Wireless communication device, wireless communication method, and program

Abstract

The invention relates to a wireless communication device, a wireless communication method, and a program. A first wireless communication device (10) is provided with a control unit (110) and a communication unit (120). In order to join a second wireless communication device into a cluster including a plurality of wireless communication devices, the communication unit (120) is configured to transmit a wireless frame for discovering the second wireless communication device to the second wireless communication device using a second frequency band lower than the first frequency band, and the control unit (110) is configured to discover the second wireless communication device in response to receiving a response frame from the second wireless communication device. The communication unit (120) selects either the first frequency band or the second frequency band, and is configured to transmit, to the second wireless communication device, a wireless frame for synchronization with the second wireless communication device using the selected frequency band.

Description

[0001] Cross-references of related applications

[0002] This application is based on and claims priority to Japanese Patent Application No. 2024-076276, filed on May 9, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a wireless communication device, a wireless communication method, and a program. Background Technology

[0004] The wireless communication technology known as "Wi-Fi" (registered trademark) is widely recognized. Wi-Fi uses IEEE 802.11, the standard for wireless LANs (WLANs). Wi-Fi is certified by the industry association "Wi-Fi Alliance" (registered trademark).

[0005] The Wi-Fi Alliance has released "Wi-Fi Aware" (a registered trademark), a technology that allows multiple wireless communication devices to form a cluster to send and receive information between them. Wi-Fi Aware discovers wireless communication devices and establishes communication between them by repeatedly exchanging beacon frames among devices in a nearby range, thus enabling multiple wireless communication devices to form a cluster.

[0006] Existing technical documents

[0007] Non-patent literature

[0008] Non-patent document 1: Wi-Fi Aware Specification Version 4.0 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] This disclosure provides a first wireless communication device. In order for a second wireless communication device to join a cluster comprising multiple wireless communication devices, the first wireless communication device uses a second frequency band lower than the first frequency band to send a wireless frame for discovering the second wireless communication device. In response to receiving a response frame from the second wireless communication device, it selects either the first frequency band or the second frequency band, and uses the selected frequency band to send a wireless frame for synchronizing with the second wireless communication device.

[0011] Additionally, this disclosure provides a method performed by a first wireless communication device. The method includes: in order to enable a second wireless communication device to join a cluster comprising multiple wireless communication devices, transmitting a wireless frame for discovering the second wireless communication device to the second wireless communication device using a second frequency band lower than the first frequency band; in response to receiving a response frame from the second wireless communication device, selecting either the first frequency band or the second frequency band; and using the selected frequency band, transmitting a wireless frame for synchronizing with the second wireless communication device to the second wireless communication device. Attached Figure Description

[0012] Figure 1 This is a block diagram illustrating the configuration of a wireless communication system.

[0013] Figure 2 This is a block diagram illustrating the physical configuration of a wireless communication device.

[0014] Figure 3 This is a block diagram illustrating the logical configuration of a wireless communication device.

[0015] Figure 4 This is a flowchart illustrating the NAN cluster formation process involved in the prior art.

[0016] Figure 5 This is a flowchart illustrating the NAN cluster formation process according to the first embodiment.

[0017] Figure 6 This is a flowchart illustrating the FTM process involved in the first embodiment.

[0018] Figure 7 This is a flowchart illustrating the NAN cluster formation process according to the second embodiment.

[0019] Figure 8 This is a diagram showing an example of a wireless communication device in motion.

[0020] Figure 9 This is a diagram showing an example of a wireless communication device in motion.

[0021] Figure 10 This is a flowchart illustrating the NAN cluster formation process according to the third embodiment.

[0022] Figure 11 This is a diagram illustrating an example of a NAN cluster according to the fourth embodiment.

[0023] Figure 12 This is a diagram illustrating an example of a NAN cluster according to the fourth embodiment.

[0024] Figure 13This is a flowchart illustrating the NAN cluster formation process according to the fourth embodiment.

[0025] Figure 14 This is a diagram illustrating an example of a NAN cluster according to the fifth embodiment.

[0026] Figure 15 This is a diagram illustrating an example of a NAN cluster according to the fifth embodiment.

[0027] Figure 16 This is a flowchart illustrating the NAN cluster formation process according to the fifth embodiment.

[0028] Figure 17 This is a flowchart illustrating the NAN cluster formation process according to the sixth embodiment. Detailed Implementation

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements that can be described in the same way are labeled with the same reference numerals, thus omitting repeated descriptions.

[0030] The embodiments described below are merely examples of configurations that can implement this embodiment. The embodiments described below can be appropriately modified or changed depending on the configuration of the apparatus to which this embodiment is applied and various conditions. Not all combinations of elements included in the embodiments described below are necessary to implement this embodiment, and some elements can be appropriately omitted. Therefore, the scope of this embodiment is not limited to the configurations described in the embodiments described below. Configurations combining multiple configurations described in the embodiments described below can also be used, provided they do not contradict each other.

[0031] The following describes examples of the technology described in this embodiment being applied to applications such as autonomous driving. In such applications, the wireless communication device described below is installed inside a vehicle. The wireless communication device communicates wirelessly with wireless communication devices installed in other vehicles and / or with wireless communication devices installed on the road and functioning as sensors.

[0032] Non-patent document 1 describes the specifications for Wi-Fi sensing. Wi-Fi sensing is specified by the "NAN: Neighbor Awareness Networking" protocol. In the NAN protocol, wireless communication devices are discovered by exchanging NAN beacon frames between wireless communication devices located within a nearby range.

[0033] According to the technology described in Non-Patent Document 1, since wireless communication devices are discovered by exchanging NAN beacon frames, wireless communication devices can be discovered without exchanging location information. Furthermore, in the NAN protocol, communication is established between wireless communication devices through repeated discovery, thus enabling the formation of large-scale clusters of wireless communication devices.

[0034] Non-Patent Document 1 does not disclose a technique for extending the range of arrival of wireless frames for detecting wireless communication devices. This disclosure provides a technique for extending the range of arrival of wireless frames for detecting wireless communication devices.

[0035] 1. First Implementation Method

[0036] 1-1 Wireless Communication System

[0037] like Figure 1 As shown, the wireless communication system S involved in this embodiment includes a plurality of wireless communication devices 10. The wireless communication devices 10 are devices that conform to the IEEE 802.11 standard and communicate wirelessly with each other.

[0038] Multiple wireless communication devices 10 form a cluster by following the NAN protocol. As described later, the NAN protocol does not support frequency bands below 1 GHz. In this embodiment, a cluster is formed by exchanging radio frames such as discovery beacon frames among the wireless communication devices using a frequency band below 1 GHz. Although a frequency band below 1 GHz is used in this specification, performing the same process as the NAN protocol is equivalent to "forming a cluster by following the NAN protocol". Therefore, the cluster formed in this way is also called a "NAN cluster".

[0039] exist Figure 1 In this network, wireless communication devices 10a, 10b, and 10c form NAN cluster 1, and wireless communication devices 10d, 10e, and 10n form NAN cluster 2. Furthermore, for example, NAN cluster 1 and NAN cluster 2 are connected by communication between wireless communication device 10a within NAN cluster 1 and wireless communication device 10d within NAN cluster 2. Thus, a NAN network comprising multiple NAN clusters is established (not shown).

[0040] Furthermore, although not illustrated, NAN cluster 1 can connect to a Basic Service Set (BSS) and / or an Independent Basic Service Set (IBSS) as defined by the IEEE 802.11 standard. A BSS is a network configuration known as Infrastructure Mode, which includes both APs and STAs. An IBSS is a network configuration known as Ad-Hoc Mode, which includes only STAs.

[0041] Wireless communication device 10 functions as a station (STA) and / or access point (AP) as defined in the IEEE 802.11 standard. Wireless communication device 10 may also be referred to as a "node" or "NAN device".

[0042] Next, refer to Figure 2 The physical configuration of the wireless communication device 10 is described. For example... Figure 2 As shown, the wireless communication device 10 includes a processor 101, a memory 102, an input / output interface 103, a transmitter / receiver 104, and an antenna 105 as physical elements. These elements in the wireless communication device 10 are interconnected via an internal bus. Furthermore, the wireless communication device 10 may also include... Figure 2 Physical elements other than those shown.

[0043] The processor 101 is a computing element that implements various functions of the wireless communication device 10. The processor 101 may be a SoC (System-on-a-Chip) that includes elements such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a memory controller.

[0044] The memory 102 includes storage media such as RAM (Random Access Memory) and eMMC (embedded MultiMedia Card). The memory 102 is an element that temporarily or permanently stores programs and data used to perform various processes in the wireless communication device 10. The aforementioned programs include one or more instructions for the operation of the wireless communication device 10. The processor 101 implements the functions of the wireless communication device 10 by expanding the program stored in the memory 102 into the memory 102 and / or a system memory (not shown) and executing it.

