WO2025225069A1 - Communication device, communication control method, and program - Google Patents

Abstract

A communication device (1) (second equipment (1B)) comprises: a communication circuit that communicates with each of a first communication device (first equipment (1A)) and a second communication device (access point (2)); and a processing circuit that controls the communication circuit. The processing circuit determines whether or not direct communication with the first communication device in a first mode (LPI mode) is available on the basis of a reception result regarding a signal received by the communication circuit from the second communication device. In a case of determining that direct communication with the first communication device in the first mode is available, the processing circuit controls the communication circuit to carry out direct communication with the first communication device in the first mode. In a case of determining that direct communication with the first communication device in the first mode is unavailable, the processing circuit controls the processing circuit to carry out direct communication with the first communication device in a second mode (VLP mode) different from the first mode.

Description

Communication device, communication control method, and program

This disclosure relates to communication devices and the like that communicate using radio waves.

For example, Patent Document 1 discloses a repeater for a wireless LAN (Local Area Network) equipped with a wireless communication circuit capable of communication in the 6 GHz band.

JP 2023-97385 A

This disclosure provides a communication device that makes it easy to maintain direct communication with other communication devices.

A communication device according to one aspect of the present disclosure includes a communication circuit that communicates with each of a first communication device and a second communication device, and a processing circuit that controls the communication circuit. The processing circuit determines whether direct communication with the first communication device is possible in a first mode based on a reception result of a signal received by the communication circuit from the second communication device. If the processing circuit determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit to perform the direct communication with the first communication device in the first mode. If the processing circuit determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit to perform the direct communication with the first communication device in a second mode different from the first mode.

A communication device according to one aspect of the present disclosure includes a communication circuit that communicates with each of a first communication device and a second communication device, and a processing circuit that controls the communication circuit. The processing circuit determines whether direct communication with the first communication device is possible in a first mode based on a reception result of a signal received by the communication circuit from the second communication device. If the processing circuit determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit to send an instruction to the first communication device to perform the direct communication with the communication circuit in the first mode. If the processing circuit determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit to send an instruction to the first communication device to perform the direct communication with the communication circuit in a second mode different from the first mode.

A communication control method according to one aspect of the present disclosure uses a communication circuit to communicate with each of a first communication device and a second communication device. The communication control method determines whether direct communication with the first communication device is possible in a first mode based on a reception result of a signal received by the communication circuit from the second communication device. If the communication control method determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit to perform the direct communication with the first communication device in the first mode. If the communication control method determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit to perform the direct communication with the first communication device in a second mode different from the first mode.

A communication control method according to one aspect of the present disclosure uses a communication circuit to communicate with a first communication device and a second communication device. The communication control method determines whether direct communication with the first communication device is possible in a first mode based on a reception result of a signal received by the communication circuit from the second communication device. If the communication control method determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit to send an instruction to the first communication device to perform the direct communication with the communication circuit in the first mode. If the communication control method determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit to send an instruction to the first communication device to perform the direct communication with the communication circuit in a second mode different from the first mode.

A program according to one aspect of the present disclosure causes one or more processors to execute the communication control method.

The communication devices disclosed herein have the advantage of making it easier to maintain direct communication with other communication devices.

FIG. 1 is a diagram illustrating the problem of communication between slave stations. FIG. 2 is a diagram illustrating an outline of communication between slave stations using a communication device according to an embodiment. FIG. 3 is a block diagram illustrating an example of the configuration of a communication device according to an embodiment. FIG. 4 is a diagram illustrating an example of data stored in the memory of the communication device according to the embodiment. FIG. 5 is an explanatory diagram of an example of a basic operation using the communication device according to the embodiment. FIG. 6 is a sequence diagram illustrating an example of a basic operation using the communication device according to the embodiment. FIG. 7 is an explanatory diagram of a first operation example using the communication device according to the embodiment. FIG. 8 is a sequence diagram illustrating a first operation example using the communication device according to the embodiment. FIG. 9 is a flowchart showing the operation of the first device in the first operation example using the communication device according to the embodiment. FIG. 10 is a flowchart illustrating the operation of the second device in the first operation example using the communication device according to the embodiment. FIG. 11 is an explanatory diagram of a second operation example using the communication device according to the embodiment. FIG. 12 is a sequence diagram illustrating a second operation example using the communication device according to the embodiment. FIG. 13 is a flowchart illustrating the operation of the first device in the second operation example using the communication device according to the embodiment. FIG. 14 is a flowchart illustrating the operation of the second device in the second operation example using the communication device according to the embodiment. FIG. 15 is an explanatory diagram of a third operation example using the communication device according to the embodiment.

[1. Findings that form the basis of this disclosure]
First, the inventor's point of view will be explained below.

In recent years, the 6 GHz band (5925 MHz to 6425 MHz in Japan) has been opened up as a frequency band available for wireless LANs. However, at present, due to the need to share frequencies with existing systems such as fixed-line communication systems, satellite communication systems, and broadcast program relay systems, use of the 6 GHz band for wireless LANs is limited to indoor use. Furthermore, in Japan, the Radio Law Enforcement Regulations currently stipulate that communication between slave stations in LPI (Low Power Indoor) mode must operate within a range where the master station's signal strength spectral density is -95 dBm per MHz or less, limiting the locations in which it can be used.

When using the 6 GHz band for wireless LAN, the Radio Law Enforcement Regulations stipulate that communication devices must transmit radio waves in either LPI mode or VLP (Very Low Power) mode. LPI mode is a mode in which the radio wave transmission power is relatively high, with the maximum equivalent isotropic radiated power set to be greater than 25 milliwatts and less than 200 milliwatts, and as mentioned above, there are currently restrictions on the use of LPI mode for communication between satellite stations. VLP mode is a mode in which the radio wave transmission power is lower than LPI mode, with the maximum equivalent isotropic radiated power set to be less than 25 milliwatts, but there are no particular restrictions on its use for communication between satellite stations.

Furthermore, communication between slave stations refers to establishing a peer-to-peer connection between two communication devices (slave stations) when the two devices are connected to a wireless LAN with an access point as the parent station, and communicating directly without going through the access point. Communication between slave stations is achieved using communication standards such as TDLS (Tunneled Direct Link Setup). Communication between slave stations is used, for example, when executing a mirroring function that displays an image displayed on one slave station, such as a smartphone, on another slave station, such as a television receiver.

As already mentioned, there are restrictions on communication between slave stations in LPI mode. Specifically, as long as the two communication devices (slave stations) are located within a specified range based on the access point (master station), communication between the slave stations in LPI mode between the communication devices is permitted. Here, the specified range is the range in which the radio wave strength of the signal transmitted from the access point is above a threshold, and the threshold must be checked at least once every four seconds.

Here, we will explain the issues with communication between slave stations. Figure 1 is an explanatory diagram of the issues with communication between slave stations. Figure 1(a) shows a case where the first slave station 101 and the second slave station 102 are both located within a specified range A1 based on the master station 103, while Figure 1(b) shows a case where one of the slave stations (in this case, the second slave station 102) has moved outside of the specified range A1.

