Communication control device

Abstract

[Problem] To provide a communication device capable of performing communication using a non-primary channel even if a primary channel is being used. [Solution] A communication control device according to the present disclosure comprises a first control unit that controls a first wireless communication unit included in a first communication device, the first wireless communication unit performing wireless communication with a second communication device via one or more access channels. The first control unit controls the first wireless communication unit such that the first wireless communication unit transmits a first frame to the second communication device and in response to reception of a second frame serving as a response to the first frame, transmits a third frame including first data to the second communication device. The first frame includes information relating to the type of the first data.

Description

Communication control device

[0001] The present disclosure relates to a communication control device.

[0002] In a wireless LAN (Local Area Network) communication system, for each access category (AC) by EDCA (Enhanced distributed channel access), a technique is adopted in which an arbitration interframe space (AIFS) and the set value of a contention window (CW) are set with a difference to preferentially transmit specific application data.

[0003] In this technique, when a collision occurs in data transmission between two communications, the length of the CW is doubled and a backoff time is set. By setting such a backoff time, it is devised so that data with a higher priority is transmitted preferentially over other data.

[0004] Japanese Unexamined Patent Application Publication No. 2009-094733

[0005] In an environment where a large number of communication devices are accommodated in a network, and when there are communication devices that hold data of the same AC, there is a high possibility that the set value of the CW will become exactly the same, and it is assumed that transmissions will start simultaneously.

[0006] At this time, if a collision occurs again, the length of the CW will be further doubled during retransmission, and the backoff time will increase exponentially, and it may also happen that data with a lower priority is interrupted first.

[0007] Also, when it is desired to transmit data with low latency and a large capacity, since the data length becomes long, it takes time to detect a collision by the return of a Block ACK frame exchanged after data transmission.

[0008] The techniques described above are for improving data transmission efficiency. After changing the transmission rate of the communication device, aggregation is prohibited for a predetermined period. There is also a description of the case where the communication device receives an ACK after transmitting an MPDU (MAC Layer protocol data unit) that has not been aggregated, and the case where it receives a Block ACK frame after transmitting an aggregated A-MPDU (aggregate MPDU), but the relationship between these two cases is not described.

[0009] Therefore, in view of these issues, this disclosure provides a communication control device that can detect collisions in a short time and enable efficient data transmission, even when backoff conflicts occur.

[0010] The communication control device of this disclosure includes a first wireless communication unit included in a first communication device, and a first control unit that controls the first wireless communication unit which performs wireless communication with a second communication device over one or more access channels, wherein the first control unit controls the first wireless communication unit to transmit a first frame to the second communication device and, in response to receiving a second frame which is a response to the first frame, transmit a third frame containing first data to the second communication device, and the first frame contains information regarding the type of the first data.

[0011] This shows an example of the overall configuration of the wireless communication system in this embodiment. This is a diagram illustrating an example of setting AIFS and CW for each AC using EDCA in the wireless communication system. This is another diagram illustrating an example of setting AIFS and CW for each AC using EDCA in the wireless communication system. This is a diagram illustrating access control of the STA in this embodiment. This is another diagram illustrating access control of the STA in this embodiment. This is a diagram illustrating access control of the STA in a comparative example. This is another diagram illustrating access control of the STA in a comparative example. This is yet another diagram illustrating access control of the This is the first example of the frame format of the response frame in this embodiment. This is the second example of the frame format of the response frame in this embodiment. This is the third example of the frame format of the response frame in this embodiment. This is the fourth example of the frame format of the response frame in this embodiment. This is an example of a flowchart showing the operation of the data transmitting device in this embodiment. This is an example of a flowchart showing the operation of the data receiving device in this embodiment. This is a diagram illustrating the access control of the STA in a modified example of this embodiment. This is another diagram illustrating the access control of the STA in this embodiment. This is an example of a sequence diagram of access control in a modified example of this embodiment.This is a block diagram showing an example of the hardware configuration of a computer that executes a series of processes according to this embodiment by program. This is a block diagram showing a schematic configuration example of a smartphone to which this embodiment is applied. This is a block diagram showing an example of a schematic configuration of an in-vehicle device to which this embodiment is applied. This is a block diagram showing an example of a schematic configuration of a wireless AP to which this embodiment is applied.

[0012] Embodiments of this disclosure will be described in detail below with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate. The drawings are simplified, and any other components necessary for implementation will be appropriately provided in addition to those shown in the drawings. Furthermore, when terms such as "first," "second," etc. are used in this specification or the claims, unless otherwise specified, they do not indicate any order or importance, but are used to distinguish one configuration from another.

[0013] Figure 1 shows an example of the overall configuration of the wireless communication system 200 in this embodiment.

[0014] The wireless communication system 200 in Figure 1 is an autonomous distributed control type system equipped with AP100 and STA1-3, and is a wireless LAN system conforming to the IEEE 802.11 standard, such as IEEE 802.11a / b / g / n / ac / ax / be / bn or its successor standards. In this embodiment, terminal devices conforming to the IEEE 802.11 standard, such as STA1-3 which are equivalent to terminals and AP100 which is equivalent to a base station, and wireless LAN base stations are described as examples of communication devices. Furthermore, among the non-AP STAs (also simply referred to as STA) described below, STA1 and 2 which perform data transmission are examples of first communication devices, and AP is an example of second communication devices. Furthermore, among the STAs, STA3 which suppresses its own terminal transmission in response to data transmission by STA1 and 2 is an example of a third communication device.

[0015] The data used for data transmission may, for example, be data generated at the application layer in the OSI reference model. Alternatively, the data used for data transmission may be data stored in the Frame body of a Data frame, which is defined as one of the frames in the MAC layer of the IEEE standard. Furthermore, the first and second data described later are transmitted or received in Data frame format.

[0016] This diagram shows an example where three STAs (STA1-STA3) are connected to one AP100. AP100 can connect to more STAs than this number, and communication with these many communication terminals operates according to a predetermined algorithm.

[0017] A link refers to a physical path between each STA and AP100 that can transmit MAC Service Data Units (MSDUs). Links formed to different STAs are treated as separate links.

[0018] In the wireless communication system 200, each link used by an STA may be a channel selected from the same frequency band, or it may be a channel selected from different frequency bands. Furthermore, AP 100 and STAs 1-3 may be multi-link devices (also called MLDs) capable of Multi-Link Operation using links in different frequency bands. In this case, the number of links used between AP 100 and each STA is not limited to one, but may be two or more links used for communication. The links described above are examples of access channels.

[0019] Figure 2 illustrates an example of setting AIFS and CW for each AC using EDCA in the wireless communication system 200.

[0020] In the wireless communication system 200, differences are set in the AIFS and CW settings for each AC in EDCA, employing a technology that prioritizes the transmission of data belonging to a specific access category.

[0021] For AC_VO data, the STA sets a backoff time between 0 and 3, with AIFS = 2 and CW min (the minimum value for CW) being 3. If no transmissions are received from other terminals before the backoff time ends, the STA gains access control rights and can transmit data.

[0022] For AC_VI data, with AIFS = 2 and CW min = 7, the STA sets a backoff time between 0 and 7. If no transmissions are received from other terminals before the backoff time ends, the STA acquires access control rights and can transmit data.

[0023] For AC_BE data, with AIFS = 3 and CW min = 15, the STA sets a backoff time between 0 and 15. If no transmissions are received from other terminals before the backoff time ends, the STA acquires access control rights and can transmit data.

[0024] For AC_BK data, the STA sets a backoff time between 0 and 15, with AIFS = 7 and CW min = 15. If no transmissions are received from other terminals before the backoff time ends, the STA gains access control rights and can transmit data.

[0025] In the case of non-QoS data that does not use this mechanism, in addition to DIFS (Distributed Interframe Space), a backoff time is set by the STA between 0 and 15, with a minimum CW value of 15. If no transmissions are received from other terminals before the backoff time ends, the STA acquires access control rights and can transmit data.

[0026] Figure 3 is another diagram illustrating an example of setting AIFS and CW for each AC using EDCA in the wireless communication system 200.

[0027] After the aforementioned backoff time has ended, the STA transmits data, and if a collision occurs with another STA, the data transmission is retransmitted. At this time, the STA sets the backoff time again, but the CW is configured to increase the backoff time from the CW min length before the collision to the CW max length.

[0028] In other words, in the case of AC_VO data, CW is expanded to a length of 7, which is the CW max; in the case of AC_VI, CW is expanded to a length of 15, which is the CW max; and in the case of AC_BE data, CW is expanded to a length of 31, which is the CW max.

[0029] For AC_BK and Non-QoS data, CW is extended to 31, which is about twice the length of CW min. If a collision occurs, it can be further extended to a maximum of 1023, the length of CW max, causing the CW setting to increase exponentially.

[0030] With this backoff setting, data belonging to higher-priority ACs will be transmitted preferentially over data belonging to lower-priority ACs.

[0031] However, in an environment where a large number of STAs are located within the network, and multiple STAs hold data belonging to the same AC, there is a high probability that the CW setting value will be exactly the same, and data transmission may start simultaneously between multiple STAs. When transmitting long data frames, such as large data volumes, detection takes time, and depending on the CW setting value during retransmission, it is conceivable that data belonging to a lower AC may be sent to AP100 first. Therefore, in this embodiment, after the backoff time ends, the STA first sends a short data frame to AP100 that does not require time for collision detection, and if the communication is successful, it sends the long data, which is the actual transmission data, to AP100. This control, which performs collision detection using a short data frame in this embodiment (Single Data Backoff control), will be explained below.