[0045] The input / output interface 103 is an interface that receives operations from the wireless communication device 10, provides them to the processor 101, and presents various information to the user. The input / output interface 103 may include, for example, a touch panel.

[0046] Transmitter / receiver 104 includes a transmitter (not shown) and a receiver, and is circuitry that performs various signal processing steps to enable wireless communication. Transmitter / receiver 104 includes a baseband processor and RF circuitry. Transmitter / receiver 104 exchanges wireless signals with other wireless communication devices 10 via antenna 105.

[0047] Next, refer to Figure 3 The logical configuration of the wireless communication device 10 is described below. Figure 3 As shown, the wireless communication device 10 includes a control unit 110 and a communication unit 120 as logical elements. The communication unit 120 includes a transmitting unit 121 and a receiving unit 122.

[0048] The control unit 110 includes a processor 101 and a memory 102. In other words, the control unit 110 is implemented by the processor 101 and the memory 102. The control unit 110 performs various control processes in the wireless communication device 10. For example, the control unit 110 controls wireless communication with other wireless communication devices 10 via the communication unit 120. By operating the control unit 110, various processes of the wireless communication device 10 of this embodiment are executed.

[0049] The communication unit 120 includes a transmitter / receiver 104 and an antenna 105. In other words, the communication unit 120 is implemented by the transmitter / receiver 104 and the antenna 105. The communication unit 120 communicates wirelessly with other wireless communication devices 10 by exchanging wireless signals with them.

[0050] 1-2NAN Protocol

[0051] The NAN protocol according to existing technology is explained below. As described above, Non-Patent Document 1 specifies the NAN protocol. According to the NAN protocol, the wireless communication device 10 functions as either a master device or a non-master sync device to form a NAN cluster. Hereinafter, the wireless communication device 10 that functions as a master device will be referred to as the NAN master device (“master” or “master device”). The wireless communication device 10 that functions as a non-master device will be referred to as the NAN non-master device (“non-master” or “non-master device”).

[0052] The NAN master device enables other wireless communication devices 10 (NAN non-master devices) to join the NAN cluster. NAN non-master devices join the NAN cluster by performing a predetermined process with the NAN master device. For the role of the master device, a NAN master selection procedure is used to select any wireless communication device 10.

[0053] Reference Figure 4 This describes the process by which a NAN master device, conforming to the NAN protocol, adds a NAN non-master device to the NAN cluster, thus forming a NAN cluster. Figure 4 In the example shown, let's set it as Figure 1The wireless communication device 10a shown acts as the master device, while the wireless communication device 10b acts as a non-master device.

[0054] exist Figure 4 As shown in the process, the NAN master device discovers and synchronizes with the NAN non-master device, thereby enabling the NAN non-master device to join the NAN cluster. According to the NAN protocol, this process is called NAN synchronization.

[0055] The NAN synchronization process is performed by exchanging radio frames between NAN master devices and NAN non-master devices. Radio frames can be referred to as radio signals. Radio frames include MAC frames exchanged at the Media Access Control (MAC) layer. MAC frames are defined in the IEEE 802.11 standard.

[0056] First, the NAN master device sends a NAN discovery beacon frame (signal) (step S401). The discovery beacon frame is sent at regular intervals. The discovery beacon frame is received by NAN non-master devices within its range. Next, the NAN non-master devices send a beacon response frame to the NAN master device (step S402). Through the processing in steps S401 and S402, NAN non-master devices located in the vicinity of the NAN master device can be discovered.

[0057] Through the processing of steps S401 and S402, a time duration called the Discovery Window (DW) begins. The DW is the time period during which the NAN master device synchronizes with the NAN non-master device, the NAN master device notifies the NAN non-master device that it is providing services, and the NAN non-master device requests services from the NAN master device.

[0058] During NAN synchronization, two types of beacon frames are used: NAN discovery beacon frames and NAN synchronization beacon frames. These two types of beacon frames are collectively referred to as NAN beacon frames.

[0059] Next, the NAN master device sends a NAN synchronization beacon frame to the NAN non-master device (step S403). Next, the NAN non-master device sends a beacon response frame to the NAN master device (step S404). Through the processing in steps S403 and S404, the NAN master device and the NAN non-master device can be synchronized.

[0060] Next, the NAN master device sends a publish frame to the NAN non-master device (step S405). The publish frame is a message used to notify the NAN master device that it is providing services to the NAN non-master device.

[0061] Next, the NAN non-master device sends a Subscribe frame to the NAN master device (step S406). The Subscribe frame is a message used by the NAN non-master device to request services from the NAN master device.

[0062] In addition, Figure 4 The processing described herein illustrates examples of a NAN master device sending a publish frame to a NAN non-master device and a NAN non-master device sending a subscribe frame to a NAN master device, but it is not limited to such examples. It is also possible for a NAN non-master device to send a publish frame to a NAN master device and for a NAN master device to send a subscribe frame to a NAN non-master device.

[0063] In addition, although not illustrated, NAN master devices and NAN non-master devices exchange follow-up frames, which are used to notify each other of additional service-related information within the DW. Publish frames, subscribe frames, and follow-up frames are collectively referred to as Service Discovery Frames (SDF).

[0064] Through steps S401 to S404 or steps S401 to S406, NAN non-master devices can join the NAN cluster. NAN master devices can form a large-scale cluster by performing NAN synchronization processes with multiple NAN non-master devices located in the vicinity.

[0065] Non-Patent Document 1 describes the NAN protocol supporting the 2.4 GHz, 5 GHz, and 6 GHz frequency bands for exchanging radio frames. These bands are effective for transmitting large amounts of data, but may not allow NAN beacon frames to reach a wide range. Non-Patent Document 1 does not describe any technology for extending the reach of NAN beacon frames.

[0066] Next, an outline of the first embodiment will be described. In this embodiment, a frequency band lower than the frequency band supported in the NAN protocol is used to transmit beacon frames. A frequency band lower than the frequency band supported in the NAN protocol is, for example, a 920MHz frequency band, that is, a frequency band less than 1GHz (sub-1GHz).

[0067] The IEEE 802.11ah standard specifies the use of the 920MHz frequency band for transmitting wireless frames. The IEEE 802.11ah standard is also known as Wi-Fi HaLow (registered trademark). The 920MHz band has the following characteristics: its radio wave propagation is weaker than that of the 2.4GHz, 5GHz, and 6GHz bands. Therefore, wireless frames transmitted using the 920MHz band can propagate over a wider range.

[0068] In this embodiment, by transmitting beacon frames using a frequency band lower than the frequency bands supported in the NAN protocol, wireless communication devices 10 existing over a wider range can be discovered. Furthermore, in this embodiment, it is chosen whether to use a frequency band supported in the NAN protocol, i.e., a 2.4 GHz, 5 GHz, or 6 GHz band, to communicate wirelessly with the discovered wireless communication device 10, or to follow the IEEE 802.11ah standard, i.e., use a 920 MHz band, to communicate wirelessly with the discovered wireless communication device 10.

[0069] Hereinafter, the wireless communication method using the frequency band supported in the NAN protocol will be referred to as the "first wireless communication method." The frequency band used for the first wireless communication method will be referred to as the "first frequency band." Furthermore, the wireless communication method conforming to the IEEE 802.11ah standard, i.e., the wireless communication method using the 920MHz frequency band, will be referred to as the "second wireless communication method." The frequency band used for the second wireless communication method will be referred to as the "second frequency band."

[0070] 1-3 NAN Cluster Formation Process

[0071] Reference Figure 5 This describes the NAN cluster formation process involved in the first embodiment. Figure 5 In the example shown, Figure 1 The wireless communication device 10a detects the wireless communication device 10b and causes the wireless communication device 10b to join the NAN cluster. The NAN cluster is a collection of multiple wireless communication devices 10 that communicate with each other via a first wireless communication method or a second wireless communication method. The wireless communication device 10a is, for example, installed inside a vehicle, and the wireless communication device 10b is, for example, installed on a road and implemented as a sensor.

[0072] First, the communication unit 120 of the wireless communication device 10a sends a discovery beacon frame to the wireless communication device 10b using the second frequency band (step S501). In order to distinguish it from the NAN discovery beacon frame, that is, the beacon frame sent using the first frequency band, this discovery beacon frame is called a "sub-1GHz (discovery) beacon frame" or "S1G (discovery) beacon frame".

[0073] Next, the communication unit 120 of the wireless communication device 10b uses the second frequency band to send a beacon response frame to the wireless communication device 10a (step S502). Through the processing of steps S501 and S502, compared to sending using the first frequency band, wireless communication devices 10 existing in a wider range can be detected. Through the processing of steps S501 and S502, DW (Direct Wire) is initiated.

