Communication device, communication method, and program

Abstract

To start communication earlier to improve communication efficiency when only part of requested TIDs and links is accepted.SOLUTION: A communication device capable of establishing a plurality of links in parallel with other communication devices, is configured to transmit requests on the allocation of traffic identifiers (TIDs) indicating the priority of data and the links; and cause communication using a first link corresponding to a first request to start before completion of the allocation of a second link corresponding to a second request when the first request among the requests is accepted and the second request among the requests is not accepted,.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a communication device, a communication method, and a program for performing wireless communication. [Background technology]

[0002] In recent years, development of wireless communication technologies such as wireless LANs (Local Area Networks) has been progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as a major communication standard for wireless LANs. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax. For example, the latest standard, IEEE 802.11ax, uses OFDMA (orthogonal frequency division multiple access) to standardize technology that not only achieves a high peak throughput of up to 9.6 gigabits per second (Gbps) but also improves communication speeds under congested conditions (see Patent Document 1). OFDMA stands for Orthogonal Frequency-Division Multiple Access.

[0003] A task group called IEEE802.11be was established as a successor standard aiming to further improve throughput, frequency utilization efficiency, and communication latency.

[0004] IEEE802.11be is considering multi-link communication, in which one AP establishes multiple links with one STA (Station) in frequency bands such as 2.4 GHz, 5 GHz, and 6 GHz, and communicates simultaneously. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-50133 Summary of the Invention [Problem to be solved by the invention]

[0006] In the multi-link communication that is being considered for introduction in IEEE802.11be, it is being considered to associate (assign) a TID, which is an identifier that indicates the priority of data, with the link to be established. By assigning a TID to a link in advance, it becomes possible to appropriately select which link to use for data communication depending on the priority of the data.

[0007] TID allocation is performed when one communication device (Non-AP MLD) requests an allocation from another communication device (AP MLD), and the communication device that receives the request accepts the request. For example, assume that there are three TIDs, "0," "1," and "2," and four links, "1" to "4." In this case, suppose that Non-AP MLD requests that link "1" be assigned to TID "0," link "2" be assigned to TID "1," and links "3" and "4" be assigned to TID "2." In this situation, if AP MLD accepts all of these, the allocation will be determined as desired by Non-AP MLD. On the other hand, if AP MLD does not accept all of them (if it rejects all of them), AP MLD can notify Non-AP MLD of alternative allocation proposals.

[0008] However, it is possible that some of the TIDs requested by Non-AP MLD (for example, TID "0" in the above example) may be accepted, while the remaining (for example, TIDs "1" and "2" in the above example) may not be accepted. In this case, the process of allocation will continue for the TIDs that were not accepted.

[0009] In other words, even if the allocation of some TIDs has been decided, communication cannot start until the allocation of other TIDs is completed. Therefore, an object of the present invention is to improve communication efficiency by starting communication earlier when only some of the requested TIDs and link allocations are accepted. [Means for solving the problem]

[0010] In order to solve the above problem, the communication device of the present invention is a communication device capable of establishing multiple links in parallel with other communication devices, and is characterized by comprising: a transmission means for transmitting a TID (Traffic identifier) ​​indicating the priority of data and a request regarding the allocation of a link; and a control means for starting communication using the first link corresponding to the first request before the allocation of the second link corresponding to the second request is completed, when a first request is accepted and a second request is not accepted among the requests transmitted by the transmission means.

[0011] In addition, the communication device of the present invention is a communication device capable of establishing multiple links in parallel with other communication devices, and is characterized by comprising: a receiving means for receiving a TID (Traffic identifier) ​​indicating the priority of data and a request regarding the allocation of a link; and a control means for, when the receiving means accepts a first request and does not accept a second request, starting communication using the first link corresponding to the first request before the allocation of the second link corresponding to the second request is completed. [Effects of the Invention]

