Access point and wireless terminal device

Abstract

An access point according to one embodiment of the present invention is provided with a receiving unit, a determination unit, and a transmission unit. The receiving unit receives, from a wireless terminal device, a probe request including feature information indicating a feature of the wireless terminal device. The determination unit determines whether the access point is available to the wireless terminal device on the basis of the feature information included in the received probe request. The transmission unit transmits a probe response to the wireless terminal device if the access point has been determined to be available to the wireless terminal device, the probe response including a service set identifier (SSID) of a wireless network formed by the access point. The transmission unit does not transmit the probe response to the wireless terminal device if the access point has been determined not to be available to the wireless terminal device.

Description

Access Point and Wireless Terminal Device

[0001] The present invention relates to wireless communication.

[0002] In a wireless LAN (local area network) system compliant with the IEEE 802.11 standard, an access point uses an SSID (service set identifier) as an identifier indicating a wireless network (e.g., BSS: basic service set or ESS: extended service set, etc.) formed by itself. The access point notifies the terminal of the existence of its BSS / ESS by including this SSID in a beacon frame or a probe response frame.

[0003] The terminal recognizes the access point to be connected to by using either or both of passive scanning and active scanning. In passive scanning, the terminal recognizes the SSID by receiving a beacon frame from the access point. In active scanning, the terminal specifies a specific SSID in the SSID Element of the probe request frame transmitted, and recognizes the existence of the BSS / ESS corresponding to the specified SSID by receiving a probe response frame with the SSID described from the access point, or specifies a wildcard SSID in the SSID Element of the probe request frame transmitted, and recognizes the SSIDs of surrounding access points by receiving a probe response frame with the SSID described from the access point.

[0004] Conventionally, when an access point does not want to notify an unspecified number of terminals of the SSID, this can be achieved by the following three functions. (a) Do not notify the beacon frame. (b) Do not describe the SSID in the SSID Element of the beacon frame. (c) Do not return a probe response frame for a probe request frame with a wildcard SSID specified in the SSID Element.

[0005] These features only give the terminal a choice between exposing its SSID or not. In order to connect to a BSS / ESS that matches the terminal's purpose (e.g., terminal type or services used), the terminal must have a connection profile (e.g., SSID and authentication information) in advance and explicitly perform the connection process.

[0006] IEEE Std 802.11-2020, “9.3.3.2 Beacon frame format”, pp.824-828, and “11.1.4 Acquiring synchronization, scanning”, pp.2058-2076, February 26, 2021.

[0007] The present invention aims to provide a technology that enables the search for a suitable wireless network without explicitly specifying a wireless network.

[0008] An access point according to one aspect of the present invention comprises a receiving unit, a determination unit, and a transmitting unit. The receiving unit receives a probe request from a wireless terminal device, which includes characteristic information indicating the characteristics of the wireless terminal device. The determination unit determines whether the access point is available to the wireless terminal device based on the characteristic information included in the received probe request. If the transmission unit determines that the access point is available to the wireless terminal device, it transmits a probe response to the wireless terminal device, which includes the SSID (service set identifier) ​​of the wireless network formed by the access point. If the transmission unit determines that the access point is not available to the wireless terminal device, it does not transmit the probe response to the wireless terminal device.

[0009] According to the present invention, it is possible to provide a technology that enables the search for a suitable wireless network without explicitly specifying a wireless network.

[0010] Figure 1 is a block diagram of a communication system according to an embodiment. Figure 2 is a block diagram of the hardware configuration of an access point according to an embodiment. Figure 3 is a block diagram of the hardware configuration of a terminal according to an embodiment. Figure 4 is a block diagram of the functional configuration of an access point according to an embodiment. Figure 5 is a block diagram of the functional configuration of a terminal according to an embodiment. Figure 6 is a flowchart of the BSS search process in active scanning according to an embodiment. Figure 7 is a flowchart of the BSS search process in active scanning according to an embodiment. Figure 8 is a flowchart of the BSS search process in active scanning according to an embodiment. Figure 9 is a flowchart of the BSS search process in passive scanning according to an embodiment. Figure 10 is a flowchart of the BSS search process in passive scanning according to an embodiment. Figure 11 is a flowchart of the BSS search process in passive scanning according to an embodiment.

[0011] Embodiments of the present invention will be described below with reference to the drawings. The embodiments are illustrative of devices and methods for realizing the technical idea of ​​the invention and are not intended to limit the scope of the invention. The drawings are schematic or conceptual. In the following, components having similar functions or configurations may be given the same reference numerals. Subscripts may be added to reference numerals to distinguish between components having similar functions or configurations. Subscripts are added after the reference numeral, separated by a hyphen "-".

[0012] This section describes an example of applying the wireless communication method according to the embodiment to the IEEE 802.11 standard. The wireless communication method according to the embodiment is not limited to the IEEE 802.11 standard, but can also be applied to other wireless communication standards.

[0013] The IEEE 802.11 standard defines the first layer and the MAC sublayer within the second layer of the OSI (Open Systems Interconnection) reference model. In the OSI reference model, communication functions are divided into seven layers (Layer 1: Physical Layer, Layer 2: Data Link Layer, Layer 3: Network Layer, Layer 4: Transport Layer, Layer 5: Session Layer, Layer 6: Presentation Layer, Layer 7: Application Layer).

[0014] The data link layer includes the LLC (logical link control) sublayer and the MAC (media access control) sublayer. The LLC sublayer generates LLC packets by, for example, adding DSAP (destination service access point) headers and SSAP (source service access point) headers to data input from the upper layer. The MAC sublayer generates MAC frames by, for example, adding MAC headers to LLC packets. MAC frames are sometimes called MPDUs (MAC protocol data units). The physical layer generates wireless frames by, for example, adding preambles to MAC frames. Wireless frames are sometimes called PPDUs (physical layer (PHY) protocol data units).

[0015] Figure 1 schematically shows a communication system 30 according to one embodiment. As shown in Figure 1, the communication system 30 includes an access point (AP) 10 and terminals 20. In the example shown in Figure 1, four access points 10-1 to 10-4 are shown as access points, and four terminals 20-1 to 20-4 are shown as terminals 20.

