Communication device, control method, and program

Abstract

To define a method for handling a wireless MAC header sent and received between a Lower AP and an STA when communicating between an AP that processes an Upper MAC and an AP that processes a Lower MAC while there is also consideration of a configuration where the AP that processes the Upper MAC (Upper AP) and the AP that processes the Lower MAC are different.SOLUTION: A communication device has communication means for receiving a wireless frame that conforms to IEEE802.11, header acquisition means for acquiring a header from the wireless frame, frame generation means for generating a new frame in which part or all of the acquired header is placed after a header that conforms to Ethernet, and separate communication means for transmitting the new frame to another communication device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a communication device, a control method, and a program that are compliant with IEEE802.11. [Background technology]

[0002] In recent years, with the increase in the amount of data being communicated, the development of communication technologies such as wireless LANs (Local Area Networks) has been progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax / be.

[0003] For example, the IEEE802.11be standard considers Multi-Link communication, in which one AP (Access Point) establishes multiple links with one STA (Station) via multiple different frequency channels and communicates in parallel (Patent Document 1). Note that the two or more links may be selected from the same frequency band (any of the 2.4 GHz band, 3.6 GHz band, 4.9 and 5 GHz bands, and 6 GHz band), or may be selected from different frequency bands. The IEEE802.11be standard also specifies APs and STAs that support Multi-Link as AP MLD (Multi-Link Device) and STA MLD. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-103805 Summary of the Invention [Problem to be solved by the invention]

[0005] In the successor standard to IEEE802.11be, a method is being considered to improve usability by using Multi-Link. Specifically, the AP that processes the Upper MAC (Upper AP) and the AP that processes the Lower MAC (Lower AP) will have different configurations. This reduces the processing load on the Lower AP, making it possible to make it smaller and consume less power. This makes it possible to form a network at low cost while still maintaining communication coverage.

[0006] As mentioned above, a configuration in which the AP that processes the Upper MAC (Upper AP) and the AP that processes the Lower MAC are different is being considered. However, when communicating between the AP that processes the Upper MAC and the AP that processes the Lower MAC, it has not been specified how to handle the MAC header of the wireless data transmitted and received between the Lower AP and the STA. [Means for solving the problem]

[0007] In order to achieve the above object, a communication device according to one aspect of the present invention comprises: A communication means for receiving a wireless frame conforming to IEEE802.11; a header acquisition means for acquiring a header from the wireless frame; a frame generating means for generating a new frame by placing a part or all of the acquired header after a header conforming to Ethernet, and further placing a frame body of the received wireless frame after the header; another communication means for transmitting the new frame to another communication device; has. Effect of the Invention

[0008] Frames including wireless MAC header information can be communicated between the Upper AP and the Lower AP, making it possible for multiple APs to operate as a single AP and communicate with STAs. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an example of a network configuration. [Diagram 2] FIG. 2 is a diagram illustrating an example of the hardware configuration of an AP / STA. [Diagram 3] FIG. 2 is a diagram illustrating an example of the functional configuration of an AP / STA. [Figure 4] FIG. 11 is a flowchart illustrating an example of a data transfer process of a Lower AP. [Diagram 5] 11 is a flowchart illustrating an example of a data reception process of an Upper AP. FIG. [Figure 6] FIG. 11 is a flowchart illustrating an example of a data transmission process of an Upper AP. [Figure 7] FIG. 11 is a flowchart illustrating an example of a data transfer process of a Lower AP. [Figure 8] FIG. 13 is a diagram illustrating an example of a sequence. [Figure 9] 10 is a diagram illustrating an example of a frame configuration for communication between a lower AP and an upper AP. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments are merely examples for explaining the present invention and are not intended to limit the scope of the present invention.

[0011] (Configuration of wireless communication system) FIG. 1 shows an example of the configuration of a network according to this embodiment. FIG. 1 shows a configuration in which a STA (Station) (STA102) participates in a network constructed by an Upper AP (Access Point) 104 (AP104) and Lower APs 101 and 103 (AP101 and AP103, respectively). In addition, the AP101 operates with the same parameters as the AP103 and AP104, and the three APs are assumed to operate as one AP. The range that radio waves from the AP101 can reach is indicated by 100. In other words, the STA102 can transmit and receive signals transmitted and received by the AP101. The AP101 can transmit and receive signals directly to and from the AP104, and the AP103 can transmit and receive signals directly to and from the AP104.