[0012] According to the present invention, communication efficiency can be improved by starting communication sooner when only a portion of the requested TID and link assignments are accepted. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the overall configuration of a network according to the present invention; [Figure 2] FIG. 2 is a diagram illustrating a hardware configuration of a communication device according to the present invention. [Figure 3] FIG. 2 is a diagram illustrating a functional configuration of a communication device according to the present invention. [Figure 4] FIG. 1 is a diagram illustrating an overview of Multi-Link communication. [Figure 5] FIG. 2 is a sequence diagram showing link establishment in the present invention. [Figure 6] FIG. 2 is a diagram showing a frame format in the present invention. [Figure 7] 4 is a flowchart illustrating the operation of a communication device (Non-AP MLD) according to the present invention. [Figure 8] 4 is a flowchart illustrating the operation of a communication device (Non-AP MLD) according to the present invention. [Figure 9] 4 is a flowchart illustrating the operation of a communication device (AP MLD) according to the present invention. [Figure 10] 4 is a flowchart illustrating the operation of a communication device (AP MLD) according to the present invention. [Figure 11] 4 is a flowchart illustrating the operation of a communication device (AP MLD) according to the present invention. [Figure 12] FIG. 10 is a diagram illustrating an example of a procedure for assigning a TID and a link. [Figure 13] FIG. 10 is a diagram showing a list of status codes used in the frame format of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[0015] (Configuration of wireless communication system) 1 shows the configuration of a network in which a communication device 101 (hereinafter, non-AP MLD 101) according to this embodiment participates. A communication device 102 (hereinafter, AP MLD 102) is an access point (AP) that serves to construct a wireless network 100. The AP MLD 102 can communicate with the non-AP MLD 101. This embodiment is applied to both the non-AP MLD 101 and the AP MLD 102.

[0016] Each of the non-AP MLD 101 and the AP MLD 102 can perform wireless communication in accordance with the IEEE 802.11be (EHT) standard. IEEE stands for Institute of Electrical and Electronics Engineers. The non-AP MLD 101 and the AP MLD 102 can communicate in the 2.4 Hz, 5 GHz, and 6 GHz frequency bands. The frequency bands used by each communication device are not limited to these, and for example, the 60 GHz band may be used. The non-AP MLD 101 and the AP MLD 102 can also communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The bandwidths used by each communication device are not limited to these, and for example, bandwidths of 240 MHz, 4 MHz, etc. may be used.

[0017] The Non-AP MLD 101 and AP MLD 102 perform OFDMA communication compliant with the IEEE802.11be standard, enabling multi-user (MU) communication in which signals from multiple users are multiplexed. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, portions of the divided frequency band (RU, Resource Unit) are assigned to each STA without overlapping, and the carrier waves of each STA are orthogonal. This allows the AP to communicate with multiple STAs in parallel within a specified bandwidth.

[0018] Generally, the range of radio waves varies depending on the frequency; the lower the frequency, the greater the diffraction and the longer the reach, while the higher the frequency, the less diffraction and the shorter the reach. Even if there is an obstacle along the way, low-frequency radio waves can go around the obstacle and reach their destination, but high-frequency radio waves have a high degree of directivity and are difficult to go around, so they may not reach their destination. On the other hand, the 2.4 GHz frequency is often used by other devices, and microwave ovens are known to emit radio waves in the same frequency band. As such, even when radio waves are emitted by the same device, the strength of the radio waves that reach the destination and the signal-to-noise (SN) ratio can vary depending on the frequency band and the location and environment in which they are placed.

[0019] Although the non-AP MLD 101 and the AP MLD 102 are described as being compatible with the IEEE 802.11be standard, they may also be compatible with legacy standards that predate the IEEE 802.11be standard. Specifically, the non-AP MLD 101 and the AP MLD 102 may be compatible with at least one of the IEEE 802.11a / b / g / n / ac / ax standards. Alternatively, they may be compatible with a standard that succeeds IEEE 802.11be.

[0020] In addition to the IEEE802.11 series standards, other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA may be supported. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, and the like. Wired communication standards such as wired LAN may also be supported.

[0021] Specific examples of the AP MLD 102 include, but are not limited to, a wireless LAN router and a personal computer (PC). The AP MLD 102 may also be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE 802.11be standard. Specific examples of the non-AP MLD 101 include, but are not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, a printer, etc. The non-AP MLD 101 may also be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE 802.11be standard.