[0074] Furthermore, although not illustrated, if the wireless communication device 10b fails to receive the S1G discovery beacon frame even after a certain period of time following step S502, the communication unit 120 of the wireless communication device 10b may send a probe request frame to the wireless communication device 10a. In this case, the communication unit 120 of the wireless communication device 10a sends a probe response frame to the wireless communication device 10b. Both the probe request frame and the probe response frame are transmitted using the second frequency band.

[0075] Next, the control unit 110 of the wireless communication device 10a selects whether to use a first wireless communication method or a second wireless communication method in order to communicate wirelessly with the wireless communication device 10b (step S503). As described above, compared with using the first frequency band, using the second frequency band allows the beacon frame to reach a wider range, but on the other hand, it cannot transmit large amounts of data. In addition, depending on the distance between the wireless communication device 10a and the wireless communication device 10b, there are also cases where stable wireless communication cannot be achieved using the first frequency band.

[0076] To ensure stable communication of large amounts of data, it is desirable to communicate wirelessly with wireless communication device 10b in a first wireless communication mode after detecting wireless communication device 10b. From this perspective, in step S503, it is determined whether wireless communication is possible in the first wireless communication mode. Since wireless frames are exchanged in the second wireless communication mode in steps S501 and S502, if it is determined that wireless communication is possible in the first wireless communication mode, the wireless communication mode is switched from the second wireless communication mode to the first wireless communication mode.

[0077] The control unit 110 selects a first wireless communication mode or a second wireless communication mode based on (1) the distance between the wireless communication device 10a and the wireless communication device 10b, (2) the signal strength of the wireless frame from the wireless communication device 10b, and / or (3) the request from the wireless communication device 10b.

[0078] In selecting the distance between wireless communication devices 10a and 10b, for example, if the distance is less than a predetermined threshold, a first wireless communication method can be selected. The fact that the distance between wireless communication devices 10a and 10b is less than the predetermined threshold means that wireless communication devices 10a and 10b are within a certain range. Therefore, in such a case, the first wireless communication method can be used instead of a second wireless communication method to stably communicate large amounts of data.

[0079] On the other hand, if the distance between wireless communication device 10a and wireless communication device 10b exceeds a predetermined threshold, a second wireless communication method can be selected. The fact that the distance between wireless communication device 10a and wireless communication device 10b exceeds the predetermined threshold means that wireless communication devices 10a and 10b are outside a certain range. Therefore, in such a case, the two devices can use the second wireless communication method instead of the first wireless communication method to achieve stable wireless communication.

[0080] The distance between wireless communication device 10a and wireless communication device 10b can be measured using a Fine Timing Measurement (FTM) procedure. FTM is a protocol used to measure the distance between wireless communication devices 10a and 10b based on the arrival time of wireless frames exchanged between them, and it is specified in the IEEE 802.11 standard.

[0081] Reference Figure 6 This explains the FTM process. Figure 6 During the FTM process shown, FTM frames are exchanged between wireless communication device 10a and wireless communication device 10b.

[0082] In step S601, the communication unit 120 of the wireless communication device 10a sends an FTM request frame to the wireless communication device 10b. The FTM request frame is a wireless frame that requests the start of the FTM process from the wireless communication device 10b. Next, the wireless communication device 10b sends an Ack frame to the wireless communication device 10a (step S602).

[0083] Next, the communication unit 120 of the wireless communication device 10b sends an FTM frame to the wireless communication device 10a (step S603). The FTM frame includes a parameter indicating that the departure time (ToD) of the FTM frame is zero, and a parameter indicating that the arrival time (ToA) of the FTM frame is zero. In addition, the control unit 110 of the wireless communication device 10b records the transmission time of the FTM frame (T = t1_1).

[0084] Next, the communication unit 120 of the wireless communication device 10a receives the FTM frame and sends an Ack to the wireless communication device 10b (step S604). In addition, the control unit 110 of the wireless communication device 10a records the reception time of the FTM frame (T = t2_1) and the Ack transmission time (T = t3_1).

[0085] Next, the communication unit 120 of the wireless communication device 10b receives the Ack (step S605). Additionally, the control unit 110 of the wireless communication device 10b records the time of Ack reception (T = t4_1).

[0086] Next, the communication unit 120 of the wireless communication device 10b sends an FTM frame to the wireless communication device 10a (step S606). The FTM frame includes a parameter indicating ToD = t1_1 and a parameter indicating ToA = t4_1. In addition, the control unit 110 of the wireless communication device 10b records the transmission time of the FTM frame (T = t2_1).

[0087] Next, the communication unit 120 of the wireless communication device 10a receives the FTM frame and sends an Ack to the wireless communication device 10b (step S607). In addition, the control unit 110 of the wireless communication device 10a records the reception time of the FTM frame (T = t2_2) and the transmission time of the Ack (T = t3_2).

[0088] Next, the communication unit 120 of the wireless communication device 10b receives the Ack (step S608). Additionally, the control unit 110 of the wireless communication device 10b records the time of Ack reception (T = t4_2).

[0089] Next, the control unit 110 of the wireless communication device 10a calculates the round-trip time (RTT) according to equation (1) and calculates the distance D according to equation (2) (step S609). In equation (2), c is the propagation speed of the wireless frame.

[0090] RTT=(t4_1-t1_1)-(t3_1-t2_1) Formula (1)

[0091] D = c × (RTT / 2) Equation (2)

[0092] The distance between wireless communication device 10a and wireless communication device 10b can be measured by sending location information such as GPS information from wireless communication device 10b to wireless communication device 10a, instead of measuring according to the FTM process. The GPS information can be transmitted, for example, in the beacon response frame or probe response frame (not shown) sent in step S502.

[0093] In selecting the received signal strength based on the wireless frame from wireless communication device 10b, for example, if the signal strength exceeds a predetermined threshold, a first wireless communication method can be selected. A signal strength exceeding the predetermined threshold means that wireless communication devices 10a and 10b are within a certain range. Therefore, in such a case, it can be considered that both can stably communicate large amounts of data using the first wireless communication method compared to using the second wireless communication method.

[0094] On the other hand, if the signal strength is less than a predetermined threshold, a second wireless communication method can be selected. A signal strength less than the predetermined threshold means that wireless communication devices 10a and 10b are outside a certain range. Therefore, in such a case, both devices can use the second wireless communication method instead of the first wireless communication method to achieve stable wireless communication.

[0095] Signal strength is measured, for example, based on the Received Signal Strength Indicator (RSSI). Furthermore, when selecting based on received signal strength, the signal strength differs between wireless frames transmitted using the first frequency band and wireless frames transmitted using the second frequency band. Taking this into account, the signal strength of wireless frames transmitted from the wireless communication device 10b using the first frequency band can be measured.

[0096] In the above situation, in step S503, for example, wireless communication device 10a may request wireless communication device 10b to use the first frequency band to transmit wireless frames.

[0097] Furthermore, in Japan and other countries, it is stipulated that in wireless communication methods conforming to the IEEE 802.11ah standard, the transmission time is limited to within 10% of the total transmission time (10% duty cycle). Under this limitation, transmitting large amounts of data / long-duration data in the first wireless communication method is not preferred. Considering this limitation, if the distance between wireless communication device 10a and wireless communication device 10b exceeds a predetermined threshold, or if the signal strength is less than a predetermined threshold, wireless communication device 10a may refuse to communicate with wireless communication device 10b and instead choose to use the second wireless communication method.

[0098] In selecting a request based on a request from wireless communication device 10b, for example, if wireless communication device 10b requests communication of a large amount of data, it may wish to use a higher frequency band. Therefore, in such a case, a first wireless communication method can be selected. To address such a request, wireless communication device 10b may notify wireless communication device 10a, for example, of the data type or data request, in a beacon response frame or another wireless frame sent in step S502. The data type or data request may, for example, indicate "1: Large-capacity communication," "2: Small-capacity communication," etc.

[0099] Furthermore, for example, in order to detect car collisions, information from a wireless communication device 10b, which is installed on roads and functions as a sensor, is considered to be urgent / high-priority data communication. Thus, in the case of a request from the wireless communication device 10b for urgent / high-priority data communication, a lower frequency band is desirable for wider-range communication. In such cases, a second wireless communication method can be selected. Regarding such urgent requests and priorities, the wireless communication device 10b can notify the wireless communication device 10a, for example, of the data category or data priority, in a beacon response frame or another wireless frame sent in step S502. The data category or data priority can, for example, indicate "1: High Priority", "2: Urgent", etc.

[0100] Furthermore, wireless communication can be employed using any combination of the distance between the wireless communication device 10a and the wireless communication device 10b, the received signal strength of the wireless frame from the wireless communication device 10b, and the request made by the wireless communication device 10b.

[0101] return Figure 5 The explanation is that, under the wireless communication mode selected in step S503, steps S504 to S507 are executed. Furthermore, although not illustrated, in step S503, if communication with the wireless communication device 10b is refused, the process ends at that point. Figure 5 The processing shown.

