Wireless communication system, wireless communication method, and wireless communication device

Abstract

The present disclosure relates to a wireless communication system, a wireless communication method, and a wireless communication device. The wireless communication system according to the present disclosure comprises a base station having multilink function, and a terminal having multilink function, and is configured to perform communication between the base station and the terminal through a plurality of links. The base station comprises an upper MAC for receiving a packet generated in an upper layer and lower MACs each of which is present in a corresponding one of the plurality of links, and is configured to execute: a dummy packet transmission process for transmitting a dummy packet from the upper MAC to the respective lower MACs; a process for replacing a high-priority packet having a high priority level with the dummy packet; and a process for transmitting the packet held in each of the lower MACs to the terminal through the links.

Description

[Technical Field]

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, and a wireless communication device. [Background technology]

[0002] Wireless LAN base stations and terminals use CSMA / CA to access channels and transmit data.

[0003] The wireless LAN communication standard IEEE 802.11be is equipped with a multi-link function that allows multiple frequency bands to be used simultaneously. By using the multi-link function, multiple links using multiple frequency bands can be formed simultaneously between a base station and a terminal. This allows different data to be transmitted simultaneously over multiple frequency bands, improving throughput and delay characteristics.

[0004] When transmitting data, packets generated in the upper layer are first passed to the Upper MAC (Media Access Controller). The Upper MAC passes the packet to the Lower MAC, which exists for each link. When the Lower MAC acquires the right to transmit a frame, the packet that has come to the front of the queue in order of its holdings is passed to the PHY (Physical) layer, which is the physical layer, and then transmitted. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE802.11 2020 IEEE Standard for Information Technology-Telecommunications and Information Exchange between SystemsLocal and Metropolitan Area Networks-Specific Requirements [Non-patent document 2] IEEE802.11be D2.0 Draft Standard for Information technology- Telecommunications and information exchange between systems Local and metropolitan area networks- Specific requirements Summary of the Invention [Problem to be solved by the invention]

[0006] However, when performing high-volume communications, there are cases where the Lower MACs of all links used by the multi-link function already have multiple packets being transmitted. In this case, suppose a high-priority packet, which is a transmission packet for an application that requires low latency, is generated. This high-priority packet cannot be immediately handed over to the PHY for transmission, regardless of which link is used. In other words, there is a problem of queuing delays.

[0007] In order to solve the above-mentioned problems, a first object of the present disclosure is to provide a wireless communication system that can reduce queuing delay of high-priority packets.

[0008] A second object of the present disclosure is to provide a wireless communication method that can reduce queuing delay of high-priority packets.

[0009] A third object of the present disclosure is to provide a wireless communication device that can reduce queuing delay of high-priority packets. [Means for solving the problem]

[0010] A first aspect of the present disclosure is a wireless communication system comprising a base station having a multi-link function and a terminal having a multi-link function, and configured so that the base station and the terminal communicate via multiple links, wherein the base station preferably comprises an Upper MAC that receives packets generated in a higher layer and a Lower MAC that exists for each link, and is configured to execute a dummy packet transmission process for transmitting dummy packets from the Upper MAC to the Lower MAC, a process for replacing high-priority packets with dummy packets, and a process for transmitting packets held by the Lower MAC to the terminal via the links.

[0011] A second aspect of the present disclosure is a wireless communication method performed by a wireless communication system including a base station having a multi-link function and a terminal having a multi-link function, and configured so that the base station and the terminal communicate via multiple links, wherein the base station preferably includes an Upper MAC that receives packets generated in a higher layer and a Lower MAC that exists for each link, and the wireless communication method preferably includes the steps of causing the Upper MAC to transmit a dummy packet to the Lower MAC, replacing a high-priority packet with a dummy packet, and causing the Lower MAC to transmit the packet to the terminal via the link.