In the case shown in (a) of Figure 1, the first slave station 101 and the second slave station 102 are both located within the specified range A1, so communication between the slave stations in LPI mode is possible. However, in the case shown in (b) of Figure 1, the second slave station 102 is located outside the specified range A1, so the first slave station 101 and the second slave station 102 are unable to communicate between the slave stations in LPI mode. In this case, the first slave station 101 and the second slave station 102 must stop communication between the slave stations and change to communication via the master station 103.

However, in this case, there is an issue that communication between the first slave station 101 and the second slave station 102 is temporarily interrupted when switching from inter-slave station communication to communication via the master station 103. In addition, in this case, there is an issue that the communication speed (e.g., bits per second) of communication between the first slave station 101 and the second slave station 102 is lower than the communication speed for inter-slave station communication, resulting in increased delays during transmission.

In consideration of the above, the inventors have come up with the present disclosure.

The following describes the embodiments in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in independent claims will be described as optional components.

Note that each figure is a schematic diagram and is not necessarily an exact illustration. Furthermore, in each figure, substantially identical components are assigned the same reference numerals, and duplicate explanations may be omitted or simplified.

(Embodiment)
[2. Overview]
First, an overview of communication between slave stations using a communication device 1 according to an embodiment will be described with reference to FIG. 2 . FIG. 2 is an explanatory diagram of the overview of communication between slave stations using a communication device 1 according to an embodiment. In the following description, a first device 1A, a second device 1B, and an access point 2 will appear, but either the first device 1A or the second device 1B will be referred to as the communication device 1. Furthermore, for example, when either the first device 1A or the first device 1B is referred to as the "communication device 1," the other device may be referred to as the "first communication device," and the access point 2 as the "second communication device." In the embodiment, the second device 1B will be referred to as the "communication device 1," the first device 1A as the "first communication device," and the access point 2 as the "second communication device."

In this embodiment, the second device 1B is a portable television receiver, and the first device 1A is a tuner. A tuner is, for example, a device that receives television broadcasts and transmits the received television broadcasts to the portable television receiver via wireless communication. Note that the first device 1A and the second device 1B are not limited to these devices, and may be any device capable of inter-substation communication.

(a) in Figure 2 shows a case where both the first device 1A and the second device 1B are located within a specified range A1 based on the access point 2, while (b) in Figure 2 shows a case where one of the devices (here, the second device 1B) has moved outside of the specified range A1.

In the case shown in Figure 2(a), the first device 1A and the second device 1B are both located within the specified range A1, so communication between the slave stations in LPI mode is possible. On the other hand, in the case shown in Figure 2(b), the second device 1B is located outside the specified range A1, so the first device 1A and the second device 1B are unable to communicate between the slave stations in LPI mode.

Therefore, when the second device 1B, which is the communication device 1, moves outside the specified range A1, it changes from LPI mode to VLP mode. As already mentioned, VLP mode does not place any particular restrictions on the location that can be used for inter-substation communication, so it is possible to maintain inter-substation communication between the first device 1A and the second device 1B.

3. Configuration
The configuration of a communication device 1 according to an embodiment will be described below with reference to FIG. 3. FIG. 3 is a block diagram showing an example configuration of a communication device 1 according to an embodiment. Both a first device 1A and a second device 1B have the configuration of the communication device 1 described below. Here, the description will be given assuming that the communication device 1 is the second device 1B. The communication device 1 includes a communication circuit 11, a processing circuit 12, and a memory 13.

The communication circuit 11 is a circuit that communicates with each of the first communication device (here, the first device 1A) and the second communication device (here, the access point 2). The communication circuit 11 has an antenna 111, an RF-SW 112, a receiving circuit 113, a transmitting circuit 114, and an RF power control circuit 115.

When antenna 111 receives radio waves in a predetermined frequency band (here, the 6 GHz band), it converts the radio waves into electrical signals and outputs the converted electrical signals to receiving circuit 113 via RF switch (hereinafter referred to as "RF-SW") 112. Antenna 111 also converts electrical signals received from transmitting circuit 114 via RF-SW 112 into radio waves in a predetermined frequency band and outputs the converted radio waves to the outside. Note that antenna 111 is not limited to the predetermined frequency band and may also be capable of transmitting and receiving radio waves in other frequency bands (for example, the 2.4 GHz band or the 5 GHz band).

The RF-SW 112 is a switch that switches the path of a high-frequency signal. When receiving radio waves, the RF-SW 112 switches to a path that connects the antenna 111 and the receiving circuit 113. When transmitting radio waves, the RF-SW 112 switches to a path that connects the antenna 111 and the transmitting circuit 114.

The receiving circuit 113 demodulates the electrical signal output from the antenna 111 via the RF-SW 112, and outputs the demodulated electrical signal (hereinafter also referred to as the "received signal") to the processing circuit 12. In this embodiment, the receiving circuit 113 employs, for example, a direct conversion system or a superheterodyne system. The receiving circuit 113 also has an RF detector, measures the RSSI (Received Signal Strength Indicator) value of the received signal, and outputs the measured RSSI value to the processing circuit 12.

The transmission circuit 114 modulates and amplifies the electrical signal (hereinafter also referred to as the "transmission signal") output from the processing circuit 12, and outputs the modulated and amplified electrical signal to the antenna 111 via the RF-SW 112. In this embodiment, the modulation method is a multi-carrier modulation method such as the OFDM (Orthogonal Frequency-Division Multiplexing) method.

The RF power control circuit 115 is a circuit that controls the amplifier included in the transmission circuit 114, and controls the transmission power of the radio waves output from the antenna 111. In this embodiment, the RF power control circuit 115 controls the transmission power in accordance with instructions from the processing circuit 12. Specifically, when the communication device 1 is operated in LPI mode (first mode), the RF power control circuit 115 controls the amplifier so that the transmission power of the radio waves output from the antenna 111 is transmission power corresponding to the LPI mode. Furthermore, when the communication device 1 is operated in VLP mode (second mode), the RF power control circuit 115 controls the amplifier so that the transmission power of the radio waves output from the antenna 111 is transmission power corresponding to the VLP mode.

The processing circuit 12 is a baseband circuit that performs information processing based on the received signal output from the receiving circuit 113, and information processing that outputs a transmission signal to the transmitting circuit 114. The processing circuit 12 is, for example, an MCU (Micro Controller Unit). The above-mentioned information processing is realized by the processing circuit 12 executing a computer program stored in the memory 13.

Memory 13 is a storage device that stores computer programs executed by processing circuit 12 and information necessary to realize various functions. Memory 13 is realized, for example, by semiconductor memory. Note that memory 13 may also be realized as built-in memory of processing circuit 12, rather than as external memory of processing circuit 12.

Here, the processing circuit 12 performs the following two processes each time the communication circuit 11 receives a signal from the second communication device (access point 2).

First, the processing circuit 12 performs a process (hereinafter also referred to as the "determination process") to determine whether the communication device 1 (second device 1B) is capable of direct communication (inter-slave station communication) in the first mode (LPI mode) with the first communication device (first device 1A) based on the reception result of the signal (received signal) received by the communication circuit 11 from the second communication device (access point 2). The determination process corresponds to the process of determining whether the communication device 1 (second device 1B) is located within the specified range A1.