[0022] Furthermore, the non-AP MLD 101 and the AP MLD 102 establish links via multiple frequency channels to perform multi-link communication. The IEEE 802.11 series of standards defines the bandwidth of each frequency channel as 20 MHz. Here, a frequency channel refers to a frequency channel defined in the IEEE 802.11 series of standards, which defines multiple frequency channels for each of the 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz frequency bands. By bonding adjacent frequency channels, a single frequency channel may utilize a bandwidth of 40 MHz or more.

[0023] For example, the AP MLD 102 is capable of establishing a link with the non-AP MLD 101 via a first frequency channel in the 2.4 GHz band and communicating with it. In parallel with this, the non-AP MLD 101 is capable of establishing a link with the AP MLD 102 via a second frequency channel in the 5 GHz band and communicating with it. In this case, the non-AP MLD 101 performs multi-link communication, maintaining a second link via the second frequency channel in parallel with the link via the first frequency channel. In this way, the AP MLD 102 can improve the throughput of communication with the non-AP MLD 101 by establishing links with the non-AP MLD 101 via multiple frequency channels.

[0024] In multi-link communication, multiple links using different frequency bands may be established between communication devices. For example, the non-AP MLD 101 may be able to establish links in the 2.4 GHz, 5 GHz, and 6 GHz bands. Alternatively, links may be established via multiple different channels within the same frequency band. For example, a link on channel 6 in the 2.4 GHz band may be established as the first link, and a link on channel 1 in the 2.4 GHz band may be established as the second link. Links using the same frequency band and links using different frequency bands may be mixed. For example, the non-AP MLD 101 may be able to establish a first link on channel 6 in the 2.4 GHz band, as well as a link on channel 1 in the 2.4 GHz band and a link on channel 149 in the 5 GHz band. By establishing multiple connections using different frequencies between the non-AP MLD 101 and the AP, even if one band is congested, communication with the non-AP MLD 101 can be established in another band. This prevents degradation of throughput and communication delays in communication with the non-AP MLD 101.

[0025] Although the wireless network in Figure 1 has one AP MLD and one non-AP MLD, the number and placement of the AP MLDs and non-AP MLDs are not limited to this. For example, one non-AP MLD may be added to the wireless network in Figure 1. In this case, the frequency band of each link to be established, the number of links, and the frequency width are not important.

[0026] When multi-link communication is performed, the AP MLD 102 and the non-AP MLD 101 transmit and receive data to and from the other device via multiple links.

[0027] The AP MLD 102 and the non-AP MLD 101 may also be capable of MIMO (Multiple-Input and Multiple-Output) communication. In this case, the AP MLD 102 and the non-AP MLD 101 each have multiple antennas, and one of them transmits different signals from each antenna using the same frequency channel. The receiving side simultaneously receives all signals arriving from multiple streams using multiple antennas, and separates and decodes the signals from each stream. By performing MIMO communication in this way, the AP MLD 102 and the non-AP MLD 101 can communicate more data in the same amount of time than if they did not perform MIMO communication. Furthermore, when performing multi-link communication, the AP MLD 102 and the non-AP MLD 101 may perform MIMO communication on some of the links.

[0028] 2 shows an example of the hardware configuration of the non-AP MLD 101 in this embodiment. The non-AP MLD 101 has a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that there may be multiple antennas.

[0029] The storage unit 201 is configured with one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the storage unit 201 may also use storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs. Furthermore, the storage unit 201 may include multiple memories.

[0030] The control unit 202 is configured with one or more processors such as a CPU or MPU, and controls the entire Non-AP MLD 101 by executing a computer program stored in the storage unit 201. The control unit 202 may also control the entire Non-AP MLD 101 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 also generates data and signals (wireless frames) to be transmitted in communications with other communication devices. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may also be equipped with multiple processors such as multi-core processors, and the entire Non-AP MLD 101 may be controlled by the multiple processors.

[0031] Furthermore, the control unit 202 controls the function unit 203 to perform predetermined processes such as wireless communication, image capture, printing, projection, etc. The function unit 203 is hardware that enables the non-AP MLD 101 to perform predetermined processes.

[0032] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user via a monitor screen or a speaker. Here, the output from the output unit 205 may be a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel. Furthermore, the input unit 204 and the output unit 205 may be integrated with the Non-AP MLD 101, or may be separate units.

