JP6777324B2 - Wireless communication equipment, power control method and program - Google Patents

Description

The present disclosure relates to wireless communication devices, communication control methods and programs.

In recent years, wireless communication devices compatible with wireless LAN (Local Area Network) have become common. The wireless communication device that operates as an access point communicates irregularly with a wireless communication terminal that operates as a wireless slave unit. Therefore, it is difficult to save power in a wireless communication device that operates as an access point.

Therefore, in a wireless communication device that operates as an access point, a technique for reducing power consumption has been studied (for example, Patent Document 1). In Patent Document 1, when the access point has no transmission / reception data in the wireless channel, that is, when the wireless channel is in a free state, the access point transmits a dummy frame in which the sleep time is set. Then, the access point discloses a technique for shifting its own device to a sleep state during a set sleep time to save power.

Japanese Unexamined Patent Publication No. 2004-336401

However, the access point disclosed in Patent Document 1 cannot save power when the wireless channel is not free. That is, even if the access point disclosed in Patent Document 1 is used, it may not be possible to save power.

An object of the present disclosure is to solve such a problem, and to provide a wireless communication device, a power supply control method, and a program capable of saving power.

The wireless communication device according to the first aspect is
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. Then, when data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmission. A communication control unit that sets a pause time including a time when data to be transmitted to the wireless communication terminal is generated by transmitting data in a second transmittable time after the possible time.
It includes a power supply control unit that shifts the own device to a power saving state during the set pause time.

The power supply control method according to the second aspect is
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
This includes transitioning the own device to a power saving state during the set pause time.

The program according to the third aspect is
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
It is a program that causes a computer to execute the transition of its own device to the power saving state during the set pause time.

According to the above aspect, it is possible to save power.

It is a block diagram which shows the structural example of the wireless communication apparatus which concerns on the outline of embodiment. It is the schematic which shows the outline of the wireless communication system which concerns on Embodiment 1. FIG. It is a figure explaining the relationship between the transmittable time, the receivable time, and the pause time. It is a figure for demonstrating the processing of the communication control part using a transmission buffer. It is a flowchart which shows the operation example of the AP which concerns on Embodiment 1. FIG. It is the schematic which shows the outline of the wireless communication system which concerns on Embodiment 2. FIG. It is a figure for demonstrating the configuration example of the communication control part which concerns on Embodiment 2. FIG. It is a figure for demonstrating the configuration example of the communication control part which concerns on Embodiment 2. FIG. It is a flowchart explaining the operation example of the AP which concerns on Embodiment 2. FIG. It is the schematic which shows the outline of the wireless communication system which concerns on Embodiment 3. FIG. It is a figure explaining the structural example of the communication control part which concerns on Embodiment 3. FIG. It is a flowchart explaining the operation example of the AP which concerns on Embodiment 3. FIG. It is a schematic block diagram which shows the structural example of the wireless communication apparatus and AP which concerns on other embodiment.

Hereinafter, embodiments will be described with reference to the drawings. In the embodiment, the same elements are designated by the same reference numerals, and duplicate description is omitted.
(Outline of Embodiment)
First, an outline of the embodiment will be described prior to the embodiment. The wireless communication device 1 according to the outline of the embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram showing a configuration example of a wireless communication device according to an outline of an embodiment.

The wireless communication device 1 is a communication device that supports wireless LAN communication, and may be, for example, a mobile router, a wireless LAN access point, a repeater, a mobile phone terminal, a smartphone terminal, a tablet terminal, a personal computer device, or the like. .. The wireless communication device 1 is a wireless communication device corresponding to the CSMA-CA (Carrier Sense Multiple Access / Collision Avoidance) method. The wireless communication device 1 includes a communication control unit 2 and a power supply control unit 3.

The communication control unit 2 can transmit data to the wireless communication terminal, which is the communicable time acquired with another wireless communication device by the CSMA-CA method and the communicable time with the wireless communication terminal (not shown). It is divided into at least one communication cycle including the transmittable time. When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the communication control unit 2 first transmits the data. It is controlled to transmit at the second transmittable time after the transmittable time of. The communication control unit 2 sets the time including the time of the generated data to be transmitted to the wireless communication terminal as the pause time.
The power supply control unit 3 shifts its own device to the power saving state during the pause time set by the communication control unit 2.

As described above, the communication control unit 2 divides the communicable time with the wireless communication terminal into a communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. Then, the communication control unit 2 controls to transmit the data to be transmitted to the wireless communication terminal in the transmittable time, and allocates the time of the data generated other than the transmittable time to the pause time. The power supply control unit 3 shifts its own device to the power saving state during the pause time set by the communication control unit 2. That is, the wireless communication device 1 according to the outline of the embodiment controls data transmission to the wireless communication terminal to create a pause time even when the wireless channel is not free, and puts the own device in a power saving state. To transition to. Therefore, according to the wireless communication device 1 according to the outline of the embodiment, it is possible to save power.

(Embodiment 1)
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. First, the first embodiment will be described.
<Configuration example of wireless communication system>
The wireless communication system 100 according to the first embodiment will be described with reference to FIG. FIG. 2 is a schematic diagram showing an outline of the wireless communication system according to the embodiment. The wireless communication system 100 is a wireless LAN system. The wireless communication system 100 includes an AP (Access Point) 10 and a wireless slave unit 20.

The AP10 corresponds to the wireless communication device 1 in the outline of the embodiment. The AP10 is a wireless communication device that functions as an access point for a wireless LAN. The AP 10 connects to the wireless slave unit 20 and enables communication with the wireless slave unit 20. That is, the AP10 and the wireless slave unit 20 form one wireless LAN network. The AP 10 is connected to the Internet 30, and the wireless slave unit 20 receives the data on the Internet 30 and transmits the data to the wireless slave unit 20, for example, when browsing the data of the Web server on the Internet 30. Further, the AP10 corresponds to the CSMA-CA method, and when the AP10 transmits / receives data, the AP10 acquires a communicable time with another wireless communication device and transmits / receives the data.

The wireless slave unit 20 corresponds to the wireless communication terminal in the outline of the embodiment. The wireless slave unit 20 is a slave unit of a wireless LAN whose master unit is the AP10. The wireless handset 20 may be a mobile phone terminal, a smartphone terminal, a tablet terminal, a mobile router, a personal computer device, or the like.

<AP configuration example>
Subsequently, a configuration example of AP10 will be described. The AP 10 includes a wireless communication unit 11, a control unit 12, a transmission buffer 13, and a network I / F (Interface) 14.

The wireless communication unit 11 is a communication unit that connects to the wireless slave unit 20 and transmits / receives data to / from the wireless slave unit 20. The wireless communication unit 11 includes a wireless module and an antenna (not shown). The wireless module complies with, for example, the IEEE (The Institute of Electrical and Electronics Engineers) 802.11 standard, and connects and communicates with the wireless slave unit 20 via an antenna and a wireless line.

The control unit 12 is a control unit that performs various controls in the AP 10, and is a CPU (Central Processing Unit). The control unit 12 executes the operation of the AP 10 by expanding and executing a program such as firmware stored in a FROM (not shown) in the RAM. Further, the control unit 12 functions as a communication control unit 121 and a power supply control unit 122 by executing the program stored in the FROM.

The communication control unit 121 corresponds to the communication control unit 2 according to the outline of the embodiment. The communication control unit 121 is a control unit that controls communication with other wireless communication devices including the wireless slave unit 20. The communication control unit 121 divides the communicable time acquired with another wireless communication device, which is the communicable time with the wireless slave unit 20, into at least one communication cycle. ..

Specifically, the communication control unit 121 uses a beacon cycle indicating a beacon signal transmission interval used for synchronizing the communication available time with the wireless slave unit 20 as a communication cycle. In the following description, the communication cycle may be referred to as a beacon cycle.