Specifically, the processing circuit 12 compares the RSSI value of the signal transmitted from access point 2, which is included in the received signal acquired from the receiving circuit 113, with a threshold value pre-stored in memory 13. If the RSSI value is equal to or greater than the threshold value, it determines that direct communication is possible in the first mode, and if the RSSI value is less than the threshold value, it determines that direct communication is not possible in the first mode. In other words, if the radio wave strength of the signal from the second communication device (access point 2) received by the communication circuit 11 is below the threshold value, the processing circuit 12 determines that direct communication (communication between slave stations) with the first communication device (first device 1A) is not possible in the first mode (LPI mode). Here, the threshold value is, for example, -95 dBm/MHz.

In this embodiment, the memory 13 stores a threshold for each of the five types of occupied frequency bandwidth used in the OFDM modulation method. The processing circuit 12 then compares the RSSI value with the threshold corresponding to the occupied frequency bandwidth being used. For example, if the occupied frequency bandwidth is 20 MHz, the threshold is -82 dBm. Also, for example, if the occupied frequency bandwidth is 40 MHz, the threshold is -79 dBm. Also, for example, if the occupied frequency bandwidth is 80 MHz, the threshold is -76 dBm. Also, for example, if the occupied frequency bandwidth is 160 MHz, the threshold is -73 dBm. Also, for example, if the occupied frequency bandwidth is 320 MHz, the threshold is -70 dBm.

Second, the processing circuit 12 executes a process (hereinafter also referred to as the "mode determination process") that determines the operating mode of the communication device 1 based on the determination result of the determination process. Specifically, if the processing circuit 12 determines in the determination process that the communication device 1 (second device 1B) is capable of direct communication (inter-slave station communication) with the first communication device (first device 1A) in the first mode (LPI mode), the processing circuit 12 controls the communication circuit 11 to communicate directly with the first communication device in the first mode (i.e., determines the operating mode of the communication device 1 to be the first mode). More specifically, the processing circuit 12 references data pre-stored in the memory 13, reads data indicating the gain corresponding to the first mode, and outputs this data to the RF power control circuit 115. As a result, the RF power control circuit 115 controls the amplifier so that the transmission power of the radio waves output from the antenna 111 is the transmission power corresponding to the first mode.

Furthermore, if the processing circuit 12 determines in the determination process that the communication device 1 cannot communicate directly with the first communication device in the first mode, it controls the communication circuit 11 to communicate directly with the first communication device in a second mode (VLP mode) different from the first mode (i.e., it determines the operating mode of the communication device 1 to be the second mode). Specifically, the processing circuit 12 references data pre-stored in the memory 13, reads data indicating the gain corresponding to the second mode, and outputs this data to the RF power control circuit 115. As a result, the RF power control circuit 115 controls the amplifier so that the transmission power of the radio waves output from the antenna 111 is transmission power corresponding to the second mode.

In other words, the processing circuit 12 measures the RSSI value of the beacon signal transmitted from the access point 2 and determines whether the communication device 1 is within the specified range A1 based on the measured RSSI value. If the RSSI value is equal to or greater than the threshold, the processing circuit 12 determines that the communication device 1 is within the specified range A1 and sets the operating mode to LPI mode (first mode). Furthermore, if the RSSI value is below the threshold, the processing circuit 12 determines that the communication device 1 is outside the specified range A1 and changes the operating mode from LPI mode (first mode) to VLP mode (second mode).

If the determination result is the same as the previous determination result, the processing circuit 12 does not output data indicating the gain to the RF power control circuit 115. In this case, the operating mode of the communication device 1 is not changed and is maintained.

FIG. 4 is a diagram showing an example of data stored in memory 13 of communication device 1 according to an embodiment. (a) of FIG. 4 shows an example of data referenced by processing circuit 12, and (b) of FIG. 4 shows another example of data referenced by processing circuit 12. Note that in the embodiment, the data stored in memory 13 is either the data shown in (a) of FIG. 4 or the data shown in (b) of FIG. 4.

In the example shown in Figure 4(a), the processing circuit 12 reads data indicating the gain corresponding to the second mode by changing the reference in a file (here, "Table A.txt") stored in memory 13. Specifically, the processing circuit 12 changes the reference from [JP-LPI], which describes the gain corresponding to the first mode, to [JP-VLP], which describes the gain corresponding to the second mode.

In the example shown in Figure 4(b), the processing circuit 12 reads data indicating the gain corresponding to the second mode by changing the reference from a file stored in memory 13 (here, "Table A.txt") to another file (here, "Table B.txt"). Specifically, the processing circuit 12 changes the reference from "Table A.txt," which includes [JP-LPI] describing the gain corresponding to the first mode, to "Table B.txt," which includes [JP-VLP] describing the gain corresponding to the second mode.

[4. Operation]
An example of operation using the communication device 1 according to the embodiment, that is, an example of a communication control method, will be described below.

[4-1. Basic operation example]
An example of a basic operation using the communication device 1 according to the embodiment will be described below with reference to Fig. 5 and Fig. 6. Fig. 5 is an explanatory diagram of an example of a basic operation using the communication device 1 according to the embodiment. Fig. 6 is a sequence diagram showing an example of a basic operation using the communication device 1 according to the embodiment.

First, as shown in (a) of FIG. 5 and step S101 of FIG. 6, a process is executed to connect the first device 1A (first communication device) and the second device 1B (communication device 1) to the wireless LAN by connecting them to the access point 2 (second communication device). This process can be executed, for example, by the user performing a predetermined operation on each of the first device 1A and the second device 1B. As a result, the access point 2 acts as the parent station, and the first device 1A and the second device 1B are each connected to the access point 2 as a child station.

Next, as shown in (b) of FIG. 5 and steps S102 and S103 of FIG. 6, processing is performed to perform inter-slave communication between the first device 1A and the second device 1B in LPI mode. In this embodiment, inter-slave communication between the first device 1A and the second device 1B is performed using TDLS.

First, in step S102, the first device 1A sends a search packet called a "TDLS Discovery request" ("request" shown in Figure 6) to another slave station (here, the second device 1B) via access point 2. Upon receiving the search packet, the second device 1B sends a response packet called a "TDLS Discovery response" ("response" shown in Figure 6) to the sender of the search packet (here, the first device 1A). This enables the first device 1A to discover the second device 1B, which may be a target for TDLS inter-slave station communication. Note that step S102 is executed periodically regardless of whether the first device 1A and the second device 1B are performing inter-slave station communication.

Next, in step S103, the first device 1A sends a connection request packet called a "TDLS Setup request" ("Setup request" shown in Figure 6) to the second device 1B. Upon receiving the connection request packet, the second device 1B sends a packet indicating acceptance of the connection request ("Accept" shown in Figure 6) to the sender of the connection request packet (here, the first device 1A). This establishes a TDLS connection between the first device 1A and the second device 1B, and communication between the slave stations of the first device 1A and the second device 1B in LPI mode (first mode) begins.