[0012] A third aspect of the present disclosure is preferably a wireless communication device comprising an Upper MAC that receives packets generated in a higher layer and a Lower MAC that exists for each link, and having a function of transmitting dummy packets from the Upper MAC to the Lower MAC, a function of replacing high-priority packets with dummy packets, and a function of transmitting packets held by the Lower MAC via the link. [Effects of the Invention]

[0013] According to the first, second and third aspects of the present disclosure, it is possible to reduce queuing delay of high priority packets. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 10 is a diagram illustrating an example of the configuration of a wireless communication system without a multi-link function. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system having a multi-link function. [Figure 3] 10 is a flowchart showing a multi-link setup procedure. [Figure 4] FIG. 10 is a diagram illustrating a packet categorization process. [Figure 5] 1 is a diagram illustrating a configuration example of a wireless communication system according to a first embodiment of the present disclosure. [Figure 6] 4 is a flowchart illustrating a packet processing method according to the first embodiment of the present disclosure. [Figure 7] 4 is a flowchart showing a method for managing dummy packets according to the first embodiment of the present disclosure. [Figure 8] 1 is a block diagram showing a device configuration of a base station according to a first embodiment of the present disclosure. [Figure 9] 1 is a block diagram showing a device configuration of a terminal according to a first embodiment of the present disclosure. [Figure 10] 10 is a table illustrating an example of data held by a dummy packet management unit according to the first embodiment of the present disclosure. [Figure 11] FIG. 10 is a diagram illustrating a configuration example of a wireless communication system according to a second embodiment of the present disclosure. [Figure 12] FIG. 11 is a diagram illustrating a configuration example of a wireless communication system according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiment 1 [Conventional wireless communication system] Before describing the first embodiment, a conventionally used multi-link will be described. Fig. 1 is a diagram showing an example of the configuration of a wireless communication system without a multi-link function. That is, a wireless communication system 500 transmits multiple types of packets using a single link.

[0016] The wireless communication system 500 includes a base station 2. The base station 2 transmits a high-priority packet 4 generated in an upper layer to a MAC unit 12. The MAC unit 12 includes a queue 8. The queue 8 holds received packets in an ordered manner so that the packets can be transmitted in the order in which they were received. When a frame transmission right is acquired, the order of the packets held in the queue 8 is checked and the packets are transmitted in order starting from the front packet. When the wireless communication system used is Wi-Fi (registered trademark), the base station corresponds to an access point.

[0017] Because the base station 2 does not have a multi-link function, it has only one queue 8. Therefore, even if a high-priority packet 4 occurs, if the queue 8 already contains multiple packets 6, the high-priority packet 4 is ordered so that it becomes the last of the packets held by the queue 8.

[0018] The MAC unit 12 transmits the packets to the PHY 10. More specifically, the packet that has arrived at the front of the queue 8 is transmitted to the PHY 10. That is, the high-priority packet 4 transmitted to the PHY 10 is transmitted to the terminal 16 after all packets 6 held in the queue 8 up to that point have been transmitted. Note that the base station 2 does not have a multi-link function and therefore has only one PHY 10.

[0019] As described above, in the wireless communication system 500 using only one link, even if a high priority packet 4 occurs, no processing is performed to give priority to the packet.

[0020] 2 is a diagram showing an example of the configuration of a wireless communication system with a multi-link function. Here, a wireless communication system 600 that forms three links by utilizing the multi-link function will be described.

[0021] The wireless communication system 600 includes a base station 2. The base station 2 transmits a high priority packet 4 generated in an upper layer to a MAC unit 12. The MAC unit 12 includes an upper MAC 18 and lower MACs 20a, 20b, and 20c that exist for each link.

[0022] The MAC unit 12 first receives the high priority packet 4 at the Upper MAC 18. The Upper MAC 18 distributes the high priority packet 4 to one of the Lower MACs 20a, 20b, and 20c. More specifically, the high priority packet 4 is ordered so that it becomes the last of the packets held in the queue of the Lower MAC to which it was distributed. This distribution is performed based on a predetermined process. Here, it is assumed that the process is to distribute the packet to the queue with the shortest waiting time out of the queues 8a, 8b, and 8c that each of the Lower MACs 20a, 20b, and 20c has. Note that the waiting time in this case varies depending on the number or size of packets 6 held in each queue.

[0023] The MAC unit 12 transmits the packets to the PHY unit 14. This PHY unit 14 includes PHYs 10a, 10b, and 10c. More specifically, among the packets, the packets that arrive at the front of the queues 8a, 8b, and 8c are transmitted to the PHYs 10a, 10b, and 10c, respectively. That is, the high-priority packet 4 is transmitted to the terminal 16 after all the packets 6 held in the assigned queues have been transmitted.

