104 . Next, the switching channel setting unit 84 changes the channel for communication by the wireless communication unit 81 to the 5 GHz band (step 106). Further, the DFS processing unit 85 performs radar detection for a predetermined time (60 seconds) on the changed channel to determine whether or not channel interference occurs (step 108). If no channel interference occurs, a negative determination is made, and the switching channel setting section 84 sets this channel as the channel used by the wireless communication section 81 (step 110). The wireless communication unit 81 performs wireless communication operation using the set use channel (step 112).

After that, the DFS processing unit 85 determines whether or not the user has instructed to turn off the power (step 114). For example, if an accessory switch (not shown) of the vehicle is turned off to instruct to turn off the power supply, a negative determination is made in step 114 while the accessory switch is not turned off. In this case, the process returns to step 108 and the operation of determining channel interference is repeated.

Also, when radar is detected and the occurrence of channel interference is detected, a positive determination is made in the determination of step 108 . When channel interference occurs, the DFS processing unit 85 performs a DFS scan to search for other channels free of channel interference (step 116). In this embodiment, priority is given to the radio band of 5 GHz band, which has higher throughput than the communication band of 2.4 GHz, and in step 116, other channels of 5 GHz band in which channel interference does not occur are searched. After that, the process proceeds to step 110, and this newly searched channel is set as the used channel.

Also, when the user instructs to turn off the power (the accessory switch is turned off), the determination in step 114 is affirmative, and the communication operation performed by the wireless communication device 80 ends.

As described above, in the in-vehicle device 100 (wireless communication device 80) of the present embodiment, by setting the first channel that does not cause channel interference as the used channel when the power is turned on, the channel interference when the power is turned on is reliably eliminated. can be avoided. Further, after that, by setting the second channel, which may cause channel interference, as the used channel at a predetermined timing, it is possible to perform efficient communication. In addition, since the channel setting that is set when the power is turned on is simply switched at a predetermined timing thereafter, it is sufficient to prepare only one system of wireless communication means, and it is possible to simplify the configuration and reduce the product cost. .

In addition, by setting the above-described predetermined timing to be the point in time when the communication operation performed via the first channel in response to the user's instruction immediately after activation of the own device ends, It is possible to reliably perform a communication operation corresponding to some operation performed while avoiding channel interference.

Further, by setting the above-described predetermined timing to be the point in time when the vehicle in which the self-device is mounted shifts from the stopped state to the running state, the vehicle in which the self-device is mounted can start running immediately after the start-up. Communication operations that take place can be reliably performed while avoiding channel interference.

Further, by setting the above-described predetermined timing to be the time when a communication operation with a data volume equal to or greater than a predetermined value is started, it is possible to efficiently perform a communication operation with a large data volume via a channel capable of high-speed communication. becomes.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, the wireless communication device 80 mounted on a vehicle has been described, but the present invention can also be applied when a mobile terminal device such as a smart phone is used as an access point.

As described above, according to the present invention, when the power is turned on, by setting the first channel in which channel interference does not occur as the used channel, it is possible to reliably avoid channel interference when the power is turned on. Further, after that, by setting the second channel, which may cause channel interference, as the used channel at a predetermined timing, it is possible to perform efficient communication without restrictions considering channel interference. In addition, since the channel setting that is set when the power is turned on is simply switched at a predetermined timing thereafter, it is sufficient to prepare only one system of wireless communication means, and it is possible to simplify the configuration and reduce the product cost. .

REFERENCE SIGNS LIST 100 in-vehicle device 10 navigation processing unit 80 wireless communication device 81 wireless communication unit 82 activation channel setting unit 83 channel switching determination unit 84 switching channel setting unit 85 DFS processing unit

Claims (5)

activation channel setting means for setting a first channel, in which channel interference does not occur, as a channel to be used when power is turned on;
channel changing means for changing the used channel to a second channel that may cause channel interference at a predetermined timing after power is turned on;
wireless communication means for performing communication using the used channel;
and wherein the predetermined timing is a point in time when a communication operation performed via the first channel in response to a user's instruction is completed immediately after the radio communication apparatus is started. . activation channel setting means for setting a first channel, in which channel interference does not occur, as a channel to be used when power is turned on;
channel changing means for changing the used channel to a second channel that may cause channel interference at a predetermined timing after power is turned on;
wireless communication means for performing communication using the used channel;
, wherein the predetermined timing is a point in time when a vehicle in which the device is mounted shifts from a stopped state to a running state. 3. The apparatus further comprises a switch determination means for determining whether or not the predetermined timing has arrived after the power is turned on and when the first channel is set as the channel to be used. 3. The wireless communication device according to 1 or 2 . 4. The method according to any one of claims 1 to 3 , wherein a communication speed of communication performed via said second channel is faster than a communication speed of communication performed via said first channel. A wireless communication device as described. The first channel is a channel included in a 2.4 GHz band communication band, and the second channel is a channel included in a 5 GHz band communication band. The wireless communication device according to item 1.

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