After that, as shown in step S104 of FIG. 6, the first device 1A transmits a packet directly to the second device 1B in LPI mode without going through the access point 2, and the second device 1B returns an ACK (Acknowledgement) for that packet directly to the first device 1A in LPI mode without going through the access point 2. This process is repeated. As a result, data is sent and received between the first device 1A and the second device 1B via inter-slave station communication.

Here, the first device 1A and the second device 1B periodically (for example, every few seconds) perform a determination process. Specifically, each of the first device 1A and the second device 1B measures the RSSI value of a beacon signal periodically transmitted from the access point 2, and determines whether it is present within the specified range A1 based on the measured RSSI value. The first device 1A may, for example, measure the RSSI value of a response packet periodically transmitted from the second device 1B via the access point 2, and determine whether it is present within the specified range A1 based on the measured RSSI value. The second device 1B may, for example, measure the RSSI value of a search packet periodically transmitted from the first device 1A via the access point 2, and determine whether it is present within the specified range A1 based on the measured RSSI value.

Then, as shown in (c) of FIG. 5 and step S105 of FIG. 6, if the second device 1B moves outside the specified range A1, for example because the user carries the second device 1B, the second device 1B (processing circuit 12 of the communication device 1) determines that it is outside the specified range A1. Then, as shown in (c) of FIG. 5 and step S106 of FIG. 6, the second device 1B changes its operating mode from LPI mode (first mode) to VLP mode (second mode) through mode determination processing. This allows communication between the slave stations of the first device 1A and the second device 1B to continue uninterrupted thereafter.

After that, as shown in step S107 of FIG. 6, the first device 1A transmits a packet directly to the second device 1B in LPI mode without going through the access point 2, and the second device 1B returns an ACK for that packet directly to the first device 1A in VLP mode without going through the access point 2. This process is repeated. As a result, data is sent and received between the first device 1A and the second device 1B via inter-slave station communication.

[4-2. First operation example]
A first operation example using the communication device 1 according to the embodiment will be described below with reference to Figs. 7, 8, 9, and 10. Fig. 7 is an explanatory diagram of the first operation example using the communication device 1 according to the embodiment. Fig. 8 is a sequence diagram showing the first operation example using the communication device 1 according to the embodiment. Fig. 9 is a flowchart showing the operation of the first device 1A (first communication device) in the first operation example using the communication device 1 according to the embodiment. Fig. 10 is a flowchart showing the operation of the second device 1B (communication device 1) in the first operation example using the communication device 1 according to the embodiment.

In the first operation example, steps S201 to S204 in FIG. 8 are the same as steps S101 to S104 in FIG. 6 of the basic operation example, and therefore will not be described here. The following description begins from the point at which inter-substation communication between the first device 1A (first communication device) and the second device 1B (communication device 1) begins. After inter-substation communication begins, the first device 1A repeats steps S301 to S307 in FIG. 9 until inter-substation communication is stopped. Furthermore, after inter-substation communication begins, the second device 1B repeats steps S401 to S412 in FIG. 10 until inter-substation communication is stopped.

The first device 1A acquires wireless information (step S301 in FIG. 9). Similarly, the second device 1B acquires wireless information (step S401 in FIG. 10).

Here, the wireless information acquired by the first device 1A includes the RSSI value of the signal transmitted from the access point 2 to the second device 1B, and information related to the communication quality of the communication between the slave stations. The information related to communication quality includes, for example, the measurement results of the RSSI value of the signal transmitted from the second device 1B, the MCS (Modulation and Coding Scheme), and the degree of data transmission errors such as the packet loss rate.

By receiving response packets periodically transmitted via access point 2, first device 1A can obtain the RSSI value of the signal transmitted from access point 2 to second device 1B, which is included in the response packets. Furthermore, by receiving ACKs received in inter-substation communication with second device 1B, first device 1A can obtain information regarding the communication quality of inter-substation communication.

Similarly, the wireless information acquired by the second device 1B includes the RSSI value of the signal transmitted from the access point 2 to the first device 1A, and information related to the communication quality of the communication between the slave stations. The information related to communication quality includes, for example, the measurement result of the RSSI value of the signal transmitted from the first device 1A, the MCS, and the degree of data transmission errors such as the packet loss rate.

By receiving a search packet that is periodically transmitted via access point 2, second device 1B can obtain the RSSI value of the signal transmitted from access point 2 to first device 1A, which is included in the search packet. Furthermore, by receiving packets received in inter-substation communication with first device 1A, second device 1B can obtain information regarding the communication quality of inter-substation communication.

Then, as shown in step S205 in FIGS. 7 and 8, if the second device 1B moves outside the specified range A1, for example because the user carries the second device 1B, the second device 1B (processing circuit 12 of the communication device 1) determines that it is outside the specified range A1 (step S402: Yes in FIG. 10). Note that while the second device 1B determines that it is not outside the specified range A1, that is, that it is within the specified range A1 (step S402: No in FIG. 10 and step S410: No), it continues communication between slave stations in LPI mode (first mode) (step S412 in FIG. 10).

If the second device 1B is outside the specified range A1 and moves from within the specified range A1 to outside it (step S403 in FIG. 10: Yes), it notifies the first device 1A that it is outside the specified range A1, as shown in step S206 in FIG. 8 and step S404 in FIG. 10. On the other hand, if the first device 1B continues to be outside the specified range A1 (step S403 in FIG. 10: No), it continues inter-station communication between the first device 1A and the second device 1B without interruption (step S408 in FIG. 10).

When the first device 1A receives a notification from the second device 1B (step S302 in FIG. 9), it executes a process to determine the communication mode. Specifically, the first device 1A determines whether communication between the local stations or communication via access point 2 is better by referencing information related to communication quality included in the wireless information (step S303 in FIG. 9). Here, the first device 1A compares the communication quality of communication between the local stations when the operating mode of the second device 1B is changed to VLP mode with the communication quality of communication via access point 2. These communication qualities may be estimated values assuming that the operating mode of the second device 1B is changed to VLP mode, or may be actual measured values when the operating mode of the second device 1B is actually changed to VLP mode.

If it is determined that the communication quality between the substations is better (step S303 in FIG. 9: Yes), the first device 1A instructs the second device 1B to continue the substation communication (step S304 in FIG. 9). When the second device 1B receives the instruction from the first device 1A (step S405 in FIG. 10), since the instruction is to continue the substation communication (step S406 in FIG. 10: Yes), the second device 1B performs a mode determination process to change the operating mode from LPI mode (first mode) to VLP mode (second mode) (step S407 in FIG. 10). This allows the substation communication between the first device 1A and the second device 1B to continue uninterrupted (step S305 in FIG. 9 and step S408 in FIG. 10).

On the other hand, if it is determined that the communication quality between the sub-stations is not better (step S303: No in FIG. 9), the first device 1A instructs the second device 1B to stop the sub-station communication and change to communication via access point 2 (step S306 in FIG. 9). Then, the first device 1A stops the sub-station communication and starts communication via access point 2 (step S307 in FIG. 9). When the second device 1B receives the instruction from the first device 1A (step S405 in FIG. 10), the instruction is to change to communication via access point 2 (step S406 in FIG. 10: No), so the second device 1B stops the sub-station communication and starts communication via access point 2 (step S409 in FIG. 10). As a result, from then on, the first device 1A and the second device 1B communicate via access point 2, as shown in FIG. 7.