[0102] In step S504, wireless communication device 10a sends a synchronization beacon frame to wireless communication device 10b. When the first wireless communication mode is selected in step S503, the synchronization beacon frame is equivalent to a NAN beacon frame. When the second wireless communication mode is selected, the synchronization beacon frame is equivalent to an S1G beacon frame.

[0103] Next, wireless communication device 10b sends a beacon response frame to wireless communication device 10a (step S505). If a first wireless communication mode was selected in step S503, the beacon response frame is sent using the first frequency band. If a second wireless communication mode was selected, the beacon response frame is sent using the second frequency band.

[0104] Furthermore, even when the first wireless communication mode is selected in step S503, the distance between wireless communication device 10a and wireless communication device 10b, or obstacles in between, may cause the NAN synchronization beacon frame to fail to reach wireless communication device 10b. Considering this situation, if wireless communication device 10a does not receive a beacon response frame within a predetermined time period after sending the NAN synchronization beacon frame, it can use the second frequency band to send an error response frame to wireless communication device 10b.

[0105] Next, wireless communication device 10a sends a publishing frame to wireless communication device 10b (step S506). If a first wireless communication mode was selected in step S503, the publishing frame is sent using the first frequency band. If a second wireless communication mode was selected, the publishing frame is sent using the second frequency band.

[0106] Next, the NAN non-master device sends a subscription frame to the NAN master device (step S507). If the first wireless communication mode was selected in step S503, the subscription frame is sent using the first frequency band. If the second wireless communication mode was selected, the subscription frame is sent using the second frequency band. In this way, the wireless communication device 10 can discover wireless communication devices 10 located in a wider range, enabling the discovered wireless communication devices 10 to join the NAN cluster.

[0107] The first embodiment has been described above. According to the first embodiment, compared to the prior art, wireless communication devices located over a wider area can be detected to form a NAN cluster. Furthermore, since the wireless communication method is selected based on factors such as the distance to the detected wireless communication devices and the requirements of the wireless communication devices, stable wireless communication can be achieved after the NAN cluster is formed.

[0108] 2. Second Implementation Method

[0109] Next, the second implementation will be described. As mentioned above, in wireless communication methods conforming to the IEEE 802.11ah standard, the duty cycle is limited to within 10%. Therefore, there are also cases where it is not preferable to use the second frequency band to transmit discovery beacon frames without restriction.

[0110] In the second embodiment, in addition to the example described in the first embodiment, it is also determined whether to use the second frequency band to send discovery beacon frames during the NAN cluster formation process.

[0111] Reference Figure 7 This describes the NAN cluster formation process involved in the second embodiment. Figure 7 In the example shown, wireless communication device 10a also discovers wireless communication device 10b, causing wireless communication device 10b to join the NAN cluster.

[0112] The NAN cluster formation process described in the first embodiment, i.e., the detection of wireless communication devices 10b existing over a wider range, is envisioned to be primarily applied to situations where wireless communication devices 10a are moving. On the other hand, it is envisioned that in situations where wireless communication devices 10a are fixed or stationary, the necessity for detecting wireless communication devices 10b existing over a wider range is sometimes low.

[0113] In this embodiment, when there is no need to discover wireless communication devices 10b existing in a wider range, NAN discovery beacon frames are sent during the NAN cluster formation process; that is, discovery beacon frames are sent using the first frequency band. When such a process is performed, wireless communication device 10a is in "first mode".

[0114] On the other hand, when there is a need to detect wireless communication devices 10b existing in a wider range, during the NAN cluster formation process, S1G discovery beacon frames are transmitted, that is, discovery beacon frames are transmitted using the second frequency band. When such a process is performed, wireless communication device 10a is in "second mode".

[0115] In step S701, the control unit 110 of the wireless communication device 10a determines whether the wireless communication device 10a is in a first mode or a second mode based on whether the wireless communication device 10a is moving. Whether the wireless communication device 10a is in the first mode or the second mode is controlled by a state machine. For example, in response to receiving information from a navigation system installed in a car indicating that the car's engine is running, the control unit 110 controls the state machine to switch the mode of the wireless communication device 10a to the second mode. Alternatively, the wireless communication device 10a may switch to the second mode in response to an operation performed by the driver on the input / output interface 103.

[0116] As described above, the shift of the wireless communication device 10a to the second mode via engine operation and driver input is merely an example. The wireless communication device 10a may also shift between the first and second modes based on other criteria.

[0117] Next, the communication unit 120 of the wireless communication device 10a sends a discovery beacon frame to the wireless communication device 10b (step S702). If it is determined in step S701 that the wireless communication device 10a is in the first mode, the discovery beacon frame is sent using the first frequency band. If it is determined that the wireless communication device 10a is in the second mode, the discovery beacon frame is sent using the second frequency band.

[0118] Next, the communication unit 120 of the wireless communication device 10b uses the second frequency band to send a beacon response frame to the wireless communication device 10a (step S703). When it is determined in step S701 that the wireless communication device 10a is in the first mode, the first frequency band is used to send the beacon response frame. When it is determined that the wireless communication device 10a is in the second mode, the second frequency band is used to send the beacon response frame.

[0119] Next, steps S704 to S708 are executed. The processes of steps S704 to S708 are referenced. Figure 5 The processes in steps S503 to S507 are the same, therefore, their detailed descriptions are omitted.

[0120] The second embodiment has been described above. According to the second embodiment, when the necessity for transmitting beacon frames is low due to the presence of wireless communication devices over a wider range, the use of the second frequency band is restricted. Therefore, in addition to the advantages described in the first embodiment, the duty cycle limitation inherent in wireless communication methods conforming to the IEEE 802.11ah standard can be suppressed.

[0121] 3. Third Implementation Method

[0122] Next, the third embodiment will be described. In the first and second embodiments, examples were described of selecting whether to use the first wireless communication method or the second wireless communication method after sending the S1G discovery beacon frame. In the third embodiment, in addition to the examples described in the first and second embodiments, after receiving the response frame from the S1G discovery beacon frame, a certain period of time is waited before selecting whether to use the first wireless communication method or the second wireless communication method.

[0123] For example, consider the following scenario: a wireless communication device 10a installed in a car detects a wireless communication device 10b installed on the road and functioning as a sensor. Figure 8As shown, imagine a car equipped with wireless communication device 10a moving towards wireless communication device 10b. In this case, after wireless communication device 10a discovers wireless communication device 10b by sending an S1G discovery beacon frame to wireless communication device 10b, wireless communication device 10a approaches wireless communication device 10b. In this situation, wireless communication device 10a can reliably communicate with wireless communication device 10b after discovering it.

[0124] Conversely, such as Figure 9 As shown, imagine a car equipped with wireless communication device 10a is traveling in the opposite direction to wireless communication device 10b. In this case, after wireless communication device 10a detects wireless communication device 10b, wireless communication device 10a moves away from wireless communication device 10b. In such a situation, with Figure 8 In contrast to the example shown, wireless communication device 10a cannot reliably communicate with wireless communication device 10b after detecting it. Furthermore, it is also conceivable that since wireless communication device 10a is moving away from wireless communication device 10b, it would not need to communicate with wireless communication device 10b in the first place.

[0125] As described above, when the wireless communication device 10a moves, the distance between the wireless communication device 10a and the wireless communication device 10b changes, which may affect communication stability. If the wireless communication device 10a immediately performs the process of selecting whether to use the first radio communication method or the second radio communication method after detecting the wireless communication device 10b, it may not be able to accurately determine the aforementioned change. The third embodiment addresses this issue.

[0126] Reference Figure 10 This describes the NAN cluster formation process involved in the third implementation method. Figure 10 In the example shown, wireless communication device 10a also discovers wireless communication device 10b, causing wireless communication device 10b to join the NAN cluster.

[0127] First, the communication unit 120 of wireless communication device 10a sends a discovery beacon frame to wireless communication device 10b using the second frequency band (step S1001). Next, the communication unit 120 of wireless communication device 10b sends a beacon response frame to wireless communication device 10a using the second frequency band (step S1002). Through the processing of steps S1001 and S1002, DW begins.

[0128] The control unit 110 of the wireless communication device 10a measures the timer (step S1003). Then, the control unit 110 monitors whether the predetermined time of the timer has expired (step S1004). If the timer has not expired, the process of step S1004 continues; if the timer has expired, the process transitions to step S1005.

[0129] Next, in order to communicate wirelessly with wireless communication device 10b, the control unit 110 of wireless communication device 10a selects whether to use a first wireless communication method or a second wireless communication method (step S1003). (Refer to reference...) Figure 5 The process described in step S503 is performed in the same way as step S1003.