[0024] As described above, the high-priority packet 4 is assigned to the queue that minimizes the waiting time, which increases the likelihood that the packet will be transmitted to the PHY with a shorter waiting time than in the wireless communication system 500 that uses only one link.

[0025] In this way, by using the multi-link function to simultaneously transmit different data over multiple frequency bands, throughput and delay characteristics can be improved. However, there are cases where the Lower MACs of all links used with the multi-link function already have multiple packets to transmit. In this case, the generated high-priority packet cannot be immediately passed to the PHY for transmission, regardless of which link is used. In other words, a problem occurs in which queuing delays occur. The present disclosure solves this problem.

[0026] Fig. 3 is a flowchart showing the procedure for setting up a multi-link. Dummy packet management units 64 and 74, which will be described later, perform the process shown in Fig. 3 to set up wireless communication via specific links. This allows the wireless communication system to establish multi-link communication.

[0027] 4 shows a process for categorizing packets. A wireless communication system transmits multiple types of packets. This shows a process for identifying the multiple types of packets by traffic in the STA unit (described later).

[0028] Packets with a MAC header added at a higher layer are input to one of queues 22, 24, 26, and 28. The destination queue is determined by the TID (Traffic Indicator) included in the MAC header. For example, when WME (Wireless Multimedia Extensions) assigns priorities, queue 22 can be identified as the VO category related to voice, queue 24 as the VI category related to video, queue 26 as the BE category related to best effort, and queue 28 as the BK category related to background.

[0029] Packets input to each queue are input to CSMA / CA units 32, 34, 36, 38, and 40. Each CSMA / CA unit accesses the channel using its own access parameters and performs CSMA / CA. The unique access parameters include, for example, Cwmax, Cwmin, AIFS, and TXOPlimit. When each CSMA / CA unit obtains the transmission right, it acquires a MAC frame from its queue and outputs it to the internal collision resolution unit 42.

[0030] The CSMA / CA units 32, 34, 36 and 38 process data that arrives at the front of the queues 22, 24, 26 and 28. The CSMA / CA unit 40 processes low-delay data.

[0031] When multiple CSMA / CA units simultaneously acquire the transmission right, the internal conflict resolution unit 42 selects and outputs the one with the highest priority.

[0032] [Wireless communication system of the present disclosure] 5 is a diagram illustrating a configuration example of a wireless communication system according to a first embodiment of the present disclosure. The wireless communication system according to the first embodiment differs from conventional systems in that a dummy packet is periodically transmitted to one of the links used by the multi-link function. Here, a wireless communication system 100 that forms three links by utilizing the multi-link function will be described.

[0033] The wireless communication system 100 transmits packets in the same procedure as the wireless communication system 600. However, the wireless communication system 100 periodically transmits dummy packets 44 in addition to packets generated in higher layers. The dummy packets 44 form a queue, similar to the packets 6 and high-priority packets 4. When the dummy packets 44 reach the head of the queue, they start counting down the CW (Contention Window) value.

[0034] If a high priority packet 4 occurs during the countdown of the CW value, the high priority packet 4 is replaced with a dummy packet 44. This process may be performed immediately after the high priority packet 4 occurs, or when the CW value reaches a specific value.

[0035] If no high-priority packet is generated during the countdown of the CW value, the transmission process of the dummy packet 44 is considered to be completed. First, when the CW value reaches 0 or a specific value, the transmission process of the dummy packet 44 is canceled.

[0036] After canceling the transmission process of the dummy packet 44, the packet next to the dummy packet 44 is moved to the head of the queue. Then, the CW value of that packet is not counted down, and the process moves directly to frame transmission processing. In other words, the packet that is now at the head of the queue where the dummy packet 44 was located performs frame transmission processing instead of the dummy packet 44.

[0037] As a process after canceling the transmission process of the dummy packet 44, the packet that was performing the CW value countdown at the head of a different link may be moved to the link where the dummy packet 44 was present, and the frame transmission process may be performed.

[0038] Alternatively, it is also possible to only perform the process of canceling the transmission process of the dummy packet 44. That is, after canceling the transmission process of the dummy packet 44, the packet next to the dummy packet 44 is moved to the head of the queue as usual. Then, the countdown of the CW value of that packet may begin, and then the frame transmission process may be carried out as usual.

[0039] [Packet processing method of the present disclosure] 6 is a flowchart showing a packet processing method according to the first embodiment of the present disclosure. First, in step 100, the Upper MAC 18 receives a packet from an upper layer.