The communication control unit 121 may classify the communicable time as a communication cycle for each predetermined time, which is different from the beacon cycle. Alternatively, the communication control unit 121 may change the time of the communication cycle based on the amount of data transmitted to the wireless slave unit 20 in the elapsed communication cycle.

The communication control unit 121 sets a transmittable time during which data can be transmitted to the wireless slave unit 20 and a receiveable time during which data can be received from the wireless slave unit 20 within the beacon cycle. Further, the communication control unit 121 sets a non-communication timer for determining whether or not data has been received from the wireless slave unit 20 within a predetermined time after the elapse of the transmittable time. The non-communication timer can also be said to be a non-communication monitoring timer that monitors whether or not communication with the wireless slave unit 20 is being performed. In the following description, the transmittable time may be referred to as a transmission gate.

The transmittable time (transmission gate) may be a time that can be arbitrarily set. For example, the transmittable time (transmission gate) may be half the time of the beacon cycle. Alternatively, the transmittable time (transmission gate) may be 3/4 of the beacon cycle. Alternatively, the transmittable time (transmission gate) may be a time arbitrarily set by the administrator who manages the AP10. For convenience of explanation, in the following description, the transmittable time (transmission gate) will be described as half the time of the beacon cycle.

The receivable time is set so as to overlap with the receivable time. The receivable time may be an arbitrarily set time. For example, the receivable time may be the time from the start to the end of the beacon cycle. Alternatively, the receivable time may be a longer time than the receivable time in the beacon cycle and may be a limited time. For convenience of explanation, the receivable time will be described as the time from the start to the end of the beacon cycle in the following description.

Further, the communication control unit 121 controls the transmission of data to be transmitted to the wireless slave unit 20, and controls so that the data to be transmitted to the wireless slave unit 20 is transmitted to the transmission gate. In other words, the communication control unit 121 controls to transmit the data to be transmitted to the wireless slave unit 20 to the transmission gate, which is generated at a time other than the transmission gate, and the transmission time of the data generated at the time other than the transmission gate. Is assigned to a pause time during which communication with the wireless slave unit 20 is not performed. There is a frame Aggregation technique as a mechanism for efficiently transmitting transmission data, but in the present embodiment, the communication control unit 121 further sets a transmission gate to limit the period for transmitting transmission data, thereby clearly transmitting the transmission data. Create time when not (pause time). Further, the communication control unit 121 uses a non-communication timer to control the creation of a pause time in consideration of the generation status of data received from the wireless slave unit 20.

When the pause time is set, the communication control unit 121 transmits dummy data including the pause time to the wireless slave unit 20 to prevent data from being transmitted from another wireless communication device including the wireless slave unit 20. Specifically, the communication control unit 121 sets the pause time to the transmission prohibition time NAV (Network Allocation Vector) of the header information, generates dummy data that does not include the data portion, and transmits the dummy data to the wireless slave unit 20. Dummy data can be said to be Null data because it is data that does not include a data portion. In the following description, dummy data may be referred to as Null data.

In the present embodiment, the set pause time is transmitted to another wireless communication device by using the above Null data, but CTS-to-Self may be used. In this case, the communication control unit 121 transmits CTS (Clear To Send) instead of transmitting Null data. The communication control unit 121 may set a pause time in the NAV included in the CTS.

Further, even after the set pause time is released, it is assumed that the condition for setting the pause time is met again, for example, when there is no transmission / reception data. In this case, the communication control unit 121 The Null data may be transmitted twice or more.

Further, when the transmission gate is completed, the communication control unit 121 controls the transmission gate based on the amount of data stored in the transmission buffer 13 described later. Specifically, the communication control unit 121 has the amount of data stored in the transmission buffer 13 at the end of the transmission gate at the end of the transmission gate, and the end time of the transmission gate immediately before the transmission gate. The amount of data stored in the transmission buffer 13 is compared. When the amount of data stored in the transmission buffer 13 at the end of the transmission gate is larger than the amount of data stored in the transmission buffer 13 at the end of the previous transmission gate, the communication control unit 121 sends the transmission data. It can be judged that the processing could not be completed. Therefore, the communication control unit 121 controls to further set the transmission gate in the beacon cycle including the transmission gate.

The communication control unit 121 may control to set the entire beacon cycle including the transmission gate to the transmission gate. Alternatively, the communication control unit 121 may further set, for example, half the time of the transmission gate as the transmission gate in the beacon cycle including the transmission gate. Alternatively, the communication control unit 121 may serve as a transmission gate that further sets a time arbitrarily set by the administrator of the AP10. Alternatively, the communication control unit 121 may determine the transmission gate to be set based on the amount of data remaining in the transmission buffer described later, and may further set the determined transmission gate. Alternatively, the communication control unit 121 may control the transmission gate of the beacon cycle next to the beacon cycle including the transmission gate to have a longer time than the transmission gate. For convenience of explanation, in the following description, it is assumed that the communication control unit 121 sets all the beacon cycles including the transmission gate to the transmission gate. The configuration of the communication control unit 121 described above will be further described below with reference to the drawings.

Next, the power supply control unit 122 will be described. The power supply control unit 122 corresponds to the power supply control unit 3 according to the outline of the embodiment. When the communication control unit 121 sets the pause time, the power supply control unit 122 shifts the AP 10 to the power saving state during the pause time. The power control unit 122 may shift the AP 10 to the power saving state by stopping the power supply to the wireless communication unit 11. Alternatively, the power supply control unit 122 instructs the wireless communication unit 11 not to communicate with the wireless slave unit 20, and the wireless communication unit 11 cuts off the communication with the wireless slave unit 20 to save power. You may transition to the state.

Next, the transmission buffer 13 will be described. The transmission buffer 13 is a buffer that temporarily stores transmission data to be transmitted to the wireless slave unit 20. When the communication control unit 121 controls the transmission data to be transmitted to the wireless slave unit 20, the transmission buffer 13 extracts the transmission data to be transmitted to the wireless slave unit 20 from the accumulated transmission data, and causes the wireless communication unit 11 to transmit the transmission data. It is transmitted to the wireless slave unit 20 via. When transmission data is transmitted to the wireless slave unit 20, the transmission buffer 13 subtracts the amount of transmitted data. On the other hand, when the transmission buffer 13 receives the data to be transmitted to the wireless slave unit 20, the amount of the data is added.

The network I / F 14 is a communication unit that connects and communicates with the Internet 30. For example, when the wireless slave unit 20 browses a WEB page or the like, data is transmitted / received between the WEB server provided on the Internet 30 and the wireless slave unit 20 via the wireless communication unit 11 and the network I / F14. ..

<Details of communication control unit configuration>
Subsequently, the details of the configuration of the communication control unit 121 will be described. First, the transmittable time, the receivable time, and the pause time will be described with reference to FIG. FIG. 3 is a diagram for explaining the relationship between the transmittable time, the receivable time, and the pause time. Further, FIG. 3 is a diagram showing the relationship between the time and the data transmission / reception status and power consumption in the AP10.

FIG. 3A is a diagram showing the generation status of data to be transmitted to the wireless slave unit 20 (transmission data) and data to be received from the wireless slave unit 20 (received data) during the communicable time with the wireless slave unit 20. is there. FIG. 3B is a diagram showing a situation after the communication control unit 121 controls.

3 (A) and 3 (B) are diagrams in which the horizontal axis is time and the vertical axis is the current consumption in AP10. The horizontal axis of FIG. 3 (A) corresponds to the scales of the horizontal axis and the vertical axis of FIG. 3 (B), and tx (natural number of x: 1 or more) indicates that it is the time tx. .. In FIGS. 3 (A) and 3 (B), the hatched blocks indicate data transmitted and received in the AP10. The blocks hatched by diagonal lines indicate beacon signals, and the blocks hatched by horizontal lines indicate transmission data to be transmitted to the wireless slave unit 20. The blocks hatched by the vertical lines indicate the received data received from the wireless slave unit 20, and the blocks hatched by the dots indicate the Null data.