[0012] The AP 104 operates as an Upper AP. Its roles are (1) to (9) as shown in Table 1.

[0013] [Table 1]

[0014] The roles of (1) to (9) are described in detail below.

[0015] IEEE802.1X authentication is a server-based authentication method that allows STA connection control. The MSDU data limit determines how much data can be received or sent. A-MSDU is a frame concatenation method that allows multiple frame bodies to be included in one MAC (Media Access Control) frame. Block Ack is a mechanism for returning Acks for multiple pieces of data at once, and generates the Block Ack. The sequence number is a number assigned to each frame, and indicates the order of the frames. When returning a Block Ack, it serves as an index, making it possible to indicate which frames were received. The packet number is also an incremented number, but it is a number used for encryption and decryption. This packet number and the generated encryption key are used to encrypt and decrypt MPDU. TID-to-Link Mapping determines which TID (Traffic Identifier) ​​is assigned to which AP, and if the AP supports Multi-Link, which TID is assigned to each Link. Duplicate detection is performed by detecting duplicate sequence numbers and packet numbers.

[0016] AP101 and AP103 operate as Lower APs and have the following roles (1) to (4) as shown in Table 2.

[0017] [Table 2]

[0018] The roles of (1) to (4) are described in detail below.

[0019] Generating and checking the CRC involves generating the FCS (Frame Check Sequence) value attached to the end of a frame, or checking the FCS value included in a received frame. A-MPDU is a frame concatenation method that includes multiple frames in the frame to be transmitted, and these are combined and disassembled. Destination address filtering checks whether the destination address included in the frame is that of AP101, AP103, or a multicast address or broadcast address that includes AP101 and AP103. If it is an address that should be received by AP104, it is accepted and forwarded to AP104. If it is not an address that should be received by AP104, it is discarded. It also records the sequence number of the Block Ack.

[0020] The AP 101, STA 102, AP 103, and AP 104 can perform wireless communication in accordance with the IEEE 802.11bn (Ultra High Reliability) standard, which is a successor standard to IEEE 802.11be. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Each communication device can communicate at frequencies of 2.4 GHz band, 3.6 GHz band, 5 GHz band, 6 GHz band, and 45 GHz band and 60 GHz band called millimeter wave. The frequency band used by each communication device is not limited to these, and a different frequency band such as the Sub 1 GHz band may be used. In addition, the AP 101 and STA 102 can communicate using bandwidths of 20 GHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidth used by each communication device is not limited to this, and may be a multiple of 20 MHz, such as 60 MHz or 240 MHz, or may not be a multiple of 20 MHz, such as 4 MHz or 24 MHz.

[0021] Although the AP 101, the STA 102, the AP 103, and the AP 104 are described as being compatible with the IEEE 802.11bn standard, they may also be compatible with a legacy standard that is a standard that precedes the IEEE 802.11bn standard. Specifically, the AP 101, the STA 102, the AP 103, and the AP 104 may be compatible with at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards. In addition to the IEEE 802.11 series standards, they may also be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication.

[0022] UWB includes wireless USB, wireless 1394, WiNET, etc. It may also be compatible with communication standards for wired communication such as wired LAN.

[0023] In this embodiment, the communication between the AP104 and the AP101 and AP103 is wired communication. The communication between the AP101 and the STA102 is wireless communication. Specific examples of the AP101, AP103, and AP104 include, but are not limited to, a wireless LAN router and a personal computer (PC). The AP101 may be an information processing device such as a wireless chip capable of performing wireless communication conforming to the IEEE802.11bn standard. Specific examples of the STA102 include, but are not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, and a headset. The STA102 may be an information processing device such as a wireless chip capable of performing wireless communication conforming to the IEEE802.11bn standard.

[0024] In the IEEE802.11 series of standards, the bandwidth of each frequency channel in the 2.4GHz, 5GHz, and 6GHz bands is defined as 20MHz. The bandwidth of each frequency channel in the 45GHz band is defined as 540MHz, and in the 60GHz band it is defined as 1080MHz or 2160MHz. Here, a frequency channel is a frequency channel defined in the IEEE802.11 series of standards, and multiple frequency channels are defined in each of the 2.4GHz, 5GHz, 6GHz, 45GHz, and 60GHz bands. Note that a single frequency channel may use a bandwidth of 40MHz or more by bonding with adjacent frequency channels.