[0040] Next, in step 102, it is confirmed whether the priority of the received packet is high. The priority is determined by the MLD unit 59 of the base station, which will be described later. This determination may be made using the TID. For example, a method can be considered in which a packet assigned a pre-specified TID or a TID indicating a higher priority than that TID is determined to be a "high priority packet." If the priority is high, the process proceeds to step 104. If the priority is not high, the process proceeds to step 108.

[0041] In step 104, it is checked whether a dummy packet exists in all links used in the wireless communication system. In the case of the wireless communication system 100, it is checked whether a dummy packet exists in all links including the Lower MACs 20a, 20b, and 20c. If a dummy packet exists, the process proceeds to step 106. If a dummy packet does not exist, the process proceeds to step 108.

[0042] In step 106, the dummy packet and the high priority packet are swapped. For example, a process is performed in which the tag indicating the order of packets held in the queue of the Lower MAC 20a is swapped between the dummy packet 44 and the high priority packet 4. Alternatively, a process is performed in which the bit information of the high priority packet 4 is transcribed onto the bit information of the dummy packet 44. This process may be performed immediately after the high priority packet 4 is generated, or when the CW value reaches a specific value.

[0043] In step 108, normal queuing is performed, that is, packets held by each Lower MAC are transmitted in order regardless of their type.

[0044] As described above, in the first embodiment, dummy packets are periodically sent to one of the links used by the multi-link function. Then, if a high-priority packet occurs later, the high-priority packet is replaced with a dummy packet. This makes it possible to reduce the queuing delay of a high-priority packet, regardless of when it occurs.

[0045] The size of the dummy packet may be specified as a predetermined size in advance. For example, the maximum size that can be set may be specified. Alternatively, the size may be determined by referring to the size of the high-priority packet that the Upper MAC received immediately before. If the sizes of the dummy packet and the high-priority packet do not match, processing such as padding may be performed during replacement or aggregation processing.

[0046] [Method for managing dummy packets disclosed herein] An example of a method for managing dummy packets is shown. Fig. 7 is a flowchart showing the method for managing dummy packets according to the first embodiment of the present disclosure. Here, an example is shown in which a base station 2 that forms links using a multi-link function transmits dummy packets 44 to three links in order. Note that the three links including Lower MACs 20a, 20b, and 20c are assumed to have been assigned numbers 1, 2, and 3 in advance.

[0047] First, in step 110, the Upper MAC 18 generates a dummy packet 44 and transmits it to link 1. When the dummy packet 44 reaches the head of the queue for link 1, the CW value starts to count down. After a certain period of time has passed, the CW value for link 1 becomes 0, as in step 112.

[0048] Next, in step 114, the Upper MAC 18 generates a dummy packet 44 and transmits it to link 2. When the dummy packet 44 reaches the head of the queue for link 2, a countdown of the CW value begins. After a certain period of time has elapsed, the CW value for link 2 becomes 0, as in step 116.

[0049] Next, in step 118, the Upper MAC 18 generates a dummy packet 44 and transmits it to link 3. When the dummy packet 44 reaches the head of the queue for link 3, the CW value starts to count down. After a certain period of time has passed, the CW value for link 3 becomes 0, as in step 120. After this, the process returns to step 110 and the same process is repeated.

[0050] The timing for generating the dummy packet 44 shown in steps 112, 116 and 120 may be when the CW value becomes a specific value other than 0.

[0051] The link through which the dummy packet 44 is transmitted may also be selected based on pre-measured statistics. More specifically, a selection method based on a PER (Packet Error Rate) value or an average CW value calculated from pre-measured statistics is conceivable. For example, by transmitting the dummy packet 44 to the link with the lowest PER value, the high-priority packet 4 is more likely to be transmitted to the link with the lowest PER value. In other words, the queuing delay of the high-priority packet 4 is more likely to be shortened.

[0052] By using the above procedure, the size of the queue occupied by dummy packets can be dispersed by appropriately changing the link to which the dummy packets are sent. In addition, since the delay time of each link changes over time, determining the destination based on this information improves the probability that high-priority packets will be distributed to links with short delay times.

[0053] [Configuration of devices included in the wireless communication system of the present disclosure] 8 is a block diagram showing the device configuration of the base station according to the first embodiment of the present disclosure. First, data transmission from the base station 2 to other terminals will be described.