[0016] Access point 10 is a wireless LAN (local area network) access point. Access point 10 is sometimes called a base station. Access point 10 is connected to a communication network (not shown) which may include the Internet and / or an intranet. Access points 10-1 to 10-4 may be connected to the same communication network or to different communication networks.

[0017] Access point 10 forms individual wireless networks. The wireless networks may be BSS or ESS. The SSID of access point 10-1 is "A", the SSID of access point 10-2 is "B", the SSID of access point 10-3 is "C", and the SSID of access point 10-4 is "D". The SSID of access point 10-i refers to the SSID of the wireless network formed by access point 10-i and is an identifier for identifying the wireless network formed by access point 10-i.

[0018] Terminal 20 is a wireless terminal device equipped with a wireless communication module that functions as a client of a wireless LAN. Examples of wireless terminal devices include personal computers (PCs), smartphones, automated guided vehicles (AGVs), VR (virtual reality) devices, XR (extended reality) devices, and sensor devices. In the example shown in Figure 1, terminal 20-1 is a smartphone, terminal 20-2 is an AGV, terminal 20-3 is a VR headset, and terminal 20-4 is a laptop PC.

[0019] Terminal 20 displays an SSID list on its display containing one or more BSS SSIDs available to Terminal 20. When the user of Terminal 20 selects one of the displayed SSIDs, Terminal 20 initiates the connection process to the access point 10 corresponding to the selected SSID. As a result, a wireless link is logically established between the access point 10 and Terminal 20. Terminal 20 exchanges data with the access point 10 using the established wireless link.

[0020] Terminal 20 can be configured with its intended use, such as terminal type or service used. For example, terminal 20 can be configured with a terminal type selected by the user from a predetermined set of terminal types. Alternatively, the terminal type may be configured on terminal 20 during the manufacturing stage. Terminal 20-1 is a "smartphone", terminal 20-2 is an "AGV", terminal 20-3 is a "VR", and terminal 20-1 is a "guest PC".

[0021] Access point 10 can be configured to specify the uses, such as terminal types or services, that it supports (specifically, the BSS formed by access point 10). For example, access point 10 can set a terminal type selected by the user from a predetermined set of terminal types as a terminal type that it supports. Access point 10-1 is for unspecified uses and supports all terminal types. Similarly, access point 10 that does not have a specified supported terminal type, such as a legacy access point, also supports all terminal types. Access point 10-2 supports "AGV", access point 10-3 supports "XR" and "VR", and access point 10-4 supports "Guest PC".

[0022] In an active scan, terminal 20 sends (broadcasts) a probe request frame containing terminal type information indicating the terminal type of terminal 20 in order to search for access points 10 present in its vicinity. Hereafter, the probe request frame will be simply referred to as a probe request. Upon receiving a probe request from terminal 20, access point 10 decides whether or not to send a probe response frame back to terminal 20 based on the terminal type information contained in the received probe request. The probe response frame is used as a response to terminal 20 that sent the probe request frame and includes the SSID of access point 10. Hereafter, the probe response frame will be simply referred to as a probe response. Access point 10 decides to send a probe response back to terminal 20 if it supports the terminal type indicated by the terminal type information, and decides not to send a probe response back to terminal 20 if it does not support the terminal type indicated by the terminal type information.

[0023] If access point 10 decides to send a probe response to terminal 20, it sends the probe response to terminal 20. When terminal 20 receives the probe response from access point 10, it registers the SSID included in the received probe response in its SSID list.

[0024] If access point 10 decides not to send a probe response to terminal 20, terminal 20 will not receive a probe response from access point 10, and therefore access point 10's SSID will not be added to terminal 20's SSID list.

[0025] In passive scanning, access point 10 transmits (broadcasts) a beacon frame containing the SSID of access point 10 and terminal type information indicating the terminal types supported by access point 10. Hereafter, the beacon frame will be simply referred to as a beacon. Terminal 20, upon receiving a beacon from access point 10, decides whether or not to expose the SSID contained in the received beacon to the user based on the terminal type information contained in the received beacon. For example, if terminal 20's terminal type matches the terminal type indicated by the terminal type information, terminal 20 decides to expose the SSID contained in the received beacon to the user and adds access point 10's SSID to its SSID list. If terminal 20's terminal type does not match the terminal type indicated by the terminal type information, terminal 20 decides not to expose the SSID contained in the received beacon to the user and does not add access point 10's SSID to its SSID list.

[0026] In the example shown in Figure 1, access point 10-2 supports terminal type "AGV," so the SSID of access point 10-2 is exposed on terminal 20-2, which is set to terminal type "AGV," but not on terminals 20-1, 20-3, and 20-4. The SSID of access point 10-4, which supports terminal type "Guest PC," is exposed on all terminals 20-1 to 20-4, but it may be configured to be exposed only on terminal 20-4, which is set to terminal type "Guest PC."

[0027] In this way, when the terminal type of terminal 20 matches the terminal type supported by access point 10, the SSID of access point 10 is exposed on terminal 20.

[0028] If the terminal type of terminal 20 matches the terminal types supported by access point 10, terminal 20 may be prompted to initiate a connection process with access point 10. For example, terminal 20-2 may display the SSID list in a way that highlights "B", which is the SSID of access point 10-2. For example, SSID "B" may be displayed at the top. Alternatively, SSID "B" may be highlighted. In another example, terminal 20-2 may display a message prompting connection to access point 10-2 along with the SSID list. In yet another example, terminal 20-2 may automatically start the connection process with access point 10-2.

[0029] The terminal type information indicating the terminal type of terminal 20 is an example of feature information indicating the characteristics of terminal 20, and the terminal type information indicating the terminal types supported by access point 10 is an example of feature information indicating the characteristics supported by access point 10.

[0030] The characteristic information may also be a grade value representing a grade, such as a QoS (quality of service) class (level). The grade corresponds to priority. For example, the grade value is defined such that a higher grade corresponds to a higher grade value. If the grade value of terminal 20 is equal to or greater than the grade value of access point 10, the SSID of access point 10 is exposed on terminal 20. If the grade value of terminal 20 is lower than the grade value of access point 10, the SSID of access point 10 is not exposed on terminal 20. For example, if access point 10 supports grade 3 (the grade value of access point 10 is 3), the SSID of access point 10 is exposed on terminal 20 with grade 3 and terminal 20 with grade 4.