First, FIG. 3A will be described. As an example, in FIG. 3A, reception data is received from the wireless slave unit 20 by time t1 (received data is generated), and transmission data to be transmitted to the wireless slave unit 20 is generated between time t1 and t2. It shows that it is doing. Further, during the time t2 to t3, the received data is received from the wireless slave unit 20, and during the time t3 to t4, the beacon signal for synchronizing with the wireless slave unit 20 is transmitted. Shown. It is shown that neither transmission data nor reception data is generated between the times t7 and t8.

Next, FIG. 3B will be described. As shown in FIG. 3B, the communication control unit 121 divides the communicable time with the wireless slave unit 20 into a beacon cycle indicating a beacon transmission interval. In FIG. 3B, the communication control unit 121 shows that the communication possible time is divided into beacon cycles # n-1, #n and # n + 1 (natural numbers of n: 1 or more).

Then, the communication control unit 121 sets the transmission gate and the receivable time in the beacon cycle. Taking beacon cycle #n as an example, the communication control unit 121 sets the time from time t3 to t14 to the transmission gate #n, and sets the time from time t3 to t10 to the receivable time #n. Similarly, the communication control unit 121 sets the transmission gate and the receivable time also in the beacon cycles # n-1 and # n + 1.

Here, the communication control unit 121 controls to transmit the transmission data generated at a time other than the transmission gate to the transmission gate in the next beacon cycle, and sets the time of the generated transmission data as the pause time. ..

More specifically, in FIG. 3A, the transmission data Data # 1 is generated between the times t1 and t2. However, as shown in FIG. 3B, the transmission gate # n-1 of the beacon cycle # n-1 has ended at the time t13 (time t13 <time t1). Therefore, the communication control unit 121 controls to transmit the transmission data Data # 1 to the transmission gate # n next to the transmission gate # n-1, and pauses so as to include the transmission time of the transmission data Data # 1. Set to time. The communication control unit 121 sets the smaller time of the remaining time until the transmission of the next beacon signal and the maximum transmission time (Max-TXOP) as the pause time. In other words, the pause time is the time to the end of the communication cycle including the set pause time, and the smaller time of the maximum transmission time (Max-TXOP).

The communication control unit 121 sets the set pause time to the transmission prohibition time NAV of the header information, generates Null data # 1 that does not include the data part, and transmits it to another wireless communication device including the wireless slave unit 20. .. For example, if the communication control unit 121 sets the remaining time until the transmission of the next beacon signal as the pause time, at time t1 in FIG. 3B, the Null data # 1 including the set pause time is set to another radio. Send to the communication device. Then, since the transmission prohibited time is set between the times t1 and t3, it is possible to suppress the transmission of data from other wireless communication devices including the wireless slave unit 20. That is, since it is possible to set a state in which neither transmission data nor reception data is generated, the communication control unit 121 sets the pause time from time t1 to t3, and sets the pause time in the power supply control unit 122. Notify that you have done it. When the communication control unit 121 transmits the Null data, the power supply control unit 122 shifts the AP10 to the power saving state.

Further, the communication control unit 121 sets a non-communication timer in the receivable time after the transmission gate has elapsed. The communication control unit 121 sets a pause time when data is not received from the wireless slave unit 20 or when data to be transmitted to the wireless slave unit 20 is not generated before the non-communication timer expires. If no data is received from the wireless slave unit 20 before the non-communication timer expires, the communication control unit 121 is in a state in which data is not accumulated in the transmission buffer of the wireless slave unit 20 (empty state). This is because it can be judged. When setting the pause time, the communication control unit 121 transmits the Null data in which the pause time is set to the transmission prohibition time NAV of the header information to other wireless communication devices including the wireless slave unit 20 in the same manner as described above. When data is received from the wireless slave unit 20 during the non-communication timer, the communication control unit 121 initializes the non-communication timer and continues a state of waiting for data to be received from the wireless slave unit 20. ..

Specifically, in FIG. 3B, when the transmission gate #n ends at time t14, the communication control unit 121 sets the non-communication timer. Received data is generated between the times t14 and t7. Therefore, after the non-communication timer expires, the communication control unit 121 initializes the non-communication timer and continues to start the non-communication timer.

If the data from the wireless slave unit 20 ends and the non-communication timer expires at time t7, the communication control unit 121 can determine that the transmission buffer in the wireless slave unit 20 is empty. So, set the pause time. For example, assuming that the communication control unit 121 sets the remaining time until the transmission of the next beacon signal as the pause time, at time t7 in FIG. 3B, the Null data # 2 including the set pause time is set to another radio. Send to the communication device. Then, since the transmission prohibited time is set from the time t7 to t10, it is possible to suppress the transmission of data from another wireless communication device. That is, since it is possible to set the state in which neither transmission data nor reception data is generated, the communication control unit 121 sets the pause time from time t7 to t10, and sets the pause time in the power supply control unit 122. Notify that you have done it.

As shown in FIG. 3A, the transmission data Data # 3 is generated between the times t8 and t9, but the transmission data Data # 3 is set to the transmission gate # n + 1, which is the next transmission gate. Control to send. In this case, since the pause time has already been set, the communication control unit 121 does not set the pause time again.

Subsequently, the processing of the communication control unit 121 using the transmission buffer 13 will be described with reference to FIG. FIG. 4 is a diagram for explaining the processing of the communication control unit using the transmission buffer. FIG. 4 shows, for example, the status of transmitted / received data generated when the wireless slave unit 20 browses a Web page or the like. Further, FIG. 4 is a diagram showing the relationship between the time and the data transmission / reception status, the power consumption, and the state of the transmission buffer 13 in the AP 10.

The upper figure of FIG. 4 shows the state of the transmission buffer 13. The cylindrical block indicates the amount of data that can be stored in the transmission buffer 13, and the hatched portion of the cylindrical block is the transmission data that is stored in the transmission buffer 13 and is transmitted to the wireless slave unit 20 ( It will be described as accumulated data).

As shown in the upper figure of FIG. 4, most wireless communications are intermittent operations unless the wireless slave unit 20 downloads a large file by FTP. The capacity of the wireless LAN transmission load varies depending on whether the physical layer protocol is IEEE 802.11ac or IEEE 802.11n, but in many cases during intermittent communication, the required throughput is the capacity. Much lower than. In the present embodiment, the transmission buffer 13 is used as an index for knowing whether or not the transmission is smoothly handled. The fact that the accumulated data in the transmission buffer 13 is full indicates that the data exceeding the transmission capacity of the AP 10 is accumulated, and the fact that the transmission buffer 13 is empty indicates that the data to be transmitted is empty. Indicates a state without.

The lower figure of FIG. 4 shows a diagram in which the horizontal axis is time and the vertical axis is the current consumption in AP10, as in FIGS. 3 (A) and 3 (B). Further, since the hatched blocks in the lower figure of FIG. 4 are the same as those in FIG. 3 (B), the description thereof will be omitted. Further, in FIG. 4, the communication control unit 121 divides the communication available time into a beacon cycle #m (a natural number of m: 1 or more) and a beacon cycle # m + 1, and each beacon cycle includes a transmission gate and a receivable time. Indicates that is set.

In FIG. 4, the beacon cycle #m shows the status of the transmission / reception data and the status of the transmission buffer 13 when the communication control unit 121 sets the pause time, as described above. Further, in FIG. 4, the beacon cycle # m + 1 shows the status of the transmission / reception data and the status of the transmission buffer 13 when the communication control unit 121 further sets the transmission gate without setting the pause time.