After that, as shown in step S207 of FIG. 8, the first device 1A transmits a packet to the second device 1B in LPI mode via the access point 2, and the second device 1B returns an ACK for that packet to the first device 1A in LPI mode via the access point 2. This process is repeated.

Thereafter, if the second device 1B moves into the specified range A1, for example, by the user carrying the second device 1B, the second device 1B determines that it is within the specified range A1 (step S402 in FIG. 10: No) and that it has moved from outside the specified range A1 into the specified range A1 (step S410 in FIG. 10: Yes). The second device 1B then performs a mode determination process to change its operating mode from VLP mode (second mode) to LPI mode (first mode) (step S411 in FIG. 10). This allows communication between the slave stations of the first device 1A and the second device 1B to continue uninterrupted thereafter (step S412 in FIG. 10).

In the first operation example, the first device 1A executes the process for determining the communication mode, but the second device 1B may execute the process for determining the communication mode. In this case, if the second device 1B determines that it is outside the specified range A1, it executes the process for determining the communication mode and issues instructions to the first device 1A according to the results.

As described above, in the first operation example, if the processing circuit 12 determines that direct communication with the first communication device (here, first device 1A) is not possible in the first mode (here, LPI mode), it causes the communication device 1 and the first communication device to execute a process of determining whether direct communication or communication via the second communication device (here, access point 2) has better communication quality, and if it determines that communication quality via the second communication device is good, a process of communicating with the first communication device via the second communication device.

[4-3. Second operation example]
A second operation example using the communication device 1 according to the embodiment will be described below with reference to Figs. 11, 12, 13, and 14. Fig. 11 is an explanatory diagram of the second operation example using the communication device 1 according to the embodiment. Fig. 12 is a sequence diagram showing the second operation example using the communication device 1 according to the embodiment. Fig. 13 is a flowchart showing the operation of the first device 1A (first communication device) in the second operation example using the communication device 1 according to the embodiment. Fig. 14 is a flowchart showing the operation of the second device 1B (communication device 1) in the second operation example using the communication device 1 according to the embodiment.

In the second operation example, steps S502 to S508 in FIG. 12 are the same as steps S101 to S107 in FIG. 6 of the basic operation example, and therefore will not be described here. Note that in step S502, the second device 1B first executes a process to instruct the first device 1A to connect to access point 2, and the process from this step onwards is the same as step S101. Also, steps S601 to S607 in FIG. 13 are the same as steps S301 to S307 in FIG. 9 of the first operation example, and therefore will not be described here. Also, steps S701 to S712 in FIG. 14 are the same as steps S401 to S412 in FIG. 10 of the first operation example, and therefore will not be described here. After communication between the slave stations is initiated, the first device 1A repeats steps S601 to S610 in FIG. 13 until communication between the slave stations is stopped. Furthermore, after inter-slave station communication has started, the second device 1B repeats steps S701 to S716 in FIG. 14 until inter-slave station communication is stopped.

In the second operation example, as shown in step S501 in FIG. 12, before communication between the first device 1A (first communication device) and the second device 1B (communication device 1) begins, the first device 1A and the second device 1B are connected as a parent-child device. Specifically, the first device 1A makes a connection request to the second device 1B, and the second device 1B accepts the connection request, enabling parent-child communication with the first device 1A as the parent station and the second device 1B as the child station. Parent-child communication refers to establishing a peer-to-peer connection between the two communication devices and communicating directly without going through the access point 2, without connecting to a wireless LAN with the access point 2 as the parent station. In other words, in parent-child communication, the first device 1A and the second device 1B send and receive data without being connected to a wide area network such as the Internet.

The following explanation begins from the point at which the second device 1B moves out of the specified range A1, changing the operating mode from LPI mode (first mode) to VLP mode (second mode) and continuing communication between slave stations.

As shown in step S509 of FIG. 12 and FIG. 11, if the second device 1B moves outside the communication range A2 of the access point 2, for example because the user carries the second device 1B, the second device 1B (processing circuit 12 of the communication device 1) determines that it is outside the range of the access point 2, i.e., that it cannot communicate with the access point 2 (step S713 of FIG. 14: Yes). Note that the second device 1B continues communication between slave stations in VLP mode while it determines that it is within the communication range A2 (step S713 of FIG. 14: No).

Then, as shown in step S510 of FIG. 12, the first device 1A and the second device 1B reconnect as a parent and child. Specifically, the second device 1B notifies the first device 1A that it is out of range of the access point 2 (step S714 of FIG. 14). Upon receiving the notification from the second device 1B (step S608 of FIG. 13), the first device 1A stops communication between child stations, changes itself to the parent station, and performs processing similar to that of step S501 to reconnect with the second device 1B as a parent and child (step S609 of FIG. 13). Similarly, the second device 1B stops communication between child stations and performs processing similar to that of step S501 to reconnect with the first device 1A, which is the parent station, as a parent and child (step S715 of FIG. 14). This initiates parent-child communication in LPI mode, with the first device 1A as the parent station and the second device 1B as the child station (step S610 in FIG. 13 and step S716 in FIG. 14).

After that, as shown in step S511 in FIG. 12, with neither the first device 1A nor the second device 1B connected to the access point 2, the first device 1A transmits a packet to the second device 1B in LPI mode, and the second device 1B returns an ACK for that packet to the first device 1A in LPI mode. This process is repeated.

Thereafter, as shown in step S512 of FIG. 12, if the second device 1B moves from outside the specified range A1 to within the communication range A2, for example by the user carrying the second device 1B, the second device 1B determines that it is within the range of the access point 2 but outside the specified range A1. Then, as shown in step S513 of FIG. 12, the second device 1B notifies the first device 1A that it is outside the specified range A1. Here, the second device 1B changes its operating mode from LPI mode to VLP mode and notifies the first device 1A.

As shown in step S513 of FIG. 12, when the first device 1A receives a notification from the second device 1B, it executes processing to determine the communication mode, similar to the first operation example. Here, the first device 1A determines that communication between slave stations has better communication quality, and instructs the second device 1B to connect to access point 2. The first device 1A and second device 1B then each execute processing to connect to access point 2. As a result, the first device 1A and second device 1B are each connected to access point 2 as slave stations, with access point 2 as the parent station.

Next, the first device 1A sends a connection request packet to the second device 1B. Upon receiving the connection request packet, the second device 1B changes its operating mode from LPI mode to VLP mode and sends a packet indicating acceptance of the connection request to the first device 1A. This establishes a TDLS connection between the first device 1A and the second device 1B, and communication between the slave stations of the first device 1A and the second device 1B begins.

After that, as shown in step S514 of FIG. 12, the first device 1A transmits a packet directly to the second device 1B in LPI mode without going through the access point 2, and the second device 1B returns an ACK for that packet directly to the first device 1A in VLP mode without going through the access point 2. This process is repeated. As a result, data is sent and received between the first device 1A and the second device 1B via inter-slave station communication.