[0031] The characteristic information may be values ​​related to communication performance, such as latency, jitter, and throughput. If the access point 10 meets the terminal 20's requirements regarding communication performance, the SSID of the access point 10 is disclosed on the terminal 20. If the access point 10 does not meet the terminal 20's requirements regarding communication performance, the SSID of the access point 10 is not disclosed on the terminal 20. For example, if the minimum latency guaranteed or supported by the access point 10 is 50 ms and the terminal 20's required latency is 10 ms, the SSID of the access point 10 is not disclosed on the terminal 20. The value representing the communication performance required by the terminal 20 is called the communication performance requirement value or service performance requirement value, and the value representing the communication performance guaranteed by the access point 10 is called the communication performance guarantee value or service performance guarantee value.

[0032] Figure 2 schematically shows an example of the hardware configuration of access point 10. The access point 10 shown in Figure 2 corresponds to any or each of the access points 10-1 to 10-4 shown in Figure 1. As shown in Figure 2, access point 10 includes a CPU (central processing unit) 11 as a hardware processor, ROM (read-only memory) 12, RAM (random access memory) 13, a wireless communication module 14, and a wired communication module 15. The CPU 11 is connected to the ROM 12, RAM 13, wireless communication module 14, and wired communication module 15 via a bus.

[0033] The CPU 11 is an integrated circuit capable of executing various programs and controls the overall operation of the access point 10. The ROM 12 is a non-volatile semiconductor memory that stores programs and control data for controlling the access point 10. The RAM 13 is a volatile semiconductor memory used as a workspace for the CPU 11. At least part of the processing described with respect to the access point 10 can be performed by the CPU 11 executing programs stored in the ROM 12.

[0034] The wireless communication module 14 is a circuit configured to send and receive wireless signals via an antenna and is used for communication with the terminal 20. The wired communication module 15 is a circuit used for sending and receiving data and the like using electrical signals and is used for communication with a communication network.

[0035] Note that the hardware configuration shown in Figure 2 is illustrative, and the access point 10 may have a different hardware configuration than that shown in Figure 2. For example, in an example where the access point 10 communicates wirelessly with a communication network, the wired communication module 15 may be omitted.

[0036] Figure 3 schematically shows an example of the hardware configuration of terminal 20. The terminal 20 shown in Figure 3 corresponds to any or each of terminals 20-1 to 20-4 shown in Figure 1. As shown in Figure 3, terminal 20 includes a CPU 21 as a hardware processor, ROM 22, RAM 23, wireless communication module 24, storage 25, display 26, and input device 27. The CPU 21 is connected to the ROM 22, RAM 23, wireless communication module 24, storage 25, display 26, and input device 27 via a bus.

[0037] The CPU 21 is an integrated circuit capable of executing various programs and controls the overall operation of the terminal 20. The ROM 22 is a non-volatile semiconductor memory that stores programs and control data for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as a workspace for the CPU 21. At least part of the processing described with respect to the terminal 20 can be performed by the CPU 21 executing programs stored in the ROM 22.

[0038] The wireless communication module 24 is a circuit configured to send and receive wireless signals via an antenna and is used for communication with the access point 10. The storage 25 is a non-volatile storage device that stores, for example, the system software, application software, and data of the terminal 20. The display 26 is, for example, a liquid crystal display device that displays information such as an SSID list. The input device 27 is used to input information such as the terminal type. In an example where the terminal 20 is a smartphone, a touchscreen can be used as a combination of the display 26 and the input device 27.

[0039] Note that the hardware configuration shown in Figure 3 is illustrative, and the terminal 20 may have a different hardware configuration than that shown in Figure 3. For example, if the terminal 20 is an AGV, the terminal 20 may further include a mobility mechanism such as a trolley. Also, the display 26 and input device 27 may be omitted from the terminal 20. In this case, the user of the terminal 20 operates the terminal 20 using an external device such as a PC. For example, the user operates the external device to set the terminal type for the terminal 20.

[0040] Figure 4 schematically shows an example of the functional configuration of access point 10. The access point 10 shown in Figure 4 corresponds to any or each of the access points 10-1 to 10-4 shown in Figure 1. As shown in Figure 4, access point 10 comprises a wireless communication unit 110, a management unit 120, a MAC processing unit 130, a higher layer processing unit 140, an LLC processing unit 150, and a data processing unit 160. The higher layer processing unit 140 and the LLC processing unit 150 can be implemented, for example, by a combination of a CPU 11 and a wired communication module 15. The wireless communication unit 110, the management unit 120, the MAC processing unit 130, and the data processing unit 160 can be implemented, for example, by a wireless communication module 14 or by a combination of a CPU 11 and a wireless communication module 14.

[0041] The wireless communication unit 110 performs processing at the PHY layer (physical layer). The wireless communication unit 110 is configured to transmit and receive wireless signals.

[0042] The wireless communication unit 110 receives a MAC frame from the MAC processing unit 130, adds a preamble and the like to the received MAC frame to generate a wireless frame, converts the wireless frame into a wireless signal by performing predetermined modulation processing, and radiates the wireless signal via an antenna. The predetermined modulation processing includes, for example, error correction coding, interleaving, subcarrier modulation, inverse fast Fourier transform (IFFT), orthogonal frequency division multiplexing (OFDM) modulation, and frequency conversion.

[0043] Furthermore, the wireless communication unit 110 receives a wireless signal via an antenna, performs predetermined demodulation processing on the received wireless signal to obtain a wireless frame. The predetermined demodulation processing includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform (FFT), subcarrier demodulation, deinterleaving, and error correction decoding. Then, the wireless communication unit 110 extracts a MAC frame from the wireless frame and sends the extracted MAC frame to the MAC processing unit 130.

[0044] The management unit 120 manages the connection with the terminal 20. The management unit 120 includes a setting unit 121, a beacon transmission unit 122, a probe request reception unit 123, a determination unit 124, a probe response transmission unit 125, and a connection processing unit 126.