[0033] The communication unit 206 controls wireless communication conforming to the IEEE 802.11be standard. The communication unit 206 may also control wireless communication conforming to other IEEE 802.11 series standards in addition to the IEEE 802.11be standard, and may control wired communication such as a wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals generated by the control unit 202 for wireless communication.

[0034] If the non-AP MLD 101 supports the NFC standard, Bluetooth standard, or the like in addition to the IEEE802.11be standard, it may control wireless communications in accordance with these communication standards. If the non-AP MLD 101 can perform wireless communications in accordance with multiple communication standards, it may be configured with separate communication units and antennas compatible with each communication standard. The non-AP MLD 101 communicates data such as image data, document data, and video data with the non-AP MLD 101 via the communication unit 206. The antenna 207 may be configured separately from the communication unit 206, or may be configured together with the communication unit 206 as a single module.

[0035] Antenna 207 is an antenna capable of communication in the 2.4 GHz band, 5 GHz band, and 6 GHz band. In this embodiment, non-AP MLD 101 has one antenna, but it may have three antennas. Alternatively, it may have a different antenna for each frequency band. Furthermore, if non-AP MLD 101 has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0036] The AP MLD 102 is assumed to have the same hardware configuration as the non-AP MLD 101, but is not limited to this. For example, the configurations of the input unit 204 and output unit 205 may be different between the AP MLD 102 and the non-AP MLD 101.

[0037] 3 shows a block diagram of the functional configuration of the non-AP MLD 101 in this embodiment. It should be noted that the AP MLD 102 is also assumed to have a similar configuration, but some parts may be different. Here, it is assumed that the non-AP MLD 101 includes a wireless LAN control unit 301. The number of wireless LAN control units is not limited to one, and may be two, or three or more. The non-AP MLD 101 further includes a frame processing unit 302, a TID-To-Link Mapping management unit 303, a UI control unit 304, a storage unit 305, and a wireless antenna 306.

[0038] The wireless LAN control unit 301 includes an antenna and circuit for transmitting and receiving wireless signals to and from other wireless LAN devices, and a program for controlling them. The wireless LAN control unit 301 controls wireless LAN communications based on frames generated by the frame generation unit 302 in accordance with the IEEE 802.11 standard series.

[0039] The frame processing unit 302 processes wireless control frames transmitted and received by the wireless LAN control unit 301. The contents of the wireless control generated and analyzed by the frame processing unit 302 may be restricted by settings stored in the storage unit 305. They may also be changed by user settings from the UI control unit 304. Information on the generated frame is sent to the wireless LAN control unit 301 and transmitted to the communication partner. Information on the frame received by the wireless LAN control unit 301 is passed to the frame processing unit 302 and analyzed.

[0040] The TID-To-Link Mapping management unit 303 manages which TID is associated with which link. A TID (Traffic Identifier) ​​is an identifier used for QoS purposes to indicate the priority of data, and there are eight types, from "0" to "7." Among the eight types, there are TIDs for transmitting, for example, video data and voice data, and each TID must be assigned to at least one link.

[0041] The UI control unit 304 is configured to include hardware related to a user interface, such as a touch panel or buttons, and a program for controlling these, for accepting user operations on the Non-AP MLD 101. The UI control unit 304 also has a function for presenting information to the user, such as displaying images or outputting audio.

[0042] The storage unit 305 is a storage device that can be configured with a ROM, a RAM, etc., that stores programs and data that the Non-AP MLD 101 runs on.

[0043] FIG. 4 shows an overview of multi-link communication performed by the AP MLD 102 and the non-AP MLD 101 in this embodiment.

[0044] A communication device that operates in Multi-Link is called an MLD (Multi-Link Device), and one MLD has multiple STAs and APs corresponding to each link. An MLD with AP functionality is called an AP MLD, and an MLD without AP functionality is called a Non-AP MLD. Note that even if a communication device has AP functionality, it does not operate as an AP and participates in a network established by another AP-MLD, and is also called a Non-AP MLD.

[0045] 4, AP1 401 and STA1 404 establish Link1 407 over a first frequency channel. Similarly, AP2 402 and STA2 405 establish Link2 408 over a second frequency channel, and AP3 403 and STA3 406 establish Link3 409 over a third frequency channel.