[0032] In the following, the short data used for collision detection will also be referred to as Single Data. The longer data transmitted after collision detection will also be referred to as Multiple Data. These frame formats will be described later. Multiple Data is an example of the first data.

[0033] Figure 4 illustrates the access control of STA in this embodiment.

[0034] In this embodiment, we will explain an example in which STA1 and STA2 transmit data belonging to high-priority AC to AP100, and STA3 transmits data belonging to low-priority AC to AP100. In this figure, the horizontal axis represents the time axis, and the time changes as you move from left to right. In this figure, the transmitted data is shown as an upward-convex rectangle, and the length along the time axis represents the length of the data. In other words, the longer the data length, the longer the horizontal dimension, and the shorter the data length, the shorter the horizontal dimension.

[0035] Furthermore, the parallelograms present before data transmission indicate the time corresponding to the backoff setting. In other words, the more parallelograms there are, the longer the backoff time for that STA, and the fewer parallelograms there are, the shorter the backoff time. The number of these parallelograms represents the number of backoff counters, and each terminal decrements the backoff counter set for its device every predetermined time. When the number of backoff counters reaches zero, the backoff time ends, and the terminal can send a short data frame to AP100.

[0036] Furthermore, a downward-curving rectangle indicates that a signal is being detected from another communication device, and this state is treated as "Busy" on the transmission path.

[0037] In this embodiment, after the backoff time has ended, the STA sends a short data frame (for example, a "Data frame" as defined in the IEEE 802.11 standard) to the AP 100 to detect a collision with another terminal in a short time. If a collision is detected, access control is performed again by random backoff. If the transmission of the short data frame is successful, the STA then sends a long data frame (for example, a "Data frame" as defined in the IEEE 802.11 standard) to the AP 100.

[0038] Collision detection is performed by determining whether the STA receives a signal containing a response frame, such as a Block ACK. For example, if the STA does not receive a response frame within the timeout period, the STA detects that a collision has occurred. By using short data frames, the STA can shorten the timeout period before collision detection, thus enabling earlier detection of collisions.

[0039] Figure 4 shows an example where STA1 and STA2 transmit data belonging to AC with a relatively higher priority, and STA3 transmits data belonging to AC with a relatively lower priority.

[0040] Furthermore, in this diagram, STA1 and STA2 have the same backoff time set, and a collision occurs when both terminals transmit data after the backoff time has ended, following the acquisition of access control rights. In other words, AP100 detects signals above a predetermined level due to transmissions from both sides, but it is unable to correctly combine this information, resulting in no response frame being sent. The lower convex dashed line in the diagram indicates that AP100 could not receive a response frame.

[0041] On the other hand, STA3 is attempting to transmit data belonging to an AC with a lower priority. When STA3 receives a signal transmitted upon acquisition of access control rights by STA1 or 2, it once stops subtracting the random backoff counter and sets a NAV (Network Allocation Vector) for the time indicated by this signal at its own terminal to perform transmission suppression.

[0042] After a collision occurs, STA1 and 2 set a random backoff time again. At this time, if different backoff times are set between STA1 and STA2, collisions of data belonging to the same AC can be prevented. In this figure, the backoff time set by STA1 is shorter than that of STA2. After acquiring access control rights, STA1 retransmits a short data frame and transmits a long data frame after receiving a response frame from AP100. The response frame is transmitted from AP100, for example, by broadcast, and terminals other than STA1 that receive this frame set a NAV at their own terminals based on the information contained in this frame.

[0043] After receiving a long data frame, AP100 may transmit a Block ACK frame as necessary. Each terminal can know that the transmission of the long data frame by STA1 has been completed by receiving the Block ACK frame.

[0044] Also, a NAV may be set at STA1 after receiving the Block ACK frame. For example, the setting of the NAV is performed for the time until receiving a Block ACK frame associated with the transmission of a long data frame by STA2. Thereby, collisions of data with STA2 can be avoided. Also, it can prevent STA1 from continuously performing data transmission and ensure an opportunity for other terminals to perform data transmission.

[0045] After receiving the Block ACK frame, STA2 and STA3 start subtracting the backoff counter again. In this example, STA2 whose backoff counter reaches 0 acquires the access control right earlier than STA3 and transmits a short data frame to AP100 again. After receiving the response frame, STA2 transmits a long data frame to AP100.

[0046] Similar to the above operation, when STA3 receives the response frame transmitted from AP100 accompanying the transmission of the short data frame by STA2, STA3 sets the NAV for its own terminal. STA3 can know the completion of the transmission of the long data frame by STA2 through receiving the Block ACK frame, and after receiving this signal, it starts subtracting the backoff counter again. When the backoff counter reaches 0, STA3 transmits the data belonging to the AC with lower priority to AC100.

[0047] In the example of FIG. 4, the operation is that the STA transmits a short data frame, and after the transmission of the data is completed, it transmits a long data frame accompanying the reception of the response frame. However, in the access control in this embodiment, it may be determined whether or not it is implemented according to the AC. For example, for the data belonging to the AC with low priority, a configuration may be adopted in which the data transmission is started as usual after the end of the backoff time without transmitting the short data frame as in this embodiment. Also, not limited to the AC, it may be determined whether or not the access control in this embodiment is implemented according to the type of the transmitted data.

[0048] Also in this case, after the data transmission by STA3 is completed, AP100 may transmit the Block ACK frame to each terminal.

[0049] Hereinafter, the short data frame is also referred to as the first frame, and the response frame of the first frame is also referred to as the second frame. Also, the long data frame is also referred to as the third frame, and the Block ACK frame serving as the response of the third frame is also referred to as the fourth frame.

[0050] Figure 5 is another diagram illustrating the access control of the STA in this embodiment.

[0051] In this diagram, STA1 and STA2 are set to have different backoff times. Because STA1 has a shorter backoff time, STA1 sends a shorter data frame to AP100 before STA2. This example shows a case where no collision occurs between STA1 and STA2.

[0052] Thus, if no data collision occurs between STA1 and STA2, STA1 will send a short data frame, wait for a response frame from AP100, and then send a longer data frame. However, since this time is short, data transmission can be performed without reducing efficiency.

[0053] Figure 6 illustrates the access control of STA in a comparative example.

[0054] This diagram illustrates an example where, with the EDCA backoff setting in the comparative example, data belonging to a lower-priority AC is transmitted before data belonging to a higher-priority AC. In the comparative example, after the backoff time ends, a long data frame is not transmitted, but a long data frame is transmitted to AC100.

[0055] If STA1 and STA2 each set the same value for backoff time, the data transmitted from their respective terminals will collide. After a data collision occurs, if a longer backoff time is set for retransmission, the backoff time for STA3, which holds the data belonging to the lower-priority AC, will end first, and this data will be transmitted to AC100 before the data belonging to the higher-priority AC. Upon acquiring access control rights for STA3, STA1 and STA2 set NAV on their own terminals.

[0056] After STA3 completes data transmission, STA1 and STA2 begin decrementing their backoff counters again. In this example, STA1, whose backoff time has finished first, begins data transmission. At this time, STA2 sets NAV on its terminal. Similarly, after STA1 completes data transmission, STA2 begins decrementing its backoff counter and transmits data after the backoff time has ended.

[0057] Figure 7 is another diagram illustrating the access control of STA in a comparative example.

[0058] This figure shows an example where, in the comparative example, the STA performs acknowledgment of receipt of a Block ACK frame or the like, sent from AP100, with the EDCA backoff setting.

[0059] If STA1 and STA2 start transmitting data simultaneously, a collision will occur. When a collision occurs, the MAC header portions embedded in the headers of the data transmitted from STA1 and STA2 will also collide. As a result, AP100 may not be able to recognize that the data is addressed to itself, and may not be able to send a Block ACK frame correctly.

[0060] Figure 8 is yet another diagram illustrating access control in a comparative example.

[0061] This diagram illustrates an example where STA1 and STA2 are set to the same backoff time, and after a collision occurs, the end of the backoff time set by STA2 when retransmitting data coincides with the end of the backoff time set by STA3, resulting in a collision of data transmitted by these terminals. In this way, when a collision occurs in retransmitted data, a second retransmission is performed with an even longer backoff time, leading to an unnecessarily increased backoff time.

[0062] Figure 9 illustrates the access control of AP100 in a comparative example.

[0063] In this diagram, AP100 performs acknowledgment of received data using a Block ACK frame. STA1 and STA2 are given the same backoff time, and after a collision occurs due to simultaneous data transmission from both terminals, each terminal sets a new backoff time for data retransmission. This diagram illustrates an example where the end of the backoff time set by STA1 and the end of the backoff time set by STA3 coincide, resulting in a data collision between these terminals. Since data belonging to low-priority ACs has a large CW max value set, frequent retransmissions of such data will cause the backoff time to increase exponentially.

[0064] Figure 10 is a block diagram showing an example of the configuration of the communication device in this embodiment.

[0065] In this diagram, AP100 is used as the communication device, but STA1 has a similar configuration. The communication device in this embodiment includes an internet connection module 11, an information input module 12, an equipment control module 13, an information output module 14, and a wireless communication module 15. This configuration is just one example, and other modules may be used depending on the type of communication device, and unnecessary modules may be simplified or omitted.

[0066] The internet connection module 11 is configured to implement functions such as a communication modem for connecting to the internet network, for example, when AP 100 is operating as an access point. In other words, the internet connection module 11 is configured to perform internet connectivity via a public communication line and an internet service provider. The internet connection module 11 is an example of an internet connection unit.