[0045] The setting unit 121 sets the characteristics of the terminals supported by the access point 10. In one example, the setting unit 121 sets the terminal types supported by the access point 10. For example, a PC (not shown) may be communicably connected to the access point 10, and a user who manages the access point 10 may specify the terminal type via the PC. In this case, the setting unit 121 sets the terminal type specified by the user as the terminal type supported by the access point 10. In another example, the setting unit 121 sets a grade value representing the grade supported by the access point 10. In a further example, the setting unit 121 sets the communication performance guaranteed by the access point 10.

[0046] The beacon transmitter 122 transmits a beacon via the wireless communication unit 110 that includes feature information indicating the characteristics of terminals supported by the access point 10. In one example, the beacon transmitter 122 transmits a beacon that includes terminal type information indicating the type of terminal supported by the access point 10 as feature information. In another example, the beacon transmitter 122 transmits a beacon that includes the grade value of the access point 10 as feature information. In yet another example, the beacon transmitter 122 transmits a beacon that includes guaranteed communication performance information indicating the communication performance guaranteed by the access point 10 as feature information. The guaranteed communication performance information includes the guaranteed communication performance value of the access point 10.

[0047] The probe request receiving unit 123 receives a probe request from the terminal 20 via the wireless communication unit 110, which includes feature information indicating the characteristics of the terminal 20. In one example, the probe request includes terminal type information indicating the terminal type of the terminal 20 as feature information. In another example, the probe request includes a grade value representing the grade of the terminal 20 as feature information. In yet another example, the probe request includes requirement conditions as feature information, which are the conditions that the terminal 20 requires regarding communication performance. The requirement conditions include a value representing the communication performance required by the terminal 20.

[0048] The determination unit 124 determines whether the access point 10 is available for the terminal 20 based on a comparison between the features supported by the access point 10 and the features of the terminal 20 indicated by the feature information included in the probe request. In one example, the determination unit 124 determines that the access point 10 is available for the terminal 20 when the terminal type of the terminal 20 matches the terminal type supported by the access point 10, and determines that the access point 10 is not available for the terminal 20 when the terminal type of the terminal 20 does not match the terminal type supported by the access point 10. The terminal type of the terminal 20 is indicated by the terminal type information included in the probe request received from the terminal 20. In another example, the determination unit 124 determines that the access point 10 is available for the terminal 20 when the grade value of the terminal 20 is equal to or greater than the grade value of the access point 10, and determines that the access point 10 is not available for the terminal 20 when the grade value of the terminal 20 is less than the grade value of the access point 10. The grade value of the terminal 20 is included in the probe request received from the terminal 20. In a further example, the determination unit 124 determines that the access point 10 is available for the terminal 20 when the access point 10 satisfies the request conditions of the terminal 20, and determines that the access point 10 is not available for the terminal 20 when the access point 10 does not satisfy the request conditions of the terminal 20. The request conditions of the terminal 20 are included in the probe request received from the terminal 20.

[0049] When it is determined that the access point 10 is available for the terminal 20, the probe response transmission unit 125 transmits a probe response including the SSID of the access point 10 to the terminal 20 via the wireless communication unit 110. When it is determined that the access point 1 not available for the terminal 20, the probe response transmission unit 125 does not transmit a probe response to the terminal 20.

[0050] For example, there may be terminals 20 that do not support storing feature information in probe requests, such as legacy terminals. The determination unit 124 may determine that the access point 10 is unavailable to terminal 20 if the probe request received from terminal 20 does not contain feature information. Therefore, if the probe request received from terminal 20 does not contain feature information, the probe response is not sent to terminal 20.

[0051] The connection processing unit 126 performs connection procedures, including authentication and association, to establish a wireless link between the access point 10 and the terminal 20. For example, when the connection processing unit 126 receives an association request frame from the terminal 20 via the wireless communication unit 110, it sends an association response frame to the terminal 20 via the wireless communication unit 110. Hereafter, the association request frame will be simply referred to as the association request, and the association response frame will be simply referred to as the association response.

[0052] When the MAC processing unit 130 receives a MAC frame (specifically a management frame or control frame) from the management unit 120, it sends the MAC frame to the wireless communication unit 110. Examples of control frames received from the management unit 120 include beacons, probe responses, and association responses. When the MAC processing unit 130 receives a MAC frame (specifically a data frame) from the data processing unit 160, it sends the MAC frame to the wireless communication unit 110. When the MAC processing unit 130 receives a MAC frame from the wireless communication unit 110, it sends the MAC frame to the management unit 120 or the data processing unit 160 depending on the type of MAC frame. If the MAC frame received from the wireless communication unit 110 is a management frame or a control frame, the MAC processing unit 130 sends the MAC frame to the management unit 120; if the MAC frame received from the wireless communication unit 110 is a data frame, it sends the MAC frame to the data processing unit 160. Examples of control frames received from terminal 20 and sent to management unit 120 include probe requests and association requests.

[0053] The access point 10 exchanges data with the terminal 20 using a wireless link established between the access point 10 and the terminal 20. The upper layer processing unit 140, the LLC processing unit 150, and the data processing unit 160 are involved in the data exchange.

[0054] In downlink data transmission, the upper layer processing unit 140 receives data destined for the terminal 20 from the communication network and sends the received data to the LLC processing unit 150. The LLC processing unit 150 receives the data from the upper layer processing unit 140, adds a DSAP header and an SSAP header to the received data to generate an LLC packet, and sends the generated LLC packet to the data processing unit 160. The data processing unit 160 receives the LLC packet from the LLC processing unit 150, adds a MAC header to the received LLC packet to generate a MAC frame (specifically a data frame), and sends the generated MAC frame to the wireless communication unit 110. The wireless communication unit 110 receives the MAC frame from the data processing unit 160 via the MAC processing unit 130, generates a wireless frame from the received MAC frame, converts the generated wireless frame into a wireless signal, and radiates the wireless signal via the antenna.