[0046] Here, the AP MLD 102 and the non-AP MLD 101 establish a connection via frequency channels in the sub-GHz band, 2.4 GHz band, 3.6 GHz band, 4.9 and 5 GHz bands, 60 GHz band, and 6 GHz band. The AP MLD 102 and the non-AP MLD 101 maintain a second link connection via a second frequency channel in parallel with a first link connection via a first frequency channel. Also, instead of connections via different frequency bands, multiple connections via different frequency channels in the same frequency band may be established.

[0047] 5 is a sequence diagram showing link establishment in this embodiment. The Non-AP MLD 101 transmits an Association Request (501). The Association Request includes a TID-To-Link Mapping element, which will be described later. Upon receiving this, the AP-MLD 102 transmits an Association Response (502) including information indicating whether or not the requested allocation is accepted. At this time, if at least some of the allocations are not accepted, the TID-To-Link Mapping element is included in the Association Response.

[0048] If at least a portion of the allocation is accepted by the AP-MLD 102, communication using that link becomes possible (503).

[0049] On the other hand, if at least some of the allocations are rejected by the AP-MLD 102, the Non-AP MLD 101 transmits a TID-To-Link Mapping Request (504). The TID-To-Link Mapping Request also includes a TID-To-Link Mapping element. In response to this, the AP-MLD 102 transmits a TID-to-Link Mapping Response (505) that includes information indicating whether or not the requested allocations are accepted. At this time, if at least some of the allocations are not accepted, the TID-To-Link Mapping element is included in the TID-to-Link Mapping Response.

[0050] If at least a portion of the allocation is accepted by the AP-MLD 102, communication using that link becomes possible (506).

[0051] Fig. 6 shows an example of the frame format of the TID-To-Link Mapping element in this embodiment. Note that in this embodiment, the name of the element shown in Fig. 6 is TID-To-Link Mapping element, but it is not limited to this and may be named otherwise. This element is stored in a management frame such as an Association Request frame or an Association Response frame. This element is also stored in an action frame such as a TID-To-Link Mapping Request frame or a TID-To-Link Mapping Response frame.

[0052] The TID-To-Link Mapping element includes an Element ID 601, a Length 602, an Element ID Extension 603, and a TID-To-Link Mapping Control 604. Furthermore, the TID-To-Link Mapping element includes Link Mapping of TIDs 605#1 to #8.

[0053] The TID-To-Link Mapping Control 604 includes a Direction 607 , a Default Link Mapping 608 , and a Link Mapping Presence Indicator 609 .

[0054] Direction 607 is a field indicating whether the direction is UL or DL. Default Link Mapping 608 is a field indicating that TID allocation is performed in default mode. Here, default mode is a mode in which all TIDs are assigned to all links.

[0055] Link Mapping Presence Indicator 609 is a field indicating whether or not this element includes Link Mapping of TID 605. If Link Mapping of TID 605 is not included in this element, Link Mapping Presence Indicator 609 may not be included.

[0056] Link Mapping of TID 605#1 to #8 is a field that indicates which link each TID is assigned to, and is generated for each TID. That is, as mentioned above, there are eight types of TIDs, from "0" to "7," so Link Mapping of TID 605 includes eight, from #1 to #8.

[0057] This will be explained in more detail using Link Mapping of TID 605#8. Link Mapping of TID 605#8 has a number of bits 610 equal to the number of established links (maximum 16), and the value of each bit indicates whether each link is assigned to TID "7". For example, consider a case where a connection is established using link "1", link "2", and link "3", and TID "7" is assigned to link "1" and link "3". In this case, Link Mapping of TID 605#8 stores values ​​of 1, 0, and 1 in the bits corresponding to link "1", link "2", and link "3", respectively.

[0058] 7, the flow of the TID and link allocation process that is realized by the control unit 202 executing a program stored in the storage unit 201 of the communication device operating as the Non-AP MLD 101 will be described. This flowchart starts when the Non-AP MLD 101 receives the Association Response described in 502 after transmitting the Association Request described in 501 of FIG.

[0059] In S701, it is determined whether the Status Code of the received Association Response is "SUCCESS".