[0067] The information input module 12 receives input of information that conveys instructions from the user. The information input module 12 may be configured as, for example, a push button or a keyboard, or it may receive input of information via a user interface such as a GUI, in which case it may be configured as a touch panel or the like. The information input module 12 is an example of an information input unit.

[0068] The device control module 13 controls the desired communication device to operate as an access point. The device control module 13 is an example of a device control unit.

[0069] The information output module 14 displays the operating status of the communication device and information obtained via the internet. The information output module 14 consists of display elements such as LED displays, liquid crystal panels, and organic EL displays, as well as speakers that output sound and music, and outputs information to the user according to a pre-programmed output method. The information output module 14 is an example of an information output unit.

[0070] The wireless communication module 15 performs wireless communication processing. The wireless communication module 15 is, for example, a package that implements wireless communication functionality, and supports one or more of the IEEE 802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be and subsequent wireless LAN standards equivalent to these, and performs wireless communication. A detailed block diagram of the wireless communication module 15 will be described later. The wireless communication module 15 is an example of a wireless communication unit.

[0071] Figure 11 is an example of a block diagram showing the configuration of the wireless communication module 15 in this embodiment.

[0072] The wireless communication module 15 includes an interface 101, a data buffer 102, a backoff management unit 103, a Single / Multiple Data control unit 104, a transmission data construction unit 105, an access control unit 106, a transmission signal processing unit 107, an antenna control unit 108, a reception signal processing unit 109, a reception data extraction unit 110, and a Multiple Data Duration determination unit 111. AP100 and STA1 are also composed of similar blocks.

[0073] Furthermore, in this package, the functional blocks of the backoff management unit 103, Single / Multiple Data control unit 104, transmission data construction unit 105, transmission signal processing unit 107, antenna control unit 108, reception signal processing unit 109, reception data extraction unit 110, and Multiple Data Duration determination unit 111 are also referred to as control units. The control units are implemented, for example, by controlling a chip composed of one or more LSIs. Hereinafter, the chip and communication device that control the wireless communication module 15 will be collectively referred to as a communication control device.

[0074] Interface 101 connects the wireless communication module 15 to other modules (for example, the equipment control module 13). Application data to be transmitted and application data received are stored in a data buffer 102, which is composed of memory and the like.

[0075] The backoff management unit 103 sets a random backoff time and manages this time when implementing access control in this embodiment. The Single / Multiple Data control unit 104 switches between transmitting Single Data and Multiple Data in order to implement access control in this embodiment.

[0076] The transmission data construction unit 105 constructs the data frame to be actually transmitted. The access control unit 106 performs access control for signal transmission based on the received signal and the set backoff time. The transmission signal processing unit 107 constructs the transmission signal according to the data frame to be transmitted.

[0077] The antenna control unit 108 performs control to transmit a transmission signal from the antenna in the transmitting side control. The antenna control unit 108 also performs control to receive a reception signal from the antenna in the receiving side control. Furthermore, depending on the type of communication device, such as a smartphone, the antenna control unit 108 may be connected to the antenna. Alternatively, the antenna control unit 108 may be connected to the antenna via an amplifier.

[0078] The received signal processing unit 109 notifies the access control unit of the signal level detected from the received signal. When the access control unit 106 detects the received signal as a predetermined preamble signal, the received data extraction unit 110 decodes the received signal and extracts it as data or other information. The received data is stored in the data buffer 102.

[0079] The Multiple Data Duration determination unit 111, upon receiving a short data frame via the antenna control unit 108, analyzes parameters indicating the data length information of the long data and calculates a period (duration) (Multiple Duration) based on the time required to transmit the signal containing the long data frame. The Multiple Data Duration determination unit 111 transmits a response frame containing the Multiple Duration information calculated by AP 100 to STA1-3 via the Single / Multiple Data control unit 104.

[0080] In the example described above, STA1 and STA2 transmit a short data frame to AP100 using their transmitting functional blocks (transmit data construction unit 105, transmit signal processing unit 107, and antenna control unit 108, etc.), and then receive a response frame from AP100 using their receiving functional blocks (antenna control unit 108, received signal processing unit 109, and received data extraction unit 110, etc.). After receiving the response frame, STA1 and STA2 transmit a longer data frame using their transmitting functional blocks.

[0081] Furthermore, if the communication device is an MLD, the wireless communication module may be configured to perform wireless communication using n access channels (where n is an integer of 1 or more) for communication.

[0082] The wireless communication unit included in the first communication device described above is also called the first wireless communication unit, and the control unit that controls it is also called the first control unit. Similarly, the wireless communication unit included in the mth communication device (where m is an integer of 1 or more) is also called the mth wireless communication unit, and the control unit that controls it is also called the mth control unit.

[0083] Figure 12 shows an example of the parameter exchange sequence when implementing access control by STA1 and AP100 in this embodiment.

[0084] In this embodiment, the identification information used when performing control is called a parameter. This example describes the parameter exchange sequence between STA1 and AP100, but the parameter exchange between STA2 to STA4 and AP100 follows a similar sequence. For example, when STA1 is associated, STA1 and AP100 exchange a Single Data Backoff Control Information Element as one of the parameters exchanged. Specifically, STA1 sends a Single Data Backoff Control Request to AP100, which includes a request for control that performs collision detection using short data after backoff. After receiving this request, AP100 sends a Single Data Backoff Control Response to STA1 as a response, which includes information indicating whether or not to perform this control.

[0085] Furthermore, these parameters may be exchanged as arbitrary action frames, for example, when a large-capacity application is started on STA1 or AP100. Parameter exchange is not limited to the examples described above. Parameter exchange is achieved by sending some request from one communication device to the other communication device to implement the access control described in this embodiment, and by sending a response from the other communication device to the first communication device containing parameter information available to the other communication device, prior to the transmission and reception of the short data frames described above.

[0086] Figure 13 shows an example of an information element that describes the parameters used in access control in this embodiment (parameters exchanged in the parameter exchange sequence described above).

[0087] The Single Data Backoff Control Information Element includes Element Type, which indicates the type of element; Length, which indicates the length of the data; Sub Type, which indicates the subtype of the element; and Single Data Backoff Parameters, which are various parameters. The Single Data Backoff Parameters include EDCA Control, which indicates the control information of the EDCA access category; Backoff Type, which indicates the format of the backoff; Backoff Control, which lists the parameters controlled by the backoff; Single Data Type, which indicates the format of the short frame; Response Format, which indicates the format of the response frame; After Waiting, which indicates that the system waits until the other party's communication is completed after a collision occurs; MAX TXOP Duration, which indicates the maximum duration of the transmit opportunity (TXOP); Application Type, which indicates the type of application that will be given priority for transmission; Single Data Duration, which indicates the period (duration) based on the time required to transmit a signal containing a short data frame; Access Category, which indicates the type of access category; Low Latency Data, which indicates that the data is low latency; and Real Time Data, which indicates that the data is real time. The duration based on the time required to transmit a signal including frames may be only the time required to transmit a signal including short data frames, or it may be the sum of the time required to transmit a signal including short data frames and the time required to transmit a response signal (Ack, Block Ack, or Multi-STA Block Ack), or it may be the sum of a certain time interval between frames, such as SIFS (Short Interframe Space), for a number of applicable minutes.

[0088] Information regarding whether or not to implement collision detection control using short data may be described, for example, in a Subtype.

[0089] The parameters to be included in the information element are not limited to the examples shown in this figure. Any parameters are acceptable as long as STA1 and AP100 initiate access control in this embodiment based on a control request and response to a collision detection request using short data after backoff.

[0090] Figure 14 is an example of an access control sequence diagram in this embodiment.

[0091] This sequence diagram shows the operation of access control in this embodiment from top to bottom, following the progression of time, focusing on STA1 to STA3 and AP100. Furthermore, this sequence diagram will explain the operation following Figure 4.

[0092] Similar to the case in Figure 4, if the same value is set as the backoff time setting for both STA1 and STA2, both will send a short data frame (labeled as Single Data Frame in the figure) to AP100 at the same time after the backoff time has ended.

[0093] If no collision occurs, a response frame will be sent from AP100 to each STA, as shown by the dashed line in the diagram. However, AP100 decides not to send a response frame to each STA because the signals are colliding and it is unable to correctly decode them.

[0094] Therefore, STA1 and STA2 set random backoff times again and attempt to transmit again. In this case, STA1's backoff time ends first, so STA1 resends a short data frame.

[0095] After AP100 receives the short data frame retransmitted by STA1, it sends a response frame to STA1. Meanwhile, STA2 and STA3, having received the response frame via broadcast or other means, set NAV on their own terminals for the time indicated by this signal.

[0096] Meanwhile, after receiving the response frame, STA1 sends a long data frame (labeled as Multiple Data Frame in the diagram) to AP100. After STA1 has finished sending the data, AP100 sends STA1 a Block ACK frame containing information about whether or not there is any undelivered data. Similarly, after STA2 and STA3 receive this frame, they start decrementing their backoff counters again.

[0097] In this case, STA1 may be controlled to refrain from transmitting new data until STA2, which has experienced a signal collision, has completed its data transmission.

[0098] STA2 transmits data in the same way as STA1 after the backoff period ends. In this diagram, data transmission for lower access categories sent from STA3 is omitted.

[0099] Figure 15 shows the first example of a frame format for short data in this embodiment.

[0100] In the example in Figure 15, a short data frame is contained within a single MPDU (Single MPDU). This frame format is a conventional MPDU frame, consisting of a preamble (L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, UHR-STF, UHR-LTF) at the beginning and a single MPDU at the end. The example MPDU in Figure 15 also includes a predetermined MAC Header, Data payload, and Frame Check Sequence (FCS).