[0025] (AP / STA configuration) 2 shows an example of the hardware configuration of the AP 101 in this embodiment. The AP 103, AP 104, and STA 102 also have the same configuration. The AP 101 has a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a wired communication unit 206, a wireless communication unit 207, and an antenna 208. There may be multiple antennas.

[0026] The storage unit 201 is composed of one or more memories such as a ROM and a RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. As the storage unit 201, in addition to memories such as ROM and RAM, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs may be used. Furthermore, the storage unit 201 may include multiple memories.

[0027] The control unit 202 is configured with one or more processors such as a CPU or MPU, and controls the entire AP 101 by executing a computer program stored in the storage unit 201. The control unit 202 may control the entire AP 101 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 also generates data and signals (wireless frames) to be transmitted in communication with other communication devices. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may also include multiple processors such as multi-core processors, and the entire STA 102 may be controlled by the multiple processors.

[0028] Furthermore, the control unit 202 controls the functional unit 203 to execute predetermined processes such as wireless communication, imaging, printing, projection, etc. The functional unit 203 is hardware that enables the AP 101 to execute predetermined processes.

[0029] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user via a monitor screen or a speaker. Here, the output by the output unit 205 may be a display on a monitor screen, a voice output by a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be realized by a single module, such as a touch panel. Also, the input unit 204 and the output unit 205 may be integrated with the AP 101, or may be separate from it.

[0030] The wireless communication unit 207 controls wireless communication conforming to the IEEE802.11bn standard. The wireless communication unit 207 also controls wireless communication conforming to other IEEE802.11 series standards in addition to the IEEE802.11bn standard, and controls the antenna 208 to transmit and receive signals for wireless communication generated by the control unit 202.

[0031] The wired communication unit 206 controls wired communication such as a wired LAN conforming to the Ethernet standard. The Ethernet standard may be any of 10BASE-T, 100BASE-TX, 1000BASE-T, and 1000BASE-TX, or may be another standard.

[0032] If the AP 101 supports the NFC standard, Bluetooth standard, etc. in addition to the IEEE802.11bn standard, the AP 101 may control wireless communication in accordance with these communication standards. If the AP 101 can perform wireless communication in accordance with a plurality of communication standards, the AP 101 may have a wireless communication unit and an antenna that support each communication standard. The AP 101 communicates data such as image data, document data, and video data with the STA 102 via the wireless communication unit 207. The antenna 208 may be configured as a separate unit from the wireless communication unit 207, or may be configured as a single module together with the wireless communication unit 207.

[0033] The antenna 208 is an antenna capable of communication in the 2.4 GHz band, the 5 GHz band, the 6 GHz band, the 45 GHz band, and the 60 GHz band. In this embodiment, the AP 101 has two antennas, but may have three or more antennas. Also, a different antenna may be provided for each frequency band. Also, when the AP 101 has a plurality of antennas, it may have a wireless communication unit 207 corresponding to each antenna.

[0034] It should be noted that the STA 102 does not necessarily have to include the wired communication unit 206 .

[0035] 3 is a block diagram showing the functional configuration of the AP 101 in this embodiment. The AP 103, AP 104, and STA 102 also have the same configuration.

[0036] The AP 101 is composed of a multi-AP control unit 301 , a wireless communication control unit 302 , a wired communication control unit 303 , and a frame transfer control unit 304 .

[0037] The multi-AP control unit 301 is a control unit that controls communication processing so that the AP 101 can operate as one AP in cooperation with the AP 104. This control unit performs frame generation and frame analysis so that the AP 101 can operate as a lower AP.

[0038] The wireless communication control unit 302 is a control unit that performs control for wireless communication with the STA 102. The wireless communication control unit 302 transmits a frame to the STA 102 instructed by the frame transfer control unit 304, or sends a frame received from the STA 102 to the frame transfer control unit 304.

[0039] The wired communication control unit 303 is a control unit that performs control for wired communication with the AP 104. The wired communication control unit 303 transmits a frame instructed by the frame transfer control unit 304 to be transmitted to the AP 104, or sends a frame received from the AP 104 to the frame transfer control unit 304.