[0060] 13(a) and (b) are diagrams showing a list of Status Codes. Of these, the Status Code "1" shown in FIG. 13(a) is associated with "SUCCESS." That is, in S701, it is determined whether the Status Code is "1." If the result of the determination is that the Status Code indicates "SUCCESS," the process proceeds to S702; otherwise, the process proceeds to S705. Note that, as will be described later as Modifications 2 and 3 on the AP-MLD 102 side, "PREFERRED_TID_TO_LINK_MAPPING_SUGGESTED" or "ACCEPT_PARTIAL_TID_TO_LINK_MAPPING" may be introduced. In this case, it may be determined whether the Status Code is one of these before proceeding to S705. In this case, if the Status Code does not correspond to any of the Status Codes, the process may end in error.

[0061] In S702, it is determined whether or not the received Association Response includes a TID-To-Link Mapping element. If the result of the determination is that a TID-To-Link Mapping element is included, the process proceeds to S706; if not, the process proceeds to S703.

[0062] In S703, it is determined that all requests from the Non-AP MLD 101 have been accepted based on the fact that the Status Code is "SUCCESS" and the TID-To-Link Mapping element is not included. Then, in the following S704, communication is started based on the accepted allocation.

[0063] On the other hand, in S705, similar to S702, it is determined whether or not the received Association Response includes a TID-To-Link Mapping element. If the result of the determination is that a TID-To-Link Mapping element is included, the process proceeds to S706; if not, the process proceeds to S709.

[0064] In S709, based on the fact that the Status Code is not "SUCCESS" and the TID-To-Link Mapping element is not included, it is determined that all requests from the Non-AP MLD 101 have been rejected. Then, in the following S708, a process of updating the TID-To-Link Mapping is performed. Details of this process will be described later using FIG. 8.

[0065] Meanwhile, in S706, it is determined whether the requested allocation has been accepted based on the TID-To-Link Mapping element included in the Association Response. If there is at least one Link Mapping of TID 605 that is not included in the received TID-To-Link Mapping element, it is determined that the requested allocation has been accepted for the corresponding TID. In this case, in the following S707, communication is initiated based on the accepted allocation. On the other hand, for the TID whose corresponding Link Mapping of TID 605 is included in the received TID-To-Link Mapping element, it is determined that the requested allocation has been rejected. For such TIDs, in S708, a TID-To-Link Mapping update process is performed. That is, control is performed to start communication using the link corresponding to the accepted first TID of the transmitted request before the allocation of the unaccepted second TID is completed. Then, a request for the unaccepted second TID is transmitted again.

[0066] Details of S708 will be explained using Figure 8. In S801, it is determined whether all requests have been rejected. If all requests have been rejected, the process transitions from S709 to S708. This also applies if, in the determination of S706, there is no Link Mapping of TID605 that is not included in the TID-To-Link Mapping element. This means that Link Mapping of TID605 for all TIDs is included. If the result of the determination is that all requests have been rejected, the process proceeds to S803; otherwise, the process proceeds to S802.

[0067] In S802 and S803, processing is performed to re-request some or all of the rejected allocations. Note that in S802, processing is performed using a TID-to-Link Mapping Request, whereas in S803, processing is performed using an Association Request. This difference is because if all requests are rejected, it is necessary to start over from the association procedure, whereas if some requests are accepted, it is sufficient to only update the TID-to-Link Mapping.

[0068] 9, a description will be given of the flow of the TID and link allocation process that is realized by the control unit 202 executing a program stored in the storage unit 201 of the communication device operating as the AP MLD 102. This flowchart starts when the Non-AP MLD 101 receives the Association Request described in 501 of FIG.

[0069] In S901, it is determined whether it is possible to accept all of the allocations requested by the Non-AP MLD 101. If the result of the determination is that all of the allocations can be accepted, the process proceeds to S902, and if not (i.e., if there is even a part of the allocation that cannot be accepted), the process proceeds to S904.

[0070] In S902, an Association Response that does not include a TID-To-Link Mapping element is transmitted to the Non-AP MLD 101. At this time, the Status Code of the Association Response is set to "1", which means "SUCCESS".