[0101] Note that UHR-STF and UHR-STF are examples, and these fields store data equivalent to the STF (Short Training Field) and LTF (Long Training Field) of IEEE 802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be and subsequent standards similar to these.

[0102] In addition to address fields (Address 1 to Address 4) indicating the destination and source addresses, the MAC header also includes QoS Control information regarding the type of data being transmitted. By referring to the parameters listed in this field, it is possible to infer information such as which AC the transmitted data belongs to.

[0103] This frame is constructed using a conventional MPDU frame, but it may also be constructed using other frames, such as A-MPDU.

[0104] Furthermore, an MPDU may be a single data block, or it may consist only of short data of a predetermined fixed length. The MPDU only needs to include information indicating that the data belongs to a predetermined QoS category, such as which AC the long data to be transmitted belongs to.

[0105] In the frame configuration shown in Figure 15, the USIG portion, which is part of the preamble, may contain parameters indicating the presence of the long data described in this embodiment.

[0106] As a parameter indicating the presence of long data, parameters related to backoff control using short data are described. For example, a Single Data Backoff Control Parameter field may be provided in the U-SIG section, and parameters such as Data Category, which explicitly indicates the AC of the data; Backoff Type, which indicates the type of backoff; Backoff Control, which indicates that the backoff described in this embodiment is used; Multiple Length, which indicates information about the length of the long data; Multiple Length, which indicates the type of response frame; and Response Time, which indicates the type of response frame, may be described.

[0107] Figure 16 shows a second example of a frame format for short data in this embodiment.

[0108] In the example in Figure 16, the short data frame contains multiple MPDUs and takes the form of an A-MPDU frame. In this frame format, a predetermined preamble and the portion corresponding to one of the multiple MPDUs contain parameters related to backoff control using the short data. In other words, this portion contains parameters such as Data Category, Backoff Type, Backoff Control, Multiple Length, and Response Type mentioned above.

[0109] Figure 17 shows a third example of a frame format for short data in this embodiment.

[0110] The example in Figure 17 is a conventional MPDU frame, where short data frames are contained within a single MPDU. Unlike the example in Figure 15, the MPDU portion contains parameters corresponding to a predetermined MAC Header, and the Data payload contains parameters related to backoff control using short data. In other words, this portion contains the parameters such as Data Category, Backoff Type, Backoff Control, Multiple Length, and Response Type mentioned above.

[0111] Figure 18 shows a fourth example of a frame format for short data in this embodiment.

[0112] In the example in Figure 18, a short data frame contains multiple MPDUs and is structured as an A-MPDU frame. Although this frame format uses an A-MPDU frame structure, it contains only one MPDU frame. The delimiter portion, which is added before the MPDU frame (more specifically, after the PHY header and before the MAC header), contains parameters such as information about the length of the long data.

[0113] In other words, following a predetermined preamble in the PHY header, the Multiple Length is included as the minimum necessary parameter in a delimiter corresponding to one MPDU. Parameters for backoff control using short data may be included in the delimiter or in the MPDU frame.

[0114] Here, four frame formats are illustrated in Figures 15 to 18, but any of these forms may be used, or the format may be constructed by adding some parameters to these forms.

[0115] Figure 19 shows an example of a frame format for long data in this embodiment.

[0116] In the example shown in Figure 19, the data frame is configured as a conventional A-MPDU frame, and in addition to a predetermined preamble (L-STF, L-LTF, L-SIG, LR-SIG, U-SIG, EHT-STF, and EHT-LTF), it includes multiple MPDUs.

[0117] In this frame format, the MPDU contains a data frame configured as a MAC Layer Protocol Data Unit, which includes a MAC Header, Data Payload, and FSS.

[0118] Additionally, each MPDU may be preceded by a delimiter, if necessary, to indicate the boundary between one MPDU and another.

[0119] Figure 20 shows one example of the frame format of the response frame in this embodiment.

[0120] The example in Figure 20 shows the frame format of a response frame that AP100 sends to the STA, the source of the short data frame, after receiving the short data frame. The response frame includes Frame Control, which indicates that it is a predetermined frame format; Multiple Duration, which indicates the period (duration) based on the time required to transmit the signal containing the long data frame that is sent after the short data frame; RA, which indicates the address of the receiver; TA, which indicates the address of the destination; and Response Control and FCS, which may include parameters as needed during the response. The period based on the time required to transmit the signal containing the frame may be only the time required to transmit the signal containing the short data frame, or it may be the sum of the time required to transmit the signal containing the short data frame and the time required to transmit the response signal (Ack, Block Ack, or Multi-STA Block Ack), or it may be a specific time interval between frames, such as SIFS (Short Interframe Space), added to these by a certain number of applicable minutes.

[0121] Frame Control may be defined as one of the new control frames. For example, a new control frame may be defined by setting Type to 01 and Subtype to 0001.

[0122] Multiple Duration calculates the duration (period) based on the time required to transmit a signal containing a long data frame, for example, from parameters such as Multiple Length contained in a short data frame.

[0123] Response Control may include various necessary information, such as specifying the time range to be set as the backoff time from the receiving device to the transmitting device.

[0124] Alternatively, instead of determining whether to perform the access control described in this embodiment, AP100 may decide whether to perform the access control when it transmits a response frame. In such cases, the response frame may include information indicating whether to perform collision detection control by transmitting short data (Single + Multi OK in the figure).

[0125] This information may be included in, for example, the Response Control section, or it may be set by replacing specific bits of the Frame Control.

[0126] Furthermore, for example, an STA that receives a response frame other than one addressed to itself via broadcast may set the NAV based on Multiple Duration.

[0127] Figure 21 shows a second example of the frame format of the response frame in this embodiment.

[0128] Here too, the Response Frame may include information indicating whether or not to perform collision detection control by sending short data (Single + Multi OK in the diagram), and may be set by replacing, for example, a specific bit of Frame Control.

[0129] Unlike the example in Figure 20, this frame format does not include Response Control. If there is no information to include as Response Control in the response, this format may be used without that information.

[0130] Figure 22 shows a third example of the frame format of the response frame in this embodiment.

[0131] The example in Figure 22 shows the frame format of a response frame using a conventional Clear To Send (CTS) frame. Conventional Clear To Send frames include Frame Control, Duration, RA, and FCS. On the other hand, in the response frame of this embodiment, the Duration section includes Multiple Duration, which indicates the period (duration) based on the time required to transmit a signal containing a long data frame. By transmitting a response frame using a conventional CTS frame, the access control described above can be applied even to terminals that cannot identify the new control frame.

[0132] Here too, the Response Frame may include information indicating whether or not to perform collision detection control by sending short data (Single + Multi OK in the diagram), and may be set by replacing, for example, a specific bit of Frame Control.

[0133] Figure 23 shows a fourth example of the frame format of the response frame in this embodiment.

[0134] Figure 23 shows the frame format of a response frame using a conventional ACK frame. A conventional ACK frame includes Frame Control, Duration, RA, and FCS. In contrast, the response frame in this embodiment includes Multiple Duration in the Duration section, which indicates the period (duration) based on the time required to transmit a signal containing a long data frame. By transmitting a response frame using a conventional ACK frame, the access control described above can be applied even to terminals that cannot identify the new control frame.

[0135] Here too, the Response Frame may include information indicating whether or not to perform collision detection control by sending short data (Single + Multi OK in the diagram), and may be set by replacing, for example, a specific bit of Frame Control.

[0136] Figure 24 is an example of a flowchart showing the operation of the data transmission device in this embodiment.

[0137] This example primarily focuses on the operation of STA1 and explains the flow of how to complete the transmission of a long data frame to AP100.

[0138] In step S101, STA1 sends a control request to AP100 to perform collision detection using short data after backoff. STA1 also exchanges parameters related to this control by receiving a response from AP100 containing information indicating whether or not to perform this control. This parameter exchange is performed, for example, during STA1's association. In step S102, STA1 determines whether or not the data to be transmitted is transmittable. For example, STA1 determines that the data is transmittable if it is stored in the data buffer 102. If STA1 determines that the data is not transmittable (NO in step S102), STA1 waits until the target data is stored.

[0139] If STA1 determines in step S102 that it can transmit data (YES in step S102), in step S103, STA1 sets the EDCA backoff time according to the AC of the data and performs the backoff while the transmission path is available. After the backoff time has ended, in step S104, STA1 determines whether or not to perform control to transmit a short data frame and perform collision detection based on the parameters exchanged in step S101.

[0140] If this control is performed (YES in step S104), in step S105, STA1 sends a short data frame to AP100. At this time, STA1 sends a short data frame to AP100 using, for example, the frame format shown in Figures 15 to 18. In step S106, STA1 waits until it receives a response frame from AP100. If STA1 times out without receiving a response frame from AP100 (NO in step S106), the process returns to step S103 to retransmit the short data frame, and STA1 sets the backoff time again as necessary.

[0141] If STA1 receives a response frame from AP100 (YES in step S106), in step S107, STA1 sends a long data frame to AP100. At this time, STA1 sends the data using, for example, the frame format shown in Figure 19. If, in step S104, STA determines that it will not perform the control in this embodiment, it will not send a short data frame as in normal operation, but will construct and send a long data frame to AP100. In step S108, STA1 receives a Block ACK frame from AP100 along with the transmission of the long data frame. In step S109, STA1 determines from the received Block ACK frame whether there is any undelivered data to AP100. If there is undelivered data (NO in step S109), the process returns to step S102, and STA1 determines whether the undelivered data to be sent can be retransmitted. If there is no undelivered data (YES in step S109), the process ends.