[0130] Alternatively, when selecting the wireless communication mode based on the distance between wireless communication device 10a and wireless communication device 10b, the control unit 110 can measure the distance between wireless communication device 10a and wireless communication device 10b twice and determine whether the difference between the measured distances is positive or negative. In this case, the distance between wireless communication device 10a and wireless communication device 10b is measured twice, before and after step S1003, that is, before the timer expires and after the timer expires.

[0131] For example, the control unit 110 calculates the difference diff between the distance D1 measured before the timer expires and the distance D2 measured after the timer expires using equation (3). D .

[0132] diff D =D1-D2 Equation (3)

[0133] diff D A negative value indicates that the distance between wireless communication device 10a and wireless communication device 10b increases between the timer expires and the timer expires. That is, it means that wireless communication device 10a is moving away from wireless communication device 10b. In such a case, wireless communication device 10a may employ a second wireless communication method or refuse to communicate with wireless communication device 10b in order to achieve communication over a longer distance.

[0134] On the other hand, diff D A positive value means that the distance between wireless communication device 10a and wireless communication device 10b decreases between the timer expires and the timer expires. That is, it means that wireless communication device 10a is moving closer to wireless communication device 10b. In this case, wireless communication device 10a does not need communication over a longer distance, and therefore uses the first wireless communication method.

[0135] When selecting a wireless communication mode based on the received signal strength of a wireless frame from wireless communication device 10b, control unit 110 can measure the received signal strength of the wireless frame from wireless communication device 10b twice and determine whether the difference between the measured received signal strengths is positive or negative. In this case, the received signal strength of the wireless frame from wireless communication device 10b is also measured twice, before and after the timer expires.

[0136] For example, the control unit 110 calculates the difference diff between the received signal strength P1 measured before the timer expires and the received signal strength P2 measured after the timer expires using equation (4). P .

[0137] diff P =P1-P2 Equation (4)

[0138] diff P A positive value indicates that the received signal strength of the wireless frame from wireless communication device 10b weakens before and after the timer expires. This means that wireless communication device 10a is moving away from wireless communication device 10b. In such a case, wireless communication device 10a may employ a second wireless communication method or refuse communication with wireless communication device 10b in order to achieve communication over a longer distance.

[0139] On the other hand, diff P A negative value indicates that the received signal strength of the wireless frame from wireless communication device 10b increases before and after the timer expires. This means that wireless communication device 10a is moving closer to wireless communication device 10b. In this case, wireless communication device 10a does not require communication over longer distances, and therefore employs the first wireless communication method.

[0140] return Figure 10 Following the explanation, steps S1006 to S1009 will be executed. The processes of steps S1006 to S1009 are as follows: Figure 5 The processes described in steps S504 to S507 are the same, therefore, their detailed descriptions are omitted.

[0141] Furthermore, in the third embodiment, as described in the second embodiment, it is possible to determine whether the wireless communication device 10a is in the first mode or the second mode during the formation of the NAN cluster.

[0142] The third embodiment has been described above. According to the third embodiment, changes such as the distance the wireless communication device 10a moves are accurately determined. Therefore, in addition to the advantages described in the first and second embodiments, an appropriate wireless communication method can be adopted based on the communication stability caused by the changes.

[0143] 4. Fourth Implementation Method

[0144] Next, the fourth embodiment will be described. In the first to third embodiments, the following example was described: when wireless communication devices existing in a wider range are discovered, a second frequency band is used to transmit discovery beacon frames.

[0145] By using the second frequency band to transmit discovery beacon frames, it is possible to discover wireless communication devices existing over a wider range. On the other hand, there are also cases where discovery beacon frames will arrive sufficiently even when using the first frequency band for wireless communication devices existing at close range.

[0146] As mentioned above, in wireless communication methods conforming to the IEEE 802.11ah standard, the duty cycle is limited to within 10%. Therefore, there are also situations where it is not preferable to use the second frequency band to transmit discovery beacon frames without restriction.

[0147] In the fourth embodiment, in addition to the examples described in the first to third embodiments, a NAN cluster formation process using the second frequency band is performed after the NAN cluster formation process using the first frequency band is performed during the NAN cluster formation process.

[0148] The NAN cluster formation process using the first frequency band, that is, according to... Figure 4 The existing NAN cluster formation process described herein enables wireless communication devices existing at close range to join the NAN cluster.

[0149] For example, consider the scenario where wireless communication device 10a enables wireless communication devices 10b, 10c, 10d, 10e, and 10n to join a NAN cluster. Assume that wireless communication device 10a transmits radio frames using a first frequency band, reaching wireless communication devices 10b and 10c, but not reaching wireless communication devices 10d, 10e, and 10n. On the other hand, assume that wireless communication device 10a transmits radio frames using a second frequency band, reaching wireless communication devices 10d, 10e, and 10n.

[0150] Wireless communication device 10a first performs a NAN trunking formation process using the first frequency band. For example... Figure 11As shown, this process can only detect wireless communication devices 10b and 10c that are located in close proximity, and add them to the NAN cluster. On the other hand, wireless frames transmitted using the first frequency band do not reach wireless communication devices 10d, 10e, and 10n, and therefore cannot be detected.

[0151] Subsequently, wireless communication device 10a performs a NAN trunking formation process using the second frequency band. For example... Figure 12 As shown, this process can discover wireless communication devices 10d, 10e, and 10n that exist in a wider range and add them to the NAN cluster.

[0152] exist Figure 11 as well as Figure 12 In the examples shown, for wireless communication devices 10b and 10c, it is not necessary to perform the NAN trunking formation process using the second frequency band. In the fourth embodiment, for wireless communication devices existing at close range, the NAN trunking formation process using the first frequency band is performed. Subsequently, for wireless communication devices existing over a wider range, the NAN trunking formation process using the second frequency band is performed.

[0153] Reference Figure 13 This describes the NAN cluster formation process involved in the fourth embodiment. Figure 10 In the example shown, wireless communication device 10a discovers wireless communication devices 10b and 10e, causing wireless communication devices 10b and 10e to join the NAN cluster. Wireless communication device 10b is within range of wireless frames transmitted using the first frequency band. Wireless communication device 10e is within range of wireless frames transmitted using the first frequency band, but not within range of wireless frames transmitted using the second frequency band.

[0154] First, the communication unit 120 of wireless communication device 10a uses the first frequency band to send a discovery beacon frame to wireless communication devices 10b and 10e (step S1301). That is, it sends a NAN discovery beacon frame. As a result, only wireless communication device 10b receives the discovery beacon frame.

[0155] Next, the communication unit 120 of the wireless communication device 10b uses the first frequency band to send a beacon response frame to the wireless communication device 10a (step S1302). Through the processing of steps S1301 and S1302, DW begins.

[0156] Next, the communication unit 120 of wireless communication device 10a uses the first frequency band to send a synchronization beacon frame to wireless communication device 10b (step S1303). That is, it sends a NAN synchronization beacon frame. Next, wireless communication device 10b uses the first frequency band to send a beacon response frame to wireless communication device 10a (step S1304). During this process, wireless communication device 10b is able to join the NAN cluster. Furthermore, although wireless communication devices 10a and 10b actually exchange SDFs, the description of this process is omitted.

[0157] Next, steps S1305 to S1309 are executed. The processing of steps S1305 to S1309 is referenced. Figure 5 The processes described in steps S501 to S505 are the same, therefore, their detailed description is omitted. Through the processes in steps S1305 to S1309, wireless communication device 10a discovers wireless communication device 10e, and wireless communication device 10e is able to join the NAN cluster. Furthermore, although in practice wireless communication devices 10a and 10e exchange SDFs, the description of such a process is omitted.

[0158] Furthermore, in the fourth embodiment, as described in the second embodiment, it can be determined whether the wireless communication device 10a is in the first mode or the second mode before the processing in step S1305. Additionally, in the fourth embodiment, as described in the third embodiment, after the processing in step S1306, a timer can be measured and the process can wait until the timer expires.

[0159] The fourth embodiment has been described above. According to the fourth embodiment, for wireless communication devices that do not require the NAN trunking formation process using the second frequency band, this process is not performed. Therefore, in addition to the advantages described in the first to third embodiments, the duty cycle limitation under wireless communication methods conforming to the IEEE 802.11ah standard can be suppressed.

[0160] 5. Fifth Implementation Method

[0161] Next, the fifth embodiment will be described. In the first to fourth embodiments, the following example was described: when a wireless communication device existing in a wider range is discovered, a second frequency band is used to transmit a discovery beacon frame.

[0162] In the fifth embodiment, multiple wireless communication devices act as NAN master devices to discover wireless communication devices existing in a wider range and add them to the cluster.

[0163] For example, consider the case where wireless communication device 10a enables wireless communication devices 10b, 10c, 10d, 10e, and 10n to join a NAN cluster. Assume that wireless communication device 10a transmits wireless frames using the second frequency band that reach wireless communication devices 10b and 10c, but not wireless communication devices 10d, 10e, and 10n.