As described above, in the second operation example, if the first communication device (here, first device 1A) cannot communicate with the second communication device (here, access point 2), the processing circuit 12 causes communication device 1 and the first communication device to execute processing for parent-child communication, with one of communication device 1 and the first communication device acting as the parent station and the other as the child station.

[4-4. Third operation example]
A third operation example using the communication device 1 according to the embodiment will be described below with reference to Fig. 15. Fig. 15 is an explanatory diagram of the third operation example using the communication device 1 according to the embodiment. In Fig. 15, solid arrows represent radio waves in the 6 GHz band (first frequency band), and dotted arrows represent radio waves in the 5 GHz band (second frequency band).

In the third operation example, as shown in FIG. 15, the first device 1A (first communication device), the second device 1B (communication device 1), and the access point 2 (second communication device) not only transmit and receive radio waves in the 6 GHz band with each other, but also transmit and receive radio waves in the 5 GHz band. The third operation example can be realized when using the first device 1A, the second device 1B, and the access point 2 that support a specified wireless communication standard, such as Wi-Fi CERTIFIED 7 (registered trademark).

In the third operation example, with respect to the 6 GHz band, the operations of the first device 1A, the second device 1B, and the access point 2 are the same as in the basic operation example. That is, as shown in FIG. 15(a), when the second device 1B is within the specified range A1, it continues communication between the sub-stations in LPI mode (first mode). Then, as shown in FIG. 15(b), when the second device 1B moves outside the specified range A1, it changes its operation mode from LPI mode (first mode) to VLP mode (second mode) and continues communication between the sub-stations. On the other hand, in the third operation example, with respect to the 5 GHz band, the first device 1A, the second device 1B, and the access point 2 send and receive packets in the same way as with 6 GHz band radio waves, regardless of whether the second device 1B is outside the specified range A1.

As described above, in the third operation example, the processing circuit 12 controls the communication circuit 11 to perform both communication with each of the first communication device (here, first device 1A) and the second communication device (here, access point 2) in a first frequency band (here, 6 GHz band) using a first mode (here, LPI mode) and a second mode (here, VLP mode), and communication with each of the first communication device and the second communication device in a second frequency band (here, 5 GHz band or 2.4 GHz band) different from the first frequency band.

[4-5. Fourth operation example]
A fourth operation example using the communication device 1 according to the embodiment will be described below. In the fourth operation example, when the second device 1B (the processing circuit 12 of the communication device 1) determines that it is outside the specified range A1 and changes its operation mode from the LPI mode (first mode) to the VLP mode (second mode), it outputs information (hereinafter also referred to as "notification information") to the outside that it is outside the specified range A1, in other words, that the radio wave strength of the signal from the access point 2 is weak. The notification information may include, for example, information suggesting that the second device 1B be moved into the specified range A1.

For example, if the second device 1B has a display, it outputs the notification information to the outside by displaying it on the display. Also, if the second device 1B has a speaker, it outputs the notification information to the outside by outputting the notification information as audio from the speaker. Also, if the first device 1A has a display or speaker, the second device 1B sends an instruction to the first device 1A to output the notification information. In this case, the first device 1A outputs the notification information to the outside via the display or speaker.

Furthermore, when the second device 1B determines that it is within the specified range A1 but near the boundary of the specified range A1, it may output notification information to the outside indicating that the radio wave strength of the signal from the access point 2 is weak. In this case, the notification information may include information warning the second device 1B not to move any further away from the access point 2.

As described above, in the fourth operation example, when the processing circuit 12 determines that the radio wave strength of a signal from a second communication device (here, access point 2) received by either the communication device 1 or the first communication device (here, first device 1A) is within a predetermined range, it causes either the communication device 1 or the first communication device to output information indicating that the radio wave strength is weak to the outside.

[4-6. Fifth operation example]
The following describes a fifth operation example using the communication device 1 according to the embodiment. In the fifth operation example, the second device 1B (the processing circuit 12 of the communication device 1) further determines whether either itself or the first device 1A (the first communication device) is outdoors.

For example, if the second device 1B has an illuminance sensor, and the detected illuminance is greater than a predetermined illuminance (for example, the general illuminance of lighting), it will determine that the second device 1B is illuminated by sunlight, i.e., is outdoors. If the first device 1A has an illuminance sensor, the second device 1B can determine whether the first device 1A is outdoors by obtaining the detection results of the illuminance sensor.

Furthermore, for example, if the second device 1B has an optical sensor, it analyzes the spectrum of the detected light, and if the light is sunlight, it determines that it is illuminated by sunlight, i.e., that it is outdoors. Note that if the first device 1A has an optical sensor, the second device 1B can obtain the detection results of the optical sensor and thereby determine whether the first device 1A is outdoors.

Furthermore, for example, if the second device 1B has a positioning circuit such as a GPS (Global Positioning System) circuit, it determines whether or not it is outdoors based on the positioning results. Furthermore, if the first device 1A has a positioning circuit, it is possible to determine whether or not the first device 1A is outdoors by obtaining the positioning results of the positioning circuit.

Then, when the second device 1B determines that either itself or the first device 1A is outdoors, it changes its operating mode from LPI mode (first mode) to VLP mode (second mode) regardless of whether it is outside the specified range A1.

As described above, in the fifth operation example, the processing circuit 12 further determines whether either the communication device 1 or the first communication device (here, the first device 1A) is located outdoors. If the processing circuit 12 determines that either the communication device 1 or the first communication device is located outdoors, it controls the communication circuit 11 to communicate directly with the first communication device in a second mode (here, the VLP mode) different from the first mode (here, the LPI mode).

[5. Effects, etc.]
The advantages of the communication device 1 (communication control method) according to the embodiment will be described below. As described above, when the processing circuit 12 of the communication device 1 (here, the second device 1B) determines that direct communication with the first communication device (here, the first device 1A) is not possible in the first mode (here, the LPI mode), the processing circuit 12 controls the communication circuit 11 to communicate directly with the first communication device in a second mode (e.g., the VLP mode) different from the first mode. Therefore, the communication device 1 can continue communication between the slave stations without temporarily interrupting the communication between the slave stations. In other words, the communication device 1 has the advantage of easily maintaining direct communication with other communication devices.

Therefore, the embodiment can resolve the issue of temporary interruptions in communication between slave stations, as described in [1. Knowledge forming the basis of this disclosure]. Furthermore, the embodiment has the advantage that, when the communication speed in VLP mode is faster than the communication speed via access point 2, it is easier to prevent a decrease in the communication speed of communication between communication device 1 and the first communication device, compared to switching to communication via access point 2.

6. Other embodiments
Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments.

In the above embodiment, communication device 1 changes its own operating mode when it determines that it is outside specified range A1, but this is not limited to this. For example, communication device 1 may instruct a change in the operating mode of a first communication device, with which it is communicating between slave stations, when it determines that the first communication device is outside specified range A1.