[0142] Figure 25 is an example of a flowchart showing the operation of the data receiving device in this embodiment.

[0143] This example primarily focuses on the operation of AP100 and explains the flow from the completion of receiving a long data frame from STA1.

[0144] In step S201, AP100 receives a request from STA1 for a control to perform collision detection using a short data after backoff. AP100 also performs parameter exchange related to this control by sending a response to STA1 that includes information indicating whether or not to perform this control. This parameter exchange is performed, for example, when STA1 is associated. In step S202, when AP100 receives any data, it determines whether or not the data is a frame addressed to its own device. If the received data is not a frame addressed to its own device (NO in step S202), it obtains the duration information as needed, discards the data, and waits again.

[0145] If the received data is a frame destined for its own base station (NO in step S203), in step S203, AP100 determines whether the received data is a short data frame. If the received data is a short data frame (YES in step S203), in step S204, AP100 determines whether it is simultaneously receiving short data frames from multiple STAs, i.e., whether a collision has occurred. For example, if AP100 is simultaneously receiving short data frames from, for example, STA2, and detects a predetermined received signal level, it determines that a collision has occurred if it cannot correctly decode the signal. If a collision due to short data frames has occurred (NO in step S204), the AP returns to step S202 to wait for a retransmission of short data frames from STA1 or STA2.

[0146] If a short data frame is received without collision (YES in step S204), in step S205, AP 100 obtains the Multiple Length contained in the short data frame and calculates the Multiple Duration. In step S206, AP 100 includes the calculated Multiple Duration in the response frame and transmits it to STA 1. For example, the response frame may be broadcast. This allows other STAs on the wireless communication system to set up NAV based on the received response frame. At this time, AP 100 transmits the response frame using, for example, the frame format shown in Figures 20 to 23.

[0147] In step S207, AP100 receives a long data frame from STA1. If the data received by AP100 in step S203 is not a short data frame (NO in step S203), then in step S207, AP100 receives the long data frame in the normal operation, not the operation in this embodiment. In step S208, AP100 sends a Block ACK frame to STA1 based on the received long data frame. In step S209, AP100 determines whether or not there is any undelivered data in the received long data. If there is undelivered data (NO in step S209), AP100 returns to step S202 to wait for the retransmission of this data and waits for the reception of frames addressed to itself. If there is no undelivered data (YES in step S209), the process ends.

[0148] Figure 26 illustrates the access control of the STA in a modified example of this embodiment.

[0149] In this modified example, we will explain an example in which STA1 and STA2 transmit data belonging to high-priority ACs to AP100, and STA3 transmits data belonging to low-priority ACs to AP100.

[0150] In this modified version, after the backoff time ends, a short data frame is sent to AP100 to detect a collision with another terminal in a short time. If a collision is detected, access control is performed again by random backoff. After the random backoff ends, the STA, having acquired access control rights, sends both a short and a long data frame to AP100 instead of sending another short data frame.

[0151] As shown in Figure 26, after a collision occurs, STA1 and STA2 set random backoff times again. At this time, different backoff times are set between STA1 and STA2 to prevent collisions of data of the same AC. In this figure, the backoff time set by STA1 is shorter than that of STA2. After acquiring access control rights, STA1 retransmits a short data frame and sends a long data frame after receiving a response frame from AP100. The response frame is sent from AP100, for example, by broadcast, and terminals other than STA1 that receive this frame set NAV on their own terminals based on the information contained in this frame.

[0152] AP100 may, if necessary, send a Block ACK frame after it has finished receiving the long data frame. Each terminal can know that STA1 has finished sending the long data frame by receiving the Block ACK frame.

[0153] After STA1 completes its data transmission, STA2 then acquires access control rights. Since STA1 has already completed its data transmission at this point, STA2 transmits all data to AP100, including the long data in addition to the short data used to acquire access control rights with STA1.

[0154] Figure 27 is another diagram illustrating the access control of the STA in this embodiment.

[0155] In this diagram, STA1 and STA2 are set to have different backoff times. Because STA1 has a shorter backoff time, STA1 sends a shorter data frame to AP100 before STA2. This example shows a case where no collision occurs between STA1 and STA2.

[0156] Furthermore, if STA2 acquires access control rights after STA1 has completed its transmission, STA2 will send all data to AP100, including the long data in addition to the short data used to acquire access control rights with STA1.

[0157] Thus, if no data collision occurs between STA1 and STA2, STA1 will send a short data frame, wait for a response frame from AP100, and then send a longer data frame. However, since this time is short, data transmission can be performed without reducing efficiency.

[0158] Figure 28 shows an example of an access control sequence diagram in a modified version of this embodiment.

[0159] This sequence diagram shows the operation of access control in this embodiment from top to bottom, with STA1 to STA3 and AP100 as they progress over time.

[0160] Similar to the case in Figure 4, if the same value is set as the backoff time setting for STA1 and STA2, both will send a short data frame to AP100 at the same time after the backoff time has ended.

[0161] If no collision occurs, a response frame will be sent from AP100 to each STA, as shown by the dashed line in the diagram. However, AP100 decides not to send a response frame to each STA because the signals are colliding and it is unable to correctly decode them.

[0162] Therefore, STA1 and STA2 again set random backoff times and attempt to retransmit the short data frame. In this case, STA1's backoff time ends first, allowing STA1 to retransmit the short data frame.

[0163] After AP100 receives the short data frame retransmitted by STA1, it sends a response frame to STA1. Upon receiving the response frame, STA2 and STA3 set the time NAV indicated by this signal on their respective terminals.

[0164] Meanwhile, after receiving the response frame, STA1 sends a long data frame to AP100. After STA1 has finished transmitting the data, AP100 sends a Block ACK frame to STA1 to acknowledge receipt. STA2 and STA3 also receive this frame and begin decrementing their backoff counters again.

[0165] In this case, STA1 may be controlled to refrain from transmitting new data until STA2, which has experienced a signal collision, has completed its data transmission.

[0166] After the backoff period ends, STA2 acquires access control rights and, instead of retransmitting the short data frame, sends all the data, including the short data, to AP100.

[0167] According to this embodiment and its modified form, after the backoff time ends, the STA first sends a short data frame to the AP 100, and after determining from the response frame that it is possible to send a longer data frame, it sends the longer data frame to the AP 100. As a result, even if a collision occurs between multiple STAs due to backoff competition, the collision can be detected in a short time without occupying the transmission path for a long period of time, and efficient data transmission can be achieved.

[0168] For example, even if multiple STAs transmitting data belonging to the same AC start transmitting data simultaneously, collisions can be clearly detected by the presence or absence of short data frames and their response frames. In other words, if the short data frames transmitted by STA1 and STA2 collide, AP100 can detect the collision early by not transmitting a response frame.

[0169] Furthermore, according to this embodiment and its modifications, by configuring the system to determine whether or not to perform collision detection control using short data frames between the STA and AP 100 depending on the data AC, this access control can be applied only when a conflict occurs between STAs present in the wireless communication system.

[0170] Furthermore, according to this embodiment and its modified form, the STA transmits to the AP 100 that it includes information about the length of the long data within the short data frame it transmits, allowing the AP 100 to calculate the duration based on the time required to transmit the signal containing the long data frame, and to respond whether or not it has been received.

[0171] Furthermore, according to this embodiment and its modified form, the STA includes information about the type of data being transmitted in the short data frame it transmits to the AP 100, thereby enabling the AP 100 to detect when data of the same AC is colliding.

[0172] Furthermore, according to this embodiment and its modified versions, the STA can set a random backoff time corresponding to its AC by including information about the type of data to be transmitted in the short data frame to be transmitted.

[0173] Furthermore, according to this embodiment and its modified versions, the STA can maintain compatibility with conventional STAs and AP100s without defining a new frame structure by using the conventional MPDU frame as the frame format for the short data frames to be transmitted, and can easily detect data collisions of the same AC.

[0174] Furthermore, according to this embodiment and its modifications, the STA can prevent the unnecessary occupation of the transmission path by collision data over a long period of time by transmitting a long data frame after receiving a response frame from the AP 100.

[0175] Furthermore, according to this embodiment and its modified form, AP 100 sends a response frame to multiple STAs that includes, in addition to the destination STA's information, a period (duration) based on the time required to transmit a signal containing a long data frame. This allows STAs other than the destination STA to set up NAVs on their own terminals, thereby suppressing transmissions by these STAs.

[0176] Furthermore, according to this embodiment and its modifications, the AP 100 can use conventional frame formats such as CTS and ACK for response frames, allowing even STAs that can only recognize conventional frames to understand the usage status of the transmission path. In other words, NAV can be set even with conventional STAs. This enables these terminals to more effectively perform virtual carrier sensing of the transmission path, thereby realizing highly reliable data communication.

[0177] Furthermore, according to a modified version of this embodiment, among multiple STAs that transmit the same AC data, the STA whose backoff time ends later can retransmit all the data in a shorter time by sending both a short data frame and a long data frame together.

[0178] <Example of Computer Configuration> The series of processes described above can be executed by hardware or by software. When the series of processes are executed by software, the programs that make up the software are installed from a program storage medium onto a computer that is built into dedicated hardware, or a general-purpose personal computer.

[0179] Figure 29 is a block diagram showing an example of the hardware configuration of a computer that executes the series of processes described above by a program.

[0180] The CPU (Central Processing Unit) 801, ROM (Read Only Memory) 802, and RAM (Random Access Memory) 803 are interconnected by a bus 804.