[0040] The frame transfer control unit 304 is a control unit that controls frame transfer to operate as a Lower AP. The frame transfer control unit 304 is further divided into a header acquisition unit and a frame generation unit, not shown. When a frame received from the STA 102 is received from the wireless communication control unit 302, the header acquisition unit acquires the header of the frame received from the wireless communication control unit 302. The frame generation unit places a part or all of the acquired header behind the header for wired communication to make a frame that can be transferred to wired communication, and sends it to the wired communication control unit 303. Also, when a frame received from the AP 104 is received from the wired communication control unit 303, the header acquisition unit acquires the header of the frame received from the wired communication control unit 303. The frame generation unit discards the header for wired communication, and if there is a header that is missing for wireless communication, adds the missing header, makes a frame that can be transferred to wireless communication, and sends it to the wireless communication control unit 302.

[0041] It should be noted that the AP 104 does not necessarily have to include the frame forwarding control unit 304 , and the STA 102 does not necessarily have to include the multi-AP control unit 301 , the wired communication control unit 303 , and the frame forwarding control unit 304 .

[0042] (Processing flow) Next, the flow of the processes executed by the AP / STA and the sequence in the wireless communication system will be described.

[0043] In this embodiment, a data frame is transmitted from the STA 102, and when the AP 101 receives the data frame, it forwards it to the AP 104. After that, the AP 104 transmits a data frame, and when the AP 101 receives the data frame, it forwards it to the STA 102. Note that, although a data frame is forwarded in this embodiment, other frames may also be forwarded in the same manner. For example, a management frame used for disconnection and a control frame used for communication control may also be forwarded in the same manner.

[0044] FIG. 4 is a flowchart showing the flow of processing performed by the control unit 302 executing a program stored in the storage unit 301 of the AP 101. This flowchart shows processing when the AP 101 starts operating as an AP and receives data by wireless communication. This processing starts when the AP 101 starts functioning as an AP, such as when the power of the AP 101 is turned on, when the AP 101 receives an instruction to operate as an AP, or when the wireless function is turned on. In the embodiment, only the STA 102 is connected, but multiple units may be connected at the same time. In this processing, it is assumed that the AP 101, the AP 104, and the AP 103 operate as an integrated AP when viewed from the STA 102, and that the settings for operating as the Upper AP and the Lower AP have been completed in advance. In other words, the AP 104 operates as the Upper AP, and the AP 101 and the AP 103 operate as the Lower AP, and mutual identification has also been completed. In addition, in this embodiment, it is assumed that the STA 102 and the AP 101 are connected in order to consider the transfer of data frames, but this is not the case when transferring management frames. This process may be performed from the point where the STA 102 connects to the AP 101 .

[0045] The AP 101 checks whether a frame has been received from the connected STA 102 (S401). Next, it is determined whether the received frame should be transferred to the AP 104 (S402). For example, if the setting is such that only Control frames are not transferred, the result is No when a Control frame is received. Alternatively, it is possible to transfer Ack frames among Control frames, but not other Control frames. In addition, it is also possible to simultaneously connect a STA that transmits and receives in cooperation with the AP 104 and a self-contained STA. It is possible that the STA that should be connected in cooperation with the AP 104 is a STA that supports IEEE802.11bn and supports Multi-AP, the frame is transferred, and the other STAs are not transferred. In addition, for example, if the STA supports IEEE802.11bn but does not support Multi-AP, the frame may not be transferred. If the result is No in S402, the AP 101 processes the frame itself (S403). If the frame is to be transferred (Yes in S402), the MAC header of the received wireless frame is obtained, and the obtained header is placed after the MAC header to be transmitted by wire. As will be described later with reference to the frame configuration in Fig. 9, a frame body in which the data of the wireless frame and the like are stored is placed after the MAC header of the wireless frame. Then, the generated frame is encapsulated (S404). The MAC header of the wireless communication to be encapsulated at this time may include all of the acquired MAC header information of the wireless communication. Alternatively, it may include only the Frame Control field, Sequence Control field, and QoS Control field of the MAC header of the wireless communication. Alternatively, it may be only a part of them. Since the MAC header of the wireless communication differs depending on the frame, the fields to be transferred may be changed according to the frame, or some of them may be deleted.

[0046] Once the frame encapsulation is complete, it is checked whether the length exceeds the maximum frame length (S405). This is because the addition of the wireless header may cause the data frame to exceed its maximum length. If the maximum length is exceeded, the frame is divided and encapsulated (S406) and then forwarded (S407). Information indicating that the frame has been divided in wired communication may be included in the wired communication header or after the wired communication header, between the wireless communication header. This allows the STA 102 to avoid performing different processing for IEEE802.11bn and other standards such as IEEE802.11be. If the data frame is not divided and forwarded, the STA 102 may adjust the length of the data frame so that it does not exceed the maximum length. If the data frame does not exceed the maximum length, the frame is forwarded to the AP 104 as is (S411).