First, the beacon cycle #m in FIG. 4 will be described. In FIG. 4, the state 1 of the transmission buffer 13 indicates the state of the transmission buffer 13 at the time when the transmission gate # m starts. When the transmission gate # m starts, the communication control unit 121 takes out the transmission data to be transmitted to the wireless slave unit 20 from the accumulated data in the transmission buffer 13 and transmits it to the wireless slave unit 20. In the example shown in FIG. 4, the communication control unit 121 controls to take out the transmission data Data # 11 and the transmission data Data # 12 from the transmission buffer 13 and transmit them to the wireless slave unit 20.

The state 2 of the transmission buffer 13 indicates the state of the transmission buffer 13 at the time when the transmission gate # m ends. In the state 2, since the transmission data Data # 11 and the transmission data Data # 12 are taken out from the transmission buffer 13, a data amount smaller than the storage data amount in the state 1 is accumulated.

When the transmission gate # m is completed, the communication control unit 121 determines the amount of accumulated data in the transmission buffer 13 when the transmission gate # m has elapsed, and the amount of accumulated data in the transmission buffer 13 when the transmission gate # m-1 has elapsed. And compare. As a result of comparison, when the accumulated data amount of the transmission buffer 13 when the transmission gate # m has elapsed is smaller than the accumulated data amount of the transmission buffer 13 when the transmission gate # m-1 has elapsed, the communication control unit 121 , It can be determined that the transmitted data is transmitted without delay. Therefore, the communication control unit 121 determines that it is not necessary to further set the transmission gate, and sets the pause time if the pause time can be set. When the communication control unit 121 sets the pause time in the beacon cycle #m, as described above, the Null data # 11 is transmitted to another wireless communication device to transition to the power saving state. Since the network I / F 14 can operate even in the power saving state, transmission data to be transmitted to the wireless slave unit 20 may be generated, but the generated transmission data is stored in the transmission buffer 13.

Subsequently, the beacon cycle # m + 1 will be described. The state 3 of the transmission buffer 13 indicates the state of the transmission buffer 13 at the time when the transmission gate # m + 1 starts. When a large amount of transmission data is generated in the pause time #m, the state of the transmission buffer 13 is such that the amount of accumulated data is accumulated more than the amount of accumulated data in the state # 1, as in the state # 3. When the transmission gate # m + 1 starts, the communication control unit 121 takes out the transmission data to be transmitted to the wireless slave unit 20 from the accumulated data of the transmission buffer 13 and transmits the transmission data to the wireless slave unit 20 as in the transmission gate # m. .. In the example shown in FIG. 4, the communication control unit 121 controls to take out the transmission data Data # 13 and the transmission data Data # 14 from the transmission buffer 13 and transmit them to the wireless slave unit 20.

The state 4 of the transmission buffer 13 indicates the state of the transmission buffer 13 when the transmission gate # m + 1 ends. In the state 4, since the transmission data Data # 13 and the transmission data Data # 14 are taken out from the transmission buffer 13, a data amount smaller than the accumulated data amount in the state 3 is accumulated.

When the transmission gate # m + 1 is completed, the communication control unit 121 determines the amount of accumulated data in the transmission buffer 13 when the transmission gate # m + 1 has elapsed, the amount of accumulated data in the transmission buffer 13 when the transmission gate # m has elapsed, and the amount of accumulated data in the transmission buffer 13. To compare. As a result of comparison, when the amount of accumulated data in the transmission buffer 13 when the transmission gate # m + 1 has elapsed is larger than the amount of accumulated data in the transmission buffer 13 when the transmission gate # m has elapsed, the communication control unit 121 transmits. It is judged that the data exceeding the capacity is accumulated. Therefore, the communication control unit 121 controls so as to further set the transmission gate in the beacon cycle # m + 1. The communication control unit 121 further sets the transmission gate # m + 1'in the beacon cycle # m + 1.

When the transmission gate # m + 1'starts, the communication control unit 121 performs the same processing as described above, and transmits the transmission data Data # 15 and the transmission data Data # 16 to the wireless slave unit 20. Then, the state of the transmission buffer 13 can be set to a data amount smaller than the accumulated data amount in the state 4, as in the state 5.

In this way, the communication control unit 121 compares the amount of accumulated data at the time when the transmission gate before the transmission gate ends with the amount of accumulated data at the time when the transmission gate ends at the time when the transmission gate ends. I do. Then, the communication control unit 121 controls so as to create a pause time when the transmission data can be transmitted without delay based on the comparison result. On the other hand, when the amount of data exceeding the transmission capacity is stored in the transmission buffer 13, the communication control unit 121 controls to further set the transmission gate so that the transmission data can be transmitted without delay. By performing such control, the influence on the communication with the wireless slave unit 20 is reduced, and the control is performed so as to create a pause time.

<AP operation example>
Subsequently, an operation example of the AP10 according to the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing an operation example of the AP according to the first embodiment. First, as a premise, the communication control unit 121 divides the communicable time with the wireless slave unit 20 into beacon cycles, and sets the transmission gate and the receivable time. FIG. 5 shows an operation performed for each beacon cycle.

First, when the beacon cycle is started, the communication control unit 121 transmits a beacon signal via the wireless communication unit 11 (step S1). Next, the communication control unit 121 determines whether or not it is inside the transmission gate (step S2).

When the communication control unit 121 determines that the data is in the transmission gate (YES in step S2), if there is transmission data, it is taken out from the transmission buffer 13 and transmitted to the wireless slave unit 20 (step S3). Then, the process returns to step S2, and if there is transmission data, it is taken out from the transmission buffer 13 and transmitted to the wireless slave unit 20 until the transmission gate is completed.

On the other hand, if it is determined in step S2 that the communication control unit 121 is not inside the transmission gate (NO in step S2), the communication control unit 121 determines whether or not the beacon cycle has ended (step S4). When the communication control unit 121 determines that the beacon cycle has ended (YES in step S4), the communication control unit 121 ends the process.

On the other hand, when the communication control unit 121 determines that the beacon cycle has not ended (NO in step S4), is the amount of accumulated data in the transmission buffer 13 larger than the amount of accumulated data at the end of the previous transmission gate? Is determined (step S5).

When the communication control unit 121 determines that the amount of accumulated data in the transmission buffer 13 is smaller than the amount of accumulated data at the end of the previous transmission gate (NO in step S5), the communication control unit 121 sets a non-communication timer (initialization). (Step S6).

Next, the communication control unit 121 determines whether it is within the receivable time (step S7). If it is within the receivable time (YES in step S7), the process proceeds to step S8. On the other hand, if it is within the receivable time, that is, when the receivable time ends (NO in step S7), the process ends.

In step S8, the communication control unit 121 determines whether there is transmission data or reception data (step S8). In step S8, when there is received data, that is, when data is received from the wireless slave unit 20, the process returns to step S6.

On the other hand, in step S8, when there is no received data or there is transmitted data, the communication control unit 121 transfers the Null data in which the pause time is set as the header information to another wireless communication device via the wireless communication unit 11. (Step S9). That is, in step S8, when the non-communication timer expires, or when transmission data is generated after the transmission gate has elapsed, the communication control unit 121 sets the pause time. Then, the communication control unit 121 transmits the Null data in which the pause time is set as the header information to another wireless communication device via the wireless communication unit 11. Further, when the communication control unit 121 transmits the Null data, the communication control unit 121 notifies the power supply control unit 122.

Next, the power supply control unit 122 shifts the AP10 to the power saving state (step S10) during the pause time set by the communication control unit 121, and ends the process. The AP10 releases the power saving state at the timing when the next beacon cycle is started, and performs the operation shown in FIG.