That is, the communication device 1 includes a communication circuit 11 that communicates with each of a first communication device (e.g., second device 1B) and a second communication device (e.g., access point 2), and a processing circuit 12 that controls the communication circuit 11. The processing circuit 12 determines whether direct communication with the first communication device is possible in a first mode (e.g., LPI mode) based on the reception result of a signal received by the communication circuit 11 from the second communication device. If the processing circuit 12 determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit 11 to send an instruction to the first communication device to communicate directly with the communication circuit 11 in the first mode. If the processing circuit 12 determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit 11 to send an instruction to the first communication device to communicate directly with the communication circuit 11 in a second mode (e.g., VLP mode) different from the first mode.

Furthermore, the order of the processes described in the above embodiments is an example. The order of multiple processes may be changed, and multiple processes may be performed in parallel. Furthermore, processes performed by a specific processing unit may be performed by another processing unit. Furthermore, part of the digital signal processing described in the above embodiments may be achieved by analog signal processing.

Furthermore, in the above embodiments, each component may be realized by executing a software program appropriate for that component. Each component may also be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

Furthermore, each component may be realized by hardware. For example, each component may be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or each may be a separate circuit. Furthermore, each of these circuits may be a general-purpose circuit or a dedicated circuit.

Furthermore, general or specific aspects of the present disclosure may be realized as a system, device, method, integrated circuit, computer program, or computer-readable recording medium such as a CD-ROM. They may also be realized as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media. For example, the present disclosure may be implemented as a communication control method executed by a computer, or may be realized as a program for causing a computer to execute such a communication control method. The present disclosure may also be realized as a computer-readable non-transitory recording medium on which such a program is recorded. Note that the program here includes an application program for causing a general-purpose information terminal to function as the communication device of the above-mentioned embodiment.

In addition, this disclosure also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art would conceive, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the spirit of this disclosure.

(summary)
As described above, the communication device 1 (e.g., second device 1B) according to the first aspect includes a communication circuit 11 that communicates with each of a first communication device (e.g., first device 1A) and a second communication device (e.g., access point 2), and a processing circuit 12 that controls the communication circuit 11. The processing circuit 12 determines whether direct communication with the first communication device is possible in a first mode (e.g., LPI mode) based on a reception result of a signal received by the communication circuit 11 from the second communication device. If the processing circuit 12 determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit 11 to communicate directly with the first communication device in the first mode. If the processing circuit 12 determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit 11 to communicate directly with the first communication device in a second mode (e.g., VLP mode) different from the first mode.

This has the advantage that direct communication can continue without temporarily interrupting it by changing the operating mode, making it easier to maintain direct communication with other communication devices.

Furthermore, in the communication device 1 according to the second aspect, in the first aspect, the processing circuit 12 determines that direct communication with the first communication device in the first mode is not possible if the radio wave intensity of the signal received by the communication circuit 11 from the second communication device is below a threshold.

This has the advantage that, because the determination is based on the radio wave strength of the signal from the second communication device, it is easier to improve the accuracy of determining that direct communication with the first communication device in the first mode is not possible.

Furthermore, a communication device 1 according to a third aspect includes a communication circuit 11 that communicates with each of a first communication device (e.g., second device 1B) and a second communication device (e.g., access point 2), and a processing circuit 12 that controls the communication circuit 11. The processing circuit 12 determines whether direct communication with the first communication device is possible in a first mode (e.g., LPI mode) based on the reception result of a signal received by the communication circuit 11 from the second communication device. If the processing circuit 12 determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit 11 to send an instruction to the first communication device to communicate directly with the communication circuit 11 in the first mode. If the processing circuit 12 determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit 11 to send an instruction to the first communication device to communicate directly with the communication circuit 11 in a second mode (e.g., VLP mode) different from the first mode.

This has the advantage that direct communication can continue without temporarily interrupting it by changing the operating mode, making it easier to maintain direct communication with other communication devices.

Furthermore, in the communication device 1 according to the fourth aspect, in the third aspect, the processing circuit 12 determines that direct communication with the first communication device in the first mode is not possible if the radio wave intensity of the signal received by the first communication device from the second communication device is below a threshold.

This has the advantage that, because the determination is based on the radio wave strength of the signal from the second communication device, it is easier to improve the accuracy of determining that direct communication with the first communication device in the first mode is not possible.

Furthermore, in the communication device 1 according to the fifth aspect, in any one of the first to fourth aspects, the transmission power in the second mode is lower than that in the first mode.

This has the advantage that existing systems are less susceptible to radio interference caused by the signal compared to when the signal is transmitted in the first mode.

Furthermore, in the communication device 1 according to the sixth aspect, in the fifth aspect, the second communication device is the access point 2. The first mode is the LPI mode. The second mode is the VLP mode.

This has the advantage of making it easier to maintain direct communication between communication device 1 and the first communication device while complying with the conditions set forth in the Radio Law Enforcement Regulations, etc.

Furthermore, in the communication device 1 according to the seventh aspect, in any one of the first to sixth aspects, if the processing circuit 12 determines that direct communication with the first communication device in the first mode is not possible, it causes the communication device 1 and the first communication device to execute a process of determining whether direct communication or communication via the second communication device has better communication quality, and if it determines that communication quality via the second communication device is good, a process of communicating with the first communication device via the second communication device.

This has the advantage that communication between communication device 1 and the first communication device can be carried out using the communication with the better communication quality, making it easier to improve the communication quality between communication device 1 and the first communication device.

Furthermore, in the communication device 1 according to the eighth aspect, in any one of the first to seventh aspects, if the first communication device cannot communicate with the second communication device, the processing circuit 12 causes the communication device 1 and the first communication device to execute processing for parent-child communication, with one of the communication device 1 and the first communication device acting as the parent station and the other as the child station.

This has the advantage that even if the first communication device cannot communicate with the second communication device, it is easier to maintain communication between communication device 1 and the first communication device.

Furthermore, in the communication device 1 according to the ninth aspect, in any one of the first to eighth aspects, the processing circuit 12 controls the communication circuit 11 to perform both communication with each of the first and second communication devices in a first frequency band (e.g., the 6 GHz band) using the first and second modes, and communication with each of the first and second communication devices in a second frequency band (e.g., the 5 GHz band or the 2.4 GHz band) different from the first frequency band.

This has the advantage that even if communication between communication device 1 and the first communication device cannot be performed in the first frequency band, communication between communication device 1 and the first communication device can be performed in the second frequency band, making it easier to maintain communication between communication device 1 and the first communication device.

Furthermore, in the communication device 1 according to the tenth aspect, in any one of the first to ninth aspects, when the processing circuit 12 determines that the radio wave strength of a signal received by either the communication device 1 or the first communication device from the second communication device is within a predetermined range, it causes either the communication device 1 or the first communication device to output information indicating that the radio wave strength is weak to the outside.

Furthermore, in the communication device 1 according to the eleventh aspect, in any one of the first to tenth aspects, the processing circuit 12 further determines whether either the communication device 1 or the first communication device is outdoors. If the processing circuit 12 determines that either the communication device 1 or the first communication device is outdoors, it controls the communication circuit 11 to communicate directly with the first communication device in a second mode different from the first mode.