[0047] Fig. 5 shows the flow of processing when AP104 receives a frame forwarded from AP101. This flowchart shows the processing when AP104 starts operating as an AP and receives data via wireless communication. This processing starts when AP104 starts functioning as an AP, such as when the power of AP104 is turned on, when AP104 receives an instruction to operate as an AP, or when the wireless function is turned on. This processing is considered to be similar to the flowchart of Fig. 4, with AP101, AP104, and AP103 operating as a single AP when viewed from STA102, and with settings completed in advance to operate as an Upper AP and a Lower AP.

[0048] The AP 104 checks whether there is a received frame (501). If there is a received frame, it checks whether it is a frame forwarded from the AP 101 or AP 103 (502). This is used to determine whether the frame was received from the connected STA when the AP 104 is directly connected to the STA. If the frame was received directly from the connected STA, it processes it all by itself (503).

[0049] In the case of a forwarded frame (Yes in 502), it is necessary to analyze the information in the MAC header used in wireless communication. First, the MAC header used in wired communication is removed from the forwarded frame, and the information in the header portion used in wireless communication is read (504). It is then confirmed from the header whether the frame has been divided (505). If it has been divided, the divided frames are integrated and then analyzed (506). If it has not been divided, the received frame is analyzed as is (509).

[0050] The AP 104 analyzes the wireless header, reads the sequence number, packet number, and source MAC address from the analysis results, and decrypts the encrypted data frame for wireless communication (507). The key used for decryption here is the shared key shared when connecting with the STA 104. The received packet number is also used for decryption. Once it is determined that the received data has been received, it sends an Ack to the STA 102 (508). Alternatively, to return an Ack for multiple frames collectively, it records the sequence number of the Block Ack and returns the Block Ack later. When the Ack frame is sent from the AP 104, it arrives at the STA 102 via the AP 101.

[0051] Next, a process will be presented in which a frame transmitted by the upper AP AP 104 is transmitted to the STA 102 via the AP 101.

[0052] FIG. 6 shows the flow of processing when the AP 104 transmits a frame. This flowchart shows processing when the AP 104 starts operating as an AP and receives data by wireless communication. This processing starts when the AP 101 is powered on, when the AP 104 receives an instruction to operate as an AP, or when the wireless function is turned on, and when the AP starts to function as an AP. In the embodiment, only the STA 102 is connected, but multiple units may be connected at the same time. In this processing, similar to the flowchart in FIG. 4, the AP 101, AP 104, and AP 103 are considered to operate as a single AP when viewed from the STA 102, and settings to operate as an Upper AP and a Lower AP have been completed in advance. This processing may proceed simultaneously with the processing shown in FIG. 5.

[0053] The AP 104 checks whether there is data to be transmitted to each STA (601). If there is a frame to be transmitted, the data is encrypted for transmission by wireless communication (602). Then, the AP 104 checks whether the frame to be transmitted is to be transferred to either the AP 101 or the AP 103 (603). The frame to be transferred is a frame directed to the STA 102 connected to the AP 101. The frame may also be a broadcast frame such as a Beacon frame or a FILS Discovery frame periodically transmitted by the AP. Alternatively, the frame may be a multicast frame directed to multiple STAs and APs including the STA 102. When transferring a frame to the STA 102, the AP 104 checks which AP the STA 102 is directly connected to and instructs one of the APs to transfer the frame. In this embodiment, the AP 101 is instructed to transfer the frame. For example, when the STA 102 is simultaneously connected to both the AP 101 and the AP 103, the AP 101 or the AP 103 may instruct the AP 102 to transfer the frame, or both APs may be instructed to transfer the frame.

[0054] When the frame is not to be forwarded to AP101 and AP103, AP104 creates a frame for wireless communication by itself and transmits it via wireless communication (604). In the case of a broadcast frame, in addition to the frame to be forwarded, 604 may be performed for the frame not to be forwarded. In the case of a frame to be forwarded, a frame including a MAC header for wireless communication is created, and a frame header for wired communication between AP101 and AP103 is added to this (605). At this time, it is confirmed whether the maximum frame length for wired communication is exceeded (606). If it exceeds, the frame is divided (607). If it does not exceed, the frame is created as is (608). A packet number and a sequence number are assigned to the created frame. The frame is also encrypted using the packet number and a shared key held by AP104. The created frame is transmitted to AP101 and AP103 via wired communication (609). In addition, AP104 may create a frame for wireless communication by adjusting the length of the data frame in advance to prevent frame division.