Further, in step S5, when the communication control unit 121 determines that the amount of accumulated data in the transmission buffer 13 is larger than the amount of accumulated data at the end of the previous transmission gate (YES in step S5), the same beacon cycle Further set the transmission gate to (step S11). When the AP10 performs the operation of step S11, it returns to step S2.

As described above, the communication control unit 121 controls the transmission of data to be transmitted to the wireless slave unit 20 to the transmittable time, and creates and sets the pause time. Then, the power supply control unit 122 shifts its own device to the power saving state during the pause time set by the communication control unit 121. Therefore, by using the AP10 according to the first embodiment, it is possible to save power even when the wireless channel is not in an empty state.

Then, the communication control unit 121 controls the transmission of the data to be transmitted to the wireless slave unit 20, and transmits the data to the wireless slave unit 20 collectively at the transmittable time. Therefore, normally, even when the generation time of the data to be transmitted to the wireless slave unit 20 is dispersed and the transmission efficiency is lowered, the transmission efficiency can be improved by using the AP10 according to the present embodiment. Is possible.

Further, the communication control unit 121 sets a non-communication timer after the transmission gate is completed, and sets a pause time when there is no data received from the wireless slave unit 20 during the non-communication timer. Then, the power supply control unit 122 shifts its own device to the power saving state during the pause time set by the communication control unit 121. Therefore, by using the AP10 according to the first embodiment, it is possible to save power even in the receivable time when the received data can be generated irregularly.

As described above, for example, when the wireless slave unit 20 browses a Web page or the like, it is important to reduce the standby power consumption when receiving data in order to reduce the power consumption of the AP during intermittent communication. The wireless slave unit 20 can save power at an arbitrary timing by using, for example, the PS-Poll method or the like. On the other hand, the AP must always activate the receiving circuit because the received data may be generated irregularly. Therefore, by configuring the AP10 according to the embodiment as described above, it is possible to save power even in a situation where received data may be generated irregularly.

Further, the communication control unit 121 sets the pause time when the received data is not received from the wireless slave unit 20 even if the non-communication timer expires. Further, the communication control unit 121 sets the pause time only when the transmission data can be transmitted without delay based on the accumulated data amount of the transmission buffer 13. Therefore, according to the first embodiment, it is possible to save power while reducing the influence on the communication with the wireless slave unit 20.

Furthermore, the communication control unit 121 suppresses data transmission in the other wireless communication device by transmitting the Null data for which the pause time is set to the other wireless communication device. Therefore, according to the present embodiment, other wireless communication devices also have an effect that power consumption can be reduced during the pause time.

(Embodiment 2)
Subsequently, the second embodiment will be described. The second embodiment is an improved example of the first embodiment. First, before explaining the details of the second embodiment, the outline of the second embodiment will be described.

Each wireless communication device in the wireless communication system can coexist independently based on the CSMA-CA method in order to share the atmosphere, which is one medium, with many wireless communication devices. However, if each AP monitors all the information in all the received data, it becomes necessary to always monitor all the information in all the received data even if there is no transmitted data. It ends up. Therefore, in this case, each AP cannot transition to the power saving state.

Therefore, in the present embodiment, each AP determines whether or not the received data is the data addressed to its own device. Then, when it is determined that the data is not addressed to the own device, each AP controls to transition to the power saving state in the time for the data after the determination that the data is not addressed to the own device among the received data. Now, the details of the second embodiment will be described.

<Configuration example of wireless communication system>
The wireless communication system 200 according to the second embodiment will be described with reference to FIG. FIG. 6 is a schematic diagram showing an outline of the wireless communication system according to the second embodiment.

The wireless communication system 200 includes APs 40 and 50 and wireless slave units 20 and 60. That is, the wireless communication system 200 has a configuration in which the AP 10 is replaced with the AP 40, and the AP 50 and the wireless slave unit 60 are further provided, as compared with the wireless communication system 100 according to the first embodiment.

The APs 40 and 50 are wireless communication devices that function as wireless LAN access points. AP40 and 50 are access points corresponding to the CSMA-CA system. The AP40 corresponds to the AP10 of the first embodiment. APs 40 and 50 may have the same configuration or different configurations. In the following description, the configuration of the AP50 will be described as having the same configuration as the configuration of the AP40. Further, in FIG. 6, the AP 50 is shown so as not to be connected to the Internet 30, but may be connected to the Internet 30.

The AP 40 connects to the wireless slave unit 20 and enables communication with the wireless slave unit 20. The AP 50 connects to the wireless slave unit 60 and enables communication with the wireless slave unit 60. The AP40 and the wireless slave unit 20 form a wireless LAN network. The AP50 and the wireless slave unit 60 form a wireless LAN network different from the wireless LAN network formed by the AP40 and the wireless slave unit 20. That is, the wireless communication system 200 can be said to be a wireless communication system including a plurality of wireless LAN networks.

The identifier of the wireless LAN network formed by the AP 40 and the wireless slave unit 20 is BSS (Basic Service Set) # 1, and the identifier of the wireless LAN network formed by the AP 50 and the wireless slave unit 60 is BSS # 2. A unique BSSID is assigned to each of BSS # 1 and BSS # 2, and does not communicate with communication devices (access points, wireless slave units) of different wireless LAN networks. In BSS # 1 and BSS # 2, only one wireless slave unit (wireless slave unit 20 or wireless slave unit 60) is described, but of course, even if a plurality of wireless slave units are provided. Good. Further, the number of wireless LAN networks included in the wireless communication system 200 may be three or more.

The wireless slave units 20 and 60 are wireless LAN slave units having AP40 and 50 as master units, respectively. The wireless slave unit 20 corresponds to the wireless slave unit 20 according to the first embodiment. The wireless slave units 20 and 60 may be mobile phone terminals, smartphone terminals, tablet terminals, mobile routers, personal computer devices, and the like.

<AP configuration example>
Subsequently, a configuration example of the AP according to the second embodiment will be described. As described above, since the APs 40 and 50 have the same configuration, the configuration example of the AP according to the second embodiment will be described using the AP40.

In the AP40, the control unit 12 is replaced with the control unit 42 in the configuration of the AP10 according to the first embodiment. Specifically, in the AP40, the communication control unit 121 is replaced by the communication control unit 421, and the power supply control unit 122 is replaced by the power supply control unit 422. The configuration of the control unit 42 is basically the same as that of the control unit 12 of the first embodiment. Further, among the configurations of AP40, other configurations are the same as those in the first embodiment. Therefore, in the present embodiment, the configurations of the communication control unit 421 and the power supply control unit 422 will be described.

The communication control unit 421 has basically the same configuration as the communication control unit 121 according to the first embodiment, but differs in the following points. Therefore, in the present embodiment, among the configurations of the communication control unit 421, the points different from the configuration of the communication control unit 121 of the first embodiment will be described, and the description of the same configuration as that of the first embodiment will be omitted.

A configuration example of the communication control unit 421 will be described with reference to FIGS. 7 and 8. 7 and 8 are diagrams for explaining a configuration example of the communication control unit.

First, FIG. 7 will be described. FIG. 7 is a diagram showing an example of a data structure transmitted / received in the atmosphere, which is one medium of the wireless communication system 200 (FIG. 7A), and a diagram illustrating a configuration example of the communication control unit 421 (FIG. 7). It is a figure including (B) and FIG. 7 (C).

FIG. 7A shows a structure of data (referred to as a Wi-Fi frame) conforming to the IEEE802.11ac communication standard. The Wi-Fi frame shown in FIG. 7A includes a PLCP (Physical Layer Convergence Protocol / Procedure) preamble, a Signal, a MAC (Media Access Control) Header, and a Packet Data. Since the frame structure of FIG. 7A is the same as the data structure conforming to the general IEEE802.11ac communication standard, detailed description thereof will be omitted.