[0054] The base station 2 includes an LLC unit 58. The LLC unit 58 is a sublayer that performs logical link control. The LLC unit 58 outputs input packets to an MLD unit 59.

[0055] The MLD unit 59 is a link management unit and includes a data processing unit 60. The data processing unit 60 processes data and outputs the results to a base station measurement unit 62 and a dummy packet management unit 64. The base station measurement unit 62 records the link numbers through which dummy packets are sent and measures the PER of each link, etc.

[0056] The dummy packet management unit 64 selects a link for transmitting a dummy packet. This link selection is performed based on the information of each link obtained by the base station measurement unit 62. Then, the dummy packet management unit 64 transmits the dummy packet to the STA unit corresponding to the selected link.

[0057] The dummy packet management unit 64 also switches between high-priority packets and dummy packets. Furthermore, the dummy packet management unit 64 performs the multi-link setup described with reference to FIG.

[0058] The STA units 66a, 66b, and 66c are transmitting / receiving units that receive packets input from the dummy packet management unit 64. Then, they transmit MAC frames contained in the packets as wireless frames to other terminals. Note that data transmission and reception with other terminals is performed via antennas.

[0059] Next, a description will be given of data transmission from other terminals to the base station 2. The STA units 66a, 66b, and 66c output wireless frames received from other terminals to the dummy packet management unit 64.

[0060] The dummy packet management unit 64 processes the header and the like from the MAC frame included in the input wireless frame, and outputs the obtained data to the data processing unit 60. The data processing unit 60 outputs this data to the LLC unit 58.

[0061] 9 is a block diagram showing the device configuration of a terminal according to the first embodiment of the present disclosure. First, data transmission from terminal 16 to another terminal will be described.

[0062] The terminal 16 includes an LLC unit 68. The LLC unit 68 outputs the input packet to an MLD unit 69.

[0063] The MLD unit 69 includes a data processing unit 70. The data processing unit 70 processes packets and outputs the results to a terminal measurement unit 72 and a dummy packet management unit 74. The terminal measurement unit 72 measures the PER of each link as necessary. The measurement results are notified to the base station measurement unit 62 of the base station in the wireless communication system. The terminal measurement unit 72 may have the same functions as the base station measurement unit 62. The dummy packet management unit 74 has the same functions as the dummy packet management unit 64.

[0064] The STA units 76a, 76b, and 76c receive packets input from the dummy packet management unit 74. Then, they transmit the MAC frames included in the packets as wireless frames to other terminals. Note that data transmission and reception with other terminals is performed via antennas.

[0065] Next, a description will be given of data transmission from other terminals to the terminal 16. The STA units 76a, 76b, and 76c output wireless frames received from other terminals to the dummy packet management unit 74.

[0066] The dummy packet management unit 74 processes the header and the like from the MAC frame included in the input wireless frame, and outputs the obtained data to the data processing unit 70. The data processing unit 70 outputs this data to the LLC unit 68.

[0067] The terminal 16 may not have the dummy packet management unit 74. In this case, no dummy packets are generated in the terminal 16. The terminal 16 notifies the base station of only information such as the PER measured on the terminal side.

[0068] 10 is a table illustrating an example of data stored in a dummy packet management unit according to the first embodiment of the present disclosure. The dummy packet management unit stores various data for each link in order to manage dummy packets. As an example, a data group in a base station equipped with three STA units is shown here.

[0069] In this example, STA1, 2, and 3 all support the multilink function. However, only STA1 and 2 are used for multilink transmission. And only STA1 is used as the destination for dummy packets. STA1 currently has a dummy packet, and its CW value is 6. Packets are distributed based on this data.

[0070] The PER value is also stored here. It can be seen that the PER values ​​indicated by the three STAs are different. It is also possible to set the destination link for the dummy packet based on this PER value.

[0071] Embodiment 2 11 is a diagram illustrating a configuration example of a wireless communication system according to a second embodiment of the present disclosure. The wireless communication system according to the second embodiment differs from the first embodiment in that a plurality of terminals are targets of wireless communication with one base station.

[0072] The wireless communication system 200 includes a base station 2. The base station 2 performs wireless communication with terminals 16a, 16b, and 16c. This configuration makes it possible to reduce queuing delays when high-priority packets occur, even in wireless communication that targets a wide area, such as when multiple terminals are involved.