[0181] An input / output interface 805 is further connected to the bus 804. An input unit 806 consisting of a keyboard, mouse, etc., and an output unit 807 consisting of a display, speakers, etc. are connected to the input / output interface 805. In addition, a storage unit 808 consisting of a hard disk, non-volatile memory, etc., a communication unit 809 consisting of a network interface, etc., and a drive 810 that drives removable media 811 are connected to the input / output interface 805.

[0182] In a computer configured as described above, the CPU 801 performs the aforementioned series of processes by loading a program stored in the memory unit 808 into the RAM 803 via the input / output interface 805 and the bus 804 and executing it.

[0183] The program executed by the CPU 801 is recorded on removable media 811, for example, or provided via a wired or wireless transmission medium such as a local area network, the internet, or digital broadcasting, and installed in the storage unit 808.

[0184] The programs executed by the computer may be programs that are processed chronologically in the order described herein, or they may be programs that are processed in parallel or at necessary times, such as when a call is made.

[0185] <Application Examples> This technology can be applied to a variety of products. For example, the communication device shown in Figure 1 may be implemented as a mobile terminal such as a smartphone, tablet PC (Personal Computer), notebook PC, portable game terminal, or digital camera; a fixed terminal such as a television receiver, projector, printer, digital scanner, or network storage; or an in-vehicle terminal such as a car navigation system. The communication device may also be implemented as an M2M (Machine To Machine Communication) terminal such as a smart meter, vending machine, remote monitoring device, or POS (Point Of Sale) terminal. Furthermore, the communication device may be a wireless communication module (for example, an integrated circuit module consisting of a single die) mounted on these terminals.

[0186] On the other hand, for example, the communication device may be implemented as a wireless LAN AP (wireless base station) with or without router functionality. Alternatively, the communication device may be implemented as a mobile wireless LAN router. Furthermore, the communication device may be a wireless communication module (for example, an integrated circuit module consisting of a single die) mounted on these devices.

[0187] <Example of Smartphone Configuration> Figure 30 is a block diagram showing a schematic example of the configuration of a smartphone to which this technology is applied.

[0188] The smartphone 900 includes a processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, and display device 910. The smartphone 900 also includes a speaker 911, wireless communication interface 913, antenna switch 914, antenna 915, bus 917, battery 918, and auxiliary controller 919.

[0189] The processor 901 may be, for example, a CPU or a SoC (System on Chip), and it limits the functionality of the application layer and other layers of the smartphone 900.

[0190] The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901.

[0191] The storage 903 includes a storage medium such as semiconductor memory or a hard disk.

[0192] The external connection interface 904 is an interface for connecting external devices such as memory cards or USB (Universal Serial Bus) devices to the smartphone 900.

[0193] The camera 906 has an image sensor, such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), and generates an image.

[0194] The sensor 907 includes, for example, a group of sensors such as a positioning sensor, a gyroscope, a geomagnetic sensor, and an acceleration sensor.

[0195] Microphone 908 converts the audio input to smartphone 900 into an audio signal.

[0196] The input device 909 includes, for example, a touch sensor that detects touches on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and accepts operations or information input from the user.

[0197] The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display and displays the output image from the smartphone 900. The display device 910 may also be configured as a projector that projects the output image onto a screen. The speaker 911 converts the audio signal output from the smartphone 900 into sound. The processor 901 controls the display of the display device 910 based on information received via the first or second link and the user's operation of the input device 909.

[0198] The wireless communication interface 913 supports one or more wireless LAN standards such as IEEE 802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, and 11be, and performs wireless communication.

[0199] In infrastructure mode, the wireless communication interface 913 communicates with other devices via the wireless LAN access point (AP). In ad-hoc mode or direct communication modes such as Wi-Fi Direct, the wireless communication interface 913 communicates directly with other devices.

[0200] In Wi-Fi Direct, unlike ad-hoc mode, one of the two devices acts as the access point (AP), but communication takes place directly between those devices.

[0201] The wireless communication interface 913 typically includes a baseband processor, an RF (Radio Frequency) circuit, and a power amplifier. The wireless communication interface 913 may also be a single-chip module integrating a memory for storing a communication control program, a processor for executing the program, and related circuits.

[0202] In addition to the wireless LAN method, the wireless communication interface 913 may support other types of wireless communication methods such as short-range wireless communication, proximity wireless communication, or cellular communication.

[0203] The antenna switch 914 switches the destination of the antenna 915 among multiple circuits included in the wireless communication interface 913 (for example, circuits for different wireless communication schemes).

[0204] Antenna 915 has one or more antenna elements (for example, multiple antenna elements that constitute a MIMO (Multiple Input Multiple Output) antenna) and is used for transmitting and receiving radio signals via wireless communication interface 913. For example, if antenna 915 has multiple antenna elements, it may have a second antenna element in addition to a first antenna element to constitute a MIMO antenna. Furthermore, there may be multiple antennas 915, and if the multiple antennas 915 include a first antenna and a second antenna, they may communicate via a first link and a second link, respectively.

[0205] Note that the smartphone 900 is not limited to the example shown in Figure 30, and may be equipped with multiple antennas (for example, an antenna for wireless LAN and an antenna for proximity wireless communication). In that case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.

[0206] The bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 913, and auxiliary controller 919 to each other.

[0207] The battery 918 supplies power to each block of the smartphone 900 shown in Figure 30 via power supply lines partially shown by dashed lines in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in sleep mode.

[0208] In the smartphone 900 shown in Figure 30, for example, the wireless communication module 15 in Figure 10 may be implemented in the wireless communication interface 913. Furthermore, at least some of these functions may be implemented in the processor 901 or the auxiliary controller 919.

[0209] The smartphone 900 may also operate as a wireless AP (software AP) by having the processor 901 execute AP functions at the application level. Furthermore, the wireless communication interface 913 may also have wireless AP functionality.

[0210] Furthermore, the smartphone 900 may be equipped with a biometric authentication unit (fingerprint authentication, palm print authentication, voice authentication, vascular authentication, facial authentication, iris authentication, retinal authentication). In this case, the wireless communication interface 913 on which the wireless communication module 15 shown in Figure 10 is implemented is configured to receive power from the same battery 918 as at least one of the display device 910, the speaker 911, and the biometric authentication unit.

[0211] Furthermore, in the smartphone 900, information is displayed from at least one of the display device 910 and the speaker 911 based on communication with an external device via the wireless communication interface 913. In this case, information related to this technology may be output from at least one of the display device 910 and the speaker 911.

[0212] <Example of In-Vehicle Device Configuration> Figure 31 is a block diagram showing an example of a schematic configuration of an in-vehicle device 920 to which this technology is applied.

[0213] The in-vehicle device 920 is configured to include a processor 921, memory 922, GNSS (Global Navigation Satellite System) module 924, sensor 925, data interface 926, content player 927, and storage medium interface 928. The in-vehicle device 920 is also configured to include an input device 929, display device 930, speaker 931, wireless communication interface 933, antenna switch 934, antenna 935, and battery 938.

[0214] The processor 921 may be, for example, a CPU or a SoC, and controls the navigation function and other functions of the in-vehicle device 920. The processor 921 can also control the vehicle's drive system, such as the brakes, accelerator, or steering, based on information obtained through communication based on this technology.

[0215] The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921.

[0216] The GNSS module 924 uses GNSS signals received from GNSS satellites to measure the position (e.g., latitude, longitude, and altitude) of the on-board device 920.

[0217] The sensor 925 includes, for example, a group of sensors such as a gyro sensor, a geomagnetic sensor, and a barometric pressure sensor.

[0218] The data interface 926 is connected to the in-vehicle network 941 via, for example, terminals (not shown), and acquires data generated on the vehicle side, such as in-vehicle data.

[0219] The content player 927 plays content stored on a storage medium (e.g., a CD or DVD) inserted into the storage medium interface 928. The storage medium interface 928 is an example of an external connection interface, and the storage medium is an example of an external storage medium.

[0220] The input device 929 includes, for example, a touch sensor, a button, or a switch that detects touches on the screen of the display device 930, and accepts operations or information input from the user.

[0221] The display device 930 has a screen such as an LCD or OLED display and displays information such as navigation functions or images of content being played. The processor 921 controls the display of the display device 930 based on information received via the first or second link and the user's operation of the input device 929.

[0222] The speaker 931 outputs audio for navigation functions or the content being played.

[0223] Note that in the in-vehicle device 920, the navigation function and the functions provided by the content player 927 are optional. The navigation function and the content player 927 may be omitted from the configuration of the in-vehicle device 920.

[0224] The wireless communication interface 933 supports one or more wireless LAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, and 11be, and performs wireless communication. In infrastructure mode, the wireless communication interface 933 communicates with other devices via wireless LAN access points (APs). In ad-hoc mode or direct communication modes such as Wi-Fi Direct, the wireless communication interface 933 communicates directly with other devices.

[0225] The wireless communication interface 933 typically includes a baseband processor, RF circuitry, and power amplifier. The wireless communication interface 933 may be a single-chip module integrating a memory for storing a communication control program, a processor for executing the program, or related circuitry. In addition to the wireless LAN method, the wireless communication interface 933 may support other types of wireless communication methods such as short-range wireless communication, proximity wireless communication, or cellular communication.

[0226] The antenna switch 934 switches the destination of the antenna 935 among the multiple circuits included in the wireless communication interface 933.

[0227] The antenna 935 has one or more antenna elements and is used for transmitting and receiving radio signals via the wireless communication interface 933. For example, if the antenna 935 has multiple antenna elements, it may have a second antenna element in addition to the first antenna element to constitute a MIMO antenna.