[0164] Wireless communication device 10a performs a NAN trunking formation process using a second frequency band. For example... Figure 14 As shown, this process can only discover wireless communication devices 10b and 10c, enabling them to join the NAN cluster. On the other hand, wireless frames transmitted using the second frequency band do not reach wireless communication devices 10d, 10e, and 10n, thus failing to discover wireless communication devices 10d, 10e, and 10n.

[0165] In the fifth embodiment, after the wireless communication device 10a performs the NAN cluster formation process, either the wireless communication devices 10b and 10c that have joined the NAN cluster perform the NAN cluster formation process using the second frequency band. For example, it is assumed that the wireless communication device 10c is located closer to the wireless communication devices 10d, 10e, and 10n than the wireless communication device 10a.

[0166] like Figure 15 As shown, when the wireless frame transmitted by the wireless communication device 10c using the second frequency band arrives at the wireless communication devices 10d, 10e, and 10n, the wireless communication device 10c can act as the NAN master device, thereby enabling the wireless communication devices 10d, 10e, and 10n to join the NAN cluster.

[0167] Reference Figure 16 This describes the NAN cluster formation process involved in the fifth embodiment. Figure 16 In the example shown, wireless communication device 10a discovers wireless communication device 10c and causes wireless communication device 10c to join the NAN cluster. Additionally, wireless communication device 10a instructs wireless communication device 10c to act as a NAN master. Wireless communication device 10c performs the same NAN cluster formation process as wireless communication device 10a. Wireless communication device 10c discovers wireless communication device 10d and causes wireless communication device 10d to join the NAN cluster.

[0168] First, wireless communication device 10a, acting as the NAN master device, executes the NAN cluster formation process. The NAN clustering process is performed in steps S1601 to S1605. The processing and reference of steps S1601 to S1605 are as follows. Figure 5The processes described in steps S501 to S505 are the same, therefore, their detailed description is omitted. Through the processes in steps S1601 to S1605, wireless communication device 10a discovers wireless communication device 10c, and wireless communication device 10c is able to join the NAN cluster. Furthermore, although wireless communication devices 10a, 10b, and 10c actually exchange SDFs, the description of such a process is omitted.

[0169] Next, the control unit 110 of the wireless communication device 10a selects the wireless communication device 10 that operates as the NAN master device among the wireless communication devices 10 that have joined the NAN cluster (step S1606). Figure 16 In the example shown, wireless communication device 10c is selected.

[0170] For example, the wireless communication device 10 that operates as the NAN master device can be selected based on the location measured in step S1603. For example, the wireless communication device 10 located at the distance furthest from the wireless communication device 10a can be selected. In this way, a NAN cluster can be formed over a wider range. Alternatively, the wireless communication device 10 that operates as the NAN master device can be selected randomly.

[0171] Next, the control unit 110 instructs the wireless communication device 10c selected in step S1606 to operate as a NAN master device (step S1607). This instruction is given by sending any wireless frame, such as a synchronization beacon frame, to the wireless communication device 10c.

[0172] In the NAN protocol, wireless communication device 10 periodically exchanges synchronization beacon frames, including a value called AnchorMaster Rank (AMR), and records its own AMR. Based on this AMR record, the wireless communication device 10 with the highest AMR in the NAN cluster acts as the NAN master device.

[0173] In this embodiment, the wireless communication device 10a instructs the selected wireless communication device 10c to act as a NAN master device.

[0174] Next, wireless communication device 10c, acting as the NAN master device, executes the NAN cluster formation process. The NAN clustering process is performed in steps S1608 to S1612. The processing and reference of steps S1608 to S1612 are as follows. Figure 5The processes described in steps S501 to S505 are the same, therefore, their detailed description is omitted. Through the processes in steps S1608 to S1612, wireless communication device 10c discovers wireless communication device 10d, and wireless communication device 10d is able to join the NAN cluster. Furthermore, although wireless communication devices 10c and 10d actually exchange SDFs, the description of such a process is omitted.

[0175] exist Figure 16 In the example shown, only the wireless communication device 10c that has joined the NAN cluster acts as the NAN master device, but multiple wireless communication devices 10 can also act as NAN master devices in sequence.

[0176] exist Figure 16 In step S1603, wireless communication device 10a selects whether to use a first wireless communication method or a second wireless communication method in order to communicate wirelessly with wireless communication device 10c. Similarly, in step S1610, wireless communication device 10a selects whether to use a first wireless communication method or a second wireless communication method in order to communicate wirelessly with wireless communication device 10d.

[0177] The above description includes cases where, for example, a first wireless communication method is selected in the process of step S1603, and a second wireless communication method is selected in the process of step S1610. In this case, when using... Figure 16 In the NAN cluster formed by the processing, wireless communication using wireless communication devices 10a and 10c using the first wireless communication method coexists with wireless communication using wireless communication devices 10a and 10d using the second wireless communication method.

[0178] This embodiment enables communication using a first wireless communication method to coexist with communication using a second wireless communication method. Thus, this embodiment can select the optimal wireless communication method based on the communication status between the wireless communication devices 10, forming a NAN cluster with different wireless communication methods coexisting.

[0179] Furthermore, in the fifth embodiment, as described in the second embodiment, it can be determined whether the wireless communication device 10a is in the first mode or the second mode before the processing in step S1601. Additionally, in the fifth embodiment, as described in the third embodiment, a timer can be measured after the processing in step S1602 and after S1609, and the process can wait until the timer expires. Furthermore, in the fifth embodiment, as described in the fourth embodiment, the NAN trunking process using the first frequency band can be performed before the NAN trunking process using the second frequency band is performed.

[0180] The fifth embodiment has been described above. According to the fifth embodiment, each of the plurality of wireless communication devices operates as a NAN master device. Therefore, in addition to the advantages described in the first to fourth embodiments, it is possible to configure a NAN cluster utilizing wireless communication devices existing in a wider range.

[0181] 6. Sixth Implementation Method

[0182] Next, the sixth implementation will be described. In the fifth implementation, an example was described in which multiple wireless communication devices act as NAN master devices to discover wireless communication devices existing in a wider range and add them to the cluster.

[0183] In the sixth embodiment, multiple wireless communication devices also act as NAN master devices to discover wireless communication devices existing in a wider range and add them to the cluster.

[0184] For example, consider the scenario where wireless communication device 10a enables wireless communication devices 10b, 10c, 10d, 10e, and 10n to join a NAN cluster. Assume that wireless communication device 10a transmits radio frames using the second frequency band, which reach wireless communication devices 10b, 10c, 10d, 10e, and 10n. Conversely, assume that radio frames transmitted using the first frequency band do not reach wireless communication devices 10d, 10e, and 10n.

[0185] Even if wireless communication device 10a can detect wireless communication devices 10d, 10e, and 10n, it cannot use the first frequency band to radio communicate with them. In such cases, for example, when wireless communication devices 10d, 10e, and 10n require high-capacity data communication, stable communication is impossible.

[0186] In the sixth embodiment, after the wireless communication device 10a performs the NAN cluster formation process, either the wireless communication device 10b or 10c that has joined the NAN cluster performs the NAN cluster formation process. For example, it is assumed that the wireless communication device 10c is located closer to the wireless communication devices 10d, 10e, and 10n than the wireless communication device 10a.

[0187] Reference Figure 17 This describes the NAN cluster formation process involved in the sixth embodiment. Figure 17In the example shown, wireless communication device 10a discovers wireless communication device 10c and causes wireless communication device 10c to join the NAN cluster. Additionally, wireless communication device 10a discovers wireless communication device 10d, but cannot reliably communicate with wireless communication device 10d under the first wireless communication mode. Then, wireless communication device 10a instructs wireless communication device 10c to act as a NAN master device. Wireless communication device 10c performs the same NAN cluster formation process as wireless communication device 10a. Wireless communication device 10c discovers wireless communication device 10d and causes wireless communication device 10d to join the NAN cluster.

[0188] exist Figure 17 In the example shown, it is assumed that wireless communication device 10c joins the NAN cluster through the NAN cluster formation process with wireless communication device 10a. Furthermore, it is assumed that wireless communication device 10c is capable of wireless communication with wireless communication device 10d in the first wireless communication mode.

[0189] First, the communication unit 120 of the wireless communication device 10a sends a discovery beacon frame to the wireless communication device 10d using the second frequency band (step S1701). Next, the communication unit 120 of the wireless communication device 10d sends a beacon response frame to the wireless communication device 10a using the second frequency band (step S1702). Through the processing of steps S1701 and S1702, DW begins.

[0190] Next, in order to communicate wirelessly with the wireless communication device 10d, the control unit 110 of the wireless communication device 10a selects whether to use a first wireless communication method or a second wireless communication method (step S1703). This selection is performed in the same manner as described in the first embodiment, etc.