[0055] FIG. 7 shows the flow of processing when AP101 receives a data frame from AP104 and transfers it to STA102. This processing is started when AP101 starts functioning as an AP, such as when the power of AP101 is turned on, when AP101 receives an instruction to operate as an AP, or when the wireless function is turned on. In the embodiment, only STA102 is connected, but multiple units may be connected at the same time. This processing is considered to be similar to the flowchart of FIG. 4, with AP101, AP104, and AP103 operating as an integrated AP when viewed from STA102, and settings to operate as an Upper AP and a Lower AP being completed in advance. In addition, in this embodiment, it is assumed that STA102 and AP101 are connected to take into consideration the transfer of data frames, but this is not the case when transferring management frames. This processing may be performed from the point where STA102 connects to AP101.

[0056] The AP101 checks whether data has been received from the AP104 (701). When a frame is received from the AP104, it checks whether the STA needs to forward the frame (702). If the frame was sent from the AP104 to the AP101, it does not need to be forwarded, so it analyzes and processes the frame itself (703). If the frame is addressed to a connected STA, it prepares to forward the frame to the specified STA. First, it analyzes the Ethernet MAC header used for wired communication among the frames received from the AP104 (704). The frame received from the AP104 has a configuration shown in FIG. 9, which will be described later, for example. If there is insufficient information in the MAC header for wireless communication depending on the type of frame, it is necessary to add the missing information when transmitting the frame via wireless communication. It analyzes the Ethernet MAC header and checks whether the frame is divided (705). If it is divided, it consolidates the frames and then creates a data frame (706). If it is not divided, it starts creating the data frame as it is (707). When the analysis of the data frame is finished, the Ethernet MAC header used for wired communication is discarded.

[0057] Finally, if a MAC header for wireless communication is sent from the AP 104, it is forwarded as is, and if there is missing information, that information is added to the MAC header for wireless communication and then transmitted (708).

[0058] FIG. 8 shows an example of the data frame flow shown in FIG. 4 to FIG. 7. The data frame transmitted from STA102 is forwarded by AP101 (801), and is transmitted from AP101 to AP104 via wired connection (802). The data frame transmitted from AP104 via wired connection (803) is also forwarded by AP101 and transmitted to STA102 via wireless communication (804). The frames transmitted here include not only data frames, but also Ack frames indicating that the data frame has been received, management frames used for disconnecting the connection, and action and control frames for facilitating data communication. As can be seen from the above frame flow, communication is performed between the Upper AP (AP104) and the Lower AP (AP101), and when viewed from STA102, AP101 and AP104 appear to operate as a single AP.

[0059] FIG. 9 shows an example of a frame when performing wired communication between the AP 101 and the AP 104. In FIG.

[0060] This is a frame configuration with a new wired MAC header added. Frame Control field 901 to Frame Body field 911 are the frame itself received from STA 102 via wireless communication. MAC headers 920 to 922 defined in Ethernet are added here.

[0061] An example of a frame when data is sent from the STA 102 to the AP 104 via the AP 101 will be described.

[0062] The Frame Control field 901 defines the type of frame used in wireless communication. For example, data frames and management frames can be identified here. The Duration field 902 indicates how long the channel is occupied in wireless communication. The A1 field 903 indicates the destination MAC address in wireless communication. In this embodiment, it indicates the MAC address of the AP 101. The A2 field 904 indicates the source MAC address in wireless communication. In this embodiment, it indicates the MAC address of the STA 102. Since the AP 104 uses the information in the A2 field 904 to decrypt the contents of the encrypted data frame, the AP 101 needs to transfer it to the AP 104. If the A2 field is not transferred as is, information is input to the source MAC address field 921 for wired communication. The values ​​of the A3 field 905 and the A4 field 907, including their presence or absence, differ depending on the type and direction of the frame used. The BSSID (Basic Service Set Identifier) ​​and the MAC address of the destination server are entered. The Sequence Control field 906 indicates the sequence number of the frame. Each time a frame of the same type is transmitted, the value of the field is incremented. The QoS (Quality of Service) field 908 contains information related to QoS, such as the frame's TID and Ack Policy. The HT Control field 909 contains additional information for wireless communication. The CCMP (Counter mode with CBC-MAC Protocol) Header field 910 contains a packet number required for encryption and decryption of data frames. The Frame Body field 911 contains the contents of the encrypted data and information related to connection and disconnection.