[0055] In uplink data transmission, the wireless communication unit 110 receives a wireless signal from the terminal 20 via the antenna and performs a predetermined demodulation process on the received wireless signal to obtain a wireless frame. The wireless communication unit 110 then extracts a MAC frame from the wireless frame and sends the extracted MAC frame to the data processing unit 160. The data processing unit 160 receives the MAC frame from the wireless communication unit 110 via the MAC processing unit 130, extracts LLC packets from the MAC frame, and sends the extracted packets to the LLC processing unit 150. The LLC processing unit 150 receives the LLC packets from the data processing unit 160, extracts data from the received LLC packets, and sends the extracted data to the upper layer processing unit 140. The upper layer processing unit 140 receives the data from the LLC processing unit 150 and sends the received data to the communication network. For example, the upper layer processing unit 140 transmits the data to a computer that is the destination of the data via the communication network.

[0056] Figure 5 schematically shows an example of the functional configuration of terminal 20. Terminal 20 shown in Figure 5 corresponds to any or each of terminals 20-1 to 20-4 shown in Figure 1. As shown in Figure 5, terminal 20 comprises a wireless communication unit 210, a management unit 220, a MAC processing unit 230, a higher layer processing unit 240, an LLC processing unit 250, a data processing unit 260, and a display control unit 270. The higher layer processing unit 240, the LLC processing unit 250, the data processing unit 260, and the display control unit 270 can be implemented, for example, by a CPU 21. The wireless communication unit 210, the management unit 220, and the MAC processing unit 230 can be implemented, for example, by a wireless communication module 24 or by a combination of the CPU 21 and the wireless communication module 24.

[0057] Since the wireless communication unit 210, MAC processing unit 230, LLC processing unit 250, and data processing unit 260 are the same components as the wireless communication unit 110, MAC processing unit 130, LLC processing unit 150, and data processing unit 160 shown in Figure 4, a detailed explanation of the wireless communication unit 210, MAC processing unit 230, LLC processing unit 250, and data processing unit 260 will be omitted.

[0058] The wireless communication unit 210 is configured to send and receive wireless signals. The wireless communication unit 110 receives a MAC frame from the MAC processing unit 230, adds a preamble and the like to the received MAC frame to generate a wireless frame, performs a predetermined modulation process to convert the wireless frame into a wireless signal, and radiates the wireless signal through the antenna. Furthermore, the wireless communication unit 210 receives the wireless signal through the antenna and performs a predetermined demodulation process on the received wireless signal to obtain a wireless frame. Then, the wireless communication unit 210 extracts the MAC frame from the wireless frame and sends the extracted MAC frame to the MAC processing unit 230.

[0059] The management unit 220 manages the connection with the access point 10. The management unit 220 includes a setting unit 221, a beacon receiving unit 222, a determination unit 223, a registration unit 224, a probe request transmission unit 225, a probe response receiving unit 226, and a connection processing unit 227.

[0060] The configuration unit 221 sets the characteristics of the terminal 20. In one example, the configuration unit 221 sets the terminal type of the access point 10. For example, the user of terminal 20 may specify the terminal type using the input device 27 (Figure 3). In this case, the configuration unit 221 sets the terminal type specified by the user as the terminal type of terminal 20. In another example, the configuration unit 221 sets the grade value of terminal 20. In yet another example, the configuration unit 221 sets the communication performance required by terminal 20.

[0061] The beacon receiver 222 receives a beacon from the access point 10 via the wireless communication unit 210, which contains feature information indicating the characteristics of the terminals supported by the access point 10. In one example, the beacon receiver 222 receives a beacon that contains terminal type information indicating the terminal types supported by the access point 10 as feature information. In another example, the beacon receiver 222 receives a beacon that contains the grade value of the access point 10 as feature information. In yet another example, the beacon receiver 222 receives a beacon that contains guaranteed communication performance information indicating the communication performance guaranteed by the access point 10 as feature information. The guaranteed communication performance information includes the communication performance guaranteed value of the access point 10.

[0062] The determination unit 223 determines whether the access point 10 is available to the terminal 20 based on a comparison between the features supported by the access point 10, indicated by the feature information contained in the beacon, and the features of the terminal 20. In one example, the determination unit 223 determines that the access point 10 is available to the terminal 20 if the terminal type of the terminal 20 matches the terminal type supported by the access point 10, and determines that the access point 10 is not available to the terminal 20 if the terminal type of the terminal 20 does not match the terminal type supported by the access point 10. The terminal types supported by the access point 10 are indicated by the terminal type information contained in the beacon received from the access point 10. In another example, the determination unit 223 determines that the access point 10 is available to the terminal 20 if the grade value of the terminal 20 is equal to or greater than the grade value of the access point 10, and determines that the access point 10 is not available to the terminal 20 if the grade value of the terminal 20 is lower than the grade value of the access point 10. The grade value of the terminal 20 is contained in the beacon received from the access point 10. In a further example, the determination unit 223 determines whether the access point 10 meets the requirements for communication performance that the terminal 20 has requested, based on a comparison between the communication performance guarantee value contained in the beacon received from the access point 10 and the communication performance requirement value of the terminal 20. The determination unit 223 determines that the access point 10 is available to the terminal 20 if it meets the requirements of the terminal 20, and determines that the access point 10 is not available to the terminal 20 if it does not meet the requirements of the terminal 20.

[0063] If the registration unit 224 determines that the access point 10 is available to the terminal 20, it registers the SSID of the access point 10 contained in the beacon received from the access point 10 in the SSID list. If the registration unit 224 determines that the access point 10 is not available to the terminal 20, it does not register the SSID of the access point 10 contained in the beacon received from the access point 10 in the SSID list.

[0064] The probe request transmission unit 225 transmits a probe request via the wireless communication unit 210 that includes feature information indicating the characteristics of the terminal 20. In one example, the probe request includes terminal type information indicating the terminal type of the terminal 20 as feature information. In another example, the probe request includes the grade value of the terminal 20 as feature information. In yet another example, the probe request includes the requirements that the terminal 20 requests regarding communication performance as feature information. The requirements include a value representing the communication performance requested by the terminal 20.

[0065] The probe response receiving unit 226 receives a probe response from the access point 10, including the SSID of the access point 10, via the wireless communication unit 110. The registration unit 224 obtains the SSID of the access point 10 from the beacon or probe response received from the access point 10 and registers it in the SSID list.