[0191] In step S1703, if it is determined that wireless communication with wireless communication device 10d is impossible under the first wireless communication mode, the control unit 110 of wireless communication device 10a selects the wireless communication device 10 that is operating as the NAN master device among the wireless communication devices 10 that have joined the NAN cluster (step S1704). Figure 17 In the example shown, wireless communication device 10c is selected. The NAN master device is selected in the same manner as described in the fifth embodiment.

[0192] Furthermore, although not illustrated, in step S1704, if it is determined that wireless communication with wireless communication device 10d is possible under the first wireless communication mode, wireless communication device 10a sends a synchronization beacon frame to wireless communication device 10d, thereby enabling wireless communication device 10d to join the NAN cluster.

[0193] Next, the control unit 110 instructs the wireless communication device 10c selected in step S1604 to operate as a NAN master device (step S1705). This instruction is given by sending any wireless frame, such as a synchronization beacon frame, to the wireless communication device 10c.

[0194] Next, wireless communication device 10c, acting as the NAN master device, executes the NAN cluster formation process. The NAN clustering process is performed in steps S1706 to S1710. The processing and reference of steps S1706 to S1710 are as follows. Figure 5 The processes described in steps S501 to S505 are the same, therefore, their detailed description is omitted. Through the processes in steps S1706 to S1710, wireless communication device 10c discovers wireless communication device 10d, and wireless communication device 10d is able to join the NAN cluster. Furthermore, although in practice wireless communication device 10c and wireless communication device 10d exchange SDFs, the description of such a process is omitted.

[0195] exist Figure 17 In the example shown, only the wireless communication device 10c that has joined the NAN cluster acts as the NAN master device, but multiple wireless communication devices 10 can also act as NAN master devices in sequence.

[0196] Furthermore, in the sixth embodiment, as described in the second embodiment, it can be determined whether the wireless communication device 10a is in the first mode or the second mode before the processing in step S1601. Additionally, in the fifth embodiment, as described in the third embodiment, a timer can be measured after the processing in steps S1702 and S1707, and the process can wait until the timer expires. Furthermore, in the fifth embodiment, as described in the fourth embodiment, the NAN trunking process using the first frequency band can be performed before the NAN trunking process using the second frequency band is performed.

[0197] The sixth embodiment has been described above. According to the sixth embodiment, each of the plurality of wireless communication devices operates as a NAN master device. Therefore, in addition to the advantages described in the first to fifth embodiments, it is possible to configure a NAN cluster utilizing wireless communication devices existing in a wider range, where the wireless communication devices within the cluster can stably perform wireless communication on large volumes of data.

[0198] The words, phrases, etc., used in the above embodiments are merely exemplary and can be replaced with substantially the same or similar expressions. In particular, since the technologies involved in the above embodiments are related to technical specifications, the expressions in the above embodiments can be replaced with substantially the same or similar expressions in technical specifications (e.g., the technical specifications cited in this application specification).

[0199] In the above embodiments, the information sent and received may be exchanged within the same or different messages or elements already described in the technical specifications, or it may be exchanged within newly defined messages or elements. The information exchanged in the above embodiments may be exchanged using different layers and / or different channels than those described in the above embodiments.

[0200] The manner and / or function provided by the apparatus described in the above embodiments can be provided by software recorded in a physical memory device and a computer executing the software, by software alone, by hardware alone, or by a combination thereof. For example, in the case where any of the above-described apparatuses is provided by electronic circuitry as hardware, it can be provided by digital circuitry or analog circuitry including multiple logic circuits.

[0201] The apparatus described in the above embodiments executes a program stored in a non-transitory tangible storage medium. By executing this program, a method corresponding to the program is performed.

[0202] 7. Postscript

[0203] The above-described embodiments and variations may be described in whole or in part as in the following notes, but are not limited to the content of the following notes. Hereinafter, the relationship of a note belonging to a note belonging to a note belonging to a note belonging to a note belonging to a note is described. All the subordinate relationships of the notes described below are included in the above-described embodiments.

[0204] (Postscript 1)

[0205] A first wireless communication device, the first wireless communication device comprising a processor and a memory storing instructions,

[0206] The aforementioned processor is configured to execute the aforementioned instructions such that:

[0207] In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices,

[0208] Using a second frequency band lower than the first frequency band, a wireless frame for discovering the aforementioned second wireless communication device is sent to the aforementioned second wireless communication device.

[0209] In response to receiving a response frame from the aforementioned second wireless communication device, either the aforementioned first frequency band or the aforementioned second frequency band is selected.

[0210] Using the selected frequency band, a wireless frame for synchronization with the second wireless communication device is sent to the second wireless communication device.

[0211] (Postscript 2)

[0212] According to the first wireless communication device described in Appendix 1, the aforementioned processor is further configured to execute the aforementioned instructions such that: based on the distance to the aforementioned second wireless communication device, either the aforementioned first frequency band or the aforementioned second frequency band is selected.

[0213] (Note 3)

[0214] According to the first wireless communication device described in Appendix 2, the aforementioned processor is further configured to execute the aforementioned instructions such that: the aforementioned distance is measured based on the departure time and arrival time of the wireless frames exchanged with the aforementioned second wireless communication device.

[0215] (Note 4)

[0216] According to the first wireless communication device described in Appendix 2, the aforementioned processor is further configured to execute the aforementioned instructions such that: the aforementioned distance is measured based on the location information received from the aforementioned second wireless communication device.

[0217] (Note 5)

[0218] According to any one of Appendices 1 to 4, the processor of the first wireless communication device is further configured to execute the aforementioned instructions such that: either the first frequency band or the second frequency band is selected based on the signal strength of the wireless frame received from the second wireless communication device.

[0219] (Note 6)

[0220] According to any one of Appendices 1 to 5, the processor of the first wireless communication device is further configured to execute the aforementioned instructions such that: based on a request indicated by the aforementioned second wireless communication device, either the aforementioned first frequency band or the aforementioned second frequency band is selected.

[0221] (Note 7)

[0222] According to any one of Appendices 1 to 6, the processor of the first wireless communication device is further configured to execute the aforementioned instructions such that either the first frequency band or the second frequency band is selected based on the priority indicated by the second wireless communication device.

[0223] (Note 8)

[0224] According to any one of Appendices 1 to 7, the first wireless communication device has a first frequency band of 2.4 GHz, 5 GHz or 6 GHz, and the second frequency band is less than 1 GHz.

[0225] (Note 9)

[0226] According to any one of Appendices 1 to 8, the first wireless communication device is specified in the NAN protocol and the second frequency band is specified in IEEE 802.11ah.

[0227] (Postscript 10)

[0228] According to any one of Appendices 1 to 9, in the first wireless communication device, the aforementioned processor is further configured to execute the aforementioned instructions such that: it is determined whether the aforementioned first wireless communication device is in a first mode or a second mode.

[0229] If it is determined that the first wireless communication device is in the second mode, the second frequency band is used to send the aforementioned wireless frame for discovering the second wireless communication device to the second wireless communication device.

[0230] (Postscript 11)

[0231] According to Appendix 10, the processor is further configured to execute the aforementioned instructions such that, if it is determined that the first wireless communication device is in the aforementioned first mode, the processor sends the aforementioned wireless frame for discovering the second wireless communication device to the second wireless communication device using the aforementioned first frequency band.

[0232] (Postscript 12)

[0233] According to Appendix 10 or 11, the processor is further configured to execute the aforementioned instructions such that: based on whether the first wireless communication device is moving, it is determined whether it is in the first mode or the second mode.

[0234] (Postscript 13)

[0235] According to any one of Appendices 1 to 12, the processor of the first wireless communication device is further configured to execute the aforementioned instructions such that: in response to receiving the aforementioned response frame from the second wireless communication device...

[0236] Measurement timer,

[0237] When the timer has elapsed for a predetermined period of time, either the first frequency band or the second frequency band mentioned above will be selected.

[0238] (Postscript 14)

[0239] According to Appendix 13, the processor is further configured to execute the aforementioned instructions such that: based on the difference between a first distance and a second distance, either the aforementioned first frequency band or the aforementioned second frequency band is selected, wherein the aforementioned first distance is the distance to the aforementioned second wireless communication device measured before the aforementioned timer expires, and the aforementioned second distance is the distance to the aforementioned second wireless communication device measured after the aforementioned timer expires.

[0240] (Postscript 15)

[0241] According to Appendix 13 or 14, the processor is further configured to execute the aforementioned instructions such that: based on the difference between a first signal strength and a second signal strength, either the first frequency band or the second frequency band is selected, wherein the first signal strength is the signal strength of a wireless frame received from the second wireless communication device before the expiration of the aforementioned timer, and the second signal strength is the signal strength of a wireless frame received from the second wireless communication device after the expiration of the aforementioned timer.