[0073] The link for transmitting dummy packets and the transmission rate of dummy packets may be determined by referring to the PER of all terminals 16 or to the PER of a specific terminal 16. An example of a method for selecting a specific terminal 16 of interest is to select the terminal with the highest high-priority frame transmission rate.

[0074] The selection of the link for transmitting the dummy packet may be set independently by the base station 2 and the terminal 16. Alternatively, the selection may be set so that the base station 2 and a specific terminal 16 are synchronized or not synchronized.

[0075] It is not necessary to transmit dummy packets to all links used by the multi-link function. For example, if there is a link where many legacy base stations exist, dummy packets may not be sent to that link.

[0076] Embodiment 3 12 is a diagram illustrating a configuration example of a wireless communication system according to a third embodiment of the present disclosure. The wireless communication system according to the third embodiment differs from the first embodiment in that a controller that aggregates a plurality of base stations is installed.

[0077] The wireless communication system 300 includes a controller 46. The controller 46 is connected to base stations 2a and 2b. The base station 2a performs wireless communication with a terminal 16a. The base station 2b performs wireless communication with a terminal 16b. With this configuration, even in wireless communication covering a wide area such as multiple base stations, it is possible to reduce queuing delays when high-priority packets occur.

[0078] The method of selecting the link for transmitting the dummy packets may be specified independently within each base station and terminal, or the controller 46 may specify the link for transmitting the dummy packets for the connected base stations 2a and 2b.

[0079] In the above case, the controller 46 may specify the link for transmitting the dummy packet based on the degree of congestion or PER of the channel used by the terminal 16. For example, the link may be specified so that the ratio of dummy packets is not biased between channels. [Explanation of symbols]

[0080] 2, 2a, 2b base station 4 High Priority Packets 6 packets 16, 16a, 16b terminals 44 dummy packets 46 Controller 100, 200, 300, 500, 600 wireless communication systems

Claims

1. A wireless communication system comprising a base station having a multi-link function and a terminal having a multi-link function, the base station and the terminal being configured to communicate with each other via a plurality of links, The base station an Upper MAC that receives packets generated in an upper layer; a Lower MAC present for each of the links; a dummy packet transmission process for transmitting a dummy packet from the upper MAC to the lower MAC; a process of replacing the dummy packet with a high-priority packet having a high priority; A process of transmitting a packet held by the Lower MAC to the terminal via the link; 1. A wireless communication system configured to perform

2. The dummy packet transmission process The size of the dummy packet is determined by referring to the size of the high-priority packet received by the Upper MAC immediately before.

10. The wireless communication system of claim 1.

3. The dummy packet transmission process a process of transmitting the dummy packets to different links at regular intervals; transmitting the dummy packets to a link selected based on pre-measured statistics; 2. The wireless communication system according to claim 1, comprising at least one of:

4. the terminal includes a plurality of terminals; The base station performs wireless communication with the plurality of terminals.

10. The wireless communication system of claim 1.

5. the base station includes a plurality of base stations; a controller for controlling the plurality of base stations; The controller specifies a destination of the dummy packet.

10. The wireless communication system of claim 1.

6. The terminal an Upper MAC that receives packets generated in an upper layer; a Lower MAC present for each of the links; A process of transmitting a dummy packet from the Upper MAC to the Lower MAC; a process of replacing the dummy packet with a high-priority packet having a high priority; and a process of transmitting the packet held by the Lower MAC to the terminal via the link.

10. The wireless communication system of claim 1.

7. A wireless communication method performed by a wireless communication system comprising a base station having a multi-link function and a terminal having a multi-link function, the base station and the terminal being configured to communicate via a plurality of links, The base station an Upper MAC that receives packets generated in an upper layer; a Lower MAC present for each of the links; transmitting a dummy packet from the Upper MAC to the Lower MAC; replacing the dummy packet with a high-priority packet; transmitting a packet held by the Lower MAC to the terminal via the link; A wireless communication method comprising:

8. an Upper MAC that receives packets generated in an upper layer; A Lower MAC exists for each link; a function of transmitting a dummy packet from the Upper MAC to the Lower MAC; a function of replacing the dummy packet with a high-priority packet having a high priority; A function of transmitting packets held by the Lower MAC via the link; A wireless communication device comprising:

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