[0066] The connection processing unit 227 performs connection procedures, including authentication and association, to establish a wireless link between the access point 10 and the terminal 20. For example, when a user of terminal 20 selects one of the SSIDs included in the SSID list, the connection processing unit 227 sends an association request to the access point 10 corresponding to the selected SSID via the wireless communication unit 210.

[0067] The display control unit 270 displays information such as the SSID list on the display 26 (Figure 3).

[0068] When the MAC processing unit 230 receives a MAC frame (specifically a management frame or control frame) from the management unit 220, it sends the MAC frame to the wireless communication unit 210. Examples of control frames received from the management unit 220 include probe requests and association requests. When the MAC processing unit 230 receives a MAC frame (specifically a data frame) from the data processing unit 260, it sends the MAC frame to the wireless communication unit 210. When the MAC processing unit 230 receives a MAC frame from the wireless communication unit 210, it sends the MAC frame to the management unit 220 or the data processing unit 260 depending on the type of MAC frame. If the MAC frame received from the wireless communication unit 210 is a management frame or a control frame, the MAC processing unit 230 sends the MAC frame to the management unit 220; if the MAC frame received from the wireless communication unit 210 is a data frame, it sends the MAC frame to the data processing unit 260. Examples of control frames received from access point 10 and sent to management unit 220 include beacons, probe responses, and association responses.

[0069] Terminal 20 exchanges data with access point 10 using a wireless link established between access point 10 and terminal 20. The upper layer processing unit 240, LLC processing unit 250, and data processing unit 260 are involved in the data exchange.

[0070] In uplink data transmission, the upper layer processing unit 240 executes an application that exchanges data with a computer on the communication network connected to the access point 10. The upper layer processing unit 240 sends the data generated by the application to the LLC processing unit 250. The LLC processing unit 250 receives the data from the upper layer processing unit 240, generates an LLC packet from the received data, and sends the generated LLC packet to the data processing unit 260. The data processing unit 160 receives the LLC packet from the LLC processing unit 150, generates a MAC frame (specifically a data frame) from the received LLC packet, and sends the generated MAC frame to the wireless communication unit 210. The wireless communication unit 210 receives the MAC frame from the data processing unit 260 via the MAC processing unit 230, generates a wireless frame from the received MAC frame, converts the generated wireless frame into a wireless signal, and radiates the wireless signal via the antenna.

[0071] In downlink data transmission, the wireless communication unit 210 receives a wireless signal from the access point 10 via the antenna, performs a predetermined demodulation process on the received wireless signal to obtain a wireless frame. The wireless communication unit 210 then extracts a MAC frame from the wireless frame and sends the extracted MAC frame to the data processing unit 260. The data processing unit 260 receives the MAC frame from the wireless communication unit 210 via the MAC processing unit 230, extracts LLC packets from the MAC frame, and sends the extracted packets to the LLC processing unit 250. The LLC processing unit 250 receives the LLC packets from the data processing unit 260, extracts data from the received LLC packets, and sends the extracted data to the upper layer processing unit 240. The upper layer processing unit 240 receives the data from the LLC processing unit 150 and provides the received data to, for example, a running application.

[0072] As described above, if it is determined that access point 10 is available to terminal 20, the SSID of access point 10 is registered in the SSID list of terminal 20, and the SSID of access point 10 is made public on terminal 20. Therefore, determining whether or not access point 10 is available to terminal 20 is equivalent to determining whether or not to make the SSID of access point 10 public on terminal 20.

[0073] Figure 6 schematically shows an example of the procedure for searching for a wireless network using active scanning according to this embodiment.

[0074] In step S601 of Figure 6, terminal 20 sends a probe request that includes terminal type information indicating the terminal type of terminal 20 in order to search for access points present around terminal 20.

[0075] In step S602, the access point 10, upon receiving a probe request from terminal 20, recognizes the terminal type indicated by the terminal type information included in the received probe request as the terminal type of terminal 20, and determines whether the terminal type of terminal 20 matches the terminal types supported by the access point 10.

[0076] If the terminal type of terminal 20 matches the terminal type supported by access point 10 (step S602; Yes), the flow proceeds to step S603. In step S603, access point 10 notifies terminal 20 of its SSID. Specifically, access point 10 sends a probe response containing its SSID to terminal 20. Terminal 20 receives the probe response from access point 10, obtains the SSID of access point 10 from the received probe response, and adds the SSID of access point 10 to its SSID list.

[0077] If the terminal type of terminal 20 does not match the terminal types supported by access point 10 (step S602; No), the flow proceeds to step S604. In step S604, access point 10 does not notify terminal 20 of its SSID. Specifically, access point 10 does not respond to the probe request received from terminal 20.

[0078] According to the procedure shown in Figure 6, it becomes possible to search for a BSS that matches the intended use of terminal 20 without specifying a particular SSID in the probe request.

[0079] Figure 7 schematically illustrates another example of the procedure for discovering a wireless network using an active scan according to the embodiment.

[0080] In step S701 of Figure 7, terminal 20 broadcasts a probe request containing a grade value representing the grade of terminal 20 in order to search for access points present around terminal 20.

[0081] In step S702, the access point 10, upon receiving a probe request from terminal 20, recognizes the grade value included in the received probe request as the grade value of terminal 20 and determines whether the grade value of terminal 20 is equal to or greater than the grade value of access point 10.

[0082] If the grade value of terminal 20 is equal to or greater than the grade value of access point 10 (step S702; Yes), the flow proceeds to step S703. In step S703, access point 10 sends a probe response containing the SSID of access point 10 to terminal 20. Terminal 20 receives the probe response from access point 10, obtains the SSID of access point 10 from the received probe response, and adds the SSID of access point 10 to the SSID list.

[0083] If the grade value of terminal 20 is lower than the grade value of access point 10 (step S702; No), the flow proceeds to step S704. In step S704, access point 10 does not notify terminal 20 of its SSID.

[0084] According to the procedure shown in Figure 7, it becomes possible to search for a BSS that can handle the grade of terminal 20 without specifying a particular SSID in the probe request.

[0085] Figure 8 schematically illustrates a further example of the procedure for exploring a wireless network using an active scan according to the embodiment.

[0086] In step S801 of Figure 8, terminal 20 broadcasts a probe request containing requirements for communication performance that terminal 20 requests in order to search for access points present around terminal 20. The requirements include service performance requirements such as request delay.