Next, a configuration example of the communication control unit 421 will be described with reference to FIGS. 7 (B) and 7 (C). Using FIG. 7B, the communication control unit 421 when the AP40 is an access point compliant with the IEEE802.11n communication standard and receives the Wi-Fi frame of the IEEE802.11ac shown in FIG. 7A. A configuration example will be described.

When the AP40 receives the Wi-Fi frame shown in FIG. 7A, the communication control unit 421 confirms the PLCP Preamble and the Signal, and determines whether or not the data is addressed to the own device. In this case, the communication control unit 421 can determine that the Wi-Fi frame shown in FIG. 7A is a Wi-Fi frame having a communication standard different from that of its own device by checking the PLCP Preamble and the Signal. That is, the communication control unit 421 can determine that the received Wi-Fi frame is a Wi-Fi frame that is not addressed to the own device. Therefore, the communication control unit 421 does not read the data after the MAC Header, but shifts to the power saving state in the time for the data after the MAC Header via the power supply control unit 422.

Next, using FIG. 7C, a configuration example of the communication control unit 421 when the AP10 is an access point compliant with the IEEE802.11ac communication standard and receives a Wi-Fi frame not addressed to the own device. explain.

When the AP40 receives the Wi-Fi frame shown in FIG. 7A, the communication control unit 421 confirms the MAC address of the MAC Header because the communication standard is the same, and determines whether or not it is addressed to its own device. .. When the communication control unit 421 confirms the MAC address and determines that the received Wi-Fi frame is a Wi-Fi frame that is not addressed to the own device, the communication control unit 421 does not read the data after Packet Data. Then, the communication control unit 421 transitions to the power saving state in the time for the data after Packet Data via the power supply control unit 422.

In this way, when the communication control unit 421 receives the data, the communication control unit 421 confirms the header information of the received data and determines whether or not the data is addressed to its own device.

Next, a configuration example of the communication control unit 421 will be described with reference to FIG. 8 when a part of the received data includes data that is not addressed to the own device. FIG. 8 is a diagram showing the relationship between the time and the data transmission / reception status and power consumption of the AP40.

FIG. 8A shows the data transmission / reception status of the AP40. At the time t31 to t32 and the time t33 to t34 of the beacon cycle #l (natural number of l: 1 or more), the AP40 is connected to the wireless slave unit 20. Indicates that data is being received. Further, at times t32 to t33 and from time t34 to t35, AP40 indicates that the data of BSS # 2 has been received.

FIG. 8B is a diagram showing a situation after the communication control unit 421 controls in the situation of FIG. 8A. When the communication control unit 421 receives the data, it determines whether or not the received data is the data addressed to the own device by checking the header information of the data. Then, the communication control unit 421 determines that the data other than the data addressed to the own device has been received at the time t32 to t33 and the time t34 to t35. Therefore, as shown in FIG. 8B, the communication control unit 421 shifts the AP40 to the power saving state from the time t32 to t33 and from the time t34 to t35 via the power supply control unit 422. As described above, the communication control unit 421 determines the header information of the received data. Therefore, as shown in FIG. 8B, after determining that the received data is not the data addressed to the own device, The AP40 is transitioned to the power saving state.

Subsequently, the power supply control unit 422 will be described with reference to FIGS. 6 and 8. The power supply control unit 422 has basically the same configuration as the power supply control unit 122 according to the first embodiment, but differs in the following points. Therefore, in the present embodiment, among the configurations of the power supply control unit 422, the points different from the configuration of the power supply control unit 122 of the first embodiment will be described, and the description of the same configuration as that of the first embodiment will be omitted.

When the communication control unit 421 determines that the received data is not the data addressed to the own device, the power control unit 422 sets the time for the data after the determination that the data is not addressed to the own device. , Transition the own device to the power saving state.

<AP operation example>
Subsequently, an operation example of the AP40 according to the second embodiment will be described with reference to FIG. FIG. 9 is a flowchart illustrating an operation example of the AP according to the second embodiment. FIG. 9 is an operation example performed when the AP40 receives data.

First, when the AP40 receives the data (step S21), the communication control unit 421 determines whether or not the received data is the data addressed to the own device (step S22). When the communication control unit 421 determines that the data is addressed to its own device (YES in step S22), it does nothing in particular and performs the same operation as in the first embodiment.

On the other hand, when the communication control unit 421 determines that the received data is not the data addressed to the own device (NO in step S22), the power supply control is performed during the time for the data after the determination that the data is not addressed to the own device. The transition to the power saving state is performed via the unit 422 (step S23). After that, when the data after determining that the data is not addressed to the own device is completed among the received data, the power supply control unit 422 cancels the power saving state and performs the same operation as that of the first embodiment. Do.

As described above, the communication control unit 421 determines whether or not the received data is the data addressed to the own device, and if the data is not the data addressed to the own device, the communication control unit 421 passes through the power control unit 422 to the own device. To the power saving state. This is because when other BSS communications are being performed, it is possible to put the own device in the power saving state, and it is preferable to put the power saving state. By using the AP40 according to the present embodiment, it is possible to save power in consideration of the communication status of other BSSs. Therefore, according to the present embodiment, it is possible to save power as compared with the first embodiment.

Further, in the wireless communication system 200, in a congested environment where the radio is congested, the communication of other BSSs may increase. Therefore, in such a case, it is possible to achieve more effective power saving by dispersing the AP40 according to the present embodiment.

(Embodiment 3)
Subsequently, the third embodiment will be described. The third embodiment is an improved example of the first and second embodiments. Therefore, the third embodiment will be described with reference to the second embodiment. The AP according to the third embodiment is an access point corresponding to the CSMA-CA system as in the second embodiment. The AP according to the present embodiment determines whether the wireless environment in the wireless communication system is not congested by determining the presence / absence of other communication and the presence / absence of noise generated by the electronic device, and the wireless environment is congested. If not, set a further pause.

<Configuration example of wireless communication system>
The wireless communication system 300 according to the third embodiment will be described with reference to FIG. FIG. 10 is a schematic diagram showing an outline of the wireless communication system according to the third embodiment.

The wireless communication system 300 includes APs 50 and 70, wireless slave units 20 and 60, and an electronic device 80. That is, the wireless communication system 300 has a configuration in which the AP 40 is replaced with the AP 70 and the electronic device 80 is further provided, as compared with the wireless communication system 200 according to the second embodiment. In the wireless communication system 300, the APs 50 and 70 are access points corresponding to the CSMA-CA system as in the second embodiment. Since APs 50 and 70 and wireless slave units 20 and 60 are basically the same as those in the second embodiment, the description thereof will be omitted. Further, AP50 and 70 may have the same configuration or may have different configurations as in the second embodiment. In the following description, AP50 and 70 will be described as having the same configuration.

The electronic device 80 is, for example, an electronic device such as a microwave oven. The electronic device 80 emits radio waves when the electronic device 80 operates. The radio wave becomes a radio wave that becomes noise for communication devices belonging to BSS # 1 and BSS # 2. Although only one electronic device 80 is shown in FIG. 10, a plurality of electronic devices 80 may be used.

<AP configuration example>
Subsequently, a configuration example of the AP will be described using the AP70. In the AP 70, the control unit 42 is replaced with the control unit 72 in the configuration of the AP 40 according to the second embodiment. Specifically, in the AP 70, the communication control unit 421 is replaced by the communication control unit 721, and the power supply control unit 422 is replaced by the power supply control unit 722. The configuration of the control unit 72 is basically the same as that of the control unit 42 of the second embodiment. Further, among the configurations of AP70, other configurations are the same as those in the second embodiment. Therefore, in the present embodiment, the configurations of the communication control unit 721 and the power supply control unit 722 will be described.

The communication control unit 721 has basically the same configuration as the communication control unit 421 according to the second embodiment, but differs in the following points. Therefore, in the present embodiment, among the configurations of the communication control unit 721, the points different from the configuration of the communication control unit 421 of the second embodiment will be described, and the description of the same configuration as that of the second embodiment will be omitted.