[0228] Note that the in-vehicle device 920 is not limited to the example shown in Figure 31, and may include multiple antennas 935. In that case, the antenna switch 934 may be omitted from the configuration of the in-vehicle device 920.

[0229] The battery 938 supplies power to the in-vehicle device 920 shown in Figure 31 via a power supply line partially shown by a dashed line in the figure. For example, the wireless communication module 15 in Figure 10 may be implemented in the wireless communication interface 933. At least some of these functions may also be implemented in the processor 921. The battery 938 is an example of a power sharing unit. The power sharing unit supplies power to the processor 921, the input device 929, the display device 930, and the first and second antenna elements.

[0230] Furthermore, the wireless communication interface 933 may operate as the communication device described above and provide wireless connectivity to terminals owned by users in the vehicle.

[0231] Furthermore, this technology may be implemented as an in-vehicle system (or vehicle) 940 including one or more blocks of the above-described in-vehicle device 920, an in-vehicle network 941, and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or fault information, and outputs the generated data to the in-vehicle network 941.

[0232] <Example of Wireless AP Configuration> Figure 32 is a block diagram showing an example of a schematic configuration of a wireless AP 950 to which this technology is applied.

[0233] The wireless AP 950 includes a controller 951, memory 952, input device 954, display device 955, network interface 957, wireless communication interface 963, antenna switch 964, and antenna 965.

[0234] The controller 951 may be, for example, a CPU or a DSP (Digital Signal Processor), and it operates various functions of the wireless AP 950 at the IP (Internet Protocol) layer and higher layers (e.g., access restriction, routing, encryption, firewall, and log management).

[0235] Memory 952 includes RAM and ROM and stores programs executed by the controller 951, as well as various control information (e.g., terminal list, routing table, encryption key, security settings, and logs).

[0236] The input device 954 includes, for example, buttons and switches, and accepts operations from the user.

[0237] The display device 955 includes an LED lamp and displays information such as the operating status of the wireless AP 950. The display device 910 may also be configured as a projector that projects output images onto a screen. A processor (not shown) controls the display of the display device 955 based on information received via the first or second link and the user's operation of the input device 954. The processor may also be implemented within the controller 951.

[0238] The network interface 957 is a wired communication interface for the wireless AP 950 to connect to the wired communication network 958. The network interface 957 may have multiple connection terminals. The wired communication network 958 may be a LAN such as Ethernet (registered trademark), or a WAN (Wide Area Network).

[0239] The wireless communication interface 963 supports one or more wireless LAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, and 11be, and provides wireless connectivity as an AP to nearby terminals.

[0240] The wireless communication interface 963 typically includes a baseband processor, RF circuitry, and power amplifiers.

[0241] The wireless communication interface 963 may be a single-chip module integrating a memory for storing a communication control program, a processor for executing the program, or related circuits.

[0242] The antenna switch 964 switches the connection destination of the antenna 965 among several circuits included in the wireless communication interface 963. The antenna 965 has one or more antenna elements and is used for transmitting and receiving wireless signals by the wireless communication interface 963. For example, if the antenna 965 has multiple antenna elements, it has a second antenna element in addition to a first antenna element.

[0243] In the wireless AP 950 shown in Figure 32, for example, the wireless communication module 15 in Figure 10 may also be implemented in the wireless communication interface 963. Furthermore, at least some of these functions may be implemented in the controller 951.

[0244] The above-described embodiments are merely examples of how to realize this technology, and there is a corresponding relationship between the matters in the embodiments and the inventive features in the claims. Similarly, there is a corresponding relationship between the inventive features in the claims and the matters in the embodiments of this technology that bear the same name. However, this technology is not limited to the embodiments and can be realized by making various modifications to the embodiments without departing from the gist of the technology.

[0245] Furthermore, the processing procedure described in the above-described embodiment may be considered as a method comprising these steps, or as a program or recording medium that stores such a program for causing the computer to execute these steps.

[0246] For example, CDs (Compact Discs), MDs (MiniDiscs), DVDs (Digital Versatile Discs), memory cards, and Blu-ray Discs (Blu-ray® Discs) can be used as recording media.

[0247] In this specification, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all components are located in the same enclosure. Therefore, multiple devices housed in separate enclosures and connected via a network, and a single device containing multiple modules within a single enclosure, are both considered systems.

[0248] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0249] The embodiments of this technology are not limited to those described above, and various modifications are possible without departing from the spirit of this technology.

[0250] For example, this technology can be configured as cloud computing, where a single function is shared and processed collaboratively by multiple devices via a network.

[0251] Furthermore, each step described in the flowchart above can be performed by a single device, or it can be divided and performed by multiple devices.

[0252] Furthermore, if a single step includes multiple processes, those processes can be executed by a single device or shared among multiple devices.

[0253] This embodiment may also have the following configuration. [Note] [Item 1] A first wireless communication unit included in a first communication device, comprising a first control unit that controls the first wireless communication unit which performs wireless communication with a second communication device over one or more access channels, wherein the first control unit controls the first wireless communication unit to transmit a first frame to the second communication device, and transmit a third frame containing first data to the second communication device in response to the reception of a second frame which is a response to the first frame, wherein the first frame contains information about the type of the first data. [Item 2] The communication control device according to Item 1, wherein the information about the type of the first data is information indicating the access category of the first data. [Item 3] The communication control device according to Items 1 to 2, wherein the first frame is a data frame. [Item 4] The communication control device according to Items 1 to 3, wherein the first frame further contains information about the length of the first data and information about at least one of the address of the first communication device which is the source and the address of the second communication device which is the destination. [Item 5] The communication control device according to items 1 to 4, wherein the second frame includes information indicating a period based on the time required to transmit a signal including the third frame. [Item 6] The communication control device according to items 1 to 4, wherein the first control unit controls the first wireless communication unit to transmit the first frame when the backoff time set based on the type of first data has ended. [Item 7] The communication control device according to items 1 to 6, wherein the first control unit further includes control to determine whether or not to transmit the first frame to the second communication device to perform collision detection, depending on the type of first data. [Item 8] The communication control device according to items 1 to 7, wherein the first control unit controls the first wireless communication unit to retransmit the first frame to the second communication device after the backoff time has ended if the second frame has not been received. [Item 9] The communication control device according to items 1 to 7, wherein the first control unit controls the first wireless communication unit to transmit the first frame and the third frame together to the second communication device after the backoff time has ended if the second frame has not been received.[Item 10] The communication control device according to items 1 to 9, wherein the first control unit receives a fourth frame from the second communication device which is a response to the third frame after the first wireless communication unit has transmitted the third frame, and controls the first control unit to suppress transmission after receiving the fourth frame. [Item 11] The communication control device according to items 1 to 10, wherein the first control unit transmits a request to the second communication device for collision detection using the first frame before the first wireless communication unit has transmitted the first frame. [Item 12] The communication control device according to any one of items 1 to 3 and items 5 to 11, wherein the preamble preceding the first frame further includes information on the length of the first data. [Item 13] The communication control device according to item 11, wherein the request includes at least one of a period based on the time required to transmit a signal including the first frame and information indicating the type of the first data. [Item 14] The communication control device according to items 1 to 13, wherein the first frame is included in an MPDU frame, and the Data payload in the MPDU frame includes information on the length of the first data. [Item 15] The communication control device according to Items 1 to 13, wherein the first frame is included in one MPDU frame among the A-MPDU frames. [Item 16] The communication control device according to Item 15, wherein the portion of the A-MPDU frame that is after the PHY header and before the MAC header contains information about the length of the first data. [Item 17] The communication control device according to Items 1 to 13, wherein the third frame is included in the A-MPDU frame. [Item 18] The communication control device according to Items 1 to 17, wherein the second frame is a CTS frame or an ACK frame. [Item 19] The communication control device according to Item 9, wherein the fourth frame is a Block ACK frame.[Item 20] A communication control device comprising: a second wireless communication unit included in a second communication device, the second wireless communication unit which performs wireless communication with a first communication device over one or more access channels, wherein the second control unit controls the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame which is a response to the first frame to the first communication device, and receive a third frame containing the first data from the first communication device based on the transmission of the second frame, wherein the first frame contains information about the type of the first data. [Item 21] The communication control device according to Item 1, further comprising: a processor, an input device which accepts operations from a user, a display device, and a first antenna element, wherein the processor controls the display of the display device based on information received over one or more access channels and the operations. [Item 22] The communication control device according to Item 21, further comprising: a speaker; an external connection interface for connecting to a memory card or a USB (Universal Serial Bus) device; a second antenna element that constitutes a MIMO antenna together with the first antenna element; the control unit; the processor; the input device; the display device; the and second antenna elements; and the power sharing unit that supplies power to the external connection interface. [Item 23] The communication control device according to Item 21, further comprising: a content player for playing content stored on an external storage medium connected via the external connection interface. [Item 24] The communication control device according to Item 21, wherein the display device is an LED lamp that displays the operating status of the communication device.[Item 25] A vehicle comprising a first wireless communication unit included in a first communication device, the first wireless communication unit which performs wireless communication with a second communication device over one or more access channels, wherein the first control unit controls the first wireless communication unit to transmit a first frame to the second communication device, and transmit a third frame containing first data to the second communication device in response to the reception of a second frame which is a response to the first frame, wherein the first frame contains information relating to the type of the first data. [Item 26] A vehicle comprising a second wireless communication unit included in a second communication device, the second control unit which controls the second wireless communication unit which performs wireless communication with a first communication device over one or more access channels, wherein the second control unit controls the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame which is a response to the first frame to the first communication device, and receive a third frame containing first data from the first communication device based on the transmission of the second frame. [Item 27] ​​A first communication control method for controlling a first wireless communication unit included in a first communication device, which performs wireless communication with a second communication device over one or more access channels, wherein the first communication control method includes a method for controlling the first wireless communication unit to transmit a first frame to the second communication device, and in response to the receipt of a second frame which is a response to the first frame, transmit a third frame containing first data to the second communication device, wherein the first frame contains information relating to the type of the first data.[Item 28] A second communication control method for controlling a second wireless communication unit included in a second communication device, which performs wireless communication with a first communication device over one or more access channels, wherein the second communication control method includes receiving a first frame from the first communication device which includes information about the category of received data and is used for receiving data, transmitting a second frame to the first communication device which is a response to the first frame, and receiving a third frame from the first communication device which includes the received data and is used for receiving data, based on the transmission of the second frame, wherein the second control method includes a method for controlling the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame to the first communication device which is a response to the first frame, and receive a third frame including the first data from the first communication device based on the transmission of the second frame, wherein the first frame includes information about the type of the first data, [Item 29] A first communication control method for controlling a first wireless communication unit included in a first communication device, which performs wireless communication with a second communication device over one or more access channels, wherein the first communication control method includes a method for controlling the first wireless communication unit to transmit a first frame to the second communication device, and in response to receiving a second frame which is a response to the first frame, transmit a third frame containing first data to the second communication device, wherein the first frame contains information about the type of the first data, and a communication program that causes a computer to execute the first communication control method.[Item 30] A second communication control method for controlling a second wireless communication unit included in a second communication device, the second wireless communication unit which performs wireless communication with a first communication device over one or more access channels, wherein the second communication control method includes a method for controlling the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame which is a response to the first frame to the first communication device, and receive a third frame containing the first data from the first communication device based on the transmission of the second frame, wherein the first frame contains information about the type of the first data, and a communication program for causing a computer to execute the second communication control method. [Item 31] A first communication control method for controlling a first wireless communication unit included in a first communication device, which performs wireless communication with a second communication device over one or more access channels, wherein the first communication control method includes a method for controlling the first wireless communication unit to transmit a first frame to the second communication device, and in response to the receipt of a second frame which is a response to the first frame, transmit a third frame containing first data to the second communication device, wherein the first frame contains information about the type of first data, and a non-temporary media on which a communication program causing a computer to execute the first communication control method is recorded. [Item 32] A second communication control method for controlling a second wireless communication unit included in a second communication device, the second wireless communication unit which performs wireless communication with a first communication device over one or more access channels, the second communication control method includes a method for controlling the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame which is a response to the first frame to the first communication device, and receive a third frame containing the first data from the first communication device based on the transmission of the second frame, wherein the first frame contains information about the type of the first data, and a non-temporary media on which a communication program causing a computer to execute the second communication control method is recorded.[Item 33] The communication control device according to Item 20, further comprising control of the second control unit not to transmit the second frame if the first frame transmitted from the first communication device and the first frame transmitted from the third communication device collide. [Item 34] The communication control device according to Item 20 or 33, wherein the second frame includes information indicating a period based on the time required to transmit a signal including the third frame. [Item 35] The communication control device according to Item 20, 33 or 34, further comprising at least one of the following: information on the length of the first data and information on at least one of the address of the first communication device that is the source and the address of the second communication device that is the destination. [Item 36] The communication control device according to any one of Items 20 and 33 to 35, wherein the second control unit controls the second wireless communication unit to receive the first frame retransmitted from the first communication device if the second frame is not transmitted. [Item 37] The communication control device according to any one of items 20 and 33 to 35, wherein the second control unit controls the second wireless communication unit to receive the first frame and the third frame transmitted from the first communication device together if the second frame is not transmitted. [Item 38] The communication control device according to any one of items 20 and 33 to 37, wherein the second control unit controls the second wireless communication unit to transmit a fourth frame, which is a response to the third frame, to the first communication device after receiving the third frame. [Item 39] The communication control device according to any one of items 20 and 33 to 38, wherein the second control unit controls the second wireless communication unit to receive a request from the first communication device for control to perform collision detection using the first frame before receiving the first frame. [Item 40] The communication control device according to item 39, wherein the second control unit controls the second wireless communication unit to transmit a response to the request to the first communication device after receiving the request for control to perform collision detection using the first frame.[Item 41] The communication control device according to any one of items 20 and 33-40, wherein the second frame is a CTS (Clear To Send) frame or an ACK frame.