[0071] On the other hand, in S904, a TID-To-Link Mapping element is generated that includes the Link Mapping of TID 605 that corresponds to the unaccepted TID. Then, an Association Response that includes the TID-To-Link Mapping element is sent. At this time, the Status Code of the Association Response is set to "1", which means "SUCCESS".

[0072] In the next step S903, communication for each link is started based on the accepted TID allocation. Note that if all requested allocations are rejected, communication is not started in step S903.

[0073] <Variation 1> Fig. 10 illustrates the flow of the TID and link allocation process, which is realized by the control unit 202 executing a program stored in the storage unit 201 of the communication device operating as the AP MLD 102, and is a modified example of Fig. 9. Steps S1001 to S1003 are similar to the steps S901 to S903 in Fig. 9, and therefore their explanation will be omitted.

[0074] In S1004, it is determined whether all requested allocations are unacceptable. If the result of the determination is that all requested allocations are unacceptable, the process proceeds to S1006; otherwise, the process proceeds to S1005.

[0075] In S1005, a TID-To-Link Mapping element is generated that includes the Link Mapping of TID 605 that corresponds to the TID that is not accepted. Then, an Association Response that includes this TID-To-Link Mapping element is transmitted to Non-AP MLD 101. At this time, the Status Code of the Association Response is set to "1", which means "SUCCESS".

[0076] In S1006, a TID-To-Link Mapping element is generated that includes the Link Mapping of TID 605 corresponding to all TIDs. Then, an Association Response that includes the TID-To-Link Mapping element is transmitted. At this time, the Status Code of the Association Response is set to "22," which means "PREFERRED_TID_TO_LINK_MAPPING_SUGGESTED."

[0077] The reason why the Status Code is different between S1005 and S1006 is to make it easy for the Non-AP MLD side to determine whether some requests have been accepted or all requests have been rejected. In the example of Fig. 7, all cases where the Status Code is other than "1" are processed in the same way, but the processing may be different for "PREFERRED_TID_TO_LINK_MAPPING_SUGGESTED" and other cases.

[0078] <Variation 2> Fig. 11 illustrates the flow of the TID and link allocation process that is realized by the control unit 202 executing a program stored in the storage unit 201 of the communication device operating as the AP MLD 102, and is a further modification of Fig. 9. Comparing Fig. 10 and Fig. 11, the process of S1005 has been changed to S1105, but other than that, the same processes are executed in the corresponding steps.

[0079] In S1105, a TID-To-Link Mapping element is generated that includes the Link Mapping of TID 605 that corresponds to the TID that is not accepted. Then, an Association Response that includes this TID-To-Link Mapping element is transmitted to the Non-AP MLD 101. At this time, the Status Code of the Association Response is set to "23", which means "ACCEPT_PARTIAL_TID_TO_LINK_MAPPING".

[0080] The reason why the Status Code is different between S1102 and S1105 is to enable the Non-AP MLD side to easily determine whether some requests have been rejected or whether all requests have been accepted.

[0081] <Example of allocation process> FIG. 12 shows a specific example of the process of assigning TIDs and links. For example, assume that there are three types of TIDs, "0," "1," and "2," and four links, "1" to "4." In this case, the Non-AP MLD 101 requests that link "1" be assigned to TID "0," link "2" to TID "1," and links "3" and "4" to TID "2" (1201). However, the AP-MLD 102 accepts the request for TID "0," but rejects the requests for TID "1" and "2." In this case, the Association Response sent by the AP-MLD 102 includes a TID-To-Link Mapping element that includes the Link Mapping of TID 605 corresponding to TID "1" and TID "2." However, the Link Mapping of TID 605 corresponding to TID "0" is not included (1202). Upon receiving this Association Response, the Non-AP MLD 101 determines that the request for TID "0" has been accepted, and starts communication on Link "1" with TID=0. Note that, since the TID assignment for Links "2" to "4" has not been accepted, communication does not start. (1203) Next, if the Non-AP MLD 101 agrees with the allocation proposed by the AP-MLD 102, it generates a TID-To-Link Mapping element including the corresponding Link Mapping of TID 605. Then, it transmits a TID-To-Link Mapping Request including the TID-To-Link Mapping element (1204). The AP-MLD 102 accepts all re-requests from the Non-AP MLD. At this time, the TID-To-Link Mapping Response sent by the AP-MLD 102 does not include a TID-To-Link Mapping element.