Here, the configuration of the communication control unit 721 will be described with reference to FIG. FIG. 11 is a diagram illustrating a configuration example of the communication control unit according to the third embodiment. FIG. 11 shows the transmission / reception status of BSS # 1 data including AP70, the generation status of radio waves of the electronic device 80 (the emission status of Noise Energy), and the transmission / reception status of BSS # 2 data including AP50. ing.

AP70 is an access point corresponding to the CSMA-CA system. Therefore, the communication control unit 721 performs carrier sense (Carrier Sense) and energy detection (Energy Detection) based on the backoff time before transmission / reception of data so that the transmission / reception data does not collide with the data transmitted / received by other wireless communication devices. I do.

In the example shown in FIG. 11, after the communication by the BSS # 1 including the AP 70 is completed, the Noise Energy by the electronic device 80 is emitted, and the communication of the BSS # 2 is performed after waiting for the noise to disappear. That is, the communication of BSS # 2 is started when the noise of the electronic device 80 is no longer detected. The communication control unit 721 sets the backoff time 1101 after the communication of the BSS # 1 is finished, the noise of the electronic device 80 is no longer detected, and the communication of the BSS # 2 is finished. Then, the communication control unit 721 monitors and determines the presence / absence of other communication or the presence / absence of operation of the electronic device 80 during the backoff time 1101. That is, the communication control unit 721 sets the backoff time 1101 and monitors and determines whether or not the radio channel is free until the backoff time 1101 elapses. The backoff time 1101 may be the maximum value CWmax of the contention window.

When the communication control unit 721 determines that there is no other communication even after the backoff time 1101 has elapsed, that is, the wireless channel is in a free state, the communication control unit 721 sets the pause time 1102 in order to guard the subsequent communication. To do.

In the example shown in FIG. 11, the communication control unit 721 of the AP70 generates noise of the electronic device 80 within the backoff time 1101 set when the communication of the BSS # 1 ends, and the communication control unit 721 makes noise. Since it has been detected, the communication control unit 721 does nothing. Further, since the communication of BSS # 2 is generated within the backoff time 1101 set when the noise of the electronic device 80 is no longer detected, the communication control unit 721 does nothing. On the other hand, no other communication is generated within the backoff time 1101 set when the communication of BSS # 2 is completed, and no noise is generated due to the operation of the electronic device 80. In this case, the communication control unit 721 determines that the radio channel is free and sets the pause time 1102.

Then, the communication control unit 721 generates Null data in which the pause time 1102 is set as the header information, and transmits it to another wireless communication device. When the communication control unit 721 transmits the Null data for which the pause time 1102 is set, the communication control unit 721 notifies the power supply control unit 722. As in the first embodiment, the communication control unit 721 sets the pause time 1102 to be the smaller of the time until the next beacon signal is transmitted and the maximum transmission time (Max-TXOP).

Similar to the first and second embodiments, the power supply control unit 722 shifts the AP 70 to the power saving state during the pause time 1102 set by the communication control unit 721.

<AP operation example>
Subsequently, an operation example of the AP 70 according to the third embodiment will be described with reference to FIG. FIG. 12 is a flowchart illustrating an operation example of the AP according to the third embodiment. The operation shown in FIG. 12 is an operation performed when the communication of the BSS # 1 including the own device is completed, when the communication of the BSS # 2 is completed, and when the noise of the electronic device 80 is no longer detected.

First, when the communication or operation of the BSS # 1, the electronic device 80 and the BSS # 2 is completed, the communication control unit 721 sets the backoff time 1101 and occurs when another communication presence / absence or the electronic device 80 operates. Monitor the presence or absence of noise (step S31).

Next, the communication control unit 721 determines the presence / absence of other communication and the presence / absence of noise in the backoff time 1101 (step S32). That is, the communication control unit 721 determines whether or not the wireless channel is free in the backoff time 1101. In step S32, at the backoff time 1101, if there is other communication and / or there is noise, the process ends. The case where there is noise is a case where the communication control unit 721 no longer detects the noise generated by the electronic device 80.

On the other hand, in step S32, when there is no other communication at the backoff time 1101 and there is no noise due to the operation of the electronic device 80, the communication control unit 721 sets the Null data with the pause time 1102 to another radio. It is transmitted to the communication device (step S33). That is, the communication control unit 721 determines that the wireless channel is in an empty state when there is no other communication and there is no noise associated with the operation of the electronic device 80 at the backoff time 1101. Then, the communication control unit 721 transmits the Null data for which the pause time 1102 is set to another wireless communication device. At the same time as transmitting the Null data, the communication control unit 721 notifies the power supply control unit 722 that it is possible to shift its own device to the power saving state.

Next, the power supply control unit 722 shifts the AP70 to the power saving state during the pause time 1102 set in the Null data (step S34). When the pause time elapses, the power control unit 722 releases the power saving state and performs a normal operation.

As described above, in the present embodiment, the communication control unit 721 satisfies at least one of the cases where the communication between the BSS # 1 and the BSS # 2 is terminated and the noise of the electronic device 80 is no longer detected. In this case, it is determined whether or not the wireless channel is free, and if it is determined that the wireless channel is free, a pause time is set in the communication cycle immediately after. Therefore, according to the present embodiment, it is possible to further save power when the wireless channel is in an empty state.

Further, the communication control unit 721 transmits the Null data for which the pause time is set to another wireless communication device when the wireless channel is in a free state. The other wireless communication device that has received the Null data controls not to communicate during the pause time. That is, according to the present embodiment, since communication of not only the own device but also other wireless communication devices is suppressed, it is possible to reduce the power consumption of not only the own device but also other wireless communication devices. ..

(Other embodiments)
FIG. 13 is a block diagram showing a configuration example of the wireless communication devices 1, AP10, 40, 50 and 70 (hereinafter, referred to as wireless communication device 1 and the like) described in the above-described embodiment. Referring to FIG. 13, the wireless communication device 1 and the like include a network interface 1201, a processor 1202, and a memory 1203. Network interface 1201 is used to communicate with other wireless communication devices. The network interface 1201 may include, for example, an IEEE 802.11 series, an IEEE 802.3 series compliant network interface card (NIC).

The processor 1202 reads the software (computer program) from the memory 1203 and executes it to perform the processing of the wireless communication device 1 and the like described by using the flowchart in the above-described embodiment. The processor 1202 may be, for example, a microprocessor, an MPU (Micro Processing Unit), or a CPU (Central Processing Unit). Processor 1202 may include a plurality of processors.

The memory 1203 is composed of a combination of a volatile memory and a non-volatile memory. Memory 1203 may include storage located away from processor 1202. In this case, processor 1202 may access memory 1203 via an I / O interface (not shown).

In the example of FIG. 13, memory 1203 is used to store software modules. By reading these software modules from the memory 1203 and executing the processor 1202, the processor 1202 can perform the processing of the wireless communication device 1 and the like described in the above-described embodiment.

As described with reference to FIG. 13, each of the processors included in the wireless communication device 1 and the like executes one or more programs including a set of instructions for causing the computer to perform the algorithm described with reference to the drawings.

In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks). Further, examples of non-transitory computer-readable media include CD-ROM (Read Only Memory), CD-R, and CD-R / W. Further, examples of non-transitory computer-readable media include semiconductor memory. The semiconductor memory includes, for example, a mask ROM, a PROM (Programmable ROM), an EPROM (Erasable PROM), a flash ROM, and a RAM (Random Access Memory). The program may also be supplied to the computer by various types of transient computer readable media. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

The present disclosure is not limited to the above embodiment, and can be appropriately modified without departing from the spirit. Further, the present disclosure may be carried out by appropriately combining the respective embodiments.