[0087] In step S802, the access point 10, having received a probe request from terminal 20, recognizes the requirements of terminal 20 included in the received probe request and determines whether the access point 10 satisfies the requirements of terminal 20.

[0088] If access point 10 satisfies the requirements of terminal 20 (step S802; Yes), the flow proceeds to step S803. In step S803, access point 10 sends a probe response containing access point 10's SSID to terminal 20. Terminal 20 receives the probe response from access point 10, obtains access point 10's SSID from the received probe response, and adds access point 10's SSID to its SSID list.

[0089] If access point 10 does not meet the requirements of terminal 20 (step S802; No), the flow proceeds to step S804. In step S804, access point 10 does not notify terminal 20 of its SSID.

[0090] According to the procedure shown in Figure 8, it becomes possible to search for a BSS that satisfies the requirements of terminal 20 without specifying a particular SSID in the probe request.

[0091] Figure 9 schematically shows an example of the procedure for searching for a wireless network using passive scanning according to this embodiment.

[0092] In step S901 of Figure 9, the access point 10 broadcasts a beacon that includes the SSID of the access point 10 and terminal type information indicating the terminal types supported by the access point 10.

[0093] In step S902, terminal 20, which has received a beacon from access point 10, recognizes the terminal type indicated by the terminal type information contained in the received beacon as a terminal type supported by access point 10, and determines whether the terminal type of terminal 20 matches a terminal type supported by access point 10.

[0094] If the terminal type of terminal 20 matches the terminal type supported by access point 10 (step S902; Yes), the flow proceeds to step S903. If terminal type information is not included in the received beacon, terminal 20 determines that the terminal type of terminal 20 matches the terminal type supported by access point 10. In step 903, terminal 20 adds the SSID of access point 10 contained in the beacon received from access point 10 to the SSID list.

[0095] If the terminal type of terminal 20 does not match the terminal types supported by access point 10 (step S902; No), the flow proceeds to step S904. In step S904, terminal 20 does not add the SSID of access point 10 contained in the beacon received from access point 10 to the SSID list.

[0096] According to the procedure shown in Figure 9, it becomes possible to search for a BSS that matches the intended use of terminal 20 without explicitly specifying a wireless network.

[0097] Figure 10 schematically illustrates another example of the procedure for exploring a wireless network using passive scanning according to the embodiment.

[0098] In step S1001 of Figure 10, the access point 10 broadcasts a beacon that includes the SSID of the access point 10 and a grade value representing the grade of the access point 10.

[0099] In step S1002, terminal 20, which has received a beacon from access point 10, recognizes the grade value of access point 10 contained in the received beacon and determines whether the grade value of terminal 20 is equal to or greater than the grade value of access point 10.

[0100] If the grade value of terminal 20 is equal to or greater than the grade value of access point 10 (step S1002; Yes), the flow proceeds to step S1003. In step 1003, terminal 20 adds the SSID of access point 10, which is included in the beacon received from access point 10, to the SSID list.

[0101] If the grade value of terminal 20 is lower than the grade value of access point 10 (step S1002; No), the flow proceeds to step S1004. In step S1004, terminal 20 does not register the SSID of access point 10 contained in the beacon received from access point 10 in the SSID list.

[0102] According to the procedure shown in Figure 10, it becomes possible to search for a BSS that can handle the grade of terminal 20 without explicitly specifying the wireless network.

[0103] Figure 11 schematically illustrates a further example of the procedure for exploring a wireless network using passive scanning according to the embodiment.

[0104] In step S1101 of Figure 11, the access point 10 broadcasts a beacon that includes the access point's SSID and the guarantee conditions that the access point 10 guarantees regarding communication performance. The guarantee conditions include service performance guarantee values ​​such as the minimum latency guaranteed by the access point 10.

[0105] In step S1102, terminal 20, having received a beacon from access point 10, recognizes the guarantee conditions of access point 10 included in the received beacon and determines whether access point 10 satisfies terminal 20's requirements. Terminal 20's requirements indicate the conditions that terminal 20 requires regarding communication performance.

[0106] If the access point 10 satisfies the requirements of the terminal 20 (step S1102; Yes), the flow proceeds to step S1103. In step 1103, the terminal 20 adds the SSID contained in the beacon received from the access point 10 to the SSID list.

[0107] If the access point 10 does not meet the requirements of the terminal 20 (step S1102; No), the flow proceeds to step S1104. In step S1104, the terminal 20 does not add the SSID contained in the beacon received from the access point 10 to the SSID list.

[0108] According to the procedure shown in Figure 11, it is possible to search for a BSS that satisfies the requirements of terminal 20 without explicitly specifying a wireless network.

[0109] The following information, as defined in IEEE Std 802.11-2020, can be used as terminal type information, service performance requirements, and service performance guarantee values: (1) Interworking element The interworking element is included in beacons, probe requests, and probe responses. An unused value in the Access Network Type field within the Access Network Options field in the interworking element can be defined as the terminal type (or service used). Alternatively, the terminal type can be notified by an unused or default value in the Venue Info field, an unused value in the Venue Group subfield or Venue Type subfield within the Venue Info field, or a combination of these including the Access Network Type field. (2) FILS Request Parameters element The FILS (fast initial link setup) Request Parameters element is included in probe requests. The requirement value described in the Max Delay Limit subfield in the FILS Request Parameters element can be used as the service performance requirement value. (3) Vendor Specific element / Vendor Specific Request element A Vendor Specific element is included in beacons, probe requests, probe responses, etc., and a Vendor Specific Request element is included in probe requests. Within the Requested Vendor Specific Information in the Vendor Specific element / Vendor Specific Request element, a field for describing terminal type information or service performance requirements can be added as appropriate.(4) BSS Available Admission Capacity element The BSS Available Admission Capacity element is included in the beacon and probe response. The User Priority, Access Category (AC), or unused value described in Available Admission Capacity Reported in the Available Admission Capacity Bitmask field of the BSS Available Admission Capacity element can be used as AP terminal type information or service performance guarantee value. (5) BSS Average Access Delay element The BSS Average Access Delay element is included in the beacon and probe response. The AP Average Access Delay in the BSS Average Access Delay element can be used as a service performance guarantee value. (6) QoS Traffic Capability element The QoS Traffic Capability element is included in the beacon and probe response. The Count number that matches the corresponding terminal category shown by the AC STA Count List in the QoS Traffic Capability element can be used as the criterion for determining whether to make it public or not. (7) QMF Policy element The QMF (quality-of-service management frame) Policy element defines the QMF access category mapping (QACM) of the management frame and is included in the beacon and probe response. Terminal 20 may determine the terminal type supported by access point 10 or the service performance guarantee value of access point 10 based on QACM.