[0063] The FCS (Frame Check Sequence) field 912 is a field for detecting frame errors. In this embodiment, the AP 101 checks the FCS value when transferring a frame from the AP 101 to the AP 104. The FCS field 912 may transfer the value received by wireless communication to the wired communication as is, and a new FCS field for wired communication may be added to the end. In this embodiment, the wireless communication is not transferred during wired communication, and a new FCS value for wired communication is calculated and added. In other words, wireless communication error detection is performed within the AP 101.

[0064] The destination MAC field 920 indicates a destination MAC address in wired communication. In this embodiment, it is the MAC address of AP 104. The source MAC field 921 indicates a source MAC address in wired communication. In this embodiment, it is the MAC address of AP 101. However, the value entered in this field may be the MAC address of STA 104. The Type field 722 is a frame type specified in wired communication. Instead of this field, it may be a field indicating the frame length. Note that the frame to be transferred may be encrypted except for the wired MAC headers 920 to 922.

[0065] (Other embodiments) In this embodiment, all the MAC headers of wireless communication are communicated between AP101 and AP104, but this is not limited. For example, among the MAC headers of wireless communication, the destination MAC address 903, the source MAC address 904, the A3 field 905, and the A4 field 907 do not need to be transferred. This makes it possible to keep the frame length short. Also, by not transferring the HT Control field 909, the AP101 can determine the state of the wireless channel in the wireless communication and transmit and receive. Alternatively, by not transferring the Duration field 902, the AP101 can adjust and change the MCS (Modulation and Coding Scheme) of the data rate. Since the encryption and decryption of messages are performed by the AP104, which is the upper AP, the Sequence Control field needs to be transferred. Also, in order to identify the type of frame, the Frame Control field 901 needs to be transferred. On the other hand, if the Type field and the Subtype field of the Frame Control field 901 are transferred, the type of frame can be determined, so only these subfields may be transferred.

[0066] A recording medium on which the program code of the software for realizing the above-mentioned functions is recorded may be supplied to the system or device, and the computer (CPU, MPU) of the system or device may read and execute the program code stored in the recording medium. In this case, the program code itself read from the storage medium will realize the functions of the above-mentioned embodiments, and the storage medium on which the program code is stored will constitute the above-mentioned device.

[0067] Examples of storage media for supplying the program code include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs.

[0068] In addition, the above-mentioned functions may be realized not only by the computer executing the read program code, but also by the OS running on the computer performing all or part of the actual processing based on the instructions of the program code. OS is an abbreviation for Operating System.

[0069] Furthermore, the program code read from the storage medium may be written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, and a CPU provided in the function expansion board or function expansion unit may perform part or all of the actual processing based on instructions in the program code to realize the above-mentioned functions.

[0070] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0071] The disclosure of this specification includes the configurations described in the following items.

[0072] (Item 1) 1. A communication device, comprising: A communication means for receiving a wireless frame conforming to IEEE802.11; a header acquisition means for acquiring a header from the wireless frame; a frame generating means for generating a new frame by placing a part or all of the acquired header after a header conforming to Ethernet, and further placing a frame body of the received wireless frame after the header; another communication means for transmitting the new frame to another communication device; A communication device comprising:

[0073] (Item 2) 1. A communication device, comprising: A communication means for receiving frames conforming to Ethernet; a header acquisition means for acquiring a header conforming to IEEE 802.11 in the frame; a frame generating means for generating a new frame conforming to IEEE 802.11 using a part or all of the acquired header; another communication means for transmitting the new frame to another communication device; A communication device comprising:

[0074] (Item 3) 3. The communication device according to item 1 or 2, wherein the header is a MAC header defined in IEEE 802.11.

[0075] (Item 4) 4. The communication device according to any one of items 1 to 3, wherein the header includes a Frame Control field defined in IEEE 802.11.

[0076] (Item 5) 5. The communication device according to any one of items 1 to 4, wherein the header includes a QoS field defined in IEEE 802.11.

[0077] (Item 6) 6. The communication device according to any one of items 1 to 5, wherein the header includes a Sequence Control field defined in IEEE 802.11.