[0242] (Postscript 16)

[0243] According to any one of Appendices 1 to 15, the processor of the first wireless communication device is further configured to execute the aforementioned instructions such that: in order to allow the third wireless communication device to join the aforementioned cluster before allowing the second wireless communication device to join the aforementioned cluster,

[0244] Using the aforementioned first frequency band, a wireless frame for discovering the aforementioned third wireless communication device is sent to the aforementioned third wireless communication device. In response to receiving a response frame from the aforementioned third wireless communication device, a wireless frame for synchronizing with the aforementioned third wireless communication device is sent to the aforementioned third wireless communication device using the aforementioned first frequency band.

[0245] (Postscript 17)

[0246] According to the first wireless communication device described in Appendices 1 to 16, the aforementioned processor is further configured to execute the aforementioned instructions such that: after causing the aforementioned second wireless communication device to join the aforementioned cluster, a wireless frame for instructing the aforementioned second wireless communication device to act as a master device is sent to the aforementioned second wireless communication device, the aforementioned master device being used to perform the process for causing the fourth wireless communication device to join the aforementioned cluster.

[0247] (Postscript 18)

[0248] According to the first wireless communication device described in Appendices 1 to 17, the aforementioned processor is further configured to execute the aforementioned instructions such that: in order to enable the fifth wireless communication device to join the aforementioned cluster,

[0249] Using the aforementioned second frequency band, a wireless frame for discovering the aforementioned fifth wireless communication device is sent to the aforementioned fifth wireless communication device.

[0250] In response to receiving a response frame from the aforementioned fifth wireless communication device, either the aforementioned first frequency band or the aforementioned second frequency band is selected.

[0251] Without selecting the first frequency band, after the second wireless communication device joins the cluster, a wireless frame is sent to the second wireless communication device to instruct it to act as a master device. The master device then performs the process of joining the fifth wireless communication device into the cluster.

[0252] (Postscript 19)

[0253] A method, performed by a first wireless communication device, the method comprising:

[0254] In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices,

[0255] Using a second frequency band lower than the first frequency band, a wireless frame for discovering the aforementioned second wireless communication device is sent to the aforementioned second wireless communication device.

[0256] In response to receiving a response frame from the aforementioned second wireless communication device, select either the aforementioned first frequency band or the aforementioned second frequency band; and

[0257] Using the selected frequency band, a wireless frame for synchronization with the second wireless communication device is sent to the second wireless communication device.

[0258] (Postscript 20)

[0259] A program, when executed, causes a processor in a first wireless communication device to perform the following:

[0260] In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices,

[0261] Using a second frequency band lower than the first frequency band, a wireless frame for discovering the aforementioned second wireless communication device is sent to the aforementioned second wireless communication device.

[0262] In response to receiving a response frame from the aforementioned second wireless communication device, select either the aforementioned first frequency band or the aforementioned second frequency band; and

[0263] Using the selected frequency band, a wireless frame for synchronization with the second wireless communication device is sent to the second wireless communication device.

[0264] (Postscript 21)

[0265] A computer-readable, non-transient tangible recording medium storing a program that, when executed, causes a processor in a first wireless communication device to perform the following:

[0266] In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices,

[0267] Using a second frequency band lower than the first frequency band, a wireless frame for discovering the aforementioned second wireless communication device is sent to the aforementioned second wireless communication device.

[0268] In response to receiving a response frame from the aforementioned second wireless communication device, select either the aforementioned first frequency band or the aforementioned second frequency band; and

[0269] Using the selected frequency band, a wireless frame for synchronization with the second wireless communication device is sent to the second wireless communication device.

[0270] Figure Labels

[0271] 10 Wireless communication device, 101 Processor, 102 Memory, 104 Transmitter / receiver, 110 Control unit, 120 Communication unit.

Claims

1. A first wireless communication device, the first wireless communication device comprising a processor and a memory storing instructions, The processor is configured to execute the instructions such that: In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices, Using a second frequency band lower than the first frequency band, a wireless frame for discovering the second wireless communication device is sent to the second wireless communication device. In response to receiving a response frame from the second wireless communication device, either the first frequency band or the second frequency band is selected. Using the selected frequency band, transmit wireless frames to the second wireless communication device for synchronization with the second wireless communication device.

2. The first wireless communication device according to claim 1, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on the distance to the second wireless communication device.

3. The first wireless communication device according to claim 2, wherein the processor is further configured to execute the instructions such that: the distance is measured based on the departure time and arrival time of the wireless frames exchanged with the second wireless communication device.

4. The first wireless communication device according to claim 2, wherein the processor is further configured to execute the instructions such that: the distance is measured based on location information received from the second wireless communication device.

5. The first wireless communication device according to claim 1, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on the signal strength of a wireless frame received from the second wireless communication device.

6. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on a request indicated by the second wireless communication device.

7. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on a priority indicated by the second wireless communication device.

8. The first wireless communication device according to claim 1, wherein the first frequency band is 2.4 GHz, 5 GHz or 6 GHz, and the second frequency band is less than 1 GHz.

9. The first wireless communication device according to claim 1, wherein the first frequency band is specified in the NAN protocol and the second frequency band is specified in IEEE 802.11ah.

10. The first wireless communication device according to claim 1, wherein the processor is further configured to execute the instructions such that: determining which of the first wireless communication device is in a first mode and a second mode, If it is determined that the first wireless communication device is in the second mode, the second frequency band is used to send the wireless frame for discovering the second wireless communication device to the second wireless communication device.

11. The first wireless communication device according to claim 10, wherein the processor is further configured to execute the instructions such that: when it is determined that the first wireless communication device is in the first mode, the processor sends the wireless frame for discovering the second wireless communication device to the second wireless communication device using the first frequency band.

12. The first wireless communication device of claim 10, wherein the processor is further configured to execute the instructions such that: based on whether the first wireless communication device is moving, it is determined whether it is in the first mode or the second mode.

13. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: in response to receiving the response frame from the second wireless communication device, Measurement timer, When the timer has elapsed for a predetermined period of time, either the first frequency band or the second frequency band is selected.

14. The first wireless communication device of claim 13, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on the difference between a first distance and a second distance, wherein the first distance is the distance to the second wireless communication device measured before the timer expires, and the second distance is the distance to the second wireless communication device measured after the timer expires.

15. The first wireless communication device of claim 13, wherein the processor is further configured to execute the instructions such that: either the first frequency band or the second frequency band is selected based on the difference between a first signal strength and a second signal strength, wherein the first signal strength is the signal strength of a wireless frame received from the second wireless communication device before the timer expires, and the second signal strength is the signal strength of a wireless frame received from the second wireless communication device after the timer expires.

16. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: in order to cause the third wireless communication device to join the cluster before causing the second wireless communication device to join the cluster, Using the first frequency band, a wireless frame for discovering the third wireless communication device is sent to the third wireless communication device; in response to receiving a response frame from the third wireless communication device, a wireless frame for synchronizing with the third wireless communication device is sent to the third wireless communication device using the first frequency band.

17. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: after causing the second wireless communication device to join the cluster, a wireless frame is sent to the second wireless communication device to indicate an action as a master device, the master device being configured to perform a process for causing a fourth wireless communication device to join the cluster.

18. The first wireless communication device of claim 1, wherein the processor is further configured to execute the instructions such that: in order to enable the fifth wireless communication device to join the cluster, Using the second frequency band, a wireless frame for discovering the fifth wireless communication device is sent to the fifth wireless communication device. In response to receiving a response frame from the fifth wireless communication device, either the first frequency band or the second frequency band is selected. Without selecting the first frequency band, after enabling the second wireless communication device to join the cluster, a wireless frame is sent to the second wireless communication device to instruct it to act as a master device, the master device being used to perform the process of enabling the fifth wireless communication device to join the cluster.

19. A method performed by a first wireless communication device, the method comprising: In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices, Using a second frequency band lower than the first frequency band, a wireless frame for discovering the second wireless communication device is sent to the second wireless communication device. In response to receiving a response frame from the second wireless communication device, either the first frequency band or the second frequency band is selected; as well as Using the selected frequency band, transmit wireless frames to the second wireless communication device for synchronization with the second wireless communication device.

20. A computer-readable, non-transient tangible recording medium storing a program that, when executed, causes a processor in a first wireless communication device to perform: In order for the second wireless communication device to join a cluster that includes multiple wireless communication devices, Using a second frequency band lower than the first frequency band, a wireless frame for discovering the second wireless communication device is sent to the second wireless communication device. In response to receiving a response frame from the second wireless communication device, either the first frequency band or the second frequency band is selected; as well as Using the selected frequency band, transmit wireless frames to the second wireless communication device for synchronization with the second wireless communication device.

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