[0082] Note that, although an example has been shown here in which the Non-AP MLD agrees to all of the allocations proposed by the AP-MLD 102 in 1202, if the Non-AP MLD does not agree to at least some of them, it may request a new allocation in 1204.

[0083] Also, although an example in which one TID is assigned to one link has been shown here, multiple TIDs may be assigned to one link.

[0084] In the above-described embodiment, an example has been described in which a request is accepted or rejected on a TID-by-TID basis, but this is not limiting. That is, when a request is made to assign the same TID to multiple links, some links may be accepted and others may be rejected. In this case, the determinations in S702 and S705 are made to determine whether or not an accepted link exists, instead of determining whether or not a TID-To-Link Mapping element is included. This determination is made by referencing bit 610 in Link Mapping of TID 605 #8. In this case, in S707, even if the TID is the same, communication is initiated for the accepted link and not for the rejected link.

[0085] <Other embodiments> It is also possible to provide a system or device with a recording medium storing software program code for implementing the above-described functions, and have the computer (CPU, MPU) of the system or device read and execute the program code stored in the recording medium. In this case, the program code itself read from the recording medium will implement the functions of the above-described embodiments, and the recording medium storing the program code will constitute the above-described device.

[0086] Examples of storage media that can be used to supply the program code include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs.

[0087] In addition, the above-mentioned functions may be realized not only by the computer executing the read program code, but also by the operating system (OS) running on the computer performing some or all of the actual processing based on the instructions of the program code. OS is an abbreviation for Operating System.

[0088] Furthermore, the program code read from the storage medium may be written to a memory provided on a function expansion board inserted into a computer or a function expansion unit connected to the computer, and a CPU provided on the function expansion board or function expansion unit may then perform some or all of the actual processing based on the instructions of the program code to realize the above-mentioned functions.

[0089] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions. [Explanation of symbols]

[0090] 201 Storage section 202 Control section 203 Functional Department 204 Input section 205 Output section 206 Communications Department

Claims

1. A communication device capable of establishing multiple links in parallel with other communication devices, a transmitting means for transmitting a request for link allocation and a traffic identifier (TID) indicating the priority of data; a control means for starting communication using a first link corresponding to the first request before allocation of a second link corresponding to the second request is completed when a first request is accepted and a second request is not accepted among the requests transmitted by the transmission means; A communication device comprising:

2. 2. The communication device according to claim 1, wherein the transmitting means transmits the request for allocation of the second link again after communication using the first link has started.

3. 3. The communication device according to claim 1, wherein said control means does not start communication on any of said plurality of links if none of the requests sent by said transmission means are accepted.

4. 4. The communication device according to claim 1, wherein the request transmitted by said transmission means is an association request.

5. 5. The communication device according to claim 4, wherein the association request includes a TID-to-link mapping element indicating allocation of a TID and a link.

6. A communication device capable of establishing multiple links in parallel with other communication devices, a receiving means for receiving a request for link allocation and a traffic identifier (TID) indicating the priority of data; a control means for starting communication using a first link corresponding to the first request before allocation of a second link corresponding to the second request is completed when a first request is accepted and a second request is not accepted among the requests received by the receiving means; A communication device comprising:

7. A communication method in a communication device capable of establishing multiple links in parallel with other communication devices, comprising: a transmitting step of transmitting a request for link allocation and a traffic identifier (TID) indicating the priority of data; a control step of starting communication using a first link corresponding to the first request before allocation of a second link corresponding to the second request is completed, when a first request is accepted and a second request is not accepted among the requests transmitted in the transmission step; A communication method comprising:

8. A communication method in a communication device capable of establishing multiple links in parallel with other communication devices, comprising: a receiving step of receiving a traffic identifier (TID) indicating the priority of data and a request for link allocation; a control step of, when accepting a first request and not accepting a second request among the requests received in the receiving step, starting communication using a first link corresponding to the first request before allocation of a second link corresponding to the second request is completed; A communication method comprising:

9. A program for causing a computer to function as each of the means of the communication device according to any one of claims 1 to 6.

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