[0110] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple components disclosed. For example, if the problem can be solved and effects can be obtained even if some components are deleted from all the components shown in the embodiment, then the configuration with these components deleted can be extracted as an invention.

[0111] 10…Access Point 11…CPU 12…ROM 13…RAM 14…Wireless Communication Module 15…Wired Communication Module 20…Terminal 21…CPU 22…ROM 23…RAM 24…Wireless Communication Module 25…Storage 26…Display 27…Input Device 30…Communication System 110…Wireless Communication Unit 120…Management Unit 121…Setting Unit 122…Beacon Transmission Unit 123…Probe Request Reception Unit 124…Determination Unit 125…Probe Response Transmission Unit 126…Connection Processing Unit 130…MAC Processing Unit 140…Upper Layer Processing Unit 150…LLC Processing Unit 160…Data Processing Unit 210…Wireless Communication Unit 220…Management Unit 221…Setting Unit 222…Beacon Reception Unit 223…Determination Unit 224…Registration Unit 225…Probe Request Transmission Unit 226…Probe Response Reception Unit 227...Connection Processing Unit 230...MAC Processing Unit 240...Upper Layer Processing Unit 250...LLC Processing Unit 260...Data Processing Unit 270...Display Control Unit

Claims

1. An access point comprising: a receiving unit that receives a probe request from a wireless terminal device including characteristic information indicating the characteristics of the wireless terminal device; a determination unit that determines whether the access point is available to the wireless terminal device based on the characteristic information included in the received probe request; and a transmitting unit that, when it is determined that the access point is available to the wireless terminal device, transmits a probe response to the wireless terminal device including the SSID (service set identifier) ​​of the wireless network formed by the access point, and when it is determined that the access point is not available to the wireless terminal device, does not transmit the probe response to the wireless terminal device.

2. The access point according to claim 1, wherein the receiving unit receives a probe request that includes terminal type information indicating the terminal type of the wireless terminal device as the feature information, the determination unit determines whether the terminal type indicated by the terminal type information included in the probe request matches a terminal type supported by the access point, and the transmitting unit transmits the probe response to the wireless terminal device if the terminal type indicated by the terminal type information matches a terminal type supported by the access point, and does not transmit the probe response to the wireless terminal device if the terminal type indicated by the terminal type information does not match a terminal type supported by the access point.

3. The access point according to claim 1, wherein the receiving unit receives the probe request which includes a first grade value representing the grade of the wireless terminal device as characteristic information, the determination unit determines whether the first grade value included in the received probe request is equal to or greater than a second grade value representing the grade supported by the access point, and the transmitting unit transmits the probe response to the wireless terminal device if the first grade value is equal to or greater than the second grade value, and does not transmit the probe response to the wireless terminal device if the first grade value is less than the second grade value.

4. The access point according to claim 1, wherein the receiving unit receives the probe request which includes the requirement conditions that the wireless terminal device requires regarding communication performance as the feature information, the determination unit determines whether the access point satisfies the requirement conditions included in the received probe request, and the determination unit transmits the probe response to the wireless terminal device if the access point satisfies the requirement conditions, and does not transmit the probe response to the wireless terminal device if the access point does not satisfy the requirement conditions.

5. The access point according to claim 1, wherein if the receiving unit receives a probe request from another wireless terminal device that does not contain characteristic information indicating the characteristics of the other wireless terminal device, the determination unit determines that the access point is not available to the other wireless terminal device, and the transmitting unit does not transmit the probe response to the other wireless terminal device.

6. A wireless communication device comprising: a receiving unit that receives a beacon from an access point that includes the SSID (service set identifier) ​​of a wireless network formed by the access point and characteristic information indicating the characteristics of a terminal supported by the access point; a determination unit that determines whether the access point is available to the wireless communication device based on the characteristic information contained in the received beacon; and a registration unit that, if it is determined that the access point is available to the wireless communication device, registers the SSID contained in the received beacon in an SSID list, and if it is determined that the access point is not available to the wireless communication device, does not register the SSID contained in the received beacon in the SSID list.

7. The wireless terminal device according to claim 6, wherein the receiving unit receives a beacon that includes terminal type information indicating the terminal type supported by the access point as characteristic information, the determination unit determines whether the terminal type of the wireless communication device matches the terminal type indicated by the terminal type information included in the received beacon, and the registration unit registers the SSID included in the received beacon in the SSID list if the terminal type of the wireless communication device matches the terminal type indicated by the terminal type information, and does not register the SSID included in the received beacon in the SSID list if the terminal type of the wireless communication device does not match the terminal type indicated by the terminal type information.

8. The wireless terminal device according to claim 6, wherein the receiving unit receives a beacon that includes a first grade value representing the grade supported by the access point as characteristic information, the determination unit determines whether a second grade value representing the grade of the wireless terminal device is equal to or greater than the first grade value included in the received beacon, and the registration unit registers the SSID included in the received beacon in the SSID list if the second grade value is equal to or greater than the first grade value, and does not register the SSID included in the received beacon in the SSID list if the second grade value is less than the first grade value.

9. The wireless terminal device according to claim 6, wherein the receiving unit receives a beacon that includes guaranteed communication performance information indicating the communication performance guaranteed by the access point as characteristic information, the determination unit determines whether the access point satisfies the requirements that the wireless terminal device requires regarding communication performance based on the guaranteed communication performance information contained in the received beacon, and the registration unit registers the SSID contained in the received beacon in the SSID list if the access point satisfies the requirements, and does not register the SSID contained in the received beacon in the SSID list if the access point does not satisfy the requirements.

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