[0254] 1 STA 2 STA 3 STA 11 Internet connection module 12 Information input module 13 Device control module 14 Information output module 15 Wireless communication module 100 AP 101 Interface 102 Data buffer 103 Backoff management unit 104 Single / Multiple Data control unit 105 Transmit data construction unit 106 Access control unit 107 Transmit signal processing unit 108 Antenna control unit 109 Received signal processing unit 110 Received data extraction unit 111 Multiple Data Duration determination unit 200 Wireless communication system 301 Interface 302 Transmit buffer 303 Channel management unit 304 Frame construction unit 305 Available channel determination unit 306 Primary channel setting unit 307 Secondary channel setting unit 308 Transmit signal processing unit 309 Access control unit 311 Received signal detection unit 312 CCA determination unit 313 Frame analysis unit 314 NAV settings section 315 Receive buffer 801 CPU 802 ROM 803 RAM 804 Bus 805 Input / Output interface 806 Input section 807 Output section 808 Memory section 809 Communication section 810 Drive 811 Removable media 900 Smartphone 901 Processor 902 Memory 903 Storage 904 External connection interface 906 Camera 907 Sensor 908 Microphone 909 Input device 910 Display device 911 Speaker 913 Wireless communication interface 914 Antenna switch 915 Antenna 917 Bus 918 Battery 919 Auxiliary controller 920 In-vehicle device 921 Processor 922 Memory 924 GNSS module 925 Sensor 926 Data interface 927 Content player 928 Storage medium interface 929 Input device 930 Display device 931 Speaker 933 Wireless communication interface 934 Antenna switch 935 Antenna 938 Battery 940 In-vehicle system (or vehicle) 941 In-vehicle network 942 Vehicle-side module 951 Controller 952 Memory 954 Input device955 Display device 957 Network interface 958 Wired communication network 963 Wireless communication interface 964 Antenna switch 965 Antenna

Claims

1. A communication control device comprising a first wireless communication unit included in a first communication device, the first control unit controlling the first wireless communication unit which performs wireless communication with a second communication device over one or more access channels, wherein the first control unit controls the first wireless communication unit to transmit a first frame to the second communication device, and transmit a third frame containing first data to the second communication device in response to the reception of a second frame which is a response to the first frame, and the first frame contains information regarding the type of the first data.

2. The communication control device according to claim 1, wherein the information relating to the type of the first data is information indicating the access category of the first data.

3. The communication control device according to claim 2, wherein the first frame is a data frame.

4. The communication control device according to claim 1, wherein the first frame further includes information on the length of the first data and information on at least one of the address of the first communication device that is the source and the address of the second communication device that is the destination.

5. The communication control device according to claim 1, wherein the second frame includes information indicating a period of time based on the time required to transmit the signal including the third frame.

6. The communication control device according to claim 1, wherein the first control unit controls the first wireless communication unit to transmit the first frame in response to the end of the backoff time set based on the type of first data.

7. The communication control device according to claim 1, further comprising control of whether or not to transmit the first frame to the second communication device to perform collision detection, depending on the type of the first data.

8. The communication control device according to claim 1, wherein the first control unit controls the first wireless communication unit to retransmit the first frame to the second communication device after the backoff time has ended if the second frame has not been received.

9. The communication control device according to claim 1, wherein the first control unit controls the first wireless communication unit to transmit the first frame and the third frame together to the second communication device after the backoff time has ended if the second frame has not been received.

10. The communication control device according to claim 1, wherein the first control unit controls the first wireless communication unit to receive a fourth frame from the second communication device which is a response to the third frame after transmitting the third frame, and to suppress the transmission of its own device after receiving the fourth frame.

11. The communication control device according to claim 1, wherein the first control unit controls the first wireless communication unit to transmit a request to the second communication device for collision detection using the first frame before transmitting the first frame.

12. The communication control device according to claim 1, wherein the preamble preceding the first frame further includes information on the length of the first data.

13. The communication control device according to claim 11, wherein the request includes at least one of a period based on the time required to transmit the signal including the first frame and information indicating the type of the first data.

14. The communication control device according to claim 1, wherein the first frame is included in an MPDU frame, and the Data payload in the MPDU frame includes information about the length of the first data.

15. The communication control device according to claim 1, wherein the first frame is included in one MPDU frame among the A-MPDU frames.

16. The communication control device according to claim 15, wherein in the A-MPDU frame, information regarding the length of the first data is included in the portion that is after the PHY header and before the MAC header.

17. The communication control device according to claim 1, wherein the third frame is included in the A-MPDU frame.

18. The communication control device according to claim 1, wherein the second frame is a CTS (Clear To Send) frame or an ACK frame.

19. The communication control device according to claim 10, wherein the fourth frame is a Block ACK frame.

20. A second wireless communication unit included in a second communication device, comprising a second control unit that controls the second wireless communication unit which performs wireless communication with a first communication device over one or more access channels, wherein the second control unit controls the second wireless communication unit to receive a first frame from the first communication device, transmit a second frame which is a response to the first frame to the first communication device, and receive a third frame containing first data from the first communication device based on the transmission of the second frame, wherein the first frame contains information regarding the type of the first data, a communication control device.

Images