[0078] (Item 7) 7. The communication device according to any one of items 1 to 6, wherein the header includes a CCMP Header field defined in IEEE 802.11.

[0079] (Item 8) 8. The communication device according to any one of items 1 to 7, wherein the communication device is an AP (Access Point) conforming to IEEE802.11.

[0080] (Item 9) 9. The communication device according to any one of items 2 to 8, wherein the frame generating means discards a header that complies with Ethernet.

[0081] (Item 10) The other communication device, A communication means for receiving the new frame; means for parsing a part or all of the IEEE 802.11 compliant header in the new frame; and a means for decrypting a part or the whole of the frame based on a packet number included in the frame conforming to IEEE802.11 and a shared key held by the other communication device from the analysis result. The communication device according to items 1, 3 to 9 (Item 11) 1. A method for controlling communications, comprising: A communication step of receiving a wireless frame conforming to IEEE 802.11; a header acquisition step of acquiring a header from the wireless frame; a frame generating step of generating a new frame by placing a part or all of the acquired header after a header conforming to Ethernet, and further placing a frame body of the received wireless frame after the header; another communication step of transmitting the new frame to another communication device; A control method comprising the steps of:

[0082] (Item 12) 1. A method for controlling communications, comprising: a communication step of receiving a frame conforming to Ethernet; a header acquisition step of acquiring a header conforming to IEEE 802.11 in the frame; a frame generation step of generating a new frame conforming to IEEE 802.11 using a part or all of the acquired header; another communication step of transmitting the new frame to another communication device; A control method comprising the steps of:

[0083] (Item 13) A program for causing a computer to operate as the communication device according to any one of items 11 and 12. [Explanation of symbols]

[0084] 201 Storage section 202 Control section 203 Functional Department 204 Input section 205 Output section 206 Wired Communications Department 207 Wireless Communication Department

Claims

1. 1. A communication device, comprising: A communication means for receiving a wireless frame conforming to IEEE 802.11; a header acquisition means for acquiring a header from the wireless frame; a frame generating means for generating a new frame by placing a part or all of the acquired header after a header conforming to Ethernet, and further placing a frame body of the received wireless frame after the header; another communication means for transmitting the new frame to another communication device; A communication device comprising:

2. 1. A communication device, comprising: A communication means for receiving a frame conforming to Ethernet; a header acquisition means for acquiring a header conforming to IEEE 802.11 in the frame; a frame generating means for generating a new frame conforming to IEEE 802.11 using a part or all of the acquired header; another communication means for transmitting the new frame to another communication device; A communication device comprising:

3. 3. The communication device according to claim 1, wherein the header is a MAC header defined in IEEE 802.

11.

4. 3. The communication device according to claim 1, wherein the header includes a Frame Control field defined in IEEE 802.

11.

5. 3. The communication device according to claim 1, wherein the header includes a QoS field defined in IEEE 802.

11.

6. 3. The communication device according to claim 1, wherein the header includes a Sequence Control field defined in IEEE 802.

11.

7. 3. The communication device according to claim 1, wherein the header includes a CCMP Header field defined in IEEE 802.

11.

8. 3. The communication device according to claim 1, wherein the communication device is an AP (Access Point) conforming to IEEE802.

11.

9. 3. The communication device according to claim 2, wherein said frame generating means discards a header conforming to Ethernet.

10. The other communication device, A communication means for receiving the new frame; means for parsing a part or all of the IEEE 802.11 compliant header in the new frame; and a means for decrypting a part or the whole of a frame based on a packet number included in the frame conforming to IEEE 802.11 and a shared key held by the other communication device from the analysis result. The communication device according to claim 1 .

11. 1. A method for controlling a communication device, comprising: A communication step of receiving a wireless frame conforming to IEEE 802.11; a header acquisition step of acquiring a header from the wireless frame; a frame generating step of generating a new frame in which a part or all of the acquired header is placed after a header conforming to Ethernet, and a frame body of the received wireless frame is further placed after the header; another communication step of transmitting the new frame to another communication device; A control method comprising the steps of:

12. 1. A method for controlling a communication device, comprising: a communication step of receiving a frame conforming to Ethernet; a header acquisition step of acquiring a header conforming to IEEE 802.11 in the frame; a frame generating step of generating a new frame conforming to IEEE 802.11 using a part or all of the acquired header; another communication step of transmitting the new frame to another communication device; A control method comprising the steps of:

13. A program for causing a computer to operate as the communication device according to claim 11 or 12.

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