This has the advantage that, for example, in cases where there are conditions under the Radio Law Enforcement Regulations that prohibit direct communication between communication device 1 and the first communication device outdoors, it is easier to maintain direct communication between communication device 1 and the first communication device while complying with those conditions.

Furthermore, in a communication control method according to a twelfth aspect, communication is performed with each of a first communication device (e.g., first device 1A) and a second communication device (e.g., access point 2) using a communication circuit 11. The communication control method determines whether direct communication with the first communication device is possible in a first mode (e.g., LPI mode) based on the reception result of a signal received by the communication circuit 11 from the second communication device. If the communication control method determines that direct communication with the first communication device is possible in the first mode, it controls the communication circuit 11 to communicate directly with the first communication device in the first mode. If the communication control method determines that direct communication with the first communication device is not possible in the first mode, it controls the communication circuit 11 to communicate directly with the first communication device in a second mode (e.g., VLP mode) different from the first mode.

This has the advantage that direct communication can continue without temporarily interrupting it by changing the operating mode, making it easier to maintain direct communication with other communication devices.

Furthermore, in a communication control method according to a thirteenth aspect, communication is performed between a first communication device (e.g., second device 1B) and a second communication device (e.g., access point 2) using a communication circuit 11. In the communication control method, based on the reception result of a signal received by the communication circuit 11 from the second communication device, it is determined whether direct communication with the first communication device is possible in a first mode (e.g., LPI mode). In the communication control method, if it is determined that direct communication with the first communication device is possible in the first mode, the communication circuit 11 is controlled to send to the first communication device an instruction to communicate directly with the communication device 1 in the first mode. In the communication control method, if it is determined that direct communication with the first communication device is not possible in the first mode, the communication circuit 11 is controlled to send to the first communication device an instruction to communicate directly with the communication device 1 in a second mode (e.g., VLP mode) different from the first mode.

This has the advantage that direct communication can continue without temporarily interrupting it by changing the operating mode, making it easier to maintain direct communication with other communication devices.

Furthermore, a program according to a fourteenth aspect causes one or more processors to execute the communication control method according to the twelfth or thirteenth aspect.

This has the advantage that direct communication can continue without temporarily interrupting it by changing the operating mode, making it easier to maintain direct communication with other communication devices.

The communication devices disclosed herein can be applied to devices that communicate using radio waves.

1 Communication device 11 Communication circuit 111 Antenna 112 RF-SW
113 Receiving circuit 114 Transmitting circuit 115 RF power control circuit 12 Processing circuit 13 Memory 1A First device (first communication device)
1B Second device 2 Access point (second communication device)
101 First slave station 102 Second slave station 103 Master station A1 Specified range A2 Communication range

Claims (14)

a communication circuit for communicating with each of the first communication device and the second communication device;
a processing circuit for controlling the communication circuit;
The processing circuitry
determining whether direct communication with the first communication device in a first mode is possible based on a reception result of a signal received by the communication circuit from the second communication device;
when it is determined that the direct communication with the first communication device is possible in the first mode, controlling the communication circuit to perform the direct communication with the first communication device in the first mode;
when it is determined that the direct communication with the first communication device cannot be performed in the first mode, controlling the communication circuit so as to perform the direct communication with the first communication device in a second mode different from the first mode.
Communication equipment. The processing circuitry
If the radio wave intensity of the signal received by the communication circuit from the second communication device is below a threshold, it is determined that the direct communication with the first communication device in the first mode is not possible.
The communication device according to claim 1 . a communication circuit for communicating with each of the first communication device and the second communication device;
a processing circuit for controlling the communication circuit;
The processing circuitry
determining whether direct communication with the first communication device in a first mode is possible based on a reception result of a signal received by the communication circuit from the second communication device;
When it is determined that the direct communication with the first communication device is possible in the first mode, the communication circuit is controlled to transmit an instruction to the first communication device to perform the direct communication with the communication circuit in the first mode;
when it is determined that the direct communication with the first communication device is not possible in the first mode, controlling the communication circuit to transmit to the first communication device an instruction to perform the direct communication with the communication circuit in a second mode different from the first mode.
Communication equipment. The processing circuitry
If the radio wave intensity of the signal received by the first communication device from the second communication device is below a threshold, it is determined that the direct communication with the first communication device in the first mode is not possible.
The communication device according to claim 3 . The second mode has a lower transmission power than the first mode.
The communication device according to any one of claims 1 to 4. the second communication device is an access point;
the first mode is a low power indoor (LPI) mode,
The second mode is a VLP (Very Low Power) mode.
The communication device according to claim 5 . The processing circuitry
a process of determining whether the direct communication or the communication via the second communication device has better communication quality when it is determined that the direct communication with the first communication device is not possible in the first mode; and
when it is determined that the communication quality via the second communication device is good, causing the communication device and the first communication device to execute a process of communicating with the first communication device via the second communication device;
3. The communication device according to claim 1 or 2. The processing circuitry
when the first communication device cannot communicate with the second communication device, causing the communication device and the first communication device to perform a process of performing parent-child communication in which one of the communication device and the first communication device serves as a parent station and the other serves as a child station;
3. The communication device according to claim 1 or 2. The processing circuitry
controlling the communication circuit to perform both communication with each of the first communication device and the second communication device in a first frequency band using the first mode and the second mode, and communication with each of the first communication device and the second communication device in a second frequency band different from the first frequency band;
3. The communication device according to claim 1 or 2. The processing circuitry
When it is determined that the radio wave intensity of the signal from the second communication device received by either the communication device or the first communication device is within a predetermined range, information indicating that the radio wave intensity is weak is output from either the communication device or the first communication device to the outside.
3. The communication device according to claim 1 or 2. The processing circuitry
further determining whether one of the communication device and the first communication device is outdoors;
when it is determined that either the communication device or the first communication device is present outdoors, controlling the communication circuit to perform the direct communication with the first communication device in a second mode different from the first mode.
3. The communication device according to claim 1 or 2. communicating with each of the first communication device and the second communication device using a communication circuit;
determining whether direct communication with the first communication device in a first mode is possible based on a reception result of a signal received by the communication circuit from the second communication device;
when it is determined that the direct communication with the first communication device is possible in the first mode, controlling the communication circuit to perform the direct communication with the first communication device in the first mode;
when it is determined that the direct communication with the first communication device cannot be performed in the first mode, controlling the communication circuit so as to perform the direct communication with the first communication device in a second mode different from the first mode.
Communication control method. communicating with the first communication device and the second communication device using the communication circuit;
determining whether direct communication with the first communication device in a first mode is possible based on a reception result of a signal received by the communication circuit from the second communication device;
When it is determined that the direct communication with the first communication device is possible in the first mode, the communication circuit is controlled to transmit an instruction to the first communication device to perform the direct communication with the communication circuit in the first mode;
when it is determined that the direct communication with the first communication device is not possible in the first mode, controlling the communication circuit to transmit to the first communication device an instruction to perform the direct communication with the communication circuit in a second mode different from the first mode.
Communication control method. one or more processors,
Executing the communication control method according to claim 12 or 13,
program.