In addition, some or all of the above embodiments may be described as in the following appendix, but are not limited to the following.
(Appendix 1)
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. Then, when data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmission. A communication control unit that sets a pause time including a time when data to be transmitted to the wireless communication terminal is generated by transmitting data in a second transmittable time after the possible time.
A wireless communication device including a power supply control unit that shifts its own device to a power saving state during the set pause time.
(Appendix 2)
If the communication control unit does not receive data from the wireless communication terminal within a predetermined time after the elapse of the first transmittable time and until the end of the communication cycle including the first transmittable time, the communication control unit may perform the above. The wireless communication device according to Appendix 1, wherein a pause time is set between the elapse of a predetermined time and the end of a communication cycle including the first transmittable time.
(Appendix 3)
The communication control unit transmits dummy data including the set pause time to another wireless communication device including the wireless communication terminal.
The wireless communication device according to Appendix 1 or 2, wherein the power supply control unit shifts its own device to a power saving state during the set pause time after transmitting the dummy data.
(Appendix 4)
A transmission buffer for temporarily storing data to be transmitted to the wireless communication terminal is further provided.
At the end of the first transmittable time, the communication control unit has the first data amount stored in the transmission buffer at the end of the first transmittable time and the first transmittable time. The amount of the second data stored in the transmission buffer at the end of the third transmittable time immediately before the above is compared with the communication cycle including the first transmittable time based on the comparison result. The wireless communication device according to any one of Items 1 to 3, which controls the transmittable time of the above.
(Appendix 5)
The communication control unit further sets a transmittable time in a communication cycle including the first transmittable time when the first data amount is larger than the second data amount, as described in Appendix 4. Wireless communication device.
(Appendix 6)
When the communication control unit receives data from another wireless communication device, the communication control unit determines whether or not the received data is data destined for the own device.
When the communication control unit determines that the received data is not the data destined for the own device, the power supply control unit shifts the own device to the power saving state until the end of the received data. The wireless communication device according to any one of Appendix 1 to 5.
(Appendix 7)
The communication control unit satisfies at least one of the cases where the communication of the own device is terminated, the communication of another wireless communication device is terminated, and the noise of the electronic device that emits a radio wave that becomes noise is no longer detected. In this case, it is determined whether or not the wireless channel is free, and when it is determined that the wireless channel is free, a pause time is set in the communication cycle immediately after determining that the wireless channel is free. , The wireless communication device according to any one of Supplementary Provisions 1 to 6.
(Appendix 8)
The communication control unit satisfies at least one of the cases where the communication of the own device is terminated, the communication of another wireless communication device is terminated, and the noise of the electronic device that emits a radio wave that becomes noise is no longer detected. When the back-off time is set and at least one of the case where communication is not performed in the other wireless communication device and the case where the noise is not detected is satisfied during the back-off time, the wireless channel is in a free state. The wireless communication device according to Appendix 7 for determination.
(Appendix 9)
The wireless communication device according to any one of Supplementary note 1 to 8, wherein the pause time is the time until the end of the communication cycle including the set pause time and the smaller time of the maximum transmission time.
(Appendix 10)
The wireless communication device according to any one of Items 1 to 9, wherein the communication cycle is a beacon signal transmission cycle.
(Appendix 11)
A wireless communication unit that communicates with the wireless communication terminal is further provided.
The wireless communication device according to any one of Supplementary note 1 to 10, wherein the power supply control unit shifts its own device to a power saving state by stopping power supply to the wireless communication unit.
(Appendix 12)
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
A power supply control method including, for example, transitioning the own device to a power saving state during the set pause time.
(Appendix 13)
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
A program that causes a computer to execute a transition of its own device to a power saving state during the set pause time.
(Appendix 14)
A wireless communication device and a wireless communication terminal that communicates with the wireless communication device are provided.
The wireless communication device is
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. Then, when data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmission. A communication control unit that sets a pause time including a time when data to be transmitted to the wireless communication terminal is generated by transmitting data in a second transmittable time after the possible time.
A wireless communication system including a power supply control unit that shifts its own device to a power saving state during the set pause time.
(Appendix 15)
If the communication control unit does not receive data from the wireless communication terminal within a predetermined time after the elapse of the first transmittable time and until the end of the communication cycle including the first transmittable time, the communication control unit may perform the above. The wireless communication system according to Appendix 14, wherein a pause time is set between the elapse of a predetermined time and the end of a communication cycle including the first transmittable time.

1 Wireless communication device 2, 121, 421, 721 Communication control unit 3, 122, 422, 722 Power supply control unit 10, 40, 50, 70 AP
11 Wireless communication unit 12, 42, 72 Control unit 13 Transmission buffer 14 Network I / F
20, 60 Wireless handset 30 Internet 80 Electronic device 100, 200 Wireless communication system

Claims (10)

The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. Then, when data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmission. A communication control unit that sets a pause time including a time when data to be transmitted to the wireless communication terminal is generated by transmitting data in a second transmittable time after the possible time.
A wireless communication device including a power supply control unit that shifts its own device to a power saving state during the set pause time. If the communication control unit does not receive data from the wireless communication terminal within a predetermined time after the elapse of the first transmittable time and before the end of the communication cycle including the first transmittable time, the communication control unit may perform the above. The wireless communication device according to claim 1, wherein a pause time is set between the elapse of a predetermined time and the end of the communication cycle including the first transmittable time. The communication control unit transmits dummy data including the set pause time to another wireless communication device including the wireless communication terminal.
The wireless communication device according to claim 1 or 2, wherein the power supply control unit shifts its own device to a power saving state during the set pause time after transmitting the dummy data. A transmission buffer for temporarily storing data to be transmitted to the wireless communication terminal is further provided.
At the end of the first transmittable time, the communication control unit has the first data amount stored in the transmission buffer at the end of the first transmittable time and the first transmittable time. The amount of the second data stored in the transmission buffer at the end of the third transmittable time immediately before the above is compared with the communication cycle including the first transmittable time based on the comparison result. The wireless communication device according to any one of claims 1 to 3, which controls the transmittable time of the above. The fourth aspect of the present invention, wherein the communication control unit further sets a transmittable time in a communication cycle including the first transmittable time when the first data amount is larger than the second data amount. Wireless communication device. When the communication control unit receives data from another wireless communication device, the communication control unit determines whether or not the received data is data destined for the own device.
When the communication control unit determines that the received data is not the data destined for the own device, the power supply control unit shifts the own device to the power saving state until the end of the received data. The wireless communication device according to any one of claims 1 to 5. The communication control unit satisfies at least one of the cases where the communication of the own device is terminated, the communication of another wireless communication device is terminated, and the noise of the electronic device that emits a radio wave that becomes noise is no longer detected. In this case, it is determined whether or not the wireless channel is free, and when it is determined that the wireless channel is free, a pause time is set in the communication cycle immediately after determining that the wireless channel is free. , The wireless communication device according to any one of claims 1 to 6. The wireless communication device according to any one of claims 1 to 7, wherein the pause time is a time until the end of a communication cycle including the set pause time, and a smaller time of the maximum transmission time. A power control method performed by a wireless communication device.
The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
A power supply control method comprising transitioning the wireless communication device to a power saving state during the set pause time. The communicable time acquired with another wireless communication device, which is the communicable time with the wireless communication terminal, is divided into at least one communication cycle including the transmittable time during which data can be transmitted to the wireless communication terminal. To do and
When data to be transmitted to the wireless communication terminal is generated between the elapse of the first transmittable time and the end of the communication cycle including the first transmittable time, the data is transmitted to the first transmittable time. To set a pause time including the time when the data to be transmitted to the wireless communication terminal is generated by transmitting the data in the second transmittable time after that.
A program that causes a computer to execute a transition of its own device to a power saving state during the set pause time.

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